From nobody Mon Sep 16 19:51:48 2024 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 44B26175B6 for ; Mon, 15 Jan 2024 15:16:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="PdO17wa/" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1705331811; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=dqjthjaFFdHcHkZA01AKebv1RjaCFSHUn2HyjPTFQXI=; b=PdO17wa/OkMvSPnYnEY75+NKpALoAxTQKQ7eUa3MBvNcwSI1XcVgle0PbO1eXT5YGQCuCO gIc+R386l+T6EVHm1kLAPCoI04Lb/aHhVx2BEvZgys7mAVyaqWr+fPZQdmbdpiIBU3osdq ONvRy2upYMbuZS/KVPa/qaBbE6i3Pns= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-46-j1P6KS7ENmKMHjVAoaa0Aw-1; Mon, 15 Jan 2024 10:16:49 -0500 X-MC-Unique: j1P6KS7ENmKMHjVAoaa0Aw-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id A7A529230EA for ; Mon, 15 Jan 2024 15:16:48 +0000 (UTC) Received: from gerbillo.redhat.com (unknown [10.45.225.49]) by smtp.corp.redhat.com (Postfix) with ESMTP id 36BBB1C060B2 for ; Mon, 15 Jan 2024 15:16:48 +0000 (UTC) From: Paolo Abeni To: mptcp@lists.linux.dev Subject: [PATCH mptcp-net 2/4] mptcp: fix rcv space initialization Date: Mon, 15 Jan 2024 16:16:31 +0100 Message-ID: In-Reply-To: References: Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.7 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8"; x-default="true" mptcp_rcv_space_init() is supposed to happen under the msk socket lock, but active msk socket does that without such protection. Leverage the existing mptcp_propagate_state() helper to that extent. We need to ensure mptcp_rcv_space_init will happen before mptcp_rcv_space_adjust(), and the release_cb does not assure that: explicitly check for such condition. While at it, move the wnd_end initialization out of mptcp_rcv_space_init(), it never belonged there. Note that the race does not produce ill effect in practice, but change allows cleaning-up and defying better the locking model. Fixes: a6b118febbab ("mptcp: add receive buffer auto-tuning") Signed-off-by: Paolo Abeni --- net/mptcp/protocol.c | 10 ++++++---- net/mptcp/protocol.h | 3 ++- net/mptcp/subflow.c | 4 ++-- 3 files changed, 10 insertions(+), 7 deletions(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 5129e1235cc5..c41f49532a0a 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1963,6 +1963,9 @@ static void mptcp_rcv_space_adjust(struct mptcp_sock = *msk, int copied) if (copied <=3D 0) return; =20 + if (!msk->rcvspace_init) + mptcp_rcv_space_init(msk, msk->first); + msk->rcvq_space.copied +=3D copied; =20 mstamp =3D div_u64(tcp_clock_ns(), NSEC_PER_USEC); @@ -3163,6 +3166,7 @@ static int mptcp_disconnect(struct sock *sk, int flag= s) msk->bytes_received =3D 0; msk->bytes_sent =3D 0; msk->bytes_retrans =3D 0; + msk->rcvspace_init =3D 0; =20 WRITE_ONCE(sk->sk_shutdown, 0); sk_error_report(sk); @@ -3250,6 +3254,7 @@ void mptcp_rcv_space_init(struct mptcp_sock *msk, con= st struct sock *ssk) { const struct tcp_sock *tp =3D tcp_sk(ssk); =20 + msk->rcvspace_init =3D 1; msk->rcvq_space.copied =3D 0; msk->rcvq_space.rtt_us =3D 0; =20 @@ -3260,8 +3265,6 @@ void mptcp_rcv_space_init(struct mptcp_sock *msk, con= st struct sock *ssk) TCP_INIT_CWND * tp->advmss); if (msk->rcvq_space.space =3D=3D 0) msk->rcvq_space.space =3D TCP_INIT_CWND * TCP_MSS_DEFAULT; - - WRITE_ONCE(msk->wnd_end, msk->snd_nxt + tcp_sk(ssk)->snd_wnd); } =20 void mptcp_destroy_common(struct mptcp_sock *msk, unsigned int flags) @@ -3481,10 +3484,9 @@ void mptcp_finish_connect(struct sock *ssk) WRITE_ONCE(msk->write_seq, subflow->idsn + 1); WRITE_ONCE(msk->snd_nxt, msk->write_seq); WRITE_ONCE(msk->snd_una, msk->write_seq); + WRITE_ONCE(msk->wnd_end, msk->snd_nxt + tcp_sk(ssk)->snd_wnd); =20 mptcp_pm_new_connection(msk, ssk, 0); - - mptcp_rcv_space_init(msk, ssk); } =20 void mptcp_sock_graft(struct sock *sk, struct socket *parent) diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index ebb32b7563be..385aa92926d7 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -304,7 +304,8 @@ struct mptcp_sock { nodelay:1, fastopening:1, in_accept_queue:1, - free_first:1; + free_first:1, + rcvspace_init:1; struct work_struct work; struct sk_buff *ooo_last_skb; struct rb_root out_of_order_queue; diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 90984b053adc..23f639e0d8c3 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -424,6 +424,8 @@ void __mptcp_sync_state(struct sock *sk, int state) struct mptcp_sock *msk =3D mptcp_sk(sk); =20 __mptcp_propagate_sndbuf(sk, msk->first); + if (!msk->rcvspace_init) + mptcp_rcv_space_init(msk, msk->first); if (sk->sk_state =3D=3D TCP_SYN_SENT) { mptcp_set_state(sk, state); sk->sk_state_change(sk); @@ -545,7 +547,6 @@ static void subflow_finish_connect(struct sock *sk, con= st struct sk_buff *skb) } } else if (mptcp_check_fallback(sk)) { fallback: - mptcp_rcv_space_init(msk, sk); mptcp_propagate_state(parent, sk); } return; @@ -1744,7 +1745,6 @@ static void subflow_state_change(struct sock *sk) msk =3D mptcp_sk(parent); if (subflow_simultaneous_connect(sk)) { mptcp_do_fallback(sk); - mptcp_rcv_space_init(msk, sk); pr_fallback(msk); subflow->conn_finished =3D 1; mptcp_propagate_state(parent, sk); --=20 2.43.0