Re: [ros-dev] NTOSKRNL bugcheck when clicking on "My Computer C disk icon" = FIXED

[Gge]

Hartmut Birr wrote:
> Gge wrote:
> > With svn 14668 , Ros bugchecks when I click on the "my computer " icon
> > and o then on the "C" disk drive icon as per debug messages below.
> > This is a regression and it is always reproductible .
> > I cannot say exactly when it has been broken.
> > Any idea ?
>
> It may be a result of my changes in 14418. The mdl is only allocated if
> the read/write length is greater 0. Can you add my patch and try it again?
> Hartmut
> Index: drivers/fs/vfat/rw.c
>
> --- drivers/fs/vfat/rw.c	(revision 14480)
> +++ drivers/fs/vfat/rw.c	(working copy)
> @@ -617,6 +617,7 @@
>     }
>     if (Length == 0)
>     {
>  DPRINT1("Length is 0\n");
>  IrpContext->Irp->IoStatus.Information = 0;
>  Status = STATUS_SUCCESS;
>  goto ByeBye;
> Index: ntoskrnl/io/cleanup.c
>
> --- ntoskrnl/io/cleanup.c	(revision 14480)
> +++ ntoskrnl/io/cleanup.c	(working copy)
> @@ -1,4 +1,4 @@
> -/* $Id:$
> +/* $Id$
> COPYRIGHT:       See COPYING in the top level directory
> PROJECT:         ReactOS kernel
>
> @@ -109,7 +109,10 @@
> if (DeviceObject->Flags & DO_DIRECT_IO)
> {
>  IoFreeMdl(Irp->MdlAddress);
>  if (Irp->MdlAddress)
>  {
>     IoFreeMdl(Irp->MdlAddress);
>  }
> }
>
> }

Thanks Harmut,

I have tested successfully your path with an additional fix from Royce3 
below.

These fixes can be committed
Regards
Gerard

--------------   Royce3 patch   -------------------------------

/*
  * @implemented
  */
VOID STDCALL
IoFreeMdl(PMDL Mdl)
{
    /*
     * This unmaps partial mdl's from kernel space but also asserts that
non-partial
     * mdl's isn't still mapped into kernel space.
     */

ASSERT(Mdl);
    ASSERT_IRQL(DISPATCH_LEVEL);

MmPrepareMdlForReuse(Mdl);

ExFreePool(Mdl);
}