MD RAID10: Fix oops when creating RAID10 arrays via dm-raid.c

Commit 2863b9eb didn't take into account the changes to add TRIM support to
RAID10 (commit 532a2a3fb).  That is, when using dm-raid.c to create the
RAID10 arrays, there is no mddev->gendisk or mddev->queue.  The code added
to support TRIM simply assumes that mddev->queue is available without
checking.  The result is an oops any time dm-raid.c attempts to create a
RAID10 device.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 906ccbd0f7dcdc6710869c5b990f9375d020d370..d1295aff41739eea048f0e43513dfba6ade4c8f1 100644 (file)
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1783,7 +1783,7 @@ static int raid10_add_disk(struct mddev *mddev, struct md_rdev *rdev)
                clear_bit(Unmerged, &rdev->flags);
        }
        md_integrity_add_rdev(rdev, mddev);
-       if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
+       if (mddev->queue && blk_queue_discard(bdev_get_queue(rdev->bdev)))
                queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
 
        print_conf(conf);
@@ -3613,11 +3613,14 @@ static int run(struct mddev *mddev)
                        discard_supported = true;
        }
 
-       if (discard_supported)
-               queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
-       else
-               queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
-
+       if (mddev->queue) {
+               if (discard_supported)
+                       queue_flag_set_unlocked(QUEUE_FLAG_DISCARD,
+                                               mddev->queue);
+               else
+                       queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD,
+                                                 mddev->queue);
+       }
        /* need to check that every block has at least one working mirror */
        if (!enough(conf, -1)) {
                printk(KERN_ERR "md/raid10:%s: not enough operational mirrors.\n",