netfilter: conntrack: avoid unconditional local_bh_disable

Now that the conntrack entry isn't placed on the pcpu list anymore the
bh only needs to be disabled in the 'expectation present' case.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nf_conntrack_core.c

@@ -1736,10 +1736,9 @@ init_conntrack(struct net *net, struct nf_conn *tmpl,
 				 ecache ? ecache->expmask : 0,
 			     GFP_ATOMIC);
 
-	local_bh_disable();
 	cnet = nf_ct_pernet(net);
 	if (cnet->expect_count) {
-		spin_lock(&nf_conntrack_expect_lock);
+		spin_lock_bh(&nf_conntrack_expect_lock);
 		exp = nf_ct_find_expectation(net, zone, tuple);
 		if (exp) {
 			pr_debug("expectation arrives ct=%p exp=%p\n",
@@ -1762,16 +1761,14 @@ init_conntrack(struct net *net, struct nf_conn *tmpl,
 #endif
 			NF_CT_STAT_INC(net, expect_new);
 		}
-		spin_unlock(&nf_conntrack_expect_lock);
+		spin_unlock_bh(&nf_conntrack_expect_lock);
 	}
 	if (!exp)
 		__nf_ct_try_assign_helper(ct, tmpl, GFP_ATOMIC);
 
 	/* Now it is going to be associated with an sk_buff, set refcount to 1. */
 	refcount_set(&ct->ct_general.use, 1);
 
-	local_bh_enable();
-
 	if (exp) {
 		if (exp->expectfn)
 			exp->expectfn(ct, exp);