device_cio_free.conf

[Dan Horák]

Waiki Wright píše v Út 06. 09. 2011 v 18:27 -0400: 
> Hello Dan,
> I saw your name in one of the bugs related to device_cio_free.conf and 
> hope that you may be able to answer my question.  If you prefer me to 
> send my inquire to a mailing list, please let me know.

I'm sending the reply to mailing list, so more people can comment.

> I am using s390utils-1.8.2-28.el6.s390x package and I am wondering if 
> there will be a race condition between rcS and device_cio_free.
> 
> The device_cio_free.conf file said that it will start when rcS.conf is 
> starting:
> #
> # free all devices on startup
> #
> 
> start on starting rcS
> 
> task
> 
> console output
> 
> exec /sbin/device_cio_free
> 
> However, in the /sbin/device_cio_free script,  it depends on /proc is 
> mounted before the script is called:
> 
> BLACKLIST=/proc/cio_ignore
> .
> .
> .
> if [ ! -f $BLACKLIST ]; then
>      echo "Error: $BLACKLIST kernel interface doesn't exist"
>      exit 2
> fi
> 
> If the file system is mounted later (from rcS), then device_cio_free 
> script will fail.  So should it be better if
> device_cio_free.conf to start on after /proc is mounted?
> 
> Your thought?

Your conclusion looks logical. However this upstart job was proposed by
our upstart maintainer when I asked him for a solution to the following
problem: need to start an action before the system will try to mount
non-root filesystem devices or bring network interfaces up. Also it
shouldn't interfere with the startup process on primary arches.

Staring with Fedora 15 there is a systemd solution, see
device_cio_free.service in s390utils-1.14.0-1.fc16 [1]


Dan

[1] http://s390.koji.fedoraproject.org/koji/buildinfo?buildID=74738