block: move the NEED_PART_SCAN flag to struct gendisk

We can only scan for partitions on the whole disk, so move the flag
from struct block_device to struct gendisk.

Signed-off-by: Christoph Hellwig <[e-mail]>
Signed-off-by: Jens Axboe <[e-mail]>

block/genhd.c

···
 	if (!bdev)
 		goto exit;
 
-	set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags);
+	set_bit(GD_NEED_PART_SCAN, &disk->state);
 	err = blkdev_get(bdev, FMODE_READ, NULL);
 	if (err < 0)
 		goto exit;
···
 	if (__invalidate_device(bdev, true))
 		pr_warn("VFS: busy inodes on changed media %s\n",
 			bdev->bd_disk->disk_name);
-	set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags);
+	set_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state);
 	return true;
 }
 EXPORT_SYMBOL(bdev_check_media_change);

drivers/block/nbd.c

···
 			bd_set_nr_sectors(bdev, nr_sectors);
 			set_blocksize(bdev, config->blksize);
 		} else
-			set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags);
+			set_bit(GD_NEED_PART_SCAN, &nbd->disk->state);
 		bdput(bdev);
 	}
 	kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE);
···
 		return ret;
 
 	if (max_part)
-		set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags);
+		set_bit(GD_NEED_PART_SCAN, &nbd->disk->state);
 	mutex_unlock(&nbd->config_lock);
 	ret = wait_event_interruptible(config->recv_wq,
 					 atomic_read(&config->recv_threads) == 0);
···
 		refcount_set(&nbd->config_refs, 1);
 		refcount_inc(&nbd->refs);
 		mutex_unlock(&nbd->config_lock);
-		set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags);
+		set_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state);
 	} else if (nbd_disconnected(nbd->config)) {
-		set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags);
+		set_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state);
 	}
 out:
 	mutex_unlock(&nbd_index_mutex);

drivers/ide/ide-gd.c

···
 				bdev->bd_disk->disk_name);
 		drive->disk_ops->get_capacity(drive);
 		set_capacity(disk, ide_gd_capacity(drive));
-		set_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags);
+		set_bit(GD_NEED_PART_SCAN, &disk->state);
 	} else if (drive->dev_flags & IDE_DFLAG_FORMAT_IN_PROGRESS) {
 		ret = -EBUSY;
 		goto out_put_idkp;

fs/block_dev.c

···
 		bdev->bd_super = NULL;
 		bdev->bd_inode = inode;
 		bdev->bd_part_count = 0;
-		bdev->bd_flags = 0;
 		inode->i_mode = S_IFBLK;
 		inode->i_rdev = dev;
 		inode->i_bdev = bdev;
···
 
 	lockdep_assert_held(&bdev->bd_mutex);
 
-	clear_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags);
+	clear_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state);
 
 rescan:
 	ret = blk_drop_partitions(bdev);
···
 			 * The latter is necessary to prevent ghost
 			 * partitions on a removed medium.
 			 */
-			if (test_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags) &&
+			if (test_bit(GD_NEED_PART_SCAN, &disk->state) &&
 			    (!ret || ret == -ENOMEDIUM))
 				bdev_disk_changed(bdev, ret == -ENOMEDIUM);
 
···
 			if (bdev->bd_disk->fops->open)
 				ret = bdev->bd_disk->fops->open(bdev, mode);
 			/* the same as first opener case, read comment there */
-			if (test_bit(BDEV_NEED_PART_SCAN, &bdev->bd_flags) &&
+			if (test_bit(GD_NEED_PART_SCAN, &disk->state) &&
 			    (!ret || ret == -ENOMEDIUM))
 				bdev_disk_changed(bdev, ret == -ENOMEDIUM);
 			if (ret)

include/linux/blk_types.h

···
 typedef void (bio_end_io_t) (struct bio *);
 struct bio_crypt_ctx;
 
-#define BDEV_NEED_PART_SCAN		0
-
 struct block_device {
 	dev_t			bd_dev;
 	int			bd_openers;
···
 	struct hd_struct *	bd_part;
 	/* number of times partitions within this device have been opened. */
 	unsigned		bd_part_count;
-	unsigned long		bd_flags;
+
 	spinlock_t		bd_size_lock; /* for bd_inode->i_size updates */
 	struct gendisk *	bd_disk;
 	struct backing_dev_info *bd_bdi;

include/linux/genhd.h

···
 	void *private_data;
 
 	int flags;
+	unsigned long state;
+#define GD_NEED_PART_SCAN		0
 	struct rw_semaphore lookup_sem;
 	struct kobject *slave_dir;