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Diffstat (limited to 'net/batman-adv/routing.c')
-rw-r--r--net/batman-adv/routing.c43
1 files changed, 17 insertions, 26 deletions
diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c
index 3d199478c405..7e8dc648b95a 100644
--- a/net/batman-adv/routing.c
+++ b/net/batman-adv/routing.c
@@ -74,11 +74,23 @@ static void _batadv_update_route(struct batadv_priv *bat_priv,
if (!orig_ifinfo)
return;
- rcu_read_lock();
- curr_router = rcu_dereference(orig_ifinfo->router);
- if (curr_router && !kref_get_unless_zero(&curr_router->refcount))
- curr_router = NULL;
- rcu_read_unlock();
+ spin_lock_bh(&orig_node->neigh_list_lock);
+ /* curr_router used earlier may not be the current orig_ifinfo->router
+ * anymore because it was dereferenced outside of the neigh_list_lock
+ * protected region. After the new best neighbor has replace the current
+ * best neighbor the reference counter needs to decrease. Consequently,
+ * the code needs to ensure the curr_router variable contains a pointer
+ * to the replaced best neighbor.
+ */
+ curr_router = rcu_dereference_protected(orig_ifinfo->router, true);
+
+ /* increase refcount of new best neighbor */
+ if (neigh_node)
+ kref_get(&neigh_node->refcount);
+
+ rcu_assign_pointer(orig_ifinfo->router, neigh_node);
+ spin_unlock_bh(&orig_node->neigh_list_lock);
+ batadv_orig_ifinfo_put(orig_ifinfo);
/* route deleted */
if ((curr_router) && (!neigh_node)) {
@@ -100,27 +112,6 @@ static void _batadv_update_route(struct batadv_priv *bat_priv,
curr_router->addr);
}
- if (curr_router)
- batadv_neigh_node_put(curr_router);
-
- spin_lock_bh(&orig_node->neigh_list_lock);
- /* curr_router used earlier may not be the current orig_ifinfo->router
- * anymore because it was dereferenced outside of the neigh_list_lock
- * protected region. After the new best neighbor has replace the current
- * best neighbor the reference counter needs to decrease. Consequently,
- * the code needs to ensure the curr_router variable contains a pointer
- * to the replaced best neighbor.
- */
- curr_router = rcu_dereference_protected(orig_ifinfo->router, true);
-
- /* increase refcount of new best neighbor */
- if (neigh_node)
- kref_get(&neigh_node->refcount);
-
- rcu_assign_pointer(orig_ifinfo->router, neigh_node);
- spin_unlock_bh(&orig_node->neigh_list_lock);
- batadv_orig_ifinfo_put(orig_ifinfo);
-
/* decrease refcount of previous best neighbor */
if (curr_router)
batadv_neigh_node_put(curr_router);