fs_unmount_volume
extern status_t fs_unmount_volume(const char *path, uint32 flags);
status = fs_unmount_volume(path, flags);
status = fs_unmount_volume(path.Path(), unmountFlags);
status = fs_unmount_volume(mountPoint.Path(), 0);
status = fs_unmount_volume(mountPoint.Path(), B_FORCE_UNMOUNT);
err = fs_unmount_volume(path, 0);
status_t status = fs_unmount_volume(mountPoint, 0);