Re: NFS client hang on attempt to do async blocking posix lock enqueue

["J. Bruce Fields" <bfields@fieldses.org>]

On Fri, Feb 08, 2008 at 07:15:02AM -0500, Jeff Layton wrote:
> On Thu, 7 Feb 2008 18:26:18 -0500
> "J. Bruce Fields" <bfields@fieldses.org> wrote:
> 
> > On Sun, Jan 20, 2008 at 09:58:59AM -0500, Oleg Drokin wrote:
> > > Hello!
> > >
> > > On Jan 18, 2008, at 6:07 PM, J. Bruce Fields wrote:
> > >
> > >> On Thu, Nov 29, 2007 at 02:41:57PM -0800, Marc Eshel wrote:
> > >>> The problem seems to be with the fact that the client and server are 
> > >>> on
> > >>> the same machine. This test work fine with or without an underlaying 
> > >>> fs
> > >>> that supports locking when the client and the server are on a  
> > >>> different
> > >>> machines. Like you said the server is trying to send the grant  
> > >>> message to
> > >>> the client but for some reason it fails when the client is on the  
> > >>> same
> > >>> machine.
> > >> That *shouldn't* make a difference, so we need to take another look at
> > >> this--Oleg, this problem is still unfixed, right?
> > >
> > > Yes, I just pulled your latest nfs tree and I still can reproduce the  
> > > problem.
> > 
> > OK, we have finally reproduced this problem here, and David's working on
> > debugging.  It does indeed seem to only be reproduceable with client and
> > server on the same machine.  Thanks for the report....
> > 
> > --b.
> 
> It might be worth testing this both with and without the patchset I
> posted to linux-nfs recently to take care of the lockd hang. If
> lockd is stuck trying to rpc_ping itself then it probably would hang
> like this, wouldn't it?

Of course!  Yes, that fits.

--b.