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);
}