Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6

[platform/adaptation/renesas_rcar/renesas_kernel.git] / block / blk-barrier.c

diff --git a/block/blk-barrier.c b/block/blk-barrier.c
index eefbde8..f0faefc 100644 (file)
--- a/block/blk-barrier.c
+++ b/block/blk-barrier.c
@@ -134,8 +134,9 @@ static void queue_flush(struct request_queue *q, unsigned which)
        }
 
        blk_rq_init(q, rq);
+       rq->cmd_type = REQ_TYPE_FS;
        rq->cmd_flags = REQ_HARDBARRIER | REQ_FLUSH;
-       rq->rq_disk = q->bar_rq.rq_disk;
+       rq->rq_disk = q->orig_bar_rq->rq_disk;
        rq->end_io = end_io;
 
        elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
@@ -310,6 +311,15 @@ int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
        if (!q)
                return -ENXIO;
 
+       /*
+        * some block devices may not have their queue correctly set up here
+        * (e.g. loop device without a backing file) and so issuing a flush
+        * here will panic. Ensure there is a request function before issuing
+        * the barrier.
+        */
+       if (!q->make_request_fn)
+               return -ENXIO;
+
        bio = bio_alloc(gfp_mask, 0);
        bio->bi_end_io = bio_end_empty_barrier;
        bio->bi_bdev = bdev;