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     PCCB Ccb;
  58     PFCB Fcb;
  59
  60     DPRINT("CdfsReadFile(ReadOffset %lu  Length %lu)\n", ReadOffset, Length);
  61
  62     *LengthRead = 0;
  63
  64     if (Length == 0)
  65         return(STATUS_SUCCESS);
  66
  67     Ccb = (PCCB)FileObject->FsContext2;
  68     Fcb = (PFCB)FileObject->FsContext;
  69
  70     if (ReadOffset >= Fcb->Entry.DataLengthL)
  71         return(STATUS_END_OF_FILE);
  72
  73     DPRINT("Reading %d bytes at %d\n", Length, ReadOffset);
  74
  75     if (!(IrpFlags & (IRP_NOCACHE|IRP_PAGING_IO)))
  76     {
  77         LARGE_INTEGER FileOffset;
  78         IO_STATUS_BLOCK IoStatus;
  79         CC_FILE_SIZES FileSizes;
  80
  81         if (ReadOffset + Length > Fcb->Entry.DataLengthL)
  82             Length = Fcb->Entry.DataLengthL - ReadOffset;
  83
  84         if (FileObject->PrivateCacheMap == NULL)
  85         {
  86             FileSizes.AllocationSize = Fcb->RFCB.AllocationSize;
  87             FileSizes.FileSize = Fcb->RFCB.FileSize;
  88             FileSizes.ValidDataLength = Fcb->RFCB.ValidDataLength;
  89
  90             DPRINT("Attach FCB to File: Size %08x%08x\n",
  91                 Fcb->RFCB.ValidDataLength.HighPart,
  92                 Fcb->RFCB.ValidDataLength.LowPart);
  93
  94             CcInitializeCacheMap(FileObject,
  95                 &FileSizes,
  96                 FALSE,
  97                 &(CdfsGlobalData->CacheMgrCallbacks),
  98                 Fcb);
  99         }
 100
 101         FileOffset.QuadPart = (LONGLONG)ReadOffset;
 102         CcCopyRead(FileObject,
 103             &FileOffset,
 104             Length,
 105             TRUE,
 106             Buffer,
 107             &IoStatus);
 108         *LengthRead = IoStatus.Information;
 109
 110         return(IoStatus.Status);
 111     }
 112
 113     if ((ReadOffset % BLOCKSIZE) != 0 || (Length % BLOCKSIZE) != 0)
 114     {
 115         /* Then we need to do a partial or misaligned read ... */
 116         PVOID PageBuf = ExAllocatePool(NonPagedPool, BLOCKSIZE);
 117         PCHAR ReadInPage = (PCHAR)PageBuf + (ReadOffset & (BLOCKSIZE - 1));
 118         PCHAR TargetRead = (PCHAR)Buffer;
 119         ULONG ActualReadOffset, EndOfExtent, ReadLen;
 120
 121         if (!PageBuf)
 122         {
 123             return STATUS_NO_MEMORY;
 124         }
 125
 126         ActualReadOffset = ReadOffset & ~(BLOCKSIZE - 1);
 127         EndOfExtent = ReadOffset + Length;
 128
 129         while (ActualReadOffset < EndOfExtent)
 130         {
 131             Status = CdfsReadSectors
 132                 (DeviceExt->StorageDevice,
 133                 Fcb->Entry.ExtentLocationL + (ActualReadOffset / BLOCKSIZE),
 134                 1,
 135                 PageBuf,
 136                 FALSE);
 137
 138             if (!NT_SUCCESS(Status))
 139                 break;
 140
 141             ReadLen = BLOCKSIZE - (ActualReadOffset & (BLOCKSIZE - 1));
 142             if (ReadLen > EndOfExtent - ActualReadOffset)
 143             {
 144                 ReadLen = EndOfExtent - ActualReadOffset;
 145             }
 146
 147             RtlCopyMemory(TargetRead, ReadInPage, ReadLen);
 148
 149             ActualReadOffset += ReadLen;
 150             TargetRead += ReadLen;
 151         }
 152
 153         ExFreePool(PageBuf);
 154     }
 155     else
 156     {
 157         if (ReadOffset + Length > ROUND_UP(Fcb->Entry.DataLengthL, BLOCKSIZE))
 158             Length = ROUND_UP(Fcb->Entry.DataLengthL, BLOCKSIZE) - ReadOffset;
 159
 160         Status = CdfsReadSectors(DeviceExt->StorageDevice,
 161             Fcb->Entry.ExtentLocationL + (ReadOffset / BLOCKSIZE),
 162             Length / BLOCKSIZE,
 163             Buffer,
 164             FALSE);
 165         if (NT_SUCCESS(Status))
 166         {
 167             *LengthRead = Length;
 168             if (Length + ReadOffset > Fcb->Entry.DataLengthL)
 169             {
 170                 memset(Buffer + Fcb->Entry.DataLengthL - ReadOffset,
 171                     0,
 172                     Length + ReadOffset - Fcb->Entry.DataLengthL);
 173             }
 174         }
 175     }
 176
 177     return Status;
 178 }
 179
 180
 181 NTSTATUS NTAPI
 182 CdfsRead(PDEVICE_OBJECT DeviceObject,
 183          PIRP Irp)
 184 {
 185     PDEVICE_EXTENSION DeviceExt;
 186     PIO_STACK_LOCATION Stack;
 187     PFILE_OBJECT FileObject;
 188     PVOID Buffer = NULL;
 189     ULONG ReadLength;
 190     LARGE_INTEGER ReadOffset;
 191     ULONG ReturnedReadLength = 0;
 192     NTSTATUS Status = STATUS_SUCCESS;
 193
 194     DPRINT("CdfsRead(DeviceObject %x, Irp %x)\n",DeviceObject,Irp);
 195
 196     DeviceExt = DeviceObject->DeviceExtension;
 197     Stack = IoGetCurrentIrpStackLocation(Irp);
 198     FileObject = Stack->FileObject;
 199
 200     ReadLength = Stack->Parameters.Read.Length;
 201     ReadOffset = Stack->Parameters.Read.ByteOffset;
 202     if (ReadLength) Buffer = MmGetSystemAddressForMdl(Irp->MdlAddress);
 203
 204     Status = CdfsReadFile(DeviceExt,
 205         FileObject,
 206         Buffer,
 207         ReadLength,
 208         ReadOffset.u.LowPart,
 209         Irp->Flags,
 210         &ReturnedReadLength);
 211     if (NT_SUCCESS(Status))
 212     {
 213         if (FileObject->Flags & FO_SYNCHRONOUS_IO)
 214         {
 215             FileObject->CurrentByteOffset.QuadPart =
 216                 ReadOffset.QuadPart + ReturnedReadLength;
 217         }
 218         Irp->IoStatus.Information = ReturnedReadLength;
 219     }
 220     else
 221     {
 222         Irp->IoStatus.Information = 0;
 223     }
 224
 225     Irp->IoStatus.Status = Status;
 226     IoCompleteRequest(Irp,IO_NO_INCREMENT);
 227
 228     return(Status);
 229 }
 230
 231
 232 NTSTATUS NTAPI
 233 CdfsWrite(PDEVICE_OBJECT DeviceObject,
 234           PIRP Irp)
 235 {
 236     DPRINT("CdfsWrite(DeviceObject %x Irp %x)\n",DeviceObject,Irp);
 237
 238     Irp->IoStatus.Status = STATUS_NOT_SUPPORTED;
 239     Irp->IoStatus.Information = 0;
 240     return(STATUS_NOT_SUPPORTED);
 241 }
 242
 243 /* EOF */