block: Fix bad range check in bio_sector_offset

DM would occasionally end up splitting data integrity-enabled requests
incorrectly. The culprit was a bad range check in bio_sector_offset.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/fs/bio.c b/fs/bio.c
index 9bfade8a609bfa33c9f78b9f2faa9d01dfea9176..b9a67441ec21cd637606efc24d0e9db210a6c75c 100644 (file)
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -1552,8 +1552,8 @@ sector_t bio_sector_offset(struct bio *bio, unsigned short index,
        sector_sz = queue_logical_block_size(bio->bi_bdev->bd_disk->queue);
        sectors = 0;
 
-       if (index >= bio->bi_idx)
-               index = bio->bi_vcnt - 1;
+       if (index > bio->bi_vcnt)
+               return 0;
 
        __bio_for_each_segment(bv, bio, i, 0) {
                if (i == index) {