[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>
This commit is contained in:
Stephen Hemminger 2008-01-22 21:56:34 -08:00 committed by David S. Miller
parent a88ee22925
commit 9195bef7fb

View file

@ -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)
/*
* 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;
struct tnode *tp = node_parent((struct node *) 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
*/
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;