-int set_state_private(struct extent_io_tree *tree, u64 start, u64 private);
-void extent_cache_csums_dio(struct extent_io_tree *tree, u64 start, u32 csums[],
- int count);
-void extent_cache_csums(struct extent_io_tree *tree, struct bio *bio,
- int bvec_index, u32 csums[], int count);