[PATCH net-next 07/10] batman-adv: use __dev_get_by_index instead of dev_get_by_index to find interface

Ying Xue
2014-01-14T07:42:48Z

The following call chains indicate that batadv_is_on_batman_iface()
is always under rtnl_lock protection as call_netdevice_notifier()
is protected by rtnl_lock. So if __dev_get_by_index() rather than
dev_get_by_index() is used to find interface handler in it, this
would help us avoid to change interface reference counter.

call_netdevice_notifier()
batadv_hard_if_event()
batadv_hardif_add_interface()
batadv_is_valid_iface()
batadv_is_on_batman_iface()

Cc: Antonio Quartulli <antonio@meshcoding.com>
Signed-off-by: Ying Xue <ying.xue@windriver.com>
---
net/batman-adv/hard-interface.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c
index bebd46c..115d14e 100644
--- a/net/batman-adv/hard-interface.c
+++ b/net/batman-adv/hard-interface.c
@@ -86,15 +86,13 @@ static bool batadv_is_on_batman_iface(const struct net_device *net_dev)
return false;

/* recurse over the parent device */
- parent_dev = dev_get_by_index(&init_net, net_dev->iflink);
+ parent_dev = __dev_get_by_index(&init_net, net_dev->iflink);
/* if we got a NULL parent_dev there is something broken.. */
if (WARN(!parent_dev, "Cannot find parent device"))
return false;

ret = batadv_is_on_batman_iface(parent_dev);

- if (parent_dev)
- dev_put(parent_dev);
return ret;
}

--
1.7.9.5