create.c

来自「winNT技术操作系统,国外开放的原代码和LIUX一样」· C语言 代码 · 共 291 行

/*
 *  ReactOS kernel
 *  Copyright (C) 2002, 2003, 2004 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
/* $Id: create.c 21710 2006-04-22 16:36:21Z tretiakov $
 *
 * COPYRIGHT:        See COPYING in the top level directory
 * PROJECT:          ReactOS kernel
 * FILE:             services/fs/cdfs/cdfs.c
 * PURPOSE:          CDROM (ISO 9660) filesystem driver
 * PROGRAMMER:       Art Yerkes
 *                   Eric Kohl
 */

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

#include "cdfs.h"

#define NDEBUG
#include <debug.h>

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

static NTSTATUS
CdfsMakeAbsoluteFilename(PFILE_OBJECT FileObject,
			 PUNICODE_STRING RelativeFileName,
			 PUNICODE_STRING AbsoluteFileName)
{
  ULONG Length;
  PFCB Fcb;
  NTSTATUS Status;

  DPRINT("try related for %wZ\n", RelativeFileName);
  Fcb = FileObject->FsContext;
  ASSERT(Fcb);

  /* verify related object is a directory and target name
     don't start with \. */
  if ((Fcb->Entry.FileFlags & FILE_FLAG_DIRECTORY) == 0 ||
      RelativeFileName->Buffer[0] == L'\\')
    {
      return STATUS_INVALID_PARAMETER;
    }

  /* construct absolute path name */
  Length = (wcslen(Fcb->PathName) * sizeof(WCHAR)) +
           sizeof(WCHAR) +
           RelativeFileName->Length +
           sizeof(WCHAR);
  AbsoluteFileName->Length = 0;
  AbsoluteFileName->MaximumLength = Length;
  AbsoluteFileName->Buffer = ExAllocatePool(NonPagedPool,
					    Length);
  if (AbsoluteFileName->Buffer == NULL)
    {
      return STATUS_INSUFFICIENT_RESOURCES;
    }

  Status = RtlAppendUnicodeToString(AbsoluteFileName,
				    Fcb->PathName);
  if (!NT_SUCCESS(Status))
    {
      RtlFreeUnicodeString(AbsoluteFileName);
      return Status;
    }

  if (!CdfsFCBIsRoot(Fcb))
    {
      Status = RtlAppendUnicodeToString(AbsoluteFileName,
					L"\\");
      if (!NT_SUCCESS(Status))
	{
	  RtlFreeUnicodeString(AbsoluteFileName);
	  return Status;
	}
    }

  Status = RtlAppendUnicodeStringToString(AbsoluteFileName,
					  RelativeFileName);
  if (!NT_SUCCESS(Status))
    {
      RtlFreeUnicodeString(AbsoluteFileName);
      return Status;
    }

  return STATUS_SUCCESS;
}


/*
 * FUNCTION: Opens a file
 */
static NTSTATUS
CdfsOpenFile(PDEVICE_EXTENSION DeviceExt,
	     PFILE_OBJECT FileObject,
	     PUNICODE_STRING FileName)
{
  PFCB ParentFcb;
  PFCB Fcb;
  NTSTATUS Status;
  UNICODE_STRING AbsFileName;

  DPRINT("CdfsOpenFile(%08lx, %08lx, %wZ)\n", DeviceExt, FileObject, FileName);

  if (FileObject->RelatedFileObject)
    {
      DPRINT("Converting relative filename to absolute filename\n");

      Status = CdfsMakeAbsoluteFilename(FileObject->RelatedFileObject,
					FileName,
					&AbsFileName);
      if (!NT_SUCCESS(Status))
	{
	  return Status;
	}

      FileName = &AbsFileName;
    }

  Status = CdfsDeviceIoControl (DeviceExt->StorageDevice,
				IOCTL_CDROM_CHECK_VERIFY,
				NULL,
				0,
				NULL,
				0,
				FALSE);
  DPRINT ("Status %lx\n", Status);
  if (!NT_SUCCESS(Status))
    {
      DPRINT1 ("Status %lx\n", Status);
      return Status;
    }

  DPRINT("PathName to open: %wZ\n", FileName);

  /*  try first to find an existing FCB in memory  */
  DPRINT("Checking for existing FCB in memory\n");
  Fcb = CdfsGrabFCBFromTable(DeviceExt,
			     FileName);
  if (Fcb == NULL)
    {
      DPRINT("No existing FCB found, making a new one if file exists.\n");
      Status = CdfsGetFCBForFile(DeviceExt,
				 &ParentFcb,
				 &Fcb,
				 FileName);
      if (ParentFcb != NULL)
	{
	  CdfsReleaseFCB(DeviceExt,
			 ParentFcb);
	}

      if (!NT_SUCCESS (Status))
	{
	  DPRINT("Could not make a new FCB, status: %x\n", Status);

	  if (FileName == &AbsFileName)
	    RtlFreeUnicodeString(&AbsFileName);

	  return Status;
	}
    }

  DPRINT("Attaching FCB to fileObject\n");
  Status = CdfsAttachFCBToFileObject(DeviceExt,
				     Fcb,
				     FileObject);

  if ((FileName == &AbsFileName) && AbsFileName.Buffer)
    ExFreePool(AbsFileName.Buffer);

  return Status;
}


/*
 * FUNCTION: Opens a file
 */
static NTSTATUS
CdfsCreateFile(PDEVICE_OBJECT DeviceObject,
	       PIRP Irp)
{
  PDEVICE_EXTENSION DeviceExt;
  PIO_STACK_LOCATION Stack;
  PFILE_OBJECT FileObject;
  ULONG RequestedDisposition;
  ULONG RequestedOptions;
  PFCB Fcb;
  NTSTATUS Status;

  DPRINT("CdfsCreateFile() called\n");

  DeviceExt = DeviceObject->DeviceExtension;
  ASSERT(DeviceExt);
  Stack = IoGetCurrentIrpStackLocation (Irp);
  ASSERT(Stack);

  RequestedDisposition = ((Stack->Parameters.Create.Options >> 24) & 0xff);
  RequestedOptions = Stack->Parameters.Create.Options & FILE_VALID_OPTION_FLAGS;
  DPRINT("RequestedDisposition %x, RequestedOptions %x\n",
         RequestedDisposition, RequestedOptions);

  FileObject = Stack->FileObject;

  if (RequestedDisposition == FILE_CREATE ||
      RequestedDisposition == FILE_OVERWRITE_IF ||
      RequestedDisposition == FILE_SUPERSEDE)
    {
      return STATUS_ACCESS_DENIED;
    }

  Status = CdfsOpenFile(DeviceExt,
			FileObject,
			&FileObject->FileName);
  if (NT_SUCCESS(Status))
    {
      Fcb = FileObject->FsContext;

      /* Check whether the file has the requested attributes */
      if (RequestedOptions & FILE_NON_DIRECTORY_FILE && CdfsFCBIsDirectory(Fcb))
	{
	  CdfsCloseFile (DeviceExt, FileObject);
	  return STATUS_FILE_IS_A_DIRECTORY;
	}

      if (RequestedOptions & FILE_DIRECTORY_FILE && !CdfsFCBIsDirectory(Fcb))
	{
	  CdfsCloseFile (DeviceExt, FileObject);
	  return STATUS_NOT_A_DIRECTORY;
	}
  }

  /*
   * If the directory containing the file to open doesn't exist then
   * fail immediately
   */
  Irp->IoStatus.Information = (NT_SUCCESS(Status)) ? FILE_OPENED : 0;
  Irp->IoStatus.Status = Status;

  return Status;
}


NTSTATUS STDCALL
CdfsCreate(PDEVICE_OBJECT DeviceObject,
	   PIRP Irp)
{
  PDEVICE_EXTENSION DeviceExt;
  NTSTATUS Status;

  if (DeviceObject == CdfsGlobalData->DeviceObject)
    {
      /* DeviceObject represents FileSystem instead of logical volume */
      DPRINT("Opening file system\n");
      Irp->IoStatus.Information = FILE_OPENED;
      Status = STATUS_SUCCESS;
      goto ByeBye;
    }

  DeviceExt = DeviceObject->DeviceExtension;

  ExAcquireResourceExclusiveLite(&DeviceExt->DirResource,
				 TRUE);
  Status = CdfsCreateFile(DeviceObject,
			  Irp);
  ExReleaseResourceLite(&DeviceExt->DirResource);

ByeBye:
  Irp->IoStatus.Status = Status;
  IoCompleteRequest(Irp,
		    NT_SUCCESS(Status) ? IO_DISK_INCREMENT : IO_NO_INCREMENT);

  return Status;
}

/* EOF */