tcp: Do not tack on TSO data to non-TSO packet

If a socket starts out on a non-TSO route, and then switches to
a TSO route, then we will tack on data to the tail of the tx queue
even if it started out life as non-TSO.  This is suboptimal because
all of it will then be copied and checksummed unnecessarily.

This patch fixes this by ensuring that skb->ip_summed is set to
CHECKSUM_PARTIAL before appending extra data beyond the MSS.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Herbert Xu 2009-06-28 18:06:41 +00:00 committed by David S. Miller
parent 8e5b9dda99
commit 6828b92bd2

View file

@ -903,13 +903,17 @@ int tcp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
iov++;
while (seglen > 0) {
int copy;
int copy = 0;
int max = size_goal;
skb = tcp_write_queue_tail(sk);
if (tcp_send_head(sk)) {
if (skb->ip_summed == CHECKSUM_NONE)
max = mss_now;
copy = max - skb->len;
}
if (!tcp_send_head(sk) ||
(copy = size_goal - skb->len) <= 0) {
if (copy <= 0) {
new_segment:
/* Allocate new segment. If the interface is SG,
* allocate skb fitting to single page.
@ -930,6 +934,7 @@ int tcp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
skb_entail(sk, skb);
copy = size_goal;
max = size_goal;
}
/* Try to append data to the end of skb. */
@ -1028,7 +1033,7 @@ int tcp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
if ((seglen -= copy) == 0 && iovlen == 0)
goto out;
if (skb->len < size_goal || (flags & MSG_OOB))
if (skb->len < max || (flags & MSG_OOB))
continue;
if (forced_push(tp)) {