nfsd41: use SEQ4_STATUS_BACKCHANNEL_FAULT when cb_sequence is invalid

Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index e8c2a3e..b51ad43 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1945,8 +1945,14 @@
 
 		nfsd4_get_session(cstate->session);
 		atomic_inc(&clp->cl_refcount);
-		if (clp->cl_cb_state == NFSD4_CB_DOWN)
+		switch (clp->cl_cb_state) {
+		case NFSD4_CB_DOWN:
 			seq->status_flags |= SEQ4_STATUS_CB_PATH_DOWN;
+			break;
+		case NFSD4_CB_FAULT:
+			seq->status_flags |= SEQ4_STATUS_BACKCHANNEL_FAULT;
+			break;
+		}
 	}
 	kfree(conn);
 	spin_unlock(&client_lock);