Completion routine not called

NTFSD
1
  1. Why my completion routine for MJ_CREATE is sometimes not called? What
    I have is: receive MJ_CREATE, set completion routine, it gets never
    called and then I receive some MJ_QUERY_INFORMATION and MJ_READ for that
    file object although I haven’t seen the create to finish. At the MJ_READ
    time the system crashes, bug check.
  2. Is there a function to obtain the available non-paged memory? Maybe I
    have some memory leaks with late effects.

Daniel

2

Run the Driver Verifier for memory leaks.
This sounds like incorrect pending or completing (by either your driver
or some other driver in the stack) of IRPs.

Daniel Turcanu wrote:

  1. Why my completion routine for MJ_CREATE is sometimes not called? What
    I have is: receive MJ_CREATE, set completion routine, it gets never
    called and then I receive some MJ_QUERY_INFORMATION and MJ_READ for that
    file object although I haven’t seen the create to finish. At the MJ_READ
    time the system crashes, bug check.
  2. Is there a function to obtain the available non-paged memory? Maybe I
    have some memory leaks with late effects.

Daniel

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3

I think this could happen if there is another FS filter driver lower on the
stack that causes
reentrancy. Here’s a scenario:

Your driver gets MJ_CREATE, sets a completion routine, and forwards to the
next lower driver.
Lower driver also sets a completion routine and forwards on to NTFS.
NTFS completes the CREATE.
I/O manager calls lower driver’s completion routine.
Lower driver calls ZwQueryInformationFile or ObQueryNameString, or some
other function that will reenter from the top of the I/O stack. YOU will
see the MJ_QUERY_INFORMATION before your completion routine is called. YOUR
completion routine won’t be called until the lower driver’s completion
routine returns.

Carl

“Daniel Turcanu” wrote in message news:xxxxx@ntfsd…
>
> 1. Why my completion routine for MJ_CREATE is sometimes not called? What
> I have is: receive MJ_CREATE, set completion routine, it gets never
> called and then I receive some MJ_QUERY_INFORMATION and MJ_READ for that
> file object although I haven’t seen the create to finish. At the MJ_READ
> time the system crashes, bug check.
> 2. Is there a function to obtain the available non-paged memory? Maybe I
> have some memory leaks with late effects.
>
> Daniel
>
>
>
>
>
>