dm: fix potential for q->make_request_fn NULL pointer

[linux-2.6-microblaze.git] / drivers / md / dm.c

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index e8f9661..b89f07e 100644 (file)
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1859,6 +1859,7 @@ static void dm_init_normal_md_queue(struct mapped_device *md)
        /*
         * Initialize aspects of queue that aren't relevant for blk-mq
         */
+       md->queue->backing_dev_info->congested_data = md;
        md->queue->backing_dev_info->congested_fn = dm_any_congested;
 }
 
@@ -1949,7 +1950,12 @@ static struct mapped_device *alloc_dev(int minor)
        if (!md->queue)
                goto bad;
        md->queue->queuedata = md;
-       md->queue->backing_dev_info->congested_data = md;
+       /*
+        * default to bio-based required ->make_request_fn until DM
+        * table is loaded and md->type established. If request-based
+        * table is loaded: blk-mq will override accordingly.
+        */
+       blk_queue_make_request(md->queue, dm_make_request);
 
        md->disk = alloc_disk_node(1, md->numa_node_id);
        if (!md->disk)
@@ -2264,7 +2270,6 @@ int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t)
        case DM_TYPE_DAX_BIO_BASED:
        case DM_TYPE_NVME_BIO_BASED:
                dm_init_normal_md_queue(md);
-               blk_queue_make_request(md->queue, dm_make_request);
                break;
        case DM_TYPE_NONE:
                WARN_ON_ONCE(true);