Re: deadlocked xfs

[Mark Goodwin <markgw@sgi.com>]

Dave Chinner wrote:
> On Fri, Jul 11, 2008 at 12:48:11PM +1000, Mark Goodwin wrote:
>> Thanks for the report Eric. This looks very similar to a
>> deadlock Lachlan recently hit in the patch for
>> "Use atomics for iclog reference counting"
>> http://oss.sgi.com/archives/xfs/2008-02/msg00130.html
>>
>> It seems this patch can cause deadlocks under heavy log traffic.
>> I don't think anyone has a fix yet ... Lachlan is out this week,
>> but Tim can follow-up here ...
> 
> Nice to know - why didn't anyone email me or report this to the
> list when the bug was first found? I mean, I wrote that code, I know
> what it is supposed to be doing and as a result should be able

Only recently found and didn't think it was this easy to hit.
But no excuses ...

> help find and fix the bug. Can you please post what details you have
> about the problem (test case, stack traces, debugging info, etc)
> so I can try to find the problem.

See Tim's follow-up.

> This is a regression that is in the mainline kernel that is due to
> be released probably in the next couple of days. Having a little
> bit of time to try and find the bug would have been nice...

At this stage, I think it would be safest to back-out the commit,
all the way to mainline. Tim, can you please work thru that today
with priority.

Thanks

-- 

  Mark Goodwin                                  markgw@sgi.com
  Engineering Manager for XFS and PCP    Phone: +61-3-99631937
  SGI Australian Software Group           Cell: +61-4-18969583
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