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>

8 files changed, 112 insertions, 119 deletions

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index ee57a89252bb..b4f03748adc0 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -8396,12 +8396,14 @@ static int parse_tc_actions(struct ixgbe_adapter *adapter,
 			    struct tcf_exts *exts, u64 *action, u8 *queue)
 {
 	const struct tc_action *a;
+	LIST_HEAD(actions);
 	int err;
 
 	if (tc_no_actions(exts))
 		return -EINVAL;
 
-	tc_for_each_action(a, exts) {
+	tcf_exts_to_list(exts, &actions);
+	list_for_each_entry(a, &actions, list) {
 
 		/* Drop action */
 		if (is_tcf_gact_shot(a)) {
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
index 0f19b01e3fff..dc8b1cb0fdc8 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
@@ -318,6 +318,7 @@ static int parse_tc_nic_actions(struct mlx5e_priv *priv, struct tcf_exts *exts,
 				u32 *action, u32 *flow_tag)
 {
 	const struct tc_action *a;
+	LIST_HEAD(actions);
 
 	if (tc_no_actions(exts))
 		return -EINVAL;
@@ -325,7 +326,8 @@ static int parse_tc_nic_actions(struct mlx5e_priv *priv, struct tcf_exts *exts,
 	*flow_tag = MLX5_FS_DEFAULT_FLOW_TAG;
 	*action = 0;
 
-	tc_for_each_action(a, exts) {
+	tcf_exts_to_list(exts, &actions);
+	list_for_each_entry(a, &actions, list) {
 		/* Only support a single action per rule */
 		if (*action)
 			return -EINVAL;
@@ -362,13 +364,15 @@ static int parse_tc_fdb_actions(struct mlx5e_priv *priv, struct tcf_exts *exts,
 				u32 *action, u32 *dest_vport)
 {
 	const struct tc_action *a;
+	LIST_HEAD(actions);
 
 	if (tc_no_actions(exts))
 		return -EINVAL;
 
 	*action = 0;
 
-	tc_for_each_action(a, exts) {
+	tcf_exts_to_list(exts, &actions);
+	list_for_each_entry(a, &actions, list) {
 		/* Only support a single action per rule */
 		if (*action)
 			return -EINVAL;
@@ -503,6 +507,7 @@ int mlx5e_stats_flower(struct mlx5e_priv *priv,
 	struct mlx5e_tc_flow *flow;
 	struct tc_action *a;
 	struct mlx5_fc *counter;
+	LIST_HEAD(actions);
 	u64 bytes;
 	u64 packets;
 	u64 lastuse;
@@ -518,7 +523,8 @@ int mlx5e_stats_flower(struct mlx5e_priv *priv,
 
 	mlx5_fc_query_cached(counter, &bytes, &packets, &lastuse);
 
-	tc_for_each_action(a, f->exts)
+	tcf_exts_to_list(f->exts, &actions);
+	list_for_each_entry(a, &actions, list)
 		tcf_action_stats_update(a, bytes, packets, lastuse);
 
 	return 0;
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
index 1fe9fbdc9102..1f8168906811 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
@@ -1121,6 +1121,7 @@ static int mlxsw_sp_port_add_cls_matchall(struct mlxsw_sp_port *mlxsw_sp_port,
 					  bool ingress)
 {
 	const struct tc_action *a;
+	LIST_HEAD(actions);
 	int err;
 
 	if (!tc_single_action(cls->exts)) {
@@ -1128,7 +1129,8 @@ static int mlxsw_sp_port_add_cls_matchall(struct mlxsw_sp_port *mlxsw_sp_port,
 		return -ENOTSUPP;
 	}
 
-	tc_for_each_action(a, cls->exts) {
+	tcf_exts_to_list(cls->exts, &actions);
+	list_for_each_entry(a, &actions, list) {
 		if (!is_tcf_mirred_mirror(a) || protocol != htons(ETH_P_ALL))
 			return -ENOTSUPP;
 
diff --git a/include/net/act_api.h b/include/net/act_api.h
index 41e6a24a44b9..82f3c912a5b1 100644
--- a/include/net/act_api.h
+++ b/include/net/act_api.h
@@ -176,8 +176,8 @@ int tcf_register_action(struct tc_action_ops *a, struct pernet_operations *ops);
 int tcf_unregister_action(struct tc_action_ops *a,
 			  struct pernet_operations *ops);
 int tcf_action_destroy(struct list_head *actions, int bind);
-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);
 int tcf_action_init(struct net *net, struct nlattr *nla,
 				  struct nlattr *est, char *n, int ovr,
 				  int bind, struct list_head *);
@@ -189,30 +189,17 @@ int tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int, int);
 int tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int, int);
 int tcf_action_copy_stats(struct sk_buff *, struct tc_action *, int);
 
-#define tc_no_actions(_exts) \
-	(list_empty(&(_exts)->actions))
-
-#define tc_for_each_action(_a, _exts) \
-	list_for_each_entry(a, &(_exts)->actions, list)
-
-#define tc_single_action(_exts) \
-	(list_is_singular(&(_exts)->actions))
+#endif /* CONFIG_NET_CLS_ACT */
 
 static inline void tcf_action_stats_update(struct tc_action *a, u64 bytes,
 					   u64 packets, u64 lastuse)
 {
+#ifdef CONFIG_NET_CLS_ACT
 	if (!a->ops->stats_update)
 		return;
 
 	a->ops->stats_update(a, bytes, packets, lastuse);
+#endif
 }
 
-#else /* CONFIG_NET_CLS_ACT */
-
-#define tc_no_actions(_exts) true
-#define tc_for_each_action(_a, _exts) while ((void)(_a), 0)
-#define tc_single_action(_exts) false
-#define tcf_action_stats_update(a, bytes, packets, lastuse)
-
-#endif /* CONFIG_NET_CLS_ACT */
 #endif
diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
index 6f8d65342d3a..c99508d426cc 100644
--- a/include/net/pkt_cls.h
+++ b/include/net/pkt_cls.h
@@ -59,7 +59,8 @@ tcf_unbind_filter(struct tcf_proto *tp, struct tcf_result *r)
 struct tcf_exts {
 #ifdef CONFIG_NET_CLS_ACT
 	__u32	type; /* for backward compat(TCA_OLD_COMPAT) */
-	struct list_head actions;
+	int nr_actions;
+	struct tc_action **actions;
 #endif
 	/* Map to export classifier specific extension TLV types to the
 	 * generic extensions API. Unsupported extensions must be set to 0.
@@ -72,7 +73,10 @@ static inline void tcf_exts_init(struct tcf_exts *exts, int action, int police)
 {
 #ifdef CONFIG_NET_CLS_ACT
 	exts->type = 0;
-	INIT_LIST_HEAD(&exts->actions);
+	exts->nr_actions = 0;
+	exts->actions = kcalloc(TCA_ACT_MAX_PRIO, sizeof(struct tc_action *),
+				GFP_KERNEL);
+	WARN_ON(!exts->actions); /* TODO: propagate the error to callers */
 #endif
 	exts->action = action;
 	exts->police = police;
@@ -89,7 +93,7 @@ static inline int
 tcf_exts_is_predicative(struct tcf_exts *exts)
 {
 #ifdef CONFIG_NET_CLS_ACT
-	return !list_empty(&exts->actions);
+	return exts->nr_actions;
 #else
 	return 0;
 #endif
@@ -108,6 +112,20 @@ tcf_exts_is_available(struct tcf_exts *exts)
 	return tcf_exts_is_predicative(exts);
 }
 
+static inline void tcf_exts_to_list(const struct tcf_exts *exts,
+				    struct list_head *actions)
+{
+#ifdef CONFIG_NET_CLS_ACT
+	int i;
+
+	for (i = 0; i < exts->nr_actions; i++) {
+		struct tc_action *a = exts->actions[i];
+
+		list_add(&a->list, actions);
+	}
+#endif
+}
+
 /**
  * tcf_exts_exec - execute tc filter extensions
  * @skb: socket buffer
@@ -124,12 +142,25 @@ tcf_exts_exec(struct sk_buff *skb, struct tcf_exts *exts,
 	       struct tcf_result *res)
 {
 #ifdef CONFIG_NET_CLS_ACT
-	if (!list_empty(&exts->actions))
-		return tcf_action_exec(skb, &exts->actions, res);
+	if (exts->nr_actions)
+		return tcf_action_exec(skb, exts->actions, exts->nr_actions,
+				       res);
 #endif
 	return 0;
 }
 
+#ifdef CONFIG_NET_CLS_ACT
+
+#define tc_no_actions(_exts)  ((_exts)->nr_actions == 0)
+#define tc_single_action(_exts) ((_exts)->nr_actions == 1)
+
+#else /* CONFIG_NET_CLS_ACT */
+
+#define tc_no_actions(_exts) true
+#define tc_single_action(_exts) false
+
+#endif /* CONFIG_NET_CLS_ACT */
+
 int tcf_exts_validate(struct net *net, struct tcf_proto *tp,
 		      struct nlattr **tb, struct nlattr *rate_tlv,
 		      struct tcf_exts *exts, bool ovr);
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) {