batman-adv: Make bat_priv->primary_if an rcu protected pointer

[pandora-kernel.git] / net / batman-adv / hard-interface.c

diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c
index b3058e4..3e888f1 100644 (file)
--- a/net/batman-adv/hard-interface.c
+++ b/net/batman-adv/hard-interface.c
@@ -110,47 +110,60 @@ out:
        return hard_iface;
 }
 
-static void update_primary_addr(struct bat_priv *bat_priv)
+static void primary_if_update_addr(struct bat_priv *bat_priv)
 {
        struct vis_packet *vis_packet;
+       struct hard_iface *primary_if;
+
+       primary_if = primary_if_get_selected(bat_priv);
+       if (!primary_if)
+               goto out;
 
        vis_packet = (struct vis_packet *)
                                bat_priv->my_vis_info->skb_packet->data;
-       memcpy(vis_packet->vis_orig,
-              bat_priv->primary_if->net_dev->dev_addr, ETH_ALEN);
+       memcpy(vis_packet->vis_orig, primary_if->net_dev->dev_addr, ETH_ALEN);
        memcpy(vis_packet->sender_orig,
-              bat_priv->primary_if->net_dev->dev_addr, ETH_ALEN);
+              primary_if->net_dev->dev_addr, ETH_ALEN);
+
+out:
+       if (primary_if)
+               hardif_free_ref(primary_if);
 }
 
-static void set_primary_if(struct bat_priv *bat_priv,
-                          struct hard_iface *hard_iface)
+static void primary_if_select(struct bat_priv *bat_priv,
+                             struct hard_iface *new_hard_iface)
 {
+       struct hard_iface *curr_hard_iface;
        struct batman_packet *batman_packet;
-       struct hard_iface *old_if;
 
-       if (hard_iface && !atomic_inc_not_zero(&hard_iface->refcount))
-               hard_iface = NULL;
+       spin_lock_bh(&hardif_list_lock);
 
-       old_if = bat_priv->primary_if;
-       bat_priv->primary_if = hard_iface;
+       if (new_hard_iface && !atomic_inc_not_zero(&new_hard_iface->refcount))
+               new_hard_iface = NULL;
 
-       if (old_if)
-               hardif_free_ref(old_if);
+       curr_hard_iface = bat_priv->primary_if;
+       rcu_assign_pointer(bat_priv->primary_if, new_hard_iface);
 
-       if (!bat_priv->primary_if)
-               return;
+       if (curr_hard_iface)
+               hardif_free_ref(curr_hard_iface);
 
-       batman_packet = (struct batman_packet *)(hard_iface->packet_buff);
+       if (!new_hard_iface)
+               goto out;
+
+       batman_packet = (struct batman_packet *)(new_hard_iface->packet_buff);
        batman_packet->flags = PRIMARIES_FIRST_HOP;
        batman_packet->ttl = TTL;
 
-       update_primary_addr(bat_priv);
+       primary_if_update_addr(bat_priv);
 
        /***
         * hacky trick to make sure that we send the HNA information via
         * our new primary interface
         */
        atomic_set(&bat_priv->hna_local_changed, 1);
+
+out:
+       spin_unlock_bh(&hardif_list_lock);
 }
 
 static bool hardif_is_iface_up(struct hard_iface *hard_iface)
@@ -236,9 +249,10 @@ void update_min_mtu(struct net_device *soft_iface)
 static void hardif_activate_interface(struct hard_iface *hard_iface)
 {
        struct bat_priv *bat_priv;
+       struct hard_iface *primary_if = NULL;
 
        if (hard_iface->if_status != IF_INACTIVE)
-               return;
+               goto out;
 
        bat_priv = netdev_priv(hard_iface->soft_iface);
 
@@ -249,14 +263,18 @@ static void hardif_activate_interface(struct hard_iface *hard_iface)
         * the first active interface becomes our primary interface or
         * the next active interface after the old primay interface was removed
         */
-       if (!bat_priv->primary_if)
-               set_primary_if(bat_priv, hard_iface);
+       primary_if = primary_if_get_selected(bat_priv);
+       if (!primary_if)
+               primary_if_select(bat_priv, hard_iface);
 
        bat_info(hard_iface->soft_iface, "Interface activated: %s\n",
                 hard_iface->net_dev->name);
 
        update_min_mtu(hard_iface->soft_iface);
-       return;
+
+out:
+       if (primary_if)
+               hardif_free_ref(primary_if);
 }
 
 static void hardif_deactivate_interface(struct hard_iface *hard_iface)
@@ -386,12 +404,13 @@ err:
 void hardif_disable_interface(struct hard_iface *hard_iface)
 {
        struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
+       struct hard_iface *primary_if = NULL;
 
        if (hard_iface->if_status == IF_ACTIVE)
                hardif_deactivate_interface(hard_iface);
 
        if (hard_iface->if_status != IF_INACTIVE)
-               return;
+               goto out;
 
        bat_info(hard_iface->soft_iface, "Removing interface: %s\n",
                 hard_iface->net_dev->name);
@@ -400,11 +419,12 @@ void hardif_disable_interface(struct hard_iface *hard_iface)
        bat_priv->num_ifaces--;
        orig_hash_del_if(hard_iface, bat_priv->num_ifaces);
 
-       if (hard_iface == bat_priv->primary_if) {
+       primary_if = primary_if_get_selected(bat_priv);
+       if (hard_iface == primary_if) {
                struct hard_iface *new_if;
 
                new_if = hardif_get_active(hard_iface->soft_iface);
-               set_primary_if(bat_priv, new_if);
+               primary_if_select(bat_priv, new_if);
 
                if (new_if)
                        hardif_free_ref(new_if);
@@ -425,6 +445,10 @@ void hardif_disable_interface(struct hard_iface *hard_iface)
 
        hard_iface->soft_iface = NULL;
        hardif_free_ref(hard_iface);
+
+out:
+       if (primary_if)
+               hardif_free_ref(primary_if);
 }
 
 static struct hard_iface *hardif_add_interface(struct net_device *net_dev)
@@ -514,6 +538,7 @@ static int hard_if_event(struct notifier_block *this,
 {
        struct net_device *net_dev = (struct net_device *)ptr;
        struct hard_iface *hard_iface = hardif_get_by_netdev(net_dev);
+       struct hard_iface *primary_if = NULL;
        struct bat_priv *bat_priv;
 
        if (!hard_iface && event == NETDEV_REGISTER)
@@ -549,8 +574,12 @@ static int hard_if_event(struct notifier_block *this,
                update_mac_addresses(hard_iface);
 
                bat_priv = netdev_priv(hard_iface->soft_iface);
-               if (hard_iface == bat_priv->primary_if)
-                       update_primary_addr(bat_priv);
+               primary_if = primary_if_get_selected(bat_priv);
+               if (!primary_if)
+                       goto hardif_put;
+
+               if (hard_iface == primary_if)
+                       primary_if_update_addr(bat_priv);
                break;
        default:
                break;
@@ -559,6 +588,8 @@ static int hard_if_event(struct notifier_block *this,
 hardif_put:
        hardif_free_ref(hard_iface);
 out:
+       if (primary_if)
+               hardif_free_ref(primary_if);
        return NOTIFY_DONE;
 }