From nobody Tue Feb 10 15:28:16 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 CDC37EE49B0 for ; Fri, 25 Aug 2023 03:15:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237344AbjHYDOh (ORCPT ); Thu, 24 Aug 2023 23:14:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47666 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233966AbjHYDOS (ORCPT ); Thu, 24 Aug 2023 23:14:18 -0400 Received: from dggsgout11.his.huawei.com (unknown [45.249.212.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0CD641BDA; Thu, 24 Aug 2023 20:14:16 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.169]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4RX4mh56Hwz4f3l8d; Fri, 25 Aug 2023 11:14:12 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.104.67]) by APP4 (Coremail) with SMTP id gCh0CgAnBah_HOhkveEWBg--.3212S7; Fri, 25 Aug 2023 11:14:13 +0800 (CST) From: Yu Kuai To: agk@redhat.com, snitzer@kernel.org, dm-devel@redhat.com, song@kernel.org, xni@redhat.com Cc: linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, yukuai3@huawei.com, yukuai1@huaweicloud.com, yi.zhang@huawei.com, yangerkun@huawei.com Subject: [PATCH -next v2 3/7] md: don't rely on 'mddev->pers' to be set in mddev_suspend() Date: Fri, 25 Aug 2023 11:09:52 +0800 Message-Id: <20230825030956.1527023-4-yukuai1@huaweicloud.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230825030956.1527023-1-yukuai1@huaweicloud.com> References: <20230825030956.1527023-1-yukuai1@huaweicloud.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: gCh0CgAnBah_HOhkveEWBg--.3212S7 X-Coremail-Antispam: 1UD129KBjvdXoWrKFy8XFyDGr15urWkZr18Krg_yoWkZFgEgF s8u34DXr10vF9rKrn0qa1Fvry5KFn8WwsrZFyrCryftF95Jry0yF95Ww1Yqwn2yrZrJa4U tryUKr17Ars5XjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUb6kFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k26cxKx2IYs7xG 6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUWwA2048vs2IY02 0Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxSw2x7M28EF7xv wVC0I7IYx2IY67AKxVWDJVCq3wA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxVWxJr0_GcWl84 ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_GcCE3s1le2I2 62IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcV AFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkEbVWUJVW8JwACjcxG 0xvY0x0EwIxGrwACjI8F5VA0II8E6IAqYI8I648v4I1lFIxGxcIEc7CjxVA2Y2ka0xkIwI 1l42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWU JVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r1q6r43MIIYrxkI7V AKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E14v26r4j 6F4UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVWUJVW8JwCI42 IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvjfUojjgUUUUU 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 'active_io' used to be initialized while the array is running, and 'mddev->pers' is set while the array is running as well. Hence caller must hold 'reconfig_mutex' and guarantee 'mddev->pers' is set before calling mddev_suspend(). Now that 'active_io' is initialized when mddev is allocated, such restriction doesn't exist anymore. In the meantime, follow up patches will refactor mddev_suspend(), hence add checking for 'mddev->pers' to prevent null-ptr-deref. Signed-off-by: Yu Kuai --- drivers/md/md.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index e6faeb73172d..e787900d51d7 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -449,7 +449,7 @@ void mddev_suspend(struct mddev *mddev) set_bit(MD_ALLOW_SB_UPDATE, &mddev->flags); percpu_ref_kill(&mddev->active_io); =20 - if (mddev->pers->prepare_suspend) + if (mddev->pers && mddev->pers->prepare_suspend) mddev->pers->prepare_suspend(mddev); =20 wait_event(mddev->sb_wait, percpu_ref_is_zero(&mddev->active_io)); --=20 2.39.2