On 10/26/18 10:28 AM, Vivek Goyal wrote: > On Fri, Oct 26, 2018 at 10:16:40AM -0400, Vivek Goyal wrote: >> On Fri, Oct 26, 2018 at 04:10:27PM +0200, Miklos Szeredi wrote: >>> On Fri, Oct 26, 2018 at 3:43 PM, Vivek Goyal <vgoyal@xxxxxxxxxx> wrote: >>>> Assume a user wanted to enable metadata only copy-up and passes metacopy=on. >>>> If this feature can't be enabled, we disable metacopy=off and just leave >>>> a warning in logs. metacopy=on requires redirect_dir=on (for upper dir) >>>> or redirect_dir=follow (for non-upper mount). >>> What's the reason we can't enable these for metacopy=on automatically? >>> >>> I mean, the simplest and least surprising behavior would be if >>> metacopy would simply imply redirect_dir, no? >> redirect_dir=on is a significant change. And it might be better if >> users passes it in (instead of enabling it automatically). >> >> For example, when redirect_dir is enabled, container runtime software >> (docker, podman), their logic to generate image does not work and >> they have to fall back to *slower* method of diff. >> >> https://github.com/moby/moby/pull/34342 > Having said that, metacopy=on will have same issue and user need to > fall back to slower naivediff interface for image generation. > > So enabling redirect_dir automatically probably is good. We could > just drop a message in logs that it has been enabled automatically. > > IOW, I can go either way depending on how others feel about it. > > Thanks > Vivek I think turning them both on and DOCUMENTING the behavior would be good.
