[PATCH v2 04/10] block: Handle meta bounce buffer correctly in case of split

[Christoph Hellwig]

On Wed, Jun 26, 2024 at 03:36:54PM +0530, Anuj Gupta wrote:
> @@ -105,9 +105,12 @@ static void bio_integrity_unpin_bvec(struct bio_vec *bv, int nr_vecs,
>  
>  static void bio_integrity_uncopy_user(struct bio_integrity_payload *bip)
>  {
> +	struct bio *bio = bip->bip_bio;
> +	struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
>  	unsigned short nr_vecs = bip->bip_max_vcnt - 1;
>  	struct bio_vec *copy = &bip->bip_vec[1];
> -	size_t bytes = bip->bip_iter.bi_size;
> +	size_t bytes = bio_integrity_bytes(bi,
> +					   bvec_iter_sectors(bip->bio_iter));

Maybe add a well documented helper that calculates the metadata bytes
based on the iter given that this is probably going to become more
common now that we're doing proper cloning?

> -	bip->bip_flags = bip_src->bip_flags & ~BIP_BLOCK_INTEGRITY;
> -
> +	bip->bip_flags = bip_src->bip_flags & ~(BIP_BLOCK_INTEGRITY |
> +						BIP_COPY_USER);

We're probably better off say what flags should be cloned and not
which ones should not.  Preferably with a new #define in bio.h.