[Drbd-dev] [PATCH 08/10] drbd: use bvec_kmap_local in drbd_csum_bio

[Ira Weiny]

On Tue, Feb 22, 2022 at 04:51:54PM +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>

Reviewed-by: Ira Weiny <ira.weiny at intel.com>

> ---
>  drivers/block/drbd/drbd_worker.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c
> index a5e04b38006b6..1b48c8172a077 100644
> --- a/drivers/block/drbd/drbd_worker.c
> +++ b/drivers/block/drbd/drbd_worker.c
> @@ -326,9 +326,9 @@ void drbd_csum_bio(struct crypto_shash *tfm, struct bio *bio, void *digest)
>  	bio_for_each_segment(bvec, bio, iter) {
>  		u8 *src;
>  
> -		src = kmap_atomic(bvec.bv_page);
> -		crypto_shash_update(desc, src + bvec.bv_offset, bvec.bv_len);
> -		kunmap_atomic(src);
> +		src = bvec_kmap_local(&bvec);
> +		crypto_shash_update(desc, src, bvec.bv_len);
> +		kunmap_local(src);
>  
>  		/* REQ_OP_WRITE_SAME has only one segment,
>  		 * checksum the payload only once. */
> -- 
> 2.30.2
> 
>