reactos/reactos/drivers/filesystems/ntfs/misc.c

/*
 *  ReactOS kernel
 *  Copyright (C) 2008 ReactOS Team
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * COPYRIGHT:        See COPYING in the top level directory
 * PROJECT:          ReactOS kernel
 * FILE:             drivers/filesystem/ntfs/misc.c
 * PURPOSE:          NTFS filesystem driver
 * PROGRAMMER:       Pierre Schweitzer
 * UPDATE HISTORY:
 */

/* INCLUDES *****************************************************************/

#include "ntfs.h"

#define NDEBUG
#include <debug.h>

/* GLOBALS *****************************************************************/


/* FUNCTIONS ****************************************************************/

/*
 * FUNCTION: Used with IRP to set them to TopLevelIrp field
 * ARGUMENTS:
 *           Irp = The IRP to set
 * RETURNS: TRUE if top level was null, else FALSE
 */
BOOLEAN
NtfsIsIrpTopLevel(PIRP Irp)
{
  BOOLEAN	ReturnCode = FALSE;
  
  TRACE_(NTFS, "NtfsIsIrpTopLevel()\n");

  if (IoGetTopLevelIrp() == NULL)
  {
    IoSetTopLevelIrp(Irp);
    ReturnCode = TRUE;
  }

  return ReturnCode;
}

/*
 * FUNCTION: Allocate and fill an NTFS_IRP_CONTEXT struct in order to use it for IRP
 * ARGUMENTS:
 *           DeviceObject = Used to fill in struct 
 *           Irp = The IRP that need IRP_CONTEXT struct
 * RETURNS: NULL or PNTFS_IRP_CONTEXT
 */
PNTFS_IRP_CONTEXT
NtfsAllocateIrpContext(PDEVICE_OBJECT DeviceObject,
                       PIRP Irp)
{
  PNTFS_IRP_CONTEXT IrpContext;
  PIO_STACK_LOCATION IoStackLocation;
  
  TRACE_(NTFS, "NtfsAllocateIrpContext()\n");
  
  IrpContext = (PNTFS_IRP_CONTEXT)ExAllocatePoolWithTag(NonPagedPool, sizeof(NTFS_IRP_CONTEXT), 'PRIN');
  if (IrpContext == NULL)
    return NULL;
  RtlZeroMemory(IrpContext, sizeof(NTFS_IRP_CONTEXT));

  IrpContext->Identifier.Type = NTFS_TYPE_IRP_CONTEST;
  IrpContext->Identifier.Size = sizeof(NTFS_IRP_CONTEXT);
  IrpContext->Irp = Irp;
  IrpContext->DeviceObject = DeviceObject;
  if (Irp)
  {
    IoStackLocation = IoGetCurrentIrpStackLocation(Irp);
    ASSERT(IoStackLocation);

    IrpContext->MajorFunction = IoStackLocation->MajorFunction;
    IrpContext->MinorFunction = IoStackLocation->MinorFunction;
    IrpContext->IsTopLevel = (IoGetTopLevelIrp() == Irp);
  }
  
  return IrpContext;
}