diff mbox series

[v2,03/10] block: copy bip_max_vcnt vecs instead of bip_vcnt during clone

Message ID 20240626100700.3629-4-anuj20.g@samsung.com (mailing list archive)
State New
Headers show
Series Read/Write with meta/integrity | expand

Commit Message

Anuj Gupta June 26, 2024, 10:06 a.m. UTC 
If bio_integrity_copy_user is used to process the meta buffer, bip_max_vcnt
is one greater than bip_vcnt. In this case bip_max_vcnt vecs needs to be
copied to cloned bip.

Signed-off-by: Anuj Gupta <anuj20.g@samsung.com>
Signed-off-by: Kanchan Joshi <joshi.k@samsung.com>
---
 block/bio-integrity.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Christoph Hellwig June 27, 2024, 6:14 a.m. UTC | #1 
On Wed, Jun 26, 2024 at 03:36:53PM +0530, Anuj Gupta wrote:
> If bio_integrity_copy_user is used to process the meta buffer, bip_max_vcnt
> is one greater than bip_vcnt.

Why?

> @@ -647,12 +647,12 @@ 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, bip_src->bip_max_vcnt);
>  	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_src->bip_max_vcnt * sizeof(struct bio_vec));
>  
>  	bip->bip_vcnt = bip_src->bip_vcnt;
>  	bip->bip_iter = bip_src->bip_iter;

So trying to compare this to how the bio data path is cloned, it seems
like bio_integrity_clone is still copying the bvec array.  With the
concept of the immutable bvecs we've had for years this should not
be required.  That is reuse the actual bio_vecs, and just copy
the iter similar to bio_alloc_clone/__bio_clone.
diff mbox series

Patch

diff --git a/block/bio-integrity.c b/block/bio-integrity.c
index af79d9fbf413..5e7596b74ef1 100644
--- a/block/bio-integrity.c
+++ b/block/bio-integrity.c
@@ -647,12 +647,12 @@  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, bip_src->bip_max_vcnt);
 	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_src->bip_max_vcnt * sizeof(struct bio_vec));
 
 	bip->bip_vcnt = bip_src->bip_vcnt;
 	bip->bip_iter = bip_src->bip_iter;