NFSv4: handle ERR_GRACE on delegation recalls

JIRA: https://issues.redhat.com/browse/RHEL-115855

commit be390f9
Author: Olga Kornievskaia <okorniev@redhat.com>
Date:   Mon Aug 11 14:18:48 2025 -0400

    NFSv4: handle ERR_GRACE on delegation recalls

    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>
    Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>

Signed-off-by: Scott Mayhew <smayhew@redhat.com>

Author: scottmayhew

fs/nfs/nfs4proc.c

@@ -7826,10 +7826,10 @@ 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);
 }