<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/md, branch v6.1.78</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>md: Whenassemble the array, consult the superblock of the freshest device</title>
<updated>2024-02-05T20:12:53+00:00</updated>
<author>
<name>Alex Lyakas</name>
<email>alex.lyakas@zadara.com</email>
</author>
<published>2023-12-13T12:24:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=fd9a2c700323f6e9e2f201f6adfae079f740c9ff'/>
<id>fd9a2c700323f6e9e2f201f6adfae079f740c9ff</id>
<content type='text'>
[ Upstream commit dc1cc22ed58f11d58d8553c5ec5f11cbfc3e3039 ]

Upon assembling the array, both kernel and mdadm allow the devices to have event
counter difference of 1, and still consider them as up-to-date.
However, a device whose event count is behind by 1, may in fact not be up-to-date,
and array resync with such a device may cause data corruption.
To avoid this, consult the superblock of the freshest device about the status
of a device, whose event counter is behind by 1.

Signed-off-by: Alex Lyakas &lt;alex.lyakas@zadara.com&gt;
Signed-off-by: Song Liu &lt;song@kernel.org&gt;
Link: https://lore.kernel.org/r/1702470271-16073-1-git-send-email-alex.lyakas@zadara.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit dc1cc22ed58f11d58d8553c5ec5f11cbfc3e3039 ]

Upon assembling the array, both kernel and mdadm allow the devices to have event
counter difference of 1, and still consider them as up-to-date.
However, a device whose event count is behind by 1, may in fact not be up-to-date,
and array resync with such a device may cause data corruption.
To avoid this, consult the superblock of the freshest device about the status
of a device, whose event counter is behind by 1.

Signed-off-by: Alex Lyakas &lt;alex.lyakas@zadara.com&gt;
Signed-off-by: Song Liu &lt;song@kernel.org&gt;
Link: https://lore.kernel.org/r/1702470271-16073-1-git-send-email-alex.lyakas@zadara.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Revert "Revert "md/raid5: Wait for MD_SB_CHANGE_PENDING in raid5d""</title>
<updated>2024-01-25T23:27:52+00:00</updated>
<author>
<name>Song Liu</name>
<email>song@kernel.org</email>
</author>
<published>2024-01-25T08:21:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=cfa46838285814c3a27faacf7357f0a65bb5d152'/>
<id>cfa46838285814c3a27faacf7357f0a65bb5d152</id>
<content type='text'>
This reverts commit bed9e27baf52a09b7ba2a3714f1e24e17ced386d.

The original set [1][2] was expected to undo a suboptimal fix in [2], and
replace it with a better fix [1]. However, as reported by Dan Moulding [2]
causes an issue with raid5 with journal device.

Revert [2] for now to close the issue. We will follow up on another issue
reported by Juxiao Bi, as [2] is expected to fix it. We believe this is a
good trade-off, because the latter issue happens less freqently.

In the meanwhile, we will NOT revert [1], as it contains the right logic.

[1] commit d6e035aad6c0 ("md: bypass block throttle for superblock update")
[2] commit bed9e27baf52 ("Revert "md/raid5: Wait for MD_SB_CHANGE_PENDING in raid5d"")

Reported-by: Dan Moulding &lt;dan@danm.net&gt;
Closes: https://lore.kernel.org/linux-raid/20240123005700.9302-1-dan@danm.net/
Fixes: bed9e27baf52 ("Revert "md/raid5: Wait for MD_SB_CHANGE_PENDING in raid5d"")
Cc: stable@vger.kernel.org # v5.19+
Cc: Junxiao Bi &lt;junxiao.bi@oracle.com&gt;
Cc: Yu Kuai &lt;yukuai3@huawei.com&gt;
Signed-off-by: Song Liu &lt;song@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This reverts commit bed9e27baf52a09b7ba2a3714f1e24e17ced386d.

The original set [1][2] was expected to undo a suboptimal fix in [2], and
replace it with a better fix [1]. However, as reported by Dan Moulding [2]
causes an issue with raid5 with journal device.

Revert [2] for now to close the issue. We will follow up on another issue
reported by Juxiao Bi, as [2] is expected to fix it. We believe this is a
good trade-off, because the latter issue happens less freqently.

In the meanwhile, we will NOT revert [1], as it contains the right logic.

[1] commit d6e035aad6c0 ("md: bypass block throttle for superblock update")
[2] commit bed9e27baf52 ("Revert "md/raid5: Wait for MD_SB_CHANGE_PENDING in raid5d"")

Reported-by: Dan Moulding &lt;dan@danm.net&gt;
Closes: https://lore.kernel.org/linux-raid/20240123005700.9302-1-dan@danm.net/
Fixes: bed9e27baf52 ("Revert "md/raid5: Wait for MD_SB_CHANGE_PENDING in raid5d"")
Cc: stable@vger.kernel.org # v5.19+
Cc: Junxiao Bi &lt;junxiao.bi@oracle.com&gt;
Cc: Yu Kuai &lt;yukuai3@huawei.com&gt;
Signed-off-by: Song Liu &lt;song@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>md/raid1: Use blk_opf_t for read and write operations</title>
<updated>2024-01-25T23:27:43+00:00</updated>
<author>
<name>Bart Van Assche</name>
<email>bvanassche@acm.org</email>
</author>
<published>2024-01-08T00:12:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f5c29a3a7e683510771fc58accf264c206e6e87a'/>
<id>f5c29a3a7e683510771fc58accf264c206e6e87a</id>
<content type='text'>
commit 7dab24554dedd4e6f408af8eb2d25c89997a6a1f upstream.

Use the type blk_opf_t for read and write operations instead of int. This
patch does not affect the generated code but fixes the following sparse
warning:

drivers/md/raid1.c:1993:60: sparse: sparse: incorrect type in argument 5 (different base types)
     expected restricted blk_opf_t [usertype] opf
     got int rw

Cc: Song Liu &lt;song@kernel.org&gt;
Cc: Jens Axboe &lt;axboe@kernel.dk&gt;
Fixes: 3c5e514db58f ("md/raid1: Use the new blk_opf_t type")
Cc: stable@vger.kernel.org # v6.0+
Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Closes: https://lore.kernel.org/oe-kbuild-all/202401080657.UjFnvQgX-lkp@intel.com/
Signed-off-by: Bart Van Assche &lt;bvanassche@acm.org&gt;
Signed-off-by: Song Liu &lt;song@kernel.org&gt;
Link: https://lore.kernel.org/r/20240108001223.23835-1-bvanassche@acm.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 7dab24554dedd4e6f408af8eb2d25c89997a6a1f upstream.

Use the type blk_opf_t for read and write operations instead of int. This
patch does not affect the generated code but fixes the following sparse
warning:

drivers/md/raid1.c:1993:60: sparse: sparse: incorrect type in argument 5 (different base types)
     expected restricted blk_opf_t [usertype] opf
     got int rw

Cc: Song Liu &lt;song@kernel.org&gt;
Cc: Jens Axboe &lt;axboe@kernel.dk&gt;
Fixes: 3c5e514db58f ("md/raid1: Use the new blk_opf_t type")
Cc: stable@vger.kernel.org # v6.0+
Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Closes: https://lore.kernel.org/oe-kbuild-all/202401080657.UjFnvQgX-lkp@intel.com/
Signed-off-by: Bart Van Assche &lt;bvanassche@acm.org&gt;
Signed-off-by: Song Liu &lt;song@kernel.org&gt;
Link: https://lore.kernel.org/r/20240108001223.23835-1-bvanassche@acm.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>md: synchronize flush io with array reconfiguration</title>
<updated>2024-01-25T23:27:25+00:00</updated>
<author>
<name>Yu Kuai</name>
<email>yukuai3@huawei.com</email>
</author>
<published>2023-11-29T02:02:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f9f2d957a8ea93c73182aebf7de30935a58c027d'/>
<id>f9f2d957a8ea93c73182aebf7de30935a58c027d</id>
<content type='text'>
[ Upstream commit fa2bbff7b0b4e211fec5e5686ef96350690597b5 ]

Currently rcu is used to protect iterating rdev from submit_flushes():

submit_flushes			remove_and_add_spares
				synchronize_rcu
				pers-&gt;hot_remove_disk()
 rcu_read_lock()
 rdev_for_each_rcu
  if (rdev-&gt;raid_disk &gt;= 0)
				rdev-&gt;radi_disk = -1;
   atomic_inc(&amp;rdev-&gt;nr_pending)
   rcu_read_unlock()
   bi = bio_alloc_bioset()
   bi-&gt;bi_end_io = md_end_flush
   bi-&gt;private = rdev
   submit_bio
   // issue io for removed rdev

Fix this problem by grabbing 'acive_io' before iterating rdev, make sure
that remove_and_add_spares() won't concurrent with submit_flushes().

Fixes: a2826aa92e2e ("md: support barrier requests on all personalities.")
Signed-off-by: Yu Kuai &lt;yukuai3@huawei.com&gt;
Signed-off-by: Song Liu &lt;song@kernel.org&gt;
Link: https://lore.kernel.org/r/20231129020234.1586910-1-yukuai1@huaweicloud.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit fa2bbff7b0b4e211fec5e5686ef96350690597b5 ]

Currently rcu is used to protect iterating rdev from submit_flushes():

submit_flushes			remove_and_add_spares
				synchronize_rcu
				pers-&gt;hot_remove_disk()
 rcu_read_lock()
 rdev_for_each_rcu
  if (rdev-&gt;raid_disk &gt;= 0)
				rdev-&gt;radi_disk = -1;
   atomic_inc(&amp;rdev-&gt;nr_pending)
   rcu_read_unlock()
   bi = bio_alloc_bioset()
   bi-&gt;bi_end_io = md_end_flush
   bi-&gt;private = rdev
   submit_bio
   // issue io for removed rdev

Fix this problem by grabbing 'acive_io' before iterating rdev, make sure
that remove_and_add_spares() won't concurrent with submit_flushes().

Fixes: a2826aa92e2e ("md: support barrier requests on all personalities.")
Signed-off-by: Yu Kuai &lt;yukuai3@huawei.com&gt;
Signed-off-by: Song Liu &lt;song@kernel.org&gt;
Link: https://lore.kernel.org/r/20231129020234.1586910-1-yukuai1@huaweicloud.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Revert "md/raid5: Wait for MD_SB_CHANGE_PENDING in raid5d"</title>
<updated>2024-01-20T10:50:10+00:00</updated>
<author>
<name>Junxiao Bi</name>
<email>junxiao.bi@oracle.com</email>
</author>
<published>2023-11-08T18:22:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bed0acf330b2c50c688f6d9cfbcac2aa57a8e613'/>
<id>bed0acf330b2c50c688f6d9cfbcac2aa57a8e613</id>
<content type='text'>
commit bed9e27baf52a09b7ba2a3714f1e24e17ced386d upstream.

This reverts commit 5e2cf333b7bd5d3e62595a44d598a254c697cd74.

That commit introduced the following race and can cause system hung.

 md_write_start:             raid5d:
 // mddev-&gt;in_sync == 1
 set "MD_SB_CHANGE_PENDING"
                            // running before md_write_start wakeup it
                             waiting "MD_SB_CHANGE_PENDING" cleared
                             &gt;&gt;&gt;&gt;&gt;&gt;&gt;&gt;&gt; hung
 wakeup mddev-&gt;thread
 ...
 waiting "MD_SB_CHANGE_PENDING" cleared
 &gt;&gt;&gt;&gt; hung, raid5d should clear this flag
 but get hung by same flag.

The issue reverted commit fixing is fixed by last patch in a new way.

Fixes: 5e2cf333b7bd ("md/raid5: Wait for MD_SB_CHANGE_PENDING in raid5d")
Cc: stable@vger.kernel.org # v5.19+
Signed-off-by: Junxiao Bi &lt;junxiao.bi@oracle.com&gt;
Reviewed-by: Yu Kuai &lt;yukuai3@huawei.com&gt;
Signed-off-by: Song Liu &lt;song@kernel.org&gt;
Link: https://lore.kernel.org/r/20231108182216.73611-2-junxiao.bi@oracle.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit bed9e27baf52a09b7ba2a3714f1e24e17ced386d upstream.

This reverts commit 5e2cf333b7bd5d3e62595a44d598a254c697cd74.

That commit introduced the following race and can cause system hung.

 md_write_start:             raid5d:
 // mddev-&gt;in_sync == 1
 set "MD_SB_CHANGE_PENDING"
                            // running before md_write_start wakeup it
                             waiting "MD_SB_CHANGE_PENDING" cleared
                             &gt;&gt;&gt;&gt;&gt;&gt;&gt;&gt;&gt; hung
 wakeup mddev-&gt;thread
 ...
 waiting "MD_SB_CHANGE_PENDING" cleared
 &gt;&gt;&gt;&gt; hung, raid5d should clear this flag
 but get hung by same flag.

The issue reverted commit fixing is fixed by last patch in a new way.

Fixes: 5e2cf333b7bd ("md/raid5: Wait for MD_SB_CHANGE_PENDING in raid5d")
Cc: stable@vger.kernel.org # v5.19+
Signed-off-by: Junxiao Bi &lt;junxiao.bi@oracle.com&gt;
Reviewed-by: Yu Kuai &lt;yukuai3@huawei.com&gt;
Signed-off-by: Song Liu &lt;song@kernel.org&gt;
Link: https://lore.kernel.org/r/20231108182216.73611-2-junxiao.bi@oracle.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dm audit: fix Kconfig so DM_AUDIT depends on BLK_DEV_DM</title>
<updated>2024-01-20T10:50:08+00:00</updated>
<author>
<name>Mike Snitzer</name>
<email>snitzer@kernel.org</email>
</author>
<published>2023-12-13T19:46:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=87e2739656f4919aa43c7999427e8e9fbaee6e74'/>
<id>87e2739656f4919aa43c7999427e8e9fbaee6e74</id>
<content type='text'>
[ Upstream commit 6849302fdff126997765d16df355b73231f130d4 ]

Signed-off-by: Mike Snitzer &lt;snitzer@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 6849302fdff126997765d16df355b73231f130d4 ]

Signed-off-by: Mike Snitzer &lt;snitzer@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dm-integrity: don't modify bio's immutable bio_vec in integrity_metadata()</title>
<updated>2024-01-01T12:39:07+00:00</updated>
<author>
<name>Mikulas Patocka</name>
<email>mpatocka@redhat.com</email>
</author>
<published>2023-12-05T15:39:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7f7efa30fa87e60ae43574edf0ff1d63bd1dcee2'/>
<id>7f7efa30fa87e60ae43574edf0ff1d63bd1dcee2</id>
<content type='text'>
commit b86f4b790c998afdbc88fe1aa55cfe89c4068726 upstream.

__bio_for_each_segment assumes that the first struct bio_vec argument
doesn't change - it calls "bio_advance_iter_single((bio), &amp;(iter),
(bvl).bv_len)" to advance the iterator. Unfortunately, the dm-integrity
code changes the bio_vec with "bv.bv_len -= pos". When this code path
is taken, the iterator would be out of sync and dm-integrity would
report errors. This happens if the machine is out of memory and
"kmalloc" fails.

Fix this bug by making a copy of "bv" and changing the copy instead.

Fixes: 7eada909bfd7 ("dm: add integrity target")
Cc: stable@vger.kernel.org	# v4.12+
Signed-off-by: Mikulas Patocka &lt;mpatocka@redhat.com&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit b86f4b790c998afdbc88fe1aa55cfe89c4068726 upstream.

__bio_for_each_segment assumes that the first struct bio_vec argument
doesn't change - it calls "bio_advance_iter_single((bio), &amp;(iter),
(bvl).bv_len)" to advance the iterator. Unfortunately, the dm-integrity
code changes the bio_vec with "bv.bv_len -= pos". When this code path
is taken, the iterator would be out of sync and dm-integrity would
report errors. This happens if the machine is out of memory and
"kmalloc" fails.

Fix this bug by making a copy of "bv" and changing the copy instead.

Fixes: 7eada909bfd7 ("dm: add integrity target")
Cc: stable@vger.kernel.org	# v4.12+
Signed-off-by: Mikulas Patocka &lt;mpatocka@redhat.com&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dm thin metadata: Fix ABBA deadlock by resetting dm_bufio_client</title>
<updated>2024-01-01T12:39:05+00:00</updated>
<author>
<name>Li Lingfeng</name>
<email>lilingfeng3@huawei.com</email>
</author>
<published>2023-06-05T07:03:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=93da3d8af9ee2ae6c93badd48539aafba3251a01'/>
<id>93da3d8af9ee2ae6c93badd48539aafba3251a01</id>
<content type='text'>
[ Upstream commit d48300120627a1cb98914738fff38b424625b8ad ]

As described in commit 8111964f1b85 ("dm thin: Fix ABBA deadlock between
shrink_slab and dm_pool_abort_metadata"), ABBA deadlocks will be
triggered because shrinker_rwsem currently needs to held by
dm_pool_abort_metadata() as a side-effect of thin-pool metadata
operation failure.

The following three problem scenarios have been noticed:

1) Described by commit 8111964f1b85 ("dm thin: Fix ABBA deadlock between
   shrink_slab and dm_pool_abort_metadata")

2) shrinker_rwsem and throttle-&gt;lock
          P1(drop cache)                        P2(kworker)
drop_caches_sysctl_handler
 drop_slab
  shrink_slab
   down_read(&amp;shrinker_rwsem)  - LOCK A
   do_shrink_slab
    super_cache_scan
     prune_icache_sb
      dispose_list
       evict
        ext4_evict_inode
         ext4_clear_inode
          ext4_discard_preallocations
           ext4_mb_load_buddy_gfp
            ext4_mb_init_cache
             ext4_wait_block_bitmap
              __ext4_error
               ext4_handle_error
                ext4_commit_super
                 ...
                 dm_submit_bio
                                     do_worker
                                      throttle_work_update
                                       down_write(&amp;t-&gt;lock) -- LOCK B
                                      process_deferred_bios
                                       commit
                                        metadata_operation_failed
                                         dm_pool_abort_metadata
                                          dm_block_manager_create
                                           dm_bufio_client_create
                                            register_shrinker
                                             down_write(&amp;shrinker_rwsem)
                                             -- LOCK A
                 thin_map
                  thin_bio_map
                   thin_defer_bio_with_throttle
                    throttle_lock
                     down_read(&amp;t-&gt;lock)  - LOCK B

3) shrinker_rwsem and wait_on_buffer
          P1(drop cache)                            P2(kworker)
drop_caches_sysctl_handler
 drop_slab
  shrink_slab
   down_read(&amp;shrinker_rwsem)  - LOCK A
   do_shrink_slab
   ...
    ext4_wait_block_bitmap
     __ext4_error
      ext4_handle_error
       jbd2_journal_abort
        jbd2_journal_update_sb_errno
         jbd2_write_superblock
          submit_bh
           // LOCK B
           // RELEASE B
                             do_worker
                              throttle_work_update
                               down_write(&amp;t-&gt;lock) - LOCK B
                              process_deferred_bios
                               process_bio
                               commit
                                metadata_operation_failed
                                 dm_pool_abort_metadata
                                  dm_block_manager_create
                                   dm_bufio_client_create
                                    register_shrinker
                                     register_shrinker_prepared
                                      down_write(&amp;shrinker_rwsem)  - LOCK A
                               bio_endio
      wait_on_buffer
       __wait_on_buffer

Fix these by resetting dm_bufio_client without holding shrinker_rwsem.

Fixes: 8111964f1b85 ("dm thin: Fix ABBA deadlock between shrink_slab and dm_pool_abort_metadata")
Cc: stable@vger.kernel.org
Signed-off-by: Li Lingfeng &lt;lilingfeng3@huawei.com&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit d48300120627a1cb98914738fff38b424625b8ad ]

As described in commit 8111964f1b85 ("dm thin: Fix ABBA deadlock between
shrink_slab and dm_pool_abort_metadata"), ABBA deadlocks will be
triggered because shrinker_rwsem currently needs to held by
dm_pool_abort_metadata() as a side-effect of thin-pool metadata
operation failure.

The following three problem scenarios have been noticed:

1) Described by commit 8111964f1b85 ("dm thin: Fix ABBA deadlock between
   shrink_slab and dm_pool_abort_metadata")

2) shrinker_rwsem and throttle-&gt;lock
          P1(drop cache)                        P2(kworker)
drop_caches_sysctl_handler
 drop_slab
  shrink_slab
   down_read(&amp;shrinker_rwsem)  - LOCK A
   do_shrink_slab
    super_cache_scan
     prune_icache_sb
      dispose_list
       evict
        ext4_evict_inode
         ext4_clear_inode
          ext4_discard_preallocations
           ext4_mb_load_buddy_gfp
            ext4_mb_init_cache
             ext4_wait_block_bitmap
              __ext4_error
               ext4_handle_error
                ext4_commit_super
                 ...
                 dm_submit_bio
                                     do_worker
                                      throttle_work_update
                                       down_write(&amp;t-&gt;lock) -- LOCK B
                                      process_deferred_bios
                                       commit
                                        metadata_operation_failed
                                         dm_pool_abort_metadata
                                          dm_block_manager_create
                                           dm_bufio_client_create
                                            register_shrinker
                                             down_write(&amp;shrinker_rwsem)
                                             -- LOCK A
                 thin_map
                  thin_bio_map
                   thin_defer_bio_with_throttle
                    throttle_lock
                     down_read(&amp;t-&gt;lock)  - LOCK B

3) shrinker_rwsem and wait_on_buffer
          P1(drop cache)                            P2(kworker)
drop_caches_sysctl_handler
 drop_slab
  shrink_slab
   down_read(&amp;shrinker_rwsem)  - LOCK A
   do_shrink_slab
   ...
    ext4_wait_block_bitmap
     __ext4_error
      ext4_handle_error
       jbd2_journal_abort
        jbd2_journal_update_sb_errno
         jbd2_write_superblock
          submit_bh
           // LOCK B
           // RELEASE B
                             do_worker
                              throttle_work_update
                               down_write(&amp;t-&gt;lock) - LOCK B
                              process_deferred_bios
                               process_bio
                               commit
                                metadata_operation_failed
                                 dm_pool_abort_metadata
                                  dm_block_manager_create
                                   dm_bufio_client_create
                                    register_shrinker
                                     register_shrinker_prepared
                                      down_write(&amp;shrinker_rwsem)  - LOCK A
                               bio_endio
      wait_on_buffer
       __wait_on_buffer

Fix these by resetting dm_bufio_client without holding shrinker_rwsem.

Fixes: 8111964f1b85 ("dm thin: Fix ABBA deadlock between shrink_slab and dm_pool_abort_metadata")
Cc: stable@vger.kernel.org
Signed-off-by: Li Lingfeng &lt;lilingfeng3@huawei.com&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bcache: avoid NULL checking to c-&gt;root in run_cache_set()</title>
<updated>2023-12-20T16:00:22+00:00</updated>
<author>
<name>Coly Li</name>
<email>colyli@suse.de</email>
</author>
<published>2023-11-20T05:25:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=02a4b14d17abdf76a88001ad924b44d75b14ef75'/>
<id>02a4b14d17abdf76a88001ad924b44d75b14ef75</id>
<content type='text'>
[ Upstream commit 3eba5e0b2422aec3c9e79822029599961fdcab97 ]

In run_cache_set() after c-&gt;root returned from bch_btree_node_get(), it
is checked by IS_ERR_OR_NULL(). Indeed it is unncessary to check NULL
because bch_btree_node_get() will not return NULL pointer to caller.

This patch replaces IS_ERR_OR_NULL() by IS_ERR() for the above reason.

Signed-off-by: Coly Li &lt;colyli@suse.de&gt;
Link: https://lore.kernel.org/r/20231120052503.6122-11-colyli@suse.de
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 3eba5e0b2422aec3c9e79822029599961fdcab97 ]

In run_cache_set() after c-&gt;root returned from bch_btree_node_get(), it
is checked by IS_ERR_OR_NULL(). Indeed it is unncessary to check NULL
because bch_btree_node_get() will not return NULL pointer to caller.

This patch replaces IS_ERR_OR_NULL() by IS_ERR() for the above reason.

Signed-off-by: Coly Li &lt;colyli@suse.de&gt;
Link: https://lore.kernel.org/r/20231120052503.6122-11-colyli@suse.de
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bcache: add code comments for bch_btree_node_get() and __bch_btree_node_alloc()</title>
<updated>2023-12-20T16:00:22+00:00</updated>
<author>
<name>Coly Li</name>
<email>colyli@suse.de</email>
</author>
<published>2023-11-20T05:25:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3d3f72efc77dbfceda277bc0487e927d583f0e31'/>
<id>3d3f72efc77dbfceda277bc0487e927d583f0e31</id>
<content type='text'>
[ Upstream commit 31f5b956a197d4ec25c8a07cb3a2ab69d0c0b82f ]

This patch adds code comments to bch_btree_node_get() and
__bch_btree_node_alloc() that NULL pointer will not be returned and it
is unnecessary to check NULL pointer by the callers of these routines.

Signed-off-by: Coly Li &lt;colyli@suse.de&gt;
Link: https://lore.kernel.org/r/20231120052503.6122-10-colyli@suse.de
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 31f5b956a197d4ec25c8a07cb3a2ab69d0c0b82f ]

This patch adds code comments to bch_btree_node_get() and
__bch_btree_node_alloc() that NULL pointer will not be returned and it
is unnecessary to check NULL pointer by the callers of these routines.

Signed-off-by: Coly Li &lt;colyli@suse.de&gt;
Link: https://lore.kernel.org/r/20231120052503.6122-10-colyli@suse.de
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
