Re: [B.A.T.M.A.N.] [PATCHv9 2/3] batman-adv: add sysfs framework for VLAN

On Thu, Jun 27, 2013 at 05:00:04AM +0800, Marek Lindner wrote:

On Thursday, June 27, 2013 01:02:06 Antonio Quartulli wrote:

...

+static struct batadv_softif_vlan * +batadv_kobj_to_vlan(struct batadv_priv *bat_priv, struct kobject *obj) +{

•   struct batadv_softif_vlan *vlan;
  

•   hlist_for_each_entry_rcu(vlan, &bat_priv->softif_vlan_list, list) {
  

•           if (vlan->kobj != obj)
  

•                   continue;
  

•           if (!atomic_inc_not_zero(&vlan->refcount))
  

•                   continue;
  

•           return vlan;
  

•   }
  

•   return NULL;
  

+}

Aren't we missing a rcu_lock()/rcu_unlock() combo ?

I was unsure of this because of the context where this for_each is executed. But I think there is nothing protecting the RCU..so yes, we need rcu_read_lock/unlock.

Cheers, Marek