linux.git/block, branch v6.18.21

block: break pcpu_alloc_mutex dependency on freeze_lock

2026-04-02T11:22:59+00:00

[ Upstream commit 539d1b47e935e8384977dd7e5cec370c08b7a644 ]

While nr_hw_update allocates tagset tags it acquires ->pcpu_alloc_mutex
after ->freeze_lock is acquired or queue is frozen. This potentially
creates a circular dependency involving ->fs_reclaim if reclaim is
triggered simultaneously in a code path which first acquires ->pcpu_
alloc_mutex. As the queue is already frozen while nr_hw_queue update
allocates tagsets, the reclaim can't forward progress and thus it could
cause a potential deadlock as reported in lockdep splat[1].

Fix this by pre-allocating tagset tags before we freeze queue during
nr_hw_queue update. Later the allocated tagset tags could be safely
installed and used after queue is frozen.

Reported-by: Yi Zhang 
Closes: https://lore.kernel.org/all/CAHj4cs8F=OV9s3La2kEQ34YndgfZP-B5PHS4Z8_b9euKG6J4mw@mail.gmail.com/ [1]
Signed-off-by: Nilay Shroff 
Reviewed-by: Ming Lei 
Tested-by: Yi Zhang 
Reviewed-by: Yu Kuai 
[axboe: fix brace style issue]
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

block: use trylock to avoid lockdep circular dependency in sysfs

2026-03-12T11:09:59+00:00

[ Upstream commit ce8ee8583ed83122405eabaa8fb351be4d9dc65c ]

Use trylock instead of blocking lock acquisition for update_nr_hwq_lock
in queue_requests_store() and elv_iosched_store() to avoid circular lock
dependency with kernfs active reference during concurrent disk deletion:

  update_nr_hwq_lock -> kn->active (via del_gendisk -> kobject_del)
  kn->active -> update_nr_hwq_lock (via sysfs write path)

Return -EBUSY when the lock is not immediately available.

Reported-and-tested-by: Yi Zhang 
Closes: https://lore.kernel.org/linux-block/CAHj4cs-em-4acsHabMdT=jJhXkCzjnprD-aQH1OgrZo4nTnmMw@mail.gmail.com/
Fixes: 626ff4f8ebcb ("blk-mq: convert to serialize updating nr_requests with update_nr_hwq_lock")
Signed-off-by: Ming Lei 
Tested-by: Yi Zhang 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

block: decouple secure erase size limit from discard size limit

2026-03-04T12:19:38+00:00

[ Upstream commit ee81212f74a57c5d2b56cf504f40d528dac6faaf ]

Secure erase should use max_secure_erase_sectors instead of being limited
by max_discard_sectors. Separate the handling of REQ_OP_SECURE_ERASE from
REQ_OP_DISCARD to allow each operation to use its own size limit.

Signed-off-by: Luke Wang 
Reviewed-by: Ulf Hansson 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

blk-mq-sched: unify elevators checking for async requests

2026-03-04T12:19:38+00:00

[ Upstream commit 1db61b0afdd7e8aa9289c423fdff002603b520b5 ]

bfq and mq-deadline consider sync writes as async requests and only
reserve tags for sync reads by async_depth, however, kyber doesn't
consider sync writes as async requests for now.

Consider the case there are lots of dirty pages, and user use fsync to
flush dirty pages. In this case sched_tags can be exhausted by sync writes
and sync reads can stuck waiting for tag. Hence let kyber follow what
mq-deadline and bfq did, and unify async requests checking for all
elevators.

Signed-off-by: Yu Kuai 
Reviewed-by: Nilay Shroff 
Reviewed-by: Hannes Reinecke 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

blk-mq-debugfs: add missing debugfs_mutex in blk_mq_debugfs_register_hctxs()

2026-03-04T12:19:38+00:00

[ Upstream commit 9d20fd6ce1ba9733cd5ac96fcab32faa9fc404dd ]

In blk_mq_update_nr_hw_queues(), debugfs_mutex is not held while
creating debugfs entries for hctxs. Hence add debugfs_mutex there,
it's safe because queue is not frozen.

Signed-off-by: Yu Kuai 
Reviewed-by: Nilay Shroff 
Reviewed-by: Ming Lei 
Reviewed-by: Hannes Reinecke 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

block,bfq: fix aux stat accumulation destination

2026-02-11T12:41:47+00:00

[ Upstream commit 04bdb1a04d8a2a89df504c1e34250cd3c6e31a1c ]

Route bfqg_stats_add_aux() time accumulation into the destination
stats object instead of the source, aligning with other stat fields.

Reviewed-by: Yu Kuai 
Signed-off-by: shechenglong 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

block: zero non-PI portion of auto integrity buffer

2026-01-23T10:21:16+00:00

[ Upstream commit ca22c566b89164f6e670af56ecc45f47ef3df819 ]

The auto-generated integrity buffer for writes needs to be fully
initialized before being passed to the underlying block device,
otherwise the uninitialized memory can be read back by userspace or
anyone with physical access to the storage device. If protection
information is generated, that portion of the integrity buffer is
already initialized. The integrity data is also zeroed if PI generation
is disabled via sysfs or the PI tuple size is 0. However, this misses
the case where PI is generated and the PI tuple size is nonzero, but the
metadata size is larger than the PI tuple. In this case, the remainder
("opaque") of the metadata is left uninitialized.
Generalize the BLK_INTEGRITY_CSUM_NONE check to cover any case when the
metadata is larger than just the PI tuple.

Signed-off-by: Caleb Sander Mateos 
Fixes: c546d6f43833 ("block: only zero non-PI metadata tuples in bio_integrity_prep")
Reviewed-by: Anuj Gupta 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Martin K. Petersen 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

block: validate pi_offset integrity limit

2026-01-17T15:35:33+00:00

[ Upstream commit ccb8a3c08adf8121e2afb8e704f007ce99324d79 ]

The PI tuple must be contained within the metadata value, so validate
that pi_offset + pi_tuple_size <= metadata_size. This guards against
block drivers that report invalid pi_offset values.

Signed-off-by: Caleb Sander Mateos 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

block: don't merge bios with different app_tags

2026-01-17T15:35:28+00:00

[ Upstream commit 6acd4ac5f8f0ec9b946875553e52907700bcfc77 ]

nvme_set_app_tag() uses the app_tag value from the bio_integrity_payload
of the struct request's first bio. This assumes all the request's bios
have the same app_tag. However, it is possible for bios with different
app_tag values to be merged into a single request.
Add a check in blk_integrity_merge_{bio,rq}() to prevent the merging of
bios/requests with different app_tag values if BIP_CHECK_APPTAG is set.

Signed-off-by: Caleb Sander Mateos 
Fixes: 3d8b5a22d404 ("block: add support to pass user meta buffer")
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

block: fix NULL pointer dereference in blk_zone_reset_all_bio_endio()

2026-01-08T09:17:21+00:00

commit c2b8d20628ca789640f64074a642f9440eefc623 upstream.

For zoned block devices that do not need zone write plugs (e.g. most
device mapper devices that support zones), the disk hash table of zone
write plugs is NULL. For such devices, blk_zone_reset_all_bio_endio()
should not attempt to scan this has table as that causes a NULL pointer
dereference.

Fix this by checking that the disk does have zone write plugs using the
atomic counter. This is equivalent to checking for a non-NULL hash table
but has the advantage to also speed up the execution of
blk_zone_reset_all_bio_endio() for devices that do use zone write plugs
but do not have any plug in the hash table (e.g. a disk with only full
zones).

Fixes: efae226c2ef1 ("block: handle zone management operations completions")
Reported-by: Shin'ichiro Kawasaki 
Signed-off-by: Damien Le Moal 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman