Re: [PATCH 3/6] ksmbd: replace rwlock with rcu for concurrenct access on conn list

[Sergey Senozhatsky]

On (23/01/15 18:32), Dawei Li wrote:
> 
>  void ksmbd_conn_free(struct ksmbd_conn *conn)
>  {
> -	write_lock(&conn_list_lock);
> -	list_del(&conn->conns_list);
> -	write_unlock(&conn_list_lock);
> +	spin_lock(&conn_list_lock);
> +	list_del_rcu(&conn->conns_list);
> +	spin_unlock(&conn_list_lock);
>  
>  	xa_destroy(&conn->sessions);
>  	kvfree(conn->request_buf);

>From a quick look this does not seem like a correct RCU usage. E.g.
where do you wait for grace periods and synchronize readers/writers?