* Updates to all configuration items is done under genl_lock().
   Including removal of mdevs or tconns.
 * All read non sleeping read sides are protected by rcu
 * All sleeping read sides keep reference counts to keep the
   objects alive
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>