On Fri, May 15, 2020 at 1:40 PM Michael Kerrisk (man-pages) <mtk.manpages@xxxxxxxxx> wrote: > > Hello David, Miklos, > > I've been looking at the new mount API (fsopen(), fsconfig(), > fsmount(), move_mount(), etc.) and among the details that remain > mysterious to me is this: how does one set the propagation type > (private/shared/slave/unbindable) of a new mount and change the > propagation type of an existing mount? Existing mount can be chaged with mount(NULL, path, NULL, MS_$(propflag), NULL). To do that with a detached mount created by fsmount(2) the "/proc/self/fd/$fd" trick can be used. The plan was to introduce a mount_setattr(2) syscall, but that hasn't happened yet... I'm not sure we should be adding propagation flags to fsmount(2), since that is a less generic mechanism than mount_setattr(2) or just plain mount(2) as shown above. Thanks, Miklos
