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 1.4 2002/05/14 23:16:23 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              ULONG IrpFlags,
  55              PULONG LengthRead)
  56 /*
  57  * FUNCTION: Reads data from a file
  58  */
  59 {
  60   NTSTATUS Status = STATUS_SUCCESS;
  61   PUCHAR TempBuffer;
  62   ULONG TempLength;
  63   PCCB Ccb;
  64   PFCB Fcb;
  65
  66   DPRINT("CdfsReadFile(ReadOffset %lu  Length %lu)\n", ReadOffset, Length);
  67
  68   *LengthRead = 0;
  69
  70   if (Length == 0)
  71     return STATUS_SUCCESS;
  72
  73   Ccb = (PCCB)FileObject->FsContext2;
  74   Fcb = Ccb->Fcb;
  75
  76   if (ReadOffset + Length > Fcb->Entry.DataLengthL)
  77     Length = Fcb->Entry.DataLengthL - ReadOffset;
  78
  79   DPRINT("Reading %d bytes at %d\n", Length, ReadOffset);
  80
  81   if (Length == 0)
  82     return(STATUS_UNSUCCESSFUL);
  83
  84   if (!(IrpFlags & (IRP_NOCACHE|IRP_PAGING_IO)))
  85     {
  86       LARGE_INTEGER FileOffset;
  87       IO_STATUS_BLOCK IoStatus;
  88
  89       FileOffset.QuadPart = (LONGLONG)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
 101   if ((ReadOffset % BLOCKSIZE) != 0)
 102     {
 103       TempLength = min(Length, BLOCKSIZE - (ReadOffset % BLOCKSIZE));
 104       TempBuffer = ExAllocatePool(NonPagedPool, BLOCKSIZE);
 105
 106       Status = CdfsReadSectors(DeviceExt->StorageDevice,
 107                                Fcb->Entry.ExtentLocationL + (ReadOffset / BLOCKSIZE),
 108                                1,
 109                                TempBuffer);
 110       if (NT_SUCCESS(Status))
 111         {
 112           memcpy(Buffer, TempBuffer + (ReadOffset % BLOCKSIZE), TempLength);
 113           (*LengthRead) = (*LengthRead) + TempLength;
 114           Length = Length - TempLength;
 115           Buffer = Buffer + TempLength;
 116           ReadOffset = ReadOffset + TempLength;
 117         }
 118       ExFreePool(TempBuffer);
 119     }
 120
 121   DPRINT("Status %lx\n", Status);
 122
 123   if ((Length / BLOCKSIZE) != 0 && NT_SUCCESS(Status))
 124     {
 125       TempLength = ROUND_DOWN(Length, BLOCKSIZE);
 126       Status = CdfsReadSectors(DeviceExt->StorageDevice,
 127                                Fcb->Entry.ExtentLocationL + (ReadOffset / BLOCKSIZE),
 128                                Length / BLOCKSIZE,
 129                                Buffer);
 130       if (NT_SUCCESS(Status))
 131         {
 132           (*LengthRead) = (*LengthRead) + TempLength;
 133           Length = Length - TempLength;
 134           Buffer = Buffer + TempLength;
 135           ReadOffset = ReadOffset + TempLength;
 136         }
 137     }
 138
 139   DPRINT("Status %lx\n", Status);
 140
 141   if (Length > 0 && NT_SUCCESS(Status))
 142     {
 143       TempBuffer = ExAllocatePool(NonPagedPool, BLOCKSIZE);
 144
 145       Status = CdfsReadSectors(DeviceExt->StorageDevice,
 146                                Fcb->Entry.ExtentLocationL + (ReadOffset / BLOCKSIZE),
 147                                1,
 148                                TempBuffer);
 149       if (NT_SUCCESS(Status))
 150         {
 151           memcpy(Buffer, TempBuffer, Length);
 152           (*LengthRead) = (*LengthRead) + Length;
 153         }
 154       ExFreePool(TempBuffer);
 155     }
 156
 157   return(Status);
 158 }
 159
 160
 161 NTSTATUS STDCALL
 162 CdfsRead(PDEVICE_OBJECT DeviceObject,
 163          PIRP Irp)
 164 {
 165   PDEVICE_EXTENSION DeviceExt;
 166   PIO_STACK_LOCATION Stack;
 167   PFILE_OBJECT FileObject;
 168   PVOID Buffer;
 169   ULONG ReadLength;
 170   LARGE_INTEGER ReadOffset;
 171   ULONG ReturnedReadLength = 0;
 172   NTSTATUS Status = STATUS_SUCCESS;
 173
 174   DPRINT("CdfsRead(DeviceObject %x, Irp %x)\n",DeviceObject,Irp);
 175
 176   DeviceExt = DeviceObject->DeviceExtension;
 177   Stack = IoGetCurrentIrpStackLocation(Irp);
 178   FileObject = Stack->FileObject;
 179
 180   ReadLength = Stack->Parameters.Read.Length;
 181   ReadOffset = Stack->Parameters.Read.ByteOffset;
 182   Buffer = MmGetSystemAddressForMdl(Irp->MdlAddress);
 183
 184   Status = CdfsReadFile(DeviceExt,
 185                         FileObject,
 186                         Buffer,
 187                         ReadLength,
 188                         ReadOffset.u.LowPart,
 189                         Irp->Flags,
 190                         &ReturnedReadLength);
 191
 192 ByeBye:
 193   if (NT_SUCCESS(Status))
 194     {
 195       if (FileObject->Flags & FO_SYNCHRONOUS_IO)
 196         {
 197           FileObject->CurrentByteOffset.QuadPart =
 198             ReadOffset.QuadPart + ReturnedReadLength;
 199         }
 200       Irp->IoStatus.Information = ReturnedReadLength;
 201     }
 202   else
 203     {
 204       Irp->IoStatus.Information = 0;
 205     }
 206
 207   Irp->IoStatus.Status = Status;
 208   IoCompleteRequest(Irp,IO_NO_INCREMENT);
 209
 210   return(Status);
 211 }
 212
 213
 214 NTSTATUS STDCALL
 215 CdfsWrite(PDEVICE_OBJECT DeviceObject,
 216           PIRP Irp)
 217 {
 218   DPRINT("CdfsWrite(DeviceObject %x Irp %x)\n",DeviceObject,Irp);
 219
 220   Irp->IoStatus.Status = STATUS_NOT_SUPPORTED;
 221   Irp->IoStatus.Information = 0;
 222   return(STATUS_NOT_SUPPORTED);
 223 }
 224
 225 /* EOF */