Il 25/06/2013 16:06, Kevin Wolf ha scritto: > Am 25.06.2013 um 15:49 hat Paolo Bonzini geschrieben: >> Il 25/06/2013 15:26, Kevin Wolf ha scritto: >>>>> + if (!full) { >>>>> + error_setg(&errp, "-f is not yet implemented"); >>>>> + hmp_handle_error(mon, &errp); >>>>> + return; >>>>> + } >>> Then why make it a valid option and confuse users in the help text by >>> describing options that don't really exist? >> >> Because otherwise we're stuck with a meaning of the flag that is >> different between drive-mirror and block-backup. > > Do you mean when "otherwise" isn't only "we don't add -f now", but also > "we accidentally add a -f with different meaning later"? Not sure if > there's a real danger of that when we're aware that we want -f with the > same meaning as for mirroring.
We have drive-mirror with: * the default is 'top' * -f gives 'full' block-backup for now only implements 'full'. If we do not force the user to add -f, the default is 'full' and we should not change it later. However, I would move the "not yet implemented" error from HMP to QMP. This way, both drive-mirror and block-backup will have a mandatory 'sync' argument. We plan to implement it anyway, and it makes sense imo to avoid gratuitous differences in the APIs. Paolo > Apart from that, it's HMP, so even in the unlikely case that we mess up, > fixing it is still an option. > > Kevin >