ip: convert tcp_sendmsg() to iov_iter primitives
patch is actually smaller than it seems to be - most of it is unindenting
the inner loop body in tcp_sendmsg() itself...
the bit in tcp_input.c is going to get reverted very soon - that's what
memcpy_from_msg() will become, but not in this commit; let's keep it
reasonably contained...
There's one potentially subtle change here: in case of short copy from
userland, mainline tcp_send_syn_data() discards the skb it has allocated
and falls back to normal path, where we'll send as much as possible after
rereading the same data again. This patch trims SYN+data skb instead -
that way we don't need to copy from the same place twice.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 20ab06b..722c8bc 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -3055,7 +3055,7 @@
{
struct tcp_sock *tp = tcp_sk(sk);
struct tcp_fastopen_request *fo = tp->fastopen_req;
- int syn_loss = 0, space, err = 0;
+ int syn_loss = 0, space, err = 0, copied;
unsigned long last_syn_loss = 0;
struct sk_buff *syn_data;
@@ -3093,11 +3093,16 @@
goto fallback;
syn_data->ip_summed = CHECKSUM_PARTIAL;
memcpy(syn_data->cb, syn->cb, sizeof(syn->cb));
- if (unlikely(memcpy_fromiovecend(skb_put(syn_data, space),
- fo->data->msg_iter.iov, 0, space))) {
+ copied = copy_from_iter(skb_put(syn_data, space), space,
+ &fo->data->msg_iter);
+ if (unlikely(!copied)) {
kfree_skb(syn_data);
goto fallback;
}
+ if (copied != space) {
+ skb_trim(syn_data, copied);
+ space = copied;
+ }
/* No more data pending in inet_wait_for_connect() */
if (space == fo->size)