From: Jens Axboe <axboe@kernel.dk>
Date: Thu, 5 Jan 2023 19:07:32 +0000 (-0800)
Subject: io_uring: use iter_ubuf for single range imports
X-Git-Tag: v6.6.7~3536^2~2
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=1e23db450cff5f0410480137041181d1514bda2a;p=platform%2Fkernel%2Flinux-starfive.git

io_uring: use iter_ubuf for single range imports

This is more efficient than iter_iov.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
[merge to 6.2, minor fixes]
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---

diff --git a/io_uring/rw.c b/io_uring/rw.c
index 8227af2..436a2e0 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;