From owner-freebsd-stable@FreeBSD.ORG Thu Sep 4 18:56:36 2003 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 2F28516A4BF for ; Thu, 4 Sep 2003 18:56:36 -0700 (PDT) Received: from HAL9000.homeunix.com (12-233-57-131.client.attbi.com [12.233.57.131]) by mx1.FreeBSD.org (Postfix) with ESMTP id 6482243FFB for ; Thu, 4 Sep 2003 18:56:35 -0700 (PDT) (envelope-from das@FreeBSD.ORG) Received: from HAL9000.homeunix.com (localhost [127.0.0.1]) by HAL9000.homeunix.com (8.12.9/8.12.9) with ESMTP id h851uTG7014976; Thu, 4 Sep 2003 18:56:29 -0700 (PDT) (envelope-from das@FreeBSD.ORG) Received: (from das@localhost) by HAL9000.homeunix.com (8.12.9/8.12.9/Submit) id h851uRes014975; Thu, 4 Sep 2003 18:56:27 -0700 (PDT) (envelope-from das@FreeBSD.ORG) Date: Thu, 4 Sep 2003 18:56:27 -0700 From: David Schultz To: Alexandr Kovalenko Message-ID: <20030905015627.GB14776@HAL9000.homeunix.com> Mail-Followup-To: Alexandr Kovalenko , "Marc G. Fournier" , freebsd-stable@freebsd.org References: <20030612154312.J80219@hub.org> <20030623081927.GC27017@nevermind.kiev.ua> <20030901160043.GB78655@nevermind.kiev.ua> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20030901160043.GB78655@nevermind.kiev.ua> cc: freebsd-stable@FreeBSD.ORG Subject: Re: unionfs related patch X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 05 Sep 2003 01:56:36 -0000 On Mon, Sep 01, 2003, Alexandr Kovalenko wrote: > Hello, Alexandr Kovalenko! > > On Mon, Jun 23, 2003 at 11:19:27AM +0300, you wrote: > > > > David Schultz, in his spare time, has been working through some of the > > > issues I've been able to 'tweak' in the unionfs code ... as he is > > > currently working on forward-patching it to -CURRENT right now, he can't > > > commit the code to the -STABLE tree ... in order to allow others using > > > unionfs to test the patch (I've been running it a few weeks now on a very > > > heavily loaded system), with his permission, I've posted the patch for > > > download at: > > > > > > http://www.hub.org/~scrappy/unionfs > > > > Looks like it pretty stable. I'm running ~10 days with this patch - no > > even single panic. Thank you! > > I was too optimistic. It panics on high loads after 3-10 days. > Is there any progress in work on this patch? The only thing I know to be wrong with the patch is that it looks like I forgot to MFC it. Oops. Unfortunately, there's plenty wrong with unionfs, even with the patch. Fundamentally, there are some design problems with VFS in FreeBSD that make a clean implementation of unionfs impossible; 90% of the brokenness in unionfs is due to unionfs having to create an illusion of layering that doesn't really exist. Fixing some of the underlying problems is one of the goals for FreeBSD 6.X. For now, my free time is very limited, so it's hard for me to justify spending it on fixing a hack on top of a hack. But if I get a chance, I'll see what I can do. I have a list of all the interesting PRs on the topic, including some that were closed because ``unionfs is broken''.