From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from dggsgout12.his.huawei.com (dggsgout12.his.huawei.com [45.249.212.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8E3812F8BE7; Tue, 26 Aug 2025 09:14:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756199652; cv=none; b=aNcxS/xuk1QhTZG/cIaibZoDzNoTfhaU4SEyommjMifPa1Qu2rNmhoBfV+FdFHGObuwTA3JhNfwWW+x7akGXTOrGjIH7NQJWeXWPlZhS5arYC7TEyEa6G3zyh2ON+3pCRL6BOqf8kzTIir7Kf7xCXkrYIzrMF/92NzCWUsSmv3k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756199652; c=relaxed/simple; bh=/RgWeAmBiaSdiIAMnSe77oaifrRUTgjomq97aknow6Q=; h=Subject:To:Cc:References:From:Message-ID:Date:MIME-Version: In-Reply-To:Content-Type; b=slFEDO+tTWo3Whqdf2bbdyuv4aXfPGJcYgFpjpKZPjVcRHcTZIGco2BhbA4V1LXcSwzWZOhPsJr1jU/LahIKWb6pHcWJXyn64XaPWEwZRBYWbrY9KWtt4UaFyncAEdAAGa1uuG0J30a0grfkbfFrHrnQO0UGK9q8nLeVKrZJqFg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.163.235]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTPS id 4cB2674Q9KzKHNCV; Tue, 26 Aug 2025 17:14:07 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id 39EBE1A0ABF; Tue, 26 Aug 2025 17:14:07 +0800 (CST) Received: from [10.174.179.143] (unknown [10.174.179.143]) by APP4 (Coremail) with SMTP id gCh0CgDnMY7deq1ocPNhAQ--.26341S3; Tue, 26 Aug 2025 17:14:06 +0800 (CST) Subject: Re: [PATCH RFC 4/7] md/raid10: convert read/write to use bio_submit_split() To: Christoph Hellwig , Yu Kuai Cc: colyli@kernel.org, hare@suse.de, tieren@fnnas.com, axboe@kernel.dk, tj@kernel.org, josef@toxicpanda.com, song@kernel.org, akpm@linux-foundation.org, neil@brown.name, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-raid@vger.kernel.org, yi.zhang@huawei.com, yangerkun@huawei.com, johnny.chenyi@huawei.com, John Garry , "yukuai (C)" References: <20250825093700.3731633-1-yukuai1@huaweicloud.com> <20250825093700.3731633-5-yukuai1@huaweicloud.com> <6c6b183a-bce7-b01c-8749-6e0b5a078384@huaweicloud.com> From: Yu Kuai Message-ID: Date: Tue, 26 Aug 2025 17:14:05 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.9.1 Precedence: bulk X-Mailing-List: cgroups@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=gbk; format=flowed Content-Transfer-Encoding: 8bit X-CM-TRANSID:gCh0CgDnMY7deq1ocPNhAQ--.26341S3 X-Coremail-Antispam: 1UD129KBjvdXoW7Wr47Xw13CrWrZryDKw17Wrg_yoW3ZrXEg3 yqyrnxGwn2qF13A3yrK3ZxGrZ7AF4a9F15u3WUXF4fZ34rur9rCw47C39av3s5JF4jywsI 9Fn8WrW5Ar929jkaLaAFLSUrUUUUjb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbSkFF20E14v26ryj6rWUM7CY07I20VC2zVCF04k26cxKx2IYs7xG 6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8w A2z4x0Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j 6F4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oV Cq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0 I7IYx2IY67AKxVWUGVWUXwAv7VC2z280aVAFwI0_Gr0_Cr1lOx8S6xCaFVCjc4AY6r1j6r 4UM4x0Y48IcVAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628vn2kI c2xKxwCYjI0SjxkI62AI1cAE67vIY487MxkF7I0En4kS14v26r4a6rW5MxAIw28IcxkI7V AKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCj r7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVW8ZVWrXwCIc40Y0x0EwIxGrwCI42IY6x IIjxv20xvE14v26r4j6ryUMIIF0xvE2Ix0cI8IcVCY1x0267AKxVW8Jr0_Cr1UMIIF0xvE 42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVW8JVWxJwCI42IY6I8E87Iv6x kF7I0E14v26r4UJVWxJrUvcSsGvfC2KfnxnUUI43ZEXa7sRi66wtUUUUU== X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ Hi, ÔÚ 2025/08/26 15:55, Christoph Hellwig дµÀ: > On Tue, Aug 26, 2025 at 09:13:41AM +0800, Yu Kuai wrote: >>> The NULL return should only happen for REQ_NOWAIT here, so maybe >>> give R10BIO_Returned a more descriptive name? Also please document >>> the flag in the header. >> >> And also atomic write here, if bio has to split due to badblocks here. >> The flag is refer to raid1. I can add cocument for both raid1 and raid10 >> in this case. > > Umm, that's actually a red flag. If a device guarantees atomic behavior > it can't just fail it. So I think REQ_ATOMIC should be disallowed > for md raid with bad block tracking. > I agree that do not look good, however, John explained while adding this that user should retry and fallback without REQ_ATOMIC to make things work as usual. Thanks, Kuai >> > > . >