Comment 8 for bug 1444402

This is a bad bug.

Please see my report on the Arch Linux bug tracker on it here: https://bugs.archlinux.org/task/44658#comment134665

This report is using systemd from Arch's [testing] repo which seems to be version 219 with some patches applied by the Arch maintainers which try to address this bug: systemd 219-6, https://www.archlinux.org/packages/testing/x86_64/systemd/

In summary, even when the bug has been "fixed" (allowing mounts to be made again) there are cases when systemd is unmounting things it should not be when the user runs umount (seems like it unmounts ALL mounts associated with a device whenever any mount associated with that device is umounted).

A bug that breaks filesystem mouting/unmounting seems particularly critical. Whatever new logic 219 introduced that created this bug should probably be reverted from the systemd release until all the mounting and unmounting corner cases can be tested and covered.