netfilter: replace list_head with single linked list
The netfilter hook list never uses the prev pointer, and so can be trimmed to
be a simple singly-linked list.
In addition to having a more light weight structure for hook traversal,
struct net becomes 5568 bytes (down from 6400) and struct net_device becomes
2176 bytes (down from 2240).
Signed-off-by: Aaron Conole <aconole@bytheb.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/net/bridge/br_netfilter_hooks.c b/net/bridge/br_netfilter_hooks.c
index 6029af4..2fe9345 100644
--- a/net/bridge/br_netfilter_hooks.c
+++ b/net/bridge/br_netfilter_hooks.c
@@ -1002,28 +1002,21 @@
int (*okfn)(struct net *, struct sock *,
struct sk_buff *))
{
- struct nf_hook_ops *elem;
+ struct nf_hook_entry *elem;
struct nf_hook_state state;
- struct list_head *head;
int ret;
- head = &net->nf.hooks[NFPROTO_BRIDGE][hook];
+ elem = rcu_dereference(net->nf.hooks[NFPROTO_BRIDGE][hook]);
- list_for_each_entry_rcu(elem, head, list) {
- struct nf_hook_ops *next;
+ while (elem && (elem->ops.priority <= NF_BR_PRI_BRNF))
+ elem = rcu_dereference(elem->next);
- next = list_entry_rcu(list_next_rcu(&elem->list),
- struct nf_hook_ops, list);
- if (next->priority <= NF_BR_PRI_BRNF)
- continue;
- }
-
- if (&elem->list == head)
+ if (!elem)
return okfn(net, sk, skb);
/* We may already have this, but read-locks nest anyway */
rcu_read_lock();
- nf_hook_state_init(&state, head, hook, NF_BR_PRI_BRNF + 1,
+ nf_hook_state_init(&state, elem, hook, NF_BR_PRI_BRNF + 1,
NFPROTO_BRIDGE, indev, outdev, sk, net, okfn);
ret = nf_hook_slow(skb, &state);