Re: device-specific qid.version behaviour (was Re: [9fans] QTCTL?)

["roger peppe" <rogpeppe@gmail.com>]

On 11/5/07, erik quanstrom <quanstro@quanstro.net> wrote:
> the qid.vers does get exported.

indeed it does. but if clients aren't expected to make use of it,
why *is* it exported? i guess i'm arguing that the notions of device
medium version (a.k.a. nchanges) and file version are two
separate things, and it doesn't really make sense to present
the former as the latter.

> there's another way to look at this situation.  the fileservers do not
> lie.  they are always accurate.  the client's assumptions are faulty.
> ;-)

no, no, that's so wrong! a fileserver is lying when it presents
metadata that isn't interpretable by reading the rules set out
in section 5 of the manual. the rules are sometimes
bendable, as you point out, depending on who relies on them, but i think it's
a good principle to try to stand behind.

> this issue deserves some more thought.  stat(5) says length is in bytes.
> is stat(5) wrong?

no, stat(5) is axiomatically right...

> if we allow too much freedom in 9p, then we will not be able to
> write general tools.  if we don't allow enough, we will not be able to
> write tools easily and succinctly.

i'm not sure how much bending the rules facilitates easy and succinct tool
writing. it's always tempting, but rarely worth it, i reckon, and this
particular case
definitely doesn't show that IMHO.