Re: [RFC] FUSE permission modell (Was: fuse review bits)

[Jamie Lokier <jamie@shareable.org>]

Miklos Szeredi wrote:
> > Look up the rather large linux-kernel & linux-fsdevel thread "silent
> > semantic changes with reiser4" and it's followup threads, from last
> > year.
> 
> Wow, it's 700+ messages.  I got through the first 40, and already feel
> dizzy :)

It's easier if you skip the ones by Hans and their immediate followups :)

(Nothing personal, it's that Hans is mostly justifying reiser4's
behaviour, and the posts you really need to read aren't about reiser4).

> > It's already been tried.  You will also find sensible ideas on what
> > semantics it should have to do it properly.
> 
> OK, I understand the "slash -> directory, no-slash -> regular file"
> semantics.
> 
> How do you envision implementing this for "mount directory over file"?

Somewhere deep in that thread is a discussion between Al Viro and
Linus on it.

> A new mount flag indicating that it's only to be followed down if
> there's a slash after the mountpoint?

The new flag would indicate more than that: These mounts should be
detachable in the sense that deleting the file is possible, and
perhaps renamable/linkable too.  That's the stuff Al Viro discusses in
some detail in the big thread.

Ideally we'd like automounting, a bit like the Hurd's translators.
Attached to files (using an xattr or something, and executed with the
uid/gid of the file owner), and also per-user "pattern->action"
options for matching files with a certain type (e.g. tgz/zip/deb/rpm/xml).

But that can be added much later, as it's an orthogonal feature.

-- Jamie