Filtering all directory entries in IRP_MJ_DIRECTORY_CONTROL

NTFSD
1

Hi all,
With some very useful info from list archives, I am able to hide all
or few directory entries according to my needs but I am not able to
understand the case when we need to hide all entries in a directory.
In this case, if I send the Irp downstream again, without touching
anything in the IRP, how does the FileSystem driver know and handle
this case?
Does it keep some context in some field for FindFirst -> FindNext kind
of processing?
Thanks in advance,
Pawan

2

Of course it stores state.

I can’t speak for ALL file systems, but all of those I’ve seen use the
FsContext2 pointer to store open-instance information - like directory
enumeration info. That’s also what I suggest people do when building
new file systems.

General rule: store the enumeration string and current index (offset)
into the directory. I believe you can see this in the FAT and CDFS file
system examples in the IFS Kit.

Regards,

Tony

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

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Pawan Khatri
Sent: Thursday, February 10, 2005 3:07 AM
To: ntfsd redirect
Subject: [ntfsd] Filtering all directory entries in
IRP_MJ_DIRECTORY_CONTROL

Hi all,
With some very useful info from list archives, I am able to hide all
or few directory entries according to my needs but I am not able to
understand the case when we need to hide all entries in a directory.
In this case, if I send the Irp downstream again, without touching
anything in the IRP, how does the FileSystem driver know and handle
this case?
Does it keep some context in some field for FindFirst -> FindNext kind
of processing?
Thanks in advance,
Pawan

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

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

3

I am not sure exactly what you are asking but be aware
that if there are no entries STATUS_NO_SUCH_FILE
should be returned. If anything was ever returned and
now there are no more to return, STATUS_NO_MORE_FILES
should be returned.

This is how you can hide all entries.

Randy

— Pawan Khatri wrote:

> Hi all,
> With some very useful info from list archives, I am
> able to hide all
> or few directory entries according to my needs but I
> am not able to
> understand the case when we need to hide all entries
> in a directory.
> In this case, if I send the Irp downstream again,
> without touching
> anything in the IRP, how does the FileSystem driver
> know and handle
> this case?
> Does it keep some context in some field for
> FindFirst -> FindNext kind
> of processing?
> Thanks in advance,
> Pawan
>
> —
> Questions? First check the IFS FAQ at
> https://www.osronline.com/article.cfm?id=17
>
> You are currently subscribed to ntfsd as:
> xxxxx@yahoo.com
> To unsubscribe send a blank email to
> xxxxx@lists.osr.com
>