openvswitch: fix flow stats accounting when node 0 is not possible

On a system with only node 1 as possible, all statistics is going to be
accounted on node 0 as it will have a single writer.

However, when getting and clearing the statistics, node 0 is not going
to be considered, as it's not a possible node.

Tested that statistics are not zero on a system with only node 1
possible. Also compile-tested with CONFIG_NUMA off.
Signed-off-by: NThadeu Lima de Souza Cascardo <cascardo@redhat.com>
Acked-by: NPravin B Shelar <pshelar@ovn.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/openvswitch/flow.c

@@ -142,7 +142,8 @@ void ovs_flow_stats_get(const struct sw_flow *flow,
 	*tcp_flags = 0;
 	memset(ovs_stats, 0, sizeof(*ovs_stats));
 
-	for_each_node(node) {
+	/* We open code this to make sure node 0 is always considered */
+	for (node = 0; node < MAX_NUMNODES; node = next_node(node, node_possible_map)) {
 		struct flow_stats *stats = rcu_dereference_ovsl(flow->stats[node]);
 
 		if (stats) {
@@ -165,7 +166,8 @@ void ovs_flow_stats_clear(struct sw_flow *flow)
 {
 	int node;
 
-	for_each_node(node) {
+	/* We open code this to make sure node 0 is always considered */
+	for (node = 0; node < MAX_NUMNODES; node = next_node(node, node_possible_map)) {
 		struct flow_stats *stats = ovsl_dereference(flow->stats[node]);
 
 		if (stats) {

net/openvswitch/flow_table.c

@@ -148,8 +148,9 @@ static void flow_free(struct sw_flow *flow)
 		kfree(flow->id.unmasked_key);
 	if (flow->sf_acts)
 		ovs_nla_free_flow_actions((struct sw_flow_actions __force *)flow->sf_acts);
-	for_each_node(node)
-		if (flow->stats[node])
+	/* We open code this to make sure node 0 is always considered */
+	for (node = 0; node < MAX_NUMNODES; node = next_node(node, node_possible_map))
+		if (node != 0 && flow->stats[node])
 			kmem_cache_free(flow_stats_cache,
 					(struct flow_stats __force *)flow->stats[node]);
 	kmem_cache_free(flow_cache, flow);