From nobody Tue Feb 10 19:48:34 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 2BE6FC41513 for ; Thu, 3 Aug 2023 13:28:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236274AbjHCN2B (ORCPT ); Thu, 3 Aug 2023 09:28:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47368 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235866AbjHCN1l (ORCPT ); Thu, 3 Aug 2023 09:27:41 -0400 Received: from dggsgout11.his.huawei.com (unknown [45.249.212.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9C5802728; Thu, 3 Aug 2023 06:27:34 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.143]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4RGqQW0xXVz4f46Ry; Thu, 3 Aug 2023 21:27:31 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.104.67]) by APP4 (Coremail) with SMTP id gCh0CgCnD7M6q8tk5SrlPQ--.7420S16; Thu, 03 Aug 2023 21:27:31 +0800 (CST) From: Yu Kuai To: song@kernel.org, xni@redhat.com 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 12/13] md: delay choosing sync direction to md_start_sync() Date: Thu, 3 Aug 2023 21:24:25 +0800 Message-Id: <20230803132426.2688608-13-yukuai1@huaweicloud.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230803132426.2688608-1-yukuai1@huaweicloud.com> References: <20230803132426.2688608-1-yukuai1@huaweicloud.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: gCh0CgCnD7M6q8tk5SrlPQ--.7420S16 X-Coremail-Antispam: 1UD129KBjvJXoW3Xr4rXF1DWF4xtry8tFWfuFg_yoW3Gr1kpa yfJFn8GrW8JFy3ZrW2q3WDX3y5ur1jqrZrtFW3W3s5CFn0yF4SkFy5u3W7AFWDtas2ya12 vw4kJFZrZF15uw7anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUBj14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_JF0E3s1l82xGYI kIc2x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2 z4x0Y4vE2Ix0cI8IcVAFwI0_Ar0_tr1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F 4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oVCq 3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7 IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4U M4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwCF04k20xvY0x0EwIxGrw CFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE 14v26r106r1rMI8E67AF67kF1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2 IY67AKxVW8JVW5JwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F4UJwCI42IY6xAIw20E Y4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Gr0_Cr1lIxAIcVC2z280aVCY1x0267 AKxVW8Jr0_Cr1UYxBIdaVFxhVjvjDU0xZFpf9x0JUQSdkUUUUU= 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 Before this patch, for read-write array: 1) md_check_recover() found that something need to be done, and it'll try to grab 'reconfig_mutex'. The case that md_check_recover() need to do something: - array is not suspend; - super_block need to be updated; - 'MD_RECOVERY_NEEDED' or ''MD_RECOVERY_DONE' is set; - unusual case related to safemode; 2) if 'MD_RECOVERY_RUNNING' is not set, and 'MD_RECOVERY_NEEDED' is set, md_check_recover() will try to choose a sync direction, and then queue a work md_start_sync(). 3) md_start_sync() register sync_thread; After this patch, 1) is the same; 2) if 'MD_RECOVERY_RUNNING' is not set, and 'MD_RECOVERY_NEEDED' is set, queue a work md_start_sync() directly; 3) md_start_sync() will try to choose a sync direction, and then register sync_thread(); Because 'MD_RECOVERY_RUNNING' is cleared when sync_thread is done, 2) and 3) is always runned in serial and they can never concurrent, this change should not introduce any behavior change for now. Also fix a problem that md_start_sync() can clear 'MD_RECOVERY_RUNNING' without protection in error path, which might affect the logical in md_check_recovery(). The advantage to change this is that array reconfiguration is independent from daemon now, and it'll be much easier to synchronize it with io, consider that io may rely on daemon thread to be done. Signed-off-by: Yu Kuai --- drivers/md/md.c | 126 +++++++++++++++++++++++++----------------------- 1 file changed, 67 insertions(+), 59 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 8980a41bfe97..ef88581d9a39 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -9261,6 +9261,44 @@ static int remove_and_add_spares(struct mddev *mddev) static void md_start_sync(struct work_struct *ws) { struct mddev *mddev =3D container_of(ws, struct mddev, sync_work); + int spares =3D 0; + + mddev_lock_nointr(mddev); + + /* + * No recovery is running, remove any failed drives, then add spares if + * possible. Spares are also removed and re-added, to allow the + * personality to fail the re-add. + */ + if (mddev->reshape_position !=3D MaxSector) { + if (mddev->pers->check_reshape =3D=3D NULL || + mddev->pers->check_reshape(mddev) !=3D 0) + /* Cannot proceed */ + goto not_running; + set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery); + clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery); + } else if ((spares =3D remove_and_add_spares(mddev))) { + clear_bit(MD_RECOVERY_SYNC, &mddev->recovery); + clear_bit(MD_RECOVERY_CHECK, &mddev->recovery); + clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery); + set_bit(MD_RECOVERY_RECOVER, &mddev->recovery); + } else if (mddev->recovery_cp < MaxSector) { + set_bit(MD_RECOVERY_SYNC, &mddev->recovery); + clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery); + } else if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) { + /* nothing to be done ... */ + goto not_running; + } + + if (!mddev->pers->sync_request) + goto not_running; + + /* + * We are adding a device or devices to an array which has the bitmap + * stored on all devices. So make sure all bitmap pages get written. + */ + if (spares) + md_bitmap_write_all(mddev->bitmap); =20 rcu_assign_pointer(mddev->sync_thread, md_register_thread(md_do_sync, mddev, "resync")); @@ -9268,20 +9306,27 @@ static void md_start_sync(struct work_struct *ws) pr_warn("%s: could not start resync thread...\n", mdname(mddev)); /* leave the spares where they are, it shouldn't hurt */ - clear_bit(MD_RECOVERY_SYNC, &mddev->recovery); - clear_bit(MD_RECOVERY_RESHAPE, &mddev->recovery); - clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery); - clear_bit(MD_RECOVERY_CHECK, &mddev->recovery); - clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery); - wake_up(&resync_wait); - if (test_and_clear_bit(MD_RECOVERY_RECOVER, - &mddev->recovery)) - if (mddev->sysfs_action) - sysfs_notify_dirent_safe(mddev->sysfs_action); - } else - md_wakeup_thread(mddev->sync_thread); + goto not_running; + } + + mddev_unlock(mddev); + md_wakeup_thread(mddev->sync_thread); sysfs_notify_dirent_safe(mddev->sysfs_action); md_new_event(); + return; + +not_running: + clear_bit(MD_RECOVERY_SYNC, &mddev->recovery); + clear_bit(MD_RECOVERY_RESHAPE, &mddev->recovery); + clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery); + clear_bit(MD_RECOVERY_CHECK, &mddev->recovery); + clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery); + mddev_unlock(mddev); + + wake_up(&resync_wait); + if (test_and_clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery) && + mddev->sysfs_action) + sysfs_notify_dirent_safe(mddev->sysfs_action); } =20 /* @@ -9349,7 +9394,6 @@ void md_check_recovery(struct mddev *mddev) return; =20 if (mddev_trylock(mddev)) { - int spares =3D 0; bool try_set_sync =3D mddev->safemode !=3D 0; =20 if (!mddev->external && mddev->safemode =3D=3D 1) @@ -9436,56 +9480,20 @@ void md_check_recovery(struct mddev *mddev) clear_bit(MD_RECOVERY_INTR, &mddev->recovery); clear_bit(MD_RECOVERY_DONE, &mddev->recovery); =20 - if (!test_and_clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery) || - test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)) - goto not_running; - /* no recovery is running. - * remove any failed drives, then - * add spares if possible. - * Spares are also removed and re-added, to allow - * the personality to fail the re-add. - */ - - if (mddev->reshape_position !=3D MaxSector) { - if (mddev->pers->check_reshape =3D=3D NULL || - mddev->pers->check_reshape(mddev) !=3D 0) - /* Cannot proceed */ - goto not_running; - set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery); - clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery); - } else if ((spares =3D remove_and_add_spares(mddev))) { - clear_bit(MD_RECOVERY_SYNC, &mddev->recovery); - clear_bit(MD_RECOVERY_CHECK, &mddev->recovery); - clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery); - set_bit(MD_RECOVERY_RECOVER, &mddev->recovery); - } else if (mddev->recovery_cp < MaxSector) { - set_bit(MD_RECOVERY_SYNC, &mddev->recovery); - clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery); - } else if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) - /* nothing to be done ... */ - goto not_running; - - if (mddev->pers->sync_request) { - if (spares) { - /* We are adding a device or devices to an array - * which has the bitmap stored on all devices. - * So make sure all bitmap pages get written - */ - md_bitmap_write_all(mddev->bitmap); - } + if (test_and_clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery) && + !test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)) { + /* + * Before this sync thread is done and + * MD_RECOVERY_RUNNING is cleared, new sync_work won't + * be queued. + */ queue_work(md_misc_wq, &mddev->sync_work); - goto unlock; - } - not_running: - if (!mddev->sync_thread) { + } else { clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery); wake_up(&resync_wait); - if (test_and_clear_bit(MD_RECOVERY_RECOVER, - &mddev->recovery)) - if (mddev->sysfs_action) - sysfs_notify_dirent_safe(mddev->sysfs_action); } - unlock: + +unlock: wake_up(&mddev->sb_wait); mddev_unlock(mddev); } --=20 2.39.2