reactos/drivers/fs/cdfs/rw.c

   1 /*
   2  *  ReactOS kernel
   3  *  Copyright (C) 2002 ReactOS Team
   4  *
   5  *  This program is free software; you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation; either version 2 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with this program; if not, write to the Free Software
  17  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18  */
  19 /* $Id: rw.c,v 1.1 2002/04/15 20:39:49 ekohl Exp $
  20  *
  21  * COPYRIGHT:        See COPYING in the top level directory
  22  * PROJECT:          ReactOS kernel
  23  * FILE:             services/fs/cdfs/rw.c
  24  * PURPOSE:          CDROM (ISO 9660) filesystem driver
  25  * PROGRAMMER:       Art Yerkes
  26  * UPDATE HISTORY:
  27  */
  28
  29 /* INCLUDES *****************************************************************/
  30
  31 #include <ddk/ntddk.h>
  32
  33 //#define NDEBUG
  34 #include <debug.h>
  35
  36 #include "cdfs.h"
  37
  38
  39 /* FUNCTIONS ****************************************************************/
  40
  41 static NTSTATUS
  42 CdfsReadFile(PDEVICE_EXTENSION DeviceExt,
  43              PFILE_OBJECT FileObject,
  44              PVOID Buffer,
  45              ULONG Length,
  46              ULONG Offset)
  47 /*
  48  * FUNCTION: Reads data from a file
  49  */
  50 {
  51   NTSTATUS Status;
  52   PCCB Ccb;
  53   PFCB Fcb;
  54
  55   DPRINT("CdfsReadFile(Offset %lu  Length %lu)\n", Offset, Length);
  56
  57   if (Length == 0)
  58     return STATUS_SUCCESS;
  59
  60   Ccb = (PCCB)FileObject->FsContext2;
  61   Fcb = Ccb->Fcb;
  62
  63   if (Offset + Length > Fcb->Entry.DataLengthL)
  64     Length = Fcb->Entry.DataLengthL - Offset;
  65
  66   DPRINT( "Reading %d bytes at %d\n", Offset, Length );
  67
  68   if (Length == 0)
  69     return(STATUS_UNSUCCESSFUL);
  70
  71   Status = CdfsReadSectors(DeviceExt->StorageDevice,
  72                            Fcb->Entry.ExtentLocationL + Offset / BLOCKSIZE,
  73                            Length / BLOCKSIZE,
  74                            Buffer);
  75
  76   return(Status);
  77 }
  78
  79
  80 NTSTATUS STDCALL
  81 CdfsRead(PDEVICE_OBJECT DeviceObject,
  82          PIRP Irp)
  83 {
  84   ULONG Length;
  85   PVOID Buffer;
  86   ULONG Offset;
  87   PIO_STACK_LOCATION Stack = IoGetCurrentIrpStackLocation(Irp);
  88   PFILE_OBJECT FileObject = Stack->FileObject;
  89   PDEVICE_EXTENSION DeviceExt = DeviceObject->DeviceExtension;
  90   NTSTATUS Status;
  91
  92   DPRINT("CdfsRead(DeviceObject %x, Irp %x)\n",DeviceObject,Irp);
  93
  94   Buffer = MmGetSystemAddressForMdl(Irp->MdlAddress);
  95   Length = Stack->Parameters.Read.Length;
  96   Offset = Stack->Parameters.Read.ByteOffset.u.LowPart;
  97
  98   Status = CdfsReadFile(DeviceExt,FileObject,Buffer,Length,Offset);
  99
 100   Irp->IoStatus.Status = Status;
 101   Irp->IoStatus.Information = Length;
 102   IoCompleteRequest(Irp,IO_NO_INCREMENT);
 103   return(Status);
 104 }
 105
 106
 107 NTSTATUS STDCALL
 108 CdfsWrite(PDEVICE_OBJECT DeviceObject,
 109           PIRP Irp)
 110 {
 111   DPRINT("CdfsWrite(DeviceObject %x Irp %x)\n",DeviceObject,Irp);
 112
 113   Irp->IoStatus.Status = STATUS_UNSUCCESSFUL;
 114   Irp->IoStatus.Information = 0;
 115   return(STATUS_UNSUCCESSFUL);
 116 }
 117
 118 /* EOF */