Commit Graph

5230 Commits

Author SHA1 Message Date
Randy Dunlap
0d20dcc277 block: genhd: delete duplicated words
Drop the repeated word "to" in multiple places.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-31 16:29:47 -06:00
Randy Dunlap
5b8f65e1f9 block: elevator: delete duplicated word and fix typos
Drop the repeated word "the".
Fix typos of "features" and "specified".

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-31 16:29:47 -06:00
Randy Dunlap
3cf1488917 block: bio: delete duplicated words
Drop the repeated words "a" and "the".

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-31 16:29:47 -06:00
Randy Dunlap
f06678af91 block: bfq-iosched: fix duplicated word
Change "at at" to "at a".

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-31 16:29:47 -06:00
Chengming Zhou
d9012a59db iocost: Fix check condition of iocg abs_vdebt
We shouldn't skip iocg when its abs_vdebt is not zero.

Fixes: 0b80f9866e ("iocost: protect iocg->abs_vdebt with iocg->waitq.lock")
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-30 11:45:12 -06:00
Ahmed S. Darwish
67b7b641ca iocost: Use sequence counter with associated spinlock
A sequence counter write side critical section must be protected by some
form of locking to serialize writers. A plain seqcount_t does not
contain the information of which lock must be held when entering a write
side critical section.

Use the new seqcount_spinlock_t data type, which allows to associate a
spinlock with the sequence counter. This enables lockdep to verify that
the spinlock used for writer serialization is held when the write side
critical section is entered.

If lockdep is disabled this lock association is compiled out and has
neither storage size nor runtime overhead.

Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Link: https://lkml.kernel.org/r/20200720155530.1173732-21-a.darwish@linutronix.de
2020-07-29 16:14:28 +02:00
Daniel Wagner
08c875cbf4 block: Use non _rcu version of list functions for tag_set_list
tag_set_list is only accessed under the tag_set_lock lock. There is
no need for using the _rcu list functions.

The _rcu list function were introduced to allow read access to the
tag_set_list protected under RCU, see 705cda97ee ("blk-mq: Make it
safe to use RCU to iterate over blk_mq_tag_set.tag_list") and
05b7941394 ("Revert "blk-mq: don't handle TAG_SHARED in restart"").
Those changes got reverted later but the cleanup commit missed a
couple of places to undo the changes.

Fixes: 97889f9ac2 ("blk-mq: remove synchronize_rcu() from blk_mq_del_queue_tag_set()"
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-28 09:37:09 -06:00
Alan Stern
8f38f8e0a3 scsi: block: pm: Simplify resume handling
Commit 05d18ae1cc ("scsi: pm: Balance pm_only counter of request queue
during system resume") fixed a problem in the block layer's runtime-PM
code: blk_set_runtime_active() failed to call blk_clear_pm_only().
However, the commit's implementation was awkward; it forced the SCSI
system-resume handler to choose whether to call blk_post_runtime_resume()
or blk_set_runtime_active(), depending on whether or not the SCSI device
had previously been runtime suspended.

This patch simplifies the situation considerably by adding the missing
function call directly into blk_set_runtime_active() (under the condition
that the queue is not already in the RPM_ACTIVE state).  This allows the
SCSI routine to revert back to its original form.  Furthermore, making this
change reveals that blk_post_runtime_resume() (in its success pathway) does
exactly the same thing as blk_set_runtime_active().  The duplicate code is
easily removed by making one routine call the other.

No functional changes are intended.

Link: https://lore.kernel.org/r/20200706151436.GA702867@rowland.harvard.edu
CC: Can Guo <cang@codeaurora.org>
CC: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-07-24 22:09:55 -04:00
Christoph Hellwig
b9b1a5d715 block: remove blk_queue_stack_limits
This function is just a tiny wrapper around blk_stack_limits.  Open code
it int the two callers.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Tested-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-20 15:38:52 -06:00
Christoph Hellwig
9efa82ef2b block: remove bdev_stack_limits
This function is just a tiny wrapper around blk_stack_limit and has
two callers.  Simplify the stack a bit by open coding it in the two
callers.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Tested-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-20 15:38:52 -06:00
Christoph Hellwig
3093a47972 block: inherit the zoned characteristics in blk_stack_limits
Lift the code from device mapper into blk_stack_limits to inherity
the stacking limitations.  This ensures we do the right thing for
all stacked zoned block devices.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Tested-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-20 15:38:52 -06:00
Jens Axboe
4f43d64807 Merge branch 'for-5.9/drivers' into for-5.9/block-merge
* for-5.9/drivers: (38 commits)
  block: add max_active_zones to blk-sysfs
  block: add max_open_zones to blk-sysfs
  s390/dasd: Use struct_size() helper
  s390/dasd: fix inability to use DASD with DIAG driver
  md-cluster: fix wild pointer of unlock_all_bitmaps()
  md/raid5-cache: clear MD_SB_CHANGE_PENDING before flushing stripes
  md: fix deadlock causing by sysfs_notify
  md: improve io stats accounting
  md: raid0/linear: fix dereference before null check on pointer mddev
  rsxx: switch from 'pci_free_consistent()' to 'dma_free_coherent()'
  nvme: remove ns->disk checks
  nvme-pci: use standard block status symbolic names
  nvme-pci: use the consistent return type of nvme_pci_iod_alloc_size()
  nvme-pci: add a blank line after declarations
  nvme-pci: fix some comments issues
  nvme-pci: remove redundant segment validation
  nvme: document quirked Intel models
  nvme: expose reconnect_delay and ctrl_loss_tmo via sysfs
  nvme: support for zoned namespaces
  nvme: support for multiple Command Sets Supported and Effects log pages
  ...
2020-07-20 15:38:27 -06:00
Jens Axboe
9caaa66c91 Merge branch 'for-5.9/block' into for-5.9/block-merge
* for-5.9/block: (124 commits)
  blk-cgroup: show global disk stats in root cgroup io.stat
  blk-cgroup: make iostat functions visible to stat printing
  block: improve discard bio alignment in __blkdev_issue_discard()
  block: change REQ_OP_ZONE_RESET and REQ_OP_ZONE_RESET_ALL to be odd numbers
  block: defer flush request no matter whether we have elevator
  block: make blk_timeout_init() static
  block: remove retry loop in ioc_release_fn()
  block: remove unnecessary ioc nested locking
  block: integrate bd_start_claiming into __blkdev_get
  block: use bd_prepare_to_claim directly in the loop driver
  block: refactor bd_start_claiming
  block: simplify the restart case in __blkdev_get
  Revert "blk-rq-qos: remove redundant finish_wait to rq_qos_wait."
  block: always remove partitions from blk_drop_partitions()
  block: relax jiffies rounding for timeouts
  blk-mq: remove redundant validation in __blk_mq_end_request()
  blk-mq: Remove unnecessary local variable
  writeback: remove bdi->congested_fn
  writeback: remove struct bdi_writeback_congested
  writeback: remove {set,clear}_wb_congested
  ...
2020-07-20 15:38:23 -06:00
Boris Burkov
ef45fe470e blk-cgroup: show global disk stats in root cgroup io.stat
In order to improve consistency and usability in cgroup stat accounting,
we would like to support the root cgroup's io.stat.

Since the root cgroup has processes doing io even if the system has no
explicitly created cgroups, we need to be careful to avoid overhead in
that case.  For that reason, the rstat algorithms don't handle the root
cgroup, so just turning the file on wouldn't give correct statistics.

To get around this, we simulate flushing the iostat struct by filling it
out directly from global disk stats. The result is a root cgroup io.stat
file consistent with both /proc/diskstats and io.stat.

Note that in order to collect the disk stats, we needed to iterate over
devices. To facilitate that, we had to change the linkage of a disk_type
to external so that it can be used from blk-cgroup.c to iterate over
disks.

Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Boris Burkov <boris@bur.io>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-17 20:18:00 -06:00
Boris Burkov
cd1fc4b98f blk-cgroup: make iostat functions visible to stat printing
Previously, the code which printed io.stat only needed access to the
generic rstat flushing code, but since we plan to write some more
specific code for preparing root cgroup stats, we need to manipulate
iostat structs directly. Since declaring static functions ahead does not
seem like common practice in this file, simply move the iostat functions
up. We only plan to use blkg_iostat_set, but it seems better to keep them
all together.

Signed-off-by: Boris Burkov <boris@bur.io>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-17 20:17:59 -06:00
Coly Li
9b15d109a6 block: improve discard bio alignment in __blkdev_issue_discard()
This patch improves discard bio split for address and size alignment in
__blkdev_issue_discard(). The aligned discard bio may help underlying
device controller to perform better discard and internal garbage
collection, and avoid unnecessary internal fragment.

Current discard bio split algorithm in __blkdev_issue_discard() may have
non-discarded fregment on device even the discard bio LBA and size are
both aligned to device's discard granularity size.

Here is the example steps on how to reproduce the above problem.
- On a VMWare ESXi 6.5 update3 installation, create a 51GB virtual disk
  with thin mode and give it to a Linux virtual machine.
- Inside the Linux virtual machine, if the 50GB virtual disk shows up as
  /dev/sdb, fill data into the first 50GB by,
        # dd if=/dev/zero of=/dev/sdb bs=4096 count=13107200
- Discard the 50GB range from offset 0 on /dev/sdb,
        # blkdiscard /dev/sdb -o 0 -l 53687091200
- Observe the underlying mapping status of the device
        # sg_get_lba_status /dev/sdb -m 1048 --lba=0
  descriptor LBA: 0x0000000000000000  blocks: 2048  mapped (or unknown)
  descriptor LBA: 0x0000000000000800  blocks: 16773120  deallocated
  descriptor LBA: 0x0000000000fff800  blocks: 2048  mapped (or unknown)
  descriptor LBA: 0x0000000001000000  blocks: 8386560  deallocated
  descriptor LBA: 0x00000000017ff800  blocks: 2048  mapped (or unknown)
  descriptor LBA: 0x0000000001800000  blocks: 8386560  deallocated
  descriptor LBA: 0x0000000001fff800  blocks: 2048  mapped (or unknown)
  descriptor LBA: 0x0000000002000000  blocks: 8386560  deallocated
  descriptor LBA: 0x00000000027ff800  blocks: 2048  mapped (or unknown)
  descriptor LBA: 0x0000000002800000  blocks: 8386560  deallocated
  descriptor LBA: 0x0000000002fff800  blocks: 2048  mapped (or unknown)
  descriptor LBA: 0x0000000003000000  blocks: 8386560  deallocated
  descriptor LBA: 0x00000000037ff800  blocks: 2048  mapped (or unknown)
  descriptor LBA: 0x0000000003800000  blocks: 8386560  deallocated
  descriptor LBA: 0x0000000003fff800  blocks: 2048  mapped (or unknown)
  descriptor LBA: 0x0000000004000000  blocks: 8386560  deallocated
  descriptor LBA: 0x00000000047ff800  blocks: 2048  mapped (or unknown)
  descriptor LBA: 0x0000000004800000  blocks: 8386560  deallocated
  descriptor LBA: 0x0000000004fff800  blocks: 2048  mapped (or unknown)
  descriptor LBA: 0x0000000005000000  blocks: 8386560  deallocated
  descriptor LBA: 0x00000000057ff800  blocks: 2048  mapped (or unknown)
  descriptor LBA: 0x0000000005800000  blocks: 8386560  deallocated
  descriptor LBA: 0x0000000005fff800  blocks: 2048  mapped (or unknown)
  descriptor LBA: 0x0000000006000000  blocks: 6291456  deallocated
  descriptor LBA: 0x0000000006600000  blocks: 0  deallocated

Although the discard bio starts at LBA 0 and has 50<<30 bytes size which
are perfect aligned to the discard granularity, from the above list
these are many 1MB (2048 sectors) internal fragments exist unexpectedly.

The problem is in __blkdev_issue_discard(), an improper algorithm causes
an improper bio size which is not aligned.

 25 int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 26                 sector_t nr_sects, gfp_t gfp_mask, int flags,
 27                 struct bio **biop)
 28 {
 29         struct request_queue *q = bdev_get_queue(bdev);
   [snipped]
 56
 57         while (nr_sects) {
 58                 sector_t req_sects = min_t(sector_t, nr_sects,
 59                                 bio_allowed_max_sectors(q));
 60
 61                 WARN_ON_ONCE((req_sects << 9) > UINT_MAX);
 62
 63                 bio = blk_next_bio(bio, 0, gfp_mask);
 64                 bio->bi_iter.bi_sector = sector;
 65                 bio_set_dev(bio, bdev);
 66                 bio_set_op_attrs(bio, op, 0);
 67
 68                 bio->bi_iter.bi_size = req_sects << 9;
 69                 sector += req_sects;
 70                 nr_sects -= req_sects;
   [snipped]
 79         }
 80
 81         *biop = bio;
 82         return 0;
 83 }
 84 EXPORT_SYMBOL(__blkdev_issue_discard);

At line 58-59, to discard a 50GB range, req_sects is set as return value
of bio_allowed_max_sectors(q), which is 8388607 sectors. In the above
case, the discard granularity is 2048 sectors, although the start LBA
and discard length are aligned to discard granularity, req_sects never
has chance to be aligned to discard granularity. This is why there are
some still-mapped 2048 sectors fragment in every 4 or 8 GB range.

If req_sects at line 58 is set to a value aligned to discard_granularity
and close to UNIT_MAX, then all consequent split bios inside device
driver are (almostly) aligned to discard_granularity of the device
queue. The 2048 sectors still-mapped fragment will disappear.

This patch introduces bio_aligned_discard_max_sectors() to return the
the value which is aligned to q->limits.discard_granularity and closest
to UINT_MAX. Then this patch replaces bio_allowed_max_sectors() with
this new routine to decide a more proper split bio length.

But we still need to handle the situation when discard start LBA is not
aligned to q->limits.discard_granularity, otherwise even the length is
aligned, current code may still leave 2048 fragment around every 4GB
range. Therefore, to calculate req_sects, firstly the start LBA of
discard range is checked (including partition offset), if it is not
aligned to discard granularity, the first split location should make
sure following bio has bi_sector aligned to discard granularity. Then
there won't be still-mapped fragment in the middle of the discard range.

The above is how this patch improves discard bio alignment in
__blkdev_issue_discard(). Now with this patch, after discard with same
command line mentiond previously, sg_get_lba_status returns,
descriptor LBA: 0x0000000000000000  blocks: 106954752  deallocated
descriptor LBA: 0x0000000006600000  blocks: 0  deallocated

We an see there is no 2048 sectors segment anymore, everything is clean.

Reported-and-tested-by: Acshai Manoj <acshai.manoj@microfocus.com>
Signed-off-by: Coly Li <colyli@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Xiao Ni <xni@redhat.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Enzo Matsumiya <ematsumiya@suse.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-17 07:15:10 -06:00
Yufen Yu
b5718d6c00 block: defer flush request no matter whether we have elevator
Commit 7520872c0c ("block: don't defer flushes on blk-mq + scheduling")
tried to fix deadlock for cycled wait between flush requests and data
request into flush_data_in_flight. The former holded all driver tags
and wait for data request completion, but the latter can not complete
for waiting free driver tags.

After commit 923218f616 ("blk-mq: don't allocate driver tag upfront
for flush rq"), flush requests will not get driver tag before queuing
into flush queue.

* With elevator, flush request just get sched_tags before inserting
  flush queue. It will not get driver tag until issue them to driver.
  data request on list fq->flush_data_in_flight will complete in
  the end.

* Without elevator, each flush request will get a driver tag when
  allocate request. Then data request on fq->flush_data_in_flight
  don't worry about lacking driver tag.

In both of these cases, cycled wait cannot be true. So we may allow
to defer flush request.

Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-17 07:14:28 -06:00
Wei Yongjun
943c4d9074 block: make blk_timeout_init() static
The sparse tool complains as follows:

block/blk-timeout.c:93:12: warning:
 symbol 'blk_timeout_init' was not declared. Should it be static?

Function blk_timeout_init() is not used outside of blk-timeout.c, so
mark it static.

Fixes: 9054650fac ("block: relax jiffies rounding for timeouts")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-17 07:13:42 -06:00
Kees Cook
3f649ab728 treewide: Remove uninitialized_var() usage
Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings
(e.g. "unused variable"). If the compiler thinks it is uninitialized,
either simply initialize the variable or make compiler changes.

In preparation for removing[2] the[3] macro[4], remove all remaining
needless uses with the following script:

git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \
	xargs perl -pi -e \
		's/\buninitialized_var\(([^\)]+)\)/\1/g;
		 s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;'

drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid
pathological white-space.

No outstanding warnings were found building allmodconfig with GCC 9.3.0
for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64,
alpha, and m68k.

[1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/
[2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/
[3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/
[4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/

Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5
Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB
Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers
Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-07-16 12:35:15 -07:00
John Ogness
ab96bbab46 block: remove retry loop in ioc_release_fn()
The reverse-order double lock dance in ioc_release_fn() is using a
retry loop. This is a problem on PREEMPT_RT because it could preempt
the task that would release q->queue_lock and thus live lock in the
retry loop.

RCU is already managing the freeing of the request queue and icq. If
the trylock fails, use RCU to guarantee that the request queue and
icq are not freed and re-acquire the locks in the correct order,
allowing forward progress.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-16 10:22:15 -06:00
John Ogness
a43f085f87 block: remove unnecessary ioc nested locking
The legacy CFQ IO scheduler could call put_io_context() in its exit_icq()
elevator callback. This led to a lockdep warning, which was fixed in
commit d8c66c5d59 ("block: fix lockdep warning on io_context release
put_io_context()") by using a nested subclass for the ioc spinlock.
However, with commit f382fb0bce ("block: remove legacy IO schedulers")
the CFQ IO scheduler no longer exists.

The BFQ IO scheduler also implements the exit_icq() elevator callback but
does not call put_io_context().

The nested subclass for the ioc spinlock is no longer needed. Since it
existed as an exception and no longer applies, remove the nested subclass
usage.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-16 10:22:15 -06:00
Niklas Cassel
659bf827ba block: add max_active_zones to blk-sysfs
Add a new max_active zones definition in the sysfs documentation.
This definition will be common for all devices utilizing the zoned block
device support in the kernel.

Export max_active_zones according to this new definition for NVMe Zoned
Namespace devices, ZAC ATA devices (which are treated as SCSI devices by
the kernel), and ZBC SCSI devices.

Add the new max_active_zones member to struct request_queue, rather
than as a queue limit, since this property cannot be split across stacking
drivers.

For SCSI devices, even though max active zones is not part of the ZBC/ZAC
spec, export max_active_zones as 0, signifying "no limit".

Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Reviewed-by: Javier González <javier@javigon.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-15 14:26:11 -06:00
Niklas Cassel
e15864f8ea block: add max_open_zones to blk-sysfs
Add a new max_open_zones definition in the sysfs documentation.
This definition will be common for all devices utilizing the zoned block
device support in the kernel.

Export max open zones according to this new definition for NVMe Zoned
Namespace devices, ZAC ATA devices (which are treated as SCSI devices by
the kernel), and ZBC SCSI devices.

Add the new max_open_zones member to struct request_queue, rather
than as a queue limit, since this property cannot be split across stacking
drivers.

Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Reviewed-by: Javier González <javier@javigon.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-15 14:26:11 -06:00
Jens Axboe
e791ee6885 Revert "blk-rq-qos: remove redundant finish_wait to rq_qos_wait."
This reverts commit 826f2f48da.

Qian Cai reports that this commit causes stalls with swap. Revert until
the reason can be figured out.

Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-15 09:33:37 -06:00
Ming Lei
d0f0f1b4c5 block: always remove partitions from blk_drop_partitions()
In theory, when GENHD_FL_NO_PART_SCAN is set, no partitions can be created
on one disk. However, ioctl(BLKPG, BLKPG_ADD_PARTITION) doesn't check
GENHD_FL_NO_PART_SCAN, so partitions still can be added even though
GENHD_FL_NO_PART_SCAN is set.

So far blk_drop_partitions() only removes partitions when disk_part_scan_enabled()
return true. This way can make ghost partition on loop device after changing/clearing
FD in case that PARTSCAN is disabled, such as partitions can be added
via 'parted' on loop disk even though GENHD_FL_NO_PART_SCAN is set.

Fix this issue by always removing partitions in blk_drop_partitions(), and
this way is correct because the current code supposes that no partitions
can be added in case of GENHD_FL_NO_PART_SCAN.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-15 09:23:42 -06:00
Jens Axboe
9054650fac block: relax jiffies rounding for timeouts
In doing high IOPS testing, blk-mq is generally pretty well optimized.
There are a few things that stuck out as using more CPU than what is
really warranted, and one thing is the round_jiffies_up() that we do
twice for each request. That accounts for about 0.8% of the CPU in
my testing.

We can make this cheaper by avoiding an integer division, by just adding
a rough HZ mask that we can AND with instead. The timeouts are only on a
second granularity already, we don't have to be that accurate here and
this patch barely changes that. All we care about is nice grouping.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-15 09:23:35 -06:00
Linus Torvalds
d33db70274 block-5.8-2020-07-10
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Merge tag 'block-5.8-2020-07-10' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:

 - Fix for inflight accounting, which affects only dm (Ming)

 - Fix documentation error for bfq (Yufen)

 - Fix memory leak for nbd (Zheng)

* tag 'block-5.8-2020-07-10' of git://git.kernel.dk/linux-block:
  nbd: Fix memory leak in nbd_add_socket
  blk-mq: consider non-idle request as "inflight" in blk_mq_rq_inflight()
  docs: block: update and fix tiny error for bfq
2020-07-10 09:55:46 -07:00
Baolin Wang
87890092ee blk-mq: remove redundant validation in __blk_mq_end_request()
We've already validated the 'q->elevator' before calling
->ops.completed_request() in blk_mq_sched_completed_request(), thus no
need to validate rq->internal_tag again. Rmove it.

Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-10 07:58:33 -06:00
Baolin Wang
106e71c512 blk-mq: Remove unnecessary local variable
Remove unnecessary local variable 'ret' in blk_mq_dispatch_hctx_list().

Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-10 07:58:09 -06:00
Christoph Hellwig
8c911f3d4c writeback: remove struct bdi_writeback_congested
We never set any congested bits in the group writeback instances of it.
And for the simpler bdi-wide case a simple scalar field is all that
that is needed.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-08 17:05:53 -06:00
Christoph Hellwig
a564e23f0f md: switch to ->check_events for media change notifications
md is the last driver using the legacy media_changed method.  Switch
it over to (not so) new ->clear_events approach, which also removes the
need for the ->revalidate_disk method.

Signed-off-by: Christoph Hellwig <hch@lst.de>
[axboe: remove unused 'bdops' variable in disk_clear_events()]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-08 16:19:47 -06:00
Ming Lei
568f270065 blk-mq: centralise related handling into blk_mq_get_driver_tag
Move .nr_active update and request assignment into blk_mq_get_driver_tag(),
all are good to do during getting driver tag.

Meantime blk-flush related code is simplified and flush request needn't
to update the request table manually any more.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-08 16:06:42 -06:00
Ming Lei
7bf137298c blk-mq: streamline handling of q->mq_ops->queue_rq result
Current handling of q->mq_ops->queue_rq result is a bit ugly:

- two branches which needs to 'continue' have to check if the
dispatch local list is empty, otherwise one bad request may
be retrieved via 'rq = list_first_entry(list, struct request, queuelist);'

- the branch of 'if (unlikely(ret != BLK_STS_OK))' isn't easy
to follow, since it is actually one error branch.

Streamline this handling, so the code becomes more readable, meantime
potential kernel oops can be avoided in case that the last request in
local dispatch list is failed.

Fixes: fc17b6534e ("blk-mq: switch ->queue_rq return value to blk_status_t")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-08 16:04:39 -06:00
Keith Busch
240e6ee272 nvme: support for zoned namespaces
Add support for NVM Express Zoned Namespaces (ZNS) Command Set defined
in NVM Express TP4053. Zoned namespaces are discovered based on their
Command Set Identifier reported in the namespaces Namespace
Identification Descriptor list. A successfully discovered Zoned
Namespace will be registered with the block layer as a host managed
zoned block device with Zone Append command support. A namespace that
does not support append is not supported by the driver.

Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Javier González <javier.gonz@samsung.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com>
Signed-off-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>
Signed-off-by: Ajay Joshi <ajay.joshi@wdc.com>
Signed-off-by: Aravind Ramesh <aravind.ramesh@wdc.com>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Matias Bjørling <matias.bjorling@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Keith Busch <keith.busch@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-07-08 16:16:20 +02:00
Matias Bjørling
82394db738 block: add capacity field to zone descriptors
In the zoned storage model, the sectors within a zone are typically all
writeable. With the introduction of the Zoned Namespace (ZNS) Command
Set in the NVM Express organization, the model was extended to have a
specific writeable capacity.

Extend the zone descriptor data structure with a zone capacity field to
indicate to the user how many sectors in a zone are writeable.

Introduce backward compatibility in the zone report ioctl by extending
the zone report header data structure with a flags field to indicate if
the capacity field is available.

Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Javier González <javier.gonz@samsung.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Matias Bjørling <matias.bjorling@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-07-08 16:16:19 +02:00
Jens Axboe
482c6b614a Linux 5.8-rc4
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Merge tag 'v5.8-rc4' into for-5.9/drivers

Merge in 5.8-rc4 for-5.9/block to setup for-5.9/drivers, to provide
a clean base and making the life for the NVMe changes easier.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

* tag 'v5.8-rc4': (732 commits)
  Linux 5.8-rc4
  x86/ldt: use "pr_info_once()" instead of open-coding it badly
  MIPS: Do not use smp_processor_id() in preemptible code
  MIPS: Add missing EHB in mtc0 -> mfc0 sequence for DSPen
  .gitignore: Do not track `defconfig` from `make savedefconfig`
  io_uring: fix regression with always ignoring signals in io_cqring_wait()
  x86/ldt: Disable 16-bit segments on Xen PV
  x86/entry/32: Fix #MC and #DB wiring on x86_32
  x86/entry/xen: Route #DB correctly on Xen PV
  x86/entry, selftests: Further improve user entry sanity checks
  x86/entry/compat: Clear RAX high bits on Xen PV SYSENTER
  i2c: mlxcpld: check correct size of maximum RECV_LEN packet
  i2c: add Kconfig help text for slave mode
  i2c: slave-eeprom: update documentation
  i2c: eg20t: Load module automatically if ID matches
  i2c: designware: platdrv: Set class based on DMI
  i2c: algo-pca: Add 0x78 as SCL stuck low status for PCA9665
  mm/page_alloc: fix documentation error
  vmalloc: fix the owner argument for the new __vmalloc_node_range callers
  mm/cma.c: use exact_nid true to fix possible per-numa cma leak
  ...
2020-07-08 08:02:13 -06:00
Christoph Hellwig
0e6e255e7a block: remove a bogus warning in __submit_bio_noacct_mq
If blk_mq_submit_bio flushes the plug list, bios for other disks can
show up on current->bio_list.  As that doesn't involve any stacking of
block device it is entirely harmless and we should not warn about
this case.

Fixes: ff93ea0ce7 ("block: shortcut __submit_bio_noacct for blk-mq drivers")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-07 11:45:59 -06:00
Ming Lei
05a4fed69f blk-mq: consider non-idle request as "inflight" in blk_mq_rq_inflight()
dm-multipath is the only user of blk_mq_queue_inflight().  When
dm-multipath calls blk_mq_queue_inflight() to check if it has
outstanding IO it can get a false negative.  The reason for this is
blk_mq_rq_inflight() doesn't consider requests that are no longer
MQ_RQ_IN_FLIGHT but that are now MQ_RQ_COMPLETE (->complete isn't
called or finished yet) as "inflight".

This causes request-based dm-multipath's dm_wait_for_completion() to
return before all outstanding dm-multipath requests have actually
completed.  This breaks DM multipath's suspend functionality because
blk-mq requests complete after DM's suspend has finished -- which
shouldn't happen.

Fix this by considering any request not in the MQ_RQ_IDLE state
(so either MQ_RQ_COMPLETE or MQ_RQ_IN_FLIGHT) as "inflight" in
blk_mq_rq_inflight().

Fixes: 3c94d83cb3 ("blk-mq: change blk_mq_queue_busy() to blk_mq_queue_inflight()")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-07 09:06:25 -06:00
Linus Torvalds
29206c6314 block-5.8-2020-07-05
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Merge tag 'block-5.8-2020-07-05' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:

 - NVMe fixes from Christoph:
    - Fix crash in multi-path disk add (Christoph)
    - Fix ignore of identify error (Sagi)

 - Fix a compiler complaint that a function should be static (Wei)

* tag 'block-5.8-2020-07-05' of git://git.kernel.dk/linux-block:
  block: make function __bio_integrity_free() static
  nvme: fix a crash in nvme_mpath_add_disk
  nvme: fix identify error status silent ignore
2020-07-05 10:45:31 -07:00
Linus Torvalds
7cc2a8ea10 block-5.8-2020-07-01
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Merge tag 'block-5.8-2020-07-01' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:

 - Use kvfree_sensitive() for the block keyslot free (Eric)

 - Sync blk-mq debugfs flags (Hou)

 - Memory leak fix in virtio-blk error path (Hou)

* tag 'block-5.8-2020-07-01' of git://git.kernel.dk/linux-block:
  virtio-blk: free vblk-vqs in error path of virtblk_probe()
  block/keyslot-manager: use kvfree_sensitive()
  blk-mq-debugfs: update blk_queue_flag_name[] accordingly for new flags
2020-07-02 15:13:51 -07:00
Christoph Hellwig
7c792f33c1 block: initialize current->bio_list[1] in __submit_bio_noacct_mq
bio_alloc_bioset references current->bio_list[1], so we need to
initialize it for the blk-mq submission path as well.

Fixes: ff93ea0ce7 ("block: shortcut __submit_bio_noacct for blk-mq drivers")
Reported-by: Qian Cai <cai@lca.pw>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-02 13:34:30 -06:00
Wei Yongjun
3197d48a7c block: make function __bio_integrity_free() static
Fix sparse build warning:

block/bio-integrity.c:27:6: warning:
 symbol '__bio_integrity_free' was not declared. Should it be static?

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-02 12:38:18 -06:00
Jens Axboe
4e2f62e566 Revert "blk-mq: put driver tag when this request is completed"
This reverts commits the following commits:

	37f4a24c24
	723bf178f1
	36a3df5a45

The last one is the culprit, but we have to go a bit deeper to get this
to revert cleanly. There's been a report that this breaks some MMC
setups [1], and also causes an issue with swap [2]. Until this can be
figured out, revert the offending commits.

[1] https://lore.kernel.org/linux-block/57fb09b1-54ba-f3aa-f82c-d709b0e6b281@samsung.com/
[2] https://lore.kernel.org/linux-block/20200702043721.GA1087@lca.pw/

Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-01 22:58:32 -06:00
Hongnan Li
6e2fa4dd68 blk-iolatency: only call ktime_get() if needed
ktime_to_ns(ktime_get()), which is expensive, does not need to be called
if blk_iolatency_enabled() return false in blkcg_iolatency_done_bio().
Postponing ktime_to_ns(ktime_get()) execution reduces the CPU usage when
blk_iolatency is disabled.

Signed-off-by: Hongnan Li <hongnan.li@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-01 08:02:38 -06:00
Christoph Hellwig
5a6c35f9af block: remove direct_make_request
Now that submit_bio_noacct has a decent blk-mq fast path there is no
more need for this bypass.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-01 07:27:24 -06:00
Christoph Hellwig
ff93ea0ce7 block: shortcut __submit_bio_noacct for blk-mq drivers
For blk-mq drivers bios can only be inserted for the same queue.  So
bypass the complicated sorting logic in __submit_bio_noacct with
a blk-mq simpler submission helper.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-01 07:27:24 -06:00
Christoph Hellwig
566acf2daa block: refator submit_bio_noacct
Split out a __submit_bio_noacct helper for the actual de-recursion
algorithm, and simplify the loop by using a continue when we can't
enter the queue for a bio.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-01 07:27:24 -06:00
Christoph Hellwig
ed00aabd5e block: rename generic_make_request to submit_bio_noacct
generic_make_request has always been very confusingly misnamed, so rename
it to submit_bio_noacct to make it clear that it is submit_bio minus
accounting and a few checks.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-01 07:27:24 -06:00
Christoph Hellwig
c62b37d96b block: move ->make_request_fn to struct block_device_operations
The make_request_fn is a little weird in that it sits directly in
struct request_queue instead of an operation vector.  Replace it with
a block_device_operations method called submit_bio (which describes much
better what it does).  Also remove the request_queue argument to it, as
the queue can be derived pretty trivially from the bio.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-01 07:27:24 -06:00
Christoph Hellwig
e439ab710f block: remove the nr_sectors variable in generic_make_request_checks
The variable is only used once, so just open code the bio_sector()
there.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-01 07:27:24 -06:00
Christoph Hellwig
833f84e2b9 block: remove the NULL queue check in generic_make_request_checks
All registers disks must have a valid queue pointer, so don't bother to
log a warning for that case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-01 07:27:24 -06:00
Christoph Hellwig
c817867460 block: tidy up a warning in bio_check_ro
The "generic_make_request: " prefix has no value, and will soon become
stale.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-01 07:27:23 -06:00
Christoph Hellwig
f695ca3886 block: remove the request_queue argument from blk_queue_split
The queue can be trivially derived from the bio, so pass one less
argument.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-01 07:27:23 -06:00
Hou Tao
b5fc1e8bed blk-mq: remove pointless call of list_entry_rq() in hctx_show_busy_rq()
Just use rq directly, the usage of list_entry_rq() doesn't make any
sense.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-01 07:25:36 -06:00
Colin Ian King
0b8cc25d94 blk-cgroup: clean up indentation
There is a statement that is indented one level too deeply, fix it
by removing a tab.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-30 13:00:04 -06:00
Ming Lei
37f4a24c24 blk-mq: centralise related handling into blk_mq_get_driver_tag
Move .nr_active update and request assignment into blk_mq_get_driver_tag(),
all are good to do during getting driver tag.

Meantime blk-flush related code is simplified and flush request needn't
to update the request table manually any more.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-30 12:57:59 -06:00
Ming Lei
723bf178f1 blk-mq: move blk_mq_put_driver_tag() into blk-mq.c
It is used by blk-mq.c only, so move it to the source file.

Suggested-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-30 12:57:59 -06:00
Ming Lei
570e9b73b0 blk-mq: move blk_mq_get_driver_tag into blk-mq.c
blk_mq_get_driver_tag() is only used by blk-mq.c and is supposed to
stay in blk-mq.c, so move it and preparing for cleanup code of
get/put driver tag.

Meantime hctx_may_queue() is moved to header file and it is fine
since it is defined as inline always.

No functional change.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-30 12:57:59 -06:00
Ming Lei
6e6fcbc27e blk-mq: support batching dispatch in case of io
More and more drivers want to get batching requests queued from
block layer, such as mmc, and tcp based storage drivers. Also
current in-tree users have virtio-scsi, virtio-blk and nvme.

For none, we already support batching dispatch.

But for io scheduler, every time we just take one request from scheduler
and pass the single request to blk_mq_dispatch_rq_list(). This way makes
batching dispatch not possible when io scheduler is applied. One reason
is that we don't want to hurt sequential IO performance, becasue IO
merge chance is reduced if more requests are dequeued from scheduler
queue.

Try to support batching dispatch for io scheduler by starting with the
following simple approach:

1) still make sure we can get budget before dequeueing request

2) use hctx->dispatch_busy to evaluate if queue is busy, if it is busy
we fackback to non-batching dispatch, otherwise dequeue as many as
possible requests from scheduler, and pass them to blk_mq_dispatch_rq_list().

Wrt. 2), we use similar policy for none, and turns out that SCSI SSD
performance got improved much.

In future, maybe we can develop more intelligent algorithem for batching
dispatch.

Baolin has tested this patch and found that MMC performance is improved[3].

[1] https://lore.kernel.org/linux-block/20200512075501.GF1531898@T590/#r
[2] https://lore.kernel.org/linux-block/fe6bd8b9-6ed9-b225-f80c-314746133722@grimberg.me/
[3] https://lore.kernel.org/linux-block/CADBw62o9eTQDJ9RvNgEqSpXmg6Xcq=2TxH0Hfxhp29uF2W=TXA@mail.gmail.com/

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Baolin Wang <baolin.wang7@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Baolin Wang <baolin.wang7@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-30 07:51:48 -06:00
Ming Lei
1fd40b5ea7 blk-mq: pass obtained budget count to blk_mq_dispatch_rq_list
Pass obtained budget count to blk_mq_dispatch_rq_list(), and prepare
for supporting fully batching submission.

With the obtained budget count, it is easier to put extra budgets
in case of .queue_rq failure.

Meantime remove the old 'got_budget' parameter.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Baolin Wang <baolin.wang7@gmail.com>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Baolin Wang <baolin.wang7@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-30 07:51:48 -06:00
Ming Lei
bbdb3c5d94 blk-mq: remove dead check from blk_mq_dispatch_rq_list
When BLK_STS_RESOURCE or BLK_STS_DEV_RESOURCE is returned from
.queue_rq, the 'list' variable always holds this rq which isn't
queued to LLD successfully.

So blk_mq_dispatch_rq_list() always returns false from the branch
of '!list_empty(list)'.

No functional change.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Baolin Wang <baolin.wang7@gmail.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Baolin Wang <baolin.wang7@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-30 07:51:48 -06:00
Ming Lei
7538352453 blk-mq: move getting driver tag and budget into one helper
Move code for getting driver tag and budget into one helper, so
blk_mq_dispatch_rq_list gets a bit simplified, and easier to read.

Meantime move updating of 'no_tag' and 'no_budget_available' into
the branch for handling partial dispatch because that is exactly
consumer of the two local variables.

Also rename the parameter of 'got_budget' as 'ask_budget'.

No functional change.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Baolin Wang <baolin.wang7@gmail.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Baolin Wang <baolin.wang7@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-30 07:51:48 -06:00
Ming Lei
445874e89f blk-mq: pass hctx to blk_mq_dispatch_rq_list
All requests in the 'list' of blk_mq_dispatch_rq_list belong to same
hctx, so it is better to pass hctx instead of request queue, because
blk-mq's dispatch target is hctx instead of request queue.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Baolin Wang <baolin.wang7@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Baolin Wang <baolin.wang7@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-30 07:51:48 -06:00
Ming Lei
65c7636943 blk-mq: pass request queue into get/put budget callback
blk-mq budget is abstract from scsi's device queue depth, and it is
always per-request-queue instead of hctx.

It can be quite absurd to get a budget from one hctx, then dequeue a
request from scheduler queue, and this request may not belong to this
hctx, at least for bfq and deadline.

So fix the mess and always pass request queue to get/put budget
callback.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Baolin Wang <baolin.wang7@gmail.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Baolin Wang <baolin.wang7@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-30 07:51:48 -06:00
Eric Biggers
3e20aa9630 block/keyslot-manager: use kvfree_sensitive()
Make blk_ksm_destroy() use the kvfree_sensitive() function (which was
introduced in v5.8-rc1) instead of open-coding it.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-29 13:24:05 -06:00
Christoph Hellwig
42fdc5e49c blk-mq: remove the BLK_MQ_REQ_INTERNAL flag
Just check for a non-NULL elevator directly to make the code more clear.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-29 09:56:18 -06:00
Ming Lei
36a3df5a45 blk-mq: put driver tag when this request is completed
It is natural to release driver tag when this request is completed by
LLD or device since its purpose is for LLD use.

One big benefit is that the released tag can be re-used quicker since
bio_endio() may take too long.

Meantime we don't need to release driver tag for flush request.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-29 09:56:10 -06:00
Christoph Hellwig
a2e83ef9c3 blk-cgroup: remove a dead check in blk_throtl_bio
bios must have a valid block group by the time they are submitted.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-29 09:09:08 -06:00
Christoph Hellwig
db18a53e5b blk-cgroup: remove blkcg_bio_issue_check
blkcg_bio_issue_check is a giant inline function that does three entirely
different things.  Factor out the blk-cgroup related bio initalization
into a new helper, and the open code the sequence in the only caller,
relying on the fact that all the actual functionality is stubbed out for
non-cgroup builds.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-29 09:09:08 -06:00
Christoph Hellwig
93b8063804 blk-cgroup: move rcu locking from blkcg_bio_issue_check to blk_throtl_bio
The only thing in blkcg_bio_issue_check that needs to be under
rcu_read_lock is blk_throtl_bio, so move the locking there.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-29 09:09:08 -06:00
Christoph Hellwig
13c7863d48 block: move the initial blkg lookup into blkg_tryget_closest
By moving the initial blkg lookup into blkg_tryget_closest we get
a nicely self contained routines that does all the RCU locking.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-29 09:09:08 -06:00
Christoph Hellwig
a5b97526bf block: bypass blkg_tryget_closest for the root_blkg
The root_blkg is only torn down at the very end of removing a queue.
So in the I/O submission path is always has a life reference and we
can just grab another one using blkg_get instead of doing a tryget
and parent walk that won't lead anywhere.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-29 09:09:08 -06:00
Christoph Hellwig
8c54628752 block: merge blkg_lookup_create and __blkg_lookup_create
No good reason to keep these two functions split.

Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-29 09:09:08 -06:00
Christoph Hellwig
28fc591ff9 block: move the bio cgroup associatation helpers to blk-cgroup.c
Keep the cgroup code together.

Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-29 09:09:08 -06:00
Christoph Hellwig
a18b9b1590 block: move bio_associate_blkg_from_page to mm/page_io.c
bio_associate_blkg_from_page is a special purpose helper for swap bios
that doesn't need access to bio internals.  Move it to the swap code
instead of having it in bio.c.

Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-29 09:09:08 -06:00
Christoph Hellwig
2badf06cf9 block: merge __bio_associate_blkg into bio_associate_blkg_from_css
Merge __bio_associate_blkg into the only caller, which allows to slightly
reduce the RCU crticial section and better explain the code flow.

Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-29 09:09:08 -06:00
Christoph Hellwig
d92c370a16 block: really clone the block cgroup in bio_clone_blkg_association
bio_clone_blkg_association is supposed to clone the associatation, but
actually ends up doing a search with a tryget.  As we know we have a
reference on the source cgroup just get an unconditional additional
reference to it and call it a day.  That also removes the need for
a RCU critical section.

Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-29 09:09:08 -06:00
Christoph Hellwig
db9819c76c block: remove bio_disassociate_blkg
bio_disassociate_blkg has two callers, of which one immediately assigns
a new value to >bi_blkg.  Just open code the function in the two callers.

Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-29 09:09:08 -06:00
Hou Tao
bfe373f608 blk-mq-debugfs: update blk_queue_flag_name[] accordingly for new flags
Else there may be magic numbers in /sys/kernel/debug/block/*/state.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-29 07:45:09 -06:00
Guo Xuenan
826f2f48da blk-rq-qos: remove redundant finish_wait to rq_qos_wait.
It is no need do finish_wait twice after acquiring inflight.

Signed-off-by: Guo Xuenan <guoxuenan@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-28 08:11:14 -06:00
Linus Torvalds
9b8d020796 block-5.8-2020-06-26
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Merge tag 'block-5.8-2020-06-26' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:

 - NVMe pull request from Christoph:
    - multipath deadlock fixes (Anton)
    - NUMA fixes (Max)
    - RDMA completion vector fix (Max)
    - IO deadlock fix (Sagi)
    - multipath reference fix (Sagi)
    - NS mutation fix (Sagi)

 - Use right allocator when freeing bip in error path (Chengguang)

* tag 'block-5.8-2020-06-26' of git://git.kernel.dk/linux-block:
  nvme-multipath: fix bogus request queue reference put
  nvme-multipath: fix deadlock due to head->lock
  nvme: don't protect ns mutation with ns->head->lock
  nvme-multipath: fix deadlock between ana_work and scan_work
  nvme: fix possible deadlock when I/O is blocked
  nvme-rdma: assign completion vector correctly
  nvme-loop: initialize tagset numa value to the value of the ctrl
  nvme-tcp: initialize tagset numa value to the value of the ctrl
  nvme-pci: initialize tagset numa value to the value of the ctrl
  nvme-pci: override the value of the controller's numa node
  nvme: set initial value for controller's numa node
  block: release bip in a right way in error path
2020-06-27 08:59:32 -07:00
Jan Kara
f3bdc62fd8 blktrace: Provide event for request merging
Currently blk-mq does not report any event when two requests get merged
in the elevator. This then results in difficult to understand sequence
of events like:

...
  8,0   34     1579     0.608765271  2718  I  WS 215023504 + 40 [dbench]
  8,0   34     1584     0.609184613  2719  A  WS 215023544 + 56 <- (8,4) 2160568
  8,0   34     1585     0.609184850  2719  Q  WS 215023544 + 56 [dbench]
  8,0   34     1586     0.609188524  2719  G  WS 215023544 + 56 [dbench]
  8,0    3      602     0.609684162   773  D  WS 215023504 + 96 [kworker/3:1H]
  8,0   34     1591     0.609843593     0  C  WS 215023504 + 96 [0]

and you can only guess (after quite some headscratching since the above
excerpt is intermixed with a lot of other IO) that request 215023544+56
got merged to request 215023504+40. Provide proper event for request
merging like we used to do in the legacy block layer.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-25 21:06:11 -06:00
Gustavo A. R. Silva
f61d6e259c blk-iocost: Use struct_size() in kzalloc_node()
Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes.

This code was detected with the help of Coccinelle and, audited and
fixed manually.

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Addresses-KSPP-ID: https://github.com/KSPP/linux/issues/83
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24 09:15:58 -06:00
Gustavo A. R. Silva
1f4fe21cf4 block: bio: Use struct_size() in kmalloc()
Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes.

This code was detected with the help of Coccinelle and, audited and
fixed manually.

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Addresses-KSPP-ID: https://github.com/KSPP/linux/issues/83
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24 09:15:58 -06:00
Luis Chamberlain
85e0cbbb8a block: create the request_queue debugfs_dir on registration
We were only creating the request_queue debugfs_dir only
for make_request block drivers (multiqueue), but never for
request-based block drivers. We did this as we were only
creating non-blktrace additional debugfs files on that directory
for make_request drivers. However, since blktrace *always* creates
that directory anyway, we special-case the use of that directory
on blktrace. Other than this being an eye-sore, this exposes
request-based block drivers to the same debugfs fragile
race that used to exist with make_request block drivers
where if we start adding files onto that directory we can later
run a race with a double removal of dentries on the directory
if we don't deal with this carefully on blktrace.

Instead, just simplify things by always creating the request_queue
debugfs_dir on request_queue registration. Rename the mutex also to
reflect the fact that this is used outside of the blktrace context.

Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24 09:15:58 -06:00
Luis Chamberlain
e8c7d14ac6 block: revert back to synchronous request_queue removal
Commit dc9edc44de ("block: Fix a blk_exit_rl() regression") merged on
v4.12 moved the work behind blk_release_queue() into a workqueue after a
splat floated around which indicated some work on blk_release_queue()
could sleep in blk_exit_rl(). This splat would be possible when a driver
called blk_put_queue() or blk_cleanup_queue() (which calls blk_put_queue()
as its final call) from an atomic context.

blk_put_queue() decrements the refcount for the request_queue kobject, and
upon reaching 0 blk_release_queue() is called. Although blk_exit_rl() is
now removed through commit db6d995235 ("block: remove request_list code")
on v5.0, we reserve the right to be able to sleep within
blk_release_queue() context.

The last reference for the request_queue must not be called from atomic
context. *When* the last reference to the request_queue reaches 0 varies,
and so let's take the opportunity to document when that is expected to
happen and also document the context of the related calls as best as
possible so we can avoid future issues, and with the hopes that the
synchronous request_queue removal sticks.

We revert back to synchronous request_queue removal because asynchronous
removal creates a regression with expected userspace interaction with
several drivers. An example is when removing the loopback driver, one
uses ioctls from userspace to do so, but upon return and if successful,
one expects the device to be removed. Likewise if one races to add another
device the new one may not be added as it is still being removed. This was
expected behavior before and it now fails as the device is still present
and busy still. Moving to asynchronous request_queue removal could have
broken many scripts which relied on the removal to have been completed if
there was no error. Document this expectation as well so that this
doesn't regress userspace again.

Using asynchronous request_queue removal however has helped us find
other bugs. In the future we can test what could break with this
arrangement by enabling CONFIG_DEBUG_KOBJECT_RELEASE.

While at it, update the docs with the context expectations for the
request_queue / gendisk refcount decrement, and make these
expectations explicit by using might_sleep().

Fixes: dc9edc44de ("block: Fix a blk_exit_rl() regression")
Suggested-by: Nicolai Stange <nstange@suse.de>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: yu kuai <yukuai3@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24 09:15:58 -06:00
Luis Chamberlain
763b58923a block: clarify context for refcount increment helpers
Let us clarify the context under which the helpers to increment the
refcount for the gendisk and request_queue can be called under. We
make this explicit on the places where we may sleep with might_sleep().

We don't address the decrement context yet, as that needs some extra
work and fixes, but will be addressed in the next patch.

Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24 09:15:58 -06:00
Luis Chamberlain
b5bd357cf8 block: add docs for gendisk / request_queue refcount helpers
This adds documentation for the gendisk / request_queue refcount
helpers.

Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24 09:15:57 -06:00
Christoph Hellwig
40d09b53bf blk-mq: add a new blk_mq_complete_request_remote API
This is a variant of blk_mq_complete_request_remote that only completes
the request if it needs to be bounced to another CPU or a softirq.  If
the request can be completed locally the function returns false and lets
the driver complete it without requring and indirect function call.

Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24 09:15:57 -06:00
Christoph Hellwig
963395269c blk-mq: factor out a blk_mq_complete_need_ipi helper
Add a helper to decide if we can complete locally or need an IPI.

Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24 09:15:57 -06:00
Christoph Hellwig
4c8fc19686 blk-mq: remove the get_cpu/put_cpu pair in blk_mq_complete_request
We don't really care if we get migrated during the I/O completion.
In the worth case we either perform an IPI that wasn't required, or
complete the request on a CPU which we just migrated off.

Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24 09:15:57 -06:00
Christoph Hellwig
15f73f5b3e blk-mq: move failure injection out of blk_mq_complete_request
Move the call to blk_should_fake_timeout out of blk_mq_complete_request
and into the drivers, skipping call sites that are obvious error
handlers, and remove the now superflous blk_mq_force_complete_rq helper.
This ensures we don't keep injecting errors into completions that just
terminate the Linux request after the hardware has been reset or the
command has been aborted.

Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24 09:15:57 -06:00
Christoph Hellwig
d391a7a399 blk-mq: merge the softirq vs non-softirq IPI logic
Both the softirq path for single queue devices and the multi-queue
completion handler share the same logic to figure out if we need an
IPI for the completion and eventually issue it.  Merge the two
versions into a single unified code path.

Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24 09:15:57 -06:00
Christoph Hellwig
d6cc464cc5 blk-mq: short cut the IPI path in blk_mq_force_complete_rq for !SMP
Let the compile optimize out the entire IPI path, given that we are
obviously not going to use it.

Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24 09:15:57 -06:00
Christoph Hellwig
6aab1da603 blk-mq: complete polled requests directly
Even for single queue devices there is no point in offloading a polled
completion to the softirq, given that blk_mq_force_complete_rq is called
from the polling thread in that case and thus there are no starvation
issues.

Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24 09:15:57 -06:00
Christoph Hellwig
dea6f39938 blk-mq: remove raise_blk_irq
By open coding raise_blk_irq in the only caller, and replacing the
ifdef CONFIG_SMP with an IS_ENABLED check the flow in the caller
can be significantly simplified.

Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24 09:15:57 -06:00
Christoph Hellwig
115243f553 blk-mq: factor out a helper to reise the block softirq
Add a helper to deduplicate the logic that raises the block softirq.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24 09:15:56 -06:00
Christoph Hellwig
c3077b5d97 blk-mq: merge blk-softirq.c into blk-mq.c
__blk_complete_request is only called from the blk-mq code, and
duplicates a lot of code from blk-mq.c.  Move it there to prepare
for better code sharing and simplifications.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24 09:15:56 -06:00
Chengguang Xu
0b8eb629a7 block: release bip in a right way in error path
Release bip using kfree() in error path when that was allocated
by kmalloc().

Signed-off-by: Chengguang Xu <cgxu519@mykernel.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24 08:49:07 -06:00
Jens Axboe
5a473e8311 block: provide plug based way of signaling forced no-wait semantics
Provide a way for the caller to specify that IO should be marked
with REQ_NOWAIT to avoid blocking on allocation.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-21 20:44:25 -06:00
Linus Torvalds
d2b1c81f5f block-5.8-2020-06-19
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Merge tag 'block-5.8-2020-06-19' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:

 - Use import_uuid() where appropriate (Andy)

 - bcache fixes (Coly, Mauricio, Zhiqiang)

 - blktrace sparse warnings fix (Jan)

 - blktrace concurrent setup fix (Luis)

 - blkdev_get use-after-free fix (Jason)

 - Ensure all blk-mq maps are updated (Weiping)

 - Loop invalidate bdev fix (Zheng)

* tag 'block-5.8-2020-06-19' of git://git.kernel.dk/linux-block:
  block: make function 'kill_bdev' static
  loop: replace kill_bdev with invalidate_bdev
  partitions/ldm: Replace uuid_copy() with import_uuid() where it makes sense
  block: update hctx map when use multiple maps
  blktrace: Avoid sparse warnings when assigning q->blk_trace
  blktrace: break out of blktrace setup on concurrent calls
  block: Fix use-after-free in blkdev_get()
  trace/events/block.h: drop kernel-doc for dropped function parameter
  blk-mq: Remove redundant 'return' statement
  bcache: pr_info() format clean up in bcache_device_init()
  bcache: use delayed kworker fo asynchronous devices registration
  bcache: check and adjust logical block size for backing devices
  bcache: fix potential deadlock problem in btree_gc_coalesce
2020-06-19 13:11:26 -07:00
Andy Shevchenko
bc163c2046 partitions/ldm: Replace uuid_copy() with import_uuid() where it makes sense
There is a specific API to treat raw data as UUID, i.e. import_uuid().
Use it instead of uuid_copy() with explicit casting.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-18 09:17:54 -06:00
Weiping Zhang
fe35ec58f0 block: update hctx map when use multiple maps
There is an issue when tune the number for read and write queues,
if the total queue count was not changed. The hctx->type cannot
be updated, since __blk_mq_update_nr_hw_queues will return directly
if the total queue count has not been changed.

Reproduce:

dmesg | grep "default/read/poll"
[    2.607459] nvme nvme0: 48/0/0 default/read/poll queues
cat /sys/kernel/debug/block/nvme0n1/hctx*/type | sort | uniq -c
     48 default

tune the write queues to 24:
echo 24 > /sys/module/nvme/parameters/write_queues
echo 1 > /sys/block/nvme0n1/device/reset_controller

dmesg | grep "default/read/poll"
[  433.547235] nvme nvme0: 24/24/0 default/read/poll queues

cat /sys/kernel/debug/block/nvme0n1/hctx*/type | sort | uniq -c
     48 default

The driver's hardware queue mapping is not same as block layer.

Signed-off-by: Weiping Zhang <zhangweiping@didiglobal.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-17 21:33:04 -06:00
Gustavo A. R. Silva
8a631c26bd block: Replace zero-length array with flexible-array
There is a regular need in the kernel to provide a way to declare having a
dynamically sized set of trailing elements in a structure. Kernel code should
always use “flexible array members”[1] for these cases. The older style of
one-element or zero-length arrays should no longer be used[2].

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://github.com/KSPP/linux/issues/21

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-06-15 23:08:32 -05:00
Baolin Wang
a8a5e383cf blk-mq: Remove redundant 'return' statement
The blk_mq_all_tag_iter() is a void function, thus remove
the redundant 'return' statement in this function.

Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-15 08:34:43 -06:00
Linus Torvalds
6adc19fd13 Kbuild updates for v5.8 (2nd)
- fix build rules in binderfs sample
 
  - fix build errors when Kbuild recurses to the top Makefile
 
  - covert '---help---' in Kconfig to 'help'
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Merge tag 'kbuild-v5.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull more Kbuild updates from Masahiro Yamada:

 - fix build rules in binderfs sample

 - fix build errors when Kbuild recurses to the top Makefile

 - covert '---help---' in Kconfig to 'help'

* tag 'kbuild-v5.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  treewide: replace '---help---' in Kconfig files with 'help'
  kbuild: fix broken builds because of GZIP,BZIP2,LZOP variables
  samples: binderfs: really compile this sample and fix build issues
2020-06-13 13:29:16 -07:00
Masahiro Yamada
a7f7f6248d treewide: replace '---help---' in Kconfig files with 'help'
Since commit 84af7a6194 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.

This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.

There are a variety of indentation styles found.

  a) 4 spaces + '---help---'
  b) 7 spaces + '---help---'
  c) 8 spaces + '---help---'
  d) 1 space + 1 tab + '---help---'
  e) 1 tab + '---help---'    (correct indentation)
  f) 1 tab + 1 space + '---help---'
  g) 1 tab + 2 spaces + '---help---'

In order to convert all of them to 1 tab + 'help', I ran the
following commend:

  $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-14 01:57:21 +09:00
Ming Lei
22f614bc0f blk-mq: fix blk_mq_all_tag_iter
blk_mq_all_tag_iter() is added to iterate all requests, so we should
fetch the request from ->static_rqs][] instead of ->rqs[] which is for
holding in-flight request only.

Fix it by adding flag of BT_TAG_ITER_STATIC_RQS.

Fixes: bf0beec060 ("blk-mq: drain I/O when all CPUs in a hctx are offline")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Tested-by: John Garry <john.garry@huawei.com>
Cc: Dongli Zhang <dongli.zhang@oracle.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Daniel Wagner <dwagner@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-07 08:56:50 -06:00
Christoph Hellwig
d94ecfc399 blk-mq: split out a __blk_mq_get_driver_tag helper
Allocation of the driver tag in the case of using a scheduler shares very
little code with the "normal" tag allocation.  Split out a new helper to
streamline this path, and untangle it from the complex normal tag
allocation.

This way also avoids to fail driver tag allocation because of inactive hctx
during cpu hotplug, and fixes potential hang risk.

Fixes: bf0beec060 ("blk-mq: drain I/O when all CPUs in a hctx are offline")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: John Garry <john.garry@huawei.com>
Cc: Dongli Zhang <dongli.zhang@oracle.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-07 08:56:50 -06:00
Ahmed S. Darwish
15b81ce5ab block: nr_sects_write(): Disable preemption on seqcount write
For optimized block readers not holding a mutex, the "number of sectors"
64-bit value is protected from tearing on 32-bit architectures by a
sequence counter.

Disable preemption before entering that sequence counter's write side
critical section. Otherwise, the read side can preempt the write side
section and spin for the entire scheduler tick. If the reader belongs to
a real-time scheduling class, it can spin forever and the kernel will
livelock.

Fixes: c83f6bf98d ("block: add partition resize function to blkpg ioctl")
Cc: <stable@vger.kernel.org>
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-04 21:22:28 -06:00
Christoph Hellwig
d24de76af8 block: remove the error argument to the block_bio_complete tracepoint
The status can be trivially derived from the bio itself.  That also avoid
callers like NVMe to incorrectly pass a blk_status_t instead of the errno,
and the overhead of translating the blk_status_t to the errno in the I/O
completion fast path when no tracing is enabled.

Fixes: 35fe0d12c8 ("nvme: trace bio completion")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-04 21:16:11 -06:00
yu kuai
a75ca93031 block/bio-integrity: don't free 'buf' if bio_integrity_add_page() failed
commit e7bf90e5af ("block/bio-integrity: fix a memory leak bug") added
a kfree() for 'buf' if bio_integrity_add_page() returns '0'. However,
the object will be freed in bio_integrity_free() since 'bio->bi_opf' and
'bio->bi_integrity' were set previousy in bio_integrity_alloc().

Fixes: commit e7bf90e5af ("block/bio-integrity: fix a memory leak bug")
Signed-off-by: yu kuai <yukuai3@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Bob Liu <bob.liu@oracle.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-02 17:21:50 -06:00
Linus Torvalds
bce159d734 for-5.8/drivers-2020-06-01
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Merge tag 'for-5.8/drivers-2020-06-01' of git://git.kernel.dk/linux-block

Pull block driver updates from Jens Axboe:
 "On top of the core changes, here are the block driver changes for this
  merge window:

   - NVMe changes:
        - NVMe over Fibre Channel protocol updates, which also reach
          over to drivers/scsi/lpfc (James Smart)
        - namespace revalidation support on the target (Anthony
          Iliopoulos)
        - gcc zero length array fix (Arnd Bergmann)
        - nvmet cleanups (Chaitanya Kulkarni)
        - misc cleanups and fixes (me, Keith Busch, Sagi Grimberg)
        - use a SRQ per completion vector (Max Gurtovoy)
        - fix handling of runtime changes to the queue count (Weiping
          Zhang)
        - t10 protection information support for nvme-rdma and
          nvmet-rdma (Israel Rukshin and Max Gurtovoy)
        - target side AEN improvements (Chaitanya Kulkarni)
        - various fixes and minor improvements all over, icluding the
          nvme part of the lpfc driver"

   - Floppy code cleanup series (Willy, Denis)

   - Floppy contention fix (Jiri)

   - Loop CONFIGURE support (Martijn)

   - bcache fixes/improvements (Coly, Joe, Colin)

   - q->queuedata cleanups (Christoph)

   - Get rid of ioctl_by_bdev (Christoph, Stefan)

   - md/raid5 allocation fixes (Coly)

   - zero length array fixes (Gustavo)

   - swim3 task state fix (Xu)"

* tag 'for-5.8/drivers-2020-06-01' of git://git.kernel.dk/linux-block: (166 commits)
  bcache: configure the asynchronous registertion to be experimental
  bcache: asynchronous devices registration
  bcache: fix refcount underflow in bcache_device_free()
  bcache: Convert pr_<level> uses to a more typical style
  bcache: remove redundant variables i and n
  lpfc: Fix return value in __lpfc_nvme_ls_abort
  lpfc: fix axchg pointer reference after free and double frees
  lpfc: Fix pointer checks and comments in LS receive refactoring
  nvme: set dma alignment to qword
  nvmet: cleanups the loop in nvmet_async_events_process
  nvmet: fix memory leak when removing namespaces and controllers concurrently
  nvmet-rdma: add metadata/T10-PI support
  nvmet: add metadata support for block devices
  nvmet: add metadata/T10-PI support
  nvme: add Metadata Capabilities enumerations
  nvmet: rename nvmet_check_data_len to nvmet_check_transfer_len
  nvmet: rename nvmet_rw_len to nvmet_rw_data_len
  nvmet: add metadata characteristics for a namespace
  nvme-rdma: add metadata/T10-PI support
  nvme-rdma: introduce nvme_rdma_sgl structure
  ...
2020-06-02 15:37:03 -07:00
Linus Torvalds
750a02ab8d for-5.8/block-2020-06-01
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Merge tag 'for-5.8/block-2020-06-01' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:
 "Core block changes that have been queued up for this release:

   - Remove dead blk-throttle and blk-wbt code (Guoqing)

   - Include pid in blktrace note traces (Jan)

   - Don't spew I/O errors on wouldblock termination (me)

   - Zone append addition (Johannes, Keith, Damien)

   - IO accounting improvements (Konstantin, Christoph)

   - blk-mq hardware map update improvements (Ming)

   - Scheduler dispatch improvement (Salman)

   - Inline block encryption support (Satya)

   - Request map fixes and improvements (Weiping)

   - blk-iocost tweaks (Tejun)

   - Fix for timeout failing with error injection (Keith)

   - Queue re-run fixes (Douglas)

   - CPU hotplug improvements (Christoph)

   - Queue entry/exit improvements (Christoph)

   - Move DMA drain handling to the few drivers that use it (Christoph)

   - Partition handling cleanups (Christoph)"

* tag 'for-5.8/block-2020-06-01' of git://git.kernel.dk/linux-block: (127 commits)
  block: mark bio_wouldblock_error() bio with BIO_QUIET
  blk-wbt: rename __wbt_update_limits to wbt_update_limits
  blk-wbt: remove wbt_update_limits
  blk-throttle: remove tg_drain_bios
  blk-throttle: remove blk_throtl_drain
  null_blk: force complete for timeout request
  blk-mq: drain I/O when all CPUs in a hctx are offline
  blk-mq: add blk_mq_all_tag_iter
  blk-mq: open code __blk_mq_alloc_request in blk_mq_alloc_request_hctx
  blk-mq: use BLK_MQ_NO_TAG in more places
  blk-mq: rename BLK_MQ_TAG_FAIL to BLK_MQ_NO_TAG
  blk-mq: move more request initialization to blk_mq_rq_ctx_init
  blk-mq: simplify the blk_mq_get_request calling convention
  blk-mq: remove the bio argument to ->prepare_request
  nvme: force complete cancelled requests
  blk-mq: blk-mq: provide forced completion method
  block: fix a warning when blkdev.h is included for !CONFIG_BLOCK builds
  block: blk-crypto-fallback: remove redundant initialization of variable err
  block: reduce part_stat_lock() scope
  block: use __this_cpu_add() instead of access by smp_processor_id()
  ...
2020-06-02 15:29:19 -07:00
Matthew Wilcox (Oracle)
cee9a0c4e8 mm: move readahead prototypes from mm.h
Patch series "Change readahead API", v11.

This series adds a readahead address_space operation to replace the
readpages operation.  The key difference is that pages are added to the
page cache as they are allocated (and then looked up by the filesystem)
instead of passing them on a list to the readpages operation and having
the filesystem add them to the page cache.  It's a net reduction in code
for each implementation, more efficient than walking a list, and solves
the direct-write vs buffered-read problem reported by yu kuai at
http://lkml.kernel.org/r/20200116063601.39201-1-yukuai3@huawei.com

The only unconverted filesystems are those which use fscache.  Their
conversion is pending Dave Howells' rewrite which will make the
conversion substantially easier.  This should be completed by the end of
the year.

I want to thank the reviewers/testers; Dave Chinner, John Hubbard, Eric
Biggers, Johannes Thumshirn, Dave Sterba, Zi Yan, Christoph Hellwig and
Miklos Szeredi have done a marvellous job of providing constructive
criticism.

These patches pass an xfstests run on ext4, xfs & btrfs with no
regressions that I can tell (some of the tests seem a little flaky
before and remain flaky afterwards).

This patch (of 25):

The readahead code is part of the page cache so should be found in the
pagemap.h file.  force_page_cache_readahead is only used within mm, so
move it to mm/internal.h instead.  Remove the parameter names where they
add no value, and rename the ones which were actively misleading.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Chao Yu <yuchao0@huawei.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Gao Xiang <gaoxiang25@huawei.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Link: http://lkml.kernel.org/r/20200414150233.24495-1-willy@infradead.org
Link: http://lkml.kernel.org/r/20200414150233.24495-2-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-02 10:59:06 -07:00
Guoqing Jiang
4d89e1d112 blk-wbt: rename __wbt_update_limits to wbt_update_limits
Now let's rename __wbt_update_limits to wbt_update_limits after the
previous one is deleted.

Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-29 16:30:39 -06:00
Guoqing Jiang
26e0ca12e0 blk-wbt: remove wbt_update_limits
No one call this function after commit 2af2783f2e ("rq-qos: get rid of
redundant wbt_update_limits()"), so remove it.

Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-29 16:30:39 -06:00
Guoqing Jiang
32e3374304 blk-throttle: remove tg_drain_bios
After blk_throtl_drain is removed, there is no caller of tg_drain_bios,
so remove it as well.

Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-29 16:30:39 -06:00
Guoqing Jiang
b77412372b blk-throttle: remove blk_throtl_drain
After the commit 5addeae1be ("blk-cgroup: remove blkcg_drain_queue"),
there is no caller of blk_throtl_drain, so let's remove it.

Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-29 16:30:39 -06:00
Ming Lei
bf0beec060 blk-mq: drain I/O when all CPUs in a hctx are offline
Most of blk-mq drivers depend on managed IRQ's auto-affinity to setup
up queue mapping. Thomas mentioned the following point[1]:

"That was the constraint of managed interrupts from the very beginning:

 The driver/subsystem has to quiesce the interrupt line and the associated
 queue _before_ it gets shutdown in CPU unplug and not fiddle with it
 until it's restarted by the core when the CPU is plugged in again."

However, current blk-mq implementation doesn't quiesce hw queue before
the last CPU in the hctx is shutdown.  Even worse, CPUHP_BLK_MQ_DEAD is a
cpuhp state handled after the CPU is down, so there isn't any chance to
quiesce the hctx before shutting down the CPU.

Add new CPUHP_AP_BLK_MQ_ONLINE state to stop allocating from blk-mq hctxs
where the last CPU goes away, and wait for completion of in-flight
requests.  This guarantees that there is no inflight I/O before shutting
down the managed IRQ.

Add a BLK_MQ_F_STACKING and set it for dm-rq and loop, so we don't need
to wait for completion of in-flight requests from these drivers to avoid
a potential dead-lock. It is safe to do this for stacking drivers as those
do not use interrupts at all and their I/O completions are triggered by
underlying devices I/O completion.

[1] https://lore.kernel.org/linux-block/alpine.DEB.2.21.1904051331270.1802@nanos.tec.linutronix.de/

[hch: different retry mechanism, merged two patches, minor cleanups]

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-29 10:23:25 -06:00
Ming Lei
602380d28e blk-mq: add blk_mq_all_tag_iter
Add a new blk_mq_all_tag_iter function to iterate over all allocated
scheduler tags and driver tags.  This is more flexible than the existing
blk_mq_all_tag_busy_iter function as it allows the callers to do whatever
they want on allocated request instead of being limited to started
requests.

It will be used to implement draining allocated requests on specified
hctx in this patchset.

[hch: switch from the two booleans to a more readable flags field and
 consolidate the tags iter functions]

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Bart van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-29 10:23:25 -06:00
Christoph Hellwig
600c3b0cea blk-mq: open code __blk_mq_alloc_request in blk_mq_alloc_request_hctx
blk_mq_alloc_request_hctx is only used for NVMeoF connect commands, so
tailor it to the specific requirements, and don't bother the general
fast path code with its special twinkles.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-29 10:23:25 -06:00
Christoph Hellwig
766473681c blk-mq: use BLK_MQ_NO_TAG in more places
Replace various magic -1 constants for tags with BLK_MQ_NO_TAG.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-29 10:23:25 -06:00
Christoph Hellwig
419c3d5e80 blk-mq: rename BLK_MQ_TAG_FAIL to BLK_MQ_NO_TAG
To prepare for wider use of this constant give it a more applicable name.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-29 10:23:25 -06:00
Christoph Hellwig
7ea4d8a4d6 blk-mq: move more request initialization to blk_mq_rq_ctx_init
Don't split request initialization between __blk_mq_alloc_request and
blk_mq_rq_ctx_init.  Also remove the op argument as it can be derived
from the blk_mq_alloc_data structure.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-29 10:23:24 -06:00
Christoph Hellwig
e6e7abffe3 blk-mq: simplify the blk_mq_get_request calling convention
The bio argument is entirely unused, and the request_queue can be passed
through the alloc_data, given that it needs to be filled out for the
low-level tag allocation anyway.  Also rename the function to
__blk_mq_alloc_request as the switch between get and alloc in the call
chains is rather confusing.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-29 10:23:24 -06:00
Christoph Hellwig
5d9c305b8e blk-mq: remove the bio argument to ->prepare_request
None of the I/O schedulers actually needs it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-29 10:23:24 -06:00
Keith Busch
7b11eab041 blk-mq: blk-mq: provide forced completion method
Drivers may need to bypass error injection for error recovery. Rename
__blk_mq_complete_request() to blk_mq_force_complete_rq() and export
that function so drivers may skip potential fake timeouts after they've
reclaimed lost requests.

Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-29 10:21:59 -06:00
Jens Axboe
b0beb28097 Revert "block: end bio with BLK_STS_AGAIN in case of non-mq devs and REQ_NOWAIT"
This reverts commit c58c1f8343.

io_uring does do the right thing for this case, and we're still returning
-EAGAIN to userspace for the cases we don't support. Revert this change
to avoid doing endless spins of resubmits.

Cc: stable@vger.kernel.org # v5.6
Reported-by: Bijan Mottahedeh <bijan.mottahedeh@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-28 13:20:39 -06:00
Colin Ian King
e7ecc142e9 block: blk-crypto-fallback: remove redundant initialization of variable err
The variable err is being initialized with a value that is never read
and it is being updated later with a new value.  The initialization is
redundant and can be removed.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Satya Tangirala <satyat@google.com>
Addresses-Coverity: ("Unused value")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-27 05:41:59 -06:00
Christoph Hellwig
524f9ffd6a block: reduce part_stat_lock() scope
We only need the stats lock (aka preempt_disable()) for updating the
states, not for looking up or dropping the hd_struct reference.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-27 05:21:23 -06:00
Konstantin Khlebnikov
8ab1d40a64 block: remove rcu_read_lock() from part_stat_lock()
The RCU lock is required only in disk_map_sector_rcu() to lookup the
partition.  After that request holds reference to related hd_struct.

Replace get_cpu() with preempt_disable() - returned cpu index is unused.

[hch: rebased]

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-27 05:21:23 -06:00
Konstantin Khlebnikov
b5af37ab3a block: add a blk_account_io_merge_bio helper
Move the non-"new_io" branch of blk_account_io_start() into separate
function.  Fix merge accounting for discards (they were counted as write
merges).

The new blk_account_io_merge_bio() doesn't call update_io_ticks() unlike
blk_account_io_start(), as there is no reason for that.

[hch: rebased]

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-27 05:21:23 -06:00
Konstantin Khlebnikov
b9c54f5660 block: account merge of two requests
Also rename blk_account_io_merge() into blk_account_io_merge_request() to
distinguish it from merging request and bio.

[hch: rebased]

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-27 05:21:23 -06:00
Christoph Hellwig
58d4f14fc3 block: always use a percpu variable for disk stats
percpu variables have a perfectly fine working stub implementation
for UP kernels, so use that.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-27 05:21:23 -06:00
Christoph Hellwig
9123bf6f21 block: move update_io_ticks to blk-core.c
All callers are in blk-core.c, so move update_io_ticks over.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-27 05:21:23 -06:00
Christoph Hellwig
e722fff238 block: remove generic_{start,end}_io_acct
Remove these now unused functions.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-27 05:21:23 -06:00
Christoph Hellwig
956d510ee7 block: add disk/bio-based accounting helpers
Add two new helpers to simplify I/O accounting for bio based drivers.
Currently these drivers use the generic_start_io_acct and
generic_end_io_acct helpers which have very cumbersome calling
conventions, don't actually return the time they started accounting,
and try to deal with accounting for partitions, which can't happen
for bio based drivers.  The new helpers will be used to subsequently
replace uses of the old helpers.

The main API is the bio based wrappes in blkdev.h, but for zram
which wants to account rw_page based I/O lower level routines are
provided as well.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-27 05:21:23 -06:00
Christoph Hellwig
c81b49d4d6 block: remove the disk and queue NULL checks in blkdev_issue_flush
Both of these never can be NULL for a live block device.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-22 08:45:59 -06:00
Christoph Hellwig
9398554fb3 block: remove the error_sector argument to blkdev_issue_flush
The argument isn't used by any caller, and drivers don't fill out
bi_sector for flush requests either.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-22 08:45:46 -06:00
Stefan Haberland
26d7e28e38 s390/dasd: remove ioctl_by_bdev calls
The IBM partition parser requires device type specific information only
available to the DASD driver to correctly register partitions. The
current approach of using ioctl_by_bdev with a fake user space pointer
is discouraged.

Fix this by replacing IOCTL calls with direct in-kernel function calls.

Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
Reviewed-by: Jan Hoeppner <hoeppner@linux.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-21 08:22:20 -06:00
Baolin Wang
172ce41db4 block: Remove unused flush_queue_delayed in struct blk_flush_queue
The flush_queue_delayed was introdued to hold queue if flush is
running for non-queueable flush drive by commit 3ac0cc4508
("hold queue if flush is running for non-queueable flush drive"),
but the non mq parts of the flush code had been removed by
commit 7e992f847a ("block: remove non mq parts from the flush code"),
as well as removing the usage of the flush_queue_delayed flag.
Thus remove the unused flush_queue_delayed flag.

Signed-off-by: Baolin Wang <baolin.wang7@gmail.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-19 09:42:46 -06:00
Bart Van Assche
c8210a5765 block: Fix type of first compat_put_{,u}long() argument
This patch fixes the following sparse warnings:

block/ioctl.c:209:16: warning: incorrect type in argument 1 (different address spaces)
block/ioctl.c:209:16:    expected void const volatile [noderef] <asn:1> *
block/ioctl.c:209:16:    got signed int [usertype] *argp
block/ioctl.c:214:16: warning: incorrect type in argument 1 (different address spaces)
block/ioctl.c:214:16:    expected void const volatile [noderef] <asn:1> *
block/ioctl.c:214:16:    got unsigned int [usertype] *argp
block/ioctl.c:666:40: warning: incorrect type in argument 1 (different address spaces)
block/ioctl.c:666:40:    expected signed int [usertype] *argp
block/ioctl.c:666:40:    got void [noderef] <asn:1> *argp
block/ioctl.c:672:41: warning: incorrect type in argument 1 (different address spaces)
block/ioctl.c:672:41:    expected unsigned int [usertype] *argp
block/ioctl.c:672:41:    got void [noderef] <asn:1> *argp

Fixes: 9b81648cb5 ("compat_ioctl: simplify up block/ioctl.c")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-19 09:40:29 -06:00
Christoph Hellwig
10ec5e86f9 block: merge part_{inc,dev}_in_flight into their only callers
part_inc_in_flight and part_dec_in_flight only have one caller each, and
those callers are purely for bio based drivers.  Merge each function into
the only caller, and remove the superflous blk-mq checks.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-19 09:35:24 -06:00
Christoph Hellwig
76268f3ac0 block: don't call part_{inc,dec}_in_flight for blk-mq devices
part_inc_in_flight and part_dec_in_flight are no-ops for blk-mq queues,
so remove the calls in purely blk-mq callers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-19 09:35:24 -06:00
Christoph Hellwig
b2f609e191 block: move the blk-mq calls out of part_in_flight{,_rw}
Don't bother to call part_in_flight / part_in_flight_rw on blk-mq
devices, just call the blk-mq versions directly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-19 09:35:24 -06:00
Christoph Hellwig
f1394b7988 block: mark blk_account_io_completion static
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-19 09:35:24 -06:00
Christoph Hellwig
ac7c5675fa blk-mq: allow blk_mq_make_request to consume the q_usage_counter reference
blk_mq_make_request currently needs to grab an q_usage_counter
reference when allocating a request.  This is because the block layer
grabs one before calling blk_mq_make_request, but also releases it as
soon as blk_mq_make_request returns.  Remove the blk_queue_exit call
after blk_mq_make_request returns, and instead let it consume the
reference.  This works perfectly fine for the block layer caller, just
device mapper needs an extra reference as the old problem still
persists there.  Open code blk_queue_enter_live in device mapper,
as there should be no other callers and this allows better documenting
why we do a non-try get.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-19 09:34:29 -06:00
Christoph Hellwig
35b371ff01 blk-mq: remove a pointless queue enter pair in blk_mq_alloc_request_hctx
No need for two queue references.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-19 09:34:29 -06:00
Christoph Hellwig
22fa792cd8 blk-mq: remove a pointless queue enter pair in blk_mq_alloc_request
No need for two queue references.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-19 09:34:29 -06:00
Christoph Hellwig
a5ea581105 blk-mq: move the call to blk_queue_enter_live out of blk_mq_get_request
Move the blk_queue_enter_live calls into the callers, where they can
successively be cleaned up.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-19 09:34:29 -06:00
Satya Tangirala
488f6682c8 block: blk-crypto-fallback for Inline Encryption
Blk-crypto delegates crypto operations to inline encryption hardware
when available. The separately configurable blk-crypto-fallback contains
a software fallback to the kernel crypto API - when enabled, blk-crypto
will use this fallback for en/decryption when inline encryption hardware
is not available.

This lets upper layers not have to worry about whether or not the
underlying device has support for inline encryption before deciding to
specify an encryption context for a bio. It also allows for testing
without actual inline encryption hardware - in particular, it makes it
possible to test the inline encryption code in ext4 and f2fs simply by
running xfstests with the inlinecrypt mount option, which in turn allows
for things like the regular upstream regression testing of ext4 to cover
the inline encryption code paths.

For more details, refer to Documentation/block/inline-encryption.rst.

Signed-off-by: Satya Tangirala <satyat@google.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-14 09:48:03 -06:00
Satya Tangirala
d145dc2303 block: Make blk-integrity preclude hardware inline encryption
Whenever a device supports blk-integrity, make the kernel pretend that
the device doesn't support inline encryption (essentially by setting the
keyslot manager in the request queue to NULL).

There's no hardware currently that supports both integrity and inline
encryption. However, it seems possible that there will be such hardware
in the near future (like the NVMe key per I/O support that might support
both inline encryption and PI).

But properly integrating both features is not trivial, and without
real hardware that implements both, it is difficult to tell if it will
be done correctly by the majority of hardware that support both.
So it seems best not to support both features together right now, and
to decide what to do at probe time.

Signed-off-by: Satya Tangirala <satyat@google.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-14 09:48:03 -06:00
Satya Tangirala
a892c8d52c block: Inline encryption support for blk-mq
We must have some way of letting a storage device driver know what
encryption context it should use for en/decrypting a request. However,
it's the upper layers (like the filesystem/fscrypt) that know about and
manages encryption contexts. As such, when the upper layer submits a bio
to the block layer, and this bio eventually reaches a device driver with
support for inline encryption, the device driver will need to have been
told the encryption context for that bio.

We want to communicate the encryption context from the upper layer to the
storage device along with the bio, when the bio is submitted to the block
layer. To do this, we add a struct bio_crypt_ctx to struct bio, which can
represent an encryption context (note that we can't use the bi_private
field in struct bio to do this because that field does not function to pass
information across layers in the storage stack). We also introduce various
functions to manipulate the bio_crypt_ctx and make the bio/request merging
logic aware of the bio_crypt_ctx.

We also make changes to blk-mq to make it handle bios with encryption
contexts. blk-mq can merge many bios into the same request. These bios need
to have contiguous data unit numbers (the necessary changes to blk-merge
are also made to ensure this) - as such, it suffices to keep the data unit
number of just the first bio, since that's all a storage driver needs to
infer the data unit number to use for each data block in each bio in a
request. blk-mq keeps track of the encryption context to be used for all
the bios in a request with the request's rq_crypt_ctx. When the first bio
is added to an empty request, blk-mq will program the encryption context
of that bio into the request_queue's keyslot manager, and store the
returned keyslot in the request's rq_crypt_ctx. All the functions to
operate on encryption contexts are in blk-crypto.c.

Upper layers only need to call bio_crypt_set_ctx with the encryption key,
algorithm and data_unit_num; they don't have to worry about getting a
keyslot for each encryption context, as blk-mq/blk-crypto handles that.
Blk-crypto also makes it possible for request-based layered devices like
dm-rq to make use of inline encryption hardware by cloning the
rq_crypt_ctx and programming a keyslot in the new request_queue when
necessary.

Note that any user of the block layer can submit bios with an
encryption context, such as filesystems, device-mapper targets, etc.

Signed-off-by: Satya Tangirala <satyat@google.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-14 09:47:53 -06:00
Satya Tangirala
1b26283970 block: Keyslot Manager for Inline Encryption
Inline Encryption hardware allows software to specify an encryption context
(an encryption key, crypto algorithm, data unit num, data unit size) along
with a data transfer request to a storage device, and the inline encryption
hardware will use that context to en/decrypt the data. The inline
encryption hardware is part of the storage device, and it conceptually sits
on the data path between system memory and the storage device.

Inline Encryption hardware implementations often function around the
concept of "keyslots". These implementations often have a limited number
of "keyslots", each of which can hold a key (we say that a key can be
"programmed" into a keyslot). Requests made to the storage device may have
a keyslot and a data unit number associated with them, and the inline
encryption hardware will en/decrypt the data in the requests using the key
programmed into that associated keyslot and the data unit number specified
with the request.

As keyslots are limited, and programming keys may be expensive in many
implementations, and multiple requests may use exactly the same encryption
contexts, we introduce a Keyslot Manager to efficiently manage keyslots.

We also introduce a blk_crypto_key, which will represent the key that's
programmed into keyslots managed by keyslot managers. The keyslot manager
also functions as the interface that upper layers will use to program keys
into inline encryption hardware. For more information on the Keyslot
Manager, refer to documentation found in block/keyslot-manager.c and
linux/keyslot-manager.h.

Co-developed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Satya Tangirala <satyat@google.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-14 09:46:54 -06:00
Tejun Heo
81ca627a93 iocost: don't let vrate run wild while there's no saturation signal
When the QoS targets are met and nothing is being throttled, there's
no way to tell how saturated the underlying device is - it could be
almost entirely idle, at the cusp of saturation or anywhere inbetween.
Given that there's no information, it's best to keep vrate as-is in
this state.  Before 7cd806a9a9 ("iocost: improve nr_lagging
handling"), this was the case - if the device isn't missing QoS
targets and nothing is being throttled, busy_level was reset to zero.

While fixing nr_lagging handling, 7cd806a9a9 ("iocost: improve
nr_lagging handling") broke this.  Now, while the device is hitting
QoS targets and nothing is being throttled, vrate keeps getting
adjusted according to the existing busy_level.

This led to vrate keeping climing till it hits max when there's an IO
issuer with limited request concurrency if the vrate started low.
vrate starts getting adjusted upwards until the issuer can issue IOs
w/o being throttled.  From then on, QoS targets keeps getting met and
nothing on the system needs throttling and vrate keeps getting
increased due to the existing busy_level.

This patch makes the following changes to the busy_level logic.

* Reset busy_level if nr_shortages is zero to avoid the above
  scenario.

* Make non-zero nr_lagging block lowering nr_level but still clear
  positive busy_level if there's clear non-saturation signal - QoS
  targets are met and nr_shortages is non-zero.  nr_lagging's role is
  preventing adjusting vrate upwards while there are long-running
  commands and it shouldn't keep busy_level positive while there's
  clear non-saturation signal.

* Restructure code for clarity and add comments.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Andy Newell <newella@fb.com>
Fixes: 7cd806a9a9 ("iocost: improve nr_lagging handling")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-14 09:32:09 -06:00
Ming Lei
71ac860af8 block: move blk_io_schedule() out of header file
blk_io_schedule() isn't called from performance sensitive code path, and
it is easier to maintain by exporting it as symbol.

Also blk_io_schedule() is only called by CONFIG_BLOCK code, so it is safe
to do this way. Meantime fixes build failure when CONFIG_BLOCK is off.

Cc: Christoph Hellwig <hch@infradead.org>
Fixes: e6249cdd46 ("block: add blk_io_schedule() for avoiding task hung in sync dio")
Reported-by: Satya Tangirala <satyat@google.com>
Tested-by: Satya Tangirala <satyat@google.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-14 08:06:04 -06:00
Johannes Thumshirn
29b2a3aa29 block: export bio_release_pages and bio_iov_iter_get_pages
Export bio_release_pages and bio_iov_iter_get_pages, so they can be used
from modular code.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-12 20:36:28 -06:00
Damien Le Moal
e732671aa5 block: Modify revalidate zones
Modify the interface of blk_revalidate_disk_zones() to add an optional
driver callback function that a driver can use to extend processing
done during zone revalidation. The callback, if defined, is executed
with the device request queue frozen, after all zones have been
inspected.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-12 20:36:28 -06:00
Johannes Thumshirn
1392d37018 block: introduce blk_req_zone_write_trylock
Introduce blk_req_zone_write_trylock(), which either grabs the write-lock
for a sequential zone or returns false, if the zone is already locked.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-12 20:36:28 -06:00
Keith Busch
0512a75b98 block: Introduce REQ_OP_ZONE_APPEND
Define REQ_OP_ZONE_APPEND to append-write sectors to a zone of a zoned
block device. This is a no-merge write operation.

A zone append write BIO must:
* Target a zoned block device
* Have a sector position indicating the start sector of the target zone
* The target zone must be a sequential write zone
* The BIO must not cross a zone boundary
* The BIO size must not be split to ensure that a single range of LBAs
  is written with a single command.

Implement these checks in generic_make_request_checks() using the
helper function blk_check_zone_append(). To avoid write append BIO
splitting, introduce the new max_zone_append_sectors queue limit
attribute and ensure that a BIO size is always lower than this limit.
Export this new limit through sysfs and check these limits in bio_full().

Also when a LLDD can't dispatch a request to a specific zone, it
will return BLK_STS_ZONE_RESOURCE indicating this request needs to
be delayed, e.g.  because the zone it will be dispatched to is still
write-locked. If this happens set the request aside in a local list
to continue trying dispatching requests such as READ requests or a
WRITE/ZONE_APPEND requests targetting other zones. This way we can
still keep a high queue depth without starving other requests even if
one request can't be served due to zone write-locking.

Finally, make sure that the bio sector position indicates the actual
write position as indicated by the device on completion.

Signed-off-by: Keith Busch <kbusch@kernel.org>
[ jth: added zone-append specific add_page and merge_page helpers ]
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-12 20:36:28 -06:00
Christoph Hellwig
e458110577 block: rename __bio_add_pc_page to bio_add_hw_page
Rename __bio_add_pc_page() to bio_add_hw_page() and explicitly pass in a
max_sectors argument.

This max_sectors argument can be used to specify constraints from the
hardware.

Signed-off-by: Christoph Hellwig <hch@lst.de>
[ jth: rebased and made public for blk-map.c ]
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-12 20:36:28 -06:00
Ming Lei
27eb3af9a3 block: don't hold part0's refcount in IO path
gendisk can't be gone when there is IO activity, so not hold
part0's refcount in IO path.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Cc: Yufen Yu <yuyufen@huawei.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hou Tao <houtao1@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-12 20:31:40 -06:00
Ming Lei
07c4e1e834 block: only define 'nr_sects_seq' in hd_part for 32bit SMP
The seqcount of 'nr_sects_seq' is only needed in case of 32bit SMP,
so define it just for 32bit SMP.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Cc: Yufen Yu <yuyufen@huawei.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hou Tao <houtao1@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-12 20:31:39 -06:00
Ming Lei
b7d6c30333 block: fix use-after-free on cached last_lookup partition
delete_partition() clears the cached last_lookup partition. However the
.last_lookup cache may be overwritten by one IO path after it is cleared
from delete_partition(). Then another IO path may use the cached deleting
partition after hd_struct_free() is called, then use-after-free is triggered
on the cached partition.

Fixes the issue by the following approach:

1) always get the partition's refcount via hd_struct_try_get() before
setting .last_lookup

2) move clearing .last_lookup from delete_partition() to hd_struct_free()
which is the release handle of the partition's percpu-refcount, so that no
IO path can cache deleteing partition via .last_lookup.

It is one candidate approach of Yufen's patch[1] which adds overhead
in fast path by indirect lookup which may introduce one extra cacheline
in IO path. Also this patch relies on percpu-refcount's protection, and
it is easier to understand and verify.

[1] https://lore.kernel.org/linux-block/20200109013551.GB9655@ming.t460p/T/#t

Reported-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hou Tao <houtao1@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-12 20:31:39 -06:00
Weiping Zhang
aa880ad690 block: reset mapping if failed to update hardware queue count
When we increase hardware queue count, blk_mq_update_queue_map will
reset the mapping between cpu and hardware queue base on the hardware
queue count(set->nr_hw_queues). The mapping cannot be reset if it
encounters error in blk_mq_realloc_hw_ctxs, but the fallback flow will
continue using it, then blk_mq_map_swqueue will touch a invalid memory,
because the mapping points to a wrong hctx.

blktest block/030:

null_blk: module loaded
Increasing nr_hw_queues to 8 fails, fallback to 1
==================================================================
BUG: KASAN: null-ptr-deref in blk_mq_map_swqueue+0x2f2/0x830
Read of size 8 at addr 0000000000000128 by task nproc/8541

CPU: 5 PID: 8541 Comm: nproc Not tainted 5.7.0-rc4-dbg+ #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.13.0-0-gf21b5a4-rebuilt.opensuse.org 04/01/2014
Call Trace:
dump_stack+0xa5/0xe6
__kasan_report.cold+0x65/0xbb
kasan_report+0x45/0x60
check_memory_region+0x15e/0x1c0
__kasan_check_read+0x15/0x20
blk_mq_map_swqueue+0x2f2/0x830
__blk_mq_update_nr_hw_queues+0x3df/0x690
blk_mq_update_nr_hw_queues+0x32/0x50
nullb_device_submit_queues_store+0xde/0x160 [null_blk]
configfs_write_file+0x1c4/0x250 [configfs]
__vfs_write+0x4c/0x90
vfs_write+0x14b/0x2d0
ksys_write+0xdd/0x180
__x64_sys_write+0x47/0x50
do_syscall_64+0x6f/0x310
entry_SYSCALL_64_after_hwframe+0x49/0xb3

Signed-off-by: Weiping Zhang <zhangweiping@didiglobal.com>
Tested-by: Bart van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-12 20:20:22 -06:00
Christoph Hellwig
1cd925d583 bdi: remove the name field in struct backing_dev_info
The name is only printed for a not registered bdi in writeback.  Use the
device name there as is more useful anyway for the unlike case that the
warning triggers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-09 16:15:13 -06:00
Christoph Hellwig
aef33c2ff8 bdi: simplify bdi_alloc
Merge the _node vs normal version and drop the superflous gfp_t argument.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-09 16:15:13 -06:00
Christoph Hellwig
3c5d202b55 bdi: remove bdi_register_owner
Split out a new bdi_set_owner helper to set the owner, and move the policy
for creating the bdi name back into genhd.c, where it belongs.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-09 16:15:13 -06:00
Weiping Zhang
79fab52879 block: rename blk_mq_alloc_rq_maps
rename blk_mq_alloc_rq_maps to blk_mq_alloc_map_and_requests,
this function allocs both map and request, make function name align
with funtion.

Signed-off-by: Weiping Zhang <zhangweiping@didiglobal.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-09 16:15:13 -06:00
Weiping Zhang
03b63b029d block: rename __blk_mq_alloc_rq_map
rename __blk_mq_alloc_rq_map to __blk_mq_alloc_map_and_request,
actually it alloc both map and request, make function name
align with function.

Signed-off-by: Weiping Zhang <zhangweiping@didiglobal.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-09 16:15:13 -06:00
Ming Lei
fd689871bb block: alloc map and request for new hardware queue
Alloc new map and request for new hardware queue when increse
hardware queue count. Before this patch, it will show a
warning for each new hardware queue, but it's not enough, these
hctx have no maps and reqeust, when a bio was mapped to these
hardware queue, it will trigger kernel panic when get request
from these hctx.

Test environment:
 * A NVMe disk supports 128 io queues
 * 96 cpus in system

A corner case can always trigger this panic, there are 96
io queues allocated for HCTX_TYPE_DEFAULT type, the corresponding kernel
log: nvme nvme0: 96/0/0 default/read/poll queues. Now we set nvme write
queues to 96, then nvme will alloc others(32) queues for read, but
blk_mq_update_nr_hw_queues does not alloc map and request for these new
added io queues. So when process read nvme disk, it will trigger kernel
panic when get request from these hardware context.

Reproduce script:

nr=$(expr `cat /sys/block/nvme0n1/device/queue_count` - 1)
echo $nr > /sys/module/nvme/parameters/write_queues
echo 1 > /sys/block/nvme0n1/device/reset_controller
dd if=/dev/nvme0n1 of=/dev/null bs=4K count=1

[ 8040.805626] ------------[ cut here ]------------
[ 8040.805627] WARNING: CPU: 82 PID: 12921 at block/blk-mq.c:2578 blk_mq_map_swqueue+0x2b6/0x2c0
[ 8040.805627] Modules linked in: nvme nvme_core nf_conntrack_netlink xt_addrtype br_netfilter overlay xt_CHECKSUM xt_MASQUERADE xt_conntrack ipt_REJECT nft_counter nf_nat_tftp nf_conntrack_tftp nft_masq nf_tables_set nft_fib_inet nft_f
ib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack tun bridge nf_defrag_ipv6 nf_defrag_ipv4 stp llc ip6_tables ip_tables nft_compat rfkill ip_set nf_tables nfne
tlink sunrpc intel_rapl_msr intel_rapl_common skx_edac nfit libnvdimm x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm irqbypass ipmi_ssif crct10dif_pclmul crc32_pclmul iTCO_wdt iTCO_vendor_support ghash_clmulni_intel intel_
cstate intel_uncore raid0 joydev intel_rapl_perf ipmi_si pcspkr mei_me ioatdma sg ipmi_devintf mei i2c_i801 dca lpc_ich ipmi_msghandler acpi_power_meter acpi_pad xfs libcrc32c sd_mod ast i2c_algo_bit drm_vram_helper drm_ttm_helper ttm d
rm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops
[ 8040.805637]  ahci drm i40e libahci crc32c_intel libata t10_pi wmi dm_mirror dm_region_hash dm_log dm_mod [last unloaded: nvme_core]
[ 8040.805640] CPU: 82 PID: 12921 Comm: kworker/u194:2 Kdump: loaded Tainted: G        W         5.6.0-rc5.78317c+ #2
[ 8040.805640] Hardware name: Inspur SA5212M5/YZMB-00882-104, BIOS 4.0.9 08/27/2019
[ 8040.805641] Workqueue: nvme-reset-wq nvme_reset_work [nvme]
[ 8040.805642] RIP: 0010:blk_mq_map_swqueue+0x2b6/0x2c0
[ 8040.805643] Code: 00 00 00 00 00 41 83 c5 01 44 39 6d 50 77 b8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 48 8b bb 98 00 00 00 89 d6 e8 8c 81 03 00 eb 83 <0f> 0b e9 52 ff ff ff 0f 1f 00 0f 1f 44 00 00 41 57 48 89 f1 41 56
[ 8040.805643] RSP: 0018:ffffba590d2e7d48 EFLAGS: 00010246
[ 8040.805643] RAX: 0000000000000000 RBX: ffff9f013e1ba800 RCX: 000000000000003d
[ 8040.805644] RDX: ffff9f00ffff6000 RSI: 0000000000000003 RDI: ffff9ed200246d90
[ 8040.805644] RBP: ffff9f00f6a79860 R08: 0000000000000000 R09: 000000000000003d
[ 8040.805645] R10: 0000000000000001 R11: ffff9f0138c3d000 R12: ffff9f00fb3a9008
[ 8040.805645] R13: 000000000000007f R14: ffffffff96822660 R15: 000000000000005f
[ 8040.805645] FS:  0000000000000000(0000) GS:ffff9f013fa80000(0000) knlGS:0000000000000000
[ 8040.805646] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 8040.805646] CR2: 00007f7f397fa6f8 CR3: 0000003d8240a002 CR4: 00000000007606e0
[ 8040.805647] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 8040.805647] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 8040.805647] PKRU: 55555554
[ 8040.805647] Call Trace:
[ 8040.805649]  blk_mq_update_nr_hw_queues+0x31b/0x390
[ 8040.805650]  nvme_reset_work+0xb4b/0xeab [nvme]
[ 8040.805651]  process_one_work+0x1a7/0x370
[ 8040.805652]  worker_thread+0x1c9/0x380
[ 8040.805653]  ? max_active_store+0x80/0x80
[ 8040.805655]  kthread+0x112/0x130
[ 8040.805656]  ? __kthread_parkme+0x70/0x70
[ 8040.805657]  ret_from_fork+0x35/0x40
[ 8040.805658] ---[ end trace b5f13b1e73ccb5d3 ]---
[ 8229.365135] BUG: kernel NULL pointer dereference, address: 0000000000000004
[ 8229.365165] #PF: supervisor read access in kernel mode
[ 8229.365178] #PF: error_code(0x0000) - not-present page
[ 8229.365191] PGD 0 P4D 0
[ 8229.365201] Oops: 0000 [#1] SMP PTI
[ 8229.365212] CPU: 77 PID: 13024 Comm: dd Kdump: loaded Tainted: G        W         5.6.0-rc5.78317c+ #2
[ 8229.365232] Hardware name: Inspur SA5212M5/YZMB-00882-104, BIOS 4.0.9 08/27/2019
[ 8229.365253] RIP: 0010:blk_mq_get_tag+0x227/0x250
[ 8229.365265] Code: 44 24 04 44 01 e0 48 8b 74 24 38 65 48 33 34 25 28 00 00 00 75 33 48 83 c4 40 5b 5d 41 5c 41 5d 41 5e c3 48 8d 68 10 4c 89 ef <44> 8b 60 04 48 89 ee e8 dd f9 ff ff 83 f8 ff 75 c8 e9 67 fe ff ff
[ 8229.365304] RSP: 0018:ffffba590e977970 EFLAGS: 00010246
[ 8229.365317] RAX: 0000000000000000 RBX: ffff9f00f6a79860 RCX: ffffba590e977998
[ 8229.365333] RDX: 0000000000000000 RSI: ffff9f012039b140 RDI: ffffba590e977a38
[ 8229.365349] RBP: 0000000000000010 R08: ffffda58ff94e190 R09: ffffda58ff94e198
[ 8229.365365] R10: 0000000000000011 R11: ffff9f00f6a79860 R12: 0000000000000000
[ 8229.365381] R13: ffffba590e977a38 R14: ffff9f012039b140 R15: 0000000000000001
[ 8229.365397] FS:  00007f481c230580(0000) GS:ffff9f013f940000(0000) knlGS:0000000000000000
[ 8229.365415] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 8229.365428] CR2: 0000000000000004 CR3: 0000005f35e26004 CR4: 00000000007606e0
[ 8229.365444] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 8229.365460] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 8229.365476] PKRU: 55555554
[ 8229.365484] Call Trace:
[ 8229.365498]  ? finish_wait+0x80/0x80
[ 8229.365512]  blk_mq_get_request+0xcb/0x3f0
[ 8229.365525]  blk_mq_make_request+0x143/0x5d0
[ 8229.365538]  generic_make_request+0xcf/0x310
[ 8229.365553]  ? scan_shadow_nodes+0x30/0x30
[ 8229.365564]  submit_bio+0x3c/0x150
[ 8229.365576]  mpage_readpages+0x163/0x1a0
[ 8229.365588]  ? blkdev_direct_IO+0x490/0x490
[ 8229.365601]  read_pages+0x6b/0x190
[ 8229.365612]  __do_page_cache_readahead+0x1c1/0x1e0
[ 8229.365626]  ondemand_readahead+0x182/0x2f0
[ 8229.365639]  generic_file_buffered_read+0x590/0xab0
[ 8229.365655]  new_sync_read+0x12a/0x1c0
[ 8229.365666]  vfs_read+0x8a/0x140
[ 8229.365676]  ksys_read+0x59/0xd0
[ 8229.365688]  do_syscall_64+0x55/0x1d0
[ 8229.365700]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Weiping Zhang <zhangweiping@didiglobal.com>
Tested-by: Weiping Zhang <zhangweiping@didiglobal.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-09 16:15:13 -06:00
Weiping Zhang
a2584e43f5 block: save previous hardware queue count before udpate
blk_mq_realloc_tag_set_tags will update set->nr_hw_queues, so
save old set->nr_hw_queues before call this function.

Signed-off-by: Weiping Zhang <zhangweiping@didiglobal.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-09 16:15:12 -06:00
Weiping Zhang
2e194422f1 block: free both rq_map and request
Allocation:

__blk_mq_alloc_rq_map
	blk_mq_alloc_rq_map
		blk_mq_alloc_rq_map
			tags = blk_mq_init_tags : kzalloc_node:
			tags->rqs = kcalloc_node
			tags->static_rqs = kcalloc_node
	blk_mq_alloc_rqs
		p = alloc_pages_node
		tags->static_rqs[i] = p + offset;

Free:

blk_mq_free_rq_map
	kfree(tags->rqs);
	kfree(tags->static_rqs);
	blk_mq_free_tags
		kfree(tags);

The page allocated in blk_mq_alloc_rqs cannot be released,
so we should use blk_mq_free_map_and_requests here.

blk_mq_free_map_and_requests
	blk_mq_free_rqs
		__free_pages : cleanup for blk_mq_alloc_rqs
	blk_mq_free_rq_map : cleanup for blk_mq_alloc_rq_map

Signed-off-by: Weiping Zhang <zhangweiping@didiglobal.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-09 16:15:12 -06:00
Jens Axboe
873f1c8df7 Merge branch 'block-5.7' into for-5.8/block
Pull in block-5.7 fixes for 5.8. Mostly to resolve a conflict with
the blk-iocost changes, but we also need the base of the bdi
use-after-free as well as we build on top of it.

* block-5.7:
  nvme: fix possible hang when ns scanning fails during error recovery
  nvme-pci: fix "slimmer CQ head update"
  bdi: add a ->dev_name field to struct backing_dev_info
  bdi: use bdi_dev_name() to get device name
  bdi: move bdi_dev_name out of line
  vboxsf: don't use the source name in the bdi name
  iocost: protect iocg->abs_vdebt with iocg->waitq.lock
  block: remove the bd_openers checks in blk_drop_partitions
  nvme: prevent double free in nvme_alloc_ns() error handling
  null_blk: Cleanup zoned device initialization
  null_blk: Fix zoned command handling
  block: remove unused header
  blk-iocost: Fix error on iocost_ioc_vrate_adj
  bdev: Reduce time holding bd_mutex in sync in blkdev_close()
  buffer: remove useless comment and WB_REASON_FREE_MORE_MEM, reason.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-09 16:13:58 -06:00
Yufen Yu
d51cfc53ad bdi: use bdi_dev_name() to get device name
Use the common interface bdi_dev_name() to get device name.

Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>

Add missing <linux/backing-dev.h> include BFQ

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-09 16:07:39 -06:00
Tejun Heo
0b80f9866e iocost: protect iocg->abs_vdebt with iocg->waitq.lock
abs_vdebt is an atomic_64 which tracks how much over budget a given cgroup
is and controls the activation of use_delay mechanism. Once a cgroup goes
over budget from forced IOs, it has to pay it back with its future budget.
The progress guarantee on debt paying comes from the iocg being active -
active iocgs are processed by the periodic timer, which ensures that as time
passes the debts dissipate and the iocg returns to normal operation.

However, both iocg activation and vdebt handling are asynchronous and a
sequence like the following may happen.

1. The iocg is in the process of being deactivated by the periodic timer.

2. A bio enters ioc_rqos_throttle(), calls iocg_activate() which returns
   without anything because it still sees that the iocg is already active.

3. The iocg is deactivated.

4. The bio from #2 is over budget but needs to be forced. It increases
   abs_vdebt and goes over the threshold and enables use_delay.

5. IO control is enabled for the iocg's subtree and now IOs are attributed
   to the descendant cgroups and the iocg itself no longer issues IOs.

This leaves the iocg with stuck abs_vdebt - it has debt but inactive and no
further IOs which can activate it. This can end up unduly punishing all the
descendants cgroups.

The usual throttling path has the same issue - the iocg must be active while
throttled to ensure that future event will wake it up - and solves the
problem by synchronizing the throttling path with a spinlock. abs_vdebt
handling is another form of overage handling and shares a lot of
characteristics including the fact that it isn't in the hottest path.

This patch fixes the above and other possible races by strictly
synchronizing abs_vdebt and use_delay handling with iocg->waitq.lock.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Vlad Dmitriev <vvd@fb.com>
Cc: stable@vger.kernel.org # v5.4+
Fixes: e1518f63f2 ("blk-iocost: Don't let merges push vtime into the future")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-05 09:23:18 -06:00
Tejun Heo
cd006509b0 blk-iocost: account for IO size when testing latencies
On each IO completion, iocost decides whether the IO met or missed its latency
target. Currently, the targets are fixed numbers per IO type. While this can be
good enough for loose latency targets way higher than typical completion
latencies, the effect of IO size makes it difficult to tighten the latency
target - a target adequate for 4k IOs might be too tight for 512k IOs and
vice-versa.

iocost already has all the necessary information to account for different IO
sizes when testing whether the latency target is met as iocost can calculate the
size vtime cost of a given IO. This patch updates the completion path to
calculate the size vtime cost of the IO, deduct the nsec equivalent from the
observed latency and use the adjusted value to decide whether the target is met.

This makes latency targets independent from IO size and enables determining
adequate latency targets with fixed size fio runs.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Andy Newell <newella@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-30 15:54:45 -06:00
Tejun Heo
54c52e10dc blk-iocost: switch to fixed non-auto-decaying use_delay
The use_delay mechanism was introduced by blk-iolatency to hold memory
allocators accountable for the reclaim and other shared IOs they cause. The
duration of the delay is dynamically balanced between iolatency increasing the
value on each target miss and it auto-decaying as time passes and threads get
delayed on it.

While this works well for iolatency, iocost's control model isn't compatible
with it. There is no repeated "violation" events which can be balanced against
auto-decaying. iocost instead knows how much a given cgroup is over budget and
wants to prevent that cgroup from issuing IOs while over budget. Until now,
iocost has been adding the cost of force-issued IOs. However, this doesn't
reflect the amount which is already over budget and is simply not enough to
counter the auto-decaying allowing anon-memory leaking low priority cgroup to
go over its alloted share of IOs.

As auto-decaying doesn't make much sense for iocost, this patch introduces a
different mode of operation for use_delay - when blkcg_set_delay() are used
insted of blkcg_add/use_delay(), the delay duration is not auto-decayed until it
is explicitly cleared with blkcg_clear_delay(). iocost is updated to keep the
delay duration synchronized to the budget overage amount.

With this change, iocost can effectively police cgroups which generate
significant amount of force-issued IOs.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-30 15:54:45 -06:00
Christoph Hellwig
10c70d95c0 block: remove the bd_openers checks in blk_drop_partitions
When replacing the bd_super check with a bd_openers I followed a logical
conclusion, which turns out to be utterly wrong.  When a block device has
bd_super sets it has a mount file system on it (although not every
mounted file system sets bd_super), but that also implies it doesn't even
have partitions to start with.

So instead of trying to come up with a logical check for all openers,
just remove the check entirely.

Fixes: d3ef553627 ("block: fix busy device checking in blk_drop_partitions")
Fixes: cb6b771b05 ("block: fix busy device checking in blk_drop_partitions again")
Reported-by: Michal Koutný <mkoutny@suse.com>
Reported-by: Yang Xu <xuyang2018.jy@cn.fujitsu.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-30 10:25:43 -06:00
Christoph Hellwig
accea322f5 block: add a bio_queue_enter helper
Add a little helper that passes the right nowait flag to blk_queue_enter
based on the bio flag, and terminates the bio with the right error code
if entering the queue fails.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-29 09:33:26 -06:00
Christoph Hellwig
0376e9efe1 block: replace BIO_QUEUE_ENTERED with BIO_CGROUP_ACCT
BIO_QUEUE_ENTERED is only used for cgroup accounting now, so rename
the flag and move setting it into the cgroup code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-29 09:33:26 -06:00
Christoph Hellwig
760f83ea63 block: cleanup the memory stall accounting in submit_bio
Instead of a convoluted chain just check for REQ_OP_READ directly,
and keep all the memory stall code together in a single unlikely
branch.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-29 09:33:26 -06:00
Christoph Hellwig
3fdd40861d block: improve the submit_bio and generic_make_request documentation
The current documentation is a little weird, as it doesn't clearly
explain which function to use, and also has the guts of the information
on generic_make_request, which is the internal interface for stacking
drivers.

Fix this up by properly documenting submit_bio, and only documenting
the differences and the use case for generic_make_request.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-29 09:33:26 -06:00
Zheng Bin
e1b586f2b8 blk-mq: make function '__blk_mq_sched_dispatch_requests' static
Fix sparse warnings:

block/blk-mq-sched.c:209:5: warning: symbol '__blk_mq_sched_dispatch_requests' was not declared. Should it be static?

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zheng Bin <zhengbin13@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-29 09:16:53 -06:00
Christoph Hellwig
8cf7961dab block: bypass ->make_request_fn for blk-mq drivers
Call blk_mq_make_request when no ->make_request_fn is set.  This is
safe now that blk_alloc_queue always sets up the pointer for make_request
based drivers.  This avoids an indirect call in the blk-mq driver I/O
fast path, which is rather expensive due to spectre mitigations.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-25 09:45:44 -06:00
Christoph Hellwig
3e82c3485e block: remove create_io_context
create_io_context just has a single caller, which also happens to not
even use the return value.  Just open code it there.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-25 09:44:40 -06:00
Salman Qazi
28d65729b0 block: Limit number of items taken from the I/O scheduler in one go
Flushes bypass the I/O scheduler and get added to hctx->dispatch
in blk_mq_sched_bypass_insert.  This can happen while a kworker is running
hctx->run_work work item and is past the point in
blk_mq_sched_dispatch_requests where hctx->dispatch is checked.

The blk_mq_do_dispatch_sched call is not guaranteed to end in bounded time,
because the I/O scheduler can feed an arbitrary number of commands.

Since we have only one hctx->run_work, the commands waiting in
hctx->dispatch will wait an arbitrary length of time for run_work to be
rerun.

A similar phenomenon exists with dispatches from the software queue.

The solution is to poll hctx->dispatch in blk_mq_do_dispatch_sched and
blk_mq_do_dispatch_ctx and return from the run_work handler and let it
rerun.

Signed-off-by: Salman Qazi <sqazi@google.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-24 09:16:56 -06:00
Christoph Hellwig
bdf8710d69 block: move dma_pad handling from blk_rq_map_sg into the callers
There are only two callers of blk_rq_map_sg/__blk_rq_map_sg that set
the dma_pad value in the queue.  Move the handling into those callers
instead of burdening the common code, and move the ->extra_len field
from struct request to struct scsi_cmnd.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-22 10:47:39 -06:00
Christoph Hellwig
cc97923a5b block: move dma drain handling to scsi
Don't burden the common block code with with specifics of the libata DMA
draining mechanism.  Instead move most of the code to the scsi midlayer.

That also means the nr_phys_segments adjustments in the blk-mq fast path
can go away entirely, given that SCSI never looks at nr_phys_segments
after mapping the request to a scatterlist.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-22 10:47:35 -06:00
Christoph Hellwig
89de1504d5 block: provide a blk_rq_map_sg variant that returns the last element
To be able to move some of the special purpose hacks in blk_rq_map_sg
into the callers we need a variant that returns the last mapped
S/G list element to the caller.  Add that variant as __blk_rq_map_sg
and make blk_rq_map_sg a trivial inline wrapper around it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-22 10:47:06 -06:00
Christoph Hellwig
e64a0e1692 block: remove RQF_COPY_USER
The RQF_COPY_USER is set for bio where the passthrough request mapping
helpers decided that bounce buffering is required.  It is then used to
pad scatterlist for drivers that required it.  But given that
non-passthrough requests are per definition aligned, and directly mapped
pass-through request must be aligned it is not actually required at all.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-22 10:47:06 -06:00
Waiman Long
d6c8e949a3 blk-iocost: Fix error on iocost_ioc_vrate_adj
Systemtap 4.2 is unable to correctly interpret the "u32 (*missed_ppm)[2]"
argument of the iocost_ioc_vrate_adj trace entry defined in
include/trace/events/iocost.h leading to the following error:

  /tmp/stapAcz0G0/stap_c89c58b83cea1724e26395efa9ed4939_6321_aux_6.c:78:8:
  error: expected ‘;’, ‘,’ or ‘)’ before ‘*’ token
   , u32[]* __tracepoint_arg_missed_ppm

That argument type is indeed rather complex and hard to read. Looking
at block/blk-iocost.c. It is just a 2-entry u32 array. By simplifying
the argument to a simple "u32 *missed_ppm" and adjusting the trace
entry accordingly, the compilation error was gone.

Fixes: 7caa47151a ("blkcg: implement blk-iocost")
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-21 09:49:36 -06:00
Christoph Hellwig
9bc5c397d8 block: fold bdev_unhash_inode into invalidate_partition
invalidate_partition and bdev_unhash_inode are always paired, and
invalidate_partition already does an icache lookup for the block device
inode.  Piggy back on that to remove the inode from the hash.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-20 11:33:00 -06:00
Christoph Hellwig
02d33b6771 block: mark invalidate_partition static
invalidate_partition is only used in genhd.c, so mark it static.  Also
drop the return value given that is is always ignored.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-20 11:32:59 -06:00
Christoph Hellwig
d5f3178ec9 block: simplify block device syncing in bdev_del_partition
We just checked a little above that the block device for the partition
im busy.  That implies no file system is mounted, and thus the only
thing in fsync_bdev that actually is used is sync_blockdev.  Just call
sync_blockdev directly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-20 11:32:59 -06:00
Christoph Hellwig
e669c1da03 block: don't call invalidate_partition from blk_drop_partitions
Given that the device must not be busy, most of the calls from
invalidate_partition that are related to file system metadata are
guranteed to not happen.  Just open code the calls to sync_blockdev
and invalidate_bdev instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-20 11:32:59 -06:00
Christoph Hellwig
21be6cdc00 dasd: use blk_drop_partitions instead of badly reimplementing it
Use the blk_drop_partitions function instead of messing around with
ioctls that get kernel pointers.  For this blk_drop_partitions needs
to be exported, which it normally shouldn't - make an exception for
s390 only.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-20 11:32:59 -06:00
Christoph Hellwig
d46430bf5a block: remove the disk argument from blk_drop_partitions
The gendisk can be trivially deducted from the block_device.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-20 11:32:59 -06:00
Christoph Hellwig
4377b48da6 block: remove hd_struct_kill
The function has a single caller, so just open code it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-20 11:32:59 -06:00
Christoph Hellwig
8da2892e27 block: cleanup hd_struct freeing
Move hd_ref_init out of line as there it isn't anywhere near a fast path,
and rename the rcu ref freeing callbacks to be more descriptive.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-20 11:32:59 -06:00
Christoph Hellwig
cddae808ae block: pass a hd_struct to delete_partition
All callers have the hd_struct at hand, so pass it instead of performing
another lookup.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-20 11:32:59 -06:00
Christoph Hellwig
fa9156ae59 block: refactor blkpg_ioctl
Split each sub-command out into a separate helper, and move those helpers
to block/partitions/core.c instead of having a lot of partition
manipulation logic open coded in block/ioctl.c.

Signed-off-by: Christoph Hellwig <hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-20 11:32:59 -06:00
Douglas Anderson
a0823421a4 blk-mq: Rerun dispatching in the case of budget contention
If ever a thread running blk-mq code tries to get budget and fails it
immediately stops doing work and assumes that whenever budget is freed
up that queues will be kicked and whatever work the thread was trying
to do will be tried again.

One path where budget is freed and queues are kicked in the normal
case can be seen in scsi_finish_command().  Specifically:
- scsi_finish_command()
  - scsi_device_unbusy()
    - # Decrement "device_busy", AKA release budget
  - scsi_io_completion()
    - scsi_end_request()
      - blk_mq_run_hw_queues()

The above is all well and good.  The problem comes up when a thread
claims the budget but then releases it without actually dispatching
any work.  Since we didn't schedule any work we'll never run the path
of finishing work / kicking the queues.

This isn't often actually a problem which is why this issue has
existed for a while and nobody noticed.  Specifically we only get into
this situation when we unexpectedly found that we weren't going to do
any work.  Code that later receives new work kicks the queues.  All
good, right?

The problem shows up, however, if timing is just wrong and we hit a
race.  To see this race let's think about the case where we only have
a budget of 1 (only one thread can hold budget).  Now imagine that a
thread got budget and then decided not to dispatch work.  It's about
to call put_budget() but then the thread gets context switched out for
a long, long time.  While in this state, any and all kicks of the
queue (like the when we received new work) will be no-ops because
nobody can get budget.  Finally the thread holding budget gets to run
again and returns.  All the normal kicks will have been no-ops and we
have an I/O stall.

As you can see from the above, you need just the right timing to see
the race.  To start with, the only case it happens if we thought we
had work, actually managed to get the budget, but then actually didn't
have work.  That's pretty rare to start with.  Even then, there's
usually a very small amount of time between realizing that there's no
work and putting the budget.  During this small amount of time new
work has to come in and the queue kick has to make it all the way to
trying to get the budget and fail.  It's pretty unlikely.

One case where this could have failed is illustrated by an example of
threads running blk_mq_do_dispatch_sched():

* Threads A and B both run has_work() at the same time with the same
  "hctx".  Imagine has_work() is exact.  There's no lock, so it's OK
  if Thread A and B both get back true.
* Thread B gets interrupted for a long time right after it decides
  that there is work.  Maybe its CPU gets an interrupt and the
  interrupt handler is slow.
* Thread A runs, get budget, dispatches work.
* Thread A's work finishes and budget is released.
* Thread B finally runs again and gets budget.
* Since Thread A already took care of the work and no new work has
  come in, Thread B will get NULL from dispatch_request().  I believe
  this is specifically why dispatch_request() is allowed to return
  NULL in the first place if has_work() must be exact.
* Thread B will now be holding the budget and is about to call
  put_budget(), but hasn't called it yet.
* Thread B gets interrupted for a long time (again).  Dang interrupts.
* Now Thread C (maybe with a different "hctx" but the same queue)
  comes along and runs blk_mq_do_dispatch_sched().
* Thread C won't do anything because it can't get budget.
* Finally Thread B will run again and put the budget without kicking
  any queues.

Even though the example above is with blk_mq_do_dispatch_sched() I
believe the race is possible any time someone is holding budget but
doesn't do work.

Unfortunately, the unlikely has become more likely if you happen to be
using the BFQ I/O scheduler.  BFQ, by design, sometimes returns "true"
for has_work() but then NULL for dispatch_request() and stays in this
state for a while (currently up to 9 ms).  Suddenly you only need one
race to hit, not two races in a row.  With my current setup this is
easy to reproduce in reboot tests and traces have actually shown that
we hit a race similar to the one described above.

Note that we only need to fix blk_mq_do_dispatch_sched() and
blk_mq_do_dispatch_ctx() and not the other places that put budget.  In
other cases we know that we have work to do on at least one "hctx" and
code already exists to kick that "hctx"'s queue.  When that work
finally finishes all the queues will be kicked using the normal flow.

One last note is that (at least in the SCSI case) budget is shared by
all "hctx"s that have the same queue.  Thus we need to make sure to
kick the whole queue, not just re-run dispatching on a single "hctx".

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-20 10:34:56 -06:00
Douglas Anderson
b9151e7bca blk-mq: Add blk_mq_delay_run_hw_queues() API call
We have:
* blk_mq_run_hw_queue()
* blk_mq_delay_run_hw_queue()
* blk_mq_run_hw_queues()

...but not blk_mq_delay_run_hw_queues(), presumably because nobody
needed it before now.  Since we need it for a later patch in this
series, add it.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-20 10:34:56 -06:00
Douglas Anderson
ab3cee3762 blk-mq: In blk_mq_dispatch_rq_list() "no budget" is a reason to kick
In blk_mq_dispatch_rq_list(), if blk_mq_sched_needs_restart() returns
true and the driver returns BLK_STS_RESOURCE then we'll kick the
queue.  However, there's another case where we might need to kick it.
If we were unable to get budget we can be in much the same state as
when the driver returns BLK_STS_RESOURCE, so we should treat it the
same.

It should be noted that even if we add a whole bunch of extra kicking
to the queue in other patches this patch is still important.
Specifically any kicking that happened before we re-spliced leftover
requests into 'hctx->dispatch' wouldn't have found any work, so we
really need to make sure we kick ourselves after we've done the
splicing.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-20 10:34:56 -06:00
Tommi Rantala
3a89c25d98 blk-wbt: Use tracepoint_string() for wbt_step tracepoint string literals
Use tracepoint_string() for string literals that are used in the
wbt_step tracepoint, so that userspace tools can display the string
content.

Signed-off-by: Tommi Rantala <tommi.t.rantala@nokia.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-17 08:21:44 -06:00
John Garry
5fe56de799 blk-mq: Put driver tag in blk_mq_dispatch_rq_list() when no budget
If in blk_mq_dispatch_rq_list() we find no budget, then we break of the
dispatch loop, but the request may keep the driver tag, evaulated
in 'nxt' in the previous loop iteration.

Fix by putting the driver tag for that request.

Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-16 09:27:03 -06:00
Linus Torvalds
8df2a0a6da block-5.7-2020-04-10
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Merge tag 'block-5.7-2020-04-10' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:
 "Here's a set of fixes that should go into this merge window. This
  contains:

   - NVMe pull request from Christoph with various fixes

   - Better discard support for loop (Evan)

   - Only call ->commit_rqs() if we have queued IO (Keith)

   - blkcg offlining fixes (Tejun)

   - fix (and fix the fix) for busy partitions"

* tag 'block-5.7-2020-04-10' of git://git.kernel.dk/linux-block:
  block: fix busy device checking in blk_drop_partitions again
  block: fix busy device checking in blk_drop_partitions
  nvmet-rdma: fix double free of rdma queue
  blk-mq: don't commit_rqs() if none were queued
  nvme-fc: Revert "add module to ops template to allow module references"
  nvme: fix deadlock caused by ANA update wrong locking
  nvmet-rdma: fix bonding failover possible NULL deref
  loop: Better discard support for block devices
  loop: Report EOPNOTSUPP properly
  nvmet: fix NULL dereference when removing a referral
  nvme: inherit stable pages constraint in the mpath stack device
  blkcg: don't offline parent blkcg first
  blkcg: rename blkcg->cgwb_refcnt to ->online_pin and always use it
  nvme-tcp: fix possible crash in recv error flow
  nvme-tcp: don't poll a non-live queue
  nvme-tcp: fix possible crash in write_zeroes processing
  nvmet-fc: fix typo in comment
  nvme-rdma: Replace comma with a semicolon
  nvme-fcloop: fix deallocation of working context
  nvme: fix compat address handling in several ioctls
2020-04-10 10:06:54 -07:00
Christoph Hellwig
cb6b771b05 block: fix busy device checking in blk_drop_partitions again
The previous fix had an off by one in the bd_openers checking, counting
the callers blkdev_get.

Fixes: d3ef553627 ("block: fix busy device checking in blk_drop_partitions")
Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Qian Cai <cai@lca.pw>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-10 08:34:11 -06:00
Christoph Hellwig
d3ef553627 block: fix busy device checking in blk_drop_partitions
bd_super is only set by get_tree_bdev and mount_bdev, and thus not by
other openers like btrfs or the XFS realtime and log devices, as well as
block devices directly opened from user space.  Check bd_openers
instead.

Fixes: 77032ca66f ("Return EBUSY from BLKRRPART for mounted whole-dev fs")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-07 14:42:59 -06:00
Keith Busch
536167d47a blk-mq: don't commit_rqs() if none were queued
Unburden the drivers from checking if a call to commit_rqs() is valid by
not calling it when there are no requests to commit.

Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-06 13:43:56 -06:00
Linus Torvalds
79f51b7b9c SCSI misc on 20200402
update changing all our txt files to rst ones.  Excluding that, we
 have the usual driver updates (qla2xxx, ufs, lpfc, zfcp, ibmvfc,
 pm80xx, aacraid), a treewide update for scnprintf and some other minor
 updates.  The major core update is Hannes moving functions out of the
 aacraid driver and into the core.
 
 Signed-off-by: James E.J. Bottomley <jejb@linux.ibm.com>
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Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull SCSI updates from James Bottomley:
 "This series has a huge amount of churn because it pulls in Mauro's doc
  update changing all our txt files to rst ones.

  Excluding that, we have the usual driver updates (qla2xxx, ufs, lpfc,
  zfcp, ibmvfc, pm80xx, aacraid), a treewide update for scnprintf and
  some other minor updates.

  The major core change is Hannes moving functions out of the aacraid
  driver and into the core"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (223 commits)
  scsi: aic7xxx: aic97xx: Remove FreeBSD-specific code
  scsi: ufs: Do not rely on prefetched data
  scsi: dc395x: remove dc395x_bios_param
  scsi: libiscsi: Fix error count for active session
  scsi: hpsa: correct race condition in offload enabled
  scsi: message: fusion: Replace zero-length array with flexible-array member
  scsi: qedi: Add PCI shutdown handler support
  scsi: qedi: Add MFW error recovery process
  scsi: ufs: Enable block layer runtime PM for well-known logical units
  scsi: ufs-qcom: Override devfreq parameters
  scsi: ufshcd: Let vendor override devfreq parameters
  scsi: ufshcd: Update the set frequency to devfreq
  scsi: ufs: Resume ufs host before accessing ufs device
  scsi: ufs-mediatek: customize the delay for enabling host
  scsi: ufs: make HCE polling more compact to improve initialization latency
  scsi: ufs: allow custom delay prior to host enabling
  scsi: ufs-mediatek: use common delay function
  scsi: ufs: introduce common and flexible delay function
  scsi: ufs: use an enum for host capabilities
  scsi: ufs: fix uninitialized tx_lanes in ufshcd_disable_tx_lcc()
  ...
2020-04-02 17:03:53 -07:00
Linus Torvalds
69c1fd9726 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial tree updates from Jiri Kosina:
 "My attempt to revitalize trivial queue I've been neglecting for years
  (what a disaster that was for this world, right? :) ) with patches
  collected from backlog that were still relevant and not applied
  elsewhere in the meantime"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial:
  err.h: remove deprecated PTR_RET for good
  blk-mq: Fix typo in comment
  x86/boot: Fix comment spelling
  sh: mach-highlander: Fix comment spelling
  s390/dasd: Fix comment spelling
  mfd: wm8994: Fix comment spelling
  docs: Add reference in binfmt-misc.rst
  genirq: fix kerneldoc comment for irq_desc
  drm/amdgpu: fix two documentation mismatch issues
  HID: fix Kconfig word ordering
  list/hashtable: minor documentation corrections.
2020-04-01 14:52:59 -07:00
Tejun Heo
4308a434e5 blkcg: don't offline parent blkcg first
blkcg->cgwb_refcnt is used to delay blkcg offlining so that blkgs
don't get offlined while there are active cgwbs on them.  However, it
ends up making offlining unordered sometimes causing parents to be
offlined before children.

Let's fix this by making child blkcgs pin the parents' online states.

Note that pin/unpin names are chosen over get/put intentionally
because css uses get/put online for something different.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-01 14:56:44 -06:00
Tejun Heo
d866dbf617 blkcg: rename blkcg->cgwb_refcnt to ->online_pin and always use it
blkcg->cgwb_refcnt is used to delay blkcg offlining so that blkgs
don't get offlined while there are active cgwbs on them.  However, it
ends up making offlining unordered sometimes causing parents to be
offlined before children.

To fix it, we want child blkcgs to pin the parents' online states
turning the refcnt into a more generic online pinning mechanism.

In prepartion,

* blkcg->cgwb_refcnt -> blkcg->online_pin
* blkcg_cgwb_get/put() -> blkcg_pin/unpin_online()
* Take them out of CONFIG_CGROUP_WRITEBACK

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-01 14:56:42 -06:00
Linus Torvalds
a776c270a0 Merge branch 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull EFI updates from Ingo Molnar:
 "The EFI changes in this cycle are much larger than usual, for two
  (positive) reasons:

   - The GRUB project is showing signs of life again, resulting in the
     introduction of the generic Linux/UEFI boot protocol, instead of
     x86 specific hacks which are increasingly difficult to maintain.
     There's hope that all future extensions will now go through that
     boot protocol.

   - Preparatory work for RISC-V EFI support.

  The main changes are:

   - Boot time GDT handling changes

   - Simplify handling of EFI properties table on arm64

   - Generic EFI stub cleanups, to improve command line handling, file
     I/O, memory allocation, etc.

   - Introduce a generic initrd loading method based on calling back
     into the firmware, instead of relying on the x86 EFI handover
     protocol or device tree.

   - Introduce a mixed mode boot method that does not rely on the x86
     EFI handover protocol either, and could potentially be adopted by
     other architectures (if another one ever surfaces where one
     execution mode is a superset of another)

   - Clean up the contents of 'struct efi', and move out everything that
     doesn't need to be stored there.

   - Incorporate support for UEFI spec v2.8A changes that permit
     firmware implementations to return EFI_UNSUPPORTED from UEFI
     runtime services at OS runtime, and expose a mask of which ones are
     supported or unsupported via a configuration table.

   - Partial fix for the lack of by-VA cache maintenance in the
     decompressor on 32-bit ARM.

   - Changes to load device firmware from EFI boot service memory
     regions

   - Various documentation updates and minor code cleanups and fixes"

* 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (114 commits)
  efi/libstub/arm: Fix spurious message that an initrd was loaded
  efi/libstub/arm64: Avoid image_base value from efi_loaded_image
  partitions/efi: Fix partition name parsing in GUID partition entry
  efi/x86: Fix cast of image argument
  efi/libstub/x86: Use ULONG_MAX as upper bound for all allocations
  efi: Fix a mistype in comments mentioning efivar_entry_iter_begin()
  efi/libstub: Avoid linking libstub/lib-ksyms.o into vmlinux
  efi/x86: Preserve %ebx correctly in efi_set_virtual_address_map()
  efi/x86: Ignore the memory attributes table on i386
  efi/x86: Don't relocate the kernel unless necessary
  efi/x86: Remove extra headroom for setup block
  efi/x86: Add kernel preferred address to PE header
  efi/x86: Decompress at start of PE image load address
  x86/boot/compressed/32: Save the output address instead of recalculating it
  efi/libstub/x86: Deal with exit() boot service returning
  x86/boot: Use unsigned comparison for addresses
  efi/x86: Avoid using code32_start
  efi/x86: Make efi32_pe_entry() more readable
  efi/x86: Respect 32-bit ABI in efi32_pe_entry()
  efi/x86: Annotate the LOADED_IMAGE_PROTOCOL_GUID with SYM_DATA
  ...
2020-03-30 16:13:08 -07:00
Linus Torvalds
1592614838 for-5.7/drivers-2020-03-29
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Merge tag 'for-5.7/drivers-2020-03-29' of git://git.kernel.dk/linux-block

Pull block driver updates from Jens Axboe:

 - floppy driver cleanup series from Willy

 - NVMe updates and fixes (Various)

 - null_blk trace improvements (Chaitanya)

 - bcache fixes (Coly)

 - md fixes (via Song)

 - loop block size change optimizations (Martijn)

 - scnprintf() use (Takashi)

* tag 'for-5.7/drivers-2020-03-29' of git://git.kernel.dk/linux-block: (81 commits)
  null_blk: add trace in null_blk_zoned.c
  null_blk: add tracepoint helpers for zoned mode
  block: add a zone condition debug helper
  nvme: cleanup namespace identifier reporting in nvme_init_ns_head
  nvme: rename __nvme_find_ns_head to nvme_find_ns_head
  nvme: refactor nvme_identify_ns_descs error handling
  nvme-tcp: Add warning on state change failure at nvme_tcp_setup_ctrl
  nvme-rdma: Add warning on state change failure at nvme_rdma_setup_ctrl
  nvme: Fix controller creation races with teardown flow
  nvme: Make nvme_uninit_ctrl symmetric to nvme_init_ctrl
  nvme: Fix ctrl use-after-free during sysfs deletion
  nvme-pci: Re-order nvme_pci_free_ctrl
  nvme: Remove unused return code from nvme_delete_ctrl_sync
  nvme: Use nvme_state_terminal helper
  nvme: release ida resources
  nvme: Add compat_ioctl handler for NVME_IOCTL_SUBMIT_IO
  nvmet-tcp: optimize tcp stack TX when data digest is used
  nvme-fabrics: Use scnprintf() for avoiding potential buffer overflow
  nvme-multipath: do not reset on unknown status
  nvmet-rdma: allocate RW ctxs according to mdts
  ...
2020-03-30 11:43:51 -07:00
Linus Torvalds
10f36b1e80 for-5.7/block-2020-03-29
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Merge tag 'for-5.7/block-2020-03-29' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:

 - Online capacity resizing (Balbir)

 - Number of hardware queue change fixes (Bart)

 - null_blk fault injection addition (Bart)

 - Cleanup of queue allocation, unifying the node/no-node API
   (Christoph)

 - Cleanup of genhd, moving code to where it makes sense (Christoph)

 - Cleanup of the partition handling code (Christoph)

 - disk stat fixes/improvements (Konstantin)

 - BFQ improvements (Paolo)

 - Various fixes and improvements

* tag 'for-5.7/block-2020-03-29' of git://git.kernel.dk/linux-block: (72 commits)
  block: return NULL in blk_alloc_queue() on error
  block: move bio_map_* to blk-map.c
  Revert "blkdev: check for valid request queue before issuing flush"
  block: simplify queue allocation
  bcache: pass the make_request methods to blk_queue_make_request
  null_blk: use blk_mq_init_queue_data
  block: add a blk_mq_init_queue_data helper
  block: move the ->devnode callback to struct block_device_operations
  block: move the part_stat* helpers from genhd.h to a new header
  block: move block layer internals out of include/linux/genhd.h
  block: move guard_bio_eod to bio.c
  block: unexport get_gendisk
  block: unexport disk_map_sector_rcu
  block: unexport disk_get_part
  block: mark part_in_flight and part_in_flight_rw static
  block: mark block_depr static
  block: factor out requeue handling from dispatch code
  block/diskstats: replace time_in_queue with sum of request times
  block/diskstats: accumulate all per-cpu counters in one pass
  block/diskstats: more accurate approximation of io_ticks for slow disks
  ...
2020-03-30 11:20:13 -07:00
Chaitanya Kulkarni
654a3667df block: return NULL in blk_alloc_queue() on error
This patch fixes follwoing warning:

block/blk-core.c: In function ‘blk_alloc_queue’:
block/blk-core.c:558:10: warning: returning ‘int’ from a function with return type ‘struct request_queue *’ makes pointer from integer without a cast [-Wint-conversion]
   return -EINVAL;

Fixes: 3d745ea5b0 ("block: simplify queue allocation")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-29 10:08:26 -06:00
Chaitanya Kulkarni
02694e8635 block: add a zone condition debug helper
Add a helper to stringify the zone conditions. We use this helper in the
next patch to track zone conditions in tracepoints.

Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-27 13:39:09 -06:00
Christoph Hellwig
130879f1ee block: move bio_map_* to blk-map.c
The bio_map_* helpers are just the low-level helpers for the
blk_rq_map_* APIs.  Move them together for better logical grouping,
as no there isn't much overlap with other code in bio.c.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-27 12:04:34 -06:00
Christoph Hellwig
f01b411f41 Revert "blkdev: check for valid request queue before issuing flush"
This reverts commit f10d9f617a.

We can't have queues without a make_request_fn any more (and the
loop device uses blk-mq these days anyway..).

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-27 10:23:44 -06:00
Christoph Hellwig
3d745ea5b0 block: simplify queue allocation
Current make_request based drivers use either blk_alloc_queue_node or
blk_alloc_queue to allocate a queue, and then set up the make_request_fn
function pointer and a few parameters using the blk_queue_make_request
helper.  Simplify this by passing the make_request pointer to
blk_alloc_queue, and while at it merge the _node variant into the main
helper by always passing a node_id, and remove the superfluous gfp_mask
parameter.  A lower-level __blk_alloc_queue is kept for the blk-mq case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-27 10:23:43 -06:00
Christoph Hellwig
2f227bb999 block: add a blk_mq_init_queue_data helper
This allows a driver to pass a queuedata member before ->init_hctx is
called.  null_blk currently open codes this logic, but I'd rather have
it in the core to ease future maintainance.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-27 10:23:43 -06:00
Christoph Hellwig
348e114bbd block: move the ->devnode callback to struct block_device_operations
There really isn't any good reason to stash a method directly into
struct gendisk.  Move it together with the other block device
operations.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-27 09:50:05 -06:00
Christoph Hellwig
c6a564ffad block: move the part_stat* helpers from genhd.h to a new header
These macros are just used by a few files.  Move them out of genhd.h,
which is included everywhere into a new standalone header.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25 09:50:09 -06:00
Christoph Hellwig
581e26004a block: move block layer internals out of include/linux/genhd.h
None of this needs to be exposed to drivers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25 09:50:08 -06:00
Christoph Hellwig
29125ed624 block: move guard_bio_eod to bio.c
This is bio layer functionality and not related to buffer heads.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25 09:50:08 -06:00
Christoph Hellwig
1b4d4dbdae block: unexport get_gendisk
get_gendisk is not used by any modular code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25 09:50:08 -06:00
Christoph Hellwig
a7818aedda block: unexport disk_map_sector_rcu
disk_map_sector_rcu is not used by any modular code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25 09:50:08 -06:00
Christoph Hellwig
572e7fc85b block: unexport disk_get_part
disk_get_part is not used by any modular code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25 09:50:08 -06:00
Christoph Hellwig
6005771c17 block: mark part_in_flight and part_in_flight_rw static
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25 09:50:08 -06:00
Christoph Hellwig
31eb618679 block: mark block_depr static
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25 09:50:08 -06:00
Johannes Thumshirn
c92a41031a block: factor out requeue handling from dispatch code
Factor out the requeue handling from the dispatch code, this will make
subsequent addition of different requeueing schemes easier.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25 09:40:24 -06:00
Konstantin Khlebnikov
8cd5b8fc00 block/diskstats: replace time_in_queue with sum of request times
Column "time_in_queue" in diskstats is supposed to show total waiting time
of all requests. I.e. value should be equal to the sum of times from other
columns. But this is not true, because column "time_in_queue" is counted
separately in jiffies rather than in nanoseconds as other times.

This patch removes redundant counter for "time_in_queue" and shows total
time of read, write, discard and flush requests.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25 08:49:12 -06:00
Konstantin Khlebnikov
ea18e0f0a6 block/diskstats: accumulate all per-cpu counters in one pass
Reading /proc/diskstats iterates over all cpus for summing each field.
It's faster to sum all fields in one pass.

Hammering /proc/diskstats with fio shows 2x performance improvement:

fio --name=test --numjobs=$JOBS --filename=/proc/diskstats \
    --size=1k --bs=1k --fallocate=none --create_on_open=1 \
    --time_based=1 --runtime=10 --invalidate=0 --group_report

	  JOBS=1	JOBS=10
Before:	  7k iops	64k iops
After:	 18k iops      120k iops

Also this way code is more compact:

add/remove: 1/0 grow/shrink: 0/2 up/down: 194/-1540 (-1346)
Function                                     old     new   delta
part_stat_read_all                             -     194    +194
diskstats_show                              1344     631    -713
part_stat_show                              1219     392    -827
Total: Before=14966947, After=14965601, chg -0.01%

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25 08:49:10 -06:00
Konstantin Khlebnikov
2b8bd42361 block/diskstats: more accurate approximation of io_ticks for slow disks
Currently io_ticks is approximated by adding one at each start and end of
requests if jiffies counter has changed. This works perfectly for requests
shorter than a jiffy or if one of requests starts/ends at each jiffy.

If disk executes just one request at a time and they are longer than two
jiffies then only first and last jiffies will be accounted.

Fix is simple: at the end of request add up into io_ticks jiffies passed
since last update rather than just one jiffy.

Example: common HDD executes random read 4k requests around 12ms.

fio --name=test --filename=/dev/sdb --rw=randread --direct=1 --runtime=30 &
iostat -x 10 sdb

Note changes of iostat's "%util" 8,43% -> 99,99% before/after patch:

Before:

Device:         rrqm/s   wrqm/s     r/s     w/s    rkB/s    wkB/s avgrq-sz avgqu-sz   await r_await w_await  svctm  %util
sdb               0,00     0,00   82,60    0,00   330,40     0,00     8,00     0,96   12,09   12,09    0,00   1,02   8,43

After:

Device:         rrqm/s   wrqm/s     r/s     w/s    rkB/s    wkB/s avgrq-sz avgqu-sz   await r_await w_await  svctm  %util
sdb               0,00     0,00   82,50    0,00   330,00     0,00     8,00     1,00   12,10   12,10    0,00  12,12  99,99

Now io_ticks does not loose time between start and end of requests, but
for queue-depth > 1 some I/O time between adjacent starts might be lost.

For load estimation "%util" is not as useful as average queue length,
but it clearly shows how often disk queue is completely empty.

Fixes: 5b18b5a737 ("block: delete part_round_stats and switch to less precise counting")
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25 08:49:08 -06:00
Christoph Hellwig
387048bf67 block: merge partition-generic.c and check.c
Merge block/partition-generic.c and block/partitions/check.c into
a single block/partitions/core.c as the content is closely related
and both files are tiny.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-24 07:57:08 -06:00
Christoph Hellwig
3f4fc59c13 block: move the various x86 Unix label formats out of genhd.h
All these are just used in block/partitions/msdos.c, so move them out of the
genhd.h driver included by every driver.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-24 07:57:08 -06:00
Christoph Hellwig
cb0ab52652 partitions/msdos: remove LINUX_SWAP_PARTITION
Just always use NEW_SOLARIS_X86_PARTITION and explain the situation,
as that is less confusing than two names for a single value.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-24 07:57:08 -06:00
Christoph Hellwig
0226e9ead4 block: move the *_PARTITION enum out of genhd.h
The enum containing the *_PARTITION symbolic names is only relevant
for the partition parser.  More specifically most values are MSDOS
partition table system indicators and thus should go straight into
msdos.c.  One value is only used by the sun partition parser, and the
sun and sgi partition parsers use the same value as the x86 Linux
RAID indicator to also indicate RAID autodetection.  Duplicate them
in sun.c and sgi.c given that the different partition types use
entirely different values otherwise.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-24 07:57:08 -06:00
Christoph Hellwig
1442f76d43 block: move struct partition out of genhd.h
struct partition is the on-disk format of a MSDOS partition table entry.
Move it out of genhd.h into a new msdos_partition.h header and give it
a msdos_ prefix to avoid confusion.
Also move the magic number from block/partitions/msdos.h to the new
header so that it can be used by the SCSI drivers looking at the DOS
partition tables.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-24 07:57:08 -06:00
Christoph Hellwig
cbb5cb3b29 block: remove block/partitions/sun.h
Just move the two defines to block/partitions/sun.c.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-24 07:57:08 -06:00
Christoph Hellwig
95f77ef35a block: remove block/partitions/sgi.h
Just move the single define to block/partitions/sgi.c.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-24 07:57:08 -06:00
Christoph Hellwig
3466f63a7c block: remove block/partitions/osf.h
Just move the single define to block/partitions/osf.c.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-24 07:57:08 -06:00
Christoph Hellwig
f6d17358dc block: remove block/partitions/karma.h
Just move the single define to block/partitions/karma.c.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-24 07:57:08 -06:00
Christoph Hellwig
3f1b95ef81 block: declare all partition detection routines in check.h
There is no good reason to include one header per partition type in
core.c.  Instead move the prototypes for the detection routins to
check.h, and remove all now empty headers in block/partitions/.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-24 07:57:08 -06:00
Christoph Hellwig
ffa9ed647a block: remove warn_no_part
The warn_no_part is initialized to 1 and never changed.  Remove
it and execute the code keyed off from it unconditionally.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-24 07:57:08 -06:00
Christoph Hellwig
74cc979c3c block: cleanup how md_autodetect_dev is called
Add a new include/linux/raid/detect.h header to declare the
md_autodetect_dev prototype which can be shared between md and
the partition code.  Then use IS_BUILTIN to call it instead of the
ifdef magic.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-24 07:57:08 -06:00