tipc: remove joining group member from congested list

When we receive a JOIN message from a peer member, the message may
contain an advertised window value ADV_IDLE that permits removing the
member in question from the tipc_group::congested list. However, since
the removal has been made conditional on that the advertised window is
*not* ADV_IDLE, we miss this case. This has the effect that a sender
sometimes may enter a state of permanent, false, broadcast congestion.

We fix this by unconditinally removing the member from the congested
list before calling tipc_member_update(), which might potentially sort
it into the list again.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/tipc/group.c

@@ -689,10 +689,8 @@ void tipc_group_proto_rcv(struct tipc_group *grp, bool *usr_wakeup,
 			msg_set_grp_bc_seqno(ehdr, m->bc_syncpt);
 			__skb_queue_tail(inputq, m->event_msg);
 		}
-		if (m->window < ADV_IDLE)
+		list_del_init(&m->congested);
-			tipc_group_update_member(m, 0);
+		tipc_group_update_member(m, 0);
-		else
-			list_del_init(&m->congested);
 		return;
 	case GRP_LEAVE_MSG:
 		if (!m)