batman-adv: Place kref_get for orig_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/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c
index 9ed4f1f..3c7900d 100644 (file)
--- a/net/batman-adv/bat_iv_ogm.c
+++ b/net/batman-adv/bat_iv_ogm.c
@@ -324,17 +324,18 @@ batadv_iv_ogm_orig_get(struct batadv_priv *bat_priv, const u8 *addr)
        if (!orig_node->bat_iv.bcast_own_sum)
                goto free_orig_node;
 
+       kref_get(&orig_node->refcount);
        hash_added = batadv_hash_add(bat_priv->orig_hash, batadv_compare_orig,
                                     batadv_choose_orig, orig_node,
                                     &orig_node->hash_entry);
        if (hash_added != 0)
-               goto free_orig_node;
+               goto free_orig_node_hash;
 
        return orig_node;
 
-free_orig_node:
-       /* free twice, as batadv_orig_node_new sets refcount to 2 */
+free_orig_node_hash:
        batadv_orig_node_put(orig_node);
+free_orig_node:
        batadv_orig_node_put(orig_node);
 
        return NULL;

diff --git a/net/batman-adv/bat_v_ogm.c b/net/batman-adv/bat_v_ogm.c
index 6fbba4e..1aeeadc 100644 (file)
--- a/net/batman-adv/bat_v_ogm.c
+++ b/net/batman-adv/bat_v_ogm.c
@@ -73,13 +73,12 @@ struct batadv_orig_node *batadv_v_ogm_orig_get(struct batadv_priv *bat_priv,
        if (!orig_node)
                return NULL;
 
+       kref_get(&orig_node->refcount);
        hash_added = batadv_hash_add(bat_priv->orig_hash, batadv_compare_orig,
                                     batadv_choose_orig, orig_node,
                                     &orig_node->hash_entry);
        if (hash_added != 0) {
-               /* orig_node->refcounter is initialised to 2 by
-                * batadv_orig_node_new()
-                */
+               /* remove refcnt for newly created orig_node and hash entry */
                batadv_orig_node_put(orig_node);
                batadv_orig_node_put(orig_node);
                orig_node = NULL;

diff --git a/net/batman-adv/gateway_client.c b/net/batman-adv/gateway_client.c
index c2928c2..b889e1f 100644 (file)
--- a/net/batman-adv/gateway_client.c
+++ b/net/batman-adv/gateway_client.c
@@ -339,8 +339,8 @@ static void batadv_gw_node_add(struct batadv_priv *bat_priv,
        if (!gw_node)
                return;
 
-       kref_get(&orig_node->refcount);
        INIT_HLIST_NODE(&gw_node->list);
+       kref_get(&orig_node->refcount);
        gw_node->orig_node = orig_node;
        gw_node->bandwidth_down = ntohl(gateway->bandwidth_down);
        gw_node->bandwidth_up = ntohl(gateway->bandwidth_up);

diff --git a/net/batman-adv/network-coding.c b/net/batman-adv/network-coding.c
index 293ef4f..3814cfb 100644 (file)
--- a/net/batman-adv/network-coding.c
+++ b/net/batman-adv/network-coding.c
@@ -856,14 +856,13 @@ batadv_nc_get_nc_node(struct batadv_priv *bat_priv,
        if (!nc_node)
                return NULL;
 
-       kref_get(&orig_neigh_node->refcount);
-
        /* Initialize nc_node */
        INIT_LIST_HEAD(&nc_node->list);
-       ether_addr_copy(nc_node->addr, orig_node->orig);
-       nc_node->orig_node = orig_neigh_node;
        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;
 
        /* Select ingoing or outgoing coding node */
        if (in_coding) {

diff --git a/net/batman-adv/originator.c b/net/batman-adv/originator.c
index 0792de8..0b7d57a 100644 (file)
--- a/net/batman-adv/originator.c
+++ b/net/batman-adv/originator.c
@@ -989,7 +989,6 @@ struct batadv_orig_node *batadv_orig_node_new(struct batadv_priv *bat_priv,
 
        /* extra reference for return */
        kref_init(&orig_node->refcount);
-       kref_get(&orig_node->refcount);
 
        orig_node->bat_priv = bat_priv;
        ether_addr_copy(orig_node->orig, addr);