Re: [PATCH 1/1] NFSv4: handle ERR_GRACE on delegation recalls

[Trond Myklebust <trondmy@kernel.org>]

On Fri, 2025-09-12 at 10:21 -0400, Olga Kornievskaia wrote:
> Any comments on or objections to this patch? It does lead to possible
> data corruption.
> 

Sorry, I think was travelling when you originally sent this patch.

> On Mon, Aug 11, 2025 at 2:25 PM Olga Kornievskaia
> <okorniev@redhat.com> wrote:
> > 
> > RFC7530 states that clients should be prepared for the return of
> > NFS4ERR_GRACE errors for non-reclaim lock and I/O requests.
> > 
> > Signed-off-by: Olga Kornievskaia <okorniev@redhat.com>
> > ---
> >  fs/nfs/nfs4proc.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
> > index 341740fa293d..fa9b81300604 100644
> > --- a/fs/nfs/nfs4proc.c
> > +++ b/fs/nfs/nfs4proc.c
> > @@ -7867,10 +7867,10 @@ int nfs4_lock_delegation_recall(struct
> > file_lock *fl, struct nfs4_state *state,
> >                 return err;
> >         do {
> >                 err = _nfs4_do_setlk(state, F_SETLK, fl,
> > NFS_LOCK_NEW);
> > -               if (err != -NFS4ERR_DELAY)
> > +               if (err != -NFS4ERR_DELAY && err != -NFS4ERR_GRACE)
> >                         break;
> >                 ssleep(1);
> > -       } while (err == -NFS4ERR_DELAY);
> > +       } while (err == -NFS4ERR_DELAY || err == -NFSERR_GRACE);
> >         return nfs4_handle_delegation_recall_error(server, state,
> > stateid, fl, err);
> >  }
> > 
> > --
> > 2.47.1
> > 
> > 

Should the server be sending NFS4ERR_GRACE in this case, though? The
client already holds a delegation, so it is clear that other clients
cannot reclaim any locks that would conflict.

..or is the issue that this could happen before the client has a chance
to reclaim the delegation after a reboot?

-- 
Trond Myklebust
Linux NFS client maintainer, Hammerspace
trondmy@kernel.org, trond.myklebust@hammerspace.com