batman-adv: Move bonding / iface alternating router search to own functions

This decreases the size of find_router() by outsourcing the router
search for the bonding and interface alternating modes to their own sub
functions. This shall make it easier to keep track of the correct
refcounting later.

Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>

diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c
index c172f5d..f212abe 100644 (file)
--- a/net/batman-adv/routing.c
+++ b/net/batman-adv/routing.c
@@ -1092,6 +1092,106 @@ out:
        return ret;
 }
 
+/* In the bonding case, send the packets in a round
+ * robin fashion over the remaining interfaces.
+ *
+ * This method rotates the bonding list and increases the
+ * returned router's refcount. */
+static struct neigh_node *find_bond_router(struct orig_node *primary_orig,
+                                          struct hard_iface *recv_if)
+{
+       struct neigh_node *tmp_neigh_node;
+       struct neigh_node *router = NULL, *first_candidate = NULL;
+
+       rcu_read_lock();
+       list_for_each_entry_rcu(tmp_neigh_node, &primary_orig->bond_list,
+                               bonding_list) {
+               if (!first_candidate)
+                       first_candidate = tmp_neigh_node;
+
+               /* recv_if == NULL on the first node. */
+               if (tmp_neigh_node->if_incoming == recv_if)
+                       continue;
+
+               if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
+                       continue;
+
+               router = tmp_neigh_node;
+               break;
+       }
+
+       /* use the first candidate if nothing was found. */
+       if (!router && first_candidate &&
+           atomic_inc_not_zero(&first_candidate->refcount))
+               router = first_candidate;
+
+       if (!router)
+               goto out;
+
+       /* selected should point to the next element
+        * after the current router */
+       spin_lock_bh(&primary_orig->neigh_list_lock);
+       /* this is a list_move(), which unfortunately
+        * does not exist as rcu version */
+       list_del_rcu(&primary_orig->bond_list);
+       list_add_rcu(&primary_orig->bond_list,
+                    &router->bonding_list);
+       spin_unlock_bh(&primary_orig->neigh_list_lock);
+
+out:
+       rcu_read_unlock();
+       return router;
+}
+
+/* Interface Alternating: Use the best of the
+ * remaining candidates which are not using
+ * this interface.
+ *
+ * Increases the returned router's refcount */
+static struct neigh_node *find_ifalter_router(struct orig_node *primary_orig,
+                                             struct hard_iface *recv_if)
+{
+       struct neigh_node *tmp_neigh_node;
+       struct neigh_node *router = NULL, *first_candidate = NULL;
+
+       rcu_read_lock();
+       list_for_each_entry_rcu(tmp_neigh_node, &primary_orig->bond_list,
+                               bonding_list) {
+               if (!first_candidate)
+                       first_candidate = tmp_neigh_node;
+
+               /* recv_if == NULL on the first node. */
+               if (tmp_neigh_node->if_incoming == recv_if)
+                       continue;
+
+               if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
+                       continue;
+
+               /* if we don't have a router yet
+                * or this one is better, choose it. */
+               if ((!router) ||
+                   (tmp_neigh_node->tq_avg > router->tq_avg)) {
+                       /* decrement refcount of
+                        * previously selected router */
+                       if (router)
+                               neigh_node_free_ref(router);
+
+                       router = tmp_neigh_node;
+                       atomic_inc_not_zero(&router->refcount);
+               }
+
+               neigh_node_free_ref(tmp_neigh_node);
+       }
+
+       /* use the first candidate if nothing was found. */
+       if (!router && first_candidate &&
+           atomic_inc_not_zero(&first_candidate->refcount))
+               router = first_candidate;
+
+       rcu_read_unlock();
+       return router;
+}
+
 /* find a suitable router for this originator, and use
  * bonding if possible. increases the found neighbors
  * refcount.*/
@@ -1101,7 +1201,7 @@ struct neigh_node *find_router(struct bat_priv *bat_priv,
 {
        struct orig_node *primary_orig_node;
        struct orig_node *router_orig;
-       struct neigh_node *router, *first_candidate, *tmp_neigh_node;
+       struct neigh_node *router;
        static uint8_t zero_mac[ETH_ALEN] = {0, 0, 0, 0, 0, 0};
        int bonding_enabled;
 
@@ -1157,82 +1257,12 @@ struct neigh_node *find_router(struct bat_priv *bat_priv,
         * in. */
 
        neigh_node_free_ref(router);
-       first_candidate = NULL;
-       router = NULL;
-
-       if (bonding_enabled) {
-               /* in the bonding case, send the packets in a round
-                * robin fashion over the remaining interfaces. */
-
-               list_for_each_entry_rcu(tmp_neigh_node,
-                               &primary_orig_node->bond_list, bonding_list) {
-                       if (!first_candidate)
-                               first_candidate = tmp_neigh_node;
-                       /* recv_if == NULL on the first node. */
-                       if (tmp_neigh_node->if_incoming != recv_if &&
-                           atomic_inc_not_zero(&tmp_neigh_node->refcount)) {
-                               router = tmp_neigh_node;
-                               break;
-                       }
-               }
-
-               /* use the first candidate if nothing was found. */
-               if (!router && first_candidate &&
-                   atomic_inc_not_zero(&first_candidate->refcount))
-                       router = first_candidate;
 
-               if (!router) {
-                       rcu_read_unlock();
-                       return NULL;
-               }
-
-               /* selected should point to the next element
-                * after the current router */
-               spin_lock_bh(&primary_orig_node->neigh_list_lock);
-               /* this is a list_move(), which unfortunately
-                * does not exist as rcu version */
-               list_del_rcu(&primary_orig_node->bond_list);
-               list_add_rcu(&primary_orig_node->bond_list,
-                               &router->bonding_list);
-               spin_unlock_bh(&primary_orig_node->neigh_list_lock);
-
-       } else {
-               /* if bonding is disabled, use the best of the
-                * remaining candidates which are not using
-                * this interface. */
-               list_for_each_entry_rcu(tmp_neigh_node,
-                       &primary_orig_node->bond_list, bonding_list) {
-                       if (!first_candidate)
-                               first_candidate = tmp_neigh_node;
-
-                       /* recv_if == NULL on the first node. */
-                       if (tmp_neigh_node->if_incoming == recv_if)
-                               continue;
-
-                       if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
-                               continue;
-
-                       /* if we don't have a router yet
-                        * or this one is better, choose it. */
-                       if ((!router) ||
-                           (tmp_neigh_node->tq_avg > router->tq_avg)) {
-                               /* decrement refcount of
-                                * previously selected router */
-                               if (router)
-                                       neigh_node_free_ref(router);
-
-                               router = tmp_neigh_node;
-                               atomic_inc_not_zero(&router->refcount);
-                       }
-
-                       neigh_node_free_ref(tmp_neigh_node);
-               }
+       if (bonding_enabled)
+               router = find_bond_router(primary_orig_node, recv_if);
+       else
+               router = find_ifalter_router(primary_orig_node, recv_if);
 
-               /* use the first candidate if nothing was found. */
-               if (!router && first_candidate &&
-                   atomic_inc_not_zero(&first_candidate->refcount))
-                       router = first_candidate;
-       }
 return_router:
        rcu_read_unlock();
        return router;