[arch-projects] [PATCH] shutdown: add a shutdown hook

[Dave Reisner]

On Fri, Jul 22, 2011 at 09:31:23AM -0400, Dave Reisner wrote:
> On Fri, Jul 22, 2011 at 03:10:58PM +0200, Tom Gundersen wrote:
> > On Fri, Jul 22, 2011 at 2:58 PM, Tom Gundersen <teg at jklm.no> wrote:
> > > On Fri, Jul 22, 2011 at 1:45 PM, Tom Gundersen <teg at jklm.no> wrote:
> > >> Enabling the shutdown hook and using systemd v31
> > >> (which is yet to be released), means that on shutdown the root
> > >> will be pivoted to /run/initramfs, from where the rootfs and
> > >> all its submonuts (such as /usr) are unmounted cleanly.
> > >
> > > Looks like I made a mistake. This only works with busybox from
> > > [community], not with mkinitcpio-busybox from [core].
> > >
> > > It looks like there are two problematic differences: our busybox does
> > > not come with "tr", and the --install function creates symlinkes to
> > > /bin/busybox, rather than to the calling binary
> > > (/run/initramfs/bin/busybox, in this case).
> > 
> > Looks easy to fix. Any objections to changing the mkinitrd-busybox config
> > from:
> > CONFIG_BUSYBOX_EXEC_PATH="/bin/busybox"
> > # CONFIG_TR is not set
> > to:
> > CONFIG_BUSYBOX_EXEC_PATH="/proc/self/exe"
> > CONFIG_TR=y
> > 
> > When busybox is installed in the initramfs, we have /proc/self/exe ->
> > /bin/busybox, so it should not make a difference (though, I have not
> > actually tried, will do later).
> > 
> > Cheers,
> > 
> > Tom
> 
> I object. The usage of tr isn't necessary in your pipeline. You can
> remove it and everything will still just work. Furthermore....
> 
>   umount $(mount | awk '
>   $3 ~ /^\/oldroot/ {
>     umount[NR] = $3;
>   }
>   END { for (i = NR; i >= 0; i--) {
>     if (umount[i]) {
>       umount[i]

Of course i meant 'print umount[i]' here.

>     }
>   }')
> 
> How does busybox behave with the exec path as /proc/self/exe prior to
> /proc being mounted?
> 
> d