1 files changed, 17 insertions, 9 deletions

diff --git a/net/sched/cls_route.c b/net/sched/cls_route.c
index 2ecd24688554..08a3b0a6f5ab 100644
--- a/net/sched/cls_route.c
+++ b/net/sched/cls_route.c
@@ -258,6 +258,13 @@ static unsigned long route4_get(struct tcf_proto *tp, u32 handle)
 
 static int route4_init(struct tcf_proto *tp)
 {
+	struct route4_head *head;
+
+	head = kzalloc(sizeof(struct route4_head), GFP_KERNEL);
+	if (head == NULL)
+		return -ENOBUFS;
+
+	rcu_assign_pointer(tp->root, head);
 	return 0;
 }
 
@@ -270,13 +277,20 @@ route4_delete_filter(struct rcu_head *head)
 	kfree(f);
 }
 
-static void route4_destroy(struct tcf_proto *tp)
+static bool route4_destroy(struct tcf_proto *tp, bool force)
 {
 	struct route4_head *head = rtnl_dereference(tp->root);
 	int h1, h2;
 
 	if (head == NULL)
-		return;
+		return true;
+
+	if (!force) {
+		for (h1 = 0; h1 <= 256; h1++) {
+			if (rcu_access_pointer(head->table[h1]))
+				return false;
+		}
+	}
 
 	for (h1 = 0; h1 <= 256; h1++) {
 		struct route4_bucket *b;
@@ -301,6 +315,7 @@ static void route4_destroy(struct tcf_proto *tp)
 	}
 	RCU_INIT_POINTER(tp->root, NULL);
 	kfree_rcu(head, rcu);
+	return true;
 }
 
 static int route4_delete(struct tcf_proto *tp, unsigned long arg)
@@ -484,13 +499,6 @@ static int route4_change(struct net *net, struct sk_buff *in_skb,
 			return -EINVAL;
 
 	err = -ENOBUFS;
-	if (head == NULL) {
-		head = kzalloc(sizeof(struct route4_head), GFP_KERNEL);
-		if (head == NULL)
-			goto errout;
-		rcu_assign_pointer(tp->root, head);
-	}
-
 	f = kzalloc(sizeof(struct route4_filter), GFP_KERNEL);
 	if (!f)
 		goto errout;