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Date: Tue, 25 Jun 2013 16:06:21 +0200
From: Kevin Wolf <kwolf@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH] block: add drive_backup HMP command
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To: Paolo Bonzini <pbonzini@redhat.com>
Cc: imain@redhat.com, Fam Zheng <famz@redhat.com>, qemu-devel@nongnu.org, Stefan Hajnoczi <stefanha@redhat.com>

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.

Apart from that, it's HMP, so even in the unlikely case that we mess up,
fixing it is still an option.

Kevin