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=-6.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 7DEE4C433E0 for ; Thu, 4 Mar 2021 23:50:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3DA7B64FF1 for ; Thu, 4 Mar 2021 23:50:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232956AbhCDXuK (ORCPT ); Thu, 4 Mar 2021 18:50:10 -0500 Received: from mail.kernel.org ([198.145.29.99]:50612 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232543AbhCDXuK (ORCPT ); Thu, 4 Mar 2021 18:50:10 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id A8F7F64FEA; Thu, 4 Mar 2021 23:50:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1614901809; bh=la+/LlUFeQYvhLySDR4vAFpG+8JYc37BPuVHhh/Xkwo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=AKCe315TTti7vXaDkftIB9RAiJKo7klEiBS5CoaUGufcb2RT0N6rraHjbpFBjG670 zodPbs7P67fX4UvV0tbq0GuaoGMl+f1YGJH0AEnJlMT0VvH9OaDMjs0G7F+djIB13h a0QayLF3Cc7bYfl/Z5x44VhKF8ijlhkS0SIFIfcYQF0tTzhgzvM3R806Sptq/7AztU cSeOmck9FCU63eeS3robzcrzFCv5XDlbI2/l9MdYA8V6nKY80KiwbQ5zc0waiij5NO TkD8cNwNDDV3xmipHZWxB8s3i4hBiAdk6vwUDsVQrT1O3ZqiSHDlshsRU2xFJoEbjj pT3Qz5nwZR4SQ== Date: Thu, 4 Mar 2021 15:50:06 -0800 From: "Darrick J. Wong" To: "Alejandro Colomar (man-pages)" Cc: linux-man@vger.kernel.org, Amir Goldstein , Michael Kerrisk , Luis Henriques , Steve French , Greg KH , Anna Schumaker , Jeff Layton , Miklos Szeredi , Trond Myklebust , Alexander Viro , "Darrick J. Wong" , Dave Chinner , Nicolas Boichat , Ian Lance Taylor , Luis Lozano , Andreas Dilger , Olga Kornievskaia , Christoph Hellwig , ceph-devel , linux-kernel , CIFS , samba-technical , linux-fsdevel , Linux NFS Mailing List , Walter Harms Subject: Re: [RFC v4] copy_file_range.2: Update cross-filesystem support for 5.12 Message-ID: <20210304235006.GW7269@magnolia> References: <20210224142307.7284-1-lhenriques@suse.de> <20210304093806.10589-1-alx.manpages@gmail.com> <20210304171350.GC7267@magnolia> <37df00f9-a88e-3f16-d0b4-3297248aee66@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <37df00f9-a88e-3f16-d0b4-3297248aee66@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org On Thu, Mar 04, 2021 at 07:24:02PM +0100, Alejandro Colomar (man-pages) wrote: > Hi Darrick, > > On 3/4/21 6:13 PM, Darrick J. Wong wrote: > > On Thu, Mar 04, 2021 at 10:38:07AM +0100, Alejandro Colomar wrote: > > > +However, on some virtual filesystems, > > > +the call failed to copy, while still reporting success. > > > > ...success, or merely a short copy? > > Okay. > > > > > (The rest looks reasonable (at least by c_f_r standards) to me.) > > I'm curious, what does "c_f_r standards" mean? :) c_f_r is shorthand for "copy_file_range". As for standards... well... I'll just say that this being the /second/ major shift in behavior reflects our poor community development processes. The door to general cross-fs copies should not have been thrown open with as little testing as it did. There are legendary dchinner rants about how obviously broken the generic fallback was when it was introduced. There's a reason why we usually wire up new kernel functionality on an opt-in basis, and that is to foster gradual enablement as QA resources permit. It's one thing for maintainers to blow up their own subsystems in isolation, and an entirely different thing to do it between projects with no coordination. Did c_f_r work between an ext4 and an xfs? I have no idea. It seemed to work between xfses of a similar vintage and featureset, at least, but that's about as much testing as I have ever managed. --D > > Cheers, > > Alex > > -- > Alejandro Colomar > Linux man-pages comaintainer; https://www.kernel.org/doc/man-pages/ > http://www.alejandro-colomar.es/