From owner-freebsd-fs@FreeBSD.ORG Fri Jun 24 00:23:51 2011 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (unknown [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id A9D56106566B; Fri, 24 Jun 2011 00:23:51 +0000 (UTC) (envelope-from rmacklem@uoguelph.ca) Received: from esa-jnhn.mail.uoguelph.ca (esa-jnhn.mail.uoguelph.ca [131.104.91.44]) by mx1.freebsd.org (Postfix) with ESMTP id 3BED88FC15; Fri, 24 Jun 2011 00:23:50 +0000 (UTC) X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: Ap0EAFPYA06DaFvO/2dsb2JhbABShEmjXYhzsVyQcYErg3iBCgSRcpAq X-IronPort-AV: E=Sophos;i="4.65,416,1304308800"; d="scan'208";a="128858867" Received: from erie.cs.uoguelph.ca (HELO zcs3.mail.uoguelph.ca) ([131.104.91.206]) by esa-jnhn-pri.mail.uoguelph.ca with ESMTP; 23 Jun 2011 20:23:49 -0400 Received: from zcs3.mail.uoguelph.ca (localhost.localdomain [127.0.0.1]) by zcs3.mail.uoguelph.ca (Postfix) with ESMTP id 0D7BCB3F3B; Thu, 23 Jun 2011 20:23:50 -0400 (EDT) Date: Thu, 23 Jun 2011 20:23:50 -0400 (EDT) From: Rick Macklem To: Kostik Belousov Message-ID: <1437987696.1010265.1308875030014.JavaMail.root@erie.cs.uoguelph.ca> In-Reply-To: <20110623222630.GU48734@deviant.kiev.zoral.com.ua> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Originating-IP: [172.17.91.202] X-Mailer: Zimbra 6.0.10_GA_2692 (ZimbraWebClient - IE7 (Win)/6.0.10_GA_2692) Cc: freebsd-fs@freebsd.org, Robert Watson , Garance A Drosehn Subject: Re: [rfc] 64-bit inode numbers X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 24 Jun 2011 00:23:51 -0000 Kostik Belousov wrote: > On Thu, Jun 23, 2011 at 06:05:56PM -0400, Garance A Drosehn wrote: > > On 6/23/11 4:11 AM, Kostik Belousov wrote: > > >On Thu, Jun 23, 2011 at 09:43:33AM +0300, Gleb Kurtsou wrote: > > > > > >>On (22/06/2011 19:19), Garance A Drosehn wrote: > > >> > > >>>Sorry for replying to an older message, but a reply made in a > > >>>different > > >>>thread reminded me about this project... > > >>> > > >>>Also, I may have asked this before. In fact, I'm almost sure that > > >>>I > > >>>started > > >>>a reply to this back in Jan/Feb, but my email client claims I > > >>>never > > >>>replied > > >>>to this topic... > > >>> > > >>>Are you increasing only the size of ino_t, or could you also look > > >>>at > > >>>increasing the size of dev_t? (just curious...) > > >>> > > >>Sure. Incorporating as much of similar changes as possible is > > >>good. > > >>I've added Kostik and Matthew to CC list, it's for them to decide. > > >> > > >>dev_t on other OSes: > > >> NetBSD - uint64_t > > >> DragonFly - uint32_t > > >> Darwin - __int32_t > > >> OpenSolaris - ulong_t > > >> Linux - __u32 > > >> > > >>Considering this I think 3rd party software is not ready for such > > >>change. > > >> > > >>Major/minor mapping to dev_t will get more complicated. > > >> > > >>And the most important question: what would you want it for? [...] > > >> > > >Indeed, this is the right question. > > > > > Consider the thread "Increasing the size of dev_t and ino_t" from > > freebsd-arch in 2002: > > > > http://docs.freebsd.org/mail/archive/2002/freebsd-arch/20020317.freebsd-arch.html > > > > In particular, this message by Robert Watson: > > > > http://docs.freebsd.org/cgi/getmsg.cgi?fetch=139853+0+archive/2002/freebsd-arch/20020317.freebsd-arch > > > > I just participated in an online conference for OpenAFS, and while > > it > > isn't exactly taking the world by storm, I keep thinking it would be > > useful if FreeBSD could map individual AFS volumes to unique dev_t > > identifiers. And given the way AFS is implemented (as a global > > filesystem > > with many cells all reachable at the same time), and given the way > > most > > sites deploy AFS (with thousands or tens-of-thousands of individual > > AFS > > volumes *per site*), that adds up to a lot of values for dev_t. > > > > The upcoming release of OpenAFS should include a working and pretty > > stable AFS client for FreeBSD, so having a larger dev_t would have a > > more immediate application than it did back in 2002. > Am I right that the issue is the uniqueness of the dev_t for each > AFS volume, as reported by stat(2) ? > > Shouldn't the AFS client synthesize the dev_t for each new volume > mounted ? It seems that the current 32bit dev_t would be enough, > since I do not expect to see hundreds of thousands of mounts > on an single system. > I think the main concern is making sure that the value is not the same as what another mount already has. That's why mnt_stat.f_fsid is synthesized for NFS, I think? > Please note that we do not guarantee dev_t stability across reboots > even > for real devices.