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 95F07C4332F for ; Tue, 12 Dec 2023 03:21:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345855AbjLLDVb (ORCPT ); Mon, 11 Dec 2023 22:21:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56016 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345805AbjLLDV3 (ORCPT ); Mon, 11 Dec 2023 22:21:29 -0500 Received: from dggsgout11.his.huawei.com (unknown [45.249.212.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A086BBA; Mon, 11 Dec 2023 19:21:35 -0800 (PST) Received: from mail.maildlp.com (unknown [172.19.163.235]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4Sq3mk5M0Yz4f3l1W; Tue, 12 Dec 2023 11:21:26 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.112]) by mail.maildlp.com (Postfix) with ESMTP id A70151A055E; Tue, 12 Dec 2023 11:21:31 +0800 (CST) Received: from [10.174.176.73] (unknown [10.174.176.73]) by APP1 (Coremail) with SMTP id cCh0CgBHShC40XdlxCalDQ--.54352S3; Tue, 12 Dec 2023 11:21:30 +0800 (CST) Subject: Re: [PATCH] md: Don't clear MD_CLOSING when the raid is about to stop To: Mariusz Tkaczyk , linan666@huaweicloud.com Cc: song@kernel.org, zlliu@suse.com, neilb@suse.com, shli@fb.com, linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org, yi.zhang@huawei.com, houtao1@huawei.com, yangerkun@huawei.com, "yukuai (C)" References: <20231211081714.1923567-1-linan666@huaweicloud.com> <20231211105620.00001753@linux.intel.com> From: Yu Kuai Message-ID: Date: Tue, 12 Dec 2023 11:21:28 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20231211105620.00001753@linux.intel.com> Content-Type: text/plain; charset=gbk; format=flowed Content-Transfer-Encoding: 8bit X-CM-TRANSID: cCh0CgBHShC40XdlxCalDQ--.54352S3 X-Coremail-Antispam: 1UD129KBjvJXoW7uF17XryfGw45Gw48Kw1fXrb_yoW8uFWfpa yxXF1ayan0y3W8Cw42qw18GFyFqwn3trWDtFyIkFn5Aa45ZFyUGr4Sga90gF4DWFWfKF4j g3W7J3WDX3Wvg37anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUvab4IE77IF4wAFF20E14v26r4j6ryUM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4 vEj48ve4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Ar0_tr1l84ACjcxK6xIIjxv20xvEc7Cj xVAFwI0_Gr1j6F4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x 0267AKxVW0oVCq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG 6I80ewAv7VC0I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFV Cjc4AY6r1j6r4UM4x0Y48IcVAKI48JM4IIrI8v6xkF7I0E8cxan2IY04v7Mxk0xIA0c2IE e2xFo4CEbIxvr21l42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxV Aqx4xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r1q 6r43MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6x kF7I0E14v26r4j6F4UMIIF0xvE42xK8VAvwI8IcIk0rVWrZr1j6s0DMIIF0xvEx4A2jsIE 14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr1j6F4UJbIYCTnIWIevJa73UjIFyT uYvjxUrR6zUUUUU X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, ÔÚ 2023/12/11 17:56, Mariusz Tkaczyk дµÀ: > On Mon, 11 Dec 2023 16:17:14 +0800 > linan666@huaweicloud.com wrote: > >> From: Li Nan >> >> The raid should not be opened anymore when it is about to be stopped. >> However, other processes can open it again if the flag MD_CLOSING is >> cleared before exiting. From now on, this flag will not be cleared when >> the raid will be stopped. >> >> Fixes: 065e519e71b2 ("md: MD_CLOSING needs to be cleared after called >> md_set_readonly or do_md_stop") Signed-off-by: Li Nan > > Hello Li Nan, > I was there when I needed to fix this: > https://git.kernel.org/pub/scm/linux/kernel/git/song/md.git/commit/?h=md-next&id=c8870379a21fbd9ad14ca36204ccfbe9d25def43 > > For sure, you have to consider applying same solution for array_store "clear". > Minor nit below. > > Thanks, > Mariusz > >> --- >> drivers/md/md.c | 8 +++----- >> 1 file changed, 3 insertions(+), 5 deletions(-) >> >> diff --git a/drivers/md/md.c b/drivers/md/md.c >> index 4e9fe5cbeedc..ebdfc9068a60 100644 >> --- a/drivers/md/md.c >> +++ b/drivers/md/md.c >> @@ -6238,7 +6238,6 @@ static void md_clean(struct mddev *mddev) >> mddev->persistent = 0; >> mddev->level = LEVEL_NONE; >> mddev->clevel[0] = 0; >> - mddev->flags = 0; > > I recommend (safety recommendation): > mddev->flags = MD_CLOSING; Taking a look I think both MD_CLOSING and MD_DELETED should not be cleared, however, there is no guarantee that MD_CLOSING will be set before md_clean, because mdadm can be removed without running. Hence I think just set MD_CLOSING is werid. I think the proper way is to keep MD_CLOSING and MD_DELETED if they are set. However, there is no such api to clear other bits at once. Since we're not expecting anyone else to write flags, following maybe acceptable: mddev->flags &= BIT_ULL_MASK(MD_CLOSING) | BIT_ULL_MASK(MD_DELETED); Or after making sure other flags cannot race, this patch is ok. Thanks, Kuai > > Unless you can prove that other flags cannot race. > >> mddev->sb_flags = 0; >> mddev->ro = MD_RDWR; >> mddev->metadata_type[0] = 0; > > . >