From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga04-in.huawei.com (szxga04-in.huawei.com [45.249.212.190]) (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 89E1317C60; Wed, 24 Jan 2024 09:20:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.190 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706088007; cv=none; b=UEwXs4bfgB99OQAxHrjdEdCC5rJvt9mnUyAvaniDti6SJbT59xCNnP7cFOLQ2YPuTBK7/gBxxZOZiMg5IEbem0mM1c8MWFM8VvV50M7N8RqPif5nvZBrQMfDBFgrtr36b49oUEteD+Lo4nPNsh89YxTrXHtRgd7tbcSb6LLX8B4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706088007; c=relaxed/simple; bh=NnnCt3x2MjeWU+TuhRK8/jx2gmdbjoesdllieJVuNzE=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Q2YUnxbE2zOiTMe3dI0w5Y44YWMaHlTeaEOdzlzKpUhsAkLyiwiRTIUJhrH6acdVSbOMtrIJtru2vyBhjiypMYKySR8CPH1suinwjDG13pLkskBEl2tbZ83C5ZFC0OBB2AzAzfR4kFySAtSA2kMJ4m5pRevDmXplq+9Ey7lZutc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.190 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.88.214]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4TKdff2KZwz29kjF; Wed, 24 Jan 2024 17:18:18 +0800 (CST) Received: from kwepemm600009.china.huawei.com (unknown [7.193.23.164]) by mail.maildlp.com (Postfix) with ESMTPS id 8AB011A016B; Wed, 24 Jan 2024 17:19:47 +0800 (CST) Received: from huawei.com (10.175.104.67) by kwepemm600009.china.huawei.com (7.193.23.164) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.35; Wed, 24 Jan 2024 17:18:22 +0800 From: Yu Kuai To: , , , , , , , , , , , CC: , , , , Subject: [PATCH v2 06/11] dm-raid: really frozen sync_thread during suspend Date: Wed, 24 Jan 2024 17:14:16 +0800 Message-ID: <20240124091421.1261579-7-yukuai3@huawei.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240124091421.1261579-1-yukuai3@huawei.com> References: <20240124091421.1261579-1-yukuai3@huawei.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To kwepemm600009.china.huawei.com (7.193.23.164) 1) The flag MD_RECOVERY_FROZEN doesn't mean that sync thread is frozen, it only prevent new sync_thread to start, and it can't stop the running sync thread; 2) The flag MD_RECOVERY_FROZEN doesn't mean that writes are stopped, use it as condition for md_stop_writes() in raid_postsuspend() doesn't look correct. 3) raid_message can set/clear the flag MD_RECOVERY_FROZEN at anytime, and if MD_RECOVERY_FROZEN is cleared while the array is suspended, new sync_thread can start unexpected. Fix above problems by using the new helper to suspend the array during suspend, also disallow raid_message() to change sync_thread status during suspend. Note that after commit f52f5c71f3d4 ("md: fix stopping sync thread"), the test shell/lvconvert-raid-reshape.sh start to hang in stop_sync_thread(), and with previous fixes, the test won't hang there anymore, however, the test will still fail and complain that ext4 is corrupted. And with this patch, the test won't hang due to stop_sync_thread() or fail due to ext4 is corrupted anymore. However, there is still a deadlock related to dm-raid456 that will be fixed in following patches. Reported-by: Mikulas Patocka Closes: https://lore.kernel.org/all/e5e8afe2-e9a8-49a2-5ab0-958d4065c55e@redhat.com/ Fixes: 1af2048a3e87 ("dm raid: fix deadlock caused by premature md_stop_writes()") Fixes: 9dbd1aa3a81c ("dm raid: add reshaping support to the target") Fixes: f52f5c71f3d4 ("md: fix stopping sync thread") Signed-off-by: Yu Kuai --- drivers/md/dm-raid.c | 38 +++++++++++++++++++++++++++++--------- 1 file changed, 29 insertions(+), 9 deletions(-) diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c index eb009d6bb03a..5ce3c6020b1b 100644 --- a/drivers/md/dm-raid.c +++ b/drivers/md/dm-raid.c @@ -3240,11 +3240,12 @@ static int raid_ctr(struct dm_target *ti, unsigned int argc, char **argv) rs->md.ro = 1; rs->md.in_sync = 1; - /* Keep array frozen until resume. */ - set_bit(MD_RECOVERY_FROZEN, &rs->md.recovery); - /* Has to be held on running the array */ mddev_suspend_and_lock_nointr(&rs->md); + + /* Keep array frozen until resume. */ + md_frozen_sync_thread(&rs->md); + r = md_run(&rs->md); rs->md.in_sync = 0; /* Assume already marked dirty */ if (r) { @@ -3722,6 +3723,9 @@ static int raid_message(struct dm_target *ti, unsigned int argc, char **argv, if (!mddev->pers || !mddev->pers->sync_request) return -EINVAL; + if (test_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags)) + return -EBUSY; + if (!strcasecmp(argv[0], "frozen")) set_bit(MD_RECOVERY_FROZEN, &mddev->recovery); else @@ -3791,15 +3795,31 @@ static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits) blk_limits_io_opt(limits, chunk_size_bytes * mddev_data_stripes(rs)); } +static void raid_presuspend(struct dm_target *ti) +{ + struct raid_set *rs = ti->private; + + mddev_lock_nointr(&rs->md); + md_frozen_sync_thread(&rs->md); + mddev_unlock(&rs->md); +} + +static void raid_presuspend_undo(struct dm_target *ti) +{ + struct raid_set *rs = ti->private; + + mddev_lock_nointr(&rs->md); + md_unfrozen_sync_thread(&rs->md); + mddev_unlock(&rs->md); +} + static void raid_postsuspend(struct dm_target *ti) { struct raid_set *rs = ti->private; if (!test_and_set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags)) { /* Writes have to be stopped before suspending to avoid deadlocks. */ - if (!test_bit(MD_RECOVERY_FROZEN, &rs->md.recovery)) - md_stop_writes(&rs->md); - + md_stop_writes(&rs->md); mddev_suspend(&rs->md, false); } } @@ -4012,8 +4032,6 @@ static int raid_preresume(struct dm_target *ti) } /* Check for any resize/reshape on @rs and adjust/initiate */ - /* Be prepared for mddev_resume() in raid_resume() */ - set_bit(MD_RECOVERY_FROZEN, &mddev->recovery); if (mddev->recovery_cp && mddev->recovery_cp < MaxSector) { set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery); mddev->resync_min = mddev->recovery_cp; @@ -4056,9 +4074,9 @@ static void raid_resume(struct dm_target *ti) rs_set_capacity(rs); mddev_lock_nointr(mddev); - clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery); mddev->ro = 0; mddev->in_sync = 0; + md_unfrozen_sync_thread(mddev); mddev_unlock_and_resume(mddev); } } @@ -4074,6 +4092,8 @@ static struct target_type raid_target = { .message = raid_message, .iterate_devices = raid_iterate_devices, .io_hints = raid_io_hints, + .presuspend = raid_presuspend, + .presuspend_undo = raid_presuspend_undo, .postsuspend = raid_postsuspend, .preresume = raid_preresume, .resume = raid_resume, -- 2.39.2