reactos/drivers/fs/vfat/rw.c

   1
   2 /* $Id: rw.c,v 1.48 2002/09/08 10:22:12 chorns Exp $
   3  *
   4  * COPYRIGHT:        See COPYING in the top level directory
   5  * PROJECT:          ReactOS kernel
   6  * FILE:             services/fs/vfat/rw.c
   7  * PURPOSE:          VFAT Filesystem
   8  * PROGRAMMER:       Jason Filby (jasonfilby@yahoo.com)
   9  *
  10  */
  11
  12 /* INCLUDES *****************************************************************/
  13
  14 #include <ddk/ntddk.h>
  15 #include <wchar.h>
  16 #include <ntos/minmax.h>
  17
  18 #define NDEBUG
  19 #include <debug.h>
  20
  21 #include "vfat.h"
  22
  23 /* FUNCTIONS *****************************************************************/
  24
  25 NTSTATUS
  26 NextCluster(PDEVICE_EXTENSION DeviceExt,
  27             PVFATFCB Fcb,
  28             ULONG FirstCluster,
  29             PULONG CurrentCluster,
  30             BOOLEAN Extend)
  31      /*
  32       * Return the next cluster in a FAT chain, possibly extending the chain if
  33       * necessary
  34       */
  35 {
  36   if (Fcb != NULL && Fcb->Flags & FCB_IS_PAGE_FILE)
  37     {
  38       ULONG i;
  39       PULONG FatChain;
  40       NTSTATUS Status;
  41       DPRINT("NextCluster(Fcb %x, FirstCluster %x, Extend %d)\n", Fcb,
  42              FirstCluster, Extend);
  43       if (Fcb->FatChainSize == 0)
  44         {
  45           /* Paging file with zero length. */
  46           *CurrentCluster = 0xffffffff;
  47           if (Extend)
  48             {
  49               Fcb->FatChain = ExAllocatePool(NonPagedPool, sizeof(ULONG));
  50               if (Fcb->FatChain == NULL)
  51                 {
  52                   return(STATUS_NO_MEMORY);
  53                 }
  54               Status = GetNextCluster(DeviceExt, 0, CurrentCluster, TRUE);
  55               if (!NT_SUCCESS(Status))
  56                 {
  57                   ExFreePool(Fcb->FatChain);
  58                   return(Status);
  59                 }
  60               Fcb->FatChain[0] = *CurrentCluster;
  61               Fcb->FatChainSize = 1;
  62               return Status;
  63             }
  64           else
  65             {
  66               return STATUS_UNSUCCESSFUL;
  67             }
  68         }
  69       else
  70         {
  71           for (i = 0; i < Fcb->FatChainSize; i++)
  72             {
  73               if (Fcb->FatChain[i] == *CurrentCluster)
  74                 break;
  75             }
  76           if (i >= Fcb->FatChainSize)
  77             {
  78               return STATUS_UNSUCCESSFUL;
  79             }
  80           if (i == Fcb->FatChainSize - 1)
  81             {
  82               if (Extend)
  83                 {
  84                   FatChain = ExAllocatePool(NonPagedPool,
  85                                             (i + 2) * sizeof(ULONG));
  86                   if (!FatChain)
  87                     {
  88                       *CurrentCluster = 0xffffffff;
  89                       return STATUS_NO_MEMORY;
  90                     }
  91                   Status = GetNextCluster(DeviceExt, *CurrentCluster,
  92                                           CurrentCluster, TRUE);
  93                   if (NT_SUCCESS(Status) && *CurrentCluster != 0xffffffff)
  94                     {
  95                       memcpy(FatChain, Fcb->FatChain, (i + 1) * sizeof(ULONG));
  96                       FatChain[i + 1] = *CurrentCluster;
  97                       ExFreePool(Fcb->FatChain);
  98                       Fcb->FatChain = FatChain;
  99                       Fcb->FatChainSize = i + 2;
 100                     }
 101                   else
 102                     {
 103                       ExFreePool(FatChain);
 104                     }
 105                   return Status;
 106                 }
 107               else
 108                 {
 109                   *CurrentCluster = 0xffffffff;
 110                   return STATUS_SUCCESS;
 111                 }
 112             }
 113           *CurrentCluster = Fcb->FatChain[i + 1];
 114           return STATUS_SUCCESS;
 115         }
 116     }
 117   if (FirstCluster == 1)
 118     {
 119       (*CurrentCluster) += DeviceExt->FatInfo.SectorsPerCluster;
 120       return(STATUS_SUCCESS);
 121     }
 122   else
 123     {
 124       /*
 125        * CN: FIXME: Real bug here or in dirwr, where CurrentCluster isn't
 126        * initialized when 0
 127        */
 128       if (FirstCluster == 0)
 129         {
 130           NTSTATUS Status;
 131
 132           Status = GetNextCluster(DeviceExt, 0, CurrentCluster,
 133                                   Extend);
 134           return(Status);
 135         }
 136       else
 137         {
 138           NTSTATUS Status;
 139
 140           Status = GetNextCluster(DeviceExt, (*CurrentCluster), CurrentCluster,
 141                                   Extend);
 142           return(Status);
 143         }
 144     }
 145 }
 146
 147 NTSTATUS
 148 OffsetToCluster(PDEVICE_EXTENSION DeviceExt,
 149                 PVFATFCB Fcb,
 150                 ULONG FirstCluster,
 151                 ULONG FileOffset,
 152                 PULONG Cluster,
 153                 BOOLEAN Extend)
 154      /*
 155       * Return the cluster corresponding to an offset within a file,
 156       * possibly extending the file if necessary
 157       */
 158 {
 159   ULONG CurrentCluster;
 160   ULONG i;
 161   NTSTATUS Status;
 162   DPRINT("OffsetToCluster(DeviceExt %x, Fcb %x, FirstCluster %x,"
 163          " FileOffset %x, Cluster %x, Extend %d)\n", DeviceExt,
 164          Fcb, FirstCluster, FileOffset, Cluster, Extend);
 165   if (FirstCluster == 0)
 166   {
 167     DbgPrint("OffsetToCluster is called with FirstCluster = 0!\n");
 168     KeBugCheck(0);
 169   }
 170
 171   if (Fcb != NULL && Fcb->Flags & FCB_IS_PAGE_FILE)
 172     {
 173       ULONG NCluster;
 174       ULONG Offset = FileOffset / DeviceExt->FatInfo.BytesPerCluster;
 175       PULONG FatChain;
 176       int i;
 177       if (Fcb->FatChainSize == 0)
 178       {
 179         DbgPrint("OffsetToCluster is called with FirstCluster = %x"
 180                  " and Fcb->FatChainSize = 0!\n", FirstCluster);
 181         KeBugCheck(0);
 182       }
 183       if (Offset < Fcb->FatChainSize)
 184       {
 185         *Cluster = Fcb->FatChain[Offset];
 186         return STATUS_SUCCESS;
 187       }
 188       else
 189       {
 190         if (!Extend)
 191         {
 192           *Cluster = 0xffffffff;
 193           return STATUS_UNSUCCESSFUL;
 194         }
 195         else
 196         {
 197           FatChain = ExAllocatePool(NonPagedPool, (Offset + 1) * sizeof(ULONG));
 198           if (!FatChain)
 199           {
 200             *Cluster = 0xffffffff;
 201             return STATUS_UNSUCCESSFUL;
 202           }
 203
 204           CurrentCluster = Fcb->FatChain[Fcb->FatChainSize - 1];
 205           FatChain[Fcb->FatChainSize - 1] = CurrentCluster;
 206           for (i = Fcb->FatChainSize; i < Offset + 1; i++)
 207           {
 208             Status = GetNextCluster(DeviceExt, CurrentCluster, &CurrentCluster, TRUE);
 209             if (!NT_SUCCESS(Status) || CurrentCluster == 0xFFFFFFFF)
 210             {
 211               while (i >= Fcb->FatChainSize)
 212               {
 213                 WriteCluster(DeviceExt, FatChain[i - 1], 0xFFFFFFFF);
 214                 i--;
 215               }
 216               *Cluster = 0xffffffff;
 217               ExFreePool(FatChain);
 218               if (!NT_SUCCESS(Status))
 219                  return Status;
 220               return STATUS_UNSUCCESSFUL;
 221             }
 222             FatChain[i] = CurrentCluster;
 223           }
 224           memcpy (FatChain, Fcb->FatChain, Fcb->FatChainSize * sizeof(ULONG));
 225           ExFreePool(Fcb->FatChain);
 226           Fcb->FatChain = FatChain;
 227           Fcb->FatChainSize = Offset + 1;
 228         }
 229       }
 230       *Cluster = CurrentCluster;
 231       return(STATUS_SUCCESS);
 232     }
 233   if (FirstCluster == 1)
 234     {
 235       /* root of FAT16 or FAT12 */
 236       *Cluster = DeviceExt->FatInfo.rootStart + FileOffset
 237         / (DeviceExt->FatInfo.BytesPerCluster) * DeviceExt->FatInfo.SectorsPerCluster;
 238       return(STATUS_SUCCESS);
 239     }
 240   else
 241     {
 242       CurrentCluster = FirstCluster;
 243       for (i = 0; i < FileOffset / DeviceExt->FatInfo.BytesPerCluster; i++)
 244         {
 245           Status = GetNextCluster (DeviceExt, CurrentCluster, &CurrentCluster,
 246                                    Extend);
 247           if (!NT_SUCCESS(Status))
 248             {
 249               return(Status);
 250             }
 251         }
 252       *Cluster = CurrentCluster;
 253       return(STATUS_SUCCESS);
 254     }
 255 }
 256
 257 NTSTATUS
 258 VfatReadFileData (PVFAT_IRP_CONTEXT IrpContext, PVOID Buffer,
 259                   ULONG Length, LARGE_INTEGER ReadOffset, PULONG LengthRead)
 260 /*
 261  * FUNCTION: Reads data from a file
 262  */
 263 {
 264   ULONG CurrentCluster;
 265   ULONG FirstCluster;
 266   ULONG StartCluster;
 267   ULONG ClusterCount;
 268   LARGE_INTEGER StartOffset;
 269   PDEVICE_EXTENSION DeviceExt;
 270   BOOLEAN First = TRUE;
 271   PVFATFCB Fcb;
 272   PVFATCCB Ccb;
 273   NTSTATUS Status;
 274   ULONG BytesDone;
 275   ULONG BytesPerSector;
 276   ULONG BytesPerCluster;
 277
 278   /* PRECONDITION */
 279   assert (IrpContext);
 280   DeviceExt = IrpContext->DeviceExt;
 281   assert (DeviceExt);
 282   assert (DeviceExt->FatInfo.BytesPerCluster);
 283   assert (IrpContext->FileObject);
 284   assert (IrpContext->FileObject->FsContext2 != NULL);
 285
 286   DPRINT("VfatReadFileData(DeviceExt %x, FileObject %x, Buffer %x, "
 287          "Length %d, ReadOffset 0x%I64x)\n", DeviceExt,
 288          IrpContext->FileObject, Buffer, Length, ReadOffset.QuadPart);
 289
 290   *LengthRead = 0;
 291
 292   Ccb = (PVFATCCB)IrpContext->FileObject->FsContext2;
 293   Fcb = Ccb->pFcb;
 294   BytesPerSector = DeviceExt->FatInfo.BytesPerSector;
 295   BytesPerCluster = DeviceExt->FatInfo.BytesPerCluster;
 296
 297   assert(ReadOffset.QuadPart + Length <= ROUND_UP(Fcb->RFCB.FileSize.QuadPart, BytesPerSector));
 298   assert(ReadOffset.u.LowPart % BytesPerSector == 0);
 299   assert(Length % BytesPerSector == 0);
 300
 301   /* Is this a read of the FAT? */
 302   if (Fcb->Flags & FCB_IS_FAT)
 303   {
 304     ReadOffset.QuadPart += DeviceExt->FatInfo.FATStart * BytesPerSector;
 305     Status = VfatReadDisk(DeviceExt->StorageDevice, &ReadOffset, Length, Buffer);
 306
 307     if (NT_SUCCESS(Status))
 308     {
 309       *LengthRead = Length;
 310     }
 311     else
 312     {
 313       DPRINT1("FAT reading failed, Status %x\n", Status);
 314     }
 315     return Status;
 316   }
 317   /* Is this a read of the Volume ? */
 318   if (Fcb->Flags & FCB_IS_VOLUME)
 319   {
 320     Status = VfatReadDisk(DeviceExt->StorageDevice, &ReadOffset, Length, Buffer);
 321     if (NT_SUCCESS(Status))
 322     {
 323       *LengthRead = Length;
 324     }
 325     else
 326     {
 327       DPRINT1("Volume reading failed, Status %x\n", Status);
 328     }
 329     return Status;
 330   }
 331
 332   /*
 333    * Find the first cluster
 334    */
 335   FirstCluster = CurrentCluster =
 336     vfatDirEntryGetFirstCluster (DeviceExt, &Fcb->entry);
 337
 338   if (FirstCluster == 1)
 339   {
 340     // Directory of FAT12/16 needs a special handling
 341     CHECKPOINT;
 342     if (ReadOffset.u.LowPart + Length > DeviceExt->FatInfo.rootDirectorySectors * BytesPerSector)
 343     {
 344       Length = DeviceExt->FatInfo.rootDirectorySectors * BytesPerSector - ReadOffset.u.LowPart;
 345     }
 346     ReadOffset.u.LowPart += DeviceExt->FatInfo.rootStart * BytesPerSector;
 347
 348     // Fire up the read command
 349
 350     Status = VfatReadDisk (DeviceExt->StorageDevice, &ReadOffset, Length, Buffer);
 351     if (NT_SUCCESS(Status))
 352     {
 353       *LengthRead += Length;
 354     }
 355     return Status;
 356   }
 357   /*
 358    * Find the cluster to start the read from
 359    */
 360   if (Ccb->LastCluster > 0 && ReadOffset.u.LowPart > Ccb->LastOffset)
 361   {
 362     CurrentCluster = Ccb->LastCluster;
 363   }
 364   Status = OffsetToCluster(DeviceExt, Fcb, FirstCluster,
 365                            ROUND_DOWN(ReadOffset.u.LowPart, BytesPerCluster),
 366                            &CurrentCluster, FALSE);
 367   if (!NT_SUCCESS(Status))
 368   {
 369     return(Status);
 370   }
 371
 372   Ccb->LastCluster = CurrentCluster;
 373   Ccb->LastOffset = ROUND_DOWN (ReadOffset.u.LowPart, BytesPerCluster);
 374
 375   while (Length > 0 && CurrentCluster != 0xffffffff && NT_SUCCESS(Status))
 376   {
 377     StartCluster = CurrentCluster;
 378     StartOffset.QuadPart = ClusterToSector(DeviceExt, StartCluster) * BytesPerSector;
 379     BytesDone = 0;
 380     ClusterCount = 0;
 381
 382     do
 383     {
 384       ClusterCount++;
 385       if (First)
 386       {
 387         BytesDone =  min (Length, BytesPerCluster - (ReadOffset.u.LowPart % BytesPerCluster));
 388         StartOffset.QuadPart += ReadOffset.u.LowPart % BytesPerCluster;
 389         First = FALSE;
 390       }
 391       else
 392       {
 393         if (Length - BytesDone > BytesPerCluster)
 394         {
 395           BytesDone += BytesPerCluster;
 396         }
 397         else
 398         {
 399           BytesDone = Length;
 400         }
 401       }
 402       Status = NextCluster(DeviceExt, Fcb, FirstCluster, &CurrentCluster, FALSE);
 403     }
 404     while (StartCluster + ClusterCount == CurrentCluster && NT_SUCCESS(Status) && Length > BytesDone);
 405     DPRINT("start %08x, next %08x, count %d\n",
 406            StartCluster, CurrentCluster, ClusterCount);
 407
 408     Ccb->LastCluster = StartCluster + (ClusterCount - 1);
 409     Ccb->LastOffset = ReadOffset.u.LowPart + (ClusterCount - 1) * BytesPerCluster;
 410
 411     // Fire up the read command
 412     Status = VfatReadDisk (DeviceExt->StorageDevice, &StartOffset, BytesDone, Buffer);
 413
 414     if (NT_SUCCESS(Status))
 415     {
 416       *LengthRead += BytesDone;
 417       Buffer += BytesDone;
 418       Length -= BytesDone;
 419       ReadOffset.u.LowPart += BytesDone;
 420     }
 421   }
 422   return Status;
 423 }
 424
 425 NTSTATUS VfatWriteFileData(PVFAT_IRP_CONTEXT IrpContext,
 426                            PVOID Buffer,
 427                            ULONG Length,
 428                            LARGE_INTEGER WriteOffset)
 429 {
 430    PDEVICE_EXTENSION DeviceExt;
 431    PVFATFCB Fcb;
 432    PVFATCCB Ccb;
 433    ULONG Count;
 434    ULONG FirstCluster;
 435    ULONG CurrentCluster;
 436    ULONG BytesDone;
 437    ULONG StartCluster;
 438    ULONG ClusterCount;
 439    NTSTATUS Status;
 440    BOOLEAN First = TRUE;
 441    ULONG BytesPerSector;
 442    ULONG BytesPerCluster;
 443    LARGE_INTEGER StartOffset;
 444
 445    /* PRECONDITION */
 446    assert (IrpContext);
 447    DeviceExt = IrpContext->DeviceExt;
 448    assert (DeviceExt);
 449    assert (DeviceExt->FatInfo.BytesPerCluster);
 450    assert (IrpContext->FileObject);
 451    assert (IrpContext->FileObject->FsContext2 != NULL);
 452
 453    Ccb = (PVFATCCB)IrpContext->FileObject->FsContext2;
 454    Fcb = Ccb->pFcb;
 455    BytesPerCluster = DeviceExt->FatInfo.BytesPerCluster;
 456    BytesPerSector = DeviceExt->FatInfo.BytesPerSector;
 457
 458    DPRINT("VfatWriteFileData(DeviceExt %x, FileObject %x, Buffer %x, "
 459           "Length %d, WriteOffset 0x%I64x), '%S'\n", DeviceExt,
 460           IrpContext->FileObject, Buffer, Length, WriteOffset,
 461           Fcb->PathName);
 462
 463    assert(WriteOffset.QuadPart + Length <= Fcb->RFCB.AllocationSize.QuadPart);
 464    assert(WriteOffset.u.LowPart % BytesPerSector == 0);
 465    assert(Length % BytesPerSector == 0)
 466
 467    // Is this a write of the volume ?
 468    if (Fcb->Flags & FCB_IS_VOLUME)
 469    {
 470       Status = VfatWriteDisk(DeviceExt->StorageDevice, &WriteOffset, Length, Buffer);
 471       if (!NT_SUCCESS(Status))
 472       {
 473          DPRINT1("Volume writing failed, Status %x\n", Status);
 474       }
 475       return Status;
 476    }
 477
 478    // Is this a write to the FAT ?
 479    if (Fcb->Flags & FCB_IS_FAT)
 480    {
 481       WriteOffset.u.LowPart += DeviceExt->FatInfo.FATStart * BytesPerSector;
 482       for (Count = 0; Count < DeviceExt->FatInfo.FATCount; Count++)
 483       {
 484          Status = VfatWriteDisk(DeviceExt->StorageDevice, &WriteOffset, Length, Buffer);
 485          if (!NT_SUCCESS(Status))
 486          {
 487             DPRINT1("FAT writing failed, Status %x\n", Status);
 488          }
 489          WriteOffset.u.LowPart += Fcb->RFCB.FileSize.u.LowPart;
 490       }
 491       return Status;
 492    }
 493
 494    /*
 495     * Find the first cluster
 496     */
 497    FirstCluster = CurrentCluster =
 498       vfatDirEntryGetFirstCluster (DeviceExt, &Fcb->entry);
 499
 500    if (FirstCluster == 1)
 501    {
 502       assert(WriteOffset.u.LowPart + Length <= DeviceExt->FatInfo.rootDirectorySectors * BytesPerSector);
 503       // Directory of FAT12/16 needs a special handling
 504       WriteOffset.u.LowPart += DeviceExt->FatInfo.rootStart * BytesPerSector;
 505       // Fire up the write command
 506       Status = VfatWriteDisk (DeviceExt->StorageDevice, &WriteOffset, Length, Buffer);
 507       return Status;
 508    }
 509
 510    /*
 511     * Find the cluster to start the write from
 512     */
 513    if (Ccb->LastCluster > 0 && WriteOffset.u.LowPart > Ccb->LastOffset)
 514    {
 515       CurrentCluster = Ccb->LastCluster;
 516    }
 517
 518    Status = OffsetToCluster(DeviceExt, Fcb, FirstCluster,
 519                             ROUND_DOWN(WriteOffset.u.LowPart, BytesPerCluster),
 520                             &CurrentCluster, FALSE);
 521
 522    if (!NT_SUCCESS(Status))
 523    {
 524       return(Status);
 525    }
 526
 527    Ccb->LastCluster = CurrentCluster;
 528    Ccb->LastOffset = ROUND_DOWN (WriteOffset.u.LowPart, BytesPerCluster);
 529
 530    while (Length > 0 && CurrentCluster != 0xffffffff && NT_SUCCESS(Status))
 531    {
 532       StartCluster = CurrentCluster;
 533       StartOffset.QuadPart = ClusterToSector(DeviceExt, StartCluster) * BytesPerSector;
 534       BytesDone = 0;
 535       ClusterCount = 0;
 536
 537       do
 538       {
 539          ClusterCount++;
 540          if (First)
 541          {
 542             BytesDone =  min (Length, BytesPerCluster - (WriteOffset.u.LowPart % BytesPerCluster));
 543             StartOffset.QuadPart += WriteOffset.u.LowPart % BytesPerCluster;
 544             First = FALSE;
 545          }
 546          else
 547          {
 548             if (Length - BytesDone > BytesPerCluster)
 549             {
 550                BytesDone += BytesPerCluster;
 551             }
 552             else
 553             {
 554                BytesDone = Length;
 555             }
 556          }
 557          Status = NextCluster(DeviceExt, Fcb, FirstCluster, &CurrentCluster, FALSE);
 558       }
 559       while (StartCluster + ClusterCount == CurrentCluster && NT_SUCCESS(Status) && Length > BytesDone);
 560       DPRINT("start %08x, next %08x, count %d\n",
 561              StartCluster, CurrentCluster, ClusterCount);
 562
 563       Ccb->LastCluster = StartCluster + (ClusterCount - 1);
 564       Ccb->LastOffset = WriteOffset.u.LowPart + (ClusterCount - 1) * BytesPerCluster;
 565
 566       // Fire up the write command
 567       Status = VfatWriteDisk (DeviceExt->StorageDevice, &StartOffset, BytesDone, Buffer);
 568       if (NT_SUCCESS(Status))
 569       {
 570          Buffer += BytesDone;
 571          Length -= BytesDone;
 572          WriteOffset.u.LowPart += BytesDone;
 573       }
 574    }
 575    return Status;
 576 }
 577
 578 NTSTATUS
 579 VfatRead(PVFAT_IRP_CONTEXT IrpContext)
 580 {
 581    NTSTATUS Status;
 582    PVFATFCB Fcb;
 583    PVFATCCB Ccb;
 584    ULONG Length;
 585    ULONG ReturnedLength = 0;
 586    PERESOURCE Resource = NULL;
 587    LARGE_INTEGER ByteOffset;
 588    PVOID Buffer;
 589    PDEVICE_OBJECT DeviceToVerify;
 590    ULONG BytesPerSector;
 591
 592    assert(IrpContext);
 593
 594    DPRINT("VfatRead(IrpContext %x)\n", IrpContext);
 595
 596    assert(IrpContext->DeviceObject);
 597
 598    // This request is not allowed on the main device object
 599    if (IrpContext->DeviceObject == VfatGlobalData->DeviceObject)
 600    {
 601       DPRINT("VfatRead is called with the main device object.\n");
 602       Status = STATUS_INVALID_DEVICE_REQUEST;
 603       goto ByeBye;
 604    }
 605
 606    assert(IrpContext->DeviceExt);
 607    assert(IrpContext->FileObject);
 608    Ccb = (PVFATCCB) IrpContext->FileObject->FsContext2;
 609    assert(Ccb);
 610    Fcb =  Ccb->pFcb;
 611    assert(Fcb);
 612
 613    DPRINT("<%S>\n", Fcb->PathName);
 614
 615    ByteOffset = IrpContext->Stack->Parameters.Read.ByteOffset;
 616    Length = IrpContext->Stack->Parameters.Read.Length;
 617    BytesPerSector = IrpContext->DeviceExt->FatInfo.BytesPerSector;
 618
 619    /* fail if file is a directory and no paged read */
 620    if (Fcb->entry.Attrib & FILE_ATTRIBUTE_DIRECTORY && !(IrpContext->Irp->Flags & IRP_PAGING_IO))
 621    {
 622       Status = STATUS_INVALID_PARAMETER;
 623       goto ByeBye;
 624    }
 625
 626
 627    DPRINT("'%S', Offset: %d, Length %d\n", Fcb->PathName, ByteOffset.u.LowPart, Length);
 628
 629    if (ByteOffset.u.HighPart && !(Fcb->Flags & FCB_IS_VOLUME))
 630    {
 631       Status = STATUS_INVALID_PARAMETER;
 632       goto ByeBye;
 633    }
 634    if (ByteOffset.QuadPart >= Fcb->RFCB.FileSize.QuadPart)
 635    {
 636       IrpContext->Irp->IoStatus.Information = 0;
 637       Status = STATUS_END_OF_FILE;
 638       goto ByeBye;
 639    }
 640    if (IrpContext->Irp->Flags & (IRP_PAGING_IO | IRP_NOCACHE) || (Fcb->Flags & FCB_IS_VOLUME))
 641    {
 642       if (ByteOffset.u.LowPart % BytesPerSector != 0 || Length % BytesPerSector != 0)
 643       {
 644          DPRINT("%d %d\n", ByteOffset.u.LowPart, Length);
 645          // non chached read must be sector aligned
 646          Status = STATUS_INVALID_PARAMETER;
 647          goto ByeBye;
 648       }
 649    }
 650    if (Length == 0)
 651    {
 652       IrpContext->Irp->IoStatus.Information = 0;
 653       Status = STATUS_SUCCESS;
 654       goto ByeBye;
 655    }
 656
 657    if (Fcb->Flags & FCB_IS_VOLUME)
 658    {
 659       Resource = &IrpContext->DeviceExt->DirResource;
 660    }
 661    else if (IrpContext->Irp->Flags & IRP_PAGING_IO)
 662    {
 663       Resource = &Fcb->PagingIoResource;
 664    }
 665    else
 666    {
 667       Resource = &Fcb->MainResource;
 668    }
 669    if (!ExAcquireResourceSharedLite(Resource, IrpContext->Flags & IRPCONTEXT_CANWAIT))
 670    {
 671       Resource = NULL;
 672       Status = STATUS_PENDING;
 673       goto ByeBye;
 674    }
 675    if (!(IrpContext->Irp->Flags & (IRP_NOCACHE|IRP_PAGING_IO)) &&
 676      !(Fcb->Flags & (FCB_IS_PAGE_FILE|FCB_IS_VOLUME)))
 677    {
 678       // cached read
 679       CHECKPOINT;
 680       Status = STATUS_SUCCESS;
 681       if (ByteOffset.u.LowPart + Length > Fcb->RFCB.FileSize.u.LowPart)
 682       {
 683          Length = Fcb->RFCB.FileSize.u.LowPart - ByteOffset.u.LowPart;
 684          Status = /*STATUS_END_OF_FILE*/STATUS_SUCCESS;
 685       }
 686
 687       Buffer = VfatGetUserBuffer(IrpContext->Irp);
 688       if (!Buffer)
 689       {
 690          Status = STATUS_INVALID_USER_BUFFER;
 691          goto ByeBye;
 692       }
 693
 694       CHECKPOINT;
 695       if (IrpContext->FileObject->PrivateCacheMap == NULL)
 696       {
 697           ULONG CacheSize;
 698           CacheSize = IrpContext->DeviceExt->FatInfo.BytesPerCluster;
 699           if (CacheSize < PAGESIZE)
 700           {
 701              CacheSize = PAGESIZE;
 702           }
 703           CcRosInitializeFileCache(IrpContext->FileObject, &Fcb->RFCB.Bcb, CacheSize);
 704       }
 705       if (!CcCopyRead(IrpContext->FileObject, &ByteOffset, Length,
 706                       IrpContext->Flags & IRPCONTEXT_CANWAIT, Buffer,
 707                       &IrpContext->Irp->IoStatus))
 708       {
 709          Status = STATUS_PENDING;
 710          goto ByeBye;
 711       }
 712       CHECKPOINT;
 713       if (!NT_SUCCESS(IrpContext->Irp->IoStatus.Status))
 714       {
 715         Status = IrpContext->Irp->IoStatus.Status;
 716       }
 717    }
 718    else
 719    {
 720       // non cached read
 721       CHECKPOINT;
 722       if (ByteOffset.QuadPart + Length > ROUND_UP(Fcb->RFCB.FileSize.QuadPart, BytesPerSector))
 723       {
 724          Length = ROUND_UP(Fcb->RFCB.FileSize.QuadPart, BytesPerSector) - ByteOffset.QuadPart;
 725       }
 726
 727       Buffer = VfatGetUserBuffer(IrpContext->Irp);
 728       if (!Buffer)
 729       {
 730          Status = STATUS_INVALID_USER_BUFFER;
 731          goto ByeBye;
 732       }
 733
 734       Status = VfatReadFileData(IrpContext, Buffer, Length, ByteOffset, &ReturnedLength);
 735 /*
 736       if (Status == STATUS_VERIFY_REQUIRED)
 737       {
 738          DPRINT("VfatReadFile returned STATUS_VERIFY_REQUIRED\n");
 739          DeviceToVerify = IoGetDeviceToVerify(KeGetCurrentThread());
 740          IoSetDeviceToVerify(KeGetCurrentThread(), NULL);
 741          Status = IoVerifyVolume (DeviceToVerify, FALSE);
 742
 743          if (NT_SUCCESS(Status))
 744          {
 745             Status = VfatReadFileData(IrpContext, Buffer, Length,
 746                                       ByteOffset.u.LowPart, &ReturnedLength);
 747          }
 748       }
 749 */
 750       if (NT_SUCCESS(Status))
 751       {
 752          IrpContext->Irp->IoStatus.Information = ReturnedLength;
 753       }
 754    }
 755
 756 ByeBye:
 757    if (Resource)
 758    {
 759       ExReleaseResourceLite(Resource);
 760    }
 761
 762    if (Status == STATUS_PENDING)
 763    {
 764       Status = VfatLockUserBuffer(IrpContext->Irp, Length, IoWriteAccess);
 765       if (NT_SUCCESS(Status))
 766       {
 767          Status = VfatQueueRequest(IrpContext);
 768       }
 769       else
 770       {
 771          IrpContext->Irp->IoStatus.Status = Status;
 772          IoCompleteRequest(IrpContext->Irp, IO_NO_INCREMENT);
 773          VfatFreeIrpContext(IrpContext);
 774       }
 775    }
 776    else
 777    {
 778       IrpContext->Irp->IoStatus.Status = Status;
 779       if (IrpContext->FileObject->Flags & FO_SYNCHRONOUS_IO &&
 780           !(IrpContext->Irp->Flags & IRP_PAGING_IO) &&
 781           (NT_SUCCESS(Status) || Status==STATUS_END_OF_FILE))
 782       {
 783          IrpContext->FileObject->CurrentByteOffset.QuadPart =
 784            ByteOffset.QuadPart + IrpContext->Irp->IoStatus.Information;
 785       }
 786
 787       IoCompleteRequest(IrpContext->Irp,
 788                         NT_SUCCESS(Status) ? IO_DISK_INCREMENT : IO_NO_INCREMENT);
 789       VfatFreeIrpContext(IrpContext);
 790    }
 791    DPRINT("%x\n", Status);
 792    return Status;
 793 }
 794
 795 NTSTATUS VfatWrite (PVFAT_IRP_CONTEXT IrpContext)
 796 {
 797    PVFATCCB Ccb;
 798    PVFATFCB Fcb;
 799    PERESOURCE Resource = NULL;
 800    LARGE_INTEGER ByteOffset;
 801    LARGE_INTEGER OldFileSize;
 802    NTSTATUS Status = STATUS_SUCCESS;
 803    ULONG Length;
 804    ULONG OldAllocationSize;
 805    PVOID Buffer;
 806    ULONG BytesPerSector;
 807
 808    assert (IrpContext);
 809
 810    DPRINT("VfatWrite(IrpContext %x)\n", IrpContext);
 811
 812    assert(IrpContext->DeviceObject);
 813
 814    // This request is not allowed on the main device object
 815    if (IrpContext->DeviceObject == VfatGlobalData->DeviceObject)
 816    {
 817       DPRINT("VfatWrite is called with the main device object.\n");
 818       Status = STATUS_INVALID_DEVICE_REQUEST;
 819       goto ByeBye;
 820    }
 821
 822    assert(IrpContext->DeviceExt);
 823    assert(IrpContext->FileObject);
 824    Ccb = (PVFATCCB) IrpContext->FileObject->FsContext2;
 825    assert(Ccb);
 826    Fcb =  Ccb->pFcb;
 827    assert(Fcb);
 828
 829    DPRINT("<%S>\n", Fcb->PathName);
 830
 831    /* fail if file is a directory and no paged read */
 832    if (Fcb->entry.Attrib & FILE_ATTRIBUTE_DIRECTORY && !(IrpContext->Irp->Flags & IRP_PAGING_IO))
 833    {
 834       Status = STATUS_INVALID_PARAMETER;
 835       goto ByeBye;
 836    }
 837
 838    ByteOffset = IrpContext->Stack->Parameters.Write.ByteOffset;
 839    Length = IrpContext->Stack->Parameters.Write.Length;
 840    BytesPerSector = IrpContext->DeviceExt->FatInfo.BytesPerSector;
 841
 842    if (ByteOffset.u.HighPart && !(Fcb->Flags & FCB_IS_VOLUME))
 843    {
 844       Status = STATUS_INVALID_PARAMETER;
 845       goto ByeBye;
 846    }
 847
 848    if (Fcb->Flags & (FCB_IS_FAT | FCB_IS_VOLUME) ||
 849        1 == vfatDirEntryGetFirstCluster (IrpContext->DeviceExt, &Fcb->entry))
 850    {
 851       if (ByteOffset.QuadPart + Length > Fcb->RFCB.FileSize.QuadPart)
 852       {
 853          // we can't extend the FAT, the volume or the root on FAT12/FAT16
 854          Status = STATUS_END_OF_FILE;
 855          goto ByeBye;
 856       }
 857    }
 858
 859    if (IrpContext->Irp->Flags & (IRP_PAGING_IO|IRP_NOCACHE) || (Fcb->Flags & FCB_IS_VOLUME))
 860    {
 861       if (ByteOffset.u.LowPart % BytesPerSector != 0 || Length % BytesPerSector != 0)
 862       {
 863          // non chached write must be sector aligned
 864          Status = STATUS_INVALID_PARAMETER;
 865          goto ByeBye;
 866       }
 867    }
 868
 869    if (Length == 0)
 870    {
 871       IrpContext->Irp->IoStatus.Information = 0;
 872       Status = STATUS_SUCCESS;
 873       goto ByeBye;
 874    }
 875
 876    if (IrpContext->Irp->Flags & IRP_PAGING_IO)
 877    {
 878       if (ByteOffset.u.LowPart + Length > Fcb->RFCB.AllocationSize.u.LowPart)
 879       {
 880          Status = STATUS_INVALID_PARAMETER;
 881          goto ByeBye;
 882       }
 883       if (ByteOffset.u.LowPart + Length > ROUND_UP(Fcb->RFCB.AllocationSize.u.LowPart, BytesPerSector))
 884       {
 885          Length =  ROUND_UP(Fcb->RFCB.FileSize.u.LowPart, BytesPerSector) - ByteOffset.u.LowPart;
 886       }
 887    }
 888
 889    if (Fcb->Flags & FCB_IS_VOLUME)
 890    {
 891       Resource = &IrpContext->DeviceExt->DirResource;
 892    }
 893    else if (IrpContext->Irp->Flags & IRP_PAGING_IO)
 894    {
 895       Resource = &Fcb->PagingIoResource;
 896    }
 897    else
 898    {
 899       Resource = &Fcb->MainResource;
 900    }
 901
 902    if (Fcb->Flags & FCB_IS_PAGE_FILE)
 903    {
 904       if (!ExAcquireResourceSharedLite(Resource, IrpContext->Flags & IRPCONTEXT_CANWAIT))
 905       {
 906          Resource = NULL;
 907          Status = STATUS_PENDING;
 908          goto ByeBye;
 909       }
 910    }
 911    else
 912    {
 913       if (!ExAcquireResourceExclusiveLite(Resource, IrpContext->Flags & IRPCONTEXT_CANWAIT))
 914       {
 915          Resource = NULL;
 916          Status = STATUS_PENDING;
 917          goto ByeBye;
 918       }
 919    }
 920
 921    if (!(IrpContext->Flags & IRPCONTEXT_CANWAIT) && !(Fcb->Flags & FCB_IS_VOLUME))
 922    {
 923       if (ByteOffset.u.LowPart + Length > Fcb->RFCB.AllocationSize.u.LowPart)
 924       {
 925         Status = STATUS_PENDING;
 926         goto ByeBye;
 927       }
 928    }
 929
 930    OldFileSize = Fcb->RFCB.FileSize;
 931    OldAllocationSize = Fcb->RFCB.AllocationSize.u.LowPart;
 932
 933    if (!(Fcb->Flags & (FCB_IS_FAT|FCB_IS_VOLUME)) &&
 934        !(IrpContext->Irp->Flags & IRP_PAGING_IO) &&
 935        ByteOffset.u.LowPart + Length > Fcb->RFCB.FileSize.u.LowPart)
 936    {
 937       LARGE_INTEGER AllocationSize;
 938       AllocationSize.QuadPart = ByteOffset.u.LowPart + Length;
 939       Status = VfatSetAllocationSizeInformation(IrpContext->FileObject, Fcb,
 940                                                 IrpContext->DeviceExt, &AllocationSize);
 941       if (!NT_SUCCESS (Status))
 942       {
 943          CHECKPOINT;
 944          goto ByeBye;
 945       }
 946    }
 947
 948    if (ByteOffset.QuadPart > OldFileSize.QuadPart)
 949    {
 950       CcZeroData(IrpContext->FileObject, &OldFileSize, &ByteOffset, TRUE);
 951    }
 952
 953    if (!(IrpContext->Irp->Flags & (IRP_NOCACHE|IRP_PAGING_IO)) &&
 954       !(Fcb->Flags & (FCB_IS_PAGE_FILE|FCB_IS_VOLUME)))
 955    {
 956       // cached write
 957       CHECKPOINT;
 958
 959       Buffer = VfatGetUserBuffer(IrpContext->Irp);
 960       if (!Buffer)
 961       {
 962          Status = STATUS_INVALID_USER_BUFFER;
 963          goto ByeBye;
 964       }
 965       CHECKPOINT;
 966       if (IrpContext->FileObject->PrivateCacheMap == NULL)
 967       {
 968           ULONG CacheSize;
 969           CacheSize = IrpContext->DeviceExt->FatInfo.BytesPerCluster;
 970           if (CacheSize < PAGESIZE)
 971           {
 972              CacheSize = PAGESIZE;
 973           }
 974           CcRosInitializeFileCache(IrpContext->FileObject, &Fcb->RFCB.Bcb, CacheSize);
 975       }
 976       if (CcCopyWrite(IrpContext->FileObject, &ByteOffset, Length,
 977                       1 /*IrpContext->Flags & IRPCONTEXT_CANWAIT*/, Buffer))
 978       {
 979          IrpContext->Irp->IoStatus.Information = Length;
 980          Status = STATUS_SUCCESS;
 981       }
 982       else
 983       {
 984          Status = STATUS_UNSUCCESSFUL;
 985       }
 986       CHECKPOINT;
 987    }
 988    else
 989    {
 990       // non cached write
 991       CHECKPOINT;
 992
 993       Buffer = VfatGetUserBuffer(IrpContext->Irp);
 994       if (!Buffer)
 995       {
 996          Status = STATUS_INVALID_USER_BUFFER;
 997          goto ByeBye;
 998       }
 999
1000       Status = VfatWriteFileData(IrpContext, Buffer, Length, ByteOffset);
1001       if (NT_SUCCESS(Status))
1002       {
1003          IrpContext->Irp->IoStatus.Information = Length;
1004       }
1005    }
1006
1007    if (!(IrpContext->Irp->Flags & IRP_PAGING_IO) &&
1008       !(Fcb->Flags & (FCB_IS_FAT|FCB_IS_VOLUME)))
1009    {
1010       if(!(Fcb->entry.Attrib & FILE_ATTRIBUTE_DIRECTORY))
1011       {
1012          LARGE_INTEGER SystemTime, LocalTime;
1013          // set dates and times
1014          KeQuerySystemTime (&SystemTime);
1015          ExSystemTimeToLocalTime (&SystemTime, &LocalTime);
1016          FsdFileTimeToDosDateTime ((TIME*)&LocalTime, &Fcb->entry.UpdateDate,
1017                                    &Fcb->entry.UpdateTime);
1018          Fcb->entry.AccessDate = Fcb->entry.UpdateDate;
1019          // update dates/times and length
1020          if (OldAllocationSize != Fcb->RFCB.AllocationSize.u.LowPart)
1021          {
1022             VfatUpdateEntry (IrpContext->DeviceExt, IrpContext->FileObject);
1023             Fcb->Flags &= ~FCB_UPDATE_DIRENTRY;
1024          }
1025          else
1026             Fcb->Flags |= FCB_UPDATE_DIRENTRY;
1027       }
1028    }
1029
1030 ByeBye:
1031    if (Resource)
1032    {
1033       ExReleaseResourceLite(Resource);
1034    }
1035
1036    if (Status == STATUS_PENDING)
1037    {
1038       Status = VfatLockUserBuffer(IrpContext->Irp, Length, IoReadAccess);
1039       if (NT_SUCCESS(Status))
1040       {
1041          Status = VfatQueueRequest(IrpContext);
1042       }
1043       else
1044       {
1045          IrpContext->Irp->IoStatus.Status = Status;
1046          IoCompleteRequest(IrpContext->Irp, IO_NO_INCREMENT);
1047          VfatFreeIrpContext(IrpContext);
1048       }
1049    }
1050    else
1051    {
1052       IrpContext->Irp->IoStatus.Status = Status;
1053       if (IrpContext->FileObject->Flags & FO_SYNCHRONOUS_IO &&
1054           !(IrpContext->Irp->Flags & IRP_PAGING_IO) && NT_SUCCESS(Status))
1055       {
1056          IrpContext->FileObject->CurrentByteOffset.QuadPart =
1057            ByteOffset.QuadPart + IrpContext->Irp->IoStatus.Information;
1058       }
1059
1060       IoCompleteRequest(IrpContext->Irp,
1061                         NT_SUCCESS(Status) ? IO_DISK_INCREMENT : IO_NO_INCREMENT);
1062       VfatFreeIrpContext(IrpContext);
1063    }
1064    DPRINT("%x\n", Status);
1065    return Status;
1066 }
1067
1068