Re: [PATCH] (1/8) Eliminate brlock in psnap

[Roman Zippel]

Hi,

On 11 Mar 2003, Stephen Hemminger wrote:

>  void unregister_snap_client(struct datalink_proto *proto)
>  {
> -	br_write_lock_bh(BR_NETPROTO_LOCK);
> +	static RCU_HEAD(snap_rcu);
>  
> -	list_del(&proto->node);
> -	kfree(proto);
> +	spin_lock_bh(&snap_lock);
> +	list_del_rcu(&proto->node);
> +	spin_unlock_bh(&snap_lock);
>  
> -	br_write_unlock_bh(BR_NETPROTO_LOCK);
> +	call_rcu(&snap_rcu, (void (*)(void *)) kfree, proto);
>  }

Is this really correct? What happens with snap_rcu, if 
unregister_snap_client is called again, before the call_rcu callback 
finished?

bye, Roman