_req_mod
_req_mod(req, BARRIER_ACKED, peer_device);
_req_mod(req, what, peer_device);
_req_mod(req, ABORT_DISK_IO, NULL);
_req_mod(req, QUEUE_AS_DRBD_BARRIER, peer_device);
_req_mod(req, TO_BE_SENT, peer_device);
_req_mod(req, QUEUE_FOR_NET_WRITE, peer_device);
_req_mod(req, QUEUE_FOR_SEND_OOS, peer_device);
_req_mod(req, TO_BE_SENT, peer_device);
_req_mod(req, QUEUE_FOR_NET_READ, peer_device);
_req_mod(req, TO_BE_SUBMITTED, NULL);