Re: [Qemu-devel] [PATCH v2] qemu-img: check block status of backing file when converting.

[Ren Kimura]

> So the correct way to test this would be:

> if (!(ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO))
> Or, shorter:
> if (!(ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ZERO)))

Oops! It's very trivial mistake. I'll fix it.

> I originally said (in my reply to v1) that we may not fall through to
> the backing file if the range is allocated in the overlay. That is
> correct, but now it turns out that we can also skip falling through if
> the range is not allocated in the overlay but the contents of the
> backing file don't matter anyway.

Aha. It's totally true. But I'd like to keep these operations simple and easy to read.

So I'll fix only first one.

Thank you for reviewing.

 Ren