Re: [9fans] 9pfuse and O_APPEND

[erik quanstrom <quanstro@quanstro.net>]

> Agreed. Now, here's a bit that I still don't quite
> understand: Plan9 does have DMAPPEND on
> a per-Qid basis. Why was it decided not to
> have it on a per-Fid basis (which would match
> POSIX semantics 100%)?
>
> The way I understand -- DMAPPEND is just a hint
> to the server to *alway* ignore the offset in
> incoming writes. It seems that ignoring offsets
> in writes for the Fids that asked for it wouldn't be
> much more difficult, would it?

DMAPPEND, for servers that implement it, is not
a hint to the server, it's a write to the end of the file,
whatever offset that might be.

since the end is computed on the file server, multiple
concurrent writers don't cause a problem. since the
fs is in a position to serialize appends to the same
file.

- erik