Re: [PATCH 08/10] drbd: use bvec_kmap_local in drbd_csum_bio

Ira Weiny
2022-03-01T04:06:42Z

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@lst.de>

Reviewed-by: Ira Weiny <ira.weiny@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
>
>