On Thu, 2011-08-04 at 19:27 +0200, Frank van Maarseveen wrote:
> On Thu, Aug 04, 2011 at 01:10:20PM -0400, Trond Myklebust wrote:
> > On Thu, 2011-08-04 at 12:49 -0400, J. Bruce Fields wrote:
> > > On Thu, Aug 04, 2011 at 06:43:13PM +0200, Frank van Maarseveen wrote:
> > > > On Thu, Aug 04, 2011 at 12:34:52PM -0400, J. Bruce Fields wrote:
> > > > > On Thu, Aug 04, 2011 at 12:30:19PM +0200, Frank van Maarseveen wrote:
> > > > > > Both client- and server run 2.6.39.3, NFSv3 over UDP (without the
> > > > > > relock_filesystem patch proposed earlier).
> > > > > >
> > > > > > A second client has an exclusive lock on a file on the server. The
> > > > > > client under test calls fcntl(F_SETLKW) to wait for the same exclusive
> > > > > > lock. Wireshark sees NLM V4 LOCK calls resulting in NLM_BLOCKED.
> > > > > >
> > > > > > Next the server is rebooted. The second client recovers the lock
> > > > > > correctly. The client under test now receives NLM_DENIED_GRACE_PERIOD for
> > > > > > every NLM V4 LOCK request resulting from the waiting fcntl(F_SETLKW). When
> > > > > > this changes to NLM_BLOCKED after grace period expiration the fcntl
> > > > > > returns -ENOLCK ("No locks available.") instead of continuing to wait.
> > > > >
> > > > > So that sounds like a client bug, and correct behavior from the server
> > > > > (assuming the second client was still holding the lock throughout).
> > > >
> > > > yes.
> >
> > Is the client actually asking for a blocking lock after the grace period
> > expires?
>
> yes, according to my interpretation of that of wireshark, see reply to Bruce.
>
OK... Does the following patch help?
Cheers
Trond
---
diff --git a/fs/lockd/clntproc.c b/fs/lockd/clntproc.c
index 8392cb8..40c0d88 100644
--- a/fs/lockd/clntproc.c
+++ b/fs/lockd/clntproc.c
@@ -270,6 +270,9 @@ nlmclnt_call(struct rpc_cred *cred, struct nlm_rqst *req, u32 proc)
return -ENOLCK;
msg.rpc_proc = &clnt->cl_procinfo[proc];
+ /* Reset the reply status */
+ if (argp->block)
+ resp->status = nlm_lck_blocked;
/* Perform the RPC call. If an error occurs, try again */
if ((status = rpc_call_sync(clnt, &msg, 0)) < 0) {
dprintk("lockd: rpc_call returned error %d\n", -status);
--
Trond Myklebust
Linux NFS client maintainer
NetApp
Trond.Myklebust@xxxxxxxxxx
www.netapp.com
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