Commit Graph

7938 Commits

Author SHA1 Message Date
Christoph Hellwig
e7200d6afa block: require LBA dma_alignment when using PI
[ Upstream commit 4c8cf6bd28d6fea23819f082ddc8063fd6fa963a ]

The block layer PI generation / verification code expects the bio_vecs
to have at least LBA size (or more correctly integrity internal)
granularity.  With the direct I/O alignment relaxation in 2022, user
space can now feed bios with less alignment than that, leading to
scribbling outside the PI buffers.  Apparently this wasn't noticed so far
because none of the tests generate such buffers, but since 851c4c96db00
("xfs: implement XFS_IOC_DIOINFO in terms of vfs_getattr"), xfstests
generic/013 by default generates such I/O now that the relaxed alignment
is advertised by the XFS_IOC_DIOINFO ioctl.

Fix this by increasing the required alignment when using PI, although
handling arbitrary alignment in the long run would be even nicer.

Fixes: bf8d08532b ("iomap: add support for dma aligned direct-io")
Fixes: b1a000d3b8 ("block: relax direct io memory alignment")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-29 14:10:28 +01:00
Ming Lei
46ef903d8c block: Remove elevator_lock usage from blkg_conf frozen operations
[ Upstream commit 08823e89e3e269bf4c4a20b4c24a8119920cc7a4 ]

Remove the acquisition and release of q->elevator_lock in the
blkg_conf_open_bdev_frozen() and blkg_conf_exit_frozen() functions. The
elevator lock is no longer needed in these code paths since commit
78c271344b ("block: move wbt_enable_default() out of queue freezing
from sched ->exit()") which introduces `disk->rqos_state_mutex` for
protecting wbt state change, and not necessary to abuse elevator_lock
for this purpose.

This change helps to solve the lockdep warning reported from Yu Kuai[1].

Pass blktests/throtl with lockdep enabled.

Links: https://lore.kernel.org/linux-block/e5e7ac3f-2063-473a-aafb-4d8d43e5576e@yukuai.org.cn/ [1]
Fixes: commit 78c271344b ("block: move wbt_enable_default() out of queue freezing from sched ->exit()")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-23 16:24:37 +02:00
Yu Kuai
4f487c64b7 blk-mq: fix stale tag depth for shared sched tags in blk_mq_update_nr_requests()
[ Upstream commit dc96cefef0d3032c69e46a21b345c60e56b18934 ]

Commit 7f2799c546db ("blk-mq: cleanup shared tags case in
blk_mq_update_nr_requests()") moves blk_mq_tag_update_sched_shared_tags()
before q->nr_requests is updated, however, it's still using the old
q->nr_requests to resize tag depth.

Fix this problem by passing in expected new tag depth.

Fixes: 7f2799c546db ("blk-mq: cleanup shared tags case in blk_mq_update_nr_requests()")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Reported-by: Chris Mason <clm@meta.com>
Link: https://lore.kernel.org/linux-block/20251014130507.4187235-2-clm@meta.com/
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-23 16:24:37 +02:00
Yu Kuai
79465347fd blk-crypto: fix missing blktrace bio split events
commit 06d712d297649f48ebf1381d19bd24e942813b37 upstream.

trace_block_split() is missing, resulting in blktrace inability to catch
BIO split events and making it harder to analyze the BIO sequence.

Cc: stable@vger.kernel.org
Fixes: 488f6682c8 ("block: blk-crypto-fallback for Inline Encryption")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-19 16:37:23 +02:00
Yu Kuai
76c6babc71 blk-throttle: fix throtl_data leak during disk release
[ Upstream commit 336aec7b06be860477be80a4299263a2e9355789 ]

Tightening the throttle activation check in blk_throtl_activated() to
require both q->td presence and policy bit set introduced a memory leak
during disk release:

blkg_destroy_all() clears the policy bit first during queue deactivation,
causing subsequent blk_throtl_exit() to skip throtl_data cleanup when
blk_throtl_activated() fails policy check.

Idealy we should avoid modifying blk_throtl_exit() activation check because
it's intuitive that blk-throtl start from blk_throtl_init() and end in
blk_throtl_exit(). However, call blk_throtl_exit() before
blkg_destroy_all() will make a long term deadlock problem easier to
trigger[1], hence fix this problem by checking if q->td is NULL from
blk_throtl_exit(), and remove policy deactivation as well since it's
useless.

[1] https://lore.kernel.org/all/CAHj4cs9p9H5yx+ywsb3CMUdbqGPhM+8tuBvhW=9ADiCjAqza9w@mail.gmail.com/#t

Fixes: bd9fd5be6bc0 ("blk-throttle: fix access race during throttle policy activation")
Reported-by: Yi Zhang <yi.zhang@redhat.com>
Closes: https://lore.kernel.org/all/CAHj4cs-p-ZwBEKigBj7T6hQCOo-H68-kVwCrV6ZvRovrr9Z+HA@mail.gmail.com/
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-15 12:03:34 +02:00
John Garry
17fd1dd9f5 block: fix stacking of atomic writes when atomics are not supported
[ Upstream commit f2d8c5a2f79c28569edf4948b611052253b5e99a ]

Atomic writes support may not always be possible when stacking devices
which support atomic writes. Such as case is a different atomic write
boundary between stacked devices (which is not supported).

In the case that atomic writes cannot supported, the top device queue HW
limits are set to 0.

However, in blk_stack_atomic_writes_limits(), we detect that we are
stacking the first bottom device by checking the top device
atomic_write_hw_max value == 0. This get confused with the case of atomic
writes not supported, above.

Make the distinction between stacking the first bottom device and no
atomics supported by initializing stacked device atomic_write_hw_max =
UINT_MAX and checking that for stacking the first bottom device.

Fixes: d7f36dc446 ("block: Support atomic writes limits for stacked devices")
Signed-off-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-15 12:03:34 +02:00
John Garry
8f192ff4d5 block: update validation of atomic writes boundary for stacked devices
[ Upstream commit bfd4037296bd7e1f95394a2e3daf8e3c1796c3b3 ]

In commit 63d092d1c1 ("block: use chunk_sectors when evaluating stacked
atomic write limits"), it was missed to use a chunk sectors limit check
in blk_stack_atomic_writes_boundary_head(), so update that function to
do the proper check.

Fixes: 63d092d1c1 ("block: use chunk_sectors when evaluating stacked atomic write limits")
Signed-off-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-15 12:03:34 +02:00
Yu Kuai
8d26acf847 blk-mq: fix potential deadlock while nr_requests grown
[ Upstream commit b86433721f46d934940528f28d49c1dedb690df1 ]

Allocate and free sched_tags while queue is freezed can deadlock[1],
this is a long term problem, hence allocate memory before freezing
queue and free memory after queue is unfreezed.

[1] https://lore.kernel.org/all/0659ea8d-a463-47c8-9180-43c719e106eb@linux.ibm.com/
Fixes: e3a2b3f931 ("blk-mq: allow changing of queue depth through sysfs")

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-15 12:03:29 +02:00
Yu Kuai
b75c7a8020 blk-mq-sched: add new parameter nr_requests in blk_mq_alloc_sched_tags()
[ Upstream commit 6293e336f6d7d3f3415346ce34993b3398846166 ]

This helper only support to allocate the default number of requests,
add a new parameter to support specific number of requests.

Prepare to fix potential deadlock in the case nr_requests grow.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Stable-dep-of: b86433721f46 ("blk-mq: fix potential deadlock while nr_requests grown")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-15 12:03:29 +02:00
Yu Kuai
fc0328336c blk-mq: split bitmap grow and resize case in blk_mq_update_nr_requests()
[ Upstream commit e63200404477456ec60c62dd8b3b1092aba2e211 ]

No functional changes are intended, make code cleaner and prepare to fix
the grow case in following patches.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Stable-dep-of: b86433721f46 ("blk-mq: fix potential deadlock while nr_requests grown")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-15 12:03:29 +02:00
Yu Kuai
64cb378502 blk-mq: cleanup shared tags case in blk_mq_update_nr_requests()
[ Upstream commit 7f2799c546dba9e12f9ff4d07936601e416c640d ]

For shared tags case, all hctx->sched_tags/tags are the same, it doesn't
make sense to call into blk_mq_tag_update_depth() multiple times for the
same tags.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Stable-dep-of: b86433721f46 ("blk-mq: fix potential deadlock while nr_requests grown")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-15 12:03:29 +02:00
Yu Kuai
b1b9ba3c2e blk-mq: convert to serialize updating nr_requests with update_nr_hwq_lock
[ Upstream commit 626ff4f8ebcb7207f01e7810acb85812ccf06bd8 ]

request_queue->nr_requests can be changed by:

a) switch elevator by updating nr_hw_queues
b) switch elevator by elevator sysfs attribute
c) configue queue sysfs attribute nr_requests

Current lock order is:

1) update_nr_hwq_lock, case a,b
2) freeze_queue
3) elevator_lock, case a,b,c

And update nr_requests is seriablized by elevator_lock() already,
however, in the case c, we'll have to allocate new sched_tags if
nr_requests grow, and do this with elevator_lock held and queue
freezed has the risk of deadlock.

Hence use update_nr_hwq_lock instead, make it possible to allocate
memory if tags grow, meanwhile also prevent nr_requests to be changed
concurrently.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Stable-dep-of: b86433721f46 ("blk-mq: fix potential deadlock while nr_requests grown")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-15 12:03:29 +02:00
Yu Kuai
10bc65a048 blk-mq: check invalid nr_requests in queue_requests_store()
[ Upstream commit b46d4c447db76e36906ed59ebb9b3ef8f3383322 ]

queue_requests_store() is the only caller of
blk_mq_update_nr_requests(), and blk_mq_update_nr_requests() is the
only caller of blk_mq_tag_update_depth(), however, they all have
checkings for nr_requests input by user.

Make code cleaner by moving all the checkings to the top function:

1) nr_requests > reserved tags;
2) if there is elevator, 4 <= nr_requests <= 2048;
3) if elevator is none, 4 <= nr_requests <= tag_set->queue_depth;

Meanwhile, case 2 is the only case tags can grow and -ENOMEM might be
returned.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Stable-dep-of: b86433721f46 ("blk-mq: fix potential deadlock while nr_requests grown")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-15 12:03:28 +02:00
Yu Kuai
5ae84131b0 blk-mq: remove useless checkings in blk_mq_update_nr_requests()
[ Upstream commit 8bd7195fea6d9662aa3b32498a3828bfd9b63185 ]

1) queue_requests_store() is the only caller of
blk_mq_update_nr_requests(), where queue is already freezed, no need to
check mq_freeze_depth;
2) q->tag_set must be set for request based device, and queue_is_mq() is
already checked in blk_mq_queue_attr_visible(), no need to check
q->tag_set.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Stable-dep-of: b86433721f46 ("blk-mq: fix potential deadlock while nr_requests grown")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-15 12:03:28 +02:00
Yu Kuai
fa6a3dd139 block: fix ordering of recursive split IO
[ Upstream commit b2f5974079d82a4761f002e80601064d4e39a81f ]

Currently, split bio will be chained to original bio, and original bio
will be resubmitted to the tail of current->bio_list, waiting for
split bio to be issued. However, if split bio get split again, the IO
order will be messed up. This problem, on the one hand, will cause
performance degradation, especially for mdraid with large IO size; on
the other hand, will cause write errors for zoned block devices[1].

For example, in raid456 IO will first be split by max_sector from
md_submit_bio(), and then later be split again by chunksize for internal
handling:

For example, assume max_sectors is 1M, and chunksize is 512k

1) issue a 2M IO:

bio issuing: 0+2M
current->bio_list: NULL

2) md_submit_bio() split by max_sector:

bio issuing: 0+1M
current->bio_list: 1M+1M

3) chunk_aligned_read() split by chunksize:

bio issuing: 0+512k
current->bio_list: 1M+1M -> 512k+512k

4) after first bio issued, __submit_bio_noacct() will contuine issuing
next bio:

bio issuing: 1M+1M
current->bio_list: 512k+512k
bio issued: 0+512k

5) chunk_aligned_read() split by chunksize:

bio issuing: 1M+512k
current->bio_list: 512k+512k -> 1536k+512k
bio issued: 0+512k

6) no split afterwards, finally the issue order is:

0+512k -> 1M+512k -> 512k+512k -> 1536k+512k

This behaviour will cause large IO read on raid456 endup to be small
discontinuous IO in underlying disks. Fix this problem by placing split
bio to the head of current->bio_list.

Test script: test on 8 disk raid5 with 64k chunksize
dd if=/dev/md0 of=/dev/null bs=4480k iflag=direct

Test results:
Before this patch
1) iostat results:
Device            r/s     rMB/s   rrqm/s  %rrqm r_await rareq-sz  aqu-sz  %util
md0           52430.00   3276.87     0.00   0.00    0.62    64.00   32.60  80.10
sd*           4487.00    409.00  2054.00  31.40    0.82    93.34    3.68  71.20
2) blktrace G stage:
  8,0    0   486445    11.357392936   843  G   R 14071424 + 128 [dd]
  8,0    0   486451    11.357466360   843  G   R 14071168 + 128 [dd]
  8,0    0   486454    11.357515868   843  G   R 14071296 + 128 [dd]
  8,0    0   486468    11.357968099   843  G   R 14072192 + 128 [dd]
  8,0    0   486474    11.358031320   843  G   R 14071936 + 128 [dd]
  8,0    0   486480    11.358096298   843  G   R 14071552 + 128 [dd]
  8,0    0   486490    11.358303858   843  G   R 14071808 + 128 [dd]
3) io seek for sdx:
Noted io seek is the result from blktrace D stage, statistic of:
ABS((offset of next IO) - (offset + len of previous IO))

Read|Write seek
cnt 55175, zero cnt 25079
    >=(KB) .. <(KB)     : count       ratio |distribution                            |
         0 .. 1         : 25079       45.5% |########################################|
         1 .. 2         : 0            0.0% |                                        |
         2 .. 4         : 0            0.0% |                                        |
         4 .. 8         : 0            0.0% |                                        |
         8 .. 16        : 0            0.0% |                                        |
        16 .. 32        : 0            0.0% |                                        |
        32 .. 64        : 12540       22.7% |#####################                   |
        64 .. 128       : 2508         4.5% |#####                                   |
       128 .. 256       : 0            0.0% |                                        |
       256 .. 512       : 10032       18.2% |#################                       |
       512 .. 1024      : 5016         9.1% |#########                               |

After this patch:
1) iostat results:
Device            r/s     rMB/s   rrqm/s  %rrqm r_await rareq-sz  aqu-sz  %util
md0           87965.00   5271.88     0.00   0.00    0.16    61.37   14.03  90.60
sd*           6020.00    658.44  5117.00  45.95    0.44   112.00    2.68  86.50
2) blktrace G stage:
  8,0    0   206296     5.354894072   664  G   R 7156992 + 128 [dd]
  8,0    0   206305     5.355018179   664  G   R 7157248 + 128 [dd]
  8,0    0   206316     5.355204438   664  G   R 7157504 + 128 [dd]
  8,0    0   206319     5.355241048   664  G   R 7157760 + 128 [dd]
  8,0    0   206333     5.355500923   664  G   R 7158016 + 128 [dd]
  8,0    0   206344     5.355837806   664  G   R 7158272 + 128 [dd]
  8,0    0   206353     5.355960395   664  G   R 7158528 + 128 [dd]
  8,0    0   206357     5.356020772   664  G   R 7158784 + 128 [dd]
3) io seek for sdx
Read|Write seek
cnt 28644, zero cnt 21483
    >=(KB) .. <(KB)     : count       ratio |distribution                            |
         0 .. 1         : 21483       75.0% |########################################|
         1 .. 2         : 0            0.0% |                                        |
         2 .. 4         : 0            0.0% |                                        |
         4 .. 8         : 0            0.0% |                                        |
         8 .. 16        : 0            0.0% |                                        |
        16 .. 32        : 0            0.0% |                                        |
        32 .. 64        : 7161        25.0% |##############                          |

BTW, this looks like a long term problem from day one, and large
sequential IO read is pretty common case like video playing.

And even with this patch, in this test case IO is merged to at most 128k
is due to block layer plug limit BLK_PLUG_FLUSH_SIZE, increase such
limit can get even better performance. However, we'll figure out how to do
this properly later.

[1] https://lore.kernel.org/all/e40b076d-583d-406b-b223-005910a9f46f@acm.org/

Fixes: d89d87965d ("When stacked block devices are in-use (e.g. md or dm), the recursive calls")
Reported-by: Tie Ren <tieren@fnnas.com>
Closes: https://lore.kernel.org/all/7dro5o7u5t64d6bgiansesjavxcuvkq5p2pok7dtwkav7b7ape@3isfr44b6352/
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-15 12:03:28 +02:00
Yu Kuai
14d4f1eaa6 block: skip unnecessary checks for split bio
[ Upstream commit 0b64682e78f7a53ea863e368b1aa66f05767858d ]

Lots of checks are already done while submitting this bio the first
time, and there is no need to check them again when this bio is
resubmitted after split.

Hence open code should_fail_bio() and blk_throtl_bio() that are still
necessary from submit_bio_split_bioset().

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Stable-dep-of: b2f5974079d8 ("block: fix ordering of recursive split IO")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-15 12:03:28 +02:00
Yu Kuai
9f7b1537e3 block: factor out a helper bio_submit_split_bioset()
[ Upstream commit e37b5596a19be9a150cb194ec32e78f295a3574b ]

No functional changes are intended, some drivers like mdraid will split
bio by internal processing, prepare to unify bio split codes.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Stable-dep-of: b2f5974079d8 ("block: fix ordering of recursive split IO")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-15 12:03:28 +02:00
Yu Kuai
8668afa4d6 block: initialize bio issue time in blk_mq_submit_bio()
[ Upstream commit 1f963bdd6420b6080bcfd0ee84a75c96f35545a6 ]

bio->issue_time_ns is only used by blk-iolatency, which can only be
enabled for rq-based disk, hence it's not necessary to initialize
the time for bio-based disk.

Meanwhile, if bio is split by blk_crypto_fallback_split_bio_if_needed(),
the issue time is not initialized for new split bio, this can be fixed
as well.

Noted the next patch will optimize better that bio issue time will
only be used when blk-iolatency is really enabled by the disk.

Fixes: 488f6682c8 ("block: blk-crypto-fallback for Inline Encryption")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-15 12:03:28 +02:00
Yu Kuai
e7f67fe190 block: cleanup bio_issue
[ Upstream commit 1733e88874838ddebf7774440c285700865e6b08 ]

Now that bio->bi_issue is only used by blk-iolatency to get bio issue
time, replace bio_issue with u64 time directly and remove bio_issue to
make code cleaner.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Stable-dep-of: 1f963bdd6420 ("block: initialize bio issue time in blk_mq_submit_bio()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-15 12:03:28 +02:00
Han Guangjiang
6a0c394300 blk-throttle: fix access race during throttle policy activation
[ Upstream commit bd9fd5be6bc0836820500f68fff144609fbd85a9 ]

On repeated cold boots we occasionally hit a NULL pointer crash in
blk_should_throtl() when throttling is consulted before the throttle
policy is fully enabled for the queue. Checking only q->td != NULL is
insufficient during early initialization, so blkg_to_pd() for the
throttle policy can still return NULL and blkg_to_tg() becomes NULL,
which later gets dereferenced.

 Unable to handle kernel NULL pointer dereference
 at virtual address 0000000000000156
 ...
 pc : submit_bio_noacct+0x14c/0x4c8
 lr : submit_bio_noacct+0x48/0x4c8
 sp : ffff800087f0b690
 x29: ffff800087f0b690 x28: 0000000000005f90 x27: ffff00068af393c0
 x26: 0000000000080000 x25: 000000000002fbc0 x24: ffff000684ddcc70
 x23: 0000000000000000 x22: 0000000000000000 x21: 0000000000000000
 x20: 0000000000080000 x19: ffff000684ddcd08 x18: ffffffffffffffff
 x17: 0000000000000000 x16: ffff80008132a550 x15: 0000ffff98020fff
 x14: 0000000000000000 x13: 1fffe000d11d7021 x12: ffff000688eb810c
 x11: ffff00077ec4bb80 x10: ffff000688dcb720 x9 : ffff80008068ef60
 x8 : 00000a6fb8a86e85 x7 : 000000000000111e x6 : 0000000000000002
 x5 : 0000000000000246 x4 : 0000000000015cff x3 : 0000000000394500
 x2 : ffff000682e35e40 x1 : 0000000000364940 x0 : 000000000000001a
 Call trace:
  submit_bio_noacct+0x14c/0x4c8
  verity_map+0x178/0x2c8
  __map_bio+0x228/0x250
  dm_submit_bio+0x1c4/0x678
  __submit_bio+0x170/0x230
  submit_bio_noacct_nocheck+0x16c/0x388
  submit_bio_noacct+0x16c/0x4c8
  submit_bio+0xb4/0x210
  f2fs_submit_read_bio+0x4c/0xf0
  f2fs_mpage_readpages+0x3b0/0x5f0
  f2fs_readahead+0x90/0xe8

Tighten blk_throtl_activated() to also require that the throttle policy
bit is set on the queue:

  return q->td != NULL &&
         test_bit(blkcg_policy_throtl.plid, q->blkcg_pols);

This prevents blk_should_throtl() from accessing throttle group state
until policy data has been attached to blkgs.

Fixes: a3166c5170 ("blk-throttle: delay initialization until configuration")
Co-developed-by: Liang Jie <liangjie@lixiang.com>
Signed-off-by: Liang Jie <liangjie@lixiang.com>
Signed-off-by: Han Guangjiang <hanguangjiang@lixiang.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-15 12:03:26 +02:00
Yu Kuai
ba51132ae0 blk-mq: fix elevator depth_updated method
[ Upstream commit 7d337eef4affc5e26e0570513168c69ddbc40f92 ]

Current depth_updated has some problems:

1) depth_updated() will be called for each hctx, while all elevators
will update async_depth for the disk level, this is not related to hctx;
2) In blk_mq_update_nr_requests(), if previous hctx update succeed and
this hctx update failed, q->nr_requests will not be updated, while
async_depth is already updated with new nr_reqeuests in previous
depth_updated();
3) All elevators are using q->nr_requests to calculate async_depth now,
however, q->nr_requests is still the old value when depth_updated() is
called from blk_mq_update_nr_requests();

Those problems are first from error path, then mq-deadline, and recently
for bfq and kyber, fix those problems by:

- pass in request_queue instead of hctx;
- move depth_updated() after q->nr_requests is updated in
  blk_mq_update_nr_requests();
- add depth_updated() call inside init_sched() method to initialize
  async_depth;
- remove init_hctx() method for mq-deadline and bfq that is useless now;

Fixes: 77f1e0a52d ("bfq: update internal depth state when queue depth changes")
Fixes: 39823b47bb ("block/mq-deadline: Fix the tag reservation code")
Fixes: 42e6c6ce03 ("lib/sbitmap: convert shallow_depth from one word to the whole sbitmap")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Li Nan <linan122@huawei.com>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Link: https://lore.kernel.org/r/20250821060612.1729939-2-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-15 12:03:24 +02:00
Qianfeng Rong
9e3fe3b696 block: use int to store blk_stack_limits() return value
[ Upstream commit b0b4518c992eb5f316c6e40ff186cbb7a5009518 ]

Change the 'ret' variable in blk_stack_limits() from unsigned int to int,
as it needs to store negative value -1.

Storing the negative error codes in unsigned type, or performing equality
comparisons (e.g., ret == -1), doesn't cause an issue at runtime [1] but
can be confusing.  Additionally, assigning negative error codes to unsigned
type may trigger a GCC warning when the -Wsign-conversion flag is enabled.

No effect on runtime.

Link: https://lore.kernel.org/all/x3wogjf6vgpkisdhg3abzrx7v7zktmdnfmqeih5kosszmagqfs@oh3qxrgzkikf/ #1
Signed-off-by: Qianfeng Rong <rongqianfeng@vivo.com>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Fixes: fe0b393f2c ("block: Correct handling of bottom device misaligment")
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20250902130930.68317-1-rongqianfeng@vivo.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-15 12:03:23 +02:00
Li Nan
d5ddd76ee5 blk-mq: check kobject state_in_sysfs before deleting in blk_mq_unregister_hctx
[ Upstream commit 4c7ef92f6d4d08a27d676e4c348f4e2922cab3ed ]

In __blk_mq_update_nr_hw_queues() the return value of
blk_mq_sysfs_register_hctxs() is not checked. If sysfs creation for hctx
fails, later changing the number of hw_queues or removing disk will
trigger the following warning:

  kernfs: can not remove 'nr_tags', no directory
  WARNING: CPU: 2 PID: 637 at fs/kernfs/dir.c:1707 kernfs_remove_by_name_ns+0x13f/0x160
  Call Trace:
   remove_files.isra.1+0x38/0xb0
   sysfs_remove_group+0x4d/0x100
   sysfs_remove_groups+0x31/0x60
   __kobject_del+0x23/0xf0
   kobject_del+0x17/0x40
   blk_mq_unregister_hctx+0x5d/0x80
   blk_mq_sysfs_unregister_hctxs+0x94/0xd0
   blk_mq_update_nr_hw_queues+0x124/0x760
   nullb_update_nr_hw_queues+0x71/0xf0 [null_blk]
   nullb_device_submit_queues_store+0x92/0x120 [null_blk]

kobjct_del() was called unconditionally even if sysfs creation failed.
Fix it by checkig the kobject creation statusbefore deleting it.

Fixes: 477e19dedc ("blk-mq: adjust debugfs and sysfs register when updating nr_hw_queues")
Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20250826084854.1030545-1-linan666@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-15 12:03:22 +02:00
Yu Kuai
392b1d6491 blk-mq: fix blk_mq_tags double free while nr_requests grown
commit ba28afbd9eff2a6370f23ef4e6a036ab0cfda409 upstream.

In the case user trigger tags grow by queue sysfs attribute nr_requests,
hctx->sched_tags will be freed directly and replaced with a new
allocated tags, see blk_mq_tag_update_depth().

The problem is that hctx->sched_tags is from elevator->et->tags, while
et->tags is still the freed tags, hence later elevator exit will try to
free the tags again, causing kernel panic.

Fix this problem by replacing et->tags with new allocated tags as well.

Noted there are still some long term problems that will require some
refactor to be fixed thoroughly[1].

[1] https://lore.kernel.org/all/20250815080216.410665-1-yukuai1@huaweicloud.com/
Fixes: f5a6604f7a ("block: fix lockdep warning caused by lock dependency in elv_iosched_store")

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Li Nan <linan122@huawei.com>
Link: https://lore.kernel.org/r/20250821060612.1729939-3-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-06 11:20:04 +02:00
Linus Torvalds
3a654ee549 Merge tag 'block-6.17-20250925' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux
Pull block fixes from Jens Axboe:
 "A regression fix for this series where an attempt to silence an EOD
  error got messed up a bit, and then a change of git trees for the
  block and io_uring trees.

  Switching the git trees to kernel.org now, as I've just about had it
  trying to battle AI bots that bring the box to its knees, continually.
  At least I don't have to maintain the kernel.org side"

* tag 'block-6.17-20250925' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
  MAINTAINERS: update io_uring and block tree git trees
  block: fix EOD return for device with nr_sectors == 0
2025-09-26 09:46:51 -07:00
Jens Axboe
ab073abf6d block: fix EOD return for device with nr_sectors == 0
A recent commit skipped dumping the usual "attempt to access beyond end
of device" message if the device size is 0 sectors, as that's a common
pattern for devices that have been hot removed. But while it stopped
that message, it also prevented returning -EIO for that condition.
Reinstate the -EIO return, while retaining the quiet operation for
triggering EOD for a device with 0 sectors.

Reported-by: syzbot+4b12286339fe4c2700c1@syzkaller.appspotmail.com
Reported-by: Sahil Chandna <chandna.linuxkernel@gmail.com>
Fixes: d0a2b527d8 ("block: tone down bio_check_eod")
Tested-by: Sahil Chandna <chandna.linuxkernel@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-09-22 09:35:24 -06:00
Linus Torvalds
f777d1112e Merge tag 'vfs-6.17-rc6.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs fixes from Christian Brauner:
 "fuse:

   - Prevent opening of non-regular backing files.

     Fuse doesn't support non-regular files anyway.

   - Check whether copy_file_range() returns a larger size than
     requested.

   - Prevent overflow in copy_file_range() as fuse currently only
     supports 32-bit sized copies.

   - Cache the blocksize value if the server returned a new value as
     inode->i_blkbits isn't modified directly anymore.

   - Fix i_blkbits handling for iomap partial writes.

     By default i_blkbits is set to PAGE_SIZE which causes iomap to mark
     the whole folio as uptodate even on a partial write. But fuseblk
     filesystems support choosing a blocksize smaller than PAGE_SIZE
     risking data corruption. Simply enforce PAGE_SIZE as blocksize for
     fuseblk's internal inode for now.

   - Prevent out-of-bounds acces in fuse_dev_write() when the number of
     bytes to be retrieved is truncated to the fc->max_pages limit.

  virtiofs:

   - Fix page faults for DAX page addresses.

  Misc:

   - Tighten file handle decoding from userns.

     Check that the decoded dentry itself has a valid idmapping in the
     user namespace.

   - Fix mount-notify selftests.

   - Fix some indentation errors.

   - Add an FMODE_ flag to indicate IOCB_HAS_METADATA availability.

     This will be moved to an FOP_* flag with a bit more rework needed
     for that to happen not suitable for a fix.

   - Don't silently ignore metadata for sync read/write.

   - Don't pointlessly log warning when reading coredump sysctls"

* tag 'vfs-6.17-rc6.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  fuse: virtio_fs: fix page fault for DAX page address
  selftests/fs/mount-notify: Fix compilation failure.
  fhandle: use more consistent rules for decoding file handle from userns
  fuse: Block access to folio overlimit
  fuse: fix fuseblk i_blkbits for iomap partial writes
  fuse: reflect cached blocksize if blocksize was changed
  fuse: prevent overflow in copy_file_range return value
  fuse: check if copy_file_range() returns larger than requested size
  fuse: do not allow mapping a non-regular backing file
  coredump: don't pointlessly check and spew warnings
  fs: fix indentation style
  block: don't silently ignore metadata for sync read/write
  fs: add a FMODE_ flag to indicate IOCB_HAS_METADATA availability
  Please enter a commit message to explain why this merge is necessary,
  especially if it merges an updated upstream into a topic branch.
2025-09-08 07:53:01 -07:00
Christian Brauner
e23654f5b1 Merge tag 'fuse-fixes-6.17-rc5' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse into vfs.fixes
fuse fixes for 6.17-rc5

* tag 'fuse-fixes-6.17-rc5' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: (6 commits)
  fuse: Block access to folio overlimit
  fuse: fix fuseblk i_blkbits for iomap partial writes
  fuse: reflect cached blocksize if blocksize was changed
  fuse: prevent overflow in copy_file_range return value
  fuse: check if copy_file_range() returns larger than requested size
  fuse: do not allow mapping a non-regular backing file

Link: https://lore.kernel.org/CAJfpeguEVMMyw_zCb+hbOuSxdE2Z3Raw=SJsq=Y56Ae6dn2W3g@mail.gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-09-01 12:48:28 +02:00
Nilay Shroff
e3ef9445cd block: validate QoS before calling __rq_qos_done_bio()
If a bio has BIO_QOS_xxx set, it doesn't guarantee that q->rq_qos is
also present at-least for stacked block devices. For instance, in case
of NVMe when multipath is enabled, the bottom device may have QoS
enabled but top device doesn't. So always validate QoS is enabled and
q->rq_qos is present before calling __rq_qos_done_bio().

Fixes: 370ac285f2 ("block: avoid cpu_hotplug_lock depedency on freeze_lock")
Reported-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Closes: https://lore.kernel.org/all/3a07b752-06a4-4eee-b302-f4669feb859d@linux.ibm.com/
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Link: https://lore.kernel.org/r/20250826163128.1952394-1-nilay@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-08-26 10:34:08 -06:00
Bart Van Assche
198f36f902 blk-zoned: Fix a lockdep complaint about recursive locking
If preparing a write bio fails then blk_zone_wplug_bio_work() calls
bio_endio() with zwplug->lock held. If a device mapper driver is stacked
on top of the zoned block device then this results in nested locking of
zwplug->lock. The resulting lockdep complaint is a false positive
because this is nested locking and not recursive locking. Suppress this
false positive by calling blk_zone_wplug_bio_io_error() without holding
zwplug->lock. This is safe because no code in
blk_zone_wplug_bio_io_error() depends on zwplug->lock being held. This
patch suppresses the following lockdep complaint:

WARNING: possible recursive locking detected
--------------------------------------------
kworker/3:0H/46 is trying to acquire lock:
ffffff882968b830 (&zwplug->lock){-...}-{2:2}, at: blk_zone_write_plug_bio_endio+0x64/0x1f0

but task is already holding lock:
ffffff88315bc230 (&zwplug->lock){-...}-{2:2}, at: blk_zone_wplug_bio_work+0x8c/0x48c

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&zwplug->lock);
  lock(&zwplug->lock);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

3 locks held by kworker/3:0H/46:
 #0: ffffff8809486758 ((wq_completion)sdd_zwplugs){+.+.}-{0:0}, at: process_one_work+0x1bc/0x65c
 #1: ffffffc085de3d70 ((work_completion)(&zwplug->bio_work)){+.+.}-{0:0}, at: process_one_work+0x1e4/0x65c
 #2: ffffff88315bc230 (&zwplug->lock){-...}-{2:2}, at: blk_zone_wplug_bio_work+0x8c/0x48c

stack backtrace:
CPU: 3 UID: 0 PID: 46 Comm: kworker/3:0H Tainted: G        W  OE      6.12.38-android16-5-maybe-dirty-4k #1 8b362b6f76e3645a58cd27d86982bce10d150025
Tainted: [W]=WARN, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
Hardware name: Spacecraft board based on MALIBU (DT)
Workqueue: sdd_zwplugs blk_zone_wplug_bio_work
Call trace:
 dump_backtrace+0xfc/0x17c
 show_stack+0x18/0x28
 dump_stack_lvl+0x40/0xa0
 dump_stack+0x18/0x24
 print_deadlock_bug+0x38c/0x398
 __lock_acquire+0x13e8/0x2e1c
 lock_acquire+0x134/0x2b4
 _raw_spin_lock_irqsave+0x5c/0x80
 blk_zone_write_plug_bio_endio+0x64/0x1f0
 bio_endio+0x9c/0x240
 __dm_io_complete+0x214/0x260
 clone_endio+0xe8/0x214
 bio_endio+0x218/0x240
 blk_zone_wplug_bio_work+0x204/0x48c
 process_one_work+0x26c/0x65c
 worker_thread+0x33c/0x498
 kthread+0x110/0x134
 ret_from_fork+0x10/0x20

Cc: stable@vger.kernel.org
Cc: Damien Le Moal <dlemoal@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Fixes: dd291d77cc ("block: Introduce zone write plugging")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20250825182720.1697203-1-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-08-26 08:27:24 -06:00
Nilay Shroff
370ac285f2 block: avoid cpu_hotplug_lock depedency on freeze_lock
A recent lockdep[1] splat observed while running blktest block/005
reveals a potential deadlock caused by the cpu_hotplug_lock dependency
on ->freeze_lock. This dependency was introduced by commit 033b667a82
("block: blk-rq-qos: guard rq-qos helpers by static key").

That change added a static key to avoid fetching q->rq_qos when
neither blk-wbt nor blk-iolatency is configured. The static key
dynamically patches kernel text to a NOP when disabled, eliminating
overhead of fetching q->rq_qos in the I/O hot path. However, enabling
a static key at runtime requires acquiring both cpu_hotplug_lock and
jump_label_mutex. When this happens after the queue has already been
frozen (i.e., while holding ->freeze_lock), it creates a locking
dependency from cpu_hotplug_lock to ->freeze_lock, which leads to a
potential deadlock reported by lockdep [1].

To resolve this, replace the static key mechanism with q->queue_flags:
QUEUE_FLAG_QOS_ENABLED. This flag is evaluated in the fast path before
accessing q->rq_qos. If the flag is set, we proceed to fetch q->rq_qos;
otherwise, the access is skipped.

Since q->queue_flags is commonly accessed in IO hotpath and resides in
the first cacheline of struct request_queue, checking it imposes minimal
overhead while eliminating the deadlock risk.

This change avoids the lockdep splat without introducing performance
regressions.

[1] https://lore.kernel.org/linux-block/4fdm37so3o4xricdgfosgmohn63aa7wj3ua4e5vpihoamwg3ui@fq42f5q5t5ic/

Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Closes: https://lore.kernel.org/linux-block/4fdm37so3o4xricdgfosgmohn63aa7wj3ua4e5vpihoamwg3ui@fq42f5q5t5ic/
Fixes: 033b667a82 ("block: blk-rq-qos: guard rq-qos helpers by static key")
Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20250814082612.500845-4-nilay@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-08-21 07:11:11 -06:00
Nilay Shroff
ade1beea1c block: decrement block_rq_qos static key in rq_qos_del()
rq_qos_add() increments the block_rq_qos static key when a QoS
policy is attached. When a QoS policy is removed via rq_qos_del(),
we must symmetrically decrement the static key. If this removal drops
the last QoS policy from the queue (q->rq_qos becomes NULL), the
static branch can be disabled and the jump label patched to a NOP,
avoiding overhead on the hot path.

This change ensures rq_qos_add()/rq_qos_del() keep the
block_rq_qos static key balanced and prevents leaving the branch
permanently enabled after the last policy is removed.

Fixes: 033b667a82 ("block: blk-rq-qos: guard rq-qos helpers by static key")
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20250814082612.500845-3-nilay@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-08-21 07:11:11 -06:00
Nilay Shroff
275332877e block: skip q->rq_qos check in rq_qos_done_bio()
If a bio has BIO_QOS_THROTTLED or BIO_QOS_MERGED set,
it implicitly guarantees that q->rq_qos is present.
Avoid re-checking q->rq_qos in this case and call
__rq_qos_done_bio() directly as a minor optimization.

Suggested-by : Yu Kuai <yukuai1@huaweicloud.com>

Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20250814082612.500845-2-nilay@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-08-21 07:11:11 -06:00
Ming Lei
2d82f3bd89 blk-mq: fix lockdep warning in __blk_mq_update_nr_hw_queues
Commit 5989bfe6ac ("block: restore two stage elevator switch while
running nr_hw_queue update") reintroduced a lockdep warning by calling
blk_mq_freeze_queue_nomemsave() before switching the I/O scheduler.

The function blk_mq_elv_switch_none() calls elevator_change_done().
Running this while the queue is frozen causes a lockdep warning.

Fix this by reordering the operations: first, switch the I/O scheduler
to 'none', and then freeze the queue. This ensures that elevator_change_done()
is not called on an already frozen queue. And this way is safe because
elevator_set_none() does freeze queue before switching to none.

Also we still have to rely on blk_mq_elv_switch_back() for switching
back, and it has to cover unfrozen queue case.

Cc: Nilay Shroff <nilay@linux.ibm.com>
Cc: Yu Kuai <yukuai3@huawei.com>
Fixes: 5989bfe6ac ("block: restore two stage elevator switch while running nr_hw_queue update")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Link: https://lore.kernel.org/r/20250815131737.331692-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-08-21 05:34:19 -06:00
Christoph Hellwig
2729a60bbf block: don't silently ignore metadata for sync read/write
The block fops don't try to handle metadata for synchronous requests,
probably because the completion handler looks at dio->iocb which is not
valid for synchronous requests.

But silently ignoring metadata (or warning in case of
__blkdev_direct_IO_simple) is a really bad idea as that can cause
silent data corruption if a user ever shows up.

Instead simply handle metadata for synchronous requests as the completion
handler can simply check for bio_integrity() as the block layer default
integrity will already be freed at this point, and thus bio_integrity()
will only return true for user mapped integrity.

Fixes: 3d8b5a22d4 ("block: add support to pass user meta buffer")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/20250819082517.2038819-3-hch@lst.de
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-08-20 11:13:01 +02:00
Christoph Hellwig
d072148a86 fs: add a FMODE_ flag to indicate IOCB_HAS_METADATA availability
Currently the kernel will happily route io_uring requests with metadata
to file operations that don't support it.  Add a FMODE_ flag to guard
that.

Fixes: 4de2ce04c8 ("fs: introduce IOCB_HAS_METADATA for metadata")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/20250819082517.2038819-2-hch@lst.de
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-08-20 11:12:58 +02:00
Christoph Hellwig
d0a2b527d8 block: tone down bio_check_eod
bdev_nr_sectors() == 0 is a pattern used for block devices that have
been hot removed, don't spam the log about them.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250818101102.1604551-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-08-18 13:27:05 -06:00
Christoph Hellwig
f4ae174403 block: remove newlines from the warnings in blk_validate_integrity_limits
Otherwise they are very hard to read in the kernel log.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anuj Gupta <anuj20.g@samsung.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20250818045456.1482889-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-08-18 10:17:49 -06:00
Christoph Hellwig
61ca3b891b block: handle pi_tuple_size in queue_limits_stack_integrity
queue_limits_stack_integrity needs to handle the new pi_tuple_size field,
otherwise stacking PI-capable devices will always fail.

Fixes: 76e45252a4 ("block: introduce pi_tuple_size field in blk_integrity")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anuj Gupta <anuj20.g@samsung.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20250818045456.1482889-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-08-18 10:17:49 -06:00
Julian Sun
8f5845e074 block: restore default wbt enablement
The commit 245618f8e4 ("block: protect wbt_lat_usec using
q->elevator_lock") protected wbt_enable_default() with
q->elevator_lock; however, it also placed wbt_enable_default()
before blk_queue_flag_set(QUEUE_FLAG_REGISTERED, q);, resulting
in wbt failing to be enabled.

Moreover, the protection of wbt_enable_default() by q->elevator_lock
was removed in commit 78c271344b ("block: move wbt_enable_default()
out of queue freezing from sched ->exit()"), so we can directly fix
this issue by placing wbt_enable_default() after
blk_queue_flag_set(QUEUE_FLAG_REGISTERED, q);.

Additionally, this issue also causes the inability to read the
wbt_lat_usec file, and the scenario is as follows:

root@q:/sys/block/sda/queue# cat wbt_lat_usec
cat: wbt_lat_usec: Invalid argument

root@q:/data00/sjc/linux# ls /sys/kernel/debug/block/sda/rqos
cannot access '/sys/kernel/debug/block/sda/rqos': No such file or directory

root@q:/data00/sjc/linux# find /sys -name wbt
/sys/kernel/debug/tracing/events/wbt

After testing with this patch, wbt can be enabled normally.

Signed-off-by: Julian Sun <sunjunchao@bytedance.com>
Cc: stable@vger.kernel.org
Fixes: 245618f8e4 ("block: protect wbt_lat_usec using q->elevator_lock")
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250812154257.57540-1-sunjunchao@bytedance.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-08-13 05:33:48 -06:00
Tang Yizhou
bccdfcd56d blk-wbt: Eliminate ambiguity in the comments of struct rq_wb
In the current implementation, the last_issue and last_comp members of
struct rq_wb are used only by read requests and not by non-throttled write
requests. Therefore, eliminate the ambiguity here.

Signed-off-by: Tang Yizhou <yizhou.tang@shopee.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20250727173959.160835-3-yizhou.tang@shopee.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-08-11 10:21:38 -06:00
Tang Yizhou
d8b96a7962 blk-wbt: Optimize wbt_done() for non-throttled writes
In the current implementation, the sync_cookie and last_cookie members of
struct rq_wb are used only by read requests and not by non-throttled write
requests. Based on this, we can optimize wbt_done() by removing one if
condition check for non-throttled write requests.

Signed-off-by: Tang Yizhou <yizhou.tang@shopee.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20250727173959.160835-2-yizhou.tang@shopee.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-08-11 10:21:38 -06:00
Zheng Qixing
343dc5423b block: fix kobject double initialization in add_disk
Device-mapper can call add_disk() multiple times for the same gendisk
due to its two-phase creation process (dm create + dm load). This leads
to kobject double initialization errors when the underlying iSCSI devices
become temporarily unavailable and then reappear.

However, if the first add_disk() call fails and is retried, the queue_kobj
gets initialized twice, causing:

kobject: kobject (ffff88810c27bb90): tried to init an initialized object,
something is seriously wrong.
 Call Trace:
  <TASK>
  dump_stack_lvl+0x5b/0x80
  kobject_init.cold+0x43/0x51
  blk_register_queue+0x46/0x280
  add_disk_fwnode+0xb5/0x280
  dm_setup_md_queue+0x194/0x1c0
  table_load+0x297/0x2d0
  ctl_ioctl+0x2a2/0x480
  dm_ctl_ioctl+0xe/0x20
  __x64_sys_ioctl+0xc7/0x110
  do_syscall_64+0x72/0x390
  entry_SYSCALL_64_after_hwframe+0x76/0x7e

Fix this by separating kobject initialization from sysfs registration:
 - Initialize queue_kobj early during gendisk allocation
 - add_disk() only adds the already-initialized kobject to sysfs
 - del_gendisk() removes from sysfs but doesn't destroy the kobject
 - Final cleanup happens when the disk is released

Fixes: 2bd85221a6 ("block: untangle request_queue refcounting from sysfs")
Reported-by: Li Lingfeng <lilingfeng3@huawei.com>
Closes: https://lore.kernel.org/all/83591d0b-2467-433c-bce0-5581298eb161@huawei.com/
Signed-off-by: Zheng Qixing <zhengqixing@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Link: https://lore.kernel.org/r/20250808053609.3237836-1-zhengqixing@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-08-11 08:00:49 -06:00
Qianfeng Rong
196447c712 blk-cgroup: remove redundant __GFP_NOWARN
Commit 16f5dfbc85 ("gfp: include __GFP_NOWARN in GFP_NOWAIT") made
GFP_NOWAIT implicitly include __GFP_NOWARN.

Therefore, explicit __GFP_NOWARN combined with GFP_NOWAIT (e.g.,
`GFP_NOWAIT | __GFP_NOWARN`) is now redundant.  Let's clean up these
redundant flags across subsystems.

Signed-off-by: Qianfeng Rong <rongqianfeng@vivo.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20250809141358.168781-1-rongqianfeng@vivo.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-08-11 07:59:40 -06:00
Qianfeng Rong
8f3e4e87b0 block, bfq: remove redundant __GFP_NOWARN
Commit 16f5dfbc85 ("gfp: include __GFP_NOWARN in GFP_NOWAIT") made
GFP_NOWAIT implicitly include __GFP_NOWARN.

Therefore, explicit __GFP_NOWARN combined with GFP_NOWAIT (e.g.,
`GFP_NOWAIT | __GFP_NOWARN`) is now redundant.  Let's clean up these
redundant flags across subsystems.

Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Qianfeng Rong <rongqianfeng@vivo.com>
Link: https://lore.kernel.org/r/20250811081135.374315-1-rongqianfeng@vivo.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-08-11 07:59:22 -06:00
Linus Torvalds
2988dfed8a Merge tag 'block-6.17-20250808' of git://git.kernel.dk/linux
Pull more block updates from Jens Axboe:

 - MD pull request via Yu:
      - mddev null-ptr-dereference fix, by Erkun
      - md-cluster fail to remove the faulty disk regression fix, by
        Heming
      - minor cleanup, by Li Nan and Jinchao
      - mdadm lifetime regression fix reported by syzkaller, by Yu Kuai

 - MD pull request via Christoph
      - add support for getting the FDP featuee in fabrics passthru path
        (Nitesh Shetty)
      - add capability to connect to an administrative controller
        (Kamaljit Singh)
      - fix a leak on sgl setup error (Keith Busch)
      - initialize discovery subsys after debugfs is initialized
        (Mohamed Khalfella)
      - fix various comment typos (Bjorn Helgaas)
      - remove unneeded semicolons (Jiapeng Chong)

 - nvmet debugfs ordering issue fix

 - Fix UAF in the tag_set in zloop

 - Ensure sbitmap shallow depth covers entire set

 - Reduce lock roundtrips in io context lookup

 - Move scheduler tags alloc/free out of elevator and freeze lock, to
   fix some lockdep found issues

 - Improve robustness of queue limits checking

 - Fix a regression with IO priorities, if no io context exists

* tag 'block-6.17-20250808' of git://git.kernel.dk/linux: (26 commits)
  lib/sbitmap: make sbitmap_get_shallow() internal
  lib/sbitmap: convert shallow_depth from one word to the whole sbitmap
  nvmet: exit debugfs after discovery subsystem exits
  block, bfq: Reorder struct bfq_iocq_bfqq_data
  md: make rdev_addable usable for rcu mode
  md/raid1: remove struct pool_info and related code
  md/raid1: change r1conf->r1bio_pool to a pointer type
  block: ensure discard_granularity is zero when discard is not supported
  zloop: fix KASAN use-after-free of tag set
  block: Fix default IO priority if there is no IO context
  nvme: fix various comment typos
  nvme-auth: remove unneeded semicolon
  nvme-pci: fix leak on sgl setup error
  nvmet: initialize discovery subsys after debugfs is initialized
  nvme: add capability to connect to an administrative controller
  nvmet: add support for FDP in fabrics passthru path
  md: rename recovery_cp to resync_offset
  md/md-cluster: handle REMOVE message earlier
  md: fix create on open mddev lifetime regression
  block: fix potential deadlock while running nr_hw_queue update
  ...
2025-08-09 08:47:28 +03:00
Yu Kuai
42e6c6ce03 lib/sbitmap: convert shallow_depth from one word to the whole sbitmap
Currently elevators will record internal 'async_depth' to throttle
asynchronous requests, and they both calculate shallow_dpeth based on
sb->shift, with the respect that sb->shift is the available tags in one
word.

However, sb->shift is not the availbale tags in the last word, see
__map_depth:

if (index == sb->map_nr - 1)
  return sb->depth - (index << sb->shift);

For consequence, if the last word is used, more tags can be get than
expected, for example, assume nr_requests=256 and there are four words,
in the worst case if user set nr_requests=32, then the first word is
the last word, and still use bits per word, which is 64, to calculate
async_depth is wrong.

One the ohter hand, due to cgroup qos, bfq can allow only one request
to be allocated, and set shallow_dpeth=1 will still allow the number
of words request to be allocated.

Fix this problems by using shallow_depth to the whole sbitmap instead
of per word, also change kyber, mq-deadline and bfq to follow this,
a new helper __map_depth_with_shallow() is introduced to calculate
available bits in each word.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20250807032413.1469456-2-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-08-07 06:30:17 -06:00
Christophe JAILLET
407728da41 block, bfq: Reorder struct bfq_iocq_bfqq_data
The size of struct bfq_iocq_bfqq_data can be reduced by moving a few
fields around.

On a x86_64, with allmodconfig, this shrinks the size from 144 to 128
bytes. The main benefit is to reduce the size of struct bfq_io_cq from
1360 to 1232.

This structure is stored in a dedicated slab cache. So reducing its size
improves cache usage.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/79394db1befaa658e8066b8e3348073ce27d9d26.1754119538.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-08-04 09:22:44 -06:00
Linus Torvalds
beace86e61 Merge tag 'mm-stable-2025-07-30-15-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
 "As usual, many cleanups. The below blurbiage describes 42 patchsets.
  21 of those are partially or fully cleanup work. "cleans up",
  "cleanup", "maintainability", "rationalizes", etc.

  I never knew the MM code was so dirty.

  "mm: ksm: prevent KSM from breaking merging of new VMAs" (Lorenzo Stoakes)
     addresses an issue with KSM's PR_SET_MEMORY_MERGE mode: newly
     mapped VMAs were not eligible for merging with existing adjacent
     VMAs.

  "mm/damon: introduce DAMON_STAT for simple and practical access monitoring" (SeongJae Park)
     adds a new kernel module which simplifies the setup and usage of
     DAMON in production environments.

  "stop passing a writeback_control to swap/shmem writeout" (Christoph Hellwig)
     is a cleanup to the writeback code which removes a couple of
     pointers from struct writeback_control.

  "drivers/base/node.c: optimization and cleanups" (Donet Tom)
     contains largely uncorrelated cleanups to the NUMA node setup and
     management code.

  "mm: userfaultfd: assorted fixes and cleanups" (Tal Zussman)
     does some maintenance work on the userfaultfd code.

  "Readahead tweaks for larger folios" (Ryan Roberts)
     implements some tuneups for pagecache readahead when it is reading
     into order>0 folios.

  "selftests/mm: Tweaks to the cow test" (Mark Brown)
     provides some cleanups and consistency improvements to the
     selftests code.

  "Optimize mremap() for large folios" (Dev Jain)
     does that. A 37% reduction in execution time was measured in a
     memset+mremap+munmap microbenchmark.

  "Remove zero_user()" (Matthew Wilcox)
     expunges zero_user() in favor of the more modern memzero_page().

  "mm/huge_memory: vmf_insert_folio_*() and vmf_insert_pfn_pud() fixes" (David Hildenbrand)
     addresses some warts which David noticed in the huge page code.
     These were not known to be causing any issues at this time.

  "mm/damon: use alloc_migrate_target() for DAMOS_MIGRATE_{HOT,COLD" (SeongJae Park)
     provides some cleanup and consolidation work in DAMON.

  "use vm_flags_t consistently" (Lorenzo Stoakes)
     uses vm_flags_t in places where we were inappropriately using other
     types.

  "mm/memfd: Reserve hugetlb folios before allocation" (Vivek Kasireddy)
     increases the reliability of large page allocation in the memfd
     code.

  "mm: Remove pXX_devmap page table bit and pfn_t type" (Alistair Popple)
     removes several now-unneeded PFN_* flags.

  "mm/damon: decouple sysfs from core" (SeongJae Park)
     implememnts some cleanup and maintainability work in the DAMON
     sysfs layer.

  "madvise cleanup" (Lorenzo Stoakes)
     does quite a lot of cleanup/maintenance work in the madvise() code.

  "madvise anon_name cleanups" (Vlastimil Babka)
     provides additional cleanups on top or Lorenzo's effort.

  "Implement numa node notifier" (Oscar Salvador)
     creates a standalone notifier for NUMA node memory state changes.
     Previously these were lumped under the more general memory
     on/offline notifier.

  "Make MIGRATE_ISOLATE a standalone bit" (Zi Yan)
     cleans up the pageblock isolation code and fixes a potential issue
     which doesn't seem to cause any problems in practice.

  "selftests/damon: add python and drgn based DAMON sysfs functionality tests" (SeongJae Park)
     adds additional drgn- and python-based DAMON selftests which are
     more comprehensive than the existing selftest suite.

  "Misc rework on hugetlb faulting path" (Oscar Salvador)
     fixes a rather obscure deadlock in the hugetlb fault code and
     follows that fix with a series of cleanups.

  "cma: factor out allocation logic from __cma_declare_contiguous_nid" (Mike Rapoport)
     rationalizes and cleans up the highmem-specific code in the CMA
     allocator.

  "mm/migration: rework movable_ops page migration (part 1)" (David Hildenbrand)
     provides cleanups and future-preparedness to the migration code.

  "mm/damon: add trace events for auto-tuned monitoring intervals and DAMOS quota" (SeongJae Park)
     adds some tracepoints to some DAMON auto-tuning code.

  "mm/damon: fix misc bugs in DAMON modules" (SeongJae Park)
     does that.

  "mm/damon: misc cleanups" (SeongJae Park)
     also does what it claims.

  "mm: folio_pte_batch() improvements" (David Hildenbrand)
     cleans up the large folio PTE batching code.

  "mm/damon/vaddr: Allow interleaving in migrate_{hot,cold} actions" (SeongJae Park)
     facilitates dynamic alteration of DAMON's inter-node allocation
     policy.

  "Remove unmap_and_put_page()" (Vishal Moola)
     provides a couple of page->folio conversions.

  "mm: per-node proactive reclaim" (Davidlohr Bueso)
     implements a per-node control of proactive reclaim - beyond the
     current memcg-based implementation.

  "mm/damon: remove damon_callback" (SeongJae Park)
     replaces the damon_callback interface with a more general and
     powerful damon_call()+damos_walk() interface.

  "mm/mremap: permit mremap() move of multiple VMAs" (Lorenzo Stoakes)
     implements a number of mremap cleanups (of course) in preparation
     for adding new mremap() functionality: newly permit the remapping
     of multiple VMAs when the user is specifying MREMAP_FIXED. It still
     excludes some specialized situations where this cannot be performed
     reliably.

  "drop hugetlb_free_pgd_range()" (Anthony Yznaga)
     switches some sparc hugetlb code over to the generic version and
     removes the thus-unneeded hugetlb_free_pgd_range().

  "mm/damon/sysfs: support periodic and automated stats update" (SeongJae Park)
     augments the present userspace-requested update of DAMON sysfs
     monitoring files. Automatic update is now provided, along with a
     tunable to control the update interval.

  "Some randome fixes and cleanups to swapfile" (Kemeng Shi)
     does what is claims.

  "mm: introduce snapshot_page" (Luiz Capitulino and David Hildenbrand)
     provides (and uses) a means by which debug-style functions can grab
     a copy of a pageframe and inspect it locklessly without tripping
     over the races inherent in operating on the live pageframe
     directly.

  "use per-vma locks for /proc/pid/maps reads" (Suren Baghdasaryan)
     addresses the large contention issues which can be triggered by
     reads from that procfs file. Latencies are reduced by more than
     half in some situations. The series also introduces several new
     selftests for the /proc/pid/maps interface.

  "__folio_split() clean up" (Zi Yan)
     cleans up __folio_split()!

  "Optimize mprotect() for large folios" (Dev Jain)
     provides some quite large (>3x) speedups to mprotect() when dealing
     with large folios.

  "selftests/mm: reuse FORCE_READ to replace "asm volatile("" : "+r" (XXX));" and some cleanup" (wang lian)
     does some cleanup work in the selftests code.

  "tools/testing: expand mremap testing" (Lorenzo Stoakes)
     extends the mremap() selftest in several ways, including adding
     more checking of Lorenzo's recently added "permit mremap() move of
     multiple VMAs" feature.

  "selftests/damon/sysfs.py: test all parameters" (SeongJae Park)
     extends the DAMON sysfs interface selftest so that it tests all
     possible user-requested parameters. Rather than the present minimal
     subset"

* tag 'mm-stable-2025-07-30-15-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (370 commits)
  MAINTAINERS: add missing headers to mempory policy & migration section
  MAINTAINERS: add missing file to cgroup section
  MAINTAINERS: add MM MISC section, add missing files to MISC and CORE
  MAINTAINERS: add missing zsmalloc file
  MAINTAINERS: add missing files to page alloc section
  MAINTAINERS: add missing shrinker files
  MAINTAINERS: move memremap.[ch] to hotplug section
  MAINTAINERS: add missing mm_slot.h file THP section
  MAINTAINERS: add missing interval_tree.c to memory mapping section
  MAINTAINERS: add missing percpu-internal.h file to per-cpu section
  mm/page_alloc: remove trace_mm_alloc_contig_migrate_range_info()
  selftests/damon: introduce _common.sh to host shared function
  selftests/damon/sysfs.py: test runtime reduction of DAMON parameters
  selftests/damon/sysfs.py: test non-default parameters runtime commit
  selftests/damon/sysfs.py: generalize DAMON context commit assertion
  selftests/damon/sysfs.py: generalize monitoring attributes commit assertion
  selftests/damon/sysfs.py: generalize DAMOS schemes commit assertion
  selftests/damon/sysfs.py: test DAMOS filters commitment
  selftests/damon/sysfs.py: generalize DAMOS scheme commit assertion
  selftests/damon/sysfs.py: test DAMOS destinations commitment
  ...
2025-07-31 14:57:54 -07:00
Christoph Hellwig
fad6551fcf block: ensure discard_granularity is zero when discard is not supported
Documentation/ABI/stable/sysfs-block states:

  What: /sys/block/<disk>/queue/discard_granularity
  [...]
  A discard_granularity of 0 means that the device does not support
  discard functionality.

but this got broken when sorting out the block limits updates.  Fix this
by setting the discard_granularity limit to zero when the combined
max_discard_sectors is zero.

Fixes: 3c407dc723 ("block: default the discard granularity to sector size")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20250731152228.873923-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-31 15:01:35 -06:00