io_uring: switch network send/recv to ITER_UBUF

This is more efficient than iter_iov.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
[merged to 6.2]
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

io_uring/net.c

@@ -181,7 +181,7 @@ static int io_setup_async_msg(struct io_kiocb *req,
 	if (async_msg->msg.msg_name)
 		async_msg->msg.msg_name = &async_msg->addr;
 	/* if were using fast_iov, set it to the new one */
-	if (!kmsg->free_iov) {
+	if (iter_is_iovec(&kmsg->msg.msg_iter) && !kmsg->free_iov) {
 		size_t fast_idx = kmsg->msg.msg_iter.iov - kmsg->fast_iov;
 		async_msg->msg.msg_iter.iov = &async_msg->fast_iov[fast_idx];
 	}
@@ -344,7 +344,6 @@ int io_send(struct io_kiocb *req, unsigned int issue_flags)
 	struct sockaddr_storage __address;
 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
 	struct msghdr msg;
-	struct iovec iov;
 	struct socket *sock;
 	unsigned flags;
 	int min_ret = 0;
@@ -378,7 +377,7 @@ int io_send(struct io_kiocb *req, unsigned int issue_flags)
 	if (unlikely(!sock))
 		return -ENOTSOCK;
 
-	ret = import_single_range(ITER_SOURCE, sr->buf, sr->len, &iov, &msg.msg_iter);
+	ret = import_ubuf(ITER_SOURCE, sr->buf, sr->len, &msg.msg_iter);
 	if (unlikely(ret))
 		return ret;
 
@@ -764,10 +763,7 @@ int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags)
 			}
 		}
 
-		kmsg->fast_iov[0].iov_base = buf;
-		kmsg->fast_iov[0].iov_len = len;
-		iov_iter_init(&kmsg->msg.msg_iter, ITER_DEST, kmsg->fast_iov, 1,
-				len);
+		iov_iter_ubuf(&kmsg->msg.msg_iter, ITER_DEST, buf, len);
 	}
 
 	flags = sr->msg_flags;
@@ -835,7 +831,6 @@ 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);
 	struct msghdr msg;
 	struct socket *sock;
-	struct iovec iov;
 	unsigned int cflags;
 	unsigned flags;
 	int ret, min_ret = 0;
@@ -863,7 +858,7 @@ int io_recv(struct io_kiocb *req, unsigned int issue_flags)
 		sr->buf = buf;
 	}
 
-	ret = import_single_range(ITER_DEST, sr->buf, len, &iov, &msg.msg_iter);
+	ret = import_ubuf(ITER_DEST, sr->buf, len, &msg.msg_iter);
 	if (unlikely(ret))
 		goto out_free;
 
@@ -1074,7 +1069,6 @@ int io_send_zc(struct io_kiocb *req, unsigned int issue_flags)
 	struct sockaddr_storage __address;
 	struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg);
 	struct msghdr msg;
-	struct iovec iov;
 	struct socket *sock;
 	unsigned msg_flags;
 	int ret, min_ret = 0;
@@ -1116,8 +1110,7 @@ int io_send_zc(struct io_kiocb *req, unsigned int issue_flags)
 		msg.sg_from_iter = io_sg_from_iter;
 	} else {
 		io_notif_set_extended(zc->notif);
-		ret = import_single_range(ITER_SOURCE, zc->buf, zc->len, &iov,
-					  &msg.msg_iter);
+		ret = import_ubuf(ITER_SOURCE, zc->buf, zc->len, &msg.msg_iter);
 		if (unlikely(ret))
 			return ret;
 		ret = io_notif_account_mem(zc->notif, zc->len);