From db04e18dbb0146d3c753dc05f7233350375bbc48 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Wed, 19 Aug 2020 14:34:03 +0200 Subject: [PATCH 001/191] block: Make request_queue.rpm_status an enum request_queue.rpm_status is assigned values of the rpm_status enum only, so reflect that in its type. Note that including is (currently) a no-op, as it is already included through and , but it is better to play it safe. Signed-off-by: Geert Uytterhoeven Acked-by: Rafael J. Wysocki Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index bb5636cc17b9..0a1730b30ad2 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -24,6 +24,7 @@ #include #include #include +#include struct module; struct scsi_ioctl_command; @@ -458,7 +459,7 @@ struct request_queue { #ifdef CONFIG_PM struct device *dev; - int rpm_status; + enum rpm_status rpm_status; unsigned int nr_pending; #endif From 611bee526b4a89d49f1b9914a770bfdc101d5fb5 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sun, 23 Aug 2020 11:10:41 +0200 Subject: [PATCH 002/191] block: replace bd_set_size with bd_set_nr_sectors Replace bd_set_size with a version that takes the number of sectors instead, as that fits most of the current and future callers much better. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Reviewed-by: Sagi Grimberg Signed-off-by: Jens Axboe --- drivers/block/loop.c | 4 ++-- drivers/block/nbd.c | 7 ++++--- drivers/block/pktcdvd.c | 2 +- drivers/nvme/host/nvme.h | 2 +- fs/block_dev.c | 10 +++++----- include/linux/genhd.h | 2 +- 6 files changed, 14 insertions(+), 13 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index d3394191e168..cb1191d6e945 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -253,7 +253,7 @@ static void loop_set_size(struct loop_device *lo, loff_t size) { struct block_device *bdev = lo->lo_device; - bd_set_size(bdev, size << SECTOR_SHIFT); + bd_set_nr_sectors(bdev, size); set_capacity_revalidate_and_notify(lo->lo_disk, size, false); } @@ -1251,7 +1251,7 @@ static int __loop_clr_fd(struct loop_device *lo, bool release) set_capacity(lo->lo_disk, 0); loop_sysfs_exit(lo); if (bdev) { - bd_set_size(bdev, 0); + bd_set_nr_sectors(bdev, 0); /* let user-space know about this change */ kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE); } diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index edf8b632e3d2..a54f2d155a31 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -300,6 +300,7 @@ static void nbd_size_update(struct nbd_device *nbd) { struct nbd_config *config = nbd->config; struct block_device *bdev = bdget_disk(nbd->disk, 0); + sector_t nr_sectors = config->bytesize >> 9; if (config->flags & NBD_FLAG_SEND_TRIM) { nbd->disk->queue->limits.discard_granularity = config->blksize; @@ -308,10 +309,10 @@ static void nbd_size_update(struct nbd_device *nbd) } blk_queue_logical_block_size(nbd->disk->queue, config->blksize); blk_queue_physical_block_size(nbd->disk->queue, config->blksize); - set_capacity(nbd->disk, config->bytesize >> 9); + set_capacity(nbd->disk, nr_sectors); if (bdev) { if (bdev->bd_disk) { - bd_set_size(bdev, config->bytesize); + bd_set_nr_sectors(bdev, nr_sectors); set_blocksize(bdev, config->blksize); } else bdev->bd_invalidated = 1; @@ -1138,7 +1139,7 @@ static void nbd_bdev_reset(struct block_device *bdev) { if (bdev->bd_openers > 1) return; - bd_set_size(bdev, 0); + bd_set_nr_sectors(bdev, 0); } static void nbd_parse_flags(struct nbd_device *nbd) diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c index 1034e445680c..17f2e6ff1223 100644 --- a/drivers/block/pktcdvd.c +++ b/drivers/block/pktcdvd.c @@ -2192,7 +2192,7 @@ static int pkt_open_dev(struct pktcdvd_device *pd, fmode_t write) set_capacity(pd->disk, lba << 2); set_capacity(pd->bdev->bd_disk, lba << 2); - bd_set_size(pd->bdev, (loff_t)lba << 11); + bd_set_nr_sectors(pd->bdev, lba << 2); q = bdev_get_queue(pd->bdev); if (write) { diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h index 2910f6caab7d..aab130f31e25 100644 --- a/drivers/nvme/host/nvme.h +++ b/drivers/nvme/host/nvme.h @@ -688,7 +688,7 @@ static inline void nvme_mpath_update_disk_size(struct gendisk *disk) struct block_device *bdev = bdget_disk(disk, 0); if (bdev) { - bd_set_size(bdev, get_capacity(disk) << SECTOR_SHIFT); + bd_set_nr_sectors(bdev, get_capacity(disk)); bdput(bdev); } } diff --git a/fs/block_dev.c b/fs/block_dev.c index 8ae833e00443..f52597172c8b 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1371,13 +1371,13 @@ int check_disk_change(struct block_device *bdev) EXPORT_SYMBOL(check_disk_change); -void bd_set_size(struct block_device *bdev, loff_t size) +void bd_set_nr_sectors(struct block_device *bdev, sector_t sectors) { inode_lock(bdev->bd_inode); - i_size_write(bdev->bd_inode, size); + i_size_write(bdev->bd_inode, (loff_t)sectors << SECTOR_SHIFT); inode_unlock(bdev->bd_inode); } -EXPORT_SYMBOL(bd_set_size); +EXPORT_SYMBOL(bd_set_nr_sectors); static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part); @@ -1514,7 +1514,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder, } if (!ret) { - bd_set_size(bdev,(loff_t)get_capacity(disk)<<9); + bd_set_nr_sectors(bdev, get_capacity(disk)); set_init_blocksize(bdev); } @@ -1542,7 +1542,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder, ret = -ENXIO; goto out_clear; } - bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9); + bd_set_nr_sectors(bdev, bdev->bd_part->nr_sects); set_init_blocksize(bdev); } diff --git a/include/linux/genhd.h b/include/linux/genhd.h index 4ab853461dff..39025dc0397c 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -375,7 +375,7 @@ void unregister_blkdev(unsigned int major, const char *name); int revalidate_disk(struct gendisk *disk); int check_disk_change(struct block_device *bdev); int __invalidate_device(struct block_device *bdev, bool kill_dirty); -void bd_set_size(struct block_device *bdev, loff_t size); +void bd_set_nr_sectors(struct block_device *bdev, sector_t sectors); /* for drivers/char/raw.c: */ int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long); From c2b4bb8cb3741c0bacf3683e4c1ecd04c977ada3 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sun, 23 Aug 2020 11:10:42 +0200 Subject: [PATCH 003/191] block: fix locking for struct block_device size updates Two different callers use two different mutexes for updating the block device size, which obviously doesn't help to actually protect against concurrent updates from the different callers. In addition one of the locks, bd_mutex is rather prone to deadlocks with other parts of the block stack that use it for high level synchronization. Switch to using a new spinlock protecting just the size updates, as that is all we need, and make sure everyone does the update through the proper helper. This fixes a bug reported with the nvme revalidating disks during a hot removal operation, which can currently deadlock on bd_mutex. Reported-by: Xianting Tian Signed-off-by: Christoph Hellwig Reviewed-by: Sagi Grimberg Signed-off-by: Jens Axboe --- block/partitions/core.c | 4 ++-- drivers/block/aoe/aoecmd.c | 4 +--- drivers/md/dm.c | 15 ++------------- drivers/s390/block/dasd_ioctl.c | 9 ++------- fs/block_dev.c | 25 ++++++++++++++----------- include/linux/blk_types.h | 1 + 6 files changed, 22 insertions(+), 36 deletions(-) diff --git a/block/partitions/core.c b/block/partitions/core.c index 5b4869c08fb3..b1c0b50ca92d 100644 --- a/block/partitions/core.c +++ b/block/partitions/core.c @@ -592,8 +592,8 @@ int bdev_resize_partition(struct block_device *bdev, int partno, if (partition_overlaps(bdev->bd_disk, start, length, partno)) goto out_unlock; - part_nr_sects_write(part, (sector_t)length); - i_size_write(bdevp->bd_inode, length << SECTOR_SHIFT); + part_nr_sects_write(part, length); + bd_set_nr_sectors(bdevp, length); ret = 0; out_unlock: diff --git a/drivers/block/aoe/aoecmd.c b/drivers/block/aoe/aoecmd.c index 6dba41395155..313f0b946fe2 100644 --- a/drivers/block/aoe/aoecmd.c +++ b/drivers/block/aoe/aoecmd.c @@ -900,9 +900,7 @@ aoecmd_sleepwork(struct work_struct *work) ssize = get_capacity(d->gd); bd = bdget_disk(d->gd, 0); if (bd) { - inode_lock(bd->bd_inode); - i_size_write(bd->bd_inode, (loff_t)ssize<<9); - inode_unlock(bd->bd_inode); + bd_set_nr_sectors(bd, ssize); bdput(bd); } spin_lock_irq(&d->lock); diff --git a/drivers/md/dm.c b/drivers/md/dm.c index fb0255d25e4b..3dedd9cc4fb6 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -2097,18 +2097,6 @@ static void event_callback(void *context) dm_issue_global_event(); } -/* - * Protected by md->suspend_lock obtained by dm_swap_table(). - */ -static void __set_size(struct mapped_device *md, sector_t size) -{ - lockdep_assert_held(&md->suspend_lock); - - set_capacity(md->disk, size); - - i_size_write(md->bdev->bd_inode, (loff_t)size << SECTOR_SHIFT); -} - /* * Returns old map, which caller must destroy. */ @@ -2131,7 +2119,8 @@ static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t, if (size != dm_get_size(md)) memset(&md->geometry, 0, sizeof(md->geometry)); - __set_size(md, size); + set_capacity(md->disk, size); + bd_set_nr_sectors(md->bdev, size); dm_table_event_callback(t, event_callback, md); diff --git a/drivers/s390/block/dasd_ioctl.c b/drivers/s390/block/dasd_ioctl.c index 777734d1b4e5..faaf5596e31c 100644 --- a/drivers/s390/block/dasd_ioctl.c +++ b/drivers/s390/block/dasd_ioctl.c @@ -55,10 +55,7 @@ dasd_ioctl_enable(struct block_device *bdev) dasd_enable_device(base); /* Formatting the dasd device can change the capacity. */ - mutex_lock(&bdev->bd_mutex); - i_size_write(bdev->bd_inode, - (loff_t)get_capacity(base->block->gdp) << 9); - mutex_unlock(&bdev->bd_mutex); + bd_set_nr_sectors(bdev, get_capacity(base->block->gdp)); dasd_put_device(base); return 0; } @@ -91,9 +88,7 @@ dasd_ioctl_disable(struct block_device *bdev) * Set i_size to zero, since read, write, etc. check against this * value. */ - mutex_lock(&bdev->bd_mutex); - i_size_write(bdev->bd_inode, 0); - mutex_unlock(&bdev->bd_mutex); + bd_set_nr_sectors(bdev, 0); dasd_put_device(base); return 0; } diff --git a/fs/block_dev.c b/fs/block_dev.c index f52597172c8b..08158bb2e76c 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -876,6 +876,7 @@ struct block_device *bdget(dev_t dev) bdev = &BDEV_I(inode)->bdev; if (inode->i_state & I_NEW) { + spin_lock_init(&bdev->bd_size_lock); bdev->bd_contains = NULL; bdev->bd_super = NULL; bdev->bd_inode = inode; @@ -1290,6 +1291,7 @@ static void check_disk_size_change(struct gendisk *disk, { loff_t disk_size, bdev_size; + spin_lock(&bdev->bd_size_lock); disk_size = (loff_t)get_capacity(disk) << 9; bdev_size = i_size_read(bdev->bd_inode); if (disk_size != bdev_size) { @@ -1299,11 +1301,15 @@ static void check_disk_size_change(struct gendisk *disk, disk->disk_name, bdev_size, disk_size); } i_size_write(bdev->bd_inode, disk_size); - if (bdev_size > disk_size && __invalidate_device(bdev, false)) + } + bdev->bd_invalidated = 0; + spin_unlock(&bdev->bd_size_lock); + + if (bdev_size > disk_size) { + if (__invalidate_device(bdev, false)) pr_warn("VFS: busy inodes on resized disk %s\n", disk->disk_name); } - bdev->bd_invalidated = 0; } /** @@ -1328,13 +1334,10 @@ int revalidate_disk(struct gendisk *disk) if (!(disk->flags & GENHD_FL_HIDDEN)) { struct block_device *bdev = bdget_disk(disk, 0); - if (!bdev) - return ret; - - mutex_lock(&bdev->bd_mutex); - check_disk_size_change(disk, bdev, ret == 0); - mutex_unlock(&bdev->bd_mutex); - bdput(bdev); + if (bdev) { + check_disk_size_change(disk, bdev, ret == 0); + bdput(bdev); + } } return ret; } @@ -1373,9 +1376,9 @@ EXPORT_SYMBOL(check_disk_change); void bd_set_nr_sectors(struct block_device *bdev, sector_t sectors) { - inode_lock(bdev->bd_inode); + spin_lock(&bdev->bd_size_lock); i_size_write(bdev->bd_inode, (loff_t)sectors << SECTOR_SHIFT); - inode_unlock(bdev->bd_inode); + spin_unlock(&bdev->bd_size_lock); } EXPORT_SYMBOL(bd_set_nr_sectors); diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 4ecf4fed171f..5accc2549d22 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -38,6 +38,7 @@ struct block_device { /* number of times partitions within this device have been opened. */ unsigned bd_part_count; int bd_invalidated; + spinlock_t bd_size_lock; /* for bd_inode->i_size updates */ struct gendisk * bd_disk; struct backing_dev_info *bd_bdi; From c13f0fbc4c191aab5e95b01589ff5bbc6556e4f6 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sun, 23 Aug 2020 11:10:43 +0200 Subject: [PATCH 004/191] nvme: don't call revalidate_disk from nvme_set_queue_dying In nvme_set_queue_dying we really just want to ensure the disk and bdev sizes are set to zero. Going through revalidate_disk leads to a somewhat arcance and complex callchain relying on special behavior in a few places. Instead just lift the set_capacity directly to nvme_set_queue_dying, and rename and move the nvme_mpath_update_disk_size helper so that we can use it in nvme_set_queue_dying to propagate the size to the bdev without detours. Signed-off-by: Christoph Hellwig Reviewed-by: Sagi Grimberg Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- drivers/nvme/host/core.c | 33 +++++++++++++++++++++++---------- drivers/nvme/host/nvme.h | 13 ------------- 2 files changed, 23 insertions(+), 23 deletions(-) diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index d543bc1747fd..c7e01d9667ad 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -94,21 +94,34 @@ static void nvme_put_subsystem(struct nvme_subsystem *subsys); static void nvme_remove_invalid_namespaces(struct nvme_ctrl *ctrl, unsigned nsid); +static void nvme_update_bdev_size(struct gendisk *disk) +{ + struct block_device *bdev = bdget_disk(disk, 0); + + if (bdev) { + bd_set_nr_sectors(bdev, get_capacity(disk)); + bdput(bdev); + } +} + +/* + * Prepare a queue for teardown. + * + * This must forcibly unquiesce queues to avoid blocking dispatch, and only set + * the capacity to 0 after that to avoid blocking dispatchers that may be + * holding bd_butex. This will end buffered writers dirtying pages that can't + * be synced. + */ static void nvme_set_queue_dying(struct nvme_ns *ns) { - /* - * Revalidating a dead namespace sets capacity to 0. This will end - * buffered writers dirtying pages that can't be synced. - */ if (test_and_set_bit(NVME_NS_DEAD, &ns->flags)) return; + blk_set_queue_dying(ns->queue); - /* Forcibly unquiesce queues to avoid blocking dispatch */ blk_mq_unquiesce_queue(ns->queue); - /* - * Revalidate after unblocking dispatchers that may be holding bd_butex - */ - revalidate_disk(ns->disk); + + set_capacity(ns->disk, 0); + nvme_update_bdev_size(ns->disk); } static void nvme_queue_scan(struct nvme_ctrl *ctrl) @@ -2134,7 +2147,7 @@ static int __nvme_revalidate_disk(struct gendisk *disk, struct nvme_id_ns *id) nvme_update_disk_info(ns->head->disk, ns, id); blk_stack_limits(&ns->head->disk->queue->limits, &ns->queue->limits, 0); - nvme_mpath_update_disk_size(ns->head->disk); + nvme_update_bdev_size(ns->head->disk); } #endif return 0; diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h index aab130f31e25..87737fa32360 100644 --- a/drivers/nvme/host/nvme.h +++ b/drivers/nvme/host/nvme.h @@ -683,16 +683,6 @@ static inline void nvme_trace_bio_complete(struct request *req, trace_block_bio_complete(ns->head->disk->queue, req->bio); } -static inline void nvme_mpath_update_disk_size(struct gendisk *disk) -{ - struct block_device *bdev = bdget_disk(disk, 0); - - if (bdev) { - bd_set_nr_sectors(bdev, get_capacity(disk)); - bdput(bdev); - } -} - extern struct device_attribute dev_attr_ana_grpid; extern struct device_attribute dev_attr_ana_state; extern struct device_attribute subsys_attr_iopolicy; @@ -767,9 +757,6 @@ static inline void nvme_mpath_wait_freeze(struct nvme_subsystem *subsys) static inline void nvme_mpath_start_freeze(struct nvme_subsystem *subsys) { } -static inline void nvme_mpath_update_disk_size(struct gendisk *disk) -{ -} #endif /* CONFIG_NVME_MULTIPATH */ #ifdef CONFIG_BLK_DEV_ZONED From f3256075ba49d80835b601bfbff350a2140b2924 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 27 Aug 2020 17:37:45 +0200 Subject: [PATCH 005/191] block: remove the BIO_NULL_MAPPED flag We can simply use a boolean flag in the bio_map_data data structure instead. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/blk-map.c | 9 +++++---- include/linux/blk_types.h | 1 - 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/block/blk-map.c b/block/blk-map.c index 6e804892d5ec..51e6195f878d 100644 --- a/block/blk-map.c +++ b/block/blk-map.c @@ -12,7 +12,8 @@ #include "blk.h" struct bio_map_data { - int is_our_pages; + bool is_our_pages : 1; + bool is_null_mapped : 1; struct iov_iter iter; struct iovec iov[]; }; @@ -108,7 +109,7 @@ static int bio_uncopy_user(struct bio *bio) struct bio_map_data *bmd = bio->bi_private; int ret = 0; - if (!bio_flagged(bio, BIO_NULL_MAPPED)) { + if (!bmd || !bmd->is_null_mapped) { /* * if we're in a workqueue, the request is orphaned, so * don't copy into a random user address space, just free @@ -158,7 +159,7 @@ static struct bio *bio_copy_user_iov(struct request_queue *q, * The caller provided iov might point to an on-stack or otherwise * shortlived one. */ - bmd->is_our_pages = map_data ? 0 : 1; + bmd->is_our_pages = !map_data; nr_pages = DIV_ROUND_UP(offset + len, PAGE_SIZE); if (nr_pages > BIO_MAX_PAGES) @@ -234,7 +235,7 @@ static struct bio *bio_copy_user_iov(struct request_queue *q, bio->bi_private = bmd; if (map_data && map_data->null_mapped) - bio_set_flag(bio, BIO_NULL_MAPPED); + bmd->is_null_mapped = true; return bio; cleanup: if (!map_data) diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 5accc2549d22..78b073956884 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -257,7 +257,6 @@ enum { BIO_CLONED, /* doesn't own data */ BIO_BOUNCED, /* bio is a bounce bio */ BIO_USER_MAPPED, /* contains user pages */ - BIO_NULL_MAPPED, /* contains invalid user pages */ BIO_WORKINGSET, /* contains userspace workingset pages */ BIO_QUIET, /* Make BIO Quiet */ BIO_CHAIN, /* chained bio, ->bi_remaining in effect */ From 7b63c052a580d7d5ed83a6e2a327e85881fa679a Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 27 Aug 2020 17:37:46 +0200 Subject: [PATCH 006/191] block: remove __blk_rq_unmap_user Open code __blk_rq_unmap_user in the two callers. Both never pass a NULL bio, and one of them can use an existing local variable instead of the bio flag. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/blk-map.c | 29 +++++++++++------------------ 1 file changed, 11 insertions(+), 18 deletions(-) diff --git a/block/blk-map.c b/block/blk-map.c index 51e6195f878d..10de4809edf9 100644 --- a/block/blk-map.c +++ b/block/blk-map.c @@ -558,20 +558,6 @@ int blk_rq_append_bio(struct request *rq, struct bio **bio) } EXPORT_SYMBOL(blk_rq_append_bio); -static int __blk_rq_unmap_user(struct bio *bio) -{ - int ret = 0; - - if (bio) { - if (bio_flagged(bio, BIO_USER_MAPPED)) - bio_unmap_user(bio); - else - ret = bio_uncopy_user(bio); - } - - return ret; -} - static int __blk_rq_map_user_iov(struct request *rq, struct rq_map_data *map_data, struct iov_iter *iter, gfp_t gfp_mask, bool copy) @@ -599,7 +585,10 @@ static int __blk_rq_map_user_iov(struct request *rq, */ ret = blk_rq_append_bio(rq, &bio); if (ret) { - __blk_rq_unmap_user(orig_bio); + if (copy) + bio_uncopy_user(orig_bio); + else + bio_unmap_user(orig_bio); return ret; } bio_get(bio); @@ -701,9 +690,13 @@ int blk_rq_unmap_user(struct bio *bio) if (unlikely(bio_flagged(bio, BIO_BOUNCED))) mapped_bio = bio->bi_private; - ret2 = __blk_rq_unmap_user(mapped_bio); - if (ret2 && !ret) - ret = ret2; + if (bio_flagged(mapped_bio, BIO_USER_MAPPED)) { + bio_unmap_user(mapped_bio); + } else { + ret2 = bio_uncopy_user(mapped_bio); + if (ret2 && !ret) + ret = ret2; + } mapped_bio = bio; bio = bio->bi_next; From 7589ad6729d6a707c6ce97693106d42cbb121b42 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 27 Aug 2020 17:37:47 +0200 Subject: [PATCH 007/191] block: remove __blk_rq_map_user_iov Just duplicate a small amount of code in the low-level map into the bio and copy to the bio routines, leading to much easier to follow and maintain code, and better shared error handling. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/blk-map.c | 144 ++++++++++++++++++------------------------------ 1 file changed, 54 insertions(+), 90 deletions(-) diff --git a/block/blk-map.c b/block/blk-map.c index 10de4809edf9..427962ac2f67 100644 --- a/block/blk-map.c +++ b/block/blk-map.c @@ -127,24 +127,12 @@ static int bio_uncopy_user(struct bio *bio) return ret; } -/** - * bio_copy_user_iov - copy user data to bio - * @q: destination block queue - * @map_data: pointer to the rq_map_data holding pages (if necessary) - * @iter: iovec iterator - * @gfp_mask: memory allocation flags - * - * Prepares and returns a bio for indirect user io, bouncing data - * to/from kernel pages as necessary. Must be paired with - * call bio_uncopy_user() on io completion. - */ -static struct bio *bio_copy_user_iov(struct request_queue *q, - struct rq_map_data *map_data, struct iov_iter *iter, - gfp_t gfp_mask) +static int bio_copy_user_iov(struct request *rq, struct rq_map_data *map_data, + struct iov_iter *iter, gfp_t gfp_mask) { struct bio_map_data *bmd; struct page *page; - struct bio *bio; + struct bio *bio, *bounce_bio; int i = 0, ret; int nr_pages; unsigned int len = iter->count; @@ -152,7 +140,7 @@ static struct bio *bio_copy_user_iov(struct request_queue *q, bmd = bio_alloc_map_data(iter, gfp_mask); if (!bmd) - return ERR_PTR(-ENOMEM); + return -ENOMEM; /* * We need to do a deep copy of the iov_iter including the iovecs. @@ -169,8 +157,7 @@ static struct bio *bio_copy_user_iov(struct request_queue *q, bio = bio_kmalloc(gfp_mask, nr_pages); if (!bio) goto out_bmd; - - ret = 0; + bio->bi_opf |= req_op(rq); if (map_data) { nr_pages = 1 << map_data->page_order; @@ -187,7 +174,7 @@ static struct bio *bio_copy_user_iov(struct request_queue *q, if (map_data) { if (i == map_data->nr_entries * nr_pages) { ret = -ENOMEM; - break; + goto cleanup; } page = map_data->pages[i / nr_pages]; @@ -195,14 +182,14 @@ static struct bio *bio_copy_user_iov(struct request_queue *q, i++; } else { - page = alloc_page(q->bounce_gfp | gfp_mask); + page = alloc_page(rq->q->bounce_gfp | gfp_mask); if (!page) { ret = -ENOMEM; - break; + goto cleanup; } } - if (bio_add_pc_page(q, bio, page, bytes, offset) < bytes) { + if (bio_add_pc_page(rq->q, bio, page, bytes, offset) < bytes) { if (!map_data) __free_page(page); break; @@ -212,9 +199,6 @@ static struct bio *bio_copy_user_iov(struct request_queue *q, offset = 0; } - if (ret) - goto cleanup; - if (map_data) map_data->offset += bio->bi_iter.bi_size; @@ -236,39 +220,42 @@ static struct bio *bio_copy_user_iov(struct request_queue *q, bio->bi_private = bmd; if (map_data && map_data->null_mapped) bmd->is_null_mapped = true; - return bio; + + bounce_bio = bio; + ret = blk_rq_append_bio(rq, &bounce_bio); + if (ret) + goto cleanup; + + /* + * We link the bounce buffer in and could have to traverse it later, so + * we have to get a ref to prevent it from being freed + */ + bio_get(bounce_bio); + return 0; cleanup: if (!map_data) bio_free_pages(bio); bio_put(bio); out_bmd: kfree(bmd); - return ERR_PTR(ret); + return ret; } -/** - * bio_map_user_iov - map user iovec into bio - * @q: the struct request_queue for the bio - * @iter: iovec iterator - * @gfp_mask: memory allocation flags - * - * Map the user space address into a bio suitable for io to a block - * device. Returns an error pointer in case of error. - */ -static struct bio *bio_map_user_iov(struct request_queue *q, - struct iov_iter *iter, gfp_t gfp_mask) +static int bio_map_user_iov(struct request *rq, struct iov_iter *iter, + gfp_t gfp_mask) { - unsigned int max_sectors = queue_max_hw_sectors(q); - int j; - struct bio *bio; + unsigned int max_sectors = queue_max_hw_sectors(rq->q); + struct bio *bio, *bounce_bio; int ret; + int j; if (!iov_iter_count(iter)) - return ERR_PTR(-EINVAL); + return -EINVAL; bio = bio_kmalloc(gfp_mask, iov_iter_npages(iter, BIO_MAX_PAGES)); if (!bio) - return ERR_PTR(-ENOMEM); + return -ENOMEM; + bio->bi_opf |= req_op(rq); while (iov_iter_count(iter)) { struct page **pages; @@ -284,7 +271,7 @@ static struct bio *bio_map_user_iov(struct request_queue *q, npages = DIV_ROUND_UP(offs + bytes, PAGE_SIZE); - if (unlikely(offs & queue_dma_alignment(q))) { + if (unlikely(offs & queue_dma_alignment(rq->q))) { ret = -EINVAL; j = 0; } else { @@ -296,7 +283,7 @@ static struct bio *bio_map_user_iov(struct request_queue *q, if (n > bytes) n = bytes; - if (!bio_add_hw_page(q, bio, page, n, offs, + if (!bio_add_hw_page(rq->q, bio, page, n, offs, max_sectors, &same_page)) { if (same_page) put_page(page); @@ -323,18 +310,30 @@ static struct bio *bio_map_user_iov(struct request_queue *q, bio_set_flag(bio, BIO_USER_MAPPED); /* - * subtle -- if bio_map_user_iov() ended up bouncing a bio, - * it would normally disappear when its bi_end_io is run. - * however, we need it for the unmap, so grab an extra - * reference to it + * Subtle: if we end up needing to bounce a bio, it would normally + * disappear when its bi_end_io is run. However, we need the original + * bio for the unmap, so grab an extra reference to it */ bio_get(bio); - return bio; + bounce_bio = bio; + ret = blk_rq_append_bio(rq, &bounce_bio); + if (ret) + goto out_put_orig; + + /* + * We link the bounce buffer in and could have to traverse it + * later, so we have to get a ref to prevent it from being freed + */ + bio_get(bounce_bio); + return 0; + + out_put_orig: + bio_put(bio); out_unmap: bio_release_pages(bio, false); bio_put(bio); - return ERR_PTR(ret); + return ret; } /** @@ -558,44 +557,6 @@ int blk_rq_append_bio(struct request *rq, struct bio **bio) } EXPORT_SYMBOL(blk_rq_append_bio); -static int __blk_rq_map_user_iov(struct request *rq, - struct rq_map_data *map_data, struct iov_iter *iter, - gfp_t gfp_mask, bool copy) -{ - struct request_queue *q = rq->q; - struct bio *bio, *orig_bio; - int ret; - - if (copy) - bio = bio_copy_user_iov(q, map_data, iter, gfp_mask); - else - bio = bio_map_user_iov(q, iter, gfp_mask); - - if (IS_ERR(bio)) - return PTR_ERR(bio); - - bio->bi_opf &= ~REQ_OP_MASK; - bio->bi_opf |= req_op(rq); - - orig_bio = bio; - - /* - * We link the bounce buffer in and could have to traverse it - * later so we have to get a ref to prevent it from being freed - */ - ret = blk_rq_append_bio(rq, &bio); - if (ret) { - if (copy) - bio_uncopy_user(orig_bio); - else - bio_unmap_user(orig_bio); - return ret; - } - bio_get(bio); - - return 0; -} - /** * blk_rq_map_user_iov - map user data to a request, for passthrough requests * @q: request queue where request should be inserted @@ -639,7 +600,10 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq, i = *iter; do { - ret =__blk_rq_map_user_iov(rq, map_data, &i, gfp_mask, copy); + if (copy) + ret = bio_copy_user_iov(rq, map_data, &i, gfp_mask); + else + ret = bio_map_user_iov(rq, &i, gfp_mask); if (ret) goto unmap_rq; if (!bio) From 3310eebafe6f9a872c1f757b3d822dafae9c0cd8 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 27 Aug 2020 17:37:48 +0200 Subject: [PATCH 008/191] block: remove the BIO_USER_MAPPED flag Just check if there is private data, in which case the bio must have originated from bio_copy_user_iov. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/blk-map.c | 10 ++++------ include/linux/blk_types.h | 1 - 2 files changed, 4 insertions(+), 7 deletions(-) diff --git a/block/blk-map.c b/block/blk-map.c index 427962ac2f67..be118926ccf4 100644 --- a/block/blk-map.c +++ b/block/blk-map.c @@ -109,7 +109,7 @@ static int bio_uncopy_user(struct bio *bio) struct bio_map_data *bmd = bio->bi_private; int ret = 0; - if (!bmd || !bmd->is_null_mapped) { + if (!bmd->is_null_mapped) { /* * if we're in a workqueue, the request is orphaned, so * don't copy into a random user address space, just free @@ -307,8 +307,6 @@ static int bio_map_user_iov(struct request *rq, struct iov_iter *iter, break; } - bio_set_flag(bio, BIO_USER_MAPPED); - /* * Subtle: if we end up needing to bounce a bio, it would normally * disappear when its bi_end_io is run. However, we need the original @@ -654,12 +652,12 @@ int blk_rq_unmap_user(struct bio *bio) if (unlikely(bio_flagged(bio, BIO_BOUNCED))) mapped_bio = bio->bi_private; - if (bio_flagged(mapped_bio, BIO_USER_MAPPED)) { - bio_unmap_user(mapped_bio); - } else { + if (bio->bi_private) { ret2 = bio_uncopy_user(mapped_bio); if (ret2 && !ret) ret = ret2; + } else { + bio_unmap_user(mapped_bio); } mapped_bio = bio; diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 78b073956884..63a39e47fc60 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -256,7 +256,6 @@ enum { BIO_NO_PAGE_REF, /* don't put release vec pages */ BIO_CLONED, /* doesn't own data */ BIO_BOUNCED, /* bio is a bounce bio */ - BIO_USER_MAPPED, /* contains user pages */ BIO_WORKINGSET, /* contains userspace workingset pages */ BIO_QUIET, /* Make BIO Quiet */ BIO_CHAIN, /* chained bio, ->bi_remaining in effect */ From c4823983538d5fdf38575b3f3ba3a0d10b7f021a Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 19 Aug 2020 09:35:33 +0200 Subject: [PATCH 009/191] raw: deprecate the raw driver The raw driver has been replaced by O_DIRECT support on the block device in 2002. Deprecate it to prepare for removal in a few kernel releases. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- drivers/char/raw.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/char/raw.c b/drivers/char/raw.c index 380bf518338e..ccf5bd528642 100644 --- a/drivers/char/raw.c +++ b/drivers/char/raw.c @@ -63,6 +63,11 @@ static int raw_open(struct inode *inode, struct file *filp) return 0; } + pr_warn_ratelimited( + "process %s (pid %d) is using the deprecated raw device\n" + "support will be removed in Linux 5.14.\n", + current->comm, current->pid); + mutex_lock(&raw_mutex); /* From 4ce790632803bf2ec47271895a59936c70df7e78 Mon Sep 17 00:00:00 2001 From: Tian Tao Date: Fri, 21 Aug 2020 09:19:15 +0800 Subject: [PATCH 010/191] virtio-blk: Use kobj_to_dev() instead of container_of() Use kobj_to_dev() instead of container_of() Signed-off-by: Tian Tao Reviewed-by: Bart Van Assche Reviewed-by: Stefan Hajnoczi Reviewed-by: Stefano Garzarella Signed-off-by: Jens Axboe --- drivers/block/virtio_blk.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index b2e48dac1ebd..ca63a41059d6 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -646,7 +646,7 @@ static struct attribute *virtblk_attrs[] = { static umode_t virtblk_attrs_are_visible(struct kobject *kobj, struct attribute *a, int n) { - struct device *dev = container_of(kobj, struct device, kobj); + struct device *dev = kobj_to_dev(kobj); struct gendisk *disk = dev_to_disk(dev); struct virtio_blk *vblk = disk->private_data; struct virtio_device *vdev = vblk->vdev; From 339b5a25c28c1d85afd0ce882f57962ad550bc6a Mon Sep 17 00:00:00 2001 From: Danny Lin Date: Sat, 29 Aug 2020 02:13:53 -0700 Subject: [PATCH 011/191] blk-wbt: Remove obsolete multiqueue I/O scheduling comment This comment was added before the multiqueue I/O scheduler framework was introduced; multiqueue has support for I/O scheduling now, so this obsolete comment can be removed. Signed-off-by: Danny Lin Signed-off-by: Jens Axboe --- block/Kconfig | 2 -- 1 file changed, 2 deletions(-) diff --git a/block/Kconfig b/block/Kconfig index bbad5e8bbffe..a2297edfdde8 100644 --- a/block/Kconfig +++ b/block/Kconfig @@ -161,8 +161,6 @@ config BLK_WBT_MQ depends on BLK_WBT help Enable writeback throttling by default on multiqueue devices. - Multiqueue currently doesn't have support for IO scheduling, - enabling this option is recommended. config BLK_DEBUG_FS bool "Block layer debugging information in debugfs" From 8e756373d7c8eb6f8876411bed45e4b1c736eb53 Mon Sep 17 00:00:00 2001 From: Baolin Wang Date: Fri, 28 Aug 2020 10:52:54 +0800 Subject: [PATCH 012/191] block: Move bio merge related functions into blk-merge.c It's better to move bio merge related functions into blk-merge.c, which contains all merge related functions. Reviewed-by: Christoph Hellwig Signed-off-by: Baolin Wang Signed-off-by: Jens Axboe --- block/blk-core.c | 156 --------------------------------------------- block/blk-merge.c | 157 ++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 157 insertions(+), 156 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 10c08ac50697..11661f5b64d6 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -643,162 +643,6 @@ void blk_put_request(struct request *req) } EXPORT_SYMBOL(blk_put_request); -static void blk_account_io_merge_bio(struct request *req) -{ - if (!blk_do_io_stat(req)) - return; - - part_stat_lock(); - part_stat_inc(req->part, merges[op_stat_group(req_op(req))]); - part_stat_unlock(); -} - -bool bio_attempt_back_merge(struct request *req, struct bio *bio, - unsigned int nr_segs) -{ - const int ff = bio->bi_opf & REQ_FAILFAST_MASK; - - if (!ll_back_merge_fn(req, bio, nr_segs)) - return false; - - trace_block_bio_backmerge(req->q, req, bio); - rq_qos_merge(req->q, req, bio); - - if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff) - blk_rq_set_mixed_merge(req); - - req->biotail->bi_next = bio; - req->biotail = bio; - req->__data_len += bio->bi_iter.bi_size; - - bio_crypt_free_ctx(bio); - - blk_account_io_merge_bio(req); - return true; -} - -bool bio_attempt_front_merge(struct request *req, struct bio *bio, - unsigned int nr_segs) -{ - const int ff = bio->bi_opf & REQ_FAILFAST_MASK; - - if (!ll_front_merge_fn(req, bio, nr_segs)) - return false; - - trace_block_bio_frontmerge(req->q, req, bio); - rq_qos_merge(req->q, req, bio); - - if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff) - blk_rq_set_mixed_merge(req); - - bio->bi_next = req->bio; - req->bio = bio; - - req->__sector = bio->bi_iter.bi_sector; - req->__data_len += bio->bi_iter.bi_size; - - bio_crypt_do_front_merge(req, bio); - - blk_account_io_merge_bio(req); - return true; -} - -bool bio_attempt_discard_merge(struct request_queue *q, struct request *req, - struct bio *bio) -{ - unsigned short segments = blk_rq_nr_discard_segments(req); - - if (segments >= queue_max_discard_segments(q)) - goto no_merge; - if (blk_rq_sectors(req) + bio_sectors(bio) > - blk_rq_get_max_sectors(req, blk_rq_pos(req))) - goto no_merge; - - rq_qos_merge(q, req, bio); - - req->biotail->bi_next = bio; - req->biotail = bio; - req->__data_len += bio->bi_iter.bi_size; - req->nr_phys_segments = segments + 1; - - blk_account_io_merge_bio(req); - return true; -no_merge: - req_set_nomerge(q, req); - return false; -} - -/** - * blk_attempt_plug_merge - try to merge with %current's plugged list - * @q: request_queue new bio is being queued at - * @bio: new bio being queued - * @nr_segs: number of segments in @bio - * @same_queue_rq: pointer to &struct request that gets filled in when - * another request associated with @q is found on the plug list - * (optional, may be %NULL) - * - * Determine whether @bio being queued on @q can be merged with a request - * on %current's plugged list. Returns %true if merge was successful, - * otherwise %false. - * - * Plugging coalesces IOs from the same issuer for the same purpose without - * going through @q->queue_lock. As such it's more of an issuing mechanism - * than scheduling, and the request, while may have elvpriv data, is not - * added on the elevator at this point. In addition, we don't have - * reliable access to the elevator outside queue lock. Only check basic - * merging parameters without querying the elevator. - * - * Caller must ensure !blk_queue_nomerges(q) beforehand. - */ -bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio, - unsigned int nr_segs, struct request **same_queue_rq) -{ - struct blk_plug *plug; - struct request *rq; - struct list_head *plug_list; - - plug = blk_mq_plug(q, bio); - if (!plug) - return false; - - plug_list = &plug->mq_list; - - list_for_each_entry_reverse(rq, plug_list, queuelist) { - bool merged = false; - - if (rq->q == q && same_queue_rq) { - /* - * Only blk-mq multiple hardware queues case checks the - * rq in the same queue, there should be only one such - * rq in a queue - **/ - *same_queue_rq = rq; - } - - if (rq->q != q || !blk_rq_merge_ok(rq, bio)) - continue; - - switch (blk_try_merge(rq, bio)) { - case ELEVATOR_BACK_MERGE: - merged = bio_attempt_back_merge(rq, bio, nr_segs); - break; - case ELEVATOR_FRONT_MERGE: - merged = bio_attempt_front_merge(rq, bio, nr_segs); - break; - case ELEVATOR_DISCARD_MERGE: - merged = bio_attempt_discard_merge(q, rq, bio); - break; - default: - break; - } - - if (merged) - return true; - } - - return false; -} - static void handle_bad_sector(struct bio *bio, sector_t maxsector) { char b[BDEVNAME_SIZE]; diff --git a/block/blk-merge.c b/block/blk-merge.c index f685d633bcc9..3aa2de57b57f 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -11,6 +11,7 @@ #include #include "blk.h" +#include "blk-rq-qos.h" static inline bool bio_will_gap(struct request_queue *q, struct request *prev_rq, struct bio *prev, struct bio *next) @@ -895,3 +896,159 @@ enum elv_merge blk_try_merge(struct request *rq, struct bio *bio) return ELEVATOR_FRONT_MERGE; return ELEVATOR_NO_MERGE; } + +static void blk_account_io_merge_bio(struct request *req) +{ + if (!blk_do_io_stat(req)) + return; + + part_stat_lock(); + part_stat_inc(req->part, merges[op_stat_group(req_op(req))]); + part_stat_unlock(); +} + +bool bio_attempt_back_merge(struct request *req, struct bio *bio, + unsigned int nr_segs) +{ + const int ff = bio->bi_opf & REQ_FAILFAST_MASK; + + if (!ll_back_merge_fn(req, bio, nr_segs)) + return false; + + trace_block_bio_backmerge(req->q, req, bio); + rq_qos_merge(req->q, req, bio); + + if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff) + blk_rq_set_mixed_merge(req); + + req->biotail->bi_next = bio; + req->biotail = bio; + req->__data_len += bio->bi_iter.bi_size; + + bio_crypt_free_ctx(bio); + + blk_account_io_merge_bio(req); + return true; +} + +bool bio_attempt_front_merge(struct request *req, struct bio *bio, + unsigned int nr_segs) +{ + const int ff = bio->bi_opf & REQ_FAILFAST_MASK; + + if (!ll_front_merge_fn(req, bio, nr_segs)) + return false; + + trace_block_bio_frontmerge(req->q, req, bio); + rq_qos_merge(req->q, req, bio); + + if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff) + blk_rq_set_mixed_merge(req); + + bio->bi_next = req->bio; + req->bio = bio; + + req->__sector = bio->bi_iter.bi_sector; + req->__data_len += bio->bi_iter.bi_size; + + bio_crypt_do_front_merge(req, bio); + + blk_account_io_merge_bio(req); + return true; +} + +bool bio_attempt_discard_merge(struct request_queue *q, struct request *req, + struct bio *bio) +{ + unsigned short segments = blk_rq_nr_discard_segments(req); + + if (segments >= queue_max_discard_segments(q)) + goto no_merge; + if (blk_rq_sectors(req) + bio_sectors(bio) > + blk_rq_get_max_sectors(req, blk_rq_pos(req))) + goto no_merge; + + rq_qos_merge(q, req, bio); + + req->biotail->bi_next = bio; + req->biotail = bio; + req->__data_len += bio->bi_iter.bi_size; + req->nr_phys_segments = segments + 1; + + blk_account_io_merge_bio(req); + return true; +no_merge: + req_set_nomerge(q, req); + return false; +} + +/** + * blk_attempt_plug_merge - try to merge with %current's plugged list + * @q: request_queue new bio is being queued at + * @bio: new bio being queued + * @nr_segs: number of segments in @bio + * @same_queue_rq: pointer to &struct request that gets filled in when + * another request associated with @q is found on the plug list + * (optional, may be %NULL) + * + * Determine whether @bio being queued on @q can be merged with a request + * on %current's plugged list. Returns %true if merge was successful, + * otherwise %false. + * + * Plugging coalesces IOs from the same issuer for the same purpose without + * going through @q->queue_lock. As such it's more of an issuing mechanism + * than scheduling, and the request, while may have elvpriv data, is not + * added on the elevator at this point. In addition, we don't have + * reliable access to the elevator outside queue lock. Only check basic + * merging parameters without querying the elevator. + * + * Caller must ensure !blk_queue_nomerges(q) beforehand. + */ +bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio, + unsigned int nr_segs, struct request **same_queue_rq) +{ + struct blk_plug *plug; + struct request *rq; + struct list_head *plug_list; + + plug = blk_mq_plug(q, bio); + if (!plug) + return false; + + plug_list = &plug->mq_list; + + list_for_each_entry_reverse(rq, plug_list, queuelist) { + bool merged = false; + + if (rq->q == q && same_queue_rq) { + /* + * Only blk-mq multiple hardware queues case checks the + * rq in the same queue, there should be only one such + * rq in a queue + **/ + *same_queue_rq = rq; + } + + if (rq->q != q || !blk_rq_merge_ok(rq, bio)) + continue; + + switch (blk_try_merge(rq, bio)) { + case ELEVATOR_BACK_MERGE: + merged = bio_attempt_back_merge(rq, bio, nr_segs); + break; + case ELEVATOR_FRONT_MERGE: + merged = bio_attempt_front_merge(rq, bio, nr_segs); + break; + case ELEVATOR_DISCARD_MERGE: + merged = bio_attempt_discard_merge(q, rq, bio); + break; + default: + break; + } + + if (merged) + return true; + } + + return false; +} From bdc6a287bc98e8f32bf52c9cb2d1bdf75975f5a0 Mon Sep 17 00:00:00 2001 From: Baolin Wang Date: Fri, 28 Aug 2020 10:52:55 +0800 Subject: [PATCH 013/191] block: Move blk_mq_bio_list_merge() into blk-merge.c Move the blk_mq_bio_list_merge() into blk-merge.c and rename it as a generic name. Reviewed-by: Christoph Hellwig Signed-off-by: Baolin Wang Signed-off-by: Jens Axboe --- block/blk-merge.c | 44 ++++++++++++++++++++++++++++++++++++++++ block/blk-mq-sched.c | 46 +----------------------------------------- block/blk.h | 2 ++ block/kyber-iosched.c | 2 +- include/linux/blk-mq.h | 2 -- 5 files changed, 48 insertions(+), 48 deletions(-) diff --git a/block/blk-merge.c b/block/blk-merge.c index 3aa2de57b57f..b09e9fc44236 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -1052,3 +1052,47 @@ bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio, return false; } + +/* + * Iterate list of requests and see if we can merge this bio with any + * of them. + */ +bool blk_bio_list_merge(struct request_queue *q, struct list_head *list, + struct bio *bio, unsigned int nr_segs) +{ + struct request *rq; + int checked = 8; + + list_for_each_entry_reverse(rq, list, queuelist) { + bool merged = false; + + if (!checked--) + break; + + if (!blk_rq_merge_ok(rq, bio)) + continue; + + switch (blk_try_merge(rq, bio)) { + case ELEVATOR_BACK_MERGE: + if (blk_mq_sched_allow_merge(q, rq, bio)) + merged = bio_attempt_back_merge(rq, bio, + nr_segs); + break; + case ELEVATOR_FRONT_MERGE: + if (blk_mq_sched_allow_merge(q, rq, bio)) + merged = bio_attempt_front_merge(rq, bio, + nr_segs); + break; + case ELEVATOR_DISCARD_MERGE: + merged = bio_attempt_discard_merge(q, rq, bio); + break; + default: + continue; + } + + return merged; + } + + return false; +} +EXPORT_SYMBOL_GPL(blk_bio_list_merge); diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index d2790e5b06d1..82acff96c093 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -391,50 +391,6 @@ bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio, } EXPORT_SYMBOL_GPL(blk_mq_sched_try_merge); -/* - * Iterate list of requests and see if we can merge this bio with any - * of them. - */ -bool blk_mq_bio_list_merge(struct request_queue *q, struct list_head *list, - struct bio *bio, unsigned int nr_segs) -{ - struct request *rq; - int checked = 8; - - list_for_each_entry_reverse(rq, list, queuelist) { - bool merged = false; - - if (!checked--) - break; - - if (!blk_rq_merge_ok(rq, bio)) - continue; - - switch (blk_try_merge(rq, bio)) { - case ELEVATOR_BACK_MERGE: - if (blk_mq_sched_allow_merge(q, rq, bio)) - merged = bio_attempt_back_merge(rq, bio, - nr_segs); - break; - case ELEVATOR_FRONT_MERGE: - if (blk_mq_sched_allow_merge(q, rq, bio)) - merged = bio_attempt_front_merge(rq, bio, - nr_segs); - break; - case ELEVATOR_DISCARD_MERGE: - merged = bio_attempt_discard_merge(q, rq, bio); - break; - default: - continue; - } - - return merged; - } - - return false; -} -EXPORT_SYMBOL_GPL(blk_mq_bio_list_merge); - /* * Reverse check our software queue for entries that we could potentially * merge with. Currently includes a hand-wavy stop count of 8, to not spend @@ -449,7 +405,7 @@ static bool blk_mq_attempt_merge(struct request_queue *q, lockdep_assert_held(&ctx->lock); - if (blk_mq_bio_list_merge(q, &ctx->rq_lists[type], bio, nr_segs)) { + if (blk_bio_list_merge(q, &ctx->rq_lists[type], bio, nr_segs)) { ctx->rq_merged++; return true; } diff --git a/block/blk.h b/block/blk.h index 49e2928a1632..d6152d20d4e2 100644 --- a/block/blk.h +++ b/block/blk.h @@ -177,6 +177,8 @@ bool bio_attempt_discard_merge(struct request_queue *q, struct request *req, struct bio *bio); bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio, unsigned int nr_segs, struct request **same_queue_rq); +bool blk_bio_list_merge(struct request_queue *q, struct list_head *list, + struct bio *bio, unsigned int nr_segs); void blk_account_io_start(struct request *req); void blk_account_io_done(struct request *req, u64 now); diff --git a/block/kyber-iosched.c b/block/kyber-iosched.c index a38c5ab103d1..6d4ba0e9688e 100644 --- a/block/kyber-iosched.c +++ b/block/kyber-iosched.c @@ -573,7 +573,7 @@ static bool kyber_bio_merge(struct blk_mq_hw_ctx *hctx, struct bio *bio, bool merged; spin_lock(&kcq->lock); - merged = blk_mq_bio_list_merge(hctx->queue, rq_list, bio, nr_segs); + merged = blk_bio_list_merge(hctx->queue, rq_list, bio, nr_segs); spin_unlock(&kcq->lock); return merged; diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index 9d2d5ad367a4..21a02e0577dd 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -489,8 +489,6 @@ void blk_mq_kick_requeue_list(struct request_queue *q); void blk_mq_delay_kick_requeue_list(struct request_queue *q, unsigned long msecs); void blk_mq_complete_request(struct request *rq); bool blk_mq_complete_request_remote(struct request *rq); -bool blk_mq_bio_list_merge(struct request_queue *q, struct list_head *list, - struct bio *bio, unsigned int nr_segs); bool blk_mq_queue_stopped(struct request_queue *q); void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx); void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx); From 7d7ca7c5269becab86c9f595309c8e90ce268967 Mon Sep 17 00:00:00 2001 From: Baolin Wang Date: Fri, 28 Aug 2020 10:52:56 +0800 Subject: [PATCH 014/191] block: Add a new helper to attempt to merge a bio There are lots of duplicated code when trying to merge a bio from plug list and sw queue, we can introduce a new helper to attempt to merge a bio, which can simplify the blk_bio_list_merge() and blk_attempt_plug_merge(). Reviewed-by: Christoph Hellwig Signed-off-by: Baolin Wang Signed-off-by: Jens Axboe --- block/blk-merge.c | 104 ++++++++++++++++++++++--------------------- block/blk-mq-sched.c | 6 +-- block/blk.h | 21 ++++++--- 3 files changed, 71 insertions(+), 60 deletions(-) diff --git a/block/blk-merge.c b/block/blk-merge.c index b09e9fc44236..80c974484a3f 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -907,13 +907,14 @@ static void blk_account_io_merge_bio(struct request *req) part_stat_unlock(); } -bool bio_attempt_back_merge(struct request *req, struct bio *bio, - unsigned int nr_segs) +enum bio_merge_status bio_attempt_back_merge(struct request *req, + struct bio *bio, + unsigned int nr_segs) { const int ff = bio->bi_opf & REQ_FAILFAST_MASK; if (!ll_back_merge_fn(req, bio, nr_segs)) - return false; + return BIO_MERGE_FAILED; trace_block_bio_backmerge(req->q, req, bio); rq_qos_merge(req->q, req, bio); @@ -928,16 +929,17 @@ bool bio_attempt_back_merge(struct request *req, struct bio *bio, bio_crypt_free_ctx(bio); blk_account_io_merge_bio(req); - return true; + return BIO_MERGE_OK; } -bool bio_attempt_front_merge(struct request *req, struct bio *bio, - unsigned int nr_segs) +enum bio_merge_status bio_attempt_front_merge(struct request *req, + struct bio *bio, + unsigned int nr_segs) { const int ff = bio->bi_opf & REQ_FAILFAST_MASK; if (!ll_front_merge_fn(req, bio, nr_segs)) - return false; + return BIO_MERGE_FAILED; trace_block_bio_frontmerge(req->q, req, bio); rq_qos_merge(req->q, req, bio); @@ -954,11 +956,12 @@ bool bio_attempt_front_merge(struct request *req, struct bio *bio, bio_crypt_do_front_merge(req, bio); blk_account_io_merge_bio(req); - return true; + return BIO_MERGE_OK; } -bool bio_attempt_discard_merge(struct request_queue *q, struct request *req, - struct bio *bio) +enum bio_merge_status bio_attempt_discard_merge(struct request_queue *q, + struct request *req, + struct bio *bio) { unsigned short segments = blk_rq_nr_discard_segments(req); @@ -976,10 +979,39 @@ bool bio_attempt_discard_merge(struct request_queue *q, struct request *req, req->nr_phys_segments = segments + 1; blk_account_io_merge_bio(req); - return true; + return BIO_MERGE_OK; no_merge: req_set_nomerge(q, req); - return false; + return BIO_MERGE_FAILED; +} + +static enum bio_merge_status blk_attempt_bio_merge(struct request_queue *q, + struct request *rq, + struct bio *bio, + unsigned int nr_segs, + bool sched_allow_merge) +{ + if (!blk_rq_merge_ok(rq, bio)) + return BIO_MERGE_NONE; + + switch (blk_try_merge(rq, bio)) { + case ELEVATOR_BACK_MERGE: + if (!sched_allow_merge || + (sched_allow_merge && blk_mq_sched_allow_merge(q, rq, bio))) + return bio_attempt_back_merge(rq, bio, nr_segs); + break; + case ELEVATOR_FRONT_MERGE: + if (!sched_allow_merge || + (sched_allow_merge && blk_mq_sched_allow_merge(q, rq, bio))) + return bio_attempt_front_merge(rq, bio, nr_segs); + break; + case ELEVATOR_DISCARD_MERGE: + return bio_attempt_discard_merge(q, rq, bio); + default: + return BIO_MERGE_NONE; + } + + return BIO_MERGE_FAILED; } /** @@ -1018,8 +1050,6 @@ bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio, plug_list = &plug->mq_list; list_for_each_entry_reverse(rq, plug_list, queuelist) { - bool merged = false; - if (rq->q == q && same_queue_rq) { /* * Only blk-mq multiple hardware queues case checks the @@ -1029,24 +1059,11 @@ bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio, *same_queue_rq = rq; } - if (rq->q != q || !blk_rq_merge_ok(rq, bio)) + if (rq->q != q) continue; - switch (blk_try_merge(rq, bio)) { - case ELEVATOR_BACK_MERGE: - merged = bio_attempt_back_merge(rq, bio, nr_segs); - break; - case ELEVATOR_FRONT_MERGE: - merged = bio_attempt_front_merge(rq, bio, nr_segs); - break; - case ELEVATOR_DISCARD_MERGE: - merged = bio_attempt_discard_merge(q, rq, bio); - break; - default: - break; - } - - if (merged) + if (blk_attempt_bio_merge(q, rq, bio, nr_segs, false) == + BIO_MERGE_OK) return true; } @@ -1064,33 +1081,18 @@ bool blk_bio_list_merge(struct request_queue *q, struct list_head *list, int checked = 8; list_for_each_entry_reverse(rq, list, queuelist) { - bool merged = false; - if (!checked--) break; - if (!blk_rq_merge_ok(rq, bio)) - continue; - - switch (blk_try_merge(rq, bio)) { - case ELEVATOR_BACK_MERGE: - if (blk_mq_sched_allow_merge(q, rq, bio)) - merged = bio_attempt_back_merge(rq, bio, - nr_segs); - break; - case ELEVATOR_FRONT_MERGE: - if (blk_mq_sched_allow_merge(q, rq, bio)) - merged = bio_attempt_front_merge(rq, bio, - nr_segs); - break; - case ELEVATOR_DISCARD_MERGE: - merged = bio_attempt_discard_merge(q, rq, bio); - break; - default: + switch (blk_attempt_bio_merge(q, rq, bio, nr_segs, true)) { + case BIO_MERGE_NONE: continue; + case BIO_MERGE_OK: + return true; + case BIO_MERGE_FAILED: + return false; } - return merged; } return false; diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index 82acff96c093..94db0c9d59b8 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -368,7 +368,7 @@ bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio, case ELEVATOR_BACK_MERGE: if (!blk_mq_sched_allow_merge(q, rq, bio)) return false; - if (!bio_attempt_back_merge(rq, bio, nr_segs)) + if (bio_attempt_back_merge(rq, bio, nr_segs) != BIO_MERGE_OK) return false; *merged_request = attempt_back_merge(q, rq); if (!*merged_request) @@ -377,14 +377,14 @@ bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio, case ELEVATOR_FRONT_MERGE: if (!blk_mq_sched_allow_merge(q, rq, bio)) return false; - if (!bio_attempt_front_merge(rq, bio, nr_segs)) + if (bio_attempt_front_merge(rq, bio, nr_segs) != BIO_MERGE_OK) return false; *merged_request = attempt_front_merge(q, rq); if (!*merged_request) elv_merged_request(q, rq, ELEVATOR_FRONT_MERGE); return true; case ELEVATOR_DISCARD_MERGE: - return bio_attempt_discard_merge(q, rq, bio); + return bio_attempt_discard_merge(q, rq, bio) == BIO_MERGE_OK; default: return false; } diff --git a/block/blk.h b/block/blk.h index d6152d20d4e2..a180443ac13f 100644 --- a/block/blk.h +++ b/block/blk.h @@ -29,6 +29,12 @@ struct blk_flush_queue { spinlock_t mq_flush_lock; }; +enum bio_merge_status { + BIO_MERGE_OK, + BIO_MERGE_NONE, + BIO_MERGE_FAILED, +}; + extern struct kmem_cache *blk_requestq_cachep; extern struct kobj_type blk_queue_ktype; extern struct ida blk_queue_ida; @@ -169,12 +175,15 @@ static inline void blk_integrity_del(struct gendisk *disk) unsigned long blk_rq_timeout(unsigned long timeout); void blk_add_timer(struct request *req); -bool bio_attempt_front_merge(struct request *req, struct bio *bio, - unsigned int nr_segs); -bool bio_attempt_back_merge(struct request *req, struct bio *bio, - unsigned int nr_segs); -bool bio_attempt_discard_merge(struct request_queue *q, struct request *req, - struct bio *bio); +enum bio_merge_status bio_attempt_front_merge(struct request *req, + struct bio *bio, + unsigned int nr_segs); +enum bio_merge_status bio_attempt_back_merge(struct request *req, + struct bio *bio, + unsigned int nr_segs); +enum bio_merge_status bio_attempt_discard_merge(struct request_queue *q, + struct request *req, + struct bio *bio); bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio, unsigned int nr_segs, struct request **same_queue_rq); bool blk_bio_list_merge(struct request_queue *q, struct list_head *list, From cdfcef9ee87745d9511ad8825e1d2b8b861884da Mon Sep 17 00:00:00 2001 From: Baolin Wang Date: Fri, 28 Aug 2020 10:52:57 +0800 Subject: [PATCH 015/191] block: Remove blk_mq_attempt_merge() function The small blk_mq_attempt_merge() function is only called by __blk_mq_sched_bio_merge(), just open code it. Reviewed-by: Christoph Hellwig Signed-off-by: Baolin Wang Signed-off-by: Jens Axboe --- block/blk-mq-sched.c | 44 ++++++++++++++++---------------------------- 1 file changed, 16 insertions(+), 28 deletions(-) diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index 94db0c9d59b8..205d9716f7a5 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -391,28 +391,6 @@ bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio, } EXPORT_SYMBOL_GPL(blk_mq_sched_try_merge); -/* - * Reverse check our software queue for entries that we could potentially - * merge with. Currently includes a hand-wavy stop count of 8, to not spend - * too much time checking for merges. - */ -static bool blk_mq_attempt_merge(struct request_queue *q, - struct blk_mq_hw_ctx *hctx, - struct blk_mq_ctx *ctx, struct bio *bio, - unsigned int nr_segs) -{ - enum hctx_type type = hctx->type; - - lockdep_assert_held(&ctx->lock); - - if (blk_bio_list_merge(q, &ctx->rq_lists[type], bio, nr_segs)) { - ctx->rq_merged++; - return true; - } - - return false; -} - bool __blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio, unsigned int nr_segs) { @@ -426,14 +404,24 @@ bool __blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio, return e->type->ops.bio_merge(hctx, bio, nr_segs); type = hctx->type; - if ((hctx->flags & BLK_MQ_F_SHOULD_MERGE) && - !list_empty_careful(&ctx->rq_lists[type])) { - /* default per sw-queue merge */ - spin_lock(&ctx->lock); - ret = blk_mq_attempt_merge(q, hctx, ctx, bio, nr_segs); - spin_unlock(&ctx->lock); + if (!(hctx->flags & BLK_MQ_F_SHOULD_MERGE) || + list_empty_careful(&ctx->rq_lists[type])) + return false; + + /* default per sw-queue merge */ + spin_lock(&ctx->lock); + /* + * Reverse check our software queue for entries that we could + * potentially merge with. Currently includes a hand-wavy stop + * count of 8, to not spend too much time checking for merges. + */ + if (blk_bio_list_merge(q, &ctx->rq_lists[type], bio, nr_segs)) { + ctx->rq_merged++; + ret = true; } + spin_unlock(&ctx->lock); + return ret; } From e44a6a2359808e0b97ff894569748ad2593b06f9 Mon Sep 17 00:00:00 2001 From: Xianting Tian Date: Thu, 27 Aug 2020 14:34:17 +0800 Subject: [PATCH 016/191] blk-mq: use BLK_MQ_NO_TAG for no tag Replace various magic -1 constants for tags with BLK_MQ_NO_TAG. Signed-off-by: Xianting Tian Signed-off-by: Jens Axboe --- block/blk-core.c | 4 ++-- block/blk-mq-sched.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 11661f5b64d6..062efdedc994 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -116,8 +116,8 @@ void blk_rq_init(struct request_queue *q, struct request *rq) rq->__sector = (sector_t) -1; INIT_HLIST_NODE(&rq->hash); RB_CLEAR_NODE(&rq->rb_node); - rq->tag = -1; - rq->internal_tag = -1; + rq->tag = BLK_MQ_NO_TAG; + rq->internal_tag = BLK_MQ_NO_TAG; rq->start_time_ns = ktime_get_ns(); rq->part = NULL; refcount_set(&rq->ref, 1); diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index 205d9716f7a5..501a85ceaccb 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -475,7 +475,7 @@ void blk_mq_sched_insert_request(struct request *rq, bool at_head, goto run; } - WARN_ON(e && (rq->tag != -1)); + WARN_ON(e && (rq->tag != BLK_MQ_NO_TAG)); if (blk_mq_sched_bypass_insert(hctx, !!e, rq)) { /* From 7b8917f5e29c377be1db5680249fe30e038cb3eb Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 31 Aug 2020 20:02:33 +0200 Subject: [PATCH 017/191] block: remove the alignment_offset field from struct hd_struct The alignment offset is only used in slow path callers, so just calculate it on the fly. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/partitions/core.c | 7 ++++--- include/linux/blkdev.h | 5 ++--- include/linux/genhd.h | 1 - 3 files changed, 6 insertions(+), 7 deletions(-) diff --git a/block/partitions/core.c b/block/partitions/core.c index b1c0b50ca92d..94c2fb39e602 100644 --- a/block/partitions/core.c +++ b/block/partitions/core.c @@ -199,7 +199,10 @@ static ssize_t part_alignment_offset_show(struct device *dev, struct device_attribute *attr, char *buf) { struct hd_struct *p = dev_to_part(dev); - return sprintf(buf, "%llu\n", (unsigned long long)p->alignment_offset); + + return sprintf(buf, "%u\n", + queue_limit_alignment_offset(&part_to_disk(p)->queue->limits, + p->start_sect)); } static ssize_t part_discard_alignment_show(struct device *dev, @@ -405,8 +408,6 @@ static struct hd_struct *add_partition(struct gendisk *disk, int partno, pdev = part_to_dev(p); p->start_sect = start; - p->alignment_offset = - queue_limit_alignment_offset(&disk->queue->limits, start); p->discard_alignment = queue_limit_discard_alignment(&disk->queue->limits, start); p->nr_sects = len; diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 0a1730b30ad2..ba1f5f5e11c6 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1456,10 +1456,9 @@ static inline int bdev_alignment_offset(struct block_device *bdev) if (q->limits.misaligned) return -1; - if (bdev != bdev->bd_contains) - return bdev->bd_part->alignment_offset; - + return queue_limit_alignment_offset(&q->limits, + bdev->bd_part->start_sect); return q->limits.alignment_offset; } diff --git a/include/linux/genhd.h b/include/linux/genhd.h index 39025dc0397c..bfa411c80dbb 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -65,7 +65,6 @@ struct hd_struct { struct disk_stats __percpu *dkstats; struct percpu_ref ref; - sector_t alignment_offset; unsigned int discard_alignment; struct device __dev; struct kobject *holder_dir; From 7cf34d97ab45203b975396393ded9d3867dfa8bf Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 31 Aug 2020 20:02:34 +0200 Subject: [PATCH 018/191] block: remove the discard_alignment field from struct hd_struct The alignment offset is only used in slow path callers, so just calculate it on the fly. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/partitions/core.c | 7 ++++--- include/linux/blkdev.h | 4 ++-- include/linux/genhd.h | 1 - 3 files changed, 6 insertions(+), 6 deletions(-) diff --git a/block/partitions/core.c b/block/partitions/core.c index 94c2fb39e602..e596a85bba1e 100644 --- a/block/partitions/core.c +++ b/block/partitions/core.c @@ -209,7 +209,10 @@ static ssize_t part_discard_alignment_show(struct device *dev, struct device_attribute *attr, char *buf) { struct hd_struct *p = dev_to_part(dev); - return sprintf(buf, "%u\n", p->discard_alignment); + + return sprintf(buf, "%u\n", + queue_limit_discard_alignment(&part_to_disk(p)->queue->limits, + p->start_sect)); } static DEVICE_ATTR(partition, 0444, part_partition_show, NULL); @@ -408,8 +411,6 @@ static struct hd_struct *add_partition(struct gendisk *disk, int partno, pdev = part_to_dev(p); p->start_sect = start; - p->discard_alignment = - queue_limit_discard_alignment(&disk->queue->limits, start); p->nr_sects = len; p->partno = partno; p->policy = get_disk_ro(disk); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index ba1f5f5e11c6..d0d61bc81615 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1498,8 +1498,8 @@ static inline int bdev_discard_alignment(struct block_device *bdev) struct request_queue *q = bdev_get_queue(bdev); if (bdev != bdev->bd_contains) - return bdev->bd_part->discard_alignment; - + return queue_limit_discard_alignment(&q->limits, + bdev->bd_part->start_sect); return q->limits.discard_alignment; } diff --git a/include/linux/genhd.h b/include/linux/genhd.h index bfa411c80dbb..9ea2ca31c278 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -65,7 +65,6 @@ struct hd_struct { struct disk_stats __percpu *dkstats; struct percpu_ref ref; - unsigned int discard_alignment; struct device __dev; struct kobject *holder_dir; int policy, partno; From 46d40cfad13ccbd0739019d754d46d8f93e1d5aa Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 31 Aug 2020 20:02:35 +0200 Subject: [PATCH 019/191] block: remove an outdated comment on the bd_dev field kdev_t is long gone, so we don't need to comment a field isn't one.. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- include/linux/blk_types.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 63a39e47fc60..59d9150165c4 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -20,7 +20,7 @@ typedef void (bio_end_io_t) (struct bio *); struct bio_crypt_ctx; struct block_device { - dev_t bd_dev; /* not a kdev_t - it's a search key */ + dev_t bd_dev; int bd_openers; struct inode * bd_inode; /* will die */ struct super_block * bd_super; From e5c7fb400227df5c7822a3c59b193d23e849d0ac Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 31 Aug 2020 20:02:36 +0200 Subject: [PATCH 020/191] block: move the devcgroup_inode_permission call to blkdev_get devcgroup_inode_permission is never called for the recusive case, so move it out into blkdev_get. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- fs/block_dev.c | 36 +++++++++++++++++------------------- 1 file changed, 17 insertions(+), 19 deletions(-) diff --git a/fs/block_dev.c b/fs/block_dev.c index 08158bb2e76c..990e97bcbeaf 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1449,22 +1449,8 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder, struct gendisk *disk; int ret; int partno; - int perm = 0; bool first_open = false, unblock_events = true, need_restart; - if (mode & FMODE_READ) - perm |= MAY_READ; - if (mode & FMODE_WRITE) - perm |= MAY_WRITE; - /* - * hooks: /n/, see "layering violations". - */ - if (!for_part) { - ret = devcgroup_inode_permission(bdev->bd_inode, perm); - if (ret != 0) - return ret; - } - restart: need_restart = false; ret = -ENXIO; @@ -1637,12 +1623,24 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder, */ int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder) { - int res; + int ret, perm = 0; - res =__blkdev_get(bdev, mode, holder, 0); - if (res) - bdput(bdev); - return res; + if (mode & FMODE_READ) + perm |= MAY_READ; + if (mode & FMODE_WRITE) + perm |= MAY_WRITE; + ret = devcgroup_inode_permission(bdev->bd_inode, perm); + if (ret) + goto bdput; + + ret =__blkdev_get(bdev, mode, holder, 0); + if (ret) + goto bdput; + return 0; + +bdput: + bdput(bdev); + return ret; } EXPORT_SYMBOL(blkdev_get); From f93af2a494e1d28377065a2320d11da98110a970 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 31 Aug 2020 20:02:37 +0200 Subject: [PATCH 021/191] block: cleanup __alloc_disk_node Use early returns and goto-based unwinding to simplify the flow a bit. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/genhd.c | 73 +++++++++++++++++++++++++++------------------------ 1 file changed, 38 insertions(+), 35 deletions(-) diff --git a/block/genhd.c b/block/genhd.c index 99c64641c314..055ce9cf1835 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -1729,45 +1729,48 @@ struct gendisk *__alloc_disk_node(int minors, int node_id) } disk = kzalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id); - if (disk) { - disk->part0.dkstats = alloc_percpu(struct disk_stats); - if (!disk->part0.dkstats) { - kfree(disk); - return NULL; - } - init_rwsem(&disk->lookup_sem); - disk->node_id = node_id; - if (disk_expand_part_tbl(disk, 0)) { - free_percpu(disk->part0.dkstats); - kfree(disk); - return NULL; - } - ptbl = rcu_dereference_protected(disk->part_tbl, 1); - rcu_assign_pointer(ptbl->part[0], &disk->part0); + if (!disk) + return NULL; - /* - * set_capacity() and get_capacity() currently don't use - * seqcounter to read/update the part0->nr_sects. Still init - * the counter as we can read the sectors in IO submission - * patch using seqence counters. - * - * TODO: Ideally set_capacity() and get_capacity() should be - * converted to make use of bd_mutex and sequence counters. - */ - hd_sects_seq_init(&disk->part0); - if (hd_ref_init(&disk->part0)) { - hd_free_part(&disk->part0); - kfree(disk); - return NULL; - } + disk->part0.dkstats = alloc_percpu(struct disk_stats); + if (!disk->part0.dkstats) + goto out_free_disk; - disk->minors = minors; - rand_initialize_disk(disk); - disk_to_dev(disk)->class = &block_class; - disk_to_dev(disk)->type = &disk_type; - device_initialize(disk_to_dev(disk)); + init_rwsem(&disk->lookup_sem); + disk->node_id = node_id; + if (disk_expand_part_tbl(disk, 0)) { + free_percpu(disk->part0.dkstats); + goto out_free_disk; } + + ptbl = rcu_dereference_protected(disk->part_tbl, 1); + rcu_assign_pointer(ptbl->part[0], &disk->part0); + + /* + * set_capacity() and get_capacity() currently don't use + * seqcounter to read/update the part0->nr_sects. Still init + * the counter as we can read the sectors in IO submission + * patch using seqence counters. + * + * TODO: Ideally set_capacity() and get_capacity() should be + * converted to make use of bd_mutex and sequence counters. + */ + hd_sects_seq_init(&disk->part0); + if (hd_ref_init(&disk->part0)) + goto out_free_part0; + + disk->minors = minors; + rand_initialize_disk(disk); + disk_to_dev(disk)->class = &block_class; + disk_to_dev(disk)->type = &disk_type; + device_initialize(disk_to_dev(disk)); return disk; + +out_free_part0: + hd_free_part(&disk->part0); +out_free_disk: + kfree(disk); + return NULL; } EXPORT_SYMBOL(__alloc_disk_node); From 8328eb28369a7dbfab6ff26366dbe8094425acc4 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 31 Aug 2020 20:02:38 +0200 Subject: [PATCH 022/191] block: remove the disk argument to delete_partition We can trivially derive the gendisk from the hd_struct. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/blk.h | 2 +- block/genhd.c | 2 +- block/partitions/core.c | 9 +++++---- 3 files changed, 7 insertions(+), 6 deletions(-) diff --git a/block/blk.h b/block/blk.h index a180443ac13f..c08762e10b04 100644 --- a/block/blk.h +++ b/block/blk.h @@ -361,7 +361,7 @@ char *disk_name(struct gendisk *hd, int partno, char *buf); #define ADDPART_FLAG_NONE 0 #define ADDPART_FLAG_RAID 1 #define ADDPART_FLAG_WHOLEDISK 2 -void delete_partition(struct gendisk *disk, struct hd_struct *part); +void delete_partition(struct hd_struct *part); int bdev_add_partition(struct block_device *bdev, int partno, sector_t start, sector_t length); int bdev_del_partition(struct block_device *bdev, int partno); diff --git a/block/genhd.c b/block/genhd.c index 055ce9cf1835..2055b5bf637a 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -913,7 +913,7 @@ void del_gendisk(struct gendisk *disk) DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE); while ((part = disk_part_iter_next(&piter))) { invalidate_partition(disk, part->partno); - delete_partition(disk, part); + delete_partition(part); } disk_part_iter_exit(&piter); diff --git a/block/partitions/core.c b/block/partitions/core.c index e596a85bba1e..dd6811422a87 100644 --- a/block/partitions/core.c +++ b/block/partitions/core.c @@ -324,8 +324,9 @@ int hd_ref_init(struct hd_struct *part) * Must be called either with bd_mutex held, before a disk can be opened or * after all disk users are gone. */ -void delete_partition(struct gendisk *disk, struct hd_struct *part) +void delete_partition(struct hd_struct *part) { + struct gendisk *disk = part_to_disk(part); struct disk_part_tbl *ptbl = rcu_dereference_protected(disk->part_tbl, 1); @@ -333,7 +334,7 @@ void delete_partition(struct gendisk *disk, struct hd_struct *part) * ->part_tbl is referenced in this part's release handler, so * we have to hold the disk device */ - get_device(disk_to_dev(part_to_disk(part))); + get_device(disk_to_dev(disk)); rcu_assign_pointer(ptbl->part[part->partno], NULL); kobject_put(part->holder_dir); device_del(part_to_dev(part)); @@ -556,7 +557,7 @@ int bdev_del_partition(struct block_device *bdev, int partno) sync_blockdev(bdevp); invalidate_bdev(bdevp); - delete_partition(bdev->bd_disk, part); + delete_partition(part); ret = 0; out_unlock: mutex_unlock(&bdev->bd_mutex); @@ -636,7 +637,7 @@ int blk_drop_partitions(struct block_device *bdev) disk_part_iter_init(&piter, bdev->bd_disk, DISK_PITER_INCL_EMPTY); while ((part = disk_part_iter_next(&piter))) - delete_partition(bdev->bd_disk, part); + delete_partition(part); disk_part_iter_exit(&piter); return 0; From 1f06959bd2c96342dbac8e29994dd4f69deb956e Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 31 Aug 2020 20:02:39 +0200 Subject: [PATCH 023/191] block: remove the unused q argument to part_in_flight and part_in_flight_rw Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/genhd.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) diff --git a/block/genhd.c b/block/genhd.c index 2055b5bf637a..5fc6d82e6c68 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -110,8 +110,7 @@ static void part_stat_read_all(struct hd_struct *part, struct disk_stats *stat) } } -static unsigned int part_in_flight(struct request_queue *q, - struct hd_struct *part) +static unsigned int part_in_flight(struct hd_struct *part) { unsigned int inflight = 0; int cpu; @@ -126,8 +125,7 @@ static unsigned int part_in_flight(struct request_queue *q, return inflight; } -static void part_in_flight_rw(struct request_queue *q, struct hd_struct *part, - unsigned int inflight[2]) +static void part_in_flight_rw(struct hd_struct *part, unsigned int inflight[2]) { int cpu; @@ -1301,7 +1299,7 @@ ssize_t part_stat_show(struct device *dev, if (queue_is_mq(q)) inflight = blk_mq_in_flight(q, p); else - inflight = part_in_flight(q, p); + inflight = part_in_flight(p); return sprintf(buf, "%8lu %8lu %8llu %8u " @@ -1343,7 +1341,7 @@ ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr, if (queue_is_mq(q)) blk_mq_in_flight_rw(q, p, inflight); else - part_in_flight_rw(q, p, inflight); + part_in_flight_rw(p, inflight); return sprintf(buf, "%8u %8u\n", inflight[0], inflight[1]); } @@ -1623,7 +1621,7 @@ static int diskstats_show(struct seq_file *seqf, void *v) if (queue_is_mq(gp->queue)) inflight = blk_mq_in_flight(gp->queue, hd); else - inflight = part_in_flight(gp->queue, hd); + inflight = part_in_flight(hd); seq_printf(seqf, "%4d %7d %s " "%lu %lu %lu %u " From 5e124f74325d8181b3275a704e87e44246c484f6 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 1 Sep 2020 14:52:33 -0400 Subject: [PATCH 024/191] blk-iocost: use local[64]_t for percpu stat blk-iocost has been reading percpu stat counters from remote cpus which on some archs can lead to torn reads in really rare occassions. Use local[64]_t for those counters. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- block/blk-iocost.c | 37 +++++++++++++++++++++++++++---------- 1 file changed, 27 insertions(+), 10 deletions(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index d37b55db2409..e2266e7692b4 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -179,6 +179,8 @@ #include #include #include +#include +#include #include "blk-rq-qos.h" #include "blk-stat.h" #include "blk-wbt.h" @@ -373,8 +375,8 @@ struct ioc_params { }; struct ioc_missed { - u32 nr_met; - u32 nr_missed; + local_t nr_met; + local_t nr_missed; u32 last_met; u32 last_missed; }; @@ -382,7 +384,7 @@ struct ioc_missed { struct ioc_pcpu_stat { struct ioc_missed missed[2]; - u64 rq_wait_ns; + local64_t rq_wait_ns; u64 last_rq_wait_ns; }; @@ -1278,8 +1280,8 @@ static void ioc_lat_stat(struct ioc *ioc, u32 *missed_ppm_ar, u32 *rq_wait_pct_p u64 this_rq_wait_ns; for (rw = READ; rw <= WRITE; rw++) { - u32 this_met = READ_ONCE(stat->missed[rw].nr_met); - u32 this_missed = READ_ONCE(stat->missed[rw].nr_missed); + u32 this_met = local_read(&stat->missed[rw].nr_met); + u32 this_missed = local_read(&stat->missed[rw].nr_missed); nr_met[rw] += this_met - stat->missed[rw].last_met; nr_missed[rw] += this_missed - stat->missed[rw].last_missed; @@ -1287,7 +1289,7 @@ static void ioc_lat_stat(struct ioc *ioc, u32 *missed_ppm_ar, u32 *rq_wait_pct_p stat->missed[rw].last_missed = this_missed; } - this_rq_wait_ns = READ_ONCE(stat->rq_wait_ns); + this_rq_wait_ns = local64_read(&stat->rq_wait_ns); rq_wait_ns += this_rq_wait_ns - stat->last_rq_wait_ns; stat->last_rq_wait_ns = this_rq_wait_ns; } @@ -1908,6 +1910,7 @@ static void ioc_rqos_done_bio(struct rq_qos *rqos, struct bio *bio) static void ioc_rqos_done(struct rq_qos *rqos, struct request *rq) { struct ioc *ioc = rqos_to_ioc(rqos); + struct ioc_pcpu_stat *ccs; u64 on_q_ns, rq_wait_ns, size_nsec; int pidx, rw; @@ -1931,13 +1934,17 @@ static void ioc_rqos_done(struct rq_qos *rqos, struct request *rq) rq_wait_ns = rq->start_time_ns - rq->alloc_time_ns; size_nsec = div64_u64(calc_size_vtime_cost(rq, ioc), VTIME_PER_NSEC); + ccs = get_cpu_ptr(ioc->pcpu_stat); + if (on_q_ns <= size_nsec || on_q_ns - size_nsec <= ioc->params.qos[pidx] * NSEC_PER_USEC) - this_cpu_inc(ioc->pcpu_stat->missed[rw].nr_met); + local_inc(&ccs->missed[rw].nr_met); else - this_cpu_inc(ioc->pcpu_stat->missed[rw].nr_missed); + local_inc(&ccs->missed[rw].nr_missed); - this_cpu_add(ioc->pcpu_stat->rq_wait_ns, rq_wait_ns); + local64_add(rq_wait_ns, &ccs->rq_wait_ns); + + put_cpu_ptr(ccs); } static void ioc_rqos_queue_depth_changed(struct rq_qos *rqos) @@ -1977,7 +1984,7 @@ static int blk_iocost_init(struct request_queue *q) { struct ioc *ioc; struct rq_qos *rqos; - int ret; + int i, cpu, ret; ioc = kzalloc(sizeof(*ioc), GFP_KERNEL); if (!ioc) @@ -1989,6 +1996,16 @@ static int blk_iocost_init(struct request_queue *q) return -ENOMEM; } + for_each_possible_cpu(cpu) { + struct ioc_pcpu_stat *ccs = per_cpu_ptr(ioc->pcpu_stat, cpu); + + for (i = 0; i < ARRAY_SIZE(ccs->missed); i++) { + local_set(&ccs->missed[i].nr_met, 0); + local_set(&ccs->missed[i].nr_missed, 0); + } + local64_set(&ccs->rq_wait_ns, 0); + } + rqos = &ioc->rqos; rqos->id = RQ_QOS_COST; rqos->ops = &ioc_rqos_ops; From 00410f1b09fe7c9a12bde07f0bb4b978a3367f3a Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 1 Sep 2020 14:52:34 -0400 Subject: [PATCH 025/191] blk-iocost: rename propagate_active_weights() to propagate_weights() It already propagates two weights - active and inuse - and there will be another soon. Let's drop the confusing misnomers. Rename [__]propagate_active_weights() to [__]propagate_weights() and commit_active_weights() to commit_weights(). This is pure rename. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- block/blk-iocost.c | 40 ++++++++++++++++++++-------------------- 1 file changed, 20 insertions(+), 20 deletions(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index e2266e7692b4..78e6919153d8 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -479,7 +479,7 @@ struct ioc_gq { atomic64_t active_period; struct list_head active_list; - /* see __propagate_active_weight() and current_hweight() for details */ + /* see __propagate_weights() and current_hweight() for details */ u64 child_active_sum; u64 child_inuse_sum; int hweight_gen; @@ -890,7 +890,7 @@ static void ioc_start_period(struct ioc *ioc, struct ioc_now *now) * Update @iocg's `active` and `inuse` to @active and @inuse, update level * weight sums and propagate upwards accordingly. */ -static void __propagate_active_weight(struct ioc_gq *iocg, u32 active, u32 inuse) +static void __propagate_weights(struct ioc_gq *iocg, u32 active, u32 inuse) { struct ioc *ioc = iocg->ioc; int lvl; @@ -935,7 +935,7 @@ static void __propagate_active_weight(struct ioc_gq *iocg, u32 active, u32 inuse ioc->weights_updated = true; } -static void commit_active_weights(struct ioc *ioc) +static void commit_weights(struct ioc *ioc) { lockdep_assert_held(&ioc->lock); @@ -947,10 +947,10 @@ static void commit_active_weights(struct ioc *ioc) } } -static void propagate_active_weight(struct ioc_gq *iocg, u32 active, u32 inuse) +static void propagate_weights(struct ioc_gq *iocg, u32 active, u32 inuse) { - __propagate_active_weight(iocg, active, inuse); - commit_active_weights(iocg->ioc); + __propagate_weights(iocg, active, inuse); + commit_weights(iocg->ioc); } static void current_hweight(struct ioc_gq *iocg, u32 *hw_activep, u32 *hw_inusep) @@ -966,9 +966,9 @@ static void current_hweight(struct ioc_gq *iocg, u32 *hw_activep, u32 *hw_inusep goto out; /* - * Paired with wmb in commit_active_weights(). If we saw the - * updated hweight_gen, all the weight updates from - * __propagate_active_weight() are visible too. + * Paired with wmb in commit_weights(). If we saw the updated + * hweight_gen, all the weight updates from __propagate_weights() are + * visible too. * * We can race with weight updates during calculation and get it * wrong. However, hweight_gen would have changed and a future @@ -1018,7 +1018,7 @@ static void weight_updated(struct ioc_gq *iocg) weight = iocg->cfg_weight ?: iocc->dfl_weight; if (weight != iocg->weight && iocg->active) - propagate_active_weight(iocg, weight, + propagate_weights(iocg, weight, DIV64_U64_ROUND_UP(iocg->inuse * weight, iocg->weight)); iocg->weight = weight; } @@ -1090,8 +1090,8 @@ static bool iocg_activate(struct ioc_gq *iocg, struct ioc_now *now) */ iocg->hweight_gen = atomic_read(&ioc->hweight_gen) - 1; list_add(&iocg->active_list, &ioc->active_iocgs); - propagate_active_weight(iocg, iocg->weight, - iocg->last_inuse ?: iocg->weight); + propagate_weights(iocg, iocg->weight, + iocg->last_inuse ?: iocg->weight); TRACE_IOCG_PATH(iocg_activate, iocg, now, last_period, cur_period, vtime); @@ -1384,13 +1384,13 @@ static void ioc_timer_fn(struct timer_list *timer) } else if (iocg_is_idle(iocg)) { /* no waiter and idle, deactivate */ iocg->last_inuse = iocg->inuse; - __propagate_active_weight(iocg, 0, 0); + __propagate_weights(iocg, 0, 0); list_del_init(&iocg->active_list); } spin_unlock(&iocg->waitq.lock); } - commit_active_weights(ioc); + commit_weights(ioc); /* calc usages and see whether some weights need to be moved around */ list_for_each_entry(iocg, &ioc->active_iocgs, active_list) { @@ -1483,8 +1483,8 @@ static void ioc_timer_fn(struct timer_list *timer) TRACE_IOCG_PATH(inuse_takeback, iocg, &now, iocg->inuse, new_inuse, hw_inuse, new_hwi); - __propagate_active_weight(iocg, iocg->weight, - new_inuse); + __propagate_weights(iocg, iocg->weight, + new_inuse); } } else { /* genuninely out of vtime */ @@ -1524,11 +1524,11 @@ static void ioc_timer_fn(struct timer_list *timer) TRACE_IOCG_PATH(inuse_giveaway, iocg, &now, iocg->inuse, new_inuse, hw_inuse, new_hwi); - __propagate_active_weight(iocg, iocg->weight, new_inuse); + __propagate_weights(iocg, iocg->weight, new_inuse); } } skip_surplus_transfers: - commit_active_weights(ioc); + commit_weights(ioc); /* * If q is getting clogged or we're missing too much, we're issuing @@ -1753,7 +1753,7 @@ static void ioc_rqos_throttle(struct rq_qos *rqos, struct bio *bio) TRACE_IOCG_PATH(inuse_reset, iocg, &now, iocg->inuse, iocg->weight, hw_inuse, hw_active); spin_lock_irq(&ioc->lock); - propagate_active_weight(iocg, iocg->weight, iocg->weight); + propagate_weights(iocg, iocg->weight, iocg->weight); spin_unlock_irq(&ioc->lock); current_hweight(iocg, &hw_active, &hw_inuse); } @@ -2114,7 +2114,7 @@ static void ioc_pd_free(struct blkg_policy_data *pd) if (ioc) { spin_lock_irqsave(&ioc->lock, flags); if (!list_empty(&iocg->active_list)) { - propagate_active_weight(iocg, 0, 0); + propagate_weights(iocg, 0, 0); list_del_init(&iocg->active_list); } spin_unlock_irqrestore(&ioc->lock, flags); From db84a72af6be422abf2089a5896293590dda5066 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 1 Sep 2020 14:52:35 -0400 Subject: [PATCH 026/191] blk-iocost: clamp inuse and skip noops in __propagate_weights() __propagate_weights() currently expects the callers to clamp inuse within [1, active], which is needlessly fragile. The inuse adjustment logic is going to be revamped, in preparation, let's make __propagate_weights() clamp inuse on entry. Also, make it avoid weight updates altogether if neither active or inuse is changed. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- block/blk-iocost.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index 78e6919153d8..8dfe73dde2a8 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -897,7 +897,10 @@ static void __propagate_weights(struct ioc_gq *iocg, u32 active, u32 inuse) lockdep_assert_held(&ioc->lock); - inuse = min(active, inuse); + inuse = clamp_t(u32, inuse, 1, active); + + if (active == iocg->active && inuse == iocg->inuse) + return; for (lvl = iocg->level - 1; lvl >= 0; lvl--) { struct ioc_gq *parent = iocg->ancestors[lvl]; From 6ef20f787b0aa337dc901d42efa44854e09c87e1 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 1 Sep 2020 14:52:36 -0400 Subject: [PATCH 027/191] blk-iocost: move iocg_kick_delay() above iocg_kick_waitq() We'll make iocg_kick_waitq() call iocg_kick_delay(). Reorder them in preparation. This is pure code reorganization. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- block/blk-iocost.c | 120 ++++++++++++++++++++++----------------------- 1 file changed, 60 insertions(+), 60 deletions(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index 8dfe73dde2a8..ac22d761a350 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -1115,6 +1115,66 @@ static bool iocg_activate(struct ioc_gq *iocg, struct ioc_now *now) return false; } +static bool iocg_kick_delay(struct ioc_gq *iocg, struct ioc_now *now) +{ + struct ioc *ioc = iocg->ioc; + struct blkcg_gq *blkg = iocg_to_blkg(iocg); + u64 vtime = atomic64_read(&iocg->vtime); + u64 vmargin = ioc->margin_us * now->vrate; + u64 margin_ns = ioc->margin_us * NSEC_PER_USEC; + u64 delta_ns, expires, oexpires; + u32 hw_inuse; + + lockdep_assert_held(&iocg->waitq.lock); + + /* debt-adjust vtime */ + current_hweight(iocg, NULL, &hw_inuse); + vtime += abs_cost_to_cost(iocg->abs_vdebt, hw_inuse); + + /* + * Clear or maintain depending on the overage. Non-zero vdebt is what + * guarantees that @iocg is online and future iocg_kick_delay() will + * clear use_delay. Don't leave it on when there's no vdebt. + */ + if (!iocg->abs_vdebt || time_before_eq64(vtime, now->vnow)) { + blkcg_clear_delay(blkg); + return false; + } + if (!atomic_read(&blkg->use_delay) && + time_before_eq64(vtime, now->vnow + vmargin)) + return false; + + /* use delay */ + delta_ns = DIV64_U64_ROUND_UP(vtime - now->vnow, + now->vrate) * NSEC_PER_USEC; + blkcg_set_delay(blkg, delta_ns); + expires = now->now_ns + delta_ns; + + /* if already active and close enough, don't bother */ + oexpires = ktime_to_ns(hrtimer_get_softexpires(&iocg->delay_timer)); + if (hrtimer_is_queued(&iocg->delay_timer) && + abs(oexpires - expires) <= margin_ns / 4) + return true; + + hrtimer_start_range_ns(&iocg->delay_timer, ns_to_ktime(expires), + margin_ns / 4, HRTIMER_MODE_ABS); + return true; +} + +static enum hrtimer_restart iocg_delay_timer_fn(struct hrtimer *timer) +{ + struct ioc_gq *iocg = container_of(timer, struct ioc_gq, delay_timer); + struct ioc_now now; + unsigned long flags; + + spin_lock_irqsave(&iocg->waitq.lock, flags); + ioc_now(iocg->ioc, &now); + iocg_kick_delay(iocg, &now); + spin_unlock_irqrestore(&iocg->waitq.lock, flags); + + return HRTIMER_NORESTART; +} + static int iocg_wake_fn(struct wait_queue_entry *wq_entry, unsigned mode, int flags, void *key) { @@ -1211,66 +1271,6 @@ static enum hrtimer_restart iocg_waitq_timer_fn(struct hrtimer *timer) return HRTIMER_NORESTART; } -static bool iocg_kick_delay(struct ioc_gq *iocg, struct ioc_now *now) -{ - struct ioc *ioc = iocg->ioc; - struct blkcg_gq *blkg = iocg_to_blkg(iocg); - u64 vtime = atomic64_read(&iocg->vtime); - u64 vmargin = ioc->margin_us * now->vrate; - u64 margin_ns = ioc->margin_us * NSEC_PER_USEC; - u64 delta_ns, expires, oexpires; - u32 hw_inuse; - - lockdep_assert_held(&iocg->waitq.lock); - - /* debt-adjust vtime */ - current_hweight(iocg, NULL, &hw_inuse); - vtime += abs_cost_to_cost(iocg->abs_vdebt, hw_inuse); - - /* - * Clear or maintain depending on the overage. Non-zero vdebt is what - * guarantees that @iocg is online and future iocg_kick_delay() will - * clear use_delay. Don't leave it on when there's no vdebt. - */ - if (!iocg->abs_vdebt || time_before_eq64(vtime, now->vnow)) { - blkcg_clear_delay(blkg); - return false; - } - if (!atomic_read(&blkg->use_delay) && - time_before_eq64(vtime, now->vnow + vmargin)) - return false; - - /* use delay */ - delta_ns = DIV64_U64_ROUND_UP(vtime - now->vnow, - now->vrate) * NSEC_PER_USEC; - blkcg_set_delay(blkg, delta_ns); - expires = now->now_ns + delta_ns; - - /* if already active and close enough, don't bother */ - oexpires = ktime_to_ns(hrtimer_get_softexpires(&iocg->delay_timer)); - if (hrtimer_is_queued(&iocg->delay_timer) && - abs(oexpires - expires) <= margin_ns / 4) - return true; - - hrtimer_start_range_ns(&iocg->delay_timer, ns_to_ktime(expires), - margin_ns / 4, HRTIMER_MODE_ABS); - return true; -} - -static enum hrtimer_restart iocg_delay_timer_fn(struct hrtimer *timer) -{ - struct ioc_gq *iocg = container_of(timer, struct ioc_gq, delay_timer); - struct ioc_now now; - unsigned long flags; - - spin_lock_irqsave(&iocg->waitq.lock, flags); - ioc_now(iocg->ioc, &now); - iocg_kick_delay(iocg, &now); - spin_unlock_irqrestore(&iocg->waitq.lock, flags); - - return HRTIMER_NORESTART; -} - static void ioc_lat_stat(struct ioc *ioc, u32 *missed_ppm_ar, u32 *rq_wait_pct_p) { u32 nr_met[2] = { }; From 7b84b49e381a8538626f200785dd918a402c62d7 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 1 Sep 2020 14:52:37 -0400 Subject: [PATCH 028/191] blk-iocost: make iocg_kick_waitq() call iocg_kick_delay() after paying debt iocg_kick_waitq() is the function which pays debt and iocg_kick_delay() updates the actual delay status accordingly. If iocg_kick_delay() is not called after iocg_kick_delay() updated debt, unnecessarily large delays can be applied temporarily. Let's make sure such conditions don't occur by making iocg_kick_waitq() always call iocg_kick_delay() after paying debt. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- block/blk-iocost.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index ac22d761a350..b2b8dfbeee5a 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -1226,6 +1226,8 @@ static void iocg_kick_waitq(struct ioc_gq *iocg, struct ioc_now *now) atomic64_add(delta, &iocg->vtime); atomic64_add(delta, &iocg->done_vtime); iocg->abs_vdebt -= abs_delta; + + iocg_kick_delay(iocg, now); } /* @@ -1383,7 +1385,6 @@ static void ioc_timer_fn(struct timer_list *timer) if (waitqueue_active(&iocg->waitq) || iocg->abs_vdebt) { /* might be oversleeping vtime / hweight changes, kick */ iocg_kick_waitq(iocg, &now); - iocg_kick_delay(iocg, &now); } else if (iocg_is_idle(iocg)) { /* no waiter and idle, deactivate */ iocg->last_inuse = iocg->inuse; From fe20cdb516377e6ac6300254d5ca0dd7d8621ea8 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 1 Sep 2020 14:52:38 -0400 Subject: [PATCH 029/191] blk-iocost: s/HWEIGHT_WHOLE/WEIGHT_ONE/g We're gonna use HWEIGHT_WHOLE for regular weights too. Let's rename it to WEIGHT_ONE. Pure rename. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- block/blk-iocost.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index b2b8dfbeee5a..5e6d56eec1c9 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -68,7 +68,7 @@ * gets 300/(100+300) or 75% share, and A0 and A1 equally splits the rest, * 12.5% each. The distribution mechanism only cares about these flattened * shares. They're called hweights (hierarchical weights) and always add - * upto 1 (HWEIGHT_WHOLE). + * upto 1 (WEIGHT_ONE). * * A given cgroup's vtime runs slower in inverse proportion to its hweight. * For example, with 12.5% weight, A0's time runs 8 times slower (100/12.5) @@ -246,7 +246,7 @@ enum { MIN_VALID_USAGES = 2, /* 1/64k is granular enough and can easily be handled w/ u32 */ - HWEIGHT_WHOLE = 1 << 16, + WEIGHT_ONE = 1 << 16, /* * As vtime is used to calculate the cost of each IO, it needs to @@ -285,8 +285,8 @@ enum { * donate the surplus. */ SURPLUS_SCALE_PCT = 125, /* * 125% */ - SURPLUS_SCALE_ABS = HWEIGHT_WHOLE / 50, /* + 2% */ - SURPLUS_MIN_ADJ_DELTA = HWEIGHT_WHOLE / 33, /* 3% */ + SURPLUS_SCALE_ABS = WEIGHT_ONE / 50, /* + 2% */ + SURPLUS_MIN_ADJ_DELTA = WEIGHT_ONE / 33, /* 3% */ /* switch iff the conditions are met for longer than this */ AUTOP_CYCLE_NSEC = 10LLU * NSEC_PER_SEC, @@ -491,7 +491,7 @@ struct ioc_gq { struct hrtimer waitq_timer; struct hrtimer delay_timer; - /* usage is recorded as fractions of HWEIGHT_WHOLE */ + /* usage is recorded as fractions of WEIGHT_ONE */ int usage_idx; u32 usages[NR_USAGE_SLOTS]; @@ -658,7 +658,7 @@ static struct ioc_cgrp *blkcg_to_iocc(struct blkcg *blkcg) */ static u64 abs_cost_to_cost(u64 abs_cost, u32 hw_inuse) { - return DIV64_U64_ROUND_UP(abs_cost * HWEIGHT_WHOLE, hw_inuse); + return DIV64_U64_ROUND_UP(abs_cost * WEIGHT_ONE, hw_inuse); } /* @@ -666,7 +666,7 @@ static u64 abs_cost_to_cost(u64 abs_cost, u32 hw_inuse) */ static u64 cost_to_abs_cost(u64 cost, u32 hw_inuse) { - return DIV64_U64_ROUND_UP(cost * hw_inuse, HWEIGHT_WHOLE); + return DIV64_U64_ROUND_UP(cost * hw_inuse, WEIGHT_ONE); } static void iocg_commit_bio(struct ioc_gq *iocg, struct bio *bio, u64 cost) @@ -980,7 +980,7 @@ static void current_hweight(struct ioc_gq *iocg, u32 *hw_activep, u32 *hw_inusep */ smp_rmb(); - hwa = hwi = HWEIGHT_WHOLE; + hwa = hwi = WEIGHT_ONE; for (lvl = 0; lvl <= iocg->level - 1; lvl++) { struct ioc_gq *parent = iocg->ancestors[lvl]; struct ioc_gq *child = iocg->ancestors[lvl + 1]; @@ -2088,8 +2088,8 @@ static void ioc_pd_init(struct blkg_policy_data *pd) atomic64_set(&iocg->done_vtime, now.vnow); atomic64_set(&iocg->active_period, atomic64_read(&ioc->cur_period)); INIT_LIST_HEAD(&iocg->active_list); - iocg->hweight_active = HWEIGHT_WHOLE; - iocg->hweight_inuse = HWEIGHT_WHOLE; + iocg->hweight_active = WEIGHT_ONE; + iocg->hweight_inuse = WEIGHT_ONE; init_waitqueue_head(&iocg->waitq); hrtimer_init(&iocg->waitq_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); From bd0adb91a68b2fbf384ace5287bb46f135e8d889 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 1 Sep 2020 14:52:39 -0400 Subject: [PATCH 030/191] blk-iocost: use WEIGHT_ONE based fixed point number for weights To improve weight donations, we want to able to scale inuse with a greater accuracy and down below 1. Let's make non-hierarchical weights to use WEIGHT_ONE based fixed point numbers too like hierarchical ones. This doesn't cause any behavior changes yet. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- block/blk-iocost.c | 25 +++++++++++++------------ 1 file changed, 13 insertions(+), 12 deletions(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index 5e6d56eec1c9..00c5a3ad2b5b 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -984,8 +984,8 @@ static void current_hweight(struct ioc_gq *iocg, u32 *hw_activep, u32 *hw_inusep for (lvl = 0; lvl <= iocg->level - 1; lvl++) { struct ioc_gq *parent = iocg->ancestors[lvl]; struct ioc_gq *child = iocg->ancestors[lvl + 1]; - u32 active_sum = READ_ONCE(parent->child_active_sum); - u32 inuse_sum = READ_ONCE(parent->child_inuse_sum); + u64 active_sum = READ_ONCE(parent->child_active_sum); + u64 inuse_sum = READ_ONCE(parent->child_inuse_sum); u32 active = READ_ONCE(child->active); u32 inuse = READ_ONCE(child->inuse); @@ -993,11 +993,11 @@ static void current_hweight(struct ioc_gq *iocg, u32 *hw_activep, u32 *hw_inusep if (!active_sum || !inuse_sum) continue; - active_sum = max(active, active_sum); - hwa = hwa * active / active_sum; /* max 16bits * 10000 */ + active_sum = max_t(u64, active, active_sum); + hwa = div64_u64((u64)hwa * active, active_sum); - inuse_sum = max(inuse, inuse_sum); - hwi = hwi * inuse / inuse_sum; /* max 16bits * 10000 */ + inuse_sum = max_t(u64, inuse, inuse_sum); + hwi = div64_u64((u64)hwi * inuse, inuse_sum); } iocg->hweight_active = max_t(u32, hwa, 1); @@ -1022,7 +1022,8 @@ static void weight_updated(struct ioc_gq *iocg) weight = iocg->cfg_weight ?: iocc->dfl_weight; if (weight != iocg->weight && iocg->active) propagate_weights(iocg, weight, - DIV64_U64_ROUND_UP(iocg->inuse * weight, iocg->weight)); + DIV64_U64_ROUND_UP((u64)iocg->inuse * weight, + iocg->weight)); iocg->weight = weight; } @@ -2050,7 +2051,7 @@ static struct blkcg_policy_data *ioc_cpd_alloc(gfp_t gfp) if (!iocc) return NULL; - iocc->dfl_weight = CGROUP_WEIGHT_DFL; + iocc->dfl_weight = CGROUP_WEIGHT_DFL * WEIGHT_ONE; return &iocc->cpd; } @@ -2136,7 +2137,7 @@ static u64 ioc_weight_prfill(struct seq_file *sf, struct blkg_policy_data *pd, struct ioc_gq *iocg = pd_to_iocg(pd); if (dname && iocg->cfg_weight) - seq_printf(sf, "%s %u\n", dname, iocg->cfg_weight); + seq_printf(sf, "%s %u\n", dname, iocg->cfg_weight / WEIGHT_ONE); return 0; } @@ -2146,7 +2147,7 @@ static int ioc_weight_show(struct seq_file *sf, void *v) struct blkcg *blkcg = css_to_blkcg(seq_css(sf)); struct ioc_cgrp *iocc = blkcg_to_iocc(blkcg); - seq_printf(sf, "default %u\n", iocc->dfl_weight); + seq_printf(sf, "default %u\n", iocc->dfl_weight / WEIGHT_ONE); blkcg_print_blkgs(sf, blkcg, ioc_weight_prfill, &blkcg_policy_iocost, seq_cft(sf)->private, false); return 0; @@ -2172,7 +2173,7 @@ static ssize_t ioc_weight_write(struct kernfs_open_file *of, char *buf, return -EINVAL; spin_lock(&blkcg->lock); - iocc->dfl_weight = v; + iocc->dfl_weight = v * WEIGHT_ONE; hlist_for_each_entry(blkg, &blkcg->blkg_list, blkcg_node) { struct ioc_gq *iocg = blkg_to_iocg(blkg); @@ -2203,7 +2204,7 @@ static ssize_t ioc_weight_write(struct kernfs_open_file *of, char *buf, } spin_lock(&iocg->ioc->lock); - iocg->cfg_weight = v; + iocg->cfg_weight = v * WEIGHT_ONE; weight_updated(iocg); spin_unlock(&iocg->ioc->lock); From ce95570acf741ea306baddcb43aba0b59b920a21 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 1 Sep 2020 14:52:40 -0400 Subject: [PATCH 031/191] blk-iocost: make ioc_now->now and ioc->period_at 64bit They are in microseconds and wrap in around 1.2 hours with u32. While unlikely, confusions from wraparounds are still possible. We aren't saving anything meaningful by keeping these u32. Let's make them u64. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- block/blk-iocost.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index 00c5a3ad2b5b..dc72cd965837 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -409,7 +409,7 @@ struct ioc { atomic64_t vtime_rate; seqcount_spinlock_t period_seqcount; - u32 period_at; /* wallclock starttime */ + u64 period_at; /* wallclock starttime */ u64 period_at_vtime; /* vtime starttime */ atomic64_t cur_period; /* inc'd each period */ @@ -508,7 +508,7 @@ struct ioc_cgrp { struct ioc_now { u64 now_ns; - u32 now; + u64 now; u64 vnow; u64 vrate; }; From 7ca5b2e60bfa4aa5b8d52e9c3e2a757c581bec1d Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 1 Sep 2020 14:52:41 -0400 Subject: [PATCH 032/191] blk-iocost: streamline vtime margin and timer slack handling The margin handling was pretty inconsistent. * ioc->margin_us and ioc->inuse_margin_vtime were used as vtime margin thresholds. However, the two are in different units with the former requiring conversion to vtime on use. * iocg_kick_waitq() was using a quarter of WAITQ_TIMER_MARGIN_PCT of period_us as the timer slack - ~1.2%. While iocg_kick_delay() was using a quarter of ioc->margin_us - ~12.5%. There aren't strong reasons to use different values for the two. This patch cleans up margin and timer slack handling: * vtime margins are now recorded in ioc->margins.{min, max} on period duration changes and used consistently. * Timer slack is now 1% of period_us and recorded in ioc->timer_slack_ns and used consistently for iocg_kick_waitq() and iocg_kick_delay(). The only functional change is shortening of timer slack. No meaningful visible change is expected. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- block/blk-iocost.c | 67 ++++++++++++++++++++++++++-------------------- 1 file changed, 38 insertions(+), 29 deletions(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index dc72cd965837..f36988657594 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -221,11 +221,11 @@ enum { * serves as its IO credit buffer. Surplus weight adjustment is * immediately canceled if the vtime margin runs below 10%. */ - MARGIN_PCT = 50, - INUSE_MARGIN_PCT = 10, + MARGIN_MIN_PCT = 10, + MARGIN_MAX_PCT = 50, - /* Have some play in waitq timer operations */ - WAITQ_TIMER_MARGIN_PCT = 5, + /* Have some play in timer operations */ + TIMER_SLACK_PCT = 1, /* * vtime can wrap well within a reasonable uptime when vrate is @@ -374,6 +374,11 @@ struct ioc_params { u32 too_slow_vrate_pct; }; +struct ioc_margins { + s64 min; + s64 max; +}; + struct ioc_missed { local_t nr_met; local_t nr_missed; @@ -395,8 +400,9 @@ struct ioc { bool enabled; struct ioc_params params; + struct ioc_margins margins; u32 period_us; - u32 margin_us; + u32 timer_slack_ns; u64 vrate_min; u64 vrate_max; @@ -415,7 +421,6 @@ struct ioc { atomic64_t cur_period; /* inc'd each period */ int busy_level; /* saturation history */ - u64 inuse_margin_vtime; bool weights_updated; atomic_t hweight_gen; /* for lazy hweights */ @@ -678,6 +683,16 @@ static void iocg_commit_bio(struct ioc_gq *iocg, struct bio *bio, u64 cost) #define CREATE_TRACE_POINTS #include +static void ioc_refresh_margins(struct ioc *ioc) +{ + struct ioc_margins *margins = &ioc->margins; + u32 period_us = ioc->period_us; + u64 vrate = atomic64_read(&ioc->vtime_rate); + + margins->min = (period_us * MARGIN_MIN_PCT / 100) * vrate; + margins->max = (period_us * MARGIN_MAX_PCT / 100) * vrate; +} + /* latency Qos params changed, update period_us and all the dependent params */ static void ioc_refresh_period_us(struct ioc *ioc) { @@ -711,9 +726,10 @@ static void ioc_refresh_period_us(struct ioc *ioc) /* calculate dependent params */ ioc->period_us = period_us; - ioc->margin_us = period_us * MARGIN_PCT / 100; - ioc->inuse_margin_vtime = DIV64_U64_ROUND_UP( - period_us * VTIME_PER_USEC * INUSE_MARGIN_PCT, 100); + ioc->timer_slack_ns = div64_u64( + (u64)period_us * NSEC_PER_USEC * TIMER_SLACK_PCT, + 100); + ioc_refresh_margins(ioc); } static int ioc_autop_idx(struct ioc *ioc) @@ -1031,7 +1047,7 @@ static bool iocg_activate(struct ioc_gq *iocg, struct ioc_now *now) { struct ioc *ioc = iocg->ioc; u64 last_period, cur_period, max_period_delta; - u64 vtime, vmargin, vmin; + u64 vtime, vmin; int i; /* @@ -1077,8 +1093,7 @@ static bool iocg_activate(struct ioc_gq *iocg, struct ioc_now *now) */ max_period_delta = DIV64_U64_ROUND_UP(VTIME_VALID_DUR, ioc->period_us); vtime = atomic64_read(&iocg->vtime); - vmargin = ioc->margin_us * now->vrate; - vmin = now->vnow - vmargin; + vmin = now->vnow - ioc->margins.max; if (last_period + max_period_delta < cur_period || time_before64(vtime, vmin)) { @@ -1121,8 +1136,6 @@ static bool iocg_kick_delay(struct ioc_gq *iocg, struct ioc_now *now) struct ioc *ioc = iocg->ioc; struct blkcg_gq *blkg = iocg_to_blkg(iocg); u64 vtime = atomic64_read(&iocg->vtime); - u64 vmargin = ioc->margin_us * now->vrate; - u64 margin_ns = ioc->margin_us * NSEC_PER_USEC; u64 delta_ns, expires, oexpires; u32 hw_inuse; @@ -1142,7 +1155,7 @@ static bool iocg_kick_delay(struct ioc_gq *iocg, struct ioc_now *now) return false; } if (!atomic_read(&blkg->use_delay) && - time_before_eq64(vtime, now->vnow + vmargin)) + time_before_eq64(vtime, now->vnow + ioc->margins.max)) return false; /* use delay */ @@ -1154,11 +1167,11 @@ static bool iocg_kick_delay(struct ioc_gq *iocg, struct ioc_now *now) /* if already active and close enough, don't bother */ oexpires = ktime_to_ns(hrtimer_get_softexpires(&iocg->delay_timer)); if (hrtimer_is_queued(&iocg->delay_timer) && - abs(oexpires - expires) <= margin_ns / 4) + abs(oexpires - expires) <= ioc->timer_slack_ns) return true; hrtimer_start_range_ns(&iocg->delay_timer, ns_to_ktime(expires), - margin_ns / 4, HRTIMER_MODE_ABS); + ioc->timer_slack_ns, HRTIMER_MODE_ABS); return true; } @@ -1206,8 +1219,6 @@ static void iocg_kick_waitq(struct ioc_gq *iocg, struct ioc_now *now) { struct ioc *ioc = iocg->ioc; struct iocg_wake_ctx ctx = { .iocg = iocg }; - u64 margin_ns = (u64)(ioc->period_us * - WAITQ_TIMER_MARGIN_PCT / 100) * NSEC_PER_USEC; u64 vdebt, vshortage, expires, oexpires; s64 vbudget; u32 hw_inuse; @@ -1243,20 +1254,20 @@ static void iocg_kick_waitq(struct ioc_gq *iocg, struct ioc_now *now) if (WARN_ON_ONCE(ctx.vbudget >= 0)) return; - /* determine next wakeup, add a quarter margin to guarantee chunking */ + /* determine next wakeup, add a timer margin to guarantee chunking */ vshortage = -ctx.vbudget; expires = now->now_ns + DIV64_U64_ROUND_UP(vshortage, now->vrate) * NSEC_PER_USEC; - expires += margin_ns / 4; + expires += ioc->timer_slack_ns; /* if already active and close enough, don't bother */ oexpires = ktime_to_ns(hrtimer_get_softexpires(&iocg->waitq_timer)); if (hrtimer_is_queued(&iocg->waitq_timer) && - abs(oexpires - expires) <= margin_ns / 4) + abs(oexpires - expires) <= ioc->timer_slack_ns) return; hrtimer_start_range_ns(&iocg->waitq_timer, ns_to_ktime(expires), - margin_ns / 4, HRTIMER_MODE_ABS); + ioc->timer_slack_ns, HRTIMER_MODE_ABS); } static enum hrtimer_restart iocg_waitq_timer_fn(struct hrtimer *timer) @@ -1399,7 +1410,7 @@ static void ioc_timer_fn(struct timer_list *timer) /* calc usages and see whether some weights need to be moved around */ list_for_each_entry(iocg, &ioc->active_iocgs, active_list) { - u64 vdone, vtime, vusage, vmargin, vmin; + u64 vdone, vtime, vusage, vmin; u32 hw_active, hw_inuse, usage; /* @@ -1450,8 +1461,7 @@ static void ioc_timer_fn(struct timer_list *timer) } /* see whether there's surplus vtime */ - vmargin = ioc->margin_us * now.vrate; - vmin = now.vnow - vmargin; + vmin = now.vnow - ioc->margins.max; iocg->has_surplus = false; @@ -1623,8 +1633,7 @@ static void ioc_timer_fn(struct timer_list *timer) nr_surpluses); atomic64_set(&ioc->vtime_rate, vrate); - ioc->inuse_margin_vtime = DIV64_U64_ROUND_UP( - ioc->period_us * vrate * INUSE_MARGIN_PCT, 100); + ioc_refresh_margins(ioc); } else if (ioc->busy_level != prev_busy_level || nr_lagging) { trace_iocost_ioc_vrate_adj(ioc, atomic64_read(&ioc->vtime_rate), missed_ppm, rq_wait_pct, nr_lagging, @@ -1754,7 +1763,7 @@ static void ioc_rqos_throttle(struct rq_qos *rqos, struct bio *bio) current_hweight(iocg, &hw_active, &hw_inuse); if (hw_inuse < hw_active && - time_after_eq64(vtime + ioc->inuse_margin_vtime, now.vnow)) { + time_after_eq64(vtime + ioc->margins.min, now.vnow)) { TRACE_IOCG_PATH(inuse_reset, iocg, &now, iocg->inuse, iocg->weight, hw_inuse, hw_active); spin_lock_irq(&ioc->lock); From da437b95db83106319d337a5859e6dfb464b085a Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 1 Sep 2020 14:52:42 -0400 Subject: [PATCH 033/191] blk-iocost: grab ioc->lock for debt handling Currently, debt handling requires only iocg->waitq.lock. In the future, we want to adjust and propagate inuse changes depending on debt status. Let's grab ioc->lock in debt handling paths in preparation. * Because ioc->lock nests outside iocg->waitq.lock, the decision to grab ioc->lock needs to be made before entering the critical sections. * Add and use iocg_[un]lock() which handles the conditional double locking. * Add @pay_debt to iocg_kick_waitq() so that debt payment happens only when the caller grabbed both locks. This patch is prepatory and the comments contain references to future changes. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- block/blk-iocost.c | 92 ++++++++++++++++++++++++++++++++++++---------- 1 file changed, 73 insertions(+), 19 deletions(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index f36988657594..23b173e34591 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -680,6 +680,26 @@ static void iocg_commit_bio(struct ioc_gq *iocg, struct bio *bio, u64 cost) atomic64_add(cost, &iocg->vtime); } +static void iocg_lock(struct ioc_gq *iocg, bool lock_ioc, unsigned long *flags) +{ + if (lock_ioc) { + spin_lock_irqsave(&iocg->ioc->lock, *flags); + spin_lock(&iocg->waitq.lock); + } else { + spin_lock_irqsave(&iocg->waitq.lock, *flags); + } +} + +static void iocg_unlock(struct ioc_gq *iocg, bool unlock_ioc, unsigned long *flags) +{ + if (unlock_ioc) { + spin_unlock(&iocg->waitq.lock); + spin_unlock_irqrestore(&iocg->ioc->lock, *flags); + } else { + spin_unlock_irqrestore(&iocg->waitq.lock, *flags); + } +} + #define CREATE_TRACE_POINTS #include @@ -1215,11 +1235,17 @@ static int iocg_wake_fn(struct wait_queue_entry *wq_entry, unsigned mode, return 0; } -static void iocg_kick_waitq(struct ioc_gq *iocg, struct ioc_now *now) +/* + * Calculate the accumulated budget, pay debt if @pay_debt and wake up waiters + * accordingly. When @pay_debt is %true, the caller must be holding ioc->lock in + * addition to iocg->waitq.lock. + */ +static void iocg_kick_waitq(struct ioc_gq *iocg, bool pay_debt, + struct ioc_now *now) { struct ioc *ioc = iocg->ioc; struct iocg_wake_ctx ctx = { .iocg = iocg }; - u64 vdebt, vshortage, expires, oexpires; + u64 vshortage, expires, oexpires; s64 vbudget; u32 hw_inuse; @@ -1229,25 +1255,39 @@ static void iocg_kick_waitq(struct ioc_gq *iocg, struct ioc_now *now) vbudget = now->vnow - atomic64_read(&iocg->vtime); /* pay off debt */ - vdebt = abs_cost_to_cost(iocg->abs_vdebt, hw_inuse); - if (vdebt && vbudget > 0) { + if (pay_debt && iocg->abs_vdebt && vbudget > 0) { + u64 vdebt = abs_cost_to_cost(iocg->abs_vdebt, hw_inuse); u64 delta = min_t(u64, vbudget, vdebt); u64 abs_delta = min(cost_to_abs_cost(delta, hw_inuse), iocg->abs_vdebt); + lockdep_assert_held(&ioc->lock); + atomic64_add(delta, &iocg->vtime); atomic64_add(delta, &iocg->done_vtime); iocg->abs_vdebt -= abs_delta; + vbudget -= vdebt; iocg_kick_delay(iocg, now); } + /* + * Debt can still be outstanding if we haven't paid all yet or the + * caller raced and called without @pay_debt. Shouldn't wake up waiters + * under debt. Make sure @vbudget reflects the outstanding amount and is + * not positive. + */ + if (iocg->abs_vdebt) { + s64 vdebt = abs_cost_to_cost(iocg->abs_vdebt, hw_inuse); + vbudget = min_t(s64, 0, vbudget - vdebt); + } + /* * Wake up the ones which are due and see how much vtime we'll need * for the next one. */ ctx.hw_inuse = hw_inuse; - ctx.vbudget = vbudget - vdebt; + ctx.vbudget = vbudget; __wake_up_locked_key(&iocg->waitq, TASK_NORMAL, &ctx); if (!waitqueue_active(&iocg->waitq)) return; @@ -1273,14 +1313,15 @@ static void iocg_kick_waitq(struct ioc_gq *iocg, struct ioc_now *now) static enum hrtimer_restart iocg_waitq_timer_fn(struct hrtimer *timer) { struct ioc_gq *iocg = container_of(timer, struct ioc_gq, waitq_timer); + bool pay_debt = READ_ONCE(iocg->abs_vdebt); struct ioc_now now; unsigned long flags; ioc_now(iocg->ioc, &now); - spin_lock_irqsave(&iocg->waitq.lock, flags); - iocg_kick_waitq(iocg, &now); - spin_unlock_irqrestore(&iocg->waitq.lock, flags); + iocg_lock(iocg, pay_debt, &flags); + iocg_kick_waitq(iocg, pay_debt, &now); + iocg_unlock(iocg, pay_debt, &flags); return HRTIMER_NORESTART; } @@ -1396,7 +1437,7 @@ static void ioc_timer_fn(struct timer_list *timer) if (waitqueue_active(&iocg->waitq) || iocg->abs_vdebt) { /* might be oversleeping vtime / hweight changes, kick */ - iocg_kick_waitq(iocg, &now); + iocg_kick_waitq(iocg, true, &now); } else if (iocg_is_idle(iocg)) { /* no waiter and idle, deactivate */ iocg->last_inuse = iocg->inuse; @@ -1743,6 +1784,8 @@ static void ioc_rqos_throttle(struct rq_qos *rqos, struct bio *bio) struct iocg_wait wait; u32 hw_active, hw_inuse; u64 abs_cost, cost, vtime; + bool use_debt, ioc_locked; + unsigned long flags; /* bypass IOs if disabled or for root cgroup */ if (!ioc->enabled || !iocg->level) @@ -1786,15 +1829,26 @@ static void ioc_rqos_throttle(struct rq_qos *rqos, struct bio *bio) } /* - * We activated above but w/o any synchronization. Deactivation is - * synchronized with waitq.lock and we won't get deactivated as long - * as we're waiting or has debt, so we're good if we're activated - * here. In the unlikely case that we aren't, just issue the IO. + * We're over budget. This can be handled in two ways. IOs which may + * cause priority inversions are punted to @ioc->aux_iocg and charged as + * debt. Otherwise, the issuer is blocked on @iocg->waitq. Debt handling + * requires @ioc->lock, waitq handling @iocg->waitq.lock. Determine + * whether debt handling is needed and acquire locks accordingly. */ - spin_lock_irq(&iocg->waitq.lock); + use_debt = bio_issue_as_root_blkg(bio) || fatal_signal_pending(current); + ioc_locked = use_debt || READ_ONCE(iocg->abs_vdebt); + iocg_lock(iocg, ioc_locked, &flags); + + /* + * @iocg must stay activated for debt and waitq handling. Deactivation + * is synchronized against both ioc->lock and waitq.lock and we won't + * get deactivated as long as we're waiting or has debt, so we're good + * if we're activated here. In the unlikely cases that we aren't, just + * issue the IO. + */ if (unlikely(list_empty(&iocg->active_list))) { - spin_unlock_irq(&iocg->waitq.lock); + iocg_unlock(iocg, ioc_locked, &flags); iocg_commit_bio(iocg, bio, cost); return; } @@ -1816,12 +1870,12 @@ static void ioc_rqos_throttle(struct rq_qos *rqos, struct bio *bio) * clear them and leave @iocg inactive w/ dangling use_delay heavily * penalizing the cgroup and its descendants. */ - if (bio_issue_as_root_blkg(bio) || fatal_signal_pending(current)) { + if (use_debt) { iocg->abs_vdebt += abs_cost; if (iocg_kick_delay(iocg, &now)) blkcg_schedule_throttle(rqos->q, (bio->bi_opf & REQ_SWAP) == REQ_SWAP); - spin_unlock_irq(&iocg->waitq.lock); + iocg_unlock(iocg, ioc_locked, &flags); return; } @@ -1845,9 +1899,9 @@ static void ioc_rqos_throttle(struct rq_qos *rqos, struct bio *bio) wait.committed = false; /* will be set true by waker */ __add_wait_queue_entry_tail(&iocg->waitq, &wait.wait); - iocg_kick_waitq(iocg, &now); + iocg_kick_waitq(iocg, ioc_locked, &now); - spin_unlock_irq(&iocg->waitq.lock); + iocg_unlock(iocg, ioc_locked, &flags); while (true) { set_current_state(TASK_UNINTERRUPTIBLE); From 97eb19751f155903489f8d42ea658ace2c59faf7 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 1 Sep 2020 14:52:43 -0400 Subject: [PATCH 034/191] blk-iocost: add absolute usage stat Currently, iocost doesn't collect or expose any statistics punting off all monitoring duties to drgn based iocost_monitor.py. While it works for some scenarios, there are some usability and data availability challenges. For example, accurate per-cgroup usage information can't be tracked by vtime progression at all and the number available in iocg->usages[] are really short-term snapshots used for control heuristics with possibly significant errors. This patch implements per-cgroup absolute usage stat counter and exposes it through io.stat along with the current vrate. Usage stat collection and flushing employ the same method as cgroup rstat on the active iocg's and the only hot path overhead is preemption toggling and adding to a percpu counter. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- block/blk-iocost.c | 155 +++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 149 insertions(+), 6 deletions(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index 23b173e34591..f30f9b37fcf0 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -431,6 +431,14 @@ struct ioc { bool user_cost_model:1; }; +struct iocg_pcpu_stat { + local64_t abs_vusage; +}; + +struct iocg_stat { + u64 usage_us; +}; + /* per device-cgroup pair */ struct ioc_gq { struct blkg_policy_data pd; @@ -492,10 +500,19 @@ struct ioc_gq { u32 hweight_inuse; bool has_surplus; + struct list_head walk_list; + struct wait_queue_head waitq; struct hrtimer waitq_timer; struct hrtimer delay_timer; + /* statistics */ + struct iocg_pcpu_stat __percpu *pcpu_stat; + struct iocg_stat local_stat; + struct iocg_stat desc_stat; + struct iocg_stat last_stat; + u64 last_stat_abs_vusage; + /* usage is recorded as fractions of WEIGHT_ONE */ int usage_idx; u32 usages[NR_USAGE_SLOTS]; @@ -674,10 +691,17 @@ static u64 cost_to_abs_cost(u64 cost, u32 hw_inuse) return DIV64_U64_ROUND_UP(cost * hw_inuse, WEIGHT_ONE); } -static void iocg_commit_bio(struct ioc_gq *iocg, struct bio *bio, u64 cost) +static void iocg_commit_bio(struct ioc_gq *iocg, struct bio *bio, + u64 abs_cost, u64 cost) { + struct iocg_pcpu_stat *gcs; + bio->bi_iocost_cost = cost; atomic64_add(cost, &iocg->vtime); + + gcs = get_cpu_ptr(iocg->pcpu_stat); + local64_add(abs_cost, &gcs->abs_vusage); + put_cpu_ptr(gcs); } static void iocg_lock(struct ioc_gq *iocg, bool lock_ioc, unsigned long *flags) @@ -1221,7 +1245,7 @@ static int iocg_wake_fn(struct wait_queue_entry *wq_entry, unsigned mode, if (ctx->vbudget < 0) return -1; - iocg_commit_bio(ctx->iocg, wait->bio, cost); + iocg_commit_bio(ctx->iocg, wait->bio, wait->abs_cost, cost); /* * autoremove_wake_function() removes the wait entry only when it @@ -1382,6 +1406,87 @@ static bool iocg_is_idle(struct ioc_gq *iocg) return true; } +/* + * Call this function on the target leaf @iocg's to build pre-order traversal + * list of all the ancestors in @inner_walk. The inner nodes are linked through + * ->walk_list and the caller is responsible for dissolving the list after use. + */ +static void iocg_build_inner_walk(struct ioc_gq *iocg, + struct list_head *inner_walk) +{ + int lvl; + + WARN_ON_ONCE(!list_empty(&iocg->walk_list)); + + /* find the first ancestor which hasn't been visited yet */ + for (lvl = iocg->level - 1; lvl >= 0; lvl--) { + if (!list_empty(&iocg->ancestors[lvl]->walk_list)) + break; + } + + /* walk down and visit the inner nodes to get pre-order traversal */ + while (++lvl <= iocg->level - 1) { + struct ioc_gq *inner = iocg->ancestors[lvl]; + + /* record traversal order */ + list_add_tail(&inner->walk_list, inner_walk); + } +} + +/* collect per-cpu counters and propagate the deltas to the parent */ +static void iocg_flush_stat_one(struct ioc_gq *iocg, struct ioc_now *now) +{ + struct iocg_stat new_stat; + u64 abs_vusage = 0; + u64 vusage_delta; + int cpu; + + lockdep_assert_held(&iocg->ioc->lock); + + /* collect per-cpu counters */ + for_each_possible_cpu(cpu) { + abs_vusage += local64_read( + per_cpu_ptr(&iocg->pcpu_stat->abs_vusage, cpu)); + } + vusage_delta = abs_vusage - iocg->last_stat_abs_vusage; + iocg->last_stat_abs_vusage = abs_vusage; + + iocg->local_stat.usage_us += div64_u64(vusage_delta, now->vrate); + + new_stat.usage_us = + iocg->local_stat.usage_us + iocg->desc_stat.usage_us; + + /* propagate the deltas to the parent */ + if (iocg->level > 0) { + struct iocg_stat *parent_stat = + &iocg->ancestors[iocg->level - 1]->desc_stat; + + parent_stat->usage_us += + new_stat.usage_us - iocg->last_stat.usage_us; + } + + iocg->last_stat = new_stat; +} + +/* get stat counters ready for reading on all active iocgs */ +static void iocg_flush_stat(struct list_head *target_iocgs, struct ioc_now *now) +{ + LIST_HEAD(inner_walk); + struct ioc_gq *iocg, *tiocg; + + /* flush leaves and build inner node walk list */ + list_for_each_entry(iocg, target_iocgs, active_list) { + iocg_flush_stat_one(iocg, now); + iocg_build_inner_walk(iocg, &inner_walk); + } + + /* keep flushing upwards by walking the inner list backwards */ + list_for_each_entry_safe_reverse(iocg, tiocg, &inner_walk, walk_list) { + iocg_flush_stat_one(iocg, now); + list_del_init(&iocg->walk_list); + } +} + /* returns usage with margin added if surplus is large enough */ static u32 surplus_adjusted_hweight_inuse(u32 usage, u32 hw_inuse) { @@ -1422,6 +1527,8 @@ static void ioc_timer_fn(struct timer_list *timer) return; } + iocg_flush_stat(&ioc->active_iocgs, &now); + /* * Waiters determine the sleep durations based on the vrate they * saw at the time of sleep. If vrate has increased, some waiters @@ -1824,7 +1931,7 @@ static void ioc_rqos_throttle(struct rq_qos *rqos, struct bio *bio) */ if (!waitqueue_active(&iocg->waitq) && !iocg->abs_vdebt && time_before_eq64(vtime + cost, now.vnow)) { - iocg_commit_bio(iocg, bio, cost); + iocg_commit_bio(iocg, bio, abs_cost, cost); return; } @@ -1849,7 +1956,7 @@ static void ioc_rqos_throttle(struct rq_qos *rqos, struct bio *bio) */ if (unlikely(list_empty(&iocg->active_list))) { iocg_unlock(iocg, ioc_locked, &flags); - iocg_commit_bio(iocg, bio, cost); + iocg_commit_bio(iocg, bio, abs_cost, cost); return; } @@ -1948,7 +2055,7 @@ static void ioc_rqos_merge(struct rq_qos *rqos, struct request *rq, */ if (rq->bio && rq->bio->bi_iocost_cost && time_before_eq64(atomic64_read(&iocg->vtime) + cost, now.vnow)) { - iocg_commit_bio(iocg, bio, cost); + iocg_commit_bio(iocg, bio, abs_cost, cost); return; } @@ -1962,7 +2069,7 @@ static void ioc_rqos_merge(struct rq_qos *rqos, struct request *rq, iocg->abs_vdebt += abs_cost; iocg_kick_delay(iocg, &now); } else { - iocg_commit_bio(iocg, bio, cost); + iocg_commit_bio(iocg, bio, abs_cost, cost); } spin_unlock_irqrestore(&iocg->waitq.lock, flags); } @@ -2133,6 +2240,12 @@ static struct blkg_policy_data *ioc_pd_alloc(gfp_t gfp, struct request_queue *q, if (!iocg) return NULL; + iocg->pcpu_stat = alloc_percpu_gfp(struct iocg_pcpu_stat, gfp); + if (!iocg->pcpu_stat) { + kfree(iocg); + return NULL; + } + return &iocg->pd; } @@ -2152,6 +2265,7 @@ static void ioc_pd_init(struct blkg_policy_data *pd) atomic64_set(&iocg->done_vtime, now.vnow); atomic64_set(&iocg->active_period, atomic64_read(&ioc->cur_period)); INIT_LIST_HEAD(&iocg->active_list); + INIT_LIST_HEAD(&iocg->walk_list); iocg->hweight_active = WEIGHT_ONE; iocg->hweight_inuse = WEIGHT_ONE; @@ -2181,18 +2295,46 @@ static void ioc_pd_free(struct blkg_policy_data *pd) if (ioc) { spin_lock_irqsave(&ioc->lock, flags); + if (!list_empty(&iocg->active_list)) { propagate_weights(iocg, 0, 0); list_del_init(&iocg->active_list); } + + WARN_ON_ONCE(!list_empty(&iocg->walk_list)); + spin_unlock_irqrestore(&ioc->lock, flags); hrtimer_cancel(&iocg->waitq_timer); hrtimer_cancel(&iocg->delay_timer); } + free_percpu(iocg->pcpu_stat); kfree(iocg); } +static size_t ioc_pd_stat(struct blkg_policy_data *pd, char *buf, size_t size) +{ + struct ioc_gq *iocg = pd_to_iocg(pd); + struct ioc *ioc = iocg->ioc; + size_t pos = 0; + + if (!ioc->enabled) + return 0; + + if (iocg->level == 0) { + unsigned vp10k = DIV64_U64_ROUND_CLOSEST( + atomic64_read(&ioc->vtime_rate) * 10000, + VTIME_PER_USEC); + pos += scnprintf(buf + pos, size - pos, " cost.vrate=%u.%02u", + vp10k / 100, vp10k % 100); + } + + pos += scnprintf(buf + pos, size - pos, " cost.usage=%llu", + iocg->last_stat.usage_us); + + return pos; +} + static u64 ioc_weight_prfill(struct seq_file *sf, struct blkg_policy_data *pd, int off) { @@ -2606,6 +2748,7 @@ static struct blkcg_policy blkcg_policy_iocost = { .pd_alloc_fn = ioc_pd_alloc, .pd_init_fn = ioc_pd_init, .pd_free_fn = ioc_pd_free, + .pd_stat_fn = ioc_pd_stat, }; static int __init ioc_init(void) From 1aa50d020c7148f5f0bde15ca80fe6f91a8c5a4e Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 1 Sep 2020 14:52:44 -0400 Subject: [PATCH 035/191] blk-iocost: calculate iocg->usages[] from iocg->local_stat.usage_us Currently, iocg->usages[] which are used to guide inuse adjustments are calculated from vtime deltas. This, however, assumes that the hierarchical inuse weight at the time of calculation held for the entire period, which often isn't true and can lead to significant errors. Now that we have absolute usage information collected, we can derive iocg->usages[] from iocg->local_stat.usage_us so that inuse adjustment decisions are made based on actual absolute usage. The calculated usage is clamped between 1 and WEIGHT_ONE and WEIGHT_ONE is also used to signal saturation regardless of the current hierarchical inuse weight. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- block/blk-iocost.c | 70 ++++++++++++++++++++++------------- include/trace/events/iocost.h | 7 +--- 2 files changed, 46 insertions(+), 31 deletions(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index f30f9b37fcf0..2496674bbbf4 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -476,14 +476,10 @@ struct ioc_gq { * `vtime_done` is the same but progressed on completion rather * than issue. The delta behind `vtime` represents the cost of * currently in-flight IOs. - * - * `last_vtime` is used to remember `vtime` at the end of the last - * period to calculate utilization. */ atomic64_t vtime; atomic64_t done_vtime; u64 abs_vdebt; - u64 last_vtime; /* * The period this iocg was last active in. Used for deactivation @@ -506,6 +502,9 @@ struct ioc_gq { struct hrtimer waitq_timer; struct hrtimer delay_timer; + /* timestamp at the latest activation */ + u64 activated_at; + /* statistics */ struct iocg_pcpu_stat __percpu *pcpu_stat; struct iocg_stat local_stat; @@ -514,6 +513,7 @@ struct ioc_gq { u64 last_stat_abs_vusage; /* usage is recorded as fractions of WEIGHT_ONE */ + u32 usage_delta_us; int usage_idx; u32 usages[NR_USAGE_SLOTS]; @@ -1159,7 +1159,7 @@ static bool iocg_activate(struct ioc_gq *iocg, struct ioc_now *now) TRACE_IOCG_PATH(iocg_activate, iocg, now, last_period, cur_period, vtime); - iocg->last_vtime = vtime; + iocg->activated_at = now->now; if (ioc->running == IOC_IDLE) { ioc->running = IOC_RUNNING; @@ -1451,7 +1451,8 @@ static void iocg_flush_stat_one(struct ioc_gq *iocg, struct ioc_now *now) vusage_delta = abs_vusage - iocg->last_stat_abs_vusage; iocg->last_stat_abs_vusage = abs_vusage; - iocg->local_stat.usage_us += div64_u64(vusage_delta, now->vrate); + iocg->usage_delta_us = div64_u64(vusage_delta, now->vrate); + iocg->local_stat.usage_us += iocg->usage_delta_us; new_stat.usage_us = iocg->local_stat.usage_us + iocg->desc_stat.usage_us; @@ -1558,8 +1559,9 @@ static void ioc_timer_fn(struct timer_list *timer) /* calc usages and see whether some weights need to be moved around */ list_for_each_entry(iocg, &ioc->active_iocgs, active_list) { - u64 vdone, vtime, vusage, vmin; + u64 vdone, vtime, usage_us, vmin; u32 hw_active, hw_inuse, usage; + int uidx; /* * Collect unused and wind vtime closer to vnow to prevent @@ -1583,27 +1585,44 @@ static void ioc_timer_fn(struct timer_list *timer) time_before64(vdone, now.vnow - period_vtime)) nr_lagging++; - if (waitqueue_active(&iocg->waitq)) - vusage = now.vnow - iocg->last_vtime; - else if (time_before64(iocg->last_vtime, vtime)) - vusage = vtime - iocg->last_vtime; - else - vusage = 0; - - iocg->last_vtime += vusage; /* - * Factor in in-flight vtime into vusage to avoid - * high-latency completions appearing as idle. This should - * be done after the above ->last_time adjustment. + * Determine absolute usage factoring in pending and in-flight + * IOs to avoid stalls and high-latency completions appearing as + * idle. */ - vusage = max(vusage, vtime - vdone); + usage_us = iocg->usage_delta_us; + if (waitqueue_active(&iocg->waitq) && time_before64(vtime, now.vnow)) + usage_us += DIV64_U64_ROUND_UP( + cost_to_abs_cost(now.vnow - vtime, hw_inuse), + now.vrate); + if (vdone != vtime) { + u64 inflight_us = DIV64_U64_ROUND_UP( + cost_to_abs_cost(vtime - vdone, hw_inuse), + now.vrate); + usage_us = max(usage_us, inflight_us); + } - /* calculate hweight based usage ratio and record */ - if (vusage) { - usage = DIV64_U64_ROUND_UP(vusage * hw_inuse, - period_vtime); - iocg->usage_idx = (iocg->usage_idx + 1) % NR_USAGE_SLOTS; - iocg->usages[iocg->usage_idx] = usage; + /* convert to hweight based usage ratio and record */ + uidx = (iocg->usage_idx + 1) % NR_USAGE_SLOTS; + + if (time_after64(vtime, now.vnow - ioc->margins.min)) { + iocg->usage_idx = uidx; + iocg->usages[uidx] = WEIGHT_ONE; + } else if (usage_us) { + u64 started_at, dur; + + if (time_after64(iocg->activated_at, ioc->period_at)) + started_at = iocg->activated_at; + else + started_at = ioc->period_at; + + dur = max_t(u64, now.now - started_at, 1); + usage = clamp_t(u32, + DIV64_U64_ROUND_UP(usage_us * WEIGHT_ONE, dur), + 1, WEIGHT_ONE); + + iocg->usage_idx = uidx; + iocg->usages[uidx] = usage; } else { usage = 0; } @@ -1620,7 +1639,6 @@ static void ioc_timer_fn(struct timer_list *timer) /* throw away surplus vtime */ atomic64_add(delta, &iocg->vtime); atomic64_add(delta, &iocg->done_vtime); - iocg->last_vtime += delta; /* if usage is sufficiently low, maybe it can donate */ if (surplus_adjusted_hweight_inuse(usage, hw_inuse)) { iocg->has_surplus = true; diff --git a/include/trace/events/iocost.h b/include/trace/events/iocost.h index c2f580fd371b..a905ecc0342f 100644 --- a/include/trace/events/iocost.h +++ b/include/trace/events/iocost.h @@ -26,7 +26,6 @@ TRACE_EVENT(iocost_iocg_activate, __field(u64, vrate) __field(u64, last_period) __field(u64, cur_period) - __field(u64, last_vtime) __field(u64, vtime) __field(u32, weight) __field(u32, inuse) @@ -42,7 +41,6 @@ TRACE_EVENT(iocost_iocg_activate, __entry->vrate = now->vrate; __entry->last_period = last_period; __entry->cur_period = cur_period; - __entry->last_vtime = iocg->last_vtime; __entry->vtime = vtime; __entry->weight = iocg->weight; __entry->inuse = iocg->inuse; @@ -51,13 +49,12 @@ TRACE_EVENT(iocost_iocg_activate, ), TP_printk("[%s:%s] now=%llu:%llu vrate=%llu " - "period=%llu->%llu vtime=%llu->%llu " + "period=%llu->%llu vtime=%llu " "weight=%u/%u hweight=%llu/%llu", __get_str(devname), __get_str(cgroup), __entry->now, __entry->vnow, __entry->vrate, __entry->last_period, __entry->cur_period, - __entry->last_vtime, __entry->vtime, - __entry->inuse, __entry->weight, + __entry->vtime, __entry->inuse, __entry->weight, __entry->hweight_inuse, __entry->hweight_active ) ); From 8692d2db8e01f1a5718f9b67c219b823a64b2088 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 1 Sep 2020 14:52:45 -0400 Subject: [PATCH 036/191] blk-iocost: replace iocg->has_surplus with ->surplus_list Instead of marking iocgs with surplus with a flag and filtering for them while walking all active iocgs, build a surpluses list. This doesn't make much difference now but will help implementing improved donation logic which will iterate iocgs with surplus multiple times. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- block/blk-iocost.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index 2496674bbbf4..c1cd66cfa2a8 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -494,9 +494,9 @@ struct ioc_gq { int hweight_gen; u32 hweight_active; u32 hweight_inuse; - bool has_surplus; struct list_head walk_list; + struct list_head surplus_list; struct wait_queue_head waitq; struct hrtimer waitq_timer; @@ -1507,6 +1507,7 @@ static void ioc_timer_fn(struct timer_list *timer) struct ioc *ioc = container_of(timer, struct ioc, timer); struct ioc_gq *iocg, *tiocg; struct ioc_now now; + LIST_HEAD(surpluses); int nr_surpluses = 0, nr_shortages = 0, nr_lagging = 0; u32 ppm_rthr = MILLION - ioc->params.qos[QOS_RPPM]; u32 ppm_wthr = MILLION - ioc->params.qos[QOS_WPPM]; @@ -1630,8 +1631,7 @@ static void ioc_timer_fn(struct timer_list *timer) /* see whether there's surplus vtime */ vmin = now.vnow - ioc->margins.max; - iocg->has_surplus = false; - + WARN_ON_ONCE(!list_empty(&iocg->surplus_list)); if (!waitqueue_active(&iocg->waitq) && time_before64(vtime, vmin)) { u64 delta = vmin - vtime; @@ -1641,7 +1641,7 @@ static void ioc_timer_fn(struct timer_list *timer) atomic64_add(delta, &iocg->done_vtime); /* if usage is sufficiently low, maybe it can donate */ if (surplus_adjusted_hweight_inuse(usage, hw_inuse)) { - iocg->has_surplus = true; + list_add(&iocg->surplus_list, &surpluses); nr_surpluses++; } } else if (hw_inuse < hw_active) { @@ -1677,13 +1677,10 @@ static void ioc_timer_fn(struct timer_list *timer) goto skip_surplus_transfers; /* there are both shortages and surpluses, transfer surpluses */ - list_for_each_entry(iocg, &ioc->active_iocgs, active_list) { + list_for_each_entry(iocg, &surpluses, surplus_list) { u32 usage, hw_active, hw_inuse, new_hwi, new_inuse; int nr_valid = 0; - if (!iocg->has_surplus) - continue; - /* base the decision on max historical usage */ for (i = 0, usage = 0; i < NR_USAGE_SLOTS; i++) { if (iocg->usages[i]) { @@ -1711,6 +1708,10 @@ static void ioc_timer_fn(struct timer_list *timer) skip_surplus_transfers: commit_weights(ioc); + /* surplus list should be dissolved after use */ + list_for_each_entry_safe(iocg, tiocg, &surpluses, surplus_list) + list_del_init(&iocg->surplus_list); + /* * If q is getting clogged or we're missing too much, we're issuing * too much IO and should lower vtime rate. If we're not missing @@ -2284,6 +2285,7 @@ static void ioc_pd_init(struct blkg_policy_data *pd) atomic64_set(&iocg->active_period, atomic64_read(&ioc->cur_period)); INIT_LIST_HEAD(&iocg->active_list); INIT_LIST_HEAD(&iocg->walk_list); + INIT_LIST_HEAD(&iocg->surplus_list); iocg->hweight_active = WEIGHT_ONE; iocg->hweight_inuse = WEIGHT_ONE; @@ -2320,6 +2322,7 @@ static void ioc_pd_free(struct blkg_policy_data *pd) } WARN_ON_ONCE(!list_empty(&iocg->walk_list)); + WARN_ON_ONCE(!list_empty(&iocg->surplus_list)); spin_unlock_irqrestore(&ioc->lock, flags); From 065655c862fedf4b04e1b28b83ca6f338d81cf0b Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 1 Sep 2020 14:52:46 -0400 Subject: [PATCH 037/191] blk-iocost: decouple vrate adjustment from surplus transfers Budget donations are inaccurate and could take multiple periods to converge. To prevent triggering vrate adjustments while surplus transfers were catching up, vrate adjustment was suppressed if donations were increasing, which was indicated by non-zero nr_surpluses. This entangling won't be necessary with the scheduled rewrite of donation mechanism which will make it precise and immediate. Let's decouple the two in preparation. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- block/blk-iocost.c | 19 +++++++------------ include/trace/events/iocost.h | 13 ++++--------- 2 files changed, 11 insertions(+), 21 deletions(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index c1cd66cfa2a8..a3889a8b0a33 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -1508,7 +1508,7 @@ static void ioc_timer_fn(struct timer_list *timer) struct ioc_gq *iocg, *tiocg; struct ioc_now now; LIST_HEAD(surpluses); - int nr_surpluses = 0, nr_shortages = 0, nr_lagging = 0; + int nr_shortages = 0, nr_lagging = 0; u32 ppm_rthr = MILLION - ioc->params.qos[QOS_RPPM]; u32 ppm_wthr = MILLION - ioc->params.qos[QOS_WPPM]; u32 missed_ppm[2], rq_wait_pct; @@ -1640,10 +1640,8 @@ static void ioc_timer_fn(struct timer_list *timer) atomic64_add(delta, &iocg->vtime); atomic64_add(delta, &iocg->done_vtime); /* if usage is sufficiently low, maybe it can donate */ - if (surplus_adjusted_hweight_inuse(usage, hw_inuse)) { + if (surplus_adjusted_hweight_inuse(usage, hw_inuse)) list_add(&iocg->surplus_list, &surpluses); - nr_surpluses++; - } } else if (hw_inuse < hw_active) { u32 new_hwi, new_inuse; @@ -1673,7 +1671,7 @@ static void ioc_timer_fn(struct timer_list *timer) } } - if (!nr_shortages || !nr_surpluses) + if (!nr_shortages || list_empty(&surpluses)) goto skip_surplus_transfers; /* there are both shortages and surpluses, transfer surpluses */ @@ -1738,11 +1736,9 @@ static void ioc_timer_fn(struct timer_list *timer) /* * If there are IOs spanning multiple periods, wait - * them out before pushing the device harder. If - * there are surpluses, let redistribution work it - * out first. + * them out before pushing the device harder. */ - if (!nr_lagging && !nr_surpluses) + if (!nr_lagging) ioc->busy_level--; } else { /* @@ -1796,15 +1792,14 @@ static void ioc_timer_fn(struct timer_list *timer) } trace_iocost_ioc_vrate_adj(ioc, vrate, missed_ppm, rq_wait_pct, - nr_lagging, nr_shortages, - nr_surpluses); + nr_lagging, nr_shortages); atomic64_set(&ioc->vtime_rate, vrate); ioc_refresh_margins(ioc); } else if (ioc->busy_level != prev_busy_level || nr_lagging) { trace_iocost_ioc_vrate_adj(ioc, atomic64_read(&ioc->vtime_rate), missed_ppm, rq_wait_pct, nr_lagging, - nr_shortages, nr_surpluses); + nr_shortages); } ioc_refresh_params(ioc, false); diff --git a/include/trace/events/iocost.h b/include/trace/events/iocost.h index a905ecc0342f..ee024fe8fef6 100644 --- a/include/trace/events/iocost.h +++ b/include/trace/events/iocost.h @@ -128,11 +128,9 @@ DEFINE_EVENT(iocg_inuse_update, iocost_inuse_reset, TRACE_EVENT(iocost_ioc_vrate_adj, TP_PROTO(struct ioc *ioc, u64 new_vrate, u32 *missed_ppm, - u32 rq_wait_pct, int nr_lagging, int nr_shortages, - int nr_surpluses), + u32 rq_wait_pct, int nr_lagging, int nr_shortages), - TP_ARGS(ioc, new_vrate, missed_ppm, rq_wait_pct, nr_lagging, nr_shortages, - nr_surpluses), + TP_ARGS(ioc, new_vrate, missed_ppm, rq_wait_pct, nr_lagging, nr_shortages), TP_STRUCT__entry ( __string(devname, ioc_name(ioc)) @@ -144,7 +142,6 @@ TRACE_EVENT(iocost_ioc_vrate_adj, __field(u32, rq_wait_pct) __field(int, nr_lagging) __field(int, nr_shortages) - __field(int, nr_surpluses) ), TP_fast_assign( @@ -157,15 +154,13 @@ TRACE_EVENT(iocost_ioc_vrate_adj, __entry->rq_wait_pct = rq_wait_pct; __entry->nr_lagging = nr_lagging; __entry->nr_shortages = nr_shortages; - __entry->nr_surpluses = nr_surpluses; ), - TP_printk("[%s] vrate=%llu->%llu busy=%d missed_ppm=%u:%u rq_wait_pct=%u lagging=%d shortages=%d surpluses=%d", + TP_printk("[%s] vrate=%llu->%llu busy=%d missed_ppm=%u:%u rq_wait_pct=%u lagging=%d shortages=%d", __get_str(devname), __entry->old_vrate, __entry->new_vrate, __entry->busy_level, __entry->read_missed_ppm, __entry->write_missed_ppm, - __entry->rq_wait_pct, __entry->nr_lagging, __entry->nr_shortages, - __entry->nr_surpluses + __entry->rq_wait_pct, __entry->nr_lagging, __entry->nr_shortages ) ); From 93f7d2db80e4aea2731619d7b907a029e0d14259 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 1 Sep 2020 14:52:47 -0400 Subject: [PATCH 038/191] blk-iocost: restructure surplus donation logic The way the surplus donation logic is structured isn't great. There are two separate paths for starting/increasing donations and decreasing them making the logic harder to follow and is prone to unnecessary behavior differences. In preparation for improved donation handling, this patch restructures the code so that * All donors - new, increasing and decreasing - are funneled through the same code path. * The target donation calculation is factored into hweight_after_donation() which is called once from the same spot for all possible donors. * Actual inuse adjustment is factored into trasnfer_surpluses(). This change introduces a few behavior differences - e.g. donation amount reduction now uses the max usage of the recent three periods just like new and increasing donations, and inuse now gets adjusted upwards the same way it gets downwards. These differences are unlikely to have severely negative implications and the whole logic will be revamped soon. This patch also removes two tracepoints. The existing TPs don't quite fit the new implementation. A later patch will update and reinstate them. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- block/blk-iocost.c | 181 ++++++++++++++++++++++++++------------------- 1 file changed, 104 insertions(+), 77 deletions(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index a3889a8b0a33..61b008d0801f 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -494,6 +494,7 @@ struct ioc_gq { int hweight_gen; u32 hweight_active; u32 hweight_inuse; + u32 hweight_after_donation; struct list_head walk_list; struct list_head surplus_list; @@ -1070,6 +1071,32 @@ static void current_hweight(struct ioc_gq *iocg, u32 *hw_activep, u32 *hw_inusep *hw_inusep = iocg->hweight_inuse; } +/* + * Calculate the hweight_inuse @iocg would get with max @inuse assuming all the + * other weights stay unchanged. + */ +static u32 current_hweight_max(struct ioc_gq *iocg) +{ + u32 hwm = WEIGHT_ONE; + u32 inuse = iocg->active; + u64 child_inuse_sum; + int lvl; + + lockdep_assert_held(&iocg->ioc->lock); + + for (lvl = iocg->level - 1; lvl >= 0; lvl--) { + struct ioc_gq *parent = iocg->ancestors[lvl]; + struct ioc_gq *child = iocg->ancestors[lvl + 1]; + + child_inuse_sum = parent->child_inuse_sum + inuse - child->inuse; + hwm = div64_u64((u64)hwm * inuse, child_inuse_sum); + inuse = DIV64_U64_ROUND_UP(parent->active * child_inuse_sum, + parent->child_active_sum); + } + + return max_t(u32, hwm, 1); +} + static void weight_updated(struct ioc_gq *iocg) { struct ioc *ioc = iocg->ioc; @@ -1488,20 +1515,58 @@ static void iocg_flush_stat(struct list_head *target_iocgs, struct ioc_now *now) } } -/* returns usage with margin added if surplus is large enough */ -static u32 surplus_adjusted_hweight_inuse(u32 usage, u32 hw_inuse) +/* + * Determine what @iocg's hweight_inuse should be after donating unused + * capacity. @hwm is the upper bound and used to signal no donation. This + * function also throws away @iocg's excess budget. + */ +static u32 hweight_after_donation(struct ioc_gq *iocg, u32 hwm, u32 usage, + struct ioc_now *now) { + struct ioc *ioc = iocg->ioc; + u64 vtime = atomic64_read(&iocg->vtime); + s64 excess; + + /* see whether minimum margin requirement is met */ + if (waitqueue_active(&iocg->waitq) || + time_after64(vtime, now->vnow - ioc->margins.min)) + return hwm; + + /* throw away excess above max */ + excess = now->vnow - vtime - ioc->margins.max; + if (excess > 0) { + atomic64_add(excess, &iocg->vtime); + atomic64_add(excess, &iocg->done_vtime); + vtime += excess; + } + /* add margin */ usage = DIV_ROUND_UP(usage * SURPLUS_SCALE_PCT, 100); usage += SURPLUS_SCALE_ABS; /* don't bother if the surplus is too small */ - if (usage + SURPLUS_MIN_ADJ_DELTA > hw_inuse) - return 0; + if (usage + SURPLUS_MIN_ADJ_DELTA > hwm) + return hwm; return usage; } +static void transfer_surpluses(struct list_head *surpluses, struct ioc_now *now) +{ + struct ioc_gq *iocg; + + list_for_each_entry(iocg, surpluses, surplus_list) { + u32 old_hwi, new_hwi, new_inuse; + + current_hweight(iocg, NULL, &old_hwi); + new_hwi = iocg->hweight_after_donation; + + new_inuse = DIV64_U64_ROUND_UP((u64)iocg->inuse * new_hwi, + old_hwi); + __propagate_weights(iocg, iocg->weight, new_inuse); + } +} + static void ioc_timer_fn(struct timer_list *timer) { struct ioc *ioc = container_of(timer, struct ioc, timer); @@ -1560,9 +1625,9 @@ static void ioc_timer_fn(struct timer_list *timer) /* calc usages and see whether some weights need to be moved around */ list_for_each_entry(iocg, &ioc->active_iocgs, active_list) { - u64 vdone, vtime, usage_us, vmin; + u64 vdone, vtime, usage_us; u32 hw_active, hw_inuse, usage; - int uidx; + int uidx, nr_valid; /* * Collect unused and wind vtime closer to vnow to prevent @@ -1618,92 +1683,54 @@ static void ioc_timer_fn(struct timer_list *timer) started_at = ioc->period_at; dur = max_t(u64, now.now - started_at, 1); - usage = clamp_t(u32, - DIV64_U64_ROUND_UP(usage_us * WEIGHT_ONE, dur), - 1, WEIGHT_ONE); iocg->usage_idx = uidx; - iocg->usages[uidx] = usage; - } else { - usage = 0; + iocg->usages[uidx] = clamp_t(u32, + DIV64_U64_ROUND_UP(usage_us * WEIGHT_ONE, dur), + 1, WEIGHT_ONE); } - /* see whether there's surplus vtime */ - vmin = now.vnow - ioc->margins.max; - - WARN_ON_ONCE(!list_empty(&iocg->surplus_list)); - if (!waitqueue_active(&iocg->waitq) && - time_before64(vtime, vmin)) { - u64 delta = vmin - vtime; - - /* throw away surplus vtime */ - atomic64_add(delta, &iocg->vtime); - atomic64_add(delta, &iocg->done_vtime); - /* if usage is sufficiently low, maybe it can donate */ - if (surplus_adjusted_hweight_inuse(usage, hw_inuse)) - list_add(&iocg->surplus_list, &surpluses); - } else if (hw_inuse < hw_active) { - u32 new_hwi, new_inuse; - - /* was donating but might need to take back some */ - if (waitqueue_active(&iocg->waitq)) { - new_hwi = hw_active; - } else { - new_hwi = max(hw_inuse, - usage * SURPLUS_SCALE_PCT / 100 + - SURPLUS_SCALE_ABS); - } - - new_inuse = div64_u64((u64)iocg->inuse * new_hwi, - hw_inuse); - new_inuse = clamp_t(u32, new_inuse, 1, iocg->active); - - if (new_inuse > iocg->inuse) { - TRACE_IOCG_PATH(inuse_takeback, iocg, &now, - iocg->inuse, new_inuse, - hw_inuse, new_hwi); - __propagate_weights(iocg, iocg->weight, - new_inuse); - } - } else { - /* genuninely out of vtime */ - nr_shortages++; - } - } - - if (!nr_shortages || list_empty(&surpluses)) - goto skip_surplus_transfers; - - /* there are both shortages and surpluses, transfer surpluses */ - list_for_each_entry(iocg, &surpluses, surplus_list) { - u32 usage, hw_active, hw_inuse, new_hwi, new_inuse; - int nr_valid = 0; - /* base the decision on max historical usage */ - for (i = 0, usage = 0; i < NR_USAGE_SLOTS; i++) { + for (i = 0, usage = 0, nr_valid = 0; i < NR_USAGE_SLOTS; i++) { if (iocg->usages[i]) { usage = max(usage, iocg->usages[i]); nr_valid++; } } if (nr_valid < MIN_VALID_USAGES) - continue; + usage = WEIGHT_ONE; - current_hweight(iocg, &hw_active, &hw_inuse); - new_hwi = surplus_adjusted_hweight_inuse(usage, hw_inuse); - if (!new_hwi) - continue; + /* see whether there's surplus vtime */ + WARN_ON_ONCE(!list_empty(&iocg->surplus_list)); + if (hw_inuse < hw_active || + (!waitqueue_active(&iocg->waitq) && + time_before64(vtime, now.vnow - ioc->margins.max))) { + u32 hwm, new_hwi; - new_inuse = DIV64_U64_ROUND_UP((u64)iocg->inuse * new_hwi, - hw_inuse); - if (new_inuse < iocg->inuse) { - TRACE_IOCG_PATH(inuse_giveaway, iocg, &now, - iocg->inuse, new_inuse, - hw_inuse, new_hwi); - __propagate_weights(iocg, iocg->weight, new_inuse); + /* + * Already donating or accumulated enough to start. + * Determine the donation amount. + */ + hwm = current_hweight_max(iocg); + new_hwi = hweight_after_donation(iocg, hwm, usage, + &now); + if (new_hwi < hwm) { + iocg->hweight_after_donation = new_hwi; + list_add(&iocg->surplus_list, &surpluses); + } else { + __propagate_weights(iocg, iocg->active, + iocg->active); + nr_shortages++; + } + } else { + /* genuinely short on vtime */ + nr_shortages++; } } -skip_surplus_transfers: + + if (!list_empty(&surpluses) && nr_shortages) + transfer_surpluses(&surpluses, &now); + commit_weights(ioc); /* surplus list should be dissolved after use */ From e08d02aa5fc9978ed42240bd80d3fb5dd28ecac0 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 1 Sep 2020 14:52:48 -0400 Subject: [PATCH 039/191] blk-iocost: implement Andy's method for donation weight updates iocost implements work conservation by reducing iocg->inuse and propagating the adjustment upwards proportionally. However, while I knew the target absolute hierarchical proportion - adjusted hweight_inuse, I couldn't figure out how to determine the iocg->inuse adjustment to achieve that and approximated the adjustment by scaling iocg->inuse using the proportion of the needed hweight_inuse changes. When nested, these scalings aren't accurate even when adjusting a single node as the donating node also receives the benefit of the donated portion. When multiple nodes are donating as they often do, they can be wildly wrong. iocost employed various safety nets to combat the inaccuracies. There are ample buffers in determining how much to donate, the adjustments are conservative and gradual. While it can achieve a reasonable level of work conservation in simple scenarios, the inaccuracies can easily add up leading to significant loss of total work. This in turn makes it difficult to closely cap vrate as vrate adjustment is needed to compensate for the loss of work. The combination of inaccurate donation calculations and vrate adjustments can lead to wide fluctuations and clunky overall behaviors. Andy Newell devised a method to calculate the needed ->inuse updates to achieve the target hweight_inuse's. The method is compatible with the proportional inuse adjustment propagation which allows all hot path operations to be local to each iocg. To roughly summarize, Andy's method divides the tree into donating and non-donating parts, calculates global donation rate which is used to determine the target hweight_inuse for each node, and then derives per-level proportions. There's non-trivial amount of math involved. Please refer to the following pdfs for detailed descriptions. https://drive.google.com/file/d/1PsJwxPFtjUnwOY1QJ5AeICCcsL7BM3bo https://drive.google.com/file/d/1vONz1-fzVO7oY5DXXsLjSxEtYYQbOvsE https://drive.google.com/file/d/1WcrltBOSPN0qXVdBgnKm4mdp9FhuEFQN This patch implements Andy's method in transfer_surpluses(). This makes the donation calculations accurate per cycle and enables further improvements in other parts of the donation logic. Signed-off-by: Tejun Heo Cc: Andy Newell Signed-off-by: Jens Axboe --- block/blk-iocost.c | 252 +++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 244 insertions(+), 8 deletions(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index 61b008d0801f..ecc23b827e5d 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -491,9 +491,11 @@ struct ioc_gq { /* see __propagate_weights() and current_hweight() for details */ u64 child_active_sum; u64 child_inuse_sum; + u64 child_adjusted_sum; int hweight_gen; u32 hweight_active; u32 hweight_inuse; + u32 hweight_donating; u32 hweight_after_donation; struct list_head walk_list; @@ -1551,20 +1553,252 @@ static u32 hweight_after_donation(struct ioc_gq *iocg, u32 hwm, u32 usage, return usage; } +/* + * For work-conservation, an iocg which isn't using all of its share should + * donate the leftover to other iocgs. There are two ways to achieve this - 1. + * bumping up vrate accordingly 2. lowering the donating iocg's inuse weight. + * + * #1 is mathematically simpler but has the drawback of requiring synchronous + * global hweight_inuse updates when idle iocg's get activated or inuse weights + * change due to donation snapbacks as it has the possibility of grossly + * overshooting what's allowed by the model and vrate. + * + * #2 is inherently safe with local operations. The donating iocg can easily + * snap back to higher weights when needed without worrying about impacts on + * other nodes as the impacts will be inherently correct. This also makes idle + * iocg activations safe. The only effect activations have is decreasing + * hweight_inuse of others, the right solution to which is for those iocgs to + * snap back to higher weights. + * + * So, we go with #2. The challenge is calculating how each donating iocg's + * inuse should be adjusted to achieve the target donation amounts. This is done + * using Andy's method described in the following pdf. + * + * https://drive.google.com/file/d/1PsJwxPFtjUnwOY1QJ5AeICCcsL7BM3bo + * + * Given the weights and target after-donation hweight_inuse values, Andy's + * method determines how the proportional distribution should look like at each + * sibling level to maintain the relative relationship between all non-donating + * pairs. To roughly summarize, it divides the tree into donating and + * non-donating parts, calculates global donation rate which is used to + * determine the target hweight_inuse for each node, and then derives per-level + * proportions. + * + * The following pdf shows that global distribution calculated this way can be + * achieved by scaling inuse weights of donating leaves and propagating the + * adjustments upwards proportionally. + * + * https://drive.google.com/file/d/1vONz1-fzVO7oY5DXXsLjSxEtYYQbOvsE + * + * Combining the above two, we can determine how each leaf iocg's inuse should + * be adjusted to achieve the target donation. + * + * https://drive.google.com/file/d/1WcrltBOSPN0qXVdBgnKm4mdp9FhuEFQN + * + * The inline comments use symbols from the last pdf. + * + * b is the sum of the absolute budgets in the subtree. 1 for the root node. + * f is the sum of the absolute budgets of non-donating nodes in the subtree. + * t is the sum of the absolute budgets of donating nodes in the subtree. + * w is the weight of the node. w = w_f + w_t + * w_f is the non-donating portion of w. w_f = w * f / b + * w_b is the donating portion of w. w_t = w * t / b + * s is the sum of all sibling weights. s = Sum(w) for siblings + * s_f and s_t are the non-donating and donating portions of s. + * + * Subscript p denotes the parent's counterpart and ' the adjusted value - e.g. + * w_pt is the donating portion of the parent's weight and w'_pt the same value + * after adjustments. Subscript r denotes the root node's values. + */ static void transfer_surpluses(struct list_head *surpluses, struct ioc_now *now) { - struct ioc_gq *iocg; + LIST_HEAD(over_hwa); + LIST_HEAD(inner_walk); + struct ioc_gq *iocg, *tiocg, *root_iocg; + u32 after_sum, over_sum, over_target, gamma; + /* + * It's pretty unlikely but possible for the total sum of + * hweight_after_donation's to be higher than WEIGHT_ONE, which will + * confuse the following calculations. If such condition is detected, + * scale down everyone over its full share equally to keep the sum below + * WEIGHT_ONE. + */ + after_sum = 0; + over_sum = 0; list_for_each_entry(iocg, surpluses, surplus_list) { - u32 old_hwi, new_hwi, new_inuse; + u32 hwa; - current_hweight(iocg, NULL, &old_hwi); - new_hwi = iocg->hweight_after_donation; + current_hweight(iocg, &hwa, NULL); + after_sum += iocg->hweight_after_donation; - new_inuse = DIV64_U64_ROUND_UP((u64)iocg->inuse * new_hwi, - old_hwi); - __propagate_weights(iocg, iocg->weight, new_inuse); + if (iocg->hweight_after_donation > hwa) { + over_sum += iocg->hweight_after_donation; + list_add(&iocg->walk_list, &over_hwa); + } } + + if (after_sum >= WEIGHT_ONE) { + /* + * The delta should be deducted from the over_sum, calculate + * target over_sum value. + */ + u32 over_delta = after_sum - (WEIGHT_ONE - 1); + WARN_ON_ONCE(over_sum <= over_delta); + over_target = over_sum - over_delta; + } else { + over_target = 0; + } + + list_for_each_entry_safe(iocg, tiocg, &over_hwa, walk_list) { + if (over_target) + iocg->hweight_after_donation = + div_u64((u64)iocg->hweight_after_donation * + over_target, over_sum); + list_del_init(&iocg->walk_list); + } + + /* + * Build pre-order inner node walk list and prepare for donation + * adjustment calculations. + */ + list_for_each_entry(iocg, surpluses, surplus_list) { + iocg_build_inner_walk(iocg, &inner_walk); + } + + root_iocg = list_first_entry(&inner_walk, struct ioc_gq, walk_list); + WARN_ON_ONCE(root_iocg->level > 0); + + list_for_each_entry(iocg, &inner_walk, walk_list) { + iocg->child_adjusted_sum = 0; + iocg->hweight_donating = 0; + iocg->hweight_after_donation = 0; + } + + /* + * Propagate the donating budget (b_t) and after donation budget (b'_t) + * up the hierarchy. + */ + list_for_each_entry(iocg, surpluses, surplus_list) { + struct ioc_gq *parent = iocg->ancestors[iocg->level - 1]; + + parent->hweight_donating += iocg->hweight_donating; + parent->hweight_after_donation += iocg->hweight_after_donation; + } + + list_for_each_entry_reverse(iocg, &inner_walk, walk_list) { + if (iocg->level > 0) { + struct ioc_gq *parent = iocg->ancestors[iocg->level - 1]; + + parent->hweight_donating += iocg->hweight_donating; + parent->hweight_after_donation += iocg->hweight_after_donation; + } + } + + /* + * Calculate inner hwa's (b) and make sure the donation values are + * within the accepted ranges as we're doing low res calculations with + * roundups. + */ + list_for_each_entry(iocg, &inner_walk, walk_list) { + if (iocg->level) { + struct ioc_gq *parent = iocg->ancestors[iocg->level - 1]; + + iocg->hweight_active = DIV64_U64_ROUND_UP( + (u64)parent->hweight_active * iocg->active, + parent->child_active_sum); + + } + + iocg->hweight_donating = min(iocg->hweight_donating, + iocg->hweight_active); + iocg->hweight_after_donation = min(iocg->hweight_after_donation, + iocg->hweight_donating - 1); + if (WARN_ON_ONCE(iocg->hweight_active <= 1 || + iocg->hweight_donating <= 1 || + iocg->hweight_after_donation == 0)) { + pr_warn("iocg: invalid donation weights in "); + pr_cont_cgroup_path(iocg_to_blkg(iocg)->blkcg->css.cgroup); + pr_cont(": active=%u donating=%u after=%u\n", + iocg->hweight_active, iocg->hweight_donating, + iocg->hweight_after_donation); + } + } + + /* + * Calculate the global donation rate (gamma) - the rate to adjust + * non-donating budgets by. No need to use 64bit multiplication here as + * the first operand is guaranteed to be smaller than WEIGHT_ONE + * (1<<16). + * + * gamma = (1 - t_r') / (1 - t_r) + */ + gamma = DIV_ROUND_UP( + (WEIGHT_ONE - root_iocg->hweight_after_donation) * WEIGHT_ONE, + WEIGHT_ONE - root_iocg->hweight_donating); + + /* + * Calculate adjusted hwi, child_adjusted_sum and inuse for the inner + * nodes. + */ + list_for_each_entry(iocg, &inner_walk, walk_list) { + struct ioc_gq *parent; + u32 inuse, wpt, wptp; + u64 st, sf; + + if (iocg->level == 0) { + /* adjusted weight sum for 1st level: s' = s * b_pf / b'_pf */ + iocg->child_adjusted_sum = DIV64_U64_ROUND_UP( + iocg->child_active_sum * (WEIGHT_ONE - iocg->hweight_donating), + WEIGHT_ONE - iocg->hweight_after_donation); + continue; + } + + parent = iocg->ancestors[iocg->level - 1]; + + /* b' = gamma * b_f + b_t' */ + iocg->hweight_inuse = DIV64_U64_ROUND_UP( + (u64)gamma * (iocg->hweight_active - iocg->hweight_donating), + WEIGHT_ONE) + iocg->hweight_after_donation; + + /* w' = s' * b' / b'_p */ + inuse = DIV64_U64_ROUND_UP( + (u64)parent->child_adjusted_sum * iocg->hweight_inuse, + parent->hweight_inuse); + + /* adjusted weight sum for children: s' = s_f + s_t * w'_pt / w_pt */ + st = DIV64_U64_ROUND_UP( + iocg->child_active_sum * iocg->hweight_donating, + iocg->hweight_active); + sf = iocg->child_active_sum - st; + wpt = DIV64_U64_ROUND_UP( + (u64)iocg->active * iocg->hweight_donating, + iocg->hweight_active); + wptp = DIV64_U64_ROUND_UP( + (u64)inuse * iocg->hweight_after_donation, + iocg->hweight_inuse); + + iocg->child_adjusted_sum = sf + DIV64_U64_ROUND_UP(st * wptp, wpt); + } + + /* + * All inner nodes now have ->hweight_inuse and ->child_adjusted_sum and + * we can finally determine leaf adjustments. + */ + list_for_each_entry(iocg, surpluses, surplus_list) { + struct ioc_gq *parent = iocg->ancestors[iocg->level - 1]; + u32 inuse; + + /* w' = s' * b' / b'_p, note that b' == b'_t for donating leaves */ + inuse = DIV64_U64_ROUND_UP( + parent->child_adjusted_sum * iocg->hweight_after_donation, + parent->hweight_inuse); + __propagate_weights(iocg, iocg->active, inuse); + } + + /* walk list should be dissolved after use */ + list_for_each_entry_safe(iocg, tiocg, &inner_walk, walk_list) + list_del_init(&iocg->walk_list); } static void ioc_timer_fn(struct timer_list *timer) @@ -1705,16 +1939,18 @@ static void ioc_timer_fn(struct timer_list *timer) if (hw_inuse < hw_active || (!waitqueue_active(&iocg->waitq) && time_before64(vtime, now.vnow - ioc->margins.max))) { - u32 hwm, new_hwi; + u32 hwa, hwm, new_hwi; /* * Already donating or accumulated enough to start. * Determine the donation amount. */ + current_hweight(iocg, &hwa, NULL); hwm = current_hweight_max(iocg); new_hwi = hweight_after_donation(iocg, hwm, usage, &now); if (new_hwi < hwm) { + iocg->hweight_donating = hwa; iocg->hweight_after_donation = new_hwi; list_add(&iocg->surplus_list, &surpluses); } else { From f1de2439ec43b74764f2a26e3a310b24407e3bde Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 1 Sep 2020 14:52:49 -0400 Subject: [PATCH 040/191] blk-iocost: revamp donation amount determination iocost has various safety nets to combat inuse adjustment calculation inaccuracies. With Andy's method implemented in transfer_surpluses(), inuse adjustment calculations are now accurate and we can make donation amount determinations accurate too. * Stop keeping track of past usage history and using the maximum. Act on the immediate usage information. * Remove donation constraints defined by SURPLUS_* constants. Donate whatever isn't used. * Determine the donation amount so that the iocg will end up with MARGIN_TARGET_PCT budget at the end of the coming period assuming the same usage as the previous period. TARGET is set at 50% of period, which is the previous maximum. This provides smooth convergence for most repetitive IO patterns. * Apply donation logic early at 20% budget. There's no risk in doing so as the calculation is based on the delta between the current budget and the target budget at the end of the coming period. * Remove preemptive iocg activation for zero cost IOs. As donation can reach near zero now, the mere activation doesn't provide any protection anymore. In the unlikely case that this becomes a problem, the right solution is assigning appropriate costs for such IOs. This significantly improves the donation determination logic while also simplifying it. Now all donations are immediate, exact and smooth. Signed-off-by: Tejun Heo Cc: Andy Newell Signed-off-by: Jens Axboe --- block/blk-iocost.c | 133 +++++++++++++++++---------------------------- 1 file changed, 51 insertions(+), 82 deletions(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index ecc23b827e5d..694f1487208a 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -217,12 +217,14 @@ enum { MAX_PERIOD = USEC_PER_SEC, /* - * A cgroup's vtime can run 50% behind the device vtime, which + * iocg->vtime is targeted at 50% behind the device vtime, which * serves as its IO credit buffer. Surplus weight adjustment is * immediately canceled if the vtime margin runs below 10%. */ MARGIN_MIN_PCT = 10, - MARGIN_MAX_PCT = 50, + MARGIN_LOW_PCT = 20, + MARGIN_TARGET_PCT = 50, + MARGIN_MAX_PCT = 100, /* Have some play in timer operations */ TIMER_SLACK_PCT = 1, @@ -234,17 +236,6 @@ enum { */ VTIME_VALID_DUR = 300 * USEC_PER_SEC, - /* - * Remember the past three non-zero usages and use the max for - * surplus calculation. Three slots guarantee that we remember one - * full period usage from the last active stretch even after - * partial deactivation and re-activation periods. Don't start - * giving away weight before collecting two data points to prevent - * hweight adjustments based on one partial activation period. - */ - NR_USAGE_SLOTS = 3, - MIN_VALID_USAGES = 2, - /* 1/64k is granular enough and can easily be handled w/ u32 */ WEIGHT_ONE = 1 << 16, @@ -280,14 +271,6 @@ enum { /* don't let cmds which take a very long time pin lagging for too long */ MAX_LAGGING_PERIODS = 10, - /* - * If usage% * 1.25 + 2% is lower than hweight% by more than 3%, - * donate the surplus. - */ - SURPLUS_SCALE_PCT = 125, /* * 125% */ - SURPLUS_SCALE_ABS = WEIGHT_ONE / 50, /* + 2% */ - SURPLUS_MIN_ADJ_DELTA = WEIGHT_ONE / 33, /* 3% */ - /* switch iff the conditions are met for longer than this */ AUTOP_CYCLE_NSEC = 10LLU * NSEC_PER_SEC, @@ -376,6 +359,8 @@ struct ioc_params { struct ioc_margins { s64 min; + s64 low; + s64 target; s64 max; }; @@ -514,11 +499,7 @@ struct ioc_gq { struct iocg_stat desc_stat; struct iocg_stat last_stat; u64 last_stat_abs_vusage; - - /* usage is recorded as fractions of WEIGHT_ONE */ - u32 usage_delta_us; - int usage_idx; - u32 usages[NR_USAGE_SLOTS]; + u64 usage_delta_us; /* this iocg's depth in the hierarchy and ancestors including self */ int level; @@ -737,6 +718,8 @@ static void ioc_refresh_margins(struct ioc *ioc) u64 vrate = atomic64_read(&ioc->vtime_rate); margins->min = (period_us * MARGIN_MIN_PCT / 100) * vrate; + margins->low = (period_us * MARGIN_LOW_PCT / 100) * vrate; + margins->target = (period_us * MARGIN_TARGET_PCT / 100) * vrate; margins->max = (period_us * MARGIN_MAX_PCT / 100) * vrate; } @@ -1228,7 +1211,7 @@ static bool iocg_kick_delay(struct ioc_gq *iocg, struct ioc_now *now) return false; } if (!atomic_read(&blkg->use_delay) && - time_before_eq64(vtime, now->vnow + ioc->margins.max)) + time_before_eq64(vtime, now->vnow + ioc->margins.target)) return false; /* use delay */ @@ -1527,7 +1510,7 @@ static u32 hweight_after_donation(struct ioc_gq *iocg, u32 hwm, u32 usage, { struct ioc *ioc = iocg->ioc; u64 vtime = atomic64_read(&iocg->vtime); - s64 excess; + s64 excess, delta, target, new_hwi; /* see whether minimum margin requirement is met */ if (waitqueue_active(&iocg->waitq) || @@ -1542,15 +1525,28 @@ static u32 hweight_after_donation(struct ioc_gq *iocg, u32 hwm, u32 usage, vtime += excess; } - /* add margin */ - usage = DIV_ROUND_UP(usage * SURPLUS_SCALE_PCT, 100); - usage += SURPLUS_SCALE_ABS; + /* + * Let's say the distance between iocg's and device's vtimes as a + * fraction of period duration is delta. Assuming that the iocg will + * consume the usage determined above, we want to determine new_hwi so + * that delta equals MARGIN_TARGET at the end of the next period. + * + * We need to execute usage worth of IOs while spending the sum of the + * new budget (1 - MARGIN_TARGET) and the leftover from the last period + * (delta): + * + * usage = (1 - MARGIN_TARGET + delta) * new_hwi + * + * Therefore, the new_hwi is: + * + * new_hwi = usage / (1 - MARGIN_TARGET + delta) + */ + delta = div64_s64(WEIGHT_ONE * (now->vnow - vtime), + now->vnow - ioc->period_at_vtime); + target = WEIGHT_ONE * MARGIN_TARGET_PCT / 100; + new_hwi = div64_s64(WEIGHT_ONE * usage, WEIGHT_ONE - target + delta); - /* don't bother if the surplus is too small */ - if (usage + SURPLUS_MIN_ADJ_DELTA > hwm) - return hwm; - - return usage; + return clamp_t(s64, new_hwi, 1, hwm); } /* @@ -1812,7 +1808,7 @@ static void ioc_timer_fn(struct timer_list *timer) u32 ppm_wthr = MILLION - ioc->params.qos[QOS_WPPM]; u32 missed_ppm[2], rq_wait_pct; u64 period_vtime; - int prev_busy_level, i; + int prev_busy_level; /* how were the latencies during the period? */ ioc_lat_stat(ioc, missed_ppm, &rq_wait_pct); @@ -1857,11 +1853,10 @@ static void ioc_timer_fn(struct timer_list *timer) } commit_weights(ioc); - /* calc usages and see whether some weights need to be moved around */ + /* calc usage and see whether some weights need to be moved around */ list_for_each_entry(iocg, &ioc->active_iocgs, active_list) { - u64 vdone, vtime, usage_us; - u32 hw_active, hw_inuse, usage; - int uidx, nr_valid; + u64 vdone, vtime, usage_us, usage_dur; + u32 usage, hw_active, hw_inuse; /* * Collect unused and wind vtime closer to vnow to prevent @@ -1886,15 +1881,11 @@ static void ioc_timer_fn(struct timer_list *timer) nr_lagging++; /* - * Determine absolute usage factoring in pending and in-flight - * IOs to avoid stalls and high-latency completions appearing as - * idle. + * Determine absolute usage factoring in in-flight IOs to avoid + * high-latency completions appearing as idle. */ usage_us = iocg->usage_delta_us; - if (waitqueue_active(&iocg->waitq) && time_before64(vtime, now.vnow)) - usage_us += DIV64_U64_ROUND_UP( - cost_to_abs_cost(now.vnow - vtime, hw_inuse), - now.vrate); + if (vdone != vtime) { u64 inflight_us = DIV64_U64_ROUND_UP( cost_to_abs_cost(vtime - vdone, hw_inuse), @@ -1902,43 +1893,22 @@ static void ioc_timer_fn(struct timer_list *timer) usage_us = max(usage_us, inflight_us); } - /* convert to hweight based usage ratio and record */ - uidx = (iocg->usage_idx + 1) % NR_USAGE_SLOTS; + /* convert to hweight based usage ratio */ + if (time_after64(iocg->activated_at, ioc->period_at)) + usage_dur = max_t(u64, now.now - iocg->activated_at, 1); + else + usage_dur = max_t(u64, now.now - ioc->period_at, 1); - if (time_after64(vtime, now.vnow - ioc->margins.min)) { - iocg->usage_idx = uidx; - iocg->usages[uidx] = WEIGHT_ONE; - } else if (usage_us) { - u64 started_at, dur; - - if (time_after64(iocg->activated_at, ioc->period_at)) - started_at = iocg->activated_at; - else - started_at = ioc->period_at; - - dur = max_t(u64, now.now - started_at, 1); - - iocg->usage_idx = uidx; - iocg->usages[uidx] = clamp_t(u32, - DIV64_U64_ROUND_UP(usage_us * WEIGHT_ONE, dur), + usage = clamp_t(u32, + DIV64_U64_ROUND_UP(usage_us * WEIGHT_ONE, + usage_dur), 1, WEIGHT_ONE); - } - - /* base the decision on max historical usage */ - for (i = 0, usage = 0, nr_valid = 0; i < NR_USAGE_SLOTS; i++) { - if (iocg->usages[i]) { - usage = max(usage, iocg->usages[i]); - nr_valid++; - } - } - if (nr_valid < MIN_VALID_USAGES) - usage = WEIGHT_ONE; /* see whether there's surplus vtime */ WARN_ON_ONCE(!list_empty(&iocg->surplus_list)); if (hw_inuse < hw_active || (!waitqueue_active(&iocg->waitq) && - time_before64(vtime, now.vnow - ioc->margins.max))) { + time_before64(vtime, now.vnow - ioc->margins.low))) { u32 hwa, hwm, new_hwi; /* @@ -2175,15 +2145,14 @@ static void ioc_rqos_throttle(struct rq_qos *rqos, struct bio *bio) if (!ioc->enabled || !iocg->level) return; - /* always activate so that even 0 cost IOs get protected to some level */ - if (!iocg_activate(iocg, &now)) - return; - /* calculate the absolute vtime cost */ abs_cost = calc_vtime_cost(bio, iocg, false); if (!abs_cost) return; + if (!iocg_activate(iocg, &now)) + return; + iocg->cursor = bio_end_sector(bio); vtime = atomic64_read(&iocg->vtime); From b0853ab4a238c54b8f97ca7dde1ae156e2bbd5e4 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 1 Sep 2020 14:52:50 -0400 Subject: [PATCH 041/191] blk-iocost: revamp in-period donation snapbacks When the margin drops below the minimum on a donating iocg, donation is immediately canceled in full. There are a couple shortcomings with the current behavior. * It's abrupt. A small temporary budget deficit can lead to a wide swing in weight allocation and a large surplus. * It's open coded in the issue path but not implemented for the merge path. A series of merges at a low inuse can make the iocg incur debts and stall incorrectly. This patch reimplements in-period donation snapbacks so that * inuse adjustment and cost calculations are factored into adjust_inuse_and_calc_cost() which is called from both the issue and merge paths. * Snapbacks are more gradual. It occurs in quarter steps. * A snapback triggers if the margin goes below the low threshold and is lower than the budget at the time of the last adjustment. * For the above, __propagate_weights() stores the margin in iocg->saved_margin. Move iocg->last_inuse storing together into __propagate_weights() for consistency. * Full snapback is guaranteed when there are waiters. * With precise donation and gradual snapbacks, inuse adjustments are now a lot more effective and the value of scaling inuse on weight changes isn't clear. Removed inuse scaling from weight_update(). Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- block/blk-iocost.c | 133 ++++++++++++++++++++++++++++++++------------- 1 file changed, 96 insertions(+), 37 deletions(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index 694f1487208a..d09b4011449c 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -226,6 +226,8 @@ enum { MARGIN_TARGET_PCT = 50, MARGIN_MAX_PCT = 100, + INUSE_ADJ_STEP_PCT = 25, + /* Have some play in timer operations */ TIMER_SLACK_PCT = 1, @@ -443,12 +445,17 @@ struct ioc_gq { * * `last_inuse` remembers `inuse` while an iocg is idle to persist * surplus adjustments. + * + * `inuse` may be adjusted dynamically during period. `saved_*` are used + * to determine and track adjustments. */ u32 cfg_weight; u32 weight; u32 active; u32 inuse; + u32 last_inuse; + s64 saved_margin; sector_t cursor; /* to detect randio */ @@ -934,9 +941,11 @@ static void ioc_start_period(struct ioc *ioc, struct ioc_now *now) /* * Update @iocg's `active` and `inuse` to @active and @inuse, update level - * weight sums and propagate upwards accordingly. + * weight sums and propagate upwards accordingly. If @save, the current margin + * is saved to be used as reference for later inuse in-period adjustments. */ -static void __propagate_weights(struct ioc_gq *iocg, u32 active, u32 inuse) +static void __propagate_weights(struct ioc_gq *iocg, u32 active, u32 inuse, + bool save, struct ioc_now *now) { struct ioc *ioc = iocg->ioc; int lvl; @@ -945,6 +954,10 @@ static void __propagate_weights(struct ioc_gq *iocg, u32 active, u32 inuse) inuse = clamp_t(u32, inuse, 1, active); + iocg->last_inuse = iocg->inuse; + if (save) + iocg->saved_margin = now->vnow - atomic64_read(&iocg->vtime); + if (active == iocg->active && inuse == iocg->inuse) return; @@ -996,9 +1009,10 @@ static void commit_weights(struct ioc *ioc) } } -static void propagate_weights(struct ioc_gq *iocg, u32 active, u32 inuse) +static void propagate_weights(struct ioc_gq *iocg, u32 active, u32 inuse, + bool save, struct ioc_now *now) { - __propagate_weights(iocg, active, inuse); + __propagate_weights(iocg, active, inuse, save, now); commit_weights(iocg->ioc); } @@ -1082,7 +1096,7 @@ static u32 current_hweight_max(struct ioc_gq *iocg) return max_t(u32, hwm, 1); } -static void weight_updated(struct ioc_gq *iocg) +static void weight_updated(struct ioc_gq *iocg, struct ioc_now *now) { struct ioc *ioc = iocg->ioc; struct blkcg_gq *blkg = iocg_to_blkg(iocg); @@ -1093,9 +1107,7 @@ static void weight_updated(struct ioc_gq *iocg) weight = iocg->cfg_weight ?: iocc->dfl_weight; if (weight != iocg->weight && iocg->active) - propagate_weights(iocg, weight, - DIV64_U64_ROUND_UP((u64)iocg->inuse * weight, - iocg->weight)); + propagate_weights(iocg, weight, iocg->inuse, true, now); iocg->weight = weight; } @@ -1165,8 +1177,9 @@ static bool iocg_activate(struct ioc_gq *iocg, struct ioc_now *now) */ iocg->hweight_gen = atomic_read(&ioc->hweight_gen) - 1; list_add(&iocg->active_list, &ioc->active_iocgs); + propagate_weights(iocg, iocg->weight, - iocg->last_inuse ?: iocg->weight); + iocg->last_inuse ?: iocg->weight, true, now); TRACE_IOCG_PATH(iocg_activate, iocg, now, last_period, cur_period, vtime); @@ -1789,7 +1802,7 @@ static void transfer_surpluses(struct list_head *surpluses, struct ioc_now *now) inuse = DIV64_U64_ROUND_UP( parent->child_adjusted_sum * iocg->hweight_after_donation, parent->hweight_inuse); - __propagate_weights(iocg, iocg->active, inuse); + __propagate_weights(iocg, iocg->active, inuse, true, now); } /* walk list should be dissolved after use */ @@ -1844,8 +1857,7 @@ static void ioc_timer_fn(struct timer_list *timer) iocg_kick_waitq(iocg, true, &now); } else if (iocg_is_idle(iocg)) { /* no waiter and idle, deactivate */ - iocg->last_inuse = iocg->inuse; - __propagate_weights(iocg, 0, 0); + __propagate_weights(iocg, 0, 0, false, &now); list_del_init(&iocg->active_list); } @@ -1925,7 +1937,7 @@ static void ioc_timer_fn(struct timer_list *timer) list_add(&iocg->surplus_list, &surpluses); } else { __propagate_weights(iocg, iocg->active, - iocg->active); + iocg->active, true, &now); nr_shortages++; } } else { @@ -2055,6 +2067,50 @@ static void ioc_timer_fn(struct timer_list *timer) spin_unlock_irq(&ioc->lock); } +static u64 adjust_inuse_and_calc_cost(struct ioc_gq *iocg, u64 vtime, + u64 abs_cost, struct ioc_now *now) +{ + struct ioc *ioc = iocg->ioc; + struct ioc_margins *margins = &ioc->margins; + u32 adj_step = DIV_ROUND_UP(iocg->active * INUSE_ADJ_STEP_PCT, 100); + u32 hwi; + s64 margin; + u64 cost, new_inuse; + + current_hweight(iocg, NULL, &hwi); + cost = abs_cost_to_cost(abs_cost, hwi); + margin = now->vnow - vtime - cost; + + /* + * We only increase inuse during period and do so iff the margin has + * deteriorated since the previous adjustment. + */ + if (margin >= iocg->saved_margin || margin >= margins->low || + iocg->inuse == iocg->active) + return cost; + + spin_lock_irq(&ioc->lock); + + /* we own inuse only when @iocg is in the normal active state */ + if (list_empty(&iocg->active_list)) { + spin_unlock_irq(&ioc->lock); + return cost; + } + + /* bump up inuse till @abs_cost fits in the existing budget */ + new_inuse = iocg->inuse; + do { + new_inuse = new_inuse + adj_step; + propagate_weights(iocg, iocg->active, new_inuse, true, now); + current_hweight(iocg, NULL, &hwi); + cost = abs_cost_to_cost(abs_cost, hwi); + } while (time_after64(vtime + cost, now->vnow) && + iocg->inuse != iocg->active); + + spin_unlock_irq(&ioc->lock); + return cost; +} + static void calc_vtime_cost_builtin(struct bio *bio, struct ioc_gq *iocg, bool is_merge, u64 *costp) { @@ -2136,7 +2192,6 @@ static void ioc_rqos_throttle(struct rq_qos *rqos, struct bio *bio) struct ioc_gq *iocg = blkg_to_iocg(blkg); struct ioc_now now; struct iocg_wait wait; - u32 hw_active, hw_inuse; u64 abs_cost, cost, vtime; bool use_debt, ioc_locked; unsigned long flags; @@ -2154,21 +2209,8 @@ static void ioc_rqos_throttle(struct rq_qos *rqos, struct bio *bio) return; iocg->cursor = bio_end_sector(bio); - vtime = atomic64_read(&iocg->vtime); - current_hweight(iocg, &hw_active, &hw_inuse); - - if (hw_inuse < hw_active && - time_after_eq64(vtime + ioc->margins.min, now.vnow)) { - TRACE_IOCG_PATH(inuse_reset, iocg, &now, - iocg->inuse, iocg->weight, hw_inuse, hw_active); - spin_lock_irq(&ioc->lock); - propagate_weights(iocg, iocg->weight, iocg->weight); - spin_unlock_irq(&ioc->lock); - current_hweight(iocg, &hw_active, &hw_inuse); - } - - cost = abs_cost_to_cost(abs_cost, hw_inuse); + cost = adjust_inuse_and_calc_cost(iocg, vtime, abs_cost, &now); /* * If no one's waiting and within budget, issue right away. The @@ -2190,7 +2232,7 @@ static void ioc_rqos_throttle(struct rq_qos *rqos, struct bio *bio) */ use_debt = bio_issue_as_root_blkg(bio) || fatal_signal_pending(current); ioc_locked = use_debt || READ_ONCE(iocg->abs_vdebt); - +retry_lock: iocg_lock(iocg, ioc_locked, &flags); /* @@ -2232,6 +2274,17 @@ static void ioc_rqos_throttle(struct rq_qos *rqos, struct bio *bio) return; } + /* guarantee that iocgs w/ waiters have maximum inuse */ + if (iocg->inuse != iocg->active) { + if (!ioc_locked) { + iocg_unlock(iocg, false, &flags); + ioc_locked = true; + goto retry_lock; + } + propagate_weights(iocg, iocg->active, iocg->active, true, + &now); + } + /* * Append self to the waitq and schedule the wakeup timer if we're * the first waiter. The timer duration is calculated based on the @@ -2274,8 +2327,7 @@ static void ioc_rqos_merge(struct rq_qos *rqos, struct request *rq, struct ioc *ioc = iocg->ioc; sector_t bio_end = bio_end_sector(bio); struct ioc_now now; - u32 hw_inuse; - u64 abs_cost, cost; + u64 vtime, abs_cost, cost; unsigned long flags; /* bypass if disabled or for root cgroup */ @@ -2287,8 +2339,9 @@ static void ioc_rqos_merge(struct rq_qos *rqos, struct request *rq, return; ioc_now(ioc, &now); - current_hweight(iocg, NULL, &hw_inuse); - cost = abs_cost_to_cost(abs_cost, hw_inuse); + + vtime = atomic64_read(&iocg->vtime); + cost = adjust_inuse_and_calc_cost(iocg, vtime, abs_cost, &now); /* update cursor if backmerging into the request at the cursor */ if (blk_rq_pos(rq) < bio_end && @@ -2530,7 +2583,7 @@ static void ioc_pd_init(struct blkg_policy_data *pd) } spin_lock_irqsave(&ioc->lock, flags); - weight_updated(iocg); + weight_updated(iocg, &now); spin_unlock_irqrestore(&ioc->lock, flags); } @@ -2544,7 +2597,10 @@ static void ioc_pd_free(struct blkg_policy_data *pd) spin_lock_irqsave(&ioc->lock, flags); if (!list_empty(&iocg->active_list)) { - propagate_weights(iocg, 0, 0); + struct ioc_now now; + + ioc_now(ioc, &now); + propagate_weights(iocg, 0, 0, false, &now); list_del_init(&iocg->active_list); } @@ -2612,6 +2668,7 @@ static ssize_t ioc_weight_write(struct kernfs_open_file *of, char *buf, struct blkcg *blkcg = css_to_blkcg(of_css(of)); struct ioc_cgrp *iocc = blkcg_to_iocc(blkcg); struct blkg_conf_ctx ctx; + struct ioc_now now; struct ioc_gq *iocg; u32 v; int ret; @@ -2632,7 +2689,8 @@ static ssize_t ioc_weight_write(struct kernfs_open_file *of, char *buf, if (iocg) { spin_lock_irq(&iocg->ioc->lock); - weight_updated(iocg); + ioc_now(iocg->ioc, &now); + weight_updated(iocg, &now); spin_unlock_irq(&iocg->ioc->lock); } } @@ -2658,7 +2716,8 @@ static ssize_t ioc_weight_write(struct kernfs_open_file *of, char *buf, spin_lock(&iocg->ioc->lock); iocg->cfg_weight = v * WEIGHT_ONE; - weight_updated(iocg); + ioc_now(iocg->ioc, &now); + weight_updated(iocg, &now); spin_unlock(&iocg->ioc->lock); blkg_conf_finish(&ctx); From c421a3eb2e27402c14131a14390551ae6cdb15fa Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 1 Sep 2020 14:52:51 -0400 Subject: [PATCH 042/191] blk-iocost: revamp debt handling Debt handling had several issues. * How much inuse a debtor carries wasn't clearly defined. inuse would be driven down over time from not issuing IOs but it'd be better to clamp it to minimum immediately once in debt. * How much can be paid off was determined by hweight_inuse. As inuse was driven down, the payment amount would fall together regardless of the debtor's active weight. This means that the debtors were punished harshly. * ioc_rqos_merge() wasn't calling blkcg_schedule_throttle() after iocg_kick_delay(). This patch revamps debt handling so that * Debt handling owns inuse for iocgs in debt and keeps them at zero. * Payment amount is determined by hweight_active. This is more deterministic and safer than hweight_inuse but still far from ideal in that it doesn't factor in possible donations from other iocgs for debt payments. This likely needs further improvements in the future. * iocg_rqos_merge() now calls blkcg_schedule_throttle() as necessary. Signed-off-by: Tejun Heo Cc: Andy Newell Signed-off-by: Jens Axboe --- block/blk-iocost.c | 117 +++++++++++++++++++++++++++++++++++---------- 1 file changed, 93 insertions(+), 24 deletions(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index d09b4011449c..d2b69d87f3e7 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -1206,13 +1206,13 @@ static bool iocg_kick_delay(struct ioc_gq *iocg, struct ioc_now *now) struct blkcg_gq *blkg = iocg_to_blkg(iocg); u64 vtime = atomic64_read(&iocg->vtime); u64 delta_ns, expires, oexpires; - u32 hw_inuse; + u32 hwa; lockdep_assert_held(&iocg->waitq.lock); /* debt-adjust vtime */ - current_hweight(iocg, NULL, &hw_inuse); - vtime += abs_cost_to_cost(iocg->abs_vdebt, hw_inuse); + current_hweight(iocg, &hwa, NULL); + vtime += abs_cost_to_cost(iocg->abs_vdebt, hwa); /* * Clear or maintain depending on the overage. Non-zero vdebt is what @@ -1258,6 +1258,47 @@ static enum hrtimer_restart iocg_delay_timer_fn(struct hrtimer *timer) return HRTIMER_NORESTART; } +static void iocg_incur_debt(struct ioc_gq *iocg, u64 abs_cost, + struct ioc_now *now) +{ + struct iocg_pcpu_stat *gcs; + + lockdep_assert_held(&iocg->ioc->lock); + lockdep_assert_held(&iocg->waitq.lock); + WARN_ON_ONCE(list_empty(&iocg->active_list)); + + /* + * Once in debt, debt handling owns inuse. @iocg stays at the minimum + * inuse donating all of it share to others until its debt is paid off. + */ + if (!iocg->abs_vdebt && abs_cost) + propagate_weights(iocg, iocg->active, 0, false, now); + + iocg->abs_vdebt += abs_cost; + + gcs = get_cpu_ptr(iocg->pcpu_stat); + local64_add(abs_cost, &gcs->abs_vusage); + put_cpu_ptr(gcs); +} + +static void iocg_pay_debt(struct ioc_gq *iocg, u64 abs_vpay, + struct ioc_now *now) +{ + lockdep_assert_held(&iocg->ioc->lock); + lockdep_assert_held(&iocg->waitq.lock); + + /* make sure that nobody messed with @iocg */ + WARN_ON_ONCE(list_empty(&iocg->active_list)); + WARN_ON_ONCE(iocg->inuse > 1); + + iocg->abs_vdebt -= min(abs_vpay, iocg->abs_vdebt); + + /* if debt is paid in full, restore inuse */ + if (!iocg->abs_vdebt) + propagate_weights(iocg, iocg->active, iocg->last_inuse, + false, now); +} + static int iocg_wake_fn(struct wait_queue_entry *wq_entry, unsigned mode, int flags, void *key) { @@ -1296,26 +1337,25 @@ static void iocg_kick_waitq(struct ioc_gq *iocg, bool pay_debt, struct iocg_wake_ctx ctx = { .iocg = iocg }; u64 vshortage, expires, oexpires; s64 vbudget; - u32 hw_inuse; + u32 hwa; lockdep_assert_held(&iocg->waitq.lock); - current_hweight(iocg, NULL, &hw_inuse); + current_hweight(iocg, &hwa, NULL); vbudget = now->vnow - atomic64_read(&iocg->vtime); /* pay off debt */ if (pay_debt && iocg->abs_vdebt && vbudget > 0) { - u64 vdebt = abs_cost_to_cost(iocg->abs_vdebt, hw_inuse); - u64 delta = min_t(u64, vbudget, vdebt); - u64 abs_delta = min(cost_to_abs_cost(delta, hw_inuse), - iocg->abs_vdebt); + u64 abs_vbudget = cost_to_abs_cost(vbudget, hwa); + u64 abs_vpay = min_t(u64, abs_vbudget, iocg->abs_vdebt); + u64 vpay = abs_cost_to_cost(abs_vpay, hwa); lockdep_assert_held(&ioc->lock); - atomic64_add(delta, &iocg->vtime); - atomic64_add(delta, &iocg->done_vtime); - iocg->abs_vdebt -= abs_delta; - vbudget -= vdebt; + atomic64_add(vpay, &iocg->vtime); + atomic64_add(vpay, &iocg->done_vtime); + iocg_pay_debt(iocg, abs_vpay, now); + vbudget -= vpay; iocg_kick_delay(iocg, now); } @@ -1327,17 +1367,20 @@ static void iocg_kick_waitq(struct ioc_gq *iocg, bool pay_debt, * not positive. */ if (iocg->abs_vdebt) { - s64 vdebt = abs_cost_to_cost(iocg->abs_vdebt, hw_inuse); + s64 vdebt = abs_cost_to_cost(iocg->abs_vdebt, hwa); vbudget = min_t(s64, 0, vbudget - vdebt); } /* - * Wake up the ones which are due and see how much vtime we'll need - * for the next one. + * Wake up the ones which are due and see how much vtime we'll need for + * the next one. As paying off debt restores hw_inuse, it must be read + * after the above debt payment. */ - ctx.hw_inuse = hw_inuse; ctx.vbudget = vbudget; + current_hweight(iocg, NULL, &ctx.hw_inuse); + __wake_up_locked_key(&iocg->waitq, TASK_NORMAL, &ctx); + if (!waitqueue_active(&iocg->waitq)) return; if (WARN_ON_ONCE(ctx.vbudget >= 0)) @@ -1525,6 +1568,10 @@ static u32 hweight_after_donation(struct ioc_gq *iocg, u32 hwm, u32 usage, u64 vtime = atomic64_read(&iocg->vtime); s64 excess, delta, target, new_hwi; + /* debt handling owns inuse for debtors */ + if (iocg->abs_vdebt) + return 1; + /* see whether minimum margin requirement is met */ if (waitqueue_active(&iocg->waitq) || time_after64(vtime, now->vnow - ioc->margins.min)) @@ -1798,6 +1845,18 @@ static void transfer_surpluses(struct list_head *surpluses, struct ioc_now *now) struct ioc_gq *parent = iocg->ancestors[iocg->level - 1]; u32 inuse; + /* + * In-debt iocgs participated in the donation calculation with + * the minimum target hweight_inuse. Configuring inuse + * accordingly would work fine but debt handling expects + * @iocg->inuse stay at the minimum and we don't wanna + * interfere. + */ + if (iocg->abs_vdebt) { + WARN_ON_ONCE(iocg->inuse > 1); + continue; + } + /* w' = s' * b' / b'_p, note that b' == b'_t for donating leaves */ inuse = DIV64_U64_ROUND_UP( parent->child_adjusted_sum * iocg->hweight_after_donation, @@ -2081,6 +2140,10 @@ static u64 adjust_inuse_and_calc_cost(struct ioc_gq *iocg, u64 vtime, cost = abs_cost_to_cost(abs_cost, hwi); margin = now->vnow - vtime - cost; + /* debt handling owns inuse for debtors */ + if (iocg->abs_vdebt) + return cost; + /* * We only increase inuse during period and do so iff the margin has * deteriorated since the previous adjustment. @@ -2092,7 +2155,7 @@ static u64 adjust_inuse_and_calc_cost(struct ioc_gq *iocg, u64 vtime, spin_lock_irq(&ioc->lock); /* we own inuse only when @iocg is in the normal active state */ - if (list_empty(&iocg->active_list)) { + if (iocg->abs_vdebt || list_empty(&iocg->active_list)) { spin_unlock_irq(&ioc->lock); return cost; } @@ -2266,7 +2329,7 @@ static void ioc_rqos_throttle(struct rq_qos *rqos, struct bio *bio) * penalizing the cgroup and its descendants. */ if (use_debt) { - iocg->abs_vdebt += abs_cost; + iocg_incur_debt(iocg, abs_cost, &now); if (iocg_kick_delay(iocg, &now)) blkcg_schedule_throttle(rqos->q, (bio->bi_opf & REQ_SWAP) == REQ_SWAP); @@ -2275,7 +2338,7 @@ static void ioc_rqos_throttle(struct rq_qos *rqos, struct bio *bio) } /* guarantee that iocgs w/ waiters have maximum inuse */ - if (iocg->inuse != iocg->active) { + if (!iocg->abs_vdebt && iocg->inuse != iocg->active) { if (!ioc_locked) { iocg_unlock(iocg, false, &flags); ioc_locked = true; @@ -2363,14 +2426,20 @@ static void ioc_rqos_merge(struct rq_qos *rqos, struct request *rq, * be for the vast majority of cases. See debt handling in * ioc_rqos_throttle() for details. */ - spin_lock_irqsave(&iocg->waitq.lock, flags); + spin_lock_irqsave(&ioc->lock, flags); + spin_lock(&iocg->waitq.lock); + if (likely(!list_empty(&iocg->active_list))) { - iocg->abs_vdebt += abs_cost; - iocg_kick_delay(iocg, &now); + iocg_incur_debt(iocg, abs_cost, &now); + if (iocg_kick_delay(iocg, &now)) + blkcg_schedule_throttle(rqos->q, + (bio->bi_opf & REQ_SWAP) == REQ_SWAP); } else { iocg_commit_bio(iocg, bio, abs_cost, cost); } - spin_unlock_irqrestore(&iocg->waitq.lock, flags); + + spin_unlock(&iocg->waitq.lock); + spin_unlock_irqrestore(&ioc->lock, flags); } static void ioc_rqos_done_bio(struct rq_qos *rqos, struct bio *bio) From 5160a5a53c0c4ae3708959d9465ea43ad5d90542 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 1 Sep 2020 14:52:52 -0400 Subject: [PATCH 043/191] blk-iocost: implement delay adjustment hysteresis Curently, iocost syncs the delay duration to the outstanding debt amount, which seemed enough to protect the system from anon memory hogs. However, that was mostly because the delay calcuation was using hweight_inuse which quickly converges towards zero under debt for delay duration calculation, often pusnishing debtors overly harshly for longer than deserved. The previous patch fixed the delay calcuation and now the protection against anonymous memory hogs isn't enough because the effect of delay is indirect and non-linear and a huge amount of future debt can accumulate abruptly while unthrottled. This patch implements delay hysteresis so that delay is decayed exponentially over time instead of getting cleared immediately as debt is paid off. While the overall behavior is similar to the blk-cgroup implementation used by blk-iolatency, a lot of the details are different and due to the empirical nature of the mechanism, it's challenging to adapt the mechanism for one controller without negatively impacting the other. As the delay is gradually decayed now, there's no point in running it from its own hrtimer. Periodic updates are now performed from ioc_timer_fn() and the dedicated hrtimer is removed. Signed-off-by: Tejun Heo Cc: Josef Bacik Signed-off-by: Jens Axboe --- block/blk-cgroup.c | 23 ++++++--- block/blk-iocost.c | 123 ++++++++++++++++++++++++++------------------- 2 files changed, 88 insertions(+), 58 deletions(-) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index c195365c9817..d33dd6be1d9c 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -1613,16 +1613,24 @@ static void blkcg_scale_delay(struct blkcg_gq *blkg, u64 now) static void blkcg_maybe_throttle_blkg(struct blkcg_gq *blkg, bool use_memdelay) { unsigned long pflags; + bool clamp; u64 now = ktime_to_ns(ktime_get()); u64 exp; u64 delay_nsec = 0; int tok; while (blkg->parent) { - if (atomic_read(&blkg->use_delay)) { + int use_delay = atomic_read(&blkg->use_delay); + + if (use_delay) { + u64 this_delay; + blkcg_scale_delay(blkg, now); - delay_nsec = max_t(u64, delay_nsec, - atomic64_read(&blkg->delay_nsec)); + this_delay = atomic64_read(&blkg->delay_nsec); + if (this_delay > delay_nsec) { + delay_nsec = this_delay; + clamp = use_delay > 0; + } } blkg = blkg->parent; } @@ -1634,10 +1642,13 @@ static void blkcg_maybe_throttle_blkg(struct blkcg_gq *blkg, bool use_memdelay) * Let's not sleep for all eternity if we've amassed a huge delay. * Swapping or metadata IO can accumulate 10's of seconds worth of * delay, and we want userspace to be able to do _something_ so cap the - * delays at 1 second. If there's 10's of seconds worth of delay then - * the tasks will be delayed for 1 second for every syscall. + * delays at 0.25s. If there's 10's of seconds worth of delay then the + * tasks will be delayed for 0.25 second for every syscall. If + * blkcg_set_delay() was used as indicated by negative use_delay, the + * caller is responsible for regulating the range. */ - delay_nsec = min_t(u64, delay_nsec, 250 * NSEC_PER_MSEC); + if (clamp) + delay_nsec = min_t(u64, delay_nsec, 250 * NSEC_PER_MSEC); if (use_memdelay) psi_memstall_enter(&pflags); diff --git a/block/blk-iocost.c b/block/blk-iocost.c index d2b69d87f3e7..9cb8f29f01f5 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -270,6 +270,31 @@ enum { /* unbusy hysterisis */ UNBUSY_THR_PCT = 75, + /* + * The effect of delay is indirect and non-linear and a huge amount of + * future debt can accumulate abruptly while unthrottled. Linearly scale + * up delay as debt is going up and then let it decay exponentially. + * This gives us quick ramp ups while delay is accumulating and long + * tails which can help reducing the frequency of debt explosions on + * unthrottle. The parameters are experimentally determined. + * + * The delay mechanism provides adequate protection and behavior in many + * cases. However, this is far from ideal and falls shorts on both + * fronts. The debtors are often throttled too harshly costing a + * significant level of fairness and possibly total work while the + * protection against their impacts on the system can be choppy and + * unreliable. + * + * The shortcoming primarily stems from the fact that, unlike for page + * cache, the kernel doesn't have well-defined back-pressure propagation + * mechanism and policies for anonymous memory. Fully addressing this + * issue will likely require substantial improvements in the area. + */ + MIN_DELAY_THR_PCT = 500, + MAX_DELAY_THR_PCT = 25000, + MIN_DELAY = 250, + MAX_DELAY = 250 * USEC_PER_MSEC, + /* don't let cmds which take a very long time pin lagging for too long */ MAX_LAGGING_PERIODS = 10, @@ -473,6 +498,10 @@ struct ioc_gq { atomic64_t done_vtime; u64 abs_vdebt; + /* current delay in effect and when it started */ + u64 delay; + u64 delay_at; + /* * The period this iocg was last active in. Used for deactivation * and invalidating `vtime`. @@ -495,7 +524,6 @@ struct ioc_gq { struct wait_queue_head waitq; struct hrtimer waitq_timer; - struct hrtimer delay_timer; /* timestamp at the latest activation */ u64 activated_at; @@ -1204,58 +1232,50 @@ static bool iocg_kick_delay(struct ioc_gq *iocg, struct ioc_now *now) { struct ioc *ioc = iocg->ioc; struct blkcg_gq *blkg = iocg_to_blkg(iocg); - u64 vtime = atomic64_read(&iocg->vtime); - u64 delta_ns, expires, oexpires; + u64 tdelta, delay, new_delay; + s64 vover, vover_pct; u32 hwa; lockdep_assert_held(&iocg->waitq.lock); - /* debt-adjust vtime */ - current_hweight(iocg, &hwa, NULL); - vtime += abs_cost_to_cost(iocg->abs_vdebt, hwa); + /* calculate the current delay in effect - 1/2 every second */ + tdelta = now->now - iocg->delay_at; + if (iocg->delay) + delay = iocg->delay >> div64_u64(tdelta, USEC_PER_SEC); + else + delay = 0; - /* - * Clear or maintain depending on the overage. Non-zero vdebt is what - * guarantees that @iocg is online and future iocg_kick_delay() will - * clear use_delay. Don't leave it on when there's no vdebt. - */ - if (!iocg->abs_vdebt || time_before_eq64(vtime, now->vnow)) { + /* calculate the new delay from the debt amount */ + current_hweight(iocg, &hwa, NULL); + vover = atomic64_read(&iocg->vtime) + + abs_cost_to_cost(iocg->abs_vdebt, hwa) - now->vnow; + vover_pct = div64_s64(100 * vover, ioc->period_us * now->vrate); + + if (vover_pct <= MIN_DELAY_THR_PCT) + new_delay = 0; + else if (vover_pct >= MAX_DELAY_THR_PCT) + new_delay = MAX_DELAY; + else + new_delay = MIN_DELAY + + div_u64((MAX_DELAY - MIN_DELAY) * + (vover_pct - MIN_DELAY_THR_PCT), + MAX_DELAY_THR_PCT - MIN_DELAY_THR_PCT); + + /* pick the higher one and apply */ + if (new_delay > delay) { + iocg->delay = new_delay; + iocg->delay_at = now->now; + delay = new_delay; + } + + if (delay >= MIN_DELAY) { + blkcg_set_delay(blkg, delay * NSEC_PER_USEC); + return true; + } else { + iocg->delay = 0; blkcg_clear_delay(blkg); return false; } - if (!atomic_read(&blkg->use_delay) && - time_before_eq64(vtime, now->vnow + ioc->margins.target)) - return false; - - /* use delay */ - delta_ns = DIV64_U64_ROUND_UP(vtime - now->vnow, - now->vrate) * NSEC_PER_USEC; - blkcg_set_delay(blkg, delta_ns); - expires = now->now_ns + delta_ns; - - /* if already active and close enough, don't bother */ - oexpires = ktime_to_ns(hrtimer_get_softexpires(&iocg->delay_timer)); - if (hrtimer_is_queued(&iocg->delay_timer) && - abs(oexpires - expires) <= ioc->timer_slack_ns) - return true; - - hrtimer_start_range_ns(&iocg->delay_timer, ns_to_ktime(expires), - ioc->timer_slack_ns, HRTIMER_MODE_ABS); - return true; -} - -static enum hrtimer_restart iocg_delay_timer_fn(struct hrtimer *timer) -{ - struct ioc_gq *iocg = container_of(timer, struct ioc_gq, delay_timer); - struct ioc_now now; - unsigned long flags; - - spin_lock_irqsave(&iocg->waitq.lock, flags); - ioc_now(iocg->ioc, &now); - iocg_kick_delay(iocg, &now); - spin_unlock_irqrestore(&iocg->waitq.lock, flags); - - return HRTIMER_NORESTART; } static void iocg_incur_debt(struct ioc_gq *iocg, u64 abs_cost, @@ -1356,10 +1376,11 @@ static void iocg_kick_waitq(struct ioc_gq *iocg, bool pay_debt, atomic64_add(vpay, &iocg->done_vtime); iocg_pay_debt(iocg, abs_vpay, now); vbudget -= vpay; - - iocg_kick_delay(iocg, now); } + if (iocg->abs_vdebt || iocg->delay) + iocg_kick_delay(iocg, now); + /* * Debt can still be outstanding if we haven't paid all yet or the * caller raced and called without @pay_debt. Shouldn't wake up waiters @@ -1906,12 +1927,13 @@ static void ioc_timer_fn(struct timer_list *timer) */ list_for_each_entry_safe(iocg, tiocg, &ioc->active_iocgs, active_list) { if (!waitqueue_active(&iocg->waitq) && !iocg->abs_vdebt && - !iocg_is_idle(iocg)) + !iocg->delay && !iocg_is_idle(iocg)) continue; spin_lock(&iocg->waitq.lock); - if (waitqueue_active(&iocg->waitq) || iocg->abs_vdebt) { + if (waitqueue_active(&iocg->waitq) || iocg->abs_vdebt || + iocg->delay) { /* might be oversleeping vtime / hweight changes, kick */ iocg_kick_waitq(iocg, true, &now); } else if (iocg_is_idle(iocg)) { @@ -2641,8 +2663,6 @@ static void ioc_pd_init(struct blkg_policy_data *pd) init_waitqueue_head(&iocg->waitq); hrtimer_init(&iocg->waitq_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); iocg->waitq_timer.function = iocg_waitq_timer_fn; - hrtimer_init(&iocg->delay_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); - iocg->delay_timer.function = iocg_delay_timer_fn; iocg->level = blkg->blkcg->css.cgroup->level; @@ -2679,7 +2699,6 @@ static void ioc_pd_free(struct blkg_policy_data *pd) spin_unlock_irqrestore(&ioc->lock, flags); hrtimer_cancel(&iocg->waitq_timer); - hrtimer_cancel(&iocg->delay_timer); } free_percpu(iocg->pcpu_stat); kfree(iocg); From dda1315f18536cb94e293a3ae0ccb5c4df53e5e4 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 1 Sep 2020 14:52:53 -0400 Subject: [PATCH 044/191] blk-iocost: halve debts if device stays idle A low weight iocg can amass a large amount of debt, for example, when anonymous memory gets reclaimed aggressively. If the system has a lot of memory paired with a slow IO device, the debt can span multiple seconds or more. If there are no other subsequent IO issuers, the in-debt iocg may end up blocked paying its debt while the IO device is idle. This patch implements a mechanism to protect against such pathological cases. If the device has been sufficiently idle for a substantial amount of time, the debts are halved. The criteria are on the conservative side as we want to resolve the rare extreme cases without impacting regular operation by forgiving debts too readily. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- block/blk-iocost.c | 49 +++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 48 insertions(+), 1 deletion(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index 9cb8f29f01f5..2a95a081cf44 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -295,6 +295,13 @@ enum { MIN_DELAY = 250, MAX_DELAY = 250 * USEC_PER_MSEC, + /* + * Halve debts if total usage keeps staying under 25% w/o any shortages + * for over 100ms. + */ + DEBT_BUSY_USAGE_PCT = 25, + DEBT_REDUCTION_IDLE_DUR = 100 * USEC_PER_MSEC, + /* don't let cmds which take a very long time pin lagging for too long */ MAX_LAGGING_PERIODS = 10, @@ -436,6 +443,9 @@ struct ioc { bool weights_updated; atomic_t hweight_gen; /* for lazy hweights */ + /* the last time debt cancel condition wasn't met */ + u64 debt_busy_at; + u64 autop_too_fast_at; u64 autop_too_slow_at; int autop_idx; @@ -1216,6 +1226,7 @@ static bool iocg_activate(struct ioc_gq *iocg, struct ioc_now *now) if (ioc->running == IOC_IDLE) { ioc->running = IOC_RUNNING; + ioc->debt_busy_at = now->now; ioc_start_period(ioc, now); } @@ -1896,7 +1907,8 @@ static void ioc_timer_fn(struct timer_list *timer) struct ioc_gq *iocg, *tiocg; struct ioc_now now; LIST_HEAD(surpluses); - int nr_shortages = 0, nr_lagging = 0; + int nr_debtors = 0, nr_shortages = 0, nr_lagging = 0; + u64 usage_us_sum = 0; u32 ppm_rthr = MILLION - ioc->params.qos[QOS_RPPM]; u32 ppm_wthr = MILLION - ioc->params.qos[QOS_WPPM]; u32 missed_ppm[2], rq_wait_pct; @@ -1936,6 +1948,8 @@ static void ioc_timer_fn(struct timer_list *timer) iocg->delay) { /* might be oversleeping vtime / hweight changes, kick */ iocg_kick_waitq(iocg, true, &now); + if (iocg->abs_vdebt) + nr_debtors++; } else if (iocg_is_idle(iocg)) { /* no waiter and idle, deactivate */ __propagate_weights(iocg, 0, 0, false, &now); @@ -1978,6 +1992,7 @@ static void ioc_timer_fn(struct timer_list *timer) * high-latency completions appearing as idle. */ usage_us = iocg->usage_delta_us; + usage_us_sum += usage_us; if (vdone != vtime) { u64 inflight_us = DIV64_U64_ROUND_UP( @@ -2036,6 +2051,38 @@ static void ioc_timer_fn(struct timer_list *timer) list_for_each_entry_safe(iocg, tiocg, &surpluses, surplus_list) list_del_init(&iocg->surplus_list); + /* + * A low weight iocg can amass a large amount of debt, for example, when + * anonymous memory gets reclaimed aggressively. If the system has a lot + * of memory paired with a slow IO device, the debt can span multiple + * seconds or more. If there are no other subsequent IO issuers, the + * in-debt iocg may end up blocked paying its debt while the IO device + * is idle. + * + * The following protects against such pathological cases. If the device + * has been sufficiently idle for a substantial amount of time, the + * debts are halved. The criteria are on the conservative side as we + * want to resolve the rare extreme cases without impacting regular + * operation by forgiving debts too readily. + */ + if (nr_shortages || + div64_u64(100 * usage_us_sum, now.now - ioc->period_at) >= + DEBT_BUSY_USAGE_PCT) + ioc->debt_busy_at = now.now; + + if (nr_debtors && + now.now - ioc->debt_busy_at >= DEBT_REDUCTION_IDLE_DUR) { + list_for_each_entry(iocg, &ioc->active_iocgs, active_list) { + if (iocg->abs_vdebt) { + spin_lock(&iocg->waitq.lock); + iocg->abs_vdebt /= 2; + iocg_kick_waitq(iocg, true, &now); + spin_unlock(&iocg->waitq.lock); + } + } + ioc->debt_busy_at = now.now; + } + /* * If q is getting clogged or we're missing too much, we're issuing * too much IO and should lower vtime rate. If we're not missing From ac33e91e2daca40fcad66c68712276da7b40f169 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 1 Sep 2020 14:52:54 -0400 Subject: [PATCH 045/191] blk-iocost: implement vtime loss compensation When an iocg accumulates too much vtime or gets deactivated, we throw away some vtime, which lowers the overall device utilization. As the exact amount which is being thrown away is known, we can compensate by accelerating the vrate accordingly so that the extra vtime generated in the current period matches what got lost. This significantly improves work conservation when involving high weight cgroups with intermittent and bursty IO patterns. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- block/blk-iocost.c | 132 ++++++++++++++++++++++++++++++--------------- 1 file changed, 90 insertions(+), 42 deletions(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index 2a95a081cf44..0270a504e6b5 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -224,20 +224,12 @@ enum { MARGIN_MIN_PCT = 10, MARGIN_LOW_PCT = 20, MARGIN_TARGET_PCT = 50, - MARGIN_MAX_PCT = 100, INUSE_ADJ_STEP_PCT = 25, /* Have some play in timer operations */ TIMER_SLACK_PCT = 1, - /* - * vtime can wrap well within a reasonable uptime when vrate is - * consistently raised. Don't trust recorded cgroup vtime if the - * period counter indicates that it's older than 5mins. - */ - VTIME_VALID_DUR = 300 * USEC_PER_SEC, - /* 1/64k is granular enough and can easily be handled w/ u32 */ WEIGHT_ONE = 1 << 16, @@ -395,7 +387,6 @@ struct ioc_margins { s64 min; s64 low; s64 target; - s64 max; }; struct ioc_missed { @@ -432,6 +423,8 @@ struct ioc { enum ioc_running running; atomic64_t vtime_rate; + u64 vtime_base_rate; + s64 vtime_err; seqcount_spinlock_t period_seqcount; u64 period_at; /* wallclock starttime */ @@ -760,12 +753,11 @@ static void ioc_refresh_margins(struct ioc *ioc) { struct ioc_margins *margins = &ioc->margins; u32 period_us = ioc->period_us; - u64 vrate = atomic64_read(&ioc->vtime_rate); + u64 vrate = ioc->vtime_base_rate; margins->min = (period_us * MARGIN_MIN_PCT / 100) * vrate; margins->low = (period_us * MARGIN_LOW_PCT / 100) * vrate; margins->target = (period_us * MARGIN_TARGET_PCT / 100) * vrate; - margins->max = (period_us * MARGIN_MAX_PCT / 100) * vrate; } /* latency Qos params changed, update period_us and all the dependent params */ @@ -831,8 +823,7 @@ static int ioc_autop_idx(struct ioc *ioc) return idx; /* step up/down based on the vrate */ - vrate_pct = div64_u64(atomic64_read(&ioc->vtime_rate) * 100, - VTIME_PER_USEC); + vrate_pct = div64_u64(ioc->vtime_base_rate * 100, VTIME_PER_USEC); now_ns = ktime_get_ns(); if (p->too_fast_vrate_pct && p->too_fast_vrate_pct <= vrate_pct) { @@ -940,6 +931,43 @@ static bool ioc_refresh_params(struct ioc *ioc, bool force) return true; } +/* + * When an iocg accumulates too much vtime or gets deactivated, we throw away + * some vtime, which lowers the overall device utilization. As the exact amount + * which is being thrown away is known, we can compensate by accelerating the + * vrate accordingly so that the extra vtime generated in the current period + * matches what got lost. + */ +static void ioc_refresh_vrate(struct ioc *ioc, struct ioc_now *now) +{ + s64 pleft = ioc->period_at + ioc->period_us - now->now; + s64 vperiod = ioc->period_us * ioc->vtime_base_rate; + s64 vcomp, vcomp_min, vcomp_max; + + lockdep_assert_held(&ioc->lock); + + /* we need some time left in this period */ + if (pleft <= 0) + goto done; + + /* + * Calculate how much vrate should be adjusted to offset the error. + * Limit the amount of adjustment and deduct the adjusted amount from + * the error. + */ + vcomp = -div64_s64(ioc->vtime_err, pleft); + vcomp_min = -(ioc->vtime_base_rate >> 1); + vcomp_max = ioc->vtime_base_rate; + vcomp = clamp(vcomp, vcomp_min, vcomp_max); + + ioc->vtime_err += vcomp * pleft; + + atomic64_set(&ioc->vtime_rate, ioc->vtime_base_rate + vcomp); +done: + /* bound how much error can accumulate */ + ioc->vtime_err = clamp(ioc->vtime_err, -vperiod, vperiod); +} + /* take a snapshot of the current [v]time and vrate */ static void ioc_now(struct ioc *ioc, struct ioc_now *now) { @@ -1152,8 +1180,8 @@ static void weight_updated(struct ioc_gq *iocg, struct ioc_now *now) static bool iocg_activate(struct ioc_gq *iocg, struct ioc_now *now) { struct ioc *ioc = iocg->ioc; - u64 last_period, cur_period, max_period_delta; - u64 vtime, vmin; + u64 last_period, cur_period; + u64 vtime, vtarget; int i; /* @@ -1192,21 +1220,15 @@ static bool iocg_activate(struct ioc_gq *iocg, struct ioc_now *now) goto fail_unlock; /* - * vtime may wrap when vrate is raised substantially due to - * underestimated IO costs. Look at the period and ignore its - * vtime if the iocg has been idle for too long. Also, cap the - * budget it can start with to the margin. + * Always start with the target budget. On deactivation, we throw away + * anything above it. */ - max_period_delta = DIV64_U64_ROUND_UP(VTIME_VALID_DUR, ioc->period_us); + vtarget = now->vnow - ioc->margins.target; vtime = atomic64_read(&iocg->vtime); - vmin = now->vnow - ioc->margins.max; - if (last_period + max_period_delta < cur_period || - time_before64(vtime, vmin)) { - atomic64_add(vmin - vtime, &iocg->vtime); - atomic64_add(vmin - vtime, &iocg->done_vtime); - vtime = vmin; - } + atomic64_add(vtarget - vtime, &iocg->vtime); + atomic64_add(vtarget - vtime, &iocg->done_vtime); + vtime = vtarget; /* * Activate, propagate weight and start period timer if not @@ -1260,7 +1282,8 @@ static bool iocg_kick_delay(struct ioc_gq *iocg, struct ioc_now *now) current_hweight(iocg, &hwa, NULL); vover = atomic64_read(&iocg->vtime) + abs_cost_to_cost(iocg->abs_vdebt, hwa) - now->vnow; - vover_pct = div64_s64(100 * vover, ioc->period_us * now->vrate); + vover_pct = div64_s64(100 * vover, + ioc->period_us * ioc->vtime_base_rate); if (vover_pct <= MIN_DELAY_THR_PCT) new_delay = 0; @@ -1421,7 +1444,8 @@ static void iocg_kick_waitq(struct ioc_gq *iocg, bool pay_debt, /* determine next wakeup, add a timer margin to guarantee chunking */ vshortage = -ctx.vbudget; expires = now->now_ns + - DIV64_U64_ROUND_UP(vshortage, now->vrate) * NSEC_PER_USEC; + DIV64_U64_ROUND_UP(vshortage, ioc->vtime_base_rate) * + NSEC_PER_USEC; expires += ioc->timer_slack_ns; /* if already active and close enough, don't bother */ @@ -1536,6 +1560,7 @@ static void iocg_build_inner_walk(struct ioc_gq *iocg, /* collect per-cpu counters and propagate the deltas to the parent */ static void iocg_flush_stat_one(struct ioc_gq *iocg, struct ioc_now *now) { + struct ioc *ioc = iocg->ioc; struct iocg_stat new_stat; u64 abs_vusage = 0; u64 vusage_delta; @@ -1551,7 +1576,7 @@ static void iocg_flush_stat_one(struct ioc_gq *iocg, struct ioc_now *now) vusage_delta = abs_vusage - iocg->last_stat_abs_vusage; iocg->last_stat_abs_vusage = abs_vusage; - iocg->usage_delta_us = div64_u64(vusage_delta, now->vrate); + iocg->usage_delta_us = div64_u64(vusage_delta, ioc->vtime_base_rate); iocg->local_stat.usage_us += iocg->usage_delta_us; new_stat.usage_us = @@ -1593,8 +1618,8 @@ static void iocg_flush_stat(struct list_head *target_iocgs, struct ioc_now *now) * capacity. @hwm is the upper bound and used to signal no donation. This * function also throws away @iocg's excess budget. */ -static u32 hweight_after_donation(struct ioc_gq *iocg, u32 hwm, u32 usage, - struct ioc_now *now) +static u32 hweight_after_donation(struct ioc_gq *iocg, u32 old_hwi, u32 hwm, + u32 usage, struct ioc_now *now) { struct ioc *ioc = iocg->ioc; u64 vtime = atomic64_read(&iocg->vtime); @@ -1609,12 +1634,13 @@ static u32 hweight_after_donation(struct ioc_gq *iocg, u32 hwm, u32 usage, time_after64(vtime, now->vnow - ioc->margins.min)) return hwm; - /* throw away excess above max */ - excess = now->vnow - vtime - ioc->margins.max; + /* throw away excess above target */ + excess = now->vnow - vtime - ioc->margins.target; if (excess > 0) { atomic64_add(excess, &iocg->vtime); atomic64_add(excess, &iocg->done_vtime); vtime += excess; + ioc->vtime_err -= div64_u64(excess * old_hwi, WEIGHT_ONE); } /* @@ -1952,6 +1978,24 @@ static void ioc_timer_fn(struct timer_list *timer) nr_debtors++; } else if (iocg_is_idle(iocg)) { /* no waiter and idle, deactivate */ + u64 vtime = atomic64_read(&iocg->vtime); + s64 excess; + + /* + * @iocg has been inactive for a full duration and will + * have a high budget. Account anything above target as + * error and throw away. On reactivation, it'll start + * with the target budget. + */ + excess = now.vnow - vtime - ioc->margins.target; + if (excess > 0) { + u32 old_hwi; + + current_hweight(iocg, NULL, &old_hwi); + ioc->vtime_err -= div64_u64(excess * old_hwi, + WEIGHT_ONE); + } + __propagate_weights(iocg, 0, 0, false, &now); list_del_init(&iocg->active_list); } @@ -1997,7 +2041,7 @@ static void ioc_timer_fn(struct timer_list *timer) if (vdone != vtime) { u64 inflight_us = DIV64_U64_ROUND_UP( cost_to_abs_cost(vtime - vdone, hw_inuse), - now.vrate); + ioc->vtime_base_rate); usage_us = max(usage_us, inflight_us); } @@ -2017,16 +2061,16 @@ static void ioc_timer_fn(struct timer_list *timer) if (hw_inuse < hw_active || (!waitqueue_active(&iocg->waitq) && time_before64(vtime, now.vnow - ioc->margins.low))) { - u32 hwa, hwm, new_hwi; + u32 hwa, old_hwi, hwm, new_hwi; /* * Already donating or accumulated enough to start. * Determine the donation amount. */ - current_hweight(iocg, &hwa, NULL); + current_hweight(iocg, &hwa, &old_hwi); hwm = current_hweight_max(iocg); - new_hwi = hweight_after_donation(iocg, hwm, usage, - &now); + new_hwi = hweight_after_donation(iocg, old_hwi, hwm, + usage, &now); if (new_hwi < hwm) { iocg->hweight_donating = hwa; iocg->hweight_after_donation = new_hwi; @@ -2130,7 +2174,7 @@ static void ioc_timer_fn(struct timer_list *timer) ioc->busy_level = clamp(ioc->busy_level, -1000, 1000); if (ioc->busy_level > 0 || (ioc->busy_level < 0 && !nr_lagging)) { - u64 vrate = atomic64_read(&ioc->vtime_rate); + u64 vrate = ioc->vtime_base_rate; u64 vrate_min = ioc->vrate_min, vrate_max = ioc->vrate_max; /* rq_wait signal is always reliable, ignore user vrate_min */ @@ -2167,7 +2211,7 @@ static void ioc_timer_fn(struct timer_list *timer) trace_iocost_ioc_vrate_adj(ioc, vrate, missed_ppm, rq_wait_pct, nr_lagging, nr_shortages); - atomic64_set(&ioc->vtime_rate, vrate); + ioc->vtime_base_rate = vrate; ioc_refresh_margins(ioc); } else if (ioc->busy_level != prev_busy_level || nr_lagging) { trace_iocost_ioc_vrate_adj(ioc, atomic64_read(&ioc->vtime_rate), @@ -2188,8 +2232,11 @@ static void ioc_timer_fn(struct timer_list *timer) ioc_start_period(ioc, &now); } else { ioc->busy_level = 0; + ioc->vtime_err = 0; ioc->running = IOC_IDLE; } + + ioc_refresh_vrate(ioc, &now); } spin_unlock_irq(&ioc->lock); @@ -2628,6 +2675,7 @@ static int blk_iocost_init(struct request_queue *q) INIT_LIST_HEAD(&ioc->active_iocgs); ioc->running = IOC_IDLE; + ioc->vtime_base_rate = VTIME_PER_USEC; atomic64_set(&ioc->vtime_rate, VTIME_PER_USEC); seqcount_spinlock_init(&ioc->period_seqcount, &ioc->lock); ioc->period_at = ktime_to_us(ktime_get()); @@ -2762,7 +2810,7 @@ static size_t ioc_pd_stat(struct blkg_policy_data *pd, char *buf, size_t size) if (iocg->level == 0) { unsigned vp10k = DIV64_U64_ROUND_CLOSEST( - atomic64_read(&ioc->vtime_rate) * 10000, + ioc->vtime_base_rate * 10000, VTIME_PER_USEC); pos += scnprintf(buf + pos, size - pos, " cost.vrate=%u.%02u", vp10k / 100, vp10k % 100); From 046037551721e8831f6718ac2149887f6bb1f802 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 1 Sep 2020 14:52:55 -0400 Subject: [PATCH 046/191] blk-iocost: restore inuse update tracepoints Update and restore the inuse update tracepoints. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- block/blk-iocost.c | 16 ++++++++++++++++ include/trace/events/iocost.h | 6 +++--- 2 files changed, 19 insertions(+), 3 deletions(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index 0270a504e6b5..9366527d8c12 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -1919,6 +1919,12 @@ static void transfer_surpluses(struct list_head *surpluses, struct ioc_now *now) inuse = DIV64_U64_ROUND_UP( parent->child_adjusted_sum * iocg->hweight_after_donation, parent->hweight_inuse); + + TRACE_IOCG_PATH(inuse_transfer, iocg, now, + iocg->inuse, inuse, + iocg->hweight_inuse, + iocg->hweight_after_donation); + __propagate_weights(iocg, iocg->active, inuse, true, now); } @@ -2076,6 +2082,10 @@ static void ioc_timer_fn(struct timer_list *timer) iocg->hweight_after_donation = new_hwi; list_add(&iocg->surplus_list, &surpluses); } else { + TRACE_IOCG_PATH(inuse_shortage, iocg, &now, + iocg->inuse, iocg->active, + iocg->hweight_inuse, new_hwi); + __propagate_weights(iocg, iocg->active, iocg->active, true, &now); nr_shortages++; @@ -2248,11 +2258,13 @@ static u64 adjust_inuse_and_calc_cost(struct ioc_gq *iocg, u64 vtime, struct ioc *ioc = iocg->ioc; struct ioc_margins *margins = &ioc->margins; u32 adj_step = DIV_ROUND_UP(iocg->active * INUSE_ADJ_STEP_PCT, 100); + u32 __maybe_unused old_inuse = iocg->inuse, __maybe_unused old_hwi; u32 hwi; s64 margin; u64 cost, new_inuse; current_hweight(iocg, NULL, &hwi); + old_hwi = hwi; cost = abs_cost_to_cost(abs_cost, hwi); margin = now->vnow - vtime - cost; @@ -2287,6 +2299,10 @@ static u64 adjust_inuse_and_calc_cost(struct ioc_gq *iocg, u64 vtime, iocg->inuse != iocg->active); spin_unlock_irq(&ioc->lock); + + TRACE_IOCG_PATH(inuse_adjust, iocg, now, + old_inuse, iocg->inuse, old_hwi, hwi); + return cost; } diff --git a/include/trace/events/iocost.h b/include/trace/events/iocost.h index ee024fe8fef6..b350860d2e71 100644 --- a/include/trace/events/iocost.h +++ b/include/trace/events/iocost.h @@ -95,7 +95,7 @@ DECLARE_EVENT_CLASS(iocg_inuse_update, ) ); -DEFINE_EVENT(iocg_inuse_update, iocost_inuse_takeback, +DEFINE_EVENT(iocg_inuse_update, iocost_inuse_shortage, TP_PROTO(struct ioc_gq *iocg, const char *path, struct ioc_now *now, u32 old_inuse, u32 new_inuse, @@ -105,7 +105,7 @@ DEFINE_EVENT(iocg_inuse_update, iocost_inuse_takeback, old_hw_inuse, new_hw_inuse) ); -DEFINE_EVENT(iocg_inuse_update, iocost_inuse_giveaway, +DEFINE_EVENT(iocg_inuse_update, iocost_inuse_transfer, TP_PROTO(struct ioc_gq *iocg, const char *path, struct ioc_now *now, u32 old_inuse, u32 new_inuse, @@ -115,7 +115,7 @@ DEFINE_EVENT(iocg_inuse_update, iocost_inuse_giveaway, old_hw_inuse, new_hw_inuse) ); -DEFINE_EVENT(iocg_inuse_update, iocost_inuse_reset, +DEFINE_EVENT(iocg_inuse_update, iocost_inuse_adjust, TP_PROTO(struct ioc_gq *iocg, const char *path, struct ioc_now *now, u32 old_inuse, u32 new_inuse, From f0bf84a5dffa0800c4f8ae52a75c579978086901 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 1 Sep 2020 14:52:56 -0400 Subject: [PATCH 047/191] blk-iocost: add three debug stat - cost.wait, indebt and indelay These are really cheap to collect and can be useful in debugging iocost behavior. Add them as debug stats for now. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- block/blk-iocost.c | 77 +++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 72 insertions(+), 5 deletions(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index 9366527d8c12..fc897bb142bc 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -452,6 +452,9 @@ struct iocg_pcpu_stat { struct iocg_stat { u64 usage_us; + u64 wait_us; + u64 indebt_us; + u64 indelay_us; }; /* per device-cgroup pair */ @@ -538,6 +541,9 @@ struct ioc_gq { struct iocg_stat last_stat; u64 last_stat_abs_vusage; u64 usage_delta_us; + u64 wait_since; + u64 indebt_since; + u64 indelay_since; /* this iocg's depth in the hierarchy and ancestors including self */ int level; @@ -1303,9 +1309,15 @@ static bool iocg_kick_delay(struct ioc_gq *iocg, struct ioc_now *now) } if (delay >= MIN_DELAY) { + if (!iocg->indelay_since) + iocg->indelay_since = now->now; blkcg_set_delay(blkg, delay * NSEC_PER_USEC); return true; } else { + if (iocg->indelay_since) { + iocg->local_stat.indelay_us += now->now - iocg->indelay_since; + iocg->indelay_since = 0; + } iocg->delay = 0; blkcg_clear_delay(blkg); return false; @@ -1325,8 +1337,10 @@ static void iocg_incur_debt(struct ioc_gq *iocg, u64 abs_cost, * Once in debt, debt handling owns inuse. @iocg stays at the minimum * inuse donating all of it share to others until its debt is paid off. */ - if (!iocg->abs_vdebt && abs_cost) + if (!iocg->abs_vdebt && abs_cost) { + iocg->indebt_since = now->now; propagate_weights(iocg, iocg->active, 0, false, now); + } iocg->abs_vdebt += abs_cost; @@ -1348,9 +1362,13 @@ static void iocg_pay_debt(struct ioc_gq *iocg, u64 abs_vpay, iocg->abs_vdebt -= min(abs_vpay, iocg->abs_vdebt); /* if debt is paid in full, restore inuse */ - if (!iocg->abs_vdebt) + if (!iocg->abs_vdebt) { + iocg->local_stat.indebt_us += now->now - iocg->indebt_since; + iocg->indebt_since = 0; + propagate_weights(iocg, iocg->active, iocg->last_inuse, false, now); + } } static int iocg_wake_fn(struct wait_queue_entry *wq_entry, unsigned mode, @@ -1436,8 +1454,17 @@ static void iocg_kick_waitq(struct ioc_gq *iocg, bool pay_debt, __wake_up_locked_key(&iocg->waitq, TASK_NORMAL, &ctx); - if (!waitqueue_active(&iocg->waitq)) + if (!waitqueue_active(&iocg->waitq)) { + if (iocg->wait_since) { + iocg->local_stat.wait_us += now->now - iocg->wait_since; + iocg->wait_since = 0; + } return; + } + + if (!iocg->wait_since) + iocg->wait_since = now->now; + if (WARN_ON_ONCE(ctx.vbudget >= 0)) return; @@ -1579,8 +1606,15 @@ static void iocg_flush_stat_one(struct ioc_gq *iocg, struct ioc_now *now) iocg->usage_delta_us = div64_u64(vusage_delta, ioc->vtime_base_rate); iocg->local_stat.usage_us += iocg->usage_delta_us; + /* propagate upwards */ new_stat.usage_us = iocg->local_stat.usage_us + iocg->desc_stat.usage_us; + new_stat.wait_us = + iocg->local_stat.wait_us + iocg->desc_stat.wait_us; + new_stat.indebt_us = + iocg->local_stat.indebt_us + iocg->desc_stat.indebt_us; + new_stat.indelay_us = + iocg->local_stat.indelay_us + iocg->desc_stat.indelay_us; /* propagate the deltas to the parent */ if (iocg->level > 0) { @@ -1589,6 +1623,12 @@ static void iocg_flush_stat_one(struct ioc_gq *iocg, struct ioc_now *now) parent_stat->usage_us += new_stat.usage_us - iocg->last_stat.usage_us; + parent_stat->wait_us += + new_stat.wait_us - iocg->last_stat.wait_us; + parent_stat->indebt_us += + new_stat.indebt_us - iocg->last_stat.indebt_us; + parent_stat->indelay_us += + new_stat.indelay_us - iocg->last_stat.indelay_us; } iocg->last_stat = new_stat; @@ -1961,8 +2001,6 @@ static void ioc_timer_fn(struct timer_list *timer) return; } - iocg_flush_stat(&ioc->active_iocgs, &now); - /* * Waiters determine the sleep durations based on the vrate they * saw at the time of sleep. If vrate has increased, some waiters @@ -1976,6 +2014,22 @@ static void ioc_timer_fn(struct timer_list *timer) spin_lock(&iocg->waitq.lock); + /* flush wait and indebt stat deltas */ + if (iocg->wait_since) { + iocg->local_stat.wait_us += now.now - iocg->wait_since; + iocg->wait_since = now.now; + } + if (iocg->indebt_since) { + iocg->local_stat.indebt_us += + now.now - iocg->indebt_since; + iocg->indebt_since = now.now; + } + if (iocg->indelay_since) { + iocg->local_stat.indelay_us += + now.now - iocg->indelay_since; + iocg->indelay_since = now.now; + } + if (waitqueue_active(&iocg->waitq) || iocg->abs_vdebt || iocg->delay) { /* might be oversleeping vtime / hweight changes, kick */ @@ -2010,6 +2064,12 @@ static void ioc_timer_fn(struct timer_list *timer) } commit_weights(ioc); + /* + * Wait and indebt stat are flushed above and the donation calculation + * below needs updated usage stat. Let's bring stat up-to-date. + */ + iocg_flush_stat(&ioc->active_iocgs, &now); + /* calc usage and see whether some weights need to be moved around */ list_for_each_entry(iocg, &ioc->active_iocgs, active_list) { u64 vdone, vtime, usage_us, usage_dur; @@ -2835,6 +2895,13 @@ static size_t ioc_pd_stat(struct blkg_policy_data *pd, char *buf, size_t size) pos += scnprintf(buf + pos, size - pos, " cost.usage=%llu", iocg->last_stat.usage_us); + if (blkcg_debug_stats) + pos += scnprintf(buf + pos, size - pos, + " cost.wait=%llu cost.indebt=%llu cost.indelay=%llu", + iocg->last_stat.wait_us, + iocg->last_stat.indebt_us, + iocg->last_stat.indelay_us); + return pos; } From a7863b3423fd5d1ab82161654ba83973764b570b Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 1 Sep 2020 14:52:57 -0400 Subject: [PATCH 048/191] blk-iocost: update iocost_monitor.py iocost went through significant internal changes. Update iocost_monitor.py accordingly. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- tools/cgroup/iocost_monitor.py | 54 ++++++++++++---------------------- 1 file changed, 19 insertions(+), 35 deletions(-) diff --git a/tools/cgroup/iocost_monitor.py b/tools/cgroup/iocost_monitor.py index f4699f9b46ba..c4ff907c078b 100644 --- a/tools/cgroup/iocost_monitor.py +++ b/tools/cgroup/iocost_monitor.py @@ -45,8 +45,7 @@ except: err('The kernel does not have iocost enabled') IOC_RUNNING = prog['IOC_RUNNING'].value_() -NR_USAGE_SLOTS = prog['NR_USAGE_SLOTS'].value_() -HWEIGHT_WHOLE = prog['HWEIGHT_WHOLE'].value_() +WEIGHT_ONE = prog['WEIGHT_ONE'].value_() VTIME_PER_SEC = prog['VTIME_PER_SEC'].value_() VTIME_PER_USEC = prog['VTIME_PER_USEC'].value_() AUTOP_SSD_FAST = prog['AUTOP_SSD_FAST'].value_() @@ -100,7 +99,7 @@ class IocStat: self.period_ms = ioc.period_us.value_() / 1_000 self.period_at = ioc.period_at.value_() / 1_000_000 self.vperiod_at = ioc.period_at_vtime.value_() / VTIME_PER_SEC - self.vrate_pct = ioc.vtime_rate.counter.value_() * 100 / VTIME_PER_USEC + self.vrate_pct = ioc.vtime_base_rate.value_() * 100 / VTIME_PER_USEC self.busy_level = ioc.busy_level.value_() self.autop_idx = ioc.autop_idx.value_() self.user_cost_model = ioc.user_cost_model.value_() @@ -136,7 +135,7 @@ class IocStat: def table_header_str(self): return f'{"":25} active {"weight":>9} {"hweight%":>13} {"inflt%":>6} ' \ - f'{"dbt":>3} {"delay":>6} {"usages%"}' + f'{"debt":>7} {"delay":>7} {"usage%"}' class IocgStat: def __init__(self, iocg): @@ -144,11 +143,11 @@ class IocgStat: blkg = iocg.pd.blkg self.is_active = not list_empty(iocg.active_list.address_of_()) - self.weight = iocg.weight.value_() - self.active = iocg.active.value_() - self.inuse = iocg.inuse.value_() - self.hwa_pct = iocg.hweight_active.value_() * 100 / HWEIGHT_WHOLE - self.hwi_pct = iocg.hweight_inuse.value_() * 100 / HWEIGHT_WHOLE + self.weight = iocg.weight.value_() / WEIGHT_ONE + self.active = iocg.active.value_() / WEIGHT_ONE + self.inuse = iocg.inuse.value_() / WEIGHT_ONE + self.hwa_pct = iocg.hweight_active.value_() * 100 / WEIGHT_ONE + self.hwi_pct = iocg.hweight_inuse.value_() * 100 / WEIGHT_ONE self.address = iocg.value_() vdone = iocg.done_vtime.counter.value_() @@ -160,23 +159,13 @@ class IocgStat: else: self.inflight_pct = 0 - # vdebt used to be an atomic64_t and is now u64, support both - try: - self.debt_ms = iocg.abs_vdebt.counter.value_() / VTIME_PER_USEC / 1000 - except: - self.debt_ms = iocg.abs_vdebt.value_() / VTIME_PER_USEC / 1000 - - self.use_delay = blkg.use_delay.counter.value_() - self.delay_ms = blkg.delay_nsec.counter.value_() / 1_000_000 - - usage_idx = iocg.usage_idx.value_() - self.usages = [] - self.usage = 0 - for i in range(NR_USAGE_SLOTS): - usage = iocg.usages[(usage_idx + 1 + i) % NR_USAGE_SLOTS].value_() - upct = usage * 100 / HWEIGHT_WHOLE - self.usages.append(upct) - self.usage = max(self.usage, upct) + self.usage = (100 * iocg.usage_delta_us.value_() / + ioc.period_us.value_()) if self.active else 0 + self.debt_ms = iocg.abs_vdebt.value_() / VTIME_PER_USEC / 1000 + if blkg.use_delay.counter.value_() != 0: + self.delay_ms = blkg.delay_nsec.counter.value_() / 1_000_000 + else: + self.delay_ms = 0 def dict(self, now, path): out = { 'cgroup' : path, @@ -189,25 +178,20 @@ class IocgStat: 'hweight_inuse_pct' : self.hwi_pct, 'inflight_pct' : self.inflight_pct, 'debt_ms' : self.debt_ms, - 'use_delay' : self.use_delay, 'delay_ms' : self.delay_ms, 'usage_pct' : self.usage, 'address' : self.address } - for i in range(len(self.usages)): - out[f'usage_pct_{i}'] = str(self.usages[i]) return out def table_row_str(self, path): out = f'{path[-28:]:28} ' \ f'{"*" if self.is_active else " "} ' \ - f'{self.inuse:5}/{self.active:5} ' \ + f'{round(self.inuse):5}/{round(self.active):5} ' \ f'{self.hwi_pct:6.2f}/{self.hwa_pct:6.2f} ' \ f'{self.inflight_pct:6.2f} ' \ - f'{min(math.ceil(self.debt_ms), 999):3} ' \ - f'{min(self.use_delay, 99):2}*'\ - f'{min(math.ceil(self.delay_ms), 999):03} ' - for u in self.usages: - out += f'{min(round(u), 999):03d}:' + f'{self.debt_ms:7.2f} ' \ + f'{self.delay_ms:7.2f} '\ + f'{min(self.usage, 999):6.2f}' out = out.rstrip(':') return out From 9d3a39a5f1e45827b008fff1ee9cf3cac3409665 Mon Sep 17 00:00:00 2001 From: Khazhismel Kumykov Date: Mon, 24 Aug 2020 15:10:34 -0700 Subject: [PATCH 049/191] block: grant IOPRIO_CLASS_RT to CAP_SYS_NICE CAP_SYS_ADMIN is too broad, and ionice fits into CAP_SYS_NICE's grouping. Retain CAP_SYS_ADMIN permission for backwards compatibility. Signed-off-by: Khazhismel Kumykov Reviewed-by: Bart Van Assche Acked-by: Serge Hallyn Signed-off-by: Jens Axboe --- block/ioprio.c | 2 +- include/uapi/linux/capability.h | 2 ++ 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/block/ioprio.c b/block/ioprio.c index 04ebd37966f1..364d2294ba90 100644 --- a/block/ioprio.c +++ b/block/ioprio.c @@ -69,7 +69,7 @@ int ioprio_check_cap(int ioprio) switch (class) { case IOPRIO_CLASS_RT: - if (!capable(CAP_SYS_ADMIN)) + if (!capable(CAP_SYS_NICE) && !capable(CAP_SYS_ADMIN)) return -EPERM; fallthrough; /* rt has prio field too */ diff --git a/include/uapi/linux/capability.h b/include/uapi/linux/capability.h index 395dd0df8d08..c6ca33034147 100644 --- a/include/uapi/linux/capability.h +++ b/include/uapi/linux/capability.h @@ -288,6 +288,8 @@ struct vfs_ns_cap_data { processes and setting the scheduling algorithm used by another process. */ /* Allow setting cpu affinity on other processes */ +/* Allow setting realtime ioprio class */ +/* Allow setting ioprio class on other processes */ #define CAP_SYS_NICE 23 From 143d2600faf1563fd4125686ab84afaab5fb513b Mon Sep 17 00:00:00 2001 From: Ritika Srivastava Date: Tue, 1 Sep 2020 13:17:30 -0700 Subject: [PATCH 050/191] block: Return blk_status_t instead of errno codes Replace returning legacy errno codes with blk_status_t in blk_cloned_rq_check_limits(). Signed-off-by: Ritika Srivastava Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/blk-core.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 062efdedc994..3fbb5b2d5385 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1145,14 +1145,14 @@ EXPORT_SYMBOL(submit_bio); * limits when retrying requests on other queues. Those requests need * to be checked against the new queue limits again during dispatch. */ -static int blk_cloned_rq_check_limits(struct request_queue *q, +static blk_status_t blk_cloned_rq_check_limits(struct request_queue *q, struct request *rq) { if (blk_rq_sectors(rq) > blk_queue_get_max_sectors(q, req_op(rq))) { printk(KERN_ERR "%s: over max size limit. (%u > %u)\n", __func__, blk_rq_sectors(rq), blk_queue_get_max_sectors(q, req_op(rq))); - return -EIO; + return BLK_STS_IOERR; } /* @@ -1165,10 +1165,10 @@ static int blk_cloned_rq_check_limits(struct request_queue *q, if (rq->nr_phys_segments > queue_max_segments(q)) { printk(KERN_ERR "%s: over max segments limit. (%hu > %hu)\n", __func__, rq->nr_phys_segments, queue_max_segments(q)); - return -EIO; + return BLK_STS_IOERR; } - return 0; + return BLK_STS_OK; } /** From 8327cce5ff9376fac9ff713a8d5c99c16ba3fa33 Mon Sep 17 00:00:00 2001 From: Ritika Srivastava Date: Tue, 1 Sep 2020 13:17:31 -0700 Subject: [PATCH 051/191] block: better deal with the delayed not supported case in blk_cloned_rq_check_limits If WRITE_ZERO/WRITE_SAME operation is not supported by the storage, blk_cloned_rq_check_limits() will return IO error which will cause device-mapper to fail the paths. Instead, if the queue limit is set to 0, return BLK_STS_NOTSUPP. BLK_STS_NOTSUPP will be ignored by device-mapper and will not fail the paths. Suggested-by: Martin K. Petersen Signed-off-by: Ritika Srivastava Reviewed-by: Martin K. Petersen Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/blk-core.c | 27 ++++++++++++++++++++++----- 1 file changed, 22 insertions(+), 5 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 3fbb5b2d5385..9f2a99abeeb9 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1148,10 +1148,24 @@ EXPORT_SYMBOL(submit_bio); static blk_status_t blk_cloned_rq_check_limits(struct request_queue *q, struct request *rq) { - if (blk_rq_sectors(rq) > blk_queue_get_max_sectors(q, req_op(rq))) { + unsigned int max_sectors = blk_queue_get_max_sectors(q, req_op(rq)); + + if (blk_rq_sectors(rq) > max_sectors) { + /* + * SCSI device does not have a good way to return if + * Write Same/Zero is actually supported. If a device rejects + * a non-read/write command (discard, write same,etc.) the + * low-level device driver will set the relevant queue limit to + * 0 to prevent blk-lib from issuing more of the offending + * operations. Commands queued prior to the queue limit being + * reset need to be completed with BLK_STS_NOTSUPP to avoid I/O + * errors being propagated to upper layers. + */ + if (max_sectors == 0) + return BLK_STS_NOTSUPP; + printk(KERN_ERR "%s: over max size limit. (%u > %u)\n", - __func__, blk_rq_sectors(rq), - blk_queue_get_max_sectors(q, req_op(rq))); + __func__, blk_rq_sectors(rq), max_sectors); return BLK_STS_IOERR; } @@ -1178,8 +1192,11 @@ static blk_status_t blk_cloned_rq_check_limits(struct request_queue *q, */ blk_status_t blk_insert_cloned_request(struct request_queue *q, struct request *rq) { - if (blk_cloned_rq_check_limits(q, rq)) - return BLK_STS_IOERR; + blk_status_t ret; + + ret = blk_cloned_rq_check_limits(q, rq); + if (ret != BLK_STS_OK) + return ret; if (rq->rq_disk && should_fail_request(&rq->rq_disk->part0, blk_rq_bytes(rq))) From 265600b7b6e88f3cc4cef2774afe0eb4abe72d72 Mon Sep 17 00:00:00 2001 From: Baolin Wang Date: Wed, 2 Sep 2020 09:45:25 +0800 Subject: [PATCH 052/191] block: Remove a duplicative condition Remove a duplicative condition to remove below cppcheck warnings: "warning: Redundant condition: sched_allow_merge. '!A || (A && B)' is equivalent to '!A || B' [redundantCondition]" Reported-by: kernel test robot Signed-off-by: Baolin Wang Signed-off-by: Jens Axboe --- block/blk-merge.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/block/blk-merge.c b/block/blk-merge.c index 80c974484a3f..6ed715835d45 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -996,13 +996,11 @@ static enum bio_merge_status blk_attempt_bio_merge(struct request_queue *q, switch (blk_try_merge(rq, bio)) { case ELEVATOR_BACK_MERGE: - if (!sched_allow_merge || - (sched_allow_merge && blk_mq_sched_allow_merge(q, rq, bio))) + if (!sched_allow_merge || blk_mq_sched_allow_merge(q, rq, bio)) return bio_attempt_back_merge(rq, bio, nr_segs); break; case ELEVATOR_FRONT_MERGE: - if (!sched_allow_merge || - (sched_allow_merge && blk_mq_sched_allow_merge(q, rq, bio))) + if (!sched_allow_merge || blk_mq_sched_allow_merge(q, rq, bio)) return bio_attempt_front_merge(rq, bio, nr_segs); break; case ELEVATOR_DISCARD_MERGE: From 653cd5341968a4648e75b1b359b3316600d50310 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 1 Sep 2020 17:57:40 +0200 Subject: [PATCH 053/191] Documentation/filesystems/locking.rst: remove an incorrect sentence unlock_native_capacity is never called from check_disk_change(), and while revalidate_disk can be called from it, it can also be called from two other places at the moment. Signed-off-by: Christoph Hellwig Reviewed-by: Josef Bacik Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe --- Documentation/filesystems/locking.rst | 3 --- 1 file changed, 3 deletions(-) diff --git a/Documentation/filesystems/locking.rst b/Documentation/filesystems/locking.rst index 64f94a18d97e..c0f2c7586531 100644 --- a/Documentation/filesystems/locking.rst +++ b/Documentation/filesystems/locking.rst @@ -488,9 +488,6 @@ getgeo: no swap_slot_free_notify: no (see below) ======================= =================== -unlock_native_capacity and revalidate_disk are called only from -check_disk_change(). - swap_slot_free_notify is called with swap_lock and sometimes the page lock held. From 6540fbf6b634071950f01ee4e4194e2ea8ca72d1 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 1 Sep 2020 17:57:41 +0200 Subject: [PATCH 054/191] block: don't clear bd_invalidated in check_disk_size_change bd_invalidated is set by check_disk_change or in add_disk to initiate a partition scan. Move it from check_disk_size_change which is called from both revalidate_disk() and bdev_disk_changed() to only the latter, as that is what is called from the block device open code (and nbd) to deal with the bd_invalidated event. revalidate_disk() on the other hand is mostly used to propagate a size update from the gendisk to the block device, which is entirely unrelated. Signed-off-by: Christoph Hellwig Reviewed-by: Josef Bacik Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe --- fs/block_dev.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/block_dev.c b/fs/block_dev.c index 990e97bcbeaf..7e32398608c6 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1302,7 +1302,6 @@ static void check_disk_size_change(struct gendisk *disk, } i_size_write(bdev->bd_inode, disk_size); } - bdev->bd_invalidated = 0; spin_unlock(&bdev->bd_size_lock); if (bdev_size > disk_size) { @@ -1391,6 +1390,8 @@ int bdev_disk_changed(struct block_device *bdev, bool invalidate) lockdep_assert_held(&bdev->bd_mutex); + bdev->bd_invalidated = 0; + rescan: ret = blk_drop_partitions(bdev); if (ret) From f4ad06f2bb8476548b08f89919ee65abc4e40212 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 1 Sep 2020 17:57:42 +0200 Subject: [PATCH 055/191] block: rename bd_invalidated Replace bd_invalidate with a new BDEV_NEED_PART_SCAN flag in a bd_flags variable to better describe the condition. Signed-off-by: Christoph Hellwig Reviewed-by: Josef Bacik Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe --- block/genhd.c | 2 +- drivers/block/nbd.c | 8 ++++---- fs/block_dev.c | 10 +++++----- include/linux/blk_types.h | 4 +++- 4 files changed, 13 insertions(+), 11 deletions(-) diff --git a/block/genhd.c b/block/genhd.c index 5fc6d82e6c68..a36be970b767 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -732,7 +732,7 @@ static void register_disk(struct device *parent, struct gendisk *disk, if (!bdev) goto exit; - bdev->bd_invalidated = 1; + set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags); err = blkdev_get(bdev, FMODE_READ, NULL); if (err < 0) goto exit; diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index a54f2d155a31..15eed210feef 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -315,7 +315,7 @@ static void nbd_size_update(struct nbd_device *nbd) bd_set_nr_sectors(bdev, nr_sectors); set_blocksize(bdev, config->blksize); } else - bdev->bd_invalidated = 1; + set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags); bdput(bdev); } kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE); @@ -1322,7 +1322,7 @@ static int nbd_start_device_ioctl(struct nbd_device *nbd, struct block_device *b return ret; if (max_part) - bdev->bd_invalidated = 1; + set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags); mutex_unlock(&nbd->config_lock); ret = wait_event_interruptible(config->recv_wq, atomic_read(&config->recv_threads) == 0); @@ -1500,9 +1500,9 @@ static int nbd_open(struct block_device *bdev, fmode_t mode) refcount_set(&nbd->config_refs, 1); refcount_inc(&nbd->refs); mutex_unlock(&nbd->config_lock); - bdev->bd_invalidated = 1; + set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags); } else if (nbd_disconnected(nbd->config)) { - bdev->bd_invalidated = 1; + set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags); } out: mutex_unlock(&nbd_index_mutex); diff --git a/fs/block_dev.c b/fs/block_dev.c index 7e32398608c6..1e6441dbe840 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -881,7 +881,7 @@ struct block_device *bdget(dev_t dev) bdev->bd_super = NULL; bdev->bd_inode = inode; bdev->bd_part_count = 0; - bdev->bd_invalidated = 0; + bdev->bd_flags = 0; inode->i_mode = S_IFBLK; inode->i_rdev = dev; inode->i_bdev = bdev; @@ -1365,7 +1365,7 @@ int check_disk_change(struct block_device *bdev) if (__invalidate_device(bdev, true)) pr_warn("VFS: busy inodes on changed media %s\n", disk->disk_name); - bdev->bd_invalidated = 1; + set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags); if (bdops->revalidate_disk) bdops->revalidate_disk(bdev->bd_disk); return 1; @@ -1390,7 +1390,7 @@ int bdev_disk_changed(struct block_device *bdev, bool invalidate) lockdep_assert_held(&bdev->bd_mutex); - bdev->bd_invalidated = 0; + clear_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags); rescan: ret = blk_drop_partitions(bdev); @@ -1514,7 +1514,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder, * The latter is necessary to prevent ghost * partitions on a removed medium. */ - if (bdev->bd_invalidated && + if (test_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags) && (!ret || ret == -ENOMEDIUM)) bdev_disk_changed(bdev, ret == -ENOMEDIUM); @@ -1544,7 +1544,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder, if (bdev->bd_disk->fops->open) ret = bdev->bd_disk->fops->open(bdev, mode); /* the same as first opener case, read comment there */ - if (bdev->bd_invalidated && + if (test_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags) && (!ret || ret == -ENOMEDIUM)) bdev_disk_changed(bdev, ret == -ENOMEDIUM); if (ret) diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 59d9150165c4..6ffa783e1633 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -19,6 +19,8 @@ struct cgroup_subsys_state; typedef void (bio_end_io_t) (struct bio *); struct bio_crypt_ctx; +#define BDEV_NEED_PART_SCAN 0 + struct block_device { dev_t bd_dev; int bd_openers; @@ -37,7 +39,7 @@ struct block_device { struct hd_struct * bd_part; /* number of times partitions within this device have been opened. */ unsigned bd_part_count; - int bd_invalidated; + unsigned long bd_flags; spinlock_t bd_size_lock; /* for bd_inode->i_size updates */ struct gendisk * bd_disk; struct backing_dev_info *bd_bdi; From 659e56ba864d37b7ee0a49cd432205b2a5ca815e Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 1 Sep 2020 17:57:43 +0200 Subject: [PATCH 056/191] block: add a new revalidate_disk_size helper revalidate_disk is a relative awkward helper for driver use, as it first calls an optional driver method and then updates the block device size, while most callers either don't need the method call at all, or want to keep state between the caller and the called method. Add a revalidate_disk_size helper that just performs the update of the block device size from the gendisk one, and switch all drivers that do not implement ->revalidate_disk to use the new helper instead of revalidate_disk() Signed-off-by: Christoph Hellwig Reviewed-by: Josef Bacik Reviewed-by: Johannes Thumshirn Acked-by: Song Liu Signed-off-by: Jens Axboe --- drivers/block/rbd.c | 2 +- drivers/block/rnbd/rnbd-clt.c | 10 ++------- drivers/block/virtio_blk.c | 2 +- drivers/block/zram/zram_drv.c | 4 ++-- drivers/md/dm-raid.c | 2 +- drivers/md/md-cluster.c | 6 ++--- drivers/md/md-linear.c | 2 +- drivers/md/md.c | 10 ++++----- fs/block_dev.c | 42 ++++++++++++++++++++++++----------- include/linux/genhd.h | 1 + 10 files changed, 46 insertions(+), 35 deletions(-) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 011539039693..5d3923c0997c 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -4921,7 +4921,7 @@ static void rbd_dev_update_size(struct rbd_device *rbd_dev) size = (sector_t)rbd_dev->mapping.size / SECTOR_SIZE; dout("setting size to %llu sectors", (unsigned long long)size); set_capacity(rbd_dev->disk, size); - revalidate_disk(rbd_dev->disk); + revalidate_disk_size(rbd_dev->disk, true); } } diff --git a/drivers/block/rnbd/rnbd-clt.c b/drivers/block/rnbd/rnbd-clt.c index cc6a4e2587ae..157538fc8be5 100644 --- a/drivers/block/rnbd/rnbd-clt.c +++ b/drivers/block/rnbd/rnbd-clt.c @@ -102,18 +102,12 @@ static int rnbd_clt_set_dev_attr(struct rnbd_clt_dev *dev, static int rnbd_clt_change_capacity(struct rnbd_clt_dev *dev, size_t new_nsectors) { - int err = 0; - rnbd_clt_info(dev, "Device size changed from %zu to %zu sectors\n", dev->nsectors, new_nsectors); dev->nsectors = new_nsectors; set_capacity(dev->gd, dev->nsectors); - err = revalidate_disk(dev->gd); - if (err) - rnbd_clt_err(dev, - "Failed to change device size from %zu to %zu, err: %d\n", - dev->nsectors, new_nsectors, err); - return err; + revalidate_disk_size(dev->gd, true); + return 0; } static int process_msg_open_rsp(struct rnbd_clt_dev *dev, diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index ca63a41059d6..a314b9382442 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -598,7 +598,7 @@ static void virtblk_update_cache_mode(struct virtio_device *vdev) struct virtio_blk *vblk = vdev->priv; blk_queue_write_cache(vblk->disk->queue, writeback, false); - revalidate_disk(vblk->disk); + revalidate_disk_size(vblk->disk, true); } static const char *const virtblk_cache_types[] = { diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 9100ac36670a..a356275605b1 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1739,7 +1739,7 @@ static ssize_t disksize_store(struct device *dev, zram->disksize = disksize; set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT); - revalidate_disk(zram->disk); + revalidate_disk_size(zram->disk, true); up_write(&zram->init_lock); return len; @@ -1786,7 +1786,7 @@ static ssize_t reset_store(struct device *dev, /* Make sure all the pending I/O are finished */ fsync_bdev(bdev); zram_reset_device(zram); - revalidate_disk(zram->disk); + revalidate_disk_size(zram->disk, true); bdput(bdev); mutex_lock(&bdev->bd_mutex); diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c index 8d2b835d7a10..56b723d012ac 100644 --- a/drivers/md/dm-raid.c +++ b/drivers/md/dm-raid.c @@ -701,7 +701,7 @@ static void rs_set_capacity(struct raid_set *rs) struct gendisk *gendisk = dm_disk(dm_table_get_md(rs->ti->table)); set_capacity(gendisk, rs->md.array_sectors); - revalidate_disk(gendisk); + revalidate_disk_size(gendisk, true); } /* diff --git a/drivers/md/md-cluster.c b/drivers/md/md-cluster.c index d50737ec4039..0580b51a156a 100644 --- a/drivers/md/md-cluster.c +++ b/drivers/md/md-cluster.c @@ -582,7 +582,7 @@ static int process_recvd_msg(struct mddev *mddev, struct cluster_msg *msg) break; case CHANGE_CAPACITY: set_capacity(mddev->gendisk, mddev->array_sectors); - revalidate_disk(mddev->gendisk); + revalidate_disk_size(mddev->gendisk, true); break; case RESYNCING: set_bit(MD_RESYNCING_REMOTE, &mddev->recovery); @@ -1296,12 +1296,12 @@ static void update_size(struct mddev *mddev, sector_t old_dev_sectors) pr_err("%s:%d: failed to send CHANGE_CAPACITY msg\n", __func__, __LINE__); set_capacity(mddev->gendisk, mddev->array_sectors); - revalidate_disk(mddev->gendisk); + revalidate_disk_size(mddev->gendisk, true); } else { /* revert to previous sectors */ ret = mddev->pers->resize(mddev, old_dev_sectors); if (!ret) - revalidate_disk(mddev->gendisk); + revalidate_disk_size(mddev->gendisk, true); ret = __sendmsg(cinfo, &cmsg); if (ret) pr_err("%s:%d: failed to send METADATA_UPDATED msg\n", diff --git a/drivers/md/md-linear.c b/drivers/md/md-linear.c index c2ae9125c4c3..5ab22069b5be 100644 --- a/drivers/md/md-linear.c +++ b/drivers/md/md-linear.c @@ -202,7 +202,7 @@ static int linear_add(struct mddev *mddev, struct md_rdev *rdev) md_set_array_sectors(mddev, linear_size(mddev, 0, 0)); set_capacity(mddev->gendisk, mddev->array_sectors); mddev_resume(mddev); - revalidate_disk(mddev->gendisk); + revalidate_disk_size(mddev->gendisk, true); kfree_rcu(oldconf, rcu); return 0; } diff --git a/drivers/md/md.c b/drivers/md/md.c index 607278207023..9562ef598ae1 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -5358,7 +5358,7 @@ array_size_store(struct mddev *mddev, const char *buf, size_t len) mddev->array_sectors = sectors; if (mddev->pers) { set_capacity(mddev->gendisk, mddev->array_sectors); - revalidate_disk(mddev->gendisk); + revalidate_disk_size(mddev->gendisk, true); } } mddev_unlock(mddev); @@ -6109,7 +6109,7 @@ int do_md_run(struct mddev *mddev) md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */ set_capacity(mddev->gendisk, mddev->array_sectors); - revalidate_disk(mddev->gendisk); + revalidate_disk_size(mddev->gendisk, true); clear_bit(MD_NOT_READY, &mddev->flags); mddev->changed = 1; kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE); @@ -6427,7 +6427,7 @@ static int do_md_stop(struct mddev *mddev, int mode, set_capacity(disk, 0); mutex_unlock(&mddev->open_mutex); mddev->changed = 1; - revalidate_disk(disk); + revalidate_disk_size(disk, true); if (mddev->ro) mddev->ro = 0; @@ -7259,7 +7259,7 @@ static int update_size(struct mddev *mddev, sector_t num_sectors) md_cluster_ops->update_size(mddev, old_dev_sectors); else if (mddev->queue) { set_capacity(mddev->gendisk, mddev->array_sectors); - revalidate_disk(mddev->gendisk); + revalidate_disk_size(mddev->gendisk, true); } } return rv; @@ -9018,7 +9018,7 @@ void md_do_sync(struct md_thread *thread) mddev_unlock(mddev); if (!mddev_is_clustered(mddev)) { set_capacity(mddev->gendisk, mddev->array_sectors); - revalidate_disk(mddev->gendisk); + revalidate_disk_size(mddev->gendisk, true); } } diff --git a/fs/block_dev.c b/fs/block_dev.c index 1e6441dbe840..9bfe37f394bd 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1311,6 +1311,34 @@ static void check_disk_size_change(struct gendisk *disk, } } +/** + * revalidate_disk_size - checks for disk size change and adjusts bdev size. + * @disk: struct gendisk to check + * @verbose: if %true log a message about a size change if there is any + * + * This routine checks to see if the bdev size does not match the disk size + * and adjusts it if it differs. When shrinking the bdev size, its all caches + * are freed. + */ +void revalidate_disk_size(struct gendisk *disk, bool verbose) +{ + struct block_device *bdev; + + /* + * Hidden disks don't have associated bdev so there's no point in + * revalidating them. + */ + if (disk->flags & GENHD_FL_HIDDEN) + return; + + bdev = bdget_disk(disk, 0); + if (bdev) { + check_disk_size_change(disk, bdev, verbose); + bdput(bdev); + } +} +EXPORT_SYMBOL(revalidate_disk_size); + /** * revalidate_disk - wrapper for lower-level driver's revalidate_disk call-back * @disk: struct gendisk to be revalidated @@ -1325,19 +1353,7 @@ int revalidate_disk(struct gendisk *disk) if (disk->fops->revalidate_disk) ret = disk->fops->revalidate_disk(disk); - - /* - * Hidden disks don't have associated bdev so there's no point in - * revalidating it. - */ - if (!(disk->flags & GENHD_FL_HIDDEN)) { - struct block_device *bdev = bdget_disk(disk, 0); - - if (bdev) { - check_disk_size_change(disk, bdev, ret == 0); - bdput(bdev); - } - } + revalidate_disk_size(disk, ret == 0); return ret; } EXPORT_SYMBOL(revalidate_disk); diff --git a/include/linux/genhd.h b/include/linux/genhd.h index 9ea2ca31c278..f76c8baf6b7d 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -371,6 +371,7 @@ int register_blkdev(unsigned int major, const char *name); void unregister_blkdev(unsigned int major, const char *name); int revalidate_disk(struct gendisk *disk); +void revalidate_disk_size(struct gendisk *disk, bool verbose); int check_disk_change(struct block_device *bdev); int __invalidate_device(struct block_device *bdev, bool kill_dirty); void bd_set_nr_sectors(struct block_device *bdev, sector_t sectors); From b8086d3f5a0e88b1912d55a158b8a6a43ad6604b Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 1 Sep 2020 17:57:44 +0200 Subject: [PATCH 057/191] block: use revalidate_disk_size in set_capacity_revalidate_and_notify Only virtio_blk and xen-blkfront set the revalidate argument to true, and both do not implement the ->revalidate_disk method. So switch to the helper that just updates the size instead. Signed-off-by: Christoph Hellwig Reviewed-by: Josef Bacik Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe --- block/genhd.c | 7 +++---- include/linux/genhd.h | 4 ++-- 2 files changed, 5 insertions(+), 6 deletions(-) diff --git a/block/genhd.c b/block/genhd.c index a36be970b767..081f1039d936 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -50,14 +50,13 @@ static void disk_release_events(struct gendisk *disk); * zero and will not be set to zero */ void set_capacity_revalidate_and_notify(struct gendisk *disk, sector_t size, - bool revalidate) + bool update_bdev) { sector_t capacity = get_capacity(disk); set_capacity(disk, size); - - if (revalidate) - revalidate_disk(disk); + if (update_bdev) + revalidate_disk_size(disk, true); if (capacity != size && capacity != 0 && size != 0) { char *envp[] = { "RESIZE=1", NULL }; diff --git a/include/linux/genhd.h b/include/linux/genhd.h index f76c8baf6b7d..02a73198b289 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -313,8 +313,8 @@ static inline int get_disk_ro(struct gendisk *disk) extern void disk_block_events(struct gendisk *disk); extern void disk_unblock_events(struct gendisk *disk); extern void disk_flush_events(struct gendisk *disk, unsigned int mask); -extern void set_capacity_revalidate_and_notify(struct gendisk *disk, - sector_t size, bool revalidate); +void set_capacity_revalidate_and_notify(struct gendisk *disk, sector_t size, + bool update_bdev); extern unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask); /* drivers/char/random.c */ From b55d3d21a05d5558440515c1a73d87bc4b1fa17c Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 1 Sep 2020 17:57:45 +0200 Subject: [PATCH 058/191] nvme: opencode revalidate_disk in nvme_validate_ns Keep control in the NVMe driver instead of going through an indirect call back into ->revalidate_disk. Also reorder the function a bit to be easier to follow with the additional code. And now that we have removed all callers of revalidate_disk() in the nvme code, ->revalidate_disk is only called from the open code when first opening the device. Which is of course totally pointless as we have a valid size since the initial scan, and will get an updated view through the asynchronous notifiation everytime the size changes. Signed-off-by: Christoph Hellwig Reviewed-by: Josef Bacik Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe --- drivers/nvme/host/core.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index c7e01d9667ad..ea1fa41fbba8 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -2352,7 +2352,6 @@ static const struct block_device_operations nvme_fops = { .open = nvme_open, .release = nvme_release, .getgeo = nvme_getgeo, - .revalidate_disk= nvme_revalidate_disk, .report_zones = nvme_report_zones, .pr_ops = &nvme_pr_ops, }; @@ -4053,14 +4052,19 @@ static void nvme_ns_remove_by_nsid(struct nvme_ctrl *ctrl, u32 nsid) static void nvme_validate_ns(struct nvme_ctrl *ctrl, unsigned nsid) { struct nvme_ns *ns; + int ret; ns = nvme_find_get_ns(ctrl, nsid); - if (ns) { - if (revalidate_disk(ns->disk)) - nvme_ns_remove(ns); - nvme_put_ns(ns); - } else + if (!ns) { nvme_alloc_ns(ctrl, nsid); + return; + } + + ret = nvme_revalidate_disk(ns->disk); + revalidate_disk_size(ns->disk, ret == 0); + if (ret) + nvme_ns_remove(ns); + nvme_put_ns(ns); } static void nvme_remove_invalid_namespaces(struct nvme_ctrl *ctrl, From 033a1b98b1f8a823fb0bd985d45290016eee54ce Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 1 Sep 2020 17:57:46 +0200 Subject: [PATCH 059/191] sd: open code revalidate_disk Instead of calling revalidate_disk just do the work directly by calling sd_revalidate_disk, and revalidate_disk_size where needed. Signed-off-by: Christoph Hellwig Reviewed-by: Josef Bacik Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe --- drivers/scsi/sd.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 95018e650f2d..2bec8cd52616 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -217,7 +217,7 @@ cache_type_store(struct device *dev, struct device_attribute *attr, sd_print_sense_hdr(sdkp, &sshdr); return -EINVAL; } - revalidate_disk(sdkp->disk); + sd_revalidate_disk(sdkp->disk); return count; } @@ -1706,8 +1706,10 @@ static int sd_sync_cache(struct scsi_disk *sdkp, struct scsi_sense_hdr *sshdr) static void sd_rescan(struct device *dev) { struct scsi_disk *sdkp = dev_get_drvdata(dev); + int ret; - revalidate_disk(sdkp->disk); + ret = sd_revalidate_disk(sdkp->disk); + revalidate_disk_size(sdkp->disk, ret == 0); } static int sd_ioctl(struct block_device *bdev, fmode_t mode, From 32f61d67570db036dba9e4fb2509b5343e28f627 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 1 Sep 2020 17:57:47 +0200 Subject: [PATCH 060/191] nvdimm: simplify revalidate_disk handling The nvdimm block driver abuse revalidate_disk in a strange way, and totally unrelated to what other drivers do. Simplify this by just calling nvdimm_revalidate_disk (which seems rather misnamed) from the probe routines, as the additional bdev size revalidation is pointless at this point, and remove the revalidate_disk methods given that it can only be triggered from add_disk, which is right before the manual calls. Signed-off-by: Christoph Hellwig Reviewed-by: Josef Bacik Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe --- drivers/nvdimm/blk.c | 3 +-- drivers/nvdimm/btt.c | 3 +-- drivers/nvdimm/bus.c | 9 +++------ drivers/nvdimm/nd.h | 2 +- drivers/nvdimm/pmem.c | 3 +-- 5 files changed, 7 insertions(+), 13 deletions(-) diff --git a/drivers/nvdimm/blk.c b/drivers/nvdimm/blk.c index 1f718381a045..22e5617b2cea 100644 --- a/drivers/nvdimm/blk.c +++ b/drivers/nvdimm/blk.c @@ -226,7 +226,6 @@ static int nsblk_rw_bytes(struct nd_namespace_common *ndns, static const struct block_device_operations nd_blk_fops = { .owner = THIS_MODULE, .submit_bio = nd_blk_submit_bio, - .revalidate_disk = nvdimm_revalidate_disk, }; static void nd_blk_release_queue(void *q) @@ -284,7 +283,7 @@ static int nsblk_attach_disk(struct nd_namespace_blk *nsblk) set_capacity(disk, available_disk_size >> SECTOR_SHIFT); device_add_disk(dev, disk, NULL); - revalidate_disk(disk); + nvdimm_check_and_set_ro(disk); return 0; } diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c index 0ff610e728ff..0d710140bf93 100644 --- a/drivers/nvdimm/btt.c +++ b/drivers/nvdimm/btt.c @@ -1513,7 +1513,6 @@ static const struct block_device_operations btt_fops = { .submit_bio = btt_submit_bio, .rw_page = btt_rw_page, .getgeo = btt_getgeo, - .revalidate_disk = nvdimm_revalidate_disk, }; static int btt_blk_init(struct btt *btt) @@ -1558,7 +1557,7 @@ static int btt_blk_init(struct btt *btt) set_capacity(btt->btt_disk, btt->nlba * btt->sector_size >> 9); device_add_disk(&btt->nd_btt->dev, btt->btt_disk, NULL); btt->nd_btt->size = btt->nlba * (u64)btt->sector_size; - revalidate_disk(btt->btt_disk); + nvdimm_check_and_set_ro(btt->btt_disk); return 0; } diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c index 955265656b96..2304c6183822 100644 --- a/drivers/nvdimm/bus.c +++ b/drivers/nvdimm/bus.c @@ -628,7 +628,7 @@ int __nd_driver_register(struct nd_device_driver *nd_drv, struct module *owner, } EXPORT_SYMBOL(__nd_driver_register); -int nvdimm_revalidate_disk(struct gendisk *disk) +void nvdimm_check_and_set_ro(struct gendisk *disk) { struct device *dev = disk_to_dev(disk)->parent; struct nd_region *nd_region = to_nd_region(dev->parent); @@ -639,16 +639,13 @@ int nvdimm_revalidate_disk(struct gendisk *disk) * read-only if the disk is already read-only. */ if (disk_ro || nd_region->ro == disk_ro) - return 0; + return; dev_info(dev, "%s read-only, marking %s read-only\n", dev_name(&nd_region->dev), disk->disk_name); set_disk_ro(disk, 1); - - return 0; - } -EXPORT_SYMBOL(nvdimm_revalidate_disk); +EXPORT_SYMBOL(nvdimm_check_and_set_ro); static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, char *buf) diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h index 85c1ae813ea3..72740108ba42 100644 --- a/drivers/nvdimm/nd.h +++ b/drivers/nvdimm/nd.h @@ -361,7 +361,7 @@ u64 nd_region_interleave_set_altcookie(struct nd_region *nd_region); void nvdimm_bus_lock(struct device *dev); void nvdimm_bus_unlock(struct device *dev); bool is_nvdimm_bus_locked(struct device *dev); -int nvdimm_revalidate_disk(struct gendisk *disk); +void nvdimm_check_and_set_ro(struct gendisk *disk); void nvdimm_drvdata_release(struct kref *kref); void put_ndd(struct nvdimm_drvdata *ndd); int nd_label_reserve_dpa(struct nvdimm_drvdata *ndd); diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index fab29b514372..140cf3b9000c 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -281,7 +281,6 @@ static const struct block_device_operations pmem_fops = { .owner = THIS_MODULE, .submit_bio = pmem_submit_bio, .rw_page = pmem_rw_page, - .revalidate_disk = nvdimm_revalidate_disk, }; static int pmem_dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff, @@ -501,7 +500,7 @@ static int pmem_attach_disk(struct device *dev, if (devm_add_action_or_reset(dev, pmem_release_disk, pmem)) return -ENOMEM; - revalidate_disk(disk); + nvdimm_check_and_set_ro(disk); pmem->bb_state = sysfs_get_dirent(disk_to_dev(disk)->kobj.sd, "badblocks"); From de09077c89183cbc627d9393706343662da7f5a3 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 1 Sep 2020 17:57:48 +0200 Subject: [PATCH 061/191] block: remove revalidate_disk() Remove the now unused helper. Signed-off-by: Christoph Hellwig Reviewed-by: Josef Bacik Reviewed-by: Johannes Thumshirn Acked-by: Song Liu Signed-off-by: Jens Axboe --- drivers/md/md.h | 2 +- fs/block_dev.c | 19 ------------------- include/linux/genhd.h | 1 - 3 files changed, 1 insertion(+), 21 deletions(-) diff --git a/drivers/md/md.h b/drivers/md/md.h index d9c4e6b7e939..f9e2ccdd22c4 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -397,7 +397,7 @@ struct mddev { * These locks are separate due to conflicting interactions * with bdev->bd_mutex. * Lock ordering is: - * reconfig_mutex -> bd_mutex : e.g. do_md_run -> revalidate_disk + * reconfig_mutex -> bd_mutex * bd_mutex -> open_mutex: e.g. __blkdev_get -> md_open */ struct mutex open_mutex; diff --git a/fs/block_dev.c b/fs/block_dev.c index 9bfe37f394bd..9cb205405f9d 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1339,25 +1339,6 @@ void revalidate_disk_size(struct gendisk *disk, bool verbose) } EXPORT_SYMBOL(revalidate_disk_size); -/** - * revalidate_disk - wrapper for lower-level driver's revalidate_disk call-back - * @disk: struct gendisk to be revalidated - * - * This routine is a wrapper for lower-level driver's revalidate_disk - * call-backs. It is used to do common pre and post operations needed - * for all revalidate_disk operations. - */ -int revalidate_disk(struct gendisk *disk) -{ - int ret = 0; - - if (disk->fops->revalidate_disk) - ret = disk->fops->revalidate_disk(disk); - revalidate_disk_size(disk, ret == 0); - return ret; -} -EXPORT_SYMBOL(revalidate_disk); - /* * This routine checks whether a removable media has been changed, * and invalidates all buffer-cache-entries in that case. This diff --git a/include/linux/genhd.h b/include/linux/genhd.h index 02a73198b289..c618b27292fc 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -370,7 +370,6 @@ extern void blk_unregister_region(dev_t devt, unsigned long range); int register_blkdev(unsigned int major, const char *name); void unregister_blkdev(unsigned int major, const char *name); -int revalidate_disk(struct gendisk *disk); void revalidate_disk_size(struct gendisk *disk, bool verbose); int check_disk_change(struct block_device *bdev); int __invalidate_device(struct block_device *bdev, bool kill_dirty); From 51db1c37ee166159c5753ce8d64d6bacf113e0f0 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Wed, 19 Aug 2020 23:20:19 +0800 Subject: [PATCH 062/191] blk-mq: Rename BLK_MQ_F_TAG_SHARED as BLK_MQ_F_TAG_QUEUE_SHARED BLK_MQ_F_TAG_SHARED actually means that tags is shared among request queues, all of which should belong to LUNs attached to same HBA. So rename it to make the point explicitly. [jpg: rebase a few times, add rnbd-clt.c change] Suggested-by: Bart Van Assche Signed-off-by: Ming Lei Signed-off-by: John Garry Tested-by: Douglas Gilbert Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- block/blk-mq-debugfs.c | 2 +- block/blk-mq-tag.h | 6 +++--- block/blk-mq.c | 20 ++++++++++---------- drivers/block/rnbd/rnbd-clt.c | 2 +- include/linux/blk-mq.h | 2 +- 5 files changed, 16 insertions(+), 16 deletions(-) diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c index 3f09bcb8a6fd..a4597febff69 100644 --- a/block/blk-mq-debugfs.c +++ b/block/blk-mq-debugfs.c @@ -240,7 +240,7 @@ static const char *const alloc_policy_name[] = { #define HCTX_FLAG_NAME(name) [ilog2(BLK_MQ_F_##name)] = #name static const char *const hctx_flag_name[] = { HCTX_FLAG_NAME(SHOULD_MERGE), - HCTX_FLAG_NAME(TAG_SHARED), + HCTX_FLAG_NAME(TAG_QUEUE_SHARED), HCTX_FLAG_NAME(BLOCKING), HCTX_FLAG_NAME(NO_SCHED), HCTX_FLAG_NAME(STACKING), diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h index b1acac518c4e..918e2cee4f43 100644 --- a/block/blk-mq-tag.h +++ b/block/blk-mq-tag.h @@ -56,7 +56,7 @@ extern void __blk_mq_tag_idle(struct blk_mq_hw_ctx *); static inline bool blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx) { - if (!(hctx->flags & BLK_MQ_F_TAG_SHARED)) + if (!(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) return false; return __blk_mq_tag_busy(hctx); @@ -64,7 +64,7 @@ static inline bool blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx) static inline void blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx) { - if (!(hctx->flags & BLK_MQ_F_TAG_SHARED)) + if (!(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) return; __blk_mq_tag_idle(hctx); @@ -79,7 +79,7 @@ static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx, { unsigned int depth, users; - if (!hctx || !(hctx->flags & BLK_MQ_F_TAG_SHARED)) + if (!hctx || !(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) return true; if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state)) return true; diff --git a/block/blk-mq.c b/block/blk-mq.c index b3d2785eefe9..75031fa1709c 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1124,7 +1124,7 @@ static bool blk_mq_get_driver_tag(struct request *rq) if (rq->tag == BLK_MQ_NO_TAG && !__blk_mq_get_driver_tag(rq)) return false; - if ((hctx->flags & BLK_MQ_F_TAG_SHARED) && + if ((hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED) && !(rq->rq_flags & RQF_MQ_INFLIGHT)) { rq->rq_flags |= RQF_MQ_INFLIGHT; atomic_inc(&hctx->nr_active); @@ -1168,7 +1168,7 @@ static bool blk_mq_mark_tag_wait(struct blk_mq_hw_ctx *hctx, wait_queue_entry_t *wait; bool ret; - if (!(hctx->flags & BLK_MQ_F_TAG_SHARED)) { + if (!(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) { blk_mq_sched_mark_restart_hctx(hctx); /* @@ -1420,7 +1420,7 @@ bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list, bool needs_restart; /* For non-shared tags, the RESTART check will suffice */ bool no_tag = prep == PREP_DISPATCH_NO_TAG && - (hctx->flags & BLK_MQ_F_TAG_SHARED); + (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED); bool no_budget_avail = prep == PREP_DISPATCH_NO_BUDGET; blk_mq_release_budgets(q, nr_budgets); @@ -2668,7 +2668,7 @@ blk_mq_alloc_hctx(struct request_queue *q, struct blk_mq_tag_set *set, spin_lock_init(&hctx->lock); INIT_LIST_HEAD(&hctx->dispatch); hctx->queue = q; - hctx->flags = set->flags & ~BLK_MQ_F_TAG_SHARED; + hctx->flags = set->flags & ~BLK_MQ_F_TAG_QUEUE_SHARED; INIT_LIST_HEAD(&hctx->hctx_list); @@ -2885,9 +2885,9 @@ static void queue_set_hctx_shared(struct request_queue *q, bool shared) queue_for_each_hw_ctx(q, hctx, i) { if (shared) - hctx->flags |= BLK_MQ_F_TAG_SHARED; + hctx->flags |= BLK_MQ_F_TAG_QUEUE_SHARED; else - hctx->flags &= ~BLK_MQ_F_TAG_SHARED; + hctx->flags &= ~BLK_MQ_F_TAG_QUEUE_SHARED; } } @@ -2913,7 +2913,7 @@ static void blk_mq_del_queue_tag_set(struct request_queue *q) list_del(&q->tag_set_list); if (list_is_singular(&set->tag_list)) { /* just transitioned to unshared */ - set->flags &= ~BLK_MQ_F_TAG_SHARED; + set->flags &= ~BLK_MQ_F_TAG_QUEUE_SHARED; /* update existing queue */ blk_mq_update_tag_set_depth(set, false); } @@ -2930,12 +2930,12 @@ static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set *set, * Check to see if we're transitioning to shared (from 1 to 2 queues). */ if (!list_empty(&set->tag_list) && - !(set->flags & BLK_MQ_F_TAG_SHARED)) { - set->flags |= BLK_MQ_F_TAG_SHARED; + !(set->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) { + set->flags |= BLK_MQ_F_TAG_QUEUE_SHARED; /* update existing queue */ blk_mq_update_tag_set_depth(set, true); } - if (set->flags & BLK_MQ_F_TAG_SHARED) + if (set->flags & BLK_MQ_F_TAG_QUEUE_SHARED) queue_set_hctx_shared(q, true); list_add_tail(&q->tag_set_list, &set->tag_list); diff --git a/drivers/block/rnbd/rnbd-clt.c b/drivers/block/rnbd/rnbd-clt.c index 157538fc8be5..d7a69741c0f6 100644 --- a/drivers/block/rnbd/rnbd-clt.c +++ b/drivers/block/rnbd/rnbd-clt.c @@ -1174,7 +1174,7 @@ static int setup_mq_tags(struct rnbd_clt_session *sess) tag_set->queue_depth = sess->queue_depth; tag_set->numa_node = NUMA_NO_NODE; tag_set->flags = BLK_MQ_F_SHOULD_MERGE | - BLK_MQ_F_TAG_SHARED; + BLK_MQ_F_TAG_QUEUE_SHARED; tag_set->cmd_size = sizeof(struct rnbd_iu); tag_set->nr_hw_queues = num_online_cpus(); diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index 21a02e0577dd..982c4f92b63c 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -378,7 +378,7 @@ struct blk_mq_ops { enum { BLK_MQ_F_SHOULD_MERGE = 1 << 0, - BLK_MQ_F_TAG_SHARED = 1 << 1, + BLK_MQ_F_TAG_QUEUE_SHARED = 1 << 1, /* * Set when this device requires underlying blk-mq device for * completing IO: From 655ac30094da0d724ce66161f15675d30da89cd8 Mon Sep 17 00:00:00 2001 From: Hannes Reinecke Date: Wed, 19 Aug 2020 23:20:20 +0800 Subject: [PATCH 063/191] blk-mq: Rename blk_mq_update_tag_set_depth() The function does not set the depth, but rather transitions from shared to non-shared queues and vice versa. So rename it to blk_mq_update_tag_set_shared() to better reflect its purpose. [jpg: take out some unrelated changes in blk_mq_init_bitmap_tags()] Signed-off-by: Hannes Reinecke Signed-off-by: John Garry Tested-by: Douglas Gilbert Signed-off-by: Jens Axboe --- block/blk-mq.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 75031fa1709c..cae46701579c 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2891,8 +2891,8 @@ static void queue_set_hctx_shared(struct request_queue *q, bool shared) } } -static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set, - bool shared) +static void blk_mq_update_tag_set_shared(struct blk_mq_tag_set *set, + bool shared) { struct request_queue *q; @@ -2915,7 +2915,7 @@ static void blk_mq_del_queue_tag_set(struct request_queue *q) /* just transitioned to unshared */ set->flags &= ~BLK_MQ_F_TAG_QUEUE_SHARED; /* update existing queue */ - blk_mq_update_tag_set_depth(set, false); + blk_mq_update_tag_set_shared(set, false); } mutex_unlock(&set->tag_list_lock); INIT_LIST_HEAD(&q->tag_set_list); @@ -2933,7 +2933,7 @@ static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set *set, !(set->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) { set->flags |= BLK_MQ_F_TAG_QUEUE_SHARED; /* update existing queue */ - blk_mq_update_tag_set_depth(set, true); + blk_mq_update_tag_set_shared(set, true); } if (set->flags & BLK_MQ_F_TAG_QUEUE_SHARED) queue_set_hctx_shared(q, true); From 4d063237b92a4e8d99350ad05492a45009a3c78c Mon Sep 17 00:00:00 2001 From: Hannes Reinecke Date: Wed, 19 Aug 2020 23:20:21 +0800 Subject: [PATCH 064/191] blk-mq: Free tags in blk_mq_init_tags() upon error Since the tags are allocated in blk_mq_init_tags(), it's better practice to free in that same function upon error, rather than a callee which is to init the bitmap tags (blk_mq_init_tags()). [jpg: Split from an earlier patch with a new commit message] Signed-off-by: Hannes Reinecke Signed-off-by: John Garry Tested-by: Douglas Gilbert Signed-off-by: Jens Axboe --- block/blk-mq-tag.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index 32d82e23b095..c2c9f369d777 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -429,24 +429,22 @@ static int bt_alloc(struct sbitmap_queue *bt, unsigned int depth, node); } -static struct blk_mq_tags *blk_mq_init_bitmap_tags(struct blk_mq_tags *tags, - int node, int alloc_policy) +static int blk_mq_init_bitmap_tags(struct blk_mq_tags *tags, + int node, int alloc_policy) { unsigned int depth = tags->nr_tags - tags->nr_reserved_tags; bool round_robin = alloc_policy == BLK_TAG_ALLOC_RR; if (bt_alloc(&tags->bitmap_tags, depth, round_robin, node)) - goto free_tags; + return -ENOMEM; if (bt_alloc(&tags->breserved_tags, tags->nr_reserved_tags, round_robin, node)) goto free_bitmap_tags; - return tags; + return 0; free_bitmap_tags: sbitmap_queue_free(&tags->bitmap_tags); -free_tags: - kfree(tags); - return NULL; + return -ENOMEM; } struct blk_mq_tags *blk_mq_init_tags(unsigned int total_tags, @@ -467,7 +465,11 @@ struct blk_mq_tags *blk_mq_init_tags(unsigned int total_tags, tags->nr_tags = total_tags; tags->nr_reserved_tags = reserved_tags; - return blk_mq_init_bitmap_tags(tags, node, alloc_policy); + if (blk_mq_init_bitmap_tags(tags, node, alloc_policy) < 0) { + kfree(tags); + return NULL; + } + return tags; } void blk_mq_free_tags(struct blk_mq_tags *tags) From 1c0706a70a64eda48477caa880657e07f5196512 Mon Sep 17 00:00:00 2001 From: John Garry Date: Wed, 19 Aug 2020 23:20:22 +0800 Subject: [PATCH 065/191] blk-mq: Pass flags for tag init/free Pass hctx/tagset flags argument down to blk_mq_init_tags() and blk_mq_free_tags() for selective init/free. For now, make it include the alloc policy flag, which can be evaluated when needed (in blk_mq_init_tags()). Signed-off-by: John Garry Tested-by: Douglas Gilbert Signed-off-by: Jens Axboe --- block/blk-mq-sched.c | 11 ++++++++--- block/blk-mq-tag.c | 12 +++++++----- block/blk-mq-tag.h | 7 ++++--- block/blk-mq.c | 23 +++++++++++++---------- block/blk-mq.h | 5 +++-- 5 files changed, 35 insertions(+), 23 deletions(-) diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index 501a85ceaccb..edfc8ea805bc 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -560,9 +560,11 @@ static void blk_mq_sched_free_tags(struct blk_mq_tag_set *set, struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx) { + unsigned int flags = set->flags; + if (hctx->sched_tags) { blk_mq_free_rqs(set, hctx->sched_tags, hctx_idx); - blk_mq_free_rq_map(hctx->sched_tags); + blk_mq_free_rq_map(hctx->sched_tags, flags); hctx->sched_tags = NULL; } } @@ -572,10 +574,11 @@ static int blk_mq_sched_alloc_tags(struct request_queue *q, unsigned int hctx_idx) { struct blk_mq_tag_set *set = q->tag_set; + unsigned int flags = set->flags; int ret; hctx->sched_tags = blk_mq_alloc_rq_map(set, hctx_idx, q->nr_requests, - set->reserved_tags); + set->reserved_tags, flags); if (!hctx->sched_tags) return -ENOMEM; @@ -593,8 +596,10 @@ static void blk_mq_sched_tags_teardown(struct request_queue *q) int i; queue_for_each_hw_ctx(q, hctx, i) { + unsigned int flags = hctx->flags; + if (hctx->sched_tags) { - blk_mq_free_rq_map(hctx->sched_tags); + blk_mq_free_rq_map(hctx->sched_tags, flags); hctx->sched_tags = NULL; } } diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index c2c9f369d777..0426f01e06a6 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -449,8 +449,9 @@ static int blk_mq_init_bitmap_tags(struct blk_mq_tags *tags, struct blk_mq_tags *blk_mq_init_tags(unsigned int total_tags, unsigned int reserved_tags, - int node, int alloc_policy) + int node, unsigned int flags) { + int alloc_policy = BLK_MQ_FLAG_TO_ALLOC_POLICY(flags); struct blk_mq_tags *tags; if (total_tags > BLK_MQ_TAG_MAX) { @@ -472,7 +473,7 @@ struct blk_mq_tags *blk_mq_init_tags(unsigned int total_tags, return tags; } -void blk_mq_free_tags(struct blk_mq_tags *tags) +void blk_mq_free_tags(struct blk_mq_tags *tags, unsigned int flags) { sbitmap_queue_free(&tags->bitmap_tags); sbitmap_queue_free(&tags->breserved_tags); @@ -494,6 +495,7 @@ int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx, */ if (tdepth > tags->nr_tags) { struct blk_mq_tag_set *set = hctx->queue->tag_set; + unsigned int flags = set->flags; struct blk_mq_tags *new; bool ret; @@ -508,17 +510,17 @@ int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx, return -EINVAL; new = blk_mq_alloc_rq_map(set, hctx->queue_num, tdepth, - tags->nr_reserved_tags); + tags->nr_reserved_tags, flags); if (!new) return -ENOMEM; ret = blk_mq_alloc_rqs(set, new, hctx->queue_num, tdepth); if (ret) { - blk_mq_free_rq_map(new); + blk_mq_free_rq_map(new, flags); return -ENOMEM; } blk_mq_free_rqs(set, *tagsptr, hctx->queue_num); - blk_mq_free_rq_map(*tagsptr); + blk_mq_free_rq_map(*tagsptr, flags); *tagsptr = new; } else { /* diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h index 918e2cee4f43..391f68d32fa1 100644 --- a/block/blk-mq-tag.h +++ b/block/blk-mq-tag.h @@ -21,9 +21,10 @@ struct blk_mq_tags { struct list_head page_list; }; - -extern struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags, unsigned int reserved_tags, int node, int alloc_policy); -extern void blk_mq_free_tags(struct blk_mq_tags *tags); +extern struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags, + unsigned int reserved_tags, + int node, unsigned int flags); +extern void blk_mq_free_tags(struct blk_mq_tags *tags, unsigned int flags); extern unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data); extern void blk_mq_put_tag(struct blk_mq_tags *tags, struct blk_mq_ctx *ctx, diff --git a/block/blk-mq.c b/block/blk-mq.c index cae46701579c..a39693dbb3c8 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2296,20 +2296,21 @@ void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, } } -void blk_mq_free_rq_map(struct blk_mq_tags *tags) +void blk_mq_free_rq_map(struct blk_mq_tags *tags, unsigned int flags) { kfree(tags->rqs); tags->rqs = NULL; kfree(tags->static_rqs); tags->static_rqs = NULL; - blk_mq_free_tags(tags); + blk_mq_free_tags(tags, flags); } struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, unsigned int hctx_idx, unsigned int nr_tags, - unsigned int reserved_tags) + unsigned int reserved_tags, + unsigned int flags) { struct blk_mq_tags *tags; int node; @@ -2318,8 +2319,7 @@ struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, if (node == NUMA_NO_NODE) node = set->numa_node; - tags = blk_mq_init_tags(nr_tags, reserved_tags, node, - BLK_MQ_FLAG_TO_ALLOC_POLICY(set->flags)); + tags = blk_mq_init_tags(nr_tags, reserved_tags, node, flags); if (!tags) return NULL; @@ -2327,7 +2327,7 @@ struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY, node); if (!tags->rqs) { - blk_mq_free_tags(tags); + blk_mq_free_tags(tags, flags); return NULL; } @@ -2336,7 +2336,7 @@ struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, node); if (!tags->static_rqs) { kfree(tags->rqs); - blk_mq_free_tags(tags); + blk_mq_free_tags(tags, flags); return NULL; } @@ -2745,10 +2745,11 @@ static void blk_mq_init_cpu_queues(struct request_queue *q, static bool __blk_mq_alloc_map_and_request(struct blk_mq_tag_set *set, int hctx_idx) { + unsigned int flags = set->flags; int ret = 0; set->tags[hctx_idx] = blk_mq_alloc_rq_map(set, hctx_idx, - set->queue_depth, set->reserved_tags); + set->queue_depth, set->reserved_tags, flags); if (!set->tags[hctx_idx]) return false; @@ -2757,7 +2758,7 @@ static bool __blk_mq_alloc_map_and_request(struct blk_mq_tag_set *set, if (!ret) return true; - blk_mq_free_rq_map(set->tags[hctx_idx]); + blk_mq_free_rq_map(set->tags[hctx_idx], flags); set->tags[hctx_idx] = NULL; return false; } @@ -2765,9 +2766,11 @@ static bool __blk_mq_alloc_map_and_request(struct blk_mq_tag_set *set, static void blk_mq_free_map_and_requests(struct blk_mq_tag_set *set, unsigned int hctx_idx) { + unsigned int flags = set->flags; + if (set->tags && set->tags[hctx_idx]) { blk_mq_free_rqs(set, set->tags[hctx_idx], hctx_idx); - blk_mq_free_rq_map(set->tags[hctx_idx]); + blk_mq_free_rq_map(set->tags[hctx_idx], flags); set->tags[hctx_idx] = NULL; } } diff --git a/block/blk-mq.h b/block/blk-mq.h index 863a2f3346d4..b86e7fe47789 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -53,11 +53,12 @@ struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx, */ void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, unsigned int hctx_idx); -void blk_mq_free_rq_map(struct blk_mq_tags *tags); +void blk_mq_free_rq_map(struct blk_mq_tags *tags, unsigned int flags); struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, unsigned int hctx_idx, unsigned int nr_tags, - unsigned int reserved_tags); + unsigned int reserved_tags, + unsigned int flags); int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, unsigned int hctx_idx, unsigned int depth); From 222a5ae03cdd12e7643f2f64689a39ed547650cb Mon Sep 17 00:00:00 2001 From: John Garry Date: Wed, 19 Aug 2020 23:20:23 +0800 Subject: [PATCH 066/191] blk-mq: Use pointers for blk_mq_tags bitmap tags Introduce pointers for the blk_mq_tags regular and reserved bitmap tags, with the goal of later being able to use a common shared tag bitmap across all HW contexts in a set. Signed-off-by: John Garry Tested-by: Don Brace #SCSI resv cmds patches used Tested-by: Douglas Gilbert Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- block/bfq-iosched.c | 4 ++-- block/blk-mq-debugfs.c | 8 ++++---- block/blk-mq-tag.c | 41 ++++++++++++++++++++++------------------- block/blk-mq-tag.h | 7 +++++-- block/blk-mq.c | 8 ++++---- block/kyber-iosched.c | 4 ++-- 6 files changed, 39 insertions(+), 33 deletions(-) diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index c34b090178a9..418ffd4b5552 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -6372,8 +6372,8 @@ static void bfq_depth_updated(struct blk_mq_hw_ctx *hctx) struct blk_mq_tags *tags = hctx->sched_tags; unsigned int min_shallow; - min_shallow = bfq_update_depths(bfqd, &tags->bitmap_tags); - sbitmap_queue_min_shallow_depth(&tags->bitmap_tags, min_shallow); + min_shallow = bfq_update_depths(bfqd, tags->bitmap_tags); + sbitmap_queue_min_shallow_depth(tags->bitmap_tags, min_shallow); } static int bfq_init_hctx(struct blk_mq_hw_ctx *hctx, unsigned int index) diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c index a4597febff69..645b7f800cb8 100644 --- a/block/blk-mq-debugfs.c +++ b/block/blk-mq-debugfs.c @@ -452,11 +452,11 @@ static void blk_mq_debugfs_tags_show(struct seq_file *m, atomic_read(&tags->active_queues)); seq_puts(m, "\nbitmap_tags:\n"); - sbitmap_queue_show(&tags->bitmap_tags, m); + sbitmap_queue_show(tags->bitmap_tags, m); if (tags->nr_reserved_tags) { seq_puts(m, "\nbreserved_tags:\n"); - sbitmap_queue_show(&tags->breserved_tags, m); + sbitmap_queue_show(tags->breserved_tags, m); } } @@ -487,7 +487,7 @@ static int hctx_tags_bitmap_show(void *data, struct seq_file *m) if (res) goto out; if (hctx->tags) - sbitmap_bitmap_show(&hctx->tags->bitmap_tags.sb, m); + sbitmap_bitmap_show(&hctx->tags->bitmap_tags->sb, m); mutex_unlock(&q->sysfs_lock); out: @@ -521,7 +521,7 @@ static int hctx_sched_tags_bitmap_show(void *data, struct seq_file *m) if (res) goto out; if (hctx->sched_tags) - sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags.sb, m); + sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags->sb, m); mutex_unlock(&q->sysfs_lock); out: diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index 0426f01e06a6..77fbeae05745 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -35,9 +35,9 @@ bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx) */ void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags, bool include_reserve) { - sbitmap_queue_wake_all(&tags->bitmap_tags); + sbitmap_queue_wake_all(tags->bitmap_tags); if (include_reserve) - sbitmap_queue_wake_all(&tags->breserved_tags); + sbitmap_queue_wake_all(tags->breserved_tags); } /* @@ -82,10 +82,10 @@ unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data) WARN_ON_ONCE(1); return BLK_MQ_NO_TAG; } - bt = &tags->breserved_tags; + bt = tags->breserved_tags; tag_offset = 0; } else { - bt = &tags->bitmap_tags; + bt = tags->bitmap_tags; tag_offset = tags->nr_reserved_tags; } @@ -131,9 +131,9 @@ unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data) data->ctx); tags = blk_mq_tags_from_data(data); if (data->flags & BLK_MQ_REQ_RESERVED) - bt = &tags->breserved_tags; + bt = tags->breserved_tags; else - bt = &tags->bitmap_tags; + bt = tags->bitmap_tags; /* * If destination hw queue is changed, fake wake up on @@ -167,10 +167,10 @@ void blk_mq_put_tag(struct blk_mq_tags *tags, struct blk_mq_ctx *ctx, const int real_tag = tag - tags->nr_reserved_tags; BUG_ON(real_tag >= tags->nr_tags); - sbitmap_queue_clear(&tags->bitmap_tags, real_tag, ctx->cpu); + sbitmap_queue_clear(tags->bitmap_tags, real_tag, ctx->cpu); } else { BUG_ON(tag >= tags->nr_reserved_tags); - sbitmap_queue_clear(&tags->breserved_tags, tag, ctx->cpu); + sbitmap_queue_clear(tags->breserved_tags, tag, ctx->cpu); } } @@ -298,9 +298,9 @@ static void __blk_mq_all_tag_iter(struct blk_mq_tags *tags, WARN_ON_ONCE(flags & BT_TAG_ITER_RESERVED); if (tags->nr_reserved_tags) - bt_tags_for_each(tags, &tags->breserved_tags, fn, priv, + bt_tags_for_each(tags, tags->breserved_tags, fn, priv, flags | BT_TAG_ITER_RESERVED); - bt_tags_for_each(tags, &tags->bitmap_tags, fn, priv, flags); + bt_tags_for_each(tags, tags->bitmap_tags, fn, priv, flags); } /** @@ -416,8 +416,8 @@ void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn, continue; if (tags->nr_reserved_tags) - bt_for_each(hctx, &tags->breserved_tags, fn, priv, true); - bt_for_each(hctx, &tags->bitmap_tags, fn, priv, false); + bt_for_each(hctx, tags->breserved_tags, fn, priv, true); + bt_for_each(hctx, tags->bitmap_tags, fn, priv, false); } blk_queue_exit(q); } @@ -435,15 +435,18 @@ static int blk_mq_init_bitmap_tags(struct blk_mq_tags *tags, unsigned int depth = tags->nr_tags - tags->nr_reserved_tags; bool round_robin = alloc_policy == BLK_TAG_ALLOC_RR; - if (bt_alloc(&tags->bitmap_tags, depth, round_robin, node)) + if (bt_alloc(&tags->__bitmap_tags, depth, round_robin, node)) return -ENOMEM; - if (bt_alloc(&tags->breserved_tags, tags->nr_reserved_tags, round_robin, - node)) + if (bt_alloc(&tags->__breserved_tags, tags->nr_reserved_tags, + round_robin, node)) goto free_bitmap_tags; + tags->bitmap_tags = &tags->__bitmap_tags; + tags->breserved_tags = &tags->__breserved_tags; + return 0; free_bitmap_tags: - sbitmap_queue_free(&tags->bitmap_tags); + sbitmap_queue_free(&tags->__bitmap_tags); return -ENOMEM; } @@ -475,8 +478,8 @@ struct blk_mq_tags *blk_mq_init_tags(unsigned int total_tags, void blk_mq_free_tags(struct blk_mq_tags *tags, unsigned int flags) { - sbitmap_queue_free(&tags->bitmap_tags); - sbitmap_queue_free(&tags->breserved_tags); + sbitmap_queue_free(&tags->__bitmap_tags); + sbitmap_queue_free(&tags->__breserved_tags); kfree(tags); } @@ -527,7 +530,7 @@ int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx, * Don't need (or can't) update reserved tags here, they * remain static and should never need resizing. */ - sbitmap_queue_resize(&tags->bitmap_tags, + sbitmap_queue_resize(tags->bitmap_tags, tdepth - tags->nr_reserved_tags); } diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h index 391f68d32fa1..5b6f25bd1966 100644 --- a/block/blk-mq-tag.h +++ b/block/blk-mq-tag.h @@ -13,8 +13,11 @@ struct blk_mq_tags { atomic_t active_queues; - struct sbitmap_queue bitmap_tags; - struct sbitmap_queue breserved_tags; + struct sbitmap_queue *bitmap_tags; + struct sbitmap_queue *breserved_tags; + + struct sbitmap_queue __bitmap_tags; + struct sbitmap_queue __breserved_tags; struct request **rqs; struct request **static_rqs; diff --git a/block/blk-mq.c b/block/blk-mq.c index a39693dbb3c8..4982bb1d75db 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1096,14 +1096,14 @@ static inline unsigned int queued_to_index(unsigned int queued) static bool __blk_mq_get_driver_tag(struct request *rq) { - struct sbitmap_queue *bt = &rq->mq_hctx->tags->bitmap_tags; + struct sbitmap_queue *bt = rq->mq_hctx->tags->bitmap_tags; unsigned int tag_offset = rq->mq_hctx->tags->nr_reserved_tags; int tag; blk_mq_tag_busy(rq->mq_hctx); if (blk_mq_tag_is_reserved(rq->mq_hctx->sched_tags, rq->internal_tag)) { - bt = &rq->mq_hctx->tags->breserved_tags; + bt = rq->mq_hctx->tags->breserved_tags; tag_offset = 0; } @@ -1145,7 +1145,7 @@ static int blk_mq_dispatch_wake(wait_queue_entry_t *wait, unsigned mode, struct sbitmap_queue *sbq; list_del_init(&wait->entry); - sbq = &hctx->tags->bitmap_tags; + sbq = hctx->tags->bitmap_tags; atomic_dec(&sbq->ws_active); } spin_unlock(&hctx->dispatch_wait_lock); @@ -1163,7 +1163,7 @@ static int blk_mq_dispatch_wake(wait_queue_entry_t *wait, unsigned mode, static bool blk_mq_mark_tag_wait(struct blk_mq_hw_ctx *hctx, struct request *rq) { - struct sbitmap_queue *sbq = &hctx->tags->bitmap_tags; + struct sbitmap_queue *sbq = hctx->tags->bitmap_tags; struct wait_queue_head *wq; wait_queue_entry_t *wait; bool ret; diff --git a/block/kyber-iosched.c b/block/kyber-iosched.c index 6d4ba0e9688e..dc89199bc8c6 100644 --- a/block/kyber-iosched.c +++ b/block/kyber-iosched.c @@ -359,7 +359,7 @@ static unsigned int kyber_sched_tags_shift(struct request_queue *q) * All of the hardware queues have the same depth, so we can just grab * the shift of the first one. */ - return q->queue_hw_ctx[0]->sched_tags->bitmap_tags.sb.shift; + return q->queue_hw_ctx[0]->sched_tags->bitmap_tags->sb.shift; } static struct kyber_queue_data *kyber_queue_data_alloc(struct request_queue *q) @@ -502,7 +502,7 @@ static int kyber_init_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx) khd->batching = 0; hctx->sched_data = khd; - sbitmap_queue_min_shallow_depth(&hctx->sched_tags->bitmap_tags, + sbitmap_queue_min_shallow_depth(hctx->sched_tags->bitmap_tags, kqd->async_depth); return 0; From 32bc15afed04bd73e29d713d8db47818d6aa89af Mon Sep 17 00:00:00 2001 From: John Garry Date: Wed, 19 Aug 2020 23:20:24 +0800 Subject: [PATCH 067/191] blk-mq: Facilitate a shared sbitmap per tagset Some SCSI HBAs (such as HPSA, megaraid, mpt3sas, hisi_sas_v3 ..) support multiple reply queues with single hostwide tags. In addition, these drivers want to use interrupt assignment in pci_alloc_irq_vectors(PCI_IRQ_AFFINITY). However, as discussed in [0], CPU hotplug may cause in-flight IO completion to not be serviced when an interrupt is shutdown. That problem is solved in commit bf0beec0607d ("blk-mq: drain I/O when all CPUs in a hctx are offline"). However, to take advantage of that blk-mq feature, the HBA HW queuess are required to be mapped to that of the blk-mq hctx's; to do that, the HBA HW queues need to be exposed to the upper layer. In making that transition, the per-SCSI command request tags are no longer unique per Scsi host - they are just unique per hctx. As such, the HBA LLDD would have to generate this tag internally, which has a certain performance overhead. However another problem is that blk-mq assumes the host may accept (Scsi_host.can_queue * #hw queue) commands. In commit 6eb045e092ef ("scsi: core: avoid host-wide host_busy counter for scsi_mq"), the Scsi host busy counter was removed, which would stop the LLDD being sent more than .can_queue commands; however, it should still be ensured that the block layer does not issue more than .can_queue commands to the Scsi host. To solve this problem, introduce a shared sbitmap per blk_mq_tag_set, which may be requested at init time. New flag BLK_MQ_F_TAG_HCTX_SHARED should be set when requesting the tagset to indicate whether the shared sbitmap should be used. Even when BLK_MQ_F_TAG_HCTX_SHARED is set, a full set of tags and requests are still allocated per hctx; the reason for this is that if tags and requests were only allocated for a single hctx - like hctx0 - it may break block drivers which expect a request be associated with a specific hctx, i.e. not always hctx0. This will introduce extra memory usage. This change is based on work originally from Ming Lei in [1] and from Bart's suggestion in [2]. [0] https://lore.kernel.org/linux-block/alpine.DEB.2.21.1904051331270.1802@nanos.tec.linutronix.de/ [1] https://lore.kernel.org/linux-block/20190531022801.10003-1-ming.lei@redhat.com/ [2] https://lore.kernel.org/linux-block/ff77beff-5fd9-9f05-12b6-826922bace1f@huawei.com/T/#m3db0a602f095cbcbff27e9c884d6b4ae826144be Signed-off-by: John Garry Tested-by: Don Brace #SCSI resv cmds patches used Tested-by: Douglas Gilbert Signed-off-by: Jens Axboe --- block/blk-mq-sched.c | 8 ++++--- block/blk-mq-tag.c | 51 ++++++++++++++++++++++++++++++++++++++---- block/blk-mq-tag.h | 7 ++++++ block/blk-mq.c | 15 +++++++++++++ block/blk-mq.h | 5 +++++ include/linux/blk-mq.h | 6 +++++ 6 files changed, 85 insertions(+), 7 deletions(-) diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index edfc8ea805bc..86d5545342ff 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -560,7 +560,7 @@ static void blk_mq_sched_free_tags(struct blk_mq_tag_set *set, struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx) { - unsigned int flags = set->flags; + unsigned int flags = set->flags & ~BLK_MQ_F_TAG_HCTX_SHARED; if (hctx->sched_tags) { blk_mq_free_rqs(set, hctx->sched_tags, hctx_idx); @@ -574,7 +574,8 @@ static int blk_mq_sched_alloc_tags(struct request_queue *q, unsigned int hctx_idx) { struct blk_mq_tag_set *set = q->tag_set; - unsigned int flags = set->flags; + /* Clear HCTX_SHARED so tags are init'ed */ + unsigned int flags = set->flags & ~BLK_MQ_F_TAG_HCTX_SHARED; int ret; hctx->sched_tags = blk_mq_alloc_rq_map(set, hctx_idx, q->nr_requests, @@ -596,7 +597,8 @@ static void blk_mq_sched_tags_teardown(struct request_queue *q) int i; queue_for_each_hw_ctx(q, hctx, i) { - unsigned int flags = hctx->flags; + /* Clear HCTX_SHARED so tags are freed */ + unsigned int flags = hctx->flags & ~BLK_MQ_F_TAG_HCTX_SHARED; if (hctx->sched_tags) { blk_mq_free_rq_map(hctx->sched_tags, flags); diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index 77fbeae05745..c6d7ebc62bdb 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -197,7 +197,7 @@ static bool bt_iter(struct sbitmap *bitmap, unsigned int bitnr, void *data) * We can hit rq == NULL here, because the tagging functions * test and set the bit before assigning ->rqs[]. */ - if (rq && rq->q == hctx->queue) + if (rq && rq->q == hctx->queue && rq->mq_hctx == hctx) return iter_data->fn(hctx, rq, iter_data->data, reserved); return true; } @@ -450,6 +450,38 @@ static int blk_mq_init_bitmap_tags(struct blk_mq_tags *tags, return -ENOMEM; } +int blk_mq_init_shared_sbitmap(struct blk_mq_tag_set *set, unsigned int flags) +{ + unsigned int depth = set->queue_depth - set->reserved_tags; + int alloc_policy = BLK_MQ_FLAG_TO_ALLOC_POLICY(set->flags); + bool round_robin = alloc_policy == BLK_TAG_ALLOC_RR; + int i, node = set->numa_node; + + if (bt_alloc(&set->__bitmap_tags, depth, round_robin, node)) + return -ENOMEM; + if (bt_alloc(&set->__breserved_tags, set->reserved_tags, + round_robin, node)) + goto free_bitmap_tags; + + for (i = 0; i < set->nr_hw_queues; i++) { + struct blk_mq_tags *tags = set->tags[i]; + + tags->bitmap_tags = &set->__bitmap_tags; + tags->breserved_tags = &set->__breserved_tags; + } + + return 0; +free_bitmap_tags: + sbitmap_queue_free(&set->__bitmap_tags); + return -ENOMEM; +} + +void blk_mq_exit_shared_sbitmap(struct blk_mq_tag_set *set) +{ + sbitmap_queue_free(&set->__bitmap_tags); + sbitmap_queue_free(&set->__breserved_tags); +} + struct blk_mq_tags *blk_mq_init_tags(unsigned int total_tags, unsigned int reserved_tags, int node, unsigned int flags) @@ -469,6 +501,9 @@ struct blk_mq_tags *blk_mq_init_tags(unsigned int total_tags, tags->nr_tags = total_tags; tags->nr_reserved_tags = reserved_tags; + if (flags & BLK_MQ_F_TAG_HCTX_SHARED) + return tags; + if (blk_mq_init_bitmap_tags(tags, node, alloc_policy) < 0) { kfree(tags); return NULL; @@ -478,8 +513,10 @@ struct blk_mq_tags *blk_mq_init_tags(unsigned int total_tags, void blk_mq_free_tags(struct blk_mq_tags *tags, unsigned int flags) { - sbitmap_queue_free(&tags->__bitmap_tags); - sbitmap_queue_free(&tags->__breserved_tags); + if (!(flags & BLK_MQ_F_TAG_HCTX_SHARED)) { + sbitmap_queue_free(tags->bitmap_tags); + sbitmap_queue_free(tags->breserved_tags); + } kfree(tags); } @@ -498,7 +535,8 @@ int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx, */ if (tdepth > tags->nr_tags) { struct blk_mq_tag_set *set = hctx->queue->tag_set; - unsigned int flags = set->flags; + /* Only sched tags can grow, so clear HCTX_SHARED flag */ + unsigned int flags = set->flags & ~BLK_MQ_F_TAG_HCTX_SHARED; struct blk_mq_tags *new; bool ret; @@ -537,6 +575,11 @@ int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx, return 0; } +void blk_mq_tag_resize_shared_sbitmap(struct blk_mq_tag_set *set, unsigned int size) +{ + sbitmap_queue_resize(&set->__bitmap_tags, size - set->reserved_tags); +} + /** * blk_mq_unique_tag() - return a tag that is unique queue-wide * @rq: request for which to compute a unique tag diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h index 5b6f25bd1966..8f4cce52ba2d 100644 --- a/block/blk-mq-tag.h +++ b/block/blk-mq-tag.h @@ -29,12 +29,19 @@ extern struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags, int node, unsigned int flags); extern void blk_mq_free_tags(struct blk_mq_tags *tags, unsigned int flags); +extern int blk_mq_init_shared_sbitmap(struct blk_mq_tag_set *set, + unsigned int flags); +extern void blk_mq_exit_shared_sbitmap(struct blk_mq_tag_set *set); + extern unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data); extern void blk_mq_put_tag(struct blk_mq_tags *tags, struct blk_mq_ctx *ctx, unsigned int tag); extern int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx, struct blk_mq_tags **tags, unsigned int depth, bool can_grow); +extern void blk_mq_tag_resize_shared_sbitmap(struct blk_mq_tag_set *set, + unsigned int size); + extern void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags, bool); void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn, void *priv); diff --git a/block/blk-mq.c b/block/blk-mq.c index 4982bb1d75db..5e8fe795edf1 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -3441,11 +3441,21 @@ int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) if (ret) goto out_free_mq_map; + if (blk_mq_is_sbitmap_shared(set->flags)) { + if (blk_mq_init_shared_sbitmap(set, set->flags)) { + ret = -ENOMEM; + goto out_free_mq_rq_maps; + } + } + mutex_init(&set->tag_list_lock); INIT_LIST_HEAD(&set->tag_list); return 0; +out_free_mq_rq_maps: + for (i = 0; i < set->nr_hw_queues; i++) + blk_mq_free_map_and_requests(set, i); out_free_mq_map: for (i = 0; i < set->nr_maps; i++) { kfree(set->map[i].mq_map); @@ -3464,6 +3474,9 @@ void blk_mq_free_tag_set(struct blk_mq_tag_set *set) for (i = 0; i < set->nr_hw_queues; i++) blk_mq_free_map_and_requests(set, i); + if (blk_mq_is_sbitmap_shared(set->flags)) + blk_mq_exit_shared_sbitmap(set); + for (j = 0; j < set->nr_maps; j++) { kfree(set->map[j].mq_map); set->map[j].mq_map = NULL; @@ -3500,6 +3513,8 @@ int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr) if (!hctx->sched_tags) { ret = blk_mq_tag_update_depth(hctx, &hctx->tags, nr, false); + if (!ret && blk_mq_is_sbitmap_shared(set->flags)) + blk_mq_tag_resize_shared_sbitmap(set, nr); } else { ret = blk_mq_tag_update_depth(hctx, &hctx->sched_tags, nr, true); diff --git a/block/blk-mq.h b/block/blk-mq.h index b86e7fe47789..3acdb56065e1 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -159,6 +159,11 @@ struct blk_mq_alloc_data { struct blk_mq_hw_ctx *hctx; }; +static inline bool blk_mq_is_sbitmap_shared(unsigned int flags) +{ + return flags & BLK_MQ_F_TAG_HCTX_SHARED; +} + static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data) { if (data->q->elevator) diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index 982c4f92b63c..df7b903ce7ae 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -231,6 +231,9 @@ enum hctx_type { * @flags: Zero or more BLK_MQ_F_* flags. * @driver_data: Pointer to data owned by the block driver that created this * tag set. + * @__bitmap_tags: A shared tags sbitmap, used over all hctx's + * @__breserved_tags: + * A shared reserved tags sbitmap, used over all hctx's * @tags: Tag sets. One tag set per hardware queue. Has @nr_hw_queues * elements. * @tag_list_lock: Serializes tag_list accesses. @@ -250,6 +253,8 @@ struct blk_mq_tag_set { unsigned int flags; void *driver_data; + struct sbitmap_queue __bitmap_tags; + struct sbitmap_queue __breserved_tags; struct blk_mq_tags **tags; struct mutex tag_list_lock; @@ -384,6 +389,7 @@ enum { * completing IO: */ BLK_MQ_F_STACKING = 1 << 2, + BLK_MQ_F_TAG_HCTX_SHARED = 1 << 3, BLK_MQ_F_BLOCKING = 1 << 5, BLK_MQ_F_NO_SCHED = 1 << 6, BLK_MQ_F_ALLOC_POLICY_START_BIT = 8, From a0235d230f3245aa4bd70b514d5effb24be61acd Mon Sep 17 00:00:00 2001 From: John Garry Date: Wed, 19 Aug 2020 23:20:25 +0800 Subject: [PATCH 068/191] blk-mq: Relocate hctx_may_queue() blk-mq.h and blk-mq-tag.h include on each other, which is less than ideal. Locate hctx_may_queue() to blk-mq.h, as it is not really tag specific code. In this way, we can drop the blk-mq-tag.h include of blk-mq.h Signed-off-by: John Garry Tested-by: Douglas Gilbert Signed-off-by: Jens Axboe --- block/blk-mq-tag.h | 33 --------------------------------- block/blk-mq.h | 32 ++++++++++++++++++++++++++++++++ 2 files changed, 32 insertions(+), 33 deletions(-) diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h index 8f4cce52ba2d..7d3e6b333a4a 100644 --- a/block/blk-mq-tag.h +++ b/block/blk-mq-tag.h @@ -2,8 +2,6 @@ #ifndef INT_BLK_MQ_TAG_H #define INT_BLK_MQ_TAG_H -#include "blk-mq.h" - /* * Tag address space map. */ @@ -81,37 +79,6 @@ static inline void blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx) __blk_mq_tag_idle(hctx); } -/* - * For shared tag users, we track the number of currently active users - * and attempt to provide a fair share of the tag depth for each of them. - */ -static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx, - struct sbitmap_queue *bt) -{ - unsigned int depth, users; - - if (!hctx || !(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) - return true; - if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state)) - return true; - - /* - * Don't try dividing an ant - */ - if (bt->sb.depth == 1) - return true; - - users = atomic_read(&hctx->tags->active_queues); - if (!users) - return true; - - /* - * Allow at least some tags - */ - depth = max((bt->sb.depth + users - 1) / users, 4U); - return atomic_read(&hctx->nr_active) < depth; -} - static inline bool blk_mq_tag_is_reserved(struct blk_mq_tags *tags, unsigned int tag) { diff --git a/block/blk-mq.h b/block/blk-mq.h index 3acdb56065e1..56dc37c21908 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -259,4 +259,36 @@ static inline struct blk_plug *blk_mq_plug(struct request_queue *q, return NULL; } +/* + * For shared tag users, we track the number of currently active users + * and attempt to provide a fair share of the tag depth for each of them. + */ +static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx, + struct sbitmap_queue *bt) +{ + unsigned int depth, users; + + if (!hctx || !(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) + return true; + if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state)) + return true; + + /* + * Don't try dividing an ant + */ + if (bt->sb.depth == 1) + return true; + + users = atomic_read(&hctx->tags->active_queues); + if (!users) + return true; + + /* + * Allow at least some tags + */ + depth = max((bt->sb.depth + users - 1) / users, 4U); + return atomic_read(&hctx->nr_active) < depth; +} + + #endif From bccf5e26d99c28980bd6ced474422a1b18402263 Mon Sep 17 00:00:00 2001 From: John Garry Date: Wed, 19 Aug 2020 23:20:26 +0800 Subject: [PATCH 069/191] blk-mq: Record nr_active_requests per queue for when using shared sbitmap The per-hctx nr_active value can no longer be used to fairly assign a share of tag depth per request queue for when using a shared sbitmap, as it does not consider that the tags are shared tags over all hctx's. For this case, record the nr_active_requests per request_queue, and make the judgement based on that value. Co-developed-with: Kashyap Desai Signed-off-by: John Garry Tested-by: Don Brace #SCSI resv cmds patches used Tested-by: Douglas Gilbert Signed-off-by: Jens Axboe --- block/blk-core.c | 2 ++ block/blk-mq.c | 4 ++-- block/blk-mq.h | 26 ++++++++++++++++++++++++-- include/linux/blkdev.h | 2 ++ 4 files changed, 30 insertions(+), 4 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 9f2a99abeeb9..093649bd252e 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -543,6 +543,8 @@ struct request_queue *blk_alloc_queue(int node_id) q->backing_dev_info->capabilities = BDI_CAP_CGROUP_WRITEBACK; q->node = node_id; + atomic_set(&q->nr_active_requests_shared_sbitmap, 0); + timer_setup(&q->backing_dev_info->laptop_mode_wb_timer, laptop_mode_timer_fn, 0); timer_setup(&q->timeout, blk_rq_timed_out_timer, 0); diff --git a/block/blk-mq.c b/block/blk-mq.c index 5e8fe795edf1..ffc5ad0c91b7 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -519,7 +519,7 @@ void blk_mq_free_request(struct request *rq) ctx->rq_completed[rq_is_sync(rq)]++; if (rq->rq_flags & RQF_MQ_INFLIGHT) - atomic_dec(&hctx->nr_active); + __blk_mq_dec_active_requests(hctx); if (unlikely(laptop_mode && !blk_rq_is_passthrough(rq))) laptop_io_completion(q->backing_dev_info); @@ -1127,7 +1127,7 @@ static bool blk_mq_get_driver_tag(struct request *rq) if ((hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED) && !(rq->rq_flags & RQF_MQ_INFLIGHT)) { rq->rq_flags |= RQF_MQ_INFLIGHT; - atomic_inc(&hctx->nr_active); + __blk_mq_inc_active_requests(hctx); } hctx->tags->rqs[rq->tag] = rq; return true; diff --git a/block/blk-mq.h b/block/blk-mq.h index 56dc37c21908..25ec73078e95 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -199,6 +199,28 @@ static inline bool blk_mq_get_dispatch_budget(struct request_queue *q) return true; } +static inline void __blk_mq_inc_active_requests(struct blk_mq_hw_ctx *hctx) +{ + if (blk_mq_is_sbitmap_shared(hctx->flags)) + atomic_inc(&hctx->queue->nr_active_requests_shared_sbitmap); + else + atomic_inc(&hctx->nr_active); +} + +static inline void __blk_mq_dec_active_requests(struct blk_mq_hw_ctx *hctx) +{ + if (blk_mq_is_sbitmap_shared(hctx->flags)) + atomic_dec(&hctx->queue->nr_active_requests_shared_sbitmap); + else + atomic_dec(&hctx->nr_active); +} + +static inline int __blk_mq_active_requests(struct blk_mq_hw_ctx *hctx) +{ + if (blk_mq_is_sbitmap_shared(hctx->flags)) + return atomic_read(&hctx->queue->nr_active_requests_shared_sbitmap); + return atomic_read(&hctx->nr_active); +} static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx, struct request *rq) { @@ -207,7 +229,7 @@ static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx, if (rq->rq_flags & RQF_MQ_INFLIGHT) { rq->rq_flags &= ~RQF_MQ_INFLIGHT; - atomic_dec(&hctx->nr_active); + __blk_mq_dec_active_requests(hctx); } } @@ -287,7 +309,7 @@ static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx, * Allow at least some tags */ depth = max((bt->sb.depth + users - 1) / users, 4U); - return atomic_read(&hctx->nr_active) < depth; + return __blk_mq_active_requests(hctx) < depth; } diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index d0d61bc81615..6277aee2aeaa 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -485,6 +485,8 @@ struct request_queue { struct timer_list timeout; struct work_struct timeout_work; + atomic_t nr_active_requests_shared_sbitmap; + struct list_head icq_list; #ifdef CONFIG_BLK_CGROUP DECLARE_BITMAP (blkcg_pols, BLKCG_MAX_POLS); From f1b49fdc1c64db110aa1315831e5fe0f8599fa56 Mon Sep 17 00:00:00 2001 From: John Garry Date: Wed, 19 Aug 2020 23:20:27 +0800 Subject: [PATCH 070/191] blk-mq: Record active_queues_shared_sbitmap per tag_set for when using shared sbitmap For when using a shared sbitmap, no longer should the number of active request queues per hctx be relied on for when judging how to share the tag bitmap. Instead maintain the number of active request queues per tag_set, and make the judgement based on that. Originally-from: Kashyap Desai Signed-off-by: John Garry Tested-by: Don Brace #SCSI resv cmds patches used Tested-by: Douglas Gilbert Signed-off-by: Jens Axboe --- block/blk-mq-tag.c | 31 ++++++++++++++++++++++++------- block/blk-mq.c | 2 ++ block/blk-mq.h | 16 +++++++++++++--- include/linux/blk-mq.h | 1 + include/linux/blkdev.h | 1 + 5 files changed, 41 insertions(+), 10 deletions(-) diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index c6d7ebc62bdb..c31c4a0478a5 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -23,9 +23,18 @@ */ bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx) { - if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state) && - !test_and_set_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state)) - atomic_inc(&hctx->tags->active_queues); + if (blk_mq_is_sbitmap_shared(hctx->flags)) { + struct request_queue *q = hctx->queue; + struct blk_mq_tag_set *set = q->tag_set; + + if (!test_bit(QUEUE_FLAG_HCTX_ACTIVE, &q->queue_flags) && + !test_and_set_bit(QUEUE_FLAG_HCTX_ACTIVE, &q->queue_flags)) + atomic_inc(&set->active_queues_shared_sbitmap); + } else { + if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state) && + !test_and_set_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state)) + atomic_inc(&hctx->tags->active_queues); + } return true; } @@ -47,11 +56,19 @@ void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags, bool include_reserve) void __blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx) { struct blk_mq_tags *tags = hctx->tags; + struct request_queue *q = hctx->queue; + struct blk_mq_tag_set *set = q->tag_set; - if (!test_and_clear_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state)) - return; - - atomic_dec(&tags->active_queues); + if (blk_mq_is_sbitmap_shared(hctx->flags)) { + if (!test_and_clear_bit(QUEUE_FLAG_HCTX_ACTIVE, + &q->queue_flags)) + return; + atomic_dec(&set->active_queues_shared_sbitmap); + } else { + if (!test_and_clear_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state)) + return; + atomic_dec(&tags->active_queues); + } blk_mq_tag_wakeup_all(tags, false); } diff --git a/block/blk-mq.c b/block/blk-mq.c index ffc5ad0c91b7..eff9d987f85b 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -3442,6 +3442,8 @@ int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) goto out_free_mq_map; if (blk_mq_is_sbitmap_shared(set->flags)) { + atomic_set(&set->active_queues_shared_sbitmap, 0); + if (blk_mq_init_shared_sbitmap(set, set->flags)) { ret = -ENOMEM; goto out_free_mq_rq_maps; diff --git a/block/blk-mq.h b/block/blk-mq.h index 25ec73078e95..a52703c98b77 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -292,8 +292,6 @@ static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx, if (!hctx || !(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) return true; - if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state)) - return true; /* * Don't try dividing an ant @@ -301,7 +299,19 @@ static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx, if (bt->sb.depth == 1) return true; - users = atomic_read(&hctx->tags->active_queues); + if (blk_mq_is_sbitmap_shared(hctx->flags)) { + struct request_queue *q = hctx->queue; + struct blk_mq_tag_set *set = q->tag_set; + + if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &q->queue_flags)) + return true; + users = atomic_read(&set->active_queues_shared_sbitmap); + } else { + if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state)) + return true; + users = atomic_read(&hctx->tags->active_queues); + } + if (!users) return true; diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index df7b903ce7ae..8279c807e1f3 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -252,6 +252,7 @@ struct blk_mq_tag_set { unsigned int timeout; unsigned int flags; void *driver_data; + atomic_t active_queues_shared_sbitmap; struct sbitmap_queue __bitmap_tags; struct sbitmap_queue __breserved_tags; diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 6277aee2aeaa..7d82959e7b86 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -618,6 +618,7 @@ struct request_queue { #define QUEUE_FLAG_PCI_P2PDMA 25 /* device supports PCI p2p requests */ #define QUEUE_FLAG_ZONE_RESETALL 26 /* supports Zone Reset All */ #define QUEUE_FLAG_RQ_ALLOC_TIME 27 /* record rq->alloc_time_ns */ +#define QUEUE_FLAG_HCTX_ACTIVE 28 /* at least one blk-mq hctx is active */ #define QUEUE_FLAG_MQ_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ (1 << QUEUE_FLAG_SAME_COMP)) From b445547ec1bbd3e7bf4b1c142550942f70527d95 Mon Sep 17 00:00:00 2001 From: Kashyap Desai Date: Wed, 19 Aug 2020 23:20:28 +0800 Subject: [PATCH 071/191] blk-mq, elevator: Count requests per hctx to improve performance High CPU utilization on "native_queued_spin_lock_slowpath" due to lock contention is possible for mq-deadline and bfq IO schedulers when nr_hw_queues is more than one. It is because kblockd work queue can submit IO from all online CPUs (through blk_mq_run_hw_queues()) even though only one hctx has pending commands. The elevator callback .has_work for mq-deadline and bfq scheduler considers pending work if there are any IOs on request queue but it does not account hctx context. Add a per-hctx 'elevator_queued' count to the hctx to avoid triggering the elevator even though there are no requests queued. [jpg: Relocated atomic_dec() in dd_dispatch_request(), update commit message per Kashyap] Signed-off-by: Kashyap Desai Signed-off-by: Hannes Reinecke Signed-off-by: John Garry Tested-by: Douglas Gilbert Signed-off-by: Jens Axboe --- block/bfq-iosched.c | 5 +++++ block/blk-mq.c | 1 + block/mq-deadline.c | 6 ++++++ include/linux/blk-mq.h | 4 ++++ 4 files changed, 16 insertions(+) diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 418ffd4b5552..a251b80d8ee5 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -4640,6 +4640,9 @@ static bool bfq_has_work(struct blk_mq_hw_ctx *hctx) { struct bfq_data *bfqd = hctx->queue->elevator->elevator_data; + if (!atomic_read(&hctx->elevator_queued)) + return false; + /* * Avoiding lock: a race on bfqd->busy_queues should cause at * most a call to dispatch for nothing @@ -5554,6 +5557,7 @@ static void bfq_insert_requests(struct blk_mq_hw_ctx *hctx, rq = list_first_entry(list, struct request, queuelist); list_del_init(&rq->queuelist); bfq_insert_request(hctx, rq, at_head); + atomic_inc(&hctx->elevator_queued); } } @@ -5933,6 +5937,7 @@ static void bfq_finish_requeue_request(struct request *rq) bfq_completed_request(bfqq, bfqd); bfq_finish_requeue_request_body(bfqq); + atomic_dec(&rq->mq_hctx->elevator_queued); spin_unlock_irqrestore(&bfqd->lock, flags); } else { diff --git a/block/blk-mq.c b/block/blk-mq.c index eff9d987f85b..4abb71459f94 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2660,6 +2660,7 @@ blk_mq_alloc_hctx(struct request_queue *q, struct blk_mq_tag_set *set, goto free_hctx; atomic_set(&hctx->nr_active, 0); + atomic_set(&hctx->elevator_queued, 0); if (node == NUMA_NO_NODE) node = set->numa_node; hctx->numa_node = node; diff --git a/block/mq-deadline.c b/block/mq-deadline.c index b57470e154c8..800ac902809b 100644 --- a/block/mq-deadline.c +++ b/block/mq-deadline.c @@ -386,6 +386,8 @@ static struct request *dd_dispatch_request(struct blk_mq_hw_ctx *hctx) spin_lock(&dd->lock); rq = __dd_dispatch_request(dd); spin_unlock(&dd->lock); + if (rq) + atomic_dec(&rq->mq_hctx->elevator_queued); return rq; } @@ -533,6 +535,7 @@ static void dd_insert_requests(struct blk_mq_hw_ctx *hctx, rq = list_first_entry(list, struct request, queuelist); list_del_init(&rq->queuelist); dd_insert_request(hctx, rq, at_head); + atomic_inc(&hctx->elevator_queued); } spin_unlock(&dd->lock); } @@ -579,6 +582,9 @@ static bool dd_has_work(struct blk_mq_hw_ctx *hctx) { struct deadline_data *dd = hctx->queue->elevator->elevator_data; + if (!atomic_read(&hctx->elevator_queued)) + return false; + return !list_empty_careful(&dd->dispatch) || !list_empty_careful(&dd->fifo_list[0]) || !list_empty_careful(&dd->fifo_list[1]); diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index 8279c807e1f3..b23eeca4d677 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -139,6 +139,10 @@ struct blk_mq_hw_ctx { * shared across request queues. */ atomic_t nr_active; + /** + * @elevator_queued: Number of queued requests on hctx. + */ + atomic_t elevator_queued; /** @cpuhp_online: List to store request if CPU is going to die */ struct hlist_node cpuhp_online; From 6dbf7bb555981fb5faf7b691e8f6169fc2b2e63b Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Fri, 4 Sep 2020 10:58:51 +0200 Subject: [PATCH 072/191] fs: Don't invalidate page buffers in block_write_full_page() If block_write_full_page() is called for a page that is beyond current inode size, it will truncate page buffers for the page and return 0. This logic has been added in 2.5.62 in commit 81eb69062588 ("fix ext3 BUG due to race with truncate") in history.git tree to fix a problem with ext3 in data=ordered mode. This particular problem doesn't exist anymore because ext3 is long gone and ext4 handles ordered data differently. Also normally buffers are invalidated by truncate code and there's no need to specially handle this in ->writepage() code. This invalidation of page buffers in block_write_full_page() is causing issues to filesystems (e.g. ext4 or ocfs2) when block device is shrunk under filesystem's hands and metadata buffers get discarded while being tracked by the journalling layer. Although it is obviously "not supported" it can cause kernel crashes like: [ 7986.689400] BUG: unable to handle kernel NULL pointer dereference at +0000000000000008 [ 7986.697197] PGD 0 P4D 0 [ 7986.699724] Oops: 0002 [#1] SMP PTI [ 7986.703200] CPU: 4 PID: 203778 Comm: jbd2/dm-3-8 Kdump: loaded Tainted: G +O --------- - - 4.18.0-147.5.0.5.h126.eulerosv2r9.x86_64 #1 [ 7986.716438] Hardware name: Huawei RH2288H V3/BC11HGSA0, BIOS 1.57 08/11/2015 [ 7986.723462] RIP: 0010:jbd2_journal_grab_journal_head+0x1b/0x40 [jbd2] ... [ 7986.810150] Call Trace: [ 7986.812595] __jbd2_journal_insert_checkpoint+0x23/0x70 [jbd2] [ 7986.818408] jbd2_journal_commit_transaction+0x155f/0x1b60 [jbd2] [ 7986.836467] kjournald2+0xbd/0x270 [jbd2] which is not great. The crash happens because bh->b_private is suddently NULL although BH_JBD flag is still set (this is because block_invalidatepage() cleared BH_Mapped flag and subsequent bh lookup found buffer without BH_Mapped set, called init_page_buffers() which has rewritten bh->b_private). So just remove the invalidation in block_write_full_page(). Note that the buffer cache invalidation when block device changes size is already careful to avoid similar problems by using invalidate_mapping_pages() which skips busy buffers so it was only this odd block_write_full_page() behavior that could tear down bdev buffers under filesystem's hands. Reported-by: Ye Bin Signed-off-by: Jan Kara Reviewed-by: Christoph Hellwig CC: stable@vger.kernel.org Signed-off-by: Jens Axboe --- fs/buffer.c | 16 ---------------- 1 file changed, 16 deletions(-) diff --git a/fs/buffer.c b/fs/buffer.c index 50bbc99e3d96..5a28a6aa7f16 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -2771,16 +2771,6 @@ int nobh_writepage(struct page *page, get_block_t *get_block, /* Is the page fully outside i_size? (truncate in progress) */ offset = i_size & (PAGE_SIZE-1); if (page->index >= end_index+1 || !offset) { - /* - * The page may have dirty, unmapped buffers. For example, - * they may have been added in ext3_writepage(). Make them - * freeable here, so the page does not leak. - */ -#if 0 - /* Not really sure about this - do we need this ? */ - if (page->mapping->a_ops->invalidatepage) - page->mapping->a_ops->invalidatepage(page, offset); -#endif unlock_page(page); return 0; /* don't care */ } @@ -2975,12 +2965,6 @@ int block_write_full_page(struct page *page, get_block_t *get_block, /* Is the page fully outside i_size? (truncate in progress) */ offset = i_size & (PAGE_SIZE-1); if (page->index >= end_index+1 || !offset) { - /* - * The page may have dirty, unmapped buffers. For example, - * they may have been added in ext3_writepage(). Make them - * freeable here, so the page does not leak. - */ - do_invalidatepage(page, 0, PAGE_SIZE); unlock_page(page); return 0; /* don't care */ } From 384d87ef2c954fc58e6c5fd8253e4a1984f5fe02 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Fri, 4 Sep 2020 10:58:52 +0200 Subject: [PATCH 073/191] block: Do not discard buffers under a mounted filesystem Discarding blocks and buffers under a mounted filesystem is hardly anything admin wants to do. Usually it will confuse the filesystem and sometimes the loss of buffer_head state (including b_private field) can even cause crashes like: BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 PGD 0 P4D 0 Oops: 0002 [#1] SMP PTI CPU: 4 PID: 203778 Comm: jbd2/dm-3-8 Kdump: loaded Tainted: G O --------- - - 4.18.0-147.5.0.5.h126.eulerosv2r9.x86_64 #1 Hardware name: Huawei RH2288H V3/BC11HGSA0, BIOS 1.57 08/11/2015 RIP: 0010:jbd2_journal_grab_journal_head+0x1b/0x40 [jbd2] ... Call Trace: __jbd2_journal_insert_checkpoint+0x23/0x70 [jbd2] jbd2_journal_commit_transaction+0x155f/0x1b60 [jbd2] kjournald2+0xbd/0x270 [jbd2] So if we don't have block device open with O_EXCL already, claim the block device while we truncate buffer cache. This makes sure any exclusive block device user (such as filesystem) cannot operate on the device while we are discarding buffer cache. Reported-by: Ye Bin Signed-off-by: Jan Kara Reviewed-by: Christoph Hellwig [axboe: fix !CONFIG_BLOCK error in truncate_bdev_range()] Signed-off-by: Jens Axboe --- block/ioctl.c | 16 ++++++++++------ fs/block_dev.c | 37 +++++++++++++++++++++++++++++++++---- include/linux/blkdev.h | 7 +++++++ 3 files changed, 50 insertions(+), 10 deletions(-) diff --git a/block/ioctl.c b/block/ioctl.c index bdb3bbb253d9..ae74d0409afa 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -112,8 +112,7 @@ static int blk_ioctl_discard(struct block_device *bdev, fmode_t mode, uint64_t range[2]; uint64_t start, len; struct request_queue *q = bdev_get_queue(bdev); - struct address_space *mapping = bdev->bd_inode->i_mapping; - + int err; if (!(mode & FMODE_WRITE)) return -EBADF; @@ -134,7 +133,11 @@ static int blk_ioctl_discard(struct block_device *bdev, fmode_t mode, if (start + len > i_size_read(bdev->bd_inode)) return -EINVAL; - truncate_inode_pages_range(mapping, start, start + len - 1); + + err = truncate_bdev_range(bdev, mode, start, start + len - 1); + if (err) + return err; + return blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL, flags); } @@ -143,8 +146,8 @@ static int blk_ioctl_zeroout(struct block_device *bdev, fmode_t mode, unsigned long arg) { uint64_t range[2]; - struct address_space *mapping; uint64_t start, end, len; + int err; if (!(mode & FMODE_WRITE)) return -EBADF; @@ -166,8 +169,9 @@ static int blk_ioctl_zeroout(struct block_device *bdev, fmode_t mode, return -EINVAL; /* Invalidate the page cache, including dirty pages */ - mapping = bdev->bd_inode->i_mapping; - truncate_inode_pages_range(mapping, start, end); + err = truncate_bdev_range(bdev, mode, start, end); + if (err) + return err; return blkdev_issue_zeroout(bdev, start >> 9, len >> 9, GFP_KERNEL, BLKDEV_ZERO_NOUNMAP); diff --git a/fs/block_dev.c b/fs/block_dev.c index 9cb205405f9d..c70c41ecba48 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -103,6 +103,35 @@ void invalidate_bdev(struct block_device *bdev) } EXPORT_SYMBOL(invalidate_bdev); +/* + * Drop all buffers & page cache for given bdev range. This function bails + * with error if bdev has other exclusive owner (such as filesystem). + */ +int truncate_bdev_range(struct block_device *bdev, fmode_t mode, + loff_t lstart, loff_t lend) +{ + struct block_device *claimed_bdev = NULL; + int err; + + /* + * If we don't hold exclusive handle for the device, upgrade to it + * while we discard the buffer cache to avoid discarding buffers + * under live filesystem. + */ + if (!(mode & FMODE_EXCL)) { + claimed_bdev = bdev->bd_contains; + err = bd_prepare_to_claim(bdev, claimed_bdev, + truncate_bdev_range); + if (err) + return err; + } + truncate_inode_pages_range(bdev->bd_inode->i_mapping, lstart, lend); + if (claimed_bdev) + bd_abort_claiming(bdev, claimed_bdev, truncate_bdev_range); + return 0; +} +EXPORT_SYMBOL(truncate_bdev_range); + static void set_init_blocksize(struct block_device *bdev) { bdev->bd_inode->i_blkbits = blksize_bits(bdev_logical_block_size(bdev)); @@ -1968,7 +1997,6 @@ static long blkdev_fallocate(struct file *file, int mode, loff_t start, loff_t len) { struct block_device *bdev = I_BDEV(bdev_file_inode(file)); - struct address_space *mapping; loff_t end = start + len - 1; loff_t isize; int error; @@ -1996,8 +2024,9 @@ static long blkdev_fallocate(struct file *file, int mode, loff_t start, return -EINVAL; /* Invalidate the page cache, including dirty pages. */ - mapping = bdev->bd_inode->i_mapping; - truncate_inode_pages_range(mapping, start, end); + error = truncate_bdev_range(bdev, file->f_mode, start, end); + if (error) + return error; switch (mode) { case FALLOC_FL_ZERO_RANGE: @@ -2024,7 +2053,7 @@ static long blkdev_fallocate(struct file *file, int mode, loff_t start, * the caller will be given -EBUSY. The third argument is * inclusive, so the rounding here is safe. */ - return invalidate_inode_pages2_range(mapping, + return invalidate_inode_pages2_range(bdev->bd_inode->i_mapping, start >> PAGE_SHIFT, end >> PAGE_SHIFT); } diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 7d82959e7b86..37ec5a73d027 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1987,11 +1987,18 @@ void bdput(struct block_device *); #ifdef CONFIG_BLOCK void invalidate_bdev(struct block_device *bdev); +int truncate_bdev_range(struct block_device *bdev, fmode_t mode, loff_t lstart, + loff_t lend); int sync_blockdev(struct block_device *bdev); #else static inline void invalidate_bdev(struct block_device *bdev) { } +static inline int truncate_bdev_range(struct block_device *bdev, fmode_t mode, + loff_t lstart, loff_t lend) +{ + return 0; +} static inline int sync_blockdev(struct block_device *bdev) { return 0; From ddfb8b0beda1c371a44897c0359adccf030f7c58 Mon Sep 17 00:00:00 2001 From: Baolin Wang Date: Mon, 7 Sep 2020 16:36:17 +0800 Subject: [PATCH 074/191] block: Remove unused blk_mq_sched_free_hctx_data() Now we usually free the hctx->sched_data by e->type->ops.exit_hctx(), and no users will use blk_mq_sched_free_hctx_data() function. Remove it. Signed-off-by: Baolin Wang Signed-off-by: Jens Axboe --- block/blk-mq-sched.c | 15 --------------- block/blk-mq-sched.h | 3 --- 2 files changed, 18 deletions(-) diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index 86d5545342ff..3e9596738852 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -18,21 +18,6 @@ #include "blk-mq-tag.h" #include "blk-wbt.h" -void blk_mq_sched_free_hctx_data(struct request_queue *q, - void (*exit)(struct blk_mq_hw_ctx *)) -{ - struct blk_mq_hw_ctx *hctx; - int i; - - queue_for_each_hw_ctx(q, hctx, i) { - if (exit && hctx->sched_data) - exit(hctx); - kfree(hctx->sched_data); - hctx->sched_data = NULL; - } -} -EXPORT_SYMBOL_GPL(blk_mq_sched_free_hctx_data); - void blk_mq_sched_assign_ioc(struct request *rq) { struct request_queue *q = rq->q; diff --git a/block/blk-mq-sched.h b/block/blk-mq-sched.h index 126021fc3a11..fe62e7ce0f9e 100644 --- a/block/blk-mq-sched.h +++ b/block/blk-mq-sched.h @@ -5,9 +5,6 @@ #include "blk-mq.h" #include "blk-mq-tag.h" -void blk_mq_sched_free_hctx_data(struct request_queue *q, - void (*exit)(struct blk_mq_hw_ctx *)); - void blk_mq_sched_assign_ioc(struct request *rq); void blk_mq_sched_request_inserted(struct request *rq); From e75ad2cc41832bae3218e3d6f38b3f03ae0a41df Mon Sep 17 00:00:00 2001 From: Wang Hai Date: Mon, 7 Sep 2020 22:06:52 +0800 Subject: [PATCH 075/191] blktrace: make function blk_trace_bio_get_cgid() static The sparse tool complains as follows: kernel/trace/blktrace.c:796:5: warning: symbol 'blk_trace_bio_get_cgid' was not declared. Should it be static? This function is not used outside of blktrace.c, so this commit marks it static. Reported-by: Hulk Robot Signed-off-by: Wang Hai Signed-off-by: Jens Axboe --- kernel/trace/blktrace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index 4b3a42fc3b24..c0887f32f647 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -793,7 +793,7 @@ static u64 blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio) return cgroup_id(bio_blkcg(bio)->css.cgroup); } #else -u64 blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio) +static u64 blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio) { return 0; } From 3562614705c6f2324f79a959a2cf1ae24d142578 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 3 Sep 2020 08:07:00 +0200 Subject: [PATCH 076/191] block: add helper macros for queue sysfs entries Add two helpers macros to avoid boilerplate code for the queue sysfs entries. Signed-off-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe --- block/blk-sysfs.c | 230 ++++++++++------------------------------------ 1 file changed, 49 insertions(+), 181 deletions(-) diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 7dda709f3ccb..9df877d3dae2 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -547,159 +547,75 @@ static ssize_t queue_dax_show(struct request_queue *q, char *page) return queue_var_show(blk_queue_dax(q), page); } -static struct queue_sysfs_entry queue_requests_entry = { - .attr = {.name = "nr_requests", .mode = 0644 }, - .show = queue_requests_show, - .store = queue_requests_store, +#define QUEUE_RO_ENTRY(_prefix, _name) \ +static struct queue_sysfs_entry _prefix##_entry = { \ + .attr = { .name = _name, .mode = 0444 }, \ + .show = _prefix##_show, \ }; -static struct queue_sysfs_entry queue_ra_entry = { - .attr = {.name = "read_ahead_kb", .mode = 0644 }, - .show = queue_ra_show, - .store = queue_ra_store, +#define QUEUE_RW_ENTRY(_prefix, _name) \ +static struct queue_sysfs_entry _prefix##_entry = { \ + .attr = { .name = _name, .mode = 0644 }, \ + .show = _prefix##_show, \ + .store = _prefix##_store, \ }; -static struct queue_sysfs_entry queue_max_sectors_entry = { - .attr = {.name = "max_sectors_kb", .mode = 0644 }, - .show = queue_max_sectors_show, - .store = queue_max_sectors_store, -}; +QUEUE_RW_ENTRY(queue_requests, "nr_requests"); +QUEUE_RW_ENTRY(queue_ra, "read_ahead_kb"); +QUEUE_RW_ENTRY(queue_max_sectors, "max_sectors_kb"); +QUEUE_RO_ENTRY(queue_max_hw_sectors, "max_hw_sectors_kb"); +QUEUE_RO_ENTRY(queue_max_segments, "max_segments"); +QUEUE_RO_ENTRY(queue_max_integrity_segments, "max_integrity_segments"); +QUEUE_RO_ENTRY(queue_max_segment_size, "max_segment_size"); +QUEUE_RW_ENTRY(elv_iosched, "scheduler"); -static struct queue_sysfs_entry queue_max_hw_sectors_entry = { - .attr = {.name = "max_hw_sectors_kb", .mode = 0444 }, - .show = queue_max_hw_sectors_show, -}; +QUEUE_RO_ENTRY(queue_logical_block_size, "logical_block_size"); +QUEUE_RO_ENTRY(queue_physical_block_size, "physical_block_size"); +QUEUE_RO_ENTRY(queue_chunk_sectors, "chunk_sectors"); +QUEUE_RO_ENTRY(queue_io_min, "minimum_io_size"); +QUEUE_RO_ENTRY(queue_io_opt, "optimal_io_size"); -static struct queue_sysfs_entry queue_max_segments_entry = { - .attr = {.name = "max_segments", .mode = 0444 }, - .show = queue_max_segments_show, -}; +QUEUE_RO_ENTRY(queue_max_discard_segments, "max_discard_segments"); +QUEUE_RO_ENTRY(queue_discard_granularity, "discard_granularity"); +QUEUE_RO_ENTRY(queue_discard_max_hw, "discard_max_hw_bytes"); +QUEUE_RW_ENTRY(queue_discard_max, "discard_max_bytes"); +QUEUE_RO_ENTRY(queue_discard_zeroes_data, "discard_zeroes_data"); -static struct queue_sysfs_entry queue_max_discard_segments_entry = { - .attr = {.name = "max_discard_segments", .mode = 0444 }, - .show = queue_max_discard_segments_show, -}; +QUEUE_RO_ENTRY(queue_write_same_max, "write_same_max_bytes"); +QUEUE_RO_ENTRY(queue_write_zeroes_max, "write_zeroes_max_bytes"); +QUEUE_RO_ENTRY(queue_zone_append_max, "zone_append_max_bytes"); -static struct queue_sysfs_entry queue_max_integrity_segments_entry = { - .attr = {.name = "max_integrity_segments", .mode = 0444 }, - .show = queue_max_integrity_segments_show, -}; +QUEUE_RO_ENTRY(queue_zoned, "zoned"); +QUEUE_RO_ENTRY(queue_nr_zones, "nr_zones"); +QUEUE_RO_ENTRY(queue_max_open_zones, "max_open_zones"); +QUEUE_RO_ENTRY(queue_max_active_zones, "max_active_zones"); -static struct queue_sysfs_entry queue_max_segment_size_entry = { - .attr = {.name = "max_segment_size", .mode = 0444 }, - .show = queue_max_segment_size_show, -}; +QUEUE_RW_ENTRY(queue_nomerges, "nomerges"); +QUEUE_RW_ENTRY(queue_rq_affinity, "rq_affinity"); +QUEUE_RW_ENTRY(queue_poll, "io_poll"); +QUEUE_RW_ENTRY(queue_poll_delay, "io_poll_delay"); +QUEUE_RW_ENTRY(queue_wc, "write_cache"); +QUEUE_RO_ENTRY(queue_fua, "fua"); +QUEUE_RO_ENTRY(queue_dax, "dax"); +QUEUE_RW_ENTRY(queue_io_timeout, "io_timeout"); +QUEUE_RW_ENTRY(queue_wb_lat, "wbt_lat_usec"); -static struct queue_sysfs_entry queue_iosched_entry = { - .attr = {.name = "scheduler", .mode = 0644 }, - .show = elv_iosched_show, - .store = elv_iosched_store, -}; +#ifdef CONFIG_BLK_DEV_THROTTLING_LOW +QUEUE_RW_ENTRY(blk_throtl_sample_time, "throttle_sample_time"); +#endif +/* legacy alias for logical_block_size: */ static struct queue_sysfs_entry queue_hw_sector_size_entry = { .attr = {.name = "hw_sector_size", .mode = 0444 }, .show = queue_logical_block_size_show, }; -static struct queue_sysfs_entry queue_logical_block_size_entry = { - .attr = {.name = "logical_block_size", .mode = 0444 }, - .show = queue_logical_block_size_show, -}; - -static struct queue_sysfs_entry queue_physical_block_size_entry = { - .attr = {.name = "physical_block_size", .mode = 0444 }, - .show = queue_physical_block_size_show, -}; - -static struct queue_sysfs_entry queue_chunk_sectors_entry = { - .attr = {.name = "chunk_sectors", .mode = 0444 }, - .show = queue_chunk_sectors_show, -}; - -static struct queue_sysfs_entry queue_io_min_entry = { - .attr = {.name = "minimum_io_size", .mode = 0444 }, - .show = queue_io_min_show, -}; - -static struct queue_sysfs_entry queue_io_opt_entry = { - .attr = {.name = "optimal_io_size", .mode = 0444 }, - .show = queue_io_opt_show, -}; - -static struct queue_sysfs_entry queue_discard_granularity_entry = { - .attr = {.name = "discard_granularity", .mode = 0444 }, - .show = queue_discard_granularity_show, -}; - -static struct queue_sysfs_entry queue_discard_max_hw_entry = { - .attr = {.name = "discard_max_hw_bytes", .mode = 0444 }, - .show = queue_discard_max_hw_show, -}; - -static struct queue_sysfs_entry queue_discard_max_entry = { - .attr = {.name = "discard_max_bytes", .mode = 0644 }, - .show = queue_discard_max_show, - .store = queue_discard_max_store, -}; - -static struct queue_sysfs_entry queue_discard_zeroes_data_entry = { - .attr = {.name = "discard_zeroes_data", .mode = 0444 }, - .show = queue_discard_zeroes_data_show, -}; - -static struct queue_sysfs_entry queue_write_same_max_entry = { - .attr = {.name = "write_same_max_bytes", .mode = 0444 }, - .show = queue_write_same_max_show, -}; - -static struct queue_sysfs_entry queue_write_zeroes_max_entry = { - .attr = {.name = "write_zeroes_max_bytes", .mode = 0444 }, - .show = queue_write_zeroes_max_show, -}; - -static struct queue_sysfs_entry queue_zone_append_max_entry = { - .attr = {.name = "zone_append_max_bytes", .mode = 0444 }, - .show = queue_zone_append_max_show, -}; - static struct queue_sysfs_entry queue_nonrot_entry = { .attr = {.name = "rotational", .mode = 0644 }, .show = queue_show_nonrot, .store = queue_store_nonrot, }; -static struct queue_sysfs_entry queue_zoned_entry = { - .attr = {.name = "zoned", .mode = 0444 }, - .show = queue_zoned_show, -}; - -static struct queue_sysfs_entry queue_nr_zones_entry = { - .attr = {.name = "nr_zones", .mode = 0444 }, - .show = queue_nr_zones_show, -}; - -static struct queue_sysfs_entry queue_max_open_zones_entry = { - .attr = {.name = "max_open_zones", .mode = 0444 }, - .show = queue_max_open_zones_show, -}; - -static struct queue_sysfs_entry queue_max_active_zones_entry = { - .attr = {.name = "max_active_zones", .mode = 0444 }, - .show = queue_max_active_zones_show, -}; - -static struct queue_sysfs_entry queue_nomerges_entry = { - .attr = {.name = "nomerges", .mode = 0644 }, - .show = queue_nomerges_show, - .store = queue_nomerges_store, -}; - -static struct queue_sysfs_entry queue_rq_affinity_entry = { - .attr = {.name = "rq_affinity", .mode = 0644 }, - .show = queue_rq_affinity_show, - .store = queue_rq_affinity_store, -}; - static struct queue_sysfs_entry queue_iostats_entry = { .attr = {.name = "iostats", .mode = 0644 }, .show = queue_show_iostats, @@ -712,54 +628,6 @@ static struct queue_sysfs_entry queue_random_entry = { .store = queue_store_random, }; -static struct queue_sysfs_entry queue_poll_entry = { - .attr = {.name = "io_poll", .mode = 0644 }, - .show = queue_poll_show, - .store = queue_poll_store, -}; - -static struct queue_sysfs_entry queue_poll_delay_entry = { - .attr = {.name = "io_poll_delay", .mode = 0644 }, - .show = queue_poll_delay_show, - .store = queue_poll_delay_store, -}; - -static struct queue_sysfs_entry queue_wc_entry = { - .attr = {.name = "write_cache", .mode = 0644 }, - .show = queue_wc_show, - .store = queue_wc_store, -}; - -static struct queue_sysfs_entry queue_fua_entry = { - .attr = {.name = "fua", .mode = 0444 }, - .show = queue_fua_show, -}; - -static struct queue_sysfs_entry queue_dax_entry = { - .attr = {.name = "dax", .mode = 0444 }, - .show = queue_dax_show, -}; - -static struct queue_sysfs_entry queue_io_timeout_entry = { - .attr = {.name = "io_timeout", .mode = 0644 }, - .show = queue_io_timeout_show, - .store = queue_io_timeout_store, -}; - -static struct queue_sysfs_entry queue_wb_lat_entry = { - .attr = {.name = "wbt_lat_usec", .mode = 0644 }, - .show = queue_wb_lat_show, - .store = queue_wb_lat_store, -}; - -#ifdef CONFIG_BLK_DEV_THROTTLING_LOW -static struct queue_sysfs_entry throtl_sample_time_entry = { - .attr = {.name = "throttle_sample_time", .mode = 0644 }, - .show = blk_throtl_sample_time_show, - .store = blk_throtl_sample_time_store, -}; -#endif - static struct attribute *queue_attrs[] = { &queue_requests_entry.attr, &queue_ra_entry.attr, @@ -769,7 +637,7 @@ static struct attribute *queue_attrs[] = { &queue_max_discard_segments_entry.attr, &queue_max_integrity_segments_entry.attr, &queue_max_segment_size_entry.attr, - &queue_iosched_entry.attr, + &elv_iosched_entry.attr, &queue_hw_sector_size_entry.attr, &queue_logical_block_size_entry.attr, &queue_physical_block_size_entry.attr, @@ -800,7 +668,7 @@ static struct attribute *queue_attrs[] = { &queue_poll_delay_entry.attr, &queue_io_timeout_entry.attr, #ifdef CONFIG_BLK_DEV_THROTTLING_LOW - &throtl_sample_time_entry.attr, + &blk_throtl_sample_time_entry.attr, #endif NULL, }; From fc93fe145316dad6186d8eb4b4f49f68b1cba0c3 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 3 Sep 2020 08:07:01 +0200 Subject: [PATCH 077/191] block: make QUEUE_SYSFS_BIT_FNS more useful Switch to the naming used by the other entries so that we can use the QUEUE_RW_ENTRY helper. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/blk-sysfs.c | 24 +++++------------------- 1 file changed, 5 insertions(+), 19 deletions(-) diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 9df877d3dae2..81722cdcf0cb 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -260,14 +260,14 @@ static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page) #define QUEUE_SYSFS_BIT_FNS(name, flag, neg) \ static ssize_t \ -queue_show_##name(struct request_queue *q, char *page) \ +queue_##name##_show(struct request_queue *q, char *page) \ { \ int bit; \ bit = test_bit(QUEUE_FLAG_##flag, &q->queue_flags); \ return queue_var_show(neg ? !bit : bit, page); \ } \ static ssize_t \ -queue_store_##name(struct request_queue *q, const char *page, size_t count) \ +queue_##name##_store(struct request_queue *q, const char *page, size_t count) \ { \ unsigned long val; \ ssize_t ret; \ @@ -610,23 +610,9 @@ static struct queue_sysfs_entry queue_hw_sector_size_entry = { .show = queue_logical_block_size_show, }; -static struct queue_sysfs_entry queue_nonrot_entry = { - .attr = {.name = "rotational", .mode = 0644 }, - .show = queue_show_nonrot, - .store = queue_store_nonrot, -}; - -static struct queue_sysfs_entry queue_iostats_entry = { - .attr = {.name = "iostats", .mode = 0644 }, - .show = queue_show_iostats, - .store = queue_store_iostats, -}; - -static struct queue_sysfs_entry queue_random_entry = { - .attr = {.name = "add_random", .mode = 0644 }, - .show = queue_show_random, - .store = queue_store_random, -}; +QUEUE_RW_ENTRY(queue_nonrot, "rotational"); +QUEUE_RW_ENTRY(queue_iostats, "iostats"); +QUEUE_RW_ENTRY(queue_random, "add_random"); static struct attribute *queue_attrs[] = { &queue_requests_entry.attr, From 95f6f3a46fc4ee1a2b216a6b46bdf2b450f1877f Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 8 Sep 2020 16:53:29 +0200 Subject: [PATCH 078/191] block: add a bdev_check_media_change helper Like check_disk_changed, except that it does not call ->revalidate_disk but leaves that to the caller. Signed-off-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- block/genhd.c | 29 ++++++++++++++++++++++++++++- fs/block_dev.c | 17 +++-------------- include/linux/genhd.h | 2 +- 3 files changed, 32 insertions(+), 16 deletions(-) diff --git a/block/genhd.c b/block/genhd.c index 081f1039d936..9d060e79eb31 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -2052,7 +2052,7 @@ void disk_flush_events(struct gendisk *disk, unsigned int mask) * CONTEXT: * Might sleep. */ -unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask) +static unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask) { struct disk_events *ev = disk->ev; unsigned int pending; @@ -2090,6 +2090,33 @@ unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask) return pending; } +/** + * bdev_check_media_change - check if a removable media has been changed + * @bdev: block device to check + * + * Check whether a removable media has been changed, and attempt to free all + * dentries and inodes and invalidates all block device page cache entries in + * that case. + * + * Returns %true if the block device changed, or %false if not. + */ +bool bdev_check_media_change(struct block_device *bdev) +{ + unsigned int events; + + events = disk_clear_events(bdev->bd_disk, DISK_EVENT_MEDIA_CHANGE | + DISK_EVENT_EJECT_REQUEST); + if (!(events & DISK_EVENT_MEDIA_CHANGE)) + return false; + + if (__invalidate_device(bdev, true)) + pr_warn("VFS: busy inodes on changed media %s\n", + bdev->bd_disk->disk_name); + set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags); + return true; +} +EXPORT_SYMBOL(bdev_check_media_change); + /* * Separate this part out so that a different pointer for clearing_ptr can be * passed in for disk_clear_events. diff --git a/fs/block_dev.c b/fs/block_dev.c index c70c41ecba48..c6ac0bd22eca 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1379,21 +1379,10 @@ EXPORT_SYMBOL(revalidate_disk_size); */ int check_disk_change(struct block_device *bdev) { - struct gendisk *disk = bdev->bd_disk; - const struct block_device_operations *bdops = disk->fops; - unsigned int events; - - events = disk_clear_events(disk, DISK_EVENT_MEDIA_CHANGE | - DISK_EVENT_EJECT_REQUEST); - if (!(events & DISK_EVENT_MEDIA_CHANGE)) + if (!bdev_check_media_change(bdev)) return 0; - - if (__invalidate_device(bdev, true)) - pr_warn("VFS: busy inodes on changed media %s\n", - disk->disk_name); - set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags); - if (bdops->revalidate_disk) - bdops->revalidate_disk(bdev->bd_disk); + if (bdev->bd_disk->fops->revalidate_disk) + bdev->bd_disk->fops->revalidate_disk(bdev->bd_disk); return 1; } diff --git a/include/linux/genhd.h b/include/linux/genhd.h index c618b27292fc..322d48a20772 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -315,7 +315,6 @@ extern void disk_unblock_events(struct gendisk *disk); extern void disk_flush_events(struct gendisk *disk, unsigned int mask); void set_capacity_revalidate_and_notify(struct gendisk *disk, sector_t size, bool update_bdev); -extern unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask); /* drivers/char/random.c */ extern void add_disk_randomness(struct gendisk *disk) __latent_entropy; @@ -372,6 +371,7 @@ void unregister_blkdev(unsigned int major, const char *name); void revalidate_disk_size(struct gendisk *disk, bool verbose); int check_disk_change(struct block_device *bdev); +bool bdev_check_media_change(struct block_device *bdev); int __invalidate_device(struct block_device *bdev, bool kill_dirty); void bd_set_nr_sectors(struct block_device *bdev, sector_t sectors); From acdfd443b32036e9040d7413fd9c64d8da267868 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 8 Sep 2020 16:53:30 +0200 Subject: [PATCH 079/191] amiflop: use bdev_check_media_change The Amiga floppy driver does not have a ->revalidate_disk method, so it can just use bdev_check_media_change without any additional changes. Signed-off-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- drivers/block/amiflop.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/block/amiflop.c b/drivers/block/amiflop.c index 226219da3da6..71c2b1564558 100644 --- a/drivers/block/amiflop.c +++ b/drivers/block/amiflop.c @@ -1670,7 +1670,7 @@ static int floppy_open(struct block_device *bdev, fmode_t mode) } if (mode & (FMODE_READ|FMODE_WRITE)) { - check_disk_change(bdev); + bdev_check_media_change(bdev); if (mode & FMODE_WRITE) { int wrprot; From 22f97164ef233fe68948b1c99dc8e6077c39c2af Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 8 Sep 2020 16:53:31 +0200 Subject: [PATCH 080/191] ataflop: use bdev_check_media_change Switch to use bdev_check_media_change instead of check_disk_change and call floppy_revalidate manually. Given that floppy_revalidate only deals with media change events, the extra call into ->revalidate_disk from bdev_disk_changed is not required either, so stop wiring up the method. Signed-off-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- drivers/block/ataflop.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/block/ataflop.c b/drivers/block/ataflop.c index a50e13af0305..3e881fdb06e0 100644 --- a/drivers/block/ataflop.c +++ b/drivers/block/ataflop.c @@ -1732,7 +1732,8 @@ static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode, /* invalidate the buffer track to force a reread */ BufferDrive = -1; set_bit(drive, &fake_change); - check_disk_change(bdev); + if (bdev_check_media_change(bdev)) + floppy_revalidate(bdev->bd_disk); return 0; default: return -EINVAL; @@ -1909,7 +1910,8 @@ static int floppy_open(struct block_device *bdev, fmode_t mode) return 0; if (mode & (FMODE_READ|FMODE_WRITE)) { - check_disk_change(bdev); + if (bdev_check_media_change(bdev)) + floppy_revalidate(bdev->bd_disk); if (mode & FMODE_WRITE) { if (p->wpstat) { if (p->ref < 0) @@ -1953,7 +1955,6 @@ static const struct block_device_operations floppy_fops = { .release = floppy_release, .ioctl = fd_ioctl, .check_events = floppy_check_events, - .revalidate_disk= floppy_revalidate, }; static const struct blk_mq_ops ataflop_mq_ops = { From 4a6f3d480edc3570a8059f3a0fb388641b6ec73f Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 8 Sep 2020 16:53:32 +0200 Subject: [PATCH 081/191] floppy: use bdev_check_media_change Switch to use bdev_check_media_change instead of check_disk_change and call floppy_revalidate manually. Given that floppy_revalidate only deals with media change events, the extra call into ->revalidate_disk from bdev_disk_changed is not required either, so stop wiring up the method. Signed-off-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- drivers/block/floppy.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c index a563b023458a..7df79ae6b0a1 100644 --- a/drivers/block/floppy.c +++ b/drivers/block/floppy.c @@ -561,6 +561,7 @@ static void floppy_release_irq_and_dma(void); * output_byte is automatically disabled when reset is set. */ static void reset_fdc(void); +static int floppy_revalidate(struct gendisk *disk); /* * These are global variables, as that's the easiest way to give @@ -3275,7 +3276,8 @@ static int invalidate_drive(struct block_device *bdev) /* invalidate the buffer track to force a reread */ set_bit((long)bdev->bd_disk->private_data, &fake_change); process_fd_request(); - check_disk_change(bdev); + if (bdev_check_media_change(bdev)) + floppy_revalidate(bdev->bd_disk); return 0; } @@ -4123,7 +4125,8 @@ static int floppy_open(struct block_device *bdev, fmode_t mode) drive_state[drive].last_checked = 0; clear_bit(FD_OPEN_SHOULD_FAIL_BIT, &drive_state[drive].flags); - check_disk_change(bdev); + if (bdev_check_media_change(bdev)) + floppy_revalidate(bdev->bd_disk); if (test_bit(FD_DISK_CHANGED_BIT, &drive_state[drive].flags)) goto out; if (test_bit(FD_OPEN_SHOULD_FAIL_BIT, &drive_state[drive].flags)) @@ -4291,7 +4294,6 @@ static const struct block_device_operations floppy_fops = { .ioctl = fd_ioctl, .getgeo = fd_getgeo, .check_events = floppy_check_events, - .revalidate_disk = floppy_revalidate, #ifdef CONFIG_COMPAT .compat_ioctl = fd_compat_ioctl, #endif From 7fe76fc04bd1b551b8c712249c921facfd98a11b Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 8 Sep 2020 16:53:33 +0200 Subject: [PATCH 082/191] swim: use bdev_check_media_change Switch to use bdev_check_media_change instead of check_disk_change and call floppy_revalidate manually. Given that floppy_revalidate only deals with media change events, the extra call into ->revalidate_disk from bdev_disk_changed is not required either, so stop wiring up the method. Signed-off-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- drivers/block/swim.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/block/swim.c b/drivers/block/swim.c index dd34504382e5..d4565c555b28 100644 --- a/drivers/block/swim.c +++ b/drivers/block/swim.c @@ -217,6 +217,8 @@ extern int swim_read_sector_header(struct swim __iomem *base, extern int swim_read_sector_data(struct swim __iomem *base, unsigned char *data); +static int floppy_revalidate(struct gendisk *disk); + static DEFINE_MUTEX(swim_mutex); static inline void set_swim_mode(struct swim __iomem *base, int enable) { @@ -638,7 +640,8 @@ static int floppy_open(struct block_device *bdev, fmode_t mode) return 0; if (mode & (FMODE_READ|FMODE_WRITE)) { - check_disk_change(bdev); + if (bdev_check_media_change(bdev)) + floppy_revalidate(bdev->bd_disk); if ((mode & FMODE_WRITE) && fs->write_protected) { err = -EROFS; goto out; @@ -760,7 +763,6 @@ static const struct block_device_operations floppy_fops = { .ioctl = floppy_ioctl, .getgeo = floppy_getgeo, .check_events = floppy_check_events, - .revalidate_disk = floppy_revalidate, }; static struct kobject *floppy_find(dev_t dev, int *part, void *data) From 433d21ce313e93200cd0938aa717639c8098d45f Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 8 Sep 2020 16:53:34 +0200 Subject: [PATCH 083/191] swim: simplify media change handling floppy_revalidate mostly duplicates work already done in floppy_open despite only beeing called from floppy_open. Remove the function and just clear the ->ejected flag directly under the right condition. Signed-off-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- drivers/block/swim.c | 24 ++---------------------- 1 file changed, 2 insertions(+), 22 deletions(-) diff --git a/drivers/block/swim.c b/drivers/block/swim.c index d4565c555b28..52dd1efa00f9 100644 --- a/drivers/block/swim.c +++ b/drivers/block/swim.c @@ -217,8 +217,6 @@ extern int swim_read_sector_header(struct swim __iomem *base, extern int swim_read_sector_data(struct swim __iomem *base, unsigned char *data); -static int floppy_revalidate(struct gendisk *disk); - static DEFINE_MUTEX(swim_mutex); static inline void set_swim_mode(struct swim __iomem *base, int enable) { @@ -640,8 +638,8 @@ static int floppy_open(struct block_device *bdev, fmode_t mode) return 0; if (mode & (FMODE_READ|FMODE_WRITE)) { - if (bdev_check_media_change(bdev)) - floppy_revalidate(bdev->bd_disk); + if (bdev_check_media_change(bdev) && fs->disk_in) + fs->ejected = 0; if ((mode & FMODE_WRITE) && fs->write_protected) { err = -EROFS; goto out; @@ -738,24 +736,6 @@ static unsigned int floppy_check_events(struct gendisk *disk, return fs->ejected ? DISK_EVENT_MEDIA_CHANGE : 0; } -static int floppy_revalidate(struct gendisk *disk) -{ - struct floppy_state *fs = disk->private_data; - struct swim __iomem *base = fs->swd->base; - - swim_drive(base, fs->location); - - if (fs->ejected) - setup_medium(fs); - - if (!fs->disk_in) - swim_motor(base, OFF); - else - fs->ejected = 0; - - return !fs->disk_in; -} - static const struct block_device_operations floppy_fops = { .owner = THIS_MODULE, .open = floppy_unlocked_open, From 3dcbad297b9976394190ee40913b53e50e9c83f2 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 8 Sep 2020 16:53:35 +0200 Subject: [PATCH 084/191] swim3: use bdev_check_media_changed Switch to use bdev_check_media_changed instead of check_disk_change and call floppy_revalidate manually. Given that floppy_revalidate only deals with media change events, the extra call into ->revalidate_disk from bdev_disk_changed is not required either, so stop wiring up the method. Signed-off-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- drivers/block/swim3.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/block/swim3.c b/drivers/block/swim3.c index aa77eb5fb7de..c2d922d125e2 100644 --- a/drivers/block/swim3.c +++ b/drivers/block/swim3.c @@ -945,7 +945,8 @@ static int floppy_open(struct block_device *bdev, fmode_t mode) if (err == 0 && (mode & FMODE_NDELAY) == 0 && (mode & (FMODE_READ|FMODE_WRITE))) { - check_disk_change(bdev); + if (bdev_check_media_change(bdev)) + floppy_revalidate(bdev->bd_disk); if (fs->ejected) err = -ENXIO; } @@ -1055,7 +1056,6 @@ static const struct block_device_operations floppy_fops = { .release = floppy_release, .ioctl = floppy_ioctl, .check_events = floppy_check_events, - .revalidate_disk= floppy_revalidate, }; static const struct blk_mq_ops swim3_mq_ops = { From f094225bfcd6fc5c093e128ec0adb7a522b38b69 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 8 Sep 2020 16:53:36 +0200 Subject: [PATCH 085/191] xsysace: use bdev_check_media_change Switch to use bdev_check_media_change instead of check_disk_change and call ace_revalidate_disk manually. Given that ace_revalidate_disk only deals with media change events, the extra call into ->revalidate_disk from bdev_disk_changed is not required either, so stop wiring up the method. Signed-off-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- drivers/block/xsysace.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/block/xsysace.c b/drivers/block/xsysace.c index 5d8e0ab3f054..eefe542f2d9f 100644 --- a/drivers/block/xsysace.c +++ b/drivers/block/xsysace.c @@ -922,7 +922,8 @@ static int ace_open(struct block_device *bdev, fmode_t mode) ace->users++; spin_unlock_irqrestore(&ace->lock, flags); - check_disk_change(bdev); + if (bdev_check_media_change(bdev)) + ace_revalidate_disk(bdev->bd_disk); mutex_unlock(&xsysace_mutex); return 0; @@ -966,7 +967,6 @@ static const struct block_device_operations ace_fops = { .open = ace_open, .release = ace_release, .check_events = ace_check_events, - .revalidate_disk = ace_revalidate_disk, .getgeo = ace_getgeo, }; From 77f93bfd0cc2e659d7135b4afcd5d0a070515bbf Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 8 Sep 2020 16:53:37 +0200 Subject: [PATCH 086/191] xsysace: simplify media change handling Pass a struct ace_device to ace_revalidate_disk, move the media changed check into the one caller that needs it, and give the routine a better name. Signed-off-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- drivers/block/xsysace.c | 26 ++++++++++---------------- 1 file changed, 10 insertions(+), 16 deletions(-) diff --git a/drivers/block/xsysace.c b/drivers/block/xsysace.c index eefe542f2d9f..8d581c7536fb 100644 --- a/drivers/block/xsysace.c +++ b/drivers/block/xsysace.c @@ -888,26 +888,20 @@ static unsigned int ace_check_events(struct gendisk *gd, unsigned int clearing) return ace->media_change ? DISK_EVENT_MEDIA_CHANGE : 0; } -static int ace_revalidate_disk(struct gendisk *gd) +static void ace_media_changed(struct ace_device *ace) { - struct ace_device *ace = gd->private_data; unsigned long flags; - dev_dbg(ace->dev, "ace_revalidate_disk()\n"); + dev_dbg(ace->dev, "requesting cf id and scheduling tasklet\n"); - if (ace->media_change) { - dev_dbg(ace->dev, "requesting cf id and scheduling tasklet\n"); + spin_lock_irqsave(&ace->lock, flags); + ace->id_req_count++; + spin_unlock_irqrestore(&ace->lock, flags); - spin_lock_irqsave(&ace->lock, flags); - ace->id_req_count++; - spin_unlock_irqrestore(&ace->lock, flags); - - tasklet_schedule(&ace->fsm_tasklet); - wait_for_completion(&ace->id_completion); - } + tasklet_schedule(&ace->fsm_tasklet); + wait_for_completion(&ace->id_completion); dev_dbg(ace->dev, "revalidate complete\n"); - return ace->id_result; } static int ace_open(struct block_device *bdev, fmode_t mode) @@ -922,8 +916,8 @@ static int ace_open(struct block_device *bdev, fmode_t mode) ace->users++; spin_unlock_irqrestore(&ace->lock, flags); - if (bdev_check_media_change(bdev)) - ace_revalidate_disk(bdev->bd_disk); + if (bdev_check_media_change(bdev) && ace->media_change) + ace_media_changed(ace); mutex_unlock(&xsysace_mutex); return 0; @@ -1080,7 +1074,7 @@ static int ace_setup(struct ace_device *ace) (unsigned long long) ace->physaddr, ace->baseaddr, ace->irq); ace->media_change = 1; - ace_revalidate_disk(ace->gd); + ace_media_changed(ace); /* Make the sysace device 'live' */ add_disk(ace->gd); From 1570d14f6713d07716861dea1bb4739df37056d5 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 8 Sep 2020 16:53:38 +0200 Subject: [PATCH 087/191] paride/pcd: use bdev_check_media_change The pcd driver does not have a ->revalidate_disk method, so it can just use bdev_check_media_change without any additional changes. Signed-off-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- drivers/block/paride/pcd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/block/paride/pcd.c b/drivers/block/paride/pcd.c index 5124eca90e83..70da8b86ce58 100644 --- a/drivers/block/paride/pcd.c +++ b/drivers/block/paride/pcd.c @@ -233,7 +233,7 @@ static int pcd_block_open(struct block_device *bdev, fmode_t mode) struct pcd_unit *cd = bdev->bd_disk->private_data; int ret; - check_disk_change(bdev); + bdev_check_media_change(bdev); mutex_lock(&pcd_mutex); ret = cdrom_open(&cd->info, bdev, mode); From faf041388c28e93be9644985d2da63f82b6f7233 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 8 Sep 2020 16:53:39 +0200 Subject: [PATCH 088/191] gdrom: use bdev_check_media_change The Sega GD-ROM driver does not have a ->revalidate_disk method, so it can just use bdev_check_media_change without any additional changes. Signed-off-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- drivers/cdrom/gdrom.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/cdrom/gdrom.c b/drivers/cdrom/gdrom.c index 09b0cd292720..9874fc1c815b 100644 --- a/drivers/cdrom/gdrom.c +++ b/drivers/cdrom/gdrom.c @@ -479,7 +479,7 @@ static int gdrom_bdops_open(struct block_device *bdev, fmode_t mode) { int ret; - check_disk_change(bdev); + bdev_check_media_change(bdev); mutex_lock(&gdrom_mutex); ret = cdrom_open(gd.cd_info, bdev, mode); From a22be69d5354c63d379cf7ecdbf3eef257f14512 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 8 Sep 2020 16:53:40 +0200 Subject: [PATCH 089/191] ide-cd: use bdev_check_media_changed Switch to use bdev_check_media_changed instead of check_disk_change and call idecd_revalidate_disk manually. Given that idecd_revalidate_disk only re-reads the TOC, and we already do the same at probe time, the extra call into ->revalidate_disk from bdev_disk_changed is not required either, so stop wiring up the method. Signed-off-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- drivers/ide/ide-cd.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c index 212bb2d8bf34..6a38cbc80aea 100644 --- a/drivers/ide/ide-cd.c +++ b/drivers/ide/ide-cd.c @@ -56,6 +56,7 @@ static DEFINE_MUTEX(ide_cd_mutex); static DEFINE_MUTEX(idecd_ref_mutex); static void ide_cd_release(struct device *); +static int idecd_revalidate_disk(struct gendisk *disk); static struct cdrom_info *ide_cd_get(struct gendisk *disk) { @@ -1611,7 +1612,8 @@ static int idecd_open(struct block_device *bdev, fmode_t mode) struct cdrom_info *info; int rc = -ENXIO; - check_disk_change(bdev); + if (bdev_check_media_change(bdev)) + idecd_revalidate_disk(bdev->bd_disk); mutex_lock(&ide_cd_mutex); info = ide_cd_get(bdev->bd_disk); @@ -1770,7 +1772,6 @@ static const struct block_device_operations idecd_ops = { .compat_ioctl = IS_ENABLED(CONFIG_COMPAT) ? idecd_compat_ioctl : NULL, .check_events = idecd_check_events, - .revalidate_disk = idecd_revalidate_disk }; /* module options */ From a367e440e15c19f5694186dda9dd8a0f9eeb0c9f Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 8 Sep 2020 16:53:41 +0200 Subject: [PATCH 090/191] ide-cd: remove idecd_revalidate_disk Just merge the trivial function into its only caller. Signed-off-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- drivers/ide/ide-cd.c | 17 +++++------------ 1 file changed, 5 insertions(+), 12 deletions(-) diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c index 6a38cbc80aea..25d2d88e82ad 100644 --- a/drivers/ide/ide-cd.c +++ b/drivers/ide/ide-cd.c @@ -56,7 +56,6 @@ static DEFINE_MUTEX(ide_cd_mutex); static DEFINE_MUTEX(idecd_ref_mutex); static void ide_cd_release(struct device *); -static int idecd_revalidate_disk(struct gendisk *disk); static struct cdrom_info *ide_cd_get(struct gendisk *disk) { @@ -1612,8 +1611,11 @@ static int idecd_open(struct block_device *bdev, fmode_t mode) struct cdrom_info *info; int rc = -ENXIO; - if (bdev_check_media_change(bdev)) - idecd_revalidate_disk(bdev->bd_disk); + if (bdev_check_media_change(bdev)) { + info = ide_drv_g(bdev->bd_disk, cdrom_info); + + ide_cd_read_toc(info->drive); + } mutex_lock(&ide_cd_mutex); info = ide_cd_get(bdev->bd_disk); @@ -1755,15 +1757,6 @@ static unsigned int idecd_check_events(struct gendisk *disk, return cdrom_check_events(&info->devinfo, clearing); } -static int idecd_revalidate_disk(struct gendisk *disk) -{ - struct cdrom_info *info = ide_drv_g(disk, cdrom_info); - - ide_cd_read_toc(info->drive); - - return 0; -} - static const struct block_device_operations idecd_ops = { .owner = THIS_MODULE, .open = idecd_open, From fec2cf607ba9305770436b1e5c485963a9f0a7bd Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 8 Sep 2020 16:53:42 +0200 Subject: [PATCH 091/191] ide-gd: stop using the disk events mechanism ide-gd is only using the disk events mechanism to be able to force an invalidation and partition scan on opening removable media. Just open code the logic without invoving the block layer. Signed-off-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- drivers/ide/ide-disk.c | 5 +---- drivers/ide/ide-floppy.c | 2 -- drivers/ide/ide-gd.c | 48 +++++----------------------------------- include/linux/ide.h | 2 -- 4 files changed, 7 insertions(+), 50 deletions(-) diff --git a/drivers/ide/ide-disk.c b/drivers/ide/ide-disk.c index 1d3407d7e095..34b9441084f8 100644 --- a/drivers/ide/ide-disk.c +++ b/drivers/ide/ide-disk.c @@ -739,12 +739,9 @@ static void ide_disk_setup(ide_drive_t *drive) set_wcache(drive, 1); if ((drive->dev_flags & IDE_DFLAG_LBA) == 0 && - (drive->head == 0 || drive->head > 16)) { + (drive->head == 0 || drive->head > 16)) printk(KERN_ERR "%s: invalid geometry: %d physical heads?\n", drive->name, drive->head); - drive->dev_flags &= ~IDE_DFLAG_ATTACH; - } else - drive->dev_flags |= IDE_DFLAG_ATTACH; } static void ide_disk_flush(ide_drive_t *drive) diff --git a/drivers/ide/ide-floppy.c b/drivers/ide/ide-floppy.c index af7503b47dbe..f5a2870aaf54 100644 --- a/drivers/ide/ide-floppy.c +++ b/drivers/ide/ide-floppy.c @@ -516,8 +516,6 @@ static void ide_floppy_setup(ide_drive_t *drive) (void) ide_floppy_get_capacity(drive); ide_proc_register_driver(drive, floppy->driver); - - drive->dev_flags |= IDE_DFLAG_ATTACH; } static void ide_floppy_flush(ide_drive_t *drive) diff --git a/drivers/ide/ide-gd.c b/drivers/ide/ide-gd.c index 05c26986637b..661e2aa9c967 100644 --- a/drivers/ide/ide-gd.c +++ b/drivers/ide/ide-gd.c @@ -225,8 +225,12 @@ static int ide_gd_open(struct block_device *bdev, fmode_t mode) * and the door_lock is irrelevant at this point. */ drive->disk_ops->set_doorlock(drive, disk, 1); - drive->dev_flags |= IDE_DFLAG_MEDIA_CHANGED; - check_disk_change(bdev); + if (__invalidate_device(bdev, true)) + pr_warn("VFS: busy inodes on changed media %s\n", + bdev->bd_disk->disk_name); + drive->disk_ops->get_capacity(drive); + set_capacity(disk, ide_gd_capacity(drive)); + set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags); } else if (drive->dev_flags & IDE_DFLAG_FORMAT_IN_PROGRESS) { ret = -EBUSY; goto out_put_idkp; @@ -284,32 +288,6 @@ static int ide_gd_getgeo(struct block_device *bdev, struct hd_geometry *geo) return 0; } -static unsigned int ide_gd_check_events(struct gendisk *disk, - unsigned int clearing) -{ - struct ide_disk_obj *idkp = ide_drv_g(disk, ide_disk_obj); - ide_drive_t *drive = idkp->drive; - bool ret; - - /* do not scan partitions twice if this is a removable device */ - if (drive->dev_flags & IDE_DFLAG_ATTACH) { - drive->dev_flags &= ~IDE_DFLAG_ATTACH; - return 0; - } - - /* - * The following is used to force revalidation on the first open on - * removeable devices, and never gets reported to userland as - * DISK_EVENT_FLAG_UEVENT isn't set in genhd->event_flags. - * This is intended as removable ide disk can't really detect - * MEDIA_CHANGE events. - */ - ret = drive->dev_flags & IDE_DFLAG_MEDIA_CHANGED; - drive->dev_flags &= ~IDE_DFLAG_MEDIA_CHANGED; - - return ret ? DISK_EVENT_MEDIA_CHANGE : 0; -} - static void ide_gd_unlock_native_capacity(struct gendisk *disk) { struct ide_disk_obj *idkp = ide_drv_g(disk, ide_disk_obj); @@ -320,18 +298,6 @@ static void ide_gd_unlock_native_capacity(struct gendisk *disk) disk_ops->unlock_native_capacity(drive); } -static int ide_gd_revalidate_disk(struct gendisk *disk) -{ - struct ide_disk_obj *idkp = ide_drv_g(disk, ide_disk_obj); - ide_drive_t *drive = idkp->drive; - - if (ide_gd_check_events(disk, 0)) - drive->disk_ops->get_capacity(drive); - - set_capacity(disk, ide_gd_capacity(drive)); - return 0; -} - static int ide_gd_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg) { @@ -364,9 +330,7 @@ static const struct block_device_operations ide_gd_ops = { .compat_ioctl = ide_gd_compat_ioctl, #endif .getgeo = ide_gd_getgeo, - .check_events = ide_gd_check_events, .unlock_native_capacity = ide_gd_unlock_native_capacity, - .revalidate_disk = ide_gd_revalidate_disk }; static int ide_gd_probe(ide_drive_t *drive) diff --git a/include/linux/ide.h b/include/linux/ide.h index a254841bd315..62653769509f 100644 --- a/include/linux/ide.h +++ b/include/linux/ide.h @@ -490,8 +490,6 @@ enum { IDE_DFLAG_NOPROBE = BIT(9), /* need to do check_media_change() */ IDE_DFLAG_REMOVABLE = BIT(10), - /* needed for removable devices */ - IDE_DFLAG_ATTACH = BIT(11), IDE_DFLAG_FORCED_GEOM = BIT(12), /* disallow setting unmask bit */ IDE_DFLAG_NO_UNMASK = BIT(13), From 818077d6e0125b4a7b728457b60b5d89e02a0ce1 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 8 Sep 2020 16:53:43 +0200 Subject: [PATCH 092/191] md: use bdev_check_media_change The md driver does not have a ->revalidate_disk method, so it can just use bdev_check_media_change without any additional changes. Signed-off-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Hannes Reinecke Acked-by: Song Liu Signed-off-by: Jens Axboe --- drivers/md/md.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 9562ef598ae1..27ed61197014 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -7848,7 +7848,7 @@ static int md_open(struct block_device *bdev, fmode_t mode) atomic_inc(&mddev->openers); mutex_unlock(&mddev->open_mutex); - check_disk_change(bdev); + bdev_check_media_change(bdev); out: if (err) mddev_put(mddev); From 471bd0af544bcd80450d61659a1ffabdd1820d7d Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 8 Sep 2020 16:53:44 +0200 Subject: [PATCH 093/191] sd: use bdev_check_media_change Switch to use bdev_check_media_change instead of check_disk_change and call sd_revalidate_disk manually. As sd also calls sd_revalidate_disk manually during probe and open, the extra call into ->revalidate_disk from bdev_disk_changed is not required either, so stop wiring up the method. Signed-off-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- drivers/scsi/sd.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 2bec8cd52616..d020639c28c6 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -1381,8 +1381,10 @@ static int sd_open(struct block_device *bdev, fmode_t mode) if (!scsi_block_when_processing_errors(sdev)) goto error_out; - if (sdev->removable || sdkp->write_prot) - check_disk_change(bdev); + if (sdev->removable || sdkp->write_prot) { + if (bdev_check_media_change(bdev)) + sd_revalidate_disk(bdev->bd_disk); + } /* * If the drive is empty, just let the open fail. @@ -1843,7 +1845,6 @@ static const struct block_device_operations sd_fops = { .compat_ioctl = sd_compat_ioctl, #endif .check_events = sd_check_events, - .revalidate_disk = sd_revalidate_disk, .unlock_native_capacity = sd_unlock_native_capacity, .report_zones = sd_zbc_report_zones, .pr_ops = &sd_pr_ops, From afd35c4f573d7eb1df9dbb7e0af0f4d93bd01f31 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 8 Sep 2020 16:53:45 +0200 Subject: [PATCH 094/191] sr: use bdev_check_media_change Switch to use bdev_check_media_change instead of check_disk_change and call sr_block_revalidate_disk manually. Also add an explicit call to sr_block_revalidate_disk just before disk_add() to ensure we always read check for a ready unit and read the TOC and then stop wiring up ->revalidate_disk. Signed-off-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe --- drivers/scsi/sr.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c index 3b3a53c6a0de..34be94b62523 100644 --- a/drivers/scsi/sr.c +++ b/drivers/scsi/sr.c @@ -86,6 +86,7 @@ static int sr_remove(struct device *); static blk_status_t sr_init_command(struct scsi_cmnd *SCpnt); static int sr_done(struct scsi_cmnd *); static int sr_runtime_suspend(struct device *dev); +static int sr_block_revalidate_disk(struct gendisk *disk); static const struct dev_pm_ops sr_pm_ops = { .runtime_suspend = sr_runtime_suspend, @@ -529,7 +530,8 @@ static int sr_block_open(struct block_device *bdev, fmode_t mode) sdev = cd->device; scsi_autopm_get_device(sdev); - check_disk_change(bdev); + if (bdev_check_media_change(bdev)) + sr_block_revalidate_disk(bdev->bd_disk); mutex_lock(&cd->lock); ret = cdrom_open(&cd->cdi, bdev, mode); @@ -688,7 +690,6 @@ static const struct block_device_operations sr_bdops = .compat_ioctl = sr_block_compat_ioctl, #endif .check_events = sr_block_check_events, - .revalidate_disk = sr_block_revalidate_disk, }; static int sr_open(struct cdrom_device_info *cdi, int purpose) @@ -802,6 +803,7 @@ static int sr_probe(struct device *dev) dev_set_drvdata(dev, cd); disk->flags |= GENHD_FL_REMOVABLE; + sr_block_revalidate_disk(disk); device_add_disk(&sdev->sdev_gendev, disk, NULL); sdev_printk(KERN_DEBUG, sdev, From 38a2b557e23874dd5ed3c767d57d28b2d10b7683 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 8 Sep 2020 16:53:46 +0200 Subject: [PATCH 095/191] sr: simplify sr_block_revalidate_disk Both callers have a valid CD struture available, so rely on that instead of getting another reference. Also move the function to avoid a forward declaration. Signed-off-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- drivers/scsi/sr.c | 36 +++++++++++++----------------------- 1 file changed, 13 insertions(+), 23 deletions(-) diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c index 34be94b62523..2b43c0f97442 100644 --- a/drivers/scsi/sr.c +++ b/drivers/scsi/sr.c @@ -86,7 +86,6 @@ static int sr_remove(struct device *); static blk_status_t sr_init_command(struct scsi_cmnd *SCpnt); static int sr_done(struct scsi_cmnd *); static int sr_runtime_suspend(struct device *dev); -static int sr_block_revalidate_disk(struct gendisk *disk); static const struct dev_pm_ops sr_pm_ops = { .runtime_suspend = sr_runtime_suspend, @@ -518,6 +517,17 @@ static blk_status_t sr_init_command(struct scsi_cmnd *SCpnt) return ret; } +static void sr_revalidate_disk(struct scsi_cd *cd) +{ + struct scsi_sense_hdr sshdr; + + /* if the unit is not ready, nothing more to do */ + if (scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr)) + return; + sr_cd_check(&cd->cdi); + get_sectorsize(cd); +} + static int sr_block_open(struct block_device *bdev, fmode_t mode) { struct scsi_cd *cd; @@ -531,7 +541,7 @@ static int sr_block_open(struct block_device *bdev, fmode_t mode) sdev = cd->device; scsi_autopm_get_device(sdev); if (bdev_check_media_change(bdev)) - sr_block_revalidate_disk(bdev->bd_disk); + sr_revalidate_disk(cd); mutex_lock(&cd->lock); ret = cdrom_open(&cd->cdi, bdev, mode); @@ -660,26 +670,6 @@ static unsigned int sr_block_check_events(struct gendisk *disk, return ret; } -static int sr_block_revalidate_disk(struct gendisk *disk) -{ - struct scsi_sense_hdr sshdr; - struct scsi_cd *cd; - - cd = scsi_cd_get(disk); - if (!cd) - return -ENXIO; - - /* if the unit is not ready, nothing more to do */ - if (scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr)) - goto out; - - sr_cd_check(&cd->cdi); - get_sectorsize(cd); -out: - scsi_cd_put(cd); - return 0; -} - static const struct block_device_operations sr_bdops = { .owner = THIS_MODULE, @@ -803,7 +793,7 @@ static int sr_probe(struct device *dev) dev_set_drvdata(dev, cd); disk->flags |= GENHD_FL_REMOVABLE; - sr_block_revalidate_disk(disk); + sr_revalidate_disk(cd); device_add_disk(&sdev->sdev_gendev, disk, NULL); sdev_printk(KERN_DEBUG, sdev, From b92b53079aedbfb56bbb9ea360e5119fb563a2a1 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 8 Sep 2020 16:53:47 +0200 Subject: [PATCH 096/191] block: remove check_disk_change Remove the now unused check_disk_change helper. Signed-off-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- fs/block_dev.c | 20 -------------------- include/linux/genhd.h | 1 - 2 files changed, 21 deletions(-) diff --git a/fs/block_dev.c b/fs/block_dev.c index c6ac0bd22eca..0b34955b9e36 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1368,26 +1368,6 @@ void revalidate_disk_size(struct gendisk *disk, bool verbose) } EXPORT_SYMBOL(revalidate_disk_size); -/* - * This routine checks whether a removable media has been changed, - * and invalidates all buffer-cache-entries in that case. This - * is a relatively slow routine, so we have to try to minimize using - * it. Thus it is called only upon a 'mount' or 'open'. This - * is the best way of combining speed and utility, I think. - * People changing diskettes in the middle of an operation deserve - * to lose :-) - */ -int check_disk_change(struct block_device *bdev) -{ - if (!bdev_check_media_change(bdev)) - return 0; - if (bdev->bd_disk->fops->revalidate_disk) - bdev->bd_disk->fops->revalidate_disk(bdev->bd_disk); - return 1; -} - -EXPORT_SYMBOL(check_disk_change); - void bd_set_nr_sectors(struct block_device *bdev, sector_t sectors) { spin_lock(&bdev->bd_size_lock); diff --git a/include/linux/genhd.h b/include/linux/genhd.h index 322d48a20772..1c97cf84f011 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -370,7 +370,6 @@ int register_blkdev(unsigned int major, const char *name); void unregister_blkdev(unsigned int major, const char *name); void revalidate_disk_size(struct gendisk *disk, bool verbose); -int check_disk_change(struct block_device *bdev); bool bdev_check_media_change(struct block_device *bdev); int __invalidate_device(struct block_device *bdev, bool kill_dirty); void bd_set_nr_sectors(struct block_device *bdev, sector_t sectors); From 192f1c6bc2d2dc59de6c39dc229156910fdf6fe8 Mon Sep 17 00:00:00 2001 From: Xianting Tian Date: Thu, 10 Sep 2020 14:15:06 +0800 Subject: [PATCH 097/191] blkcg: add plugging support for punt bio The test and the explaination of the patch as bellow. Before test we added more debug code in blkg_async_bio_workfn(): int count = 0 if (bios.head && bios.head->bi_next) { need_plug = true; blk_start_plug(&plug); } while ((bio = bio_list_pop(&bios))) { /*io_punt is a sysctl user interface to control the print*/ if(io_punt) { printk("[%s:%d] bio start,size:%llu,%d count=%d plug?%d\n", current->comm, current->pid, bio->bi_iter.bi_sector, (bio->bi_iter.bi_size)>>9, count++, need_plug); } submit_bio(bio); } if (need_plug) blk_finish_plug(&plug); Steps that need to be set to trigger *PUNT* io before testing: mount -t btrfs -o compress=lzo /dev/sda6 /btrfs mount -t cgroup2 nodev /cgroup2 mkdir /cgroup2/cg3 echo "+io" > /cgroup2/cgroup.subtree_control echo "8:0 wbps=1048576000" > /cgroup2/cg3/io.max #1000M/s echo $$ > /cgroup2/cg3/cgroup.procs Then use dd command to test btrfs PUNT io in current shell: dd if=/dev/zero of=/btrfs/file bs=64K count=100000 Test hardware environment as below: [root@localhost btrfs]# lscpu Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Byte Order: Little Endian CPU(s): 32 On-line CPU(s) list: 0-31 Thread(s) per core: 2 Core(s) per socket: 8 Socket(s): 2 NUMA node(s): 2 Vendor ID: GenuineIntel With above debug code, test command and test environment, I did the tests under 3 different system loads, which are triggered by stress: 1, Run 64 threads by command "stress -c 64 &" [53615.975974] [kworker/u66:18:1490] bio start,size:45583056,8 count=0 plug?1 [53615.975980] [kworker/u66:18:1490] bio start,size:45583064,8 count=1 plug?1 [53615.975984] [kworker/u66:18:1490] bio start,size:45583072,8 count=2 plug?1 [53615.975987] [kworker/u66:18:1490] bio start,size:45583080,8 count=3 plug?1 [53615.975990] [kworker/u66:18:1490] bio start,size:45583088,8 count=4 plug?1 [53615.975993] [kworker/u66:18:1490] bio start,size:45583096,8 count=5 plug?1 ... ... [53615.977041] [kworker/u66:18:1490] bio start,size:45585480,8 count=303 plug?1 [53615.977044] [kworker/u66:18:1490] bio start,size:45585488,8 count=304 plug?1 [53615.977047] [kworker/u66:18:1490] bio start,size:45585496,8 count=305 plug?1 [53615.977050] [kworker/u66:18:1490] bio start,size:45585504,8 count=306 plug?1 [53615.977053] [kworker/u66:18:1490] bio start,size:45585512,8 count=307 plug?1 [53615.977056] [kworker/u66:18:1490] bio start,size:45585520,8 count=308 plug?1 [53615.977058] [kworker/u66:18:1490] bio start,size:45585528,8 count=309 plug?1 2, Run 32 threads by command "stress -c 32 &" [50586.290521] [kworker/u66:6:32351] bio start,size:45806496,8 count=0 plug?1 [50586.290526] [kworker/u66:6:32351] bio start,size:45806504,8 count=1 plug?1 [50586.290529] [kworker/u66:6:32351] bio start,size:45806512,8 count=2 plug?1 [50586.290531] [kworker/u66:6:32351] bio start,size:45806520,8 count=3 plug?1 [50586.290533] [kworker/u66:6:32351] bio start,size:45806528,8 count=4 plug?1 [50586.290535] [kworker/u66:6:32351] bio start,size:45806536,8 count=5 plug?1 ... ... [50586.299640] [kworker/u66:5:32350] bio start,size:45808576,8 count=252 plug?1 [50586.299643] [kworker/u66:5:32350] bio start,size:45808584,8 count=253 plug?1 [50586.299646] [kworker/u66:5:32350] bio start,size:45808592,8 count=254 plug?1 [50586.299649] [kworker/u66:5:32350] bio start,size:45808600,8 count=255 plug?1 [50586.299652] [kworker/u66:5:32350] bio start,size:45808608,8 count=256 plug?1 [50586.299663] [kworker/u66:5:32350] bio start,size:45808616,8 count=257 plug?1 [50586.299665] [kworker/u66:5:32350] bio start,size:45808624,8 count=258 plug?1 [50586.299668] [kworker/u66:5:32350] bio start,size:45808632,8 count=259 plug?1 3, Don't run thread by stress [50861.355246] [kworker/u66:19:32376] bio start,size:13544504,8 count=0 plug?0 [50861.355288] [kworker/u66:19:32376] bio start,size:13544512,8 count=0 plug?0 [50861.355322] [kworker/u66:19:32376] bio start,size:13544520,8 count=0 plug?0 [50861.355353] [kworker/u66:19:32376] bio start,size:13544528,8 count=0 plug?0 [50861.355392] [kworker/u66:19:32376] bio start,size:13544536,8 count=0 plug?0 [50861.355431] [kworker/u66:19:32376] bio start,size:13544544,8 count=0 plug?0 [50861.355468] [kworker/u66:19:32376] bio start,size:13544552,8 count=0 plug?0 [50861.355499] [kworker/u66:19:32376] bio start,size:13544560,8 count=0 plug?0 [50861.355532] [kworker/u66:19:32376] bio start,size:13544568,8 count=0 plug?0 [50861.355575] [kworker/u66:19:32376] bio start,size:13544576,8 count=0 plug?0 [50861.355618] [kworker/u66:19:32376] bio start,size:13544584,8 count=0 plug?0 [50861.355659] [kworker/u66:19:32376] bio start,size:13544592,8 count=0 plug?0 [50861.355740] [kworker/u66:0:32346] bio start,size:13544600,8 count=0 plug?1 [50861.355748] [kworker/u66:0:32346] bio start,size:13544608,8 count=1 plug?1 [50861.355962] [kworker/u66:2:32347] bio start,size:13544616,8 count=0 plug?0 [50861.356272] [kworker/u66:7:31962] bio start,size:13544624,8 count=0 plug?0 [50861.356446] [kworker/u66:7:31962] bio start,size:13544632,8 count=0 plug?0 [50861.356567] [kworker/u66:7:31962] bio start,size:13544640,8 count=0 plug?0 [50861.356707] [kworker/u66:19:32376] bio start,size:13544648,8 count=0 plug?0 [50861.356748] [kworker/u66:15:32355] bio start,size:13544656,8 count=0 plug?0 [50861.356825] [kworker/u66:17:31970] bio start,size:13544664,8 count=0 plug?0 Analysis of above 3 test results with different system load: >From above test, we can see more and more continuous bios can be plugged with system load increasing. When run "stress -c 64 &", 310 continuous bios are plugged; When run "stress -c 32 &", 260 continuous bios are plugged; When don't run stress, at most only 2 continuous bios are plugged, in most cases, bio_list only contains one single bio. How to explain above phenomenon: We know, in submit_bio(), if the bio is a REQ_CGROUP_PUNT io, it will queue a work to workqueue blkcg_punt_bio_wq. But when the workqueue is scheduled, it depends on the system load. When system load is low, the workqueue will be quickly scheduled, and the bio in bio_list will be quickly processed in blkg_async_bio_workfn(), so there is less chance that the same io submit thread can add multiple continuous bios to bio_list before workqueue is scheduled to run. The analysis aligned with above test "3". When system load is high, there is some delay before the workqueue can be scheduled to run, the higher the system load the greater the delay. So there is more chance that the same io submit thread can add multiple continuous bios to bio_list. Then when the workqueue is scheduled to run, there are more continuous bios in bio_list, which will be processed in blkg_async_bio_workfn(). The analysis aligned with above test "1" and "2". According to test, we can get io performance improved with the patch, especially when system load is higher. Another optimazition is to use the plug only when bio_list contains at least 2 bios. Signed-off-by: Xianting Tian Signed-off-by: Jens Axboe --- block/blk-cgroup.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index d33dd6be1d9c..f9b55614d67d 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -119,6 +119,8 @@ static void blkg_async_bio_workfn(struct work_struct *work) async_bio_work); struct bio_list bios = BIO_EMPTY_LIST; struct bio *bio; + struct blk_plug plug; + bool need_plug = false; /* as long as there are pending bios, @blkg can't go away */ spin_lock_bh(&blkg->async_bio_lock); @@ -126,8 +128,15 @@ static void blkg_async_bio_workfn(struct work_struct *work) bio_list_init(&blkg->async_bios); spin_unlock_bh(&blkg->async_bio_lock); + /* start plug only when bio_list contains at least 2 bios */ + if (bios.head && bios.head->bi_next) { + need_plug = true; + blk_start_plug(&plug); + } while ((bio = bio_list_pop(&bios))) submit_bio(bio); + if (need_plug) + blk_finish_plug(&plug); } /** From 84ed2573c5427de47c71a69d8b0a18020d5f6dd5 Mon Sep 17 00:00:00 2001 From: Tian Tao Date: Fri, 11 Sep 2020 18:58:52 +0800 Subject: [PATCH 098/191] block: remove duplicate include statement in scsi_ioctl.c scsi/sg.h is included more than once, Remove the one that isn't necessary. Signed-off-by: Tian Tao Signed-off-by: Jens Axboe --- block/scsi_ioctl.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c index ef722f04f88a..4421e61c1af1 100644 --- a/block/scsi_ioctl.c +++ b/block/scsi_ioctl.c @@ -37,8 +37,6 @@ const unsigned char scsi_command_size_tbl[8] = }; EXPORT_SYMBOL(scsi_command_size_tbl); -#include - static int sg_get_version(int __user *p) { static const int sg_version_num = 30527; From 285008501c65a3fcee05d2c2c26cbf629ceff2f0 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Fri, 11 Sep 2020 18:41:14 +0800 Subject: [PATCH 099/191] blk-mq: always allow reserved allocation in hctx_may_queue NVMe shares tagset between fabric queue and admin queue or between connect_q and NS queue, so hctx_may_queue() can be called to allocate request for these queues. Tags can be reserved in these tagset. Before error recovery, there is often lots of in-flight requests which can't be completed, and new reserved request may be needed in error recovery path. However, hctx_may_queue() can always return false because there is too many in-flight requests which can't be completed during error handling. Finally, nothing can proceed. Fix this issue by always allowing reserved tag allocation in hctx_may_queue(). This is reasonable because reserved tags are supposed to always be available. Reviewed-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Cc: David Milburn Cc: Ewan D. Milne Signed-off-by: Ming Lei Signed-off-by: Jens Axboe --- block/blk-mq-tag.c | 3 ++- block/blk-mq.c | 5 +++-- 2 files changed, 5 insertions(+), 3 deletions(-) diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index c31c4a0478a5..aacf10decdbd 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -76,7 +76,8 @@ void __blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx) static int __blk_mq_get_tag(struct blk_mq_alloc_data *data, struct sbitmap_queue *bt) { - if (!data->q->elevator && !hctx_may_queue(data->hctx, bt)) + if (!data->q->elevator && !(data->flags & BLK_MQ_REQ_RESERVED) && + !hctx_may_queue(data->hctx, bt)) return BLK_MQ_NO_TAG; if (data->shallow_depth) diff --git a/block/blk-mq.c b/block/blk-mq.c index 4abb71459f94..e04b759add75 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1105,10 +1105,11 @@ static bool __blk_mq_get_driver_tag(struct request *rq) if (blk_mq_tag_is_reserved(rq->mq_hctx->sched_tags, rq->internal_tag)) { bt = rq->mq_hctx->tags->breserved_tags; tag_offset = 0; + } else { + if (!hctx_may_queue(rq->mq_hctx, bt)) + return false; } - if (!hctx_may_queue(rq->mq_hctx, bt)) - return false; tag = __sbitmap_queue_get(bt); if (tag == BLK_MQ_NO_TAG) return false; From 7b26410b05f8c262688de8a689ba8e5d0c3cff01 Mon Sep 17 00:00:00 2001 From: Song Liu Date: Mon, 31 Aug 2020 15:27:23 -0700 Subject: [PATCH 100/191] block: introduce part_[begin|end]_io_acct These functions can be used to enable iostat for partitions on devices like md, bcache. Signed-off-by: Song Liu Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/blk-core.c | 39 +++++++++++++++++++++++++++++++++------ include/linux/blkdev.h | 5 +++++ 2 files changed, 38 insertions(+), 6 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 093649bd252e..ca3f0f00c943 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1324,10 +1324,9 @@ void blk_account_io_start(struct request *rq) part_stat_unlock(); } -unsigned long disk_start_io_acct(struct gendisk *disk, unsigned int sectors, - unsigned int op) +static unsigned long __part_start_io_acct(struct hd_struct *part, + unsigned int sectors, unsigned int op) { - struct hd_struct *part = &disk->part0; const int sgrp = op_stat_group(op); unsigned long now = READ_ONCE(jiffies); @@ -1340,12 +1339,26 @@ unsigned long disk_start_io_acct(struct gendisk *disk, unsigned int sectors, return now; } + +unsigned long part_start_io_acct(struct gendisk *disk, struct hd_struct **part, + struct bio *bio) +{ + *part = disk_map_sector_rcu(disk, bio->bi_iter.bi_sector); + + return __part_start_io_acct(*part, bio_sectors(bio), bio_op(bio)); +} +EXPORT_SYMBOL_GPL(part_start_io_acct); + +unsigned long disk_start_io_acct(struct gendisk *disk, unsigned int sectors, + unsigned int op) +{ + return __part_start_io_acct(&disk->part0, sectors, op); +} EXPORT_SYMBOL(disk_start_io_acct); -void disk_end_io_acct(struct gendisk *disk, unsigned int op, - unsigned long start_time) +static void __part_end_io_acct(struct hd_struct *part, unsigned int op, + unsigned long start_time) { - struct hd_struct *part = &disk->part0; const int sgrp = op_stat_group(op); unsigned long now = READ_ONCE(jiffies); unsigned long duration = now - start_time; @@ -1356,6 +1369,20 @@ void disk_end_io_acct(struct gendisk *disk, unsigned int op, part_stat_local_dec(part, in_flight[op_is_write(op)]); part_stat_unlock(); } + +void part_end_io_acct(struct hd_struct *part, struct bio *bio, + unsigned long start_time) +{ + __part_end_io_acct(part, bio_op(bio), start_time); + hd_struct_put(part); +} +EXPORT_SYMBOL_GPL(part_end_io_acct); + +void disk_end_io_acct(struct gendisk *disk, unsigned int op, + unsigned long start_time) +{ + __part_end_io_acct(&disk->part0, op, start_time); +} EXPORT_SYMBOL(disk_end_io_acct); /* diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 37ec5a73d027..5bd96fbab9b4 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1933,6 +1933,11 @@ unsigned long disk_start_io_acct(struct gendisk *disk, unsigned int sectors, void disk_end_io_acct(struct gendisk *disk, unsigned int op, unsigned long start_time); +unsigned long part_start_io_acct(struct gendisk *disk, struct hd_struct **part, + struct bio *bio); +void part_end_io_acct(struct hd_struct *part, struct bio *bio, + unsigned long start_time); + /** * bio_start_io_acct - start I/O accounting for bio based drivers * @bio: bio to start account for From 00fe60eae94efa5629bb6caf3839045cb22017e0 Mon Sep 17 00:00:00 2001 From: Song Liu Date: Mon, 31 Aug 2020 15:27:24 -0700 Subject: [PATCH 101/191] md: use part_[begin|end]_io_acct instead of disk_[begin|end]_io_acct This enables proper statistics in /proc/diskstats for md partitions. Signed-off-by: Song Liu Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe --- drivers/md/md.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 27ed61197014..64bc22d2b606 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -464,6 +464,7 @@ struct md_io { bio_end_io_t *orig_bi_end_io; void *orig_bi_private; unsigned long start_time; + struct hd_struct *part; }; static void md_end_io(struct bio *bio) @@ -471,7 +472,7 @@ static void md_end_io(struct bio *bio) struct md_io *md_io = bio->bi_private; struct mddev *mddev = md_io->mddev; - disk_end_io_acct(mddev->gendisk, bio_op(bio), md_io->start_time); + part_end_io_acct(md_io->part, bio, md_io->start_time); bio->bi_end_io = md_io->orig_bi_end_io; bio->bi_private = md_io->orig_bi_private; @@ -517,9 +518,8 @@ static blk_qc_t md_submit_bio(struct bio *bio) bio->bi_end_io = md_end_io; bio->bi_private = md_io; - md_io->start_time = disk_start_io_acct(mddev->gendisk, - bio_sectors(bio), - bio_op(bio)); + md_io->start_time = part_start_io_acct(mddev->gendisk, + &md_io->part, bio); } /* bio could be mergeable after passing to underlayer */ From 0806e60f31ec10822cd230d12603169d1bb7840e Mon Sep 17 00:00:00 2001 From: Song Liu Date: Mon, 31 Aug 2020 15:27:25 -0700 Subject: [PATCH 102/191] bcache: use part_[begin|end]_io_acct instead of disk_[begin|end]_io_acct This enables proper statistics in /proc/diskstats for bcache partitions. Signed-off-by: Song Liu Reviewed-by: Coly Li Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe --- drivers/md/bcache/request.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c index c7cadaafa947..7f54ae223644 100644 --- a/drivers/md/bcache/request.c +++ b/drivers/md/bcache/request.c @@ -475,6 +475,7 @@ struct search { unsigned int read_dirty_data:1; unsigned int cache_missed:1; + struct hd_struct *part; unsigned long start_time; struct btree_op op; @@ -669,7 +670,7 @@ static void bio_complete(struct search *s) { if (s->orig_bio) { /* Count on bcache device */ - disk_end_io_acct(s->d->disk, bio_op(s->orig_bio), s->start_time); + part_end_io_acct(s->part, s->orig_bio, s->start_time); trace_bcache_request_end(s->d, s->orig_bio); s->orig_bio->bi_status = s->iop.status; @@ -731,7 +732,7 @@ static inline struct search *search_alloc(struct bio *bio, s->write = op_is_write(bio_op(bio)); s->read_dirty_data = 0; /* Count on the bcache device */ - s->start_time = disk_start_io_acct(d->disk, bio_sectors(bio), bio_op(bio)); + s->start_time = part_start_io_acct(d->disk, &s->part, bio); s->iop.c = d->c; s->iop.bio = NULL; s->iop.inode = d->id; @@ -1072,6 +1073,7 @@ struct detached_dev_io_private { unsigned long start_time; bio_end_io_t *bi_end_io; void *bi_private; + struct hd_struct *part; }; static void detached_dev_end_io(struct bio *bio) @@ -1083,7 +1085,7 @@ static void detached_dev_end_io(struct bio *bio) bio->bi_private = ddip->bi_private; /* Count on the bcache device */ - disk_end_io_acct(ddip->d->disk, bio_op(bio), ddip->start_time); + part_end_io_acct(ddip->part, bio, ddip->start_time); if (bio->bi_status) { struct cached_dev *dc = container_of(ddip->d, @@ -1109,7 +1111,7 @@ static void detached_dev_do_request(struct bcache_device *d, struct bio *bio) ddip = kzalloc(sizeof(struct detached_dev_io_private), GFP_NOIO); ddip->d = d; /* Count on the bcache device */ - ddip->start_time = disk_start_io_acct(d->disk, bio_sectors(bio), bio_op(bio)); + ddip->start_time = part_start_io_acct(d->disk, &ddip->part, bio); ddip->bi_end_io = bio->bi_end_io; ddip->bi_private = bio->bi_private; bio->bi_end_io = detached_dev_end_io; From 769b628de0b9a7ab0b81e6eecca5ee7bf66e978d Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 11 Sep 2020 18:40:49 -0400 Subject: [PATCH 103/191] blk-iocost: fix divide-by-zero in transfer_surpluses() Conceptually, root_iocg->hweight_donating must be less than WEIGHT_ONE but all hweight calculations round up and thus it may end up >= WEIGHT_ONE triggering divide-by-zero and other issues. Bound the value to avoid surprises. Fixes: e08d02aa5fc9 ("blk-iocost: implement Andy's method for donation weight updates") Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- block/blk-iocost.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index fc897bb142bc..6e29b4dcf356 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -1881,15 +1881,21 @@ static void transfer_surpluses(struct list_head *surpluses, struct ioc_now *now) /* * Calculate the global donation rate (gamma) - the rate to adjust - * non-donating budgets by. No need to use 64bit multiplication here as - * the first operand is guaranteed to be smaller than WEIGHT_ONE - * (1<<16). + * non-donating budgets by. + * + * No need to use 64bit multiplication here as the first operand is + * guaranteed to be smaller than WEIGHT_ONE (1<<16). + * + * We know that there are beneficiary nodes and the sum of the donating + * hweights can't be whole; however, due to the round-ups during hweight + * calculations, root_iocg->hweight_donating might still end up equal to + * or greater than whole. Limit the range when calculating the divider. * * gamma = (1 - t_r') / (1 - t_r) */ gamma = DIV_ROUND_UP( (WEIGHT_ONE - root_iocg->hweight_after_donation) * WEIGHT_ONE, - WEIGHT_ONE - root_iocg->hweight_donating); + WEIGHT_ONE - min_t(u32, root_iocg->hweight_donating, WEIGHT_ONE - 1)); /* * Calculate adjusted hwi, child_adjusted_sum and inuse for the inner From aa67db24b6761277d731cc3434420283479927ca Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 14 Sep 2020 11:05:13 -0400 Subject: [PATCH 104/191] iocost: fix infinite loop bug in adjust_inuse_and_calc_cost() adjust_inuse_and_calc_cost() is responsible for reducing the amount of donated weights dynamically in period as the budget runs low. Because we don't want to do full donation calculation in period, we keep latching up inuse by INUSE_ADJ_STEP_PCT of the active weight of the cgroup until the resulting hweight_inuse is satisfactory. Unfortunately, the adj_step calculation was reading the active weight before acquiring ioc->lock. Because the current thread could have lost race to activate the iocg to another thread before entering this function, it may read the active weight as zero before acquiring ioc->lock. When this happens, the adj_step is calculated as zero and the incremental adjustment loop becomes an infinite one. Fix it by fetching the active weight after acquiring ioc->lock. Fixes: b0853ab4a238 ("blk-iocost: revamp in-period donation snapbacks") Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- block/blk-iocost.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index 6e29b4dcf356..ef9476fca1d8 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -2323,9 +2323,8 @@ static u64 adjust_inuse_and_calc_cost(struct ioc_gq *iocg, u64 vtime, { struct ioc *ioc = iocg->ioc; struct ioc_margins *margins = &ioc->margins; - u32 adj_step = DIV_ROUND_UP(iocg->active * INUSE_ADJ_STEP_PCT, 100); u32 __maybe_unused old_inuse = iocg->inuse, __maybe_unused old_hwi; - u32 hwi; + u32 hwi, adj_step; s64 margin; u64 cost, new_inuse; @@ -2354,8 +2353,15 @@ static u64 adjust_inuse_and_calc_cost(struct ioc_gq *iocg, u64 vtime, return cost; } - /* bump up inuse till @abs_cost fits in the existing budget */ + /* + * Bump up inuse till @abs_cost fits in the existing budget. + * adj_step must be determined after acquiring ioc->lock - we might + * have raced and lost to another thread for activation and could + * be reading 0 iocg->active before ioc->lock which will lead to + * infinite loop. + */ new_inuse = iocg->inuse; + adj_step = DIV_ROUND_UP(iocg->active * INUSE_ADJ_STEP_PCT, 100); do { new_inuse = new_inuse + adj_step; propagate_weights(iocg, iocg->active, new_inuse, true, now); From b53b072c4bb579a57c14f8e1d4ce2f4942814000 Mon Sep 17 00:00:00 2001 From: Baolin Wang Date: Mon, 7 Sep 2020 16:10:13 +0800 Subject: [PATCH 105/191] blk-throttle: Fix some comments' typos Fix some comments' typos. Signed-off-by: Baolin Wang Signed-off-by: Jens Axboe --- block/blk-throttle.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/block/blk-throttle.c b/block/blk-throttle.c index fee3325edf27..2fc6c3e0d4a0 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -150,7 +150,7 @@ struct throtl_grp { /* user configured IOPS limits */ unsigned int iops_conf[2][LIMIT_CNT]; - /* Number of bytes disptached in current slice */ + /* Number of bytes dispatched in current slice */ uint64_t bytes_disp[2]; /* Number of bio's dispatched in current slice */ unsigned int io_disp[2]; @@ -852,7 +852,7 @@ static inline void throtl_trim_slice(struct throtl_grp *tg, bool rw) /* * A bio has been dispatched. Also adjust slice_end. It might happen * that initially cgroup limit was very low resulting in high - * slice_end, but later limit was bumped up and bio was dispached + * slice_end, but later limit was bumped up and bio was dispatched * sooner, then we need to reduce slice_end. A high bogus slice_end * is bad because it does not allow new slice to start. */ @@ -1082,7 +1082,7 @@ static void throtl_add_bio_tg(struct bio *bio, struct throtl_qnode *qn, * If @tg doesn't currently have any bios queued in the same * direction, queueing @bio can change when @tg should be * dispatched. Mark that @tg was empty. This is automatically - * cleaered on the next tg_update_disptime(). + * cleared on the next tg_update_disptime(). */ if (!sq->nr_queued[rw]) tg->flags |= THROTL_TG_WAS_EMPTY; @@ -1303,7 +1303,7 @@ static void throtl_pending_timer_fn(struct timer_list *t) } } } else { - /* reached the top-level, queue issueing */ + /* reached the top-level, queue issuing */ queue_work(kthrotld_workqueue, &td->dispatch_work); } out_unlock: @@ -1314,8 +1314,8 @@ static void throtl_pending_timer_fn(struct timer_list *t) * blk_throtl_dispatch_work_fn - work function for throtl_data->dispatch_work * @work: work item being executed * - * This function is queued for execution when bio's reach the bio_lists[] - * of throtl_data->service_queue. Those bio's are ready and issued by this + * This function is queued for execution when bios reach the bio_lists[] + * of throtl_data->service_queue. Those bios are ready and issued by this * function. */ static void blk_throtl_dispatch_work_fn(struct work_struct *work) @@ -2230,7 +2230,7 @@ bool blk_throtl_bio(struct bio *bio) /* * @bio passed through this layer without being throttled. - * Climb up the ladder. If we''re already at the top, it + * Climb up the ladder. If we're already at the top, it * can be executed directly. */ qn = &tg->qnode_on_parent[rw]; From ff8b22c0f258c936460b436f6d78ed49a3b2a4cf Mon Sep 17 00:00:00 2001 From: Baolin Wang Date: Mon, 7 Sep 2020 16:10:14 +0800 Subject: [PATCH 106/191] blk-throttle: Use readable READ/WRITE macros Use readable READ/WRITE macros instead of magic numbers. Signed-off-by: Baolin Wang Signed-off-by: Jens Axboe --- block/blk-throttle.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 2fc6c3e0d4a0..06e73ed3e774 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -1428,8 +1428,8 @@ static void tg_conf_updated(struct throtl_grp *tg, bool global) * that a group's limit are dropped suddenly and we don't want to * account recently dispatched IO with new low rate. */ - throtl_start_new_slice(tg, 0); - throtl_start_new_slice(tg, 1); + throtl_start_new_slice(tg, READ); + throtl_start_new_slice(tg, WRITE); if (tg->flags & THROTL_TG_PENDING) { tg_update_disptime(tg); From e675df2adc2f0b8cbc0c64111d55b69f7253cbed Mon Sep 17 00:00:00 2001 From: Baolin Wang Date: Mon, 7 Sep 2020 16:10:15 +0800 Subject: [PATCH 107/191] blk-throttle: Define readable macros instead of static variables The 'throtl_grp_quantum' and 'throtl_quantum' are both read-only variables, thus better to use readable macros instead of static variables, which can also save some spaces for .bss area. Signed-off-by: Baolin Wang Signed-off-by: Jens Axboe --- block/blk-throttle.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 06e73ed3e774..ca9002d9d2c7 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -15,10 +15,10 @@ #include "blk-cgroup-rwstat.h" /* Max dispatch from a group in 1 round */ -static int throtl_grp_quantum = 8; +#define THROTL_GRP_QUANTUM 8 /* Total max dispatch from all groups in one round */ -static int throtl_quantum = 32; +#define THROTL_QUANTUM 32 /* Throttling is performed over a slice and after that slice is renewed */ #define DFL_THROTL_SLICE_HD (HZ / 10) @@ -1175,8 +1175,8 @@ static int throtl_dispatch_tg(struct throtl_grp *tg) { struct throtl_service_queue *sq = &tg->service_queue; unsigned int nr_reads = 0, nr_writes = 0; - unsigned int max_nr_reads = throtl_grp_quantum*3/4; - unsigned int max_nr_writes = throtl_grp_quantum - max_nr_reads; + unsigned int max_nr_reads = THROTL_GRP_QUANTUM * 3 / 4; + unsigned int max_nr_writes = THROTL_GRP_QUANTUM - max_nr_reads; struct bio *bio; /* Try to dispatch 75% READS and 25% WRITES */ @@ -1226,7 +1226,7 @@ static int throtl_select_dispatch(struct throtl_service_queue *parent_sq) if (sq->nr_queued[0] || sq->nr_queued[1]) tg_update_disptime(tg); - if (nr_disp >= throtl_quantum) + if (nr_disp >= THROTL_QUANTUM) break; } From 4599ea49d4b00a6fbaab2977e7f8359cfc7e8916 Mon Sep 17 00:00:00 2001 From: Baolin Wang Date: Mon, 7 Sep 2020 16:10:16 +0800 Subject: [PATCH 108/191] blk-throttle: Avoid calculating bps/iops limitation repeatedly The tg_may_dispatch() will call tg_with_in_bps_limit() and tg_with_in_iops_limit() to check if we can dispatch a bio or not, which will calculate bps/iops limitation multiple times. But tg_may_dispatch() is always called under queue lock, which means the bps/iops limitation will not change in tg_may_dispatch(). So we can calculate the bps/iops limitation only once, and pass them to tg_with_in_bps_limit() and tg_with_in_iops_limit() to avoid calculating bps/iops limitation repeatedly. Signed-off-by: Baolin Wang Signed-off-by: Jens Axboe --- block/blk-throttle.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) diff --git a/block/blk-throttle.c b/block/blk-throttle.c index ca9002d9d2c7..8719e37c3564 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -894,7 +894,7 @@ static inline void throtl_trim_slice(struct throtl_grp *tg, bool rw) } static bool tg_with_in_iops_limit(struct throtl_grp *tg, struct bio *bio, - unsigned long *wait) + u32 iops_limit, unsigned long *wait) { bool rw = bio_data_dir(bio); unsigned int io_allowed; @@ -913,7 +913,7 @@ static bool tg_with_in_iops_limit(struct throtl_grp *tg, struct bio *bio, * have been trimmed. */ - tmp = (u64)tg_iops_limit(tg, rw) * jiffy_elapsed_rnd; + tmp = (u64)iops_limit * jiffy_elapsed_rnd; do_div(tmp, HZ); if (tmp > UINT_MAX) @@ -936,7 +936,7 @@ static bool tg_with_in_iops_limit(struct throtl_grp *tg, struct bio *bio, } static bool tg_with_in_bps_limit(struct throtl_grp *tg, struct bio *bio, - unsigned long *wait) + u64 bps_limit, unsigned long *wait) { bool rw = bio_data_dir(bio); u64 bytes_allowed, extra_bytes, tmp; @@ -951,7 +951,7 @@ static bool tg_with_in_bps_limit(struct throtl_grp *tg, struct bio *bio, jiffy_elapsed_rnd = roundup(jiffy_elapsed_rnd, tg->td->throtl_slice); - tmp = tg_bps_limit(tg, rw) * jiffy_elapsed_rnd; + tmp = bps_limit * jiffy_elapsed_rnd; do_div(tmp, HZ); bytes_allowed = tmp; @@ -963,7 +963,7 @@ static bool tg_with_in_bps_limit(struct throtl_grp *tg, struct bio *bio, /* Calc approx time to dispatch */ extra_bytes = tg->bytes_disp[rw] + bio_size - bytes_allowed; - jiffy_wait = div64_u64(extra_bytes * HZ, tg_bps_limit(tg, rw)); + jiffy_wait = div64_u64(extra_bytes * HZ, bps_limit); if (!jiffy_wait) jiffy_wait = 1; @@ -987,6 +987,8 @@ static bool tg_may_dispatch(struct throtl_grp *tg, struct bio *bio, { bool rw = bio_data_dir(bio); unsigned long bps_wait = 0, iops_wait = 0, max_wait = 0; + u64 bps_limit = tg_bps_limit(tg, rw); + u32 iops_limit = tg_iops_limit(tg, rw); /* * Currently whole state machine of group depends on first bio @@ -998,8 +1000,7 @@ static bool tg_may_dispatch(struct throtl_grp *tg, struct bio *bio, bio != throtl_peek_queued(&tg->service_queue.queued[rw])); /* If tg->bps = -1, then BW is unlimited */ - if (tg_bps_limit(tg, rw) == U64_MAX && - tg_iops_limit(tg, rw) == UINT_MAX) { + if (bps_limit == U64_MAX && iops_limit == UINT_MAX) { if (wait) *wait = 0; return true; @@ -1021,8 +1022,8 @@ static bool tg_may_dispatch(struct throtl_grp *tg, struct bio *bio, jiffies + tg->td->throtl_slice); } - if (tg_with_in_bps_limit(tg, bio, &bps_wait) && - tg_with_in_iops_limit(tg, bio, &iops_wait)) { + if (tg_with_in_bps_limit(tg, bio, bps_limit, &bps_wait) && + tg_with_in_iops_limit(tg, bio, iops_limit, &iops_wait)) { if (wait) *wait = 0; return true; From 87fbeb8813bd8d48cb4b5c884793cc6b5126f6b8 Mon Sep 17 00:00:00 2001 From: Baolin Wang Date: Mon, 7 Sep 2020 16:10:17 +0800 Subject: [PATCH 109/191] blk-throttle: Avoid checking bps/iops limitation if bps or iops is unlimited Do not need check the bps or iops limitation if bps or iops is unlimited. Signed-off-by: Baolin Wang Signed-off-by: Jens Axboe --- block/blk-throttle.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 8719e37c3564..36ba61c5cdbd 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -901,6 +901,12 @@ static bool tg_with_in_iops_limit(struct throtl_grp *tg, struct bio *bio, unsigned long jiffy_elapsed, jiffy_wait, jiffy_elapsed_rnd; u64 tmp; + if (iops_limit == UINT_MAX) { + if (wait) + *wait = 0; + return true; + } + jiffy_elapsed = jiffies - tg->slice_start[rw]; /* Round up to the next throttle slice, wait time must be nonzero */ @@ -943,6 +949,12 @@ static bool tg_with_in_bps_limit(struct throtl_grp *tg, struct bio *bio, unsigned long jiffy_elapsed, jiffy_wait, jiffy_elapsed_rnd; unsigned int bio_size = throtl_bio_data_size(bio); + if (bps_limit == U64_MAX) { + if (wait) + *wait = 0; + return true; + } + jiffy_elapsed = jiffy_elapsed_rnd = jiffies - tg->slice_start[rw]; /* Slice has just started. Consider one slice interval */ From f952eefe74a4083142b4cdf0626ebbc07378aeb5 Mon Sep 17 00:00:00 2001 From: Julia Lawall Date: Sun, 20 Sep 2020 13:26:18 +0200 Subject: [PATCH 110/191] block: drop double zeroing sg_init_table zeroes its first argument, so the allocation of that argument doesn't have to. the semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // @@ expression x; @@ x = - kzalloc + kmalloc (...) ... sg_init_table(x,...) // Signed-off-by: Julia Lawall Signed-off-by: Jens Axboe --- block/bsg-lib.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/bsg-lib.c b/block/bsg-lib.c index d185396d88bb..330fede77271 100644 --- a/block/bsg-lib.c +++ b/block/bsg-lib.c @@ -207,7 +207,7 @@ static int bsg_map_buffer(struct bsg_buffer *buf, struct request *req) BUG_ON(!req->nr_phys_segments); - buf->sg_list = kzalloc(sz, GFP_KERNEL); + buf->sg_list = kmalloc(sz, GFP_KERNEL); if (!buf->sg_list) return -ENOMEM; sg_init_table(buf->sg_list, req->nr_phys_segments); From 0385971754f0aa0507ecd7f0a0f4a48781906eda Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 23 Sep 2020 17:07:13 +0200 Subject: [PATCH 111/191] block: fix bmd->is_null_mapped initialization bmd is allocated using kmalloc in bio_alloc_map_data, so make sure is_null_mapped is properly initialized to false for the !null_mapped case. Fixes: f3256075ba49 ("block: remove the BIO_NULL_MAPPED flag") Reported-by: Marc Hartmayer Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/blk-map.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/block/blk-map.c b/block/blk-map.c index be118926ccf4..21630dccac62 100644 --- a/block/blk-map.c +++ b/block/blk-map.c @@ -148,6 +148,7 @@ static int bio_copy_user_iov(struct request *rq, struct rq_map_data *map_data, * shortlived one. */ bmd->is_our_pages = !map_data; + bmd->is_null_mapped = (map_data && map_data->null_mapped); nr_pages = DIV_ROUND_UP(offset + len, PAGE_SIZE); if (nr_pages > BIO_MAX_PAGES) @@ -218,8 +219,6 @@ static int bio_copy_user_iov(struct request *rq, struct rq_map_data *map_data, } bio->bi_private = bmd; - if (map_data && map_data->null_mapped) - bmd->is_null_mapped = true; bounce_bio = bio; ret = blk_rq_append_bio(rq, &bounce_bio); From 22ada802ede89829dd010a317d9b812b7df7111a Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Mon, 21 Sep 2020 22:32:48 -0400 Subject: [PATCH 112/191] block: use lcm_not_zero() when stacking chunk_sectors Like 'io_opt', blk_stack_limits() should stack 'chunk_sectors' using lcm_not_zero() rather than min_not_zero() -- otherwise the final 'chunk_sectors' could result in sub-optimal alignment of IO to component devices in the IO stack. Also, if 'chunk_sectors' isn't a multiple of 'physical_block_size' then it is a bug in the driver and the device should be flagged as 'misaligned'. Reviewed-by: Ming Lei Reviewed-by: Martin K. Petersen Signed-off-by: Mike Snitzer Signed-off-by: Jens Axboe --- block/blk-settings.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/block/blk-settings.c b/block/blk-settings.c index 76a7e03bcd6c..b2e1a929a6db 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -534,6 +534,7 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, t->io_min = max(t->io_min, b->io_min); t->io_opt = lcm_not_zero(t->io_opt, b->io_opt); + t->chunk_sectors = lcm_not_zero(t->chunk_sectors, b->chunk_sectors); /* Physical block size a multiple of the logical block size? */ if (t->physical_block_size & (t->logical_block_size - 1)) { @@ -556,6 +557,13 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, ret = -1; } + /* chunk_sectors a multiple of the physical block size? */ + if ((t->chunk_sectors << 9) & (t->physical_block_size - 1)) { + t->chunk_sectors = 0; + t->misaligned = 1; + ret = -1; + } + t->raid_partial_stripes_expensive = max(t->raid_partial_stripes_expensive, b->raid_partial_stripes_expensive); @@ -594,10 +602,6 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, t->discard_granularity; } - if (b->chunk_sectors) - t->chunk_sectors = min_not_zero(t->chunk_sectors, - b->chunk_sectors); - t->zoned = max(t->zoned, b->zoned); return ret; } From 07d098e6bbad04030dab5b3e64149601fcb063ce Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Mon, 21 Sep 2020 22:32:49 -0400 Subject: [PATCH 113/191] block: allow 'chunk_sectors' to be non-power-of-2 It is possible, albeit more unlikely, for a block device to have a non power-of-2 for chunk_sectors (e.g. 10+2 RAID6 with 128K chunk_sectors, which results in a full-stripe size of 1280K. This causes the RAID6's io_opt to be advertised as 1280K, and a stacked device _could_ then be made to use a blocksize, aka chunk_sectors, that matches non power-of-2 io_opt of underlying RAID6 -- resulting in stacked device's chunk_sectors being a non power-of-2). Update blk_queue_chunk_sectors() and blk_max_size_offset() to accommodate drivers that need a non power-of-2 chunk_sectors. Reviewed-by: Ming Lei Reviewed-by: Martin K. Petersen Signed-off-by: Mike Snitzer Signed-off-by: Jens Axboe --- block/blk-settings.c | 10 ++++------ include/linux/blkdev.h | 12 +++++++++--- 2 files changed, 13 insertions(+), 9 deletions(-) diff --git a/block/blk-settings.c b/block/blk-settings.c index b2e1a929a6db..5ea3de48afba 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -172,15 +172,13 @@ EXPORT_SYMBOL(blk_queue_max_hw_sectors); * * Description: * If a driver doesn't want IOs to cross a given chunk size, it can set - * this limit and prevent merging across chunks. Note that the chunk size - * must currently be a power-of-2 in sectors. Also note that the block - * layer must accept a page worth of data at any offset. So if the - * crossing of chunks is a hard limitation in the driver, it must still be - * prepared to split single page bios. + * this limit and prevent merging across chunks. Note that the block layer + * must accept a page worth of data at any offset. So if the crossing of + * chunks is a hard limitation in the driver, it must still be prepared + * to split single page bios. **/ void blk_queue_chunk_sectors(struct request_queue *q, unsigned int chunk_sectors) { - BUG_ON(!is_power_of_2(chunk_sectors)); q->limits.chunk_sectors = chunk_sectors; } EXPORT_SYMBOL(blk_queue_chunk_sectors); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 5bd96fbab9b4..6e19a7aa1672 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1063,11 +1063,17 @@ static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q, static inline unsigned int blk_max_size_offset(struct request_queue *q, sector_t offset) { - if (!q->limits.chunk_sectors) + unsigned int chunk_sectors = q->limits.chunk_sectors; + + if (!chunk_sectors) return q->limits.max_sectors; - return min(q->limits.max_sectors, (unsigned int)(q->limits.chunk_sectors - - (offset & (q->limits.chunk_sectors - 1)))); + if (likely(is_power_of_2(chunk_sectors))) + chunk_sectors -= offset & (chunk_sectors - 1); + else + chunk_sectors -= sector_div(offset, chunk_sectors); + + return min(q->limits.max_sectors, chunk_sectors); } static inline unsigned int blk_rq_get_max_sectors(struct request *rq, From 38430f0876fa8b9549ec434f569dce03e057c076 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 21 Sep 2020 09:19:45 +0200 Subject: [PATCH 114/191] block: move the NEED_PART_SCAN flag to struct gendisk We can only scan for partitions on the whole disk, so move the flag from struct block_device to struct gendisk. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/genhd.c | 4 ++-- drivers/block/nbd.c | 8 ++++---- drivers/ide/ide-gd.c | 2 +- fs/block_dev.c | 7 +++---- include/linux/blk_types.h | 4 +--- include/linux/genhd.h | 2 ++ 6 files changed, 13 insertions(+), 14 deletions(-) diff --git a/block/genhd.c b/block/genhd.c index 9d060e79eb31..7b56203c90a3 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -731,7 +731,7 @@ static void register_disk(struct device *parent, struct gendisk *disk, if (!bdev) goto exit; - set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags); + set_bit(GD_NEED_PART_SCAN, &disk->state); err = blkdev_get(bdev, FMODE_READ, NULL); if (err < 0) goto exit; @@ -2112,7 +2112,7 @@ bool bdev_check_media_change(struct block_device *bdev) if (__invalidate_device(bdev, true)) pr_warn("VFS: busy inodes on changed media %s\n", bdev->bd_disk->disk_name); - set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags); + set_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state); return true; } EXPORT_SYMBOL(bdev_check_media_change); diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 15eed210feef..2dca0aab0a9a 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -315,7 +315,7 @@ static void nbd_size_update(struct nbd_device *nbd) bd_set_nr_sectors(bdev, nr_sectors); set_blocksize(bdev, config->blksize); } else - set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags); + set_bit(GD_NEED_PART_SCAN, &nbd->disk->state); bdput(bdev); } kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE); @@ -1322,7 +1322,7 @@ static int nbd_start_device_ioctl(struct nbd_device *nbd, struct block_device *b return ret; if (max_part) - set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags); + set_bit(GD_NEED_PART_SCAN, &nbd->disk->state); mutex_unlock(&nbd->config_lock); ret = wait_event_interruptible(config->recv_wq, atomic_read(&config->recv_threads) == 0); @@ -1500,9 +1500,9 @@ static int nbd_open(struct block_device *bdev, fmode_t mode) refcount_set(&nbd->config_refs, 1); refcount_inc(&nbd->refs); mutex_unlock(&nbd->config_lock); - set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags); + set_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state); } else if (nbd_disconnected(nbd->config)) { - set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags); + set_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state); } out: mutex_unlock(&nbd_index_mutex); diff --git a/drivers/ide/ide-gd.c b/drivers/ide/ide-gd.c index 661e2aa9c967..e2b6c82586ce 100644 --- a/drivers/ide/ide-gd.c +++ b/drivers/ide/ide-gd.c @@ -230,7 +230,7 @@ static int ide_gd_open(struct block_device *bdev, fmode_t mode) bdev->bd_disk->disk_name); drive->disk_ops->get_capacity(drive); set_capacity(disk, ide_gd_capacity(drive)); - set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags); + set_bit(GD_NEED_PART_SCAN, &disk->state); } else if (drive->dev_flags & IDE_DFLAG_FORMAT_IN_PROGRESS) { ret = -EBUSY; goto out_put_idkp; diff --git a/fs/block_dev.c b/fs/block_dev.c index 0b34955b9e36..1a9325f43157 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -910,7 +910,6 @@ struct block_device *bdget(dev_t dev) bdev->bd_super = NULL; bdev->bd_inode = inode; bdev->bd_part_count = 0; - bdev->bd_flags = 0; inode->i_mode = S_IFBLK; inode->i_rdev = dev; inode->i_bdev = bdev; @@ -1385,7 +1384,7 @@ int bdev_disk_changed(struct block_device *bdev, bool invalidate) lockdep_assert_held(&bdev->bd_mutex); - clear_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags); + clear_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state); rescan: ret = blk_drop_partitions(bdev); @@ -1509,7 +1508,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder, * The latter is necessary to prevent ghost * partitions on a removed medium. */ - if (test_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags) && + if (test_bit(GD_NEED_PART_SCAN, &disk->state) && (!ret || ret == -ENOMEDIUM)) bdev_disk_changed(bdev, ret == -ENOMEDIUM); @@ -1539,7 +1538,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder, if (bdev->bd_disk->fops->open) ret = bdev->bd_disk->fops->open(bdev, mode); /* the same as first opener case, read comment there */ - if (test_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags) && + if (test_bit(GD_NEED_PART_SCAN, &disk->state) && (!ret || ret == -ENOMEDIUM)) bdev_disk_changed(bdev, ret == -ENOMEDIUM); if (ret) diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 6ffa783e1633..eb20e28184ab 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -19,8 +19,6 @@ struct cgroup_subsys_state; typedef void (bio_end_io_t) (struct bio *); struct bio_crypt_ctx; -#define BDEV_NEED_PART_SCAN 0 - struct block_device { dev_t bd_dev; int bd_openers; @@ -39,7 +37,7 @@ struct block_device { struct hd_struct * bd_part; /* number of times partitions within this device have been opened. */ unsigned bd_part_count; - unsigned long bd_flags; + spinlock_t bd_size_lock; /* for bd_inode->i_size updates */ struct gendisk * bd_disk; struct backing_dev_info *bd_bdi; diff --git a/include/linux/genhd.h b/include/linux/genhd.h index 1c97cf84f011..38f23d757013 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -191,6 +191,8 @@ struct gendisk { void *private_data; int flags; + unsigned long state; +#define GD_NEED_PART_SCAN 0 struct rw_semaphore lookup_sem; struct kobject *slave_dir; From 9301fe734384990ef9a2463cb7aeb3b00bf5dad5 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 21 Sep 2020 09:19:46 +0200 Subject: [PATCH 115/191] block: cleanup partition scanning in register_disk Use blkdev_get_by_dev instead of open coding it using bdget_disk + blkdev_get, and split the code to read the partition table into a separate helper to make it a little more obvious. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/genhd.c | 33 ++++++++++++++------------------- 1 file changed, 14 insertions(+), 19 deletions(-) diff --git a/block/genhd.c b/block/genhd.c index 7b56203c90a3..05fb27cbb667 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -673,11 +673,23 @@ static int exact_lock(dev_t devt, void *data) return 0; } +static void disk_scan_partitions(struct gendisk *disk) +{ + struct block_device *bdev; + + if (!get_capacity(disk) || !disk_part_scan_enabled(disk)) + return; + + set_bit(GD_NEED_PART_SCAN, &disk->state); + bdev = blkdev_get_by_dev(disk_devt(disk), FMODE_READ, NULL); + if (!IS_ERR(bdev)) + blkdev_put(bdev, FMODE_READ); +} + static void register_disk(struct device *parent, struct gendisk *disk, const struct attribute_group **groups) { struct device *ddev = disk_to_dev(disk); - struct block_device *bdev; struct disk_part_iter piter; struct hd_struct *part; int err; @@ -719,25 +731,8 @@ static void register_disk(struct device *parent, struct gendisk *disk, return; } - /* No minors to use for partitions */ - if (!disk_part_scan_enabled(disk)) - goto exit; + disk_scan_partitions(disk); - /* No such device (e.g., media were just removed) */ - if (!get_capacity(disk)) - goto exit; - - bdev = bdget_disk(disk, 0); - if (!bdev) - goto exit; - - set_bit(GD_NEED_PART_SCAN, &disk->state); - err = blkdev_get(bdev, FMODE_READ, NULL); - if (err < 0) - goto exit; - blkdev_put(bdev, FMODE_READ); - -exit: /* announce disk after possible partitions are created */ dev_set_uevent_suppress(ddev, 0); kobject_uevent(&ddev->kobj, KOBJ_ADD); From 478162821dfb4396c53f07ad82dc32cd0f525cea Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 21 Sep 2020 09:19:47 +0200 Subject: [PATCH 116/191] block: cleanup blkdev_bszset Use blkdev_get_by_dev instead of bdgrab + blkdev_get. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/ioctl.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/block/ioctl.c b/block/ioctl.c index ae74d0409afa..06262c28f0c6 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -478,15 +478,14 @@ static int blkdev_bszset(struct block_device *bdev, fmode_t mode, if (get_user(n, argp)) return -EFAULT; - if (!(mode & FMODE_EXCL)) { - bdgrab(bdev); - if (blkdev_get(bdev, mode | FMODE_EXCL, &bdev) < 0) - return -EBUSY; - } + if (mode & FMODE_EXCL) + return set_blocksize(bdev, n); + if (IS_ERR(blkdev_get_by_dev(bdev->bd_dev, mode | FMODE_EXCL, &bdev))) + return -EBUSY; ret = set_blocksize(bdev, n); - if (!(mode & FMODE_EXCL)) - blkdev_put(bdev, mode | FMODE_EXCL); + blkdev_put(bdev, mode | FMODE_EXCL); + return ret; } From 2d9e28a9a10c2381a267a5184560ddc9f673f71b Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 21 Sep 2020 09:19:48 +0200 Subject: [PATCH 117/191] pktcdvd: remove the if 0'ed pkt_start_recovery function Remove code which has been dead since the initial commit. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- drivers/block/pktcdvd.c | 67 ++--------------------------------------- 1 file changed, 2 insertions(+), 65 deletions(-) diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c index 17f2e6ff1223..bc870a5f15f7 100644 --- a/drivers/block/pktcdvd.c +++ b/drivers/block/pktcdvd.c @@ -1082,65 +1082,6 @@ static void pkt_put_packet_data(struct pktcdvd_device *pd, struct packet_data *p } } -/* - * recover a failed write, query for relocation if possible - * - * returns 1 if recovery is possible, or 0 if not - * - */ -static int pkt_start_recovery(struct packet_data *pkt) -{ - /* - * FIXME. We need help from the file system to implement - * recovery handling. - */ - return 0; -#if 0 - struct request *rq = pkt->rq; - struct pktcdvd_device *pd = rq->rq_disk->private_data; - struct block_device *pkt_bdev; - struct super_block *sb = NULL; - unsigned long old_block, new_block; - sector_t new_sector; - - pkt_bdev = bdget(kdev_t_to_nr(pd->pkt_dev)); - if (pkt_bdev) { - sb = get_super(pkt_bdev); - bdput(pkt_bdev); - } - - if (!sb) - return 0; - - if (!sb->s_op->relocate_blocks) - goto out; - - old_block = pkt->sector / (CD_FRAMESIZE >> 9); - if (sb->s_op->relocate_blocks(sb, old_block, &new_block)) - goto out; - - new_sector = new_block * (CD_FRAMESIZE >> 9); - pkt->sector = new_sector; - - bio_reset(pkt->bio); - bio_set_dev(pkt->bio, pd->bdev); - bio_set_op_attrs(pkt->bio, REQ_OP_WRITE, 0); - pkt->bio->bi_iter.bi_sector = new_sector; - pkt->bio->bi_iter.bi_size = pkt->frames * CD_FRAMESIZE; - pkt->bio->bi_vcnt = pkt->frames; - - pkt->bio->bi_end_io = pkt_end_io_packet_write; - pkt->bio->bi_private = pkt; - - drop_super(sb); - return 1; - -out: - drop_super(sb); - return 0; -#endif -} - static inline void pkt_set_state(struct packet_data *pkt, enum packet_data_state state) { #if PACKET_DEBUG > 1 @@ -1357,12 +1298,8 @@ static void pkt_run_state_machine(struct pktcdvd_device *pd, struct packet_data break; case PACKET_RECOVERY_STATE: - if (pkt_start_recovery(pkt)) { - pkt_start_write(pd, pkt); - } else { - pkt_dbg(2, pd, "No recovery possible\n"); - pkt_set_state(pkt, PACKET_FINISHED_STATE); - } + pkt_dbg(2, pd, "No recovery possible\n"); + pkt_set_state(pkt, PACKET_FINISHED_STATE); break; case PACKET_FINISHED_STATE: From b8d954849cf4689d88ad84fd5cdb2d71d060f66a Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 21 Sep 2020 09:19:49 +0200 Subject: [PATCH 118/191] pktcdvd: use blkdev_get_by_dev instead of open coding it Replace bdget + blkdev_get by blkdev_get_by_dev. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- drivers/block/pktcdvd.c | 25 +++++++++++-------------- 1 file changed, 11 insertions(+), 14 deletions(-) diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c index bc870a5f15f7..467dbd06b7cd 100644 --- a/drivers/block/pktcdvd.c +++ b/drivers/block/pktcdvd.c @@ -2110,16 +2110,18 @@ static int pkt_open_dev(struct pktcdvd_device *pd, fmode_t write) int ret; long lba; struct request_queue *q; + struct block_device *bdev; /* * We need to re-open the cdrom device without O_NONBLOCK to be able * to read/write from/to it. It is already opened in O_NONBLOCK mode - * so bdget() can't fail. + * so open should not fail. */ - bdget(pd->bdev->bd_dev); - ret = blkdev_get(pd->bdev, FMODE_READ | FMODE_EXCL, pd); - if (ret) + bdev = blkdev_get_by_dev(pd->bdev->bd_dev, FMODE_READ | FMODE_EXCL, pd); + if (IS_ERR(bdev)) { + ret = PTR_ERR(bdev); goto out; + } ret = pkt_get_last_written(pd, &lba); if (ret) { @@ -2163,7 +2165,7 @@ static int pkt_open_dev(struct pktcdvd_device *pd, fmode_t write) return 0; out_putdev: - blkdev_put(pd->bdev, FMODE_READ | FMODE_EXCL); + blkdev_put(bdev, FMODE_READ | FMODE_EXCL); out: return ret; } @@ -2500,7 +2502,6 @@ static int pkt_seq_show(struct seq_file *m, void *p) static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev) { int i; - int ret = 0; char b[BDEVNAME_SIZE]; struct block_device *bdev; @@ -2523,12 +2524,9 @@ static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev) } } - bdev = bdget(dev); - if (!bdev) - return -ENOMEM; - ret = blkdev_get(bdev, FMODE_READ | FMODE_NDELAY, NULL); - if (ret) - return ret; + bdev = blkdev_get_by_dev(dev, FMODE_READ | FMODE_NDELAY, NULL); + if (IS_ERR(bdev)) + return PTR_ERR(bdev); if (!blk_queue_scsi_passthrough(bdev_get_queue(bdev))) { blkdev_put(bdev, FMODE_READ | FMODE_NDELAY); return -EINVAL; @@ -2546,7 +2544,6 @@ static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev) pd->cdrw.thread = kthread_run(kcdrwd, pd, "%s", pd->name); if (IS_ERR(pd->cdrw.thread)) { pkt_err(pd, "can't start kernel thread\n"); - ret = -ENOMEM; goto out_mem; } @@ -2558,7 +2555,7 @@ static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev) blkdev_put(bdev, FMODE_READ | FMODE_NDELAY); /* This is safe: open() is still holding a reference. */ module_put(THIS_MODULE); - return ret; + return -ENOMEM; } static int pkt_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg) From 0fc66c9d63143f9437cd57cf5eab50a258fa40ec Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 21 Sep 2020 09:19:50 +0200 Subject: [PATCH 119/191] zram: cleanup backing_dev_store Use blkdev_get_by_dev instead of bdgrab + blkdev_get. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- drivers/block/zram/zram_drv.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index a356275605b1..91ccfe444525 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -491,9 +491,10 @@ static ssize_t backing_dev_store(struct device *dev, goto out; } - bdev = bdgrab(I_BDEV(inode)); - err = blkdev_get(bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL, zram); - if (err < 0) { + bdev = blkdev_get_by_dev(inode->i_rdev, + FMODE_READ | FMODE_WRITE | FMODE_EXCL, zram); + if (IS_ERR(bdev)) { + err = PTR_ERR(bdev); bdev = NULL; goto out; } From 5a56ad7882a11624043db539a2c2076923148aa6 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 21 Sep 2020 09:19:51 +0200 Subject: [PATCH 120/191] raw: don't keep unopened block device around Turn binding into a normal dev_t as the struct block device doesn't buy us anything and use blkdev_open_by_dev to actually open it. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- drivers/char/raw.c | 51 +++++++++++++++++----------------------------- 1 file changed, 19 insertions(+), 32 deletions(-) diff --git a/drivers/char/raw.c b/drivers/char/raw.c index ccf5bd528642..5d52a1f4738c 100644 --- a/drivers/char/raw.c +++ b/drivers/char/raw.c @@ -28,7 +28,8 @@ #include struct raw_device_data { - struct block_device *binding; + dev_t binding; + struct block_device *bdev; int inuse; }; @@ -73,14 +74,15 @@ static int raw_open(struct inode *inode, struct file *filp) /* * All we need to do on open is check that the device is bound. */ - bdev = raw_devices[minor].binding; err = -ENODEV; - if (!bdev) + if (!raw_devices[minor].binding) goto out; - bdgrab(bdev); - err = blkdev_get(bdev, filp->f_mode | FMODE_EXCL, raw_open); - if (err) + bdev = blkdev_get_by_dev(raw_devices[minor].binding, + filp->f_mode | FMODE_EXCL, raw_open); + if (IS_ERR(bdev)) { + err = PTR_ERR(bdev); goto out; + } err = set_blocksize(bdev, bdev_logical_block_size(bdev)); if (err) goto out1; @@ -90,6 +92,7 @@ static int raw_open(struct inode *inode, struct file *filp) file_inode(filp)->i_mapping = bdev->bd_inode->i_mapping; filp->private_data = bdev; + raw_devices[minor].bdev = bdev; mutex_unlock(&raw_mutex); return 0; @@ -110,7 +113,7 @@ static int raw_release(struct inode *inode, struct file *filp) struct block_device *bdev; mutex_lock(&raw_mutex); - bdev = raw_devices[minor].binding; + bdev = raw_devices[minor].bdev; if (--raw_devices[minor].inuse == 0) /* Here inode->i_mapping == bdev->bd_inode->i_mapping */ inode->i_mapping = &inode->i_data; @@ -133,6 +136,7 @@ raw_ioctl(struct file *filp, unsigned int command, unsigned long arg) static int bind_set(int number, u64 major, u64 minor) { dev_t dev = MKDEV(major, minor); + dev_t raw = MKDEV(RAW_MAJOR, number); struct raw_device_data *rawdev; int err = 0; @@ -166,25 +170,17 @@ static int bind_set(int number, u64 major, u64 minor) mutex_unlock(&raw_mutex); return -EBUSY; } - if (rawdev->binding) { - bdput(rawdev->binding); + if (rawdev->binding) module_put(THIS_MODULE); - } + + rawdev->binding = dev; if (!dev) { /* unbind */ - rawdev->binding = NULL; - device_destroy(raw_class, MKDEV(RAW_MAJOR, number)); + device_destroy(raw_class, raw); } else { - rawdev->binding = bdget(dev); - if (rawdev->binding == NULL) { - err = -ENOMEM; - } else { - dev_t raw = MKDEV(RAW_MAJOR, number); - __module_get(THIS_MODULE); - device_destroy(raw_class, raw); - device_create(raw_class, NULL, raw, NULL, - "raw%d", number); - } + __module_get(THIS_MODULE); + device_destroy(raw_class, raw); + device_create(raw_class, NULL, raw, NULL, "raw%d", number); } mutex_unlock(&raw_mutex); return err; @@ -192,18 +188,9 @@ static int bind_set(int number, u64 major, u64 minor) static int bind_get(int number, dev_t *dev) { - struct raw_device_data *rawdev; - struct block_device *bdev; - if (number <= 0 || number >= max_raw_minors) return -EINVAL; - - rawdev = &raw_devices[number]; - - mutex_lock(&raw_mutex); - bdev = rawdev->binding; - *dev = bdev ? bdev->bd_dev : 0; - mutex_unlock(&raw_mutex); + *dev = raw_devices[number].binding; return 0; } From 841ab72cb5be3bbf6544f28329b81c73f0f835b3 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 21 Sep 2020 09:19:52 +0200 Subject: [PATCH 121/191] dasd: cleanup dasd_scan_partitions Use blkdev_get_by_dev instead of bdget_disk + blkdev_get. Signed-off-by: Christoph Hellwig Reviewed-by: Stefan Haberland Signed-off-by: Jens Axboe --- drivers/s390/block/dasd_genhd.c | 15 ++++----------- 1 file changed, 4 insertions(+), 11 deletions(-) diff --git a/drivers/s390/block/dasd_genhd.c b/drivers/s390/block/dasd_genhd.c index af5b0ecb8f89..a9698fba9b76 100644 --- a/drivers/s390/block/dasd_genhd.c +++ b/drivers/s390/block/dasd_genhd.c @@ -101,18 +101,11 @@ int dasd_scan_partitions(struct dasd_block *block) struct block_device *bdev; int rc; - bdev = bdget_disk(block->gdp, 0); - if (!bdev) { - DBF_DEV_EVENT(DBF_ERR, block->base, "%s", - "scan partitions error, bdget returned NULL"); - return -ENODEV; - } - - rc = blkdev_get(bdev, FMODE_READ, NULL); - if (rc < 0) { + bdev = blkdev_get_by_dev(disk_devt(block->gdp), FMODE_READ, NULL); + if (IS_ERR(bdev)) { DBF_DEV_EVENT(DBF_ERR, block->base, - "scan partitions error, blkdev_get returned %d", - rc); + "scan partitions error, blkdev_get returned %ld", + PTR_ERR(bdev)); return -ENODEV; } From e455ed22906c02c7638e127dbf60634765db02cd Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 21 Sep 2020 09:19:53 +0200 Subject: [PATCH 122/191] ocfs2: cleanup o2hb_region_dev_store Use blkdev_get_by_dev instead of igrab (aka open coded bdgrab) + blkdev_get. Signed-off-by: Christoph Hellwig Reviewed-by: Joseph Qi Signed-off-by: Jens Axboe --- fs/ocfs2/cluster/heartbeat.c | 28 ++++++++++------------------ 1 file changed, 10 insertions(+), 18 deletions(-) diff --git a/fs/ocfs2/cluster/heartbeat.c b/fs/ocfs2/cluster/heartbeat.c index 89d13e0705fe..0179a73a3fa2 100644 --- a/fs/ocfs2/cluster/heartbeat.c +++ b/fs/ocfs2/cluster/heartbeat.c @@ -1766,7 +1766,6 @@ static ssize_t o2hb_region_dev_store(struct config_item *item, int sectsize; char *p = (char *)page; struct fd f; - struct inode *inode; ssize_t ret = -EINVAL; int live_threshold; @@ -1793,20 +1792,16 @@ static ssize_t o2hb_region_dev_store(struct config_item *item, reg->hr_block_bytes == 0) goto out2; - inode = igrab(f.file->f_mapping->host); - if (inode == NULL) + if (!S_ISBLK(f.file->f_mapping->host->i_mode)) goto out2; - if (!S_ISBLK(inode->i_mode)) - goto out3; - - reg->hr_bdev = I_BDEV(f.file->f_mapping->host); - ret = blkdev_get(reg->hr_bdev, FMODE_WRITE | FMODE_READ, NULL); - if (ret) { + reg->hr_bdev = blkdev_get_by_dev(f.file->f_mapping->host->i_rdev, + FMODE_WRITE | FMODE_READ, NULL); + if (IS_ERR(reg->hr_bdev)) { + ret = PTR_ERR(reg->hr_bdev); reg->hr_bdev = NULL; - goto out3; + goto out2; } - inode = NULL; bdevname(reg->hr_bdev, reg->hr_dev_name); @@ -1909,16 +1904,13 @@ static ssize_t o2hb_region_dev_store(struct config_item *item, config_item_name(®->hr_item), reg->hr_dev_name); out3: - iput(inode); + if (ret < 0) { + blkdev_put(reg->hr_bdev, FMODE_READ | FMODE_WRITE); + reg->hr_bdev = NULL; + } out2: fdput(f); out: - if (ret < 0) { - if (reg->hr_bdev) { - blkdev_put(reg->hr_bdev, FMODE_READ|FMODE_WRITE); - reg->hr_bdev = NULL; - } - } return ret; } From ef16e1d98c4e05338ab9c381ac0100a4ed0626ca Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 21 Sep 2020 09:19:54 +0200 Subject: [PATCH 123/191] mm: cleanup claim_swapfile Use blkdev_get_by_dev instead of bdgrab + blkdev_get. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- mm/swapfile.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/mm/swapfile.c b/mm/swapfile.c index 12f59e641b5e..7438c4affc75 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -2920,10 +2920,10 @@ static int claim_swapfile(struct swap_info_struct *p, struct inode *inode) int error; if (S_ISBLK(inode->i_mode)) { - p->bdev = bdgrab(I_BDEV(inode)); - error = blkdev_get(p->bdev, + p->bdev = blkdev_get_by_dev(inode->i_rdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL, p); - if (error < 0) { + if (IS_ERR(p->bdev)) { + error = PTR_ERR(p->bdev); p->bdev = NULL; return error; } From bb3247a399801ebba20bef101c89e563f5fe7f02 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 21 Sep 2020 09:19:55 +0200 Subject: [PATCH 124/191] PM: rewrite is_hibernate_resume_dev to not require an inode Just check the dev_t to help simplifying the code. Signed-off-by: Christoph Hellwig Acked-by: Rafael J. Wysocki Acked-by: Pavel Machek Signed-off-by: Jens Axboe --- fs/block_dev.c | 2 +- include/linux/suspend.h | 4 ++-- kernel/power/user.c | 12 ++++++------ 3 files changed, 9 insertions(+), 9 deletions(-) diff --git a/fs/block_dev.c b/fs/block_dev.c index 1a9325f43157..2898d69be6b3 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1885,7 +1885,7 @@ ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from) if (bdev_read_only(I_BDEV(bd_inode))) return -EPERM; - if (IS_SWAPFILE(bd_inode) && !is_hibernate_resume_dev(bd_inode)) + if (IS_SWAPFILE(bd_inode) && !is_hibernate_resume_dev(bd_inode->i_rdev)) return -ETXTBSY; if (!iov_iter_count(from)) diff --git a/include/linux/suspend.h b/include/linux/suspend.h index cb9afad82a90..8af13ba60c7e 100644 --- a/include/linux/suspend.h +++ b/include/linux/suspend.h @@ -473,9 +473,9 @@ static inline int hibernate_quiet_exec(int (*func)(void *data), void *data) { #endif /* CONFIG_HIBERNATION */ #ifdef CONFIG_HIBERNATION_SNAPSHOT_DEV -int is_hibernate_resume_dev(const struct inode *); +int is_hibernate_resume_dev(dev_t dev); #else -static inline int is_hibernate_resume_dev(const struct inode *i) { return 0; } +static inline int is_hibernate_resume_dev(dev_t dev) { return 0; } #endif /* Hibernation and suspend events */ diff --git a/kernel/power/user.c b/kernel/power/user.c index d5eedc2baa2a..b5815685b944 100644 --- a/kernel/power/user.c +++ b/kernel/power/user.c @@ -35,12 +35,12 @@ static struct snapshot_data { bool ready; bool platform_support; bool free_bitmaps; - struct inode *bd_inode; + dev_t dev; } snapshot_state; -int is_hibernate_resume_dev(const struct inode *bd_inode) +int is_hibernate_resume_dev(dev_t dev) { - return hibernation_available() && snapshot_state.bd_inode == bd_inode; + return hibernation_available() && snapshot_state.dev == dev; } static int snapshot_open(struct inode *inode, struct file *filp) @@ -101,7 +101,7 @@ static int snapshot_open(struct inode *inode, struct file *filp) data->frozen = false; data->ready = false; data->platform_support = false; - data->bd_inode = NULL; + data->dev = 0; Unlock: unlock_system_sleep(); @@ -117,7 +117,7 @@ static int snapshot_release(struct inode *inode, struct file *filp) swsusp_free(); data = filp->private_data; - data->bd_inode = NULL; + data->dev = 0; free_all_swap_pages(data->swap); if (data->frozen) { pm_restore_gfp_mask(); @@ -245,7 +245,7 @@ static int snapshot_set_swap_area(struct snapshot_data *data, if (data->swap < 0) return -ENODEV; - data->bd_inode = bdev->bd_inode; + data->dev = bdev->bd_dev; bdput(bdev); return 0; } From 21bd900572f3708e281ea25f051fc92462eb1193 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 21 Sep 2020 09:19:56 +0200 Subject: [PATCH 125/191] mm: split swap_type_of swap_type_of is used for two entirely different purposes: (1) check what swap type a given device/offset corresponds to (2) find the first available swap device that can be written to Mixing both in a single function creates an unreadable mess. Create two separate functions instead, and switch both to pass a dev_t instead of a struct block_device to further simplify the code. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- include/linux/swap.h | 3 ++- kernel/power/swap.c | 17 ++++++++--------- kernel/power/user.c | 16 ++++------------ mm/swapfile.c | 39 +++++++++++++++++++++------------------ 4 files changed, 35 insertions(+), 40 deletions(-) diff --git a/include/linux/swap.h b/include/linux/swap.h index 661046994db4..4340a7b6e7a1 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -467,7 +467,8 @@ extern int swapcache_prepare(swp_entry_t); extern void swap_free(swp_entry_t); extern void swapcache_free_entries(swp_entry_t *entries, int n); extern int free_swap_and_cache(swp_entry_t); -extern int swap_type_of(dev_t, sector_t, struct block_device **); +int swap_type_of(dev_t device, sector_t offset); +int find_first_swap(dev_t *device); extern unsigned int count_swap_pages(int, int); extern sector_t map_swap_page(struct page *, struct block_device **); extern sector_t swapdev_block(int, pgoff_t); diff --git a/kernel/power/swap.c b/kernel/power/swap.c index 01e2858b5fe3..9d3ffbfe08db 100644 --- a/kernel/power/swap.c +++ b/kernel/power/swap.c @@ -335,12 +335,17 @@ static int swsusp_swap_check(void) { int res; - res = swap_type_of(swsusp_resume_device, swsusp_resume_block, - &hib_resume_bdev); + if (swsusp_resume_device) + res = swap_type_of(swsusp_resume_device, swsusp_resume_block); + else + res = find_first_swap(&swsusp_resume_device); if (res < 0) return res; - root_swap = res; + + hib_resume_bdev = bdget(swsusp_resume_device); + if (!hib_resume_bdev) + return -ENOMEM; res = blkdev_get(hib_resume_bdev, FMODE_WRITE, NULL); if (res) return res; @@ -349,12 +354,6 @@ static int swsusp_swap_check(void) if (res < 0) blkdev_put(hib_resume_bdev, FMODE_WRITE); - /* - * Update the resume device to the one actually used, - * so the test_resume mode can use it in case it is - * invoked from hibernate() to test the snapshot. - */ - swsusp_resume_device = hib_resume_bdev->bd_dev; return res; } diff --git a/kernel/power/user.c b/kernel/power/user.c index b5815685b944..6510a8f7687f 100644 --- a/kernel/power/user.c +++ b/kernel/power/user.c @@ -69,8 +69,7 @@ static int snapshot_open(struct inode *inode, struct file *filp) memset(&data->handle, 0, sizeof(struct snapshot_handle)); if ((filp->f_flags & O_ACCMODE) == O_RDONLY) { /* Hibernating. The image device should be accessible. */ - data->swap = swsusp_resume_device ? - swap_type_of(swsusp_resume_device, 0, NULL) : -1; + data->swap = swap_type_of(swsusp_resume_device, 0); data->mode = O_RDONLY; data->free_bitmaps = false; error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls); @@ -210,7 +209,6 @@ struct compat_resume_swap_area { static int snapshot_set_swap_area(struct snapshot_data *data, void __user *argp) { - struct block_device *bdev; sector_t offset; dev_t swdev; @@ -237,16 +235,10 @@ static int snapshot_set_swap_area(struct snapshot_data *data, * User space encodes device types as two-byte values, * so we need to recode them */ - if (!swdev) { - data->swap = -1; - return -EINVAL; - } - data->swap = swap_type_of(swdev, offset, &bdev); + data->swap = swap_type_of(swdev, offset); if (data->swap < 0) - return -ENODEV; - - data->dev = bdev->bd_dev; - bdput(bdev); + return swdev ? -ENODEV : -EINVAL; + data->dev = swdev; return 0; } diff --git a/mm/swapfile.c b/mm/swapfile.c index 7438c4affc75..b90f86920743 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1801,13 +1801,12 @@ int free_swap_and_cache(swp_entry_t entry) * * This is needed for the suspend to disk (aka swsusp). */ -int swap_type_of(dev_t device, sector_t offset, struct block_device **bdev_p) +int swap_type_of(dev_t device, sector_t offset) { - struct block_device *bdev = NULL; int type; - if (device) - bdev = bdget(device); + if (!device) + return -1; spin_lock(&swap_lock); for (type = 0; type < nr_swapfiles; type++) { @@ -1816,30 +1815,34 @@ int swap_type_of(dev_t device, sector_t offset, struct block_device **bdev_p) if (!(sis->flags & SWP_WRITEOK)) continue; - if (!bdev) { - if (bdev_p) - *bdev_p = bdgrab(sis->bdev); - - spin_unlock(&swap_lock); - return type; - } - if (bdev == sis->bdev) { + if (device == sis->bdev->bd_dev) { struct swap_extent *se = first_se(sis); if (se->start_block == offset) { - if (bdev_p) - *bdev_p = bdgrab(sis->bdev); - spin_unlock(&swap_lock); - bdput(bdev); return type; } } } spin_unlock(&swap_lock); - if (bdev) - bdput(bdev); + return -ENODEV; +} +int find_first_swap(dev_t *device) +{ + int type; + + spin_lock(&swap_lock); + for (type = 0; type < nr_swapfiles; type++) { + struct swap_info_struct *sis = swap_info[type]; + + if (!(sis->flags & SWP_WRITEOK)) + continue; + *device = sis->bdev->bd_dev; + spin_unlock(&swap_lock); + return type; + } + spin_unlock(&swap_lock); return -ENODEV; } From 36daaa98f7ad9224421b18549a3f7bdf4d220414 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 21 Sep 2020 09:19:57 +0200 Subject: [PATCH 126/191] PM: mm: cleanup swsusp_swap_check Use blkdev_get_by_dev instead of bdget + blkdev_get. Signed-off-by: Christoph Hellwig Acked-by: Rafael J. Wysocki Signed-off-by: Jens Axboe --- kernel/power/swap.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/kernel/power/swap.c b/kernel/power/swap.c index 9d3ffbfe08db..71385bedcc3a 100644 --- a/kernel/power/swap.c +++ b/kernel/power/swap.c @@ -343,12 +343,10 @@ static int swsusp_swap_check(void) return res; root_swap = res; - hib_resume_bdev = bdget(swsusp_resume_device); - if (!hib_resume_bdev) - return -ENOMEM; - res = blkdev_get(hib_resume_bdev, FMODE_WRITE, NULL); - if (res) - return res; + hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device, FMODE_WRITE, + NULL); + if (IS_ERR(hib_resume_bdev)) + return PTR_ERR(hib_resume_bdev); res = set_blocksize(hib_resume_bdev, PAGE_SIZE); if (res < 0) From 1fb1a2ad75e33e646d33e42b9ed17d879d472859 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 21 Sep 2020 09:19:58 +0200 Subject: [PATCH 127/191] block: mark blkdev_get static There are no users outside the core block code left now. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- fs/block_dev.c | 3 +-- include/linux/blkdev.h | 1 - 2 files changed, 1 insertion(+), 3 deletions(-) diff --git a/fs/block_dev.c b/fs/block_dev.c index 2898d69be6b3..6b9d19ffa5af 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1616,7 +1616,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder, * RETURNS: * 0 on success, -errno on failure. */ -int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder) +static int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder) { int ret, perm = 0; @@ -1637,7 +1637,6 @@ int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder) bdput(bdev); return ret; } -EXPORT_SYMBOL(blkdev_get); /** * blkdev_get_by_path - open a block device by name diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 6e19a7aa1672..be5ef6f4ba19 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1981,7 +1981,6 @@ void blkdev_show(struct seq_file *seqf, off_t offset); #define BLKDEV_MAJOR_MAX 0 #endif -int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder); struct block_device *blkdev_get_by_path(const char *path, fmode_t mode, void *holder); struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder); From 402dd2cf46b177be5bcb138b7d7fd8f38aa130e4 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 24 Sep 2020 08:51:28 +0200 Subject: [PATCH 128/191] fs: remove the unused SB_I_MULTIROOT flag The last user of SB_I_MULTIROOT is disappeared with commit f2aedb713c28 ("NFS: Add fs_context support.") Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe --- fs/namei.c | 4 ++-- include/linux/fs.h | 1 - 2 files changed, 2 insertions(+), 3 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index e99e2a9da0f7..f1eb8ccd2be9 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -568,8 +568,8 @@ static bool path_connected(struct vfsmount *mnt, struct dentry *dentry) { struct super_block *sb = mnt->mnt_sb; - /* Bind mounts and multi-root filesystems can have disconnected paths */ - if (!(sb->s_iflags & SB_I_MULTIROOT) && (mnt->mnt_root == sb->s_root)) + /* Bind mounts can have disconnected paths */ + if (mnt->mnt_root == sb->s_root) return true; return is_subdir(dentry, mnt->mnt_root); diff --git a/include/linux/fs.h b/include/linux/fs.h index 7519ae003a08..fbd74df5ce5f 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1385,7 +1385,6 @@ extern int send_sigurg(struct fown_struct *fown); #define SB_I_CGROUPWB 0x00000001 /* cgroup-aware writeback enabled */ #define SB_I_NOEXEC 0x00000002 /* Ignore executables on this fs */ #define SB_I_NODEV 0x00000004 /* Ignore devices on this fs */ -#define SB_I_MULTIROOT 0x00000008 /* Multiple roots to the dentry tree */ /* sb->s_iflags to limit user namespace mounts */ #define SB_I_USERNS_VISIBLE 0x00000010 /* fstype already mounted */ From b807a2c5e0e2e81c96160682977c6f497cfcee96 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 24 Sep 2020 08:51:29 +0200 Subject: [PATCH 129/191] drbd: remove dead code in device_to_statistics Ever since the switch to blk-mq, a lower device not used for VM writeback will not be marked congested, so the check will never trigger. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe --- drivers/block/drbd/drbd_nl.c | 6 ------ 1 file changed, 6 deletions(-) diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c index 43c8ae4d9fca..aaff5bde3915 100644 --- a/drivers/block/drbd/drbd_nl.c +++ b/drivers/block/drbd/drbd_nl.c @@ -3370,7 +3370,6 @@ static void device_to_statistics(struct device_statistics *s, if (get_ldev(device)) { struct drbd_md *md = &device->ldev->md; u64 *history_uuids = (u64 *)s->history_uuids; - struct request_queue *q; int n; spin_lock_irq(&md->uuid_lock); @@ -3384,11 +3383,6 @@ static void device_to_statistics(struct device_statistics *s, spin_unlock_irq(&md->uuid_lock); s->dev_disk_flags = md->flags; - q = bdev_get_queue(device->ldev->backing_bdev); - s->dev_lower_blocked = - bdi_congested(q->backing_dev_info, - (1 << WB_async_congested) | - (1 << WB_sync_congested)); put_ldev(device); } s->dev_size = drbd_get_capacity(device->this_bdev); From 5d4ce78b254cde8aaeb829420c3f15d3606ad411 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 24 Sep 2020 08:51:30 +0200 Subject: [PATCH 130/191] bcache: inherit the optimal I/O size Inherit the optimal I/O size setting just like the readahead window, as any reason to do larger I/O does not apply to just readahead. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Reviewed-by: Martin K. Petersen Acked-by: Coly Li Signed-off-by: Jens Axboe --- drivers/md/bcache/super.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c index 1bbdc410ee3c..48113005ed86 100644 --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -1430,6 +1430,8 @@ static int cached_dev_init(struct cached_dev *dc, unsigned int block_size) dc->disk.disk->queue->backing_dev_info->ra_pages = max(dc->disk.disk->queue->backing_dev_info->ra_pages, q->backing_dev_info->ra_pages); + blk_queue_io_opt(dc->disk.disk->queue, + max(queue_io_opt(dc->disk.disk->queue), queue_io_opt(q))); atomic_set(&dc->io_errors, 0); dc->io_disable = false; From 9e82d35b95e55aa50d264caee64a17840e3981b7 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 24 Sep 2020 08:51:31 +0200 Subject: [PATCH 131/191] aoe: set an optimal I/O size aoe forces a larger readahead size, but any reason to do larger I/O is not limited to readahead. Also set the optimal I/O size, and remove the local constants in favor of just using SZ_2G. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Reviewed-by: Martin K. Petersen Signed-off-by: Jens Axboe --- drivers/block/aoe/aoeblk.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/block/aoe/aoeblk.c b/drivers/block/aoe/aoeblk.c index 5ca7216e9e01..d8cfc233e64b 100644 --- a/drivers/block/aoe/aoeblk.c +++ b/drivers/block/aoe/aoeblk.c @@ -347,7 +347,6 @@ aoeblk_gdalloc(void *vp) mempool_t *mp; struct request_queue *q; struct blk_mq_tag_set *set; - enum { KB = 1024, MB = KB * KB, READ_AHEAD = 2 * MB, }; ulong flags; int late = 0; int err; @@ -407,7 +406,8 @@ aoeblk_gdalloc(void *vp) WARN_ON(d->gd); WARN_ON(d->flags & DEVFL_UP); blk_queue_max_hw_sectors(q, BLK_DEF_MAX_SECTORS); - q->backing_dev_info->ra_pages = READ_AHEAD / PAGE_SIZE; + q->backing_dev_info->ra_pages = SZ_2M / PAGE_SIZE; + blk_queue_io_opt(q, SZ_2M); d->bufpool = mp; d->blkq = gd->queue = q; q->queuedata = d; From 55b2598e84e97efc5d952958cb5e34236c43276b Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 24 Sep 2020 08:51:32 +0200 Subject: [PATCH 132/191] bdi: initialize ->ra_pages and ->io_pages in bdi_init Set up a readahead size by default, as very few users have a good reason to change it. This means code, ecryptfs, and orangefs now set up the values while they were previously missing it, while ubifs, mtd and vboxsf manually set it to 0 to avoid readahead. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Acked-by: David Sterba [btrfs] Acked-by: Richard Weinberger [ubifs, mtd] Signed-off-by: Jens Axboe --- block/blk-core.c | 2 -- drivers/mtd/mtdcore.c | 2 ++ fs/9p/vfs_super.c | 6 ++++-- fs/afs/super.c | 1 - fs/btrfs/disk-io.c | 1 - fs/fuse/inode.c | 1 - fs/nfs/super.c | 9 +-------- fs/ubifs/super.c | 2 ++ fs/vboxsf/super.c | 2 ++ mm/backing-dev.c | 2 ++ 10 files changed, 13 insertions(+), 15 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index ca3f0f00c943..865d39e5be2b 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -538,8 +538,6 @@ struct request_queue *blk_alloc_queue(int node_id) if (!q->stats) goto fail_stats; - q->backing_dev_info->ra_pages = VM_READAHEAD_PAGES; - q->backing_dev_info->io_pages = VM_READAHEAD_PAGES; q->backing_dev_info->capabilities = BDI_CAP_CGROUP_WRITEBACK; q->node = node_id; diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c index 7d930569a7df..b5e5d3140f57 100644 --- a/drivers/mtd/mtdcore.c +++ b/drivers/mtd/mtdcore.c @@ -2196,6 +2196,8 @@ static struct backing_dev_info * __init mtd_bdi_init(char *name) bdi = bdi_alloc(NUMA_NO_NODE); if (!bdi) return ERR_PTR(-ENOMEM); + bdi->ra_pages = 0; + bdi->io_pages = 0; /* * We put '-0' suffix to the name to get the same name format as we diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c index 74df32be4c6a..e34fa20acf61 100644 --- a/fs/9p/vfs_super.c +++ b/fs/9p/vfs_super.c @@ -80,8 +80,10 @@ v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses, if (ret) return ret; - if (v9ses->cache) - sb->s_bdi->ra_pages = VM_READAHEAD_PAGES; + if (!v9ses->cache) { + sb->s_bdi->ra_pages = 0; + sb->s_bdi->io_pages = 0; + } sb->s_flags |= SB_ACTIVE | SB_DIRSYNC; if (!v9ses->cache) diff --git a/fs/afs/super.c b/fs/afs/super.c index b552357b1d13..3a40ee752c1e 100644 --- a/fs/afs/super.c +++ b/fs/afs/super.c @@ -456,7 +456,6 @@ static int afs_fill_super(struct super_block *sb, struct afs_fs_context *ctx) ret = super_setup_bdi(sb); if (ret) return ret; - sb->s_bdi->ra_pages = VM_READAHEAD_PAGES; /* allocate the root inode and dentry */ if (as->dyn_root) { diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index f6bba7eb1fa1..047934cea25e 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -3092,7 +3092,6 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device } sb->s_bdi->capabilities |= BDI_CAP_CGROUP_WRITEBACK; - sb->s_bdi->ra_pages = VM_READAHEAD_PAGES; sb->s_bdi->ra_pages *= btrfs_super_num_devices(disk_super); sb->s_bdi->ra_pages = max(sb->s_bdi->ra_pages, SZ_4M / PAGE_SIZE); diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index bba747520e9b..17b00670fb53 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -1049,7 +1049,6 @@ static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb) if (err) return err; - sb->s_bdi->ra_pages = VM_READAHEAD_PAGES; /* fuse does it's own writeback accounting */ sb->s_bdi->capabilities = BDI_CAP_NO_ACCT_WB | BDI_CAP_STRICTLIMIT; diff --git a/fs/nfs/super.c b/fs/nfs/super.c index 7a70287f21a2..f943e37853fa 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -1200,13 +1200,6 @@ static void nfs_get_cache_cookie(struct super_block *sb, } #endif -static void nfs_set_readahead(struct backing_dev_info *bdi, - unsigned long iomax_pages) -{ - bdi->ra_pages = VM_READAHEAD_PAGES; - bdi->io_pages = iomax_pages; -} - int nfs_get_tree_common(struct fs_context *fc) { struct nfs_fs_context *ctx = nfs_fc2context(fc); @@ -1251,7 +1244,7 @@ int nfs_get_tree_common(struct fs_context *fc) MINOR(server->s_dev)); if (error) goto error_splat_super; - nfs_set_readahead(s->s_bdi, server->rpages); + s->s_bdi->io_pages = server->rpages; server->super = s; } diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c index a2420c900275..fbddb2a1c03f 100644 --- a/fs/ubifs/super.c +++ b/fs/ubifs/super.c @@ -2177,6 +2177,8 @@ static int ubifs_fill_super(struct super_block *sb, void *data, int silent) c->vi.vol_id); if (err) goto out_close; + sb->s_bdi->ra_pages = 0; + sb->s_bdi->io_pages = 0; sb->s_fs_info = c; sb->s_magic = UBIFS_SUPER_MAGIC; diff --git a/fs/vboxsf/super.c b/fs/vboxsf/super.c index 8fe03b4a0d2b..8e3792177a85 100644 --- a/fs/vboxsf/super.c +++ b/fs/vboxsf/super.c @@ -167,6 +167,8 @@ static int vboxsf_fill_super(struct super_block *sb, struct fs_context *fc) err = super_setup_bdi_name(sb, "vboxsf-%d", sbi->bdi_id); if (err) goto fail_free; + sb->s_bdi->ra_pages = 0; + sb->s_bdi->io_pages = 0; /* Turn source into a shfl_string and map the folder */ size = strlen(fc->source) + 1; diff --git a/mm/backing-dev.c b/mm/backing-dev.c index 8e8b00627bb2..2dac3be61271 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -746,6 +746,8 @@ struct backing_dev_info *bdi_alloc(int node_id) kfree(bdi); return NULL; } + bdi->ra_pages = VM_READAHEAD_PAGES; + bdi->io_pages = VM_READAHEAD_PAGES; return bdi; } EXPORT_SYMBOL(bdi_alloc); From 16ef510139315a2147ee7525796f8dbd4e4b7864 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 24 Sep 2020 08:51:33 +0200 Subject: [PATCH 133/191] md: update the optimal I/O size on reshape The raid5 and raid10 drivers currently update the read-ahead size, but not the optimal I/O size on reshape. To prepare for deriving the read-ahead size from the optimal I/O size make sure it is updated as well. Signed-off-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Martin K. Petersen Acked-by: Song Liu Signed-off-by: Jens Axboe --- drivers/md/raid10.c | 22 ++++++++++++++-------- drivers/md/raid5.c | 10 ++++++++-- 2 files changed, 22 insertions(+), 10 deletions(-) diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index e8fa32733917..9956a04ac13b 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -3703,10 +3703,20 @@ static struct r10conf *setup_conf(struct mddev *mddev) return ERR_PTR(err); } +static void raid10_set_io_opt(struct r10conf *conf) +{ + int raid_disks = conf->geo.raid_disks; + + if (!(conf->geo.raid_disks % conf->geo.near_copies)) + raid_disks /= conf->geo.near_copies; + blk_queue_io_opt(conf->mddev->queue, (conf->mddev->chunk_sectors << 9) * + raid_disks); +} + static int raid10_run(struct mddev *mddev) { struct r10conf *conf; - int i, disk_idx, chunk_size; + int i, disk_idx; struct raid10_info *disk; struct md_rdev *rdev; sector_t size; @@ -3742,18 +3752,13 @@ static int raid10_run(struct mddev *mddev) mddev->thread = conf->thread; conf->thread = NULL; - chunk_size = mddev->chunk_sectors << 9; if (mddev->queue) { blk_queue_max_discard_sectors(mddev->queue, mddev->chunk_sectors); blk_queue_max_write_same_sectors(mddev->queue, 0); blk_queue_max_write_zeroes_sectors(mddev->queue, 0); - blk_queue_io_min(mddev->queue, chunk_size); - if (conf->geo.raid_disks % conf->geo.near_copies) - blk_queue_io_opt(mddev->queue, chunk_size * conf->geo.raid_disks); - else - blk_queue_io_opt(mddev->queue, chunk_size * - (conf->geo.raid_disks / conf->geo.near_copies)); + blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9); + raid10_set_io_opt(conf); } rdev_for_each(rdev, mddev) { @@ -4727,6 +4732,7 @@ static void end_reshape(struct r10conf *conf) stripe /= conf->geo.near_copies; if (conf->mddev->queue->backing_dev_info->ra_pages < 2 * stripe) conf->mddev->queue->backing_dev_info->ra_pages = 2 * stripe; + raid10_set_io_opt(conf); } conf->fullsync = 0; } diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 225380efd1e2..9a7d1250894e 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -7232,6 +7232,12 @@ static int only_parity(int raid_disk, int algo, int raid_disks, int max_degraded return 0; } +static void raid5_set_io_opt(struct r5conf *conf) +{ + blk_queue_io_opt(conf->mddev->queue, (conf->chunk_sectors << 9) * + (conf->raid_disks - conf->max_degraded)); +} + static int raid5_run(struct mddev *mddev) { struct r5conf *conf; @@ -7521,8 +7527,7 @@ static int raid5_run(struct mddev *mddev) chunk_size = mddev->chunk_sectors << 9; blk_queue_io_min(mddev->queue, chunk_size); - blk_queue_io_opt(mddev->queue, chunk_size * - (conf->raid_disks - conf->max_degraded)); + raid5_set_io_opt(conf); mddev->queue->limits.raid_partial_stripes_expensive = 1; /* * We can only discard a whole stripe. It doesn't make sense to @@ -8115,6 +8120,7 @@ static void end_reshape(struct r5conf *conf) / PAGE_SIZE); if (conf->mddev->queue->backing_dev_info->ra_pages < 2 * stripe) conf->mddev->queue->backing_dev_info->ra_pages = 2 * stripe; + raid5_set_io_opt(conf); } } } From c2e4cd57cfa1f627b786c764d185fff85fd12be9 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 24 Sep 2020 08:51:34 +0200 Subject: [PATCH 134/191] block: lift setting the readahead size into the block layer Drivers shouldn't really mess with the readahead size, as that is a VM concept. Instead set it based on the optimal I/O size by lifting the algorithm from the md driver when registering the disk. Also set bdi->io_pages there as well by applying the same scheme based on max_sectors. To ensure the limits work well for stacking drivers a new helper is added to update the readahead limits from the block limits, which is also called from disk_stack_limits. Signed-off-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Jan Kara Reviewed-by: Mike Snitzer Reviewed-by: Martin K. Petersen Acked-by: Coly Li Signed-off-by: Jens Axboe --- block/blk-settings.c | 18 ++++++++++++++++-- block/blk-sysfs.c | 2 ++ drivers/block/aoe/aoeblk.c | 1 - drivers/block/drbd/drbd_nl.c | 10 +--------- drivers/md/bcache/super.c | 3 --- drivers/md/dm-table.c | 3 +-- drivers/md/raid0.c | 16 ---------------- drivers/md/raid10.c | 24 +----------------------- drivers/md/raid5.c | 13 +------------ drivers/nvme/host/core.c | 1 + include/linux/blkdev.h | 1 + 11 files changed, 24 insertions(+), 68 deletions(-) diff --git a/block/blk-settings.c b/block/blk-settings.c index 5ea3de48afba..4f6eb4bb1723 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -372,6 +372,19 @@ void blk_queue_alignment_offset(struct request_queue *q, unsigned int offset) } EXPORT_SYMBOL(blk_queue_alignment_offset); +void blk_queue_update_readahead(struct request_queue *q) +{ + /* + * For read-ahead of large files to be effective, we need to read ahead + * at least twice the optimal I/O size. + */ + q->backing_dev_info->ra_pages = + max(queue_io_opt(q) * 2 / PAGE_SIZE, VM_READAHEAD_PAGES); + q->backing_dev_info->io_pages = + queue_max_sectors(q) >> (PAGE_SHIFT - 9); +} +EXPORT_SYMBOL_GPL(blk_queue_update_readahead); + /** * blk_limits_io_min - set minimum request size for a device * @limits: the queue limits @@ -450,6 +463,8 @@ EXPORT_SYMBOL(blk_limits_io_opt); void blk_queue_io_opt(struct request_queue *q, unsigned int opt) { blk_limits_io_opt(&q->limits, opt); + q->backing_dev_info->ra_pages = + max(queue_io_opt(q) * 2 / PAGE_SIZE, VM_READAHEAD_PAGES); } EXPORT_SYMBOL(blk_queue_io_opt); @@ -631,8 +646,7 @@ void disk_stack_limits(struct gendisk *disk, struct block_device *bdev, top, bottom); } - t->backing_dev_info->io_pages = - t->limits.max_sectors >> (PAGE_SHIFT - 9); + blk_queue_update_readahead(disk->queue); } EXPORT_SYMBOL(disk_stack_limits); diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 81722cdcf0cb..869ed21a9edc 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -854,6 +854,8 @@ int blk_register_queue(struct gendisk *disk) percpu_ref_switch_to_percpu(&q->q_usage_counter); } + blk_queue_update_readahead(q); + ret = blk_trace_init_sysfs(dev); if (ret) return ret; diff --git a/drivers/block/aoe/aoeblk.c b/drivers/block/aoe/aoeblk.c index d8cfc233e64b..c34e71b0c4a9 100644 --- a/drivers/block/aoe/aoeblk.c +++ b/drivers/block/aoe/aoeblk.c @@ -406,7 +406,6 @@ aoeblk_gdalloc(void *vp) WARN_ON(d->gd); WARN_ON(d->flags & DEVFL_UP); blk_queue_max_hw_sectors(q, BLK_DEF_MAX_SECTORS); - q->backing_dev_info->ra_pages = SZ_2M / PAGE_SIZE; blk_queue_io_opt(q, SZ_2M); d->bufpool = mp; d->blkq = gd->queue = q; diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c index aaff5bde3915..54a4930c04fe 100644 --- a/drivers/block/drbd/drbd_nl.c +++ b/drivers/block/drbd/drbd_nl.c @@ -1362,15 +1362,7 @@ static void drbd_setup_queue_param(struct drbd_device *device, struct drbd_backi if (b) { blk_stack_limits(&q->limits, &b->limits, 0); - - if (q->backing_dev_info->ra_pages != - b->backing_dev_info->ra_pages) { - drbd_info(device, "Adjusting my ra_pages to backing device's (%lu -> %lu)\n", - q->backing_dev_info->ra_pages, - b->backing_dev_info->ra_pages); - q->backing_dev_info->ra_pages = - b->backing_dev_info->ra_pages; - } + blk_queue_update_readahead(q); } fixup_discard_if_not_supported(q); fixup_write_zeroes(device, q); diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c index 48113005ed86..6bfa77167362 100644 --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -1427,9 +1427,6 @@ static int cached_dev_init(struct cached_dev *dc, unsigned int block_size) if (ret) return ret; - dc->disk.disk->queue->backing_dev_info->ra_pages = - max(dc->disk.disk->queue->backing_dev_info->ra_pages, - q->backing_dev_info->ra_pages); blk_queue_io_opt(dc->disk.disk->queue, max(queue_io_opt(dc->disk.disk->queue), queue_io_opt(q))); diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 5edc3079e7c1..ef2757012f59 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -1925,8 +1925,7 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, } #endif - /* Allow reads to exceed readahead limits */ - q->backing_dev_info->io_pages = limits->max_sectors >> (PAGE_SHIFT - 9); + blk_queue_update_readahead(q); } unsigned int dm_table_get_num_targets(struct dm_table *t) diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c index f54a449f97aa..aa2d72791768 100644 --- a/drivers/md/raid0.c +++ b/drivers/md/raid0.c @@ -410,22 +410,6 @@ static int raid0_run(struct mddev *mddev) mdname(mddev), (unsigned long long)mddev->array_sectors); - if (mddev->queue) { - /* calculate the max read-ahead size. - * For read-ahead of large files to be effective, we need to - * readahead at least twice a whole stripe. i.e. number of devices - * multiplied by chunk size times 2. - * If an individual device has an ra_pages greater than the - * chunk size, then we will not drive that device as hard as it - * wants. We consider this a configuration error: a larger - * chunksize should be used in that case. - */ - int stripe = mddev->raid_disks * - (mddev->chunk_sectors << 9) / PAGE_SIZE; - if (mddev->queue->backing_dev_info->ra_pages < 2* stripe) - mddev->queue->backing_dev_info->ra_pages = 2* stripe; - } - dump_zones(mddev); ret = md_integrity_register(mddev); diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index 9956a04ac13b..5d1bdee313ec 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -3873,19 +3873,6 @@ static int raid10_run(struct mddev *mddev) mddev->resync_max_sectors = size; set_bit(MD_FAILFAST_SUPPORTED, &mddev->flags); - if (mddev->queue) { - int stripe = conf->geo.raid_disks * - ((mddev->chunk_sectors << 9) / PAGE_SIZE); - - /* Calculate max read-ahead size. - * We need to readahead at least twice a whole stripe.... - * maybe... - */ - stripe /= conf->geo.near_copies; - if (mddev->queue->backing_dev_info->ra_pages < 2 * stripe) - mddev->queue->backing_dev_info->ra_pages = 2 * stripe; - } - if (md_integrity_register(mddev)) goto out_free_conf; @@ -4723,17 +4710,8 @@ static void end_reshape(struct r10conf *conf) conf->reshape_safe = MaxSector; spin_unlock_irq(&conf->device_lock); - /* read-ahead size must cover two whole stripes, which is - * 2 * (datadisks) * chunksize where 'n' is the number of raid devices - */ - if (conf->mddev->queue) { - int stripe = conf->geo.raid_disks * - ((conf->mddev->chunk_sectors << 9) / PAGE_SIZE); - stripe /= conf->geo.near_copies; - if (conf->mddev->queue->backing_dev_info->ra_pages < 2 * stripe) - conf->mddev->queue->backing_dev_info->ra_pages = 2 * stripe; + if (conf->mddev->queue) raid10_set_io_opt(conf); - } conf->fullsync = 0; } diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 9a7d1250894e..7ace1f76b147 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -7522,8 +7522,6 @@ static int raid5_run(struct mddev *mddev) int data_disks = conf->previous_raid_disks - conf->max_degraded; int stripe = data_disks * ((mddev->chunk_sectors << 9) / PAGE_SIZE); - if (mddev->queue->backing_dev_info->ra_pages < 2 * stripe) - mddev->queue->backing_dev_info->ra_pages = 2 * stripe; chunk_size = mddev->chunk_sectors << 9; blk_queue_io_min(mddev->queue, chunk_size); @@ -8111,17 +8109,8 @@ static void end_reshape(struct r5conf *conf) spin_unlock_irq(&conf->device_lock); wake_up(&conf->wait_for_overlap); - /* read-ahead size must cover two whole stripes, which is - * 2 * (datadisks) * chunksize where 'n' is the number of raid devices - */ - if (conf->mddev->queue) { - int data_disks = conf->raid_disks - conf->max_degraded; - int stripe = data_disks * ((conf->chunk_sectors << 9) - / PAGE_SIZE); - if (conf->mddev->queue->backing_dev_info->ra_pages < 2 * stripe) - conf->mddev->queue->backing_dev_info->ra_pages = 2 * stripe; + if (conf->mddev->queue) raid5_set_io_opt(conf); - } } } diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index ea1fa41fbba8..741c9bfa8e14 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -2147,6 +2147,7 @@ static int __nvme_revalidate_disk(struct gendisk *disk, struct nvme_id_ns *id) nvme_update_disk_info(ns->head->disk, ns, id); blk_stack_limits(&ns->head->disk->queue->limits, &ns->queue->limits, 0); + blk_queue_update_readahead(ns->head->disk->queue); nvme_update_bdev_size(ns->head->disk); } #endif diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index be5ef6f4ba19..282f5ca424f1 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1140,6 +1140,7 @@ extern void blk_queue_max_zone_append_sectors(struct request_queue *q, extern void blk_queue_physical_block_size(struct request_queue *, unsigned int); extern void blk_queue_alignment_offset(struct request_queue *q, unsigned int alignment); +void blk_queue_update_readahead(struct request_queue *q); extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min); extern void blk_queue_io_min(struct request_queue *q, unsigned int min); extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt); From ed7b6b4f6e915cb0bc52d0000bcc63168867b6ac Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 24 Sep 2020 08:51:35 +0200 Subject: [PATCH 135/191] bdi: remove BDI_CAP_CGROUP_WRITEBACK Just checking SB_I_CGROUPWB for cgroup writeback support is enough. Either the file system allocates its own bdi (e.g. btrfs), in which case it is known to support cgroup writeback, or the bdi comes from the block layer, which always supports cgroup writeback. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe --- block/blk-core.c | 1 - fs/btrfs/disk-io.c | 1 - include/linux/backing-dev.h | 8 +++----- 3 files changed, 3 insertions(+), 7 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 865d39e5be2b..1cc4fa6bc7fe 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -538,7 +538,6 @@ struct request_queue *blk_alloc_queue(int node_id) if (!q->stats) goto fail_stats; - q->backing_dev_info->capabilities = BDI_CAP_CGROUP_WRITEBACK; q->node = node_id; atomic_set(&q->nr_active_requests_shared_sbitmap, 0); diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 047934cea25e..e24927bddd58 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -3091,7 +3091,6 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device goto fail_sb_buffer; } - sb->s_bdi->capabilities |= BDI_CAP_CGROUP_WRITEBACK; sb->s_bdi->ra_pages *= btrfs_super_num_devices(disk_super); sb->s_bdi->ra_pages = max(sb->s_bdi->ra_pages, SZ_4M / PAGE_SIZE); diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index 0b06b2d26c9a..52583b6f2ea0 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -123,7 +123,6 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio); * BDI_CAP_NO_ACCT_WB: Don't automatically account writeback pages * BDI_CAP_STRICTLIMIT: Keep number of dirty pages below bdi threshold. * - * BDI_CAP_CGROUP_WRITEBACK: Supports cgroup-aware writeback. * BDI_CAP_SYNCHRONOUS_IO: Device is so fast that asynchronous IO would be * inefficient. */ @@ -233,9 +232,9 @@ int inode_congested(struct inode *inode, int cong_bits); * inode_cgwb_enabled - test whether cgroup writeback is enabled on an inode * @inode: inode of interest * - * cgroup writeback requires support from both the bdi and filesystem. - * Also, both memcg and iocg have to be on the default hierarchy. Test - * whether all conditions are met. + * Cgroup writeback requires support from the filesystem. Also, both memcg and + * iocg have to be on the default hierarchy. Test whether all conditions are + * met. * * Note that the test result may change dynamically on the same inode * depending on how memcg and iocg are configured. @@ -247,7 +246,6 @@ static inline bool inode_cgwb_enabled(struct inode *inode) return cgroup_subsys_on_dfl(memory_cgrp_subsys) && cgroup_subsys_on_dfl(io_cgrp_subsys) && bdi_cap_account_dirty(bdi) && - (bdi->capabilities & BDI_CAP_CGROUP_WRITEBACK) && (inode->i_sb->s_iflags & SB_I_CGROUPWB); } From a8b456d01cd6b37191f14248f3e2bdbe5ce3a89e Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 24 Sep 2020 08:51:36 +0200 Subject: [PATCH 136/191] bdi: remove BDI_CAP_SYNCHRONOUS_IO BDI_CAP_SYNCHRONOUS_IO is only checked in the swap code, and used to decided if ->rw_page can be used on a block device. Just check up for the method instead. The only complication is that zram needs a second set of block_device_operations as it can switch between modes that actually support ->rw_page and those who don't. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe --- drivers/block/brd.c | 1 - drivers/block/zram/zram_drv.c | 19 +++++++++++++------ drivers/nvdimm/btt.c | 2 -- drivers/nvdimm/pmem.c | 1 - include/linux/backing-dev.h | 9 --------- mm/swapfile.c | 2 +- 6 files changed, 14 insertions(+), 20 deletions(-) diff --git a/drivers/block/brd.c b/drivers/block/brd.c index 2723a70eb855..cc49a921339f 100644 --- a/drivers/block/brd.c +++ b/drivers/block/brd.c @@ -403,7 +403,6 @@ static struct brd_device *brd_alloc(int i) disk->flags = GENHD_FL_EXT_DEVT; sprintf(disk->disk_name, "ram%d", i); set_capacity(disk, rd_size * 2); - brd->brd_queue->backing_dev_info->capabilities |= BDI_CAP_SYNCHRONOUS_IO; /* Tell the block layer that this is not a rotational device */ blk_queue_flag_set(QUEUE_FLAG_NONROT, brd->brd_queue); diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 91ccfe444525..e21ca844d7c2 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -52,6 +52,9 @@ static unsigned int num_devices = 1; */ static size_t huge_class_size; +static const struct block_device_operations zram_devops; +static const struct block_device_operations zram_wb_devops; + static void zram_free_page(struct zram *zram, size_t index); static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec, u32 index, int offset, struct bio *bio); @@ -408,8 +411,7 @@ static void reset_bdev(struct zram *zram) zram->backing_dev = NULL; zram->old_block_size = 0; zram->bdev = NULL; - zram->disk->queue->backing_dev_info->capabilities |= - BDI_CAP_SYNCHRONOUS_IO; + zram->disk->fops = &zram_devops; kvfree(zram->bitmap); zram->bitmap = NULL; } @@ -529,8 +531,7 @@ static ssize_t backing_dev_store(struct device *dev, * freely but in fact, IO is going on so finally could cause * use-after-free when the IO is really done. */ - zram->disk->queue->backing_dev_info->capabilities &= - ~BDI_CAP_SYNCHRONOUS_IO; + zram->disk->fops = &zram_wb_devops; up_write(&zram->init_lock); pr_info("setup backing device %s\n", file_name); @@ -1820,6 +1821,13 @@ static const struct block_device_operations zram_devops = { .owner = THIS_MODULE }; +static const struct block_device_operations zram_wb_devops = { + .open = zram_open, + .submit_bio = zram_submit_bio, + .swap_slot_free_notify = zram_slot_free_notify, + .owner = THIS_MODULE +}; + static DEVICE_ATTR_WO(compact); static DEVICE_ATTR_RW(disksize); static DEVICE_ATTR_RO(initstate); @@ -1947,8 +1955,7 @@ static int zram_add(void) if (ZRAM_LOGICAL_BLOCK_SIZE == PAGE_SIZE) blk_queue_max_write_zeroes_sectors(zram->disk->queue, UINT_MAX); - zram->disk->queue->backing_dev_info->capabilities |= - (BDI_CAP_STABLE_WRITES | BDI_CAP_SYNCHRONOUS_IO); + zram->disk->queue->backing_dev_info->capabilities |= BDI_CAP_STABLE_WRITES; device_add_disk(NULL, zram->disk, zram_disk_attr_groups); strlcpy(zram->compressor, default_compressor, sizeof(zram->compressor)); diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c index 0d710140bf93..12ff6f8784ac 100644 --- a/drivers/nvdimm/btt.c +++ b/drivers/nvdimm/btt.c @@ -1537,8 +1537,6 @@ static int btt_blk_init(struct btt *btt) btt->btt_disk->private_data = btt; btt->btt_disk->queue = btt->btt_queue; btt->btt_disk->flags = GENHD_FL_EXT_DEVT; - btt->btt_disk->queue->backing_dev_info->capabilities |= - BDI_CAP_SYNCHRONOUS_IO; blk_queue_logical_block_size(btt->btt_queue, btt->sector_size); blk_queue_max_hw_sectors(btt->btt_queue, UINT_MAX); diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 140cf3b9000c..1711fdfd8d28 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -475,7 +475,6 @@ static int pmem_attach_disk(struct device *dev, disk->queue = q; disk->flags = GENHD_FL_EXT_DEVT; disk->private_data = pmem; - disk->queue->backing_dev_info->capabilities |= BDI_CAP_SYNCHRONOUS_IO; nvdimm_namespace_disk_name(ndns, disk->disk_name); set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset) / 512); diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index 52583b6f2ea0..860ea33571bc 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -122,9 +122,6 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio); * BDI_CAP_NO_WRITEBACK: Don't write pages back * BDI_CAP_NO_ACCT_WB: Don't automatically account writeback pages * BDI_CAP_STRICTLIMIT: Keep number of dirty pages below bdi threshold. - * - * BDI_CAP_SYNCHRONOUS_IO: Device is so fast that asynchronous IO would be - * inefficient. */ #define BDI_CAP_NO_ACCT_DIRTY 0x00000001 #define BDI_CAP_NO_WRITEBACK 0x00000002 @@ -132,7 +129,6 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio); #define BDI_CAP_STABLE_WRITES 0x00000008 #define BDI_CAP_STRICTLIMIT 0x00000010 #define BDI_CAP_CGROUP_WRITEBACK 0x00000020 -#define BDI_CAP_SYNCHRONOUS_IO 0x00000040 #define BDI_CAP_NO_ACCT_AND_WRITEBACK \ (BDI_CAP_NO_WRITEBACK | BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_ACCT_WB) @@ -174,11 +170,6 @@ static inline int wb_congested(struct bdi_writeback *wb, int cong_bits) long congestion_wait(int sync, long timeout); long wait_iff_congested(int sync, long timeout); -static inline bool bdi_cap_synchronous_io(struct backing_dev_info *bdi) -{ - return bdi->capabilities & BDI_CAP_SYNCHRONOUS_IO; -} - static inline bool bdi_cap_stable_pages_required(struct backing_dev_info *bdi) { return bdi->capabilities & BDI_CAP_STABLE_WRITES; diff --git a/mm/swapfile.c b/mm/swapfile.c index b90f86920743..96a7c47dd533 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -3240,7 +3240,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags) if (bdi_cap_stable_pages_required(inode_to_bdi(inode))) p->flags |= SWP_STABLE_WRITES; - if (bdi_cap_synchronous_io(inode_to_bdi(inode))) + if (p->bdev && p->bdev->bd_disk->fops->rw_page) p->flags |= SWP_SYNCHRONOUS_IO; if (p->bdev && blk_queue_nonrot(bdev_get_queue(p->bdev))) { From 5115db10a8e0a525edf8a65b2ed4eac5c8253095 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 24 Sep 2020 08:51:37 +0200 Subject: [PATCH 137/191] mm: use SWP_SYNCHRONOUS_IO more intelligently There is no point in trying to call bdev_read_page if SWP_SYNCHRONOUS_IO is not set, as the device won't support it. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe --- mm/page_io.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/mm/page_io.c b/mm/page_io.c index e485a6e8a6cd..b199b87e0aa9 100644 --- a/mm/page_io.c +++ b/mm/page_io.c @@ -403,15 +403,17 @@ int swap_readpage(struct page *page, bool synchronous) goto out; } - ret = bdev_read_page(sis->bdev, swap_page_sector(page), page); - if (!ret) { - if (trylock_page(page)) { - swap_slot_free_notify(page); - unlock_page(page); - } + if (sis->flags & SWP_SYNCHRONOUS_IO) { + ret = bdev_read_page(sis->bdev, swap_page_sector(page), page); + if (!ret) { + if (trylock_page(page)) { + swap_slot_free_notify(page); + unlock_page(page); + } - count_vm_event(PSWPIN); - goto out; + count_vm_event(PSWPIN); + goto out; + } } ret = 0; From 1cb039f3dc1619eb795c54aad0a98fdb379b4237 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 24 Sep 2020 08:51:38 +0200 Subject: [PATCH 138/191] bdi: replace BDI_CAP_STABLE_WRITES with a queue and a sb flag The BDI_CAP_STABLE_WRITES is one of the few bits of information in the backing_dev_info shared between the block drivers and the writeback code. To help untangling the dependency replace it with a queue flag and a superblock flag derived from it. This also helps with the case of e.g. a file system requiring stable writes due to its own checksumming, but not forcing it on other users of the block device like the swap code. One downside is that we an't support the stable_pages_required bdi attribute in sysfs anymore. It is replaced with a queue attribute which also is writable for easier testing. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe --- block/blk-integrity.c | 4 ++-- block/blk-mq-debugfs.c | 1 + block/blk-sysfs.c | 3 +++ drivers/block/rbd.c | 2 +- drivers/block/zram/zram_drv.c | 2 +- drivers/md/dm-table.c | 6 +++--- drivers/md/raid5.c | 8 ++++---- drivers/mmc/core/queue.c | 3 +-- drivers/nvme/host/core.c | 3 +-- drivers/nvme/host/multipath.c | 10 +++------- drivers/scsi/iscsi_tcp.c | 4 ++-- fs/super.c | 2 ++ include/linux/backing-dev.h | 6 ------ include/linux/blkdev.h | 3 +++ include/linux/fs.h | 1 + mm/backing-dev.c | 7 +++---- mm/page-writeback.c | 2 +- mm/swapfile.c | 2 +- 18 files changed, 33 insertions(+), 36 deletions(-) diff --git a/block/blk-integrity.c b/block/blk-integrity.c index c03705cbb9c9..2b36a8f9b813 100644 --- a/block/blk-integrity.c +++ b/block/blk-integrity.c @@ -408,7 +408,7 @@ void blk_integrity_register(struct gendisk *disk, struct blk_integrity *template bi->tuple_size = template->tuple_size; bi->tag_size = template->tag_size; - disk->queue->backing_dev_info->capabilities |= BDI_CAP_STABLE_WRITES; + blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, disk->queue); #ifdef CONFIG_BLK_INLINE_ENCRYPTION if (disk->queue->ksm) { @@ -428,7 +428,7 @@ EXPORT_SYMBOL(blk_integrity_register); */ void blk_integrity_unregister(struct gendisk *disk) { - disk->queue->backing_dev_info->capabilities &= ~BDI_CAP_STABLE_WRITES; + blk_queue_flag_clear(QUEUE_FLAG_STABLE_WRITES, disk->queue); memset(&disk->queue->integrity, 0, sizeof(struct blk_integrity)); } EXPORT_SYMBOL(blk_integrity_unregister); diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c index 645b7f800cb8..3094542e12ae 100644 --- a/block/blk-mq-debugfs.c +++ b/block/blk-mq-debugfs.c @@ -116,6 +116,7 @@ static const char *const blk_queue_flag_name[] = { QUEUE_FLAG_NAME(SAME_FORCE), QUEUE_FLAG_NAME(DEAD), QUEUE_FLAG_NAME(INIT_DONE), + QUEUE_FLAG_NAME(STABLE_WRITES), QUEUE_FLAG_NAME(POLL), QUEUE_FLAG_NAME(WC), QUEUE_FLAG_NAME(FUA), diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 869ed21a9edc..76b54c7750b0 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -287,6 +287,7 @@ queue_##name##_store(struct request_queue *q, const char *page, size_t count) \ QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1); QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0); QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0); +QUEUE_SYSFS_BIT_FNS(stable_writes, STABLE_WRITES, 0); #undef QUEUE_SYSFS_BIT_FNS static ssize_t queue_zoned_show(struct request_queue *q, char *page) @@ -613,6 +614,7 @@ static struct queue_sysfs_entry queue_hw_sector_size_entry = { QUEUE_RW_ENTRY(queue_nonrot, "rotational"); QUEUE_RW_ENTRY(queue_iostats, "iostats"); QUEUE_RW_ENTRY(queue_random, "add_random"); +QUEUE_RW_ENTRY(queue_stable_writes, "stable_writes"); static struct attribute *queue_attrs[] = { &queue_requests_entry.attr, @@ -645,6 +647,7 @@ static struct attribute *queue_attrs[] = { &queue_nomerges_entry.attr, &queue_rq_affinity_entry.attr, &queue_iostats_entry.attr, + &queue_stable_writes_entry.attr, &queue_random_entry.attr, &queue_poll_entry.attr, &queue_wc_entry.attr, diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 5d3923c0997c..cf5b016358cd 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -5022,7 +5022,7 @@ static int rbd_init_disk(struct rbd_device *rbd_dev) } if (!ceph_test_opt(rbd_dev->rbd_client->client, NOCRC)) - q->backing_dev_info->capabilities |= BDI_CAP_STABLE_WRITES; + blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, q); /* * disk_release() expects a queue ref from add_disk() and will diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index e21ca844d7c2..bff3d4021c18 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1955,7 +1955,7 @@ static int zram_add(void) if (ZRAM_LOGICAL_BLOCK_SIZE == PAGE_SIZE) blk_queue_max_write_zeroes_sectors(zram->disk->queue, UINT_MAX); - zram->disk->queue->backing_dev_info->capabilities |= BDI_CAP_STABLE_WRITES; + blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, zram->disk->queue); device_add_disk(NULL, zram->disk, zram_disk_attr_groups); strlcpy(zram->compressor, default_compressor, sizeof(zram->compressor)); diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index ef2757012f59..405d7cf10eb9 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -1815,7 +1815,7 @@ static int device_requires_stable_pages(struct dm_target *ti, { struct request_queue *q = bdev_get_queue(dev->bdev); - return q && bdi_cap_stable_pages_required(q->backing_dev_info); + return q && blk_queue_stable_writes(q); } /* @@ -1900,9 +1900,9 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, * because they do their own checksumming. */ if (dm_table_requires_stable_pages(t)) - q->backing_dev_info->capabilities |= BDI_CAP_STABLE_WRITES; + blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, q); else - q->backing_dev_info->capabilities &= ~BDI_CAP_STABLE_WRITES; + blk_queue_flag_clear(QUEUE_FLAG_STABLE_WRITES, q); /* * Determine whether or not this queue's I/O timings contribute diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 7ace1f76b147..d589d26c86ea 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -6638,14 +6638,14 @@ raid5_store_skip_copy(struct mddev *mddev, const char *page, size_t len) if (!conf) err = -ENODEV; else if (new != conf->skip_copy) { + struct request_queue *q = mddev->queue; + mddev_suspend(mddev); conf->skip_copy = new; if (new) - mddev->queue->backing_dev_info->capabilities |= - BDI_CAP_STABLE_WRITES; + blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, q); else - mddev->queue->backing_dev_info->capabilities &= - ~BDI_CAP_STABLE_WRITES; + blk_queue_flag_clear(QUEUE_FLAG_STABLE_WRITES, q); mddev_resume(mddev); } mddev_unlock(mddev); diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c index 6c022ef0f84d..80fe3852ce0f 100644 --- a/drivers/mmc/core/queue.c +++ b/drivers/mmc/core/queue.c @@ -472,8 +472,7 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card) } if (mmc_host_is_spi(host) && host->use_spi_crc) - mq->queue->backing_dev_info->capabilities |= - BDI_CAP_STABLE_WRITES; + blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, mq->queue); mq->queue->queuedata = mq; blk_queue_rq_timeout(mq->queue, 60 * HZ); diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 741c9bfa8e14..c190c56bf702 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -3926,8 +3926,7 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid) goto out_free_ns; if (ctrl->opts && ctrl->opts->data_digest) - ns->queue->backing_dev_info->capabilities - |= BDI_CAP_STABLE_WRITES; + blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, ns->queue); blk_queue_flag_set(QUEUE_FLAG_NONROT, ns->queue); if (ctrl->ops->flags & NVME_F_PCI_P2PDMA) diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c index d4ba736c6c89..74896be40c17 100644 --- a/drivers/nvme/host/multipath.c +++ b/drivers/nvme/host/multipath.c @@ -673,13 +673,9 @@ void nvme_mpath_add_disk(struct nvme_ns *ns, struct nvme_id_ns *id) nvme_mpath_set_live(ns); } - if (bdi_cap_stable_pages_required(ns->queue->backing_dev_info)) { - struct gendisk *disk = ns->head->disk; - - if (disk) - disk->queue->backing_dev_info->capabilities |= - BDI_CAP_STABLE_WRITES; - } + if (blk_queue_stable_writes(ns->queue) && ns->head->disk) + blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, + ns->head->disk->queue); } void nvme_mpath_remove_disk(struct nvme_ns_head *head) diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c index b5dd1caae5e9..a622f334c933 100644 --- a/drivers/scsi/iscsi_tcp.c +++ b/drivers/scsi/iscsi_tcp.c @@ -962,8 +962,8 @@ static int iscsi_sw_tcp_slave_configure(struct scsi_device *sdev) struct iscsi_conn *conn = session->leadconn; if (conn->datadgst_en) - sdev->request_queue->backing_dev_info->capabilities - |= BDI_CAP_STABLE_WRITES; + blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, + sdev->request_queue); blk_queue_dma_alignment(sdev->request_queue, 0); return 0; } diff --git a/fs/super.c b/fs/super.c index 904459b35119..a51c2083cd6b 100644 --- a/fs/super.c +++ b/fs/super.c @@ -1256,6 +1256,8 @@ static int set_bdev_super(struct super_block *s, void *data) s->s_dev = s->s_bdev->bd_dev; s->s_bdi = bdi_get(s->s_bdev->bd_bdi); + if (blk_queue_stable_writes(s->s_bdev->bd_disk->queue)) + s->s_iflags |= SB_I_STABLE_WRITES; return 0; } diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index 860ea33571bc..5da4ea3dd0cc 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -126,7 +126,6 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio); #define BDI_CAP_NO_ACCT_DIRTY 0x00000001 #define BDI_CAP_NO_WRITEBACK 0x00000002 #define BDI_CAP_NO_ACCT_WB 0x00000004 -#define BDI_CAP_STABLE_WRITES 0x00000008 #define BDI_CAP_STRICTLIMIT 0x00000010 #define BDI_CAP_CGROUP_WRITEBACK 0x00000020 @@ -170,11 +169,6 @@ static inline int wb_congested(struct bdi_writeback *wb, int cong_bits) long congestion_wait(int sync, long timeout); long wait_iff_congested(int sync, long timeout); -static inline bool bdi_cap_stable_pages_required(struct backing_dev_info *bdi) -{ - return bdi->capabilities & BDI_CAP_STABLE_WRITES; -} - static inline bool bdi_cap_writeback_dirty(struct backing_dev_info *bdi) { return !(bdi->capabilities & BDI_CAP_NO_WRITEBACK); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 282f5ca424f1..8e77f12de522 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -606,6 +606,7 @@ struct request_queue { #define QUEUE_FLAG_SAME_FORCE 12 /* force complete on same CPU */ #define QUEUE_FLAG_DEAD 13 /* queue tear-down finished */ #define QUEUE_FLAG_INIT_DONE 14 /* queue is initialized */ +#define QUEUE_FLAG_STABLE_WRITES 15 /* don't modify blks until WB is done */ #define QUEUE_FLAG_POLL 16 /* IO polling enabled if set */ #define QUEUE_FLAG_WC 17 /* Write back caching */ #define QUEUE_FLAG_FUA 18 /* device supports FUA writes */ @@ -635,6 +636,8 @@ bool blk_queue_flag_test_and_set(unsigned int flag, struct request_queue *q); #define blk_queue_noxmerges(q) \ test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags) #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags) +#define blk_queue_stable_writes(q) \ + test_bit(QUEUE_FLAG_STABLE_WRITES, &(q)->queue_flags) #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags) #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags) #define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags) diff --git a/include/linux/fs.h b/include/linux/fs.h index fbd74df5ce5f..222465b7cf41 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1385,6 +1385,7 @@ extern int send_sigurg(struct fown_struct *fown); #define SB_I_CGROUPWB 0x00000001 /* cgroup-aware writeback enabled */ #define SB_I_NOEXEC 0x00000002 /* Ignore executables on this fs */ #define SB_I_NODEV 0x00000004 /* Ignore devices on this fs */ +#define SB_I_STABLE_WRITES 0x00000008 /* don't modify blks until WB is done */ /* sb->s_iflags to limit user namespace mounts */ #define SB_I_USERNS_VISIBLE 0x00000010 /* fstype already mounted */ diff --git a/mm/backing-dev.c b/mm/backing-dev.c index 2dac3be61271..8e3802bf03a9 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -204,10 +204,9 @@ static ssize_t stable_pages_required_show(struct device *dev, struct device_attribute *attr, char *page) { - struct backing_dev_info *bdi = dev_get_drvdata(dev); - - return snprintf(page, PAGE_SIZE-1, "%d\n", - bdi_cap_stable_pages_required(bdi) ? 1 : 0); + dev_warn_once(dev, + "the stable_pages_required attribute has been removed. Use the stable_writes queue attribute instead.\n"); + return snprintf(page, PAGE_SIZE-1, "%d\n", 0); } static DEVICE_ATTR_RO(stable_pages_required); diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 4e4ddd67b71e..e9c36521461a 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -2849,7 +2849,7 @@ EXPORT_SYMBOL_GPL(wait_on_page_writeback); */ void wait_for_stable_page(struct page *page) { - if (bdi_cap_stable_pages_required(inode_to_bdi(page->mapping->host))) + if (page->mapping->host->i_sb->s_iflags & SB_I_STABLE_WRITES) wait_on_page_writeback(page); } EXPORT_SYMBOL_GPL(wait_for_stable_page); diff --git a/mm/swapfile.c b/mm/swapfile.c index 96a7c47dd533..65ef407512b5 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -3237,7 +3237,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags) goto bad_swap_unlock_inode; } - if (bdi_cap_stable_pages_required(inode_to_bdi(inode))) + if (p->bdev && blk_queue_stable_writes(p->bdev->bd_disk->queue)) p->flags |= SWP_STABLE_WRITES; if (p->bdev && p->bdev->bd_disk->fops->rw_page) From 823423ef55f4d9c470b1edc9c5b5c93d06abfaae Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 24 Sep 2020 08:51:39 +0200 Subject: [PATCH 139/191] bdi: invert BDI_CAP_NO_ACCT_WB Replace BDI_CAP_NO_ACCT_WB with a positive BDI_CAP_WRITEBACK_ACCT to make the checks more obvious. Also remove the pointless bdi_cap_account_writeback wrapper that just obsfucates the check. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe --- fs/fuse/inode.c | 3 ++- include/linux/backing-dev.h | 13 +++---------- mm/backing-dev.c | 1 + mm/page-writeback.c | 4 ++-- 4 files changed, 8 insertions(+), 13 deletions(-) diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 17b00670fb53..581329203d68 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -1050,7 +1050,8 @@ static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb) return err; /* fuse does it's own writeback accounting */ - sb->s_bdi->capabilities = BDI_CAP_NO_ACCT_WB | BDI_CAP_STRICTLIMIT; + sb->s_bdi->capabilities &= ~BDI_CAP_WRITEBACK_ACCT; + sb->s_bdi->capabilities |= BDI_CAP_STRICTLIMIT; /* * For a single fuse filesystem use max 1% of dirty + diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index 5da4ea3dd0cc..b217344a2c63 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -120,17 +120,17 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio); * * BDI_CAP_NO_ACCT_DIRTY: Dirty pages shouldn't contribute to accounting * BDI_CAP_NO_WRITEBACK: Don't write pages back - * BDI_CAP_NO_ACCT_WB: Don't automatically account writeback pages + * BDI_CAP_WRITEBACK_ACCT: Automatically account writeback pages * BDI_CAP_STRICTLIMIT: Keep number of dirty pages below bdi threshold. */ #define BDI_CAP_NO_ACCT_DIRTY 0x00000001 #define BDI_CAP_NO_WRITEBACK 0x00000002 -#define BDI_CAP_NO_ACCT_WB 0x00000004 +#define BDI_CAP_WRITEBACK_ACCT 0x00000004 #define BDI_CAP_STRICTLIMIT 0x00000010 #define BDI_CAP_CGROUP_WRITEBACK 0x00000020 #define BDI_CAP_NO_ACCT_AND_WRITEBACK \ - (BDI_CAP_NO_WRITEBACK | BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_ACCT_WB) + (BDI_CAP_NO_WRITEBACK | BDI_CAP_NO_ACCT_DIRTY) extern struct backing_dev_info noop_backing_dev_info; @@ -179,13 +179,6 @@ static inline bool bdi_cap_account_dirty(struct backing_dev_info *bdi) return !(bdi->capabilities & BDI_CAP_NO_ACCT_DIRTY); } -static inline bool bdi_cap_account_writeback(struct backing_dev_info *bdi) -{ - /* Paranoia: BDI_CAP_NO_WRITEBACK implies BDI_CAP_NO_ACCT_WB */ - return !(bdi->capabilities & (BDI_CAP_NO_ACCT_WB | - BDI_CAP_NO_WRITEBACK)); -} - static inline bool mapping_cap_writeback_dirty(struct address_space *mapping) { return bdi_cap_writeback_dirty(inode_to_bdi(mapping->host)); diff --git a/mm/backing-dev.c b/mm/backing-dev.c index 8e3802bf03a9..df18f0088dd3 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -745,6 +745,7 @@ struct backing_dev_info *bdi_alloc(int node_id) kfree(bdi); return NULL; } + bdi->capabilities = BDI_CAP_WRITEBACK_ACCT; bdi->ra_pages = VM_READAHEAD_PAGES; bdi->io_pages = VM_READAHEAD_PAGES; return bdi; diff --git a/mm/page-writeback.c b/mm/page-writeback.c index e9c36521461a..0139f9622a92 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -2738,7 +2738,7 @@ int test_clear_page_writeback(struct page *page) if (ret) { __xa_clear_mark(&mapping->i_pages, page_index(page), PAGECACHE_TAG_WRITEBACK); - if (bdi_cap_account_writeback(bdi)) { + if (bdi->capabilities & BDI_CAP_WRITEBACK_ACCT) { struct bdi_writeback *wb = inode_to_wb(inode); dec_wb_stat(wb, WB_WRITEBACK); @@ -2791,7 +2791,7 @@ int __test_set_page_writeback(struct page *page, bool keep_write) PAGECACHE_TAG_WRITEBACK); xas_set_mark(&xas, PAGECACHE_TAG_WRITEBACK); - if (bdi_cap_account_writeback(bdi)) + if (bdi->capabilities & BDI_CAP_WRITEBACK_ACCT) inc_wb_stat(inode_to_wb(inode), WB_WRITEBACK); /* From f56753ac2a90810726334df04d735e9f8f5a32d9 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 24 Sep 2020 08:51:40 +0200 Subject: [PATCH 140/191] bdi: replace BDI_CAP_NO_{WRITEBACK,ACCT_DIRTY} with a single flag Replace the two negative flags that are always used together with a single positive flag that indicates the writeback capability instead of two related non-capabilities. Also remove the pointless wrappers to just check the flag. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe --- fs/9p/vfs_file.c | 2 +- fs/fs-writeback.c | 7 +++--- include/linux/backing-dev.h | 48 ++++++++----------------------------- mm/backing-dev.c | 6 ++--- mm/filemap.c | 4 ++-- mm/memcontrol.c | 2 +- mm/memory-failure.c | 2 +- mm/migrate.c | 2 +- mm/mmap.c | 2 +- mm/page-writeback.c | 12 +++++----- 10 files changed, 29 insertions(+), 58 deletions(-) diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c index 3576123d8299..6ecf863bfa2f 100644 --- a/fs/9p/vfs_file.c +++ b/fs/9p/vfs_file.c @@ -625,7 +625,7 @@ static void v9fs_mmap_vm_close(struct vm_area_struct *vma) inode = file_inode(vma->vm_file); - if (!mapping_cap_writeback_dirty(inode->i_mapping)) + if (!mapping_can_writeback(inode->i_mapping)) wbc.nr_to_write = 0; might_sleep(); diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 149227160ff0..d4f84a2fe087 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -2321,7 +2321,7 @@ void __mark_inode_dirty(struct inode *inode, int flags) wb = locked_inode_to_wb_and_lock_list(inode); - WARN(bdi_cap_writeback_dirty(wb->bdi) && + WARN((wb->bdi->capabilities & BDI_CAP_WRITEBACK) && !test_bit(WB_registered, &wb->state), "bdi-%s not registered\n", bdi_dev_name(wb->bdi)); @@ -2346,7 +2346,8 @@ void __mark_inode_dirty(struct inode *inode, int flags) * to make sure background write-back happens * later. */ - if (bdi_cap_writeback_dirty(wb->bdi) && wakeup_bdi) + if (wakeup_bdi && + (wb->bdi->capabilities & BDI_CAP_WRITEBACK)) wb_wakeup_delayed(wb); return; } @@ -2581,7 +2582,7 @@ int write_inode_now(struct inode *inode, int sync) .range_end = LLONG_MAX, }; - if (!mapping_cap_writeback_dirty(inode->i_mapping)) + if (!mapping_can_writeback(inode->i_mapping)) wbc.nr_to_write = 0; might_sleep(); diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index b217344a2c63..44df4fcef65c 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -110,27 +110,14 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio); /* * Flags in backing_dev_info::capability * - * The first three flags control whether dirty pages will contribute to the - * VM's accounting and whether writepages() should be called for dirty pages - * (something that would not, for example, be appropriate for ramfs) - * - * WARNING: these flags are closely related and should not normally be - * used separately. The BDI_CAP_NO_ACCT_AND_WRITEBACK combines these - * three flags into a single convenience macro. - * - * BDI_CAP_NO_ACCT_DIRTY: Dirty pages shouldn't contribute to accounting - * BDI_CAP_NO_WRITEBACK: Don't write pages back - * BDI_CAP_WRITEBACK_ACCT: Automatically account writeback pages - * BDI_CAP_STRICTLIMIT: Keep number of dirty pages below bdi threshold. + * BDI_CAP_WRITEBACK: Supports dirty page writeback, and dirty pages + * should contribute to accounting + * BDI_CAP_WRITEBACK_ACCT: Automatically account writeback pages + * BDI_CAP_STRICTLIMIT: Keep number of dirty pages below bdi threshold */ -#define BDI_CAP_NO_ACCT_DIRTY 0x00000001 -#define BDI_CAP_NO_WRITEBACK 0x00000002 -#define BDI_CAP_WRITEBACK_ACCT 0x00000004 -#define BDI_CAP_STRICTLIMIT 0x00000010 -#define BDI_CAP_CGROUP_WRITEBACK 0x00000020 - -#define BDI_CAP_NO_ACCT_AND_WRITEBACK \ - (BDI_CAP_NO_WRITEBACK | BDI_CAP_NO_ACCT_DIRTY) +#define BDI_CAP_WRITEBACK (1 << 0) +#define BDI_CAP_WRITEBACK_ACCT (1 << 1) +#define BDI_CAP_STRICTLIMIT (1 << 2) extern struct backing_dev_info noop_backing_dev_info; @@ -169,24 +156,9 @@ static inline int wb_congested(struct bdi_writeback *wb, int cong_bits) long congestion_wait(int sync, long timeout); long wait_iff_congested(int sync, long timeout); -static inline bool bdi_cap_writeback_dirty(struct backing_dev_info *bdi) +static inline bool mapping_can_writeback(struct address_space *mapping) { - return !(bdi->capabilities & BDI_CAP_NO_WRITEBACK); -} - -static inline bool bdi_cap_account_dirty(struct backing_dev_info *bdi) -{ - return !(bdi->capabilities & BDI_CAP_NO_ACCT_DIRTY); -} - -static inline bool mapping_cap_writeback_dirty(struct address_space *mapping) -{ - return bdi_cap_writeback_dirty(inode_to_bdi(mapping->host)); -} - -static inline bool mapping_cap_account_dirty(struct address_space *mapping) -{ - return bdi_cap_account_dirty(inode_to_bdi(mapping->host)); + return inode_to_bdi(mapping->host)->capabilities & BDI_CAP_WRITEBACK; } static inline int bdi_sched_wait(void *word) @@ -223,7 +195,7 @@ static inline bool inode_cgwb_enabled(struct inode *inode) return cgroup_subsys_on_dfl(memory_cgrp_subsys) && cgroup_subsys_on_dfl(io_cgrp_subsys) && - bdi_cap_account_dirty(bdi) && + (bdi->capabilities & BDI_CAP_WRITEBACK) && (inode->i_sb->s_iflags & SB_I_CGROUPWB); } diff --git a/mm/backing-dev.c b/mm/backing-dev.c index df18f0088dd3..408d5051d05b 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -14,9 +14,7 @@ #include #include -struct backing_dev_info noop_backing_dev_info = { - .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK, -}; +struct backing_dev_info noop_backing_dev_info; EXPORT_SYMBOL_GPL(noop_backing_dev_info); static struct class *bdi_class; @@ -745,7 +743,7 @@ struct backing_dev_info *bdi_alloc(int node_id) kfree(bdi); return NULL; } - bdi->capabilities = BDI_CAP_WRITEBACK_ACCT; + bdi->capabilities = BDI_CAP_WRITEBACK | BDI_CAP_WRITEBACK_ACCT; bdi->ra_pages = VM_READAHEAD_PAGES; bdi->io_pages = VM_READAHEAD_PAGES; return bdi; diff --git a/mm/filemap.c b/mm/filemap.c index 1aaea26556cc..6c2a0139e22f 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -414,7 +414,7 @@ int __filemap_fdatawrite_range(struct address_space *mapping, loff_t start, .range_end = end, }; - if (!mapping_cap_writeback_dirty(mapping) || + if (!mapping_can_writeback(mapping) || !mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) return 0; @@ -1702,7 +1702,7 @@ struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index, no_page: if (!page && (fgp_flags & FGP_CREAT)) { int err; - if ((fgp_flags & FGP_WRITE) && mapping_cap_account_dirty(mapping)) + if ((fgp_flags & FGP_WRITE) && mapping_can_writeback(mapping)) gfp_mask |= __GFP_WRITE; if (fgp_flags & FGP_NOFS) gfp_mask &= ~__GFP_FS; diff --git a/mm/memcontrol.c b/mm/memcontrol.c index b807952b4d43..d2352f76d651 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -5643,7 +5643,7 @@ static int mem_cgroup_move_account(struct page *page, if (PageDirty(page)) { struct address_space *mapping = page_mapping(page); - if (mapping_cap_account_dirty(mapping)) { + if (mapping_can_writeback(mapping)) { __mod_lruvec_state(from_vec, NR_FILE_DIRTY, -nr_pages); __mod_lruvec_state(to_vec, NR_FILE_DIRTY, diff --git a/mm/memory-failure.c b/mm/memory-failure.c index f1aa6433f404..a1e73943445e 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1006,7 +1006,7 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn, */ mapping = page_mapping(hpage); if (!(flags & MF_MUST_KILL) && !PageDirty(hpage) && mapping && - mapping_cap_writeback_dirty(mapping)) { + mapping_can_writeback(mapping)) { if (page_mkclean(hpage)) { SetPageDirty(hpage); } else { diff --git a/mm/migrate.c b/mm/migrate.c index 34a842a8eb6a..9d2f42a3a162 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -503,7 +503,7 @@ int migrate_page_move_mapping(struct address_space *mapping, __dec_lruvec_state(old_lruvec, NR_SHMEM); __inc_lruvec_state(new_lruvec, NR_SHMEM); } - if (dirty && mapping_cap_account_dirty(mapping)) { + if (dirty && mapping_can_writeback(mapping)) { __dec_node_state(oldzone->zone_pgdat, NR_FILE_DIRTY); __dec_zone_state(oldzone, NR_ZONE_WRITE_PENDING); __inc_node_state(newzone->zone_pgdat, NR_FILE_DIRTY); diff --git a/mm/mmap.c b/mm/mmap.c index 40248d84ad5f..1fc0e92be4ba 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1666,7 +1666,7 @@ int vma_wants_writenotify(struct vm_area_struct *vma, pgprot_t vm_page_prot) /* Can the mapping track the dirty pages? */ return vma->vm_file && vma->vm_file->f_mapping && - mapping_cap_account_dirty(vma->vm_file->f_mapping); + mapping_can_writeback(vma->vm_file->f_mapping); } /* diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 0139f9622a92..358d6f28c627 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -1882,7 +1882,7 @@ void balance_dirty_pages_ratelimited(struct address_space *mapping) int ratelimit; int *p; - if (!bdi_cap_account_dirty(bdi)) + if (!(bdi->capabilities & BDI_CAP_WRITEBACK)) return; if (inode_cgwb_enabled(inode)) @@ -2423,7 +2423,7 @@ void account_page_dirtied(struct page *page, struct address_space *mapping) trace_writeback_dirty_page(page, mapping); - if (mapping_cap_account_dirty(mapping)) { + if (mapping_can_writeback(mapping)) { struct bdi_writeback *wb; inode_attach_wb(inode, page); @@ -2450,7 +2450,7 @@ void account_page_dirtied(struct page *page, struct address_space *mapping) void account_page_cleaned(struct page *page, struct address_space *mapping, struct bdi_writeback *wb) { - if (mapping_cap_account_dirty(mapping)) { + if (mapping_can_writeback(mapping)) { dec_lruvec_page_state(page, NR_FILE_DIRTY); dec_zone_page_state(page, NR_ZONE_WRITE_PENDING); dec_wb_stat(wb, WB_RECLAIMABLE); @@ -2513,7 +2513,7 @@ void account_page_redirty(struct page *page) { struct address_space *mapping = page->mapping; - if (mapping && mapping_cap_account_dirty(mapping)) { + if (mapping && mapping_can_writeback(mapping)) { struct inode *inode = mapping->host; struct bdi_writeback *wb; struct wb_lock_cookie cookie = {}; @@ -2625,7 +2625,7 @@ void __cancel_dirty_page(struct page *page) { struct address_space *mapping = page_mapping(page); - if (mapping_cap_account_dirty(mapping)) { + if (mapping_can_writeback(mapping)) { struct inode *inode = mapping->host; struct bdi_writeback *wb; struct wb_lock_cookie cookie = {}; @@ -2665,7 +2665,7 @@ int clear_page_dirty_for_io(struct page *page) VM_BUG_ON_PAGE(!PageLocked(page), page); - if (mapping && mapping_cap_account_dirty(mapping)) { + if (mapping && mapping_can_writeback(mapping)) { struct inode *inode = mapping->host; struct bdi_writeback *wb; struct wb_lock_cookie cookie = {}; From 250eec9e390e2be6f672f9a77cf29791c189f7da Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 3 Sep 2020 07:40:56 +0200 Subject: [PATCH 141/191] Documentation/hdio: fix up obscure bd_contains references bd_contains is an implementation detail and should not be mentioned in a userspace API documentation. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- Documentation/userspace-api/ioctl/hdio.rst | 24 +++++++++++----------- 1 file changed, 12 insertions(+), 12 deletions(-) diff --git a/Documentation/userspace-api/ioctl/hdio.rst b/Documentation/userspace-api/ioctl/hdio.rst index e822e3dff176..817371bf94e9 100644 --- a/Documentation/userspace-api/ioctl/hdio.rst +++ b/Documentation/userspace-api/ioctl/hdio.rst @@ -181,7 +181,7 @@ HDIO_SET_UNMASKINTR error return: - - EINVAL (bdev != bdev->bd_contains) (not sure what this means) + - EINVAL Called on a partition instead of the whole disk device - EACCES Access denied: requires CAP_SYS_ADMIN - EINVAL value out of range [0 1] - EBUSY Controller busy @@ -231,7 +231,7 @@ HDIO_SET_MULTCOUNT error return: - - EINVAL (bdev != bdev->bd_contains) (not sure what this means) + - EINVAL Called on a partition instead of the whole disk device - EACCES Access denied: requires CAP_SYS_ADMIN - EINVAL value out of range supported by disk. - EBUSY Controller busy or blockmode already set. @@ -295,7 +295,7 @@ HDIO_GET_IDENTITY the ATA specification. error returns: - - EINVAL (bdev != bdev->bd_contains) (not sure what this means) + - EINVAL Called on a partition instead of the whole disk device - ENOMSG IDENTIFY DEVICE information not available notes: @@ -355,7 +355,7 @@ HDIO_SET_KEEPSETTINGS error return: - - EINVAL (bdev != bdev->bd_contains) (not sure what this means) + - EINVAL Called on a partition instead of the whole disk device - EACCES Access denied: requires CAP_SYS_ADMIN - EINVAL value out of range [0 1] - EBUSY Controller busy @@ -1055,7 +1055,7 @@ HDIO_SET_32BIT error return: - - EINVAL (bdev != bdev->bd_contains) (not sure what this means) + - EINVAL Called on a partition instead of the whole disk device - EACCES Access denied: requires CAP_SYS_ADMIN - EINVAL value out of range [0 3] - EBUSY Controller busy @@ -1085,7 +1085,7 @@ HDIO_SET_NOWERR error return: - - EINVAL (bdev != bdev->bd_contains) (not sure what this means) + - EINVAL Called on a partition instead of the whole disk device - EACCES Access denied: requires CAP_SYS_ADMIN - EINVAL value out of range [0 1] - EBUSY Controller busy @@ -1113,7 +1113,7 @@ HDIO_SET_DMA error return: - - EINVAL (bdev != bdev->bd_contains) (not sure what this means) + - EINVAL Called on a partition instead of the whole disk device - EACCES Access denied: requires CAP_SYS_ADMIN - EINVAL value out of range [0 1] - EBUSY Controller busy @@ -1141,7 +1141,7 @@ HDIO_SET_PIO_MODE error return: - - EINVAL (bdev != bdev->bd_contains) (not sure what this means) + - EINVAL Called on a partition instead of the whole disk device - EACCES Access denied: requires CAP_SYS_ADMIN - EINVAL value out of range [0 255] - EBUSY Controller busy @@ -1237,7 +1237,7 @@ HDIO_SET_WCACHE error return: - - EINVAL (bdev != bdev->bd_contains) (not sure what this means) + - EINVAL Called on a partition instead of the whole disk device - EACCES Access denied: requires CAP_SYS_ADMIN - EINVAL value out of range [0 1] - EBUSY Controller busy @@ -1265,7 +1265,7 @@ HDIO_SET_ACOUSTIC error return: - - EINVAL (bdev != bdev->bd_contains) (not sure what this means) + - EINVAL Called on a partition instead of the whole disk device - EACCES Access denied: requires CAP_SYS_ADMIN - EINVAL value out of range [0 254] - EBUSY Controller busy @@ -1305,7 +1305,7 @@ HDIO_SET_ADDRESS error return: - - EINVAL (bdev != bdev->bd_contains) (not sure what this means) + - EINVAL Called on a partition instead of the whole disk device - EACCES Access denied: requires CAP_SYS_ADMIN - EINVAL value out of range [0 2] - EBUSY Controller busy @@ -1331,7 +1331,7 @@ HDIO_SET_IDE_SCSI error return: - - EINVAL (bdev != bdev->bd_contains) (not sure what this means) + - EINVAL Called on a partition instead of the whole disk device - EACCES Access denied: requires CAP_SYS_ADMIN - EINVAL value out of range [0 1] - EBUSY Controller busy From fa01b1e9733fd59ecb8b5b6d85dfb481d2025fbf Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 3 Sep 2020 07:40:57 +0200 Subject: [PATCH 142/191] block: add a bdev_is_partition helper Add a littler helper to make the somewhat arcane bd_contains checks a little more obvious. Signed-off-by: Christoph Hellwig Acked-by: Ulf Hansson Signed-off-by: Jens Axboe --- block/blk-lib.c | 2 +- block/ioctl.c | 4 ++-- block/scsi_ioctl.c | 2 +- drivers/ide/ide-ioctls.c | 4 ++-- drivers/md/dm-table.c | 2 +- drivers/mmc/core/block.c | 2 +- drivers/s390/block/dasd_ioctl.c | 8 ++++---- fs/nfsd/blocklayout.c | 4 ++-- include/linux/blkdev.h | 9 +++++++-- kernel/trace/blktrace.c | 2 +- 10 files changed, 22 insertions(+), 17 deletions(-) diff --git a/block/blk-lib.c b/block/blk-lib.c index 0d1811e57ac7..e90614fd8d6a 100644 --- a/block/blk-lib.c +++ b/block/blk-lib.c @@ -64,7 +64,7 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector, return -EINVAL; /* In case the discard request is in a partition */ - if (bdev->bd_partno) + if (bdev_is_partition(bdev)) part_offset = bdev->bd_part->start_sect; while (nr_sects) { diff --git a/block/ioctl.c b/block/ioctl.c index 06262c28f0c6..3fbc382eb926 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -23,7 +23,7 @@ static int blkpg_do_ioctl(struct block_device *bdev, return -EACCES; if (copy_from_user(&p, upart, sizeof(struct blkpg_partition))) return -EFAULT; - if (bdev != bdev->bd_contains) + if (bdev_is_partition(bdev)) return -EINVAL; if (p.pno <= 0) @@ -94,7 +94,7 @@ static int blkdev_reread_part(struct block_device *bdev) { int ret; - if (!disk_part_scan_enabled(bdev->bd_disk) || bdev != bdev->bd_contains) + if (!disk_part_scan_enabled(bdev->bd_disk) || bdev_is_partition(bdev)) return -EINVAL; if (!capable(CAP_SYS_ADMIN)) return -EACCES; diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c index 4421e61c1af1..d4abd1ed5a2d 100644 --- a/block/scsi_ioctl.c +++ b/block/scsi_ioctl.c @@ -852,7 +852,7 @@ EXPORT_SYMBOL(scsi_cmd_ioctl); int scsi_verify_blk_ioctl(struct block_device *bd, unsigned int cmd) { - if (bd && bd == bd->bd_contains) + if (bd && !bdev_is_partition(bd)) return 0; if (capable(CAP_SYS_RAWIO)) diff --git a/drivers/ide/ide-ioctls.c b/drivers/ide/ide-ioctls.c index 09491098047b..58994da10c06 100644 --- a/drivers/ide/ide-ioctls.c +++ b/drivers/ide/ide-ioctls.c @@ -49,7 +49,7 @@ int ide_setting_ioctl(ide_drive_t *drive, struct block_device *bdev, return err >= 0 ? put_user_long(err, arg) : err; set_val: - if (bdev != bdev->bd_contains) + if (bdev_is_partition(bdev)) err = -EINVAL; else { if (!capable(CAP_SYS_ADMIN)) @@ -257,7 +257,7 @@ int generic_ide_ioctl(ide_drive_t *drive, struct block_device *bdev, switch (cmd) { case HDIO_OBSOLETE_IDENTITY: case HDIO_GET_IDENTITY: - if (bdev != bdev->bd_contains) + if (bdev_is_partition(bdev)) return -EINVAL; return ide_get_identity_ioctl(drive, cmd, argp); case HDIO_GET_NICE: diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 405d7cf10eb9..12d909044c10 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -903,7 +903,7 @@ static int device_is_rq_stackable(struct dm_target *ti, struct dm_dev *dev, struct request_queue *q = bdev_get_queue(bdev); /* request-based cannot stack on partitions! */ - if (bdev != bdev->bd_contains) + if (bdev_is_partition(bdev)) return false; return queue_is_mq(q); diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c index fa313b634135..8d3df0be0355 100644 --- a/drivers/mmc/core/block.c +++ b/drivers/mmc/core/block.c @@ -723,7 +723,7 @@ static int mmc_blk_check_blkdev(struct block_device *bdev) * whole block device, not on a partition. This prevents overspray * between sibling partitions. */ - if ((!capable(CAP_SYS_RAWIO)) || (bdev != bdev->bd_contains)) + if (!capable(CAP_SYS_RAWIO) || bdev_is_partition(bdev)) return -EPERM; return 0; } diff --git a/drivers/s390/block/dasd_ioctl.c b/drivers/s390/block/dasd_ioctl.c index faaf5596e31c..cb6427fb9f3d 100644 --- a/drivers/s390/block/dasd_ioctl.c +++ b/drivers/s390/block/dasd_ioctl.c @@ -277,7 +277,7 @@ dasd_ioctl_format(struct block_device *bdev, void __user *argp) dasd_put_device(base); return -EFAULT; } - if (bdev != bdev->bd_contains) { + if (bdev_is_partition(bdev)) { pr_warn("%s: The specified DASD is a partition and cannot be formatted\n", dev_name(&base->cdev->dev)); dasd_put_device(base); @@ -304,7 +304,7 @@ static int dasd_ioctl_check_format(struct block_device *bdev, void __user *argp) base = dasd_device_from_gendisk(bdev->bd_disk); if (!base) return -ENODEV; - if (bdev != bdev->bd_contains) { + if (bdev_is_partition(bdev)) { pr_warn("%s: The specified DASD is a partition and cannot be checked\n", dev_name(&base->cdev->dev)); rc = -EINVAL; @@ -362,7 +362,7 @@ static int dasd_ioctl_release_space(struct block_device *bdev, void __user *argp rc = -EROFS; goto out_err; } - if (bdev != bdev->bd_contains) { + if (bdev_is_partition(bdev)) { pr_warn("%s: The specified DASD is a partition and tracks cannot be released\n", dev_name(&base->cdev->dev)); rc = -EINVAL; @@ -540,7 +540,7 @@ dasd_ioctl_set_ro(struct block_device *bdev, void __user *argp) if (!capable(CAP_SYS_ADMIN)) return -EACCES; - if (bdev != bdev->bd_contains) + if (bdev_is_partition(bdev)) // ro setting is not allowed for partitions return -EINVAL; if (get_user(intval, (int __user *)argp)) diff --git a/fs/nfsd/blocklayout.c b/fs/nfsd/blocklayout.c index 311e5ce80cfc..a07c39c94bbd 100644 --- a/fs/nfsd/blocklayout.c +++ b/fs/nfsd/blocklayout.c @@ -170,7 +170,7 @@ nfsd4_block_proc_getdeviceinfo(struct super_block *sb, struct nfs4_client *clp, struct nfsd4_getdeviceinfo *gdp) { - if (sb->s_bdev != sb->s_bdev->bd_contains) + if (bdev_is_partition(sb->s_bdev)) return nfserr_inval; return nfserrno(nfsd4_block_get_device_info_simple(sb, gdp)); } @@ -382,7 +382,7 @@ nfsd4_scsi_proc_getdeviceinfo(struct super_block *sb, struct nfs4_client *clp, struct nfsd4_getdeviceinfo *gdp) { - if (sb->s_bdev != sb->s_bdev->bd_contains) + if (bdev_is_partition(sb->s_bdev)) return nfserr_inval; return nfserrno(nfsd4_block_get_device_info_scsi(sb, clp, gdp)); } diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 8e77f12de522..33f283885ba5 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1353,6 +1353,11 @@ static inline int sb_issue_zeroout(struct super_block *sb, sector_t block, extern int blk_verify_command(unsigned char *cmd, fmode_t mode); +static inline bool bdev_is_partition(struct block_device *bdev) +{ + return bdev->bd_partno; +} + enum blk_default_limits { BLK_MAX_SEGMENTS = 128, BLK_SAFE_MAX_SECTORS = 255, @@ -1469,7 +1474,7 @@ static inline int bdev_alignment_offset(struct block_device *bdev) if (q->limits.misaligned) return -1; - if (bdev != bdev->bd_contains) + if (bdev_is_partition(bdev)) return queue_limit_alignment_offset(&q->limits, bdev->bd_part->start_sect); return q->limits.alignment_offset; @@ -1510,7 +1515,7 @@ static inline int bdev_discard_alignment(struct block_device *bdev) { struct request_queue *q = bdev_get_queue(bdev); - if (bdev != bdev->bd_contains) + if (bdev_is_partition(bdev)) return queue_limit_discard_alignment(&q->limits, bdev->bd_part->start_sect); return q->limits.discard_alignment; diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index c0887f32f647..ec874ea04092 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -527,7 +527,7 @@ static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, * and scsi-generic block devices we create a temporary new debugfs * directory that will be removed once the trace ends. */ - if (bdev && bdev == bdev->bd_contains) + if (bdev && !bdev_is_partition(bdev)) dir = q->debugfs_dir; else bt->dir = dir = debugfs_create_dir(buts->name, blk_debugfs_root); From 61a27e1f521ca0dd4a38302958ccc43fd95d8879 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 3 Sep 2020 07:40:58 +0200 Subject: [PATCH 143/191] md: compare bd_disk instead of bd_contains To check for partitions of the same disk bd_contains works as well, but bd_disk is way more obvious. Signed-off-by: Christoph Hellwig Acked-by: Song Liu Signed-off-by: Jens Axboe --- drivers/md/md.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 64bc22d2b606..09ed6d0c7dbe 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -2322,8 +2322,7 @@ static int match_mddev_units(struct mddev *mddev1, struct mddev *mddev2) test_bit(Journal, &rdev2->flags) || rdev2->raid_disk == -1) continue; - if (rdev->bdev->bd_contains == - rdev2->bdev->bd_contains) { + if (rdev->bdev->bd_disk == rdev2->bdev->bd_disk) { rcu_read_unlock(); return 1; } @@ -5944,8 +5943,8 @@ int md_run(struct mddev *mddev) rdev_for_each(rdev, mddev) rdev_for_each(rdev2, mddev) { if (rdev < rdev2 && - rdev->bdev->bd_contains == - rdev2->bdev->bd_contains) { + rdev->bdev->bd_disk == + rdev2->bdev->bd_disk) { pr_warn("%s: WARNING: %s appears to be on the same physical disk as %s.\n", mdname(mddev), bdevname(rdev->bdev,b), From 4245e52d255418278fc4a5eec7425ad0bfeebd31 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 3 Sep 2020 07:40:59 +0200 Subject: [PATCH 144/191] md: don't detour through bd_contains for the gendisk bd_disk is set on all block devices, including those for partitions. Signed-off-by: Christoph Hellwig Acked-by: Song Liu Signed-off-by: Jens Axboe --- drivers/md/md.c | 2 +- drivers/md/md.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 09ed6d0c7dbe..de8419b7ae98 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -8444,7 +8444,7 @@ static int is_mddev_idle(struct mddev *mddev, int init) idle = 1; rcu_read_lock(); rdev_for_each_rcu(rdev, mddev) { - struct gendisk *disk = rdev->bdev->bd_contains->bd_disk; + struct gendisk *disk = rdev->bdev->bd_disk; curr_events = (int)part_stat_read_accum(&disk->part0, sectors) - atomic_read(&disk->sync_io); /* sync IO will cause sync_io to increase before the disk_stats diff --git a/drivers/md/md.h b/drivers/md/md.h index f9e2ccdd22c4..2175a5ac4f7c 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -551,7 +551,7 @@ extern void mddev_unlock(struct mddev *mddev); static inline void md_sync_acct(struct block_device *bdev, unsigned long nr_sectors) { - atomic_add(nr_sectors, &bdev->bd_contains->bd_disk->sync_io); + atomic_add(nr_sectors, &bdev->bd_disk->sync_io); } static inline void md_sync_acct_bio(struct bio *bio, unsigned long nr_sectors) From 8c40c7c4836a1ff9e5e840e5ab28526392a5724c Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 3 Sep 2020 07:41:00 +0200 Subject: [PATCH 145/191] drbd: don't detour through bd_contains for the gendisk bd_disk is set on all block devices, including those for partitions. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- drivers/block/drbd/drbd_receiver.c | 2 +- drivers/block/drbd/drbd_worker.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c index 422363daa618..2d16fb090599 100644 --- a/drivers/block/drbd/drbd_receiver.c +++ b/drivers/block/drbd/drbd_receiver.c @@ -2789,7 +2789,7 @@ bool drbd_rs_should_slow_down(struct drbd_device *device, sector_t sector, bool drbd_rs_c_min_rate_throttle(struct drbd_device *device) { - struct gendisk *disk = device->ldev->backing_bdev->bd_contains->bd_disk; + struct gendisk *disk = device->ldev->backing_bdev->bd_disk; unsigned long db, dt, dbdt; unsigned int c_min_rate; int curr_events; diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c index 7c903de5c4e1..9107b109ba7b 100644 --- a/drivers/block/drbd/drbd_worker.c +++ b/drivers/block/drbd/drbd_worker.c @@ -1672,7 +1672,7 @@ void drbd_resync_after_changed(struct drbd_device *device) void drbd_rs_controller_reset(struct drbd_device *device) { - struct gendisk *disk = device->ldev->backing_bdev->bd_contains->bd_disk; + struct gendisk *disk = device->ldev->backing_bdev->bd_disk; struct fifo_buffer *plan; atomic_set(&device->rs_sect_in, 0); From 74f94454099e89322f82fce35f7c73142516d17d Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 3 Sep 2020 07:41:01 +0200 Subject: [PATCH 146/191] drbd: don't set ->bd_contains The ->bd_contains field is set by __blkdev_get and drivers have no business manipulating it. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- drivers/block/drbd/drbd_main.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c index 04b6bde9419d..bd8b129196d4 100644 --- a/drivers/block/drbd/drbd_main.c +++ b/drivers/block/drbd/drbd_main.c @@ -2766,8 +2766,6 @@ enum drbd_ret_code drbd_create_device(struct drbd_config_context *adm_ctx, unsig disk->private_data = device; device->this_bdev = bdget(MKDEV(DRBD_MAJOR, minor)); - /* we have no partitions. we contain only ourselves. */ - device->this_bdev->bd_contains = device->this_bdev; blk_queue_write_cache(q, true, true); /* Setting the max_hw_sectors to an odd value of 8kibyte here From 57ba10592030be8c8b17184ca093db5e45cdbb2b Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 3 Sep 2020 07:41:02 +0200 Subject: [PATCH 147/191] target/iblock: fix holder printing in iblock_show_configfs_dev_params bd_contains is never NULL for an open block device. In addition ibd_bd is always set to a block device that was exclusively opened by the target code, so the holder is guranteed to be ib_dev as well. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- drivers/target/target_core_iblock.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c index 1c181d31f4c8..f2bd2e207e0b 100644 --- a/drivers/target/target_core_iblock.c +++ b/drivers/target/target_core_iblock.c @@ -611,9 +611,8 @@ static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b) bl += sprintf(b + bl, " "); if (bd) { bl += sprintf(b + bl, "Major: %d Minor: %d %s\n", - MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ? - "" : (bd->bd_holder == ib_dev) ? - "CLAIMED: IBLOCK" : "CLAIMED: OS"); + MAJOR(bd->bd_dev), MINOR(bd->bd_dev), + "CLAIMED: IBLOCK"); } else { bl += sprintf(b + bl, "Major: 0 Minor: 0\n"); } From 8a63a86e1f933dc7f114497408c50c58a633b8bc Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 3 Sep 2020 07:41:03 +0200 Subject: [PATCH 148/191] block: use bd_partno in bdevname No need to go through the hd_struct to find the partition number. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/genhd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/genhd.c b/block/genhd.c index 05fb27cbb667..e5f17f022ec7 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -85,7 +85,7 @@ char *disk_name(struct gendisk *hd, int partno, char *buf) const char *bdevname(struct block_device *bdev, char *buf) { - return disk_name(bdev->bd_disk, bdev->bd_part->partno, buf); + return disk_name(bdev->bd_disk, bdev->bd_partno, buf); } EXPORT_SYMBOL(bdevname); From 700cd59db518edc2028df7c830d6cb6f7164573b Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 3 Sep 2020 07:41:04 +0200 Subject: [PATCH 149/191] vsprintf: use bd_partno in bdev_name No need to go through the hd_struct to find the partition number. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- lib/vsprintf.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/lib/vsprintf.c b/lib/vsprintf.c index afb9521ddf91..14c9a6af1b23 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -940,13 +940,13 @@ char *bdev_name(char *buf, char *end, struct block_device *bdev, hd = bdev->bd_disk; buf = string(buf, end, hd->disk_name, spec); - if (bdev->bd_part->partno) { + if (bdev->bd_partno) { if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) { if (buf < end) *buf = 'p'; buf++; } - buf = number(buf, end, bdev->bd_part->partno, spec); + buf = number(buf, end, bdev->bd_partno, spec); } return buf; } From 021a24460dc28e7412aecfae89f60e1847e685c0 Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Wed, 23 Sep 2020 16:06:51 -0400 Subject: [PATCH 150/191] block: add QUEUE_FLAG_NOWAIT Add QUEUE_FLAG_NOWAIT to allow a block device to advertise support for REQ_NOWAIT. Bio-based devices may set QUEUE_FLAG_NOWAIT where applicable. Update QUEUE_FLAG_MQ_DEFAULT to include QUEUE_FLAG_NOWAIT. Also update submit_bio_checks() to verify it is set for REQ_NOWAIT bios. Reported-by: Konstantin Khlebnikov Suggested-by: Christoph Hellwig Signed-off-by: Mike Snitzer Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/blk-core.c | 4 ++-- include/linux/blkdev.h | 7 +++++-- 2 files changed, 7 insertions(+), 4 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 1cc4fa6bc7fe..4884f1e7451b 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -814,9 +814,9 @@ static noinline_for_stack bool submit_bio_checks(struct bio *bio) /* * For a REQ_NOWAIT based request, return -EOPNOTSUPP - * if queue is not a request based queue. + * if queue does not support NOWAIT. */ - if ((bio->bi_opf & REQ_NOWAIT) && !queue_is_mq(q)) + if ((bio->bi_opf & REQ_NOWAIT) && !blk_queue_nowait(q)) goto not_supported; if (should_fail_bio(bio)) diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 33f283885ba5..d5a3e1a4c2f7 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -619,10 +619,12 @@ struct request_queue { #define QUEUE_FLAG_PCI_P2PDMA 25 /* device supports PCI p2p requests */ #define QUEUE_FLAG_ZONE_RESETALL 26 /* supports Zone Reset All */ #define QUEUE_FLAG_RQ_ALLOC_TIME 27 /* record rq->alloc_time_ns */ -#define QUEUE_FLAG_HCTX_ACTIVE 28 /* at least one blk-mq hctx is active */ +#define QUEUE_FLAG_HCTX_ACTIVE 28 /* at least one blk-mq hctx is active */ +#define QUEUE_FLAG_NOWAIT 29 /* device supports NOWAIT */ #define QUEUE_FLAG_MQ_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ - (1 << QUEUE_FLAG_SAME_COMP)) + (1 << QUEUE_FLAG_SAME_COMP) | \ + (1 << QUEUE_FLAG_NOWAIT)) void blk_queue_flag_set(unsigned int flag, struct request_queue *q); void blk_queue_flag_clear(unsigned int flag, struct request_queue *q); @@ -664,6 +666,7 @@ bool blk_queue_flag_test_and_set(unsigned int flag, struct request_queue *q); #define blk_queue_pm_only(q) atomic_read(&(q)->pm_only) #define blk_queue_fua(q) test_bit(QUEUE_FLAG_FUA, &(q)->queue_flags) #define blk_queue_registered(q) test_bit(QUEUE_FLAG_REGISTERED, &(q)->queue_flags) +#define blk_queue_nowait(q) test_bit(QUEUE_FLAG_NOWAIT, &(q)->queue_flags) extern void blk_set_pm_only(struct request_queue *q); extern void blk_clear_pm_only(struct request_queue *q); From 6abc49468eeaad2dd481779906aaa29605139087 Mon Sep 17 00:00:00 2001 From: Konstantin Khlebnikov Date: Wed, 23 Sep 2020 16:06:52 -0400 Subject: [PATCH 151/191] dm: add support for REQ_NOWAIT and enable it for linear target Add DM target feature flag DM_TARGET_NOWAIT which advertises that target works with REQ_NOWAIT bios. Add dm_table_supports_nowait() and update dm_table_set_restrictions() to set/clear QUEUE_FLAG_NOWAIT accordingly. Signed-off-by: Konstantin Khlebnikov Signed-off-by: Mike Snitzer Signed-off-by: Jens Axboe --- drivers/md/dm-linear.c | 5 +++-- drivers/md/dm-table.c | 32 ++++++++++++++++++++++++++++++++ drivers/md/dm.c | 4 +++- include/linux/device-mapper.h | 6 ++++++ 4 files changed, 44 insertions(+), 3 deletions(-) diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c index e1db43446327..00774b5d7668 100644 --- a/drivers/md/dm-linear.c +++ b/drivers/md/dm-linear.c @@ -228,10 +228,11 @@ static struct target_type linear_target = { .name = "linear", .version = {1, 4, 0}, #ifdef CONFIG_BLK_DEV_ZONED - .features = DM_TARGET_PASSES_INTEGRITY | DM_TARGET_ZONED_HM, + .features = DM_TARGET_PASSES_INTEGRITY | DM_TARGET_NOWAIT | + DM_TARGET_ZONED_HM, .report_zones = linear_report_zones, #else - .features = DM_TARGET_PASSES_INTEGRITY, + .features = DM_TARGET_PASSES_INTEGRITY | DM_TARGET_NOWAIT, #endif .module = THIS_MODULE, .ctr = linear_ctr, diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 12d909044c10..07c319e98581 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -1748,6 +1748,33 @@ static bool dm_table_supports_write_zeroes(struct dm_table *t) return true; } +static int device_not_nowait_capable(struct dm_target *ti, struct dm_dev *dev, + sector_t start, sector_t len, void *data) +{ + struct request_queue *q = bdev_get_queue(dev->bdev); + + return q && !blk_queue_nowait(q); +} + +static bool dm_table_supports_nowait(struct dm_table *t) +{ + struct dm_target *ti; + unsigned i = 0; + + while (i < dm_table_get_num_targets(t)) { + ti = dm_table_get_target(t, i++); + + if (!dm_target_supports_nowait(ti->type)) + return false; + + if (!ti->type->iterate_devices || + ti->type->iterate_devices(ti, device_not_nowait_capable, NULL)) + return false; + } + + return true; +} + static int device_not_discard_capable(struct dm_target *ti, struct dm_dev *dev, sector_t start, sector_t len, void *data) { @@ -1850,6 +1877,11 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, */ q->limits = *limits; + if (dm_table_supports_nowait(t)) + blk_queue_flag_set(QUEUE_FLAG_NOWAIT, q); + else + blk_queue_flag_clear(QUEUE_FLAG_NOWAIT, q); + if (!dm_table_supports_discards(t)) { blk_queue_flag_clear(QUEUE_FLAG_DISCARD, q); /* Must also clear discard limits... */ diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 3dedd9cc4fb6..59b0687f9235 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1802,7 +1802,9 @@ static blk_qc_t dm_submit_bio(struct bio *bio) if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags))) { dm_put_live_table(md, srcu_idx); - if (!(bio->bi_opf & REQ_RAHEAD)) + if (bio->bi_opf & REQ_NOWAIT) + bio_wouldblock_error(bio); + else if (!(bio->bi_opf & REQ_RAHEAD)) queue_io(md, bio); else bio_io_error(bio); diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index 93096e524e43..d6f8d4ba8d48 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -252,6 +252,12 @@ struct target_type { #define DM_TARGET_ZONED_HM 0x00000040 #define dm_target_supports_zoned_hm(type) ((type)->features & DM_TARGET_ZONED_HM) +/* + * A target handles REQ_NOWAIT + */ +#define DM_TARGET_NOWAIT 0x00000080 +#define dm_target_supports_nowait(type) ((type)->features & DM_TARGET_NOWAIT) + struct dm_target { struct dm_table *table; struct target_type *type; From ab8df828b5f6eab6377fa0c349c92a3678498256 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 17 Sep 2020 20:44:52 -0400 Subject: [PATCH 152/191] iocost: factor out ioc_forgive_debts() Debt reduction logic is going to be improved and expanded. Factor it out into ioc_forgive_debts() and generalize the comment a bit. No functional change. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- block/blk-iocost.c | 66 ++++++++++++++++++++++++---------------------- 1 file changed, 35 insertions(+), 31 deletions(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index ef9476fca1d8..bbf30bb06c07 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -1979,6 +1979,40 @@ static void transfer_surpluses(struct list_head *surpluses, struct ioc_now *now) list_del_init(&iocg->walk_list); } +/* + * A low weight iocg can amass a large amount of debt, for example, when + * anonymous memory gets reclaimed aggressively. If the system has a lot of + * memory paired with a slow IO device, the debt can span multiple seconds or + * more. If there are no other subsequent IO issuers, the in-debt iocg may end + * up blocked paying its debt while the IO device is idle. + * + * The following protects against such cases. If the device has been + * sufficiently idle for a while, the debts are halved. + */ +static void ioc_forgive_debts(struct ioc *ioc, u64 usage_us_sum, int nr_debtors, + int nr_shortages, struct ioc_now *now) +{ + if (nr_shortages || + div64_u64(100 * usage_us_sum, now->now - ioc->period_at) >= + DEBT_BUSY_USAGE_PCT) + ioc->debt_busy_at = now->now; + + if (nr_debtors && + now->now - ioc->debt_busy_at >= DEBT_REDUCTION_IDLE_DUR) { + struct ioc_gq *iocg; + + list_for_each_entry(iocg, &ioc->active_iocgs, active_list) { + if (iocg->abs_vdebt) { + spin_lock(&iocg->waitq.lock); + iocg->abs_vdebt /= 2; + iocg_kick_waitq(iocg, true, now); + spin_unlock(&iocg->waitq.lock); + } + } + ioc->debt_busy_at = now->now; + } +} + static void ioc_timer_fn(struct timer_list *timer) { struct ioc *ioc = container_of(timer, struct ioc, timer); @@ -2171,37 +2205,7 @@ static void ioc_timer_fn(struct timer_list *timer) list_for_each_entry_safe(iocg, tiocg, &surpluses, surplus_list) list_del_init(&iocg->surplus_list); - /* - * A low weight iocg can amass a large amount of debt, for example, when - * anonymous memory gets reclaimed aggressively. If the system has a lot - * of memory paired with a slow IO device, the debt can span multiple - * seconds or more. If there are no other subsequent IO issuers, the - * in-debt iocg may end up blocked paying its debt while the IO device - * is idle. - * - * The following protects against such pathological cases. If the device - * has been sufficiently idle for a substantial amount of time, the - * debts are halved. The criteria are on the conservative side as we - * want to resolve the rare extreme cases without impacting regular - * operation by forgiving debts too readily. - */ - if (nr_shortages || - div64_u64(100 * usage_us_sum, now.now - ioc->period_at) >= - DEBT_BUSY_USAGE_PCT) - ioc->debt_busy_at = now.now; - - if (nr_debtors && - now.now - ioc->debt_busy_at >= DEBT_REDUCTION_IDLE_DUR) { - list_for_each_entry(iocg, &ioc->active_iocgs, active_list) { - if (iocg->abs_vdebt) { - spin_lock(&iocg->waitq.lock); - iocg->abs_vdebt /= 2; - iocg_kick_waitq(iocg, true, &now); - spin_unlock(&iocg->waitq.lock); - } - } - ioc->debt_busy_at = now.now; - } + ioc_forgive_debts(ioc, usage_us_sum, nr_debtors, nr_shortages, &now); /* * If q is getting clogged or we're missing too much, we're issuing From 33a1fe6d822b3552fcad9bbb059b2fb93566f4c9 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 17 Sep 2020 20:44:53 -0400 Subject: [PATCH 153/191] iocost: replace nr_shortages cond in ioc_forgive_debts() with busy_level one Debt reduction was blocked if any iocg was short on budget in the past period to avoid reducing debts while some iocgs are saturated. However, this ends up unnecessarily blocking debt reduction due to temporary local imbalances when the device is generally being underutilized, while also failing to block when the underlying device is overwhelmed and the usage becomes low from high latency. Given that debt accumulation mostly happens with swapout bursts which can significantly deteriorate the underlying device's latency response, the current logic is not great. Let's replace it with ioc->busy_level based condition so that we block debt reduction when the underlying device is being saturated. ioc_forgive_debts() call is moved after busy_level determination. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- block/blk-iocost.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index bbf30bb06c07..c0499c294da9 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -287,10 +287,7 @@ enum { MIN_DELAY = 250, MAX_DELAY = 250 * USEC_PER_MSEC, - /* - * Halve debts if total usage keeps staying under 25% w/o any shortages - * for over 100ms. - */ + /* halve debts if total usage keeps staying under 25% for over 100ms */ DEBT_BUSY_USAGE_PCT = 25, DEBT_REDUCTION_IDLE_DUR = 100 * USEC_PER_MSEC, @@ -1990,9 +1987,9 @@ static void transfer_surpluses(struct list_head *surpluses, struct ioc_now *now) * sufficiently idle for a while, the debts are halved. */ static void ioc_forgive_debts(struct ioc *ioc, u64 usage_us_sum, int nr_debtors, - int nr_shortages, struct ioc_now *now) + struct ioc_now *now) { - if (nr_shortages || + if (ioc->busy_level < 0 || div64_u64(100 * usage_us_sum, now->now - ioc->period_at) >= DEBT_BUSY_USAGE_PCT) ioc->debt_busy_at = now->now; @@ -2205,8 +2202,6 @@ static void ioc_timer_fn(struct timer_list *timer) list_for_each_entry_safe(iocg, tiocg, &surpluses, surplus_list) list_del_init(&iocg->surplus_list); - ioc_forgive_debts(ioc, usage_us_sum, nr_debtors, nr_shortages, &now); - /* * If q is getting clogged or we're missing too much, we're issuing * too much IO and should lower vtime rate. If we're not missing @@ -2301,6 +2296,8 @@ static void ioc_timer_fn(struct timer_list *timer) ioc_refresh_params(ioc, false); + ioc_forgive_debts(ioc, usage_us_sum, nr_debtors, &now); + /* * This period is done. Move onto the next one. If nothing's * going on with the device, stop the timer. From d95178410b7706844491efb77fb0a37a69f7a5e6 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 17 Sep 2020 20:44:54 -0400 Subject: [PATCH 154/191] iocost: recalculate delay after debt reduction Debt sets the initial delay duration which is decayed over time. The current debt reduction halved the debt but didn't change the delay. It prevented future debts from increasing delay but didn't do anything to lower the existing delay, limiting the mechanism's ability to reduce unnecessary idling. Reset iocg->delay to 0 after debt reduction so that iocg_kick_waitq() recalculates new delay value based on the reduced debt amount. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- block/blk-iocost.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index c0499c294da9..ffcb78126ab7 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -1984,7 +1984,8 @@ static void transfer_surpluses(struct list_head *surpluses, struct ioc_now *now) * up blocked paying its debt while the IO device is idle. * * The following protects against such cases. If the device has been - * sufficiently idle for a while, the debts are halved. + * sufficiently idle for a while, the debts are halved and delays are + * recalculated. */ static void ioc_forgive_debts(struct ioc *ioc, u64 usage_us_sum, int nr_debtors, struct ioc_now *now) @@ -2002,6 +2003,7 @@ static void ioc_forgive_debts(struct ioc *ioc, u64 usage_us_sum, int nr_debtors, if (iocg->abs_vdebt) { spin_lock(&iocg->waitq.lock); iocg->abs_vdebt /= 2; + iocg->delay = 0; /* kick_waitq will recalc */ iocg_kick_waitq(iocg, true, now); spin_unlock(&iocg->waitq.lock); } From c7af2a003a411853fc9c805efe96d10dcc8adb5f Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 17 Sep 2020 20:44:55 -0400 Subject: [PATCH 155/191] iocost: reimplement debt forgiveness using average usage Debt forgiveness logic was counting the number of consecutive !busy periods as the trigger condition. While this usually works, it can easily be thrown off by temporary fluctuations especially on configurations w/ short periods. This patch reimplements debt forgiveness so that: * Use the average usage over the forgiveness period instead of counting consecutive periods. * Debt is reduced at around the target rate (1/2 every 100ms) regardless of ioc period duration. * Usage threshold is raised to 50%. Combined with the preceding changes and the switch to average usage, this makes debt forgivness a lot more effective at reducing the amount of unnecessary idleness. * Constants are renamed with DFGV_ prefix. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- block/blk-iocost.c | 90 ++++++++++++++++++++++++++++++++++------------ 1 file changed, 67 insertions(+), 23 deletions(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index ffcb78126ab7..9b1f94499432 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -287,9 +287,9 @@ enum { MIN_DELAY = 250, MAX_DELAY = 250 * USEC_PER_MSEC, - /* halve debts if total usage keeps staying under 25% for over 100ms */ - DEBT_BUSY_USAGE_PCT = 25, - DEBT_REDUCTION_IDLE_DUR = 100 * USEC_PER_MSEC, + /* halve debts if avg usage over 100ms is under 50% */ + DFGV_USAGE_PCT = 50, + DFGV_PERIOD = 100 * USEC_PER_MSEC, /* don't let cmds which take a very long time pin lagging for too long */ MAX_LAGGING_PERIODS = 10, @@ -433,8 +433,10 @@ struct ioc { bool weights_updated; atomic_t hweight_gen; /* for lazy hweights */ - /* the last time debt cancel condition wasn't met */ - u64 debt_busy_at; + /* debt forgivness */ + u64 dfgv_period_at; + u64 dfgv_period_rem; + u64 dfgv_usage_us_sum; u64 autop_too_fast_at; u64 autop_too_slow_at; @@ -1251,7 +1253,8 @@ static bool iocg_activate(struct ioc_gq *iocg, struct ioc_now *now) if (ioc->running == IOC_IDLE) { ioc->running = IOC_RUNNING; - ioc->debt_busy_at = now->now; + ioc->dfgv_period_at = now->now; + ioc->dfgv_period_rem = 0; ioc_start_period(ioc, now); } @@ -1990,25 +1993,66 @@ static void transfer_surpluses(struct list_head *surpluses, struct ioc_now *now) static void ioc_forgive_debts(struct ioc *ioc, u64 usage_us_sum, int nr_debtors, struct ioc_now *now) { - if (ioc->busy_level < 0 || - div64_u64(100 * usage_us_sum, now->now - ioc->period_at) >= - DEBT_BUSY_USAGE_PCT) - ioc->debt_busy_at = now->now; + struct ioc_gq *iocg; + u64 dur, usage_pct, nr_cycles; - if (nr_debtors && - now->now - ioc->debt_busy_at >= DEBT_REDUCTION_IDLE_DUR) { - struct ioc_gq *iocg; + /* if no debtor, reset the cycle */ + if (!nr_debtors) { + ioc->dfgv_period_at = now->now; + ioc->dfgv_period_rem = 0; + ioc->dfgv_usage_us_sum = 0; + return; + } - list_for_each_entry(iocg, &ioc->active_iocgs, active_list) { - if (iocg->abs_vdebt) { - spin_lock(&iocg->waitq.lock); - iocg->abs_vdebt /= 2; - iocg->delay = 0; /* kick_waitq will recalc */ - iocg_kick_waitq(iocg, true, now); - spin_unlock(&iocg->waitq.lock); - } - } - ioc->debt_busy_at = now->now; + /* + * Debtors can pass through a lot of writes choking the device and we + * don't want to be forgiving debts while the device is struggling from + * write bursts. If we're missing latency targets, consider the device + * fully utilized. + */ + if (ioc->busy_level > 0) + usage_us_sum = max_t(u64, usage_us_sum, ioc->period_us); + + ioc->dfgv_usage_us_sum += usage_us_sum; + if (time_before64(now->now, ioc->dfgv_period_at + DFGV_PERIOD)) + return; + + /* + * At least DFGV_PERIOD has passed since the last period. Calculate the + * average usage and reset the period counters. + */ + dur = now->now - ioc->dfgv_period_at; + usage_pct = div64_u64(100 * ioc->dfgv_usage_us_sum, dur); + + ioc->dfgv_period_at = now->now; + ioc->dfgv_usage_us_sum = 0; + + /* if was too busy, reset everything */ + if (usage_pct > DFGV_USAGE_PCT) { + ioc->dfgv_period_rem = 0; + return; + } + + /* + * Usage is lower than threshold. Let's forgive some debts. Debt + * forgiveness runs off of the usual ioc timer but its period usually + * doesn't match ioc's. Compensate the difference by performing the + * reduction as many times as would fit in the duration since the last + * run and carrying over the left-over duration in @ioc->dfgv_period_rem + * - if ioc period is 75% of DFGV_PERIOD, one out of three consecutive + * reductions is doubled. + */ + nr_cycles = dur + ioc->dfgv_period_rem; + ioc->dfgv_period_rem = do_div(nr_cycles, DFGV_PERIOD); + + list_for_each_entry(iocg, &ioc->active_iocgs, active_list) { + if (!iocg->abs_vdebt) + continue; + spin_lock(&iocg->waitq.lock); + iocg->abs_vdebt >>= nr_cycles; + iocg->delay = 0; /* kick_waitq will recalc */ + iocg_kick_waitq(iocg, true, now); + spin_unlock(&iocg->waitq.lock); } } From c5a6561b8d99ea7d8df21308249ce05bce3dd466 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 17 Sep 2020 20:44:56 -0400 Subject: [PATCH 156/191] iocost: add iocg_forgive_debt tracepoint Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- block/blk-iocost.c | 12 ++++++++++ include/trace/events/iocost.h | 41 +++++++++++++++++++++++++++++++++++ 2 files changed, 53 insertions(+) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index 9b1f94499432..328ae805e85f 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -2046,12 +2046,24 @@ static void ioc_forgive_debts(struct ioc *ioc, u64 usage_us_sum, int nr_debtors, ioc->dfgv_period_rem = do_div(nr_cycles, DFGV_PERIOD); list_for_each_entry(iocg, &ioc->active_iocgs, active_list) { + u64 __maybe_unused old_debt, __maybe_unused old_delay; + if (!iocg->abs_vdebt) continue; + spin_lock(&iocg->waitq.lock); + + old_debt = iocg->abs_vdebt; + old_delay = iocg->delay; + iocg->abs_vdebt >>= nr_cycles; iocg->delay = 0; /* kick_waitq will recalc */ iocg_kick_waitq(iocg, true, now); + + TRACE_IOCG_PATH(iocg_forgive_debt, iocg, now, usage_pct, + old_debt, iocg->abs_vdebt, + old_delay, iocg->delay); + spin_unlock(&iocg->waitq.lock); } } diff --git a/include/trace/events/iocost.h b/include/trace/events/iocost.h index b350860d2e71..0b6869980ba2 100644 --- a/include/trace/events/iocost.h +++ b/include/trace/events/iocost.h @@ -164,6 +164,47 @@ TRACE_EVENT(iocost_ioc_vrate_adj, ) ); +TRACE_EVENT(iocost_iocg_forgive_debt, + + TP_PROTO(struct ioc_gq *iocg, const char *path, struct ioc_now *now, + u32 usage_pct, u64 old_debt, u64 new_debt, + u64 old_delay, u64 new_delay), + + TP_ARGS(iocg, path, now, usage_pct, + old_debt, new_debt, old_delay, new_delay), + + TP_STRUCT__entry ( + __string(devname, ioc_name(iocg->ioc)) + __string(cgroup, path) + __field(u64, now) + __field(u64, vnow) + __field(u32, usage_pct) + __field(u64, old_debt) + __field(u64, new_debt) + __field(u64, old_delay) + __field(u64, new_delay) + ), + + TP_fast_assign( + __assign_str(devname, ioc_name(iocg->ioc)); + __assign_str(cgroup, path); + __entry->now = now->now; + __entry->vnow = now->vnow; + __entry->usage_pct = usage_pct; + __entry->old_debt = old_debt; + __entry->new_debt = new_debt; + __entry->old_delay = old_delay; + __entry->new_delay = new_delay; + ), + + TP_printk("[%s:%s] now=%llu:%llu usage=%u debt=%llu->%llu delay=%llu->%llu", + __get_str(devname), __get_str(cgroup), + __entry->now, __entry->vnow, __entry->usage_pct, + __entry->old_debt, __entry->new_debt, + __entry->old_delay, __entry->new_delay + ) +); + #endif /* _TRACE_BLK_IOCOST_H */ /* This part must be outside protection */ From bec02dbbafad534674309f8b948094900f456797 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 18 Sep 2020 14:41:27 -0400 Subject: [PATCH 157/191] iocost: consider iocgs with active delays for debt forgiveness An iocg may have 0 debt but non-zero delay. The current debt forgiveness logic doesn't act on such iocgs. This can lead to unexpected behaviors - an iocg with a little bit of debt will have its delay canceled through debt forgiveness but one w/o any debt but active delay will have to wait out until its delay decays out. This patch updates the debt handling logic so that it treats delays the same as debts. If either debt or delay is active, debt forgiveness logic kicks in and acts on both the same way. Also, avoid turning the debt and delay directly to zero as that can confuse state transitions. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- block/blk-iocost.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index 328ae805e85f..b82649c1440b 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -2048,7 +2048,7 @@ static void ioc_forgive_debts(struct ioc *ioc, u64 usage_us_sum, int nr_debtors, list_for_each_entry(iocg, &ioc->active_iocgs, active_list) { u64 __maybe_unused old_debt, __maybe_unused old_delay; - if (!iocg->abs_vdebt) + if (!iocg->abs_vdebt && !iocg->delay) continue; spin_lock(&iocg->waitq.lock); @@ -2056,8 +2056,11 @@ static void ioc_forgive_debts(struct ioc *ioc, u64 usage_us_sum, int nr_debtors, old_debt = iocg->abs_vdebt; old_delay = iocg->delay; - iocg->abs_vdebt >>= nr_cycles; - iocg->delay = 0; /* kick_waitq will recalc */ + if (iocg->abs_vdebt) + iocg->abs_vdebt = iocg->abs_vdebt >> nr_cycles ?: 1; + if (iocg->delay) + iocg->delay = iocg->delay >> nr_cycles ?: 1; + iocg_kick_waitq(iocg, true, now); TRACE_IOCG_PATH(iocg_forgive_debt, iocg, now, usage_pct, @@ -2129,7 +2132,7 @@ static void ioc_timer_fn(struct timer_list *timer) iocg->delay) { /* might be oversleeping vtime / hweight changes, kick */ iocg_kick_waitq(iocg, true, &now); - if (iocg->abs_vdebt) + if (iocg->abs_vdebt || iocg->delay) nr_debtors++; } else if (iocg_is_idle(iocg)) { /* no waiter and idle, deactivate */ From 8229cca8c3ea70bcb3b73aa105ae1d00aafbd3c8 Mon Sep 17 00:00:00 2001 From: Xianting Tian Date: Sat, 26 Sep 2020 10:39:47 +0800 Subject: [PATCH 158/191] blk-mq: add cond_resched() in __blk_mq_alloc_rq_maps() We found blk_mq_alloc_rq_maps() takes more time in kernel space when testing nvme device hot-plugging. The test and anlysis as below. Debug code, 1, blk_mq_alloc_rq_maps(): u64 start, end; depth = set->queue_depth; start = ktime_get_ns(); pr_err("[%d:%s switch:%ld,%ld] queue depth %d, nr_hw_queues %d\n", current->pid, current->comm, current->nvcsw, current->nivcsw, set->queue_depth, set->nr_hw_queues); do { err = __blk_mq_alloc_rq_maps(set); if (!err) break; set->queue_depth >>= 1; if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) { err = -ENOMEM; break; } } while (set->queue_depth); end = ktime_get_ns(); pr_err("[%d:%s switch:%ld,%ld] all hw queues init cost time %lld ns\n", current->pid, current->comm, current->nvcsw, current->nivcsw, end - start); 2, __blk_mq_alloc_rq_maps(): u64 start, end; for (i = 0; i < set->nr_hw_queues; i++) { start = ktime_get_ns(); if (!__blk_mq_alloc_rq_map(set, i)) goto out_unwind; end = ktime_get_ns(); pr_err("hw queue %d init cost time %lld ns\n", i, end - start); } Test nvme hot-plugging with above debug code, we found it totally cost more than 3ms in kernel space without being scheduled out when alloc rqs for all 16 hw queues with depth 1023, each hw queue cost about 140-250us. The cost time will be increased with hw queue number and queue depth increasing. And in an extreme case, if __blk_mq_alloc_rq_maps() returns -ENOMEM, it will try "queue_depth >>= 1", more time will be consumed. [ 428.428771] nvme nvme0: pci function 10000:01:00.0 [ 428.428798] nvme 10000:01:00.0: enabling device (0000 -> 0002) [ 428.428806] pcieport 10000:00:00.0: can't derive routing for PCI INT A [ 428.428809] nvme 10000:01:00.0: PCI INT A: no GSI [ 432.593374] [4688:kworker/u33:8 switch:663,2] queue depth 30, nr_hw_queues 1 [ 432.593404] hw queue 0 init cost time 22883 ns [ 432.593408] [4688:kworker/u33:8 switch:663,2] all hw queues init cost time 35960 ns [ 432.595953] nvme nvme0: 16/0/0 default/read/poll queues [ 432.595958] [4688:kworker/u33:8 switch:700,2] queue depth 1023, nr_hw_queues 16 [ 432.596203] hw queue 0 init cost time 242630 ns [ 432.596441] hw queue 1 init cost time 235913 ns [ 432.596659] hw queue 2 init cost time 216461 ns [ 432.596877] hw queue 3 init cost time 215851 ns [ 432.597107] hw queue 4 init cost time 228406 ns [ 432.597336] hw queue 5 init cost time 227298 ns [ 432.597564] hw queue 6 init cost time 224633 ns [ 432.597785] hw queue 7 init cost time 219954 ns [ 432.597937] hw queue 8 init cost time 150930 ns [ 432.598082] hw queue 9 init cost time 143496 ns [ 432.598231] hw queue 10 init cost time 147261 ns [ 432.598397] hw queue 11 init cost time 164522 ns [ 432.598542] hw queue 12 init cost time 143401 ns [ 432.598692] hw queue 13 init cost time 148934 ns [ 432.598841] hw queue 14 init cost time 147194 ns [ 432.598991] hw queue 15 init cost time 148942 ns [ 432.598993] [4688:kworker/u33:8 switch:700,2] all hw queues init cost time 3035099 ns [ 432.602611] nvme0n1: p1 So use this patch to trigger schedule between each hw queue init, to avoid other threads getting stuck. It is not in atomic context when executing __blk_mq_alloc_rq_maps(), so it is safe to call cond_resched(). Signed-off-by: Xianting Tian Reviewed-by: Bart Van Assche Signed-off-by: Jens Axboe --- block/blk-mq.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index e04b759add75..176698b2285b 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -3261,9 +3261,11 @@ static int __blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set) { int i; - for (i = 0; i < set->nr_hw_queues; i++) + for (i = 0; i < set->nr_hw_queues; i++) { if (!__blk_mq_alloc_map_and_request(set, i)) goto out_unwind; + cond_resched(); + } return 0; From 76cffccd606acffde1b91e8b029b39b5fd1a3117 Mon Sep 17 00:00:00 2001 From: yangerkun Date: Sat, 19 Sep 2020 11:54:25 +0800 Subject: [PATCH 159/191] block-mq: fix comments in blk_mq_queue_tag_busy_iter 'f5bbbbe4d635 ("blk-mq: sync the update nr_hw_queues with blk_mq_queue_tag_busy_iter")' introduce a bug what we may sleep between rcu lock. Then '530ca2c9bd69 ("blk-mq: Allow blocking queue tag iter callbacks")' fix it by get request_queue's ref. And 'a9a808084d6a ("block: Remove the synchronize_rcu() call from __blk_mq_update_nr_hw_queues()")' remove the synchronize_rcu in __blk_mq_update_nr_hw_queues. We need update the confused comments in blk_mq_queue_tag_busy_iter. Signed-off-by: yangerkun Signed-off-by: Jens Axboe --- block/blk-mq-tag.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index aacf10decdbd..9c92053e704d 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -416,9 +416,7 @@ void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn, /* * __blk_mq_update_nr_hw_queues() updates nr_hw_queues and queue_hw_ctx * while the queue is frozen. So we can use q_usage_counter to avoid - * racing with it. __blk_mq_update_nr_hw_queues() uses - * synchronize_rcu() to ensure this function left the critical section - * below. + * racing with it. */ if (!percpu_ref_tryget(&q->q_usage_counter)) return; From 155bd9d1abd60497f3e84ef3251b40209f7f7900 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 25 Sep 2020 18:06:17 +0200 Subject: [PATCH 160/191] drbd: remove ->this_bdev DRBD keeps a block device open just to get and set the capacity from it. Switch to primarily using the disk capacity as intended by the block layer, and sync it to the bdev using revalidate_disk_size. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- drivers/block/drbd/drbd_actlog.c | 2 +- drivers/block/drbd/drbd_int.h | 1 - drivers/block/drbd/drbd_main.c | 29 ++++++++++++----------------- drivers/block/drbd/drbd_nl.c | 10 ++++------ drivers/block/drbd/drbd_receiver.c | 10 +++++----- drivers/block/drbd/drbd_req.c | 2 +- drivers/block/drbd/drbd_worker.c | 4 ++-- 7 files changed, 25 insertions(+), 33 deletions(-) diff --git a/drivers/block/drbd/drbd_actlog.c b/drivers/block/drbd/drbd_actlog.c index b41897dceb2b..7227fc7ab8ed 100644 --- a/drivers/block/drbd/drbd_actlog.c +++ b/drivers/block/drbd/drbd_actlog.c @@ -865,7 +865,7 @@ int __drbd_change_sync(struct drbd_device *device, sector_t sector, int size, if (!get_ldev(device)) return 0; /* no disk, no metadata, no bitmap to manipulate bits in */ - nr_sectors = drbd_get_capacity(device->this_bdev); + nr_sectors = get_capacity(device->vdisk); esector = sector + (size >> 9) - 1; if (!expect(sector < nr_sectors)) diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h index 740e93bad21f..8f879e5c2f67 100644 --- a/drivers/block/drbd/drbd_int.h +++ b/drivers/block/drbd/drbd_int.h @@ -841,7 +841,6 @@ struct drbd_device { sector_t p_size; /* partner's disk size */ struct request_queue *rq_queue; - struct block_device *this_bdev; struct gendisk *vdisk; unsigned long last_reattach_jif; diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c index bd8b129196d4..85c865ab485f 100644 --- a/drivers/block/drbd/drbd_main.c +++ b/drivers/block/drbd/drbd_main.c @@ -984,7 +984,10 @@ int drbd_send_sizes(struct drbd_peer_device *peer_device, int trigger_reply, enu p->d_size = cpu_to_be64(d_size); p->u_size = cpu_to_be64(u_size); - p->c_size = cpu_to_be64(trigger_reply ? 0 : drbd_get_capacity(device->this_bdev)); + if (trigger_reply) + p->c_size = 0; + else + p->c_size = cpu_to_be64(get_capacity(device->vdisk)); p->max_bio_size = cpu_to_be32(max_bio_size); p->queue_order_type = cpu_to_be16(q_order_type); p->dds_flags = cpu_to_be16(flags); @@ -2029,17 +2032,13 @@ void drbd_init_set_defaults(struct drbd_device *device) device->local_max_bio_size = DRBD_MAX_BIO_SIZE_SAFE; } -static void _drbd_set_my_capacity(struct drbd_device *device, sector_t size) -{ - /* set_capacity(device->this_bdev->bd_disk, size); */ - set_capacity(device->vdisk, size); - device->this_bdev->bd_inode->i_size = (loff_t)size << 9; -} - void drbd_set_my_capacity(struct drbd_device *device, sector_t size) { char ppb[10]; - _drbd_set_my_capacity(device, size); + + set_capacity(device->vdisk, size); + revalidate_disk_size(device->vdisk, false); + drbd_info(device, "size = %s (%llu KB)\n", ppsize(ppb, size>>1), (unsigned long long)size>>1); } @@ -2069,7 +2068,8 @@ void drbd_device_cleanup(struct drbd_device *device) } D_ASSERT(device, first_peer_device(device)->connection->net_conf == NULL); - _drbd_set_my_capacity(device, 0); + set_capacity(device->vdisk, 0); + revalidate_disk_size(device->vdisk, false); if (device->bitmap) { /* maybe never allocated. */ drbd_bm_resize(device, 0, 1); @@ -2236,9 +2236,6 @@ void drbd_destroy_device(struct kref *kref) /* cleanup stuff that may have been allocated during * device (re-)configuration or state changes */ - if (device->this_bdev) - bdput(device->this_bdev); - drbd_backing_dev_free(device, device->ldev); device->ldev = NULL; @@ -2765,8 +2762,6 @@ enum drbd_ret_code drbd_create_device(struct drbd_config_context *adm_ctx, unsig sprintf(disk->disk_name, "drbd%d", minor); disk->private_data = device; - device->this_bdev = bdget(MKDEV(DRBD_MAJOR, minor)); - blk_queue_write_cache(q, true, true); /* Setting the max_hw_sectors to an odd value of 8kibyte here This triggers a max_bio_size message upon first attach or connect */ @@ -3042,7 +3037,7 @@ void drbd_md_write(struct drbd_device *device, void *b) memset(buffer, 0, sizeof(*buffer)); - buffer->la_size_sect = cpu_to_be64(drbd_get_capacity(device->this_bdev)); + buffer->la_size_sect = cpu_to_be64(get_capacity(device->vdisk)); for (i = UI_CURRENT; i < UI_SIZE; i++) buffer->uuid[i] = cpu_to_be64(device->ldev->md.uuid[i]); buffer->flags = cpu_to_be32(device->ldev->md.flags); @@ -3100,7 +3095,7 @@ void drbd_md_sync(struct drbd_device *device) /* Update device->ldev->md.la_size_sect, * since we updated it on metadata. */ - device->ldev->md.la_size_sect = drbd_get_capacity(device->this_bdev); + device->ldev->md.la_size_sect = get_capacity(device->vdisk); drbd_md_put_buffer(device); out: diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c index 54a4930c04fe..bf7de4c7b96c 100644 --- a/drivers/block/drbd/drbd_nl.c +++ b/drivers/block/drbd/drbd_nl.c @@ -996,7 +996,7 @@ drbd_determine_dev_size(struct drbd_device *device, enum dds_flags flags, struct goto err_out; } - if (drbd_get_capacity(device->this_bdev) != size || + if (get_capacity(device->vdisk) != size || drbd_bm_capacity(device) != size) { int err; err = drbd_bm_resize(device, size, !(flags & DDSF_NO_RESYNC)); @@ -1933,8 +1933,7 @@ int drbd_adm_attach(struct sk_buff *skb, struct genl_info *info) /* Make sure the new disk is big enough * (we may currently be R_PRIMARY with no local disk...) */ - if (drbd_get_max_capacity(nbc) < - drbd_get_capacity(device->this_bdev)) { + if (drbd_get_max_capacity(nbc) < get_capacity(device->vdisk)) { retcode = ERR_DISK_TOO_SMALL; goto fail; } @@ -3377,7 +3376,7 @@ static void device_to_statistics(struct device_statistics *s, s->dev_disk_flags = md->flags; put_ldev(device); } - s->dev_size = drbd_get_capacity(device->this_bdev); + s->dev_size = get_capacity(device->vdisk); s->dev_read = device->read_cnt; s->dev_write = device->writ_cnt; s->dev_al_writes = device->al_writ_cnt; @@ -3817,8 +3816,7 @@ static int nla_put_status_info(struct sk_buff *skb, struct drbd_device *device, if (nla_put_u32(skb, T_sib_reason, sib ? sib->sib_reason : SIB_GET_STATUS_REPLY) || nla_put_u32(skb, T_current_state, device->state.i) || nla_put_u64_0pad(skb, T_ed_uuid, device->ed_uuid) || - nla_put_u64_0pad(skb, T_capacity, - drbd_get_capacity(device->this_bdev)) || + nla_put_u64_0pad(skb, T_capacity, get_capacity(device->vdisk)) || nla_put_u64_0pad(skb, T_send_cnt, device->send_cnt) || nla_put_u64_0pad(skb, T_recv_cnt, device->recv_cnt) || nla_put_u64_0pad(skb, T_read_cnt, device->read_cnt) || diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c index 2d16fb090599..dc333dbe5232 100644 --- a/drivers/block/drbd/drbd_receiver.c +++ b/drivers/block/drbd/drbd_receiver.c @@ -1860,7 +1860,7 @@ read_in_block(struct drbd_peer_device *peer_device, u64 id, sector_t sector, struct packet_info *pi) __must_hold(local) { struct drbd_device *device = peer_device->device; - const sector_t capacity = drbd_get_capacity(device->this_bdev); + const sector_t capacity = get_capacity(device->vdisk); struct drbd_peer_request *peer_req; struct page *page; int digest_size, err; @@ -2849,7 +2849,7 @@ static int receive_DataRequest(struct drbd_connection *connection, struct packet if (!peer_device) return -EIO; device = peer_device->device; - capacity = drbd_get_capacity(device->this_bdev); + capacity = get_capacity(device->vdisk); sector = be64_to_cpu(p->sector); size = be32_to_cpu(p->blksize); @@ -4117,7 +4117,7 @@ static int receive_sizes(struct drbd_connection *connection, struct packet_info if (!peer_device) return config_unknown_volume(connection, pi); device = peer_device->device; - cur_size = drbd_get_capacity(device->this_bdev); + cur_size = get_capacity(device->vdisk); p_size = be64_to_cpu(p->d_size); p_usize = be64_to_cpu(p->u_size); @@ -4252,8 +4252,8 @@ static int receive_sizes(struct drbd_connection *connection, struct packet_info } if (device->state.conn > C_WF_REPORT_PARAMS) { - if (be64_to_cpu(p->c_size) != - drbd_get_capacity(device->this_bdev) || ldsc) { + if (be64_to_cpu(p->c_size) != get_capacity(device->vdisk) || + ldsc) { /* we have different sizes, probably peer * needs to know my new size... */ drbd_send_sizes(peer_device, 0, ddsf); diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c index 5c975af9c15f..330f851cb8f0 100644 --- a/drivers/block/drbd/drbd_req.c +++ b/drivers/block/drbd/drbd_req.c @@ -888,7 +888,7 @@ static bool drbd_may_do_local_read(struct drbd_device *device, sector_t sector, if (device->state.disk != D_INCONSISTENT) return false; esector = sector + (size >> 9) - 1; - nr_sectors = drbd_get_capacity(device->this_bdev); + nr_sectors = get_capacity(device->vdisk); D_ASSERT(device, sector < nr_sectors); D_ASSERT(device, esector < nr_sectors); diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c index 9107b109ba7b..ba56f3f05312 100644 --- a/drivers/block/drbd/drbd_worker.c +++ b/drivers/block/drbd/drbd_worker.c @@ -591,7 +591,7 @@ static int make_resync_request(struct drbd_device *const device, int cancel) struct drbd_connection *const connection = peer_device ? peer_device->connection : NULL; unsigned long bit; sector_t sector; - const sector_t capacity = drbd_get_capacity(device->this_bdev); + const sector_t capacity = get_capacity(device->vdisk); int max_bio_size; int number, rollback_i, size; int align, requeue = 0; @@ -769,7 +769,7 @@ static int make_ov_request(struct drbd_device *device, int cancel) { int number, i, size; sector_t sector; - const sector_t capacity = drbd_get_capacity(device->this_bdev); + const sector_t capacity = get_capacity(device->vdisk); bool stop_sector_reached = false; if (unlikely(cancel)) From 10ed16662da9e28a33b6c991c36c6b323b03dd5b Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 25 Sep 2020 18:06:18 +0200 Subject: [PATCH 161/191] block: add a bdget_part helper All remaining callers of bdget() outside of fs/block_dev.c want to get a reference to the struct block_device for a given struct hd_struct. Add a helper just for that and then mark bdget static. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/genhd.c | 2 +- block/partitions/core.c | 2 +- fs/block_dev.c | 9 ++++++--- include/linux/blkdev.h | 2 +- kernel/trace/blktrace.c | 9 ++------- 5 files changed, 11 insertions(+), 13 deletions(-) diff --git a/block/genhd.c b/block/genhd.c index e5f17f022ec7..0a273211fec2 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -1048,7 +1048,7 @@ struct block_device *bdget_disk(struct gendisk *disk, int partno) part = disk_get_part(disk, partno); if (part) - bdev = bdget(part_devt(part)); + bdev = bdget_part(part); disk_put_part(part); return bdev; diff --git a/block/partitions/core.c b/block/partitions/core.c index dd6811422a87..5309e0f44ba3 100644 --- a/block/partitions/core.c +++ b/block/partitions/core.c @@ -580,7 +580,7 @@ int bdev_resize_partition(struct block_device *bdev, int partno, return -ENXIO; ret = -ENOMEM; - bdevp = bdget(part_devt(part)); + bdevp = bdget_part(part); if (!bdevp) goto out_put_part; diff --git a/fs/block_dev.c b/fs/block_dev.c index 6b9d19ffa5af..9e84b1928b94 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -891,7 +891,7 @@ static int bdev_set(struct inode *inode, void *data) return 0; } -struct block_device *bdget(dev_t dev) +static struct block_device *bdget(dev_t dev) { struct block_device *bdev; struct inode *inode; @@ -920,8 +920,6 @@ struct block_device *bdget(dev_t dev) return bdev; } -EXPORT_SYMBOL(bdget); - /** * bdgrab -- Grab a reference to an already referenced block device * @bdev: Block device to grab a reference to. @@ -933,6 +931,11 @@ struct block_device *bdgrab(struct block_device *bdev) } EXPORT_SYMBOL(bdgrab); +struct block_device *bdget_part(struct hd_struct *part) +{ + return bdget(part_devt(part)); +} + long nr_blockdev_pages(void) { struct inode *inode; diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index d5a3e1a4c2f7..cf80e61b4c5e 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -2003,7 +2003,7 @@ void bd_abort_claiming(struct block_device *bdev, struct block_device *whole, void blkdev_put(struct block_device *bdev, fmode_t mode); struct block_device *I_BDEV(struct inode *inode); -struct block_device *bdget(dev_t); +struct block_device *bdget_part(struct hd_struct *part); struct block_device *bdgrab(struct block_device *bdev); void bdput(struct block_device *); diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index ec874ea04092..f1022945e346 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -1827,13 +1827,11 @@ static ssize_t sysfs_blk_trace_attr_show(struct device *dev, struct device_attribute *attr, char *buf) { - struct hd_struct *p = dev_to_part(dev); + struct block_device *bdev = bdget_part(dev_to_part(dev)); struct request_queue *q; - struct block_device *bdev; struct blk_trace *bt; ssize_t ret = -ENXIO; - bdev = bdget(part_devt(p)); if (bdev == NULL) goto out; @@ -1875,7 +1873,6 @@ static ssize_t sysfs_blk_trace_attr_store(struct device *dev, { struct block_device *bdev; struct request_queue *q; - struct hd_struct *p; struct blk_trace *bt; u64 value; ssize_t ret = -EINVAL; @@ -1895,9 +1892,7 @@ static ssize_t sysfs_blk_trace_attr_store(struct device *dev, goto out; ret = -ENXIO; - - p = dev_to_part(dev); - bdev = bdget(part_devt(p)); + bdev = bdget_part(dev_to_part(dev)); if (bdev == NULL) goto out; From 07560151db960d26b425410d6fd778e6757a5da2 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Tue, 15 Sep 2020 20:53:13 -0700 Subject: [PATCH 162/191] block: make bio_crypt_clone() able to fail bio_crypt_clone() assumes its gfp_mask argument always includes __GFP_DIRECT_RECLAIM, so that the mempool_alloc() will always succeed. However, bio_crypt_clone() might be called with GFP_ATOMIC via setup_clone() in drivers/md/dm-rq.c, or with GFP_NOWAIT via kcryptd_io_read() in drivers/md/dm-crypt.c. Neither case is currently reachable with a bio that actually has an encryption context. However, it's fragile to rely on this. Just make bio_crypt_clone() able to fail, analogous to bio_integrity_clone(). Reported-by: Miaohe Lin Signed-off-by: Eric Biggers Reviewed-by: Mike Snitzer Reviewed-by: Satya Tangirala Cc: Satya Tangirala Signed-off-by: Jens Axboe --- block/bio.c | 20 +++++++++----------- block/blk-crypto.c | 5 ++++- block/bounce.c | 19 +++++++++---------- drivers/md/dm.c | 7 ++++--- include/linux/blk-crypto.h | 20 ++++++++++++++++---- 5 files changed, 42 insertions(+), 29 deletions(-) diff --git a/block/bio.c b/block/bio.c index a9931f23d933..b42e046b12eb 100644 --- a/block/bio.c +++ b/block/bio.c @@ -713,20 +713,18 @@ struct bio *bio_clone_fast(struct bio *bio, gfp_t gfp_mask, struct bio_set *bs) __bio_clone_fast(b, bio); - bio_crypt_clone(b, bio, gfp_mask); + if (bio_crypt_clone(b, bio, gfp_mask) < 0) + goto err_put; - if (bio_integrity(bio)) { - int ret; - - ret = bio_integrity_clone(b, bio, gfp_mask); - - if (ret < 0) { - bio_put(b); - return NULL; - } - } + if (bio_integrity(bio) && + bio_integrity_clone(b, bio, gfp_mask) < 0) + goto err_put; return b; + +err_put: + bio_put(b); + return NULL; } EXPORT_SYMBOL(bio_clone_fast); diff --git a/block/blk-crypto.c b/block/blk-crypto.c index 2d5e60023b08..a3f27a19067c 100644 --- a/block/blk-crypto.c +++ b/block/blk-crypto.c @@ -95,10 +95,13 @@ void __bio_crypt_free_ctx(struct bio *bio) bio->bi_crypt_context = NULL; } -void __bio_crypt_clone(struct bio *dst, struct bio *src, gfp_t gfp_mask) +int __bio_crypt_clone(struct bio *dst, struct bio *src, gfp_t gfp_mask) { dst->bi_crypt_context = mempool_alloc(bio_crypt_ctx_pool, gfp_mask); + if (!dst->bi_crypt_context) + return -ENOMEM; *dst->bi_crypt_context = *src->bi_crypt_context; + return 0; } EXPORT_SYMBOL_GPL(__bio_crypt_clone); diff --git a/block/bounce.c b/block/bounce.c index 431be88a0240..162a6eee8999 100644 --- a/block/bounce.c +++ b/block/bounce.c @@ -267,22 +267,21 @@ static struct bio *bounce_clone_bio(struct bio *bio_src, gfp_t gfp_mask, break; } - bio_crypt_clone(bio, bio_src, gfp_mask); + if (bio_crypt_clone(bio, bio_src, gfp_mask) < 0) + goto err_put; - if (bio_integrity(bio_src)) { - int ret; - - ret = bio_integrity_clone(bio, bio_src, gfp_mask); - if (ret < 0) { - bio_put(bio); - return NULL; - } - } + if (bio_integrity(bio_src) && + bio_integrity_clone(bio, bio_src, gfp_mask) < 0) + goto err_put; bio_clone_blkg_association(bio, bio_src); blkcg_bio_issue_init(bio); return bio; + +err_put: + bio_put(bio); + return NULL; } static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig, diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 59b0687f9235..e959cd74cd4b 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1326,14 +1326,15 @@ static int clone_bio(struct dm_target_io *tio, struct bio *bio, sector_t sector, unsigned len) { struct bio *clone = &tio->clone; + int r; __bio_clone_fast(clone, bio); - bio_crypt_clone(clone, bio, GFP_NOIO); + r = bio_crypt_clone(clone, bio, GFP_NOIO); + if (r < 0) + return r; if (bio_integrity(bio)) { - int r; - if (unlikely(!dm_target_has_integrity(tio->ti->type) && !dm_target_passes_integrity(tio->ti->type))) { DMWARN("%s: the target %s doesn't support integrity data.", diff --git a/include/linux/blk-crypto.h b/include/linux/blk-crypto.h index e82342907f2b..69b24fe92cbf 100644 --- a/include/linux/blk-crypto.h +++ b/include/linux/blk-crypto.h @@ -112,12 +112,24 @@ static inline bool bio_has_crypt_ctx(struct bio *bio) #endif /* CONFIG_BLK_INLINE_ENCRYPTION */ -void __bio_crypt_clone(struct bio *dst, struct bio *src, gfp_t gfp_mask); -static inline void bio_crypt_clone(struct bio *dst, struct bio *src, - gfp_t gfp_mask) +int __bio_crypt_clone(struct bio *dst, struct bio *src, gfp_t gfp_mask); +/** + * bio_crypt_clone - clone bio encryption context + * @dst: destination bio + * @src: source bio + * @gfp_mask: memory allocation flags + * + * If @src has an encryption context, clone it to @dst. + * + * Return: 0 on success, -ENOMEM if out of memory. -ENOMEM is only possible if + * @gfp_mask doesn't include %__GFP_DIRECT_RECLAIM. + */ +static inline int bio_crypt_clone(struct bio *dst, struct bio *src, + gfp_t gfp_mask) { if (bio_has_crypt_ctx(src)) - __bio_crypt_clone(dst, src, gfp_mask); + return __bio_crypt_clone(dst, src, gfp_mask); + return 0; } #endif /* __LINUX_BLK_CRYPTO_H */ From 93f221ae08381e994ac9f9ff6aa743e612e49718 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Tue, 15 Sep 2020 20:53:14 -0700 Subject: [PATCH 163/191] block: make blk_crypto_rq_bio_prep() able to fail blk_crypto_rq_bio_prep() assumes its gfp_mask argument always includes __GFP_DIRECT_RECLAIM, so that the mempool_alloc() will always succeed. However, blk_crypto_rq_bio_prep() might be called with GFP_ATOMIC via setup_clone() in drivers/md/dm-rq.c. This case isn't currently reachable with a bio that actually has an encryption context. However, it's fragile to rely on this. Just make blk_crypto_rq_bio_prep() able to fail. Suggested-by: Satya Tangirala Signed-off-by: Eric Biggers Reviewed-by: Mike Snitzer Reviewed-by: Satya Tangirala Cc: Miaohe Lin Signed-off-by: Jens Axboe --- block/blk-core.c | 8 +++++--- block/blk-crypto-internal.h | 21 ++++++++++++++++----- block/blk-crypto.c | 18 +++++++----------- block/blk-mq.c | 7 ++++++- 4 files changed, 34 insertions(+), 20 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 4884f1e7451b..3b01e7f3c7a3 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1617,8 +1617,10 @@ int blk_rq_prep_clone(struct request *rq, struct request *rq_src, if (rq->bio) { rq->biotail->bi_next = bio; rq->biotail = bio; - } else + } else { rq->bio = rq->biotail = bio; + } + bio = NULL; } /* Copy attributes of the original request to the clone request. */ @@ -1631,8 +1633,8 @@ int blk_rq_prep_clone(struct request *rq, struct request *rq_src, rq->nr_phys_segments = rq_src->nr_phys_segments; rq->ioprio = rq_src->ioprio; - if (rq->bio) - blk_crypto_rq_bio_prep(rq, rq->bio, gfp_mask); + if (rq->bio && blk_crypto_rq_bio_prep(rq, rq->bio, gfp_mask) < 0) + goto free_and_out; return 0; diff --git a/block/blk-crypto-internal.h b/block/blk-crypto-internal.h index d2b0f565d83c..0d36aae538d7 100644 --- a/block/blk-crypto-internal.h +++ b/block/blk-crypto-internal.h @@ -142,13 +142,24 @@ static inline void blk_crypto_free_request(struct request *rq) __blk_crypto_free_request(rq); } -void __blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio, - gfp_t gfp_mask); -static inline void blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio, - gfp_t gfp_mask) +int __blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio, + gfp_t gfp_mask); +/** + * blk_crypto_rq_bio_prep - Prepare a request's crypt_ctx when its first bio + * is inserted + * @rq: The request to prepare + * @bio: The first bio being inserted into the request + * @gfp_mask: Memory allocation flags + * + * Return: 0 on success, -ENOMEM if out of memory. -ENOMEM is only possible if + * @gfp_mask doesn't include %__GFP_DIRECT_RECLAIM. + */ +static inline int blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio, + gfp_t gfp_mask) { if (bio_has_crypt_ctx(bio)) - __blk_crypto_rq_bio_prep(rq, bio, gfp_mask); + return __blk_crypto_rq_bio_prep(rq, bio, gfp_mask); + return 0; } /** diff --git a/block/blk-crypto.c b/block/blk-crypto.c index a3f27a19067c..bbe7974fd74f 100644 --- a/block/blk-crypto.c +++ b/block/blk-crypto.c @@ -283,20 +283,16 @@ bool __blk_crypto_bio_prep(struct bio **bio_ptr) return false; } -/** - * __blk_crypto_rq_bio_prep - Prepare a request's crypt_ctx when its first bio - * is inserted - * - * @rq: The request to prepare - * @bio: The first bio being inserted into the request - * @gfp_mask: gfp mask - */ -void __blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio, - gfp_t gfp_mask) +int __blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio, + gfp_t gfp_mask) { - if (!rq->crypt_ctx) + if (!rq->crypt_ctx) { rq->crypt_ctx = mempool_alloc(bio_crypt_ctx_pool, gfp_mask); + if (!rq->crypt_ctx) + return -ENOMEM; + } *rq->crypt_ctx = *bio->bi_crypt_context; + return 0; } /** diff --git a/block/blk-mq.c b/block/blk-mq.c index 176698b2285b..2e4b3cad2a61 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1940,13 +1940,18 @@ void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) static void blk_mq_bio_to_request(struct request *rq, struct bio *bio, unsigned int nr_segs) { + int err; + if (bio->bi_opf & REQ_RAHEAD) rq->cmd_flags |= REQ_FAILFAST_MASK; rq->__sector = bio->bi_iter.bi_sector; rq->write_hint = bio->bi_write_hint; blk_rq_bio_prep(rq, bio, nr_segs); - blk_crypto_rq_bio_prep(rq, bio, GFP_NOIO); + + /* This can't fail, since GFP_NOIO includes __GFP_DIRECT_RECLAIM. */ + err = blk_crypto_rq_bio_prep(rq, bio, GFP_NOIO); + WARN_ON_ONCE(err); blk_account_io_start(rq); } From cf785af19319f9fc0fc0c0604d259f1ef31b502f Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Tue, 15 Sep 2020 20:53:15 -0700 Subject: [PATCH 164/191] block: warn if !__GFP_DIRECT_RECLAIM in bio_crypt_set_ctx() bio_crypt_set_ctx() assumes its gfp_mask argument always includes __GFP_DIRECT_RECLAIM, so that the mempool_alloc() will always succeed. For now this assumption is still fine, since no callers violate it. Making bio_crypt_set_ctx() able to fail would add unneeded complexity. However, if a caller didn't use __GFP_DIRECT_RECLAIM, it would be very hard to notice the bug. Make it easier by adding a WARN_ON_ONCE(). Signed-off-by: Eric Biggers Reviewed-by: Satya Tangirala Cc: Miaohe Lin Cc: Satya Tangirala Signed-off-by: Jens Axboe --- block/blk-crypto.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/block/blk-crypto.c b/block/blk-crypto.c index bbe7974fd74f..5da43f0973b4 100644 --- a/block/blk-crypto.c +++ b/block/blk-crypto.c @@ -81,7 +81,15 @@ subsys_initcall(bio_crypt_ctx_init); void bio_crypt_set_ctx(struct bio *bio, const struct blk_crypto_key *key, const u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE], gfp_t gfp_mask) { - struct bio_crypt_ctx *bc = mempool_alloc(bio_crypt_ctx_pool, gfp_mask); + struct bio_crypt_ctx *bc; + + /* + * The caller must use a gfp_mask that contains __GFP_DIRECT_RECLAIM so + * that the mempool_alloc() can't fail. + */ + WARN_ON_ONCE(!(gfp_mask & __GFP_DIRECT_RECLAIM)); + + bc = mempool_alloc(bio_crypt_ctx_pool, gfp_mask); bc->bc_key = key; memcpy(bc->bc_dun, dun, sizeof(bc->bc_dun)); From 2b0d3d3e4fcfb19d10f9a82910b8f0f05c56ee3e Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Thu, 1 Oct 2020 23:48:41 +0800 Subject: [PATCH 165/191] percpu_ref: reduce memory footprint of percpu_ref in fast path 'struct percpu_ref' is often embedded into one user structure, and the instance is usually referenced in fast path, however actually only 'percpu_count_ptr' is needed in fast path. So move other fields into one new structure of 'percpu_ref_data', and allocate it dynamically via kzalloc(), then memory footprint of 'percpu_ref' in fast path is reduced a lot and becomes suitable to put into hot cacheline of user structure. Signed-off-by: Ming Lei Tested-by: Veronika Kabatova Reviewed-by: Christoph Hellwig Acked-by: Tejun Heo Cc: Sagi Grimberg Cc: Tejun Heo Cc: Christoph Hellwig Cc: Jens Axboe Cc: Bart Van Assche Signed-off-by: Jens Axboe --- drivers/infiniband/sw/rdmavt/mr.c | 2 +- include/linux/percpu-refcount.h | 52 ++++++------ lib/percpu-refcount.c | 131 ++++++++++++++++++++++-------- 3 files changed, 123 insertions(+), 62 deletions(-) diff --git a/drivers/infiniband/sw/rdmavt/mr.c b/drivers/infiniband/sw/rdmavt/mr.c index 2f7c25fea44a..8490fdb9c91e 100644 --- a/drivers/infiniband/sw/rdmavt/mr.c +++ b/drivers/infiniband/sw/rdmavt/mr.c @@ -499,7 +499,7 @@ static int rvt_check_refs(struct rvt_mregion *mr, const char *t) rvt_pr_err(rdi, "%s timeout mr %p pd %p lkey %x refcount %ld\n", t, mr, mr->pd, mr->lkey, - atomic_long_read(&mr->refcount.count)); + atomic_long_read(&mr->refcount.data->count)); rvt_get_mr(mr); return -EBUSY; } diff --git a/include/linux/percpu-refcount.h b/include/linux/percpu-refcount.h index 87d8a38bdea1..16c35a728b4c 100644 --- a/include/linux/percpu-refcount.h +++ b/include/linux/percpu-refcount.h @@ -92,18 +92,30 @@ enum { PERCPU_REF_ALLOW_REINIT = 1 << 2, }; -struct percpu_ref { +struct percpu_ref_data { atomic_long_t count; - /* - * The low bit of the pointer indicates whether the ref is in percpu - * mode; if set, then get/put will manipulate the atomic_t. - */ - unsigned long percpu_count_ptr; percpu_ref_func_t *release; percpu_ref_func_t *confirm_switch; bool force_atomic:1; bool allow_reinit:1; struct rcu_head rcu; + struct percpu_ref *ref; +}; + +struct percpu_ref { + /* + * The low bit of the pointer indicates whether the ref is in percpu + * mode; if set, then get/put will manipulate the atomic_t. + */ + unsigned long percpu_count_ptr; + + /* + * 'percpu_ref' is often embedded into user structure, and only + * 'percpu_count_ptr' is required in fast path, move other fields + * into 'percpu_ref_data', so we can reduce memory footprint in + * fast path. + */ + struct percpu_ref_data *data; }; int __must_check percpu_ref_init(struct percpu_ref *ref, @@ -118,6 +130,7 @@ void percpu_ref_kill_and_confirm(struct percpu_ref *ref, percpu_ref_func_t *confirm_kill); void percpu_ref_resurrect(struct percpu_ref *ref); void percpu_ref_reinit(struct percpu_ref *ref); +bool percpu_ref_is_zero(struct percpu_ref *ref); /** * percpu_ref_kill - drop the initial ref @@ -191,7 +204,7 @@ static inline void percpu_ref_get_many(struct percpu_ref *ref, unsigned long nr) if (__ref_is_percpu(ref, &percpu_count)) this_cpu_add(*percpu_count, nr); else - atomic_long_add(nr, &ref->count); + atomic_long_add(nr, &ref->data->count); rcu_read_unlock(); } @@ -231,7 +244,7 @@ static inline bool percpu_ref_tryget_many(struct percpu_ref *ref, this_cpu_add(*percpu_count, nr); ret = true; } else { - ret = atomic_long_add_unless(&ref->count, nr, 0); + ret = atomic_long_add_unless(&ref->data->count, nr, 0); } rcu_read_unlock(); @@ -279,7 +292,7 @@ static inline bool percpu_ref_tryget_live(struct percpu_ref *ref) this_cpu_inc(*percpu_count); ret = true; } else if (!(ref->percpu_count_ptr & __PERCPU_REF_DEAD)) { - ret = atomic_long_inc_not_zero(&ref->count); + ret = atomic_long_inc_not_zero(&ref->data->count); } rcu_read_unlock(); @@ -305,8 +318,8 @@ static inline void percpu_ref_put_many(struct percpu_ref *ref, unsigned long nr) if (__ref_is_percpu(ref, &percpu_count)) this_cpu_sub(*percpu_count, nr); - else if (unlikely(atomic_long_sub_and_test(nr, &ref->count))) - ref->release(ref); + else if (unlikely(atomic_long_sub_and_test(nr, &ref->data->count))) + ref->data->release(ref); rcu_read_unlock(); } @@ -339,21 +352,4 @@ static inline bool percpu_ref_is_dying(struct percpu_ref *ref) return ref->percpu_count_ptr & __PERCPU_REF_DEAD; } -/** - * percpu_ref_is_zero - test whether a percpu refcount reached zero - * @ref: percpu_ref to test - * - * Returns %true if @ref reached zero. - * - * This function is safe to call as long as @ref is between init and exit. - */ -static inline bool percpu_ref_is_zero(struct percpu_ref *ref) -{ - unsigned long __percpu *percpu_count; - - if (__ref_is_percpu(ref, &percpu_count)) - return false; - return !atomic_long_read(&ref->count); -} - #endif diff --git a/lib/percpu-refcount.c b/lib/percpu-refcount.c index 0ba686b8fe57..b6350d13538a 100644 --- a/lib/percpu-refcount.c +++ b/lib/percpu-refcount.c @@ -4,6 +4,7 @@ #include #include #include +#include #include /* @@ -64,18 +65,25 @@ int percpu_ref_init(struct percpu_ref *ref, percpu_ref_func_t *release, size_t align = max_t(size_t, 1 << __PERCPU_REF_FLAG_BITS, __alignof__(unsigned long)); unsigned long start_count = 0; + struct percpu_ref_data *data; ref->percpu_count_ptr = (unsigned long) __alloc_percpu_gfp(sizeof(unsigned long), align, gfp); if (!ref->percpu_count_ptr) return -ENOMEM; - ref->force_atomic = flags & PERCPU_REF_INIT_ATOMIC; - ref->allow_reinit = flags & PERCPU_REF_ALLOW_REINIT; + data = kzalloc(sizeof(*ref->data), gfp); + if (!data) { + free_percpu((void __percpu *)ref->percpu_count_ptr); + return -ENOMEM; + } + + data->force_atomic = flags & PERCPU_REF_INIT_ATOMIC; + data->allow_reinit = flags & PERCPU_REF_ALLOW_REINIT; if (flags & (PERCPU_REF_INIT_ATOMIC | PERCPU_REF_INIT_DEAD)) { ref->percpu_count_ptr |= __PERCPU_REF_ATOMIC; - ref->allow_reinit = true; + data->allow_reinit = true; } else { start_count += PERCPU_COUNT_BIAS; } @@ -85,14 +93,28 @@ int percpu_ref_init(struct percpu_ref *ref, percpu_ref_func_t *release, else start_count++; - atomic_long_set(&ref->count, start_count); + atomic_long_set(&data->count, start_count); - ref->release = release; - ref->confirm_switch = NULL; + data->release = release; + data->confirm_switch = NULL; + data->ref = ref; + ref->data = data; return 0; } EXPORT_SYMBOL_GPL(percpu_ref_init); +static void __percpu_ref_exit(struct percpu_ref *ref) +{ + unsigned long __percpu *percpu_count = percpu_count_ptr(ref); + + if (percpu_count) { + /* non-NULL confirm_switch indicates switching in progress */ + WARN_ON_ONCE(ref->data->confirm_switch); + free_percpu(percpu_count); + ref->percpu_count_ptr = __PERCPU_REF_ATOMIC_DEAD; + } +} + /** * percpu_ref_exit - undo percpu_ref_init() * @ref: percpu_ref to exit @@ -105,27 +127,36 @@ EXPORT_SYMBOL_GPL(percpu_ref_init); */ void percpu_ref_exit(struct percpu_ref *ref) { - unsigned long __percpu *percpu_count = percpu_count_ptr(ref); + struct percpu_ref_data *data = ref->data; + unsigned long flags; - if (percpu_count) { - /* non-NULL confirm_switch indicates switching in progress */ - WARN_ON_ONCE(ref->confirm_switch); - free_percpu(percpu_count); - ref->percpu_count_ptr = __PERCPU_REF_ATOMIC_DEAD; - } + __percpu_ref_exit(ref); + + if (!data) + return; + + spin_lock_irqsave(&percpu_ref_switch_lock, flags); + ref->percpu_count_ptr |= atomic_long_read(&ref->data->count) << + __PERCPU_REF_FLAG_BITS; + ref->data = NULL; + spin_unlock_irqrestore(&percpu_ref_switch_lock, flags); + + kfree(data); } EXPORT_SYMBOL_GPL(percpu_ref_exit); static void percpu_ref_call_confirm_rcu(struct rcu_head *rcu) { - struct percpu_ref *ref = container_of(rcu, struct percpu_ref, rcu); + struct percpu_ref_data *data = container_of(rcu, + struct percpu_ref_data, rcu); + struct percpu_ref *ref = data->ref; - ref->confirm_switch(ref); - ref->confirm_switch = NULL; + data->confirm_switch(ref); + data->confirm_switch = NULL; wake_up_all(&percpu_ref_switch_waitq); - if (!ref->allow_reinit) - percpu_ref_exit(ref); + if (!data->allow_reinit) + __percpu_ref_exit(ref); /* drop ref from percpu_ref_switch_to_atomic() */ percpu_ref_put(ref); @@ -133,7 +164,9 @@ static void percpu_ref_call_confirm_rcu(struct rcu_head *rcu) static void percpu_ref_switch_to_atomic_rcu(struct rcu_head *rcu) { - struct percpu_ref *ref = container_of(rcu, struct percpu_ref, rcu); + struct percpu_ref_data *data = container_of(rcu, + struct percpu_ref_data, rcu); + struct percpu_ref *ref = data->ref; unsigned long __percpu *percpu_count = percpu_count_ptr(ref); unsigned long count = 0; int cpu; @@ -142,7 +175,7 @@ static void percpu_ref_switch_to_atomic_rcu(struct rcu_head *rcu) count += *per_cpu_ptr(percpu_count, cpu); pr_debug("global %lu percpu %lu\n", - atomic_long_read(&ref->count), count); + atomic_long_read(&data->count), count); /* * It's crucial that we sum the percpu counters _before_ adding the sum @@ -156,11 +189,11 @@ static void percpu_ref_switch_to_atomic_rcu(struct rcu_head *rcu) * reaching 0 before we add the percpu counts. But doing it at the same * time is equivalent and saves us atomic operations: */ - atomic_long_add((long)count - PERCPU_COUNT_BIAS, &ref->count); + atomic_long_add((long)count - PERCPU_COUNT_BIAS, &data->count); - WARN_ONCE(atomic_long_read(&ref->count) <= 0, + WARN_ONCE(atomic_long_read(&data->count) <= 0, "percpu ref (%ps) <= 0 (%ld) after switching to atomic", - ref->release, atomic_long_read(&ref->count)); + data->release, atomic_long_read(&data->count)); /* @ref is viewed as dead on all CPUs, send out switch confirmation */ percpu_ref_call_confirm_rcu(rcu); @@ -186,10 +219,11 @@ static void __percpu_ref_switch_to_atomic(struct percpu_ref *ref, * Non-NULL ->confirm_switch is used to indicate that switching is * in progress. Use noop one if unspecified. */ - ref->confirm_switch = confirm_switch ?: percpu_ref_noop_confirm_switch; + ref->data->confirm_switch = confirm_switch ?: + percpu_ref_noop_confirm_switch; percpu_ref_get(ref); /* put after confirmation */ - call_rcu(&ref->rcu, percpu_ref_switch_to_atomic_rcu); + call_rcu(&ref->data->rcu, percpu_ref_switch_to_atomic_rcu); } static void __percpu_ref_switch_to_percpu(struct percpu_ref *ref) @@ -202,10 +236,10 @@ static void __percpu_ref_switch_to_percpu(struct percpu_ref *ref) if (!(ref->percpu_count_ptr & __PERCPU_REF_ATOMIC)) return; - if (WARN_ON_ONCE(!ref->allow_reinit)) + if (WARN_ON_ONCE(!ref->data->allow_reinit)) return; - atomic_long_add(PERCPU_COUNT_BIAS, &ref->count); + atomic_long_add(PERCPU_COUNT_BIAS, &ref->data->count); /* * Restore per-cpu operation. smp_store_release() is paired @@ -223,6 +257,8 @@ static void __percpu_ref_switch_to_percpu(struct percpu_ref *ref) static void __percpu_ref_switch_mode(struct percpu_ref *ref, percpu_ref_func_t *confirm_switch) { + struct percpu_ref_data *data = ref->data; + lockdep_assert_held(&percpu_ref_switch_lock); /* @@ -230,10 +266,10 @@ static void __percpu_ref_switch_mode(struct percpu_ref *ref, * its completion. If the caller ensures that ATOMIC switching * isn't in progress, this function can be called from any context. */ - wait_event_lock_irq(percpu_ref_switch_waitq, !ref->confirm_switch, + wait_event_lock_irq(percpu_ref_switch_waitq, !data->confirm_switch, percpu_ref_switch_lock); - if (ref->force_atomic || (ref->percpu_count_ptr & __PERCPU_REF_DEAD)) + if (data->force_atomic || (ref->percpu_count_ptr & __PERCPU_REF_DEAD)) __percpu_ref_switch_to_atomic(ref, confirm_switch); else __percpu_ref_switch_to_percpu(ref); @@ -266,7 +302,7 @@ void percpu_ref_switch_to_atomic(struct percpu_ref *ref, spin_lock_irqsave(&percpu_ref_switch_lock, flags); - ref->force_atomic = true; + ref->data->force_atomic = true; __percpu_ref_switch_mode(ref, confirm_switch); spin_unlock_irqrestore(&percpu_ref_switch_lock, flags); @@ -284,7 +320,7 @@ EXPORT_SYMBOL_GPL(percpu_ref_switch_to_atomic); void percpu_ref_switch_to_atomic_sync(struct percpu_ref *ref) { percpu_ref_switch_to_atomic(ref, NULL); - wait_event(percpu_ref_switch_waitq, !ref->confirm_switch); + wait_event(percpu_ref_switch_waitq, !ref->data->confirm_switch); } EXPORT_SYMBOL_GPL(percpu_ref_switch_to_atomic_sync); @@ -312,7 +348,7 @@ void percpu_ref_switch_to_percpu(struct percpu_ref *ref) spin_lock_irqsave(&percpu_ref_switch_lock, flags); - ref->force_atomic = false; + ref->data->force_atomic = false; __percpu_ref_switch_mode(ref, NULL); spin_unlock_irqrestore(&percpu_ref_switch_lock, flags); @@ -344,7 +380,8 @@ void percpu_ref_kill_and_confirm(struct percpu_ref *ref, spin_lock_irqsave(&percpu_ref_switch_lock, flags); WARN_ONCE(ref->percpu_count_ptr & __PERCPU_REF_DEAD, - "%s called more than once on %ps!", __func__, ref->release); + "%s called more than once on %ps!", __func__, + ref->data->release); ref->percpu_count_ptr |= __PERCPU_REF_DEAD; __percpu_ref_switch_mode(ref, confirm_kill); @@ -354,6 +391,34 @@ void percpu_ref_kill_and_confirm(struct percpu_ref *ref, } EXPORT_SYMBOL_GPL(percpu_ref_kill_and_confirm); +/** + * percpu_ref_is_zero - test whether a percpu refcount reached zero + * @ref: percpu_ref to test + * + * Returns %true if @ref reached zero. + * + * This function is safe to call as long as @ref is between init and exit. + */ +bool percpu_ref_is_zero(struct percpu_ref *ref) +{ + unsigned long __percpu *percpu_count; + unsigned long count, flags; + + if (__ref_is_percpu(ref, &percpu_count)) + return false; + + /* protect us from being destroyed */ + spin_lock_irqsave(&percpu_ref_switch_lock, flags); + if (ref->data) + count = atomic_long_read(&ref->data->count); + else + count = ref->percpu_count_ptr >> __PERCPU_REF_FLAG_BITS; + spin_unlock_irqrestore(&percpu_ref_switch_lock, flags); + + return count == 0; +} +EXPORT_SYMBOL_GPL(percpu_ref_is_zero); + /** * percpu_ref_reinit - re-initialize a percpu refcount * @ref: perpcu_ref to re-initialize From 0549e87c30ae0d43d7e10424f2222bcd8bbe986d Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Thu, 1 Oct 2020 23:48:42 +0800 Subject: [PATCH 166/191] block: move 'q_usage_counter' into front of 'request_queue' The field of 'q_usage_counter' is always fetched in fast path of every block driver, and move it into front of 'request_queue', so it can be fetched into 1st cacheline of 'request_queue' instance. Signed-off-by: Ming Lei Tested-by: Veronika Kabatova Reviewed-by: Christoph Hellwig Cc: Sagi Grimberg Cc: Tejun Heo Cc: Christoph Hellwig Cc: Jens Axboe Cc: Bart Van Assche Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index cf80e61b4c5e..5fc940423e5a 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -397,6 +397,8 @@ struct request_queue { struct request *last_merge; struct elevator_queue *elevator; + struct percpu_ref q_usage_counter; + struct blk_queue_stats *stats; struct rq_qos *rq_qos; @@ -569,7 +571,6 @@ struct request_queue { * percpu_ref_kill() and percpu_ref_reinit(). */ struct mutex mq_freeze_lock; - struct percpu_ref q_usage_counter; struct blk_mq_tag_set *tag_set; struct list_head tag_set_list; From 92cf2fd156b273879198bb1d7e58851f822c481f Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 6 Oct 2020 09:07:17 +0200 Subject: [PATCH 167/191] block: remove the unused blk_integrity_merge_rq export Also move the definition from the public blkdev.h to the private block/blk.h header. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/blk-integrity.c | 1 - block/blk.h | 8 ++++++++ include/linux/blkdev.h | 8 -------- 3 files changed, 8 insertions(+), 9 deletions(-) diff --git a/block/blk-integrity.c b/block/blk-integrity.c index 2b36a8f9b813..a262e069eb3f 100644 --- a/block/blk-integrity.c +++ b/block/blk-integrity.c @@ -183,7 +183,6 @@ bool blk_integrity_merge_rq(struct request_queue *q, struct request *req, return true; } -EXPORT_SYMBOL(blk_integrity_merge_rq); bool blk_integrity_merge_bio(struct request_queue *q, struct request *req, struct bio *bio) diff --git a/block/blk.h b/block/blk.h index c08762e10b04..ba4e8ac538cd 100644 --- a/block/blk.h +++ b/block/blk.h @@ -120,6 +120,9 @@ static inline bool bio_integrity_endio(struct bio *bio) return true; } +bool blk_integrity_merge_rq(struct request_queue *, struct request *, + struct request *); + static inline bool integrity_req_gap_back_merge(struct request *req, struct bio *next) { @@ -143,6 +146,11 @@ static inline bool integrity_req_gap_front_merge(struct request *req, void blk_integrity_add(struct gendisk *); void blk_integrity_del(struct gendisk *); #else /* CONFIG_BLK_DEV_INTEGRITY */ +static inline bool blk_integrity_merge_rq(struct request_queue *rq, + struct request *r1, struct request *r2) +{ + return true; +} static inline bool integrity_req_gap_back_merge(struct request *req, struct bio *next) { diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 5fc940423e5a..6a6d9ea7420a 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1664,8 +1664,6 @@ extern int blk_integrity_compare(struct gendisk *, struct gendisk *); extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *, struct scatterlist *); extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *); -extern bool blk_integrity_merge_rq(struct request_queue *, struct request *, - struct request *); extern bool blk_integrity_merge_bio(struct request_queue *, struct request *, struct bio *); @@ -1795,12 +1793,6 @@ static inline unsigned short queue_max_integrity_segments(const struct request_q { return 0; } -static inline bool blk_integrity_merge_rq(struct request_queue *rq, - struct request *r1, - struct request *r2) -{ - return true; -} static inline bool blk_integrity_merge_bio(struct request_queue *rq, struct request *r, struct bio *b) From d59da41998bc794441d7c039a059ed6eb0c2dc4d Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 6 Oct 2020 09:07:18 +0200 Subject: [PATCH 168/191] block: remove the unused blk_integrity_merge_bio export Also move the definition from the public blkdev.h to the private block/blk.h header. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/blk-integrity.c | 1 - block/blk.h | 7 +++++++ include/linux/blkdev.h | 8 -------- 3 files changed, 7 insertions(+), 9 deletions(-) diff --git a/block/blk-integrity.c b/block/blk-integrity.c index a262e069eb3f..410da060d1f5 100644 --- a/block/blk-integrity.c +++ b/block/blk-integrity.c @@ -211,7 +211,6 @@ bool blk_integrity_merge_bio(struct request_queue *q, struct request *req, return true; } -EXPORT_SYMBOL(blk_integrity_merge_bio); struct integrity_sysfs_entry { struct attribute attr; diff --git a/block/blk.h b/block/blk.h index ba4e8ac538cd..8fcb146d3003 100644 --- a/block/blk.h +++ b/block/blk.h @@ -122,6 +122,8 @@ static inline bool bio_integrity_endio(struct bio *bio) bool blk_integrity_merge_rq(struct request_queue *, struct request *, struct request *); +bool blk_integrity_merge_bio(struct request_queue *, struct request *, + struct bio *); static inline bool integrity_req_gap_back_merge(struct request *req, struct bio *next) @@ -151,6 +153,11 @@ static inline bool blk_integrity_merge_rq(struct request_queue *rq, { return true; } +static inline bool blk_integrity_merge_bio(struct request_queue *rq, + struct request *r, struct bio *b) +{ + return true; +} static inline bool integrity_req_gap_back_merge(struct request *req, struct bio *next) { diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 6a6d9ea7420a..cda786fa4341 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1664,8 +1664,6 @@ extern int blk_integrity_compare(struct gendisk *, struct gendisk *); extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *, struct scatterlist *); extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *); -extern bool blk_integrity_merge_bio(struct request_queue *, struct request *, - struct bio *); static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk) { @@ -1793,12 +1791,6 @@ static inline unsigned short queue_max_integrity_segments(const struct request_q { return 0; } -static inline bool blk_integrity_merge_bio(struct request_queue *rq, - struct request *r, - struct bio *b) -{ - return true; -} static inline unsigned int bio_integrity_intervals(struct blk_integrity *bi, unsigned int sectors) From eda5cc997abd21054085486c9dee3fee269f3592 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 6 Oct 2020 09:07:19 +0200 Subject: [PATCH 169/191] block: move blk_mq_sched_try_merge to blk-merge.c Move blk_mq_sched_try_merge to blk-merge.c, which allows to mark a lot of the merge infrastructure static there. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/blk-merge.c | 62 +++++++++++++++++++++++++++++++++++--------- block/blk-mq-sched.c | 32 ----------------------- block/blk.h | 19 -------------- 3 files changed, 50 insertions(+), 63 deletions(-) diff --git a/block/blk-merge.c b/block/blk-merge.c index 6ed715835d45..bcf5e4580603 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -580,7 +580,8 @@ int ll_back_merge_fn(struct request *req, struct bio *bio, unsigned int nr_segs) return ll_new_hw_segment(req, bio, nr_segs); } -int ll_front_merge_fn(struct request *req, struct bio *bio, unsigned int nr_segs) +static int ll_front_merge_fn(struct request *req, struct bio *bio, + unsigned int nr_segs) { if (req_gap_front_merge(req, bio)) return 0; @@ -810,7 +811,8 @@ static struct request *attempt_merge(struct request_queue *q, return next; } -struct request *attempt_back_merge(struct request_queue *q, struct request *rq) +static struct request *attempt_back_merge(struct request_queue *q, + struct request *rq) { struct request *next = elv_latter_request(q, rq); @@ -820,7 +822,8 @@ struct request *attempt_back_merge(struct request_queue *q, struct request *rq) return NULL; } -struct request *attempt_front_merge(struct request_queue *q, struct request *rq) +static struct request *attempt_front_merge(struct request_queue *q, + struct request *rq) { struct request *prev = elv_former_request(q, rq); @@ -907,9 +910,14 @@ static void blk_account_io_merge_bio(struct request *req) part_stat_unlock(); } -enum bio_merge_status bio_attempt_back_merge(struct request *req, - struct bio *bio, - unsigned int nr_segs) +enum bio_merge_status { + BIO_MERGE_OK, + BIO_MERGE_NONE, + BIO_MERGE_FAILED, +}; + +static enum bio_merge_status bio_attempt_back_merge(struct request *req, + struct bio *bio, unsigned int nr_segs) { const int ff = bio->bi_opf & REQ_FAILFAST_MASK; @@ -932,9 +940,8 @@ enum bio_merge_status bio_attempt_back_merge(struct request *req, return BIO_MERGE_OK; } -enum bio_merge_status bio_attempt_front_merge(struct request *req, - struct bio *bio, - unsigned int nr_segs) +static enum bio_merge_status bio_attempt_front_merge(struct request *req, + struct bio *bio, unsigned int nr_segs) { const int ff = bio->bi_opf & REQ_FAILFAST_MASK; @@ -959,9 +966,8 @@ enum bio_merge_status bio_attempt_front_merge(struct request *req, return BIO_MERGE_OK; } -enum bio_merge_status bio_attempt_discard_merge(struct request_queue *q, - struct request *req, - struct bio *bio) +static enum bio_merge_status bio_attempt_discard_merge(struct request_queue *q, + struct request *req, struct bio *bio) { unsigned short segments = blk_rq_nr_discard_segments(req); @@ -1096,3 +1102,35 @@ bool blk_bio_list_merge(struct request_queue *q, struct list_head *list, return false; } EXPORT_SYMBOL_GPL(blk_bio_list_merge); + +bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio, + unsigned int nr_segs, struct request **merged_request) +{ + struct request *rq; + + switch (elv_merge(q, &rq, bio)) { + case ELEVATOR_BACK_MERGE: + if (!blk_mq_sched_allow_merge(q, rq, bio)) + return false; + if (bio_attempt_back_merge(rq, bio, nr_segs) != BIO_MERGE_OK) + return false; + *merged_request = attempt_back_merge(q, rq); + if (!*merged_request) + elv_merged_request(q, rq, ELEVATOR_BACK_MERGE); + return true; + case ELEVATOR_FRONT_MERGE: + if (!blk_mq_sched_allow_merge(q, rq, bio)) + return false; + if (bio_attempt_front_merge(rq, bio, nr_segs) != BIO_MERGE_OK) + return false; + *merged_request = attempt_front_merge(q, rq); + if (!*merged_request) + elv_merged_request(q, rq, ELEVATOR_FRONT_MERGE); + return true; + case ELEVATOR_DISCARD_MERGE: + return bio_attempt_discard_merge(q, rq, bio) == BIO_MERGE_OK; + default: + return false; + } +} +EXPORT_SYMBOL_GPL(blk_mq_sched_try_merge); diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index 3e9596738852..e7a690ae86c9 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -344,38 +344,6 @@ void blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx *hctx) } } -bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio, - unsigned int nr_segs, struct request **merged_request) -{ - struct request *rq; - - switch (elv_merge(q, &rq, bio)) { - case ELEVATOR_BACK_MERGE: - if (!blk_mq_sched_allow_merge(q, rq, bio)) - return false; - if (bio_attempt_back_merge(rq, bio, nr_segs) != BIO_MERGE_OK) - return false; - *merged_request = attempt_back_merge(q, rq); - if (!*merged_request) - elv_merged_request(q, rq, ELEVATOR_BACK_MERGE); - return true; - case ELEVATOR_FRONT_MERGE: - if (!blk_mq_sched_allow_merge(q, rq, bio)) - return false; - if (bio_attempt_front_merge(rq, bio, nr_segs) != BIO_MERGE_OK) - return false; - *merged_request = attempt_front_merge(q, rq); - if (!*merged_request) - elv_merged_request(q, rq, ELEVATOR_FRONT_MERGE); - return true; - case ELEVATOR_DISCARD_MERGE: - return bio_attempt_discard_merge(q, rq, bio) == BIO_MERGE_OK; - default: - return false; - } -} -EXPORT_SYMBOL_GPL(blk_mq_sched_try_merge); - bool __blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio, unsigned int nr_segs) { diff --git a/block/blk.h b/block/blk.h index 8fcb146d3003..dfab98465db9 100644 --- a/block/blk.h +++ b/block/blk.h @@ -29,12 +29,6 @@ struct blk_flush_queue { spinlock_t mq_flush_lock; }; -enum bio_merge_status { - BIO_MERGE_OK, - BIO_MERGE_NONE, - BIO_MERGE_FAILED, -}; - extern struct kmem_cache *blk_requestq_cachep; extern struct kobj_type blk_queue_ktype; extern struct ida blk_queue_ida; @@ -190,15 +184,6 @@ static inline void blk_integrity_del(struct gendisk *disk) unsigned long blk_rq_timeout(unsigned long timeout); void blk_add_timer(struct request *req); -enum bio_merge_status bio_attempt_front_merge(struct request *req, - struct bio *bio, - unsigned int nr_segs); -enum bio_merge_status bio_attempt_back_merge(struct request *req, - struct bio *bio, - unsigned int nr_segs); -enum bio_merge_status bio_attempt_discard_merge(struct request_queue *q, - struct request *req, - struct bio *bio); bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio, unsigned int nr_segs, struct request **same_queue_rq); bool blk_bio_list_merge(struct request_queue *q, struct list_head *list, @@ -249,10 +234,6 @@ ssize_t part_timeout_store(struct device *, struct device_attribute *, void __blk_queue_split(struct bio **bio, unsigned int *nr_segs); int ll_back_merge_fn(struct request *req, struct bio *bio, unsigned int nr_segs); -int ll_front_merge_fn(struct request *req, struct bio *bio, - unsigned int nr_segs); -struct request *attempt_back_merge(struct request_queue *q, struct request *rq); -struct request *attempt_front_merge(struct request_queue *q, struct request *rq); int blk_attempt_req_merge(struct request_queue *q, struct request *rq, struct request *next); unsigned int blk_recalc_rq_segments(struct request *rq); From a926c7afffcc0f2e35e6acbccb16921bacf34617 Mon Sep 17 00:00:00 2001 From: Gabriel Krisman Bertazi Date: Tue, 6 Oct 2020 15:41:25 -0400 Subject: [PATCH 170/191] block: Consider only dispatched requests for inflight statistic According to Documentation/block/stat.rst, inflight should not include I/O requests that are in the queue but not yet dispatched to the device, but blk-mq identifies as inflight any request that has a tag allocated, which, for queues without elevator, happens at request allocation time and before it is queued in the ctx (default case in blk_mq_submit_bio). In addition, current behavior is different for queues with elevator from queues without it, since for the former the driver tag is allocated at dispatch time. A more precise approach would be to only consider requests with state MQ_RQ_IN_FLIGHT. This effectively reverts commit 6131837b1de6 ("blk-mq: count allocated but not started requests in iostats inflight") to consolidate blk-mq behavior with itself (elevator case) and with original documentation, but it differs from the behavior used by the legacy path. This version differs from v1 by using blk_mq_rq_state to access the state attribute. Avoid using blk_mq_request_started, which was suggested, since we don't want to include MQ_RQ_COMPLETE. Signed-off-by: Gabriel Krisman Bertazi Cc: Omar Sandoval Signed-off-by: Jens Axboe --- block/blk-mq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 2e4b3cad2a61..c5fefd39d0c0 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -105,7 +105,7 @@ static bool blk_mq_check_inflight(struct blk_mq_hw_ctx *hctx, { struct mq_inflight *mi = priv; - if (rq->part == mi->part) + if (rq->part == mi->part && blk_mq_rq_state(rq) == MQ_RQ_IN_FLIGHT) mi->inflight[rq_data_dir(rq)]++; return true; From fe6f0cdc49263ae61cd3d33399662808c2398e86 Mon Sep 17 00:00:00 2001 From: Johannes Thumshirn Date: Wed, 7 Oct 2020 21:35:08 +0900 Subject: [PATCH 171/191] block: soft limit zone-append sectors as well Martin rightfully noted that for normal filesystem IO we have soft limits in place, to prevent them from getting too big and not lead to unpredictable latencies. For zone append we only have the hardware limit in place. Cap the max sectors we submit via zone-append to the maximal number of sectors if the second limit is lower. Reported-by: Martin K. Petersen Signed-off-by: Johannes Thumshirn Reviewed-by: Damien Le Moal Reviewed-by: Martin K. Petersen Link: https://lore.kernel.org/linux-btrfs/yq1k0w8g3rw.fsf@ca-mkp.ca.oracle.com Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index cda786fa4341..6bd667c34777 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1407,7 +1407,10 @@ static inline unsigned int queue_max_segment_size(const struct request_queue *q) static inline unsigned int queue_max_zone_append_sectors(const struct request_queue *q) { - return q->limits.max_zone_append_sectors; + + const struct queue_limits *l = &q->limits; + + return min(l->max_zone_append_sectors, l->max_sectors); } static inline unsigned queue_logical_block_size(const struct request_queue *q) From fa1c3eaf4dae94a6109d436b4bad7dc9b072ad39 Mon Sep 17 00:00:00 2001 From: Baolin Wang Date: Mon, 28 Sep 2020 08:42:26 +0800 Subject: [PATCH 172/191] block: Remove redundant 'return' statement Remove redundant 'return' statement for 'void' functions. Signed-off-by: Baolin Wang Signed-off-by: Jens Axboe --- block/blk-iocost.c | 2 +- block/blk-iolatency.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index b82649c1440b..951ad4bb27f5 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -3405,7 +3405,7 @@ static int __init ioc_init(void) static void __exit ioc_exit(void) { - return blkcg_policy_unregister(&blkcg_policy_iocost); + blkcg_policy_unregister(&blkcg_policy_iocost); } module_init(ioc_init); diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c index f90429cf4edf..81be0096411d 100644 --- a/block/blk-iolatency.c +++ b/block/blk-iolatency.c @@ -1046,7 +1046,7 @@ static int __init iolatency_init(void) static void __exit iolatency_exit(void) { - return blkcg_policy_unregister(&blkcg_policy_iolatency); + blkcg_policy_unregister(&blkcg_policy_iolatency); } module_init(iolatency_init); From 4247d9c8ba810c1d4a9502893a9ce1cec6abbf7a Mon Sep 17 00:00:00 2001 From: Baolin Wang Date: Thu, 8 Oct 2020 11:52:22 +0800 Subject: [PATCH 173/191] blk-throttle: Remove a meaningless parameter for throtl_downgrade_state() The throtl_downgrade_state() is always used to change to LIMIT_LOW limitation, thus remove the latter meaningless parameter which indicates the limitation index. Signed-off-by: Baolin Wang Signed-off-by: Jens Axboe --- block/blk-throttle.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 36ba61c5cdbd..4007b26d4fd7 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -1970,7 +1970,7 @@ static void throtl_upgrade_state(struct throtl_data *td) queue_work(kthrotld_workqueue, &td->dispatch_work); } -static void throtl_downgrade_state(struct throtl_data *td, int new) +static void throtl_downgrade_state(struct throtl_data *td) { td->scale /= 2; @@ -1980,7 +1980,7 @@ static void throtl_downgrade_state(struct throtl_data *td, int new) return; } - td->limit_index = new; + td->limit_index = LIMIT_LOW; td->low_downgrade_time = jiffies; } @@ -2067,7 +2067,7 @@ static void throtl_downgrade_check(struct throtl_grp *tg) * cgroups */ if (throtl_hierarchy_can_downgrade(tg)) - throtl_downgrade_state(tg->td, LIMIT_LOW); + throtl_downgrade_state(tg->td); tg->last_bytes_disp[READ] = 0; tg->last_bytes_disp[WRITE] = 0; From 7901601aef35082d8431d05ab50a3567f7624b55 Mon Sep 17 00:00:00 2001 From: Baolin Wang Date: Thu, 8 Oct 2020 11:52:23 +0800 Subject: [PATCH 174/191] blk-throttle: Avoid getting the current time if tg->last_finish_time is 0 We only update the tg->last_finish_time when the low limitaion is enabled, so we can move the tg->last_finish_time validation a little forward to avoid getting the unnecessary current time stamp if the the low limitation is not enabled. Signed-off-by: Baolin Wang Signed-off-by: Jens Axboe --- block/blk-throttle.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 4007b26d4fd7..7e72102aa918 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -2077,10 +2077,14 @@ static void throtl_downgrade_check(struct throtl_grp *tg) static void blk_throtl_update_idletime(struct throtl_grp *tg) { - unsigned long now = ktime_get_ns() >> 10; + unsigned long now; unsigned long last_finish_time = tg->last_finish_time; - if (now <= last_finish_time || last_finish_time == 0 || + if (last_finish_time == 0) + return; + + now = ktime_get_ns() >> 10; + if (now <= last_finish_time || last_finish_time == tg->checked_last_finish_time) return; From b185efa78bf9f13e32f115169e4ab35e68993461 Mon Sep 17 00:00:00 2001 From: Baolin Wang Date: Thu, 8 Oct 2020 11:52:24 +0800 Subject: [PATCH 175/191] blk-throttle: Avoid tracking latency if low limit is invalid The IO latency tracking is only for LOW limit, so we should add a validation to avoid redundant latency tracking if the LOW limit is not valid. Signed-off-by: Baolin Wang Signed-off-by: Jens Axboe --- block/blk-throttle.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 7e72102aa918..b0d8f7cc5e92 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -2100,7 +2100,7 @@ static void throtl_update_latency_buckets(struct throtl_data *td) unsigned long last_latency[2] = { 0 }; unsigned long latency[2]; - if (!blk_queue_nonrot(td->queue)) + if (!blk_queue_nonrot(td->queue) || !td->limit_valid[LIMIT_LOW]) return; if (time_before(jiffies, td->last_calculate_time + HZ)) return; @@ -2338,6 +2338,8 @@ void blk_throtl_bio_endio(struct bio *bio) if (!blkg) return; tg = blkg_to_tg(blkg); + if (!tg->td->limit_valid[LIMIT_LOW]) + return; finish_time_ns = ktime_get_ns(); tg->last_finish_time = finish_time_ns >> 10; From 5b7048b89745c3c5fb4b3080fb7bced61dba2a2b Mon Sep 17 00:00:00 2001 From: Baolin Wang Date: Thu, 8 Oct 2020 11:52:25 +0800 Subject: [PATCH 176/191] blk-throttle: Fix IO hang for a corner case It can not scale up in throtl_adjusted_limit() if we set bps or iops is 1, which will cause IO hang when enable low limit. Thus we should treat 1 as a illegal value to avoid this issue. Signed-off-by: Baolin Wang Signed-off-by: Jens Axboe --- block/blk-throttle.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/block/blk-throttle.c b/block/blk-throttle.c index b0d8f7cc5e92..0649bceebf35 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -1687,13 +1687,13 @@ static ssize_t tg_set_limit(struct kernfs_open_file *of, goto out_finish; ret = -EINVAL; - if (!strcmp(tok, "rbps")) + if (!strcmp(tok, "rbps") && val > 1) v[0] = val; - else if (!strcmp(tok, "wbps")) + else if (!strcmp(tok, "wbps") && val > 1) v[1] = val; - else if (!strcmp(tok, "riops")) + else if (!strcmp(tok, "riops") && val > 1) v[2] = min_t(u64, val, UINT_MAX); - else if (!strcmp(tok, "wiops")) + else if (!strcmp(tok, "wiops") && val > 1) v[3] = min_t(u64, val, UINT_MAX); else if (off == LIMIT_LOW && !strcmp(tok, "idle")) idle_time = val; From b7b609de5a0835b2ca10c71df5d9570008eb1084 Mon Sep 17 00:00:00 2001 From: Baolin Wang Date: Thu, 8 Oct 2020 11:52:26 +0800 Subject: [PATCH 177/191] blk-throttle: Move the list operation after list validation We should move the list operation after validation. Signed-off-by: Baolin Wang Signed-off-by: Jens Axboe --- block/blk-throttle.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 0649bceebf35..f1bcb5c320e8 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -423,12 +423,13 @@ static void throtl_qnode_add_bio(struct bio *bio, struct throtl_qnode *qn, */ static struct bio *throtl_peek_queued(struct list_head *queued) { - struct throtl_qnode *qn = list_first_entry(queued, struct throtl_qnode, node); + struct throtl_qnode *qn; struct bio *bio; if (list_empty(queued)) return NULL; + qn = list_first_entry(queued, struct throtl_qnode, node); bio = bio_list_peek(&qn->bios); WARN_ON_ONCE(!bio); return bio; @@ -451,12 +452,13 @@ static struct bio *throtl_peek_queued(struct list_head *queued) static struct bio *throtl_pop_queued(struct list_head *queued, struct throtl_grp **tg_to_put) { - struct throtl_qnode *qn = list_first_entry(queued, struct throtl_qnode, node); + struct throtl_qnode *qn; struct bio *bio; if (list_empty(queued)) return NULL; + qn = list_first_entry(queued, struct throtl_qnode, node); bio = bio_list_pop(&qn->bios); WARN_ON_ONCE(!bio); From 2397611ac802c4f8028b6b2e585b9857d2f8138b Mon Sep 17 00:00:00 2001 From: Baolin Wang Date: Thu, 8 Oct 2020 11:52:27 +0800 Subject: [PATCH 178/191] blk-throttle: Move service tree validation out of the throtl_rb_first() The throtl_schedule_next_dispatch() will validate if the service queue is empty before calling update_min_dispatch_time(), and the update_min_dispatch_time() will call throtl_rb_first(), which will validate service queue again. Thus we can move the service queue validation out of the throtl_rb_first() to remove the redundant validation in the fast path. Signed-off-by: Baolin Wang Signed-off-by: Jens Axboe --- block/blk-throttle.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/block/blk-throttle.c b/block/blk-throttle.c index f1bcb5c320e8..38aed8baacf4 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -638,9 +638,6 @@ static struct throtl_grp * throtl_rb_first(struct throtl_service_queue *parent_sq) { struct rb_node *n; - /* Service tree is empty */ - if (!parent_sq->nr_pending) - return NULL; n = rb_first_cached(&parent_sq->pending_tree); WARN_ON_ONCE(!n); @@ -1224,9 +1221,13 @@ static int throtl_select_dispatch(struct throtl_service_queue *parent_sq) unsigned int nr_disp = 0; while (1) { - struct throtl_grp *tg = throtl_rb_first(parent_sq); + struct throtl_grp *tg; struct throtl_service_queue *sq; + if (!parent_sq->nr_pending) + break; + + tg = throtl_rb_first(parent_sq); if (!tg) break; From 29379674bda0739f184f1d234975605f7d6b428c Mon Sep 17 00:00:00 2001 From: Baolin Wang Date: Thu, 8 Oct 2020 11:52:28 +0800 Subject: [PATCH 179/191] blk-throttle: Open code __throtl_de/enqueue_tg() The __throtl_de/enqueue_tg() functions are only be called by throtl_de/enqueue_tg(), thus we can just open code them to make code more readable. Signed-off-by: Baolin Wang Signed-off-by: Jens Axboe --- block/blk-throttle.c | 26 +++++++++----------------- 1 file changed, 9 insertions(+), 17 deletions(-) diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 38aed8baacf4..fc5c14f66673 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -691,29 +691,21 @@ static void tg_service_queue_add(struct throtl_grp *tg) leftmost); } -static void __throtl_enqueue_tg(struct throtl_grp *tg) -{ - tg_service_queue_add(tg); - tg->flags |= THROTL_TG_PENDING; - tg->service_queue.parent_sq->nr_pending++; -} - static void throtl_enqueue_tg(struct throtl_grp *tg) { - if (!(tg->flags & THROTL_TG_PENDING)) - __throtl_enqueue_tg(tg); -} - -static void __throtl_dequeue_tg(struct throtl_grp *tg) -{ - throtl_rb_erase(&tg->rb_node, tg->service_queue.parent_sq); - tg->flags &= ~THROTL_TG_PENDING; + if (!(tg->flags & THROTL_TG_PENDING)) { + tg_service_queue_add(tg); + tg->flags |= THROTL_TG_PENDING; + tg->service_queue.parent_sq->nr_pending++; + } } static void throtl_dequeue_tg(struct throtl_grp *tg) { - if (tg->flags & THROTL_TG_PENDING) - __throtl_dequeue_tg(tg); + if (tg->flags & THROTL_TG_PENDING) { + throtl_rb_erase(&tg->rb_node, tg->service_queue.parent_sq); + tg->flags &= ~THROTL_TG_PENDING; + } } /* Call with queue lock held */ From 1da30f952a81718a9c3b651121a274b093f44932 Mon Sep 17 00:00:00 2001 From: Baolin Wang Date: Thu, 8 Oct 2020 11:52:29 +0800 Subject: [PATCH 180/191] blk-throttle: Re-use the throtl_set_slice_end() Re-use throtl_set_slice_end() to remove duplicate code. Signed-off-by: Baolin Wang Signed-off-by: Jens Axboe --- block/blk-throttle.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/blk-throttle.c b/block/blk-throttle.c index fc5c14f66673..b771c4299982 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -808,7 +808,7 @@ static inline void throtl_set_slice_end(struct throtl_grp *tg, bool rw, static inline void throtl_extend_slice(struct throtl_grp *tg, bool rw, unsigned long jiffy_end) { - tg->slice_end[rw] = roundup(jiffy_end, tg->td->throtl_slice); + throtl_set_slice_end(tg, rw, jiffy_end); throtl_log(&tg->service_queue, "[%c] extend slice start=%lu end=%lu jiffies=%lu", rw == READ ? 'R' : 'W', tg->slice_start[rw], From f4ac712e4fe009635344b9af5d890fe25fcc8c0d Mon Sep 17 00:00:00 2001 From: Tetsuo Handa Date: Thu, 8 Oct 2020 22:37:23 +0900 Subject: [PATCH 181/191] block: ratelimit handle_bad_sector() message syzbot is reporting unkillable task [1], for the caller is failing to handle a corrupted filesystem image which attempts to access beyond the end of the device. While we need to fix the caller, flooding the console with handle_bad_sector() message is unlikely useful. [1] https://syzkaller.appspot.com/bug?id=f1f49fb971d7a3e01bd8ab8cff2ff4572ccf3092 Signed-off-by: Tetsuo Handa Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/blk-core.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 3b01e7f3c7a3..ac00d2fa4eb4 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -646,11 +646,10 @@ static void handle_bad_sector(struct bio *bio, sector_t maxsector) { char b[BDEVNAME_SIZE]; - printk(KERN_INFO "attempt to access beyond end of device\n"); - printk(KERN_INFO "%s: rw=%d, want=%Lu, limit=%Lu\n", - bio_devname(bio, b), bio->bi_opf, - (unsigned long long)bio_end_sector(bio), - (long long)maxsector); + pr_info_ratelimited("attempt to access beyond end of device\n" + "%s: rw=%d, want=%llu, limit=%llu\n", + bio_devname(bio, b), bio->bi_opf, + bio_end_sector(bio), maxsector); } #ifdef CONFIG_FAIL_MAKE_REQUEST From 7ea6bf2e6c409e245a31b9ac6a4ba24949ad442f Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Fri, 9 Oct 2020 12:03:56 +0800 Subject: [PATCH 182/191] percpu_ref: don't refer to ref->data if it isn't allocated We can't check ref->data->confirm_switch directly in __percpu_ref_exit(), since ref->data may not be allocated in one not-initialized refcount. Fixes: 2b0d3d3e4fcf ("percpu_ref: reduce memory footprint of percpu_ref in fast path") Reported-by: syzbot+fd15ff734dace9e16437@syzkaller.appspotmail.com Signed-off-by: Ming Lei Signed-off-by: Jens Axboe --- lib/percpu-refcount.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/percpu-refcount.c b/lib/percpu-refcount.c index b6350d13538a..e59eda07305e 100644 --- a/lib/percpu-refcount.c +++ b/lib/percpu-refcount.c @@ -109,7 +109,7 @@ static void __percpu_ref_exit(struct percpu_ref *ref) if (percpu_count) { /* non-NULL confirm_switch indicates switching in progress */ - WARN_ON_ONCE(ref->data->confirm_switch); + WARN_ON_ONCE(ref->data && ref->data->confirm_switch); free_percpu(percpu_count); ref->percpu_count_ptr = __PERCPU_REF_ATOMIC_DEAD; } From dd1c372d656600234a1704f456f9977ca684865c Mon Sep 17 00:00:00 2001 From: Yufen Yu Date: Thu, 8 Oct 2020 23:26:27 -0400 Subject: [PATCH 183/191] block: invoke blk_mq_exit_sched no matter whether have .exit_sched We will register debugfs for scheduler no matter whether it have defined callback funciton .exit_sched. So, blk_mq_exit_sched() is always needed to unregister debugfs. Also, q->elevator should be set as NULL after exiting scheduler. For now, since all register scheduler have defined .exit_sched, it will not cause any actual problem. But It will be more reasonable to do this change. Signed-off-by: Yufen Yu Signed-off-by: Jens Axboe --- block/blk-sysfs.c | 1 - block/elevator.c | 3 +-- 2 files changed, 1 insertion(+), 3 deletions(-) diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 76b54c7750b0..e35eb1a05ad2 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -740,7 +740,6 @@ static void blk_exit_queue(struct request_queue *q) if (q->elevator) { ioc_clear_queue(q); __elevator_exit(q, q->elevator); - q->elevator = NULL; } /* diff --git a/block/elevator.c b/block/elevator.c index 90ed7a28c21d..7d76b61e157a 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -191,8 +191,7 @@ static void elevator_release(struct kobject *kobj) void __elevator_exit(struct request_queue *q, struct elevator_queue *e) { mutex_lock(&e->sysfs_lock); - if (e->type->ops.exit_sched) - blk_mq_exit_sched(q, e); + blk_mq_exit_sched(q, e); mutex_unlock(&e->sysfs_lock); kobject_put(&e->kobj); From 6251b754f5b29d44d088cc73f508d15ddfb8d978 Mon Sep 17 00:00:00 2001 From: Yufen Yu Date: Thu, 8 Oct 2020 23:26:28 -0400 Subject: [PATCH 184/191] block: remove redundant mq check elv_support_iosched() will check queue_is_mq() for us. So, remove the redundant check to clean code. Signed-off-by: Yufen Yu Signed-off-by: Jens Axboe --- block/elevator.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/block/elevator.c b/block/elevator.c index 7d76b61e157a..b506895b34c7 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -615,7 +615,7 @@ int elevator_switch_mq(struct request_queue *q, static inline bool elv_support_iosched(struct request_queue *q) { - if (!q->mq_ops || + if (!queue_is_mq(q) || (q->tag_set && (q->tag_set->flags & BLK_MQ_F_NO_SCHED))) return false; return true; @@ -763,7 +763,7 @@ ssize_t elv_iosched_store(struct request_queue *q, const char *name, { int ret; - if (!queue_is_mq(q) || !elv_support_iosched(q)) + if (!elv_support_iosched(q)) return count; ret = __elevator_change(q, name); From 75e6c00fc75c53577bfc4831d909162c56e799ce Mon Sep 17 00:00:00 2001 From: Yufen Yu Date: Thu, 8 Oct 2020 23:26:29 -0400 Subject: [PATCH 185/191] block: use helper function to test queue register We have defined common interface blk_queue_registered() to test QUEUE_FLAG_REGISTERED. Just use it. Signed-off-by: Yufen Yu Signed-off-by: Jens Axboe --- block/blk-iocost.c | 2 +- block/elevator.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index 951ad4bb27f5..bbe86d1199dc 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -669,7 +669,7 @@ static struct ioc *q_to_ioc(struct request_queue *q) static const char *q_name(struct request_queue *q) { - if (test_bit(QUEUE_FLAG_REGISTERED, &q->queue_flags)) + if (blk_queue_registered(q)) return kobject_name(q->kobj.parent); else return ""; diff --git a/block/elevator.c b/block/elevator.c index b506895b34c7..431a2a1c896e 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -672,7 +672,7 @@ void elevator_init_mq(struct request_queue *q) if (!elv_support_iosched(q)) return; - WARN_ON_ONCE(test_bit(QUEUE_FLAG_REGISTERED, &q->queue_flags)); + WARN_ON_ONCE(blk_queue_registered(q)); if (unlikely(q->elevator)) return; From 0841031ab9a8fb2551880c24a8419997b8e834bc Mon Sep 17 00:00:00 2001 From: Yufen Yu Date: Thu, 8 Oct 2020 23:26:30 -0400 Subject: [PATCH 186/191] blk-mq: use helper function to test hw stopped We have introduced helper function blk_mq_hctx_stopped() to test BLK_MQ_S_STOPPED. Signed-off-by: Yufen Yu Signed-off-by: Jens Axboe --- block/blk-mq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index c5fefd39d0c0..e11ee801ba19 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1807,7 +1807,7 @@ static void blk_mq_run_work_fn(struct work_struct *work) /* * If we are stopped, don't run the queue. */ - if (test_bit(BLK_MQ_S_STOPPED, &hctx->state)) + if (blk_mq_hctx_stopped(hctx)) return; __blk_mq_run_hw_queue(hctx); From f0c6ae09db1d39cbcf35776f889e0f7f861493d2 Mon Sep 17 00:00:00 2001 From: Yufen Yu Date: Thu, 8 Oct 2020 23:26:31 -0400 Subject: [PATCH 187/191] block: fix comment and add lockdep assert After commit b89f625e28d4 ("block: don't release queue's sysfs lock during switching elevator"), whole elevator register and unregister function are covered by sysfs_lock. So, remove wrong comment and add lockdep assert. Signed-off-by: Yufen Yu Signed-off-by: Jens Axboe --- block/elevator.c | 14 ++++---------- 1 file changed, 4 insertions(+), 10 deletions(-) diff --git a/block/elevator.c b/block/elevator.c index 431a2a1c896e..293c5c81397a 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -479,16 +479,13 @@ static struct kobj_type elv_ktype = { .release = elevator_release, }; -/* - * elv_register_queue is called from either blk_register_queue or - * elevator_switch, elevator switch is prevented from being happen - * in the two paths, so it is safe to not hold q->sysfs_lock. - */ int elv_register_queue(struct request_queue *q, bool uevent) { struct elevator_queue *e = q->elevator; int error; + lockdep_assert_held(&q->sysfs_lock); + error = kobject_add(&e->kobj, &q->kobj, "%s", "iosched"); if (!error) { struct elv_fs_entry *attr = e->type->elevator_attrs; @@ -507,13 +504,10 @@ int elv_register_queue(struct request_queue *q, bool uevent) return error; } -/* - * elv_unregister_queue is called from either blk_unregister_queue or - * elevator_switch, elevator switch is prevented from being happen - * in the two paths, so it is safe to not hold q->sysfs_lock. - */ void elv_unregister_queue(struct request_queue *q) { + lockdep_assert_held(&q->sysfs_lock); + if (q) { struct elevator_queue *e = q->elevator; From 0546858c59fb90122ca8c820e6aa221925a13bd8 Mon Sep 17 00:00:00 2001 From: Yufen Yu Date: Thu, 8 Oct 2020 23:26:32 -0400 Subject: [PATCH 188/191] block: get rid of unnecessary local variable Since whole elevator register is protectd by sysfs_lock, we don't need extras 'has_elevator'. Just use q->elevator directly. Signed-off-by: Yufen Yu Signed-off-by: Jens Axboe --- block/blk-sysfs.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index e35eb1a05ad2..bdc8cf575654 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -833,7 +833,6 @@ int blk_register_queue(struct gendisk *disk) int ret; struct device *dev = disk_to_dev(disk); struct request_queue *q = disk->queue; - bool has_elevator = false; if (WARN_ON(!q)) return -ENXIO; @@ -899,7 +898,6 @@ int blk_register_queue(struct gendisk *disk) kobject_put(&dev->kobj); return ret; } - has_elevator = true; } blk_queue_flag_set(QUEUE_FLAG_REGISTERED, q); @@ -908,7 +906,7 @@ int blk_register_queue(struct gendisk *disk) /* Now everything is ready and send out KOBJ_ADD uevent */ kobject_uevent(&q->kobj, KOBJ_ADD); - if (has_elevator) + if (q->elevator) kobject_uevent(&q->elevator->kobj, KOBJ_ADD); mutex_unlock(&q->sysfs_lock); From c728152413312de6c95731a845d30c9ae735d656 Mon Sep 17 00:00:00 2001 From: Yufen Yu Date: Thu, 8 Oct 2020 23:26:33 -0400 Subject: [PATCH 189/191] blk-mq: get rid of the dead flush handle code path After commit 923218f6166a ("blk-mq: don't allocate driver tag upfront for flush rq"), blk_mq_submit_bio() will call blk_insert_flush() directly to handle flush request rather than blk_mq_sched_insert_request() in the case of elevator. Then, all flush request either have set RQF_FLUSH_SEQ flag when call blk_mq_sched_insert_request(), or have inserted into hctx->dispatch. So, remove the dead code path. Signed-off-by: Yufen Yu Signed-off-by: Jens Axboe --- block/blk-mq-sched.c | 6 ------ 1 file changed, 6 deletions(-) diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index e7a690ae86c9..d1eafe2c045c 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -422,12 +422,6 @@ void blk_mq_sched_insert_request(struct request *rq, bool at_head, struct blk_mq_ctx *ctx = rq->mq_ctx; struct blk_mq_hw_ctx *hctx = rq->mq_hctx; - /* flush rq in flush machinery need to be dispatched directly */ - if (!(rq->rq_flags & RQF_FLUSH_SEQ) && op_is_flush(rq->cmd_flags)) { - blk_insert_flush(rq); - goto run; - } - WARN_ON(e && (rq->tag != BLK_MQ_NO_TAG)); if (blk_mq_sched_bypass_insert(hctx, !!e, rq)) { From 47ce030b7ac5a5259a9a5919f230b52497afc31a Mon Sep 17 00:00:00 2001 From: Yang Yang Date: Fri, 9 Oct 2020 01:00:14 -0700 Subject: [PATCH 190/191] blk-mq: move cancel of hctx->run_work to the front of blk_exit_queue blk_exit_queue will free elevator_data, while blk_mq_run_work_fn will access it. Move cancel of hctx->run_work to the front of blk_exit_queue to avoid use-after-free. Fixes: 1b97871b501f ("blk-mq: move cancel of hctx->run_work into blk_mq_hw_sysfs_release") Signed-off-by: Yang Yang Reviewed-by: Ming Lei Signed-off-by: Jens Axboe --- block/blk-mq-sysfs.c | 2 -- block/blk-sysfs.c | 9 ++++++++- 2 files changed, 8 insertions(+), 3 deletions(-) diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c index 062229395a50..7b52e7657b2d 100644 --- a/block/blk-mq-sysfs.c +++ b/block/blk-mq-sysfs.c @@ -36,8 +36,6 @@ static void blk_mq_hw_sysfs_release(struct kobject *kobj) struct blk_mq_hw_ctx *hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj); - cancel_delayed_work_sync(&hctx->run_work); - if (hctx->flags & BLK_MQ_F_BLOCKING) cleanup_srcu_struct(hctx->srcu); blk_free_flush_queue(hctx->fq); diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index bdc8cf575654..b513f1683af0 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -790,9 +790,16 @@ static void blk_release_queue(struct kobject *kobj) blk_free_queue_stats(q->stats); - if (queue_is_mq(q)) + if (queue_is_mq(q)) { + struct blk_mq_hw_ctx *hctx; + int i; + cancel_delayed_work_sync(&q->requeue_work); + queue_for_each_hw_ctx(q, hctx, i) + cancel_delayed_work_sync(&hctx->run_work); + } + blk_exit_queue(q); blk_queue_free_zone_bitmaps(q); From 8858e8d98d5457ba23bcd0d99ce23e272b8b09a1 Mon Sep 17 00:00:00 2001 From: Damien Le Moal Date: Fri, 9 Oct 2020 18:07:14 +0900 Subject: [PATCH 191/191] block: fix uapi blkzoned.h comments Update the kdoc comments for struct blk_zone (capacity field description missing) and for struct blk_zone_report (flags field description missing). Signed-off-by: Damien Le Moal Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe --- include/uapi/linux/blkzoned.h | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/include/uapi/linux/blkzoned.h b/include/uapi/linux/blkzoned.h index 42c3366cc25f..656a326821a2 100644 --- a/include/uapi/linux/blkzoned.h +++ b/include/uapi/linux/blkzoned.h @@ -93,12 +93,15 @@ enum blk_zone_report_flags { * @non_seq: Flag indicating that the zone is using non-sequential resources * (for host-aware zoned block devices only). * @reset: Flag indicating that a zone reset is recommended. - * @reserved: Padding to 64 B to match the ZBC/ZAC defined zone descriptor size. + * @resv: Padding for 8B alignment. + * @capacity: Zone usable capacity in 512 B sector units + * @reserved: Padding to 64 B to match the ZBC, ZAC and ZNS defined zone + * descriptor size. * - * start, len and wp use the regular 512 B sector unit, regardless of the - * device logical block size. The overall structure size is 64 B to match the - * ZBC/ZAC defined zone descriptor and allow support for future additional - * zone information. + * start, len, capacity and wp use the regular 512 B sector unit, regardless + * of the device logical block size. The overall structure size is 64 B to + * match the ZBC, ZAC and ZNS defined zone descriptor and allow support for + * future additional zone information. */ struct blk_zone { __u64 start; /* Zone start sector */ @@ -118,7 +121,7 @@ struct blk_zone { * * @sector: starting sector of report * @nr_zones: IN maximum / OUT actual - * @reserved: padding to 16 byte alignment + * @flags: one or more flags as defined by enum blk_zone_report_flags. * @zones: Space to hold @nr_zones @zones entries on reply. * * The array of at most @nr_zones must follow this structure in memory.