From 7b6620d7db566a46f49b4b9deab9fa061fd4b59b Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 15 Aug 2019 11:09:16 -0600 Subject: [PATCH] block: remove REQ_NOWAIT_INLINE We had a few issues with this code, and there's still a problem around how we deal with error handling for chained/split bios. For now, just revert the code and we'll try again with a thoroug solution. This reverts commits: e15c2ffa1091 ("block: fix O_DIRECT error handling for bio fragments") 0eb6ddfb865c ("block: Fix __blkdev_direct_IO() for bio fragments") 6a43074e2f46 ("block: properly handle IOCB_NOWAIT for async O_DIRECT IO") 893a1c97205a ("blk-mq: allow REQ_NOWAIT to return an error inline") Signed-off-by: Jens Axboe --- block/blk-mq.c | 8 ++----- fs/block_dev.c | 49 ++++----------------------------------- include/linux/blk_types.h | 5 +--- 3 files changed, 8 insertions(+), 54 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index a8e6a58f5f28..0835f4d8d42e 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1958,13 +1958,9 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) rq = blk_mq_get_request(q, bio, &data); if (unlikely(!rq)) { rq_qos_cleanup(q, bio); - - cookie = BLK_QC_T_NONE; - if (bio->bi_opf & REQ_NOWAIT_INLINE) - cookie = BLK_QC_T_EAGAIN; - else if (bio->bi_opf & REQ_NOWAIT) + if (bio->bi_opf & REQ_NOWAIT) bio_wouldblock_error(bio); - return cookie; + return BLK_QC_T_NONE; } trace_block_getrq(q, bio, bio->bi_opf); diff --git a/fs/block_dev.c b/fs/block_dev.c index eb657ab94060..677cb364d33f 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -345,24 +345,15 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages) struct bio *bio; bool is_poll = (iocb->ki_flags & IOCB_HIPRI) != 0; bool is_read = (iov_iter_rw(iter) == READ), is_sync; - bool nowait = (iocb->ki_flags & IOCB_NOWAIT) != 0; loff_t pos = iocb->ki_pos; blk_qc_t qc = BLK_QC_T_NONE; - gfp_t gfp; - int ret; + int ret = 0; if ((pos | iov_iter_alignment(iter)) & (bdev_logical_block_size(bdev) - 1)) return -EINVAL; - if (nowait) - gfp = GFP_NOWAIT; - else - gfp = GFP_KERNEL; - - bio = bio_alloc_bioset(gfp, nr_pages, &blkdev_dio_pool); - if (!bio) - return -EAGAIN; + bio = bio_alloc_bioset(GFP_KERNEL, nr_pages, &blkdev_dio_pool); dio = container_of(bio, struct blkdev_dio, bio); dio->is_sync = is_sync = is_sync_kiocb(iocb); @@ -384,7 +375,6 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages) if (!is_poll) blk_start_plug(&plug); - ret = 0; for (;;) { bio_set_dev(bio, bdev); bio->bi_iter.bi_sector = pos >> 9; @@ -409,14 +399,7 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages) task_io_account_write(bio->bi_iter.bi_size); } - /* - * Tell underlying layer to not block for resource shortage. - * And if we would have blocked, return error inline instead - * of through the bio->bi_end_io() callback. - */ - if (nowait) - bio->bi_opf |= (REQ_NOWAIT | REQ_NOWAIT_INLINE); - + dio->size += bio->bi_iter.bi_size; pos += bio->bi_iter.bi_size; nr_pages = iov_iter_npages(iter, BIO_MAX_PAGES); @@ -428,13 +411,7 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages) polled = true; } - dio->size += bio->bi_iter.bi_size; qc = submit_bio(bio); - if (qc == BLK_QC_T_EAGAIN) { - dio->size -= bio->bi_iter.bi_size; - ret = -EAGAIN; - goto error; - } if (polled) WRITE_ONCE(iocb->ki_cookie, qc); @@ -455,19 +432,8 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages) atomic_inc(&dio->ref); } - dio->size += bio->bi_iter.bi_size; - qc = submit_bio(bio); - if (qc == BLK_QC_T_EAGAIN) { - dio->size -= bio->bi_iter.bi_size; - ret = -EAGAIN; - goto error; - } - - bio = bio_alloc(gfp, nr_pages); - if (!bio) { - ret = -EAGAIN; - goto error; - } + submit_bio(bio); + bio = bio_alloc(GFP_KERNEL, nr_pages); } if (!is_poll) @@ -487,7 +453,6 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages) } __set_current_state(TASK_RUNNING); -out: if (!ret) ret = blk_status_to_errno(dio->bio.bi_status); if (likely(!ret)) @@ -495,10 +460,6 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages) bio_put(&dio->bio); return ret; -error: - if (!is_poll) - blk_finish_plug(&plug); - goto out; } static ssize_t diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 1b1fa1557e68..feff3fe4467e 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -311,7 +311,6 @@ enum req_flag_bits { __REQ_RAHEAD, /* read ahead, can fail anytime */ __REQ_BACKGROUND, /* background IO */ __REQ_NOWAIT, /* Don't wait if request will block */ - __REQ_NOWAIT_INLINE, /* Return would-block error inline */ /* * When a shared kthread needs to issue a bio for a cgroup, doing * so synchronously can lead to priority inversions as the kthread @@ -346,7 +345,6 @@ enum req_flag_bits { #define REQ_RAHEAD (1ULL << __REQ_RAHEAD) #define REQ_BACKGROUND (1ULL << __REQ_BACKGROUND) #define REQ_NOWAIT (1ULL << __REQ_NOWAIT) -#define REQ_NOWAIT_INLINE (1ULL << __REQ_NOWAIT_INLINE) #define REQ_CGROUP_PUNT (1ULL << __REQ_CGROUP_PUNT) #define REQ_NOUNMAP (1ULL << __REQ_NOUNMAP) @@ -420,13 +418,12 @@ static inline int op_stat_group(unsigned int op) typedef unsigned int blk_qc_t; #define BLK_QC_T_NONE -1U -#define BLK_QC_T_EAGAIN -2U #define BLK_QC_T_SHIFT 16 #define BLK_QC_T_INTERNAL (1U << 31) static inline bool blk_qc_t_valid(blk_qc_t cookie) { - return cookie != BLK_QC_T_NONE && cookie != BLK_QC_T_EAGAIN; + return cookie != BLK_QC_T_NONE; } static inline unsigned int blk_qc_t_to_queue_num(blk_qc_t cookie)