dcssblk: convert to blk_alloc_disk/blk_cleanup_disk

Convert the dcssblk driver to use the blk_alloc_disk and blk_cleanup_disk
helpers to simplify gendisk and request_queue allocation.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20210521055116.1053587-24-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

drivers/s390/block/dcssblk.c

@@ -90,7 +90,6 @@ struct dcssblk_dev_info {
 	int segment_type;
 	unsigned char save_pending;
 	unsigned char is_shared;
-	struct request_queue *dcssblk_queue;
 	int num_of_segments;
 	struct list_head seg_list;
 	struct dax_device *dax_dev;
@@ -429,9 +428,7 @@ dcssblk_shared_store(struct device *dev, struct device_attribute *attr, const ch
 	kill_dax(dev_info->dax_dev);
 	put_dax(dev_info->dax_dev);
 	del_gendisk(dev_info->gd);
-	blk_cleanup_queue(dev_info->dcssblk_queue);
-	dev_info->gd->queue = NULL;
-	put_disk(dev_info->gd);
+	blk_cleanup_disk(dev_info->gd);
 	up_write(&dcssblk_devices_sem);
 
 	if (device_remove_file_self(dev, attr)) {
@@ -644,18 +641,17 @@ dcssblk_add_store(struct device *dev, struct device_attribute *attr, const char
 	dev_info->dev.release = dcssblk_release_segment;
 	dev_info->dev.groups = dcssblk_dev_attr_groups;
 	INIT_LIST_HEAD(&dev_info->lh);
-	dev_info->gd = alloc_disk(DCSSBLK_MINORS_PER_DISK);
+	dev_info->gd = blk_alloc_disk(NUMA_NO_NODE);
 	if (dev_info->gd == NULL) {
 		rc = -ENOMEM;
 		goto seg_list_del;
 	}
 	dev_info->gd->major = dcssblk_major;
+	dev_info->gd->minors = DCSSBLK_MINORS_PER_DISK;
 	dev_info->gd->fops = &dcssblk_devops;
-	dev_info->dcssblk_queue = blk_alloc_queue(NUMA_NO_NODE);
-	dev_info->gd->queue = dev_info->dcssblk_queue;
 	dev_info->gd->private_data = dev_info;
-	blk_queue_logical_block_size(dev_info->dcssblk_queue, 4096);
-	blk_queue_flag_set(QUEUE_FLAG_DAX, dev_info->dcssblk_queue);
+	blk_queue_logical_block_size(dev_info->gd->queue, 4096);
+	blk_queue_flag_set(QUEUE_FLAG_DAX, dev_info->gd->queue);
 
 	seg_byte_size = (dev_info->end - dev_info->start + 1);
 	set_capacity(dev_info->gd, seg_byte_size >> 9); // size in sectors
@@ -719,9 +715,7 @@ dcssblk_add_store(struct device *dev, struct device_attribute *attr, const char
 
 put_dev:
 	list_del(&dev_info->lh);
-	blk_cleanup_queue(dev_info->dcssblk_queue);
-	dev_info->gd->queue = NULL;
-	put_disk(dev_info->gd);
+	blk_cleanup_disk(dev_info->gd);
 	list_for_each_entry(seg_info, &dev_info->seg_list, lh) {
 		segment_unload(seg_info->segment_name);
 	}
@@ -731,9 +725,7 @@ dcssblk_add_store(struct device *dev, struct device_attribute *attr, const char
 dev_list_del:
 	list_del(&dev_info->lh);
 release_gd:
-	blk_cleanup_queue(dev_info->dcssblk_queue);
-	dev_info->gd->queue = NULL;
-	put_disk(dev_info->gd);
+	blk_cleanup_disk(dev_info->gd);
 	up_write(&dcssblk_devices_sem);
 seg_list_del:
 	if (dev_info == NULL)
@@ -801,9 +793,7 @@ dcssblk_remove_store(struct device *dev, struct device_attribute *attr, const ch
 	kill_dax(dev_info->dax_dev);
 	put_dax(dev_info->dax_dev);
 	del_gendisk(dev_info->gd);
-	blk_cleanup_queue(dev_info->dcssblk_queue);
-	dev_info->gd->queue = NULL;
-	put_disk(dev_info->gd);
+	blk_cleanup_disk(dev_info->gd);
 
 	/* unload all related segments */
 	list_for_each_entry(entry, &dev_info->seg_list, lh)