On Mon, Jul 24, 2017 at 10:33 AM, Miklos Szeredi <miklos@xxxxxxxxxx> wrote: > On Fri, Jul 14, 2017 at 1:17 PM, Amir Goldstein <amir73il@xxxxxxxxx> wrote: >> On Fri, Jul 14, 2017 at 1:53 PM, Miklos Szeredi <miklos@xxxxxxxxxx> wrote: >>> On Fri, Jul 14, 2017 at 12:35 PM, Amir Goldstein <amir73il@xxxxxxxxx> wrote: >>> >>>> What? always warn on boot? on mount? I donno. To me the comment >>>> about backward compat in Kconfig seems sufficient and no sysadmin >>>> can mistakenly set index=on on mount, but as I said, don't know >>>> enough about downstream to say much. >>> >>> I meant warning in Kconfig. I see that there is a warning there, but >>> it could be made shorter and more explicit. No need to explain the >>> hows and whys, just warn that enabling this option is not backward >>> compatible. >> >> By all means. I assume you will clean that up. >> >>> >>> And if distros enable it despite this warning, and it burns their >>> users, that's their problem. >>> >> >> Hmm... but the issue related to this commit is not backward compatibility >> is the sense that is depicted in Kconfig warning. >> The warning speaks of mounting new overlay with an old kernel. >> The concern discussed in this thread is mounting an old overlay >> with a new kernel: >> >> This used to work with old kernel: >> rm -rf /u.new >> mkdir /u.new >> mount -t overlay d /m -oupperdir=/u.new,lowerdir=/l.old,workdlir=/w.old >> >> And doesn't work with new kernel with INDEX=y. >> >> Another big behavior change that me good to warn about in Kconfig >> is not being able to copy layers. > > Right. The fact is: INDEX=y is not compatible with INDEX=n. Despite > that, it might well make sense for some to enable it by default, > because compatibility of overlay images is not always (rarely?) an > issue in practice. > Miklos, Do you plan to push any changes to Kconfig warning for v4.13? Plan to relax mount failures with -oro,index=on or keep it as is? Let me know if you want me to do anything in that regard. Thanks, Amir. -- To unsubscribe from this list: send the line "unsubscribe linux-unionfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
