Determine whether File is opened or a directory!

NTFSD
1

Hi All,

How to determine from the driver (similar to Sfilter), at IRP_MJ_CREATE ,
whether it is trying to open a file or a directory ??

Is there is any flags for that?

With Regards,
A.Ilamparithi.

2

You need to look at fastfat or cdfs example, as well as get a copy of Rajeev
Nagar’s book on file systems.

The flag to check is in IrpSp->Parameters.Create.Options, and
FILE_DIRECTORY_FILE will be set if the caller is trying to open a directory.

“A.Ilamparithi” wrote in message news:xxxxx@ntfsd…
> Hi All,
>
> How to determine from the driver (similar to Sfilter), at IRP_MJ_CREATE ,
> whether it is trying to open a file or a directory ??
>
> Is there is any flags for that?
>
> With Regards,
> A.Ilamparithi.
>
>
>

3

This is not true.

This flag is only set if someone wants to make sure they are only
opening a directory. If this flag is not set and the
FILE_NON_DIRECTORY_FILE flag is not set, then you can be opening either
a directory or a file. The common case is that neither of these flags
are set.

To handle this you need to wait until the open successfully completes
and then issue a query information IRP for STANDARD information.

Neal Christiansen
Microsoft File System Filter Group Lead
This posting is provided “AS IS” with no warranties, and confers no
rights.

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Greg Pearce
Sent: Tuesday, July 13, 2004 9:56 AM
To: Windows File Systems Devs Interest List
Subject: Re:[ntfsd] Determine whether File is opened or a directory!

You need to look at fastfat or cdfs example, as well as get a copy of
Rajeev
Nagar’s book on file systems.

The flag to check is in IrpSp->Parameters.Create.Options, and
FILE_DIRECTORY_FILE will be set if the caller is trying to open a
directory.

“A.Ilamparithi” wrote in message
news:xxxxx@ntfsd…
> Hi All,
>
> How to determine from the driver (similar to Sfilter), at
IRP_MJ_CREATE ,
> whether it is trying to open a file or a directory ??
>
> Is there is any flags for that?
>
> With Regards,
> A.Ilamparithi.
>
>
>

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

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4

> To handle this you need to wait until the open successfully completes

and then issue a query information IRP for STANDARD information.

You may add one optimization here - If one of the flags
(FILE_DIRECTORY_FILE or FILE_NON_DIRECTORY_FILE)
has been set when the create request came to your filter,
and the create request succeeded, you know what has been open)

L.

5

Here is another thought. If the IoStatus.Information is FILE_OVERWRITTEN
then are we sure the thing opened was in fact a file? What about
FILE_SUPERSEDED?

Cheers
Lyndon

“Ladislav Zezula” wrote in message news:xxxxx@ntfsd…
> > To handle this you need to wait until the open successfully completes
> > and then issue a query information IRP for STANDARD information.
>
> You may add one optimization here - If one of the flags
> (FILE_DIRECTORY_FILE or FILE_NON_DIRECTORY_FILE)
> has been set when the create request came to your filter,
> and the create request succeeded, you know what has been open)
>
> L.
>
>

6

Oops - sorry - I misunderstood the question. Thanks Neal :wink:

“A.Ilamparithi” wrote in message news:xxxxx@ntfsd…
> Hi All,
>
> How to determine from the driver (similar to Sfilter), at IRP_MJ_CREATE ,
> whether it is trying to open a file or a directory ??
>
> Is there is any flags for that?
>
> With Regards,
> A.Ilamparithi.
>
>
>