static int io_accept(struct io_kiocb *req, unsigned int issue_flags)
{
	struct io_ring_ctx *ctx = req->ctx;
	struct io_accept *accept = &req->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 file *file;
	int ret, fd;

retry:
	if (!fixed) {
		fd = __get_unused_fd_flags(accept->flags, accept->nofile);
		if (unlikely(fd < 0))
			return fd;
	}
	file = do_accept(req->file, file_flags, accept->addr, accept->addr_len,
			 accept->flags);
	if (IS_ERR(file)) {
		if (!fixed)
			put_unused_fd(fd);
		ret = PTR_ERR(file);
		if (ret == -EAGAIN && force_nonblock) {
			/*
			 * if it's multishot and polled, we don't need to
			 * return EAGAIN to arm the poll infra since it
			 * has already been done
			 */
			if ((req->flags & IO_APOLL_MULTI_POLLED) ==
			    IO_APOLL_MULTI_POLLED)
				ret = 0;
			return ret;
		}
		if (ret == -ERESTARTSYS)
			ret = -EINTR;
		req_set_fail(req);
	} else if (!fixed) {
		fd_install(fd, file);
		ret = fd;
	} else {
		ret = io_fixed_fd_install(req, issue_flags, file,
						accept->file_slot);
	}

	if (!(req->flags & REQ_F_APOLL_MULTISHOT)) {
		__io_req_complete(req, issue_flags, ret, 0);
		return 0;
	}
	if (ret >= 0) {
		bool filled;

		spin_lock(&ctx->completion_lock);
		filled = io_fill_cqe_aux(ctx, req->cqe.user_data, ret,
					 IORING_CQE_F_MORE);
		io_commit_cqring(ctx);
		spin_unlock(&ctx->completion_lock);
		if (filled) {
			io_cqring_ev_posted(ctx);
			goto retry;
		}
		ret = -ECANCELED;
	}

	return ret;
}
static int io_accept(struct io_kiocb *req, unsigned int issue_flags)
{
	struct io_ring_ctx *ctx = req->ctx;
	struct io_accept *accept = &req->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 file *file;
	int ret, fd;

retry:
	if (!fixed) {
		fd = __get_unused_fd_flags(accept->flags, accept->nofile);
		if (unlikely(fd < 0))
			return fd;
	}
	file = do_accept(req->file, file_flags, accept->addr, accept->addr_len,
			 accept->flags);
	if (IS_ERR(file)) {
		if (!fixed)
			put_unused_fd(fd);
		ret = PTR_ERR(file);
		if (ret == -EAGAIN && force_nonblock) {
			 
			if ((req->flags & IO_APOLL_MULTI_POLLED) ==
			    IO_APOLL_MULTI_POLLED)
				ret = 0;
			return ret;
		}
		if (ret == -ERESTARTSYS)
			ret = -EINTR;
		req_set_fail(req);
	} else if (!fixed) {
		fd_install(fd, file);
		ret = fd;
	} else {
		ret = io_fixed_fd_install(req, issue_flags, file,
						accept->file_slot);
	}

	if (!(req->flags & REQ_F_APOLL_MULTISHOT)) {
		__io_req_complete(req, issue_flags, ret, 0);
		return 0;
	}
	if (ret >= 0) {
		bool filled;

		spin_lock(&ctx->completion_lock);
		filled = io_fill_cqe_aux(ctx, req->cqe.user_data, ret,
					 IORING_CQE_F_MORE);
		io_commit_cqring(ctx);
		spin_unlock(&ctx->completion_lock);
		if (filled) {
			io_cqring_ev_posted(ctx);
			goto retry;
		}
		ret = -ECANCELED;
	}

	return ret;
}