[PATCH for-next v4 3/4] block: add helper to map bvec iterator for passthrough

[Christoph Hellwig]

On Mon, Sep 05, 2022 at 07:18:32PM +0530, Kanchan Joshi wrote:
> +static struct bio *bio_map_get(struct request *rq, unsigned int nr_vecs,
>  		gfp_t gfp_mask)
>  {
> @@ -259,13 +252,31 @@ static int bio_map_user_iov(struct request *rq, struct iov_iter *iter,
>  		bio = bio_alloc_bioset(NULL, nr_vecs, opf, gfp_mask,
>  					&fs_bio_set);
>  		if (!bio)
> -			return -ENOMEM;
> +			return NULL;

This context looks weird?  That bio_alloc_bioset should not be there,
as biosets are only used for file system I/O, which this is not.