Messages in this thread |  | | From | Linus Torvalds <> | Date | Sat, 22 Dec 2018 15:01:55 -0800 | Subject | Re: [BREAKAGE] Since 4.18, kernel sets SB_I_NODEV implicitly on userns mounts, breaking systemd-nspawn |
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On Sat, Dec 22, 2018 at 2:49 PM Christian Brauner <christian.brauner@canonical.com> 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 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.
But I also need to know so that I can then make sure I know not to trust the person who broke rule #1.
This is not some odd corner case for the kernel. This is literally the rule we have lived with for *decades*.
So please escalate to me whenever you feel a kernel developer doesn't follow the first rule. Because the code that broke things *will* be reverted (*).
Linus
(*) Yes, there are exceptions. We have had situations where some interface was simply just a huge security issue or had some other fundamental issue. And we've had cases where the breakage was just so old that it was no longer fixable. So even rule #1 can sometimes have things that hold it back. But it is *very* rare. Certainly nothing like this.
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