Comment # 71 on bug 1055641 from Franck Bui

(In reply to Olli Tuominen from comment #65)
> Of course there is "killing all remain processes" between systemd-shutdown |
> shutdown: can this release lock to unmount system-root?

That could be indeed a possibility...

Ok last try:

 - please create the following script:

> # cat foo.sh 
> #!/bin/bash
>
> for p in /proc/[0-9]*; do
>	for l in $(ls -l $p/ $p/fd 2>/dev/null); do
>		case $l in
>		*$1*)
>			printf "%s: %s\n" $(< $p/comm) $(< $p/cmdline)
>		esac
>	done
> done

 - make it executable : chmod +x foo.sh

 - include it in the initramfs: "mkinitrd --install $(pwd)/foo.sh"
   (make sure to use an absolute path with --install otherwise dracut
    will silently ignore the option :-/)

 - make sure the script has been included : "lsinitrd | grep foo"

 - break in the *pre-shutdown* step

 - execute the script: "/root/foo.sh /oldroot"
   (assuming that the script was initially created in /root

 - please post the result of the script (if any)

Thanks.