macvlan: use rx_handler_data pointer to store macvlan_port pointer V2

Register macvlan_port pointer as rx_handler data pointer. As macvlan_port is
removed from struct net_device, another netdev priv_flag is added to indicate
the device serves as a macvlan port.

Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 16 insertions, 12 deletions

diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index 87a3bf69c4a3..e096875aa055 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -40,6 +40,11 @@ struct macvlan_port {
         struct rcu_head         rcu;
 };
 
+#define macvlan_port_get_rcu(dev) \
+        ((struct macvlan_port *) rcu_dereference(dev->rx_handler_data))
+#define macvlan_port_get(dev) ((struct macvlan_port *) dev->rx_handler_data)
+#define macvlan_port_exists(dev) (dev->priv_flags & IFF_MACVLAN_PORT)
+
 static struct macvlan_dev *macvlan_hash_lookup(const struct macvlan_port *port,
                                                const unsigned char *addr)
 {
@@ -155,7 +160,7 @@ static struct sk_buff *macvlan_handle_frame(struct sk_buff *skb)
         struct net_device *dev;
         unsigned int len;
 
-        port = rcu_dereference(skb->dev->macvlan_port);
+        port = macvlan_port_get_rcu(skb->dev);
         if (is_multicast_ether_addr(eth->h_dest)) {
                 src = macvlan_hash_lookup(port, eth->h_source);
                 if (!src)
@@ -530,14 +535,12 @@ static int macvlan_port_create(struct net_device *dev)
         INIT_LIST_HEAD(&port->vlans);
         for (i = 0; i < MACVLAN_HASH_SIZE; i++)
                 INIT_HLIST_HEAD(&port->vlan_hash[i]);
-        rcu_assign_pointer(dev->macvlan_port, port);
 
-        err = netdev_rx_handler_register(dev, macvlan_handle_frame, NULL);
-        if (err) {
-                rcu_assign_pointer(dev->macvlan_port, NULL);
+        err = netdev_rx_handler_register(dev, macvlan_handle_frame, port);
+        if (err)
                 kfree(port);
-        }
 
+        dev->priv_flags |= IFF_MACVLAN_PORT;
         return err;
 }
 
@@ -551,10 +554,10 @@ static void macvlan_port_rcu_free(struct rcu_head *head)
 
 static void macvlan_port_destroy(struct net_device *dev)
 {
-        struct macvlan_port *port = dev->macvlan_port;
+        struct macvlan_port *port = macvlan_port_get(dev);
 
+        dev->priv_flags &= ~IFF_MACVLAN_PORT;
         netdev_rx_handler_unregister(dev);
-        rcu_assign_pointer(dev->macvlan_port, NULL);
         call_rcu(&port->rcu, macvlan_port_rcu_free);
 }
 
@@ -633,12 +636,12 @@ int macvlan_common_newlink(struct net *src_net, struct net_device *dev,
         if (!tb[IFLA_ADDRESS])
                 random_ether_addr(dev->dev_addr);
 
-        if (lowerdev->macvlan_port == NULL) {
+        if (!macvlan_port_exists(lowerdev)) {
                 err = macvlan_port_create(lowerdev);
                 if (err < 0)
                         return err;
         }
-        port = lowerdev->macvlan_port;
+        port = macvlan_port_get(lowerdev);
 
         vlan->lowerdev = lowerdev;
         vlan->dev      = dev;
@@ -748,10 +751,11 @@ static int macvlan_device_event(struct notifier_block *unused,
         struct macvlan_dev *vlan, *next;
         struct macvlan_port *port;
 
-        port = dev->macvlan_port;
-        if (port == NULL)
+        if (!macvlan_port_exists(dev))
                 return NOTIFY_DONE;
 
+        port = macvlan_port_get(dev);
+
         switch (event) {
         case NETDEV_CHANGE:
                 list_for_each_entry(vlan, &port->vlans, list)