Re: [Qemu-devel] 'commit' error for 'all': No medium found

[Kevin Wolf]

Am 25.02.2013 um 16:01 hat Markus Armbruster geschrieben:
> >> The behaviour then would be nop on no medium during commit all. But if
> >> you specifically tried to just run commit() on a single device that
> >> had no medium, you would receive ENOMEDIUM.  That seems logical to me.
> >
> > I think, even "commit <blockdev-without-medium>" should not return
> > -ENOMEDIUM. That would be more consistent IMHO.
> 
> "commit FOO" makes sense only when FOO is a COW backend.  When it isn't,
> we can either ignore the non-sensical request silently, or complain.  I
> think both ways are defensible.  We just need to pick one, and stick to
> it consistently.
> 
> "commit all" should obviously apply only to COW backends.  I don't think
> that makes a "commit FOO" that complains inconsistent.  I simply read
> "all" as "all COW backends".
> 
> That said, I don't really care which way we go.  Kevin or Stefan, got a
> preference?

I don't have a very strong opinion on it, but my expectation would have
been that an explicit commit on an empty or non-COW drive would give me
an error.

Kevin