md-raid0: conditional mddev->queue access to suit dm-raid

This patch is a prerequisite for dm-raid "raid0" support to allow
dm-raid to access the MD RAID0 personality doing unconditional
accesses to mddev->queue, which is NULL in case of dm-raid stacked on
top of MD.

Most of the conditional mddev->queue accesses made it to upstream but
this missing one, which prohibits md raid0 to set disk stack limits
(being done in dm core in case of md underneath dm).

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Tested-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index 2cb59a641cd24417d996df89c2e2c81cc9eb087b..6a68ef5246d49962c5be7b152f8f121f61d4de04 100644 (file)
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -188,8 +188,9 @@ static int create_strip_zones(struct mddev *mddev, struct r0conf **private_conf)
                }
                dev[j] = rdev1;
 
-               disk_stack_limits(mddev->gendisk, rdev1->bdev,
-                                 rdev1->data_offset << 9);
+               if (mddev->queue)
+                       disk_stack_limits(mddev->gendisk, rdev1->bdev,
+                                         rdev1->data_offset << 9);
 
                if (rdev1->bdev->bd_disk->queue->merge_bvec_fn)
                        conf->has_merge_bvec = 1;