From owner-freebsd-virtualization@FreeBSD.ORG Fri Aug 22 16:31:31 2008 Return-Path: Delivered-To: freebsd-virtualization@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 0EC53106566C for ; Fri, 22 Aug 2008 16:31:31 +0000 (UTC) (envelope-from julian@elischer.org) Received: from outP.internet-mail-service.net (outp.internet-mail-service.net [216.240.47.239]) by mx1.freebsd.org (Postfix) with ESMTP id E87378FC17 for ; Fri, 22 Aug 2008 16:31:30 +0000 (UTC) (envelope-from julian@elischer.org) Received: from idiom.com (mx0.idiom.com [216.240.32.160]) by out.internet-mail-service.net (Postfix) with ESMTP id E07B52446; Fri, 22 Aug 2008 09:31:30 -0700 (PDT) Received: from julian-mac.elischer.org (localhost [127.0.0.1]) by idiom.com (Postfix) with ESMTP id 1B0C92D60D4; Fri, 22 Aug 2008 09:31:30 -0700 (PDT) Message-ID: <48AEE9DF.3000400@elischer.org> Date: Fri, 22 Aug 2008 09:31:27 -0700 From: Julian Elischer User-Agent: Thunderbird 2.0.0.16 (Macintosh/20080707) MIME-Version: 1.0 To: Brooks Davis , freebsd-virtualization@freebsd.org, James Gritton References: <20080822090448.GB57441@onelab2.iet.unipi.it> <48AE89DC.9080408@yandex.ru> <20080822120525.GA1366@haakonia.hitnet.RWTH-Aachen.DE> <20080822145616.GA61094@onelab2.iet.unipi.it> <20080822150728.GB57443@lor.one-eyed-alien.net> In-Reply-To: <20080822150728.GB57443@lor.one-eyed-alien.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Subject: Re: Magic symlinks redux X-BeenThere: freebsd-virtualization@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Discussion of various virtualization techniques FreeBSD supports." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 22 Aug 2008 16:31:31 -0000 Brooks Davis wrote: > On Fri, Aug 22, 2008 at 04:56:16PM +0200, Luigi Rizzo wrote: >> On Fri, Aug 22, 2008 at 02:05:26PM +0200, Christian Brueffer wrote: >>> On Fri, Aug 22, 2008 at 12:24:41PM +0200, Ivan Voras wrote: >> ... >>>> This patch is huge. As far as I can tell DragonflyBSD has a whole >>>> framework dedicated to varsyms, spread across a fair part of the kernel >>>> and with at least one special userland utility. It allows the operator >>>> to define his own variables that can be used in the substitutions, and I >>>> don't see that it predefines "special" variables like "uid" and >>>> "hostname". It's not necessarily a bad solution but I consider it overkill. >> ... >>> Brooks has a varsym port in p4, see //depot/user/brooks/varsym/ >> this also seems to be based on Dragonfly's code, quite intrusive. > > This code adds one global symbol, one function call in the vfs code, > and two pointers to struct proc. For that we get a system which is > significantly more flexible than the NetBSD code. > > While the simplicity of the NetBSD code is somewhat attractive, the > fact that variables can not be defined renders it useless for my > purposes which are providing partial file system virtulization for > computing job/sessions where I need to key off of externally derived job > IDs or job specific temporary paths. then this needs to be put on the virtualisation mailing list (CC'd) as Jamie and Vereo have another implementationt eh yare getting ready I thing.. (with considerably different proporties especially designed for use with virtualisation) Verio have thsi in production. > > -- Brooks > >> I am playing with a rewrite (attached below) of the original patch, >> which fixes at least one memory leak and addresses some of the >> issues that i mentioned in this thread (abuse of macros, performance, >> behaviour on errors, etc.). >> >> (i haven't looked up yet the original copyright but i guess it >> is from netbsd...) >> >> cheers >>