[03/10] block: copy result back to user meta buffer correctly in case of split

Commit Message

Kanchan Joshi April 25, 2024, 6:39 p.m. UTC

From: Anuj Gupta <[e-mail]>

In case of split, the len and offset of bvec gets updated in the iter.
Use it to fetch the right bvec, and copy it back to user meta buffer.

Signed-off-by: Anuj Gupta <[e-mail]>
Signed-off-by: Kanchan Joshi <[e-mail]>
---
 block/bio-integrity.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

Comments

Christoph Hellwig April 27, 2024, 7:04 a.m. UTC | #1

On Fri, Apr 26, 2024 at 12:09:36AM +0530, Kanchan Joshi wrote:
> From: Anuj Gupta <[e-mail]>
> 
> In case of split, the len and offset of bvec gets updated in the iter.
> Use it to fetch the right bvec, and copy it back to user meta buffer.
> 
> Signed-off-by: Anuj Gupta <[e-mail]>
> Signed-off-by: Kanchan Joshi <[e-mail]>

Looks good, but needs a fixes tag.

Patch

diff --git a/block/bio-integrity.c b/block/bio-integrity.c
index c1955f01412e..b4042414a08f 100644
--- a/block/bio-integrity.c
+++ b/block/bio-integrity.c
@@ -108,11 +108,15 @@  static void bio_integrity_uncopy_user(struct bio_integrity_payload *bip)
 	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;
+	struct bio_vec copy_bvec, src_bvec;
 	struct iov_iter iter;
 	int ret;
 
-	iov_iter_bvec(&iter, ITER_DEST, copy, nr_vecs, bytes);
-	ret = copy_to_iter(bvec_virt(bip->bip_vec), bytes, &iter);
+	copy_bvec = mp_bvec_iter_bvec(copy, bip->bip_iter);
+	src_bvec = mp_bvec_iter_bvec(bip->bip_vec, bip->bip_iter);
+
+	iov_iter_bvec(&iter, ITER_DEST, &copy_bvec, nr_vecs, bytes);
+	ret = copy_to_iter(bvec_virt(&src_bvec), bytes, &iter);
 	WARN_ON_ONCE(ret != bytes);
 
 	bio_integrity_unpin_bvec(copy, nr_vecs, true);