Merge tag 'nfsd-5.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux

Pull nfsd fixes from Chuck Lever:
 "Critical bug fixes:

   - Fix crash in NLM TEST procedure

   - NFSv4.1+ backchannel not restored after PATH_DOWN"

* tag 'nfsd-5.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
  nfsd: back channel stuck in SEQ4_STATUS_CB_PATH_DOWN
  NLM: Fix svcxdr_encode_owner()

Author: torvalds

fs/lockd/svcxdr.h

@@ -134,18 +134,9 @@ svcxdr_decode_owner(struct xdr_stream *xdr, struct xdr_netobj *obj)
 static inline bool
 svcxdr_encode_owner(struct xdr_stream *xdr, const struct xdr_netobj *obj)
 {
-	unsigned int quadlen = XDR_QUADLEN(obj->len);
-	__be32 *p;
-
-	if (xdr_stream_encode_u32(xdr, obj->len) < 0)
-		return false;
-	p = xdr_reserve_space(xdr, obj->len);
-	if (!p)
+	if (obj->len > XDR_MAX_NETOBJ)
 		return false;
-	p[quadlen - 1] = 0;	/* XDR pad */
-	memcpy(p, obj->data, obj->len);
-
-	return true;
+	return xdr_stream_encode_opaque(xdr, obj->data, obj->len) > 0;
 }
 
 #endif /* _LOCKD_SVCXDR_H_ */

fs/nfsd/nfs4state.c

@@ -3570,7 +3570,7 @@ static struct nfsd4_conn *__nfsd4_find_conn(struct svc_xprt *xpt, struct nfsd4_s
 }
 
 static __be32 nfsd4_match_existing_connection(struct svc_rqst *rqst,
-				struct nfsd4_session *session, u32 req)
+		struct nfsd4_session *session, u32 req, struct nfsd4_conn **conn)
 {
 	struct nfs4_client *clp = session->se_client;
 	struct svc_xprt *xpt = rqst->rq_xprt;
@@ -3593,6 +3593,8 @@ static __be32 nfsd4_match_existing_connection(struct svc_rqst *rqst,
 	else
 		status = nfserr_inval;
 	spin_unlock(&clp->cl_lock);
+	if (status == nfs_ok && conn)
+		*conn = c;
 	return status;
 }
 
@@ -3617,8 +3619,16 @@ __be32 nfsd4_bind_conn_to_session(struct svc_rqst *rqstp,
 	status = nfserr_wrong_cred;
 	if (!nfsd4_mach_creds_match(session->se_client, rqstp))
 		goto out;
-	status = nfsd4_match_existing_connection(rqstp, session, bcts->dir);
-	if (status == nfs_ok || status == nfserr_inval)
+	status = nfsd4_match_existing_connection(rqstp, session,
+			bcts->dir, &conn);
+	if (status == nfs_ok) {
+		if (bcts->dir == NFS4_CDFC4_FORE_OR_BOTH ||
+				bcts->dir == NFS4_CDFC4_BACK)
+			conn->cn_flags |= NFS4_CDFC4_BACK;
+		nfsd4_probe_callback(session->se_client);
+		goto out;
+	}
+	if (status == nfserr_inval)
 		goto out;
 	status = nfsd4_map_bcts_dir(&bcts->dir);
 	if (status)