ocfs2: move tree path functions to alloc.h.

Now fs/ocfs2/alloc.c has more than 7000 lines. It contains our
basic b-tree operation. Although we have already make our b-tree
operation generic, the basic structrue ocfs2_path which is used
to iterate one b-tree branch is still static and limited to only
used in alloc.c. As refcount tree need them and I don't want to
add any more b-tree unrelated code to alloc.c, export them out.

Signed-off-by: Tao Ma <tao.ma@oracle.com> 

1 files changed, 49 insertions, 0 deletions

diff --git a/fs/ocfs2/alloc.h b/fs/ocfs2/alloc.h
index df0e778a2b68..3f4348923b73 100644
--- a/fs/ocfs2/alloc.h
+++ b/fs/ocfs2/alloc.h
@@ -115,6 +115,14 @@ int ocfs2_add_clusters_in_btree(handle_t *handle,
                                 struct ocfs2_alloc_context *meta_ac,
                                 enum ocfs2_alloc_restarted *reason_ret);
 struct ocfs2_cached_dealloc_ctxt;
+struct ocfs2_path;
+int ocfs2_split_extent(handle_t *handle,
+                       struct ocfs2_extent_tree *et,
+                       struct ocfs2_path *path,
+                       int split_index,
+                       struct ocfs2_extent_rec *split_rec,
+                       struct ocfs2_alloc_context *meta_ac,
+                       struct ocfs2_cached_dealloc_ctxt *dealloc);
 int ocfs2_mark_extent_written(struct inode *inode,
                               struct ocfs2_extent_tree *et,
                               handle_t *handle, u32 cpos, u32 len, u32 phys,
@@ -254,4 +262,45 @@ static inline int ocfs2_is_empty_extent(struct ocfs2_extent_rec *rec)
         return !rec->e_leaf_clusters;
 }
 
+/*
+ * Structures which describe a path through a btree, and functions to
+ * manipulate them.
+ *
+ * The idea here is to be as generic as possible with the tree
+ * manipulation code.
+ */
+struct ocfs2_path_item {
+        struct buffer_head              *bh;
+        struct ocfs2_extent_list        *el;
+};
+
+#define OCFS2_MAX_PATH_DEPTH    5
+
+struct ocfs2_path {
+        int                             p_tree_depth;
+        ocfs2_journal_access_func       p_root_access;
+        struct ocfs2_path_item          p_node[OCFS2_MAX_PATH_DEPTH];
+};
+
+#define path_root_bh(_path) ((_path)->p_node[0].bh)
+#define path_root_el(_path) ((_path)->p_node[0].el)
+#define path_root_access(_path)((_path)->p_root_access)
+#define path_leaf_bh(_path) ((_path)->p_node[(_path)->p_tree_depth].bh)
+#define path_leaf_el(_path) ((_path)->p_node[(_path)->p_tree_depth].el)
+#define path_num_items(_path) ((_path)->p_tree_depth + 1)
+
+void ocfs2_reinit_path(struct ocfs2_path *path, int keep_root);
+void ocfs2_free_path(struct ocfs2_path *path);
+int ocfs2_find_path(struct ocfs2_caching_info *ci,
+                    struct ocfs2_path *path,
+                    u32 cpos);
+struct ocfs2_path *ocfs2_new_path_from_path(struct ocfs2_path *path);
+struct ocfs2_path *ocfs2_new_path_from_et(struct ocfs2_extent_tree *et);
+int ocfs2_path_bh_journal_access(handle_t *handle,
+                                 struct ocfs2_caching_info *ci,
+                                 struct ocfs2_path *path,
+                                 int idx);
+int ocfs2_journal_access_path(struct ocfs2_caching_info *ci,
+                              handle_t *handle,
+                              struct ocfs2_path *path);
 #endif /* OCFS2_ALLOC_H */