BSOD on network access

NTFSD
1

Hi,

I am writing this encrypt/decrypt filter driver and have overwritten Create,
Read,Write. It works fine till i work on the same machine. But if i try to
access the file on the machine from someother machine thru a shared folder
the machine crashes with NTFS_FILE_SYSTEM message. Do i have to implement
something else or there is something that i am missing. Please let me know.

Thanks
Suhail

Watch the online reality show Mixed Messages with a friend and enter to win
a trip to NY
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2

Yes you do. The network initiated file I/O will cause IRP_MN_MDL read/write.
While it will translate into non cached I/O, maybe you didn’t handle this correctly?
I.e. are you filtering paging or non-cached I/O? (should filter non-cached only)

Suhail Ansari wrote:

Hi,

I am writing this encrypt/decrypt filter driver and have overwritten Create,
Read,Write. It works fine till i work on the same machine. But if i try to
access the file on the machine from someother machine thru a shared folder
the machine crashes with NTFS_FILE_SYSTEM message. Do i have to implement
something else or there is something that i am missing. Please let me know.

Thanks
Suhail

Watch the online reality show Mixed Messages with a friend and enter to win
a trip to NY
http://www.msnmessenger-download.click-url.com/go/onm00200497ave/direct/01/

Questions? First check the IFS FAQ at https://www.osronline.com/article.cfm?id=17

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

–
Kind regards, Dejan M. MVP for DDK
http://www.alfasp.com E-mail: xxxxx@alfasp.com
Alfa Transparent File Encryptor - Transparent file encryption services.
Alfa File Protector - File protection and hiding library for Win32 developers.
Alfa File Monitor - File monitoring library for Win32 developers.

3

Yes i am filtering only non cached IO. By the way what is the significance
of IRP_MN_MDL read/write.

Thanks
Suhail

From: Dejan Maksimovic
>Reply-To: “Windows File Systems Devs Interest List”
>To: “Windows File Systems Devs Interest List”
>Subject: Re: [ntfsd] BSOD on network access
>Date: Wed, 23 Jun 2004 21:57:11 +0200
>
>
> Yes you do. The network initiated file I/O will cause IRP_MN_MDL
>read/write.
>While it will translate into non cached I/O, maybe you didn’t handle this
>correctly?
>I.e. are you filtering paging or non-cached I/O? (should filter non-cached
>only)
>
>
>Suhail Ansari wrote:
>
> > Hi,
> >
> > I am writing this encrypt/decrypt filter driver and have overwritten
>Create,
> > Read,Write. It works fine till i work on the same machine. But if i try
>to
> > access the file on the machine from someother machine thru a shared
>folder
> > the machine crashes with NTFS_FILE_SYSTEM message. Do i have to
>implement
> > something else or there is something that i am missing. Please let me
>know.
> >
> > Thanks
> > Suhail
> >
> >
> > Watch the online reality show Mixed Messages with a friend and enter to
>win
> > a trip to NY
> >
>http://www.msnmessenger-download.click-url.com/go/onm00200497ave/direct/01/
> >
> > —
> > Questions? First check the IFS FAQ at
>https://www.osronline.com/article.cfm?id=17
> >
> > You are currently subscribed to ntfsd as: xxxxx@alfasp.com
> > To unsubscribe send a blank email to xxxxx@lists.osr.com
>
>–
>Kind regards, Dejan M. MVP for DDK
>http://www.alfasp.com E-mail: xxxxx@alfasp.com
>Alfa Transparent File Encryptor - Transparent file encryption services.
>Alfa File Protector - File protection and hiding library for Win32
>developers.
>Alfa File Monitor - File monitoring library for Win32 developers.
>
>
>
>—
>Questions? First check the IFS FAQ at
>https://www.osronline.com/article.cfm?id=17
>
>You are currently subscribed to ntfsd as: xxxxx@hotmail.com
>To unsubscribe send a blank email to xxxxx@lists.osr.com
From ‘will you?’ to ‘I do,’ MSN Life Events is your resource for Getting
Married. http://lifeevents.msn.com/category.aspx?cid=married

4

It retrieve the cache manager MDL, so the drivers can omit a memory copy. Used
for network access mostly (I haven’t seen any other driver using it)

Suhail Ansari wrote:

Yes i am filtering only non cached IO. By the way what is the significance of
IRP_MN_MDL read/write.

–
Kind regards, Dejan M. MVP for DDK
http://www.alfasp.com E-mail: xxxxx@alfasp.com
Alfa Transparent File Encryptor - Transparent file encryption services.
Alfa File Protector - File protection and hiding library for Win32 developers.
Alfa File Monitor - File monitoring library for Win32 developers.

5

Hi,

In my IRP_MJ_CREATE dispatch routine i send a another IRP_MJ_CREATE to the
file system driver to open the same file for which this dispatch routine is
invoked. There i read the header in file to find out that the file is
encrypted or not.

This things works fine when i am using it on local file system but it just
shows a blue screen when i try to use the same file from network. I dont
know what is the problem. If anybody has any idea please let me know.

Thanks
SUhail

From: Dejan Maksimovic
>Reply-To: “Windows File Systems Devs Interest List”
>To: “Windows File Systems Devs Interest List”
>Subject: Re: [ntfsd] BSOD on network access
>Date: Wed, 23 Jun 2004 22:43:42 +0200
>
>
> It retrieve the cache manager MDL, so the drivers can omit a memory
>copy. Used
>for network access mostly (I haven’t seen any other driver using it)
>
>Suhail Ansari wrote:
>
> > Yes i am filtering only non cached IO. By the way what is the
>significance of
> > IRP_MN_MDL read/write.
>
>–
>Kind regards, Dejan M. MVP for DDK
>http://www.alfasp.com E-mail: xxxxx@alfasp.com
>Alfa Transparent File Encryptor - Transparent file encryption services.
>Alfa File Protector - File protection and hiding library for Win32
>developers.
>Alfa File Monitor - File monitoring library for Win32 developers.
>
>
>
>—
>Questions? First check the IFS FAQ at
>https://www.osronline.com/article.cfm?id=17
>
>You are currently subscribed to ntfsd as: xxxxx@hotmail.com
>To unsubscribe send a blank email to xxxxx@lists.osr.com

_________________________________________________________________
From ‘will you?’ to ‘I do,’ MSN Life Events is your resource for Getting
Married. http://lifeevents.msn.com/category.aspx?cid=married