From b4a24397139cd943c8fa057c372f8a019e07168d Mon Sep 17 00:00:00 2001
From: Eric Dumazet <edumazet@google.com>
Date: Fri, 9 Jun 2023 20:42:45 +0000
Subject: [PATCH] tcp: remove some dead code
Now all skbs in write queue do not contain any payload in skb->head,
we can remove some dead code.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/ipv4/tcp_output.c | 40 ++++++++++++----------------------------
1 file changed, 12 insertions(+), 28 deletions(-)
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index d039663373593..fedbe842abdd0 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1530,7 +1530,7 @@ int tcp_fragment(struct sock *sk, enum tcp_queue tcp_queue,
{
struct tcp_sock *tp = tcp_sk(sk);
struct sk_buff *buff;
- int nsize, old_factor;
+ int old_factor;
long limit;
int nlen;
u8 flags;
@@ -1538,9 +1538,7 @@ int tcp_fragment(struct sock *sk, enum tcp_queue tcp_queue,
if (WARN_ON(len > skb->len))
return -EINVAL;
- nsize = skb_headlen(skb) - len;
- if (nsize < 0)
- nsize = 0;
+ DEBUG_NET_WARN_ON_ONCE(skb_headlen(skb));
/* tcp_sendmsg() can overshoot sk_wmem_queued by one full size skb.
* We need some allowance to not penalize applications setting small
@@ -1560,7 +1558,7 @@ int tcp_fragment(struct sock *sk, enum tcp_queue tcp_queue,
return -ENOMEM;
/* Get a new skb... force flag on. */
- buff = tcp_stream_alloc_skb(sk, nsize, gfp, true);
+ buff = tcp_stream_alloc_skb(sk, 0, gfp, true);
if (!buff)
return -ENOMEM; /* We'll just try again later. */
skb_copy_decrypted(buff, skb);
@@ -1568,7 +1566,7 @@ int tcp_fragment(struct sock *sk, enum tcp_queue tcp_queue,
sk_wmem_queued_add(sk, buff->truesize);
sk_mem_charge(sk, buff->truesize);
- nlen = skb->len - len - nsize;
+ nlen = skb->len - len;
buff->truesize += nlen;
skb->truesize -= nlen;
@@ -1626,13 +1624,7 @@ static int __pskb_trim_head(struct sk_buff *skb, int len)
struct skb_shared_info *shinfo;
int i, k, eat;
- eat = min_t(int, len, skb_headlen(skb));
- if (eat) {
- __skb_pull(skb, eat);
- len -= eat;
- if (!len)
- return 0;
- }
+ DEBUG_NET_WARN_ON_ONCE(skb_headlen(skb));
eat = len;
k = 0;
shinfo = skb_shinfo(skb);
@@ -1671,12 +1663,10 @@ int tcp_trim_head(struct sock *sk, struct sk_buff *skb, u32 len)
TCP_SKB_CB(skb)->seq += len;
- if (delta_truesize) {
- skb->truesize -= delta_truesize;
- sk_wmem_queued_add(sk, -delta_truesize);
- if (!skb_zcopy_pure(skb))
- sk_mem_uncharge(sk, delta_truesize);
- }
+ skb->truesize -= delta_truesize;
+ sk_wmem_queued_add(sk, -delta_truesize);
+ if (!skb_zcopy_pure(skb))
+ sk_mem_uncharge(sk, delta_truesize);
/* Any change of skb->len requires recalculation of tso factor. */
if (tcp_skb_pcount(skb) > 1)
@@ -2126,9 +2116,7 @@ static int tso_fragment(struct sock *sk, struct sk_buff *skb, unsigned int len,
u8 flags;
/* All of a TSO frame must be composed of paged data. */
- if (skb->len != skb->data_len)
- return tcp_fragment(sk, TCP_FRAG_IN_WRITE_QUEUE,
- skb, len, mss_now, gfp);
+ DEBUG_NET_WARN_ON_ONCE(skb->len != skb->data_len);
buff = tcp_stream_alloc_skb(sk, 0, gfp, true);
if (unlikely(!buff))
@@ -2487,12 +2475,8 @@ static int tcp_mtu_probe(struct sock *sk)
} else {
TCP_SKB_CB(nskb)->tcp_flags |= TCP_SKB_CB(skb)->tcp_flags &
~(TCPHDR_FIN|TCPHDR_PSH);
- if (!skb_shinfo(skb)->nr_frags) {
- skb_pull(skb, copy);
- } else {
- __pskb_trim_head(skb, copy);
- tcp_set_skb_tso_segs(skb, mss_now);
- }
+ __pskb_trim_head(skb, copy);
+ tcp_set_skb_tso_segs(skb, mss_now);
TCP_SKB_CB(skb)->seq += copy;
}
--
2.30.2