Re: [PATCH v2 1/4] qcow2: Require that the virtual size is a multiple of the sector size

[Alberto Garcia]

On Tue 14 Jan 2020 02:47:53 PM CET, Max Reitz wrote:

>> Yes, but does it make sense to try to support images with unaligned
>> sizes if no one is going to create them ever and QEMU cannot even
>> generate them?
>
> If nobody uses such images ever, isn’t the current code fine as-is?

I'll rephrase:

1. It is possible to have a qcow2 image with a size of 1 GB + 13 bytes
   (the size field in the qcow2 header allows it).

2. qemu-img cannot currently produce such images.

3. QEMU can open them but it gets the size wrong.

4. Fixing this in QEMU involves non-trivial changes (at least at the
   moment).

5. I don't think there's any use case for such images so instead of
   fixing QEMU I propose that we simply refuse to open them.

Berto