Re: [PATCH v3] ext4: fix a possible ABBA deadlock dued to busy PA

[Theodore Ts'o]

On Tue, 23 Nov 2021 09:17:57 +0800, brookxu wrote:
> From: Chunguang Xu <brookxu@xxxxxxxxxxx>
> 
> We found on older kernel (3.10) that in the scenario of insufficient
> disk space, system may trigger an ABBA deadlock problem, it seems that
> this problem still exists in latest kernel, try to fix it here. The
> main process triggered by this problem is that task A occupies the PA
> and waits for the jbd2 transaction finish, the jbd2 transaction waits
> for the completion of task B's IO (plug_list), but task B waits for
> the release of PA by task A to finish discard, which indirectly forms
> an ABBA deadlock. The related calltrace is as follows:
> 
> [...]

Applied, thanks!

[1/1] ext4: fix a possible ABBA deadlock dued to busy PA
      commit: 1754b684bf05c9c00b40e745a57f9ca9696ad9c1

Best regards,
-- 
Theodore Ts'o <tytso@xxxxxxx>