Filter attaching between volume and volsnap

NTFSD
1

Hi all,
I’ve written a volume filter driver and I want it to load before volsnap
driver attaches to the ftdisk devices.
I’ve tried it by making the upperfilter entry in storage volumes class and
added my driver’s tag to the front of the group loader list i.e.“System Bus
Extender”. I am still not able to attach to ftdisk devices before volsnap
devices attaches to them.
Can anybody help me with this?

Thanks,
Giri.

2

> making the upperfilter entry in storage volumes class
Something is wrong here: you should have “UpperFilters” already,
that’s where you should see “VolSnap” in data.

Are you using a correct class?

Say, not “…967…” (GUID_DEVCLASS_DISKDRIVE) but
“…A27…” (GUID_DEVCLASS_VOLUME)?

Check out

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class{71A27CDD-812A-11D0-BEC7-08002BE2092F}

on any xp box.

You should have a REG_MULTI_SZ “UpperFilters” there with “VolSnap\0\0” initially and
“myfilter\0VolSnap\0\0” after you make your change.

As was noted in this list more than once, this does not guarantee that you are on top (or even that
you will stay above volsnap forever): other installs may rearrange things as they please.

----- Original Message -----
From: Giri
To: Windows File Systems Devs Interest List
Sent: Tuesday, February 28, 2006 3:47 AM
Subject: [ntfsd] Filter attaching between volume and volsnap

Hi all,
I’ve written a volume filter driver and I want it to load before volsnap driver attaches to the ftdisk devices.
I’ve tried it by making the upperfilter entry in storage volumes class and added my driver’s tag to the front of the group loader list i.e.“System Bus Extender”. I am still not able to attach to ftdisk devices before volsnap devices attaches to them.
Can anybody help me with this?

Thanks,
Giri.
— Questions? First check the IFS FAQ at https://www.osronline.com/article.cfm?id=17 You are currently subscribed to ntfsd as: unknown lmsubst tag argument: ‘’ To unsubscribe send a blank email to xxxxx@lists.osr.com

3

Hi Alex,
I have appended “myfilter” entry to the existing “Upperfilters” entry. in
2k3 the sequence “myfilter volsnap” or “volsnap myfilter” dosen’t
matter.Ialso using the volume class and not the disk class.

Following are the entries if my INF file. Can you please tell me whats
going wrong in that or how to attach filter below volsnap devices and above
volume devices?

.

.

.

.

[DefaultInstall.NT]

CopyFiles = @Myfilter.sys

AddReg = Myfilter_AddReg

[Myfilter_AddReg]

HKLM,
System\CurrentControlSet\Control\Class{71A27CDD-812A-11D0-BEC7-08002BE2092F},
UpperFilters, 0x00010008, Myfilter
[DefaultInstall.NT.Services]

AddService = Myfilter, 0x00000001 , Myfilter_Service_Inst,
Myfilter_EventLog_Inst

[Myfilter_Service_Inst]

DisplayName = % Myfilter.SvcDesc%

ServiceType = %SERVICE_KERNEL_DRIVER%

StartType = %SERVICE_BOOT_START%

ErrorControl = %SERVICE_ERROR_IGNORE%

ServiceBinary = %12%\ Myfilter.sys

LoadOrderGroup = “System bus Extender”

[Myfilter_EventLog_Inst]

AddReg = Myfilter_EventLog_AddReg

[Myfilter_EventLog_AddReg]

HKR,EventMessageFile,
%REG_EXPAND_SZ%,“%%SystemRoot%%\System32\IoLogMsg.dll;%%SystemRoot%%\System32\drivers\
Myfilter.sys”

HKR,TypesSupported, %REG_DWORD%, 7

.

.

.

.

On 2/28/06, xxxxx@Home wrote:
>
> > making the upperfilter entry in storage volumes class
> Something is wrong here: you should have “UpperFilters” already,
> that’s where you should see “VolSnap” in data.
>
> Are you using a correct class?
>
> Say, not “…967…” (GUID_DEVCLASS_DISKDRIVE) but
> “…A27…” (GUID_DEVCLASS_VOLUME)?
>
> Check out
>
>
> HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class{71A27CDD-812A-11D0-BEC7-08002BE2092F}
>
> on any xp box.
>
> You should have a REG_MULTI_SZ “UpperFilters” there with
> “VolSnap\0\0” initially and
> “myfilter\0VolSnap\0\0” after you make your change.
>
> As was noted in this list more than once, this does not guarantee that you
> are on top (or even that
> you will stay above volsnap forever): other installs may rearrange things
> as they please.
>
>
>
>
>
> ----- Original Message -----
> From: Giri
> To: Windows File Systems Devs Interest List
> Sent: Tuesday, February 28, 2006 3:47 AM
> Subject: [ntfsd] Filter attaching between volume and volsnap
>
> Hi all,
> I’ve written a volume filter driver and I want it to load before volsnap
> driver attaches to the ftdisk devices.
> I’ve tried it by making the upperfilter entry in storage volumes class and
> added my driver’s tag to the front of the group loader list i.e.“System
> Bus Extender”. I am still not able to attach to ftdisk devices before
> volsnap devices attaches to them.
> Can anybody help me with this?
>
> Thanks,
> Giri.
> — Questions? First check the IFS FAQ at
> https://www.osronline.com/article.cfm?id=17 You are currently subscribed
> to ntfsd as: unknown lmsubst tag argument: ‘’ To unsubscribe send a blank
> email to xxxxx@lists.osr.com
>
>
> —
> Questions? First check the IFS FAQ at
> https://www.osronline.com/article.cfm?id=17
>
> You are currently subscribed to ntfsd as: unknown lmsubst tag argument: ‘’
>
> To unsubscribe send a blank email to xxxxx@lists.osr.com