[PATCH 19/30] nbd: use blk_mq_alloc_disk and blk_cleanup_disk

[Christoph Hellwig <hch@xxxxxx>]

Use blk_mq_alloc_disk and blk_cleanup_disk to simplify the gendisk and
request_queue allocation.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
 drivers/block/nbd.c | 53 ++++++++++++++++++---------------------------
 1 file changed, 21 insertions(+), 32 deletions(-)

diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 45d2c28c8fc8..614d82e7fae4 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -219,15 +219,11 @@ static const struct device_attribute pid_attr = {
 static void nbd_dev_remove(struct nbd_device *nbd)
 {
        struct gendisk *disk = nbd->disk;
-       struct request_queue *q;
 
        if (disk) {
-               q = disk->queue;
                del_gendisk(disk);
-               blk_cleanup_queue(q);
                blk_mq_free_tag_set(&nbd->tag_set);
-               disk->private_data = NULL;
-               put_disk(disk);
+               blk_cleanup_disk(disk);
        }
 
        /*
@@ -1646,15 +1642,24 @@ static int nbd_dev_add(int index)
 {
        struct nbd_device *nbd;
        struct gendisk *disk;
-       struct request_queue *q;
        int err = -ENOMEM;
 
        nbd = kzalloc(sizeof(struct nbd_device), GFP_KERNEL);
        if (!nbd)
                goto out;
 
-       disk = alloc_disk(1 << part_shift);
-       if (!disk)
+       nbd->tag_set.ops = &nbd_mq_ops;
+       nbd->tag_set.nr_hw_queues = 1;
+       nbd->tag_set.queue_depth = 128;
+       nbd->tag_set.numa_node = NUMA_NO_NODE;
+       nbd->tag_set.cmd_size = sizeof(struct nbd_cmd);
+       nbd->tag_set.flags = BLK_MQ_F_SHOULD_MERGE |
+               BLK_MQ_F_BLOCKING;
+       nbd->tag_set.driver_data = nbd;
+       nbd->destroy_complete = NULL;
+
+       err = blk_mq_alloc_tag_set(&nbd->tag_set);
+       if (err)
                goto out_free_nbd;
 
        if (index >= 0) {
@@ -1668,30 +1673,15 @@ static int nbd_dev_add(int index)
                        index = err;
        }
        if (err < 0)
-               goto out_free_disk;
-
+               goto out_free_tags;
        nbd->index = index;
-       nbd->disk = disk;
-       nbd->tag_set.ops = &nbd_mq_ops;
-       nbd->tag_set.nr_hw_queues = 1;
-       nbd->tag_set.queue_depth = 128;
-       nbd->tag_set.numa_node = NUMA_NO_NODE;
-       nbd->tag_set.cmd_size = sizeof(struct nbd_cmd);
-       nbd->tag_set.flags = BLK_MQ_F_SHOULD_MERGE |
-               BLK_MQ_F_BLOCKING;
-       nbd->tag_set.driver_data = nbd;
-       nbd->destroy_complete = NULL;
 
-       err = blk_mq_alloc_tag_set(&nbd->tag_set);
-       if (err)
+       disk = blk_mq_alloc_disk(&nbd->tag_set, NULL);
+       if (IS_ERR(disk)) {
+               err = PTR_ERR(disk);
                goto out_free_idr;
-
-       q = blk_mq_init_queue(&nbd->tag_set);
-       if (IS_ERR(q)) {
-               err = PTR_ERR(q);
-               goto out_free_tags;
        }
-       disk->queue = q;
+       nbd->disk = disk;
 
        /*
         * Tell the block layer that we are not a rotational device
@@ -1712,6 +1702,7 @@ static int nbd_dev_add(int index)
        INIT_LIST_HEAD(&nbd->list);
        disk->major = NBD_MAJOR;
        disk->first_minor = index << part_shift;
+       disk->minors = 1 << part_shift;
        disk->fops = &nbd_fops;
        disk->private_data = nbd;
        sprintf(disk->disk_name, "nbd%d", index);
@@ -1719,12 +1710,10 @@ static int nbd_dev_add(int index)
        nbd_total_devices++;
        return index;
 
-out_free_tags:
-       blk_mq_free_tag_set(&nbd->tag_set);
 out_free_idr:
        idr_remove(&nbd_index_idr, index);
-out_free_disk:
-       put_disk(disk);
+out_free_tags:
+       blk_mq_free_tag_set(&nbd->tag_set);
 out_free_nbd:
        kfree(nbd);
 out:
-- 
2.30.2