Ocfs2/refcounttree: Publicize couple of funcs from refcounttree.c

The original goal of commonizing these funcs is to benefit defraging/extent_moving
codes in the future,  based on the fact that reflink and defragmentation having
the same Copy-On-Wrtie mechanism.

Signed-off-by: Tristan Ye <tristan.ye@oracle.com>
diff --git a/fs/ocfs2/refcounttree.h b/fs/ocfs2/refcounttree.h
index c8ce46f7..7754608 100644
--- a/fs/ocfs2/refcounttree.h
+++ b/fs/ocfs2/refcounttree.h
@@ -84,6 +84,17 @@
 			     struct buffer_head *ref_root_bh,
 			     u32 cpos, u32 write_len,
 			     struct ocfs2_post_refcount *post);
+int ocfs2_duplicate_clusters_by_page(handle_t *handle,
+				     struct file *file,
+				     u32 cpos, u32 old_cluster,
+				     u32 new_cluster, u32 new_len);
+int ocfs2_duplicate_clusters_by_jbd(handle_t *handle,
+				    struct file *file,
+				    u32 cpos, u32 old_cluster,
+				    u32 new_cluster, u32 new_len);
+int ocfs2_cow_sync_writeback(struct super_block *sb,
+			     struct inode *inode,
+			     u32 cpos, u32 num_clusters);
 int ocfs2_add_refcount_flag(struct inode *inode,
 			    struct ocfs2_extent_tree *data_et,
 			    struct ocfs2_caching_info *ref_ci,