On Wed, Oct 20, 2021 at 11:35:27AM -0600, Jens Axboe wrote: > On 10/20/21 11:30 AM, Christoph Hellwig wrote: > > On Wed, Oct 20, 2021 at 10:49:07AM -0600, Jens Axboe wrote: > >> It's not used for anything, and we're wasting time passing in zeroes > >> where we could just ignore it instead. Update all ki_complete users in > >> the kernel to drop that last argument. > >> > >> The exception is the USB gadget code, which passes in non-zero. But > >> since nobody every looks at ret2, it's still pointless. > > > > Yes, the USB gadget passes non-zero, and aio passes that on to > > userspace. So this is an ABI change. Does it actually matter? > > I don't know, but you could CC the relevant maintainers and list > > to try to figure that out. > > True, guess it does go out to userspace. Greg, is anyone using > it on the userspace side? I really do not know (adding linux-usb@vger) My interactions with the gadget code have not been through the aio api, thankfully :) Odds are it's fine, I think that something had to be passed in there so that was chosen? If the aio code didn't do anything with it, I can't see where the gadget code gets it back at anywhere, but I might be looking in the wrong place. Anyone else here know? thanks, greg k-h