netfilter: conntrack: keep BH enabled during lookup

No need to disable BH here anymore:

stats are switched to _ATOMIC variant (== this_cpu_inc()), which
nowadays generates same code as the non _ATOMIC NF_STAT, at least on x86.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Florian Westphal 2016-04-28 19:13:40 +02:00 committed by Pablo Neira Ayuso
parent 1ad8f48df6
commit 2cf1234807

View File

@ -472,18 +472,13 @@ ____nf_conntrack_find(struct net *net, const struct nf_conntrack_zone *zone,
struct hlist_nulls_node *n;
unsigned int bucket = hash_bucket(hash, net);
/* Disable BHs the entire time since we normally need to disable them
* at least once for the stats anyway.
*/
local_bh_disable();
begin:
hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[bucket], hnnode) {
if (nf_ct_key_equal(h, tuple, zone)) {
NF_CT_STAT_INC(net, found);
local_bh_enable();
NF_CT_STAT_INC_ATOMIC(net, found);
return h;
}
NF_CT_STAT_INC(net, searched);
NF_CT_STAT_INC_ATOMIC(net, searched);
}
/*
* if the nulls value we got at the end of this lookup is
@ -491,10 +486,9 @@ begin:
* We probably met an item that was moved to another chain.
*/
if (get_nulls_value(n) != bucket) {
NF_CT_STAT_INC(net, search_restart);
NF_CT_STAT_INC_ATOMIC(net, search_restart);
goto begin;
}
local_bh_enable();
return NULL;
}
@ -735,22 +729,19 @@ nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
zone = nf_ct_zone(ignored_conntrack);
hash = hash_conntrack(net, tuple);
/* Disable BHs the entire time since we need to disable them at
* least once for the stats anyway.
*/
rcu_read_lock_bh();
rcu_read_lock();
hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnnode) {
ct = nf_ct_tuplehash_to_ctrack(h);
if (ct != ignored_conntrack &&
nf_ct_tuple_equal(tuple, &h->tuple) &&
nf_ct_zone_equal(ct, zone, NF_CT_DIRECTION(h))) {
NF_CT_STAT_INC(net, found);
rcu_read_unlock_bh();
NF_CT_STAT_INC_ATOMIC(net, found);
rcu_read_unlock();
return 1;
}
NF_CT_STAT_INC(net, searched);
NF_CT_STAT_INC_ATOMIC(net, searched);
}
rcu_read_unlock_bh();
rcu_read_unlock();
return 0;
}