FSCTL_UNLOCK_VOLUME IOCTL (winioctl.h)

Unlocks a volume.

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

BOOL DeviceIoControl(
  (HANDLE) hDevice,            // handle to a volume
  FSCTL_UNLOCK_VOLUME,         // dwIoControlCode
  NULL,                        // lpInBuffer
  0,                           // nInBufferSize
  NULL,                        // lpOutBuffer
  0,                           // nOutBufferSize
  (LPDWORD) lpBytesReturned,   // number of bytes returned
  (LPOVERLAPPED) lpOverlapped  // OVERLAPPED structure
);

Irp->IoStatus.Status is set to STATUS_SUCCESS if the request is successful.

Otherwise, Status to the appropriate error condition as a NTSTATUS code.

For more information, see NTSTATUS Values.

Remarks

To lock a volume, use the FSCTL_LOCK_VOLUME control code.

The hDevice handle passed to DeviceIoControl must be a handle to a volume, opened for direct access. To retrieve this handle, call CreateFile with the lpFileName parameter set to a string of the following form:

\\.\X:

where X is a hard-drive partition letter, floppy disk drive, or CD-ROM drive. The application must also specify the FILE_SHARE_READ and FILE_SHARE_WRITE flags in the dwShareMode parameter of CreateFile.

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

PNP notification is issued only on the node where the FSCTL was issued.

After acquiring a lock on a CSV volume, you must close the handle used to lock that volume before opening a handle to the volume. Unlocking the volume by using FSCTL_UNLOCK_VOLUME is not sufficient.

Requirements

See also

CreateFile

DeviceIoControl

FSCTL_LOCK_VOLUME

Volume Management Control Codes