From: Christoph Hellwig <hch@infradead.org>
To: Dave Chinner <david@fromorbit.com>
Cc: Theodore Ts'o <tytso@mit.edu>,
Jiaying Zhang <jiayingz@google.com>,
linux-ext4@vger.kernel.org
Subject: Re: [URGENT PATCH] ext4: fix potential deadlock in ext4_evict_inode()
Date: Fri, 26 Aug 2011 04:50:57 -0400 [thread overview]
Message-ID: <20110826085057.GA13311@infradead.org> (raw)
In-Reply-To: <20110826084403.GA3162@dastard>
On Fri, Aug 26, 2011 at 06:44:03PM +1000, Dave Chinner wrote:
> While the lockdep report is false positive, I agree that your
> change is the right fix to make - the IO completions are already
> queued on the workqueue, so they don't need to be flushed to get
> them to complete. All that needs to be done is call
> ext4_ioend_wait() for them to complete, and that gets rid of the
> i_mutex altogether. (*)
The really correct fix is to stop using the ioend wait like I did
in my pending series for XFS. The only thing preventing ext4 from
doing that is that it marks pages uptodate from irq context,
before finishing the ioends. This has a lot of nasty implications
as the the page might be marked uptodate without actually having
that state on disk.
next prev parent reply other threads:[~2011-08-26 8:51 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-26 3:33 [URGENT PATCH] ext4: fix potential deadlock in ext4_evict_inode() Theodore Ts'o
2011-08-26 3:56 ` Tao Ma
2011-08-26 9:28 ` Tao Ma
2011-08-26 7:35 ` Dave Chinner
2011-08-26 7:42 ` Tao Ma
2011-08-26 8:44 ` Dave Chinner
2011-08-26 8:50 ` Christoph Hellwig [this message]
2011-08-26 9:10 ` Tao Ma
2011-08-26 9:17 ` Christoph Hellwig
2011-08-26 11:35 ` Theodore Tso
2011-08-26 14:53 ` Tao Ma
2011-08-26 9:03 ` Tao Ma
2011-08-26 9:24 ` Dave Chinner
2011-08-26 9:27 ` Tao Ma
2011-08-26 15:52 ` Ted Ts'o
2011-08-26 16:58 ` Jiaying Zhang
2011-08-26 20:22 ` Ted Ts'o
2011-08-27 5:17 ` Jiaying Zhang
2011-08-31 1:15 ` Jiaying Zhang
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