drbd_send_ack
extern int drbd_send_ack(struct drbd_peer_device *, enum drbd_packet,
err = drbd_send_ack(peer_device, P_RS_WRITE_ACK, peer_req);
err = drbd_send_ack(peer_device, P_NEG_ACK, peer_req);
err = drbd_send_ack(peer_device, pcmd, peer_req);
err = drbd_send_ack(peer_device, P_NEG_ACK, peer_req);
err = drbd_send_ack(peer_device, ack, peer_req);
drbd_send_ack(peer_device, P_RECV_ACK, peer_req);
err = drbd_send_ack(peer_device, P_NEG_DREPLY, peer_req);
err = drbd_send_ack(peer_device, P_RS_CANCEL, peer_req);
err = drbd_send_ack(peer_device, P_NEG_RS_DREPLY, peer_req);
err = drbd_send_ack(peer_device, P_RS_IS_IN_SYNC, peer_req);
err = drbd_send_ack(peer_device, P_NEG_RS_DREPLY, peer_req);