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NtQueryInformationFile and Filter Drive

Neil_WeicherNeil_Weicher Member Posts: 407
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.

Comments

  • OSR_Community_UserOSR_Community_User Member Posts: 110,217
    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 <[email protected]>
    To: File Systems Developers <[email protected]>
    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: [email protected]
    > To unsubscribe send a blank email to $subst('Email.Unsub')
    >
    >
  • OSR_Community_UserOSR_Community_User Member Posts: 110,217
    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:[email protected]]
    > 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 <[email protected]>
    > To: File Systems Developers <[email protected]>
    > 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: [email protected]
    > > To unsubscribe send a blank email to $subst('Email.Unsub')
    > >
    > >
    >
    >
    > ---
    > You are currently subscribed to ntfsd as: [email protected]
    > To unsubscribe send a blank email to $subst('Email.Unsub')
    >
  • Neil_WeicherNeil_Weicher Member Posts: 407
    > 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
  • OSR_Community_UserOSR_Community_User Member Posts: 110,217
    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:[email protected]]
    > 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
    >
    >
    >
    >
    >
    > ---
    > You are currently subscribed to ntfsd as: [email protected]
    > To unsubscribe send a blank email to $subst('Email.Unsub')
    >
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