tcp: remove dead code after CHECKSUM_PARTIAL adoption

Since all skbs in write/rtx queues have CHECKSUM_PARTIAL,
we can remove dead code.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 5 insertions, 33 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 0196923aec42..8795d76f987c 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1335,21 +1335,9 @@ int tcp_fragment(struct sock *sk, enum tcp_queue tcp_queue,
         TCP_SKB_CB(buff)->sacked = TCP_SKB_CB(skb)->sacked;
         tcp_skb_fragment_eor(skb, buff);
 
-        if (!skb_shinfo(skb)->nr_frags && skb->ip_summed != CHECKSUM_PARTIAL) {
-                /* Copy and checksum data tail into the new buffer. */
-                buff->csum = csum_partial_copy_nocheck(skb->data + len,
-                                                       skb_put(buff, nsize),
-                                                       nsize, 0);
-
-                skb_trim(skb, len);
-
-                skb->csum = csum_block_sub(skb->csum, buff->csum, len);
-        } else {
-                skb->ip_summed = CHECKSUM_PARTIAL;
-                skb_split(skb, buff, len);
-        }
+        skb_split(skb, buff, len);
 
-        buff->ip_summed = skb->ip_summed;
+        buff->ip_summed = CHECKSUM_PARTIAL;
 
         buff->tstamp = skb->tstamp;
         tcp_fragment_tstamp(skb, buff);
@@ -1901,7 +1889,7 @@ static int tso_fragment(struct sock *sk, enum tcp_queue tcp_queue,
 
         tcp_skb_fragment_eor(skb, buff);
 
-        buff->ip_summed = skb->ip_summed = CHECKSUM_PARTIAL;
+        buff->ip_summed = CHECKSUM_PARTIAL;
         skb_split(skb, buff, len);
         tcp_fragment_tstamp(skb, buff);
 
@@ -2134,7 +2122,7 @@ static int tcp_mtu_probe(struct sock *sk)
         TCP_SKB_CB(nskb)->tcp_flags = TCPHDR_ACK;
         TCP_SKB_CB(nskb)->sacked = 0;
         nskb->csum = 0;
-        nskb->ip_summed = skb->ip_summed;
+        nskb->ip_summed = CHECKSUM_PARTIAL;
 
         tcp_insert_write_queue_before(nskb, skb, sk);
         tcp_highest_sack_replace(sk, skb, nskb);
@@ -2142,14 +2130,7 @@ static int tcp_mtu_probe(struct sock *sk)
         len = 0;
         tcp_for_write_queue_from_safe(skb, next, sk) {
                 copy = min_t(int, skb->len, probe_size - len);
-                if (nskb->ip_summed) {
-                        skb_copy_bits(skb, 0, skb_put(nskb, copy), copy);
-                } else {
-                        __wsum csum = skb_copy_and_csum_bits(skb, 0,
-                                                             skb_put(nskb, copy),
-                                                             copy, 0);
-                        nskb->csum = csum_block_add(nskb->csum, csum, len);
-                }
+                skb_copy_bits(skb, 0, skb_put(nskb, copy), copy);
 
                 if (skb->len <= copy) {
                         /* We've eaten all the data from this skb.
@@ -2166,9 +2147,6 @@ static int tcp_mtu_probe(struct sock *sk)
                                                    ~(TCPHDR_FIN|TCPHDR_PSH);
                         if (!skb_shinfo(skb)->nr_frags) {
                                 skb_pull(skb, copy);
-                                if (skb->ip_summed != CHECKSUM_PARTIAL)
-                                        skb->csum = csum_partial(skb->data,
-                                                                 skb->len, 0);
                         } else {
                                 __pskb_trim_head(skb, copy);
                                 tcp_set_skb_tso_segs(skb, mss_now);
@@ -2746,12 +2724,6 @@ static bool tcp_collapse_retrans(struct sock *sk, struct sk_buff *skb)
         }
         tcp_highest_sack_replace(sk, next_skb, skb);
 
-        if (next_skb->ip_summed == CHECKSUM_PARTIAL)
-                skb->ip_summed = CHECKSUM_PARTIAL;
-
-        if (skb->ip_summed != CHECKSUM_PARTIAL)
-                skb->csum = csum_block_add(skb->csum, next_skb->csum, skb_size);
-
         /* Update sequence range on original skb. */
         TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(next_skb)->end_seq;