On Sat, Sep 18, 2021 at 3:41 PM Jens Axboe <axboe@xxxxxxxxx> wrote: > > On 9/18/21 7:41 AM, Victor Stewart wrote: > > just auto updated from 5.13.16 to 5.13.17, and suddenly my fixed > > file registrations fail with EOPNOTSUPP using liburing 2.0. > > > > static inline struct io_uring ring; > > static inline int *socketfds; > > > > // ... > > > > void enableFD(int fd) > > { > > int result = io_uring_register_files_update(&ring, fd, > > &(socketfds[fd] = fd), 1); > > printf("enableFD, result = %d\n", result); > > } > > > > maybe this is due to the below and related work that > > occurred at the end of 5.13 and liburing got out of sync? > > > > https://github.com/torvalds/linux/commit/992da01aa932b432ef8dc3885fa76415b5dbe43f#diff-79ffab63f24ef28eec3badbc8769e2a23e0475ab1fbe390207269ece944a0824 > > > > and can't use liburing 2.1 because of the api changes since 5.13. > > That's very strange, the -EOPNOTSUPP should only be possible if you > are not passing in the ring fd for the register syscall. You should > be able to mix and match liburing versions just fine, the only exception > is sometimes between releases (of both liburing and the kernel) where we > have the liberty to change the API of something that was added before > release. > > Can you do an strace of it and attach? oh ya the EOPNOTSUPP was my bug introduced trying to debug. here's the real bug... io_uring_register(13, IORING_REGISTER_FILES, [-1, -1, -1, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, ...], 32768) = -1 EMFILE (Too many open files) 32,768 is 1U << 15 aka IORING_MAX_FIXED_FILES, but i tried 16,000 just to try and same issue. maybe you're not allowed to have pre-filled (aka non negative 1) entries upon the initial io_uring_register_files call anymore? this was working until the 5.13.16 -> 5.13.17 transition. > > -- > Jens Axboe >