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Date: Mon, 28 Feb 2022 18:12:45 -0800
From: Ira Weiny <ira.weiny@intel.com>
To: Christoph Hellwig <hch@lst.de>
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	<20220222155156.597597-5-hch@lst.de>
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Cc: Jens Axboe <axboe@kernel.dk>, Chris Zankel <chris@zankel.net>,
	Justin Sanders <justin@coraid.com>, Minchan Kim <minchan@kernel.org>,
	Vishal Verma <vishal.l.verma@intel.com>, linux-xtensa@linux-xtensa.org,
	Philipp Reisner <philipp.reisner@linbit.com>,
	Denis Efremov <efremov@linux.com>, Coly Li <colyli@suse.de>,
	linux-block@vger.kernel.org, Max Filippov <jcmvbkbc@gmail.com>,
	linux-bcache@vger.kernel.org, nvdimm@lists.linux.dev,
	Lars Ellenberg <lars.ellenberg@linbit.com>,
	Dan Williams <dan.j.williams@intel.com>,
	Nitin Gupta <ngupta@vflare.org>, drbd-dev@lists.linbit.com
Subject: Re: [Drbd-dev] [PATCH 04/10] zram: use memcpy_from_bvec in
	zram_bvec_write
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On Tue, Feb 22, 2022 at 04:51:50PM +0100, Christoph Hellwig wrote:
> Use memcpy_from_bvec instead of open coding the logic.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Same comment regarding the dst map.  Does it need to be atomic?

Regardless,
Reviewed-by: Ira Weiny <ira.weiny@intel.com>

> ---
>  drivers/block/zram/zram_drv.c | 5 +----
>  1 file changed, 1 insertion(+), 4 deletions(-)
> 
> diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
> index 14becdf2815df..e9474b02012de 100644
> --- a/drivers/block/zram/zram_drv.c
> +++ b/drivers/block/zram/zram_drv.c
> @@ -1465,7 +1465,6 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec,
>  {
>  	int ret;
>  	struct page *page = NULL;
> -	void *src;
>  	struct bio_vec vec;
>  
>  	vec = *bvec;
> @@ -1483,11 +1482,9 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec,
>  		if (ret)
>  			goto out;
>  
> -		src = kmap_atomic(bvec->bv_page);
>  		dst = kmap_atomic(page);
> -		memcpy(dst + offset, src + bvec->bv_offset, bvec->bv_len);
> +		memcpy_from_bvec(dst + offset, bvec);
>  		kunmap_atomic(dst);
> -		kunmap_atomic(src);
>  
>  		vec.bv_page = page;
>  		vec.bv_len = PAGE_SIZE;
> -- 
> 2.30.2
> 
>