Just finished reading this, great work! Thank you so much for working on this, @carlavilla !

• Address comments

In D56165#1334631, @kib wrote:

BTW, what prevents a malicious userspace to try to sneak a mount with a type outside the allowed list after the check, but before the mount?

• Address comments

Another thing: what is the rationale for prohibiting the usermount feature from working on top of certain file system types?

Read this in its entirety, astonishing job. Thank you so much for working on this!

LGTM, thank you.

• Address comments

The added testing suite depends on not-yet-committed port and adjustments to filesystems/fusefs-libs3, which I plan to push forward once I get a positive feedback on this review.

• Address comments
• Add tests for auto_unmount and usermount features

It seems this is landed and can be closed?

Already landed.

Already landed.

Overcome by events.

I didn't get it at all. How is this change related to the STRIP env var?

In D56835#1311164, @imp wrote:

I'd like to echo the user requirement. I have not current need for it at $WORK, but can see a need in the future. Having the ability for users to tie into the startup, running as themselves, much like we allow users to add jobs to cron, at, etc would be a useful, but not gating, feature.