IoAttachDeviceToDeviceStack

NTFSD
1

Every once in a while (at some far distant customer site). The call to
IoAttachDeviceToDeviceStack fails. It is usually on the C: when the filter
driver is loading. (It is set to automatic). IoAttachDeviceToDeviceStack
does not return an error, only a NULL or device object if successful. Can
anyone tell me why this happens and how I can prevent it.

Ken
Kenneth J. Galipeau
Legato Systems, Inc.
http://www.legato.com

2

>driver is loading. (It is set to automatic). IoAttachDeviceToDeviceStack

does not return an error, only a NULL or device object if successful. Can

According to the assembly code, this can occur in 2 cases only:

  • current top-of-stack DO has DO_DEVICE_INITIALIZING flag set
  • current top-of-stack DO has DO_UNLOAD_PENDING flag set.

Max

3
  1. Check DO_DEVICE_INITIALIZING bit (DeviceObject->Flag) in device object
    you want to attach to (last device objct in attached device objects chain).
    You cannot attach to the device object with this bit set.
  2. I also check DO_UNLOAD_PENDING bit in DeviceObject->Flag, but I’m not
    sure if it is correct.

best regards
mari

-----Original Message-----
From: Kenneth J Galipeau [mailto:xxxxx@legato.com]
Sent: Friday, April 07, 2000 11:12 PM
To: File Systems Developers
Subject: [ntfsd] IoAttachDeviceToDeviceStack

Every once in a while (at some far distant customer site). The call to
IoAttachDeviceToDeviceStack fails. It is usually on the C: when the filter
driver is loading. (It is set to automatic). IoAttachDeviceToDeviceStack
does not return an error, only a NULL or device object if successful. Can
anyone tell me why this happens and how I can prevent it.

Ken

Kenneth J. Galipeau
Legato Systems, Inc.
http://www.legato.com http:</http:>

4

I got the responses about the DO_DEVICE_INITIALIZING or DO_UNLOAD_PENDING.
Thanks, that tells me how it happens. My problem is why is the C: drive
(system drive usually) “initializing/unloading” late in the boot sequence?
What can I do so I can get attached to the drive?

According to the assembly code, this can occur in 2 cases only:

  • current top-of-stack DO has DO_DEVICE_INITIALIZING flag set
  • current top-of-stack DO has DO_UNLOAD_PENDING flag set.

-----Original Message-----
From: Kenneth J Galipeau [mailto:xxxxx@legato.com]
Sent: Friday, April 07, 2000 5:12 PM
To: NTFSD
Subject: IoAttachDeviceToDeviceStack

Every once in a while (at some far distant customer site). The call to
IoAttachDeviceToDeviceStack fails. It is usually on the C: when the filter
driver is loading. (It is set to automatic). IoAttachDeviceToDeviceStack
does not return an error, only a NULL or device object if successful. Can
anyone tell me why this happens and how I can prevent it.

Ken
Kenneth J. Galipeau
Legato Systems, Inc.
http://www.legato.com