Hi,
Can some MS folks confirm whether or not any part of the OS
relies on support for this bit? I.e., would it be OK for a filter to
check for the bit, say INVALID_PARAMETER and then the caller would send
a different request?
–
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.
The primary uses for IRP_MN_MDL (as part of IRP_MJ_READ) are for SRV. In
recent versions we have observed that SRV will use the fast I/O entry point
and if *that* does not work, it will fall back to using raw buffers instead.
AFD (sockets support) still uses it for the TransmitFile API, and IIS uses
the TransmitFile API for sending HTML files directly to the network. While
I do not know if AFD falls back, I suspect that it still does.
Using MDLs is more a matter of efficiency (it eliminates data copy) than
anything else.
Regards,
Tony
Tony Mason
Consulting Partner
OSR Open Systems Resources, Inc.
http://www.osr.com
-----Original Message-----
From: Dejan Maksimovic [mailto:xxxxx@alfasp.com]
Sent: Saturday, April 05, 2003 4:12 AM
To: File Systems Developers
Subject: [ntfsd] IRP_MN_MDL handling
Hi,
Can some MS folks confirm whether or not any part of the OS
relies on support for this bit? I.e., would it be OK for a filter to
check for the bit, say INVALID_PARAMETER and then the caller would send
a different request?
–
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.
You are currently subscribed to ntfsd as: xxxxx@osr.com
To unsubscribe send a blank email to xxxxx@lists.osr.com
In an NTInsider document about SRV I see that SRV does NOT send MdlComplete
request - which would make it very hard if not impossible for a filter to handle
the scenario…
Right?
The primary uses for IRP_MN_MDL (as part of IRP_MJ_READ) are for SRV. In
recent versions we have observed that SRV will use the fast I/O entry point
and if *that* does not work, it will fall back to using raw buffers instead.
AFD (sockets support) still uses it for the TransmitFile API, and IIS uses the
TransmitFile API for sending HTML files directly to the network. While I do
not know if AFD falls back, I suspect that it still does.
Using MDLs is more a matter of efficiency (it eliminates data copy) than
anything else.
–
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.
This information is old, and that particular bug was fixed long ago (read:
FIXED in NT 4.0.)
Regards,
Tony
Tony Mason
Consulting Partner
OSR Open Systems Resources, Inc.
http://www.osr.com
-----Original Message-----
From: Dejan Maksimovic [mailto:xxxxx@alfasp.com]
Sent: Saturday, April 05, 2003 8:14 AM
To: File Systems Developers
Subject: [ntfsd] RE: IRP_MN_MDL handling
In an NTInsider document about SRV I see that SRV does NOT send
MdlComplete
request - which would make it very hard if not impossible for a filter to
handle
the scenario…
Right?
The primary uses for IRP_MN_MDL (as part of IRP_MJ_READ) are for SRV. In
recent versions we have observed that SRV will use the fast I/O entry
point
and if *that* does not work, it will fall back to using raw buffers
instead.
AFD (sockets support) still uses it for the TransmitFile API, and IIS uses
the
TransmitFile API for sending HTML files directly to the network. While I
do
not know if AFD falls back, I suspect that it still does.
Using MDLs is more a matter of efficiency (it eliminates data copy) than
anything else.
–
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.
You are currently subscribed to ntfsd as: xxxxx@osr.com
To unsubscribe send a blank email to xxxxx@lists.osr.com
Aha! The article gave an impression that it still stood in NT 4.
Good enough…
Tony Mason wrote:
This information is old, and that particular bug was fixed long ago (read:
FIXED in NT 4.0.)
–
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.