From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757719AbcBCTii (ORCPT ); Wed, 3 Feb 2016 14:38:38 -0500 Received: from smtprelay0010.hostedemail.com ([216.40.44.10]:38125 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751970AbcBCTig (ORCPT ); Wed, 3 Feb 2016 14:38:36 -0500 X-Session-Marker: 6A6F6540706572636865732E636F6D X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,joe@perches.com,:::::::::::,RULES_HIT:41:355:379:541:599:982:988:989:1260:1277:1311:1313:1314:1345:1359:1373:1437:1515:1516:1518:1534:1541:1593:1594:1711:1730:1747:1777:1792:2110:2393:2553:2559:2562:2828:3138:3139:3140:3141:3142:3352:3622:3865:3867:3868:3870:3871:3872:3873:3874:4321:5007:6261:10004:10400:10450:10455:10848:11232:11658:11914:12296:12517:12519:12740:13069:13163:13229:13311:13357:13894:14659:19904:19999:21080,0,RBL:none,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:none,Custom_rules:0:0:0,LFtime:1,LUA_SUMMARY:none X-HE-Tag: tub17_2db991c6b380a X-Filterd-Recvd-Size: 2050 Message-ID: <1454528313.7291.115.camel@perches.com> Subject: Re: [PATCH] ext4: add a line break for proc mb_groups display From: Joe Perches To: "Darrick J. Wong" Cc: Huaitong Han , tytso@mit.edu, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org Date: Wed, 03 Feb 2016 11:38:33 -0800 In-Reply-To: <20160203193233.GB5842@birch.djwong.org> References: <1454505546-4875-1-git-send-email-huaitong.han@intel.com> <20160203181356.GA5842@birch.djwong.org> <1454524232.7291.105.camel@perches.com> <20160203193233.GB5842@birch.djwong.org> Content-Type: text/plain; charset="ISO-8859-1" X-Mailer: Evolution 3.18.3-1ubuntu1 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2016-02-03 at 11:32 -0800, Darrick J. Wong wrote: > On Wed, Feb 03, 2016 at 10:30:32AM -0800, Joe Perches wrote: > > On Wed, 2016-02-03 at 10:13 -0800, Darrick J. Wong wrote: > > > On Wed, Feb 03, 2016 at 09:19:06PM +0800, Huaitong Han wrote: > > > > This patch adds a line break for proc mb_groups display. > > > > Using 2 lines for output might break any existing users. > > > > Are there any? > > It's a multiline file if you have more than one blockgroup; this just makes it > so that you don't have to special-case BG 0. And existing scripts might do that now and might fail to do properly after this change. > IOW: mb_groups scripts already had to parse multiple lines, and most likely any > script parsing it would inject a newline after the header. I've no dog in this fight really.  I just wanted to make it clear that this could cause existing scripts to fail. proc output is supposed to be unchanging except maybe adding new fields to existing lines. Your choice. cheers, Joe