2.6.27.7 vanilla, project quota enabled and process stuck in D state (repeatable every time)

[Christoph Hellwig]

On Thu, Dec 04, 2008 at 09:09:34AM +1100, Dave Chinner wrote:
> Is that the unlock of the inodes is using the incorrect lock
> type for the unlock, (inodes lock XFS_ILOCK_EXCL, unlocked XFS_ILOCK_SHARED)
> which means they don't get unlocked and the next attempt to do anything
> with those inodes will hang.
> 
> Compile-tested-only patch below that should fix the problem.

Yeah, that also explains why my patch fixes it :)  I'd say let's put
yours into 2.6.28 and -stable, and I'll rediff mine ontop for the 2.6.29
queue.  I'll also write a testcase for xfsqa based on Arkadiusz's
report.