if (m >= (1 << MINORBITS)) {
idr_remove(&_minor_idr, m);
if (m >= (1 << MINORBITS)) {
idr_remove(&_minor_idr, m);
init_rwsem(&md->io_lock);
mutex_init(&md->suspend_lock);
spin_lock_init(&md->pushback_lock);
init_rwsem(&md->io_lock);
mutex_init(&md->suspend_lock);
spin_lock_init(&md->pushback_lock);