net: Add and use skb_copy_datagram_msg() helper.

This encapsulates all of the skb_copy_datagram_iovec() callers
with call argument signature "skb, offset, msghdr->msg_iov, length".

When we move to iov_iters in the networking, the iov_iter object will
sit in the msghdr.

Having a helper like this means there will be less places to touch
during that transformation.

Based upon descriptions and patch from Al Viro.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 3 deletions

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 39ec0c379545..c239f4740d10 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1377,7 +1377,7 @@ static int tcp_peek_sndq(struct sock *sk, struct msghdr *msg, int len)
         /* XXX -- need to support SO_PEEK_OFF */
 
         skb_queue_walk(&sk->sk_write_queue, skb) {
-                err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, skb->len);
+                err = skb_copy_datagram_msg(skb, 0, msg, skb->len);
                 if (err)
                         break;
 
@@ -1833,8 +1833,7 @@ do_prequeue:
                 }
 
                 if (!(flags & MSG_TRUNC)) {
-                        err = skb_copy_datagram_iovec(skb, offset,
-                                                      msg->msg_iov, used);
+                        err = skb_copy_datagram_msg(skb, offset, msg, used);
                         if (err) {
                                 /* Exception. Bailout! */
                                 if (!copied)