bridge: Simplify interface for ATM LANE

This patch changes FDB entry check for ATM LANE bridge integration.
There's no point in holding a FDB entry around SKB building.

br_fdb_get()/br_fdb_put() pair are changed into single br_fdb_test_addr()
hook that checks if the addr has FDB entry pointing to other port
to the one the request arrived on.

FDB entry refcounting is removed as it's not used anywhere else.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 21 insertions, 22 deletions

diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
index cb3e97b..57bf05c 100644
--- a/net/bridge/br_fdb.c
+++ b/net/bridge/br_fdb.c
@@ -71,10 +71,17 @@ static inline int br_mac_hash(const unsigned char *mac)
 	return jhash_1word(key, fdb_salt) & (BR_HASH_SIZE - 1);
 }
 
+static void fdb_rcu_free(struct rcu_head *head)
+{
+	struct net_bridge_fdb_entry *ent
+		= container_of(head, struct net_bridge_fdb_entry, rcu);
+	kmem_cache_free(br_fdb_cache, ent);
+}
+
 static inline void fdb_delete(struct net_bridge_fdb_entry *f)
 {
 	hlist_del_rcu(&f->hlist);
-	br_fdb_put(f);
+	call_rcu(&f->rcu, fdb_rcu_free);
 }
 
 void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
@@ -226,33 +233,26 @@ struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,
 	return NULL;
 }
 
-/* Interface used by ATM hook that keeps a ref count */
-struct net_bridge_fdb_entry *br_fdb_get(struct net_bridge *br,
-					unsigned char *addr)
+#if defined(CONFIG_ATM_LANE) || defined(CONFIG_ATM_LANE_MODULE)
+/* Interface used by ATM LANE hook to test
+ * if an addr is on some other bridge port */
+int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
 {
 	struct net_bridge_fdb_entry *fdb;
+	int ret;
+
+	if (!dev->br_port)
+		return 0;
 
 	rcu_read_lock();
-	fdb = __br_fdb_get(br, addr);
-	if (fdb && !atomic_inc_not_zero(&fdb->use_count))
-		fdb = NULL;
+	fdb = __br_fdb_get(dev->br_port->br, addr);
+	ret = fdb && fdb->dst->dev != dev &&
+		fdb->dst->state == BR_STATE_FORWARDING;
 	rcu_read_unlock();
-	return fdb;
-}
-
-static void fdb_rcu_free(struct rcu_head *head)
-{
-	struct net_bridge_fdb_entry *ent
-		= container_of(head, struct net_bridge_fdb_entry, rcu);
-	kmem_cache_free(br_fdb_cache, ent);
-}
 
-/* Set entry up for deletion with RCU  */
-void br_fdb_put(struct net_bridge_fdb_entry *ent)
-{
-	if (atomic_dec_and_test(&ent->use_count))
-		call_rcu(&ent->rcu, fdb_rcu_free);
+	return ret;
 }
+#endif /* CONFIG_ATM_LANE */
 
 /*
  * Fill buffer with forwarding table records in
@@ -326,7 +326,6 @@ static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head,
 	fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
 	if (fdb) {
 		memcpy(fdb->addr.addr, addr, ETH_ALEN);
-		atomic_set(&fdb->use_count, 1);
 		hlist_add_head_rcu(&fdb->hlist, head);
 
 		fdb->dst = source;