ocfs2: Add support for incrementing refcount in the tree.

    Given a physical cpos and length, increment the refcount
in the tree. If the extent has not been seen before, a refcount
record is created for it. Refcount records may be merged or
split by this operation.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
diff --git a/fs/ocfs2/extent_map.h b/fs/ocfs2/extent_map.h
index b7dd973..9942f47 100644
--- a/fs/ocfs2/extent_map.h
+++ b/fs/ocfs2/extent_map.h
@@ -61,6 +61,11 @@
 			   struct buffer_head *bhs[], int flags,
 			   int (*validate)(struct super_block *sb,
 					   struct buffer_head *bh));
+int ocfs2_figure_hole_clusters(struct ocfs2_caching_info *ci,
+			       struct ocfs2_extent_list *el,
+			       struct buffer_head *eb_bh,
+			       u32 v_cluster,
+			       u32 *num_clusters);
 static inline int ocfs2_read_virt_block(struct inode *inode, u64 v_block,
 					struct buffer_head **bh,
 					int (*validate)(struct super_block *sb,