[IPV4] fib_trie: avoid extra search on delete

Get rid of extra search that made route deletion O(n).

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 2ea94eb..441c4ea 100644 (file)
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -1545,49 +1545,23 @@ found:
        return ret;
 }
 
-/* only called from updater side */
-static int trie_leaf_remove(struct trie *t, t_key key)
+/*
+ * Remove the leaf and return parent.
+ */
+static void trie_leaf_remove(struct trie *t, struct leaf *l)
 {
-       t_key cindex;
-       struct tnode *tp = NULL;
-       struct node *n = t->trie;
-       struct leaf *l;
-
-       pr_debug("entering trie_leaf_remove(%p)\n", n);
+       struct tnode *tp = node_parent((struct node *) l);
 
-       /* Note that in the case skipped bits, those bits are *not* checked!
-        * When we finish this, we will have NULL or a T_LEAF, and the
-        * T_LEAF may or may not match our key.
-        */
-
-       while (n != NULL && IS_TNODE(n)) {
-               struct tnode *tn = (struct tnode *) n;
-               check_tnode(tn);
-               n = tnode_get_child(tn, tkey_extract_bits(key,
-                                                         tn->pos, tn->bits));
-
-               BUG_ON(n && node_parent(n) != tn);
-       }
-       l = (struct leaf *) n;
-
-       if (!n || !tkey_equals(l->key, key))
-               return 0;
-
-       /*
-        * Key found.
-        * Remove the leaf and rebalance the tree
-        */
-       tp = node_parent(n);
-       tnode_free((struct tnode *) n);
+       pr_debug("entering trie_leaf_remove(%p)\n", l);
 
        if (tp) {
-               cindex = tkey_extract_bits(key, tp->pos, tp->bits);
+               t_key cindex = tkey_extract_bits(l->key, tp->pos, tp->bits);
                put_child(t, (struct tnode *)tp, cindex, NULL);
                rcu_assign_pointer(t->trie, trie_rebalance(t, tp));
        } else
                rcu_assign_pointer(t->trie, NULL);
 
-       return 1;
+       tnode_free((struct tnode *) l);
 }
 
 /*
@@ -1665,7 +1639,7 @@ static int fn_trie_delete(struct fib_table *tb, struct fib_config *cfg)
        }
 
        if (hlist_empty(&l->list))
-               trie_leaf_remove(t, key);
+               trie_leaf_remove(t, l);
 
        if (fa->fa_state & FA_S_ACCESSED)
                rt_cache_flush(-1);
@@ -1778,19 +1752,19 @@ static struct leaf *trie_nextleaf(struct leaf *l)
 static int fn_trie_flush(struct fib_table *tb)
 {
        struct trie *t = (struct trie *) tb->tb_data;
-       struct leaf *ll = NULL, *l = NULL;
+       struct leaf *l, *ll = NULL;
        int found = 0;
 
        for (l = trie_firstleaf(t); l; l = trie_nextleaf(l)) {
                found += trie_flush_leaf(t, l);
 
                if (ll && hlist_empty(&ll->list))
-                       trie_leaf_remove(t, ll->key);
+                       trie_leaf_remove(t, ll);
                ll = l;
        }
 
        if (ll && hlist_empty(&ll->list))
-               trie_leaf_remove(t, ll->key);
+               trie_leaf_remove(t, ll);
 
        pr_debug("trie_flush found=%d\n", found);
        return found;