On 8/9/23 9:09 AM, Andres Freund wrote: > Hi, > > Sorry for the delayed response, EINBOXOVERFLOW. > > On 2023-07-26 16:02:26 -0400, Jeff Moyer wrote: >> Andres Freund <andres@xxxxxxxxxxx> writes: >> >>> Hi, >>> >>> On 2023-06-30 15:10:03 +0000, Matteo Rizzo wrote: >>>> Introduce a new sysctl (io_uring_disabled) which can be either 0, 1, >>>> or 2. When 0 (the default), all processes are allowed to create io_uring >>>> instances, which is the current behavior. When 1, all calls to >>>> io_uring_setup fail with -EPERM unless the calling process has >>>> CAP_SYS_ADMIN. When 2, calls to io_uring_setup fail with -EPERM >>>> regardless of privilege. >>> >>> Hm, is there a chance that instead of requiring CAP_SYS_ADMIN, a certain group >>> could be required (similar to hugetlb_shm_group)? Requiring CAP_SYS_ADMIN >>> could have the unintended consequence of io_uring requiring tasks being run >>> with more privileges than needed... Or some other more granular way of >>> granting the right to use io_uring? >> >> That's fine with me, so long as there is still an option to completely >> disable io_uring. > > Makes sense. > > >>> ISTM that it'd be nice if e.g. a systemd service specification could allow >>> some services to use io_uring, without allowing it for everyone, or requiring >>> to run services effectively as root. >> >> Do you have a proposal for how that would work? > > I think group based permissions would allow for it, even if perhaps not in the > most beautiful manner. Systemd can configure additional groups for a service > with SupplementaryGroups, so adding a "io_uring" group or such should work. I'm going to drop the original patch until we work out a scheme that everybody is happy with, and that is flexible enough. -- Jens Axboe
