net/mlx5: Fix post parse infra to only parse every action once

Caller of mlx5e_tc_act_post_parse() needs it to parse only the subset of
actions starting after previous split and ending at the current action.
However, that range is not provided as arguments and
mlx5e_tc_act_post_parse() uses generic flow_action_for_each() that iterates
over all flow actions. Not only this is redundant, it also causes a bug
when mlx5e_tc_act->post_parse() callback is not idempotent since it will be
called for every split. For example, ct action tc_act_post_parse_ct()
callback obtains a reference to mlx5_ct_ft instance and calling it several
times during parsing stage will cause reference counter imbalance.

Fix the issue by providing a proper action range of the current split
subset to mlx5e_tc_act_post_parse() and only calling
mlx5e_tc_act->post_parse() for actions inside the subset range.

Fixes: 8300f22 ("net/mlx5e: Create new flow attr for multi table actions")
Signed-off-by: Vlad Buslov <vladbu@nvidia.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

Author: w1ldptr

drivers/net/ethernet/mellanox/mlx5/core/en/tc/act/act.c

@@ -84,7 +84,7 @@ mlx5e_tc_act_init_parse_state(struct mlx5e_tc_act_parse_state *parse_state,
 
 int
 mlx5e_tc_act_post_parse(struct mlx5e_tc_act_parse_state *parse_state,
-			struct flow_action *flow_action,
+			struct flow_action *flow_action, int from, int to,
 			struct mlx5_flow_attr *attr,
 			enum mlx5_flow_namespace_type ns_type)
 {
@@ -96,6 +96,11 @@ mlx5e_tc_act_post_parse(struct mlx5e_tc_act_parse_state *parse_state,
 	priv = parse_state->flow->priv;
 
 	flow_action_for_each(i, act, flow_action) {
+		if (i < from)
+			continue;
+		else if (i > to)
+			break;
+
 		tc_act = mlx5e_tc_act_get(act->id, ns_type);
 		if (!tc_act || !tc_act->post_parse)
 			continue;

drivers/net/ethernet/mellanox/mlx5/core/en/tc/act/act.h

@@ -112,7 +112,7 @@ mlx5e_tc_act_init_parse_state(struct mlx5e_tc_act_parse_state *parse_state,
 
 int
 mlx5e_tc_act_post_parse(struct mlx5e_tc_act_parse_state *parse_state,
-			struct flow_action *flow_action,
+			struct flow_action *flow_action, int from, int to,
 			struct mlx5_flow_attr *attr,
 			enum mlx5_flow_namespace_type ns_type);
 

drivers/net/ethernet/mellanox/mlx5/core/en_tc.c

@@ -3859,8 +3859,8 @@ parse_tc_actions(struct mlx5e_tc_act_parse_state *parse_state,
 	struct mlx5_flow_attr *prev_attr;
 	struct flow_action_entry *act;
 	struct mlx5e_tc_act *tc_act;
+	int err, i, i_split = 0;
 	bool is_missable;
-	int err, i;
 
 	ns_type = mlx5e_get_flow_namespace(flow);
 	list_add(&attr->list, &flow->attrs);
@@ -3901,7 +3901,8 @@ parse_tc_actions(struct mlx5e_tc_act_parse_state *parse_state,
 		    i < flow_action->num_entries - 1)) {
 			is_missable = tc_act->is_missable ? tc_act->is_missable(act) : false;
 
-			err = mlx5e_tc_act_post_parse(parse_state, flow_action, attr, ns_type);
+			err = mlx5e_tc_act_post_parse(parse_state, flow_action, i_split, i, attr,
+						      ns_type);
 			if (err)
 				goto out_free_post_acts;
 
@@ -3911,6 +3912,7 @@ parse_tc_actions(struct mlx5e_tc_act_parse_state *parse_state,
 				goto out_free_post_acts;
 			}
 
+			i_split = i + 1;
 			list_add(&attr->list, &flow->attrs);
 		}
 
@@ -3925,7 +3927,7 @@ parse_tc_actions(struct mlx5e_tc_act_parse_state *parse_state,
 		}
 	}
 
-	err = mlx5e_tc_act_post_parse(parse_state, flow_action, attr, ns_type);
+	err = mlx5e_tc_act_post_parse(parse_state, flow_action, i_split, i, attr, ns_type);
 	if (err)
 		goto out_free_post_acts;