On 11/02/2015 04:28 PM, John Snow wrote: > The mirror job doesn't update its total length until > it has already started running, so we should translate > a zero-length job-len as meaning 0%. > > Otherwise, we may get divide-by-zero faults. > > Signed-off-by: John Snow <js...@redhat.com> > --- > qemu-img.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-)
And indeed, this has tripped up libvirt in the past :)
My only concern is what if you truly have a 0-length job? For example,
when doing two block-stream commands with identical arguments in a row,
the second block-stream has no work to do, but can complete instantly.
Will this result in such a job never reporting 100% complete? If so,
that's bad.
If you can answer my concerns that we don't have a design bug, then the
code changes look correct, and you can add:
Reviewed-by: Eric Blake <ebl...@redhat.com>
>
> diff --git a/qemu-img.c b/qemu-img.c
> index 3025776..38b4888 100644
> --- a/qemu-img.c
> +++ b/qemu-img.c
> @@ -656,7 +656,8 @@ static void run_block_job(BlockJob *job, Error **errp)
>
> do {
> aio_poll(aio_context, true);
> - qemu_progress_print((float)job->offset / job->len * 100.f, 0);
> + qemu_progress_print(job->len ?
> + ((float)job->offset / job->len * 100.f) : 0.00,
> 0);
Also, note that this promotes to double rather than float; maybe you
want to use 0.f instead of 0.00 to keep the ternary as a float? But it
shouldn't make a difference in practice.
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
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