Re: [BREAKAGE] Since 4.18, kernel sets SB_I_NODEV implicitly on userns mounts, breaking systemd-nspawn

From: Gabriel C
Date: Sat Dec 22 2018 - 18:33:31 EST


Am So., 23. Dez. 2018 um 00:02 Uhr schrieb Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx>:
>
> On Sat, Dec 22, 2018 at 2:49 PM Christian Brauner
> <christian.brauner@xxxxxxxxxxxxx> wrote:
> >
> > To be fair, no one apart from me was pointing out that it actually
> > breaks people including systemd folks
> > even though I was bringing it up with them. I even tried to fix all of
> > userspace after this got NACKED
>
> Seriously, the "we don't break user space" is the #1 rule in the
> kernel, and people should _know_ it's the #1 rule.
>
> If somebody ignores that rule, it needs to be escalated to me.
> Immediately. Because I need to know.
>

I do that usually but I didn't saw Christian's revert the time and I
never hit that issue.
Just saw that now because the unusual [BREAKAGE] prefix.

> I need to know so that I can override the bogus NAK, and so that we
> can fix the breakage ASAP. The absolute last thing we need is some
> other user space then starting to rely on the new behavior, which just
> compounds the problem and makes it a *much* bigger problem.
>

Yes and you are right ..
https://github.com/lxc/lxc/pull/2438

I've added an comment there about 4.20.0.

BR,

Gabriel