[TCP] mtu probing: move tcp-specific data out of inet_connection_sock

This moves some TCP-specific MTU probing state out of
inet_connection_sock back to tcp_sock.

Signed-off-by: John Heffner <jheffner@psc.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 10 insertions, 6 deletions

diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index f2bb2396853f..542d39596bd8 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -343,6 +343,12 @@ struct tcp_sock {
                 __u32   seq;
                 __u32   time;
         } rcvq_space;
+
+/* TCP-specific MTU probe information. */
+        struct {
+                __u32             probe_seq_start;
+                __u32             probe_seq_end;
+        } mtu_probe;
 };
 
 static inline struct tcp_sock *tcp_sk(const struct sock *sk)
diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h
index b3abe33f4e5f..4e5a9ff99fc3 100644
--- a/include/net/inet_connection_sock.h
+++ b/include/net/inet_connection_sock.h
@@ -114,8 +114,6 @@ struct inet_connection_sock {
 
                 /* Information on the current probe. */
                 int               probe_size;
-                __u32             probe_seq_start;
-                __u32             probe_seq_end;
         } icsk_mtup;
         u32                       icsk_ca_priv[16];
 #define ICSK_CA_PRIV_SIZE       (16 * sizeof(u32))
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 0ac388e3d01d..195d83584558 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -2054,7 +2054,7 @@ tcp_fastretrans_alert(struct sock *sk, u32 prior_snd_una,
                 /* MTU probe failure: don't reduce cwnd */
                 if (icsk->icsk_ca_state < TCP_CA_CWR &&
                     icsk->icsk_mtup.probe_size &&
-                    tp->snd_una == icsk->icsk_mtup.probe_seq_start) {
+                    tp->snd_una == tp->mtu_probe.probe_seq_start) {
                         tcp_mtup_probe_failed(sk);
                         /* Restores the reduction we did in tcp_mtup_probe() */
                         tp->snd_cwnd++;
@@ -2284,7 +2284,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p)
 
                 /* MTU probing checks */
                 if (icsk->icsk_mtup.probe_size) {
-                        if (!after(icsk->icsk_mtup.probe_seq_end, TCP_SKB_CB(skb)->end_seq)) {
+                        if (!after(tp->mtu_probe.probe_seq_end, TCP_SKB_CB(skb)->end_seq)) {
                                 tcp_mtup_probe_success(sk, skb);
                         }
                 }
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 8197b5e12f1f..518e568b53f3 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1238,8 +1238,8 @@ static int tcp_mtu_probe(struct sock *sk)
                 update_send_head(sk, tp, nskb);
 
                 icsk->icsk_mtup.probe_size = tcp_mss_to_mtu(sk, nskb->len);
-                icsk->icsk_mtup.probe_seq_start = TCP_SKB_CB(nskb)->seq;
-                icsk->icsk_mtup.probe_seq_end = TCP_SKB_CB(nskb)->end_seq;
+                tp->mtu_probe.probe_seq_start = TCP_SKB_CB(nskb)->seq;
+                tp->mtu_probe.probe_seq_end = TCP_SKB_CB(nskb)->end_seq;
 
                 return 1;
         }