md raid0: access mddev->queue (request queue member) conditionally because it is...

The patch makes 3 references to mddev->queue in the raid0 personality
conditional in order to allow for it to be accessed from dm-raid.
Mandatory, because md instances underneath dm-raid don't manage
a request queue of their own which'd lead to oopses without the patch.

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 3b5d7f7..2cb59a6 100644 (file)
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -271,14 +271,16 @@ static int create_strip_zones(struct mddev *mddev, struct r0conf **private_conf)
                goto abort;
        }
 
-       blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9);
-       blk_queue_io_opt(mddev->queue,
-                        (mddev->chunk_sectors << 9) * mddev->raid_disks);
-
-       if (!discard_supported)
-               queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
-       else
-               queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
+       if (mddev->queue) {
+               blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9);
+               blk_queue_io_opt(mddev->queue,
+                                (mddev->chunk_sectors << 9) * mddev->raid_disks);
+
+               if (!discard_supported)
+                       queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
+               else
+                       queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
+       }
 
        pr_debug("md/raid0:%s: done.\n", mdname(mddev));
        *private_conf = conf;
@@ -429,9 +431,12 @@ static int raid0_run(struct mddev *mddev)
        }
        if (md_check_no_bitmap(mddev))
                return -EINVAL;
-       blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors);
-       blk_queue_max_write_same_sectors(mddev->queue, mddev->chunk_sectors);
-       blk_queue_max_discard_sectors(mddev->queue, mddev->chunk_sectors);
+
+       if (mddev->queue) {
+               blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors);
+               blk_queue_max_write_same_sectors(mddev->queue, mddev->chunk_sectors);
+               blk_queue_max_discard_sectors(mddev->queue, mddev->chunk_sectors);
+       }
 
        /* if private is not null, we are here after takeover */
        if (mddev->private == NULL) {
@@ -448,16 +453,17 @@ static int raid0_run(struct mddev *mddev)
        printk(KERN_INFO "md/raid0:%s: md_size is %llu sectors.\n",
               mdname(mddev),
               (unsigned long long)mddev->array_sectors);
-       /* calculate the max read-ahead size.
-        * For read-ahead of large files to be effective, we need to
-        * readahead at least twice a whole stripe. i.e. number of devices
-        * multiplied by chunk size times 2.
-        * If an individual device has an ra_pages greater than the
-        * chunk size, then we will not drive that device as hard as it
-        * wants.  We consider this a configuration error: a larger
-        * chunksize should be used in that case.
-        */
-       {
+
+       if (mddev->queue) {
+               /* calculate the max read-ahead size.
+                * For read-ahead of large files to be effective, we need to
+                * readahead at least twice a whole stripe. i.e. number of devices
+                * multiplied by chunk size times 2.
+                * If an individual device has an ra_pages greater than the
+                * chunk size, then we will not drive that device as hard as it
+                * wants.  We consider this a configuration error: a larger
+                * chunksize should be used in that case.
+                */
                int stripe = mddev->raid_disks *
                        (mddev->chunk_sectors << 9) / PAGE_SIZE;
                if (mddev->queue->backing_dev_info.ra_pages < 2* stripe)