how to get physicaldeviceobject

NTFSD
1

Hi,

Is it possible to get the physicaldeviceobject pointer from a file system
filter driver?
I am using sfilter from IFS Kit as an example.
How can I get the physcialdeviceobject of the deviceobject i am filtering?

Hope someone can help me.

Thank you!

cheers,
vincent

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2

You are using Plug and Play/WDM driver terminology here. File system
drivers are not PnP/WDM drivers, there is no PDO/FDO model. In fact, if you
go look, file system drivers are marked as “disabled” in the registry - so
that PnP will not load them (you have to use a different mechanism for
loading them).

Or perhaps you are looking for the physical MEDIA device on top of which a
physical file system might layer itself? If so, you can get this at the
point of attachment (in the mount request itself) since it is the FDO for
the physical media device that is passed in to mount.

If you can describe what you are trying to accomplish we might be able to
provide you with more information.

Regards,

Tony

Tony Mason
Consulting Partner
OSR Open Systems Resources, Inc.
http://www.osr.com

See you at the next File Systems Development Workshop in September 2003
(Palo Alto, CA)

-----Original Message-----
From: vincent gambit [mailto:xxxxx@hotmail.com]
Sent: Thursday, August 14, 2003 11:24 PM
To: File Systems Developers
Subject: [ntfsd] how to get physicaldeviceobject

Hi,

Is it possible to get the physicaldeviceobject pointer from a file system
filter driver?
I am using sfilter from IFS Kit as an example.
How can I get the physcialdeviceobject of the deviceobject i am filtering?

Hope someone can help me.

Thank you!

cheers,
vincent

Get 10mb of inbox space with MSN Hotmail Extra Storage
http://join.msn.com/?pgmarket=en-sg

You are currently subscribed to ntfsd as: xxxxx@osr.com
To unsubscribe send a blank email to xxxxx@lists.osr.com

3

Hi,

Thanks for your reply.

So i can never get physicaldeviceobject?
Also when you say physical MEDIA device, does it mean vpb->RealDevice?

is it possible to get the bus type of the device which the filesystem is
mounted on?
for example is it usb, pcmcia, ide, ultrabay or firewire?

or can i get the type of device the filesystem is mounted on?
for example, is it a zip drive, floppy, hard disk etc?

thank you!

cheers,
vincent

From: Tony Mason
>Reply-To: “File Systems Developers”
>To: “File Systems Developers”
>Subject: [ntfsd] RE: how to get physicaldeviceobject
>Date: Thu, 14 Aug 2003 23:32:38 -0400
>
>You are using Plug and Play/WDM driver terminology here. File system
>drivers are not PnP/WDM drivers, there is no PDO/FDO model. In fact, if
>you
>go look, file system drivers are marked as “disabled” in the registry - so
>that PnP will not load them (you have to use a different mechanism for
>loading them).
>
>Or perhaps you are looking for the physical MEDIA device on top of which a
>physical file system might layer itself? If so, you can get this at the
>point of attachment (in the mount request itself) since it is the FDO for
>the physical media device that is passed in to mount.
>
>If you can describe what you are trying to accomplish we might be able to
>provide you with more information.
>
>Regards,
>
>Tony
>
>Tony Mason
>Consulting Partner
>OSR Open Systems Resources, Inc.
>http://www.osr.com
>
>See you at the next File Systems Development Workshop in September 2003
>(Palo Alto, CA)
>
>
>-----Original Message-----
>From: vincent gambit [mailto:xxxxx@hotmail.com]
>Sent: Thursday, August 14, 2003 11:24 PM
>To: File Systems Developers
>Subject: [ntfsd] how to get physicaldeviceobject
>
>Hi,
>
>Is it possible to get the physicaldeviceobject pointer from a file system
>filter driver?
>I am using sfilter from IFS Kit as an example.
>How can I get the physcialdeviceobject of the deviceobject i am filtering?
>
>Hope someone can help me.
>
>Thank you!
>
>cheers,
>vincent
>
>
>Get 10mb of inbox space with MSN Hotmail Extra Storage
>http://join.msn.com/?pgmarket=en-sg
>
>
>
>—
>You are currently subscribed to ntfsd as: xxxxx@osr.com
>To unsubscribe send a blank email to xxxxx@lists.osr.com
>
>—
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only S$36 including GST

4

Vpb->DeviceObject is a bottom of FS volume stack.
Vpb->RealDevice is a bottom (PDO in w2k and later) of disk stack.

Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
xxxxx@storagecraft.com
http://www.storagecraft.com

----- Original Message -----
From: “vincent gambit”
To: “File Systems Developers”
Sent: Friday, August 15, 2003 7:24 AM
Subject: [ntfsd] how to get physicaldeviceobject

> Hi,
>
> Is it possible to get the physicaldeviceobject pointer from a file system
> filter driver?
> I am using sfilter from IFS Kit as an example.
> How can I get the physcialdeviceobject of the deviceobject i am filtering?
>
> Hope someone can help me.
>
> Thank you!
>
> cheers,
> vincent
>
> _________________________________________________________________
> Get 10mb of inbox space with MSN Hotmail Extra Storage
> http://join.msn.com/?pgmarket=en-sg
>
>
>
> —
> You are currently subscribed to ntfsd as: xxxxx@storagecraft.com
> To unsubscribe send a blank email to xxxxx@lists.osr.com

5

Sorry, but I’m going to disagree with this. Only physical file systems on
top of disks, tapes, and cd-roms (or devices that claim to be such) use
Vpb’s. Thus, the answer you give Max is not correct for all file systems.

Regards,

Tony

Tony Mason
Consulting Partner
OSR Open Systems Resources, Inc.
http://www.osr.com

-----Original Message-----
From: Maxim S. Shatskih [mailto:xxxxx@storagecraft.com]
Sent: Friday, August 15, 2003 8:25 AM
To: File Systems Developers
Subject: [ntfsd] Re: how to get physicaldeviceobject

Vpb->DeviceObject is a bottom of FS volume stack.
Vpb->RealDevice is a bottom (PDO in w2k and later) of disk stack.

Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
xxxxx@storagecraft.com
http://www.storagecraft.com

----- Original Message -----
From: “vincent gambit”
To: “File Systems Developers”
Sent: Friday, August 15, 2003 7:24 AM
Subject: [ntfsd] how to get physicaldeviceobject

> Hi,
>
> Is it possible to get the physicaldeviceobject pointer from a file system
> filter driver?
> I am using sfilter from IFS Kit as an example.
> How can I get the physcialdeviceobject of the deviceobject i am filtering?
>
> Hope someone can help me.
>
> Thank you!
>
> cheers,
> vincent
>
> _________________________________________________________________
> Get 10mb of inbox space with MSN Hotmail Extra Storage
> http://join.msn.com/?pgmarket=en-sg
>
>
>
> —
> You are currently subscribed to ntfsd as: xxxxx@storagecraft.com
> To unsubscribe send a blank email to xxxxx@lists.osr.com

—
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6

Hi

thanks for your reply.
so whats the other file system that is not on top of disks, tapes and
cdroms?
can give an example?
network?

thank you!

cheers,
vincent

From: Tony Mason
>Reply-To: “File Systems Developers”
>To: “File Systems Developers”
>Subject: [ntfsd] Re: how to get physicaldeviceobject
>Date: Fri, 15 Aug 2003 09:35:18 -0400
>
>Sorry, but I’m going to disagree with this. Only physical file systems on
>top of disks, tapes, and cd-roms (or devices that claim to be such) use
>Vpb’s. Thus, the answer you give Max is not correct for all file systems.
>
>
>Regards,
>
>Tony
>
>Tony Mason
>Consulting Partner
>OSR Open Systems Resources, Inc.
>http://www.osr.com
>
>
>-----Original Message-----
>From: Maxim S. Shatskih [mailto:xxxxx@storagecraft.com]
>Sent: Friday, August 15, 2003 8:25 AM
>To: File Systems Developers
>Subject: [ntfsd] Re: how to get physicaldeviceobject
>
>Vpb->DeviceObject is a bottom of FS volume stack.
>Vpb->RealDevice is a bottom (PDO in w2k and later) of disk stack.
>
>Maxim Shatskih, Windows DDK MVP
>StorageCraft Corporation
>xxxxx@storagecraft.com
>http://www.storagecraft.com
>
>----- Original Message -----
>From: “vincent gambit”
>To: “File Systems Developers”
>Sent: Friday, August 15, 2003 7:24 AM
>Subject: [ntfsd] how to get physicaldeviceobject
>
>
> > Hi,
> >
> > Is it possible to get the physicaldeviceobject pointer from a file
>system
> > filter driver?
> > I am using sfilter from IFS Kit as an example.
> > How can I get the physcialdeviceobject of the deviceobject i am
>filtering?
> >
> > Hope someone can help me.
> >
> > Thank you!
> >
> > cheers,
> > vincent
> >
> >
> > Get 10mb of inbox space with MSN Hotmail Extra Storage
> > http://join.msn.com/?pgmarket=en-sg
> >
> >
> >
> > —
> > You are currently subscribed to ntfsd as: xxxxx@storagecraft.com
> > To unsubscribe send a blank email to xxxxx@lists.osr.com
>
>
>—
>You are currently subscribed to ntfsd as: xxxxx@osr.com
>To unsubscribe send a blank email to xxxxx@lists.osr.com
>
>—
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7

HI,

i am confused here
so does that mean Vpb->RealDevice is actually the physicaldeviceobject(PDO)
in win2k and winxp?

but when i use Vpb->RealDevice as a PDO in IoGetDeviceProperty function, I
got nothing.
Why is that so?
However if I do it in disk filter for example diskperf sample, I am able to
get some of the devuce property.

Thank You!

cheers,
vincent

From: “Maxim S. Shatskih”
>Reply-To: “File Systems Developers”
>To: “File Systems Developers”
>Subject: [ntfsd] Re: how to get physicaldeviceobject
>Date: Fri, 15 Aug 2003 16:25:01 +0400
>
>Vpb->DeviceObject is a bottom of FS volume stack.
>Vpb->RealDevice is a bottom (PDO in w2k and later) of disk stack.
>
>Maxim Shatskih, Windows DDK MVP
>StorageCraft Corporation
>xxxxx@storagecraft.com
>http://www.storagecraft.com
>
>----- Original Message -----
>From: “vincent gambit”
>To: “File Systems Developers”
>Sent: Friday, August 15, 2003 7:24 AM
>Subject: [ntfsd] how to get physicaldeviceobject
>
>
> > Hi,
> >
> > Is it possible to get the physicaldeviceobject pointer from a file
>system
> > filter driver?
> > I am using sfilter from IFS Kit as an example.
> > How can I get the physcialdeviceobject of the deviceobject i am
>filtering?
> >
> > Hope someone can help me.
> >
> > Thank you!
> >
> > cheers,
> > vincent
> >
> >
> > Get 10mb of inbox space with MSN Hotmail Extra Storage
> > http://join.msn.com/?pgmarket=en-sg
> >
> >
> >
> > —
> > You are currently subscribed to ntfsd as: xxxxx@storagecraft.com
> > To unsubscribe send a blank email to xxxxx@lists.osr.com
>
>
>—
>You are currently subscribed to ntfsd as: xxxxx@hotmail.com
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8

There are more file systems that do not reside on top of physical media
volumes than do. This would include include: CIFS, WebDAV, AFS, NPFS, MSFS,
WinFS.

I generally categorize file systems into one of three categories:

  • Physical. These layer directly onto physical media volumes (disk, tape,
    cd)
  • Network. These typically utilize a protocol or mechanism for
    communicating with the backing store over a high speed communications
    mechanism but do not directly control the device.
  • Pseudo. These are drivers that present a file system upper-edge
    interface, but utilize a potentially more complex lower edge organizational
    mechanism. For example the named pipe file system (NPFS) presents a
    hierarchical name space but has no persistent back-end storage (it is an IPC
    mechanism).

Regards,

Tony

Tony Mason
Consulting Partner
OSR Open Systems Resources, Inc.
http://www.osr.com

-----Original Message-----
From: vincent gambit [mailto:xxxxx@hotmail.com]
Sent: Friday, August 15, 2003 1:01 PM
To: File Systems Developers
Subject: [ntfsd] Re: how to get physicaldeviceobject

Hi

thanks for your reply.
so whats the other file system that is not on top of disks, tapes and
cdroms?
can give an example?
network?

thank you!

cheers,
vincent

From: Tony Mason
>Reply-To: “File Systems Developers”
>To: “File Systems Developers”
>Subject: [ntfsd] Re: how to get physicaldeviceobject
>Date: Fri, 15 Aug 2003 09:35:18 -0400
>
>Sorry, but I’m going to disagree with this. Only physical file systems on
>top of disks, tapes, and cd-roms (or devices that claim to be such) use
>Vpb’s. Thus, the answer you give Max is not correct for all file systems.
>
>
>Regards,
>
>Tony
>
>Tony Mason
>Consulting Partner
>OSR Open Systems Resources, Inc.
>http://www.osr.com
>
>
>-----Original Message-----
>From: Maxim S. Shatskih [mailto:xxxxx@storagecraft.com]
>Sent: Friday, August 15, 2003 8:25 AM
>To: File Systems Developers
>Subject: [ntfsd] Re: how to get physicaldeviceobject
>
>Vpb->DeviceObject is a bottom of FS volume stack.
>Vpb->RealDevice is a bottom (PDO in w2k and later) of disk stack.
>
>Maxim Shatskih, Windows DDK MVP
>StorageCraft Corporation
>xxxxx@storagecraft.com
>http://www.storagecraft.com
>
>----- Original Message -----
>From: “vincent gambit”
>To: “File Systems Developers”
>Sent: Friday, August 15, 2003 7:24 AM
>Subject: [ntfsd] how to get physicaldeviceobject
>
>
> > Hi,
> >
> > Is it possible to get the physicaldeviceobject pointer from a file
>system
> > filter driver?
> > I am using sfilter from IFS Kit as an example.
> > How can I get the physcialdeviceobject of the deviceobject i am
>filtering?
> >
> > Hope someone can help me.
> >
> > Thank you!
> >
> > cheers,
> > vincent
> >
> >
> > Get 10mb of inbox space with MSN Hotmail Extra Storage
> > http://join.msn.com/?pgmarket=en-sg
> >
> >
> >
> > —
> > You are currently subscribed to ntfsd as: xxxxx@storagecraft.com
> > To unsubscribe send a blank email to xxxxx@lists.osr.com
>
>
>—
>You are currently subscribed to ntfsd as: xxxxx@osr.com
>To unsubscribe send a blank email to xxxxx@lists.osr.com
>
>—
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