Re: [Qemu-devel] [Qemu-block] [PATCH 0/2] qemu-img: Let "info" warn and go ahead without -U

[Fam Zheng <famz@redhat.com>]

On Mon, 01/08 18:57, Kevin Wolf wrote:
> I'm not sure if going back to the old behaviour for a while now would be
> helpful, you'd just end up with an even more confusing set of qemu
> versions, for example:
> 
>     <= 2.9          - works without a warning
>     2.10 and 2.11   - errors out
>     2.12            - prints a warning, but works
>     >= 2.13         - errors out again

What I had in mind is settle on warning for good. QEMU (including qemu-img) is a
low level tool that can be used in many ways that it isn't supposed to, this one
is not more harmful than others (e.g. "qemu-img snapshot ..." on iscsi:// qcow2
image) we allow siliently.

I know this is debatable but I think the #1 purpose of image locking is to
prevent data corruption; #2 IMO is to reduce confusion and misinformation.
While inconsistent output of "qemu-img info" is misinformation, it not working
as before is actually confusion. Though the current behavior is indeed ideal,
the proposed patch is a bit more pragmatical.

Fam