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=-7.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 C6A96C43331 for ; Tue, 12 Nov 2019 03:16:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8EEBC20818 for ; Tue, 12 Nov 2019 03:16:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="LJCo3cfI" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727022AbfKLDOj (ORCPT ); Mon, 11 Nov 2019 22:14:39 -0500 Received: from aserp2120.oracle.com ([141.146.126.78]:40096 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726924AbfKLDOi (ORCPT ); Mon, 11 Nov 2019 22:14:38 -0500 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.27/8.16.0.27) with SMTP id xAC39LSq078094; Tue, 12 Nov 2019 03:13:10 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=subject : to : references : from : message-id : date : mime-version : in-reply-to : content-type : content-transfer-encoding; s=corp-2019-08-05; bh=UTbj9nCnbDQ9XFfUZf0QpPzkozHDVf7BjKA4nNAEIGU=; b=LJCo3cfITk98gcxbL21cCKAZxH9b14BA/z3xYXVlBgoKPpkbVsBl2D0LJtGDWqJmbRJ4 P+Dvs1217q+w0rc4nQECT2BQNW1uF4X6gwcSu9cmYC0lKUUUEjZvFYHhzUT276wE9Uma PdWpAc3niLapq8DYUrNu0X9z9OA66ThyFRMaFwDGP6qjon2IoRYztYxolmhHyPuKpkW/ 7UeKYvGWWkMcSGDu63DAytBT3RvOWU5dZfgweRyQRS/F26ZgDAkaAA6Esog6w189G6qP KLwWQuuxq6Mhv95MqGA+Pd+2zmZAOB2J/klRh7/qWZqql+bC/T1anpgHIDQQyNrjr8kB ng== Received: from aserp3030.oracle.com (aserp3030.oracle.com [141.146.126.71]) by aserp2120.oracle.com with ESMTP id 2w5ndq20gn-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 12 Nov 2019 03:13:10 +0000 Received: from pps.filterd (aserp3030.oracle.com [127.0.0.1]) by aserp3030.oracle.com (8.16.0.27/8.16.0.27) with SMTP id xAC39btj195425; Tue, 12 Nov 2019 03:11:09 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by aserp3030.oracle.com with ESMTP id 2w6r8kfjkp-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 12 Nov 2019 03:11:09 +0000 Received: from abhmp0007.oracle.com (abhmp0007.oracle.com [141.146.116.13]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id xAC3B6rX013345; Tue, 12 Nov 2019 03:11:07 GMT Received: from [10.190.130.61] (/192.188.170.109) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 11 Nov 2019 19:11:06 -0800 Subject: Re: [PATCH] btrfs: mkfs: Make no-holes as default mkfs incompat features To: Qu Wenruo , dsterba@suse.cz, Qu Wenruo , linux-btrfs@vger.kernel.org References: <20191111065004.24705-1-wqu@suse.com> <20191111180256.GR3001@twin.jikos.cz> From: Anand Jain Message-ID: Date: Tue, 12 Nov 2019 11:10:57 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9438 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1910280000 definitions=main-1911120025 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9438 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1910280000 definitions=main-1911120025 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 12/11/19 9:01 AM, Qu Wenruo wrote: > > > On 2019/11/12 上午2:02, David Sterba wrote: >> On Mon, Nov 11, 2019 at 02:50:04PM +0800, Qu Wenruo wrote: >>> No-holes feature could save 53 bytes for each hole we have, and it >>> provides a pretty good workaround to prevent btrfs check from reporting >>> non-contiguous file extent holes for mixed direct/buffered IO. >>> >>> The latter feature is more helpful for developers for handle log-writes >>> based test cases. >> >> Thanks. The plan to make no-holes default has been there for some time >> already. What it needs is a full round of testing and validation before >> making it default. And as defaults change rarely, I'd like to add >> free-space-tree as mkfs default as well, there's enough demand for that >> and we want to start deprecating v1 in the future. >> >> I have in my near-top todo list to do that, with the following >> checklist: >> >> - run fstests with various features together + the new default >> - release build >> - debugging build with UBSAN, KASAN and additional useful debugging >> tools > Already running with no_holes for several previous releases. > > Not to mention new btrfs specific log-writes test cases are all already > using this feature to avoid btrfs check failure. > > So I think this part should be OK. > >> - run stress tests + the new feature > > Any extra suggestions for the stress test tool? > > Despite that, extra 24x7 host may be needed for this test. > To keep the ball rolling I can run stress tests part here, yep need extra suggestions on the stress test tools. Thanks, Anand >> - check that the documentation covers the change >> - mkfs.btrfs help string >> - manual page of mkfs.btrfs: benefits, pros/cons, conversion to/from >> the feature (if applicable), with example commands (if applicable) >> - wiki documentation update > > Forgot this part. > I'll add this info in next update. > > Thanks, > Qu >> - verify that all commonly used tools work with it (image, check, tune) >> >> For free-space-tree specifically, there's >> https://github.com/kdave/drafts/blob/master/btrfs/progs-fst-default.txt >> >> I don't have objections to the patch, that's the easy part. The above is >> non-coding work and is namely making sure that the usecase and usability >> is good, or with known documented quirks. >> >> Making it default in progs release 5.4 is IMO doable, there are probably >> 2-3 weeks before the release, but this task needs one or more persons >> willing to do the above. >> >