[Drbd-dev] [PATCH 06/10] nvdimm-btt: use bvec_kmap_local in btt_rw_integrity

[Ira Weiny]

On Tue, Feb 22, 2022 at 04:51:52PM +0100, Christoph Hellwig wrote:
> Using local kmaps slightly reduces the chances to stray writes, and
> the bvec interface cleans up the code a little bit.
> 
> Signed-off-by: Christoph Hellwig <hch at lst.de>
> ---
>  drivers/nvdimm/btt.c | 10 ++++------
>  1 file changed, 4 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c
> index cbd994f7f1fe6..9613e54c7a675 100644
> --- a/drivers/nvdimm/btt.c
> +++ b/drivers/nvdimm/btt.c
> @@ -1163,17 +1163,15 @@ static int btt_rw_integrity(struct btt *btt, struct bio_integrity_payload *bip,
>  		 */
>  
>  		cur_len = min(len, bv.bv_len);
> -		mem = kmap_atomic(bv.bv_page);
> +		mem = bvec_kmap_local(&bv);
>  		if (rw)
> -			ret = arena_write_bytes(arena, meta_nsoff,
> -					mem + bv.bv_offset, cur_len,
> +			ret = arena_write_bytes(arena, meta_nsoff, mem, cur_len,

Why drop bv.bv_offset here and below?

Ira

>  					NVDIMM_IO_ATOMIC);
>  		else
> -			ret = arena_read_bytes(arena, meta_nsoff,
> -					mem + bv.bv_offset, cur_len,
> +			ret = arena_read_bytes(arena, meta_nsoff, mem, cur_len,
>  					NVDIMM_IO_ATOMIC);
>  
> -		kunmap_atomic(mem);
> +		kunmap_local(mem);
>  		if (ret)
>  			return ret;
>  
> -- 
> 2.30.2
> 
>