From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) (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 65C8D1D12FF; Sat, 31 Aug 2024 01:13:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.51 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725066807; cv=none; b=o7M06s5Cl82E0LGaqe0kpAnwUAp+abzCAmp04UgeK0+KdTK1185Dp5Revvl8FfNSq2h2SwyejE8DGliAUpHhYiU3NinwgwsVZTAqVlcTa3lka/KHwiquzIR3VcqOa1hIvmYBGgFp2eG97VS52IrEMKaXc2ansB2GsAKoztDrF7M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725066807; c=relaxed/simple; bh=hTaqNnY/k0MH65E7HCPHNjhF7wH80l4GfI57DHlvTh4=; h=Subject:To:Cc:References:From:Message-ID:Date:MIME-Version: In-Reply-To:Content-Type; b=JGBvjhSahjwi0f5Nn4mu/BSbwz+REU9PeBPhqInC8oGJNwCjS3C5zYGtWv4h3F7wocJm6FL8xZpu4D8INHnSvwsiJH00zL/SB4XOqUI3FvZJhH4TzFLv+3Gm3+ONAKJC8u8+uk3cSV8s3jbXkuOOyUM9mXm8TaPx29Tx69drwEE= 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=45.249.212.51 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 dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4WwcTG0Tqbz4f3kvq; Sat, 31 Aug 2024 09:13:06 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id A809A1A0568; Sat, 31 Aug 2024 09:13:21 +0800 (CST) Received: from [10.174.176.73] (unknown [10.174.176.73]) by APP4 (Coremail) with SMTP id gCh0CgAXPoQvbtJmk8zEDA--.20351S3; Sat, 31 Aug 2024 09:13:21 +0800 (CST) Subject: Re: [PATCH md-6.12 4/7] md/raid1: factor out helper to handle blocked rdev from raid1_write_request() To: Mariusz Tkaczyk , Yu Kuai Cc: mariusz.tkaczyk@intel.com, song@kernel.org, linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org, yi.zhang@huawei.com, yangerkun@huawei.com, "yukuai (C)" References: <20240830072721.2112006-1-yukuai1@huaweicloud.com> <20240830072721.2112006-5-yukuai1@huaweicloud.com> <20240830130645.000076c6@linux.intel.com> From: Yu Kuai Message-ID: <3de92a0d-1650-ec6b-3a5a-d447682d1b9e@huaweicloud.com> Date: Sat, 31 Aug 2024 09:13:19 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: <20240830130645.000076c6@linux.intel.com> Content-Type: text/plain; charset=gbk; format=flowed Content-Transfer-Encoding: 8bit X-CM-TRANSID:gCh0CgAXPoQvbtJmk8zEDA--.20351S3 X-Coremail-Antispam: 1UD129KBjvJXoW7CF47WF4DAw47CF4DAFy3CFg_yoW8Zr4fpw 4fGFW3Ar48ury3A3ZIqFyUWFyFqw10qFW8Aryft3WxXrZrZryrGayrtryrWr95ArWayryY vF1UWrZrC3WI9FDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUvC14x267AKxVW8JVW5JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26w1j6s0DM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r4U JVWxJr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_Gc CE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E 2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkEbVWUJV W8JwACjcxG0xvEwIxGrwACjI8F5VA0II8E6IAqYI8I648v4I1lc7I2V7IY0VAS07AlzVAY IcxG8wCY1x0262kKe7AKxVWUtVW8ZwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbV WUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF 67kF1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42 IY6xIIjxv20xvEc7CjxVAFwI0_Jr0_Gr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF 0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Jr0_GrUvcSsGvfC2Kf nxnUUI43ZEXa7VUbGQ6JUUUUU== X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ Hi, ÔÚ 2024/08/30 19:06, Mariusz Tkaczyk дµÀ: > On Fri, 30 Aug 2024 15:27:18 +0800 > Yu Kuai wrote: > >> From: Yu Kuai >> >> Currently raid1 is preparing IO for underlying disks while checking if >> any disk is blocked, if so allocated resources must be released, then >> waiting for rdev to be unblocked and try to prepare IO again. >> >> Make code cleaner by checking blocked rdev first, it doesn't matter if >> rdev is blocked while issuing this IO. >> >> Signed-off-by: Yu Kuai >> --- >> drivers/md/raid1.c | 84 ++++++++++++++++++++++++++-------------------- >> 1 file changed, 48 insertions(+), 36 deletions(-) >> >> diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c >> index f55c8e67d059..aa30c3240c85 100644 >> --- a/drivers/md/raid1.c >> +++ b/drivers/md/raid1.c >> @@ -1406,6 +1406,49 @@ static void raid1_read_request(struct mddev *mddev, >> struct bio *bio, submit_bio_noacct(read_bio); >> } >> >> +static bool wait_blocked_rdev(struct mddev *mddev, struct bio *bio) >> +{ >> + struct r1conf *conf = mddev->private; >> + int disks = conf->raid_disks * 2; >> + int i; >> + >> +retry: >> + for (i = 0; i < disks; i++) { >> + struct md_rdev *rdev = conf->mirrors[i].rdev; >> + >> + if (!rdev) >> + continue; >> + >> + if (test_bit(Blocked, &rdev->flags)) { > Don't we need unlikely here? > > >> + if (bio->bi_opf & REQ_NOWAIT) >> + return false; >> + >> + mddev_add_trace_msg(rdev->mddev, "raid1 wait rdev %d >> blocked", >> + rdev->raid_disk); >> + atomic_inc(&rdev->nr_pending); > > > retry moves us before for (ugh, ugly) and "theoretically" we can back here > with the same disk and increase nr_pending twice or more because rdve can become > block again from different thread. Rety is always after md_wait_for_blocked_rdev(), which decrease the nr_pending. Thanks, Kuai > > This is what I suspect but it could be wrong. > > Mariusz > > > > . >