From 5ae2f8e6857968d6dddbd3879ed0a32b860e02d1 Mon Sep 17 00:00:00 2001 From: Jon Paul Maloy Date: Thu, 20 Aug 2015 02:12:55 -0400 Subject: [PATCH] tipc: interrupt link synchronization when a link goes down When we introduced the new link failover/synch mechanism in commit 6e498158a827fd515b514842e9a06bdf0f75ab86 ("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 Signed-off-by: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/link.c | 2 +- net/tipc/node.c | 11 ++++++++--- 2 files changed, 9 insertions(+), 4 deletions(-) diff --git a/net/tipc/link.c b/net/tipc/link.c index f067e54..7058c86 100644 --- a/net/tipc/link.c +++ b/net/tipc/link.c @@ -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: diff --git a/net/tipc/node.c b/net/tipc/node.c index 004834b..937cc61 100644 --- a/net/tipc/node.c +++ b/net/tipc/node.c @@ -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; -- 2.7.4