Re: Wishlist: credential file update/access collision avoidance?

On Mon, Oct 3, 2011 at 3:03 PM, Jeffrey Hutzelman <[email protected]> wrote:
> On Sun, 2011-10-02 at 17:57 -0500, Nico Williams wrote:
>> Oh, and on Unix systems, ccaches should only ever be stored in tmpfs
>> filesystems, so, yes, you can expect POSIX semantics.
>
> Um, reality check?
> I agree that storing file ccaches in such a filesystem is a good idea.
> However, not all in-memory filesystems share the properties of Solaris
> tmpfs.  "POSIX semantics" covers an awful lot of ground, and I'll bet
> that most filesystems, in-memory or not, are incompatible in some way.

What we mean here (what I take to have been meant) by POSIX semantics
here is not necessarily strict adherence to POSIX, but things like
"unlink() of open files is allowed" and "rename() is atomic and
unlink()s whatever file might have existed with the target name" --
that sort of thing.

So, where are these Unix and Unix-like systems that lack a /tmp with
these properties?

This is a question subject to empirical testing.

Nico
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