net_sched: act: use standard struct list_head

Currently actions are chained by a singly linked list,
therefore it is a bit hard to add and remove a specific
entry. Convert it to struct list_head so that in the
latter patch we can remove an action without finding
its head.

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
index 2ebef77..34fe693d 100644
--- a/include/net/pkt_cls.h
+++ b/include/net/pkt_cls.h
@@ -62,7 +62,8 @@
 
 struct tcf_exts {
 #ifdef CONFIG_NET_CLS_ACT
-	struct tc_action *action;
+	__u32	type; /* for backward compat(TCA_OLD_COMPAT) */
+	struct list_head actions;
 #endif
 };
 
@@ -74,6 +75,13 @@
 	int police;
 };
 
+static inline void tcf_exts_init(struct tcf_exts *exts)
+{
+#ifdef CONFIG_NET_CLS_ACT
+	INIT_LIST_HEAD(&exts->actions);
+#endif
+}
+
 /**
  * tcf_exts_is_predicative - check if a predicative extension is present
  * @exts: tc filter extensions handle
@@ -85,7 +93,7 @@
 tcf_exts_is_predicative(struct tcf_exts *exts)
 {
 #ifdef CONFIG_NET_CLS_ACT
-	return !!exts->action;
+	return !list_empty(&exts->actions);
 #else
 	return 0;
 #endif
@@ -120,8 +128,8 @@
 	       struct tcf_result *res)
 {
 #ifdef CONFIG_NET_CLS_ACT
-	if (exts->action)
-		return tcf_action_exec(skb, exts->action, res);
+	if (!list_empty(&exts->actions))
+		return tcf_action_exec(skb, &exts->actions, res);
 #endif
 	return 0;
 }