From owner-freebsd-hackers@FreeBSD.ORG Mon Mar 14 19:20:37 2005 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 5D86B16A4CE for ; Mon, 14 Mar 2005 19:20:37 +0000 (GMT) Received: from smtphost.cis.strath.ac.uk (smtphost.cis.strath.ac.uk [130.159.196.96]) by mx1.FreeBSD.org (Postfix) with ESMTP id A6DB143D1F for ; Mon, 14 Mar 2005 19:20:36 +0000 (GMT) (envelope-from chodgins@cis.strath.ac.uk) Received: from [192.168.0.4] (chrishodgins.force9.co.uk [84.92.20.141]) j2EJKCDp020383; Mon, 14 Mar 2005 19:20:12 GMT Message-ID: <4235E536.6080601@cis.strath.ac.uk> Date: Mon, 14 Mar 2005 19:25:42 +0000 From: Chris Hodgins User-Agent: Mozilla Thunderbird 1.0 (X11/20050204) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Anish Mistry References: <1107178792.613.22.camel@spirit> <200503131524.16075.mistry.7@osu.edu> <200503140915.53619.freebsd-hackers@evilcode.net> <200503141346.41722.mistry.7@osu.edu> In-Reply-To: <200503141346.41722.mistry.7@osu.edu> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-CIS-MailScanner-Information: Please contact support@cis.strath.ac.uk for more information X-CIS-MailScanner: Found to be clean X-CIS-MailScanner-SpamCheck: not spam, SpamAssassin (score=-4.9, required 6, BAYES_00 -4.90) X-CIS-MailScanner-From: chodgins@cis.strath.ac.uk cc: freebsd-hackers@freebsd.org cc: "Samuel J. Greear" Subject: Re: Idea about 'skeleton jail X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 14 Mar 2005 19:20:37 -0000 Anish Mistry wrote: > On Monday 14 March 2005 10:15 am, Samuel J. Greear wrote: > >>On Sunday 13 March 2005 14:24, Anish Mistry wrote: >> >>>On Sunday 13 March 2005 01:23 pm, Chris Hodgins wrote: >>> >>>>Samuel J. Greear wrote: >>>> >>>>>Not a bad 'idea' at all, although I won't comment on >>>>>semantics. I had something implemented using fs stacking (in >>>>>a very hackish way, and I believe it's lost now, so don't ask >>>>>to see it...) to implement per-jail quota's that seemed to >>>>>work quite well. >>>>> >>>>>Sam >>>> >>>>Feel free to comment on the semantics. As I said before, I am >>>>not very knowledgable about filesystems and any insight or >>>>alternative implementation you can provide would be interesting >>>>I'm sure to everyone. >>> >>>Yeah, if there was jailfs that was setup automatically for the >>>jails that supported quotas out of the box that would kill my >>>major gripe about setting up jails. >> >>Chris, your concept looks reasonable to me. I think I would >>probably do something along those lines but borrow some idea's from >>my 'jail-build' script. It has the concept of both includes and >>excludes, but it also handles another directory for what I call >>overrides. My overrides directories are per-jail and typically >>include nothing more than config. files, but it works pretty >>handily. The overrides may best be implemented in a seperate >>layer... and I don't even know that I would call something like >>this a jailfs, more like a globfs or something... I can see >>potential uses beyond jails. >> >>The reasons that I never finished implementing my jailfs with quota >>support were primarily, that stackable filesystems seem to be >>somewhat of a black-art. Secondarily, I concluded that the time >>would be better spent implementing filesystem agnostic quota's in >>the vfs layer. A proper design should enable you to do a lot of >>fun things, I was thinking something along the lines of just a >>simple aggregator that a module could hand function pointers to and >>register interest in events, with options like.. just-notify-me >>and dont-continue-without-my-approval. Throw in some helpers for >>synchronizing module state to disk. The kernel side of this >>shouldn't really be very hard, but all of the userland quota >>utilities would need to be rewritten as they are tied to UFS at the >>block level. This all from about 3 years ago, and I haven't >>implemented any of it. I rock! >> >>Sam > > Would you be able to write up some design specs for getting all this > done? This might be a prime example of something to try to get > funding for development. > I seem to have stopped receiving mail from the mailing lists. Would it be possible for someone to forward any replies on this thread for the last few hours to christopher.hodgins@gmail.com. If it would be possible for any further emails to be cc'd there as well that would be brilliant. :) Thanks Chris