Re: [RFC] perfuse permission checks

[Antti Kantee <pooka%cs.hut.fi@localhost>]

[resending with tech-kern included]

On Sat Aug 28 2010 at 05:52:54 +0200, Emmanuel Dreyfus wrote:
> Hello
> 
> I just commited code in libperfuse to check permissions on various file
> operations. On each operation comes weird questions such as "do I need
> r-x on the parent directory, or just --x?". While I attempted to
> experiment around it, I am pretty sure there are bugs left behind. 
> 
> Anyone can review the code? It is in src/lib/libperfuse/ops.c
> (search for calls to no_access)

Usually it's enough and easier to perform access checks from lookup
(plus setattr).

I don't know what gluesterfs does, though, and what kind of races are
present due to the distributed nature if you just check access in lookup.