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From: Dan Smith <danms-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
To: "Serge E. Hallyn" <serue-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
Cc: containers-qjLDD68F18O7TbgM5vRIOg@public.gmane.org
Subject: Re: [PATCH] c/r: Take uts_sem during checkpoint and restart
Date: Thu, 16 Apr 2009 09:47:45 -0700	[thread overview]
Message-ID: <87bpqwa6ku.fsf@caffeine.danplanet.com> (raw)
In-Reply-To: 20090416163340.GB20736@us.ibm.com

SH> At checkpoint, you only need the uts_sem right around the reading
SH> (and length-checking) of uts_ns->name.  You're keeping it around
SH> writing into the checkpoint image (and cr_hbuf_get).

Right, okay.

SH> At restart, you shouldn't actually need uts_sem - the nsproxy is
SH> not yet available to anyone else, so there is no chance of a race,
SH> right?  Hmm, well maybe I'm being overly optimistic, since restart
SH> is coordinated by userspace which could mess up and somehow run
SH> sethostname(2) while it's supposed to be running sys_restart().
SH> But then sys_restart() wouldn't yet have hooked up the task to the
SH> new nsproxy.

Good, you passed the test.  Yeah, that's it... :)

-- 
Dan Smith
IBM Linux Technology Center
email: danms-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org

  reply	other threads:[~2009-04-16 16:47 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-04-16 15:59 [PATCH] c/r: Take uts_sem during checkpoint and restart Dan Smith
     [not found] ` <1239897585-19246-1-git-send-email-danms-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
2009-04-16 16:33   ` Serge E. Hallyn
2009-04-16 16:47     ` Dan Smith [this message]
     [not found]       ` <87bpqwa6ku.fsf-FLMGYpZoEPULwtHQx/6qkW3U47Q5hpJU@public.gmane.org>
2009-04-16 16:51         ` Serge E. Hallyn

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