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FSCTL_GET_OBJECT_ID IOCTL (winioctl.h)

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Retrieves the object identifier for the specified file or directory.

To perform this operation, call the DeviceIoControl function with the following parameters.

BOOL DeviceIoControl(
  (HANDLE) hDevice,           // handle to device
  FSCTL_GET_OBJECT_ID,        // dwIoControlCode
  NULL,                       // lpInBuffer
  0,                          // nInBufferSize
  (LPVOID) lpOutBuffer,       // output buffer
  (DWORD) nOutBufferSize,     // size of output buffer
  (LPDWORD) lpBytesReturned,  // number of bytes returned
  (LPOVERLAPPED) lpOverlapped // OVERLAPPED structure
);

Remarks

Object identifiers are used to track files and directories. They are invisible to most applications and should never be modified by applications. Modifying an object identifier can result in the loss of data from portions of a file, up to and including entire volumes of data.

If there is no object identifier associated with the specified handle, none is created and an error is returned. To create an object identifier, use FSCTL_SET_OBJECT_ID. To retrieve an existing object identifier or generate one if there is no existing object identifier in one step, use FSCTL_CREATE_OR_GET_OBJECT_ID.

In Windows 8 and Windows Server 2012, this code is supported by the following technologies.

Technology Supported
Server Message Block (SMB) 3.0 protocol Yes
SMB 3.0 Transparent Failover (TFO) Yes
SMB 3.0 with Scale-out File Shares (SO) Yes
Cluster Shared Volume File System (CsvFS) Yes
Resilient File System (ReFS) No

Requirements

Requirement Value
Minimum supported client Windows XP [desktop apps only]
Minimum supported server Windows Server 2003 [desktop apps only]
Header winioctl.h (include Windows.h)

See also