Subject: Re: next-20090206: deadlock on ext4

From: Eric Sandeen <[email-masked]>
Date: Fri, 06 Feb 2009 14:07:18 -0600

Alexander Beregalov wrote:
> 2009/2/6 Eric Sandeen <[email-masked]>:
>> Alexander Beregalov wrote:
>>> Hi
>>>
>>> I run dbench on ext4 on loop device.
>>>
>>> EXT4-fs: barriers enabled
>>> kjournald2 starting: pid 2420, dev loop0:8, commit interval 5 seconds
>>> EXT4 FS on loop0, internal journal on loop0:8
>>> EXT4-fs: delayed allocation enabled
>>> EXT4-fs: file extents enabled
>>> EXT4-fs: mballoc enabled
>>> EXT4-fs: mounted filesystem loop0 with ordered data mode
>>> JBD: barrier-based sync failed on loop0:8 - disabling barriers
>>>
>>> INFO: task pdflush:2339 blocked for more than 120 seconds.
>> Looks a lot like a bug I filed:
>>
>> http://bugzilla.kernel.org/show_bug.cgi?id=12579
>>
>> but I'm having trouble reproducing it, now.  I'll try dbench!
> Yes, I can reproduce it easy with dbench.

Do you only hit it on loopback?  What is the filesystem hosting the loop
file?

Thanks,
-Eric