reactos/drivers/filesystems/ntfs/rw.c

   1 /*
   2  *  ReactOS kernel
   3  *  Copyright (C) 2002, 2014 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  * PROGRAMMERS:      Art Yerkes
  24  *                   Pierre Schweitzer (pierre@reactos.org)
  25  */
  26
  27 /* INCLUDES *****************************************************************/
  28
  29 #include <ntddk.h>
  30 #include "ntfs.h"
  31
  32 #define NDEBUG
  33 #include <debug.h>
  34
  35 /* FUNCTIONS ****************************************************************/
  36
  37 /*
  38  * FUNCTION: Reads data from a file
  39  */
  40 static
  41 NTSTATUS
  42 NtfsReadFile(PDEVICE_EXTENSION DeviceExt,
  43              PFILE_OBJECT FileObject,
  44              PUCHAR Buffer,
  45              ULONG Length,
  46              ULONG ReadOffset,
  47              ULONG IrpFlags,
  48              PULONG LengthRead)
  49 {
  50     NTSTATUS Status = STATUS_SUCCESS;
  51     PNTFS_FCB Fcb;
  52     PFILE_RECORD_HEADER FileRecord;
  53     PNTFS_ATTR_CONTEXT DataContext;
  54     ULONG RealLength;
  55     ULONG RealReadOffset;
  56     ULONG RealLengthRead;
  57     ULONG ToRead;
  58     BOOLEAN AllocatedBuffer = FALSE;
  59     PCHAR ReadBuffer = (PCHAR)Buffer;
  60
  61     DPRINT1("NtfsReadFile(%p, %p, %p, %u, %u, %x, %p)\n", DeviceExt, FileObject, Buffer, Length, ReadOffset, IrpFlags, LengthRead);
  62
  63     *LengthRead = 0;
  64
  65     if (Length == 0)
  66     {
  67         DPRINT1("Null read!\n");
  68         return STATUS_SUCCESS;
  69     }
  70
  71     Fcb = (PNTFS_FCB)FileObject->FsContext;
  72
  73     if (ReadOffset >= Fcb->Entry.AllocatedSize)
  74     {
  75         DPRINT1("Reading beyond file end!\n");
  76         return STATUS_END_OF_FILE;
  77     }
  78
  79     ToRead = Length;
  80     if (ReadOffset + Length > Fcb->Entry.AllocatedSize)
  81         ToRead = Fcb->Entry.AllocatedSize - ReadOffset;
  82
  83     RealReadOffset = ReadOffset;
  84     RealLength = ToRead;
  85
  86     if ((ReadOffset % DeviceExt->NtfsInfo.BytesPerSector) != 0 || (ToRead % DeviceExt->NtfsInfo.BytesPerSector) != 0)
  87     {
  88         RealReadOffset = ROUND_DOWN(ReadOffset, DeviceExt->NtfsInfo.BytesPerSector);
  89         RealLength = ROUND_UP(ToRead, DeviceExt->NtfsInfo.BytesPerSector);
  90
  91         ReadBuffer = ExAllocatePoolWithTag(NonPagedPool, RealLength + DeviceExt->NtfsInfo.BytesPerSector, TAG_NTFS);
  92         if (ReadBuffer == NULL)
  93         {
  94             DPRINT1("Not enough memory!\n");
  95             return STATUS_INSUFFICIENT_RESOURCES;
  96         }
  97         AllocatedBuffer = TRUE;
  98     }
  99
 100     FileRecord = ExAllocatePoolWithTag(NonPagedPool, DeviceExt->NtfsInfo.BytesPerFileRecord, TAG_NTFS);
 101     if (FileRecord == NULL)
 102     {
 103         DPRINT1("Not enough memory!\n");
 104         if (AllocatedBuffer)
 105         {
 106             ExFreePoolWithTag(ReadBuffer, TAG_NTFS);
 107         }
 108         return STATUS_INSUFFICIENT_RESOURCES;
 109     }
 110
 111     Status = ReadFileRecord(DeviceExt, Fcb->MFTIndex, FileRecord);
 112     if (!NT_SUCCESS(Status))
 113     {
 114         DPRINT1("Can't find record!\n");
 115         ExFreePoolWithTag(FileRecord, TAG_NTFS);
 116         if (AllocatedBuffer)
 117         {
 118             ExFreePoolWithTag(ReadBuffer, TAG_NTFS);
 119         }
 120         return Status;
 121     }
 122
 123     Status = FindAttribute(DeviceExt, FileRecord, AttributeData, L"", 0, &DataContext);
 124     if (!NT_SUCCESS(Status))
 125     {
 126         DPRINT1("No data associated with file!\n");
 127         ExFreePoolWithTag(FileRecord, TAG_NTFS);
 128         if (AllocatedBuffer)
 129         {
 130             ExFreePoolWithTag(ReadBuffer, TAG_NTFS);
 131         }
 132         return Status;
 133     }
 134
 135     DPRINT1("Effective read: %lu at %lu\n", RealLength, RealReadOffset);
 136     RealLengthRead = ReadAttribute(DeviceExt, DataContext, RealReadOffset, (PCHAR)ReadBuffer, RealLength);
 137     if (RealLengthRead != RealLength)
 138     {
 139         DPRINT1("Read failure!\n");
 140         ReleaseAttributeContext(DataContext);
 141         ExFreePoolWithTag(FileRecord, TAG_NTFS);
 142         if (AllocatedBuffer)
 143         {
 144             ExFreePoolWithTag(ReadBuffer, TAG_NTFS);
 145         }
 146         return Status;
 147     }
 148
 149     ReleaseAttributeContext(DataContext);
 150     ExFreePoolWithTag(FileRecord, TAG_NTFS);
 151
 152     *LengthRead = ToRead;
 153
 154     DPRINT1("%lu got read\n", *LengthRead);
 155
 156     if (AllocatedBuffer)
 157     {
 158         RtlCopyMemory(Buffer, ReadBuffer + (ReadOffset - RealReadOffset), ToRead);
 159     }
 160
 161     if (ToRead != Length)
 162     {
 163         RtlZeroMemory(Buffer + ToRead, Length - ToRead);
 164     }
 165
 166     if (AllocatedBuffer)
 167     {
 168         ExFreePoolWithTag(ReadBuffer, TAG_NTFS);
 169     }
 170
 171     return STATUS_SUCCESS;
 172 }
 173
 174
 175 NTSTATUS
 176 NtfsRead(PNTFS_IRP_CONTEXT IrpContext)
 177 {
 178     PDEVICE_EXTENSION DeviceExt;
 179     PIO_STACK_LOCATION Stack;
 180     PFILE_OBJECT FileObject;
 181     PVOID Buffer;
 182     ULONG ReadLength;
 183     LARGE_INTEGER ReadOffset;
 184     ULONG ReturnedReadLength = 0;
 185     NTSTATUS Status = STATUS_SUCCESS;
 186     PIRP Irp;
 187     PDEVICE_OBJECT DeviceObject;
 188
 189     DPRINT("NtfsRead(IrpContext %p)\n", IrpContext);
 190
 191     DeviceObject = IrpContext->DeviceObject;
 192     Irp = IrpContext->Irp;
 193     Stack = IrpContext->Stack;
 194     FileObject = IrpContext->FileObject;
 195
 196     DeviceExt = DeviceObject->DeviceExtension;
 197     ReadLength = Stack->Parameters.Read.Length;
 198     ReadOffset = Stack->Parameters.Read.ByteOffset;
 199     Buffer = NtfsGetUserBuffer(Irp, Irp->Flags & IRP_PAGING_IO);
 200
 201     Status = NtfsReadFile(DeviceExt,
 202                           FileObject,
 203                           Buffer,
 204                           ReadLength,
 205                           ReadOffset.u.LowPart,
 206                           Irp->Flags,
 207                           &ReturnedReadLength);
 208     if (NT_SUCCESS(Status))
 209     {
 210         if (FileObject->Flags & FO_SYNCHRONOUS_IO)
 211         {
 212             FileObject->CurrentByteOffset.QuadPart =
 213                 ReadOffset.QuadPart + ReturnedReadLength;
 214         }
 215
 216         Irp->IoStatus.Information = ReturnedReadLength;
 217     }
 218     else
 219     {
 220         Irp->IoStatus.Information = 0;
 221     }
 222
 223     return Status;
 224 }
 225
 226
 227 NTSTATUS
 228 NtfsWrite(PNTFS_IRP_CONTEXT IrpContext)
 229 {
 230     DPRINT("NtfsWrite(IrpContext %p)\n",IrpContext);
 231
 232     IrpContext->Irp->IoStatus.Information = 0;
 233     return STATUS_NOT_SUPPORTED;
 234 }
 235
 236 /* EOF */