reactos/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 /* GLOBALS *******************************************************************/
  36
  37 #define ROUND_UP(N, S) ((((N) + (S) - 1) / (S)) * (S))
  38 #define ROUND_DOWN(N, S) ((N) - ((N) % (S)))
  39
  40 /* FUNCTIONS ****************************************************************/
  41
  42 /*
  43  * FUNCTION: Reads data from a file
  44  */
  45 static
  46 NTSTATUS
  47 NtfsReadFile(PDEVICE_EXTENSION DeviceExt,
  48              PFILE_OBJECT FileObject,
  49              PUCHAR Buffer,
  50              ULONG Length,
  51              ULONG ReadOffset,
  52              ULONG IrpFlags,
  53              PULONG LengthRead)
  54 {
  55     NTSTATUS Status = STATUS_SUCCESS;
  56     PNTFS_FCB Fcb;
  57     PFILE_RECORD_HEADER FileRecord;
  58     PNTFS_ATTR_CONTEXT DataContext;
  59     ULONG RealLength;
  60     ULONG RealReadOffset;
  61     ULONG RealLengthRead;
  62     ULONG ToRead;
  63     BOOLEAN AllocatedBuffer = FALSE;
  64     PCHAR ReadBuffer = (PCHAR)Buffer;
  65
  66     DPRINT1("NtfsReadFile(%p, %p, %p, %u, %u, %x, %p)\n", DeviceExt, FileObject, Buffer, Length, ReadOffset, IrpFlags, LengthRead);
  67
  68     *LengthRead = 0;
  69
  70     if (Length == 0)
  71     {
  72         DPRINT1("Null read!\n");
  73         return STATUS_SUCCESS;
  74     }
  75
  76     Fcb = (PNTFS_FCB)FileObject->FsContext;
  77
  78     if (ReadOffset >= Fcb->Entry.AllocatedSize)
  79     {
  80         DPRINT1("Reading beyond file end!\n");
  81         return STATUS_END_OF_FILE;
  82     }
  83
  84     ToRead = Length;
  85     if (ReadOffset + Length > Fcb->Entry.AllocatedSize)
  86         ToRead = Fcb->Entry.AllocatedSize - ReadOffset;
  87
  88     RealReadOffset = ReadOffset;
  89     RealLength = ToRead;
  90
  91     if ((ReadOffset % DeviceExt->NtfsInfo.BytesPerSector) != 0 || (ToRead % DeviceExt->NtfsInfo.BytesPerSector) != 0)
  92     {
  93         RealReadOffset = ROUND_DOWN(ReadOffset, DeviceExt->NtfsInfo.BytesPerSector);
  94         RealLength = ROUND_UP(ToRead, DeviceExt->NtfsInfo.BytesPerSector);
  95
  96         ReadBuffer = ExAllocatePoolWithTag(NonPagedPool, RealLength + DeviceExt->NtfsInfo.BytesPerSector, TAG_NTFS);
  97         if (ReadBuffer == NULL)
  98         {
  99             DPRINT1("Not enough memory!\n");
 100             return STATUS_INSUFFICIENT_RESOURCES;
 101         }
 102         AllocatedBuffer = TRUE;
 103     }
 104
 105     FileRecord = ExAllocatePoolWithTag(NonPagedPool, DeviceExt->NtfsInfo.BytesPerFileRecord, TAG_NTFS);
 106     if (FileRecord == NULL)
 107     {
 108         DPRINT1("Not enough memory!\n");
 109         return STATUS_INSUFFICIENT_RESOURCES;
 110     }
 111
 112     Status = ReadFileRecord(DeviceExt, Fcb->MFTIndex, FileRecord);
 113     if (!NT_SUCCESS(Status))
 114     {
 115         DPRINT1("Can't find record!\n");
 116         ExFreePoolWithTag(FileRecord, TAG_NTFS);
 117         return Status;
 118     }
 119
 120     Status = FindAttribute(DeviceExt, FileRecord, AttributeData, L"", 0, &DataContext);
 121     if (!NT_SUCCESS(Status))
 122     {
 123         DPRINT1("No data associated with file!\n");
 124         ExFreePoolWithTag(FileRecord, TAG_NTFS);
 125         return Status;
 126     }
 127
 128     DPRINT1("Effective read: %lu at %lu\n", RealLength, RealReadOffset);
 129     RealLengthRead = ReadAttribute(DeviceExt, DataContext, RealReadOffset, (PCHAR)ReadBuffer, RealLength);
 130     if (RealLengthRead != RealLength)
 131     {
 132         DPRINT1("Read failure!\n");
 133         ReleaseAttributeContext(DataContext);
 134         ExFreePoolWithTag(FileRecord, TAG_NTFS);
 135         if (AllocatedBuffer)
 136         {
 137             ExFreePoolWithTag(ReadBuffer, TAG_NTFS);
 138         }
 139         return Status;
 140     }
 141
 142     ReleaseAttributeContext(DataContext);
 143     ExFreePoolWithTag(FileRecord, TAG_NTFS);
 144
 145     *LengthRead = ToRead;
 146
 147     DPRINT1("%lu got read\n", *LengthRead);
 148
 149     if (AllocatedBuffer)
 150     {
 151         RtlCopyMemory(Buffer, ReadBuffer + (ReadOffset - RealReadOffset), ToRead);
 152     }
 153
 154     if (ToRead != Length)
 155     {
 156         RtlZeroMemory(Buffer + ToRead, Length - ToRead);
 157     }
 158
 159     if (AllocatedBuffer)
 160     {
 161         ExFreePoolWithTag(ReadBuffer, TAG_NTFS);
 162     }
 163
 164     return STATUS_SUCCESS;
 165 }
 166
 167
 168 NTSTATUS
 169 NTAPI
 170 NtfsFsdRead(PDEVICE_OBJECT DeviceObject,
 171             PIRP Irp)
 172 {
 173     PDEVICE_EXTENSION DeviceExt;
 174     PIO_STACK_LOCATION Stack;
 175     PFILE_OBJECT FileObject;
 176     PVOID Buffer;
 177     ULONG ReadLength;
 178     LARGE_INTEGER ReadOffset;
 179     ULONG ReturnedReadLength = 0;
 180     NTSTATUS Status = STATUS_SUCCESS;
 181
 182     DPRINT("NtfsRead(DeviceObject %x, Irp %x)\n",DeviceObject,Irp);
 183
 184     DeviceExt = DeviceObject->DeviceExtension;
 185     Stack = IoGetCurrentIrpStackLocation(Irp);
 186     FileObject = Stack->FileObject;
 187
 188     ReadLength = Stack->Parameters.Read.Length;
 189     ReadOffset = Stack->Parameters.Read.ByteOffset;
 190     Buffer = MmGetSystemAddressForMdl(Irp->MdlAddress);
 191
 192     Status = NtfsReadFile(DeviceExt,
 193                           FileObject,
 194                           Buffer,
 195                           ReadLength,
 196                           ReadOffset.u.LowPart,
 197                           Irp->Flags,
 198                           &ReturnedReadLength);
 199     if (NT_SUCCESS(Status))
 200     {
 201         if (FileObject->Flags & FO_SYNCHRONOUS_IO)
 202         {
 203             FileObject->CurrentByteOffset.QuadPart =
 204                 ReadOffset.QuadPart + ReturnedReadLength;
 205         }
 206
 207         Irp->IoStatus.Information = ReturnedReadLength;
 208     }
 209     else
 210     {
 211         Irp->IoStatus.Information = 0;
 212     }
 213
 214     Irp->IoStatus.Status = Status;
 215     IoCompleteRequest(Irp,IO_NO_INCREMENT);
 216
 217     return Status;
 218 }
 219
 220
 221 NTSTATUS
 222 NTAPI
 223 NtfsFsdWrite(PDEVICE_OBJECT DeviceObject,
 224              PIRP Irp)
 225 {
 226     DPRINT("NtfwWrite(DeviceObject %x Irp %x)\n",DeviceObject,Irp);
 227
 228     Irp->IoStatus.Status = STATUS_NOT_SUPPORTED;
 229     Irp->IoStatus.Information = 0;
 230     return STATUS_NOT_SUPPORTED;
 231 }
 232
 233 /* EOF */