Re: should CONFIG_TMPFS_POSIX_ACL be so easily deselectable?

From: Hugh Dickins
Date: Fri Jun 17 2011 - 20:29:07 EST


On Fri, 17 Jun 2011, Robert P. J. Day wrote:
> On Fri, 17 Jun 2011, Hugh Dickins wrote:
> > On Fri, 17 Jun 2011, Robert P. J. Day wrote:
> > >
> > > p.s. i do notice a fairly recent change to that config file related
> > > to this:
> >
> > Yes, we were originally losing the oldconfig value of
> > TMPFS_POSIX_ACL.
> >
> > It would be easy to ack a patch from you which changes that wording
> > "If you don't know what Access Control Lists are, say N" to
> > something more informative about what the sound userspace wants.
>
> agreed -- something as simple as "if you don't know, say Y"? :-)
> or would it be better to actually take a line or two to explain the
> consequences of that option?

I think both. I've often thought "default N", "if unsure say Y"
Kconfig options contradictory, but I can see the point in this case.
Example or examples of the pain of saying N can be helpful.

> (by the way, this option affects more than just sound.)

Of course.

>
> > It would be harder to justify having SOUND select TMPFS, or changing
> > the TMPFS_POSIX_ACL default to Y. It's been N forever, and that is
> > how we prefer to add features.
>
> normally, i'd agree with you, except for the observation that, by
> far, the default config files across all architectures select that
> option. there are 48 config files that select it, and only 3 that
> don't. sometimes, that's a compelling argument that maybe it *should*
> be default yes. but for now, i'll just whip up a more informative
> help sentence or two.

I don't think architecture defconfig files necessarily correlate with
Kconfig defaults. You could argue that they should do so (so far as
arch-independent options are concerned), but I think the reality is
that arch defconfigs are produced separately, at the whim of various
people with different agendas. I may be wrong (if unsure, say Y!).

>
> rday
>
> p.s. as i mentioned, that option would appear to affect more than
> just sound. as in:
>
> $ getfacl /dev/kvm
> getfacl: Removing leading '/' from absolute path names
> # file: dev/kvm
> # owner: root
> # group: kvm
> user::rw-
> user:rpjday:rw-
> group::rw-
> mask::rw-
> other::---
>
> so wouldn't KVM suddenly start behaving badly as well?

Dunno. But certainly TMPFS_POSIX_ACLs are for whatever uses
tmpfs POSIX ACLs are being put to, not specific to sound - but
sound happens to be the case that wasted your time and Linus's.

Hugh
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