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 A79F4ECAAD3 for ; Fri, 9 Sep 2022 10:29:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229691AbiIIK3d (ORCPT ); Fri, 9 Sep 2022 06:29:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33874 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230514AbiIIK2N (ORCPT ); Fri, 9 Sep 2022 06:28:13 -0400 Received: from out30-133.freemail.mail.aliyun.com (out30-133.freemail.mail.aliyun.com [115.124.30.133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D628812F715; Fri, 9 Sep 2022 03:28:08 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R211e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046059;MF=jefflexu@linux.alibaba.com;NM=1;PH=DS;RN=8;SR=0;TI=SMTPD_---0VP9.6kE_1662719284; Received: from 172.20.10.4(mailfrom:jefflexu@linux.alibaba.com fp:SMTPD_---0VP9.6kE_1662719284) by smtp.aliyun-inc.com; Fri, 09 Sep 2022 18:28:06 +0800 Message-ID: <8a239157-de28-44ae-edef-336092c34a15@linux.alibaba.com> Date: Fri, 9 Sep 2022 18:28:04 +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 From: JeffleXu 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> <3f75d266-7ccd-be6d-657c-fe0633b25687@linux.alibaba.com> In-Reply-To: <3f75d266-7ccd-be6d-657c-fe0633b25687@linux.alibaba.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 9/9/22 5:55 PM, JeffleXu wrote: > > > 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. Sorry, why can't we also set sbi->s_fscache to NULL after decrementing the refcount in shared domain mode, to avoid the refcount being decremented twice? >> >> 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