netfilter: conntrack: spinlock per cpu to protect special lists.

One spinlock per cpu to protect dying/unconfirmed/template special lists.
(These lists are now per cpu, a bit like the untracked ct)
Add a @cpu field to nf_conn, to make sure we hold the appropriate
spinlock at removal time.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/include/net/netns/conntrack.h b/include/net/netns/conntrack.h
index fbcc7fa..c6a8994 100644
--- a/include/net/netns/conntrack.h
+++ b/include/net/netns/conntrack.h
@@ -62,6 +62,13 @@
 #endif
 };
 
+struct ct_pcpu {
+	spinlock_t		lock;
+	struct hlist_nulls_head unconfirmed;
+	struct hlist_nulls_head dying;
+	struct hlist_nulls_head tmpl;
+};
+
 struct netns_ct {
 	atomic_t		count;
 	unsigned int		expect_count;
@@ -86,9 +93,7 @@
 	struct kmem_cache	*nf_conntrack_cachep;
 	struct hlist_nulls_head	*hash;
 	struct hlist_head	*expect_hash;
-	struct hlist_nulls_head	unconfirmed;
-	struct hlist_nulls_head	dying;
-	struct hlist_nulls_head tmpl;
+	struct ct_pcpu __percpu *pcpu_lists;
 	struct ip_conntrack_stat __percpu *stat;
 	struct nf_ct_event_notifier __rcu *nf_conntrack_event_cb;
 	struct nf_exp_event_notifier __rcu *nf_expect_event_cb;