[PATCH 25/26] null_blk: convert to blk_alloc_disk/blk_cleanup_disk

[Christoph Hellwig <hch@xxxxxx>]

Convert the null_blk driver to use the blk_alloc_disk and blk_cleanup_disk
helpers to simplify gendisk and request_queue allocation.  Note that the
blk-mq mode is left with its own allocations scheme, to be handled later.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
 drivers/block/null_blk/main.c | 38 +++++++++++++++++------------------
 1 file changed, 19 insertions(+), 19 deletions(-)

diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
index 5f006d9e1472..d8e098f1e5b5 100644
--- a/drivers/block/null_blk/main.c
+++ b/drivers/block/null_blk/main.c
@@ -1597,11 +1597,10 @@ static void null_del_dev(struct nullb *nullb)
 		null_restart_queue_async(nullb);
 	}
 
-	blk_cleanup_queue(nullb->q);
+	blk_cleanup_disk(nullb->disk);
 	if (dev->queue_mode == NULL_Q_MQ &&
 	    nullb->tag_set == &nullb->__tag_set)
 		blk_mq_free_tag_set(nullb->tag_set);
-	put_disk(nullb->disk);
 	cleanup_queues(nullb);
 	if (null_cache_active(nullb))
 		null_free_device_storage(nullb->dev, true);
@@ -1700,22 +1699,19 @@ static int init_driver_queues(struct nullb *nullb)
 static int null_gendisk_register(struct nullb *nullb)
 {
 	sector_t size = ((sector_t)nullb->dev->size * SZ_1M) >> SECTOR_SHIFT;
-	struct gendisk *disk;
+	struct gendisk *disk = nullb->disk;
 
-	disk = nullb->disk = alloc_disk_node(1, nullb->dev->home_node);
-	if (!disk)
-		return -ENOMEM;
 	set_capacity(disk, size);
 
 	disk->flags |= GENHD_FL_EXT_DEVT | GENHD_FL_SUPPRESS_PARTITION_INFO;
 	disk->major		= null_major;
 	disk->first_minor	= nullb->index;
+	disk->minors		= 1;
 	if (queue_is_mq(nullb->q))
 		disk->fops		= &null_rq_ops;
 	else
 		disk->fops		= &null_bio_ops;
 	disk->private_data	= nullb;
-	disk->queue		= nullb->q;
 	strncpy(disk->disk_name, nullb->disk_name, DISK_NAME_LEN);
 
 	if (nullb->dev->zoned) {
@@ -1851,23 +1847,27 @@ static int null_add_dev(struct nullb_device *dev)
 			goto out_cleanup_queues;
 
 		if (!null_setup_fault())
-			goto out_cleanup_queues;
+			goto out_cleanup_tags;
 
+		rv = -ENOMEM;
 		nullb->tag_set->timeout = 5 * HZ;
 		nullb->q = blk_mq_init_queue_data(nullb->tag_set, nullb);
-		if (IS_ERR(nullb->q)) {
-			rv = -ENOMEM;
+		if (IS_ERR(nullb->q))
 			goto out_cleanup_tags;
-		}
+		nullb->disk = alloc_disk_node(1, nullb->dev->home_node);
+		if (!nullb->disk)
+			goto out_cleanup_disk;
+		nullb->disk->queue = nullb->q;
 	} else if (dev->queue_mode == NULL_Q_BIO) {
-		nullb->q = blk_alloc_queue(dev->home_node);
-		if (!nullb->q) {
-			rv = -ENOMEM;
+		rv = -ENOMEM;
+		nullb->disk = blk_alloc_disk(nullb->dev->home_node);
+		if (!nullb->disk)
 			goto out_cleanup_queues;
-		}
+
+		nullb->q = nullb->disk->queue;
 		rv = init_driver_queues(nullb);
 		if (rv)
-			goto out_cleanup_blk_queue;
+			goto out_cleanup_disk;
 	}
 
 	if (dev->mbps) {
@@ -1883,7 +1883,7 @@ static int null_add_dev(struct nullb_device *dev)
 	if (dev->zoned) {
 		rv = null_init_zoned_dev(dev, nullb->q);
 		if (rv)
-			goto out_cleanup_blk_queue;
+			goto out_cleanup_disk;
 	}
 
 	nullb->q->queuedata = nullb;
@@ -1921,8 +1921,8 @@ static int null_add_dev(struct nullb_device *dev)
 	return 0;
 out_cleanup_zone:
 	null_free_zoned_dev(dev);
-out_cleanup_blk_queue:
-	blk_cleanup_queue(nullb->q);
+out_cleanup_disk:
+	blk_cleanup_disk(nullb->disk);
 out_cleanup_tags:
 	if (dev->queue_mode == NULL_Q_MQ && nullb->tag_set == &nullb->__tag_set)
 		blk_mq_free_tag_set(nullb->tag_set);
-- 
2.30.2