Weird message from xfs_repair

[Ben Myers]

Hi Emmanuel,

On Wed, May 01, 2013 at 08:06:33PM +0200, Emmanuel Florac wrote:
> I've just had to resort to the latest devel version of xfs_repair to
> get back some heavily damaged filesystem (thanks to a failing RAID
> controller), and it ended with the following message:
> 
> cache_purge: shake on cache 0x672030 left 1 nodes!?
> 
> What's this about? I didn't look at the source, but a new run of
> xfs_repair detected nothing. 

xfs_repair/libxfs has caches for xfs_bufs and inodes to speed things up.
cache_purge is trying to flush out all entries from one of those caches.  After
the purge one entry was left unexpectedly, maybe because someone leaked a
reference on it or something.  The message doesn't indicate an on-disk problem,
it's a problem in xfs_repair.

Regards,
	Ben