[lvc-project] [PATCH v2] ext4: fix i_data_sem unlock order in ext4_ind_migrate()

[Theodore Ts'o]

On Sat, Apr 06, 2024 at 12:08:03AM +0300, Mikhail Ukhin wrote:
> Fuzzing reports a possible deadlock in jbd2_log_wait_commit.
> 
> The problem occurs in ext4_ind_migrate due to an incorrect order of
> unlocking of the journal and write semaphores - the order of unlocking
> must be the reverse of the order of locking.
> 
> Found by Linux Verification Center (linuxtesting.org) with syzkaller.
> 
> Reviewed-by: Ritesh Harjani (IBM) <ritesh.list at gmail.com>
> Signed-off-by: Artem Sadovnikov <ancowi69 at gmail.com>
> Signed-off-by: Mikhail Ukhin <mish.uxin2012 at yandex.ru>

Thanks.  This has been addressed by commit 00d873c17e29 ("ext4: avoid
deadlock in fs reclaim with page writeback"), with the same code
change.

						- Ted