PDEVICE_OBJECT DiskDeviceObject = FilterGetDiskObject(CurrentStackLocation->Parameters.MountVolume.Vpb->RealDevice);

UsbBuildGetDescriptorRequest(Urb,
        sizeof (struct _URB_CONTROL_DESCRIPTOR_REQUEST), 
        USB_DEVICE_DESCRIPTOR_TYPE,
        0,
        DeviceExtension->langid,
        deviceDescriptor,
        NULL,
        size,
        NULL);
         
    if(DiskDeviceObject)
        Status = DoCallUSBD(DiskDeviceObject, Urb);