On Mon, 15 September 2008 04:07:58 +0900, Ryusuke Konishi wrote: > + > +The logs include regular files, directory files, symbolic link files > +and several meta data files. The mata data files are the files used > +to maintain file system meta data. The current version of NILFS2 uses > +the following meta data files: > + > + 1) Inode file (ifile) -- Stores on-disk inodes > + 2) Checkpoint file (cpfile) -- Stores checkpoints > + 3) Segment usage file (sufile) -- Stores allocation state of segments > + 4) Data address translation file -- Maps virtual block numbers to usual > + (DAT) block numbers. This file serves to > + make on-disk blocks relocatable. > + 5) Sketch file (sketch) -- Keeps read-only data which can be > + associated with checkpoints (optional) How are the sufile and the DAT written? If you naively stick to the log-structured approach, their contents will reflect a filesystem state prior to writing them and be outdated by the time they hit the medium. So either you bend the rules here and update those files in-place or you do something tricky. Can you explain your solution? Jörn -- Write programs that do one thing and do it well. Write programs to work together. Write programs to handle text streams, because that is a universal interface. -- Doug MacIlroy -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
