From: Colin King <colin.king@canonical.com>
To: Eric Dumazet <edumazet@google.com>,
"David S . Miller" <davem@davemloft.net>,
Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
netdev@vger.kernel.org
Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] tcp: remove redundant check on tskb
Date: Thu, 4 Apr 2019 15:46:03 +0100 [thread overview]
Message-ID: <20190404144603.27682-1-colin.king@canonical.com> (raw)
From: Colin Ian King <colin.king@canonical.com>
The non-null check on tskb is always false because it is in an else
path of a check on tskb and hence tskb is null in this code block.
This is check is therefore redundant and can be removed as well
as the label coalesc.
if (tsbk) {
...
} else {
...
if (unlikely(!skb)) {
if (tskb) /* can never be true, redundant code */
goto coalesc;
return;
}
}
Addresses-Coverity: ("Logically dead code")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
net/ipv4/tcp_output.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index e265d1aeeb66..32061928b054 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -3088,7 +3088,6 @@ void tcp_send_fin(struct sock *sk)
tskb = skb_rb_last(&sk->tcp_rtx_queue);
if (tskb) {
-coalesce:
TCP_SKB_CB(tskb)->tcp_flags |= TCPHDR_FIN;
TCP_SKB_CB(tskb)->end_seq++;
tp->write_seq++;
@@ -3104,11 +3103,9 @@ void tcp_send_fin(struct sock *sk)
}
} else {
skb = alloc_skb_fclone(MAX_TCP_HEADER, sk->sk_allocation);
- if (unlikely(!skb)) {
- if (tskb)
- goto coalesce;
+ if (unlikely(!skb))
return;
- }
+
INIT_LIST_HEAD(&skb->tcp_tsorted_anchor);
skb_reserve(skb, MAX_TCP_HEADER);
sk_forced_mem_schedule(sk, skb->truesize);
--
2.20.1
next reply other threads:[~2019-04-04 14:46 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-04 14:46 Colin King [this message]
2019-04-04 15:05 ` [PATCH] tcp: remove redundant check on tskb Dan Carpenter
2019-04-05 6:47 ` Mukesh Ojha
2019-04-05 7:46 ` Eric Dumazet
2019-04-07 1:18 ` David Miller
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