block: pass a gendisk to bdev_del_partition

bdev_del_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/20210810154512.1809898-4-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

block/blk.h

@@ -349,7 +349,7 @@ void blk_free_ext_minor(unsigned int minor);
 #define ADDPART_FLAG_WHOLEDISK	2
 int bdev_add_partition(struct gendisk *disk, int partno, sector_t start,
 		sector_t length);
-int bdev_del_partition(struct block_device *bdev, int partno);
+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);
 

block/ioctl.c

@@ -31,7 +31,7 @@ static int blkpg_do_ioctl(struct block_device *bdev,
 		return -EINVAL;
 
 	if (op == BLKPG_DEL_PARTITION)
-		return bdev_del_partition(bdev, p.pno);
+		return bdev_del_partition(disk, p.pno);
 
 	start = p.start >> SECTOR_SHIFT;
 	length = p.length >> SECTOR_SHIFT;

block/partitions/core.c

@@ -476,13 +476,13 @@ int bdev_add_partition(struct gendisk *disk, int partno, sector_t start,
 	return ret;
 }
 
-int bdev_del_partition(struct block_device *bdev, int partno)
+int bdev_del_partition(struct gendisk *disk, int partno)
 {
 	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;
 
@@ -493,7 +493,7 @@ int bdev_del_partition(struct block_device *bdev, int partno)
 	delete_partition(part);
 	ret = 0;
 out_unlock:
-	mutex_unlock(&bdev->bd_disk->open_mutex);
+	mutex_unlock(&disk->open_mutex);
 	return ret;
 }