2 files changed, 12 insertions, 0 deletions

diff --git a/include/net/netfilter/nf_conntrack_count.h b/include/net/netfilter/nf_conntrack_count.h
index 9645b47fa7e4..e227d997fc71 100644
--- a/include/net/netfilter/nf_conntrack_count.h
+++ b/include/net/netfilter/nf_conntrack_count.h
@@ -10,6 +10,7 @@ struct nf_conncount_data;
 
 struct nf_conncount_list {
 	spinlock_t list_lock;
+	u32 last_gc;		/* jiffies at most recent gc */
 	struct list_head head;	/* connections with the same filtering key */
 	unsigned int count;	/* length of list */
 };
diff --git a/net/netfilter/nf_conncount.c b/net/netfilter/nf_conncount.c
index 82f36beb2e76..5d8ed6c90b7e 100644
--- a/net/netfilter/nf_conncount.c
+++ b/net/netfilter/nf_conncount.c
@@ -132,6 +132,9 @@ static int __nf_conncount_add(struct net *net,
 	struct nf_conn *found_ct;
 	unsigned int collect = 0;
 
+	if (time_is_after_eq_jiffies((unsigned long)list->last_gc))
+		goto add_new_node;
+
 	/* check the saved connections */
 	list_for_each_entry_safe(conn, conn_n, &list->head, node) {
 		if (collect > CONNCOUNT_GC_MAX_NODES)
@@ -177,6 +180,7 @@ static int __nf_conncount_add(struct net *net,
 		nf_ct_put(found_ct);
 	}
 
+add_new_node:
 	if (WARN_ON_ONCE(list->count > INT_MAX))
 		return -EOVERFLOW;
 
@@ -190,6 +194,7 @@ static int __nf_conncount_add(struct net *net,
 	conn->jiffies32 = (u32)jiffies;
 	list_add_tail(&conn->node, &list->head);
 	list->count++;
+	list->last_gc = (u32)jiffies;
 	return 0;
 }
 
@@ -214,6 +219,7 @@ void nf_conncount_list_init(struct nf_conncount_list *list)
 	spin_lock_init(&list->list_lock);
 	INIT_LIST_HEAD(&list->head);
 	list->count = 0;
+	list->last_gc = (u32)jiffies;
 }
 EXPORT_SYMBOL_GPL(nf_conncount_list_init);
 
@@ -227,6 +233,10 @@ bool nf_conncount_gc_list(struct net *net,
 	unsigned int collected = 0;
 	bool ret = false;
 
+	/* don't bother if we just did GC */
+	if (time_is_after_eq_jiffies((unsigned long)READ_ONCE(list->last_gc)))
+		return false;
+
 	/* don't bother if other cpu is already doing GC */
 	if (!spin_trylock(&list->list_lock))
 		return false;
@@ -258,6 +268,7 @@ bool nf_conncount_gc_list(struct net *net,
 
 	if (!list->count)
 		ret = true;
+	list->last_gc = (u32)jiffies;
 	spin_unlock(&list->list_lock);
 
 	return ret;