How to compare the FileObjects?

Hi,

I am developing a minifilter. In the Post-CreateCallback
routine (IRP_MJ_CREATE), i am adding the FileObject->FsContext value &
FileName which has a write access into a ListEntry. Using the
FsContext value, i am comparing the FileObjects in IRP_MJ_WRITE.

While intercepting the IRP_MJ_WRITE, I tried to match FileObject using
the FsContext value with the ListEntry. But very less files are
getting matched - .txt , .ini , .dat files & flag is
IRP_WRITE_OPERATION.

Could any one explain me, why the FsContext matching gets failed for
many extension - .exe,.doc files?

To compare the FileObjects - Do i need to compare the FileObject
pointer rather than comparing the FsContext value?

Currently i didn’t include the FAST_IO support in my minifilter.

Thanks,
SivaRaja

I am not really sure what you are trying to achieve by doing this but, I
would recommend “stepping away from the keyboard” and reading the very
informative documentation that now comes with the IFS kit.

I would highly recommend that you read, specifically, about
FltAllocateContext and its cousins.

All this nice context tracking stuff was added to the minifilter model
to make these kind of things easier. Why not use it?

If you insist on doing it yourself I would recommend searching the list
archives, or heading over to OSR as they have written a good article
about tracking files.

http://www.osronline.com/article.cfm?id=102, and that took me all of
about 10 seconds to find by searching the list!

Regards

Ben Curley

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of SivaRaja
Sent: 27 July 2005 11:06
To: Windows File Systems Devs Interest List
Subject: [ntfsd] How to compare the FileObjects?

Hi,

I am developing a minifilter. In the Post-CreateCallback
routine (IRP_MJ_CREATE), i am adding the FileObject->FsContext value &
FileName which has a write access into a ListEntry. Using the FsContext
value, i am comparing the FileObjects in IRP_MJ_WRITE.

While intercepting the IRP_MJ_WRITE, I tried to match FileObject using
the FsContext value with the ListEntry. But very less files are getting
matched - .txt , .ini , .dat files & flag is IRP_WRITE_OPERATION.

Could any one explain me, why the FsContext matching gets failed for
many extension - .exe,.doc files?

To compare the FileObjects - Do i need to compare the FileObject pointer
rather than comparing the FsContext value?

Currently i didn’t include the FAST_IO support in my minifilter.

Thanks,
SivaRaja


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

You are currently subscribed to ntfsd as: unknown lmsubst tag argument:
‘’
To unsubscribe send a blank email to xxxxx@lists.osr.com

Hi Ben,

Thanks for your suggestion. I started looking into the
http://www.osronline.com/article.cfm?id=102, & FltAllocateContext.

Thanks,
SivaRaja

On 7/27/05, Ben Curley wrote:
>
> I am not really sure what you are trying to achieve by doing this but, I
> would recommend “stepping away from the keyboard” and reading the very
> informative documentation that now comes with the IFS kit.
>
> I would highly recommend that you read, specifically, about
> FltAllocateContext and its cousins.
>
> All this nice context tracking stuff was added to the minifilter model
> to make these kind of things easier. Why not use it?
>
>
> If you insist on doing it yourself I would recommend searching the list
> archives, or heading over to OSR as they have written a good article
> about tracking files.
>
> http://www.osronline.com/article.cfm?id=102, and that took me all of
> about 10 seconds to find by searching the list!
>
> Regards
>
> Ben Curley
>
>
> -----Original Message-----
> From: xxxxx@lists.osr.com
> [mailto:xxxxx@lists.osr.com] On Behalf Of SivaRaja
> Sent: 27 July 2005 11:06
> To: Windows File Systems Devs Interest List
> Subject: [ntfsd] How to compare the FileObjects?
>
> Hi,
>
> I am developing a minifilter. In the Post-CreateCallback
> routine (IRP_MJ_CREATE), i am adding the FileObject->FsContext value &
> FileName which has a write access into a ListEntry. Using the FsContext
> value, i am comparing the FileObjects in IRP_MJ_WRITE.
>
> While intercepting the IRP_MJ_WRITE, I tried to match FileObject using
> the FsContext value with the ListEntry. But very less files are getting
> matched - .txt , .ini , .dat files & flag is IRP_WRITE_OPERATION.
>
> Could any one explain me, why the FsContext matching gets failed for
> many extension - .exe,.doc files?
>
> To compare the FileObjects - Do i need to compare the FileObject pointer
> rather than comparing the FsContext value?
>
> Currently i didn’t include the FAST_IO support in my minifilter.
>
> Thanks,
> SivaRaja
>
> —
> Questions? First check the IFS FAQ at
> https://www.osronline.com/article.cfm?id=17
>
> You are currently subscribed to ntfsd as: unknown lmsubst tag argument:
> ‘’
> To unsubscribe send a blank email to xxxxx@lists.osr.com
>
> —
> Questions? First check the IFS FAQ at https://www.osronline.com/article.cfm?id=17
>
> You are currently subscribed to ntfsd as: unknown lmsubst tag argument: ‘’
> To unsubscribe send a blank email to xxxxx@lists.osr.com
>