I am going to do the enhanced semantics first, so that somebody does not beat me to it.
David's examples are good. > > There's another note to kernel developers -- if Reiser5, 6, and 7 are > implemented as suites of plugins on top of Reiser4, then the Reiser4 > code will be maintained for a very long time. Kind of like ext2 vs > ext3, only moreso -- a Reiser5 FS may well be a Reiser4 FS mounted > with additional mount options. > > There is definitely a lot that can be done to move Reiser4 (as it is > today) closer to the Reiser4 whitepaper on the homepage. ACLs are one > thing, files as a directory are another. The idea of v4 is to do away > with many cases where a separate namespace is created for no good > reason -- for instance, where is the data in an id3 tag? It's inside > an mp3 file, and you can only get to it with tools written for id3 > tags of mp3 files. The Reiser4 concept is to allow things like that > to exist, but not require programs to know about libid3 or whatever. > Want to know what the artist of a particular file is? > > foo.mp3/.../id3/artist > > Or maybe a more generic way: > > foo.mp3/.../song-info/artist > > That way, you could have tools which don't even have to know if the > file has an id3 tag, or something entirely new, or if the metadata is > being stored outside the main file. It'd be entirely possible to > allow that file to be treated as a separate file entirely by the > plugin, rather than something derived from foo.mp3. > > The advantages don't seem immediately obvious until you consider that > the program which does this doesn't have to even know that it's > dealing with song metadata. Consider some of the one-line shell > scripts possible: > > > # Change the artist name for all songs in the directory: > for i in *; do echo 'Jimi Hendrix' > foo.mp3/.../song-info/artist; done > > # Make a playlist of all files by Hendrix, mp3 or otherwise: > for i in `find`; do > if [ `cat "$i/.../song-info/artist"` == 'Jimi Hendrix' ]; then > echo "../$i" >> playlists/hendrix.m3u; > fi; > done > > # Copy all files needed by said playlist to a USB device: > cp playlist/hendrix.m3u/.../files/* /mnt/usb > cp playlist/hendrix.m3u /mnt/usb > > > I'm sure others can think of much more interesting examples. > > All of that is planned for v4, eventually. It's very pluggable. > > Well, I think it is. I don't work here... > >
