Retrieves the first file record that is in use and is of a lesser than or equal ordinal value to the requested file reference number.

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

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


This control code enumerates file identifiers in a downward fashion, and always returns a file record that is in use. This means that the file identifier returned by this control code may not be the same as the file identifier specified in the input buffer. For example, if file identifiers 1 through 9 and 15 are in use, file identifiers 10 through 14 are not in use, and the file record corresponding to file identifier 15 is requested, that file record is returned.

If the file records that correspond to file identifiers 10 through 14 are requested, then the file record corresponding to file identifier 9 is returned. If any of the file records corresponding to file identifiers 1 through 9 are requested, those file records is returned.

To determine the correct size of the output buffer pointed to by lpOutBuffer, first call the FSCTL_GET_NTFS_VOLUME_DATA control code to get the size of one file record. This is the value of the BytesPerFileRecordSegment member of the returned NTFS_VOLUME_DATA_BUFFER structure. Then set the size of the output buffer to the following expression:

sizeof (NTFS_FILE_RECORD_OUTPUT_BUFFER) + sizeof (one file record) - 1

If a file consists of multiple file records, they must be retrieved individually.

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

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


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