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From: "Theodore Ts'o" <tytso@mit.edu>
To: Pavel Skripkin <paskripkin@gmail.com>
Cc: adilger.kernel@dilger.ca, johann@whamcloud.com,
	linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org,
	syzbot+c9ff4822a62eee994ea3@syzkaller.appspotmail.com
Subject: Re: [PATCH] ext4: avoid huge mmp update interval value
Date: Thu, 5 Aug 2021 15:45:28 -0400	[thread overview]
Message-ID: <YQw/2PuZ8z22Qice@mit.edu> (raw)
In-Reply-To: <20210805151418.30659-1-paskripkin@gmail.com>

On Thu, Aug 05, 2021 at 06:14:18PM +0300, Pavel Skripkin wrote:
> Syzbot reported task hung bug in ext4_fill_super(). The problem was in
> too huge mmp update interval.
> 
> Syzkaller reproducer setted s_mmp_update_interval to 39785 seconds. This
> update interaval is unreasonable huge and it can cause tasks to hung on
> kthread_stop() call, since it will wait until timeout timer expires.

I must be missing something.  kthread_stop() should wake up the
kmmpd() thread, which should see kthread_should_stop(), and then it
should exit.  What is causing it to wait until the timeout timer
expires?

					- Ted

  reply	other threads:[~2021-08-05 19:45 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-05 15:14 [PATCH] ext4: avoid huge mmp update interval value Pavel Skripkin
2021-08-05 19:45 ` Theodore Ts'o [this message]
2021-08-05 20:12   ` Pavel Skripkin
2021-08-05 22:59     ` Dave Chinner
2021-08-06 10:20       ` Pavel Skripkin

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