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>

1 files changed, 37 insertions, 27 deletions

diff --git a/net/mac80211/mesh_pathtbl.c b/net/mac80211/mesh_pathtbl.c
index 717f38a7134c..4a3053b09e31 100644
--- 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();
 }