The operating system tries to mount an unmounted volume as soon as an attempt is made to access it. For example, a call to GetLogicalDrives triggers the operating system to mount unmounted volumes.
你调用FSCTL_DISMOUNT_VOLUME卸载磁盘后,再调用诸如GetLogicalDrives这样的函数,会迫使windows主动去重新mount你刚刚卸载的磁盘。这就完成了卸载后重新上盘。