drivers/filesystems/ntfs/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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
  18  *
  19  * COPYRIGHT:        See COPYING in the top level directory
  20  * PROJECT:          ReactOS kernel
  21  * FILE:             drivers/filesystem/ntfs/rw.c
  22  * PURPOSE:          NTFS filesystem driver
  23  * PROGRAMMER:       Art Yerkes
  24  * UPDATE HISTORY:
  25  */
  26
  27 /* INCLUDES *****************************************************************/
  28
  29 #include <ntddk.h>
  30 #include "ntfs.h"
  31
  32 #define NDEBUG
  33 #include <debug.h>
  34
  35
  36 /* GLOBALS *******************************************************************/
  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 /*
  45  * FUNCTION: Reads data from a file
  46  */
  47 static
  48 NTSTATUS
  49 NtfsReadFile(PDEVICE_EXTENSION DeviceExt,
  50              PFILE_OBJECT FileObject,
  51              PUCHAR Buffer,
  52              ULONG Length,
  53              ULONG ReadOffset,
  54              ULONG IrpFlags,
  55              PULONG LengthRead)
  56 {
  57 #if 0
  58   NTSTATUS Status = STATUS_SUCCESS;
  59   PUCHAR TempBuffer;
  60   ULONG TempLength;
  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       if (FileObject->PrivateCacheMap == NULL)
  87       {
  88           CcRosInitializeFileCache(FileObject, PAGE_SIZE);
  89       }
  90
  91       FileOffset.QuadPart = (LONGLONG)ReadOffset;
  92       CcCopyRead(FileObject,
  93                  &FileOffset,
  94                  Length,
  95                  TRUE,
  96                  Buffer,
  97                  &IoStatus);
  98       *LengthRead = IoStatus.Information;
  99
 100       return(IoStatus.Status);
 101     }
 102
 103   if ((ReadOffset % BLOCKSIZE) != 0 || (Length % BLOCKSIZE) != 0)
 104     {
 105       return STATUS_INVALID_PARAMETER;
 106     }
 107   if (ReadOffset + Length > ROUND_UP(Fcb->Entry.DataLengthL, BLOCKSIZE))
 108     Length = ROUND_UP(Fcb->Entry.DataLengthL, BLOCKSIZE) - ReadOffset;
 109
 110   Status = CdfsReadSectors(DeviceExt->StorageDevice,
 111                            Fcb->Entry.ExtentLocationL + (ReadOffset / BLOCKSIZE),
 112                            Length / BLOCKSIZE,
 113                            Buffer);
 114   if (NT_SUCCESS(Status))
 115     {
 116       *LengthRead = Length;
 117       if (Length + ReadOffset > Fcb->Entry.DataLengthL)
 118       {
 119         memset(Buffer + Fcb->Entry.DataLengthL - ReadOffset,
 120                0, Length + ReadOffset - Fcb->Entry.DataLengthL);
 121       }
 122     }
 123
 124   return(Status);
 125 #else
 126     UNREFERENCED_PARAMETER(DeviceExt);
 127     UNREFERENCED_PARAMETER(FileObject);
 128     UNREFERENCED_PARAMETER(Buffer);
 129     UNREFERENCED_PARAMETER(Length);
 130     UNREFERENCED_PARAMETER(ReadOffset);
 131     UNREFERENCED_PARAMETER(IrpFlags);
 132     *LengthRead = 0;
 133     return STATUS_END_OF_FILE;
 134 #endif
 135 }
 136
 137
 138 NTSTATUS
 139 NTAPI
 140 NtfsFsdRead(PDEVICE_OBJECT DeviceObject,
 141             PIRP Irp)
 142 {
 143     PDEVICE_EXTENSION DeviceExt;
 144     PIO_STACK_LOCATION Stack;
 145     PFILE_OBJECT FileObject;
 146     PVOID Buffer;
 147     ULONG ReadLength;
 148     LARGE_INTEGER ReadOffset;
 149     ULONG ReturnedReadLength = 0;
 150     NTSTATUS Status = STATUS_SUCCESS;
 151
 152     DPRINT("NtfsRead(DeviceObject %x, Irp %x)\n",DeviceObject,Irp);
 153
 154     DeviceExt = DeviceObject->DeviceExtension;
 155     Stack = IoGetCurrentIrpStackLocation(Irp);
 156     FileObject = Stack->FileObject;
 157
 158     ReadLength = Stack->Parameters.Read.Length;
 159     ReadOffset = Stack->Parameters.Read.ByteOffset;
 160     Buffer = MmGetSystemAddressForMdl(Irp->MdlAddress);
 161
 162     Status = NtfsReadFile(DeviceExt,
 163                           FileObject,
 164                           Buffer,
 165                           ReadLength,
 166                           ReadOffset.u.LowPart,
 167                           Irp->Flags,
 168                           &ReturnedReadLength);
 169     if (NT_SUCCESS(Status))
 170     {
 171         if (FileObject->Flags & FO_SYNCHRONOUS_IO)
 172         {
 173             FileObject->CurrentByteOffset.QuadPart =
 174                 ReadOffset.QuadPart + ReturnedReadLength;
 175         }
 176
 177         Irp->IoStatus.Information = ReturnedReadLength;
 178     }
 179     else
 180     {
 181         Irp->IoStatus.Information = 0;
 182     }
 183
 184     Irp->IoStatus.Status = Status;
 185     IoCompleteRequest(Irp,IO_NO_INCREMENT);
 186
 187     return Status;
 188 }
 189
 190
 191 NTSTATUS
 192 NTAPI
 193 NtfsFsdWrite(PDEVICE_OBJECT DeviceObject,
 194              PIRP Irp)
 195 {
 196     DPRINT("NtfwWrite(DeviceObject %x Irp %x)\n",DeviceObject,Irp);
 197
 198     Irp->IoStatus.Status = STATUS_NOT_SUPPORTED;
 199     Irp->IoStatus.Information = 0;
 200     return STATUS_NOT_SUPPORTED;
 201 }
 202
 203 /* EOF */