NtQueryInformationFile and Filter Drive

Sometimes NtQueryInformationFile (via SetFilePointer) does not seem to call
down to my file system filter driver. None of the dispatch routines are
called, including IRP_MJ_ or FastIo. Yet the routine appears to be
functioning properly. Other times it does call all the way down to the
driver.

It is a normal file (i.e., FILE_FLAG_NO_BUFFERING is NOT set).

It is NT4 using Fast Fat.

Any ideas would be appreciated.

Thanks.

are you sure the “FastIoQueryOpen” is not called??
AFAIK the only other reason i can think of is, that some other filter driver
layered above you might have completed the IRP request

---- alexander suresh

----- Original Message -----
From: Neil Weicher
To: File Systems Developers
Sent: Wednesday, April 19, 2000 12:59 AM
Subject: [ntfsd] NtQueryInformationFile and Filter Drive

> Sometimes NtQueryInformationFile (via SetFilePointer) does not seem to
call
> down to my file system filter driver. None of the dispatch routines are
> called, including IRP_MJ_ or FastIo. Yet the routine appears to be
> functioning properly. Other times it does call all the way down to the
> driver.
>
> It is a normal file (i.e., FILE_FLAG_NO_BUFFERING is NOT set).
>
> It is NT4 using Fast Fat.
>
> Any ideas would be appreciated.
>
> Thanks.
>
>
>
> —
> You are currently subscribed to ntfsd as: xxxxx@mobiliti.com
> To unsubscribe send a blank email to $subst(‘Email.Unsub’)
>
>

The FSD does not see this request. The “IO Manager,” or
NtSetInformationFile if you prefer, handles the FilePositionInformation
request by updating FileObject->CurrentByteOffset.

-----Original Message-----
From: Alexander Suresh [mailto:xxxxx@mobiliti.com]
Sent: Wednesday, April 19, 2000 9:08 AM
To: File Systems Developers
Subject: [ntfsd] Re: NtQueryInformationFile and Filter Drive

are you sure the “FastIoQueryOpen” is not called??
AFAIK the only other reason i can think of is, that some
other filter driver
layered above you might have completed the IRP request

---- alexander suresh

----- Original Message -----
From: Neil Weicher
> To: File Systems Developers
> Sent: Wednesday, April 19, 2000 12:59 AM
> Subject: [ntfsd] NtQueryInformationFile and Filter Drive
>
>
> > Sometimes NtQueryInformationFile (via SetFilePointer) does
> not seem to
> call
> > down to my file system filter driver. None of the dispatch
> routines are
> > called, including IRP_MJ_ or FastIo. Yet the routine appears to be
> > functioning properly. Other times it does call all the way
> down to the
> > driver.
> >
> > It is a normal file (i.e., FILE_FLAG_NO_BUFFERING is NOT set).
> >
> > It is NT4 using Fast Fat.
> >
> > Any ideas would be appreciated.
> >
> > Thanks.
> >
> >
> >
> > —
> > You are currently subscribed to ntfsd as: xxxxx@mobiliti.com
> > To unsubscribe send a blank email to $subst(‘Email.Unsub’)
> >
> >
>
>
> —
> You are currently subscribed to ntfsd as: xxxxx@nsisw.com
> To unsubscribe send a blank email to $subst(‘Email.Unsub’)
>

> On Behalf Of Rob Fuller

The FSD does not see this request. The “IO Manager,” or
NtSetInformationFile if you prefer, handles the FilePositionInformation
request by updating FileObject->CurrentByteOffset.

Thanks for the tip. Can you say why the request sometimes find its way down to
the driver and sometimes does not?

Neil

In my experience, I’ve never seen the request make it down to the FSD,
except perhaps as part of a FileAllInformation request. I was under the
impression the IO Manager always handled the FilePositionInformation
request. Perhaps someone at Microsoft in the know could comment on this?

-----Original Message-----
From: Neil Weicher [mailto:xxxxx@netlib.com]
Sent: Wednesday, April 19, 2000 9:06 PM
To: File Systems Developers
Subject: [ntfsd] Re: NtQueryInformationFile and Filter Drive

> On Behalf Of Rob Fuller
> The FSD does not see this request. The “IO Manager,” or
> NtSetInformationFile if you prefer, handles the
FilePositionInformation
> request by updating FileObject->CurrentByteOffset.

Thanks for the tip. Can you say why the request sometimes
find its way down to
the driver and sometimes does not?

Neil


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