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From:   Dmitry Safonov <dima@arista.com>
To:     linux-kernel@vger.kernel.org, David Ahern <dsahern@kernel.org>,
        Eric Dumazet <edumazet@google.com>,
        Peter Zijlstra <peterz@infradead.org>
Cc:     Dmitry Safonov <dima@arista.com>, Ard Biesheuvel <ardb@kernel.org>,
        Bob Gilligan <gilligan@arista.com>,
        "David S. Miller" <davem@davemloft.net>,
        Dmitry Safonov <0x7f454c46@gmail.com>,
        Francesco Ruggeri <fruggeri@arista.com>,
        Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
        Jakub Kicinski <kuba@kernel.org>,
        Jason Baron <jbaron@akamai.com>,
        Josh Poimboeuf <jpoimboe@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Salam Noureddine <noureddine@arista.com>,
        Steven Rostedt <rostedt@goodmis.org>, netdev@vger.kernel.org
Subject: [PATCH v6 2/5] net/tcp: Separate tcp_md5sig_info allocation into tcp_md5sig_info_add()
Date:   Wed, 23 Nov 2022 17:38:56 +0000
Message-Id: <20221123173859.473629-3-dima@arista.com>
In-Reply-To: <20221123173859.473629-1-dima@arista.com>
References: <20221123173859.473629-1-dima@arista.com>
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Add a helper to allocate tcp_md5sig_info, that will help later to
do/allocate things when info allocated, once per socket.

Signed-off-by: Dmitry Safonov <dima@arista.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
---
 net/ipv4/tcp_ipv4.c | 30 +++++++++++++++++++++---------
 1 file changed, 21 insertions(+), 9 deletions(-)

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index f0343538d1f8..2d76d50b8ae8 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1172,6 +1172,24 @@ struct tcp_md5sig_key *tcp_v4_md5_lookup(const struct sock *sk,
 }
 EXPORT_SYMBOL(tcp_v4_md5_lookup);
 
+static int tcp_md5sig_info_add(struct sock *sk, gfp_t gfp)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct tcp_md5sig_info *md5sig;
+
+	if (rcu_dereference_protected(tp->md5sig_info, lockdep_sock_is_held(sk)))
+		return 0;
+
+	md5sig = kmalloc(sizeof(*md5sig), gfp);
+	if (!md5sig)
+		return -ENOMEM;
+
+	sk_gso_disable(sk);
+	INIT_HLIST_HEAD(&md5sig->head);
+	rcu_assign_pointer(tp->md5sig_info, md5sig);
+	return 0;
+}
+
 /* This can be called on a newly created socket, from other files */
 int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr,
 		   int family, u8 prefixlen, int l3index, u8 flags,
@@ -1202,17 +1220,11 @@ int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr,
 		return 0;
 	}
 
+	if (tcp_md5sig_info_add(sk, gfp))
+		return -ENOMEM;
+
 	md5sig = rcu_dereference_protected(tp->md5sig_info,
 					   lockdep_sock_is_held(sk));
-	if (!md5sig) {
-		md5sig = kmalloc(sizeof(*md5sig), gfp);
-		if (!md5sig)
-			return -ENOMEM;
-
-		sk_gso_disable(sk);
-		INIT_HLIST_HEAD(&md5sig->head);
-		rcu_assign_pointer(tp->md5sig_info, md5sig);
-	}
 
 	key = sock_kmalloc(sk, sizeof(*key), gfp | __GFP_ZERO);
 	if (!key)
-- 
2.38.1