[PATCH 1/6] bio-integrity: remove dead bio_integrity_copy_user() error path

[Caleb Sander Mateos]

If bio_integrity_add_page() in bio_integrity_copy_user() fails in the
write case, bio_integrity_copy_user() will return an error after having
already unpinned the user pages. The release_pages label in
bio_integrity_map_user() would then unpin the pages a second time.
Thankfully, bio_integrity_add_page() can't fail here because the
bio_integrity_payload is freshly allocated, so bip_vcnt is 0. Replace
the unreachable error path with a WARN_ON_ONCE().

Signed-off-by: Caleb Sander Mateos <csander at purestorage.com>
---
 block/bio-integrity.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/block/bio-integrity.c b/block/bio-integrity.c
index b23e2434d80c..8ba8bfa41f8a 100644
--- a/block/bio-integrity.c
+++ b/block/bio-integrity.c
@@ -299,19 +299,13 @@ static int bio_integrity_copy_user(struct bio *bio, struct bio_vec *bvec,
 	else
 		memcpy(&bip->bip_vec[1], bvec, nr_vecs * sizeof(*bvec));
 
 	ret = bio_integrity_add_page(bio, virt_to_page(buf), len,
 				     offset_in_page(buf));
-	if (ret != len) {
-		ret = -ENOMEM;
-		goto free_bip;
-	}
-
+	WARN_ON_ONCE(ret != len);
 	bip->bip_flags |= BIP_COPY_USER;
 	return 0;
-free_bip:
-	bio_integrity_free(bio);
 free_buf:
 	kfree(buf);
 	return ret;
 }
 
-- 
2.55.0