From: Jens Axboe <axboe@kernel.dk>
Date: Mon, 23 May 2022 02:05:39 +0000 (-0600)
Subject: io_uring: use ubuf for single range imports for read/write
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=refs%2Fheads%2Fio_uring-iter;p=linux-2.6-block.git

io_uring: use ubuf for single range imports for read/write

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/io_uring/rw.c b/io_uring/rw.c
index 1babd77da79c..0881e0ca0db0 100644
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -377,7 +377,7 @@ 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;
@@ -388,7 +388,7 @@ static struct iovec *__io_import_iovec(int ddir, struct io_kiocb *req,
 		ret = io_iov_buffer_select(req, iovec, issue_flags);
 		if (ret)
 			return ERR_PTR(ret);
-		iov_iter_init(iter, ddir, iovec, 1, iovec->iov_len);
+		iov_iter_ubuf(iter, ddir, iovec[0].iov_base, iovec[0].iov_len);
 		return NULL;
 	}
 
@@ -444,7 +444,10 @@ 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 = iter->count - iter->iov_offset;
+		} else if (!iov_iter_is_bvec(iter)) {
 			iovec = iov_iter_iovec(iter);
 		} else {
 			iovec.iov_base = u64_to_user_ptr(rw->addr);
@@ -465,7 +468,7 @@ static ssize_t loop_rw_iter(int ddir, struct io_rw *rw, struct iov_iter *iter)
 			break;
 		}
 		ret += nr;
-		if (!iov_iter_is_bvec(iter)) {
+		if (iter_is_ubuf(iter) || !iov_iter_is_bvec(iter)) {
 			iov_iter_advance(iter, nr);
 		} else {
 			rw->addr += nr;
@@ -489,7 +492,7 @@ 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;