From: Jia-Ju Bai <baijiaju1990@gmail.com>
To: viro@zeniv.linux.org.uk, Jens Axboe <axboe@kernel.dk>, hch@infradead.org
Cc: linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: [BUG] fs: super: possible ABBA deadlocks in do_thaw_all_callback() and freeze_bdev()
Date: Mon, 27 Dec 2021 10:03:35 +0800 [thread overview]
Message-ID: <e3de0d83-1170-05c8-672c-4428e781b988@gmail.com> (raw)
Hello,
My static analysis tool reports several possible ABBA deadlocks in Linux
5.10:
do_thaw_all_callback()
down_write(&sb->s_umount); --> Line 1028 (Lock A)
emergency_thaw_bdev()
thaw_bdev()
mutex_lock(&bdev->bd_fsfreeze_mutex); --> Line 602 (Lock B)
freeze_bdev()
mutex_lock(&bdev->bd_fsfreeze_mutex); --> Line 556 (Lock B)
freeze_super()
down_write(&sb->s_umount); --> Line 1716 (Lock A)
down_write(&sb->s_umount); --> Line 1738 (Lock A)
deactivate_super()
down_write(&s->s_umount); --> Line 365 (Lock A)
When do_thaw_all_callback() and freeze_bdev() are concurrently executed,
the deadlocks can occur.
I am not quite sure whether these possible deadlocks are real and how to
fix them if them are real.
Any feedback would be appreciated, thanks :)
Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Best wishes,
Jia-Ju Bai
next reply other threads:[~2021-12-27 2:03 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-27 2:03 Jia-Ju Bai [this message]
2021-12-27 2:08 ` [BUG] fs: super: possible ABBA deadlocks in do_thaw_all_callback() and freeze_bdev() Matthew Wilcox
2021-12-27 4:39 ` Theodore Ts'o
2021-12-27 9:32 ` Jia-Ju Bai
2021-12-27 13:43 ` Theodore Ts'o
2021-12-28 2:31 ` Jia-Ju Bai
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=e3de0d83-1170-05c8-672c-4428e781b988@gmail.com \
--to=baijiaju1990@gmail.com \
--cc=axboe@kernel.dk \
--cc=hch@infradead.org \
--cc=linux-block@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=viro@zeniv.linux.org.uk \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).