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Subject: Re: [PATCH 1/3] md/raid10: check replacement and rdev to prevent
 submit the same io twice
To:     linan666@huaweicloud.com, song@kernel.org,
        guoqing.jiang@cloud.ionos.com, colyli@suse.de, xni@redhat.com
Cc:     linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org,
        linan122@huawei.com, yi.zhang@huawei.com, houtao1@huawei.com,
        yangerkun@huawei.com, "yukuai (C)" <yukuai3@huawei.com>
References: <20230628015752.102267-1-linan666@huaweicloud.com>
 <20230628015752.102267-2-linan666@huaweicloud.com>
From:   Yu Kuai <yukuai1@huaweicloud.com>
Message-ID: <cf66fbb5-8174-3baf-4a00-63f46a8e41a9@huaweicloud.com>
Date:   Wed, 28 Jun 2023 14:36:10 +0800
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Hi,

?? 2023/06/28 9:57, linan666@huaweicloud.com д??:
> From: Li Nan <linan122@huawei.com>
> 
> After commit 4ca40c2ce099 ("md/raid10: Allow replacement device to be
> replace old drive."), 'rdev' and 'replacement' could appear to be
> identical. There are already checks for that in wait_blocked_dev() and
> raid10_write_request(). Add check for raid10_handle_discard() now.
> 

I'm working on synchronize io with array configuration, so that these
checks is not necessary and can be removed, however, this might take
some time, before that, this patch LGTM:

Reviewed-by: Yu Kuai <yukuai3@huawei.com>

> Signed-off-by: Li Nan <linan122@huawei.com>
> ---
>   drivers/md/raid10.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
> index fabc340aae4f..3e6a09aaaba6 100644
> --- a/drivers/md/raid10.c
> +++ b/drivers/md/raid10.c
> @@ -1811,6 +1811,8 @@ static int raid10_handle_discard(struct mddev *mddev, struct bio *bio)
>   		r10_bio->devs[disk].bio = NULL;
>   		r10_bio->devs[disk].repl_bio = NULL;
>   
> +		if (rdev == rrdev)
> +			rrdev = NULL;
>   		if (rdev && (test_bit(Faulty, &rdev->flags)))
>   			rdev = NULL;
>   		if (rrdev && (test_bit(Faulty, &rrdev->flags)))
>