batman-adv: Place kref_get for hard_iface near use

It is hard to understand why the refcnt is increased when it isn't done
near the actual place the new reference is used. So using kref_get right
before the place which requires the reference and in the same function
helps to avoid accidental problems caused by incorrect reference counting.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c
index 43c9a3e0251212bd4172be7da6c28b066554b897..9284c73f1b482afdbbe4547b3944c1668531119d 100644 (file)
--- a/net/batman-adv/hard-interface.c
+++ b/net/batman-adv/hard-interface.c
@@ -694,6 +694,7 @@ batadv_hardif_add_interface(struct net_device *net_dev)
        INIT_HLIST_HEAD(&hard_iface->neigh_list);
 
        spin_lock_init(&hard_iface->neigh_list_lock);
+       kref_init(&hard_iface->refcount);
 
        hard_iface->num_bcasts = BATADV_NUM_BCASTS_DEFAULT;
        if (batadv_is_wifi_netdev(net_dev))
@@ -701,11 +702,8 @@ batadv_hardif_add_interface(struct net_device *net_dev)
 
        batadv_v_hardif_init(hard_iface);
 
-       /* extra reference for return */
-       kref_init(&hard_iface->refcount);
-       kref_get(&hard_iface->refcount);
-
        batadv_check_known_mac_addr(hard_iface->net_dev);
+       kref_get(&hard_iface->refcount);
        list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list);
 
        return hard_iface;