Hi, On Fri, Mar 2, 2018 at 3:37 AM, Jiri Pirko <j...@resnulli.us> wrote: > Fri, Mar 02, 2018 at 04:48:40AM CET, kubak...@wp.pl wrote: >>On Thu, 1 Mar 2018 22:38:50 -0500, Alexander Aring wrote: >>> I guess to make extack working, you need to return an errno if failed. >> >>AFAIK extack is printed as a warning if operation did not fail. > > Yes, I checked this and it is printed as warning.
ouch, so far I know extack it allows only one messages delivered back to the user space. If we introduce a warning in the successful path here, it could be that in the callpath (after "successful" part of this callback), that somebody else want to add a warning and overwrites actually your warning (even, he is not aware that this warning was set - okay I suppose you can do another check on NULL and set a warning, that somebody overwrites a warning :-D). If extack messages get's append and is some kind of for_each_nested string in netlink -> we have no problem, but I guess this not how it's working. :-/ - Alex