nfsd: move nfsd4_cstate_assign_replay() earlier in open handling.

Rather than taking the rp_mutex (via nfsd4_cstate_assign_replay) in
nfsd4_cleanup_open_state() (which seems counter-intuitive), take it and
assign rp_owner as soon as possible - in nfsd4_process_open1().

This will support a future change when nfsd4_cstate_assign_replay() might
fail.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

fs/nfsd/nfs4state.c

@@ -5346,6 +5346,7 @@ nfsd4_process_open1(struct nfsd4_compound_state *cstate,
 	open->op_openowner = oo;
 	if (!oo)
 		return nfserr_jukebox;
+	nfsd4_cstate_assign_replay(cstate, &oo->oo_owner);
 	status = nfsd4_check_seqid(cstate, &oo->oo_owner, open->op_seqid);
 	if (status)
 		return status;
@@ -6120,12 +6121,8 @@ nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nf
 void nfsd4_cleanup_open_state(struct nfsd4_compound_state *cstate,
 			      struct nfsd4_open *open)
 {
-	if (open->op_openowner) {
-		struct nfs4_stateowner *so = &open->op_openowner->oo_owner;
-
-		nfsd4_cstate_assign_replay(cstate, so);
-		nfs4_put_stateowner(so);
-	}
+	if (open->op_openowner)
+		nfs4_put_stateowner(&open->op_openowner->oo_owner);
 	if (open->op_file)
 		kmem_cache_free(file_slab, open->op_file);
 	if (open->op_stp)