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 2B1B7EE3F3A for ; Mon, 11 Sep 2023 20:53:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233794AbjIKUwm (ORCPT ); Mon, 11 Sep 2023 16:52:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43080 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241772AbjIKPOI (ORCPT ); Mon, 11 Sep 2023 11:14:08 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 43087FA for ; Mon, 11 Sep 2023 08:14:04 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 82CAEC433C9; Mon, 11 Sep 2023 15:14:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1694445243; bh=3dyd74uCtZaQGmIJNWNIlG/mut3HJTJcpSlKZemfbUw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ug/i5hGk1a0DCKMiWYdsbMGplJBP7Yh/xiAGkxu7ZSAAMQG9ZWdXCYb+Ir89m1zEq jzCdG+OIemdR/a/pfqLas2Jje3rZCsFzOCAo3cZVjDqq4mE6cT7m7NBABcRNve/ygW uY5aIj/bWamJiUoQzAYv5NZJ8GVmOt2ja7F0xIAo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Li Nan , Song Liu , Sasha Levin Subject: [PATCH 6.1 278/600] md/raid10: factor out dereference_rdev_and_rrdev() Date: Mon, 11 Sep 2023 15:45:11 +0200 Message-ID: <20230911134641.814894199@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230911134633.619970489@linuxfoundation.org> References: <20230911134633.619970489@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Li Nan [ Upstream commit b99f8fd2d91eb734f13098aa1cf337edaca454b7 ] Factor out a helper to get 'rdev' and 'replacement' from config->mirrors. Just to make code cleaner and prepare to fix the bug of io loss while 'replacement' replace 'rdev'. There is no functional change. Signed-off-by: Li Nan Link: https://lore.kernel.org/r/20230701080529.2684932-3-linan666@huaweicloud.com Signed-off-by: Song Liu Stable-dep-of: 673643490b9a ("md/raid10: use dereference_rdev_and_rrdev() to get devices") Signed-off-by: Sasha Levin --- drivers/md/raid10.c | 29 ++++++++++++++++++++--------- 1 file changed, 20 insertions(+), 9 deletions(-) diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index d2098fcd6a270..49bb79f48f362 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -1317,6 +1317,25 @@ static void raid10_write_one_disk(struct mddev *mddev, struct r10bio *r10_bio, } } +static struct md_rdev *dereference_rdev_and_rrdev(struct raid10_info *mirror, + struct md_rdev **prrdev) +{ + struct md_rdev *rdev, *rrdev; + + rrdev = rcu_dereference(mirror->replacement); + /* + * Read replacement first to prevent reading both rdev and + * replacement as NULL during replacement replace rdev. + */ + smp_mb(); + rdev = rcu_dereference(mirror->rdev); + if (rdev == rrdev) + rrdev = NULL; + + *prrdev = rrdev; + return rdev; +} + static void wait_blocked_dev(struct mddev *mddev, struct r10bio *r10_bio) { int i; @@ -1460,15 +1479,7 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio, int d = r10_bio->devs[i].devnum; struct md_rdev *rdev, *rrdev; - rrdev = rcu_dereference(conf->mirrors[d].replacement); - /* - * Read replacement first to prevent reading both rdev and - * replacement as NULL during replacement replace rdev. - */ - smp_mb(); - rdev = rcu_dereference(conf->mirrors[d].rdev); - if (rdev == rrdev) - rrdev = NULL; + rdev = dereference_rdev_and_rrdev(&conf->mirrors[d], &rrdev); if (rdev && (test_bit(Faulty, &rdev->flags))) rdev = NULL; if (rrdev && (test_bit(Faulty, &rrdev->flags))) -- 2.40.1