CEPH_CON_S_CLOSED
if (con->state == CEPH_CON_S_CLOSED) {
con->state == CEPH_CON_S_CLOSED);
con->state = CEPH_CON_S_CLOSED;
if (con->state == CEPH_CON_S_CLOSED) {
con->state = CEPH_CON_S_CLOSED;
WARN_ON(con->state != CEPH_CON_S_CLOSED);
con->state = CEPH_CON_S_CLOSED;
con->state = CEPH_CON_S_CLOSED;