[PATCH v4 9/9] block: add WARN_ON_ONCE() to bio_split() for sector alignment

[Satya Tangirala]

From: Satya Tangirala <satyat@xxxxxxxxxx>

The number of sectors passed to bio_split() must be aligned to
bio_required_sector_alignment(). All callers (other than bounce.c) have
been updated to ensure this, so add a WARN_ON_ONCE() if the number of
sectors is not aligned. (bounce.c was not updated since it's legacy code
- any device that enables bounce buffering won't declare inline
encryption support, so bounce.c will never see a bio with an encryption
context).

Signed-off-by: Satya Tangirala <satyat@xxxxxxxxxx>
---
 block/bio.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/block/bio.c b/block/bio.c
index 1fab762e079b..4c7bfdeefe76 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1435,6 +1435,7 @@ struct bio *bio_split(struct bio *bio, int sectors,
 
 	BUG_ON(sectors <= 0);
 	BUG_ON(sectors >= bio_sectors(bio));
+	WARN_ON_ONCE(!IS_ALIGNED(sectors, bio_required_sector_alignment(bio)));
 
 	/* Zone append commands cannot be split */
 	if (WARN_ON_ONCE(bio_op(bio) == REQ_OP_ZONE_APPEND))
-- 
2.25.1