mac80211: Don't iterate twice over all mpaths when once in sufficient

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/net/mac80211/mesh_pathtbl.c b/net/mac80211/mesh_pathtbl.c
index 717f38a..4a3053b 100644 (file)
--- a/net/mac80211/mesh_pathtbl.c
+++ b/net/mac80211/mesh_pathtbl.c
@@ -49,7 +49,9 @@ int mesh_paths_generation;
 
 /* This lock will have the grow table function as writer and add / delete nodes
  * as readers. When reading the table (i.e. doing lookups) we are well protected
- * by RCU
+ * by RCU.  We need to take this lock when modying the number of buckets
+ * on one of the path tables but we don't need to if adding or removing mpaths
+ * from hash buckets.
  */
 static DEFINE_RWLOCK(pathtbl_resize_lock);
 
@@ -817,6 +819,32 @@ void mesh_path_flush_by_nexthop(struct sta_info *sta)
        rcu_read_unlock();
 }
 
+static void mesh_path_node_reclaim(struct rcu_head *rp)
+{
+       struct mpath_node *node = container_of(rp, struct mpath_node, rcu);
+       struct ieee80211_sub_if_data *sdata = node->mpath->sdata;
+
+       del_timer_sync(&node->mpath->timer);
+       atomic_dec(&sdata->u.mesh.mpaths);
+       kfree(node->mpath);
+       kfree(node);
+}
+
+/* needs to be called with the corresponding hashwlock taken */
+static void __mesh_path_del(struct mesh_table *tbl, struct mpath_node *node)
+{
+       struct mesh_path *mpath;
+       mpath = node->mpath;
+       spin_lock(&mpath->state_lock);
+       mpath->flags |= MESH_PATH_RESOLVING;
+       if (mpath->is_gate)
+               mesh_gate_del(tbl, mpath);
+       hlist_del_rcu(&node->list);
+       call_rcu(&node->rcu, mesh_path_node_reclaim);
+       spin_unlock(&mpath->state_lock);
+       atomic_dec(&tbl->entries);
+}
+
 static void mesh_path_flush(struct ieee80211_sub_if_data *sdata)
 {
        struct mesh_table *tbl;
@@ -829,23 +857,15 @@ static void mesh_path_flush(struct ieee80211_sub_if_data *sdata)
        tbl = rcu_dereference(mesh_paths);
        for_each_mesh_entry(tbl, p, node, i) {
                mpath = node->mpath;
-               if (mpath->sdata == sdata)
-                       mesh_path_del(mpath->dst, mpath->sdata);
+               if (mpath->sdata == sdata) {
+                       spin_lock_bh(&tbl->hashwlock[i]);
+                       __mesh_path_del(tbl, node);
+                       spin_unlock_bh(&tbl->hashwlock[i]);
+               }
        }
        rcu_read_unlock();
 }
 
-static void mesh_path_node_reclaim(struct rcu_head *rp)
-{
-       struct mpath_node *node = container_of(rp, struct mpath_node, rcu);
-       struct ieee80211_sub_if_data *sdata = node->mpath->sdata;
-
-       del_timer_sync(&node->mpath->timer);
-       atomic_dec(&sdata->u.mesh.mpaths);
-       kfree(node->mpath);
-       kfree(node);
-}
-
 static void mpp_path_flush(struct ieee80211_sub_if_data *sdata)
 {
        struct mesh_table *tbl;
@@ -859,12 +879,8 @@ static void mpp_path_flush(struct ieee80211_sub_if_data *sdata)
                                        lockdep_is_held(pathtbl_resize_lock));
        for_each_mesh_entry(tbl, p, node, i) {
                mpath = node->mpath;
-               if (mpath->sdata != sdata)
-                       continue;
                spin_lock_bh(&tbl->hashwlock[i]);
-               hlist_del_rcu(&node->list);
-               call_rcu(&node->rcu, mesh_path_node_reclaim);
-               atomic_dec(&tbl->entries);
+               __mesh_path_del(tbl, node);
                spin_unlock_bh(&tbl->hashwlock[i]);
        }
        read_unlock_bh(&pathtbl_resize_lock);
@@ -912,14 +928,7 @@ int mesh_path_del(u8 *addr, struct ieee80211_sub_if_data *sdata)
                mpath = node->mpath;
                if (mpath->sdata == sdata &&
                    memcmp(addr, mpath->dst, ETH_ALEN) == 0) {
-                       spin_lock_bh(&mpath->state_lock);
-                       if (mpath->is_gate)
-                               mesh_gate_del(tbl, mpath);
-                       mpath->flags |= MESH_PATH_RESOLVING;
-                       hlist_del_rcu(&node->list);
-                       call_rcu(&node->rcu, mesh_path_node_reclaim);
-                       atomic_dec(&tbl->entries);
-                       spin_unlock_bh(&mpath->state_lock);
+                       __mesh_path_del(tbl, node);
                        goto enddel;
                }
        }
@@ -1160,6 +1169,7 @@ void mesh_path_expire(struct ieee80211_sub_if_data *sdata)
                    (!(mpath->flags & MESH_PATH_FIXED)) &&
                     time_after(jiffies, mpath->exp_time + MESH_PATH_EXPIRE))
                        mesh_path_del(mpath->dst, mpath->sdata);
+       }
        rcu_read_unlock();
 }