Circular locking dependency warning involing xfs on 2.6.27

[Christoph Hellwig]

On Thu, Jan 21, 2010 at 10:28:20AM +0900, Tejun Heo wrote:
> Hello,
> 
> This is on a pretty old kernel but Carsten reports that it happens
> occassionally in a pretty large setup involving 1500+ machines (please
> feel free to fill in).  This happens pretty sporadically so reporting
> it just in case this is a yet unknown problem.  As I understand it,
> testing with newer kernel isn't out of question but it being a
> production environment, not a very easy thing.

I think the one below is gone.  We still have a very similar one that
can only happen during unmount, and we're trying to sort that one at the
VFS level (see the current thread on -fsdevel)