block: make sure FSEQ_DATA request has the same rq_disk as the original

rq->rq_disk and bio->bi_bdev->bd_disk may differ if a request has
passed through remapping drivers.  FSEQ_DATA request incorrectly
followed bio->bi_bdev->bd_disk ending up being issued w/ mismatching
rq_disk.  Make it follow orig_rq->rq_disk.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Tested-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/block/blk-flush.c b/block/blk-flush.c
index cb4c8440a1fc..7d1fc982e78f 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -111,6 +111,13 @@ static struct request *queue_next_fseq(struct request_queue *q)
                 break;
         case QUEUE_FSEQ_DATA:
                 init_request_from_bio(rq, orig_rq->bio);
+                /*
+                 * orig_rq->rq_disk may be different from
+                 * bio->bi_bdev->bd_disk if orig_rq got here through
+                 * remapping drivers.  Make sure rq->rq_disk points
+                 * to the same one as orig_rq.
+                 */
+                rq->rq_disk = orig_rq->rq_disk;
                 rq->cmd_flags &= ~(REQ_FLUSH | REQ_FUA);
                 rq->cmd_flags |= orig_rq->cmd_flags & (REQ_FLUSH | REQ_FUA);
                 rq->end_io = flush_data_end_io;