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=-17.6 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 6E350C433EF for ; Fri, 10 Sep 2021 08:49:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 52963611C1 for ; Fri, 10 Sep 2021 08:49:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231855AbhIJIuy (ORCPT ); Fri, 10 Sep 2021 04:50:54 -0400 Received: from szxga01-in.huawei.com ([45.249.212.187]:19024 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231502AbhIJIux (ORCPT ); Fri, 10 Sep 2021 04:50:53 -0400 Received: from dggeme754-chm.china.huawei.com (unknown [172.30.72.53]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4H5Twf31TJzbmQD; Fri, 10 Sep 2021 16:45:38 +0800 (CST) Received: from [10.174.178.185] (10.174.178.185) by dggeme754-chm.china.huawei.com (10.3.19.100) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2308.8; Fri, 10 Sep 2021 16:49:40 +0800 Subject: Re: [PATCH -next 2/6] ext4: introduce last_check_time record previous check time To: Guoqing Jiang , , , References: <20210906144754.2601607-1-yebin10@huawei.com> <20210906144754.2601607-3-yebin10@huawei.com> <03bd0982-f0ad-78b4-7b98-cbfdbab9deec@linux.dev> CC: , From: yebin Message-ID: <613B1C24.4040901@huawei.com> Date: Fri, 10 Sep 2021 16:49:40 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.1.0 MIME-Version: 1.0 In-Reply-To: <03bd0982-f0ad-78b4-7b98-cbfdbab9deec@linux.dev> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.178.185] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggeme754-chm.china.huawei.com (10.3.19.100) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021/9/9 10:20, Guoqing Jiang wrote: > > > On 9/6/21 10:47 PM, Ye Bin wrote: >> kmmpd: >> ... >> diff = jiffies - last_update_time; >> if (diff > mmp_check_interval * HZ) { >> ... >> As "mmp_check_interval = 2 * mmp_update_interval", 'diff' always little >> than 'mmp_update_interval', so there will never trigger detection. >> Introduce last_check_time record previous check time. >> >> Signed-off-by: Ye Bin >> --- >> fs/ext4/mmp.c | 14 +++++++++----- >> 1 file changed, 9 insertions(+), 5 deletions(-) >> >> diff --git a/fs/ext4/mmp.c b/fs/ext4/mmp.c >> index 12af6dc8457b..89797f12a815 100644 >> --- a/fs/ext4/mmp.c >> +++ b/fs/ext4/mmp.c >> @@ -152,6 +152,7 @@ static int kmmpd(void *data) >> int mmp_update_interval = le16_to_cpu(es->s_mmp_update_interval); >> unsigned mmp_check_interval; >> unsigned long last_update_time; >> + unsigned long last_check_time; >> unsigned long diff; >> int retval = 0; >> @@ -170,6 +171,7 @@ static int kmmpd(void *data) >> memcpy(mmp->mmp_nodename, init_utsname()->nodename, >> sizeof(mmp->mmp_nodename)); >> + last_update_time = jiffies; I'm sorry, actually i want to init 'last_check_time' at here, I will fix it in v2. Thanks, YeBin >> while (!kthread_should_stop() && !sb_rdonly(sb)) { >> if (!ext4_has_feature_mmp(sb)) { >> @@ -198,17 +200,18 @@ static int kmmpd(void *data) >> } >> diff = jiffies - last_update_time; >> - if (diff < mmp_update_interval * HZ) >> + if (diff < mmp_update_interval * HZ) { >> schedule_timeout_interruptible(mmp_update_interval * >> HZ - diff); >> + diff = jiffies - last_update_time; >> + } >> /* >> * We need to make sure that more than mmp_check_interval >> - * seconds have not passed since writing. If that has happened >> - * we need to check if the MMP block is as we left it. >> + * seconds have not passed since check. If that has happened >> + * we need to check if the MMP block is as we write it. >> */ >> - diff = jiffies - last_update_time; >> - if (diff > mmp_check_interval * HZ) { >> + if (jiffies - last_check_time > mmp_check_interval * HZ) { > > Before the above checking, seems last_check_time is not initialized yet. >> struct buffer_head *bh_check = NULL; >> struct mmp_struct *mmp_check; >> @@ -234,6 +237,7 @@ static int kmmpd(void *data) >> goto wait_to_exit; >> } >> put_bh(bh_check); >> + last_check_time = jiffies; >> } >> /* > > Thanks, > Guoqing > . >