On 1/28/20 4:36 PM, Pavel Begunkov wrote: > On 28/01/2020 22:42, Jens Axboe wrote: >> I didn't like it becoming a bit too complicated, both in terms of >> implementation and use. And the fact that we'd have to jump through >> hoops to make this work for a full chain. >> >> So I punted and just added sqe->personality and IOSQE_PERSONALITY. >> This makes it way easier to use. Same branch: >> >> https://git.kernel.dk/cgit/linux-block/log/?h=for-5.6/io_uring-vfs-creds >> >> I'd feel much better with this variant for 5.6. >> > > Checked out ("don't use static creds/mm assignments") > > 1. do we miscount cred refs? We grab one in get_current_cred() for each async > request, but if (worker->creds != work->creds) it will never be put. Yeah I think you're right, that needs a bit of fixing up. > 2. shouldn't worker->creds be named {old,saved,etc}_creds? It's set as > > worker->creds = override_creds(work->creds); > > Where override_creds() returns previous creds. And if so, then the following > fast check looks strange: > > worker->creds != work->creds Don't care too much about the naming, but the logic does appear off. I'll take a look at both of these tonight, unless you beat me to it. -- Jens Axboe