From: Theodore Ts'o <tytso@mit.edu>
To: Eric Sandeen <sandeen@redhat.com>
Cc: Ext4 Developers List <linux-ext4@vger.kernel.org>,
stable@vger.kernel.org
Subject: Re: [PATCH] ext4: fix potential deadlock in ext4_nonda_switch()
Date: Fri, 21 Sep 2012 19:59:12 -0400 [thread overview]
Message-ID: <20120921235912.GA27207@thunk.org> (raw)
In-Reply-To: <505CE635.6060101@redhat.com>
On Fri, Sep 21, 2012 at 05:12:05PM -0500, Eric Sandeen wrote:
> > - if (free_blocks < 2 * dirty_blocks)
> > - writeback_inodes_sb_if_idle(sb, WB_REASON_FS_FREE_SPACE);
> > + if ((free_blocks < 2 * dirty_blocks) && writeback_in_progress(sb->s_bdi))
> > + writeback_inodes_sb(sb, WB_REASON_FS_FREE_SPACE);
>
> Looks to me like this inverts the logic.
>
> We used to write back if idle, now we fire it off if it's already underway.
>
> Shouldn't it be:
>
> + if ((free_blocks < 2 * dirty_blocks) && !writeback_in_progress(sb->s_bdi))
> + writeback_inodes_sb(sb, WB_REASON_FS_FREE_SPACE);
Oops, nice catch. Thanks for the review!!
I've added the missing '!' to the patch.
- Ted
next prev parent reply other threads:[~2012-09-21 23:59 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-20 3:23 [PATCH] ext4: fix potential deadlock in ext4_nonda_switch() Theodore Ts'o
2012-09-21 22:12 ` Eric Sandeen
2012-09-21 23:59 ` Theodore Ts'o [this message]
2012-09-27 17:18 ` Dmitry Monakhov
2012-09-27 18:09 ` Theodore Ts'o
2012-09-27 18:16 ` Dmitry Monakhov
2012-09-27 20:14 ` Theodore Ts'o
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