4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Michael Lyle mlyle@lyle.org
commit 62530ed8b1d07a45dec94d46e521c0c6c2d476e6 upstream.
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 mlyle@lyle.org Fixes: 74d46992e0d9 ("block: replace bi_bdev with a gendisk pointer and partitions index") Reported-by: Pavel Goran via-bcache@pvgoran.name Reported-by: Campbell Steven casteven@gmail.com Reviewed-by: Coly Li colyli@suse.de Reviewed-by: Ming Lei ming.lei@redhat.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- block/bio.c | 1 + 1 file changed, 1 insertion(+)
--- a/block/bio.c +++ b/block/bio.c @@ -597,6 +597,7 @@ void __bio_clone_fast(struct bio *bio, s * 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;