On Mon, 2025-08-11 at 14:18 -0400, Olga Kornievskaia wrote:
> When v3 NLM request finds a conflicting delegation, it triggers
> a delegation recall and nfsd_open fails with EAGAIN. nfsd_open
> then translates EAGAIN into nfserr_jukebox. In nlm_fopen, instead
> of returning nlm_failed for when there is a conflicting delegation,
> drop this NLM request so that the client retries. Once delegation
> is recalled and if a local lock is claimed, a retry would lead to
> nfsd returning a nlm_lck_blocked error or a successful nlm lock.
>
> Signed-off-by: Olga Kornievskaia <okorniev@xxxxxxxxxx>
> ---
> fs/nfsd/lockd.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/fs/nfsd/lockd.c b/fs/nfsd/lockd.c
> index edc9f75dc75c..ad3e461f30c0 100644
> --- a/fs/nfsd/lockd.c
> +++ b/fs/nfsd/lockd.c
> @@ -57,6 +57,7 @@ nlm_fopen(struct svc_rqst *rqstp, struct nfs_fh *f, struct file **filp,
> switch (nfserr) {
> case nfs_ok:
> return 0;
> + case nfserr_jukebox:
> case nfserr_dropit:
> return nlm_drop_reply;
> case nfserr_stale:
This works by triggering a RPC retransmission. That could time out on
soft mounts if it takes a while to return a delegation. Looking at the
NLM spec here:
https://pubs.opengroup.org/onlinepubs/9629799/chap14.htm
What about returning NLM4_DENIED instead? The description there is:
NLM4_DENIED
The call failed. For attempts to set a lock, this status implies
that if the client retries the call later, it may succeed.
Presumably the client should redrive this effectively indefinitely that
way?
--
Jeff Layton <jlayton@xxxxxxxxxx>
