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 71702C6FA82 for ; Fri, 9 Sep 2022 09:55:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229502AbiIIJzv (ORCPT ); Fri, 9 Sep 2022 05:55:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57188 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229478AbiIIJzs (ORCPT ); Fri, 9 Sep 2022 05:55:48 -0400 Received: from out30-42.freemail.mail.aliyun.com (out30-42.freemail.mail.aliyun.com [115.124.30.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 157D6D51DE; Fri, 9 Sep 2022 02:55:45 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R511e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045168;MF=jefflexu@linux.alibaba.com;NM=1;PH=DS;RN=8;SR=0;TI=SMTPD_---0VP9-zDX_1662717341; Received: from 30.221.130.74(mailfrom:jefflexu@linux.alibaba.com fp:SMTPD_---0VP9-zDX_1662717341) by smtp.aliyun-inc.com; Fri, 09 Sep 2022 17:55:42 +0800 Message-ID: <3f75d266-7ccd-be6d-657c-fe0633b25687@linux.alibaba.com> Date: Fri, 9 Sep 2022 17:55:41 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Thunderbird/91.13.0 Subject: Re: [PATCH V2 4/5] erofs: remove duplicated unregister_cookie Content-Language: en-US To: Jia Zhu , linux-erofs@lists.ozlabs.org, xiang@kernel.org, chao@kernel.org Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, yinxin.x@bytedance.com, huyue2@coolpad.com References: <20220902105305.79687-1-zhujia.zj@bytedance.com> <20220902105305.79687-5-zhujia.zj@bytedance.com> From: JeffleXu In-Reply-To: <20220902105305.79687-5-zhujia.zj@bytedance.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 9/2/22 6:53 PM, Jia Zhu wrote: > In erofs umount scenario, erofs_fscache_unregister_cookie() is called > twice in kill_sb() and put_super(). > > It works for original semantics, cause 'ctx' will be set to NULL in > put_super() and will not be unregister again in kill_sb(). > However, in shared domain scenario, we use refcount to maintain the > lifecycle of cookie. Unregister the cookie twice will cause it to be > released early. > > For the above reasons, this patch removes duplicate unregister_cookie > and move fscache_unregister_* before shotdown_super() to prevent busy > inode(ctx->inode) when umount. > > Signed-off-by: Jia Zhu > --- > fs/erofs/super.c | 16 ++++++++-------- > 1 file changed, 8 insertions(+), 8 deletions(-) > > diff --git a/fs/erofs/super.c b/fs/erofs/super.c > index 69de1731f454..667a78f0ee70 100644 > --- a/fs/erofs/super.c > +++ b/fs/erofs/super.c > @@ -919,19 +919,20 @@ static void erofs_kill_sb(struct super_block *sb) > kill_litter_super(sb); > return; > } > - if (erofs_is_fscache_mode(sb)) > - generic_shutdown_super(sb); > - else > - kill_block_super(sb); > - > sbi = EROFS_SB(sb); > if (!sbi) > return; > > + if (erofs_is_fscache_mode(sb)) { > + erofs_fscache_unregister_cookie(&sbi->s_fscache); > + erofs_fscache_unregister_fs(sb); > + generic_shutdown_super(sb); Generally we can't do clean ups before generic_shutdown_super(), since generic_shutdown_super() may trigger IO, e.g. in sync_filesystem(), though it's not the case for erofs (read-only). How about embedding erofs_fscache_unregister_cookie() into erofs_fscache_unregister_fs(), and thus we can check domain_id in erofs_fscache_unregister_fs()? > + } else { > + kill_block_super(sb); > + } > + > erofs_free_dev_context(sbi->devs); > fs_put_dax(sbi->dax_dev, NULL); > - erofs_fscache_unregister_cookie(&sbi->s_fscache); > - erofs_fscache_unregister_fs(sb); > kfree(sbi->opt.fsid); > kfree(sbi->opt.domain_id); > kfree(sbi); > @@ -951,7 +952,6 @@ static void erofs_put_super(struct super_block *sb) > iput(sbi->managed_cache); > sbi->managed_cache = NULL; > #endif > - erofs_fscache_unregister_cookie(&sbi->s_fscache); > } > > struct file_system_type erofs_fs_type = { -- Thanks, Jingbo