Maybe we should take this off-line.
-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Ted Hess
Sent: Monday, July 28, 2003 11:07 AM
To: File Systems Developers
Subject: [ntfsd] RE: Problem with NT4.0 FileObject.DeviceObject
Yes, I may have been a little too concise in my original post. I will
elaborate…
Our filter is built on top of OSR’s FDDK. It is through their recognizer
and
filter that we do our actual work. We are both an open file manager and
a
replication change filter.
To answer your specific question: We are a file system filter attaching
to
the media device at mount / driver load time - no problem here.
What we see in a CREATE IRPs FileObject->DeviceObject is (usually - for
the
last 6-yrs) the media device object mounted. On rare occasions we see
the
NTFS device - we ignore it. In this instance, we are always seeing the
NTFS
device. So… you can see my puzzlement.
No crash, no burn, no hiccups - in fact, on this system, we aren’t even
filtering.
My question to the group was really one of curiosity - I was just
looking
for an explanation of the phenomenon. And, I have a moderately
half-backed
plan for a workaround. I would however, dearly like to know how it
happened.
(And yes, I can accept: “Your poorly written old filter is screwing with
the
system…”)
/ted
-----Original Message-----
From: Jamey Kirby [mailto:xxxxx@storagecraft.com]
Sent: Monday, July 28, 2003 1:21 PM
To: File Systems Developers
Subject: [ntfsd] RE: Problem with NT4.0 FileObject.DeviceObject
You must properly state your question. You have not done this. The
experts
on this list are asking for more specific information and you feel that
it
is not required. It is!
Given that you are with LiveVault, it may be that you are trying to
develop
some sort of “open file”/snapshot software; I am not 100% sure, but I
have
my suspicions.
We need to know how you are attaching to the device stack… Are you
loading
a disk filter driver that attaches to partitions when the AddDevice
routine
is called or are you writing a file system filter driver that is
attaching
to the disk device objects at mount time?
If it is the latter, there are several problems that I know of in doing
this
under NT 4.0. In my opinion, it is a bug in NT 4.0. The problems that I
am
speaking of can appear to work for months and then all of a sudden,
every
system you run it on will crash; something to do with the distance
between
the Earth and Mars and that distance is about to reach it closest it has
been in almost 60,000,000 years. So, hold on to your hat and please
answer
our questions.
Jamey
-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Ted Hess
Sent: Monday, July 28, 2003 8:24 AM
To: File Systems Developers
Subject: [ntfsd] RE: Problem with NT4.0 FileObject.DeviceObject
Joze -
The problem I was querying about has really nothing to do with what I am
attaching to – that part of the puzzle is correct. The problem is what
DeviceObject is in the FileObject being passed down from above.
Please note: This anomoly showed up on an unusual configuration of one
particular NT4.0 system. I have no other problem (in this area) with any
other NT4/Win200/XP/WS03 systems.
/ted
-----Original Message-----
From: Joze Fabcic [mailto:xxxxx@hermes.si]
Sent: Monday, July 28, 2003 9:34 AM
To: File Systems Developers
Subject: [ntfsd] RE: Problem with NT4.0 FileObject.DeviceObject
Can you explain your way of attaching? Do you use IoDetachDevice, too?
Do
you attach to FS or storage stack?
I’ve seen a crash dump where my driver received IRP from other driver
that
attached to my device. My workaround was to check device found in IRPs
against a list of known devices and maintain usage counts for these
devices.
Joze
-----Original Message-----
From: Ted Hess [mailto:xxxxx@livevault.com]
Sent: Friday, July 25, 2003 11:26 PM
To: File Systems Developers
Subject: [ntfsd] Problem with NT4.0 FileObject.DeviceObject
We have an NT4.0 system in our lab that has the “kitchen sink” installed
on
it (Exchange, SQL, BackOffice, Site Server, IIS, etc.). It is the only
system I have ever seen this problem on. All of our other NT4.0 systems
are
fine. OK, here’s the meat of the matter. After our filter is loaded and
we
have attached to all the appropriate devices (usually the media object
owned
by disk/ftdisk), we build a table with some extended info on these
devices.
Whenever, we receive a CREATE IRP, we lookup the DeviceObject in the
FileObject and, up until today, it has always been one that is in our
table.
On this one system, the DeviceObject field points to an NTFS device
instead.
My question to this group is: Has anyone seen this problem and… a)
Knows
why this is happening and what component is the cuprit or b) Has a
workaround. There are no other filters that I can see involved here.
What am
I missing?
We plan on rebuilding this system one component at a time to try and
isolate
the problem. I will post the results here sometime next week.
/ted
You are currently subscribed to ntfsd as: xxxxx@hermes.si
To unsubscribe send a blank email to xxxxx@lists.osr.com
You are currently subscribed to ntfsd as: xxxxx@livevault.com To
unsubscribe
send a blank email to xxxxx@lists.osr.com
You are currently subscribed to ntfsd as: xxxxx@storagecraft.com To
unsubscribe send a blank email to xxxxx@lists.osr.com
You are currently subscribed to ntfsd as: xxxxx@livevault.com To
unsubscribe
send a blank email to xxxxx@lists.osr.com
You are currently subscribed to ntfsd as: xxxxx@storagecraft.com
To unsubscribe send a blank email to xxxxx@lists.osr.com
