bridge: use rx_handler_data pointer to store net_bridge_port pointer

Register net_bridge_port pointer as rx_handler data pointer. As br_port is
removed from struct net_device, another netdev priv_flag is added to indicate
the device serves as a bridge port. Also rcuized pointers are now correctly
dereferenced in br_fdb.c and in netfilter parts.

Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_notify.c b/net/bridge/br_notify.c
index 717e1fd..404d4e1 100644
--- a/net/bridge/br_notify.c
+++ b/net/bridge/br_notify.c
@@ -32,14 +32,15 @@
 static int br_device_event(struct notifier_block *unused, unsigned long event, void *ptr)
 {
 	struct net_device *dev = ptr;
-	struct net_bridge_port *p = dev->br_port;
+	struct net_bridge_port *p = br_port_get(dev);
 	struct net_bridge *br;
 	int err;
 
 	/* not a port of a bridge */
-	if (p == NULL)
+	if (!br_port_exists(dev))
 		return NOTIFY_DONE;
 
+	p = br_port_get(dev);
 	br = p->br;
 
 	switch (event) {