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authorRobert Olsson <robert.olsson@its.uu.se>2009-05-22 00:20:59 +0200
committerDavid S. Miller <davem@davemloft.net>2009-05-22 00:20:59 +0200
commit3ed18d76d959e5cbfa5d70c8f7ba95476582a556 (patch)
tree9fbd15b820b43627440fd6961f687c30e8d4e130
parentpktgen: do not access flows[] beyond its length (diff)
downloadlinux-3ed18d76d959e5cbfa5d70c8f7ba95476582a556.tar.xz
linux-3ed18d76d959e5cbfa5d70c8f7ba95476582a556.zip
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>
-rw-r--r--net/ipv4/fib_trie.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index ec0ae490f0b6..33c7c85dfe40 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -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;
}