SRV bypass FSFD chain at create/open

NTFSD
1

Hi all,
Does anybody knows if LAN Server (SRV.SYS), in some cases of its choice,
bypasses filter driver chain, by sending create/open IRP to
IoGetBaseFileSystemDeviceObject device object (or some other FSFD device
object, that it remembers at its startup)?
WBR Primoz

2

I certainly do know that SRV stores away fast I/O entry points at the time
the file is opened (and thus subsequent filters that load do NOT get those
calls.) I have not observed it skipping around a filter in other cases, but
that does not mean it does not do so.

If you suspect that is what is happening, you can easily confirm it in a
*test driver* by replacing the FAT or NTFS IRP_MJ_CREATE handler with your
own (this is NOT suitable for a production driver, since it doesn’t work if
other drivers do it as well.)

If you have a specific path you observe, there are several people on the
list who can check and confirm if this is the case (not to mention, who can
log a bug against SRV, not that this will do anything to resolve your extant
problem.)

Regards,

Tony

Tony Mason
Consulting Partner
OSR Open Systems Resources, Inc.
http://www.osr.com

-----Original Message-----
From: Primoz Beltram [mailto:xxxxx@hermes.si]
Sent: Monday, September 30, 2002 5:42 AM
To: File Systems Developers
Subject: [ntfsd] SRV bypass FSFD chain at create/open

Hi all,
Does anybody knows if LAN Server (SRV.SYS), in some cases of its choice,
bypasses filter driver chain, by sending create/open IRP to
IoGetBaseFileSystemDeviceObject device object (or some other FSFD device
object, that it remembers at its startup)?
WBR Primoz

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3

Tony, Thank you for your suggestion, of using *test drive*. Sometimes “mind
flow” brings you in front of a wall and you can’t see an obvious way around
it. WBR Primoz

-----Original Message-----
From: Tony Mason [mailto:xxxxx@osr.com]
Sent: Monday, September 30, 2002 12:28 PM
To: File Systems Developers
Subject: [ntfsd] RE: SRV bypass FSFD chain at create/open

I certainly do know that SRV stores away fast I/O entry points at the time
the file is opened (and thus subsequent filters that load do NOT get those
calls.) I have not observed it skipping around a filter in other cases, but
that does not mean it does not do so.

If you suspect that is what is happening, you can easily confirm it in a
*test driver* by replacing the FAT or NTFS IRP_MJ_CREATE handler with your
own (this is NOT suitable for a production driver, since it doesn’t work if
other drivers do it as well.)

If you have a specific path you observe, there are several people on the
list who can check and confirm if this is the case (not to mention, who can
log a bug against SRV, not that this will do anything to resolve your extant
problem.)

Regards,

Tony

Tony Mason
Consulting Partner
OSR Open Systems Resources, Inc.
http://www.osr.com

-----Original Message-----
From: Primoz Beltram [mailto:xxxxx@hermes.si]
Sent: Monday, September 30, 2002 5:42 AM
To: File Systems Developers
Subject: [ntfsd] SRV bypass FSFD chain at create/open

Hi all,
Does anybody knows if LAN Server (SRV.SYS), in some cases of its choice,
bypasses filter driver chain, by sending create/open IRP to
IoGetBaseFileSystemDeviceObject device object (or some other FSFD device
object, that it remembers at its startup)? WBR Primoz

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

You are currently subscribed to ntfsd as: xxxxx@hermes.si To
unsubscribe send a blank email to %%email.unsub%%