From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from dggsgout12.his.huawei.com (unknown [45.249.212.56]) (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 66EBF8F44; Fri, 26 Jan 2024 02:38:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706236706; cv=none; b=AMmneK7G6SKBuXI11NIrsrYhTD/VfmveoJ41kG2a+1INjn82ljAtKRpJHBOqAeK0bmhQ+T4I2F/DZBYZWQdhlo7Meo1W/kMy3XwsJWsIJtAgHbTEqu5YdNYkZz3L3gIYzNS3irFOfukd/iHP/wl/bNlu1PEK9oUjx5YCRTKCn3s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706236706; c=relaxed/simple; bh=2ZViTyAtp+CTtBgXqyCI+DXuvTv6gWYIoVmUj6b7Acc=; h=Subject:To:Cc:References:From:Message-ID:Date:MIME-Version: In-Reply-To:Content-Type; b=V2fvpYnAn7Qrb1WAgIo0TMwN6D7r/3FLm32I43ZHnGBjwVWPOESkyFCb1588ImnJNHRdy685T7Gh8/5UKnl1rKdYes9H33/H9p/xmpYTcb+cuwfBkuLAzlT8/vBdf8zR+sg3lEDnGVhbBSnKwVTOHZ0DzqSiIE123viBNJhFyW0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.163.235]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTP id 4TLhh16kpHz4f3kG0; Fri, 26 Jan 2024 10:38:09 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.112]) by mail.maildlp.com (Postfix) with ESMTP id E34F21A0272; Fri, 26 Jan 2024 10:38:13 +0800 (CST) Received: from [10.174.176.73] (unknown [10.174.176.73]) by APP1 (Coremail) with SMTP id cCh0CgDHlxATG7Nlj97_Bw--.64714S3; Fri, 26 Jan 2024 10:38:13 +0800 (CST) Subject: Re: [PATCH v2 05/11] md: export helpers to stop sync_thread To: Yu Kuai , Xiao Ni Cc: agk@redhat.com, snitzer@kernel.org, mpatocka@redhat.com, dm-devel@lists.linux.dev, song@kernel.org, jbrassow@f14.redhat.com, neilb@suse.de, heinzm@redhat.com, shli@fb.com, akpm@osdl.org, linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, yi.zhang@huawei.com, yangerkun@huawei.com, "yukuai3 >> yukuai (C)" References: <20240124091421.1261579-1-yukuai3@huawei.com> <20240124091421.1261579-6-yukuai3@huawei.com> <85eeb8e4-d526-aa20-c50d-7e755ca6c776@huaweicloud.com> From: Yu Kuai Message-ID: <118fabe2-f2ac-e80a-32f9-0eeee2be3574@huaweicloud.com> Date: Fri, 26 Jan 2024 10:38:11 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: <85eeb8e4-d526-aa20-c50d-7e755ca6c776@huaweicloud.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit X-CM-TRANSID:cCh0CgDHlxATG7Nlj97_Bw--.64714S3 X-Coremail-Antispam: 1UD129KBjvJXoW3AF4fWF1furWxWw4kKrWrAFb_yoW7WFyxpr 4ktFZ8JrWYyrZ3Xr12ga4DZa4Yqw18ta4DtryfJFy8JrnrtrnFgr1Uur1q9rykAay8Jr1U tw15WFsxZFy5Jr7anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUU9F14x267AKxVW5JVWrJwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26w1j6s0DM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r4U JVWxJr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_Gc CE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E 2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkEbVWUJV W8JwACjcxG0xvEwIxGrwACjI8F5VA0II8E6IAqYI8I648v4I1lFIxGxcIEc7CjxVA2Y2ka 0xkIwI1lc7I2V7IY0VAS07AlzVAYIcxG8wCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7x kEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E 67AF67kF1VAFwI0_GFv_WrylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCw CI42IY6xIIjxv20xvEc7CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6rW3Jr0E 3s1lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcS sGvfC2KfnxnUUI43ZEXa7VUbQVy7UUUUU== X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ Hi, 在 2024/01/25 15:57, Yu Kuai 写道: > Hi, > > 在 2024/01/25 15:51, Xiao Ni 写道: >> On Wed, Jan 24, 2024 at 5:19 PM Yu Kuai wrote: >>> >>> The new heleprs will be used in dm-raid in later patches to fix >>> regressions and prevent calling md_reap_sync_thread() directly. >>> >>> Signed-off-by: Yu Kuai >>> --- >>>   drivers/md/md.c | 41 +++++++++++++++++++++++++++++++++++++---- >>>   drivers/md/md.h |  3 +++ >>>   2 files changed, 40 insertions(+), 4 deletions(-) >>> >>> diff --git a/drivers/md/md.c b/drivers/md/md.c >>> index 6c5d0a372927..90cf31b53804 100644 >>> --- a/drivers/md/md.c >>> +++ b/drivers/md/md.c >>> @@ -4915,30 +4915,63 @@ static void stop_sync_thread(struct mddev >>> *mddev, bool locked, bool check_seq) >>>                  mddev_lock_nointr(mddev); >>>   } >>> >>> -static void idle_sync_thread(struct mddev *mddev) >>> +void md_idle_sync_thread(struct mddev *mddev) >>>   { >>> +       lockdep_assert_held(mddev->reconfig_mutex); >>> + >> >> Hi Kuai >> >> There is a building error. It should give a pointer to >> lockdep_assert_held. And same with the other two places in this patch. > > Yes, I forgot that I disabled all the debug config in order to let tests > finish quickly. I enabled these debuging conifg, and turns out this patch has some problem, see below. > > Thanks for the notince, will fix this in v3. > > Thanks, > Kuai > >> >> Regards >> Xiao >> >>>          mutex_lock(&mddev->sync_mutex); >>>          clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery); >>> +       stop_sync_thread(mddev, true, true); >>> +       mutex_unlock(&mddev->sync_mutex); >>> +} >>> +EXPORT_SYMBOL_GPL(md_idle_sync_thread); >>> + >>> +void md_frozen_sync_thread(struct mddev *mddev) >>> +{ >>> +       lockdep_assert_held(mddev->reconfig_mutex); >>> + >>> +       mutex_lock(&mddev->sync_mutex); >>> +       set_bit(MD_RECOVERY_FROZEN, &mddev->recovery); >>> +       stop_sync_thread(mddev, true, false); stop_sync_thread() may release 'reconfig_mutex' and grab it again, hence it's not right to grab 'sync_mutex' before 'reconfig_mutex'. Since 'sync_mutex' is introduced to serialize sysfs api 'sync_action' writers, while is not involved for dm-raid. I'll remove 'sync_mutex' for the new helper in v3. Thanks, Kuai >>> +       mutex_unlock(&mddev->sync_mutex); >>> +} >>> +EXPORT_SYMBOL_GPL(md_frozen_sync_thread); >>> >>> +void md_unfrozen_sync_thread(struct mddev *mddev) >>> +{ >>> +       lockdep_assert_held(mddev->reconfig_mutex); >>> + >>> +       mutex_lock(&mddev->sync_mutex); >>> +       clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery); >>> +       set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); >>> +       md_wakeup_thread(mddev->thread); >>> +       sysfs_notify_dirent_safe(mddev->sysfs_action); >>> +       mutex_unlock(&mddev->sync_mutex); >>> +} >>> +EXPORT_SYMBOL_GPL(md_unfrozen_sync_thread); >>> + >>> +static void idle_sync_thread(struct mddev *mddev) >>> +{ >>>          if (mddev_lock(mddev)) { >>>                  mutex_unlock(&mddev->sync_mutex); >>>                  return; >>>          } >>> >>> +       mutex_lock(&mddev->sync_mutex); >>> +       clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery); >>>          stop_sync_thread(mddev, false, true); >>>          mutex_unlock(&mddev->sync_mutex); >>>   } >>> >>>   static void frozen_sync_thread(struct mddev *mddev) >>>   { >>> -       mutex_lock(&mddev->sync_mutex); >>> -       set_bit(MD_RECOVERY_FROZEN, &mddev->recovery); >>> - >>>          if (mddev_lock(mddev)) { >>>                  mutex_unlock(&mddev->sync_mutex); >>>                  return; >>>          } >>> >>> +       mutex_lock(&mddev->sync_mutex); >>> +       set_bit(MD_RECOVERY_FROZEN, &mddev->recovery); >>>          stop_sync_thread(mddev, false, false); >>>          mutex_unlock(&mddev->sync_mutex); >>>   } >>> diff --git a/drivers/md/md.h b/drivers/md/md.h >>> index 8d881cc59799..437ab70ce79b 100644 >>> --- a/drivers/md/md.h >>> +++ b/drivers/md/md.h >>> @@ -781,6 +781,9 @@ extern void md_rdev_clear(struct md_rdev *rdev); >>>   extern void md_handle_request(struct mddev *mddev, struct bio *bio); >>>   extern int mddev_suspend(struct mddev *mddev, bool interruptible); >>>   extern void mddev_resume(struct mddev *mddev); >>> +extern void md_idle_sync_thread(struct mddev *mddev); >>> +extern void md_frozen_sync_thread(struct mddev *mddev); >>> +extern void md_unfrozen_sync_thread(struct mddev *mddev); >>> >>>   extern void md_reload_sb(struct mddev *mddev, int raid_disk); >>>   extern void md_update_sb(struct mddev *mddev, int force); >>> -- >>> 2.39.2 >>> >> >> . >> > > . >