Commit f548a12e authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring: return hint on whether more data is available after receive 



For now just use a CQE flag for this, with big CQE support we could
return the actual number of bytes left.

Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent a4c76853

fs/io_uring.c

+15 −4
Original line number Diff line number Diff line
@@ -5948,6 +5948,7 @@ static int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags) 
	struct io_sr_msg *sr = &req->sr_msg;

	struct socket *sock;

	struct io_buffer *kbuf;

	unsigned int cflags;

	unsigned flags;

	int ret, min_ret = 0;

	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
@@ -5981,6 +5982,8 @@ static int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags) 
	if (flags & MSG_WAITALL)

		min_ret = iov_iter_count(&kmsg->msg.msg_iter);



	kmsg->msg.msg_get_inq = 1;



	ret = __sys_recvmsg_sock(sock, &kmsg->msg, req->sr_msg.umsg,

					kmsg->uaddr, flags);

	if (ret < min_ret) {
@@ -6006,7 +6009,10 @@ static int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags) 
		ret += sr->done_io;

	else if (sr->done_io)

		ret = sr->done_io;

	__io_req_complete(req, issue_flags, ret, io_put_kbuf(req, issue_flags));

	cflags = io_put_kbuf(req, issue_flags);

	if (kmsg->msg.msg_inq)

		cflags |= IORING_CQE_F_SOCK_NONEMPTY;

	__io_req_complete(req, issue_flags, ret, cflags);

	return 0;

}
@@ -6018,6 +6024,7 @@ static int io_recv(struct io_kiocb *req, unsigned int issue_flags) 
	void __user *buf = sr->buf;

	struct socket *sock;

	struct iovec iov;

	unsigned int cflags;

	unsigned flags;

	int ret, min_ret = 0;

	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
@@ -6038,11 +6045,12 @@ static int io_recv(struct io_kiocb *req, unsigned int issue_flags) 
		goto out_free;



	msg.msg_name = NULL;

	msg.msg_namelen = 0;

	msg.msg_control = NULL;

	msg.msg_get_inq = 1;

	msg.msg_flags = 0;

	msg.msg_controllen = 0;

	msg.msg_namelen = 0;

	msg.msg_iocb = NULL;

	msg.msg_flags = 0;



	flags = req->sr_msg.msg_flags;

	if (force_nonblock)
@@ -6073,7 +6081,10 @@ static int io_recv(struct io_kiocb *req, unsigned int issue_flags) 
		ret += sr->done_io;

	else if (sr->done_io)

		ret = sr->done_io;

	__io_req_complete(req, issue_flags, ret, io_put_kbuf(req, issue_flags));

	cflags = io_put_kbuf(req, issue_flags);

	if (msg.msg_inq)

		cflags |= IORING_CQE_F_SOCK_NONEMPTY;

	__io_req_complete(req, issue_flags, ret, cflags);

	return 0;

}

include/uapi/linux/io_uring.h

+2 −0
Original line number Diff line number Diff line
@@ -220,9 +220,11 @@ struct io_uring_cqe { 
 *

 * IORING_CQE_F_BUFFER	If set, the upper 16 bits are the buffer ID

 * IORING_CQE_F_MORE	If set, parent SQE will generate more CQE entries

 * IORING_CQE_F_SOCK_NONEMPTY	If set, more data to read after socket recv

 */

#define IORING_CQE_F_BUFFER		(1U << 0)

#define IORING_CQE_F_MORE		(1U << 1)

#define IORING_CQE_F_SOCK_NONEMPTY	(1U << 2)



enum {

	IORING_CQE_BUFFER_SHIFT		= 16,