Re: [PATCH 10/17] hurd: add fsys_get_children

[Justus Winter]

Quoting Samuel Thibault (2013-07-15 10:26:18)
> Neal H. Walfield, le Fri 12 Jul 2013 15:13:30 +0200, a écrit :
> > How do you do permission checking?
> > 
> > Making a directory executable but not readable is a useful way to
> > grant permission by knowledge of a shared secret.
> 
> Right.
> 
> That being said, I don't think we want /proc/mounts to show
> non-{root,self} translators, so it would be only about root trying to
> hide things.

Richard and I have been discussing this in #hurd and while we both
agree that this is a feature that we want, we might want to defer
this.

He mentioned that on Linux /proc/mounts does show all mounts
regardless of who opens this file and how the permissions of the mount
points parent directories are.

He has shown me how this could be implemented, but doing so requires
attaching credentials to all fsys_* by means of
e.g. libdiskfs/fsmutations.h and fixing all functions that are
affected by this. I think it's doable, but my time might be better
spent on something else. Thoughts?

Justus