btrfs: reduce scope of btrfs_scratch_superblocks()

btrfs_scratch_superblocks() isn't used anywhere outside volumes.c so
remove it from the header file and mark it as static.  Also move it
above it's callers so we don't need a forward declaration.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/volumes.c

@@ -1948,6 +1948,35 @@ static u64 btrfs_num_devices(struct btrfs_fs_info *fs_info)
 	return num_devices;
 }
 
+static void btrfs_scratch_superblocks(struct block_device *bdev,
+				      const char *device_path)
+{
+	struct buffer_head *bh;
+	struct btrfs_super_block *disk_super;
+	int copy_num;
+
+	if (!bdev)
+		return;
+
+	for (copy_num = 0; copy_num < BTRFS_SUPER_MIRROR_MAX; copy_num++) {
+		if (btrfs_read_dev_one_super(bdev, copy_num, &bh))
+			continue;
+
+		disk_super = (struct btrfs_super_block *)bh->b_data;
+
+		memset(&disk_super->magic, 0, sizeof(disk_super->magic));
+		set_buffer_dirty(bh);
+		sync_dirty_buffer(bh);
+		brelse(bh);
+	}
+
+	/* Notify udev that device has changed */
+	btrfs_kobject_uevent(bdev, KOBJ_CHANGE);
+
+	/* Update ctime/mtime for device path for libblkid */
+	update_dev_time(device_path);
+}
+
 int btrfs_rm_device(struct btrfs_fs_info *fs_info, const char *device_path,
 		u64 devid)
 {
@@ -7316,36 +7345,6 @@ int btrfs_get_dev_stats(struct btrfs_fs_info *fs_info,
 	return 0;
 }
 
-void btrfs_scratch_superblocks(struct block_device *bdev, const char *device_path)
-{
-	struct buffer_head *bh;
-	struct btrfs_super_block *disk_super;
-	int copy_num;
-
-	if (!bdev)
-		return;
-
-	for (copy_num = 0; copy_num < BTRFS_SUPER_MIRROR_MAX;
-		copy_num++) {
-
-		if (btrfs_read_dev_one_super(bdev, copy_num, &bh))
-			continue;
-
-		disk_super = (struct btrfs_super_block *)bh->b_data;
-
-		memset(&disk_super->magic, 0, sizeof(disk_super->magic));
-		set_buffer_dirty(bh);
-		sync_dirty_buffer(bh);
-		brelse(bh);
-	}
-
-	/* Notify udev that device has changed */
-	btrfs_kobject_uevent(bdev, KOBJ_CHANGE);
-
-	/* Update ctime/mtime for device path for libblkid */
-	update_dev_time(device_path);
-}
-
 /*
  * Update the size and bytes used for each device where it changed.  This is
  * delayed since we would otherwise get errors while writing out the

fs/btrfs/volumes.h

@@ -474,7 +474,6 @@ int btrfs_run_dev_stats(struct btrfs_trans_handle *trans);
 void btrfs_rm_dev_replace_remove_srcdev(struct btrfs_device *srcdev);
 void btrfs_rm_dev_replace_free_srcdev(struct btrfs_device *srcdev);
 void btrfs_destroy_dev_replace_tgtdev(struct btrfs_device *tgtdev);
-void btrfs_scratch_superblocks(struct block_device *bdev, const char *device_path);
 int btrfs_is_parity_mirror(struct btrfs_fs_info *fs_info,
 			   u64 logical, u64 len);
 unsigned long btrfs_full_stripe_len(struct btrfs_fs_info *fs_info,