IOCTL in ntddisk.h

Hello,
Few days back I was working on a disk driver on winXP and I came across a
strange thing.

For my driver system was generating an IOCtl with fucntion code 0x0017 (I
found out this function code using macro CTL_CODE as IOCTL values are
derived using CTL_CODE). But when I looked into the ntddisk.h for XP it
didnt have any such IOCTL for this value. I was totally confused why system
is generating such IOCTL. After more investigation I came to know for WIN2K
version DDK has a IOCTL "IOCTL_DISK_GET_LENGTH_INFO" for this function code.
After adding this IOCTL explicitly in the header file my problem was solved.
Can anyone comment why is it so ? Was it the case only with my installation
or with generic installation ? I even noticed DDK help showing help on this
IOCTL value.


Regards,
Rushikesh.


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Rushikesh Patil.
Persistent Systems Pvt. Ltd.
cell: +(91)98226-39056
http://www.rushikeshpatil.8m.com
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