Date: Fri, 30 Jul 2010 00:05:46 +1000
From: Nick Piggin <npiggin@suse.de>
To: Dave Chinner <david@fromorbit.com>
Cc: Nick Piggin <npiggin@kernel.dk>, xfs@oss.sgi.com
Subject: Re: XFS hang in xlog_grant_log_space
Message-ID: <20100729140546.GB7217@amd>
References: <20100722190100.GA22269@amd>
 <20100723135514.GJ32635@dastard>
 <20100727070538.GA2893@amd>
 <20100727080632.GA4958@amd>
 <20100727113626.GA2884@amd>
 <20100727133038.GP7362@dastard>
 <20100727145808.GQ7362@dastard>
 <20100728131744.GS7362@dastard>
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In-Reply-To: <20100728131744.GS7362@dastard>
User-Agent: Mutt/1.5.20 (2009-06-14)

On Wed, Jul 28, 2010 at 11:17:44PM +1000, Dave Chinner wrote:
> Something very strange is happening, and to make matters worse I
> cannot reproduce it with a debug kernel (ran for 3 hours without
> failing). Hence it smells like a race condition somewhere.
> 
> I've reproduced it without delayed logging, so it is not directly
> related to that functionality.
> 
> I've seen this warning:
> 
> Filesystem "ram0": inode 0x704680 background reclaim flush failed with 117
> 
> Which indicates we failed to mark an inode stale when freeing an
> inode cluster, but I think I've fixed that and the problem still
> shows up. It's posible the last version didn't fix it, but....

I've seen that one a couple of times too. Keeps coming back each
time you echo 3 > /proc/sys/vm/drop_caches :)


> Now I've got the ag iterator rotor patch in place as well and
> possibly a different version of the cluster free fix to what I
> previously tested and it's now been running for almost half an hour.
> I can't say yet whether I've fixed the bug of just changed the
> timing enough to avoid it. I'll leave this test running over night
> and redo individual patch testing tomorrow.

I reproduced it with fs_stress now too. Any patches I could test
for you just let me know.