Re: [PATCH] block: Error out on image creation with conflicting size options

[Kevin Wolf <kwolf@redhat.com>]

Am 26.11.2019 um 16:56 hat Eric Blake geschrieben:
> On 11/26/19 9:54 AM, Eric Blake wrote:
> > On 11/26/19 9:48 AM, Kevin Wolf wrote:
> > > If both the create options (qemu-img create -o ...) and the size
> > > parameter were given, the size parameter was silently ignored. Instead,
> > > make specifying two sizes an error.
> > > 
> > > Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> > > ---
> > >   block.c                    | 10 ++++++++--
> > >   tests/qemu-iotests/049     |  5 +++++
> > >   tests/qemu-iotests/049.out |  5 +++++
> > >   3 files changed, 18 insertions(+), 2 deletions(-)
> > 
> > Longtime bug, so not essential for 4.2-rc3.  But small enough that you
> > could sneak it in if you have other patches to queue and don't want to
> > wait for 5.0.
> > 
> > Reviewed-by: Eric Blake <eblake@redhat.com>
> 
> Actually, your patch fails to diagnose:
> 
> $ qemu-img create -o size=1m,size=2m -f qcow2 x.qcow2
> Formatting 'x.qcow2', fmt=qcow2 size=2097152 cluster_size=65536
> lazy_refcounts=off refcount_bits=16
> 
> so you may want to enhance this patch to also catch the case of -o size used
> more than once.

Hm... Isn't this something that QemuOpts should already catch? Or do we
have callers that actually expect the same option specified multiple
times?

Somehow I'm almost sure that Markus will know an example...

But anyway, I figure the same problem exists for almost all options.

Kevin