[NETFILTER]: nf_conntrack: use hlists for conntrack hash

Convert conntrack hash to hlists to reduce its size and cache
footprint. Since the default hashsize to max. entries ratio
sucks (1:16), this patch doesn't reduce the amount of memory
used for the hash by default, but instead uses a better ratio
of 1:8, which results in the same max. entries value.

One thing worth noting is early_drop. It really should use LRU,
so it now has to iterate over the entire chain to find the last
unconfirmed entry. Since chains shouldn't be very long and the
entire operation is very rare this shouldn't be a problem.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 3 deletions

diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 3d56f36074f7..0627559ca470 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -428,7 +428,7 @@ ctnetlink_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
 {
 	struct nf_conn *ct, *last;
 	struct nf_conntrack_tuple_hash *h;
-	struct list_head *i;
+	struct hlist_node *n;
 	struct nfgenmsg *nfmsg = NLMSG_DATA(cb->nlh);
 	u_int8_t l3proto = nfmsg->nfgen_family;
 
@@ -436,8 +436,8 @@ ctnetlink_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
 	last = (struct nf_conn *)cb->args[1];
 	for (; cb->args[0] < nf_conntrack_htable_size; cb->args[0]++) {
 restart:
-		list_for_each_prev(i, &nf_conntrack_hash[cb->args[0]]) {
-			h = (struct nf_conntrack_tuple_hash *) i;
+		hlist_for_each_entry(h, n, &nf_conntrack_hash[cb->args[0]],
+				     hnode) {
 			if (NF_CT_DIRECTION(h) != IP_CT_DIR_ORIGINAL)
 				continue;
 			ct = nf_ct_tuplehash_to_ctrack(h);