ceph: check the sesion state and return false in case it is closed

If the session is already in closed state, we should skip it.
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

fs/ceph/mds_client.c

@@ -4303,6 +4303,7 @@ bool check_session_state(struct ceph_mds_session *s)
 	}
 	if (s->s_state == CEPH_MDS_SESSION_NEW ||
 	    s->s_state == CEPH_MDS_SESSION_RESTARTING ||
+	    s->s_state == CEPH_MDS_SESSION_CLOSED ||
 	    s->s_state == CEPH_MDS_SESSION_REJECTED)
 		/* this mds is failed or recovering, just wait */
 		return false;