void yaffs2_clear_oldest_dirty_seq(yaffs_dev_t *dev, yaffs_block_info_t *bi);
void yaffs2_update_oldest_dirty_seq(yaffs_dev_t *dev, unsigned block_no, yaffs_block_info_t *bi);
int yaffs_block_ok_for_gc(yaffs_dev_t *dev, yaffs_block_info_t *bi);
-__u32 yaffs2_find_refresh_block(yaffs_dev_t *dev);
+u32 yaffs2_find_refresh_block(yaffs_dev_t *dev);
int yaffs2_checkpt_required(yaffs_dev_t *dev);
int yaffs_calc_checkpt_blocks_required(yaffs_dev_t *dev);