Re: undeletion at filesystem level or in extra filesystem?

[Thomas Bushnell, BSG]

nisse@lysator.liu.se (Niels Möller) writes:

> I hope you mean putting it into glibc, so that the rm program won't be
> special?

I have no particular preference here.  It's a user-interface feature,
as I see it.

> I can see two reasons to put the versioning features in the filesystem
> rather than in glibc: (1) one might want to configure versioning per
> filesystem, (2) one might want to support some filesystem with
> "native" versioning (are there any?)

Versioning and undelete are separate issues.  If you have versioning,
it's a nice way to get "undelete" too, but you can have undelete
without it.

> By the way, do you think there's any chance to change the semantics of
> open and write? I'd like the default behaviour to be as follows:

I think your proposed tweak to the semantics of open are basically
right; I don't see the need right now to nail down the exact details.

But basically, yeah, if someone opens for O_WRONLY, writes, and
closes, it would be nice if the old contents were cleanly saved as a
"version".

Note that this doesn't say anything about the semantics of unlink...