Re: [PATCH V10 09/19] block: introduce bio_bvecs()

Omar Sandoval
2018-11-16T00:26:29Z

On Thu, Nov 15, 2018 at 04:52:56PM +0800, Ming Lei wrote:
> There are still cases in which we need to use bio_bvecs() for get the
> number of multi-page segment, so introduce it.
>
> Cc: Dave Chinner <dchinner@redhat.com>
> Cc: Kent Overstreet <kent.overstreet@gmail.com>
> Cc: Mike Snitzer <snitzer@redhat.com>
> Cc: dm-devel@redhat.com
> Cc: Alexander Viro <viro@zeniv.linux.org.uk>
> Cc: linux-fsdevel@vger.kernel.org
> Cc: Shaohua Li <shli@kernel.org>
> Cc: linux-raid@vger.kernel.org
> Cc: linux-erofs@lists.ozlabs.org
> Cc: David Sterba <dsterba@suse.com>
> Cc: linux-btrfs@vger.kernel.org
> Cc: Darrick J. Wong <darrick.wong@oracle.com>
> Cc: linux-xfs@vger.kernel.org
> Cc: Gao Xiang <gaoxiang25@huawei.com>
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: Theodore Ts'o <tytso@mit.edu>
> Cc: linux-ext4@vger.kernel.org
> Cc: Coly Li <colyli@suse.de>
> Cc: linux-bcache@vger.kernel.org
> Cc: Boaz Harrosh <ooo@electrozaur.com>
> Cc: Bob Peterson <rpeterso@redhat.com>
> Cc: cluster-devel@redhat.com

Reviewed-by: Omar Sandoval <osandov@fb.com>

> Signed-off-by: Ming Lei <ming.lei@redhat.com>
> ---
> include/linux/bio.h | 30 +++++++++++++++++++++++++-----
> 1 file changed, 25 insertions(+), 5 deletions(-)
>
> diff --git a/include/linux/bio.h b/include/linux/bio.h
> index 1f0dcf109841..3496c816946e 100644
> --- a/include/linux/bio.h
> +++ b/include/linux/bio.h
> @@ -196,7 +196,6 @@ static inline unsigned bio_segments(struct bio *bio)
> * We special case discard/write same/write zeroes, because they
> * interpret bi_size differently:
> */
> -
> switch (bio_op(bio)) {
> case REQ_OP_DISCARD:
> case REQ_OP_SECURE_ERASE:
> @@ -205,13 +204,34 @@ static inline unsigned bio_segments(struct bio *bio)
> case REQ_OP_WRITE_SAME:
> return 1;
> default:
> - break;
> + bio_for_each_segment(bv, bio, iter)
> + segs++;
> + return segs;
> }
> +}
>
> - bio_for_each_segment(bv, bio, iter)
> - segs++;
> +static inline unsigned bio_bvecs(struct bio *bio)
> +{
> + unsigned bvecs = 0;
> + struct bio_vec bv;
> + struct bvec_iter iter;
>
> - return segs;
> + /*
> + * We special case discard/write same/write zeroes, because they
> + * interpret bi_size differently:
> + */
> + switch (bio_op(bio)) {
> + case REQ_OP_DISCARD:
> + case REQ_OP_SECURE_ERASE:
> + case REQ_OP_WRITE_ZEROES:
> + return 0;
> + case REQ_OP_WRITE_SAME:
> + return 1;
> + default:
> + bio_for_each_bvec(bv, bio, iter)
> + bvecs++;
> + return bvecs;
> + }
> }
>
> /*
> --
> 2.9.5
>