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[144.76.156.219]) by smtp.gmail.com with ESMTPSA id m12-20020a5d4a0c000000b00317e9c05d35sm5834308wrq.85.2023.08.11.08.58.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 11 Aug 2023 08:58:54 -0700 (PDT) From: Matthieu Baerts Date: Fri, 11 Aug 2023 17:57:26 +0200 Subject: [PATCH net-next 13/14] mptcp: get rid of msk->subflow Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20230811-upstream-net-next-20230811-mptcp-get-rid-of-msk-subflow-v1-13-36183269ade8@tessares.net> References: <20230811-upstream-net-next-20230811-mptcp-get-rid-of-msk-subflow-v1-0-36183269ade8@tessares.net> In-Reply-To: <20230811-upstream-net-next-20230811-mptcp-get-rid-of-msk-subflow-v1-0-36183269ade8@tessares.net> To: mptcp@lists.linux.dev, Mat Martineau , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , David Ahern Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Matthieu Baerts X-Mailer: b4 0.12.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=5387; i=matthieu.baerts@tessares.net; h=from:subject:message-id; bh=JOoJwlBZFYBUmiOmWbe7z+i/oWAb6YdcTuPbi7SJfsk=; b=owEBbQKS/ZANAwAIAfa3gk9CaaBzAcsmYgBk1lqv+QeEPuMBcjYRKmzxcRYgSkRQXDk9iGBun vM2a5KezHSJAjMEAAEIAB0WIQToy4X3aHcFem4n93r2t4JPQmmgcwUCZNZarwAKCRD2t4JPQmmg cyamD/wLack7Ml/PVH4WCAUD77D7IUrXDx2QwvmPDDPIrBy8extCVuY65SVGbf4MLGWc5VLR4Fh /+pyJCyslnWNGjIhYp5fzJMNKBO0XVCTaaa8g+TV1umSei3ZcF92+m08Jf1PgANT7J/70WzSQKM iJj0NboA+2HnINHXUrb460QdHWDd0VGtp8Qp2ttCHOq8mKBg4LrhLPQW7D/DU1eSTfll+2u1atP KwV5wWXWbSuKGJxOAiGKMJmBQ0EHjNOHxCYf5/AKJesmv5i2L75pOqRhvYGWB0uaQqj3OZh6BFF 34Q1AxWzJzcBLQRljg1MYlb6isWqZrRefJZ2prthzJKk+OQ9ujOfGSp3li06eJBQyVgrvL+x2qc 5dzwRrHSGl1z16xFqiUzfW8oR8CZ7n5aBrU4l+a35VSVmP060bBiBp/0R+dkzJndam3XT4eEBsF A2Pcmog4QLppbn4fwvFmgESMqtauV0CEYzYcML3xvVz0m3Aa8IIdZzFrDkXvY5N5m/C2xxBnwBX SXPwgxC4dzyrJH4J1bGTCzAWtY6YtH10XLApj0TwuWwKqEt5h31iPq0V+N0vSl734jfVZ3wAT5X xMUhV5OMqjBDl2D7YjyMHXWUNA5zPgkMsOo1IyJ0wVRCq2GP2kEt0xBwyDwBYmvZzIGZjUsCjtW mBvQOALx7hmZd0Q== X-Developer-Key: i=matthieu.baerts@tessares.net; a=openpgp; fpr=E8CB85F76877057A6E27F77AF6B7824F4269A073 From: Paolo Abeni Such field is now unused just as a flag to control the first subflow deletion at close() time. Introduce a new bit flag for that and finally drop the mentioned field. As an intended side effect, now the first subflow sock is not freed before close() even for passive sockets. The msk has no open/active subflows if the first one is closed and the subflow list is singular, update accordingly the state check in mptcp_stream_accept(). Among other benefits, the subflow removal, reduces the amount of memory used on the client side for each mptcp connection, allows passive sockets to go through successful accept()/disconnect()/connect() and makes return error code consistent for failing both passive and active sockets. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/290 Signed-off-by: Paolo Abeni Reviewed-by: Mat Martineau Signed-off-by: Matthieu Baerts --- net/mptcp/protocol.c | 25 ++++++------------------- net/mptcp/protocol.h | 13 ++++++------- 2 files changed, 12 insertions(+), 26 deletions(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index fafa83ee4a72..e715771ded7c 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -92,7 +92,6 @@ static int __mptcp_socket_create(struct mptcp_sock *msk) =20 msk->scaling_ratio =3D tcp_sk(ssock->sk)->scaling_ratio; WRITE_ONCE(msk->first, ssock->sk); - WRITE_ONCE(msk->subflow, ssock); subflow =3D mptcp_subflow_ctx(ssock->sk); list_add(&subflow->node, &msk->conn_list); sock_hold(ssock->sk); @@ -102,6 +101,7 @@ static int __mptcp_socket_create(struct mptcp_sock *msk) /* This is the first subflow, always with id 0 */ subflow->local_id_valid =3D 1; mptcp_sock_graft(msk->first, sk->sk_socket); + iput(SOCK_INODE(ssock)); =20 return 0; } @@ -2238,14 +2238,6 @@ static struct sock *mptcp_subflow_get_retrans(struct= mptcp_sock *msk) return min_stale_count > 1 ? backup : NULL; } =20 -static void mptcp_dispose_initial_subflow(struct mptcp_sock *msk) -{ - if (msk->subflow) { - iput(SOCK_INODE(msk->subflow)); - WRITE_ONCE(msk->subflow, NULL); - } -} - bool __mptcp_retransmit_pending_data(struct sock *sk) { struct mptcp_data_frag *cur, *rtx_head; @@ -2324,7 +2316,7 @@ static void __mptcp_close_ssk(struct sock *sk, struct= sock *ssk, goto out_release; } =20 - dispose_it =3D !msk->subflow || ssk !=3D msk->subflow->sk; + dispose_it =3D msk->free_first || ssk !=3D msk->first; if (dispose_it) list_del(&subflow->node); =20 @@ -2345,7 +2337,6 @@ static void __mptcp_close_ssk(struct sock *sk, struct= sock *ssk, * disconnect should never fail */ WARN_ON_ONCE(tcp_disconnect(ssk, 0)); - msk->subflow->state =3D SS_UNCONNECTED; mptcp_subflow_ctx_reset(subflow); release_sock(ssk); =20 @@ -3106,7 +3097,6 @@ struct sock *mptcp_sk_clone_init(const struct sock *s= k, msk =3D mptcp_sk(nsk); msk->local_key =3D subflow_req->local_key; msk->token =3D subflow_req->token; - WRITE_ONCE(msk->subflow, NULL); msk->in_accept_queue =3D 1; WRITE_ONCE(msk->fully_established, false); if (mp_opt->suboptions & OPTION_MPTCP_CSUMREQD) @@ -3240,10 +3230,8 @@ static void mptcp_destroy(struct sock *sk) { struct mptcp_sock *msk =3D mptcp_sk(sk); =20 - /* clears msk->subflow, allowing the following to close - * even the initial subflow - */ - mptcp_dispose_initial_subflow(msk); + /* allow the following to close even the initial subflow */ + msk->free_first =3D 1; mptcp_destroy_common(msk, 0); sk_sockets_allocated_dec(sk); } @@ -3782,11 +3770,10 @@ static int mptcp_stream_accept(struct socket *sock,= struct socket *newsock, /* Do late cleanup for the first subflow as necessary. Also * deal with bad peers not doing a complete shutdown. */ - if (msk->first && - unlikely(inet_sk_state_load(msk->first) =3D=3D TCP_CLOSE)) { + if (unlikely(inet_sk_state_load(msk->first) =3D=3D TCP_CLOSE)) { __mptcp_close_ssk(newsk, msk->first, mptcp_subflow_ctx(msk->first), 0); - if (unlikely(list_empty(&msk->conn_list))) + if (unlikely(list_is_singular(&msk->conn_list))) inet_sk_state_store(newsk, TCP_CLOSE); } } diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index dccc96dc2d6b..38c7ea013361 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -299,7 +299,8 @@ struct mptcp_sock { cork:1, nodelay:1, fastopening:1, - in_accept_queue:1; + in_accept_queue:1, + free_first:1; struct work_struct work; struct sk_buff *ooo_last_skb; struct rb_root out_of_order_queue; @@ -308,12 +309,10 @@ struct mptcp_sock { struct list_head rtx_queue; struct mptcp_data_frag *first_pending; struct list_head join_list; - struct socket *subflow; /* outgoing connect/listener/!mp_capable - * The mptcp ops can safely dereference, using suitable - * ONCE annotation, the subflow outside the socket - * lock as such sock is freed after close(). - */ - struct sock *first; + struct sock *first; /* The mptcp ops can safely dereference, using suitab= le + * ONCE annotation, the subflow outside the socket + * lock as such sock is freed after close(). + */ struct mptcp_pm_data pm; struct { u32 space; /* bytes copied in last measurement window */ --=20 2.40.1