Should I use IoGetDeviceObjectPointer or IoRegisterPlugPlayNotification for obtaining pointer to "\D

NTDEV
1

Hi,

I need to send some IOCTLs (QUERY_POINTS) to “\Device\MountManager”.

Should I use “IoRegisterPlugPlayNotification” and then obtain pointer to
device object in the callback?

Or is it ok to use IoGetDeviceObjectPointer to get the device object’s
pointer, any implications on all flavors of windows?

Please advice

Regards
Deepak

2

Assuming this is volume filter, It is ok to do IoGetDeviceObjectPointer
on Device\MountManager".

However the ioctl you send to it for a particular volume might fail if
the volume is not started (pnp) so I would query_points in POST
PNP_START notification.

Harish

From: Deepak Gupta [mailto:xxxxx@gmail.com]
Sent: Monday, November 23, 2009 8:27 AM
To: Windows System Software Devs Interest List
Subject: [ntdev] Should I use IoGetDeviceObjectPointer or
IoRegisterPlugPlayNotification for obtaining pointer to
“\Device\MountManager”

Hi,

I need to send some IOCTLs (QUERY_POINTS) to “\Device\MountManager”.

Should I use “IoRegisterPlugPlayNotification” and then obtain pointer to
device object in the callback?

Or is it ok to use IoGetDeviceObjectPointer to get the device object’s
pointer, any implications on all flavors of windows?

Please advice

Regards

Deepak

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3

Thanks Harish for the help.
Yeah it is a volume filter.

>
so I would query_points in POST PNP_START notification.
>

You mean to say after PNP_START of lower devobjs (below mine devobj) in the
stack has completed successfully, right?

Regards
Deepak

On Tue, Nov 24, 2009 at 12:29 AM, Arora, Harish wrote:

> Assuming this is volume filter, It is ok to do IoGetDeviceObjectPointer
> on Device\MountManager".
>
> However the ioctl you send to it for a particular volume might fail if the
> volume is not started (pnp) so I would query_points in POST PNP_START
> notification.
>
>
>
> Harish
>
>
>
> From: Deepak Gupta [mailto:xxxxx@gmail.com]
> Sent: Monday, November 23, 2009 8:27 AM
> To: Windows System Software Devs Interest List
> Subject: [ntdev] Should I use IoGetDeviceObjectPointer or
> IoRegisterPlugPlayNotification for obtaining pointer to
> “\Device\MountManager”
>
>
>
> Hi,
>
>
>
> I need to send some IOCTLs (QUERY_POINTS) to “\Device\MountManager”.
>
>
>
> Should I use “IoRegisterPlugPlayNotification” and then obtain pointer to
> device object in the callback?
>
>
>
> Or is it ok to use IoGetDeviceObjectPointer to get the device object’s
> pointer, any implications on all flavors of windows?
>
>
>
> Please advice
>
>
>
>
>
> Regards
>
> Deepak
>
> — NTDEV is sponsored by OSR For our schedule of WDF, WDM, debugging and
> other seminars visit: http://www.osr.com/seminars To unsubscribe, visit
> the List Server section of OSR Online at
> http://www.osronline.com/page.cfm?name=ListServer
>
> —
> NTDEV is sponsored by OSR
>
> For our schedule of WDF, WDM, debugging and other seminars visit:
> http://www.osr.com/seminars
>
> To unsubscribe, visit the List Server section of OSR Online at
> http://www.osronline.com/page.cfm?name=ListServer
>

4

? You mean to say after PNP_START of lower devobjs (below mine devobj) in the stack has completed successfully, right?

yes

From: Deepak Gupta [mailto:xxxxx@gmail.com]
Sent: Monday, November 23, 2009 11:17 AM
To: Windows System Software Devs Interest List
Subject: Re: [ntdev] Should I use IoGetDeviceObjectPointer or IoRegisterPlugPlayNotification for obtaining pointer to “\Device\MountManager”

Thanks Harish for the help.

Yeah it is a volume filter.

>

so I would query_points in POST PNP_START notification.

>

You mean to say after PNP_START of lower devobjs (below mine devobj) in the stack has completed successfully, right?

Regards

Deepak

On Tue, Nov 24, 2009 at 12:29 AM, Arora, Harish wrote:

Assuming this is volume filter, It is ok to do IoGetDeviceObjectPointer on Device\MountManager".

However the ioctl you send to it for a particular volume might fail if the volume is not started (pnp) so I would query_points in POST PNP_START notification.

Harish

From: Deepak Gupta [mailto:xxxxx@gmail.com]
Sent: Monday, November 23, 2009 8:27 AM
To: Windows System Software Devs Interest List
Subject: [ntdev] Should I use IoGetDeviceObjectPointer or IoRegisterPlugPlayNotification for obtaining pointer to “\Device\MountManager”

Hi,

I need to send some IOCTLs (QUERY_POINTS) to “\Device\MountManager”.

Should I use “IoRegisterPlugPlayNotification” and then obtain pointer to device object in the callback?

Or is it ok to use IoGetDeviceObjectPointer to get the device object’s pointer, any implications on all flavors of windows?

Please advice

Regards

Deepak

— NTDEV is sponsored by OSR For our schedule of WDF, WDM, debugging and other seminars visit: http://www.osr.com/seminars To unsubscribe, visit the List Server section of OSR Online at http://www.osronline.com/page.cfm?name=ListServer

—
NTDEV is sponsored by OSR

For our schedule of WDF, WDM, debugging and other seminars visit:
http://www.osr.com/seminars

To unsubscribe, visit the List Server section of OSR Online at http://www.osronline.com/page.cfm?name=ListServer

— NTDEV is sponsored by OSR For our schedule of WDF, WDM, debugging and other seminars visit: http://www.osr.com/seminars To unsubscribe, visit the List Server section of OSR Online at http://www.osronline.com/page.cfm?name=ListServer