reactos/drivers/filesystems/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 along
  16 *  with this program; if not, write to the Free Software Foundation, Inc.,
  17 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18 */
  19 /* $Id$
  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 "cdfs.h"
  32
  33 #define NDEBUG
  34 #include <debug.h>
  35
  36 /* FUNCTIONS ****************************************************************/
  37
  38 #define ROUND_UP(N, S) ((((N) + (S) - 1) / (S)) * (S))
  39 #define ROUND_DOWN(N, S) ((N) - ((N) % (S)))
  40
  41
  42 /* FUNCTIONS ****************************************************************/
  43
  44 static NTSTATUS
  45 CdfsReadFile(PDEVICE_EXTENSION DeviceExt,
  46              PFILE_OBJECT FileObject,
  47              PUCHAR Buffer,
  48              ULONG Length,
  49              ULONG ReadOffset,
  50              ULONG IrpFlags,
  51              PULONG LengthRead)
  52              /*
  53              * FUNCTION: Reads data from a file
  54              */
  55 {
  56     NTSTATUS Status = STATUS_SUCCESS;
  57     PFCB Fcb;
  58
  59     DPRINT("CdfsReadFile(ReadOffset %lu  Length %lu)\n", ReadOffset, Length);
  60
  61     *LengthRead = 0;
  62
  63     if (Length == 0)
  64         return(STATUS_SUCCESS);
  65
  66     Fcb = (PFCB)FileObject->FsContext;
  67
  68     if (ReadOffset >= Fcb->Entry.DataLengthL)
  69         return(STATUS_END_OF_FILE);
  70
  71     DPRINT("Reading %d bytes at %d\n", Length, ReadOffset);
  72
  73     if (!(IrpFlags & (IRP_NOCACHE|IRP_PAGING_IO)))
  74     {
  75         LARGE_INTEGER FileOffset;
  76         IO_STATUS_BLOCK IoStatus;
  77         CC_FILE_SIZES FileSizes;
  78
  79         if (ReadOffset + Length > Fcb->Entry.DataLengthL)
  80             Length = Fcb->Entry.DataLengthL - ReadOffset;
  81
  82         if (FileObject->PrivateCacheMap == NULL)
  83         {
  84             FileSizes.AllocationSize = Fcb->RFCB.AllocationSize;
  85             FileSizes.FileSize = Fcb->RFCB.FileSize;
  86             FileSizes.ValidDataLength = Fcb->RFCB.ValidDataLength;
  87
  88             DPRINT("Attach FCB to File: Size %08x%08x\n",
  89                 Fcb->RFCB.ValidDataLength.HighPart,
  90                 Fcb->RFCB.ValidDataLength.LowPart);
  91
  92             CcInitializeCacheMap(FileObject,
  93                 &FileSizes,
  94                 FALSE,
  95                 &(CdfsGlobalData->CacheMgrCallbacks),
  96                 Fcb);
  97         }
  98
  99         FileOffset.QuadPart = (LONGLONG)ReadOffset;
 100         CcCopyRead(FileObject,
 101             &FileOffset,
 102             Length,
 103             TRUE,
 104             Buffer,
 105             &IoStatus);
 106         *LengthRead = IoStatus.Information;
 107
 108         return(IoStatus.Status);
 109     }
 110
 111     if ((ReadOffset % BLOCKSIZE) != 0 || (Length % BLOCKSIZE) != 0)
 112     {
 113         /* Then we need to do a partial or misaligned read ... */
 114         PVOID PageBuf = ExAllocatePool(NonPagedPool, BLOCKSIZE);
 115         PCHAR ReadInPage = (PCHAR)PageBuf + (ReadOffset & (BLOCKSIZE - 1));
 116         PCHAR TargetRead = (PCHAR)Buffer;
 117         ULONG ActualReadOffset, EndOfExtent, ReadLen;
 118
 119         if (!PageBuf)
 120         {
 121             return STATUS_NO_MEMORY;
 122         }
 123
 124         ActualReadOffset = ReadOffset & ~(BLOCKSIZE - 1);
 125         EndOfExtent = ReadOffset + Length;
 126
 127         while (ActualReadOffset < EndOfExtent)
 128         {
 129             Status = CdfsReadSectors
 130                 (DeviceExt->StorageDevice,
 131                 Fcb->Entry.ExtentLocationL + (ActualReadOffset / BLOCKSIZE),
 132                 1,
 133                 PageBuf,
 134                 FALSE);
 135
 136             if (!NT_SUCCESS(Status))
 137                 break;
 138
 139             ReadLen = BLOCKSIZE - (ActualReadOffset & (BLOCKSIZE - 1));
 140             if (ReadLen > EndOfExtent - ActualReadOffset)
 141             {
 142                 ReadLen = EndOfExtent - ActualReadOffset;
 143             }
 144
 145             RtlCopyMemory(TargetRead, ReadInPage, ReadLen);
 146
 147             ActualReadOffset += ReadLen;
 148             TargetRead += ReadLen;
 149         }
 150
 151         ExFreePool(PageBuf);
 152     }
 153     else
 154     {
 155         if (ReadOffset + Length > ROUND_UP(Fcb->Entry.DataLengthL, BLOCKSIZE))
 156             Length = ROUND_UP(Fcb->Entry.DataLengthL, BLOCKSIZE) - ReadOffset;
 157
 158         Status = CdfsReadSectors(DeviceExt->StorageDevice,
 159             Fcb->Entry.ExtentLocationL + (ReadOffset / BLOCKSIZE),
 160             Length / BLOCKSIZE,
 161             Buffer,
 162             FALSE);
 163         if (NT_SUCCESS(Status))
 164         {
 165             *LengthRead = Length;
 166             if (Length + ReadOffset > Fcb->Entry.DataLengthL)
 167             {
 168                 memset(Buffer + Fcb->Entry.DataLengthL - ReadOffset,
 169                     0,
 170                     Length + ReadOffset - Fcb->Entry.DataLengthL);
 171             }
 172         }
 173     }
 174
 175     return Status;
 176 }
 177
 178
 179 NTSTATUS NTAPI
 180 CdfsRead(PDEVICE_OBJECT DeviceObject,
 181          PIRP Irp)
 182 {
 183     PDEVICE_EXTENSION DeviceExt;
 184     PIO_STACK_LOCATION Stack;
 185     PFILE_OBJECT FileObject;
 186     PVOID Buffer = NULL;
 187     ULONG ReadLength;
 188     LARGE_INTEGER ReadOffset;
 189     ULONG ReturnedReadLength = 0;
 190     NTSTATUS Status = STATUS_SUCCESS;
 191
 192     DPRINT("CdfsRead(DeviceObject %x, Irp %x)\n",DeviceObject,Irp);
 193
 194     DeviceExt = DeviceObject->DeviceExtension;
 195     Stack = IoGetCurrentIrpStackLocation(Irp);
 196     FileObject = Stack->FileObject;
 197
 198     ReadLength = Stack->Parameters.Read.Length;
 199     ReadOffset = Stack->Parameters.Read.ByteOffset;
 200     if (ReadLength) Buffer = MmGetSystemAddressForMdl(Irp->MdlAddress);
 201
 202     Status = CdfsReadFile(DeviceExt,
 203         FileObject,
 204         Buffer,
 205         ReadLength,
 206         ReadOffset.u.LowPart,
 207         Irp->Flags,
 208         &ReturnedReadLength);
 209     if (NT_SUCCESS(Status))
 210     {
 211         if (FileObject->Flags & FO_SYNCHRONOUS_IO)
 212         {
 213             FileObject->CurrentByteOffset.QuadPart =
 214                 ReadOffset.QuadPart + ReturnedReadLength;
 215         }
 216         Irp->IoStatus.Information = ReturnedReadLength;
 217     }
 218     else
 219     {
 220         Irp->IoStatus.Information = 0;
 221     }
 222
 223     Irp->IoStatus.Status = Status;
 224     IoCompleteRequest(Irp,IO_NO_INCREMENT);
 225
 226     return(Status);
 227 }
 228
 229
 230 NTSTATUS NTAPI
 231 CdfsWrite(PDEVICE_OBJECT DeviceObject,
 232           PIRP Irp)
 233 {
 234     DPRINT("CdfsWrite(DeviceObject %x Irp %x)\n",DeviceObject,Irp);
 235
 236     Irp->IoStatus.Status = STATUS_NOT_SUPPORTED;
 237     Irp->IoStatus.Information = 0;
 238     return(STATUS_NOT_SUPPORTED);
 239 }
 240
 241 /* EOF */