batman-adv: Place kref_get for nc_node 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/network-coding.c b/net/batman-adv/network-coding.c
index 3814cfb9484620343c229ec8e718f260479ebcd0..4f4cfe53f9730ce6192c1faab799798f45245657 100644 (file)
--- a/net/batman-adv/network-coding.c
+++ b/net/batman-adv/network-coding.c
@@ -859,7 +859,6 @@ batadv_nc_get_nc_node(struct batadv_priv *bat_priv,
        /* Initialize nc_node */
        INIT_LIST_HEAD(&nc_node->list);
        kref_init(&nc_node->refcount);
-       kref_get(&nc_node->refcount);
        ether_addr_copy(nc_node->addr, orig_node->orig);
        kref_get(&orig_neigh_node->refcount);
        nc_node->orig_node = orig_neigh_node;
@@ -878,6 +877,7 @@ batadv_nc_get_nc_node(struct batadv_priv *bat_priv,
 
        /* Add nc_node to orig_node */
        spin_lock_bh(lock);
+       kref_get(&nc_node->refcount);
        list_add_tail_rcu(&nc_node->list, list);
        spin_unlock_bh(lock);