From: Lennart Poettering <lennart@poettering.net>
To: Andrey Borzenkov <arvidjaar@gmail.com>
Cc: linux-raid@vger.kernel.org,
SystemD Devel <systemd-devel@lists.freedesktop.org>
Subject: Re: systemd kills mdmon if it was started manually by user
Date: Fri, 7 Jan 2011 01:38:27 +0100 [thread overview]
Message-ID: <20110107003827.GD21627@tango.0pointer.de> (raw)
In-Reply-To: <AANLkTimHWjC5RrgZc6egrhgDLwX3zAi9ZPSvZomB2gW-@mail.gmail.com>
On Sat, 04.12.10 11:41, Andrey Borzenkov (arvidjaar@gmail.com) wrote:
> If user starts array manually (mdadm -A -s as example) from within
> user session and array needs mdmon, mdmon becomes part of user session
> control group:
Are you suggesting that mdadm forks off mdmon from within the user
session? This is horribly ugly and broken and they shouldn't do that.
>
> ├ user
> │ └ root
> │ └ 1
> │ ├ 1916 login -- root
> │ ├ 1930 -bash
> │ ├ 1964 gpg-agent --keep-display --daemon --write-env-file /root/.gnup...
> │ └ 2062 mdmon md127
>
>
> It is then killed by systemd during shutdown as part of user session.
Well, only if you enable that the user session is completely killed on
logout, which we currently don't do by default.
I wonder if it would make sense to add an option which kills user
sessions on log out only for uid != 0. This might help here, but only
half-way, since sudo would still break. But anyway, I'll add this to the
todo list.
> It results in dirty array on next boot.
Hmm, that shouldn't happen.
> Is there any magic that allows daemon to be exempted from killing?
Well, I have been discussing this with Kay and we'll most likely add
something like DontKillOnShutdown=yes or so, which if added to a unit
file will exempt it from killing during the normal service shutdown
phase, and the first killing spree (but not the second, post-umount
killing spree). But that of course would require mdmon to be started
like any other daemon, and not forked off mdadm.
That should mostly fix the problem, but then again I do believe that the
whole idea of mdmon is just borked, since it will necessarily pin page
from the root fs into memory which will create all kinds of problems,
for example after upgrades (i.e. mdmon maps libc into memory, libc gets
updated, the old libc deleted, which cannot be written to disk as long
as mdmon stays running pinning it, which will disallow the ultimate
unmounting/remounting of the fs).
Lennart
--
Lennart Poettering - Red Hat, Inc.
_______________________________________________
systemd-devel mailing list
systemd-devel@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/systemd-devel
next prev parent reply other threads:[~2011-01-07 0:38 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-12-04 8:41 systemd kills mdmon if it was started manually by user Andrey Borzenkov
2010-12-04 9:12 ` Christian Parpart
2010-12-04 12:08 ` Andrey Borzenkov
2010-12-12 13:20 ` [systemd-devel] " Luca Berra
2011-01-07 0:40 ` Lennart Poettering
[not found] ` <20101204121413.GC11336@mother.pipebreaker.pl>
[not found] ` <AANLkTi=nTSdHc55f08G9sdEK6u8eXp276VOTHHr0jmXT@mail.gmail.com>
[not found] ` <20110125034434.GC7046@tango.0pointer.de>
[not found] ` <AANLkTik189VTXYpzLFqP=MNBg=Nx-Yq6BOKURtiby++B@mail.gmail.com>
[not found] ` <20110125042814.GA9727@tango.0pointer.de>
2011-02-04 19:55 ` Andrey Borzenkov
2011-02-08 9:48 ` [systemd-devel] " Lennart Poettering
2011-02-08 10:52 ` Andrey Borzenkov
2011-02-08 11:07 ` Lennart Poettering
2011-02-08 13:54 ` Andrey Borzenkov
2011-02-08 17:28 ` [systemd-devel] " Lennart Poettering
2011-10-23 8:00 ` Dan Williams
2011-10-24 8:04 ` Thomas Jarosch
2011-10-25 1:40 ` NeilBrown
2011-10-31 11:06 ` Lennart Poettering
2011-10-31 11:15 ` [systemd-devel] " Lennart Poettering
2011-11-02 0:44 ` NeilBrown
2011-11-02 1:16 ` Lennart Poettering
2011-11-02 2:03 ` NeilBrown
2011-11-02 13:32 ` Lennart Poettering
2011-11-02 14:33 ` Kay Sievers
2011-11-02 15:17 ` Lennart Poettering
2011-11-02 15:21 ` Kay Sievers
2011-11-02 15:29 ` [systemd-devel] " Lennart Poettering
2011-11-02 22:18 ` Williams, Dan J
2011-11-02 23:39 ` Lennart Poettering
2011-11-03 0:28 ` Williams, Dan J
2011-11-02 17:21 ` Williams, Dan J
2011-11-02 23:35 ` Lennart Poettering
2011-11-02 18:16 ` Williams, Dan J
2011-11-02 18:49 ` Kay Sievers
2011-11-02 19:31 ` Williams, Dan J
2011-11-02 19:51 ` Kay Sievers
2011-11-07 2:52 ` NeilBrown
2011-11-07 3:42 ` Kay Sievers
2011-11-07 4:30 ` NeilBrown
2011-11-07 12:00 ` Lennart Poettering
2011-11-07 19:09 ` Williams, Dan J
2011-11-08 14:43 ` Lennart Poettering
2011-11-08 23:27 ` Williams, Dan J
2011-11-08 0:11 ` Michal Soltys
2011-11-08 16:46 ` Michal Soltys
2011-11-08 20:32 ` Michal Soltys
2011-11-08 22:29 ` Williams, Dan J
2011-02-09 14:01 ` Lennart Poettering
2011-01-07 0:38 ` Lennart Poettering [this message]
2011-01-07 1:09 ` Michael Biebl
2011-01-07 1:17 ` Roman Mamedov
2011-01-07 1:16 ` NeilBrown
2011-01-07 1:42 ` Lennart Poettering
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20110107003827.GD21627@tango.0pointer.de \
--to=lennart@poettering.net \
--cc=arvidjaar@gmail.com \
--cc=linux-raid@vger.kernel.org \
--cc=systemd-devel@lists.freedesktop.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).