Remove the assumption that bv_len is a multiple of 512 bytes since this is
not guaranteed by the block layer. This assumption may cause this function
to return a smaller value than it should. This is harmless from a
correctness point of view but may result in suboptimal performance.
Note: unsigned int is sufficient for num_bytes since bio_for_each_segment()
yields at most one page per iteration and since PAGE_SIZE * BIO_MAX_VECS
fits in an unsigned int.
Suggested-by: John Garry <john.g.garry@xxxxxxxxxx>
Fixes: 488f6682c832 ("block: blk-crypto-fallback for Inline Encryption")
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
---
block/blk-crypto-fallback.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/block/blk-crypto-fallback.c b/block/blk-crypto-fallback.c
index 005c9157ffb3..3c914d2c054f 100644
--- a/block/blk-crypto-fallback.c
+++ b/block/blk-crypto-fallback.c
@@ -213,15 +213,16 @@ static bool blk_crypto_fallback_split_bio_if_needed(struct bio **bio_ptr)
{
struct bio *bio = *bio_ptr;
unsigned int i = 0;
- unsigned int num_sectors = 0;
+ unsigned int num_bytes = 0, num_sectors;
struct bio_vec bv;
struct bvec_iter iter;
bio_for_each_segment(bv, bio, iter) {
- num_sectors += bv.bv_len >> SECTOR_SHIFT;
+ num_bytes += bv.bv_len;
if (++i == BIO_MAX_VECS)
break;
}
+ num_sectors = num_bytes >> SECTOR_SHIFT;
if (num_sectors < bio_sectors(bio)) {
struct bio *split_bio;
