drbd: Runtime changeable wire protocol
The wire protocol is no longer a property that is negotiated
between the two peers. It is now expressed with two bits
(DP_SEND_WRITE_ACK and DP_SEND_RECEIVE_ACK) in each data
packet. Therefore the primary node is free to change the
wire protocol at any time without disconnect/reconnect.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index fd38594..295707e 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -1697,7 +1697,7 @@
sector_t sector = peer_req->i.sector;
int err = 0, pcmd;
- if (mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C) {
+ if (peer_req->flags & EE_SEND_WRITE_ACK) {
if (likely((peer_req->flags & EE_WAS_ERROR) == 0)) {
pcmd = (mdev->state.conn >= C_SYNC_SOURCE &&
mdev->state.conn <= C_PAUSED_SYNC_T &&
@@ -2074,20 +2074,28 @@
list_add(&peer_req->w.list, &mdev->active_ee);
spin_unlock_irq(&mdev->tconn->req_lock);
- switch (mdev->tconn->net_conf->wire_protocol) {
- case DRBD_PROT_C:
+ if (mdev->tconn->agreed_pro_version < 100) {
+ switch (mdev->tconn->net_conf->wire_protocol) {
+ case DRBD_PROT_C:
+ dp_flags |= DP_SEND_WRITE_ACK;
+ break;
+ case DRBD_PROT_B:
+ dp_flags |= DP_SEND_RECEIVE_ACK;
+ break;
+ }
+ }
+
+ if (dp_flags & DP_SEND_WRITE_ACK) {
+ peer_req->flags |= EE_SEND_WRITE_ACK;
inc_unacked(mdev);
/* corresponding dec_unacked() in e_end_block()
* respective _drbd_clear_done_ee */
- break;
- case DRBD_PROT_B:
+ }
+
+ if (dp_flags & DP_SEND_RECEIVE_ACK) {
/* I really don't like it that the receiver thread
* sends on the msock, but anyways */
drbd_send_ack(mdev, P_RECV_ACK, peer_req);
- break;
- case DRBD_PROT_A:
- /* nothing to do */
- break;
}
if (mdev->state.pdsk < D_INCONSISTENT) {
@@ -2932,7 +2940,7 @@
if (cf & CF_DRY_RUN)
set_bit(CONN_DRY_RUN, &tconn->flags);
- if (p_proto != tconn->net_conf->wire_protocol) {
+ if (p_proto != tconn->net_conf->wire_protocol && tconn->agreed_pro_version < 100) {
conn_err(tconn, "incompatible communication protocols\n");
goto disconnect;
}
@@ -4622,23 +4630,18 @@
}
switch (pi->cmd) {
case P_RS_WRITE_ACK:
- D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C);
what = WRITE_ACKED_BY_PEER_AND_SIS;
break;
case P_WRITE_ACK:
- D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C);
what = WRITE_ACKED_BY_PEER;
break;
case P_RECV_ACK:
- D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_B);
what = RECV_ACKED_BY_PEER;
break;
case P_DISCARD_WRITE:
- D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C);
what = DISCARD_WRITE;
break;
case P_RETRY_WRITE:
- D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C);
what = POSTPONE_WRITE;
break;
default:
@@ -4656,8 +4659,6 @@
struct p_block_ack *p = pi->data;
sector_t sector = be64_to_cpu(p->sector);
int size = be32_to_cpu(p->blksize);
- bool missing_ok = tconn->net_conf->wire_protocol == DRBD_PROT_A ||
- tconn->net_conf->wire_protocol == DRBD_PROT_B;
int err;
mdev = vnr_to_mdev(tconn, pi->vnr);
@@ -4674,15 +4675,13 @@
err = validate_req_change_req_state(mdev, p->block_id, sector,
&mdev->write_requests, __func__,
- NEG_ACKED, missing_ok);
+ NEG_ACKED, true);
if (err) {
/* Protocol A has no P_WRITE_ACKs, but has P_NEG_ACKs.
The master bio might already be completed, therefore the
request is no longer in the collision hash. */
/* In Protocol B we might already have got a P_RECV_ACK
but then get a P_NEG_ACK afterwards. */
- if (!missing_ok)
- return err;
drbd_set_out_of_sync(mdev, sector, size);
}
return 0;