From: Steven Whitehouse <swhiteho@redhat.com>
To: Zheng Liu <gnehzuil.liu@gmail.com>
Cc: linux-fsdevel@vger.kernel.org, Jan Kara <jack@suse.cz>,
Christoph Hellwig <hch@infradead.org>,
Dmitry Monakhov <dmonakhov@openvz.org>,
Dave Chinner <david@fromorbit.com>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Zheng Liu <wenqing.lz@taobao.com>
Subject: Re: [PATCH v3] vfs: fix a bug when we do some dio reads with append dio writes
Date: Mon, 16 Dec 2013 09:37:34 +0000 [thread overview]
Message-ID: <1387186654.2736.6.camel@menhir> (raw)
In-Reply-To: <1386413726-4610-1-git-send-email-wenqing.lz@taobao.com>
Hi,
On Sat, 2013-12-07 at 18:55 +0800, Zheng Liu wrote:
> From: Zheng Liu <wenqing.lz@taobao.com>
>
> Currently we check i_size in buffered read path after we know the page
> is update. But it could return some zero-filled pages to the userspace
> when we do some append dio writes. We could use the following code
> snippet to reproduce this problem in a ext2/3/4 filesystem.
>
If the page is not uptodate, then neither (potentially) is i_size, since
the underlying fs has not had a chance to get its own locks and update
the inode size.
I suspect that the correct fix would be to implement ->launder_page to
avoid the race that you've identified here, if I've understood it
correctly,
Steve.
next prev parent reply other threads:[~2013-12-16 9:38 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-07 10:55 [PATCH v3] vfs: fix a bug when we do some dio reads with append dio writes Zheng Liu
2013-12-16 9:37 ` Steven Whitehouse [this message]
2013-12-16 10:01 ` Jan Kara
2013-12-17 9:43 ` Steven Whitehouse
2013-12-17 11:16 ` Zheng Liu
2013-12-17 12:17 ` Steven Whitehouse
2013-12-17 16:41 ` Zheng Liu
2013-12-19 12:27 ` Steven Whitehouse
2013-12-19 22:44 ` Dave Chinner
2013-12-20 9:28 ` Steven Whitehouse
2013-12-23 3:00 ` Dave Chinner
2014-01-14 15:22 ` Steven Whitehouse
2014-01-14 19:19 ` Jan Kara
2014-01-15 7:19 ` Zheng Liu
2014-01-16 15:35 ` [RFC] [PATCH] Fix race when checking i_size on direct i/o read Steven Whitehouse
2014-01-17 10:20 ` Miklos Szeredi
2014-01-24 14:42 ` Steven Whitehouse
2014-01-27 10:13 ` Jan Kara
2013-12-17 14:01 ` [PATCH v3] vfs: fix a bug when we do some dio reads with append dio writes Jan Kara
2013-12-17 15:32 ` Steven Whitehouse
2013-12-17 16:39 ` Jan Kara
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