On 14/01/14 08:41, Ying Xue wrote:
> 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>

Acked-by: Antonio Quartulli <antonio@meshcoding.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;
>  }
>  
> 


-- 
Antonio Quartulli