IRP_MN_NOTIFY_CHANGE_DIRECTORY

NTFSD
1

Hello all,

I’m implementing Change Directory Notification in my FSD. When I click on a
directory in Windows Explorer, I see back-to-back calls into my code for
this minor function. The first one gives me a filter of 0x17, and the
second one gives me a filter of 0x03. My question is does the OS “or” these
bits together, or does the latter one replace the former one, when my driver
calls FsRtlNotifyFullChangeDirectory?

Thanks and regards

GAP

2

I forgot to add the other possibility; that is:

“or does it insert separate entries in the NotifyList for the same
fscontext?”

Thanks again

gap

3

Are you sure the second call is for the same FileObject / Fcb as the frist call ?
And the first change_notify is not cleaned up when the second is called ?

If so, FsRtlNotifyFullChangeDirectory will get it attached already in the NotifyList
and just return without doing anything. (i.e. the second call is ignored.)

Matt

“Greg Pearce” wrote :xxxxx@ntfsd…
> Hello all,
>
> I’m implementing Change Directory Notification in my FSD. When I click on a
> directory in Windows Explorer, I see back-to-back calls into my code for
> this minor function. The first one gives me a filter of 0x17, and the
> second one gives me a filter of 0x03. My question is does the OS “or” these
> bits together, or does the latter one replace the former one, when my driver
> calls FsRtlNotifyFullChangeDirectory?
>
> Thanks and regards
>
> GAP

4

Thanks for the response Matt…

Yes, the FsContext is the same, and there are no other calls of anything to
do with the notify package in between.

Thanks,

Greg

“Matt Wu” wrote in message news:xxxxx@ntfsd…
> Are you sure the second call is for the same FileObject / Fcb as the frist
call ?
> And the first change_notify is not cleaned up when the second is called ?
>
> If so, FsRtlNotifyFullChangeDirectory will get it attached already in the
NotifyList
> and just return without doing anything. (i.e. the second call is ignored.)
>
> Matt
>
>
> “Greg Pearce” wrote :xxxxx@ntfsd…
> > Hello all,
> >
> > I’m implementing Change Directory Notification in my FSD. When I click
on a
> > directory in Windows Explorer, I see back-to-back calls into my code for
> > this minor function. The first one gives me a filter of 0x17, and the
> > second one gives me a filter of 0x03. My question is does the OS “or”
these
> > bits together, or does the latter one replace the former one, when my
driver
> > calls FsRtlNotifyFullChangeDirectory?
> >
> > Thanks and regards
> >
> > GAP
>
>

5

I just checked fastfat and it receives 2 back-to-back requests with the same
ccb/dcb (for root) combination, the first being for a filter of 0x17, and
the second for a filter of 0x03…

Is this correct, that the second one gets thrown out? Of does it take
precedence? Or are they combined?

Thanks

Greg

6

Different requests? They should both be queued. The directory change
notification package allows multiple requests (even from the same
thread/process). If an operation occurs that only applies to one
request, it will be notified, but not the other. If it applies to both,
BOTH threads will be notified.

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 Greg Pearce
Sent: Monday, February 07, 2005 8:13 AM
To: ntfsd redirect
Subject: Re:[ntfsd] IRP_MN_NOTIFY_CHANGE_DIRECTORY

I just checked fastfat and it receives 2 back-to-back requests with the
same
ccb/dcb (for root) combination, the first being for a filter of 0x17,
and
the second for a filter of 0x03…

Is this correct, that the second one gets thrown out? Of does it take
precedence? Or are they combined?

Thanks

Greg

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

7

Cool - that’s the answer I was hoping for. Thanks Tony.

Regards,

GAP

“Tony Mason” wrote in message news:xxxxx@ntfsd…
Different requests? They should both be queued. The directory change
notification package allows multiple requests (even from the same
thread/process). If an operation occurs that only applies to one
request, it will be notified, but not the other. If it applies to both,
BOTH threads will be notified.

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 Greg Pearce
Sent: Monday, February 07, 2005 8:13 AM
To: ntfsd redirect
Subject: Re:[ntfsd] IRP_MN_NOTIFY_CHANGE_DIRECTORY

I just checked fastfat and it receives 2 back-to-back requests with the
same
ccb/dcb (for root) combination, the first being for a filter of 0x17,
and
the second for a filter of 0x03…

Is this correct, that the second one gets thrown out? Of does it take
precedence? Or are they combined?

Thanks

Greg

—
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