aboutsummaryrefslogtreecommitdiff
path: root/net
diff options
context:
space:
mode:
authorJarek Poplawski <jarkao2@gmail.com>2009-06-18 00:28:51 -0700
committerDavid S. Miller <davem@davemloft.net>2009-06-18 00:28:51 -0700
commit7b85576d15bf2574b0a451108f59f9ad4170dd3f (patch)
treea2d8075b9d234b0a937d7dd82b95cb16b953aec7 /net
parentb964758050f856e44f5fe645d03bea8a1b0b66bd (diff)
downloadlinux-2.6.34-ux500-7b85576d15bf2574b0a451108f59f9ad4170dd3f.tar.gz
ipv4: Fix fib_trie rebalancing, part 2
My previous patch, which explicitly delays freeing of tnodes by adding them to the list to flush them after the update is finished, isn't strict enough. It treats exceptionally tnodes without parent, assuming they are newly created, so "invisible" for the read side yet. But the top tnode doesn't have parent as well, so we have to exclude all exceptions (at least until a better way is found). Additionally we need to move rcu assignment of this node before flushing, so the return type of the trie_rebalance() function is changed. Reported-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/fib_trie.c24
1 files changed, 10 insertions, 14 deletions
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index d1a39b1277d..012cf5a6858 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -391,13 +391,8 @@ static inline void tnode_free(struct tnode *tn)
static void tnode_free_safe(struct tnode *tn)
{
BUG_ON(IS_LEAF(tn));
-
- if (node_parent((struct node *) tn)) {
- tn->tnode_free = tnode_free_head;
- tnode_free_head = tn;
- } else {
- tnode_free(tn);
- }
+ tn->tnode_free = tnode_free_head;
+ tnode_free_head = tn;
}
static void tnode_free_flush(void)
@@ -1009,7 +1004,7 @@ fib_find_node(struct trie *t, u32 key)
return NULL;
}
-static struct node *trie_rebalance(struct trie *t, struct tnode *tn)
+static void trie_rebalance(struct trie *t, struct tnode *tn)
{
int wasfull;
t_key cindex, key;
@@ -1033,12 +1028,13 @@ static struct node *trie_rebalance(struct trie *t, struct tnode *tn)
}
/* Handle last (top) tnode */
- if (IS_TNODE(tn)) {
+ if (IS_TNODE(tn))
tn = (struct tnode *)resize(t, (struct tnode *)tn);
- tnode_free_flush();
- }
- return (struct node *)tn;
+ rcu_assign_pointer(t->trie, (struct node *)tn);
+ tnode_free_flush();
+
+ return;
}
/* only used from updater-side */
@@ -1186,7 +1182,7 @@ static struct list_head *fib_insert_node(struct trie *t, u32 key, int plen)
/* Rebalance the trie */
- rcu_assign_pointer(t->trie, trie_rebalance(t, tp));
+ trie_rebalance(t, tp);
done:
return fa_head;
}
@@ -1605,7 +1601,7 @@ static void trie_leaf_remove(struct trie *t, struct leaf *l)
if (tp) {
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));
+ trie_rebalance(t, tp);
} else
rcu_assign_pointer(t->trie, NULL);