ipv4: Fix oops with FIB_TRIE

It seems we can fix this by disabling preemption while we re-balance the 
trie. This is with the CONFIG_CLASSIC_RCU. It's been stress-tested at high 
loads continuesly taking a full BGP table up/down via iproute -batch.

Note. fib_trie is not updated for CONFIG_PREEMPT_RCU

Reported-by: Andrei Popa
Signed-off-by: Robert Olsson <robert.olsson@its.uu.se>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Robert Olsson 2009-05-21 15:20:59 -07:00 committed by David S. Miller
parent 5b5f792a6a
commit 3ed18d76d9

View File

@ -986,9 +986,12 @@ fib_find_node(struct trie *t, u32 key)
static struct node *trie_rebalance(struct trie *t, struct tnode *tn)
{
int wasfull;
t_key cindex, key = tn->key;
t_key cindex, key;
struct tnode *tp;
preempt_disable();
key = tn->key;
while (tn != NULL && (tp = node_parent((struct node *)tn)) != NULL) {
cindex = tkey_extract_bits(key, tp->pos, tp->bits);
wasfull = tnode_full(tp, tnode_get_child(tp, cindex));
@ -1007,6 +1010,7 @@ static struct node *trie_rebalance(struct trie *t, struct tnode *tn)
if (IS_TNODE(tn))
tn = (struct tnode *)resize(t, (struct tnode *)tn);
preempt_enable();
return (struct node *)tn;
}