I suspect that removing this will cause a regression; GH-28 ensured that if there was no size provided then free space would be used. I think this needs to have something like this:

```ruby
if @resource[:extents]
  args.push('--extents', @resource[:extents]
end

if !@resource[:extents] and !@resource[:size]
  args.push('--extents', '100%FREE')
fi
```