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>

3 files changed, 36 insertions, 0 deletions

diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
index a48824bc1489..e553fc80eb23 100644
--- a/include/net/pkt_cls.h
+++ b/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,
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 8751bb8a682f..d988737693e4 100644
--- a/net/sched/cls_api.c
+++ b/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 @@ err_out:
         if (!rtnl_held)
                 rtnl_unlock();
 
+        if (err)
+                tc_cleanup_flow_action(flow_action);
+
         return err;
 }
 EXPORT_SYMBOL(tc_setup_flow_action);
diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index fb305bd45d93..2852fe6f50d2 100644
--- a/net/sched/cls_flower.c
+++ b/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) {