How to convert symbolic names to drive letters

NTDEV
1

If presented with a symbolic device name from one of the SetupDiXXX
calls, how can I determine the mounted drive letter that is assigned to
that symbolic name?

For example, if I’ve determined that there is a device with a Disk
Interface that has the symbolic device name (detail path) of:

\?\usbstor#disk&ven_vendor&prod_vendorproduct&rev_0.1#sernum2d51300308&
0#{53f56307-b6bf-11d0-94f2-00a0c91efb8b}

How do I find out if this device is mapped to "F:"?

I’ve tried MSDN and DDK documentation as well as google and I can’t seem
to find how to do this.

Thanks,
Mark A. Green
Sr. Software Engineer
encryptX Corporation

2

Volumes might have drive letters, but disks don’t. Luser mode includes
enough functionality to find all of the volumes for a given disk device,
although the method is indirect. If there is a 1-1 mapping of volume to
disk, then you are just about done.

See IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS and GetVolumePathNamesForVolumeName
in the luser SDK.

Use PnP to get a list of all the volume devices on the system. From this
list use IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS to find out which disks
provide storage for which volumes and correlate that to your disk device of
interest. Then use GetVolumePathNamesForVolumeName to find out where your
volumes of interest are mounted.

Simple huh?

I’m surprised that you missed this :slight_smile:

=====================
Mark Roddy

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Mark Green
Sent: Wednesday, November 24, 2004 1:59 PM
To: Windows System Software Devs Interest List
Subject: [ntdev] How to convert symbolic names to drive letters

If presented with a symbolic device name from one of the SetupDiXXX calls,
how can I determine the mounted drive letter that is assigned to that
symbolic name?

For example, if I’ve determined that there is a device with a Disk Interface
that has the symbolic device name (detail path) of:

\?\usbstor#disk&ven_vendor&prod_vendorproduct&rev_0.1#sernum2d51300308&
0#{53f56307-b6bf-11d0-94f2-00a0c91efb8b}

How do I find out if this device is mapped to "F:"?

I’ve tried MSDN and DDK documentation as well as google and I can’t seem to
find how to do this.

Thanks,
Mark A. Green
Sr. Software Engineer
encryptX Corporation

Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256

You are currently subscribed to ntdev as: unknown lmsubst tag argument: ‘’
To unsubscribe send a blank email to xxxxx@lists.osr.com

3

Mark, thanks for the response.

Unfortunately, I’m working with USB devices here and the driver doesn’t
support IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS not to mention that in order to
open a handle to the volume to send the IOCTL I’d need admin rights and I’m
not in a situation where I can guarantee that. At the same time,
GetVolumePathNamesForVolumeName is failing for the volume name of the USB
volume. To make matters even worse, I need to support at least 2K and XP if
not also 9x/Me and GetVolumePathNamesForVolumeName is an XP only API.

If you, or anyone else, has any more ideas let me know.

Thanks,
Mark A. Green
Sr. Software Engineer
encryptX Corporation

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Roddy, Mark
Sent: Wednesday, November 24, 2004 12:19 PM
To: Windows System Software Devs Interest List
Subject: RE: [ntdev] How to convert symbolic names to drive letters

Volumes might have drive letters, but disks don’t. Luser mode includes
enough functionality to find all of the volumes for a given disk device,
although the method is indirect. If there is a 1-1 mapping of volume to
disk, then you are just about done.

See IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS and GetVolumePathNamesForVolumeName
in the luser SDK.

Use PnP to get a list of all the volume devices on the system. From this
list use IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS to find out which disks
provide storage for which volumes and correlate that to your disk device of
interest. Then use GetVolumePathNamesForVolumeName to find out where your
volumes of interest are mounted.

Simple huh?

I’m surprised that you missed this :slight_smile:

=====================
Mark Roddy

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Mark Green
Sent: Wednesday, November 24, 2004 1:59 PM
To: Windows System Software Devs Interest List
Subject: [ntdev] How to convert symbolic names to drive letters

If presented with a symbolic device name from one of the SetupDiXXX calls,
how can I determine the mounted drive letter that is assigned to that
symbolic name?

For example, if I’ve determined that there is a device with a Disk Interface
that has the symbolic device name (detail path) of:

\?\usbstor#disk&ven_vendor&prod_vendorproduct&rev_0.1#sernum2d51300308&
0#{53f56307-b6bf-11d0-94f2-00a0c91efb8b}

How do I find out if this device is mapped to "F:"?

I’ve tried MSDN and DDK documentation as well as google and I can’t seem to
find how to do this.

Thanks,
Mark A. Green
Sr. Software Engineer
encryptX Corporation

Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256

You are currently subscribed to ntdev as: unknown lmsubst tag argument: ‘’
To unsubscribe send a blank email to xxxxx@lists.osr.com

Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256

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

4

This sounds like you will require a kernel driver or some other trusted
component like a service. Windows try’s to protect the system from malware
by requiring admin rights to do anything at this level for disks.

Rather than trying to work around the restriction, I recommend changing your
architecture to work within the security model provided by Windows.

Jamey

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Mark A. Green
Sent: Wednesday, November 24, 2004 2:39 PM
To: Windows System Software Devs Interest List
Subject: RE: [ntdev] How to convert symbolic names to drive letters

Mark, thanks for the response.

Unfortunately, I’m working with USB devices here and the driver doesn’t
support IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS not to mention that in order to
open a handle to the volume to send the IOCTL I’d need admin rights and I’m
not in a situation where I can guarantee that. At the same time,
GetVolumePathNamesForVolumeName is failing for the volume name of the USB
volume. To make matters even worse, I need to support at least 2K and XP if
not also 9x/Me and GetVolumePathNamesForVolumeName is an XP only API.

If you, or anyone else, has any more ideas let me know.

Thanks,
Mark A. Green
Sr. Software Engineer
encryptX Corporation

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Roddy, Mark
Sent: Wednesday, November 24, 2004 12:19 PM
To: Windows System Software Devs Interest List
Subject: RE: [ntdev] How to convert symbolic names to drive letters

Volumes might have drive letters, but disks don’t. Luser mode includes
enough functionality to find all of the volumes for a given disk device,
although the method is indirect. If there is a 1-1 mapping of volume to
disk, then you are just about done.

See IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS and GetVolumePathNamesForVolumeName
in the luser SDK.

Use PnP to get a list of all the volume devices on the system. From this
list use IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS to find out which disks
provide storage for which volumes and correlate that to your disk device of
interest. Then use GetVolumePathNamesForVolumeName to find out where your
volumes of interest are mounted.

Simple huh?

I’m surprised that you missed this :slight_smile:

=====================
Mark Roddy

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Mark Green
Sent: Wednesday, November 24, 2004 1:59 PM
To: Windows System Software Devs Interest List
Subject: [ntdev] How to convert symbolic names to drive letters

If presented with a symbolic device name from one of the SetupDiXXX calls,
how can I determine the mounted drive letter that is assigned to that
symbolic name?

For example, if I’ve determined that there is a device with a Disk Interface
that has the symbolic device name (detail path) of:

\?\usbstor#disk&ven_vendor&prod_vendorproduct&rev_0.1#sernum2d51300308&
0#{53f56307-b6bf-11d0-94f2-00a0c91efb8b}

How do I find out if this device is mapped to "F:"?

I’ve tried MSDN and DDK documentation as well as google and I can’t seem to
find how to do this.

Thanks,
Mark A. Green
Sr. Software Engineer
encryptX Corporation

Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256

You are currently subscribed to ntdev as: unknown lmsubst tag argument: ‘’
To unsubscribe send a blank email to xxxxx@lists.osr.com

Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256

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

Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256

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

5

Thanks Jamey and that was my first desired approach. Customer requirements
will prevail however, so drivers and services are out of the question.

Mark

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Jamey Kirby
Sent: Wednesday, November 24, 2004 3:53 PM
To: Windows System Software Devs Interest List
Subject: RE: [ntdev] How to convert symbolic names to drive letters

This sounds like you will require a kernel driver or some other trusted
component like a service. Windows try’s to protect the system from malware
by requiring admin rights to do anything at this level for disks.

Rather than trying to work around the restriction, I recommend changing your
architecture to work within the security model provided by Windows.

Jamey

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Mark A. Green
Sent: Wednesday, November 24, 2004 2:39 PM
To: Windows System Software Devs Interest List
Subject: RE: [ntdev] How to convert symbolic names to drive letters

Mark, thanks for the response.

Unfortunately, I’m working with USB devices here and the driver doesn’t
support IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS not to mention that in order to
open a handle to the volume to send the IOCTL I’d need admin rights and I’m
not in a situation where I can guarantee that. At the same time,
GetVolumePathNamesForVolumeName is failing for the volume name of the USB
volume. To make matters even worse, I need to support at least 2K and XP if
not also 9x/Me and GetVolumePathNamesForVolumeName is an XP only API.

If you, or anyone else, has any more ideas let me know.

Thanks,
Mark A. Green
Sr. Software Engineer
encryptX Corporation

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Roddy, Mark
Sent: Wednesday, November 24, 2004 12:19 PM
To: Windows System Software Devs Interest List
Subject: RE: [ntdev] How to convert symbolic names to drive letters

Volumes might have drive letters, but disks don’t. Luser mode includes
enough functionality to find all of the volumes for a given disk device,
although the method is indirect. If there is a 1-1 mapping of volume to
disk, then you are just about done.

See IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS and GetVolumePathNamesForVolumeName
in the luser SDK.

Use PnP to get a list of all the volume devices on the system. From this
list use IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS to find out which disks
provide storage for which volumes and correlate that to your disk device of
interest. Then use GetVolumePathNamesForVolumeName to find out where your
volumes of interest are mounted.

Simple huh?

I’m surprised that you missed this :slight_smile:

=====================
Mark Roddy

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Mark Green
Sent: Wednesday, November 24, 2004 1:59 PM
To: Windows System Software Devs Interest List
Subject: [ntdev] How to convert symbolic names to drive letters

If presented with a symbolic device name from one of the SetupDiXXX calls,
how can I determine the mounted drive letter that is assigned to that
symbolic name?

For example, if I’ve determined that there is a device with a Disk Interface
that has the symbolic device name (detail path) of:

\?\usbstor#disk&ven_vendor&prod_vendorproduct&rev_0.1#sernum2d51300308&
0#{53f56307-b6bf-11d0-94f2-00a0c91efb8b}

How do I find out if this device is mapped to "F:"?

I’ve tried MSDN and DDK documentation as well as google and I can’t seem to
find how to do this.

Thanks,
Mark A. Green
Sr. Software Engineer
encryptX Corporation

Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256

You are currently subscribed to ntdev as: unknown lmsubst tag argument: ‘’
To unsubscribe send a blank email to xxxxx@lists.osr.com

Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256

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

Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256

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

Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256

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

6

I think this is a valid case where you are allowed to shoot the client :wink:

Jamey

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Mark A. Green
Sent: Wednesday, November 24, 2004 3:11 PM
To: Windows System Software Devs Interest List
Subject: RE: [ntdev] How to convert symbolic names to drive letters

Thanks Jamey and that was my first desired approach. Customer requirements
will prevail however, so drivers and services are out of the question.

Mark

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Jamey Kirby
Sent: Wednesday, November 24, 2004 3:53 PM
To: Windows System Software Devs Interest List
Subject: RE: [ntdev] How to convert symbolic names to drive letters

This sounds like you will require a kernel driver or some other trusted
component like a service. Windows try’s to protect the system from malware
by requiring admin rights to do anything at this level for disks.

Rather than trying to work around the restriction, I recommend changing your
architecture to work within the security model provided by Windows.

Jamey

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Mark A. Green
Sent: Wednesday, November 24, 2004 2:39 PM
To: Windows System Software Devs Interest List
Subject: RE: [ntdev] How to convert symbolic names to drive letters

Mark, thanks for the response.

Unfortunately, I’m working with USB devices here and the driver doesn’t
support IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS not to mention that in order to
open a handle to the volume to send the IOCTL I’d need admin rights and I’m
not in a situation where I can guarantee that. At the same time,
GetVolumePathNamesForVolumeName is failing for the volume name of the USB
volume. To make matters even worse, I need to support at least 2K and XP if
not also 9x/Me and GetVolumePathNamesForVolumeName is an XP only API.

If you, or anyone else, has any more ideas let me know.

Thanks,
Mark A. Green
Sr. Software Engineer
encryptX Corporation

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Roddy, Mark
Sent: Wednesday, November 24, 2004 12:19 PM
To: Windows System Software Devs Interest List
Subject: RE: [ntdev] How to convert symbolic names to drive letters

Volumes might have drive letters, but disks don’t. Luser mode includes
enough functionality to find all of the volumes for a given disk device,
although the method is indirect. If there is a 1-1 mapping of volume to
disk, then you are just about done.

See IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS and GetVolumePathNamesForVolumeName
in the luser SDK.

Use PnP to get a list of all the volume devices on the system. From this
list use IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS to find out which disks
provide storage for which volumes and correlate that to your disk device of
interest. Then use GetVolumePathNamesForVolumeName to find out where your
volumes of interest are mounted.

Simple huh?

I’m surprised that you missed this :slight_smile:

=====================
Mark Roddy

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Mark Green
Sent: Wednesday, November 24, 2004 1:59 PM
To: Windows System Software Devs Interest List
Subject: [ntdev] How to convert symbolic names to drive letters

If presented with a symbolic device name from one of the SetupDiXXX calls,
how can I determine the mounted drive letter that is assigned to that
symbolic name?

For example, if I’ve determined that there is a device with a Disk Interface
that has the symbolic device name (detail path) of:

\?\usbstor#disk&ven_vendor&prod_vendorproduct&rev_0.1#sernum2d51300308&
0#{53f56307-b6bf-11d0-94f2-00a0c91efb8b}

How do I find out if this device is mapped to "F:"?

I’ve tried MSDN and DDK documentation as well as google and I can’t seem to
find how to do this.

Thanks,
Mark A. Green
Sr. Software Engineer
encryptX Corporation

Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256

You are currently subscribed to ntdev as: unknown lmsubst tag argument: ‘’
To unsubscribe send a blank email to xxxxx@lists.osr.com

Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256

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

Questions? First check the Kernel Driver FAQ at
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You are currently subscribed to ntdev as: xxxxx@tfb.com
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Questions? First check the Kernel Driver FAQ at
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7

Have you tried IOCTL_MOUNTDEV_QUERY_DEVICE_NAME and
IOCTL_MOUNTMGR_QUERY_POINTS?

Chuck

----- Original Message -----
From: “Mark Green”
To: “Windows System Software Devs Interest List”
Sent: Thursday, November 25, 2004 1:58 AM
Subject: [ntdev] How to convert symbolic names to drive letters

> If presented with a symbolic device name from one of the SetupDiXXX
> calls, how can I determine the mounted drive letter that is assigned
> to
> that symbolic name?
>
> For example, if I’ve determined that there is a device with a Disk
> Interface that has the symbolic device name (detail path) of:
>
> \?\usbstor#disk&ven_vendor&prod_vendorproduct&rev_0.1#sernum2d51300308&
> 0#{53f56307-b6bf-11d0-94f2-00a0c91efb8b}
>
> How do I find out if this device is mapped to "F:"?
>
> I’ve tried MSDN and DDK documentation as well as google and I can’t
> seem
> to find how to do this.
>
>
> Thanks,
> Mark A. Green
> Sr. Software Engineer
> encryptX Corporation