bio: ensure __bio_clone_fast copies bi_partno

A new field was introduced in 74d46992e0d9, bi_partno, instead of using
bdev->bd_contains and encoding the partition information in the bi_bdev
field.  __bio_clone_fast was changed to copy the disk information, but
not the partition information.  At minimum, this regressed bcache and
caused data corruption.

Signed-off-by: Michael Lyle <[email protected]>
Fixes: 74d46992e0d9 ("block: replace bi_bdev with a gendisk pointer and partitions index")
Reported-by: Pavel Goran <[email protected]>
Reported-by: Campbell Steven <[email protected]>
Reviewed-by: Coly Li <[email protected]>
Reviewed-by: Ming Lei <[email protected]>
Cc: <[email protected]> # 4.14
Signed-off-by: Jens Axboe <[email protected]>

diff --git a/block/bio.c b/block/bio.c
index b94a802f8ba341894d6c4eafb0c04f87eacbe1c6..459cc857f3d91647b47beb58c98cd592852e1db1 100644 (file)
--- a/block/bio.c
+++ b/block/bio.c
@@ -597,6 +597,7 @@ void __bio_clone_fast(struct bio *bio, struct bio *bio_src)
         * so we don't set nor calculate new physical/hw segment counts here
         */
        bio->bi_disk = bio_src->bi_disk;
+       bio->bi_partno = bio_src->bi_partno;
        bio_set_flag(bio, BIO_CLONED);
        bio->bi_opf = bio_src->bi_opf;
        bio->bi_write_hint = bio_src->bi_write_hint;