1 files changed, 46 insertions, 35 deletions

diff --git a/net/netfilter/ipset/ip_set_core.c b/net/netfilter/ipset/ip_set_core.c
index 3184cc6be4c9..c7ae4d9bf3d2 100644
--- a/net/netfilter/ipset/ip_set_core.c
+++ b/net/netfilter/ipset/ip_set_core.c
@@ -1172,23 +1172,50 @@ ip_set_setname_policy[IPSET_ATTR_CMD_MAX + 1] = {
 				    .len = IPSET_MAXNAMELEN - 1 },
 };
 
+/* In order to return quickly when destroying a single set, it is split
+ * into two stages:
+ * - Cancel garbage collector
+ * - Destroy the set itself via call_rcu()
+ */
+
 static void
-ip_set_destroy_set(struct ip_set *set)
+ip_set_destroy_set_rcu(struct rcu_head *head)
 {
-	pr_debug("set: %s\n",  set->name);
+	struct ip_set *set = container_of(head, struct ip_set, rcu);
 
-	/* Must call it without holding any lock */
 	set->variant->destroy(set);
 	module_put(set->type->me);
 	kfree(set);
 }
 
 static void
-ip_set_destroy_set_rcu(struct rcu_head *head)
+_destroy_all_sets(struct ip_set_net *inst)
 {
-	struct ip_set *set = container_of(head, struct ip_set, rcu);
+	struct ip_set *set;
+	ip_set_id_t i;
+	bool need_wait = false;
 
-	ip_set_destroy_set(set);
+	/* First cancel gc's: set:list sets are flushed as well */
+	for (i = 0; i < inst->ip_set_max; i++) {
+		set = ip_set(inst, i);
+		if (set) {
+			set->variant->cancel_gc(set);
+			if (set->type->features & IPSET_TYPE_NAME)
+				need_wait = true;
+		}
+	}
+	/* Must wait for flush to be really finished  */
+	if (need_wait)
+		rcu_barrier();
+	for (i = 0; i < inst->ip_set_max; i++) {
+		set = ip_set(inst, i);
+		if (set) {
+			ip_set(inst, i) = NULL;
+			set->variant->destroy(set);
+			module_put(set->type->me);
+			kfree(set);
+		}
+	}
 }
 
 static int ip_set_destroy(struct sk_buff *skb, const struct nfnl_info *info,
@@ -1202,11 +1229,10 @@ static int ip_set_destroy(struct sk_buff *skb, const struct nfnl_info *info,
 	if (unlikely(protocol_min_failed(attr)))
 		return -IPSET_ERR_PROTOCOL;
 
-
 	/* Commands are serialized and references are
 	 * protected by the ip_set_ref_lock.
 	 * External systems (i.e. xt_set) must call
-	 * ip_set_put|get_nfnl_* functions, that way we
+	 * ip_set_nfnl_get_* functions, that way we
 	 * can safely check references here.
 	 *
 	 * list:set timer can only decrement the reference
@@ -1214,8 +1240,6 @@ static int ip_set_destroy(struct sk_buff *skb, const struct nfnl_info *info,
 	 * without holding the lock.
 	 */
 	if (!attr[IPSET_ATTR_SETNAME]) {
-		/* Must wait for flush to be really finished in list:set */
-		rcu_barrier();
 		read_lock_bh(&ip_set_ref_lock);
 		for (i = 0; i < inst->ip_set_max; i++) {
 			s = ip_set(inst, i);
@@ -1226,15 +1250,7 @@ static int ip_set_destroy(struct sk_buff *skb, const struct nfnl_info *info,
 		}
 		inst->is_destroyed = true;
 		read_unlock_bh(&ip_set_ref_lock);
-		for (i = 0; i < inst->ip_set_max; i++) {
-			s = ip_set(inst, i);
-			if (s) {
-				ip_set(inst, i) = NULL;
-				/* Must cancel garbage collectors */
-				s->variant->cancel_gc(s);
-				ip_set_destroy_set(s);
-			}
-		}
+		_destroy_all_sets(inst);
 		/* Modified by ip_set_destroy() only, which is serialized */
 		inst->is_destroyed = false;
 	} else {
@@ -1255,12 +1271,12 @@ static int ip_set_destroy(struct sk_buff *skb, const struct nfnl_info *info,
 		features = s->type->features;
 		ip_set(inst, i) = NULL;
 		read_unlock_bh(&ip_set_ref_lock);
+		/* Must cancel garbage collectors */
+		s->variant->cancel_gc(s);
 		if (features & IPSET_TYPE_NAME) {
 			/* Must wait for flush to be really finished  */
 			rcu_barrier();
 		}
-		/* Must cancel garbage collectors */
-		s->variant->cancel_gc(s);
 		call_rcu(&s->rcu, ip_set_destroy_set_rcu);
 	}
 	return 0;
@@ -2365,30 +2381,25 @@ ip_set_net_init(struct net *net)
 }
 
 static void __net_exit
-ip_set_net_exit(struct net *net)
+ip_set_net_pre_exit(struct net *net)
 {
 	struct ip_set_net *inst = ip_set_pernet(net);
 
-	struct ip_set *set = NULL;
-	ip_set_id_t i;
-
 	inst->is_deleted = true; /* flag for ip_set_nfnl_put */
+}
 
-	nfnl_lock(NFNL_SUBSYS_IPSET);
-	for (i = 0; i < inst->ip_set_max; i++) {
-		set = ip_set(inst, i);
-		if (set) {
-			ip_set(inst, i) = NULL;
-			set->variant->cancel_gc(set);
-			ip_set_destroy_set(set);
-		}
-	}
-	nfnl_unlock(NFNL_SUBSYS_IPSET);
+static void __net_exit
+ip_set_net_exit(struct net *net)
+{
+	struct ip_set_net *inst = ip_set_pernet(net);
+
+	_destroy_all_sets(inst);
 	kvfree(rcu_dereference_protected(inst->ip_set_list, 1));
 }
 
 static struct pernet_operations ip_set_net_ops = {
 	.init	= ip_set_net_init,
+	.pre_exit = ip_set_net_pre_exit,
 	.exit   = ip_set_net_exit,
 	.id	= &ip_set_net_id,
 	.size	= sizeof(struct ip_set_net),