Commit ac287da2 authored by Jens Axboe's avatar Jens Axboe
Browse files

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: default avatarNorman Maurer <norman_maurer@apple.com>
Acked-by: default avatarJakub Kicinski <kuba@kernel.org>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 7951e36a

io_uring/net.c

+16 −4
Original line number Diff line number Diff line
@@ -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 @@ int io_accept(struct io_kiocb *req, unsigned int issue_flags) 
		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 @@ int io_accept(struct io_kiocb *req, unsigned int issue_flags) 
						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))

	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;

}