mount check fails for some subvolumes contains a dot (.)

[real-user]

If btrfs-subvolume is mounted inside a hidden folder then the check "systemctl is-failed {path/containing/a/.dot/mountpoint}" will fail and return fault code 4 (program or service status is unknown).

The command "systemctl -t mount" will only contain the characters \x2e for some subvolumes, for example .snapshots will be \x2esnapshots.mount

However, here is one example from /etc/fstab that will not output \x2e instead of a dot:
UUID=e3aca71c-68c0-4f38-ace9-24cfec405e6a
/home/user1/.local/share/containers btrfs subvol=containers 0 0

This will instead be printed in "systemctl -t mount" as:
home-user1-.local-share-containers.mount

This patch will only replace the dot if it is the first character e.g .snapshots, but will not replace the dot in
/home/user1/.local/share/containers.

I do not know if there are other scenarios where "systemctl -t mount" will output \x2e instead of a dot,
I have only seen it for .snapshots (folders that starts with a "." ).

This issue has not been seen until a recent update of systemctl. On my previous snapshot "systemctl is-failed {/path/not/found.mount}" returned 1, but after the update of systemctl it will return 4 in case the mount-point does not exist.

[laenion]

Or dear, that query really needs improvement. Instead of all the manual sed parsing it would be way better to just ask systemd directly what the expected mount unit name is with

systemd-escape -p "${path}"

Do you want to update your pull request, or should I implement this myself?

[real-user]

Hi,

Thanks for the feedback. A much better suggestion indeed. I made a new pull-request.
It is my first time contributing so let me know if I need to change anything else.
Appreciate it.

[laenion]

Thanks a lot! Thinking of this, there is still one case where it may fail with the current code: If /etc/fstab contains octal encoded strings (such as a space: \040), then the encoding will still be different from systemd, which encodes this as \x20.

So if ${i} was replaced with $(echo -e ${i)} to first decode the string I think it should really catch all combinations.

[real-user]

Hi, I made the update you proposed.
I also noticed that the code does not handle commented lines in /etc/fstab so I improved the awk command.
It should now ignore commented lines and avoid systemctl is-failed -q "${path}.mount" to pick up some garbage in path.

Let me know if you think it is better.
I have tested it on my system and it seem to work fine.

[laenion]

Good catch, thanks a lot!

Merging now. Thanks a lot for keeping up and implementing all my ideas, and Congratulations on your excellent first contribution :-)

[laenion]

Thinking about this again (and while having a look at it anyway), the code still had some more problems with obscure characters, so I also reworked the awk part and replaced it with findmnt now.