somtimes rc.conf missed to be start in runlevel 6

[Alex Tu]

device: Arale
reproduce steps:
1. get reboot tool from lp:~toykeeper/+junk/reboot-test/
2. $ ./reboot-test.sh -v 30m
3. reboot failed around in 8th ~10th times

Somethings different in failed case:
1. rc.config post-stop executed with $PREVLEVEL=2 $RUNLEVEL=6
Success case rc.config post-stop executed with $PREVLEVEL=N $RUNLEVEL=2

2. "/etc/init.d/rc 6" did not be executed.

The original ticket to track this issue:
https://bugs.launchpad.net/tangxi/+bug/1453286/comments/17

[Steve Langasek (vorlon)]

Hi Alex,

It is certainly possible to hit a race in upstart when changing runlevels. The /etc/init/rc.conf job is 'start on runlevel [...]' and has no 'instance' specifier. If the rc job is still running at the time that another runlevel event is emitted, then /etc/init.d/rc will not be called for the new runlevel.

In general this isn't a major issue because /etc/init.d/rc does very little on an (Ubuntu) upstart system and exits quickly. So it's very rare that a user will be trying to change runlevel before the previous runlevel switch has completed. Indeed, this bug has existed since the beginning of upstart's use and I don't believe anyone has reported it as a problem previously.

It's possible your reboot-test script should be changed so that wait_for_boot ensures the system has entered runlevel 2 before rebooting. I'm surprised if it takes longer for /etc/init.d/rc to finish than it takes for the user session to become available. Races here are also possible, however /etc/init.d/rc *should* be very quick on the phone also. If it's not - perhaps because an init script is blocking - that is something that we will want to debug.

[Steve Langasek (vorlon)]

To be clear, what I'm looking for here by way of additional information is:

- does making your script wait until 'initctl --system list | grep -q '^rc stop/waiting' returns true give you the behavior you want?

- does making this adjustment to the script result in the reboot being much slower than expected? If so - what is running at the time?

- what are the contents of /etc/rc2.d/ on the affected system? (please attach as a tarball)

[Alex Tu (alextu)]

Hi Steve,
sorry to reply late cause I comment on original LP issue https://bugs.launchpad.net/tangxi/+bug/1453286
I'm wondering which ticket we should continue to comment on.

For 1st, 2nd questions, because the owner of that script is Selene who created LP#1453286, so I think she is the better one who familiar with that script and can answer questions .

For 3th question,
The content can be found in attached file in:
https://bugs.launchpad.net/tangxi/+bug/1453286/comments/22
https://bugs.launchpad.net/tangxi/+bug/1453286/comments/24

Hope this can be help :)

[Launchpad Janitor (janitor)]

[Expired for upstart because there has been no activity for 60 days.]