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 /* $Id$
  20 *
  21 * COPYRIGHT:        See COPYING in the top level directory
  22 * PROJECT:          ReactOS kernel
  23 * FILE:             services/fs/cdfs/fcb.c
  24 * PURPOSE:          CDROM (ISO 9660) filesystem driver
  25 * PROGRAMMER:       Art Yerkes
  26 * UPDATE HISTORY:
  27 */
  28
  29 /* INCLUDES *****************************************************************/
  30
  31 #include "cdfs.h"
  32
  33 #define NDEBUG
  34 #include <debug.h>
  35
  36 /* FUNCTIONS ****************************************************************/
  37
  38 #define ROUND_UP(N, S) ((((N) + (S) - 1) / (S)) * (S))
  39
  40
  41 /* FUNCTIONS ****************************************************************/
  42
  43 static PWCHAR
  44 CdfsGetNextPathElement(PWCHAR FileName)
  45 {
  46     if (*FileName == L'\0')
  47     {
  48         return(NULL);
  49     }
  50
  51     while (*FileName != L'\0' && *FileName != L'\\')
  52     {
  53         FileName++;
  54     }
  55
  56     return(FileName);
  57 }
  58
  59
  60 static VOID
  61 CdfsWSubString(PWCHAR pTarget, const PWCHAR pSource, size_t pLength)
  62 {
  63     wcsncpy (pTarget, pSource, pLength);
  64     pTarget [pLength] = L'\0';
  65 }
  66
  67
  68 PFCB
  69 CdfsCreateFCB(PCWSTR FileName)
  70 {
  71     PFCB Fcb;
  72
  73     Fcb = ExAllocatePoolWithTag(NonPagedPool, sizeof(FCB), TAG_FCB);
  74     if(!Fcb) return NULL;
  75
  76     RtlZeroMemory(Fcb, sizeof(FCB));
  77
  78     if (FileName)
  79     {
  80         wcscpy(Fcb->PathName, FileName);
  81         if (wcsrchr(Fcb->PathName, '\\') != 0)
  82         {
  83             Fcb->ObjectName = wcsrchr(Fcb->PathName, '\\');
  84         }
  85         else
  86         {
  87             Fcb->ObjectName = Fcb->PathName;
  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(wcscmp(Fcb->PathName, L"\\") == 0);
 134 }
 135
 136
 137 VOID
 138 CdfsGrabFCB(PDEVICE_EXTENSION Vcb,
 139             PFCB Fcb)
 140 {
 141     KIRQL  oldIrql;
 142
 143     DPRINT("grabbing FCB at %x: %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 %x: %S, 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 '%S'\n", FileName, Fcb->PathName);
 214         if (_wcsicmp(FileName->Buffer, Fcb->PathName) == 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     if (LongName [0] != 0 && wcslen (DirectoryFCB->PathName) +
 368         sizeof(WCHAR) + wcslen (LongName) > MAX_PATH)
 369     {
 370         return(STATUS_OBJECT_NAME_INVALID);
 371     }
 372
 373     wcscpy(pathName, DirectoryFCB->PathName);
 374     if (!CdfsFCBIsRoot(DirectoryFCB))
 375     {
 376         wcscat(pathName, L"\\");
 377     }
 378
 379     if (LongName[0] != 0)
 380     {
 381         wcscat(pathName, LongName);
 382     }
 383     else
 384     {
 385         WCHAR entryName[MAX_PATH];
 386
 387         CdfsGetDirEntryName(Vcb, Record, entryName);
 388         wcscat(pathName, entryName);
 389     }
 390
 391     rcFCB = CdfsCreateFCB(pathName);
 392     memcpy(&rcFCB->Entry, Record, sizeof(DIR_RECORD));
 393
 394     /* Copy short name into FCB */
 395     rcFCB->ShortNameU.Length = wcslen(ShortName) * sizeof(WCHAR);
 396     rcFCB->ShortNameU.MaximumLength = rcFCB->ShortNameU.Length;
 397     rcFCB->ShortNameU.Buffer = rcFCB->ShortNameBuffer;
 398     wcscpy(rcFCB->ShortNameBuffer, ShortName);
 399
 400     Size = rcFCB->Entry.DataLengthL;
 401
 402     rcFCB->RFCB.FileSize.QuadPart = Size;
 403     rcFCB->RFCB.ValidDataLength.QuadPart = Size;
 404     rcFCB->RFCB.AllocationSize.QuadPart = ROUND_UP(Size, BLOCKSIZE);
 405     if (CdfsFCBIsDirectory(rcFCB))
 406     {
 407         CdfsFCBInitializeCache(Vcb, rcFCB);
 408     }
 409     rcFCB->IndexNumber.u.HighPart = DirectorySector;
 410     rcFCB->IndexNumber.u.LowPart = DirectoryOffset;
 411     rcFCB->RefCount++;
 412     CdfsAddFCBToTable(Vcb, rcFCB);
 413     *fileFCB = rcFCB;
 414
 415     DPRINT("%S %d %I64d\n", LongName, Size, rcFCB->RFCB.AllocationSize.QuadPart);
 416
 417     return(STATUS_SUCCESS);
 418 }
 419
 420
 421 NTSTATUS
 422 CdfsAttachFCBToFileObject(PDEVICE_EXTENSION Vcb,
 423                           PFCB Fcb,
 424                           PFILE_OBJECT FileObject)
 425 {
 426     PCCB  newCCB;
 427
 428     newCCB = ExAllocatePoolWithTag(NonPagedPool, sizeof(CCB), TAG_CCB);
 429     if (newCCB == NULL)
 430     {
 431         return(STATUS_INSUFFICIENT_RESOURCES);
 432     }
 433     memset(newCCB, 0, sizeof(CCB));
 434
 435     FileObject->ReadAccess = TRUE;
 436     FileObject->WriteAccess = FALSE;
 437     FileObject->DeleteAccess = FALSE;
 438     FileObject->SectionObjectPointer = &Fcb->SectionObjectPointers;
 439     FileObject->FsContext = Fcb;
 440     FileObject->FsContext2 = newCCB;
 441     newCCB->PtrFileObject = FileObject;
 442     Fcb->DevExt = Vcb;
 443
 444     if (CdfsFCBIsDirectory(Fcb))
 445     {
 446         CcInitializeCacheMap(FileObject,
 447             (PCC_FILE_SIZES)(&Fcb->RFCB.AllocationSize),
 448             FALSE,
 449             &(CdfsGlobalData->CacheMgrCallbacks),
 450             Fcb);
 451         Fcb->Flags |= FCB_CACHE_INITIALIZED;
 452     }
 453
 454     DPRINT("file open: fcb:%x file size: %d\n", Fcb, Fcb->Entry.DataLengthL);
 455
 456     return(STATUS_SUCCESS);
 457 }
 458
 459
 460 NTSTATUS
 461 CdfsDirFindFile(PDEVICE_EXTENSION DeviceExt,
 462                 PFCB DirectoryFcb,
 463                 PUNICODE_STRING FileToFind,
 464                 PFCB *FoundFCB)
 465 {
 466     UNICODE_STRING TempName;
 467     WCHAR Name[256];
 468     PVOID Block;
 469     ULONG DirSize;
 470     PDIR_RECORD Record;
 471     ULONG Offset;
 472     ULONG BlockOffset;
 473     NTSTATUS Status;
 474
 475     LARGE_INTEGER StreamOffset, OffsetOfEntry;
 476     PVOID Context;
 477
 478     WCHAR ShortNameBuffer[13];
 479     UNICODE_STRING ShortName;
 480     UNICODE_STRING LongName;
 481     UNICODE_STRING FileToFindUpcase;
 482
 483     ASSERT(DeviceExt);
 484     ASSERT(DirectoryFcb);
 485     ASSERT(FileToFind);
 486
 487     DPRINT("CdfsDirFindFile(VCB:%p, dirFCB:%p, File:%wZ)\n",
 488         DeviceExt,
 489         DirectoryFcb,
 490         FileToFind);
 491     DPRINT("Dir Path:%S\n", DirectoryFcb->PathName);
 492
 493     /* default to '.' if no filename specified */
 494     if (FileToFind->Length == 0)
 495     {
 496         RtlInitUnicodeString(&TempName, L".");
 497         FileToFind = &TempName;
 498     }
 499
 500     DirSize = DirectoryFcb->Entry.DataLengthL;
 501     StreamOffset.QuadPart = (LONGLONG)DirectoryFcb->Entry.ExtentLocationL * (LONGLONG)BLOCKSIZE;
 502
 503     if (!CcMapData(DeviceExt->StreamFileObject,
 504         &StreamOffset,
 505         BLOCKSIZE,
 506         TRUE,
 507         &Context,
 508         &Block))
 509     {
 510         DPRINT("CcMapData() failed\n");
 511         return STATUS_UNSUCCESSFUL;
 512     }
 513
 514     Offset = 0;
 515     BlockOffset = 0;
 516     Record = (PDIR_RECORD)Block;
 517
 518     /* Upper case the expression for FsRtlIsNameInExpression */
 519     Status = RtlUpcaseUnicodeString(&FileToFindUpcase, FileToFind, TRUE);
 520     if (!NT_SUCCESS(Status))
 521     {
 522         return Status;
 523     }
 524
 525     while(TRUE)
 526     {
 527         if (Record->RecordLength == 0)
 528         {
 529             DPRINT("RecordLength == 0  Stopped!\n");
 530             break;
 531         }
 532
 533         DPRINT("RecordLength %u  ExtAttrRecordLength %u  NameLength %u\n",
 534             Record->RecordLength, Record->ExtAttrRecordLength, Record->FileIdLength);
 535
 536         CdfsGetDirEntryName(DeviceExt, Record, Name);
 537         DPRINT ("Name '%S'\n", Name);
 538         DPRINT ("Sector %lu\n", DirectoryFcb->Entry.ExtentLocationL);
 539         DPRINT ("Offset %lu\n", Offset);
 540
 541         RtlInitUnicodeString(&LongName, Name);
 542         ShortName.Length = 0;
 543         ShortName.MaximumLength = 26;
 544         ShortName.Buffer = ShortNameBuffer;
 545         memset(ShortNameBuffer, 0, 26);
 546
 547         OffsetOfEntry.QuadPart = StreamOffset.QuadPart + Offset;
 548         CdfsShortNameCacheGet(DirectoryFcb, &OffsetOfEntry, &LongName, &ShortName);
 549
 550         DPRINT("ShortName '%wZ'\n", &ShortName);
 551
 552         if (FsRtlIsNameInExpression(&FileToFindUpcase, &LongName, TRUE, NULL) ||
 553             FsRtlIsNameInExpression(&FileToFindUpcase, &ShortName, TRUE, NULL))
 554         {
 555             DPRINT("Match found, %S\n", Name);
 556             Status = CdfsMakeFCBFromDirEntry(DeviceExt,
 557                 DirectoryFcb,
 558                 Name,
 559                 ShortNameBuffer,
 560                 Record,
 561                 DirectoryFcb->Entry.ExtentLocationL,
 562                 Offset,
 563                 FoundFCB);
 564
 565             RtlFreeUnicodeString(&FileToFindUpcase);
 566             CcUnpinData(Context);
 567
 568             return(Status);
 569         }
 570
 571         Offset += Record->RecordLength;
 572         BlockOffset += Record->RecordLength;
 573         Record = (PDIR_RECORD)((ULONG_PTR)Block + BlockOffset);
 574         if (BlockOffset >= BLOCKSIZE || Record->RecordLength == 0)
 575         {
 576             DPRINT("Map next sector\n");
 577             CcUnpinData(Context);
 578             StreamOffset.QuadPart += BLOCKSIZE;
 579             Offset = ROUND_UP(Offset, BLOCKSIZE);
 580             BlockOffset = 0;
 581
 582             if (!CcMapData(DeviceExt->StreamFileObject,
 583                 &StreamOffset,
 584                 BLOCKSIZE, TRUE,
 585                 &Context, &Block))
 586             {
 587                 DPRINT("CcMapData() failed\n");
 588                 RtlFreeUnicodeString(&FileToFindUpcase);
 589                 return(STATUS_UNSUCCESSFUL);
 590             }
 591             Record = (PDIR_RECORD)((ULONG_PTR)Block + BlockOffset);
 592         }
 593
 594         if (Offset >= DirSize)
 595             break;
 596     }
 597
 598     RtlFreeUnicodeString(&FileToFindUpcase);
 599     CcUnpinData(Context);
 600
 601     return(STATUS_OBJECT_NAME_NOT_FOUND);
 602 }
 603
 604
 605 NTSTATUS
 606 CdfsGetFCBForFile(PDEVICE_EXTENSION Vcb,
 607                   PFCB *pParentFCB,
 608                   PFCB *pFCB,
 609                   PUNICODE_STRING FileName)
 610 {
 611     UNICODE_STRING PathName;
 612     UNICODE_STRING ElementName;
 613     NTSTATUS Status;
 614     WCHAR  pathName [MAX_PATH];
 615     WCHAR  elementName [MAX_PATH];
 616     PWCHAR  currentElement;
 617     PFCB  FCB;
 618     PFCB  parentFCB;
 619
 620     DPRINT("CdfsGetFCBForFile(%x, %x, %x, '%wZ')\n",
 621         Vcb,
 622         pParentFCB,
 623         pFCB,
 624         FileName);
 625
 626     /* Trivial case, open of the root directory on volume */
 627     if (FileName->Buffer[0] == L'\0' || wcscmp(FileName->Buffer, L"\\") == 0)
 628     {
 629         DPRINT("returning root FCB\n");
 630
 631         FCB = CdfsOpenRootFCB(Vcb);
 632         *pFCB = FCB;
 633         *pParentFCB = NULL;
 634
 635         return((FCB != NULL) ? STATUS_SUCCESS : STATUS_OBJECT_PATH_NOT_FOUND);
 636     }
 637     else
 638     {
 639         currentElement = &FileName->Buffer[1];
 640         wcscpy (pathName, L"\\");
 641         FCB = CdfsOpenRootFCB (Vcb);
 642     }
 643     parentFCB = NULL;
 644
 645     /* Parse filename and check each path element for existance and access */
 646     while (CdfsGetNextPathElement(currentElement) != 0)
 647     {
 648         /*  Skip blank directory levels */
 649         if ((CdfsGetNextPathElement(currentElement) - currentElement) == 0)
 650         {
 651             currentElement++;
 652             continue;
 653         }
 654
 655         DPRINT("Parsing, currentElement:%S\n", currentElement);
 656         DPRINT("  parentFCB:%x FCB:%x\n", parentFCB, FCB);
 657
 658         /* Descend to next directory level */
 659         if (parentFCB)
 660         {
 661             CdfsReleaseFCB(Vcb, parentFCB);
 662             parentFCB = NULL;
 663         }
 664
 665         /* fail if element in FCB is not a directory */
 666         if (!CdfsFCBIsDirectory(FCB))
 667         {
 668             DPRINT("Element in requested path is not a directory\n");
 669
 670             CdfsReleaseFCB(Vcb, FCB);
 671             FCB = 0;
 672             *pParentFCB = NULL;
 673             *pFCB = NULL;
 674
 675             return(STATUS_OBJECT_PATH_NOT_FOUND);
 676         }
 677         parentFCB = FCB;
 678
 679         /* Extract next directory level into dirName */
 680         CdfsWSubString(pathName,
 681             FileName->Buffer,
 682             CdfsGetNextPathElement(currentElement) - FileName->Buffer);
 683         DPRINT("  pathName:%S\n", pathName);
 684
 685         RtlInitUnicodeString(&PathName, pathName);
 686
 687         FCB = CdfsGrabFCBFromTable(Vcb, &PathName);
 688         if (FCB == NULL)
 689         {
 690             CdfsWSubString(elementName,
 691                 currentElement,
 692                 CdfsGetNextPathElement(currentElement) - currentElement);
 693             DPRINT("  elementName:%S\n", elementName);
 694
 695             RtlInitUnicodeString(&ElementName, elementName);
 696             Status = CdfsDirFindFile(Vcb,
 697                 parentFCB,
 698                 &ElementName,
 699                 &FCB);
 700             if (Status == STATUS_OBJECT_NAME_NOT_FOUND)
 701             {
 702                 *pParentFCB = parentFCB;
 703                 *pFCB = NULL;
 704                 currentElement = CdfsGetNextPathElement(currentElement);
 705                 if (*currentElement == L'\0' || CdfsGetNextPathElement(currentElement + 1) == 0)
 706                 {
 707                     return(STATUS_OBJECT_NAME_NOT_FOUND);
 708                 }
 709                 else
 710                 {
 711                     return(STATUS_OBJECT_PATH_NOT_FOUND);
 712                 }
 713             }
 714             else if (!NT_SUCCESS(Status))
 715             {
 716                 CdfsReleaseFCB(Vcb, parentFCB);
 717                 *pParentFCB = NULL;
 718                 *pFCB = NULL;
 719
 720                 return(Status);
 721             }
 722         }
 723         currentElement = CdfsGetNextPathElement(currentElement);
 724     }
 725
 726     *pParentFCB = parentFCB;
 727     *pFCB = FCB;
 728
 729     return STATUS_SUCCESS;
 730 }
 731
 732 /* EOF */