+extern int ext4_ext_calc_metadata_amount(struct inode *inode,
+ ext4_lblk_t lblocks);
+extern int ext4_extent_tree_init(handle_t *, struct inode *);
+extern int ext4_ext_calc_credits_for_single_extent(struct inode *inode,
+ int num,
+ struct ext4_ext_path *path);
+extern int ext4_can_extents_be_merged(struct inode *inode,
+ struct ext4_extent *ex1,
+ struct ext4_extent *ex2);
+extern int ext4_ext_insert_extent(handle_t *, struct inode *,
+ struct ext4_ext_path *,
+ struct ext4_extent *, int);
+extern struct ext4_ext_path *ext4_ext_find_extent(struct inode *, ext4_lblk_t,
+ struct ext4_ext_path *);
+extern void ext4_ext_drop_refs(struct ext4_ext_path *);
+extern int ext4_ext_check_inode(struct inode *inode);
+extern int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk);