On Fri, Sep 12, 2025 at 10:29 AM Trond Myklebust <trondmy@xxxxxxxxxx> wrote:
>
> 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@xxxxxxxxxx> 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@xxxxxxxxxx>
> > > ---
> > > 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?
The scenario was, v4 client had an open file and a lock and upon
server reboot (during grace) sends the reclaim open, to which the
server replies with a delegation. How a v3 client comes in and
requests the same lock. The linux server at this point sends a
delegation recall to v4 client, the client sends its local lock
request and gets ERR_GRACE.
And the spec explicitly notes as I mention in the commit comment that
the client is supposed to handle ERR_GRACE for non-reclaim locks. Thus
this patch.
> --
> Trond Myklebust
> Linux NFS client maintainer, Hammerspace
> trondmy@xxxxxxxxxx, trond.myklebust@xxxxxxxxxxxxxxx
>
