[TCP]: Remove TCPCB_URG & TCPCB_AT_TAIL as unnecessary

The snd_up check should be enough. I suspect this has been
there to provide a minor optimization in clean_rtx_queue which
used to have a small if (!->sacked) block which could skip
snd_up check among the other work.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 4 insertions, 7 deletions

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 2cbfa6df7976..34085e3a4096 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -497,7 +497,6 @@ static inline void tcp_mark_urg(struct tcp_sock *tp, int flags,
         if (flags & MSG_OOB) {
                 tp->urg_mode = 1;
                 tp->snd_up = tp->write_seq;
-                TCP_SKB_CB(skb)->sacked |= TCPCB_URG;
         }
 }
 
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 7bac1fac065f..1e7fd8113663 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -2821,8 +2821,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets)
                 if (sacked & TCPCB_LOST)
                         tp->lost_out -= acked_pcount;
 
-                if (unlikely((sacked & TCPCB_URG) && tp->urg_mode &&
-                             !before(end_seq, tp->snd_up)))
+                if (unlikely(tp->urg_mode && !before(end_seq, tp->snd_up)))
                         tp->urg_mode = 0;
 
                 tp->packets_out -= acked_pcount;
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 821fae271428..cd21528665f3 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -711,7 +711,6 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, unsigned int mss
         TCP_SKB_CB(skb)->flags = flags & ~(TCPCB_FLAG_FIN|TCPCB_FLAG_PSH);
         TCP_SKB_CB(buff)->flags = flags;
         TCP_SKB_CB(buff)->sacked = TCP_SKB_CB(skb)->sacked;
-        TCP_SKB_CB(skb)->sacked &= ~TCPCB_AT_TAIL;
 
         if (!skb_shinfo(skb)->nr_frags && skb->ip_summed != CHECKSUM_PARTIAL) {
                 /* Copy and checksum data tail into the new buffer. */
@@ -1726,7 +1725,7 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *skb, int m
                 /* All done, get rid of second SKB and account for it so
                  * packet counting does not break.
                  */
-                TCP_SKB_CB(skb)->sacked |= TCP_SKB_CB(next_skb)->sacked&(TCPCB_EVER_RETRANS|TCPCB_AT_TAIL);
+                TCP_SKB_CB(skb)->sacked |= TCP_SKB_CB(next_skb)->sacked & TCPCB_EVER_RETRANS;
                 if (TCP_SKB_CB(next_skb)->sacked&TCPCB_SACKED_RETRANS)
                         tp->retrans_out -= tcp_skb_pcount(next_skb);
                 if (TCP_SKB_CB(next_skb)->sacked&TCPCB_LOST)
@@ -2475,7 +2474,7 @@ static int tcp_xmit_probe_skb(struct sock *sk, int urgent)
         skb_reserve(skb, MAX_TCP_HEADER);
         skb->csum = 0;
         TCP_SKB_CB(skb)->flags = TCPCB_FLAG_ACK;
-        TCP_SKB_CB(skb)->sacked = urgent;
+        TCP_SKB_CB(skb)->sacked = 0;
         skb_shinfo(skb)->gso_segs = 1;
         skb_shinfo(skb)->gso_size = 0;
         skb_shinfo(skb)->gso_type = 0;
@@ -2527,7 +2526,7 @@ int tcp_write_wakeup(struct sock *sk)
                 } else {
                         if (tp->urg_mode &&
                             between(tp->snd_up, tp->snd_una+1, tp->snd_una+0xFFFF))
-                                tcp_xmit_probe_skb(sk, TCPCB_URG);
+                                tcp_xmit_probe_skb(sk, 1);
                         return tcp_xmit_probe_skb(sk, 0);
                 }
         }