From: Jan Kara <jack@suse.cz>
To: Theodore Ts'o <tytso@mit.edu>
Cc: Jan Kara <jack@suse.cz>,
linux-ext4@vger.kernel.org,
Christian Brauner <brauner@kernel.org>,
syzbot+aacb82fca60873422114@syzkaller.appspotmail.com,
syzbot+6b7df7d5506b32467149@syzkaller.appspotmail.com
Subject: Re: [PATCH] ext4: Fix lockdep warning when enabling MMP
Date: Tue, 2 May 2023 11:51:24 +0200 [thread overview]
Message-ID: <20230502095124.gzjjnmfquciimucf@quack3> (raw)
In-Reply-To: <ZE6YeCaQa01nAWYT@mit.edu>
On Sun 30-04-23 12:34:00, Theodore Ts'o wrote:
> On Tue, Apr 11, 2023 at 02:10:19PM +0200, Jan Kara wrote:
> > When we enable MMP in ext4_multi_mount_protect() during mount or
> > remount, we end up calling sb_start_write() from write_mmp_block(). This
> > triggers lockdep warning because freeze protection ranks above s_umount
> > semaphore we are holding during mount / remount. The problem is harmless
> > because we are guaranteed the filesystem is not frozen during mount /
> > remount but still let's fix the warning by not grabbing freeze
> > protection from ext4_multi_mount_protect().
> >
> > Reported-by: syzbot+aacb82fca60873422114@syzkaller.appspotmail.com
>
> I believe this is the wrong Reported-by. The correct one looks like
> it should be:
>
> Reported-by: syzbot+6b7df7d5506b32467149@syzkaller.appspotmail.com
> Link: https://syzkaller.appspot.com/bug?id=ab7e5b6f400b7778d46f01841422e5718fb81843
Well, one of the reports of this problem has also the ID I have referenced
(https://syzkaller.appspot.com/bug?extid=6b7df7d5506b32467149). There are
apparently multiple ones...
> It's also helpful to add a Link line to the Syzkaller dashboard to
> make it easier to find the relevant Syzbot report.
Right, I'll do that next time. Thanks for the idea.
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
next prev parent reply other threads:[~2023-05-02 9:51 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-11 12:10 [PATCH] ext4: Fix lockdep warning when enabling MMP Jan Kara
2023-04-11 13:52 ` Christian Brauner
2023-04-30 16:34 ` Theodore Ts'o
2023-04-30 16:44 ` Theodore Ts'o
2023-05-02 9:51 ` Jan Kara [this message]
2023-05-13 4:59 ` Theodore Ts'o
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