I trust Alan's expertise here. IMHO, given that this patch is analog to fusefs one, should be fine. But not expert in the area.

In pf_krule we got remaining:

Updated differential according to review feedback.
Had to add patches for the utilities that were unblocked by the changes.
Applied an automated lld fix.

On one hand, there is an argument to be made that upgrading the sendmail version should trigger a restart so the new version starts running. However, if that upgrade requires an admin to either adjust or regenerate their configuration, then restarting could be dangerous (especially since the restart will likely trigger a queue run). My preference would to address the root cause -- the mqueue directory being removed when the package is upgraded. IMHO, once created, the queue directory should never be removed, even if the package is deleted. Many ports/pkgs do this instead:

This patch seems to break 2/11 of the testcases in the sys/geom/class/multipath/misc test suite with this output:

I did post some related questions to https://reviews.freebsd.org/D52625 about both the policy of passing NULL for the thread to VOP_CLOSE and the possibility of trying to make the passing of file objects to vnode ops more consistent.
But assuming everyone's ok with still passing NULL there, I'll also update VOP_OPENCLOSE.9 to note that possibility.

Use standard way to reference libc src dir.
Silence compiler warning in _bt_fill() about flags.

We should, cf. D35109

Есть совсем мелкие замечания/комментарии (пробел после открывающей скобки, отсутствие букв "ё", "в FreeBSD", а не "во FreeBSD"), принципиальных нет.
Спасибо, Владлен!

pkgbase doesn't restart sshd on upgrade, but that's something we might want to consider if it causes problems not to do so. (i haven't run into that myself, but that's probably because i run sshd from inetd.)