2 files changed, 10 insertions, 5 deletions

diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c
index ea192ec029c4..f370fc13aea5 100644
--- a/drivers/block/null_blk.c
+++ b/drivers/block/null_blk.c
@@ -495,23 +495,23 @@ static int null_add_dev(void)
 
 	spin_lock_init(&nullb->lock);
 
+	if (queue_mode == NULL_Q_MQ && use_per_node_hctx)
+		submit_queues = nr_online_nodes;
+
 	if (setup_queues(nullb))
 		goto err;
 
 	if (queue_mode == NULL_Q_MQ) {
 		null_mq_reg.numa_node = home_node;
 		null_mq_reg.queue_depth = hw_queue_depth;
+		null_mq_reg.nr_hw_queues = submit_queues;
 
 		if (use_per_node_hctx) {
 			null_mq_reg.ops->alloc_hctx = null_alloc_hctx;
 			null_mq_reg.ops->free_hctx = null_free_hctx;
-
-			null_mq_reg.nr_hw_queues = nr_online_nodes;
 		} else {
 			null_mq_reg.ops->alloc_hctx = blk_mq_alloc_single_hw_queue;
 			null_mq_reg.ops->free_hctx = blk_mq_free_single_hw_queue;
-
-			null_mq_reg.nr_hw_queues = submit_queues;
 		}
 
 		nullb->q = blk_mq_init_queue(&null_mq_reg, nullb);
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 432db1b59b00..c4a4c9006288 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -489,7 +489,7 @@ static int blkif_queue_request(struct request *req)
 
 			if ((ring_req->operation == BLKIF_OP_INDIRECT) &&
 			    (i % SEGS_PER_INDIRECT_FRAME == 0)) {
-				unsigned long pfn;
+				unsigned long uninitialized_var(pfn);
 
 				if (segments)
 					kunmap_atomic(segments);
@@ -2011,6 +2011,10 @@ static void blkif_release(struct gendisk *disk, fmode_t mode)
 
 	bdev = bdget_disk(disk, 0);
 
+	if (!bdev) {
+		WARN(1, "Block device %s yanked out from us!\n", disk->disk_name);
+		goto out_mutex;
+	}
 	if (bdev->bd_openers)
 		goto out;
 
@@ -2041,6 +2045,7 @@ static void blkif_release(struct gendisk *disk, fmode_t mode)
 
 out:
 	bdput(bdev);
+out_mutex:
 	mutex_unlock(&blkfront_mutex);
 }