device_cio_free.conf

[Waiki Wright]

On 09/07/2011 05:17 AM, Dan Horák wrote:
> 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
>
Hi Dan,
Even with the systemd implementation, there is still a possibility for 
the race condition that I mentioned above(let me know if I am wrong).  I 
haven't seen any response for my question and I wonder if this is a 
potential problem that worth for a fix.

Waiki