VPB's deviceobject pointer & mount a virtual CD-ROM

Hi All,

I write a virtual CD-ROM supported by an image file via responsing
IOCTL_CDROM_… series in NT 4.0. But so surprise to see I cannot mount the
CD-ROM. VPB’s deviceobject pointer is always zero. IRP_MJ_READ is never
called. I notice that IOCTL_CDROM_CHECK_VERIFY has many info about media
change. But the DDK document is so confusing: VPB_MOUNTED,
STATUS_VERIFY_REQUIRED, DO_VERIFY_VOLUME, etc. I cannot make it clear.

Can anyone give me a clue?

Thanks a lot.

Jeffrey Ren
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