[systemd-devel] [PATCH] Avoid reloading services when shutting down

[Martin Pitt]

Lennart Poettering [2015-02-03 17:29 +0100]:
> Hmm, why precisely does this stall for 90s? 

The current transaction has final.target and all other jobs which need
to be shut down. One of these now trigger "systemctl reload
postfix.service", but that reload isn't going to actually run in the
same transaction but in the next one. OTOH systemctl reload
waits for the reloading to finish, thus we have a deadlock.

> Isn't this a case where people should just use "--no-block"?

Kind of. Not using this is the right thing while the machine is
running, so that the reload is actually done after calling systemctl
reload, and you can go on using postfix or whatever. --no-block should
help during shutdown, or early boot (same principal bug, but slightly
different patch, see http://bugs.debian.org/624599).

So every time you call reload you'd have to check whether or not you
are in early boot/during shutdown, or in the running system, and
conditionally use --no-block. However, as such scripts should never
call systemctl directly, but "service foo reload" (to work with other
init systems or chroot), it would be also possible to move that check
there, and conditionally add --no-block. It would just be another
thing that every distro has to re-discover :-)

Thanks,

Martin

-- 
Martin Pitt                        | http://www.piware.de
Ubuntu Developer (www.ubuntu.com)  | Debian Developer  (www.debian.org)