From: Tao Ma <tm@tao.ma>
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 17:03:14 +0800 [thread overview]
Message-ID: <4E576152.9060405@tao.ma> (raw)
In-Reply-To: <20110826084403.GA3162@dastard>
On 08/26/2011 04:44 PM, Dave Chinner wrote:
> On Fri, Aug 26, 2011 at 05:35:07PM +1000, Dave Chinner wrote:
>> On Thu, Aug 25, 2011 at 11:33:44PM -0400, Theodore Ts'o wrote:
>>>
>>> Note: this will probably need to be sent to Linus as an emergency
>>> bugfix ASAP, since it was introduced in 3.1-rc1, so it represents a
>>> regression.
>>
>> It doesn't appear to be a bug. All of the new ext4 lockdep reports
>> in 3.1 I've seen (except for the mmap_sem/i_mutex one) are false
>> positives....
>
> 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. (*)
ext4_ioend_wait can't work here for a nasty bug. Please see the commit
log of 2581fdc8.
Thanks
Tao
next prev parent reply other threads:[~2011-08-26 9:03 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
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 [this message]
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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