Re: [9fans] Df command in Plan9?

["Boyd Roberts" <boyd@planete.net>]

From: Rick Hohensee <humbubba@smarty.smart.net>

> > > df, BTW, is one of those design flaws of unix that is so
> > > obvious nobody sees it. A directory has a size. It is the
> > > size of it's contents, not the size of the "file" containing
> > > the dirnames and so on. The size of a directory, it's "du-size",
> > > is something the filesystem should keep track of.
> >
> > Sigh... Rick, we've been through that how many times?
>
> Who's "we"? I don't recall mentioning this here. You and I haven't
> been over this at all that I recall. I did have some considered criticism
> of this in comp.unix.programmer, where a regular there breached the name
> Dyn-du.

oh nonsense.  directories are the size of their meta-data.

> This drops nothing. This points up the one thing you SHOULD have called me
> on, which is that the term "design flaw" is an exaggeration. Dyndufs is
> more like a design opportunity.

this is exactly the problem with linux; everything is a 'design opportunity'.
it's never ending and has not advanced the state of the art by one iota.

>
> True. When was the last time you did a du on / ? Or /usr ? Why?
>

not for a while, but when i needed to tar up a tree on multiple floppies
i used du, before invoking tar.  i see that SCO broke tar so it would
know about multiple volumes.  i wrote a script.  it's called a 'tools
approach'.

> > * Non-local operations are prone to races. Even cross-directory
> > rename(2) is a major PITA. The thing you are proposing is going to be
> > much worse.
> > * Programs that might benefit from that "du-size" are either
> > going to scan the tree anyway or belong to very small class -
> > filemanagers.
>
> You've just promoted ls to a filemanager. How Microsoftian.

kirk said that it took multiple iterations to get rename(2)
right, because it's a nasty problem.