libbe: promote activated BEs all the way

[kevans]

Summary

This matches the beadm behavior; generally, we need to keep promoting
until the BE is no longer a clone from a snapshot. This fixes scenarios
where the dataset associated with a BE's origin is itself a clone,
activating the BE previously would promote it to a clone of the origin's
origin.

We could keep using be_get_dataset_props here, except for two
annoyances:

1.) I couldn't find a clean way to just clear an nvlist rather than

having to re-alloc it, and I didn't want to just remove the one prop
we're inspecting out of it.

2.) That's a lot of overhead when all we want to do is fetch the origin

anyways.

Reported by: R. Christian McDonald <[e-mail]>

[rcm]

This looks good to me, it fixes the case I was hitting.

[rcm]

This does not completely align with beadm behavior.

Consider a default boot environment with a child dataset like:

zroot/ROOT/default
zroot/ROOT/default/usr

beadm will recursively promote both the parent and any child datasets.

We need to do the same. I have a patch and updated test case for this.

termbin.com_sf9j.txt3 KBDownload