reactos/drivers/filesystems/cdfs/fcb.c

   1 /*
   2  *  ReactOS kernel
   3  *  Copyright (C) 2002, 2004 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 /*
  20  * COPYRIGHT:        See COPYING in the top level directory
  21  * PROJECT:          ReactOS kernel
  22  * FILE:             drivers/filesystems/cdfs/fcb.c
  23  * PURPOSE:          CDROM (ISO 9660) filesystem driver
  24  * PROGRAMMER:       Art Yerkes
  25  * UPDATE HISTORY:
  26  */
  27
  28 /* INCLUDES *****************************************************************/
  29
  30 #include "cdfs.h"
  31
  32 #define NDEBUG
  33 #include <debug.h>
  34
  35 /* FUNCTIONS ****************************************************************/
  36
  37 #define ROUND_UP(N, S) ((((N) + (S) - 1) / (S)) * (S))
  38
  39
  40 /* FUNCTIONS ****************************************************************/
  41
  42 static PWCHAR
  43 CdfsGetNextPathElement(PWCHAR FileName)
  44 {
  45     if (*FileName == L'\0')
  46     {
  47         return(NULL);
  48     }
  49
  50     while (*FileName != L'\0' && *FileName != L'\\')
  51     {
  52         FileName++;
  53     }
  54
  55     return(FileName);
  56 }
  57
  58
  59 static VOID
  60 CdfsWSubString(LPWSTR pTarget, LPCWSTR pSource, size_t pLength)
  61 {
  62     wcsncpy (pTarget, pSource, pLength);
  63     pTarget [pLength] = L'\0';
  64 }
  65
  66
  67 PFCB
  68 CdfsCreateFCB(PCWSTR FileName)
  69 {
  70     PFCB Fcb;
  71
  72     Fcb = ExAllocatePoolWithTag(NonPagedPool,
  73                                 sizeof(FCB),
  74                                 CDFS_NONPAGED_FCB_TAG);
  75     if(!Fcb) return NULL;
  76
  77     RtlZeroMemory(Fcb, sizeof(FCB));
  78     RtlInitEmptyUnicodeString(&Fcb->PathName, Fcb->PathNameBuffer, sizeof(Fcb->PathNameBuffer));
  79
  80     if (FileName)
  81     {
  82         RtlAppendUnicodeToString(&Fcb->PathName, FileName);
  83         if (wcsrchr(Fcb->PathName.Buffer, '\\') != 0)
  84         {
  85             Fcb->ObjectName = wcsrchr(Fcb->PathName.Buffer, '\\');
  86         }
  87         else
  88         {
  89             Fcb->ObjectName = Fcb->PathName.Buffer;
  90         }
  91     }
  92
  93     ExInitializeResourceLite(&Fcb->PagingIoResource);
  94     ExInitializeResourceLite(&Fcb->MainResource);
  95     ExInitializeResourceLite(&Fcb->NameListResource);
  96     Fcb->RFCB.PagingIoResource = &Fcb->PagingIoResource;
  97     Fcb->RFCB.Resource = &Fcb->MainResource;
  98     Fcb->RFCB.IsFastIoPossible = FastIoIsNotPossible;
  99     InitializeListHead(&Fcb->ShortNameList);
 100
 101     return(Fcb);
 102 }
 103
 104
 105 VOID
 106 CdfsDestroyFCB(PFCB Fcb)
 107 {
 108     PLIST_ENTRY Entry;
 109
 110     ExDeleteResourceLite(&Fcb->PagingIoResource);
 111     ExDeleteResourceLite(&Fcb->MainResource);
 112
 113     while (!IsListEmpty(&Fcb->ShortNameList))
 114     {
 115         Entry = Fcb->ShortNameList.Flink;
 116         RemoveEntryList(Entry);
 117         ExFreePoolWithTag(Entry, CDFS_SHORT_NAME_TAG);
 118     }
 119
 120     ExDeleteResourceLite(&Fcb->NameListResource);
 121     ExFreePoolWithTag(Fcb, CDFS_NONPAGED_FCB_TAG);
 122 }
 123
 124
 125 BOOLEAN
 126 CdfsFCBIsDirectory(PFCB Fcb)
 127 {
 128     return(Fcb->Entry.FileFlags & FILE_FLAG_DIRECTORY);
 129 }
 130
 131
 132 BOOLEAN
 133 CdfsFCBIsRoot(PFCB Fcb)
 134 {
 135     return (Fcb->PathName.Length == sizeof(WCHAR) && Fcb->PathName.Buffer[0] == L'\\');
 136 }
 137
 138
 139 VOID
 140 CdfsGrabFCB(PDEVICE_EXTENSION Vcb,
 141             PFCB Fcb)
 142 {
 143     KIRQL  oldIrql;
 144
 145     DPRINT("grabbing FCB at %p: %S, refCount:%d\n",
 146         Fcb,
 147         Fcb->PathName,
 148         Fcb->RefCount);
 149
 150     KeAcquireSpinLock(&Vcb->FcbListLock, &oldIrql);
 151     Fcb->RefCount++;
 152     KeReleaseSpinLock(&Vcb->FcbListLock, oldIrql);
 153 }
 154
 155
 156 VOID
 157 CdfsReleaseFCB(PDEVICE_EXTENSION Vcb,
 158                PFCB Fcb)
 159 {
 160     KIRQL  oldIrql;
 161
 162     DPRINT("releasing FCB at %p: %wZ, refCount:%d\n",
 163         Fcb,
 164         &Fcb->PathName,
 165         Fcb->RefCount);
 166
 167     KeAcquireSpinLock(&Vcb->FcbListLock, &oldIrql);
 168     Fcb->RefCount--;
 169     if (Fcb->RefCount <= 0 && !CdfsFCBIsDirectory(Fcb))
 170     {
 171         RemoveEntryList(&Fcb->FcbListEntry);
 172         CdfsDestroyFCB(Fcb);
 173     }
 174     KeReleaseSpinLock(&Vcb->FcbListLock, oldIrql);
 175 }
 176
 177
 178 VOID
 179 CdfsAddFCBToTable(PDEVICE_EXTENSION Vcb,
 180                   PFCB Fcb)
 181 {
 182     KIRQL  oldIrql;
 183
 184     KeAcquireSpinLock(&Vcb->FcbListLock, &oldIrql);
 185     Fcb->DevExt = Vcb;
 186     InsertTailList(&Vcb->FcbListHead, &Fcb->FcbListEntry);
 187     KeReleaseSpinLock(&Vcb->FcbListLock, oldIrql);
 188 }
 189
 190
 191 PFCB
 192 CdfsGrabFCBFromTable(PDEVICE_EXTENSION Vcb,
 193                      PUNICODE_STRING FileName)
 194 {
 195     KIRQL  oldIrql;
 196     PFCB Fcb;
 197     PLIST_ENTRY  current_entry;
 198
 199     KeAcquireSpinLock(&Vcb->FcbListLock, &oldIrql);
 200
 201     if (FileName == NULL || FileName->Length == 0 || FileName->Buffer[0] == 0)
 202     {
 203         DPRINT("Return FCB for stream file object\n");
 204         Fcb = Vcb->StreamFileObject->FsContext;
 205         Fcb->RefCount++;
 206         KeReleaseSpinLock(&Vcb->FcbListLock, oldIrql);
 207         return(Fcb);
 208     }
 209
 210     current_entry = Vcb->FcbListHead.Flink;
 211     while (current_entry != &Vcb->FcbListHead)
 212     {
 213         Fcb = CONTAINING_RECORD(current_entry, FCB, FcbListEntry);
 214
 215         DPRINT("Comparing '%wZ' and '%wZ'\n", FileName, &Fcb->PathName);
 216         if (RtlCompareUnicodeString(FileName, &Fcb->PathName, TRUE) == 0)
 217         {
 218             Fcb->RefCount++;
 219             KeReleaseSpinLock(&Vcb->FcbListLock, oldIrql);
 220             return(Fcb);
 221         }
 222
 223         //FIXME: need to compare against short name in FCB here
 224
 225         current_entry = current_entry->Flink;
 226     }
 227     KeReleaseSpinLock(&Vcb->FcbListLock, oldIrql);
 228
 229     return(NULL);
 230 }
 231
 232
 233 NTSTATUS
 234 CdfsFCBInitializeCache(PVCB Vcb,
 235                        PFCB Fcb)
 236 {
 237     PFILE_OBJECT FileObject;
 238     PCCB  newCCB;
 239
 240     FileObject = IoCreateStreamFileObject(NULL, Vcb->StorageDevice);
 241
 242     newCCB = ExAllocatePoolWithTag(NonPagedPool, sizeof(CCB), CDFS_CCB_TAG);
 243     if (newCCB == NULL)
 244     {
 245         return STATUS_INSUFFICIENT_RESOURCES;
 246     }
 247     RtlZeroMemory(newCCB,
 248         sizeof(CCB));
 249
 250     FileObject->ReadAccess = TRUE;
 251     FileObject->WriteAccess = FALSE;
 252     FileObject->DeleteAccess = FALSE;
 253     FileObject->SectionObjectPointer = &Fcb->SectionObjectPointers;
 254     FileObject->FsContext = Fcb;
 255     FileObject->FsContext2 = newCCB;
 256     newCCB->PtrFileObject = FileObject;
 257     Fcb->FileObject = FileObject;
 258     Fcb->DevExt = Vcb;
 259
 260     _SEH2_TRY
 261     {
 262         CcInitializeCacheMap(FileObject,
 263             (PCC_FILE_SIZES)(&Fcb->RFCB.AllocationSize),
 264             FALSE,
 265             &(CdfsGlobalData->CacheMgrCallbacks),
 266             Fcb);
 267     }
 268     _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
 269     {
 270         FileObject->FsContext2 = NULL;
 271         ExFreePoolWithTag(newCCB, CDFS_CCB_TAG);
 272         ObDereferenceObject(FileObject);
 273         Fcb->FileObject = NULL;
 274         return _SEH2_GetExceptionCode();
 275     }
 276     _SEH2_END;
 277
 278     ObDereferenceObject(FileObject);
 279     Fcb->Flags |= FCB_CACHE_INITIALIZED;
 280
 281     return STATUS_SUCCESS;
 282 }
 283
 284
 285 PFCB
 286 CdfsMakeRootFCB(PDEVICE_EXTENSION Vcb)
 287 {
 288     PFCB Fcb;
 289
 290     Fcb = CdfsCreateFCB(L"\\");
 291
 292     Fcb->Entry.DataLengthL = Vcb->CdInfo.RootSize;
 293     Fcb->Entry.ExtentLocationL = Vcb->CdInfo.RootStart;
 294     Fcb->Entry.FileFlags = FILE_FLAG_DIRECTORY;
 295     Fcb->IndexNumber.QuadPart = 0LL;
 296     Fcb->RefCount = 1;
 297     Fcb->DirIndex = 0;
 298     Fcb->RFCB.FileSize.QuadPart = Vcb->CdInfo.RootSize;
 299     Fcb->RFCB.ValidDataLength.QuadPart = Vcb->CdInfo.RootSize;
 300     Fcb->RFCB.AllocationSize.QuadPart = Vcb->CdInfo.RootSize;
 301
 302     CdfsFCBInitializeCache(Vcb, Fcb);
 303     CdfsAddFCBToTable(Vcb, Fcb);
 304     CdfsGrabFCB(Vcb, Fcb);
 305
 306     return(Fcb);
 307 }
 308
 309
 310 PFCB
 311 CdfsOpenRootFCB(PDEVICE_EXTENSION Vcb)
 312 {
 313     UNICODE_STRING FileName;
 314     PFCB Fcb;
 315
 316     RtlInitUnicodeString(&FileName, L"\\");
 317
 318     Fcb = CdfsGrabFCBFromTable(Vcb,
 319         &FileName);
 320     if (Fcb == NULL)
 321     {
 322         Fcb = CdfsMakeRootFCB(Vcb);
 323     }
 324
 325     return(Fcb);
 326 }
 327
 328
 329 NTSTATUS
 330 CdfsMakeFCBFromDirEntry(PVCB Vcb,
 331                         PFCB DirectoryFCB,
 332                         PWSTR LongName,
 333                         PWSTR ShortName,
 334                         PDIR_RECORD Record,
 335                         ULONG DirectorySector,
 336                         ULONG DirectoryOffset,
 337                         PFCB * fileFCB)
 338 {
 339     WCHAR pathName[MAX_PATH];
 340     PFCB rcFCB;
 341     ULONG Size;
 342
 343     /* Check if the full string would overflow the pathName buffer (the additional characters are for '\\' and '\0') */
 344     if ((LongName[0] != 0) &&
 345         ((DirectoryFCB->PathName.Length / sizeof(WCHAR)) + 1 + wcslen(LongName) + 1 > MAX_PATH))
 346     {
 347         return(STATUS_OBJECT_NAME_INVALID);
 348     }
 349
 350     wcscpy(pathName, DirectoryFCB->PathName.Buffer);
 351     if (!CdfsFCBIsRoot(DirectoryFCB))
 352     {
 353         wcscat(pathName, L"\\");
 354     }
 355
 356     if (LongName[0] != 0)
 357     {
 358         wcscat(pathName, LongName);
 359     }
 360     else
 361     {
 362         WCHAR entryName[MAX_PATH];
 363
 364         CdfsGetDirEntryName(Vcb, Record, entryName);
 365         wcscat(pathName, entryName);
 366     }
 367
 368     rcFCB = CdfsCreateFCB(pathName);
 369     memcpy(&rcFCB->Entry, Record, sizeof(DIR_RECORD));
 370
 371     /* Copy short name into FCB */
 372     rcFCB->ShortNameU.Length = wcslen(ShortName) * sizeof(WCHAR);
 373     rcFCB->ShortNameU.MaximumLength = rcFCB->ShortNameU.Length;
 374     rcFCB->ShortNameU.Buffer = rcFCB->ShortNameBuffer;
 375     wcscpy(rcFCB->ShortNameBuffer, ShortName);
 376
 377     Size = rcFCB->Entry.DataLengthL;
 378
 379     rcFCB->RFCB.FileSize.QuadPart = Size;
 380     rcFCB->RFCB.ValidDataLength.QuadPart = Size;
 381     rcFCB->RFCB.AllocationSize.QuadPart = ROUND_UP(Size, BLOCKSIZE);
 382     if (CdfsFCBIsDirectory(rcFCB))
 383     {
 384         CdfsFCBInitializeCache(Vcb, rcFCB);
 385     }
 386     rcFCB->IndexNumber.u.HighPart = DirectorySector;
 387     rcFCB->IndexNumber.u.LowPart = DirectoryOffset;
 388     rcFCB->RefCount++;
 389     CdfsAddFCBToTable(Vcb, rcFCB);
 390     *fileFCB = rcFCB;
 391
 392     DPRINT("%S %u %I64d\n", LongName, Size, rcFCB->RFCB.AllocationSize.QuadPart);
 393
 394     return(STATUS_SUCCESS);
 395 }
 396
 397
 398 NTSTATUS
 399 CdfsAttachFCBToFileObject(PDEVICE_EXTENSION Vcb,
 400                           PFCB Fcb,
 401                           PFILE_OBJECT FileObject)
 402 {
 403     PCCB  newCCB;
 404
 405     newCCB = ExAllocatePoolWithTag(NonPagedPool, sizeof(CCB), CDFS_CCB_TAG);
 406     if (newCCB == NULL)
 407     {
 408         return(STATUS_INSUFFICIENT_RESOURCES);
 409     }
 410     memset(newCCB, 0, sizeof(CCB));
 411
 412     FileObject->ReadAccess = TRUE;
 413     FileObject->WriteAccess = FALSE;
 414     FileObject->DeleteAccess = FALSE;
 415     FileObject->SectionObjectPointer = &Fcb->SectionObjectPointers;
 416     FileObject->FsContext = Fcb;
 417     FileObject->FsContext2 = newCCB;
 418     newCCB->PtrFileObject = FileObject;
 419     Fcb->DevExt = Vcb;
 420
 421     if (CdfsFCBIsDirectory(Fcb))
 422     {
 423         _SEH2_TRY
 424         {
 425             CcInitializeCacheMap(FileObject,
 426                 (PCC_FILE_SIZES)(&Fcb->RFCB.AllocationSize),
 427                 FALSE,
 428                 &(CdfsGlobalData->CacheMgrCallbacks),
 429                 Fcb);
 430         }
 431         _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
 432         {
 433             FileObject->FsContext2 = NULL;
 434             ExFreePoolWithTag(newCCB, CDFS_CCB_TAG);
 435             return _SEH2_GetExceptionCode();
 436         }
 437         _SEH2_END;
 438         Fcb->Flags |= FCB_CACHE_INITIALIZED;
 439     }
 440
 441     DPRINT("file open: fcb:%p file size: %u\n", Fcb, Fcb->Entry.DataLengthL);
 442
 443     return(STATUS_SUCCESS);
 444 }
 445
 446
 447 NTSTATUS
 448 CdfsDirFindFile(PDEVICE_EXTENSION DeviceExt,
 449                 PFCB DirectoryFcb,
 450                 PUNICODE_STRING FileToFind,
 451                 PFCB *FoundFCB)
 452 {
 453     UNICODE_STRING TempName;
 454     WCHAR Name[256];
 455     PVOID Block;
 456     ULONG DirSize;
 457     PDIR_RECORD Record;
 458     ULONG Offset;
 459     ULONG BlockOffset;
 460     NTSTATUS Status;
 461
 462     LARGE_INTEGER StreamOffset, OffsetOfEntry;
 463     PVOID Context;
 464
 465     WCHAR ShortNameBuffer[13];
 466     UNICODE_STRING ShortName;
 467     UNICODE_STRING LongName;
 468     UNICODE_STRING FileToFindUpcase;
 469
 470     ASSERT(DeviceExt);
 471     ASSERT(DirectoryFcb);
 472     ASSERT(FileToFind);
 473
 474     DPRINT("CdfsDirFindFile(VCB:%p, dirFCB:%p, File:%wZ)\n",
 475         DeviceExt,
 476         DirectoryFcb,
 477         FileToFind);
 478     DPRINT("Dir Path:%wZ\n", &DirectoryFcb->PathName);
 479
 480     /* default to '.' if no filename specified */
 481     if (FileToFind->Length == 0)
 482     {
 483         RtlInitUnicodeString(&TempName, L".");
 484         FileToFind = &TempName;
 485     }
 486
 487     DirSize = DirectoryFcb->Entry.DataLengthL;
 488     StreamOffset.QuadPart = (LONGLONG)DirectoryFcb->Entry.ExtentLocationL * (LONGLONG)BLOCKSIZE;
 489
 490     if (!CcMapData(DeviceExt->StreamFileObject,
 491         &StreamOffset,
 492         BLOCKSIZE,
 493         TRUE,
 494         &Context,
 495         &Block))
 496     {
 497         DPRINT("CcMapData() failed\n");
 498         return STATUS_UNSUCCESSFUL;
 499     }
 500
 501     Offset = 0;
 502     BlockOffset = 0;
 503     Record = (PDIR_RECORD)Block;
 504
 505     /* Upper case the expression for FsRtlIsNameInExpression */
 506     Status = RtlUpcaseUnicodeString(&FileToFindUpcase, FileToFind, TRUE);
 507     if (!NT_SUCCESS(Status))
 508     {
 509         return Status;
 510     }
 511
 512     while(TRUE)
 513     {
 514         if (Record->RecordLength == 0)
 515         {
 516             DPRINT("RecordLength == 0  Stopped!\n");
 517             break;
 518         }
 519
 520         DPRINT("RecordLength %u  ExtAttrRecordLength %u  NameLength %u\n",
 521             Record->RecordLength, Record->ExtAttrRecordLength, Record->FileIdLength);
 522
 523         if (!CdfsIsRecordValid(DeviceExt, Record))
 524         {
 525             RtlFreeUnicodeString(&FileToFindUpcase);
 526             CcUnpinData(Context);
 527             return STATUS_DISK_CORRUPT_ERROR;
 528         }
 529
 530         CdfsGetDirEntryName(DeviceExt, Record, Name);
 531         DPRINT ("Name '%S'\n", Name);
 532         DPRINT ("Sector %lu\n", DirectoryFcb->Entry.ExtentLocationL);
 533         DPRINT ("Offset %lu\n", Offset);
 534
 535         RtlInitUnicodeString(&LongName, Name);
 536         RtlInitEmptyUnicodeString(&ShortName, ShortNameBuffer, sizeof(ShortNameBuffer));
 537         RtlZeroMemory(ShortNameBuffer, sizeof(ShortNameBuffer));
 538
 539         OffsetOfEntry.QuadPart = StreamOffset.QuadPart + Offset;
 540         CdfsShortNameCacheGet(DirectoryFcb, &OffsetOfEntry, &LongName, &ShortName);
 541
 542         DPRINT("ShortName '%wZ'\n", &ShortName);
 543
 544         ASSERT(LongName.Length >= sizeof(WCHAR));
 545         ASSERT(ShortName.Length >= sizeof(WCHAR));
 546         if (FsRtlIsNameInExpression(&FileToFindUpcase, &LongName, TRUE, NULL) ||
 547             FsRtlIsNameInExpression(&FileToFindUpcase, &ShortName, TRUE, NULL))
 548         {
 549             DPRINT("Match found, %S\n", Name);
 550             Status = CdfsMakeFCBFromDirEntry(DeviceExt,
 551                 DirectoryFcb,
 552                 Name,
 553                 ShortNameBuffer,
 554                 Record,
 555                 DirectoryFcb->Entry.ExtentLocationL,
 556                 Offset,
 557                 FoundFCB);
 558
 559             RtlFreeUnicodeString(&FileToFindUpcase);
 560             CcUnpinData(Context);
 561
 562             return(Status);
 563         }
 564
 565         Offset += Record->RecordLength;
 566         BlockOffset += Record->RecordLength;
 567         Record = (PDIR_RECORD)((ULONG_PTR)Block + BlockOffset);
 568         if (BlockOffset >= BLOCKSIZE || Record->RecordLength == 0)
 569         {
 570             DPRINT("Map next sector\n");
 571             CcUnpinData(Context);
 572             StreamOffset.QuadPart += BLOCKSIZE;
 573             Offset = ROUND_UP(Offset, BLOCKSIZE);
 574             BlockOffset = 0;
 575
 576             if (!CcMapData(DeviceExt->StreamFileObject,
 577                 &StreamOffset,
 578                 BLOCKSIZE, TRUE,
 579                 &Context, &Block))
 580             {
 581                 DPRINT("CcMapData() failed\n");
 582                 RtlFreeUnicodeString(&FileToFindUpcase);
 583                 return(STATUS_UNSUCCESSFUL);
 584             }
 585             Record = (PDIR_RECORD)((ULONG_PTR)Block + BlockOffset);
 586         }
 587
 588         if (Offset >= DirSize)
 589             break;
 590     }
 591
 592     RtlFreeUnicodeString(&FileToFindUpcase);
 593     CcUnpinData(Context);
 594
 595     return(STATUS_OBJECT_NAME_NOT_FOUND);
 596 }
 597
 598
 599 NTSTATUS
 600 CdfsGetFCBForFile(PDEVICE_EXTENSION Vcb,
 601                   PFCB *pParentFCB,
 602                   PFCB *pFCB,
 603                   PUNICODE_STRING FileName)
 604 {
 605     UNICODE_STRING PathName;
 606     UNICODE_STRING ElementName;
 607     NTSTATUS Status;
 608     WCHAR  pathName [MAX_PATH];
 609     WCHAR  elementName [MAX_PATH];
 610     PWCHAR  currentElement;
 611     PFCB  FCB;
 612     PFCB  parentFCB;
 613
 614     DPRINT("CdfsGetFCBForFile(%p, %p, %p, '%wZ')\n",
 615         Vcb,
 616         pParentFCB,
 617         pFCB,
 618         FileName);
 619
 620     /* Trivial case, open of the root directory on volume */
 621     if (FileName->Buffer[0] == L'\0' || wcscmp(FileName->Buffer, L"\\") == 0)
 622     {
 623         DPRINT("returning root FCB\n");
 624
 625         FCB = CdfsOpenRootFCB(Vcb);
 626         *pFCB = FCB;
 627         *pParentFCB = NULL;
 628
 629         return((FCB != NULL) ? STATUS_SUCCESS : STATUS_OBJECT_PATH_NOT_FOUND);
 630     }
 631     else
 632     {
 633         currentElement = &FileName->Buffer[1];
 634         wcscpy (pathName, L"\\");
 635         FCB = CdfsOpenRootFCB (Vcb);
 636     }
 637     parentFCB = NULL;
 638
 639     /* Parse filename and check each path element for existance and access */
 640     while (CdfsGetNextPathElement(currentElement) != 0)
 641     {
 642         /*  Skip blank directory levels */
 643         if ((CdfsGetNextPathElement(currentElement) - currentElement) == 0)
 644         {
 645             currentElement++;
 646             continue;
 647         }
 648
 649         DPRINT("Parsing, currentElement:%S\n", currentElement);
 650         DPRINT("  parentFCB:%p FCB:%p\n", parentFCB, FCB);
 651
 652         /* Descend to next directory level */
 653         if (parentFCB)
 654         {
 655             CdfsReleaseFCB(Vcb, parentFCB);
 656             parentFCB = NULL;
 657         }
 658
 659         /* fail if element in FCB is not a directory */
 660         if (!CdfsFCBIsDirectory(FCB))
 661         {
 662             DPRINT("Element in requested path is not a directory\n");
 663
 664             CdfsReleaseFCB(Vcb, FCB);
 665             FCB = 0;
 666             *pParentFCB = NULL;
 667             *pFCB = NULL;
 668
 669             return(STATUS_OBJECT_PATH_NOT_FOUND);
 670         }
 671         parentFCB = FCB;
 672
 673         /* Extract next directory level into dirName */
 674         CdfsWSubString(pathName,
 675             FileName->Buffer,
 676             CdfsGetNextPathElement(currentElement) - FileName->Buffer);
 677         DPRINT("  pathName:%S\n", pathName);
 678
 679         RtlInitUnicodeString(&PathName, pathName);
 680
 681         FCB = CdfsGrabFCBFromTable(Vcb, &PathName);
 682         if (FCB == NULL)
 683         {
 684             CdfsWSubString(elementName,
 685                 currentElement,
 686                 CdfsGetNextPathElement(currentElement) - currentElement);
 687             DPRINT("  elementName:%S\n", elementName);
 688
 689             RtlInitUnicodeString(&ElementName, elementName);
 690             Status = CdfsDirFindFile(Vcb,
 691                 parentFCB,
 692                 &ElementName,
 693                 &FCB);
 694             if (Status == STATUS_OBJECT_NAME_NOT_FOUND)
 695             {
 696                 *pParentFCB = parentFCB;
 697                 *pFCB = NULL;
 698                 currentElement = CdfsGetNextPathElement(currentElement);
 699                 if (*currentElement == L'\0' || CdfsGetNextPathElement(currentElement + 1) == 0)
 700                 {
 701                     return(STATUS_OBJECT_NAME_NOT_FOUND);
 702                 }
 703                 else
 704                 {
 705                     return(STATUS_OBJECT_PATH_NOT_FOUND);
 706                 }
 707             }
 708             else if (!NT_SUCCESS(Status))
 709             {
 710                 CdfsReleaseFCB(Vcb, parentFCB);
 711                 *pParentFCB = NULL;
 712                 *pFCB = NULL;
 713
 714                 return(Status);
 715             }
 716         }
 717         currentElement = CdfsGetNextPathElement(currentElement);
 718     }
 719
 720     *pParentFCB = parentFCB;
 721     *pFCB = FCB;
 722
 723     return STATUS_SUCCESS;
 724 }
 725
 726 /* EOF */