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Message-ID: <ea747f8e-257c-a4f6-6dce-5ea26de4083f@opensource.wdc.com>
Date:   Mon, 5 Sep 2022 12:54:19 +0900
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Subject: Re: [PATCH] block/blk-map: Remove set but unused variable 'added'
Content-Language: en-US
To:     Jiapeng Chong <jiapeng.chong@linux.alibaba.com>, axboe@kernel.dk
Cc:     linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
        Abaci Robot <abaci@linux.alibaba.com>
References: <20220905022553.77178-1-jiapeng.chong@linux.alibaba.com>
From:   Damien Le Moal <damien.lemoal@opensource.wdc.com>
Organization: Western Digital Research
In-Reply-To: <20220905022553.77178-1-jiapeng.chong@linux.alibaba.com>
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Precedence: bulk

On 9/5/22 11:25, Jiapeng Chong wrote:
> The variable added is not effectively used in the function, so delete
> it.
> 
> block/blk-map.c:273:16: warning: variable 'added' set but not used.
> 
> Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=2049
> Reported-by: Abaci Robot <abaci@linux.alibaba.com>
> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
> ---
>  block/blk-map.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/block/blk-map.c b/block/blk-map.c
> index 2fbe298d3822..a06919822a73 100644
> --- a/block/blk-map.c
> +++ b/block/blk-map.c
> @@ -270,7 +270,7 @@ static int bio_map_user_iov(struct request *rq, struct iov_iter *iter,
>  	while (iov_iter_count(iter)) {
>  		struct page **pages, *stack_pages[UIO_FASTIOV];
>  		ssize_t bytes;
> -		size_t offs, added = 0;
> +		size_t offs = 0;

offs is initialized with the call to iov_iter_get_pages_alloc2() so I do
not think it needs to be initialized to 0 here, unless you have a compiler
or sparse warning. If that is the case, this should be mentioned in the
commit message too.

>  		int npages;
>  
>  		if (nr_vecs <= ARRAY_SIZE(stack_pages)) {
> @@ -306,7 +306,6 @@ static int bio_map_user_iov(struct request *rq, struct iov_iter *iter,
>  					break;
>  				}
>  
> -				added += n;
>  				bytes -= n;
>  				offs = 0;
>  			}

-- 
Damien Le Moal
Western Digital Research