Problem with Windows 7's fvevol driver.

NTFSD
1

Hello,

I have a volume driver which is under fvevol driver. My application must get credentials from user and give access to the volume. But untill user doesn’t give credentials, my driver returns STATUS_ACCESS_DENIED for IRP_MJ_READ.

When removable media (USB stick) is inserted, OS tries to read some data from volume. When my driver returns an error, fvevol “remembers” it, and returns the same error (for next IRP_MJ_READ) without sending IRP down. So my driver gets IRP_MJ_READ only once.

When I remove fvevol from device stack (from registries), my driver works correctly.

Is this accepted behaviour for fvevol ?
Is this accepted behaviour for a volume driver ?

Thanks…

2

> I have a volume driver which is under fvevol driver.

Do you really need to be below and see the ciphertext? Maybe being above is a better idea?

–
Maxim S. Shatskih
Windows DDK MVP
xxxxx@storagecraft.com
http://www.storagecraft.com

3

> Do you really need to be below and see the ciphertext? Maybe being above is a

better idea?

No I don’t need to see the ciphertext.

I have put my driver up to fvevol, and everything works correctly. Thank you for that idea.

But still I doubt that fvevol works correctly. Why does it always return the same error (gotten from lower drvier) even when volume is not encrypted by “BitLocker To Go” ?

4

I have another question about installing my driver.

Is it possible to put my driver upper than fvevol during the installation of my application ?

Thanks…

5

> Is it possible to put my driver upper than fvevol during the installation of my application ?

This is just the question of adding you to a proper place to UpperFilters or LowerFilters to the Volume class.

–
Maxim S. Shatskih
Windows DDK MVP
xxxxx@storagecraft.com
http://www.storagecraft.com

6

Thanks. I’ll try to detect the correct place for my driver.

But the question

“Why does it always return the same error (gotten from lower drvier) even when volume is not encrypted by ‘BitLocker To Go’ ?”

still remains.

7

Thanks for pointing this out. I’m told the BitLocker team is aware of this issue but a release date for the fix has not been determined yet.

Scott
This posting is provided “AS IS” with no warranties, and confers no rights.

-----Original Message-----
From: xxxxx@lists.osr.com [mailto:xxxxx@lists.osr.com] On Behalf Of xxxxx@gmail.com
Sent: Wednesday, February 17, 2010 1:20 AM
To: Windows File Systems Devs Interest List
Subject: RE:[ntfsd] Problem with Windows 7’s fvevol driver.

Thanks. I’ll try to detect the correct place for my driver.

But the question

“Why does it always return the same error (gotten from lower drvier) even when volume is not encrypted by ‘BitLocker To Go’ ?”

still remains.

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8

Thank you very much.