From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44161) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b4XvW-0008BP-SV for qemu-devel@nongnu.org; Sun, 22 May 2016 14:16:35 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1b4XvS-0004Wp-P1 for qemu-devel@nongnu.org; Sun, 22 May 2016 14:16:34 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36514) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b4XvS-0004Wi-J6 for qemu-devel@nongnu.org; Sun, 22 May 2016 14:16:30 -0400 Date: Sun, 22 May 2016 19:16:25 +0100 From: "Richard W.M. Jones" Message-ID: <20160522181625.GQ1683@redhat.com> References: <1455640486-6101-1-git-send-email-pbonzini@redhat.com> <1455640486-6101-24-git-send-email-pbonzini@redhat.com> <20160517095339.GD28935@redhat.com> <573B342E.8030208@redhat.com> <5ED6FB6F-5023-4833-83F9-B24BD379E2CD@alex.org.uk> <573B3E3E.60902@redhat.com> <573B4BB9.50701@redhat.com> <20160521215312.GA8497@grep.be> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160521215312.GA8497@grep.be> Subject: Re: [Qemu-devel] [Nbd] [PULL 23/28] nbd: always query export list in fixed new style protocol List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Wouter Verhelst Cc: Eric Blake , Alex Bligh , "nbd-general@lists.sourceforge.net" , Paolo Bonzini , "Daniel P. Berrange" , "qemu-devel@nongnu.org" On Sat, May 21, 2016 at 11:53:12PM +0200, Wouter Verhelst wrote: > On Tue, May 17, 2016 at 10:50:01AM -0600, Eric Blake wrote: > > Option 2: An alternative solution would be to allow nbdkit to fail > > NBD_OPT_LIST with NBD_REP_ERR_UNSUP, at which point qemu client of 2.6 > > should just ignore the failure and proceed on to NBD_OPT_EXPORT_NAME. > > It is the fact that it is returning NBD_REP_ACK with 0 names that is > > giving qemu grief. > > I think this makes most sense. If you don't look at export names, you > effectively don't support them, and you can't be expected to send a list > of "supported" names, because *everything* is supported (or, put a > different way, nothing is). > > I note that nbdkit has been patched to now send the empty name, which > is also fine as a way to fix interoperability in this particular case -- nbdkit now fully supports export names via the '-e' option. This discussion is moot. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-p2v converts physical machines to virtual machines. Boot with a live CD or over the network (PXE) and turn machines into KVM guests. http://libguestfs.org/virt-v2v