diff mbox

[v2,12/18] batman-adv: Place kref_get for gw_node near use

Message ID 1468597173-25378-12-git-send-email-sven@narfation.org (mailing list archive)
State Accepted, archived
Commit b7981d47fb4fc64569a517170951dd2ce5615789
Delegated to: Marek Lindner
Headers

Commit Message

Sven Eckelmann July 15, 2016, 3:39 p.m. UTC 
  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 causedy incorrect reference counting.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
---
v2:
 - split patch based on type

 net/batman-adv/gateway_client.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

Comments

Marek Lindner July 19, 2016, 8:34 a.m. UTC | #1 
On Friday, July 15, 2016 17:39:27 Sven Eckelmann wrote:
> 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 causedy incorrect reference counting.
> 
> Signed-off-by: Sven Eckelmann <sven@narfation.org>
> ---
> v2:
>  - split patch based on type
> 
>  net/batman-adv/gateway_client.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)

Applied in revision b7981d4.

Thanks,
Marek
diff mbox

Patch

diff --git a/net/batman-adv/gateway_client.c b/net/batman-adv/gateway_client.c
index 94f8f9d..afa43d4 100644
--- a/net/batman-adv/gateway_client.c
+++ b/net/batman-adv/gateway_client.c
@@ -333,14 +333,15 @@  static void batadv_gw_node_add(struct batadv_priv *bat_priv,
 	if (!gw_node)
 		return;
 
+	kref_init(&gw_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);
-	kref_init(&gw_node->refcount);
 
 	spin_lock_bh(&bat_priv->gw.list_lock);
+	kref_get(&gw_node->refcount);
 	hlist_add_head_rcu(&gw_node->list, &bat_priv->gw.list);
 	spin_unlock_bh(&bat_priv->gw.list_lock);
 
@@ -351,6 +352,9 @@  static void batadv_gw_node_add(struct batadv_priv *bat_priv,
 		   ntohl(gateway->bandwidth_down) % 10,
 		   ntohl(gateway->bandwidth_up) / 10,
 		   ntohl(gateway->bandwidth_up) % 10);
+
+	/* don't return reference to new gw_node */
+	batadv_gw_node_put(gw_node);
 }
 
 /**