1 files changed, 38 insertions, 7 deletions

diff --git a/net/sched/act_sample.c b/net/sched/act_sample.c
index 274d7a0c0e25..692c4c9040fd 100644
--- a/net/sched/act_sample.c
+++ b/net/sched/act_sample.c
@@ -41,8 +41,8 @@ static int tcf_sample_init(struct net *net, struct nlattr *nla,
 	struct tc_action_net *tn = net_generic(net, sample_net_id);
 	struct nlattr *tb[TCA_SAMPLE_MAX + 1];
 	struct psample_group *psample_group;
+	u32 psample_group_num, rate, index;
 	struct tcf_chain *goto_ch = NULL;
-	u32 psample_group_num, rate;
 	struct tc_sample *parm;
 	struct tcf_sample *s;
 	bool exists = false;
@@ -59,8 +59,8 @@ static int tcf_sample_init(struct net *net, struct nlattr *nla,
 		return -EINVAL;
 
 	parm = nla_data(tb[TCA_SAMPLE_PARMS]);
-
-	err = tcf_idr_check_alloc(tn, &parm->index, a, bind);
+	index = parm->index;
+	err = tcf_idr_check_alloc(tn, &index, a, bind);
 	if (err < 0)
 		return err;
 	exists = err;
@@ -68,10 +68,10 @@ static int tcf_sample_init(struct net *net, struct nlattr *nla,
 		return 0;
 
 	if (!exists) {
-		ret = tcf_idr_create(tn, parm->index, est, a,
+		ret = tcf_idr_create(tn, index, est, a,
 				     &act_sample_ops, bind, true);
 		if (ret) {
-			tcf_idr_cleanup(tn, parm->index);
+			tcf_idr_cleanup(tn, index);
 			return ret;
 		}
 		ret = ACT_P_CREATED;
@@ -102,13 +102,17 @@ static int tcf_sample_init(struct net *net, struct nlattr *nla,
 	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 	s->rate = rate;
 	s->psample_group_num = psample_group_num;
-	RCU_INIT_POINTER(s->psample_group, psample_group);
+	rcu_swap_protected(s->psample_group, psample_group,
+			   lockdep_is_held(&s->tcf_lock));
 
 	if (tb[TCA_SAMPLE_TRUNC_SIZE]) {
 		s->truncate = true;
 		s->trunc_size = nla_get_u32(tb[TCA_SAMPLE_TRUNC_SIZE]);
 	}
 	spin_unlock_bh(&s->tcf_lock);
+
+	if (psample_group)
+		psample_group_put(psample_group);
 	if (goto_ch)
 		tcf_chain_put_by_act(goto_ch);
 
@@ -248,6 +252,32 @@ static int tcf_sample_search(struct net *net, struct tc_action **a, u32 index)
 	return tcf_idr_search(tn, a, index);
 }
 
+static void tcf_psample_group_put(void *priv)
+{
+	struct psample_group *group = priv;
+
+	psample_group_put(group);
+}
+
+static struct psample_group *
+tcf_sample_get_group(const struct tc_action *a,
+		     tc_action_priv_destructor *destructor)
+{
+	struct tcf_sample *s = to_sample(a);
+	struct psample_group *group;
+
+	spin_lock_bh(&s->tcf_lock);
+	group = rcu_dereference_protected(s->psample_group,
+					  lockdep_is_held(&s->tcf_lock));
+	if (group) {
+		psample_group_take(group);
+		*destructor = tcf_psample_group_put;
+	}
+	spin_unlock_bh(&s->tcf_lock);
+
+	return group;
+}
+
 static struct tc_action_ops act_sample_ops = {
 	.kind	  = "sample",
 	.id	  = TCA_ID_SAMPLE,
@@ -258,6 +288,7 @@ static struct tc_action_ops act_sample_ops = {
 	.cleanup  = tcf_sample_cleanup,
 	.walk	  = tcf_sample_walker,
 	.lookup	  = tcf_sample_search,
+	.get_psample_group = tcf_sample_get_group,
 	.size	  = sizeof(struct tcf_sample),
 };
 
@@ -265,7 +296,7 @@ static __net_init int sample_init_net(struct net *net)
 {
 	struct tc_action_net *tn = net_generic(net, sample_net_id);
 
-	return tc_action_net_init(tn, &act_sample_ops);
+	return tc_action_net_init(net, tn, &act_sample_ops);
 }
 
 static void __net_exit sample_exit_net(struct list_head *net_list)