IOCTL_STORAGE_GET_DEVICE_NUMBER control code

Retrieves the device type, device number, and, for a partitionable device, the partition number of a device.

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


BOOL DeviceIoControl(
  (HANDLE) hDevice,                // handle to device
  IOCTL_STORAGE_GET_DEVICE_NUMBER, // 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
);

Parameters

hDevice

A handle to the device. To obtain a device handle, call the CreateFile function.

dwIoControlCode

The control code for the operation. Use IOCTL_STORAGE_GET_DEVICE_NUMBER for this operation.

lpInBuffer

Not used with this operation; set to NULL.

nInBufferSize

Not used with this operation; set to zero.

lpOutBuffer

A pointer to a STORAGE_DEVICE_NUMBER structure that receives the device information.

nOutBufferSize

The size of the output buffer, in bytes.

lpBytesReturned

A pointer to a variable that receives the size of the data stored in the output buffer, in bytes.

If the output buffer is too small, the call fails, the GetLastError function returns ERROR_INSUFFICIENT_BUFFER, and the lpBytesReturned parameter is zero.

If the lpOverlapped parameter is NULL, lpBytesReturned cannot be NULL. Even when an operation returns no output data and the lpOutBuffer parameter is NULL, DeviceIoControl makes use of lpBytesReturned. After such an operation, the value of lpBytesReturned is meaningless.

If lpOverlapped is not NULL, lpBytesReturned can be NULL. If lpBytesReturned is not NULL and the operation returns data, lpBytesReturned is meaningless until the overlapped operation has completed. To retrieve the number of bytes returned, call the GetOverlappedResult function. If the hDevice parameter is associated with an I/O completion port, you can retrieve the number of bytes returned by calling the GetQueuedCompletionStatus function.

lpOverlapped

A pointer to an OVERLAPPED structure.

If hDevice was opened without specifying FILE_FLAG_OVERLAPPED, lpOverlapped is ignored.

If hDevice was opened with the FILE_FLAG_OVERLAPPED flag, the operation is performed as an overlapped (asynchronous) operation. In this case, lpOverlapped must point to a valid OVERLAPPED structure that contains a handle to an event object. Otherwise, the function fails in unpredictable ways.

For overlapped operations, DeviceIoControl returns immediately, and the event object is signaled when the operation has been completed. Otherwise, the function does not return until the operation has been completed or an error occurs.

Return value

If the operation completes successfully, DeviceIoControl returns a nonzero value.

If the operation fails or is pending, DeviceIoControl returns zero. To get extended error information, call GetLastError.

Remarks

The values in the STORAGE_DEVICE_NUMBER structure are guaranteed to remain unchanged until the device is removed or the system is restarted. It is not guaranteed to be persistent across device restarts or system restarts.

Requirements

Minimum supported client

Windows XP

Minimum supported server

Windows Server 2003

Header

WinIoCtl.h (include Windows.h)

See also

DeviceIoControl
STORAGE_DEVICE_NUMBER

 

 

Community Additions

ADD
Show:
© 2014 Microsoft