On Mon, Aug 12, 2024 at 03:51:12PM +0200, Matthieu Baerts wrote:

Hi Sasha, Greg,

On 28/07/2024 02:47, Sasha Levin wrote:

quoted

From: Mikulas Patocka <mpatocka@redhat.com>

[ Upstream commit cf546dd289e0f6d2594c25e2fb4e19ee67c6d988 ]

If we allocate a bio that is larger than NVMe maximum request size,
attach integrity metadata to it and send it to the NVMe subsystem, the
integrity metadata will be corrupted.

(...)

quoted

diff --git a/include/linux/blk-integrity.h b/include/linux/blk-integrity.h
index 7428cb43952da..d16dd24719841 100644
--- a/include/linux/blk-integrity.h
+++ b/include/linux/blk-integrity.h

@@ -100,14 +100,13 @@ static inline bool blk_integrity_rq(struct request *rq)
 }
 
 /*
- * Return the first bvec that contains integrity data.  Only drivers that are
- * limited to a single integrity segment should use this helper.
+ * Return the current bvec that contains the integrity data. bip_iter may be
+ * advanced to iterate over the integrity data.
  */
-static inline struct bio_vec *rq_integrity_vec(struct request *rq)
+static inline struct bio_vec rq_integrity_vec(struct request *rq)
 {
-	if (WARN_ON_ONCE(queue_max_integrity_segments(rq->q) > 1))
-		return NULL;
-	return rq->bio->bi_integrity->bip_vec;
+	return mp_bvec_iter_bvec(rq->bio->bi_integrity->bip_vec,
+				 rq->bio->bi_integrity->bip_iter);
 }
 #else /* CONFIG_BLK_DEV_INTEGRITY */
 static inline int blk_rq_count_integrity_sg(struct request_queue *q,

@@ -169,7 +168,8 @@ static inline int blk_integrity_rq(struct request *rq)
 
 static inline struct bio_vec *rq_integrity_vec(struct request *rq)
 {
-	return NULL;
+	/* the optimizer will remove all calls to this function */
+	return (struct bio_vec){ };

If CONFIG_BLK_DEV_INTEGRITY is not defined, there is a compilation error
here in v6.10 with the recently queued patches because the signature has
not been updated:

quoted

In file included from block/bdev.c:15:                                                                                                                                             
include/linux/blk-integrity.h: In function 'rq_integrity_vec':
include/linux/blk-integrity.h:172:16: error: incompatible types when returning type 'struct bio_vec' but 'struct bio_vec *' was expected
  172 |         return (struct bio_vec){ };                 
      |                ^

Could it be possible to backport the following fix to v6.10 as well please?

  69b6517687a4 ("block: use the right type for stub rq_integrity_vec()")

It is also needed for v6.6 and v6.1.

Now queued up, thanks!

greg k-h