block: pass a gendisk to bdev_resize_partition

bdev_resize_partition can only operate on the whole device.  Make that clear
by passing a gendisk instead of a block_device.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210810154512.1809898-5-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

block/blk.h

@@ -350,8 +350,8 @@ void blk_free_ext_minor(unsigned int minor);
 int bdev_add_partition(struct gendisk *disk, int partno, sector_t start,
 		sector_t length);
 int bdev_del_partition(struct gendisk *disk, int partno);
-int bdev_resize_partition(struct block_device *bdev, int partno,
-		sector_t start, sector_t length);
+int bdev_resize_partition(struct gendisk *disk, int partno, sector_t start,
+		sector_t length);
 
 int bio_add_hw_page(struct request_queue *q, struct bio *bio,
 		struct page *page, unsigned int len, unsigned int offset,

block/ioctl.c

@@ -43,7 +43,7 @@ static int blkpg_do_ioctl(struct block_device *bdev,
 			return -EINVAL;
 		return bdev_add_partition(disk, p.pno, start, length);
 	case BLKPG_RESIZE_PARTITION:
-		return bdev_resize_partition(bdev, p.pno, start, length);
+		return bdev_resize_partition(disk, p.pno, start, length);
 	default:
 		return -EINVAL;
 	}

block/partitions/core.c

@@ -497,14 +497,14 @@ int bdev_del_partition(struct gendisk *disk, int partno)
 	return ret;
 }
 
-int bdev_resize_partition(struct block_device *bdev, int partno,
-		sector_t start, sector_t length)
+int bdev_resize_partition(struct gendisk *disk, int partno, sector_t start,
+		sector_t length)
 {
 	struct block_device *part = NULL;
 	int ret = -ENXIO;
 
-	mutex_lock(&bdev->bd_disk->open_mutex);
-	part = xa_load(&bdev->bd_disk->part_tbl, partno);
+	mutex_lock(&disk->open_mutex);
+	part = xa_load(&disk->part_tbl, partno);
 	if (!part)
 		goto out_unlock;
 
@@ -513,14 +513,14 @@ int bdev_resize_partition(struct block_device *bdev, int partno,
 		goto out_unlock;
 
 	ret = -EBUSY;
-	if (partition_overlaps(bdev->bd_disk, start, length, partno))
+	if (partition_overlaps(disk, start, length, partno))
 		goto out_unlock;
 
 	bdev_set_nr_sectors(part, length);
 
 	ret = 0;
 out_unlock:
-	mutex_unlock(&bdev->bd_disk->open_mutex);
+	mutex_unlock(&disk->open_mutex);
 	return ret;
 }