Subject: Re: next-20090206: deadlock on ext4

From: Alexander Beregalov <[email-masked]>
Date: Mon, 9 Feb 2009 15:01:13 +0300

2009/2/6 Eric Sandeen <[email-masked]>:
> 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?

I have reproduced it with 2.6.29-rc4.
Loop file was on XFS.
I can not reproduce it on ext4 on raw device.
Let me know if I can do anything else to help resolving it.