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 1.2 2002/05/01 21:52:05 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 #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              PULONG LengthRead)
  55 /*
  56  * FUNCTION: Reads data from a file
  57  */
  58 {
  59   NTSTATUS Status = STATUS_SUCCESS;
  60   PUCHAR TempBuffer;
  61   ULONG TempLength;
  62   PCCB Ccb;
  63   PFCB Fcb;
  64
  65   DPRINT("CdfsReadFile(ReadOffset %lu  Length %lu)\n", ReadOffset, Length);
  66
  67   *LengthRead = 0;
  68
  69   if (Length == 0)
  70     return STATUS_SUCCESS;
  71
  72   Ccb = (PCCB)FileObject->FsContext2;
  73   Fcb = Ccb->Fcb;
  74
  75   if (ReadOffset + Length > Fcb->Entry.DataLengthL)
  76     Length = Fcb->Entry.DataLengthL - ReadOffset;
  77
  78   DPRINT("Reading %d bytes at %d\n", Length, ReadOffset);
  79
  80   if (Length == 0)
  81     return(STATUS_UNSUCCESSFUL);
  82
  83 #if 0
  84   if ((FileObject->Flags & FO_NO_INTERMEDIATE_BUFFERING) == 0)
  85     {
  86       LARGE_INTEGER FileOffset;
  87       IO_STATUS_BLOCK IoStatus;
  88
  89       FileOffset.QuadPart = ReadOffset;
  90       CcCopyRead(FileObject,
  91                  &FileOffset,
  92                  Length,
  93                  TRUE,
  94                  Buffer,
  95                  &IoStatus);
  96       *LengthRead = IoStatus.Information;
  97
  98       return(IoStatus.Status);
  99     }
 100 #endif
 101
 102   if ((ReadOffset % BLOCKSIZE) != 0)
 103     {
 104       TempLength = min(Length, BLOCKSIZE - (ReadOffset % BLOCKSIZE));
 105       TempBuffer = ExAllocatePool(NonPagedPool, BLOCKSIZE);
 106
 107       Status = CdfsReadSectors(DeviceExt->StorageDevice,
 108                                Fcb->Entry.ExtentLocationL + (ReadOffset / BLOCKSIZE),
 109                                1,
 110                                TempBuffer);
 111       if (NT_SUCCESS(Status))
 112         {
 113           memcpy(Buffer, TempBuffer + (ReadOffset % BLOCKSIZE), TempLength);
 114           (*LengthRead) = (*LengthRead) + TempLength;
 115           Length = Length - TempLength;
 116           Buffer = Buffer + TempLength;
 117           ReadOffset = ReadOffset + TempLength;
 118         }
 119       ExFreePool(TempBuffer);
 120     }
 121
 122   DPRINT("Status %lx\n", Status);
 123
 124   if ((Length / BLOCKSIZE) != 0 && NT_SUCCESS(Status))
 125     {
 126       TempLength = ROUND_DOWN(Length, BLOCKSIZE);
 127       Status = CdfsReadSectors(DeviceExt->StorageDevice,
 128                                Fcb->Entry.ExtentLocationL + (ReadOffset / BLOCKSIZE),
 129                                Length / BLOCKSIZE,
 130                                Buffer);
 131       if (NT_SUCCESS(Status))
 132         {
 133           (*LengthRead) = (*LengthRead) + TempLength;
 134           Length = Length - TempLength;
 135           Buffer = Buffer + TempLength;
 136           ReadOffset = ReadOffset + TempLength;
 137         }
 138     }
 139
 140   DPRINT("Status %lx\n", Status);
 141
 142   if (Length > 0 && NT_SUCCESS(Status))
 143     {
 144       TempBuffer = ExAllocatePool(NonPagedPool, BLOCKSIZE);
 145
 146       Status = CdfsReadSectors(DeviceExt->StorageDevice,
 147                                Fcb->Entry.ExtentLocationL + (ReadOffset / BLOCKSIZE),
 148                                1,
 149                                TempBuffer);
 150       if (NT_SUCCESS(Status))
 151         {
 152           memcpy(Buffer, TempBuffer, Length);
 153           (*LengthRead) = (*LengthRead) + Length;
 154         }
 155       ExFreePool(TempBuffer);
 156     }
 157
 158   return(Status);
 159 }
 160
 161
 162 NTSTATUS STDCALL
 163 CdfsRead(PDEVICE_OBJECT DeviceObject,
 164          PIRP Irp)
 165 {
 166   PDEVICE_EXTENSION DeviceExt;
 167   PIO_STACK_LOCATION Stack;
 168   PFILE_OBJECT FileObject;
 169   PVOID Buffer;
 170   ULONG ReadLength;
 171   LARGE_INTEGER ReadOffset;
 172   ULONG ReturnedReadLength = 0;
 173   NTSTATUS Status = STATUS_SUCCESS;
 174
 175   DPRINT("CdfsRead(DeviceObject %x, Irp %x)\n",DeviceObject,Irp);
 176
 177   if (Irp->Flags & IRP_PAGING_IO)
 178     {
 179       Status = STATUS_NOT_SUPPORTED;
 180       goto ByeBye;
 181     }
 182
 183   DeviceExt = DeviceObject->DeviceExtension;
 184   Stack = IoGetCurrentIrpStackLocation(Irp);
 185   FileObject = Stack->FileObject;
 186
 187   ReadLength = Stack->Parameters.Read.Length;
 188   ReadOffset = Stack->Parameters.Read.ByteOffset;
 189   Buffer = MmGetSystemAddressForMdl(Irp->MdlAddress);
 190
 191   Status = CdfsReadFile(DeviceExt,
 192                         FileObject,
 193                         Buffer,
 194                         ReadLength,
 195                         ReadOffset.u.LowPart,
 196                         &ReturnedReadLength);
 197
 198 ByeBye:
 199   if (NT_SUCCESS(Status))
 200     {
 201       if (FileObject->Flags & FO_SYNCHRONOUS_IO)
 202         {
 203           FileObject->CurrentByteOffset.QuadPart =
 204             ReadOffset.QuadPart + ReturnedReadLength;
 205         }
 206       Irp->IoStatus.Information = ReturnedReadLength;
 207     }
 208   else
 209     {
 210       Irp->IoStatus.Information = 0;
 211     }
 212
 213   Irp->IoStatus.Status = Status;
 214   IoCompleteRequest(Irp,IO_NO_INCREMENT);
 215
 216   return(Status);
 217 }
 218
 219
 220 NTSTATUS STDCALL
 221 CdfsWrite(PDEVICE_OBJECT DeviceObject,
 222           PIRP Irp)
 223 {
 224   DPRINT("CdfsWrite(DeviceObject %x Irp %x)\n",DeviceObject,Irp);
 225
 226   Irp->IoStatus.Status = STATUS_NOT_SUPPORTED;
 227   Irp->IoStatus.Information = 0;
 228   return(STATUS_NOT_SUPPORTED);
 229 }
 230
 231 /* EOF */