fcb.c

来自「一个类似windows」· C语言 代码 · 共 738 行 · 第 1/2 页

  if (LongName[0] != 0)
    {
      wcscat(pathName, LongName);
    }
  else
    {
      WCHAR entryName[MAX_PATH];

      CdfsGetDirEntryName(Vcb, Record, entryName);
      wcscat(pathName, entryName);
    }

  rcFCB = CdfsCreateFCB(pathName);
  memcpy(&rcFCB->Entry, Record, sizeof(DIR_RECORD));

  /* Copy short name into FCB */
  rcFCB->ShortNameU.Length = wcslen(ShortName) * sizeof(WCHAR);
  rcFCB->ShortNameU.MaximumLength = rcFCB->ShortNameU.Length;
  rcFCB->ShortNameU.Buffer = rcFCB->ShortNameBuffer;
  wcscpy(rcFCB->ShortNameBuffer, ShortName);

  Size = rcFCB->Entry.DataLengthL;

  rcFCB->RFCB.FileSize.QuadPart = Size;
  rcFCB->RFCB.ValidDataLength.QuadPart = Size;
  rcFCB->RFCB.AllocationSize.QuadPart = ROUND_UP(Size, BLOCKSIZE);
  if (CdfsFCBIsDirectory(rcFCB))
  {
     CdfsFCBInitializeCache(Vcb, rcFCB);
  }
  rcFCB->IndexNumber.u.HighPart = DirectorySector;
  rcFCB->IndexNumber.u.LowPart = DirectoryOffset;
  rcFCB->RefCount++;
  CdfsAddFCBToTable(Vcb, rcFCB);
  *fileFCB = rcFCB;

  DPRINT("%S %d %I64d\n", LongName, Size, rcFCB->RFCB.AllocationSize.QuadPart);

  return(STATUS_SUCCESS);
}


NTSTATUS
CdfsAttachFCBToFileObject(PDEVICE_EXTENSION Vcb,
			  PFCB Fcb,
			  PFILE_OBJECT FileObject)
{
  PCCB  newCCB;

  newCCB = ExAllocatePoolWithTag(NonPagedPool, sizeof(CCB), TAG_CCB);
  if (newCCB == NULL)
    {
      return(STATUS_INSUFFICIENT_RESOURCES);
    }
  memset(newCCB, 0, sizeof(CCB));

  FileObject->SectionObjectPointer = &Fcb->SectionObjectPointers;
  FileObject->FsContext = Fcb;
  FileObject->FsContext2 = newCCB;
  newCCB->PtrFileObject = FileObject;
  Fcb->DevExt = Vcb;

  if (CdfsFCBIsDirectory(Fcb))
    {
#ifdef USE_ROS_CC_AND_FS
      NTSTATUS Status;
      Status = CcRosInitializeFileCache(FileObject,
					PAGE_SIZE);
      if (!NT_SUCCESS(Status))
	{
	  DbgPrint("CcRosInitializeFileCache failed\n");
	  KEBUGCHECK(0);
	}
#else
  CcInitializeCacheMap(FileObject,
                       (PCC_FILE_SIZES)(&Fcb->RFCB.AllocationSize),
		       FALSE,
		       NULL,
		       NULL);
#endif
      Fcb->Flags |= FCB_CACHE_INITIALIZED;
    }

  DPRINT("file open: fcb:%x file size: %d\n", Fcb, Fcb->Entry.DataLengthL);

  return(STATUS_SUCCESS);
}


NTSTATUS
CdfsDirFindFile(PDEVICE_EXTENSION DeviceExt,
		PFCB DirectoryFcb,
		PUNICODE_STRING FileToFind,
		PFCB *FoundFCB)
{
  UNICODE_STRING TempName;
  WCHAR Name[256];
  PVOID Block;
  ULONG DirSize;
  PDIR_RECORD Record;
  ULONG Offset;
  ULONG BlockOffset;
  NTSTATUS Status;

  LARGE_INTEGER StreamOffset;
  PVOID Context;

  WCHAR ShortNameBuffer[13];
  UNICODE_STRING ShortName;
  UNICODE_STRING LongName;
  BOOLEAN HasSpaces;
  GENERATE_NAME_CONTEXT NameContext;


  ASSERT(DeviceExt);
  ASSERT(DirectoryFcb);
  ASSERT(FileToFind);

  DPRINT("CdfsDirFindFile(VCB:%p, dirFCB:%p, File:%wZ)\n",
	 DeviceExt,
	 DirectoryFcb,
	 FileToFind);
  DPRINT("Dir Path:%S\n", DirectoryFcb->PathName);

  /* default to '.' if no filename specified */
  if (FileToFind->Length == 0)
    {
      RtlInitUnicodeString(&TempName, L".");
      FileToFind = &TempName;
    }

  DirSize = DirectoryFcb->Entry.DataLengthL;
  StreamOffset.QuadPart = (LONGLONG)DirectoryFcb->Entry.ExtentLocationL * (LONGLONG)BLOCKSIZE;

  if (!CcMapData(DeviceExt->StreamFileObject,
		 &StreamOffset,
		 BLOCKSIZE,
		 TRUE,
		 &Context,
		 &Block))
    {
      DPRINT("CcMapData() failed\n");
      return STATUS_UNSUCCESSFUL;
    }

  Offset = 0;
  BlockOffset = 0;
  Record = (PDIR_RECORD)Block;
  while(TRUE)
    {
      if (Record->RecordLength == 0)
	{
	  DPRINT("RecordLength == 0  Stopped!\n");
	  break;
	}

      DPRINT("RecordLength %u  ExtAttrRecordLength %u  NameLength %u\n",
	     Record->RecordLength, Record->ExtAttrRecordLength, Record->FileIdLength);

      CdfsGetDirEntryName(DeviceExt, Record, Name);
      DPRINT ("Name '%S'\n", Name);
      DPRINT ("Sector %lu\n", DirectoryFcb->Entry.ExtentLocationL);
      DPRINT ("Offset %lu\n", Offset);

      RtlInitUnicodeString(&LongName, Name);
      ShortName.Length = 0;
      ShortName.MaximumLength = 26;
      ShortName.Buffer = ShortNameBuffer;
      memset(ShortNameBuffer, 0, 26);

      if ((RtlIsNameLegalDOS8Dot3(&LongName, NULL, &HasSpaces) == FALSE) ||
	  (HasSpaces == TRUE))
	{
	  /* Build short name */
	  RtlGenerate8dot3Name(&LongName,
			       FALSE,
			       &NameContext,
			       &ShortName);
	}
      else
	{
	  /* copy short name */
	  RtlUpcaseUnicodeString(&ShortName,
				 &LongName,
				 FALSE);
	}

      DPRINT("ShortName '%wZ'\n", &ShortName);

      if (FsRtlIsNameInExpression(FileToFind, &LongName, TRUE, NULL) ||
	  FsRtlIsNameInExpression(FileToFind, &ShortName, TRUE, NULL))
	{
	  DPRINT("Match found, %S\n", Name);
	  Status = CdfsMakeFCBFromDirEntry(DeviceExt,
					   DirectoryFcb,
					   Name,
					   ShortNameBuffer,
					   Record,
					   DirectoryFcb->Entry.ExtentLocationL,
					   Offset,
					   FoundFCB);

	  CcUnpinData(Context);

	  return(Status);
	}

      Offset += Record->RecordLength;
      BlockOffset += Record->RecordLength;
      Record = (PDIR_RECORD)((ULONG_PTR)Block + BlockOffset);
      if (BlockOffset >= BLOCKSIZE || Record->RecordLength == 0)
	{
	  DPRINT("Map next sector\n");
	  CcUnpinData(Context);
	  StreamOffset.QuadPart += BLOCKSIZE;
	  Offset = ROUND_UP(Offset, BLOCKSIZE);
	  BlockOffset = 0;

	  if (!CcMapData(DeviceExt->StreamFileObject,
			 &StreamOffset,
			 BLOCKSIZE, TRUE,
			 &Context, &Block))
	    {
	      DPRINT("CcMapData() failed\n");
	      return(STATUS_UNSUCCESSFUL);
	    }
	  Record = (PDIR_RECORD)((ULONG_PTR)Block + BlockOffset);
	}

      if (Offset >= DirSize)
	break;
    }

  CcUnpinData(Context);

  return(STATUS_OBJECT_NAME_NOT_FOUND);
}


NTSTATUS
CdfsGetFCBForFile(PDEVICE_EXTENSION Vcb,
		  PFCB *pParentFCB,
		  PFCB *pFCB,
		  PUNICODE_STRING FileName)
{
  UNICODE_STRING PathName;
  UNICODE_STRING ElementName;
  NTSTATUS Status;
  WCHAR  pathName [MAX_PATH];
  WCHAR  elementName [MAX_PATH];
  PWCHAR  currentElement;
  PFCB  FCB;
  PFCB  parentFCB;

  DPRINT("CdfsGetFCBForFile(%x, %x, %x, '%wZ')\n",
	 Vcb,
	 pParentFCB,
	 pFCB,
	 FileName);

  /* Trivial case, open of the root directory on volume */
  if (FileName->Buffer[0] == L'\0' || wcscmp(FileName->Buffer, L"\\") == 0)
    {
      DPRINT("returning root FCB\n");

      FCB = CdfsOpenRootFCB(Vcb);
      *pFCB = FCB;
      *pParentFCB = NULL;

      return((FCB != NULL) ? STATUS_SUCCESS : STATUS_OBJECT_PATH_NOT_FOUND);
    }
  else
    {
      currentElement = &FileName->Buffer[1];
      wcscpy (pathName, L"\\");
      FCB = CdfsOpenRootFCB (Vcb);
    }
  parentFCB = NULL;

  /* Parse filename and check each path element for existance and access */
  while (CdfsGetNextPathElement(currentElement) != 0)
    {
      /*  Skip blank directory levels */
      if ((CdfsGetNextPathElement(currentElement) - currentElement) == 0)
	{
	  currentElement++;
	  continue;
	}

      DPRINT("Parsing, currentElement:%S\n", currentElement);
      DPRINT("  parentFCB:%x FCB:%x\n", parentFCB, FCB);

      /* Descend to next directory level */
      if (parentFCB)
	{
	  CdfsReleaseFCB(Vcb, parentFCB);
	  parentFCB = NULL;
	}

      /* fail if element in FCB is not a directory */
      if (!CdfsFCBIsDirectory(FCB))
	{
	  DPRINT("Element in requested path is not a directory\n");

	  CdfsReleaseFCB(Vcb, FCB);
	  FCB = 0;
	  *pParentFCB = NULL;
	  *pFCB = NULL;

	  return(STATUS_OBJECT_PATH_NOT_FOUND);
	}
      parentFCB = FCB;

      /* Extract next directory level into dirName */
      CdfsWSubString(pathName,
		     FileName->Buffer,
		     CdfsGetNextPathElement(currentElement) - FileName->Buffer);
      DPRINT("  pathName:%S\n", pathName);

      RtlInitUnicodeString(&PathName, pathName);

      FCB = CdfsGrabFCBFromTable(Vcb, &PathName);
      if (FCB == NULL)
	{
	  CdfsWSubString(elementName,
			 currentElement,
			 CdfsGetNextPathElement(currentElement) - currentElement);
	  DPRINT("  elementName:%S\n", elementName);

	  RtlInitUnicodeString(&ElementName, elementName);
	  Status = CdfsDirFindFile(Vcb,
				   parentFCB,
				   &ElementName,
				   &FCB);
	  if (Status == STATUS_OBJECT_NAME_NOT_FOUND)
	    {
	      *pParentFCB = parentFCB;
	      *pFCB = NULL;
	      currentElement = CdfsGetNextPathElement(currentElement);
	      if (*currentElement == L'\0' || CdfsGetNextPathElement(currentElement + 1) == 0)
		{
		  return(STATUS_OBJECT_NAME_NOT_FOUND);
		}
	      else
		{
		  return(STATUS_OBJECT_PATH_NOT_FOUND);
		}
	    }
	  else if (!NT_SUCCESS(Status))
	    {
	      CdfsReleaseFCB(Vcb, parentFCB);
	      *pParentFCB = NULL;
	      *pFCB = NULL;

	      return(Status);
	    }
	}
      currentElement = CdfsGetNextPathElement(currentElement);
    }

  *pParentFCB = parentFCB;
  *pFCB = FCB;

  return STATUS_SUCCESS;
}

/* EOF */