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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 97684C5DF60 for ; Fri, 8 Nov 2019 17:22:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7839A207FA for ; Fri, 8 Nov 2019 17:22:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727959AbfKHRWd (ORCPT ); Fri, 8 Nov 2019 12:22:33 -0500 Received: from tragedy.dreamhost.com ([66.33.205.236]:50352 "EHLO tragedy.dreamhost.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726049AbfKHRWd (ORCPT ); Fri, 8 Nov 2019 12:22:33 -0500 Received: from localhost (localhost [127.0.0.1]) by tragedy.dreamhost.com (Postfix) with ESMTPS id 0F93115F884; Fri, 8 Nov 2019 09:22:29 -0800 (PST) Date: Fri, 8 Nov 2019 17:22:28 +0000 (UTC) From: Sage Weil X-X-Sender: sage@piezo.novalocal To: Luis Henriques cc: Ilya Dryomov , Jeff Layton , "Yan, Zheng" , Ceph Development , LKML Subject: Re: [RFC PATCH 0/2] ceph: safely use 'copy-from' Op on Octopus OSDs In-Reply-To: <20191108171616.GA2569@hermes.olymp> Message-ID: References: <20191108141555.31176-1-lhenriques@suse.com> <20191108164758.GA1760@hermes.olymp> <20191108171616.GA2569@hermes.olymp> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-VR-STATUS: OK X-VR-SCORE: -100 X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgedufedruddvuddguddtvdcutefuodetggdotefrodftvfcurfhrohhfihhlvgemucggtfgfnhhsuhgsshgtrhhisggvpdfftffgtefojffquffvnecuuegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjughrpeffhffvufgjkfhffgggtgesthdtredttdervdenucfhrhhomhepufgrghgvucghvghilhcuoehsrghgvgesnhgvfigurhgvrghmrdhnvghtqeenucfkphepuddvjedrtddrtddrudenucfrrghrrghmpehmohguvgepshhmthhppdhhvghloheplhhotggrlhhhohhsthdpihhnvghtpeduvdejrddtrddtrddupdhrvghtuhhrnhdqphgrthhhpefurghgvgcuhggvihhluceoshgrghgvsehnvgifughrvggrmhdrnhgvtheqpdhmrghilhhfrhhomhepshgrghgvsehnvgifughrvggrmhdrnhgvthdpnhhrtghpthhtoheplhhinhhugidqkhgvrhhnvghlsehvghgvrhdrkhgvrhhnvghlrdhorhhgnecuvehluhhsthgvrhfuihiivgeptd Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 8 Nov 2019, Luis Henriques wrote: > On Fri, Nov 08, 2019 at 04:57:27PM +0000, Sage Weil wrote: > > On Fri, 8 Nov 2019, Luis Henriques wrote: > > > On Fri, Nov 08, 2019 at 04:15:35PM +0100, Ilya Dryomov wrote: > > > > If the OSD checked for unknown flags, like newer syscalls do, it would > > > > be super easy, but it looks like it doesn't. > > > > > > > > An obvious solution is to look at require_osd_release in osdmap, but we > > > > don't decode that in the kernel because it lives the OSD portion of the > > > > osdmap. We could add that and consider the fact that the client now > > > > needs to decode more than just the client portion a design mistake. > > > > I'm not sure what can of worms does that open and if copy-from alone is > > > > worth it though. Perhaps that field could be moved to (or a copy of it > > > > be replicated in) the client portion of the osdmap starting with > > > > octopus? We seem to be running into it on the client side more and > > > > more... > > > > > > I can't say I'm thrilled with the idea of going back to hack into the > > > OSDs code again, I was hoping to be able to handle this with the > > > information we already have on the connection peer_features field. It > > > took me *months* to have the OSD fix merged in so I'm not really > > > convinced a change to the osdmap would make it into Octopus :-) > > > > > > (But I'll have a look at this and see if I can understand what moving or > > > replicating the field in the osdmap would really entail.) > > > > Adding a copy of require_osd_release in the client portion of the map is > > an easy thing to do (and probably where it should have gone in the first > > place!). Let's do that! > > Yeah, after sending my reply to Ilya I took a quick look and it _seems_ > to be as easy as adding a new encode(require_osd_release...) in the > OSDMap. And handle the versions, of course. Let me spend some time > playing with that and I'll try to come up with something during the next > few days. - You'll need to add it for both OSDMap::Incremental and OSDMap - You'll need to make the encoding condition by updating the block like the one below from OSDMap::encode() uint8_t v = 9; if (!HAVE_FEATURE(features, SERVER_LUMINOUS)) { v = 3; } else if (!HAVE_FEATURE(features, SERVER_MIMIC)) { v = 6; } else if (!HAVE_FEATURE(features, SERVER_NAUTILUS)) { v = 7; } to include a SERVER_OCTOPUS case too. Same goes for Incremental::encode() sage