From c140eb166d681f66bd7e99fb121357db1a503e7f Mon Sep 17 00:00:00 2001 From: LUU Duc Canh Date: Wed, 26 Sep 2018 21:00:54 +0200 Subject: tipc: fix failover problem We see the following scenario: 1) Link endpoint B on node 1 discovers that its peer endpoint is gone. Since there is a second working link, failover procedure is started. 2) Link endpoint A on node 1 sends a FAILOVER message to peer endpoint A on node 2. The node item 1->2 goes to state FAILINGOVER. 3) Linke endpoint A/2 receives the failover, and is supposed to take down its parallell link endpoint B/2, while producing a FAILOVER message to send back to A/1. 4) However, B/2 has already been deleted, so no FAILOVER message can created. 5) Node 1->2 remains in state FAILINGOVER forever, refusing to receive any messages that can bring B/1 up again. We are left with a non- redundant link between node 1 and 2. We fix this with letting endpoint A/2 build a dummy FAILOVER message to send to back to A/1, so that the situation can be resolved. Signed-off-by: LUU Duc Canh Signed-off-by: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/link.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'net/tipc/link.h') diff --git a/net/tipc/link.h b/net/tipc/link.h index 7bc494a33fdf..90488c538a4e 100644 --- a/net/tipc/link.h +++ b/net/tipc/link.h @@ -88,6 +88,8 @@ bool tipc_link_bc_create(struct net *net, u32 ownnode, u32 peer, struct tipc_link **link); void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl, int mtyp, struct sk_buff_head *xmitq); +void tipc_link_create_dummy_tnl_msg(struct tipc_link *tnl, + struct sk_buff_head *xmitq); void tipc_link_build_reset_msg(struct tipc_link *l, struct sk_buff_head *xmitq); int tipc_link_fsm_evt(struct tipc_link *l, int evt); bool tipc_link_is_up(struct tipc_link *l); @@ -107,6 +109,7 @@ u16 tipc_link_rcv_nxt(struct tipc_link *l); u16 tipc_link_acked(struct tipc_link *l); u32 tipc_link_id(struct tipc_link *l); char *tipc_link_name(struct tipc_link *l); +u32 tipc_link_state(struct tipc_link *l); char tipc_link_plane(struct tipc_link *l); int tipc_link_prio(struct tipc_link *l); int tipc_link_window(struct tipc_link *l); -- cgit v1.2.3