Commit 2f9c9515 authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring/net: support bundles for recv 



If IORING_OP_RECV is used with provided buffers, the caller may also set
IORING_RECVSEND_BUNDLE to turn it into a multi-buffer recv. This grabs
buffers available and receives into them, posting a single completion for
all of it.

This can be used with multishot receive as well, or without it.

Now that both send and receive support bundles, add a feature flag for
it as well. If IORING_FEAT_RECVSEND_BUNDLE is set after registering the
ring, then the kernel supports bundles for recv and send.

Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent a05d1f62

include/uapi/linux/io_uring.h

+8 −7
Original line number Diff line number Diff line
@@ -352,13 +352,13 @@ enum io_uring_op { 
 *				IORING_NOTIF_USAGE_ZC_COPIED if data was copied

 *				(at least partially).

 *

 * IORING_RECVSEND_BUNDLE	Used with IOSQE_BUFFER_SELECT. If set, send will

 *				grab as many buffers from the buffer group ID

 *				given and send them all. The completion result

 *				will be the number of buffers send, with the

 *				starting buffer ID in cqe->flags as per usual

 *				for provided buffer usage. The buffers will be

 *				contigious from the starting buffer ID.

 * IORING_RECVSEND_BUNDLE	Used with IOSQE_BUFFER_SELECT. If set, send or

 *				recv will grab as many buffers from the buffer

 *				group ID given and send them all. The completion

 *				result 	will be the number of buffers send, with

 *				the starting buffer ID in cqe->flags as per

 *				usual for provided buffer usage. The buffers

 *				will be	contigious from the starting buffer ID.

 */

#define IORING_RECVSEND_POLL_FIRST	(1U << 0)

#define IORING_RECV_MULTISHOT		(1U << 1)
@@ -529,6 +529,7 @@ struct io_uring_params { 
#define IORING_FEAT_CQE_SKIP		(1U << 11)

#define IORING_FEAT_LINKED_FILE		(1U << 12)

#define IORING_FEAT_REG_REG_RING	(1U << 13)

#define IORING_FEAT_RECVSEND_BUNDLE	(1U << 14)



/*

 * io_uring_register(2) opcodes and arguments

io_uring/io_uring.c

+2 −1
Original line number Diff line number Diff line
@@ -3583,7 +3583,8 @@ static __cold int io_uring_create(unsigned entries, struct io_uring_params *p, 
			IORING_FEAT_POLL_32BITS | IORING_FEAT_SQPOLL_NONFIXED |

			IORING_FEAT_EXT_ARG | IORING_FEAT_NATIVE_WORKERS |

			IORING_FEAT_RSRC_TAGS | IORING_FEAT_CQE_SKIP |

			IORING_FEAT_LINKED_FILE | IORING_FEAT_REG_REG_RING;

			IORING_FEAT_LINKED_FILE | IORING_FEAT_REG_REG_RING |

			IORING_FEAT_RECVSEND_BUNDLE;



	if (copy_to_user(params, p, sizeof(*p))) {

		ret = -EFAULT;

io_uring/net.c

+95 −21
Original line number Diff line number Diff line
@@ -747,7 +747,8 @@ static int io_recvmsg_prep_setup(struct io_kiocb *req) 
	return ret;

}



#define RECVMSG_FLAGS (IORING_RECVSEND_POLL_FIRST | IORING_RECV_MULTISHOT)

#define RECVMSG_FLAGS (IORING_RECVSEND_POLL_FIRST | IORING_RECV_MULTISHOT | \

			IORING_RECVSEND_BUNDLE)



int io_recvmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)

{
@@ -761,21 +762,14 @@ int io_recvmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) 
	sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));

	sr->len = READ_ONCE(sqe->len);

	sr->flags = READ_ONCE(sqe->ioprio);

	if (sr->flags & ~(RECVMSG_FLAGS))

	if (sr->flags & ~RECVMSG_FLAGS)

		return -EINVAL;

	sr->msg_flags = READ_ONCE(sqe->msg_flags);

	if (sr->msg_flags & MSG_DONTWAIT)

		req->flags |= REQ_F_NOWAIT;

	if (sr->msg_flags & MSG_ERRQUEUE)

		req->flags |= REQ_F_CLEAR_POLLIN;

	if (sr->flags & IORING_RECV_MULTISHOT) {

		if (!(req->flags & REQ_F_BUFFER_SELECT))

			return -EINVAL;

		if (sr->msg_flags & MSG_WAITALL)

			return -EINVAL;

		if (req->opcode == IORING_OP_RECV && sr->len)

			return -EINVAL;

		req->flags |= REQ_F_APOLL_MULTISHOT;

	if (req->flags & REQ_F_BUFFER_SELECT) {

		/*

		 * Store the buffer group for this multishot receive separately,

		 * as if we end up doing an io-wq based issue that selects a
@@ -785,6 +779,20 @@ int io_recvmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) 
		 * restore it.

		 */

		sr->buf_group = req->buf_index;

		req->buf_list = NULL;

	}

	if (sr->flags & IORING_RECV_MULTISHOT) {

		if (!(req->flags & REQ_F_BUFFER_SELECT))

			return -EINVAL;

		if (sr->msg_flags & MSG_WAITALL)

			return -EINVAL;

		if (req->opcode == IORING_OP_RECV && sr->len)

			return -EINVAL;

		req->flags |= REQ_F_APOLL_MULTISHOT;

	}

	if (sr->flags & IORING_RECVSEND_BUNDLE) {

		if (req->opcode == IORING_OP_RECVMSG)

			return -EINVAL;

	}



#ifdef CONFIG_COMPAT
@@ -805,19 +813,28 @@ static inline bool io_recv_finish(struct io_kiocb *req, int *ret, 
				  struct io_async_msghdr *kmsg,

				  bool mshot_finished, unsigned issue_flags)

{

	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);

	unsigned int cflags;



	if (sr->flags & IORING_RECVSEND_BUNDLE)

		cflags = io_put_kbufs(req, io_bundle_nbufs(kmsg, *ret),

				      issue_flags);

	else

		cflags = io_put_kbuf(req, issue_flags);



	if (kmsg->msg.msg_inq > 0)

		cflags |= IORING_CQE_F_SOCK_NONEMPTY;



	/* bundle with no more immediate buffers, we're done */

	if (sr->flags & IORING_RECVSEND_BUNDLE && req->flags & REQ_F_BL_EMPTY)

		goto finish;



	/*

	 * Fill CQE for this receive and see if we should keep trying to

	 * receive from this socket.

	 */

	if ((req->flags & REQ_F_APOLL_MULTISHOT) && !mshot_finished &&

	    io_req_post_cqe(req, *ret, cflags | IORING_CQE_F_MORE)) {

		struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);

		int mshot_retry_ret = IOU_ISSUE_SKIP_COMPLETE;



		io_mshot_prep_retry(req, kmsg);
@@ -837,6 +854,7 @@ static inline bool io_recv_finish(struct io_kiocb *req, int *ret, 
	}



	/* Finish the request / stop multishot. */

finish:

	io_req_set_res(req, *ret, cflags);



	if (issue_flags & IO_URING_F_MULTISHOT)
@@ -1020,6 +1038,69 @@ int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags) 
	return ret;

}



static int io_recv_buf_select(struct io_kiocb *req, struct io_async_msghdr *kmsg,

			      size_t *len, unsigned int issue_flags)

{

	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);

	int ret;



	/*

	 * If the ring isn't locked, then don't use the peek interface

	 * to grab multiple buffers as we will lock/unlock between

	 * this selection and posting the buffers.

	 */

	if (!(issue_flags & IO_URING_F_UNLOCKED) &&

	    sr->flags & IORING_RECVSEND_BUNDLE) {

		struct buf_sel_arg arg = {

			.iovs = &kmsg->fast_iov,

			.nr_iovs = 1,

			.mode = KBUF_MODE_EXPAND,

		};



		if (kmsg->free_iov) {

			arg.nr_iovs = kmsg->free_iov_nr;

			arg.iovs = kmsg->free_iov;

			arg.mode |= KBUF_MODE_FREE;

		}



		if (kmsg->msg.msg_inq > 0)

			arg.max_len = min_not_zero(sr->len, kmsg->msg.msg_inq);



		ret = io_buffers_peek(req, &arg);

		if (unlikely(ret < 0))

			return ret;



		/* special case 1 vec, can be a fast path */

		if (ret == 1) {

			sr->buf = arg.iovs[0].iov_base;

			sr->len = arg.iovs[0].iov_len;

			goto map_ubuf;

		}

		iov_iter_init(&kmsg->msg.msg_iter, ITER_DEST, arg.iovs, ret,

				arg.out_len);

		if (arg.iovs != &kmsg->fast_iov && arg.iovs != kmsg->free_iov) {

			kmsg->free_iov_nr = ret;

			kmsg->free_iov = arg.iovs;

		}

	} else {

		void __user *buf;



		*len = sr->len;

		buf = io_buffer_select(req, len, issue_flags);

		if (!buf)

			return -ENOBUFS;

		sr->buf = buf;

		sr->len = *len;

map_ubuf:

		ret = import_ubuf(ITER_DEST, sr->buf, sr->len,

				  &kmsg->msg.msg_iter);

		if (unlikely(ret))

			return ret;

	}



	return 0;

}



int io_recv(struct io_kiocb *req, unsigned int issue_flags)

{

	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
@@ -1044,17 +1125,10 @@ int io_recv(struct io_kiocb *req, unsigned int issue_flags) 


retry_multishot:

	if (io_do_buffer_select(req)) {

		void __user *buf;



		buf = io_buffer_select(req, &len, issue_flags);

		if (!buf)

			return -ENOBUFS;

		sr->buf = buf;

		sr->len = len;

		ret = import_ubuf(ITER_DEST, sr->buf, sr->len,

				  &kmsg->msg.msg_iter);

		ret = io_recv_buf_select(req, kmsg, &len, issue_flags);

		if (unlikely(ret))

			goto out_free;

		sr->buf = NULL;

	}



	kmsg->msg.msg_inq = -1;