1 files changed, 28 insertions, 19 deletions

diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c
index 2f0d42f2f913..781c5b6e6e8e 100644
--- a/net/batman-adv/hard-interface.c
+++ b/net/batman-adv/hard-interface.c
@@ -763,11 +763,6 @@ int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
 	hard_iface->soft_iface = soft_iface;
 	bat_priv = netdev_priv(hard_iface->soft_iface);
 
-	if (bat_priv->num_ifaces >= UINT_MAX) {
-		ret = -ENOSPC;
-		goto err_dev;
-	}
-
 	ret = netdev_master_upper_dev_link(hard_iface->net_dev,
 					   soft_iface, NULL, NULL, NULL);
 	if (ret)
@@ -777,16 +772,7 @@ int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
 	if (ret < 0)
 		goto err_upper;
 
-	hard_iface->if_num = bat_priv->num_ifaces;
-	bat_priv->num_ifaces++;
 	hard_iface->if_status = BATADV_IF_INACTIVE;
-	ret = batadv_orig_hash_add_if(hard_iface, bat_priv->num_ifaces);
-	if (ret < 0) {
-		bat_priv->algo_ops->iface.disable(hard_iface);
-		bat_priv->num_ifaces--;
-		hard_iface->if_status = BATADV_IF_NOT_IN_USE;
-		goto err_upper;
-	}
 
 	kref_get(&hard_iface->refcount);
 	hard_iface->batman_adv_ptype.type = ethertype;
@@ -834,6 +820,33 @@ err:
 }
 
 /**
+ * batadv_hardif_cnt() - get number of interfaces enslaved to soft interface
+ * @soft_iface: soft interface to check
+ *
+ * This function is only using RCU for locking - the result can therefore be
+ * off when another functions is modifying the list at the same time. The
+ * caller can use the rtnl_lock to make sure that the count is accurate.
+ *
+ * Return: number of connected/enslaved hard interfaces
+ */
+static size_t batadv_hardif_cnt(const struct net_device *soft_iface)
+{
+	struct batadv_hard_iface *hard_iface;
+	size_t count = 0;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
+		if (hard_iface->soft_iface != soft_iface)
+			continue;
+
+		count++;
+	}
+	rcu_read_unlock();
+
+	return count;
+}
+
+/**
  * batadv_hardif_disable_interface() - Remove hard interface from soft interface
  * @hard_iface: hard interface to be removed
  * @autodel: whether to delete soft interface when it doesn't contain any other
@@ -855,9 +868,6 @@ void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface,
 	dev_remove_pack(&hard_iface->batman_adv_ptype);
 	batadv_hardif_put(hard_iface);
 
-	bat_priv->num_ifaces--;
-	batadv_orig_hash_del_if(hard_iface, bat_priv->num_ifaces);
-
 	primary_if = batadv_primary_if_get_selected(bat_priv);
 	if (hard_iface == primary_if) {
 		struct batadv_hard_iface *new_if;
@@ -881,7 +891,7 @@ void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface,
 	batadv_hardif_recalc_extra_skbroom(hard_iface->soft_iface);
 
 	/* nobody uses this interface anymore */
-	if (bat_priv->num_ifaces == 0) {
+	if (batadv_hardif_cnt(hard_iface->soft_iface) <= 1) {
 		batadv_gw_check_client_stop(bat_priv);
 
 		if (autodel == BATADV_IF_CLEANUP_AUTO)
@@ -917,7 +927,6 @@ batadv_hardif_add_interface(struct net_device *net_dev)
 	if (ret)
 		goto free_if;
 
-	hard_iface->if_num = 0;
 	hard_iface->net_dev = net_dev;
 	hard_iface->soft_iface = NULL;
 	hard_iface->if_status = BATADV_IF_NOT_IN_USE;