panic on 4.20 server exporting xfs filesystem

[J. Bruce Fields]

On Thu, Mar 05, 2015 at 10:01:38AM -0500, J. Bruce Fields wrote:
> On Thu, Mar 05, 2015 at 02:17:31PM +0100, Christoph Hellwig wrote:
> > On Wed, Mar 04, 2015 at 11:08:49PM -0500, J. Bruce Fields wrote:
> > > Ah-hah:
> > > 
> > > 	static void
> > > 	nfsd4_cb_layout_fail(struct nfs4_layout_stateid *ls)
> > > 	{
> > > 		...
> > > 		nfsd4_cb_layout_fail(ls);
> > > 
> > > That'd do it!
> > > 
> > > Haven't tried to figure out why exactly that's getting called, and why
> > > only rarely.  Some intermittent problem with the callback path, I guess.
> > > 
> > > Anyway, I think that solves most of the mystery....
> > 
> > Ooops, that was a nasty git merge error in the last rebase, see the fix
> > below.
> 
> Thanks!

And with that fix things look good.

I'm still curious why the callbacks are failling.  It's also logging
"nfsd: client 192.168.122.32 failed to respond to layout recall".

I may not get a chance to debug for another week or two.

--b.