[OpenAFS-devel] Re: Breaking callbacks on unlink

[chas williams - CONTRACTOR]

On Wed, 25 Jan 2012 10:53:36 -0600
Andrew Deason <adeason@sinenomine.net> wrote:

> On Tue, 24 Jan 2012 19:17:07 -0500
> chas williams - CONTRACTOR <chas@cmf.nrl.navy.mil> wrote:
> 
> > i think i would prefer a logical and consistent behavior as well.
> > otherwise someone clever will rely on the inconsistent behavior and
> > suddenly find that it is indeed inconsistent.
> 
> Well, that's the issue. Maybe someone already does rely on this
> inconsistent behavior; taking it away unconditionally would break them
> (which is why I wasn't suggesting doing that).

how does one rely on something that is inconsistent?  if the behavior
is suddenly consistent and their stuff breaks that could be seen as
already within the same inconsistent behavior.  eventually they are
going to get bitten.

> Isn't this the same as the use case for the POSIX semantics on a local
> fs? Someone might be still reading the data (data, configuration, ...).
> Maybe you deleted a dso for a library that a running process is linked
> to.

i forgot about dso's.  upgrading a dso about is the only valid reason i
think for this behavior.

posix says "processes" but it doesnt say if these processes are across
multiple machines accessing the same filesystem.  i think this is a bit
of a gray area in the specification.