[arch-projects] [PATCH 4/7] udev: exit on shutdown

[Tom Gundersen]

On Thu, Oct 27, 2011 at 2:12 AM, Dan McGee <dpmcgee at gmail.com> wrote:
> 1. Is there a need to even call swapoff? I can't believe it is
> essential for swap partitions. It unfortunately does makes sense for
> swap files so we can later unmount the file system they live on, but
> it looks like there is no way to differentiate. Dave, I know you want
> to submit a patch to util-linux for this... :)

You are right in this, if we can only swapoff swap files that would be
more efficient (unless I'm missing something). Dave: thanks for the
work on this already!

> 2. Why do we do anything except unmounting filesystems after the
> kill_all call? It seems like we could move the random seed, and
> timezone set above it, and then kill udev, and then we'd be safe from
> any and all spawned processes.
> The only things following would be (hooks excluded) a umount call,
> vgchange/cryptsetup calls, a mount call, and either poweroff/reboot.

The reordering you propose makes sense to me, I'll do this with the
next round of patches (unless someone beats me to it).

> That seems pretty easy to audit, and I feel like you took a potshot at
> the killall thing when in fact udevd was the only bad boy in the
> corner causing trouble.

Our killall works if everyone behaves as they should (and to the best
of my knowledge, now they do). However, I guess it would not be
difficult to create a program that forks at the right times in such a
way that it would escape being killed. I think things are "good
enough" as they are now though, unless someone finds a real-life
problem, or someone proposes a fool-proof replacement.

-t