From nobody Fri Jan 2 22:09:47 2026 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 99C47E784AF for ; Sat, 7 Oct 2023 03:24:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343510AbjJGDYm (ORCPT ); Fri, 6 Oct 2023 23:24:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42984 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234091AbjJGDYj (ORCPT ); Fri, 6 Oct 2023 23:24:39 -0400 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F0D98BD; Fri, 6 Oct 2023 20:24:37 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.143]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4S2Vyl6DkHz4f3m6r; Sat, 7 Oct 2023 11:24:31 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.104.67]) by APP4 (Coremail) with SMTP id gCh0CgD3jd1tzyBlo9pRCQ--.28427S4; Sat, 07 Oct 2023 11:24:32 +0800 (CST) From: Yu Kuai To: song@kernel.org Cc: linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org, yukuai3@huawei.com, yukuai1@huaweicloud.com, yi.zhang@huawei.com, yangerkun@huawei.com Subject: [PATCH -next] md/raid1: don't split discard io for write behind Date: Sat, 7 Oct 2023 19:21:05 +0800 Message-Id: <20231007112105.407449-1-yukuai1@huaweicloud.com> X-Mailer: git-send-email 2.39.2 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: gCh0CgD3jd1tzyBlo9pRCQ--.28427S4 X-Coremail-Antispam: 1UD129KBjvJXoW7try8AF18Ar4rXw4DJr4fXwb_yoW8Ww1rp3 yqgFWYyr9rXr12yr1DXa4DZFyrtasFqrW7KrWfX3y7Zr13XFyUXa1ktas5Jr1kCrZ3ury3 Zr4qyrW8ua4UXrJanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUvF14x267AKxVW8JVW5JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2jI8I6cxK62vIxIIY0VWUZVW8XwA2ocxC64kIII 0Yj41l84x0c7CEw4AK67xGY2AK021l84ACjcxK6xIIjxv20xvE14v26F1j6w1UM28EF7xv wVC0I7IYx2IY6xkF7I0E14v26r4UJVWxJr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4 x0Y4vEx4A2jsIEc7CjxVAFwI0_GcCE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG 64xvF2IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r 1j6r4UMcvjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x0EwIxGrwACjI8F5VA0II8E6IAq YI8I648v4I1l42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4 xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r126r1D MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I 0E14v26r1j6r4UMIIF0xvE42xK8VAvwI8IcIk0rVWrJr0_WFyUJwCI42IY6I8E87Iv67AK xVWUJVW8JwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvj TRNgAwUUUUU X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Yu Kuai Currently, discad io is treated the same as normal write io, and for write behind case, io size is limited to: BIO_MAX_VECS * (PAGE_SIZE >> 9) For 0.5KB sector size and 4KB PAGE_SIZE, this is just 1MB. For consequence, if 'WriteMostly' is set to one of the underlying disks, then diskcard io will be splited into 1MB and it will take a long time for the diskcard to finish. Fix this problem by disable write behind for discard io. Reported-by: Roman Mamedov Closes: https://lore.kernel.org/all/6a1165f7-c792-c054-b8f0-1ad4f7b8ae01@ul= tracoder.org/ Reported-and-tested-by: Kirill Kirilenko Signed-off-by: Yu Kuai --- drivers/md/raid1.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 3a78f79ee6d5..35d12948e0a9 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -1345,6 +1345,7 @@ static void raid1_write_request(struct mddev *mddev, = struct bio *bio, int first_clone; int max_sectors; bool write_behind =3D false; + bool is_discard =3D (bio_op(bio) =3D=3D REQ_OP_DISCARD); =20 if (mddev_is_clustered(mddev) && md_cluster_ops->area_resyncing(mddev, WRITE, @@ -1405,7 +1406,7 @@ static void raid1_write_request(struct mddev *mddev, = struct bio *bio, * write-mostly, which means we could allocate write behind * bio later. */ - if (rdev && test_bit(WriteMostly, &rdev->flags)) + if (!is_discard && rdev && test_bit(WriteMostly, &rdev->flags)) write_behind =3D true; =20 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) { --=20 2.39.2