Merge tag 'net-accept-more-20240515' of git://git.kernel.dk/linux

Pull more io_uring updates from Jens Axboe:
 "This adds support for IORING_CQE_F_SOCK_NONEMPTY for io_uring accept
  requests.

  This is very similar to previous work that enabled the same hint for
  doing receives on sockets. By far the majority of the work here is
  refactoring to enable the networking side to pass back whether or not
  the socket had more pending requests after accepting the current one,
  the last patch just wires it up for io_uring.

  Not only does this enable applications to know whether there are more
  connections to accept right now, it also enables smarter logic for
  io_uring multishot accept on whether to retry immediately or wait for
  a poll trigger"

* tag 'net-accept-more-20240515' of git://git.kernel.dk/linux:
  io_uring/net: wire up IORING_CQE_F_SOCK_NONEMPTY for accept
  net: pass back whether socket was empty post accept
  net: have do_accept() take a struct proto_accept_arg argument
  net: change proto and proto_ops accept type

1 files changed, 20 insertions, 6 deletions

diff --git a/io_uring/net.c b/io_uring/net.c
index 070dea9a4eda..0a48596429d9 100644
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -1528,9 +1528,12 @@ int io_accept(struct io_kiocb *req, unsigned int issue_flags)
 {
 	struct io_accept *accept = io_kiocb_to_cmd(req, struct io_accept);
 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
-	unsigned int file_flags = force_nonblock ? O_NONBLOCK : 0;
 	bool fixed = !!accept->file_slot;
+	struct proto_accept_arg arg = {
+		.flags = force_nonblock ? O_NONBLOCK : 0,
+	};
 	struct file *file;
+	unsigned cflags;
 	int ret, fd;
 
 	if (!(req->flags & REQ_F_POLLED) &&
@@ -1543,7 +1546,9 @@ retry:
 		if (unlikely(fd < 0))
 			return fd;
 	}
-	file = do_accept(req->file, file_flags, accept->addr, accept->addr_len,
+	arg.err = 0;
+	arg.is_empty = -1;
+	file = do_accept(req->file, &arg, accept->addr, accept->addr_len,
 			 accept->flags);
 	if (IS_ERR(file)) {
 		if (!fixed)
@@ -1571,17 +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;
 }