From mboxrd@z Thu Jan  1 00:00:00 1970
From: Chris Mason <chris.mason@oracle.com>
Subject: Re: btrfsctl -d race with df -h causes hang?
Date: Fri, 20 Nov 2009 10:35:27 -0500
Message-ID: <20091120153527.GW3110@think>
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Cc: linux-btrfs@vger.kernel.org
To: John Dong <jdong@ubuntu.com>
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On Thu, Nov 19, 2009 at 06:18:49PM -0500, John Dong wrote:
> Managed to get some kernel logs this time. Some sort of deadlock?

Ok, if you can still access the machine could you please run sysrq-w and
sysrq-t.  That will print out the stacks of the stuck procs.  We've
probably got a lock inversion hiding in the df handling.

-chris