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From: krish on 12 May 2008 15:59
In the function DiskPerfDeviceControl (), for the control codes that
diskperf does not process it does the following:

...
else {
//
// Set current stack back one.
//

Irp->CurrentLocation++,
Irp->Tail.Overlay.CurrentStackLocation++;
}

I do not what understand what this code is doing? I believe the intent
here is to just pass on the control codes to the next driver. So
shouldn't it be doing IoCopyCurrentIrpStackLocationToNext (), so that
next lower driver gets the same information as diskperf. Also WDK says
that undocumented members of _IRP are for IO manager only, then why
they are being used here.

Please help. Thanks.

From: Maxim S. Shatskih on 12 May 2008 19:39
> Irp->CurrentLocation++,
> Irp->Tail.Overlay.CurrentStackLocation++;

Consider this to be IoSetPreviousIrpStackLocation

--
Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
maxim(a)storagecraft.com
http://www.storagecraft.com

From: krish on 12 May 2008 22:30
On May 12, 4:39 pm, "Maxim S. Shatskih" <ma...(a)storagecraft.com>
wrote:
> > Irp->CurrentLocation++,
> > Irp->Tail.Overlay.CurrentStackLocation++;
>
> Consider this to be IoSetPreviousIrpStackLocation
>
> --
> Maxim Shatskih, Windows DDK MVP
> StorageCraft Corporation
> ma...(a)storagecraft.comhttp://www.storagecraft.com

Hi Maxim, Thanks for the reply.

What I'm doing in my diskperf is that I'm trying to modify the
contents of the Irp->AssociatedIrp.SystemBuffer after the IoCallDriver
() from the lower driver (that is disk.sys, I believe).

so it's like:

if (IoControlCode == IOCTL_DISK_PERFORMANCE) {
// current code
}
else {
Irp->CurrentLocation++,
Irp->Tail.Overlay.CurrentStackLocation++;

status = IoCallDriver ();

// my code to modify Irp->AssociatedIrp.SystemBuffer contents goes
here...

return (status);
}

But unfortunately I'm not seeing the behavior I should see. It looks
like the SystemBuffer does not gets changed and the upper driver sees
the same contents as sent by the lower driver. Any clue what may be
going wrong. Thanks.










From: Doron Holan [MSFT] on 13 May 2008 00:09
well, then shouldn't it be IoSkipCurrentIrpStackLocation?

d

--
Please do not send e-mail directly to this alias. this alias is for
newsgroup purposes only.
This posting is provided "AS IS" with no warranties, and confers no rights.


"Maxim S. Shatskih" <maxim(a)storagecraft.com> wrote in message
news:O2R1rlItIHA.4952(a)TK2MSFTNGP05.phx.gbl...
>> Irp->CurrentLocation++,
>> Irp->Tail.Overlay.CurrentStackLocation++;
>
> Consider this to be IoSetPreviousIrpStackLocation
>
> --
> Maxim Shatskih, Windows DDK MVP
> StorageCraft Corporation
> maxim(a)storagecraft.com
> http://www.storagecraft.com
>

From: David Craig on 13 May 2008 00:49
It is your's, Microsoft's, code. In diskperf.c at line 1432 of WinDDK
6001.18000.

"Doron Holan [MSFT]" <doronh(a)online.microsoft.com> wrote in message
news:%232yFj8KtIHA.5472(a)TK2MSFTNGP06.phx.gbl...
> well, then shouldn't it be IoSkipCurrentIrpStackLocation?
>
> d
>
> --
> Please do not send e-mail directly to this alias. this alias is for
> newsgroup purposes only.
> This posting is provided "AS IS" with no warranties, and confers no
> rights.
>
>
> "Maxim S. Shatskih" <maxim(a)storagecraft.com> wrote in message
> news:O2R1rlItIHA.4952(a)TK2MSFTNGP05.phx.gbl...
>>> Irp->CurrentLocation++,
>>> Irp->Tail.Overlay.CurrentStackLocation++;
>>
>> Consider this to be IoSetPreviousIrpStackLocation
>>
>> --
>> Maxim Shatskih, Windows DDK MVP
>> StorageCraft Corporation
>> maxim(a)storagecraft.com
>> http://www.storagecraft.com
>>
>


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