ocfs2: Add functions for extents refcounted.

Add function ocfs2_mark_extent_refcounted which can mark
an extent refcounted.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
diff --git a/fs/ocfs2/alloc.h b/fs/ocfs2/alloc.h
index 0610ba1..19d5b88 100644
--- a/fs/ocfs2/alloc.h
+++ b/fs/ocfs2/alloc.h
@@ -128,6 +128,12 @@
 			      handle_t *handle, u32 cpos, u32 len, u32 phys,
 			      struct ocfs2_alloc_context *meta_ac,
 			      struct ocfs2_cached_dealloc_ctxt *dealloc);
+int ocfs2_change_extent_flag(handle_t *handle,
+			     struct ocfs2_extent_tree *et,
+			     u32 cpos, u32 len, u32 phys,
+			     struct ocfs2_alloc_context *meta_ac,
+			     struct ocfs2_cached_dealloc_ctxt *dealloc,
+			     int new_flags, int clear_flags);
 int ocfs2_remove_extent(handle_t *handle, struct ocfs2_extent_tree *et,
 			u32 cpos, u32 len,
 			struct ocfs2_alloc_context *meta_ac,