Commit 9195bef7 authored by Stephen Hemminger's avatar Stephen Hemminger Committed by David S. Miller
Browse files

[IPV4] fib_trie: avoid extra search on delete 



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

Signed-off-by: default avatarStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a88ee229

net/ipv4/fib_trie.c

+12 −38
Original line number Diff line number Diff line
@@ -1545,49 +1545,23 @@ static int fn_trie_lookup(struct fib_table *tb, const struct flowi *flp, 
	return ret;

}



/* only called from updater side */

static int trie_leaf_remove(struct trie *t, t_key key)

{

	t_key cindex;

	struct tnode *tp = NULL;

	struct node *n = t->trie;

	struct leaf *l;



	pr_debug("entering trie_leaf_remove(%p)\n", n);



	/* 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

 * Remove the leaf and return parent.

 */

	tp = node_parent(n);

	tnode_free((struct tnode *) n);

static void trie_leaf_remove(struct trie *t, struct leaf *l)

{

	struct tnode *tp = node_parent((struct node *) l);



	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;