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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1A9BBC76196 for ; Thu, 6 Apr 2023 03:52:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234824AbjDFDwu (ORCPT ); Wed, 5 Apr 2023 23:52:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54664 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231955AbjDFDwp (ORCPT ); Wed, 5 Apr 2023 23:52:45 -0400 Received: from out30-100.freemail.mail.aliyun.com (out30-100.freemail.mail.aliyun.com [115.124.30.100]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F02B73ABC for ; Wed, 5 Apr 2023 20:52:43 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R481e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046050;MF=hsiangkao@linux.alibaba.com;NM=1;PH=DS;RN=7;SR=0;TI=SMTPD_---0VfRGne1_1680753159; Received: from 30.97.49.15(mailfrom:hsiangkao@linux.alibaba.com fp:SMTPD_---0VfRGne1_1680753159) by smtp.aliyun-inc.com; Thu, 06 Apr 2023 11:52:40 +0800 Message-ID: <028a1b56-72c9-75f6-fb68-1dc5181bf2e8@linux.alibaba.com> Date: Thu, 6 Apr 2023 11:52:39 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.9.0 Subject: Re: [PATCH 2/2] erofs: remove unnecessary kobject_del() To: Yangtao Li , Gao Xiang , Chao Yu , Yue Hu , Jeffle Xu Cc: linux-erofs@lists.ozlabs.org, linux-kernel@vger.kernel.org References: <20230404142102.13226-1-frank.li@vivo.com> <20230404142102.13226-2-frank.li@vivo.com> From: Gao Xiang In-Reply-To: <20230404142102.13226-2-frank.li@vivo.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Yangtao, On 2023/4/4 22:21, Yangtao Li wrote: > kobject_put() actually covers kobject removal automatically, which is > single stage removal. So it is safe to kill kobject_del() directly. > > Signed-off-by: Yangtao Li Would you mind taking a look at commit a942da24abc5 ("fs: erofs: add sanity check for kobject in erofs_unregister_sysfs") , which could be "git-blame"ed (I'd suggest looking into these blame first), and the related discussion was: https://lore.kernel.org/r/CAD-N9QXNx=p3-QoWzk6pCznF32CZy8kM3vvo8mamfZZ9CpUKdw@mail.gmail.com https://lore.kernel.org/r/20220315075152.63789-1-dzm91@hust.edu.cn TL;DR: I guess it could be fixed as below if kobject_del() could be killed safely: if (sbi->s_kobj.state_in_sysfs) { kobject_put(&sbi->s_kobj); wait_for_completion(&sbi->s_kobj_unregister); } Thanks, Gao Xiang > --- > fs/erofs/sysfs.c | 7 ++----- > 1 file changed, 2 insertions(+), 5 deletions(-) > > diff --git a/fs/erofs/sysfs.c b/fs/erofs/sysfs.c > index 435e515c0792..c3ba981b4472 100644 > --- a/fs/erofs/sysfs.c > +++ b/fs/erofs/sysfs.c > @@ -240,11 +240,8 @@ void erofs_unregister_sysfs(struct super_block *sb) > { > struct erofs_sb_info *sbi = EROFS_SB(sb); > > - if (sbi->s_kobj.state_in_sysfs) { > - kobject_del(&sbi->s_kobj); > - kobject_put(&sbi->s_kobj); > - wait_for_completion(&sbi->s_kobj_unregister); > - } > + kobject_put(&sbi->s_kobj); > + wait_for_completion(&sbi->s_kobj_unregister); > } > > int __init erofs_init_sysfs(void)