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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,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 78386C433DF for ; Fri, 19 Jun 2020 20:40:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5298521531 for ; Fri, 19 Jun 2020 20:40:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fieldses.org header.i=@fieldses.org header.b="BPPgIJGr" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390636AbgFSUkf (ORCPT ); Fri, 19 Jun 2020 16:40:35 -0400 Received: from fieldses.org ([173.255.197.46]:44106 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390600AbgFSUke (ORCPT ); Fri, 19 Jun 2020 16:40:34 -0400 Received: by fieldses.org (Postfix, from userid 2815) id E69319240; Fri, 19 Jun 2020 16:40:33 -0400 (EDT) DKIM-Filter: OpenDKIM Filter v2.11.0 fieldses.org E69319240 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fieldses.org; s=default; t=1592599233; bh=Nwr2TjWR0twmyJl4g+UHE0HD65IQmQxNQBQDjG7MlL4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=BPPgIJGrSMzEicjrkX4pBRymXvBe6MpVKIEAB1esLdlGr3BBvEWp1y/aSguGD7R/g Kz2J1O0yxRcYsQiQL6J0nIbYiM79juBpk4yV+FyHfvnk4yoUPdy2+olfelnoz3pWCl 4ilaucsIZStRcjFQ/vPmuMILvKZ0MlxEkgcUvy2U= Date: Fri, 19 Jun 2020 16:40:33 -0400 From: "J. Bruce Fields" To: Dave Chinner Cc: Masayoshi Mizuma , Eric Sandeen , "Darrick J. Wong" , Christoph Hellwig , Theodore Ts'o , Andreas Dilger , Alexander Viro , Masayoshi Mizuma , linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-xfs , jlayton@redhat.com Subject: Re: [PATCH] fs: i_version mntopt gets visible through /proc/mounts Message-ID: <20200619204033.GB1564@fieldses.org> References: <8f0df756-4f71-9d96-7a52-45bf51482556@sandeen.net> <20200617181816.GA18315@fieldses.org> <4cbb5cbe-feb4-2166-0634-29041a41a8dc@sandeen.net> <20200617184507.GB18315@fieldses.org> <20200618013026.ewnhvf64nb62k2yx@gabell> <20200618030539.GH2005@dread.disaster.area> <20200618034535.h5ho7pd4eilpbj3f@gabell> <20200618223948.GI2005@dread.disaster.area> <20200619022005.GA25414@fieldses.org> <20200619024455.GN2005@dread.disaster.area> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200619024455.GN2005@dread.disaster.area> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On Fri, Jun 19, 2020 at 12:44:55PM +1000, Dave Chinner wrote: > On Thu, Jun 18, 2020 at 10:20:05PM -0400, J. Bruce Fields wrote: > > My memory was that after Jeff Layton's i_version patches, there wasn't > > really a significant performance hit any more, so the ability to turn it > > off is no longer useful. > > Yes, I completely agree with you here. However, with some > filesystems allowing it to be turned off, we can't just wave our > hands and force enable the option. Those filesystems - if the > maintainers chose to always enable iversion - will have to go > through a mount option deprecation period before permanently > enabling it. I don't understand why. The filesystem can continue to let people set iversion or noiversion as they like, while under the covers behaving as if iversion is always set. I can't see how that would break any application. (Or even how an application would be able to detect that the filesystem was doing this.) --b. > > > But looking back through Jeff's postings, I don't see him claiming that; > > e.g. in: > > > > https://lore.kernel.org/lkml/20171222120556.7435-1-jlayton@kernel.org/ > > https://lore.kernel.org/linux-nfs/20180109141059.25929-1-jlayton@kernel.org/ > > https://lore.kernel.org/linux-nfs/1517228795.5965.24.camel@redhat.com/ > > > > he reports comparing old iversion behavior to new iversion behavior, but > > not new iversion behavior to new noiversion behavior. > > Yeah, it's had to compare noiversion behaviour on filesystems where > it was understood that it couldn't actually be turned off. And, > realistically, the comaprison to noiversion wasn't really relevant > to the problem Jeff's patchset was addressing... > > Cheers, > > Dave. > -- > Dave Chinner > david@fromorbit.com