iov_iter: add iter_iov_addr() and iter_iov_len() helpers

These just return the address and length of the current iovec segment
in the iterator. Convert existing iov_iter_iovec() users to use them
instead of getting a copy of the current vec.

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

1 files changed, 13 insertions, 14 deletions

diff --git a/io_uring/rw.c b/io_uring/rw.c
index 7573a34ea42a..f33ba6f28247 100644
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -447,26 +447,25 @@ static ssize_t loop_rw_iter(int ddir, struct io_rw *rw, struct iov_iter *iter)
 	ppos = io_kiocb_ppos(kiocb);
 
 	while (iov_iter_count(iter)) {
-		struct iovec iovec;
+		void __user *addr;
+		size_t len;
 		ssize_t nr;
 
 		if (iter_is_ubuf(iter)) {
-			iovec.iov_base = iter->ubuf + iter->iov_offset;
-			iovec.iov_len = iov_iter_count(iter);
+			addr = iter->ubuf + iter->iov_offset;
+			len = iov_iter_count(iter);
 		} else if (!iov_iter_is_bvec(iter)) {
-			iovec = iov_iter_iovec(iter);
+			addr = iter_iov_addr(iter);
+			len = iter_iov_len(iter);
 		} else {
-			iovec.iov_base = u64_to_user_ptr(rw->addr);
-			iovec.iov_len = rw->len;
+			addr = u64_to_user_ptr(rw->addr);
+			len = rw->len;
 		}
 
-		if (ddir == READ) {
-			nr = file->f_op->read(file, iovec.iov_base,
-					      iovec.iov_len, ppos);
-		} else {
-			nr = file->f_op->write(file, iovec.iov_base,
-					       iovec.iov_len, ppos);
-		}
+		if (ddir == READ)
+			nr = file->f_op->read(file, addr, len, ppos);
+		else
+			nr = file->f_op->write(file, addr, len, ppos);
 
 		if (nr < 0) {
 			if (!ret)
@@ -482,7 +481,7 @@ static ssize_t loop_rw_iter(int ddir, struct io_rw *rw, struct iov_iter *iter)
 			if (!rw->len)
 				break;
 		}
-		if (nr != iovec.iov_len)
+		if (nr != len)
 			break;
 	}