+/*
+ * highlevel_read, highlevel_write, highlevel_lock, highlevel_lock64:
+ *
+ * These functions are called to handle transactions. They are called when a
+ * packet arrives. The flags argument contains the second word of the first
+ * header quadlet of the incoming packet (containing transaction label, retry
+ * code, transaction code and priority). These functions either return a
+ * response code or a negative number. In the first case a response will be
+ * generated. In the latter case, no response will be sent and the driver which
+ * handled the request will send the response itself.
+ */