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authorEric Dumazet <edumazet@google.com>2021-07-19 12:11:07 +0200
committerJakub Kicinski <kuba@kernel.org>2021-07-20 12:07:07 +0200
commite93abb840a2c356ed2809c31fcedb058601ac2e4 (patch)
treee52a6fb74dce8895a5314955875df8b9287f94f7 /net/ipv4/tcp_fastopen.c
parentnetlink: Deal with ESRCH error in nlmsg_notify() (diff)
downloadlinux-e93abb840a2c356ed2809c31fcedb058601ac2e4.tar.xz
linux-e93abb840a2c356ed2809c31fcedb058601ac2e4.zip
net/tcp_fastopen: remove tcp_fastopen_ctx_lock
Remove the (per netns) spinlock in favor of xchg() atomic operations. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Neal Cardwell <ncardwell@google.com> Acked-by: Wei Wang <weiwan@google.com> Link: https://lore.kernel.org/r/20210719101107.3203943-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/ipv4/tcp_fastopen.c')
-rw-r--r--net/ipv4/tcp_fastopen.c17
1 files changed, 3 insertions, 14 deletions
diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c
index 47c32604d38f..1a9fbd5448a7 100644
--- a/net/ipv4/tcp_fastopen.c
+++ b/net/ipv4/tcp_fastopen.c
@@ -55,12 +55,7 @@ void tcp_fastopen_ctx_destroy(struct net *net)
{
struct tcp_fastopen_context *ctxt;
- spin_lock(&net->ipv4.tcp_fastopen_ctx_lock);
-
- ctxt = rcu_dereference_protected(net->ipv4.tcp_fastopen_ctx,
- lockdep_is_held(&net->ipv4.tcp_fastopen_ctx_lock));
- rcu_assign_pointer(net->ipv4.tcp_fastopen_ctx, NULL);
- spin_unlock(&net->ipv4.tcp_fastopen_ctx_lock);
+ ctxt = xchg((__force struct tcp_fastopen_context **)&net->ipv4.tcp_fastopen_ctx, NULL);
if (ctxt)
call_rcu(&ctxt->rcu, tcp_fastopen_ctx_free);
@@ -89,18 +84,12 @@ int tcp_fastopen_reset_cipher(struct net *net, struct sock *sk,
ctx->num = 1;
}
- spin_lock(&net->ipv4.tcp_fastopen_ctx_lock);
if (sk) {
q = &inet_csk(sk)->icsk_accept_queue.fastopenq;
- octx = rcu_dereference_protected(q->ctx,
- lockdep_is_held(&net->ipv4.tcp_fastopen_ctx_lock));
- rcu_assign_pointer(q->ctx, ctx);
+ octx = xchg((__force struct tcp_fastopen_context **)&q->ctx, ctx);
} else {
- octx = rcu_dereference_protected(net->ipv4.tcp_fastopen_ctx,
- lockdep_is_held(&net->ipv4.tcp_fastopen_ctx_lock));
- rcu_assign_pointer(net->ipv4.tcp_fastopen_ctx, ctx);
+ octx = xchg((__force struct tcp_fastopen_context **)&net->ipv4.tcp_fastopen_ctx, ctx);
}
- spin_unlock(&net->ipv4.tcp_fastopen_ctx_lock);
if (octx)
call_rcu(&octx->rcu, tcp_fastopen_ctx_free);