http://bugs.winehq.org/show_bug.cgi?id=15551
--- Comment #13 from Alexander Morozov amorozov@etersoft.ru 2008-10-10 08:51:57 --- UserIosb is also used in IoBuildDeviceIoControlRequest. IofCompleteRequest copies IoStatus to UserIosb and so driver which called IoBuildDeviceIoControlRequest can get information about IRP processing.