Commit 5ae2f8e6 authored by Jon Paul Maloy's avatar Jon Paul Maloy Committed by David S. Miller
Browse files

tipc: interrupt link synchronization when a link goes down 



When we introduced the new link failover/synch mechanism
in commit 6e498158
("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: default avatarYing Xue <ying.xue@windriver.com>
Signed-off-by: default avatarJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 17b20630

net/tipc/link.c

+1 −1
Original line number Diff line number Diff line
@@ -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:

net/tipc/node.c

+8 −3
Original line number Diff line number Diff line
@@ -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;

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