Merge tag 'for-6.3/iter-ubuf-2023-02-16' of git://git.kernel.dk/linux

Pull io_uring ITER_UBUF conversion from Jens Axboe:
 "Since we now have ITER_UBUF available, switch to using it for single
  ranges as it's more efficient than ITER_IOVEC for that"

* tag 'for-6.3/iter-ubuf-2023-02-16' of git://git.kernel.dk/linux:
  block: use iter_ubuf for single range
  iov_iter: move iter_ubuf check inside restore WARN
  io_uring: use iter_ubuf for single range imports
  io_uring: switch network send/recv to ITER_UBUF
  iov: add import_ubuf()

2 files changed, 11 insertions, 15 deletions

diff --git a/io_uring/net.c b/io_uring/net.c
index aeb1d016e2e9..cbd4b725f58c 100644
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -182,7 +182,7 @@ 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];
 	}
@@ -345,7 +345,6 @@ 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;
@@ -379,7 +378,7 @@ 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;
 
@@ -775,10 +774,7 @@ retry_multishot:
 			}
 		}
 
-		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;
@@ -846,7 +842,6 @@ 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;
@@ -874,7 +869,7 @@ retry_multishot:
 		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;
 
@@ -1085,7 +1080,6 @@ 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;
@@ -1127,8 +1121,7 @@ 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);
diff --git a/io_uring/rw.c b/io_uring/rw.c
index efe6bfda9ca9..4c233910e200 100644
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -391,7 +391,7 @@ static struct iovec *__io_import_iovec(int ddir, struct io_kiocb *req,
 			rw->len = sqe_len;
 		}
 
-		ret = import_single_range(ddir, buf, sqe_len, s->fast_iov, iter);
+		ret = import_ubuf(ddir, buf, sqe_len, iter);
 		if (ret)
 			return ERR_PTR(ret);
 		return NULL;
@@ -450,7 +450,10 @@ static ssize_t loop_rw_iter(int ddir, struct io_rw *rw, struct iov_iter *iter)
 		struct iovec iovec;
 		ssize_t nr;
 
-		if (!iov_iter_is_bvec(iter)) {
+		if (iter_is_ubuf(iter)) {
+			iovec.iov_base = iter->ubuf + iter->iov_offset;
+			iovec.iov_len = iov_iter_count(iter);
+		} else if (!iov_iter_is_bvec(iter)) {
 			iovec = iov_iter_iovec(iter);
 		} else {
 			iovec.iov_base = u64_to_user_ptr(rw->addr);
@@ -495,7 +498,7 @@ static void io_req_map_rw(struct io_kiocb *req, const struct iovec *iovec,
 	io->free_iovec = iovec;
 	io->bytes_done = 0;
 	/* can only be fixed buffers, no need to do anything */
-	if (iov_iter_is_bvec(iter))
+	if (iov_iter_is_bvec(iter) || iter_is_ubuf(iter))
 		return;
 	if (!iovec) {
 		unsigned iov_off = 0;