Internals of ext2fs

Directories

Why isn't the name of a file in the inode?
Because on a Unix system, a file can be known by more than one name
For example, /home/mjd/Mail/.., /home/mjd/., and /home/mjd are all the same file
It's the directories that supply names, not the inodes
A directory looks like this:

        .                    802881
        ..                   673145
        .bak                 802882
        .width-errors        802888
        Flags.slides         802884
        INAMBLE              802885
        MAKE_SLIDES          802886
        Makefile             802887
        .slide_names         802890
        POSTAMBLE            802889
        ext2fs.slides        802883
        ...

Each line is called a link. It has a name and an i-number
- Hence the link and unlink system calls
The actual format of a link varies from version to version of Unix
- Originally, each link was just 14 bytes of name followed by 2 bytes of i-number
- ext2fs uses counted-length names instead of fixed-length names