net: bridge: Add support for calling FDB external learning under rcu

This is done as a preparation to moving the switchdev notifier chain
to be atomic. The FDB external learning should be called under rtnl
or rcu.

Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 0 deletions

diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 7f439927a66d..a122684b6a41 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -284,6 +284,12 @@ static inline struct net_bridge_port *br_port_get_rtnl(const struct net_device *
 		rtnl_dereference(dev->rx_handler_data) : NULL;
 }
 
+static inline struct net_bridge_port *br_port_get_rtnl_rcu(const struct net_device *dev)
+{
+	return br_port_exists(dev) ?
+		rcu_dereference_rtnl(dev->rx_handler_data) : NULL;
+}
+
 struct net_bridge {
 	spinlock_t			lock;
 	spinlock_t			hash_lock;