Is it possible to develop a Volume Filter using UMDF? Just curious.
Thanks
Suhail
AFAIK this is not possible, but there is talk of loosening the UMDF
requirements in future versions of Windows.
–
Don Burn (MVP, Windows DDK)
Windows Filesystem and Driver Consulting
Website: http://www.windrvr.com
Blog: http://msmvps.com/blogs/WinDrvr
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wrote in message news:xxxxx@ntdev…
> Is it possible to develop a Volume Filter using UMDF? Just curious.
>
> Thanks
> Suhail
>
What were you hoping to do in your filter?
-p
-----Original Message-----
From: xxxxx@lists.osr.com [mailto:xxxxx@lists.osr.com] On Behalf Of Don Burn
Sent: Thursday, November 13, 2008 9:51 AM
To: Windows System Software Devs Interest List
Subject: Re:[ntdev] Volume Filter using UMDF
AFAIK this is not possible, but there is talk of loosening the UMDF
requirements in future versions of Windows.
–
Don Burn (MVP, Windows DDK)
Windows Filesystem and Driver Consulting
Website: http://www.windrvr.com
Blog: http://msmvps.com/blogs/WinDrvr
Remove StopSpam to reply
wrote in message news:xxxxx@ntdev…
> Is it possible to develop a Volume Filter using UMDF? Just curious.
>
> Thanks
> Suhail
>
—
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We are making a Volume Filter to encrypt/decrypt the volumes just like Truecrypt does but with our own Key Management Solution. Basically we may use the same approach as Truecrypt uses and provide volume encryption/decryption to our users.
Thanks
Suhail Ansari
Okay. Read/write filtering of storage in UMDF is a LONG way off.
You should be able to use KMDF 1.9 when it comes out if you configure the queues for forward progress (e.g. to be able to throttle I/O in low-memory conditions)
-----Original Message-----
From: xxxxx@lists.osr.com [mailto:xxxxx@lists.osr.com] On Behalf Of xxxxx@hotmail.com
Sent: Thursday, November 13, 2008 11:38 AM
To: Windows System Software Devs Interest List
Subject: RE:[ntdev] Volume Filter using UMDF
We are making a Volume Filter to encrypt/decrypt the volumes just like Truecrypt does but with our own Key Management Solution. Basically we may use the same approach as Truecrypt uses and provide volume encryption/decryption to our users.
Thanks
Suhail Ansari
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So we cant use the current version of KMDF to develop the proposed solution? If we can’t then when is KMDF 1.9 coming out.
You can use the current version. The current version lacks the necessary infrastructure to guarantee fwd progress on io (namely paging io) when resource allocation has failed. Very few if any driver writers I have encountered actually care about guaranteed fwd progress and have even attempted to try it. I know of many kmdf based storage filters that have shipped that have not cared about it as well.
d
-----Original Message-----
From: xxxxx@lists.osr.com [mailto:xxxxx@lists.osr.com] On Behalf Of xxxxx@hotmail.com
Sent: Thursday, November 13, 2008 12:52 PM
To: Windows System Software Devs Interest List
Subject: RE:[ntdev] Volume Filter using UMDF
So we cant use the current version of KMDF to develop the proposed solution? If we can’t then when is KMDF 1.9 coming out.
NTDEV is sponsored by OSR
For our schedule of WDF, WDM, debugging and other seminars visit:
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Please share some more details about it.
Default forwarding using “fire and forget mode” does not require any
extra memory allocations by a filter.
Or does it ?
Harish
-----Original Message-----
From: Doron Holan [mailto:xxxxx@microsoft.com]
Sent: Thursday, November 13, 2008 1:23 PM
To: Windows System Software Devs Interest List
Subject: RE: RE:[ntdev] Volume Filter using UMDF
You can use the current version. The current version lacks the
necessary infrastructure to guarantee fwd progress on io (namely paging
io) when resource allocation has failed. Very few if any driver writers
I have encountered actually care about guaranteed fwd progress and have
even attempted to try it. I know of many kmdf based storage filters
that have shipped that have not cared about it as well.
d
-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of
xxxxx@hotmail.com
Sent: Thursday, November 13, 2008 12:52 PM
To: Windows System Software Devs Interest List
Subject: RE:[ntdev] Volume Filter using UMDF
So we cant use the current version of KMDF to develop the proposed
solution? If we can’t then when is KMDF 1.9 coming out.
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
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NTDEV is sponsored by OSR
For our schedule of WDF, WDM, debugging and other seminars visit:
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The resource allocation failure I am talking about is the failure to allocate the WDFREQUEST itself before your driver ever sees a request presented to it. in a filter we skip allocating the wdfrequest if the filter does not have a registered IO callback for it, but in this case, your filter will have a registered callback for the paging IO b/c the whole point of the filter is to see io requests.
fire and forget does not allocate any memory, so once you have a WDFREQUEST, that is not a problem to fire and forget. Formatting a request can allocate memory though.
d
-----Original Message-----
From: xxxxx@lists.osr.com [mailto:xxxxx@lists.osr.com] On Behalf Of Arora, Harish
Sent: Thursday, November 13, 2008 1:33 PM
To: Windows System Software Devs Interest List
Subject: RE: RE:[ntdev] Volume Filter using UMDF
Please share some more details about it.
Default forwarding using “fire and forget mode” does not require any
extra memory allocations by a filter.
Or does it ?
Harish
-----Original Message-----
From: Doron Holan [mailto:xxxxx@microsoft.com]
Sent: Thursday, November 13, 2008 1:23 PM
To: Windows System Software Devs Interest List
Subject: RE: RE:[ntdev] Volume Filter using UMDF
You can use the current version. The current version lacks the
necessary infrastructure to guarantee fwd progress on io (namely paging
io) when resource allocation has failed. Very few if any driver writers
I have encountered actually care about guaranteed fwd progress and have
even attempted to try it. I know of many kmdf based storage filters
that have shipped that have not cared about it as well.
d
-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of
xxxxx@hotmail.com
Sent: Thursday, November 13, 2008 12:52 PM
To: Windows System Software Devs Interest List
Subject: RE:[ntdev] Volume Filter using UMDF
So we cant use the current version of KMDF to develop the proposed
solution? If we can’t then when is KMDF 1.9 coming out.
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