tipc: interrupt link synchronization when a link goes down

When we introduced the new link failover/synch mechanism
in commit 6e498158a8
("tipc: move link synch and failover to link aggregation level"),
we missed the case when the non-tunnel link goes down during the link
synchronization period. In this case the tunnel link will remain in
state LINK_SYNCHING, something leading to unpredictable behavior when
the failover procedure is initiated.

In this commit, we ensure that the node and remaining link goes
back to regular communication state (SELF_UP_PEER_UP/LINK_ESTABLISHED)
when one of the parallel links goes down. We also ensure that we don't
re-enter synch mode if subsequent SYNCH packets arrive on the remaining
link.

Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jon Paul Maloy 2015-08-20 02:12:55 -04:00 committed by David S. Miller
parent 17b2063077
commit 5ae2f8e685
2 changed files with 9 additions and 4 deletions

View File

@ -351,11 +351,11 @@ int tipc_link_fsm_evt(struct tipc_link *l, int evt)
l->state = LINK_RESET;
break;
case LINK_ESTABLISH_EVT:
case LINK_SYNCH_END_EVT:
break;
case LINK_SYNCH_BEGIN_EVT:
l->state = LINK_SYNCHING;
break;
case LINK_SYNCH_END_EVT:
case LINK_FAILOVER_BEGIN_EVT:
case LINK_FAILOVER_END_EVT:
default:

View File

@ -423,6 +423,8 @@ static void __tipc_node_link_down(struct tipc_node *n, int *bearer_id,
/* There is still a working link => initiate failover */
tnl = node_active_link(n, 0);
tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
n->sync_point = tnl->rcv_nxt + (U16_MAX / 2 - 1);
tipc_link_tnl_prepare(l, tnl, FAILOVER_MSG, xmitq);
tipc_link_reset(l);
@ -1140,6 +1142,10 @@ static bool tipc_node_check_state(struct tipc_node *n, struct sk_buff *skb,
return true;
}
/* No synching needed if only one link */
if (!pl || !tipc_link_is_up(pl))
return true;
/* Initiate or update synch mode if applicable */
if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG)) {
syncpt = iseqno + exp_pkts - 1;
@ -1158,9 +1164,8 @@ static bool tipc_node_check_state(struct tipc_node *n, struct sk_buff *skb,
/* Open tunnel link when parallel link reaches synch point */
if ((n->state == NODE_SYNCHING) && tipc_link_is_synching(l)) {
if (pl)
dlv_nxt = mod(pl->rcv_nxt - skb_queue_len(pl->inputq));
if (!pl || more(dlv_nxt, n->sync_point)) {
dlv_nxt = pl->rcv_nxt - mod(skb_queue_len(pl->inputq));
if (more(dlv_nxt, n->sync_point)) {
tipc_link_fsm_evt(l, LINK_SYNCH_END_EVT);
tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
return true;