On Tue, Jul 2, 2024 at 7:38 PM Anuj Gupta <anuj20.g@xxxxxxxxxxx> wrote:
>
> Modify bio_integrity_clone to reuse the original bvec array instead of
> allocating and copying it, similar to how bio data path is cloned.
>
> Suggested-by: Christoph Hellwig <hch@xxxxxx>
> Signed-off-by: Anuj Gupta <anuj20.g@xxxxxxxxxxx>
> ---
> block/bio-integrity.c | 9 +++------
> 1 file changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/block/bio-integrity.c b/block/bio-integrity.c
> index c4aed1dfa497..b78c145eb026 100644
> --- a/block/bio-integrity.c
> +++ b/block/bio-integrity.c
> @@ -76,7 +76,7 @@ struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,
> &bip->bip_max_vcnt, gfp_mask);
> if (!bip->bip_vec)
> goto err;
> - } else {
> + } else if (nr_vecs) {
> bip->bip_vec = bip->bip_inline_vecs;
> }
>
> @@ -584,14 +584,11 @@ int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
>
> BUG_ON(bip_src == NULL);
>
> - bip = bio_integrity_alloc(bio, gfp_mask, bip_src->bip_vcnt);
> + bip = bio_integrity_alloc(bio, gfp_mask, 0);
> if (IS_ERR(bip))
> return PTR_ERR(bip);
>
> - memcpy(bip->bip_vec, bip_src->bip_vec,
> - bip_src->bip_vcnt * sizeof(struct bio_vec));
> -
> - bip->bip_vcnt = bip_src->bip_vcnt;
> + bip->bip_vec = bip_src->bip_vec;
> bip->bip_iter = bip_src->bip_iter;
> bip->bip_flags = bip_src->bip_flags & ~BIP_BLOCK_INTEGRITY;
I am curious how the patch avoids double free? Given nothing changes
in bip free code path and source bip_vec is associated with this bip.
Thanks,
