CEPH_MSGR_TAG_SEQ
con->v1.in_tag == CEPH_MSGR_TAG_SEQ) {
con->v1.in_tag = CEPH_MSGR_TAG_SEQ;
case CEPH_MSGR_TAG_SEQ:
if (con->v1.in_reply.tag == CEPH_MSGR_TAG_SEQ) {