reactos/drivers/fs/cdfs/rw.c

   1 /*
   2  *  ReactOS kernel
   3  *  Copyright (C) 2002, 2003 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 1.12 2003/11/13 15:25:08 ekohl Exp $
  20  *
  21  * COPYRIGHT:        See COPYING in the top level directory
  22  * PROJECT:          ReactOS kernel
  23  * FILE:             drivers/fs/cdfs/rw.c
  24  * PURPOSE:          CDROM (ISO 9660) filesystem driver
  25  * PROGRAMMER:       Art Yerkes
  26  *                   Eric Kohl
  27  */
  28
  29 /* INCLUDES *****************************************************************/
  30
  31 #include <ddk/ntddk.h>
  32 #include <ntos/minmax.h>
  33
  34 #define NDEBUG
  35 #include <debug.h>
  36
  37 #include "cdfs.h"
  38
  39
  40 /* GLOBALS *******************************************************************/
  41
  42 #define ROUND_UP(N, S) ((((N) + (S) - 1) / (S)) * (S))
  43 #define ROUND_DOWN(N, S) ((N) - ((N) % (S)))
  44
  45
  46 /* FUNCTIONS ****************************************************************/
  47
  48 static NTSTATUS
  49 CdfsReadFile(PDEVICE_EXTENSION DeviceExt,
  50              PFILE_OBJECT FileObject,
  51              PUCHAR Buffer,
  52              ULONG Length,
  53              ULONG ReadOffset,
  54              ULONG IrpFlags,
  55              PULONG LengthRead)
  56 /*
  57  * FUNCTION: Reads data from a file
  58  */
  59 {
  60   NTSTATUS Status = STATUS_SUCCESS;
  61   PCCB Ccb;
  62   PFCB Fcb;
  63
  64   DPRINT("CdfsReadFile(ReadOffset %lu  Length %lu)\n", ReadOffset, Length);
  65
  66   *LengthRead = 0;
  67
  68   if (Length == 0)
  69     return(STATUS_SUCCESS);
  70
  71   Ccb = (PCCB)FileObject->FsContext2;
  72   Fcb = (PFCB)FileObject->FsContext;
  73
  74   if (ReadOffset >= Fcb->Entry.DataLengthL)
  75     return(STATUS_END_OF_FILE);
  76
  77   DPRINT("Reading %d bytes at %d\n", Length, ReadOffset);
  78
  79   if (!(IrpFlags & (IRP_NOCACHE|IRP_PAGING_IO)))
  80     {
  81       LARGE_INTEGER FileOffset;
  82       IO_STATUS_BLOCK IoStatus;
  83
  84       if (ReadOffset + Length > Fcb->Entry.DataLengthL)
  85          Length = Fcb->Entry.DataLengthL - ReadOffset;
  86
  87       if (FileObject->PrivateCacheMap == NULL)
  88         {
  89           CcRosInitializeFileCache(FileObject, PAGE_SIZE);
  90         }
  91
  92       FileOffset.QuadPart = (LONGLONG)ReadOffset;
  93       CcCopyRead(FileObject,
  94                  &FileOffset,
  95                  Length,
  96                  TRUE,
  97                  Buffer,
  98                  &IoStatus);
  99       *LengthRead = IoStatus.Information;
 100
 101       return(IoStatus.Status);
 102     }
 103
 104   if ((ReadOffset % BLOCKSIZE) != 0 || (Length % BLOCKSIZE) != 0)
 105     {
 106       return STATUS_INVALID_PARAMETER;
 107     }
 108
 109   if (ReadOffset + Length > ROUND_UP(Fcb->Entry.DataLengthL, BLOCKSIZE))
 110     Length = ROUND_UP(Fcb->Entry.DataLengthL, BLOCKSIZE) - ReadOffset;
 111
 112   Status = CdfsReadSectors(DeviceExt->StorageDevice,
 113                            Fcb->Entry.ExtentLocationL + (ReadOffset / BLOCKSIZE),
 114                            Length / BLOCKSIZE,
 115                            Buffer,
 116                            FALSE);
 117   if (NT_SUCCESS(Status))
 118     {
 119       *LengthRead = Length;
 120       if (Length + ReadOffset > Fcb->Entry.DataLengthL)
 121         {
 122           memset(Buffer + Fcb->Entry.DataLengthL - ReadOffset,
 123                  0,
 124                  Length + ReadOffset - Fcb->Entry.DataLengthL);
 125         }
 126     }
 127
 128   return Status;
 129 }
 130
 131
 132 NTSTATUS STDCALL
 133 CdfsRead(PDEVICE_OBJECT DeviceObject,
 134          PIRP Irp)
 135 {
 136   PDEVICE_EXTENSION DeviceExt;
 137   PIO_STACK_LOCATION Stack;
 138   PFILE_OBJECT FileObject;
 139   PVOID Buffer;
 140   ULONG ReadLength;
 141   LARGE_INTEGER ReadOffset;
 142   ULONG ReturnedReadLength = 0;
 143   NTSTATUS Status = STATUS_SUCCESS;
 144
 145   DPRINT("CdfsRead(DeviceObject %x, Irp %x)\n",DeviceObject,Irp);
 146
 147   DeviceExt = DeviceObject->DeviceExtension;
 148   Stack = IoGetCurrentIrpStackLocation(Irp);
 149   FileObject = Stack->FileObject;
 150
 151   ReadLength = Stack->Parameters.Read.Length;
 152   ReadOffset = Stack->Parameters.Read.ByteOffset;
 153   Buffer = MmGetSystemAddressForMdl(Irp->MdlAddress);
 154
 155   Status = CdfsReadFile(DeviceExt,
 156                         FileObject,
 157                         Buffer,
 158                         ReadLength,
 159                         ReadOffset.u.LowPart,
 160                         Irp->Flags,
 161                         &ReturnedReadLength);
 162   if (NT_SUCCESS(Status))
 163     {
 164       if (FileObject->Flags & FO_SYNCHRONOUS_IO)
 165         {
 166           FileObject->CurrentByteOffset.QuadPart =
 167             ReadOffset.QuadPart + ReturnedReadLength;
 168         }
 169       Irp->IoStatus.Information = ReturnedReadLength;
 170     }
 171   else
 172     {
 173       Irp->IoStatus.Information = 0;
 174     }
 175
 176   Irp->IoStatus.Status = Status;
 177   IoCompleteRequest(Irp,IO_NO_INCREMENT);
 178
 179   return(Status);
 180 }
 181
 182
 183 NTSTATUS STDCALL
 184 CdfsWrite(PDEVICE_OBJECT DeviceObject,
 185           PIRP Irp)
 186 {
 187   DPRINT("CdfsWrite(DeviceObject %x Irp %x)\n",DeviceObject,Irp);
 188
 189   Irp->IoStatus.Status = STATUS_NOT_SUPPORTED;
 190   Irp->IoStatus.Information = 0;
 191   return(STATUS_NOT_SUPPORTED);
 192 }
 193
 194 /* EOF */