Changer I/O Control Codes
All public I/O control codes for drivers of changer devices use buffered I/O. Consequently, the input or output data for these requests is at Irp->AssociatedIrp.SystemBuffer.
Class drivers for changer devices handle additional public I/O control codes, along with those described in this section. For more information about requirements for storage class drivers, see General Storage I/O Control Codes.