static void check_and_drop(void *_data)
{
	struct detach_data *data = _data;

	if (!data->mountpoint && list_empty(&data->select.dispose))
		__d_drop(data->select.start);
}

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.