Merge branch 'tc_action-fixes'

Cong Wang says:

====================
net_sched: tc action fixes and updates

This patchset fixes a few regressions caused by the previous
code refactor and more. Thanks to Jamal for catching them!

Note, patch 3/7 and 4/7 are not strictly necessary for this patchset,
I just want to carry them together.

---
v4: adjust an indention for Jamal
    add two more patches

v3: avoid list for fast path, suggested by Jamal

v2: replace flex_array with regular dynamic array
    keep tcf_action_stats_update() in act_api.h
    fix macro typos found by Amir
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 56 insertions, 91 deletions

diff --git a/net/sched/act_api.c b/net/sched/act_api.c
index e4a5f2607ffa..d09d0687594b 100644
--- a/net/sched/act_api.c
+++ b/net/sched/act_api.c
@@ -64,7 +64,6 @@ int __tcf_hash_release(struct tc_action *p, bool bind, bool strict)
 		if (p->tcfa_bindcnt <= 0 && p->tcfa_refcnt <= 0) {
 			if (p->ops->cleanup)
 				p->ops->cleanup(p, bind);
-			list_del(&p->list);
 			tcf_hash_destroy(p->hinfo, p);
 			ret = ACT_P_DELETED;
 		}
@@ -421,18 +420,19 @@ static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 	return res;
 }
 
-int tcf_action_exec(struct sk_buff *skb, const struct list_head *actions,
-		    struct tcf_result *res)
+int tcf_action_exec(struct sk_buff *skb, struct tc_action **actions,
+		    int nr_actions, struct tcf_result *res)
 {
-	const struct tc_action *a;
-	int ret = -1;
+	int ret = -1, i;
 
 	if (skb->tc_verd & TC_NCLS) {
 		skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
 		ret = TC_ACT_OK;
 		goto exec_done;
 	}
-	list_for_each_entry(a, actions, list) {
+	for (i = 0; i < nr_actions; i++) {
+		const struct tc_action *a = actions[i];
+
 repeat:
 		ret = a->ops->act(skb, a, res);
 		if (ret == TC_ACT_REPEAT)
@@ -754,16 +754,6 @@ err_out:
 	return ERR_PTR(err);
 }
 
-static void cleanup_a(struct list_head *actions)
-{
-	struct tc_action *a, *tmp;
-
-	list_for_each_entry_safe(a, tmp, actions, list) {
-		list_del(&a->list);
-		kfree(a);
-	}
-}
-
 static int tca_action_flush(struct net *net, struct nlattr *nla,
 			    struct nlmsghdr *n, u32 portid)
 {
@@ -905,7 +895,7 @@ tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 		return ret;
 	}
 err:
-	cleanup_a(&actions);
+	tcf_action_destroy(&actions, 0);
 	return ret;
 }
 
@@ -942,15 +932,9 @@ tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 
 	ret = tcf_action_init(net, nla, NULL, NULL, ovr, 0, &actions);
 	if (ret)
-		goto done;
+		return ret;
 
-	/* dump then free all the actions after update; inserted policy
-	 * stays intact
-	 */
-	ret = tcf_add_notify(net, n, &actions, portid);
-	cleanup_a(&actions);
-done:
-	return ret;
+	return tcf_add_notify(net, n, &actions, portid);
 }
 
 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n)
diff --git a/net/sched/act_police.c b/net/sched/act_police.c
index b3c7e975fc9e..8a3be1d99775 100644
--- a/net/sched/act_police.c
+++ b/net/sched/act_police.c
@@ -63,49 +63,8 @@ static int tcf_act_police_walker(struct net *net, struct sk_buff *skb,
 				 const struct tc_action_ops *ops)
 {
 	struct tc_action_net *tn = net_generic(net, police_net_id);
-	struct tcf_hashinfo *hinfo = tn->hinfo;
-	int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
-	struct nlattr *nest;
-
-	spin_lock_bh(&hinfo->lock);
-
-	s_i = cb->args[0];
-
-	for (i = 0; i < (POL_TAB_MASK + 1); i++) {
-		struct hlist_head *head;
-		struct tc_action *p;
-
-		head = &hinfo->htab[tcf_hash(i, POL_TAB_MASK)];
-
-		hlist_for_each_entry_rcu(p, head, tcfa_head) {
-			index++;
-			if (index < s_i)
-				continue;
-			nest = nla_nest_start(skb, index);
-			if (nest == NULL)
-				goto nla_put_failure;
-			if (type == RTM_DELACTION)
-				err = tcf_action_dump_1(skb, p, 0, 1);
-			else
-				err = tcf_action_dump_1(skb, p, 0, 0);
-			if (err < 0) {
-				index--;
-				nla_nest_cancel(skb, nest);
-				goto done;
-			}
-			nla_nest_end(skb, nest);
-			n_i++;
-		}
-	}
-done:
-	spin_unlock_bh(&hinfo->lock);
-	if (n_i)
-		cb->args[0] += n_i;
-	return n_i;
 
-nla_put_failure:
-	nla_nest_cancel(skb, nest);
-	goto done;
+	return tcf_generic_walker(tn, skb, cb, type, ops);
 }
 
 static const struct nla_policy police_policy[TCA_POLICE_MAX + 1] = {
@@ -125,6 +84,7 @@ static int tcf_act_police_init(struct net *net, struct nlattr *nla,
 	struct tcf_police *police;
 	struct qdisc_rate_table *R_tab = NULL, *P_tab = NULL;
 	struct tc_action_net *tn = net_generic(net, police_net_id);
+	bool exists = false;
 	int size;
 
 	if (nla == NULL)
@@ -139,24 +99,24 @@ static int tcf_act_police_init(struct net *net, struct nlattr *nla,
 	size = nla_len(tb[TCA_POLICE_TBF]);
 	if (size != sizeof(*parm) && size != sizeof(struct tc_police_compat))
 		return -EINVAL;
+
 	parm = nla_data(tb[TCA_POLICE_TBF]);
+	exists = tcf_hash_check(tn, parm->index, a, bind);
+	if (exists && bind)
+		return 0;
 
-	if (parm->index) {
-		if (tcf_hash_check(tn, parm->index, a, bind)) {
-			if (ovr)
-				goto override;
-			/* not replacing */
-			return -EEXIST;
-		}
-	} else {
+	if (!exists) {
 		ret = tcf_hash_create(tn, parm->index, NULL, a,
 				      &act_police_ops, bind, false);
 		if (ret)
 			return ret;
 		ret = ACT_P_CREATED;
+	} else {
+		tcf_hash_release(*a, bind);
+		if (!ovr)
+			return -EEXIST;
 	}
 
-override:
 	police = to_police(*a);
 	if (parm->rate.rate) {
 		err = -ENOMEM;
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 843a716a4303..a7c5645373af 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -541,8 +541,12 @@ out:
 void tcf_exts_destroy(struct tcf_exts *exts)
 {
 #ifdef CONFIG_NET_CLS_ACT
-	tcf_action_destroy(&exts->actions, TCA_ACT_UNBIND);
-	INIT_LIST_HEAD(&exts->actions);
+	LIST_HEAD(actions);
+
+	tcf_exts_to_list(exts, &actions);
+	tcf_action_destroy(&actions, TCA_ACT_UNBIND);
+	kfree(exts->actions);
+	exts->nr_actions = 0;
 #endif
 }
 EXPORT_SYMBOL(tcf_exts_destroy);
@@ -554,7 +558,6 @@ int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
 	{
 		struct tc_action *act;
 
-		INIT_LIST_HEAD(&exts->actions);
 		if (exts->police && tb[exts->police]) {
 			act = tcf_action_init_1(net, tb[exts->police], rate_tlv,
 						"police", ovr,
@@ -563,14 +566,20 @@ int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
 				return PTR_ERR(act);
 
 			act->type = exts->type = TCA_OLD_COMPAT;
-			list_add(&act->list, &exts->actions);
+			exts->actions[0] = act;
+			exts->nr_actions = 1;
 		} else if (exts->action && tb[exts->action]) {
-			int err;
+			LIST_HEAD(actions);
+			int err, i = 0;
+
 			err = tcf_action_init(net, tb[exts->action], rate_tlv,
 					      NULL, ovr,
-					      TCA_ACT_BIND, &exts->actions);
+					      TCA_ACT_BIND, &actions);
 			if (err)
 				return err;
+			list_for_each_entry(act, &actions, list)
+				exts->actions[i++] = act;
+			exts->nr_actions = i;
 		}
 	}
 #else
@@ -587,37 +596,49 @@ void tcf_exts_change(struct tcf_proto *tp, struct tcf_exts *dst,
 		     struct tcf_exts *src)
 {
 #ifdef CONFIG_NET_CLS_ACT
-	LIST_HEAD(tmp);
+	struct tcf_exts old = *dst;
+
 	tcf_tree_lock(tp);
-	list_splice_init(&dst->actions, &tmp);
-	list_splice(&src->actions, &dst->actions);
+	dst->nr_actions = src->nr_actions;
+	dst->actions = src->actions;
 	dst->type = src->type;
 	tcf_tree_unlock(tp);
-	tcf_action_destroy(&tmp, TCA_ACT_UNBIND);
+
+	tcf_exts_destroy(&old);
 #endif
 }
 EXPORT_SYMBOL(tcf_exts_change);
 
-#define tcf_exts_first_act(ext)					\
-	list_first_entry_or_null(&(exts)->actions,		\
-				 struct tc_action, list)
+#ifdef CONFIG_NET_CLS_ACT
+static struct tc_action *tcf_exts_first_act(struct tcf_exts *exts)
+{
+	if (exts->nr_actions == 0)
+		return NULL;
+	else
+		return exts->actions[0];
+}
+#endif
 
 int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts)
 {
 #ifdef CONFIG_NET_CLS_ACT
 	struct nlattr *nest;
 
-	if (exts->action && !list_empty(&exts->actions)) {
+	if (exts->action && exts->nr_actions) {
 		/*
 		 * again for backward compatible mode - we want
 		 * to work with both old and new modes of entering
 		 * tc data even if iproute2  was newer - jhs
 		 */
 		if (exts->type != TCA_OLD_COMPAT) {
+			LIST_HEAD(actions);
+
 			nest = nla_nest_start(skb, exts->action);
 			if (nest == NULL)
 				goto nla_put_failure;
-			if (tcf_action_dump(skb, &exts->actions, 0, 0) < 0)
+
+			tcf_exts_to_list(exts, &actions);
+			if (tcf_action_dump(skb, &actions, 0, 0) < 0)
 				goto nla_put_failure;
 			nla_nest_end(skb, nest);
 		} else if (exts->police) {