Received-SPF: pass (google.com: domain of linux-kernel+bounces-49577-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45d1:ec00::1 as permitted sender) client-ip=2604:1380:45d1:ec00::1;
Message-ID: <c73fc514-78c1-20c6-b543-d8e7cd16f200@huaweicloud.com>
Date: Fri, 2 Feb 2024 17:26:36 +0800
Precedence: bulk
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101
 Thunderbird/91.10.0
Subject: Re: [PATCH v5 7/8] md: sync blockdev before stopping raid or setting
 readonly
To: Yu Kuai <yukuai1@huaweicloud.com>, linan666@huaweicloud.com,
 song@kernel.org, neilb@suse.com, mariusz.tkaczyk@linux.intel.com, shli@fb.com
Cc: linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org,
 yi.zhang@huawei.com, houtao1@huawei.com, yangerkun@huawei.com,
 "yukuai (C)" <yukuai3@huawei.com>
References: <20240201063404.772797-1-linan666@huaweicloud.com>
 <20240201063404.772797-8-linan666@huaweicloud.com>
 <8f6a305f-75ed-f103-4a52-9e88699d9289@huaweicloud.com>
From: Li Nan <linan666@huaweicloud.com>
In-Reply-To: <8f6a305f-75ed-f103-4a52-9e88699d9289@huaweicloud.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit


在 2024/2/2 10:12, Yu Kuai 写道:
> Hi,
> 
> 在 2024/02/01 14:34, linan666@huaweicloud.com 写道:
>> From: Li Nan <linan122@huawei.com>
>>
>> Commit a05b7ea03d72 ("md: avoid crash when stopping md array races
>> with closing other open fds.") added sync_block before stopping raid and
>> setting readonly. Later in commit 260fa034ef7a ("md: avoid deadlock when
>> dirty buffers during md_stop.") it is moved to ioctl. array_state_store()
>> was ignored. Add sync blockdev to array_state_store() now.
> 
> You're not just adding sync_blockdev() here. Please rewrite the tittle
> and commit message.
> 
>>
>> Signed-off-by: Li Nan <linan122@huawei.com>
>> ---
>>   drivers/md/md.c | 16 ++++++++++++++++
>>   1 file changed, 16 insertions(+)
>>
>> diff --git a/drivers/md/md.c b/drivers/md/md.c
>> index 4c7a0225f77d..86becf0015f5 100644
>> --- a/drivers/md/md.c
>> +++ b/drivers/md/md.c
>> @@ -4493,6 +4493,16 @@ array_state_store(struct mddev *mddev, const char 
>> *buf, size_t len)
>>       case broken:        /* cannot be set */
>>       case bad_word:
>>           return -EINVAL;
>> +    case clear:
>> +    case readonly:
>> +    case inactive:
>> +    case read_auto:
>> +        if (!mddev->pers || !md_is_rdwr(mddev))
>> +            break;
>> +        err = mddev_set_closing_and_sync_blockdev(mddev);
> 
> In this context, mddev->openers should be zero, and such check is in
> do_md_stop() and md_set_readonly():
> 

Yeah, the checks in do_md_stop() and md_set_readonly() can be removed after
this patch. However, 'mddev->open_metux' is used to protect MD_CLOSING and
'mddev->openers', it can be removed in these functions, too.

I will fix it later. Thanks for your review.

> if (atomic_read(&mddev->openers) > !!bdev).
> 
> Thanks,
> Kuai
> 


-- 
Thanks,
Nan