// By locking the volume before you dismount it, you can ensure that the volume is dismounted cleanly
// (because the system flushes all cached data to the volume before locking it)
//
// A locked volume remains locked until one of the following occurs:
// * The application uses the FSCTL_UNLOCK_VOLUME control code to unlock the volume.
// * The handle closes, either directly through CloseHandle, or indirectly when a process terminates.
// http://msdn.microsoft.com/en-us/library/bb521494(v=winembedded.5).aspx
// http://msdn.microsoft.com/en-us/library/Aa364575
/// <param name="handle">
/// The application must specify the FILE_SHARE_READ and FILE_SHARE_WRITE flags in the dwShareMode parameter of CreateFile.
/// https://msdn.microsoft.com/en-us/library/Aa364575
/// </param>
public static bool LockVolume(SafeFileHandle handle)
{
if (!handle.IsInvalid)
{
uint dummy;
bool success = PhysicalDiskControl.DeviceIoControl(handle, FSCTL_LOCK_VOLUME, IntPtr.Zero, 0, IntPtr.Zero, 0, out dummy, IntPtr.Zero);
return(success);
}
else
{
return(false);
}
}
/// <summary>
/// Note: The NTFS file system treats a locked volume as a dismounted volume.
/// </summary>
/// <param name="handle">When opening a volume, the dwShareMode parameter must have the FILE_SHARE_WRITE flag.</param>
public static bool IsVolumeMounted(SafeFileHandle handle)
{
if (!handle.IsInvalid)
{
uint dummy;
bool mounted = PhysicalDiskControl.DeviceIoControl(handle, FSCTL_IS_VOLUME_MOUNTED, IntPtr.Zero, 0, IntPtr.Zero, 0, out dummy, IntPtr.Zero);
handle.Close();
return(mounted);
}
else
{
return(false);
}
}
public static bool AllowExtendedIO(SafeFileHandle handle)
{
if (!handle.IsInvalid)
{
uint dummy;
bool success = PhysicalDiskControl.DeviceIoControl(handle, FSCTL_ALLOW_EXTENDED_DASD_IO, IntPtr.Zero, 0, IntPtr.Zero, 0, out dummy, IntPtr.Zero);
if (!success)
{
int errorCode = Marshal.GetLastWin32Error();
if (errorCode == (int)Win32Error.ERROR_ACCESS_DENIED)
{
throw new UnauthorizedAccessException();
}
}
return(success);
}
else
{
return(false);
}
}
// Forced dismount only does FSCTL_DISMOUNT_VOLUME (without locking the volume first),
// and then does the formatting write/verify operations _from this very handle_.
// Then the handle is just closed, and any next attempt to access the volume will automount it.
/// <param name="handle">
/// The application must specify the FILE_SHARE_READ and FILE_SHARE_WRITE flags in the dwShareMode parameter of CreateFile.
/// http://msdn.microsoft.com/en-us/library/windows/desktop/aa364562%28v=vs.85%29.aspx
/// </param>
public static bool DismountVolume(SafeFileHandle handle)
{
if (!handle.IsInvalid)
{
uint dummy;
bool success = PhysicalDiskControl.DeviceIoControl(handle, FSCTL_DISMOUNT_VOLUME, IntPtr.Zero, 0, IntPtr.Zero, 0, out dummy, IntPtr.Zero);
if (!success)
{
int errorCode = Marshal.GetLastWin32Error();
if (errorCode == (int)Win32Error.ERROR_ACCESS_DENIED)
{
throw new UnauthorizedAccessException();
}
}
return(success);
}
else
{
return(false);
}
}
