From ac287da2e0ea5be2523222981efec86f0ca977cd Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 9 May 2024 09:41:10 -0600 Subject: io_uring/net: wire up IORING_CQE_F_SOCK_NONEMPTY for accept If the given protocol supports passing back whether or not we had more pending accept post this one, pass back this information to userspace. This is done by setting IORING_CQE_F_SOCK_NONEMPTY in the CQE flags, just like we do for recv/recvmsg if there's more data available post a receive operation. We can also use this information to be smarter about multishot retry, as we don't need to do a pointless retry if we know for a fact that there aren't any more connections to accept. Suggested-by: Norman Maurer Acked-by: Jakub Kicinski Signed-off-by: Jens Axboe --- io_uring/net.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) diff --git a/io_uring/net.c b/io_uring/net.c index d4d1fc93635c..0a48596429d9 100644 --- a/io_uring/net.c +++ b/io_uring/net.c @@ -1533,6 +1533,7 @@ int io_accept(struct io_kiocb *req, unsigned int issue_flags) .flags = force_nonblock ? O_NONBLOCK : 0, }; struct file *file; + unsigned cflags; int ret, fd; if (!(req->flags & REQ_F_POLLED) && @@ -1545,6 +1546,8 @@ retry: if (unlikely(fd < 0)) return fd; } + arg.err = 0; + arg.is_empty = -1; file = do_accept(req->file, &arg, accept->addr, accept->addr_len, accept->flags); if (IS_ERR(file)) { @@ -1573,17 +1576,26 @@ retry: accept->file_slot); } + cflags = 0; + if (!arg.is_empty) + cflags |= IORING_CQE_F_SOCK_NONEMPTY; + if (!(req->flags & REQ_F_APOLL_MULTISHOT)) { - io_req_set_res(req, ret, 0); + io_req_set_res(req, ret, cflags); return IOU_OK; } if (ret < 0) return ret; - if (io_req_post_cqe(req, ret, IORING_CQE_F_MORE)) - goto retry; + if (io_req_post_cqe(req, ret, cflags | IORING_CQE_F_MORE)) { + if (cflags & IORING_CQE_F_SOCK_NONEMPTY || arg.is_empty == -1) + goto retry; + if (issue_flags & IO_URING_F_MULTISHOT) + return IOU_ISSUE_SKIP_COMPLETE; + return -EAGAIN; + } - io_req_set_res(req, ret, 0); + io_req_set_res(req, ret, cflags); return IOU_STOP_MULTISHOT; } -- cgit v1.2.3-58-ga151