Re: [PATCH 06/17] switch macvtap to ->read_iter()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 drivers/net/macvtap.c |   39 ++++++++++++++++-----------------------
 1 file changed, 16 insertions(+), 23 deletions(-)

diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index cea99d4..cdd820f 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c

@@ -829,16 +829,17 @@ done:
 }
 
 static ssize_t macvtap_do_read(struct macvtap_queue *q,
-			       const struct iovec *iv, unsigned long segs,
-			       unsigned long len,
+			       struct iov_iter *to,
 			       int noblock)
 {
 	DEFINE_WAIT(wait);
 	struct sk_buff *skb;
 	ssize_t ret = 0;
-	struct iov_iter iter;
 
-	while (len) {
+	if (!iov_iter_count(to))
+		return 0;
+
+	while (1) {
 		if (!noblock)
 			prepare_to_wait(sk_sleep(&q->sk), &wait,
 					TASK_INTERRUPTIBLE);

@@ -856,37 +857,27 @@ static ssize_t macvtap_do_read(struct macvtap_queue *q,
 			}
 			/* Nothing to read, let's sleep */
 			schedule();
-			continue;
 		}
-		iov_iter_init(&iter, READ, iv, segs, len);
-		ret = macvtap_put_user(q, skb, &iter);
+	}
+	if (skb) {
+		ret = macvtap_put_user(q, skb, to);
 		kfree_skb(skb);
-		break;