Platform SDK: Hardware |
Using the FSCTL_UNLOCK_VOLUME control code 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 operation NULL, // lpInBuffer; must be NULL 0, // nInBufferSize; must be zero NULL, // lpOutBuffer; must be NULL 0, // nOutBufferSize; must be zero (LPDWORD) lpBytesReturned, // number of bytes returned (LPOVERLAPPED) lpOverlapped // OVERLAPPED structure );
If lpOverlapped is NULL (nonoverlapped I/O), lpBytesReturned is used internally and cannot be NULL.
If lpOverlapped is not NULL (overlapped I/O), lpBytesReturned can be NULL.
If hDevice was opened with the FILE_FLAG_OVERLAPPED flag, lpOverlapped must point to a valid OVERLAPPED structure. In this case, the operation is performed as an overlapped (asynchronous) operation. If the device was opened with the FILE_FLAG_OVERLAPPED flag and lpOverlapped is NULL, the function fails in unpredictable ways.
If hDevice was opened without specifying the FILE_FLAG_OVERLAPPED flag, lpOverlapped is ignored and DeviceIoControl does not return until the operation has been completed, or until an error occurs.
If the operation succeeds, DeviceIoControl returns a nonzero value.
If the operation fails, DeviceIoControl returns zero. To get extended error information, call GetLastError.
An application can use the FSCTL_LOCK_VOLUME control code to lock a volume.
The hDevice handle passed to DeviceIoControl must be a handle to a volume, opened for direct access. An application can obtain such a handle by calling CreateFile with lpFileName set to a string that looks like this:
\\.\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.
Windows NT/2000: Requires Windows NT 3.5 or later.
Windows 95/98: Unsupported.
Header: Declared in Winioctl.h.
Device Input and Output Overview, Device Input and Output Control Codes, CreateFile, DeviceIoControl, FSCTL_LOCK_VOLUME