From owner-freebsd-current@FreeBSD.ORG Fri Sep 9 12:32:22 2011 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 28F8C106566B for ; Fri, 9 Sep 2011 12:32:22 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from cyrus.watson.org (cyrus.watson.org [65.122.17.42]) by mx1.freebsd.org (Postfix) with ESMTP id 00F7B8FC12 for ; Fri, 9 Sep 2011 12:32:22 +0000 (UTC) Received: from bigwig.baldwin.cx (66.111.2.69.static.nyinternet.net [66.111.2.69]) by cyrus.watson.org (Postfix) with ESMTPSA id A895646B06; Fri, 9 Sep 2011 08:32:21 -0400 (EDT) Received: from jhbbsd.localnet (unknown [209.249.190.124]) by bigwig.baldwin.cx (Postfix) with ESMTPSA id 46D7E8A037; Fri, 9 Sep 2011 08:32:21 -0400 (EDT) From: John Baldwin To: freebsd-current@freebsd.org Date: Fri, 9 Sep 2011 08:28:32 -0400 User-Agent: KMail/1.13.5 (FreeBSD/8.2-CBSD-20110617; KDE/4.5.5; amd64; ; ) References: <2047531658.973519.1315489517809.JavaMail.root@erie.cs.uoguelph.ca> In-Reply-To: <2047531658.973519.1315489517809.JavaMail.root@erie.cs.uoguelph.ca> MIME-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <201109090828.32536.jhb@freebsd.org> X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.2.6 (bigwig.baldwin.cx); Fri, 09 Sep 2011 08:32:21 -0400 (EDT) Cc: Rick Macklem Subject: Re: NFS server File Handle changing upon reboot X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 09 Sep 2011 12:32:22 -0000 On Thursday, September 08, 2011 9:45:17 am Rick Macklem wrote: > Hiroki Sato spotted a problem with NFS server file handles (FHs) > changing after a server upgrade, because the exported file > system type(s) get configured in a different order and, therefore, > assigned different vfs_typenum values. > > A patch has been worked out, after discussion with various folks, > that uses a hash function to assign the vfs_typenum values. > > This fixes the problem, except it has one downside: > - The first server boot after the patch has been applied will > result in FHs changing and, as such, NFS clients > will need to remount after this upgrade. > > So, finally to why I am posting, which is to ask for opinions > on what should be done with this patch? > 1 - Ask re@ for permission to commit this to -current for 9.0, > so that the FH change happens at the 8.X->9.0 upgrade. > (It does seem that if some variant of this should go in, then > a major release seems like the correct time to do it?) > 2 - Add a loader.conf variable to the patch, which would allow > a sysadmin to "flip the switch" when it is convenient for > them. (I do have a concern that this might just cause more > confusion w.r.t. when/what needs to be done.) > 3 - Do #2, for 8.X and make the patch the default for 9.0. > 4 - Forget the patch and leave things the way the are now. Well, I would do 3a: Generate the patch in 2 and merge it to 8, but in 8 have the default be the existing behavior. In 10 you can remove the switch altogether. -- John Baldwin