tipc: eliminate checking netns if node established

Currently, we scan over all network namespaces at each received
discovery message in order to check if the sending peer might be
present in a host local namespaces.

This is unnecessary since we can assume that a peer will not change its
location during an established session.

We now improve the condition for this testing so that we don't perform
any redundant scans.

Fixes: f73b128 ("tipc: improve throughput between nodes in netns")
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/tipc/node.c

@@ -472,10 +472,6 @@ static struct tipc_node *tipc_node_create(struct net *net, u32 addr,
 				 tipc_bc_sndlink(net),
 				 &n->bc_entry.link)) {
 		pr_warn("Broadcast rcv link creation failed, no memory\n");
-		if (n->peer_net) {
-			n->peer_net = NULL;
-			n->peer_hash_mix = 0;
-		}
 		kfree(n);
 		n = NULL;
 		goto exit;
@@ -1073,6 +1069,9 @@ void tipc_node_check_dest(struct net *net, u32 addr,
 	if (sign_match && addr_match && link_up) {
 		/* All is fine. Do nothing. */
 		reset = false;
+		/* Peer node is not a container/local namespace */
+		if (!n->peer_hash_mix)
+			n->peer_hash_mix = hash_mixes;
 	} else if (sign_match && addr_match && !link_up) {
 		/* Respond. The link will come up in due time */
 		*respond = true;
@@ -1398,11 +1397,8 @@ static void node_lost_contact(struct tipc_node *n,
 
 	/* Notify publications from this node */
 	n->action_flags |= TIPC_NOTIFY_NODE_DOWN;
-
-	if (n->peer_net) {
-		n->peer_net = NULL;
-		n->peer_hash_mix = 0;
-	}
+	n->peer_net = NULL;
+	n->peer_hash_mix = 0;
 	/* Notify sockets connected to node */
 	list_for_each_entry_safe(conn, safe, conns, list) {
 		skb = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE, TIPC_CONN_MSG,