On Fri, Apr 14, 2023 at 03:28:45AM +0000, Trond Myklebust wrote: > We already have support for directory file descriptors when mounting with move_mount(). Why not add a umountat() with similar support for the unmount side? > Then add a syscall to allow users with (e.g.) the CAP_DAC_OVERRIDE privilege to convert the mount-id into an O_PATH file descriptor. You can already do umount -l /proc/self/fd/69 if you have a descriptor. Converting mount-id to O_PATH... might be an interesting idea.
