[$] Toward a better definition for i_version

Filesystems maintain a lot of metadata about the files they hold; most ofthis metadata is for consumption by user space. Some metadata, though,stays buried within the filesystem and is not visible outside of thekernel. One such piece of metadata is the file version count, known as i_version.Current efforts to change how i_version is managed - and to makeit visible to user space - have engendered a debate on whati_version actually means and what its behavior should be.