From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D3536C31E46 for ; Wed, 12 Jun 2019 12:39:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B0C5420896 for ; Wed, 12 Jun 2019 12:39:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727762AbfFLMjh (ORCPT ); Wed, 12 Jun 2019 08:39:37 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54844 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727047AbfFLMjh (ORCPT ); Wed, 12 Jun 2019 08:39:37 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 31A7880F7C; Wed, 12 Jun 2019 12:39:31 +0000 (UTC) Received: from madhat.boston.devel.redhat.com (ovpn-116-232.phx2.redhat.com [10.3.116.232]) by smtp.corp.redhat.com (Postfix) with ESMTP id A8457614C4; Wed, 12 Jun 2019 12:39:28 +0000 (UTC) Subject: Re: [PATCH 0/9] Multiple network connections for a single NFS mount. To: NeilBrown , Chuck Lever , Olga Kornievskaia Cc: Anna Schumaker , Trond Myklebust , Linux NFS Mailing List References: <155917564898.3988.6096672032831115016.stgit@noble.brown> <001DED71-0E0D-46B1-BA34-84E6ACCBB79F@oracle.com> <87muj3tuuk.fsf@notabene.neil.brown.name> <4316E30B-1BD7-4F0E-8375-03E9F85FFD2B@oracle.com> <87lfy9vsgf.fsf@notabene.neil.brown.name> <3B887552-91FB-493A-8FDF-411562811B36@oracle.com> <16D30334-67BE-4BD2-BE69-1453F738B259@oracle.com> <877e9rwuy5.fsf@notabene.neil.brown.name> From: Steve Dickson Message-ID: Date: Wed, 12 Jun 2019 08:39:28 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <877e9rwuy5.fsf@notabene.neil.brown.name> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Wed, 12 Jun 2019 12:39:36 +0000 (UTC) Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org On 6/11/19 7:42 PM, NeilBrown wrote: > On Tue, Jun 11 2019, Chuck Lever wrote: > >> >> Earlier in this thread, Neil proposed to make nconnect a hint. Sounds >> like the long term plan is to allow "up to N" connections with some >> mechanism to create new connections on-demand." maxconn fits that idea >> better, though I'd prefer no new mount options... the point being that >> eventually, this setting is likely to be an upper bound rather than a >> fixed value. > > When I suggested making at I hint, I considered and rejected the the > idea of making it a maximum. Maybe I should have been explicit about > that. > > I think it *is* important to be able to disable multiple connections, > hence my suggestion that "nconnect=1", as a special case, could be a > firm maximum. > My intent was that if nconnect was not specified, or was given a larger > number, then the implementation should be free to use however many > connections it chose from time to time. The number given would be just > a hint - maybe an initial value. Neither a maximum nor a minimum. > Maybe we should add "nonconnect" (or similar) to enforce a single > connection, rather than overloading "nconnect=1" > > You have said elsewhere that you would prefer configuration in a config > file rather than as a mount option. > How do you imagine that configuration information getting into the > kernel? > Do we create /sys/fs/nfs/something? or add to /proc/sys/sunrpc > or /proc/net/rpc .... we have so many options !! > There is even /sys/kernel/debug/sunrpc/rpc_clnt, but that is not > a good place for configuration. > > I suspect that you don't really have an opinion, you just don't like the > mount option. However I don't have that luxury. I need to put the > configuration somewhere. As it is per-server configuration the only > existing place that works at all is a mount option. > While that might not be ideal, I do think it is most realistic. > Mount options can be deprecated, and carrying support for a deprecated > mount option is not expensive. > > The option still can be placed in a per-server part of > /etc/nfsmount.conf rather than /etc/fstab, if that is what a sysadmin > wants to do. +1 making it per-server is the way to go... IMHO... steved.