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

[Kanchan Joshi]

On Tue, Sep 06, 2022 at 08:25:22AM +0200, Christoph Hellwig wrote:
>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.

if you think it's a deal-breaker, maybe I can add a new bioset in nvme and
pass that as argument to this helper. Would you prefer that over the
current approach.