From: sfjro@users.sourceforge.net
To: Hans-Peter Jansen <hpj@urpla.net>
Cc: aufs-users@lists.sourceforge.net, linux-unionfs@vger.kernel.org
Subject: Re: aufs as root vor openvz CT
Date: Wed, 23 Jul 2014 11:59:18 +0900 [thread overview]
Message-ID: <9782.1406084358@jrobl> (raw)
In-Reply-To: <1728348.LhyPPIypjG@xrated>
Hello Pete,
Thank you very much for your contribution.
I've repeatedly asked Sergey how to reproduce and the details, but got
no good answers. I hope your contribution will make the details clearer.
Hans-Peter Jansen:
> In order to perform a proper suspend/resume cycle, the CT has to arrange
> everything to the state before the suspend. Therefore, they track the opened
> files, and restore their state during resume. Layering FS (LFS) do cause
> problems in this scenario, since files opened by them don't belong to any
> application running in the container.
I'd ask generic questions (to anyone).
- Is such handling done in the container, or in the generic linux
checkpoint/restart?
- If it is done in the generic feature, then is the linux
checkpoint/restart feature specific to the containers?
- If not, we will be able to reproduce without any containers, no
openvz, no old kernel.
As a first step, I need to know the detail steps to reproduce the
problem since I don't know much about suspend/resume.
> So, either define a special open flag for LFS internal fds, which, I guess, is
> rather unpopular, or define a respective fcntl, that those LFS should
> implement. Otherwise, every CT needs to detect the internal fds of every LFS
> implementation heuristically, which is the worst solution, of course.
It depends upon how CT finds the opend files.
I have another idea.
- add a notifier-chain into the suspend feature (if there is not
currently).
- any module who opens a file internaly regists itself to the
notifier-chain.
- when the suspend event is notified via the notifier-chain, the module
handle it.
J. R. Okajima
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next prev parent reply other threads:[~2014-07-23 2:59 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CAKG6wnaq1BwLgMNy27i8ggzt_qMnUb0KVNQg=Z85nz1LbXttUg@mail.gmail.com>
[not found] ` <29716.1405886425@jrobl>
[not found] ` <CAKG6wnYsDk8_JoG8QrHZ3ZtDicnwt__6AGTod-Ozqi5gjoZTdw@mail.gmail.com>
2014-07-22 7:32 ` aufs as root vor openvz CT Hans-Peter Jansen
2014-07-23 2:59 ` sfjro [this message]
2014-08-22 12:04 ` Sergey Korshunoff
2014-12-09 16:43 ` Sergey Korshunoff
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