net: sched: take reference to action dev before calling offloads

In order to remove dependency on rtnl lock when calling hardware offload
API, take reference to action mirred dev when initializing flow_action
structure in tc_setup_flow_action(). Implement function
tc_cleanup_flow_action(), use it to release the device after hardware
offload API is done using it.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/pkt_cls.h

@@ -505,6 +505,8 @@ tcf_match_indev(struct sk_buff *skb, int ifindex)
 
 int tc_setup_flow_action(struct flow_action *flow_action,
 			 const struct tcf_exts *exts, bool rtnl_held);
+void tc_cleanup_flow_action(struct flow_action *flow_action);
+
 int tc_setup_cb_call(struct tcf_block *block, enum tc_setup_type type,
 		     void *type_data, bool err_stop, bool rtnl_held);
 int tc_setup_cb_add(struct tcf_block *block, struct tcf_proto *tp,

net/sched/cls_api.c

@@ -3265,6 +3265,27 @@ int tc_setup_cb_reoffload(struct tcf_block *block, struct tcf_proto *tp,
 }
 EXPORT_SYMBOL(tc_setup_cb_reoffload);
 
+void tc_cleanup_flow_action(struct flow_action *flow_action)
+{
+	struct flow_action_entry *entry;
+	int i;
+
+	flow_action_for_each(i, entry, flow_action) {
+		switch (entry->id) {
+		case FLOW_ACTION_REDIRECT:
+		case FLOW_ACTION_MIRRED:
+		case FLOW_ACTION_REDIRECT_INGRESS:
+		case FLOW_ACTION_MIRRED_INGRESS:
+			if (entry->dev)
+				dev_put(entry->dev);
+			break;
+		default:
+			break;
+		}
+	}
+}
+EXPORT_SYMBOL(tc_cleanup_flow_action);
+
 int tc_setup_flow_action(struct flow_action *flow_action,
 			 const struct tcf_exts *exts, bool rtnl_held)
 {
@@ -3294,15 +3315,23 @@ int tc_setup_flow_action(struct flow_action *flow_action,
 		} else if (is_tcf_mirred_egress_redirect(act)) {
 			entry->id = FLOW_ACTION_REDIRECT;
 			entry->dev = tcf_mirred_dev(act);
+			if (entry->dev)
+				dev_hold(entry->dev);
 		} else if (is_tcf_mirred_egress_mirror(act)) {
 			entry->id = FLOW_ACTION_MIRRED;
 			entry->dev = tcf_mirred_dev(act);
+			if (entry->dev)
+				dev_hold(entry->dev);
 		} else if (is_tcf_mirred_ingress_redirect(act)) {
 			entry->id = FLOW_ACTION_REDIRECT_INGRESS;
 			entry->dev = tcf_mirred_dev(act);
+			if (entry->dev)
+				dev_hold(entry->dev);
 		} else if (is_tcf_mirred_ingress_mirror(act)) {
 			entry->id = FLOW_ACTION_MIRRED_INGRESS;
 			entry->dev = tcf_mirred_dev(act);
+			if (entry->dev)
+				dev_hold(entry->dev);
 		} else if (is_tcf_vlan(act)) {
 			switch (tcf_vlan_action(act)) {
 			case TCA_VLAN_ACT_PUSH:
@@ -3410,6 +3439,9 @@ int tc_setup_flow_action(struct flow_action *flow_action,
 	if (!rtnl_held)
 		rtnl_unlock();
 
+	if (err)
+		tc_cleanup_flow_action(flow_action);
+
 	return err;
 }
 EXPORT_SYMBOL(tc_setup_flow_action);

net/sched/cls_flower.c

@@ -465,6 +465,7 @@ static int fl_hw_replace_filter(struct tcf_proto *tp,
 
 	err = tc_setup_cb_add(block, tp, TC_SETUP_CLSFLOWER, &cls_flower,
 			      skip_sw, &f->flags, &f->in_hw_count, true);
+	tc_cleanup_flow_action(&cls_flower.rule->action);
 	kfree(cls_flower.rule);
 
 	if (err) {
@@ -1838,6 +1839,7 @@ static int fl_reoffload(struct tcf_proto *tp, bool add, flow_setup_cb_t *cb,
 					    TC_SETUP_CLSFLOWER, &cls_flower,
 					    cb_priv, &f->flags,
 					    &f->in_hw_count);
+		tc_cleanup_flow_action(&cls_flower.rule->action);
 		kfree(cls_flower.rule);
 
 		if (err) {