diff options
| author | Eric Dumazet <edumazet@google.com> | 2023-03-17 15:55:39 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2023-03-18 12:23:34 +0000 |
| commit | e9d9da91548b21e189fcd0259a0f2d26d1afc509 (patch) | |
| tree | fd943e26281cfd7a7e0948d1949d6e0009c19510 /net/ipv4/tcp_output.c | |
| parent | 403a40f2304d4730a780ab9d6a2b93d1e4ac39d2 (diff) | |
| download | lwn-e9d9da91548b21e189fcd0259a0f2d26d1afc509.tar.gz lwn-e9d9da91548b21e189fcd0259a0f2d26d1afc509.zip | |
tcp: preserve const qualifier in tcp_sk()
We can change tcp_sk() to propagate its argument const qualifier,
thanks to container_of_const().
We have two places where a const sock pointer has to be upgraded
to a write one. We have been using const qualifier for lockless
listeners to clearly identify points where writes could happen.
Add tcp_sk_rw() helper to better document these.
tcp_inbound_md5_hash(), __tcp_grow_window(), tcp_reset_check()
and tcp_rack_reo_wnd() get an additional const qualififer
for their @tp local variables.
smc_check_reset_syn_req() also needs a similar change.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_output.c')
| -rw-r--r-- | net/ipv4/tcp_output.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index b1e743b39a83..cfe128b81a01 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -4127,8 +4127,13 @@ int tcp_rtx_synack(const struct sock *sk, struct request_sock *req) if (!res) { TCP_INC_STATS(sock_net(sk), TCP_MIB_RETRANSSEGS); NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPSYNRETRANS); - if (unlikely(tcp_passive_fastopen(sk))) - tcp_sk(sk)->total_retrans++; + if (unlikely(tcp_passive_fastopen(sk))) { + /* sk has const attribute because listeners are lockless. + * However in this case, we are dealing with a passive fastopen + * socket thus we can change total_retrans value. + */ + tcp_sk_rw(sk)->total_retrans++; + } trace_tcp_retransmit_synack(sk, req); } return res; |