how to read ext4 journal information?

ext4 journal contains every actions performed to file system files.
i wanna know :

  1. how to read ext4 journal information? is there any easy-to-use tools? or i have to write my own program using jbd2 header files and other source files?
  2. is it possible to retrieve all meta infos for files under’ a specified directory from ext4 journal without walk through this directory? the meta info i mentioned should includes: file name, file path, last modified name , creation time etc.

Check debugfs man page. Maybe logdump does what you want.