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:             services/fs/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, sizeof(FCB), TAG_FCB);
  73     if(!Fcb) return NULL;
  74
  75     RtlZeroMemory(Fcb, sizeof(FCB));
  76     RtlInitEmptyUnicodeString(&Fcb->PathName, Fcb->PathNameBuffer, sizeof(Fcb->PathNameBuffer));
  77
  78     if (FileName)
  79     {
  80         RtlAppendUnicodeToString(&Fcb->PathName, FileName);
  81         if (wcsrchr(Fcb->PathName.Buffer, '\\') != 0)
  82         {
  83             Fcb->ObjectName = wcsrchr(Fcb->PathName.Buffer, '\\');
  84         }
  85         else
  86         {
  87             Fcb->ObjectName = Fcb->PathName.Buffer;
  88         }
  89     }
  90
  91     ExInitializeResourceLite(&Fcb->PagingIoResource);
  92     ExInitializeResourceLite(&Fcb->MainResource);
  93     ExInitializeResourceLite(&Fcb->NameListResource);
  94     Fcb->RFCB.PagingIoResource = &Fcb->PagingIoResource;
  95     Fcb->RFCB.Resource = &Fcb->MainResource;
  96     Fcb->RFCB.IsFastIoPossible = FastIoIsNotPossible;
  97     InitializeListHead(&Fcb->ShortNameList);
  98
  99     return(Fcb);
 100 }
 101
 102
 103 VOID
 104 CdfsDestroyFCB(PFCB Fcb)
 105 {
 106     PLIST_ENTRY Entry;
 107
 108     ExDeleteResourceLite(&Fcb->PagingIoResource);
 109     ExDeleteResourceLite(&Fcb->MainResource);
 110
 111     while (!IsListEmpty(&Fcb->ShortNameList))
 112     {
 113         Entry = Fcb->ShortNameList.Flink;
 114         RemoveEntryList(Entry);
 115         ExFreePoolWithTag(Entry, TAG_FCB);
 116     }
 117
 118     ExDeleteResourceLite(&Fcb->NameListResource);
 119     ExFreePoolWithTag(Fcb, TAG_FCB);
 120 }
 121
 122
 123 BOOLEAN
 124 CdfsFCBIsDirectory(PFCB Fcb)
 125 {
 126     return(Fcb->Entry.FileFlags & FILE_FLAG_DIRECTORY);
 127 }
 128
 129
 130 BOOLEAN
 131 CdfsFCBIsRoot(PFCB Fcb)
 132 {
 133     return (Fcb->PathName.Length == sizeof(WCHAR) && Fcb->PathName.Buffer[0] == L'\\');
 134 }
 135
 136
 137 VOID
 138 CdfsGrabFCB(PDEVICE_EXTENSION Vcb,
 139             PFCB Fcb)
 140 {
 141     KIRQL  oldIrql;
 142
 143     DPRINT("grabbing FCB at %p: %S, refCount:%d\n",
 144         Fcb,
 145         Fcb->PathName,
 146         Fcb->RefCount);
 147
 148     KeAcquireSpinLock(&Vcb->FcbListLock, &oldIrql);
 149     Fcb->RefCount++;
 150     KeReleaseSpinLock(&Vcb->FcbListLock, oldIrql);
 151 }
 152
 153
 154 VOID
 155 CdfsReleaseFCB(PDEVICE_EXTENSION Vcb,
 156                PFCB Fcb)
 157 {
 158     KIRQL  oldIrql;
 159
 160     DPRINT("releasing FCB at %p: %wZ, refCount:%d\n",
 161         Fcb,
 162         &Fcb->PathName,
 163         Fcb->RefCount);
 164
 165     KeAcquireSpinLock(&Vcb->FcbListLock, &oldIrql);
 166     Fcb->RefCount--;
 167     if (Fcb->RefCount <= 0 && !CdfsFCBIsDirectory(Fcb))
 168     {
 169         RemoveEntryList(&Fcb->FcbListEntry);
 170         CdfsDestroyFCB(Fcb);
 171     }
 172     KeReleaseSpinLock(&Vcb->FcbListLock, oldIrql);
 173 }
 174
 175
 176 VOID
 177 CdfsAddFCBToTable(PDEVICE_EXTENSION Vcb,
 178                   PFCB Fcb)
 179 {
 180     KIRQL  oldIrql;
 181
 182     KeAcquireSpinLock(&Vcb->FcbListLock, &oldIrql);
 183     Fcb->DevExt = Vcb;
 184     InsertTailList(&Vcb->FcbListHead, &Fcb->FcbListEntry);
 185     KeReleaseSpinLock(&Vcb->FcbListLock, oldIrql);
 186 }
 187
 188
 189 PFCB
 190 CdfsGrabFCBFromTable(PDEVICE_EXTENSION Vcb,
 191                      PUNICODE_STRING FileName)
 192 {
 193     KIRQL  oldIrql;
 194     PFCB Fcb;
 195     PLIST_ENTRY  current_entry;
 196
 197     KeAcquireSpinLock(&Vcb->FcbListLock, &oldIrql);
 198
 199     if (FileName == NULL || FileName->Length == 0 || FileName->Buffer[0] == 0)
 200     {
 201         DPRINT("Return FCB for stream file object\n");
 202         Fcb = Vcb->StreamFileObject->FsContext;
 203         Fcb->RefCount++;
 204         KeReleaseSpinLock(&Vcb->FcbListLock, oldIrql);
 205         return(Fcb);
 206     }
 207
 208     current_entry = Vcb->FcbListHead.Flink;
 209     while (current_entry != &Vcb->FcbListHead)
 210     {
 211         Fcb = CONTAINING_RECORD(current_entry, FCB, FcbListEntry);
 212
 213         DPRINT("Comparing '%wZ' and '%wZ'\n", FileName, &Fcb->PathName);
 214         if (RtlCompareUnicodeString(FileName, &Fcb->PathName, TRUE) == 0)
 215         {
 216             Fcb->RefCount++;
 217             KeReleaseSpinLock(&Vcb->FcbListLock, oldIrql);
 218             return(Fcb);
 219         }
 220
 221         //FIXME: need to compare against short name in FCB here
 222
 223         current_entry = current_entry->Flink;
 224     }
 225     KeReleaseSpinLock(&Vcb->FcbListLock, oldIrql);
 226
 227     return(NULL);
 228 }
 229
 230
 231 NTSTATUS
 232 CdfsFCBInitializeCache(PVCB Vcb,
 233                        PFCB Fcb)
 234 {
 235     PFILE_OBJECT FileObject;
 236     PCCB  newCCB;
 237
 238     FileObject = IoCreateStreamFileObject(NULL, Vcb->StorageDevice);
 239
 240     newCCB = ExAllocatePoolWithTag(NonPagedPool, sizeof(CCB), TAG_CCB);
 241     if (newCCB == NULL)
 242     {
 243         return STATUS_INSUFFICIENT_RESOURCES;
 244     }
 245     RtlZeroMemory(newCCB,
 246         sizeof(CCB));
 247
 248     FileObject->ReadAccess = TRUE;
 249     FileObject->WriteAccess = FALSE;
 250     FileObject->DeleteAccess = FALSE;
 251     FileObject->SectionObjectPointer = &Fcb->SectionObjectPointers;
 252     FileObject->FsContext = Fcb;
 253     FileObject->FsContext2 = newCCB;
 254     newCCB->PtrFileObject = FileObject;
 255     Fcb->FileObject = FileObject;
 256     Fcb->DevExt = Vcb;
 257
 258     CcInitializeCacheMap(FileObject,
 259         (PCC_FILE_SIZES)(&Fcb->RFCB.AllocationSize),
 260         FALSE,
 261         &(CdfsGlobalData->CacheMgrCallbacks),
 262         Fcb);
 263
 264     ObDereferenceObject(FileObject);
 265     Fcb->Flags |= FCB_CACHE_INITIALIZED;
 266
 267     return STATUS_SUCCESS;
 268 }
 269
 270
 271 PFCB
 272 CdfsMakeRootFCB(PDEVICE_EXTENSION Vcb)
 273 {
 274     PFCB Fcb;
 275
 276     Fcb = CdfsCreateFCB(L"\\");
 277
 278     Fcb->Entry.DataLengthL = Vcb->CdInfo.RootSize;
 279     Fcb->Entry.ExtentLocationL = Vcb->CdInfo.RootStart;
 280     Fcb->Entry.FileFlags = FILE_FLAG_DIRECTORY;
 281     Fcb->IndexNumber.QuadPart = 0LL;
 282     Fcb->RefCount = 1;
 283     Fcb->DirIndex = 0;
 284     Fcb->RFCB.FileSize.QuadPart = Vcb->CdInfo.RootSize;
 285     Fcb->RFCB.ValidDataLength.QuadPart = Vcb->CdInfo.RootSize;
 286     Fcb->RFCB.AllocationSize.QuadPart = Vcb->CdInfo.RootSize;
 287
 288     CdfsFCBInitializeCache(Vcb, Fcb);
 289     CdfsAddFCBToTable(Vcb, Fcb);
 290     CdfsGrabFCB(Vcb, Fcb);
 291
 292     return(Fcb);
 293 }
 294
 295
 296 PFCB
 297 CdfsOpenRootFCB(PDEVICE_EXTENSION Vcb)
 298 {
 299     UNICODE_STRING FileName;
 300     PFCB Fcb;
 301
 302     RtlInitUnicodeString(&FileName, L"\\");
 303
 304     Fcb = CdfsGrabFCBFromTable(Vcb,
 305         &FileName);
 306     if (Fcb == NULL)
 307     {
 308         Fcb = CdfsMakeRootFCB(Vcb);
 309     }
 310
 311     return(Fcb);
 312 }
 313
 314
 315 static VOID
 316 CdfsGetDirEntryName(PDEVICE_EXTENSION DeviceExt,
 317                     PDIR_RECORD Record,
 318                     PWSTR Name)
 319                     /*
 320                     * FUNCTION: Retrieves the file name from a directory record.
 321                     */
 322 {
 323     if (Record->FileIdLength == 1 && Record->FileId[0] == 0)
 324     {
 325         wcscpy(Name, L".");
 326     }
 327     else if (Record->FileIdLength == 1 && Record->FileId[0] == 1)
 328     {
 329         wcscpy(Name, L"..");
 330     }
 331     else
 332     {
 333         if (DeviceExt->CdInfo.JolietLevel == 0)
 334         {
 335             ULONG i;
 336
 337             for (i = 0; i < Record->FileIdLength && Record->FileId[i] != ';'; i++)
 338                 Name[i] = (WCHAR)Record->FileId[i];
 339             Name[i] = 0;
 340         }
 341         else
 342         {
 343             CdfsSwapString(Name,
 344                 Record->FileId,
 345                 Record->FileIdLength);
 346         }
 347     }
 348
 349     DPRINT("Name '%S'\n", Name);
 350 }
 351
 352
 353 NTSTATUS
 354 CdfsMakeFCBFromDirEntry(PVCB Vcb,
 355                         PFCB DirectoryFCB,
 356                         PWSTR LongName,
 357                         PWSTR ShortName,
 358                         PDIR_RECORD Record,
 359                         ULONG DirectorySector,
 360                         ULONG DirectoryOffset,
 361                         PFCB * fileFCB)
 362 {
 363     WCHAR pathName[MAX_PATH];
 364     PFCB rcFCB;
 365     ULONG Size;
 366
 367     /* Check if the full string would overflow the pathName buffer (the additional characters are for '\\' and '\0') */
 368     if ((LongName[0] != 0) &&
 369         ((DirectoryFCB->PathName.Length / sizeof(WCHAR)) + 1 + wcslen(LongName) + 1 > MAX_PATH))
 370     {
 371         return(STATUS_OBJECT_NAME_INVALID);
 372     }
 373
 374     wcscpy(pathName, DirectoryFCB->PathName.Buffer);
 375     if (!CdfsFCBIsRoot(DirectoryFCB))
 376     {
 377         wcscat(pathName, L"\\");
 378     }
 379
 380     if (LongName[0] != 0)
 381     {
 382         wcscat(pathName, LongName);
 383     }
 384     else
 385     {
 386         WCHAR entryName[MAX_PATH];
 387
 388         CdfsGetDirEntryName(Vcb, Record, entryName);
 389         wcscat(pathName, entryName);
 390     }
 391
 392     rcFCB = CdfsCreateFCB(pathName);
 393     memcpy(&rcFCB->Entry, Record, sizeof(DIR_RECORD));
 394
 395     /* Copy short name into FCB */
 396     rcFCB->ShortNameU.Length = wcslen(ShortName) * sizeof(WCHAR);
 397     rcFCB->ShortNameU.MaximumLength = rcFCB->ShortNameU.Length;
 398     rcFCB->ShortNameU.Buffer = rcFCB->ShortNameBuffer;
 399     wcscpy(rcFCB->ShortNameBuffer, ShortName);
 400
 401     Size = rcFCB->Entry.DataLengthL;
 402
 403     rcFCB->RFCB.FileSize.QuadPart = Size;
 404     rcFCB->RFCB.ValidDataLength.QuadPart = Size;
 405     rcFCB->RFCB.AllocationSize.QuadPart = ROUND_UP(Size, BLOCKSIZE);
 406     if (CdfsFCBIsDirectory(rcFCB))
 407     {
 408         CdfsFCBInitializeCache(Vcb, rcFCB);
 409     }
 410     rcFCB->IndexNumber.u.HighPart = DirectorySector;
 411     rcFCB->IndexNumber.u.LowPart = DirectoryOffset;
 412     rcFCB->RefCount++;
 413     CdfsAddFCBToTable(Vcb, rcFCB);
 414     *fileFCB = rcFCB;
 415
 416     DPRINT("%S %u %I64d\n", LongName, Size, rcFCB->RFCB.AllocationSize.QuadPart);
 417
 418     return(STATUS_SUCCESS);
 419 }
 420
 421
 422 NTSTATUS
 423 CdfsAttachFCBToFileObject(PDEVICE_EXTENSION Vcb,
 424                           PFCB Fcb,
 425                           PFILE_OBJECT FileObject)
 426 {
 427     PCCB  newCCB;
 428
 429     newCCB = ExAllocatePoolWithTag(NonPagedPool, sizeof(CCB), TAG_CCB);
 430     if (newCCB == NULL)
 431     {
 432         return(STATUS_INSUFFICIENT_RESOURCES);
 433     }
 434     memset(newCCB, 0, sizeof(CCB));
 435
 436     FileObject->ReadAccess = TRUE;
 437     FileObject->WriteAccess = FALSE;
 438     FileObject->DeleteAccess = FALSE;
 439     FileObject->SectionObjectPointer = &Fcb->SectionObjectPointers;
 440     FileObject->FsContext = Fcb;
 441     FileObject->FsContext2 = newCCB;
 442     newCCB->PtrFileObject = FileObject;
 443     Fcb->DevExt = Vcb;
 444
 445     if (CdfsFCBIsDirectory(Fcb))
 446     {
 447         CcInitializeCacheMap(FileObject,
 448             (PCC_FILE_SIZES)(&Fcb->RFCB.AllocationSize),
 449             FALSE,
 450             &(CdfsGlobalData->CacheMgrCallbacks),
 451             Fcb);
 452         Fcb->Flags |= FCB_CACHE_INITIALIZED;
 453     }
 454
 455     DPRINT("file open: fcb:%p file size: %u\n", Fcb, Fcb->Entry.DataLengthL);
 456
 457     return(STATUS_SUCCESS);
 458 }
 459
 460
 461 NTSTATUS
 462 CdfsDirFindFile(PDEVICE_EXTENSION DeviceExt,
 463                 PFCB DirectoryFcb,
 464                 PUNICODE_STRING FileToFind,
 465                 PFCB *FoundFCB)
 466 {
 467     UNICODE_STRING TempName;
 468     WCHAR Name[256];
 469     PVOID Block;
 470     ULONG DirSize;
 471     PDIR_RECORD Record;
 472     ULONG Offset;
 473     ULONG BlockOffset;
 474     NTSTATUS Status;
 475
 476     LARGE_INTEGER StreamOffset, OffsetOfEntry;
 477     PVOID Context;
 478
 479     WCHAR ShortNameBuffer[13];
 480     UNICODE_STRING ShortName;
 481     UNICODE_STRING LongName;
 482     UNICODE_STRING FileToFindUpcase;
 483
 484     ASSERT(DeviceExt);
 485     ASSERT(DirectoryFcb);
 486     ASSERT(FileToFind);
 487
 488     DPRINT("CdfsDirFindFile(VCB:%p, dirFCB:%p, File:%wZ)\n",
 489         DeviceExt,
 490         DirectoryFcb,
 491         FileToFind);
 492     DPRINT("Dir Path:%wZ\n", &DirectoryFcb->PathName);
 493
 494     /* default to '.' if no filename specified */
 495     if (FileToFind->Length == 0)
 496     {
 497         RtlInitUnicodeString(&TempName, L".");
 498         FileToFind = &TempName;
 499     }
 500
 501     DirSize = DirectoryFcb->Entry.DataLengthL;
 502     StreamOffset.QuadPart = (LONGLONG)DirectoryFcb->Entry.ExtentLocationL * (LONGLONG)BLOCKSIZE;
 503
 504     if (!CcMapData(DeviceExt->StreamFileObject,
 505         &StreamOffset,
 506         BLOCKSIZE,
 507         TRUE,
 508         &Context,
 509         &Block))
 510     {
 511         DPRINT("CcMapData() failed\n");
 512         return STATUS_UNSUCCESSFUL;
 513     }
 514
 515     Offset = 0;
 516     BlockOffset = 0;
 517     Record = (PDIR_RECORD)Block;
 518
 519     /* Upper case the expression for FsRtlIsNameInExpression */
 520     Status = RtlUpcaseUnicodeString(&FileToFindUpcase, FileToFind, TRUE);
 521     if (!NT_SUCCESS(Status))
 522     {
 523         return Status;
 524     }
 525
 526     while(TRUE)
 527     {
 528         if (Record->RecordLength == 0)
 529         {
 530             DPRINT("RecordLength == 0  Stopped!\n");
 531             break;
 532         }
 533
 534         DPRINT("RecordLength %u  ExtAttrRecordLength %u  NameLength %u\n",
 535             Record->RecordLength, Record->ExtAttrRecordLength, Record->FileIdLength);
 536
 537         CdfsGetDirEntryName(DeviceExt, Record, Name);
 538         DPRINT ("Name '%S'\n", Name);
 539         DPRINT ("Sector %lu\n", DirectoryFcb->Entry.ExtentLocationL);
 540         DPRINT ("Offset %lu\n", Offset);
 541
 542         RtlInitUnicodeString(&LongName, Name);
 543         ShortName.Length = 0;
 544         ShortName.MaximumLength = 26;
 545         ShortName.Buffer = ShortNameBuffer;
 546         memset(ShortNameBuffer, 0, 26);
 547
 548         OffsetOfEntry.QuadPart = StreamOffset.QuadPart + Offset;
 549         CdfsShortNameCacheGet(DirectoryFcb, &OffsetOfEntry, &LongName, &ShortName);
 550
 551         DPRINT("ShortName '%wZ'\n", &ShortName);
 552
 553         if (FsRtlIsNameInExpression(&FileToFindUpcase, &LongName, TRUE, NULL) ||
 554             FsRtlIsNameInExpression(&FileToFindUpcase, &ShortName, TRUE, NULL))
 555         {
 556             DPRINT("Match found, %S\n", Name);
 557             Status = CdfsMakeFCBFromDirEntry(DeviceExt,
 558                 DirectoryFcb,
 559                 Name,
 560                 ShortNameBuffer,
 561                 Record,
 562                 DirectoryFcb->Entry.ExtentLocationL,
 563                 Offset,
 564                 FoundFCB);
 565
 566             RtlFreeUnicodeString(&FileToFindUpcase);
 567             CcUnpinData(Context);
 568
 569             return(Status);
 570         }
 571
 572         Offset += Record->RecordLength;
 573         BlockOffset += Record->RecordLength;
 574         Record = (PDIR_RECORD)((ULONG_PTR)Block + BlockOffset);
 575         if (BlockOffset >= BLOCKSIZE || Record->RecordLength == 0)
 576         {
 577             DPRINT("Map next sector\n");
 578             CcUnpinData(Context);
 579             StreamOffset.QuadPart += BLOCKSIZE;
 580             Offset = ROUND_UP(Offset, BLOCKSIZE);
 581             BlockOffset = 0;
 582
 583             if (!CcMapData(DeviceExt->StreamFileObject,
 584                 &StreamOffset,
 585                 BLOCKSIZE, TRUE,
 586                 &Context, &Block))
 587             {
 588                 DPRINT("CcMapData() failed\n");
 589                 RtlFreeUnicodeString(&FileToFindUpcase);
 590                 return(STATUS_UNSUCCESSFUL);
 591             }
 592             Record = (PDIR_RECORD)((ULONG_PTR)Block + BlockOffset);
 593         }
 594
 595         if (Offset >= DirSize)
 596             break;
 597     }
 598
 599     RtlFreeUnicodeString(&FileToFindUpcase);
 600     CcUnpinData(Context);
 601
 602     return(STATUS_OBJECT_NAME_NOT_FOUND);
 603 }
 604
 605
 606 NTSTATUS
 607 CdfsGetFCBForFile(PDEVICE_EXTENSION Vcb,
 608                   PFCB *pParentFCB,
 609                   PFCB *pFCB,
 610                   PUNICODE_STRING FileName)
 611 {
 612     UNICODE_STRING PathName;
 613     UNICODE_STRING ElementName;
 614     NTSTATUS Status;
 615     WCHAR  pathName [MAX_PATH];
 616     WCHAR  elementName [MAX_PATH];
 617     PWCHAR  currentElement;
 618     PFCB  FCB;
 619     PFCB  parentFCB;
 620
 621     DPRINT("CdfsGetFCBForFile(%p, %p, %p, '%wZ')\n",
 622         Vcb,
 623         pParentFCB,
 624         pFCB,
 625         FileName);
 626
 627     /* Trivial case, open of the root directory on volume */
 628     if (FileName->Buffer[0] == L'\0' || wcscmp(FileName->Buffer, L"\\") == 0)
 629     {
 630         DPRINT("returning root FCB\n");
 631
 632         FCB = CdfsOpenRootFCB(Vcb);
 633         *pFCB = FCB;
 634         *pParentFCB = NULL;
 635
 636         return((FCB != NULL) ? STATUS_SUCCESS : STATUS_OBJECT_PATH_NOT_FOUND);
 637     }
 638     else
 639     {
 640         currentElement = &FileName->Buffer[1];
 641         wcscpy (pathName, L"\\");
 642         FCB = CdfsOpenRootFCB (Vcb);
 643     }
 644     parentFCB = NULL;
 645
 646     /* Parse filename and check each path element for existance and access */
 647     while (CdfsGetNextPathElement(currentElement) != 0)
 648     {
 649         /*  Skip blank directory levels */
 650         if ((CdfsGetNextPathElement(currentElement) - currentElement) == 0)
 651         {
 652             currentElement++;
 653             continue;
 654         }
 655
 656         DPRINT("Parsing, currentElement:%S\n", currentElement);
 657         DPRINT("  parentFCB:%p FCB:%p\n", parentFCB, FCB);
 658
 659         /* Descend to next directory level */
 660         if (parentFCB)
 661         {
 662             CdfsReleaseFCB(Vcb, parentFCB);
 663             parentFCB = NULL;
 664         }
 665
 666         /* fail if element in FCB is not a directory */
 667         if (!CdfsFCBIsDirectory(FCB))
 668         {
 669             DPRINT("Element in requested path is not a directory\n");
 670
 671             CdfsReleaseFCB(Vcb, FCB);
 672             FCB = 0;
 673             *pParentFCB = NULL;
 674             *pFCB = NULL;
 675
 676             return(STATUS_OBJECT_PATH_NOT_FOUND);
 677         }
 678         parentFCB = FCB;
 679
 680         /* Extract next directory level into dirName */
 681         CdfsWSubString(pathName,
 682             FileName->Buffer,
 683             CdfsGetNextPathElement(currentElement) - FileName->Buffer);
 684         DPRINT("  pathName:%S\n", pathName);
 685
 686         RtlInitUnicodeString(&PathName, pathName);
 687
 688         FCB = CdfsGrabFCBFromTable(Vcb, &PathName);
 689         if (FCB == NULL)
 690         {
 691             CdfsWSubString(elementName,
 692                 currentElement,
 693                 CdfsGetNextPathElement(currentElement) - currentElement);
 694             DPRINT("  elementName:%S\n", elementName);
 695
 696             RtlInitUnicodeString(&ElementName, elementName);
 697             Status = CdfsDirFindFile(Vcb,
 698                 parentFCB,
 699                 &ElementName,
 700                 &FCB);
 701             if (Status == STATUS_OBJECT_NAME_NOT_FOUND)
 702             {
 703                 *pParentFCB = parentFCB;
 704                 *pFCB = NULL;
 705                 currentElement = CdfsGetNextPathElement(currentElement);
 706                 if (*currentElement == L'\0' || CdfsGetNextPathElement(currentElement + 1) == 0)
 707                 {
 708                     return(STATUS_OBJECT_NAME_NOT_FOUND);
 709                 }
 710                 else
 711                 {
 712                     return(STATUS_OBJECT_PATH_NOT_FOUND);
 713                 }
 714             }
 715             else if (!NT_SUCCESS(Status))
 716             {
 717                 CdfsReleaseFCB(Vcb, parentFCB);
 718                 *pParentFCB = NULL;
 719                 *pFCB = NULL;
 720
 721                 return(Status);
 722             }
 723         }
 724         currentElement = CdfsGetNextPathElement(currentElement);
 725     }
 726
 727     *pParentFCB = parentFCB;
 728     *pFCB = FCB;
 729
 730     return STATUS_SUCCESS;
 731 }
 732
 733 /* EOF */