linux-stable.git/block, branch linux-5.15.y

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

2026-03-04T12:19:59+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

2026-02-11T12:35:29+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

blk-cgroup: Reinit blkg_iostat_set after clearing in blkcg_reset_stats()

2026-02-06T15:42:03+00:00

[ Upstream commit 3d2af77e31ade05ff7ccc3658c3635ec1bea0979 ]

When blkg_alloc() is called to allocate a blkcg_gq structure
with the associated blkg_iostat_set's, there are 2 fields within
blkg_iostat_set that requires proper initialization - blkg & sync.
The former field was introduced by commit 3b8cc6298724 ("blk-cgroup:
Optimize blkcg_rstat_flush()") while the later one was introduced by
commit f73316482977 ("blk-cgroup: reimplement basic IO stats using
cgroup rstat").

Unfortunately those fields in the blkg_iostat_set's are not properly
re-initialized when they are cleared in v1's blkcg_reset_stats(). This
can lead to a kernel panic due to NULL pointer access of the blkg
pointer. The missing initialization of sync is less problematic and
can be a problem in a debug kernel due to missing lockdep initialization.

Fix these problems by re-initializing them after memory clearing.

Fixes: 3b8cc6298724 ("blk-cgroup: Optimize blkcg_rstat_flush()")
Fixes: f73316482977 ("blk-cgroup: reimplement basic IO stats using cgroup rstat")
Signed-off-by: Waiman Long 
Reviewed-by: Ming Lei 
Acked-by: Tejun Heo 
Link: https://lore.kernel.org/r/20230606180724.2455066-1-longman@redhat.com
Signed-off-by: Jens Axboe 
[ Remove this line: bis -> blkg = blkg for blkg was introduced by commit
  3b8cc6298724 ("blk-cgroup: Optimize blkcg_rstat_flush()") since v6.2. ]
Signed-off-by: Alva Lan 
Signed-off-by: Greg Kroah-Hartman

blk-throttle: Set BIO_THROTTLED when bio has been throttled

2026-01-19T12:10:18+00:00

[ Upstream commit 5a011f889b4832aa80c2a872a5aade5c48d2756f ]

1.In current process, all bio will set the BIO_THROTTLED flag
after __blk_throtl_bio().

2.If bio needs to be throttled, it will start the timer and
stop submit bio directly. Bio will submit in
blk_throtl_dispatch_work_fn() when the timer expires.But in
the current process, if bio is throttled. The BIO_THROTTLED
will be set to bio after timer start. If the bio has been
completed, it may cause use-after-free blow.

BUG: KASAN: use-after-free in blk_throtl_bio+0x12f0/0x2c70
Read of size 2 at addr ffff88801b8902d4 by task fio/26380

 dump_stack+0x9b/0xce
 print_address_description.constprop.6+0x3e/0x60
 kasan_report.cold.9+0x22/0x3a
 blk_throtl_bio+0x12f0/0x2c70
 submit_bio_checks+0x701/0x1550
 submit_bio_noacct+0x83/0xc80
 submit_bio+0xa7/0x330
 mpage_readahead+0x380/0x500
 read_pages+0x1c1/0xbf0
 page_cache_ra_unbounded+0x471/0x6f0
 do_page_cache_ra+0xda/0x110
 ondemand_readahead+0x442/0xae0
 page_cache_async_ra+0x210/0x300
 generic_file_buffered_read+0x4d9/0x2130
 generic_file_read_iter+0x315/0x490
 blkdev_read_iter+0x113/0x1b0
 aio_read+0x2ad/0x450
 io_submit_one+0xc8e/0x1d60
 __se_sys_io_submit+0x125/0x350
 do_syscall_64+0x2d/0x40
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Allocated by task 26380:
 kasan_save_stack+0x19/0x40
 __kasan_kmalloc.constprop.2+0xc1/0xd0
 kmem_cache_alloc+0x146/0x440
 mempool_alloc+0x125/0x2f0
 bio_alloc_bioset+0x353/0x590
 mpage_alloc+0x3b/0x240
 do_mpage_readpage+0xddf/0x1ef0
 mpage_readahead+0x264/0x500
 read_pages+0x1c1/0xbf0
 page_cache_ra_unbounded+0x471/0x6f0
 do_page_cache_ra+0xda/0x110
 ondemand_readahead+0x442/0xae0
 page_cache_async_ra+0x210/0x300
 generic_file_buffered_read+0x4d9/0x2130
 generic_file_read_iter+0x315/0x490
 blkdev_read_iter+0x113/0x1b0
 aio_read+0x2ad/0x450
 io_submit_one+0xc8e/0x1d60
 __se_sys_io_submit+0x125/0x350
 do_syscall_64+0x2d/0x40
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 0:
 kasan_save_stack+0x19/0x40
 kasan_set_track+0x1c/0x30
 kasan_set_free_info+0x1b/0x30
 __kasan_slab_free+0x111/0x160
 kmem_cache_free+0x94/0x460
 mempool_free+0xd6/0x320
 bio_free+0xe0/0x130
 bio_put+0xab/0xe0
 bio_endio+0x3a6/0x5d0
 blk_update_request+0x590/0x1370
 scsi_end_request+0x7d/0x400
 scsi_io_completion+0x1aa/0xe50
 scsi_softirq_done+0x11b/0x240
 blk_mq_complete_request+0xd4/0x120
 scsi_mq_done+0xf0/0x200
 virtscsi_vq_done+0xbc/0x150
 vring_interrupt+0x179/0x390
 __handle_irq_event_percpu+0xf7/0x490
 handle_irq_event_percpu+0x7b/0x160
 handle_irq_event+0xcc/0x170
 handle_edge_irq+0x215/0xb20
 common_interrupt+0x60/0x120
 asm_common_interrupt+0x1e/0x40

Fix this by move BIO_THROTTLED set into the queue_lock.

Signed-off-by: Laibin Qiu 
Reviewed-by: Ming Lei 
Link: https://lore.kernel.org/r/20220301123919.2381579-1-qiulaibin@huawei.com
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin 
[ Keerthana: Remove 'out' and handle return with reference to commit 81c7a63 ]
Signed-off-by: Keerthana K 
Signed-off-by: Shivani Agarwal 
Signed-off-by: Greg Kroah-Hartman

block: rate-limit capacity change info log

2026-01-19T12:09:49+00:00

commit 3179a5f7f86bcc3acd5d6fb2a29f891ef5615852 upstream.

loop devices under heavy stress-ng loop streessor can trigger many
capacity change events in a short time. Each event prints an info
message from set_capacity_and_notify(), flooding the console and
contributing to soft lockups on slow consoles.

Switch the printk in set_capacity_and_notify() to
pr_info_ratelimited() so frequent capacity changes do not spam
the log while still reporting occasional changes.

Cc: stable@vger.kernel.org
Signed-off-by: Li Chen 
Reviewed-by: Chaitanya Kulkarni 
Reviewed-by: Bart Van Assche 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

blk-mq: Abort suspend when wakeup events are pending

2026-01-19T12:09:39+00:00

[ Upstream commit c196bf43d706592d8801a7513603765080e495fb ]

During system suspend, wakeup capable IRQs for block device can be
delayed, which can cause blk_mq_hctx_notify_offline() to hang
indefinitely while waiting for pending request to complete.
Skip the request waiting loop and abort suspend when wakeup events are
pending to prevent the deadlock.

Fixes: bf0beec0607d ("blk-mq: drain I/O when all CPUs in a hctx are offline")
Signed-off-by: Cong Zhang 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

Revert "block: don't add or resize partition on the disk with GENHD_FL_NO_PART"

2025-12-06T21:09:33+00:00

This reverts commit 1a721de8489fa559ff4471f73c58bb74ac5580d3.

The commit 1a721de8489f ("block: don't add or resize partition on the disk
with GENHD_FL_NO_PART") and the commit 7777f47f2ea6 ("block: Move checking
GENHD_FL_NO_PART to bdev_add_partition()") used the flag GENHD_FL_NO_PART
to prevent the add or resize of partitions in 5.15 stable kernels.But in
these 5.15 kernels, this is giving an issue with the following error
where the loop driver wants to create a partition when the partscan is
disabled on the loop device:

dd if=/dev/zero of=loopDisk.dsk bs=1M count=1 seek=10240;
losetup -f loopDisk.dsk;parted -s /dev/loop0 -- mklabel gpt mkpart primary
           2048s 4096s
1+0 records in
1+0 records out
1048576 bytes (1.0 MB, 1.0 MiB) copied, 0.0016293 s, 644 MB/s
""
Error: Partition(s) 1 on /dev/loop0 have been written, but we have been
unable to inform the kernel of the change, probably because it/they are
in use.  As a result, the old partition(s) will remain in use.  You should
reboot now before making further changes.
""
If the partition scan is not enabled on the loop device, this flag
GENHD_FL_NO_PART is getting set and when partition creation is tried,
it returns an error EINVAL thereby preventing the creation of partitions.
So, there is no such distinction between disabling of partition scan and
partition creation.

Later in 6.xxx kernels, the commit b9684a71fca7 ("block, loop: support
partitions without scanning") a new flag GD_SUPPRESS_PART_SCAN was
introduced that just disables the partition scan and uses GENHD_FL_NO_PART
only to prevent creating partition scan. So, the partition creationg can
proceed with even if partition scan is disabled.

As the commit b9684a71fca7 ("block, loop: support partitions without
scanning") is not available in 5.15 stable kernel, and since there is no
distinction between disabling of "partition scan" and "partition
creation", we need to revert the commits 1a721de8489f and 7777f47f2ea6
from 5.15 stable kernel to allow partition creation when partscan is
disabled.

Cc: stable@vger.kernel.org
Signed-off-by: Gulam Mohamed 
Signed-off-by: Greg Kroah-Hartman

Revert "block: Move checking GENHD_FL_NO_PART to bdev_add_partition()"

2025-12-06T21:09:33+00:00

This reverts commit 7777f47f2ea64efd1016262e7b59fab34adfb869.

The commit 1a721de8489f ("block: don't add or resize partition on the disk
with GENHD_FL_NO_PART") and the commit 7777f47f2ea6 ("block: Move checking
GENHD_FL_NO_PART to bdev_add_partition()") used the flag GENHD_FL_NO_PART
to prevent the add or resize of partitions in 5.15 stable kernels.But in
these 5.15 kernels, this is giving an issue with the following error
where the loop driver wants to create a partition when the partscan is
disabled on the loop device:

dd if=/dev/zero of=loopDisk.dsk bs=1M count=1 seek=10240;
losetup -f loopDisk.dsk;parted -s /dev/loop0 -- mklabel gpt mkpart primary
           2048s 4096s
1+0 records in
1+0 records out
1048576 bytes (1.0 MB, 1.0 MiB) copied, 0.0016293 s, 644 MB/s
""
Error: Partition(s) 1 on /dev/loop0 have been written, but we have been
unable to inform the kernel of the change, probably because it/they are
in use.  As a result, the old partition(s) will remain in use.  You should
reboot now before making further changes.
""
If the partition scan is not enabled on the loop device, this flag
GENHD_FL_NO_PART is getting set and when partition creation is tried,
it returns an error EINVAL thereby preventing the creation of partitions.
So, there is no such distinction between disabling of partition scan and
partition creation.

Later in 6.xxx kernels, the commit b9684a71fca7 ("block, loop: support
partitions without scanning") a new flag GD_SUPPRESS_PART_SCAN was
introduced that just disables the partition scan and uses GENHD_FL_NO_PART
only to prevent creating partition scan. So, the partition creationg can
proceed with even if partition scan is disabled.

As the commit b9684a71fca7 ("block, loop: support partitions without
scanning") is not available in 5.15 stable kernel, and since there is no
distinction between disabling of "partition scan" and "partition
creation", we need to revert the commits 1a721de8489f and 7777f47f2ea6
from 5.15 stable kernel to allow partition creation when partscan is
disabled.

Cc: stable@vger.kernel.org
Signed-off-by: Gulam Mohamed 
Signed-off-by: Greg Kroah-Hartman

blk-crypto: fix missing blktrace bio split events

2025-10-29T13:03:07+00:00

[ Upstream commit 06d712d297649f48ebf1381d19bd24e942813b37 ]

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: 488f6682c832 ("block: blk-crypto-fallback for Inline Encryption")
Signed-off-by: Yu Kuai 
Reviewed-by: Bart Van Assche 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Jens Axboe 
[ changed blk_crypto_fallback_split_bio_if_needed() to blk_crypto_split_bio_if_needed() ]
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

block: use int to store blk_stack_limits() return value

2025-10-19T14:21:30+00:00

[ 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 
Reviewed-by: John Garry 
Fixes: fe0b393f2c0a ("block: Correct handling of bottom device misaligment")
Reviewed-by: Bart Van Assche 
Link: https://lore.kernel.org/r/20250902130930.68317-1-rongqianfeng@vivo.com
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin