From patchwork Wed Jan 20 14:39:11 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Abeni X-Patchwork-Id: 367644 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 09728C433E9 for ; Wed, 20 Jan 2021 14:47:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C9B2123433 for ; Wed, 20 Jan 2021 14:47:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732957AbhATOoM (ORCPT ); Wed, 20 Jan 2021 09:44:12 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:37118 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390736AbhATOlG (ORCPT ); Wed, 20 Jan 2021 09:41:06 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1611153578; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=NWWxbfhMSythF7bI50UjZNQ/S1UP7s+OBUALVuJcfFg=; b=bscB0CSIYhTMifU8H2MJj4gdiyXcawlidqBponnLHsFar4LqUhly5qtdKbZ5zVoKIXEvA1 elP1lce2Kwuhqu9PV67KhyhEUnwOyPDEbd9Zp9Y1kBZJS2/AutY6qfj5kQfLcpBPD5Qndg VvJaPmcp1xFgJjw1KqiUXRmgZrg61b0= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-228-ln73f0wnPvyQMe5S-kb4bw-1; Wed, 20 Jan 2021 09:39:34 -0500 X-MC-Unique: ln73f0wnPvyQMe5S-kb4bw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E5C9C8066E5; Wed, 20 Jan 2021 14:39:32 +0000 (UTC) Received: from gerbillo.redhat.com (ovpn-115-164.ams2.redhat.com [10.36.115.164]) by smtp.corp.redhat.com (Postfix) with ESMTP id BEA9C5D9C2; Wed, 20 Jan 2021 14:39:31 +0000 (UTC) From: Paolo Abeni To: netdev@vger.kernel.org Cc: "David S. Miller" , Jakub Kicinski , mptcp@lists.01.org Subject: [PATCH v2 net-next 2/5] mptcp: re-enable sndbuf autotune Date: Wed, 20 Jan 2021 15:39:11 +0100 Message-Id: In-Reply-To: References: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org After commit 6e628cd3a8f7 ("mptcp: use mptcp release_cb for delayed tasks"), MPTCP never sets the flag bit SOCK_NOSPACE on its subflow. As a side effect, autotune never takes place, as it happens inside tcp_new_space(), which in turn is called only when the mentioned bit is set. Let's sendmsg() set the subflows NOSPACE bit when looking for more memory and use the subflow write_space callback to propagate the snd buf update and wake-up the user-space. Additionally, this allows dropping a bunch of duplicate code and makes the SNDBUF_LIMITED chrono relevant again for MPTCP subflows. Fixes: 6e628cd3a8f7 ("mptcp: use mptcp release_cb for delayed tasks") Reviewed-by: Mat Martineau Signed-off-by: Paolo Abeni --- net/mptcp/protocol.c | 52 +++++++++++++++++--------------------------- net/mptcp/protocol.h | 19 ++++++++++++++++ net/mptcp/subflow.c | 7 +++++- 3 files changed, 45 insertions(+), 33 deletions(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index c5c80f9253832..d07e60330df56 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -730,10 +730,14 @@ void mptcp_data_ready(struct sock *sk, struct sock *ssk) void __mptcp_flush_join_list(struct mptcp_sock *msk) { + struct mptcp_subflow_context *subflow; + if (likely(list_empty(&msk->join_list))) return; spin_lock_bh(&msk->join_list_lock); + list_for_each_entry(subflow, &msk->join_list, node) + mptcp_propagate_sndbuf((struct sock *)msk, mptcp_subflow_tcp_sock(subflow)); list_splice_tail_init(&msk->join_list, &msk->conn_list); spin_unlock_bh(&msk->join_list_lock); } @@ -1033,13 +1037,6 @@ static void __mptcp_clean_una(struct sock *sk) __mptcp_update_wmem(sk); sk_mem_reclaim_partial(sk); } - - if (sk_stream_is_writeable(sk)) { - /* pairs with memory barrier in mptcp_poll */ - smp_mb(); - if (test_and_clear_bit(MPTCP_NOSPACE, &msk->flags)) - sk_stream_write_space(sk); - } } if (snd_una == READ_ONCE(msk->snd_nxt)) { @@ -1358,8 +1355,7 @@ struct subflow_send_info { u64 ratio; }; -static struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk, - u32 *sndbuf) +static struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk) { struct subflow_send_info send_info[2]; struct mptcp_subflow_context *subflow; @@ -1370,24 +1366,17 @@ static struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk, sock_owned_by_me((struct sock *)msk); - *sndbuf = 0; if (__mptcp_check_fallback(msk)) { if (!msk->first) return NULL; - *sndbuf = msk->first->sk_sndbuf; return sk_stream_memory_free(msk->first) ? msk->first : NULL; } /* re-use last subflow, if the burst allow that */ if (msk->last_snd && msk->snd_burst > 0 && sk_stream_memory_free(msk->last_snd) && - mptcp_subflow_active(mptcp_subflow_ctx(msk->last_snd))) { - mptcp_for_each_subflow(msk, subflow) { - ssk = mptcp_subflow_tcp_sock(subflow); - *sndbuf = max(tcp_sk(ssk)->snd_wnd, *sndbuf); - } + mptcp_subflow_active(mptcp_subflow_ctx(msk->last_snd))) return msk->last_snd; - } /* pick the subflow with the lower wmem/wspace ratio */ for (i = 0; i < 2; ++i) { @@ -1400,7 +1389,6 @@ static struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk, continue; nr_active += !subflow->backup; - *sndbuf = max(tcp_sk(ssk)->snd_wnd, *sndbuf); if (!sk_stream_memory_free(subflow->tcp_sock)) continue; @@ -1430,6 +1418,7 @@ static struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk, sk_stream_wspace(msk->last_snd)); return msk->last_snd; } + return NULL; } @@ -1450,7 +1439,6 @@ static void mptcp_push_pending(struct sock *sk, unsigned int flags) }; struct mptcp_data_frag *dfrag; int len, copied = 0; - u32 sndbuf; while ((dfrag = mptcp_send_head(sk))) { info.sent = dfrag->already_sent; @@ -1461,12 +1449,7 @@ static void mptcp_push_pending(struct sock *sk, unsigned int flags) prev_ssk = ssk; __mptcp_flush_join_list(msk); - ssk = mptcp_subflow_get_send(msk, &sndbuf); - - /* do auto tuning */ - if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK) && - sndbuf > READ_ONCE(sk->sk_sndbuf)) - WRITE_ONCE(sk->sk_sndbuf, sndbuf); + ssk = mptcp_subflow_get_send(msk); /* try to keep the subflow socket lock across * consecutive xmit on the same socket @@ -1533,11 +1516,6 @@ static void __mptcp_subflow_push_pending(struct sock *sk, struct sock *ssk) while (len > 0) { int ret = 0; - /* do auto tuning */ - if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK) && - ssk->sk_sndbuf > READ_ONCE(sk->sk_sndbuf)) - WRITE_ONCE(sk->sk_sndbuf, ssk->sk_sndbuf); - if (unlikely(mptcp_must_reclaim_memory(sk, ssk))) { __mptcp_update_wmem(sk); sk_mem_reclaim_partial(sk); @@ -1575,6 +1553,15 @@ static void __mptcp_subflow_push_pending(struct sock *sk, struct sock *ssk) } } +static void mptcp_set_nospace(struct sock *sk) +{ + /* enable autotune */ + set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); + + /* will be cleared on avail space */ + set_bit(MPTCP_NOSPACE, &mptcp_sk(sk)->flags); +} + static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) { struct mptcp_sock *msk = mptcp_sk(sk); @@ -1676,7 +1663,7 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) continue; wait_for_memory: - set_bit(MPTCP_NOSPACE, &msk->flags); + mptcp_set_nospace(sk); mptcp_push_pending(sk, msg->msg_flags); ret = sk_stream_wait_memory(sk, &timeo); if (ret) @@ -3268,6 +3255,7 @@ static int mptcp_stream_accept(struct socket *sock, struct socket *newsock, mptcp_copy_inaddrs(newsk, msk->first); mptcp_rcv_space_init(msk, msk->first); + mptcp_propagate_sndbuf(newsk, msk->first); /* set ssk->sk_socket of accept()ed flows to mptcp socket. * This is needed so NOSPACE flag can be set from tcp stack. @@ -3308,7 +3296,7 @@ static __poll_t mptcp_check_writeable(struct mptcp_sock *msk) if (sk_stream_is_writeable(sk)) return EPOLLOUT | EPOLLWRNORM; - set_bit(MPTCP_NOSPACE, &msk->flags); + mptcp_set_nospace(sk); smp_mb__after_atomic(); /* msk->flags is changed by write_space cb */ if (sk_stream_is_writeable(sk)) return EPOLLOUT | EPOLLWRNORM; diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 65d200a1072bf..871534df6140f 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -522,6 +522,25 @@ static inline bool mptcp_data_fin_enabled(const struct mptcp_sock *msk) READ_ONCE(msk->write_seq) == READ_ONCE(msk->snd_nxt); } +static inline bool mptcp_propagate_sndbuf(struct sock *sk, struct sock *ssk) +{ + if ((sk->sk_userlocks & SOCK_SNDBUF_LOCK) || ssk->sk_sndbuf <= READ_ONCE(sk->sk_sndbuf)) + return false; + + WRITE_ONCE(sk->sk_sndbuf, ssk->sk_sndbuf); + return true; +} + +static inline void mptcp_write_space(struct sock *sk) +{ + if (sk_stream_is_writeable(sk)) { + /* pairs with memory barrier in mptcp_poll */ + smp_mb(); + if (test_and_clear_bit(MPTCP_NOSPACE, &mptcp_sk(sk)->flags)) + sk_stream_write_space(sk); + } +} + void mptcp_destroy_common(struct mptcp_sock *msk); void __init mptcp_token_init(void); diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 22313710d7696..1ca0c82b0dbde 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -343,6 +343,7 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb) if (subflow->conn_finished) return; + mptcp_propagate_sndbuf(parent, sk); subflow->rel_write_seq = 1; subflow->conn_finished = 1; subflow->ssn_offset = TCP_SKB_CB(skb)->seq; @@ -1040,7 +1041,10 @@ static void subflow_data_ready(struct sock *sk) static void subflow_write_space(struct sock *ssk) { - /* we take action in __mptcp_clean_una() */ + struct sock *sk = mptcp_subflow_ctx(ssk)->conn; + + mptcp_propagate_sndbuf(sk, ssk); + mptcp_write_space(sk); } static struct inet_connection_sock_af_ops * @@ -1302,6 +1306,7 @@ static void subflow_state_change(struct sock *sk) __subflow_state_change(sk); if (subflow_simultaneous_connect(sk)) { + mptcp_propagate_sndbuf(parent, sk); mptcp_do_fallback(sk); mptcp_rcv_space_init(mptcp_sk(parent), sk); pr_fallback(mptcp_sk(parent)); From patchwork Wed Jan 20 14:39:12 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Abeni X-Patchwork-Id: 367645 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 813F8C433E6 for ; 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Wed, 20 Jan 2021 09:39:35 -0500 X-MC-Unique: C7pKSm59PSOmZvzg971NVQ-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id ABBB7107ACE6; Wed, 20 Jan 2021 14:39:34 +0000 (UTC) Received: from gerbillo.redhat.com (ovpn-115-164.ams2.redhat.com [10.36.115.164]) by smtp.corp.redhat.com (Postfix) with ESMTP id 483875D9C2; Wed, 20 Jan 2021 14:39:33 +0000 (UTC) From: Paolo Abeni To: netdev@vger.kernel.org Cc: "David S. Miller" , Jakub Kicinski , mptcp@lists.01.org Subject: [PATCH v2 net-next 3/5] mptcp: do not queue excessive data on subflows Date: Wed, 20 Jan 2021 15:39:12 +0100 Message-Id: <0ee2b775b36e79bbd46828d8fd95b0b4c030928b.1611153172.git.pabeni@redhat.com> In-Reply-To: References: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The current packet scheduler can enqueue up to sndbuf data on each subflow. If the send buffer is large and the subflows are not symmetric, this could lead to suboptimal aggregate bandwidth utilization. Limit the amount of queued data to the maximum send window. Reviewed-by: Mat Martineau Signed-off-by: Paolo Abeni --- net/mptcp/protocol.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index d07e60330df56..e741201acc98f 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1389,7 +1389,7 @@ static struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk) continue; nr_active += !subflow->backup; - if (!sk_stream_memory_free(subflow->tcp_sock)) + if (!sk_stream_memory_free(subflow->tcp_sock) || !tcp_sk(ssk)->snd_wnd) continue; pace = READ_ONCE(ssk->sk_pacing_rate); @@ -1415,7 +1415,7 @@ static struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk) if (send_info[0].ssk) { msk->last_snd = send_info[0].ssk; msk->snd_burst = min_t(int, MPTCP_SEND_BURST_SIZE, - sk_stream_wspace(msk->last_snd)); + tcp_sk(msk->last_snd)->snd_wnd); return msk->last_snd; } From patchwork Wed Jan 20 14:39:14 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Abeni X-Patchwork-Id: 367643 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 40A7CC43332 for ; Wed, 20 Jan 2021 14:47:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 230782339E for ; Wed, 20 Jan 2021 14:47:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390891AbhATOof (ORCPT ); Wed, 20 Jan 2021 09:44:35 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:41169 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390762AbhATOlR (ORCPT ); Wed, 20 Jan 2021 09:41:17 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1611153587; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=d0TSEsxaCrWr4PNbs4KTDbSG4DOQ8eQUa/eakh1R+GQ=; b=HPik2JgA+WbATBnXMpcQHE67uqg5uLBN3yHSM60ZAKAmv+8H4bFZk602Kam0M7NXyNOB7o mPy340IlywHRxnznalB2xz4uXJyxUSW7PwcJD4891xmUypSHg5LOwl6AhUZS1YaGRhFFZh XZq1+/MWivrsFwgS0dKlOiAYUALNxKw= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-487-AvuYzv7CPEu1XdReFKutAg-1; Wed, 20 Jan 2021 09:39:43 -0500 X-MC-Unique: AvuYzv7CPEu1XdReFKutAg-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E7B641005504; Wed, 20 Jan 2021 14:39:37 +0000 (UTC) Received: from gerbillo.redhat.com (ovpn-115-164.ams2.redhat.com [10.36.115.164]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9CBDA5D9C2; Wed, 20 Jan 2021 14:39:36 +0000 (UTC) From: Paolo Abeni To: netdev@vger.kernel.org Cc: "David S. Miller" , Jakub Kicinski , mptcp@lists.01.org Subject: [PATCH v2 net-next 5/5] mptcp: implement delegated actions Date: Wed, 20 Jan 2021 15:39:14 +0100 Message-Id: In-Reply-To: References: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On MPTCP-level ack reception, the packet scheduler may select a subflow other then the current one. Prior to this commit we rely on the workqueue to trigger action on such subflow. This changeset introduces an infrastructure that allows any MPTCP subflow to schedule actions (MPTCP xmit) on others subflows without resorting to (multiple) process reschedule. A dummy NAPI instance is used instead. When MPTCP needs to trigger action an a different subflow, it enqueues the target subflow on the NAPI backlog and schedule such instance as needed. The dummy NAPI poll method walks the sockets backlog and tries to acquire the (BH) socket lock on each of them. If the socket is owned by the user space, the action will be completed by the sock release cb, otherwise push is started. This change leverages the delegated action infrastructure to avoid invoking the MPTCP worker to spool the pending data, when the packet scheduler picks a subflow other then the one currently processing the incoming MPTCP-level ack. Additionally we further refine the subflow selection invoking the packet scheduler for each chunk of data even inside __mptcp_subflow_push_pending(). v1 -> v2: - fix possible UaF at shutdown time, resetting sock ops after removing the ulp context Reviewed-by: Mat Martineau Signed-off-by: Paolo Abeni --- net/mptcp/protocol.c | 86 +++++++++++++++++++++++++++++++++++++++++--- net/mptcp/protocol.h | 67 ++++++++++++++++++++++++++++++++++ net/mptcp/subflow.c | 45 +++++++++++++++++++++++ 3 files changed, 194 insertions(+), 4 deletions(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 8cb582eee2862..a033bf9c26ee1 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -45,6 +45,9 @@ static struct percpu_counter mptcp_sockets_allocated; static void __mptcp_destroy_sock(struct sock *sk); static void __mptcp_check_send_data_fin(struct sock *sk); +DEFINE_PER_CPU(struct mptcp_delegated_action, mptcp_delegated_actions); +static struct net_device mptcp_napi_dev; + /* If msk has an initial subflow socket, and the MP_CAPABLE handshake has not * completed yet or has failed, return the subflow socket. * Otherwise return NULL. @@ -1506,7 +1509,9 @@ static void __mptcp_subflow_push_pending(struct sock *sk, struct sock *ssk) struct mptcp_sock *msk = mptcp_sk(sk); struct mptcp_sendmsg_info info; struct mptcp_data_frag *dfrag; + struct sock *xmit_ssk; int len, copied = 0; + bool first = true; info.flags = 0; while ((dfrag = mptcp_send_head(sk))) { @@ -1516,6 +1521,18 @@ static void __mptcp_subflow_push_pending(struct sock *sk, struct sock *ssk) while (len > 0) { int ret = 0; + /* the caller already invoked the packet scheduler, + * check for a different subflow usage only after + * spooling the first chunk of data + */ + xmit_ssk = first ? ssk : mptcp_subflow_get_send(mptcp_sk(sk)); + if (!xmit_ssk) + goto out; + if (xmit_ssk != ssk) { + mptcp_subflow_delegate(mptcp_subflow_ctx(xmit_ssk)); + goto out; + } + if (unlikely(mptcp_must_reclaim_memory(sk, ssk))) { __mptcp_update_wmem(sk); sk_mem_reclaim_partial(sk); @@ -1534,6 +1551,7 @@ static void __mptcp_subflow_push_pending(struct sock *sk, struct sock *ssk) msk->tx_pending_data -= ret; copied += ret; len -= ret; + first = false; } WRITE_ONCE(msk->first_pending, mptcp_send_next(sk)); } @@ -2242,7 +2260,6 @@ static void mptcp_worker(struct work_struct *work) if (unlikely(state == TCP_CLOSE)) goto unlock; - mptcp_push_pending(sk, 0); mptcp_check_data_fin_ack(sk); __mptcp_flush_join_list(msk); @@ -2901,10 +2918,12 @@ void __mptcp_check_push(struct sock *sk, struct sock *ssk) return; if (!sock_owned_by_user(sk)) { - if (mptcp_subflow_get_send(mptcp_sk(sk)) == ssk) + struct sock *xmit_ssk = mptcp_subflow_get_send(mptcp_sk(sk)); + + if (xmit_ssk == ssk) __mptcp_subflow_push_pending(sk, ssk); - else - mptcp_schedule_work(sk); + else if (xmit_ssk) + mptcp_subflow_delegate(mptcp_subflow_ctx(xmit_ssk)); } else { set_bit(MPTCP_PUSH_PENDING, &mptcp_sk(sk)->flags); } @@ -2955,6 +2974,20 @@ static void mptcp_release_cb(struct sock *sk) } } +void mptcp_subflow_process_delegated(struct sock *ssk) +{ + struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); + struct sock *sk = subflow->conn; + + mptcp_data_lock(sk); + if (!sock_owned_by_user(sk)) + __mptcp_subflow_push_pending(sk, ssk); + else + set_bit(MPTCP_PUSH_PENDING, &mptcp_sk(sk)->flags); + mptcp_data_unlock(sk); + mptcp_subflow_delegated_done(subflow); +} + static int mptcp_hash(struct sock *sk) { /* should never be called, @@ -3365,13 +3398,58 @@ static struct inet_protosw mptcp_protosw = { .flags = INET_PROTOSW_ICSK, }; +static int mptcp_napi_poll(struct napi_struct *napi, int budget) +{ + struct mptcp_delegated_action *delegated; + struct mptcp_subflow_context *subflow; + int work_done = 0; + + delegated = container_of(napi, struct mptcp_delegated_action, napi); + while ((subflow = mptcp_subflow_delegated_next(delegated)) != NULL) { + struct sock *ssk = mptcp_subflow_tcp_sock(subflow); + + bh_lock_sock_nested(ssk); + if (!sock_owned_by_user(ssk) && + mptcp_subflow_has_delegated_action(subflow)) + mptcp_subflow_process_delegated(ssk); + /* ... elsewhere tcp_release_cb_override already processed + * the action or will do at next release_sock(). + * In both case must dequeue the subflow here - on the same + * CPU that scheduled it. + */ + bh_unlock_sock(ssk); + sock_put(ssk); + + if (++work_done == budget) + return budget; + } + + /* always provide a 0 'work_done' argument, so that napi_complete_done + * will not try accessing the NULL napi->dev ptr + */ + napi_complete_done(napi, 0); + return work_done; +} + void __init mptcp_proto_init(void) { + struct mptcp_delegated_action *delegated; + int cpu; + mptcp_prot.h.hashinfo = tcp_prot.h.hashinfo; if (percpu_counter_init(&mptcp_sockets_allocated, 0, GFP_KERNEL)) panic("Failed to allocate MPTCP pcpu counter\n"); + init_dummy_netdev(&mptcp_napi_dev); + for_each_possible_cpu(cpu) { + delegated = per_cpu_ptr(&mptcp_delegated_actions, cpu); + INIT_LIST_HEAD(&delegated->head); + netif_tx_napi_add(&mptcp_napi_dev, &delegated->napi, mptcp_napi_poll, + NAPI_POLL_WEIGHT); + napi_enable(&delegated->napi); + } + mptcp_subflow_init(); mptcp_pm_init(); mptcp_token_init(); diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 871534df6140f..1460705aaad05 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -378,6 +378,15 @@ enum mptcp_data_avail { MPTCP_SUBFLOW_OOO_DATA }; +struct mptcp_delegated_action { + struct napi_struct napi; + struct list_head head; +}; + +DECLARE_PER_CPU(struct mptcp_delegated_action, mptcp_delegated_actions); + +#define MPTCP_DELEGATE_SEND 0 + /* MPTCP subflow context */ struct mptcp_subflow_context { struct list_head node;/* conn_list of subflows */ @@ -415,6 +424,9 @@ struct mptcp_subflow_context { u8 local_id; u8 remote_id; + long delegated_status; + struct list_head delegated_node; /* link into delegated_action, protected by local BH */ + struct sock *tcp_sock; /* tcp sk backpointer */ struct sock *conn; /* parent mptcp_sock */ const struct inet_connection_sock_af_ops *icsk_af_ops; @@ -463,6 +475,61 @@ static inline void mptcp_add_pending_subflow(struct mptcp_sock *msk, spin_unlock_bh(&msk->join_list_lock); } +void mptcp_subflow_process_delegated(struct sock *ssk); + +static inline void mptcp_subflow_delegate(struct mptcp_subflow_context *subflow) +{ + struct mptcp_delegated_action *delegated; + bool schedule; + + /* The implied barrier pairs with mptcp_subflow_delegated_done(), and + * ensures the below list check sees list updates done prior to status + * bit changes + */ + if (!test_and_set_bit(MPTCP_DELEGATE_SEND, &subflow->delegated_status)) { + /* still on delegated list from previous scheduling */ + if (!list_empty(&subflow->delegated_node)) + return; + + /* the caller held the subflow bh socket lock */ + lockdep_assert_in_softirq(); + + delegated = this_cpu_ptr(&mptcp_delegated_actions); + schedule = list_empty(&delegated->head); + list_add_tail(&subflow->delegated_node, &delegated->head); + sock_hold(mptcp_subflow_tcp_sock(subflow)); + if (schedule) + napi_schedule(&delegated->napi); + } +} + +static inline struct mptcp_subflow_context * +mptcp_subflow_delegated_next(struct mptcp_delegated_action *delegated) +{ + struct mptcp_subflow_context *ret; + + if (list_empty(&delegated->head)) + return NULL; + + ret = list_first_entry(&delegated->head, struct mptcp_subflow_context, delegated_node); + list_del_init(&ret->delegated_node); + return ret; +} + +static inline bool mptcp_subflow_has_delegated_action(const struct mptcp_subflow_context *subflow) +{ + return test_bit(MPTCP_DELEGATE_SEND, &subflow->delegated_status); +} + +static inline void mptcp_subflow_delegated_done(struct mptcp_subflow_context *subflow) +{ + /* pairs with mptcp_subflow_delegate, ensures delegate_node is updated before + * touching the status bit + */ + smp_wmb(); + clear_bit(MPTCP_DELEGATE_SEND, &subflow->delegated_status); +} + int mptcp_is_enabled(struct net *net); unsigned int mptcp_get_add_addr_timeout(struct net *net); void mptcp_subflow_fully_established(struct mptcp_subflow_context *subflow, diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 1ca0c82b0dbde..721059916c968 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -18,12 +18,15 @@ #include #if IS_ENABLED(CONFIG_MPTCP_IPV6) #include +#include #endif #include #include #include "protocol.h" #include "mib.h" +static void mptcp_subflow_ops_undo_override(struct sock *ssk); + static void SUBFLOW_REQ_INC_STATS(struct request_sock *req, enum linux_mptcp_mib_field field) { @@ -428,6 +431,7 @@ static int subflow_v4_conn_request(struct sock *sk, struct sk_buff *skb) static struct tcp_request_sock_ops subflow_request_sock_ipv6_ops; static struct inet_connection_sock_af_ops subflow_v6_specific; static struct inet_connection_sock_af_ops subflow_v6m_specific; +static struct proto tcpv6_prot_override; static int subflow_v6_conn_request(struct sock *sk, struct sk_buff *skb) { @@ -509,6 +513,8 @@ static void subflow_ulp_fallback(struct sock *sk, icsk->icsk_ulp_ops = NULL; rcu_assign_pointer(icsk->icsk_ulp_data, NULL); tcp_sk(sk)->is_mptcp = 0; + + mptcp_subflow_ops_undo_override(sk); } static void subflow_drop_ctx(struct sock *ssk) @@ -682,6 +688,7 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk, } static struct inet_connection_sock_af_ops subflow_specific; +static struct proto tcp_prot_override; enum mapping_status { MAPPING_OK, @@ -1203,6 +1210,25 @@ static void mptcp_attach_cgroup(struct sock *parent, struct sock *child) #endif /* CONFIG_SOCK_CGROUP_DATA */ } +static void mptcp_subflow_ops_override(struct sock *ssk) +{ +#if IS_ENABLED(CONFIG_MPTCP_IPV6) + if (ssk->sk_prot == &tcpv6_prot) + ssk->sk_prot = &tcpv6_prot_override; + else +#endif + ssk->sk_prot = &tcp_prot_override; +} + +static void mptcp_subflow_ops_undo_override(struct sock *ssk) +{ +#if IS_ENABLED(CONFIG_MPTCP_IPV6) + if (ssk->sk_prot == &tcpv6_prot_override) + ssk->sk_prot = &tcpv6_prot; + else +#endif + ssk->sk_prot = &tcp_prot; +} int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock) { struct mptcp_subflow_context *subflow; @@ -1258,6 +1284,7 @@ int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock) *new_sock = sf; sock_hold(sk); subflow->conn = sk; + mptcp_subflow_ops_override(sf->sk); return 0; } @@ -1274,6 +1301,7 @@ static struct mptcp_subflow_context *subflow_create_ctx(struct sock *sk, rcu_assign_pointer(icsk->icsk_ulp_data, ctx); INIT_LIST_HEAD(&ctx->node); + INIT_LIST_HEAD(&ctx->delegated_node); pr_debug("subflow=%p", ctx); @@ -1386,6 +1414,7 @@ static void subflow_ulp_release(struct sock *ssk) sock_put(sk); } + mptcp_subflow_ops_undo_override(ssk); if (release) kfree_rcu(ctx, rcu); } @@ -1439,6 +1468,16 @@ static void subflow_ulp_clone(const struct request_sock *req, } } +static void tcp_release_cb_override(struct sock *ssk) +{ + struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); + + if (mptcp_subflow_has_delegated_action(subflow)) + mptcp_subflow_process_delegated(ssk); + + tcp_release_cb(ssk); +} + static struct tcp_ulp_ops subflow_ulp_ops __read_mostly = { .name = "mptcp", .owner = THIS_MODULE, @@ -1479,6 +1518,9 @@ void __init mptcp_subflow_init(void) subflow_specific.syn_recv_sock = subflow_syn_recv_sock; subflow_specific.sk_rx_dst_set = subflow_finish_connect; + tcp_prot_override = tcp_prot; + tcp_prot_override.release_cb = tcp_release_cb_override; + #if IS_ENABLED(CONFIG_MPTCP_IPV6) subflow_request_sock_ipv6_ops = tcp_request_sock_ipv6_ops; subflow_request_sock_ipv6_ops.route_req = subflow_v6_route_req; @@ -1494,6 +1536,9 @@ void __init mptcp_subflow_init(void) subflow_v6m_specific.net_header_len = ipv4_specific.net_header_len; subflow_v6m_specific.mtu_reduced = ipv4_specific.mtu_reduced; subflow_v6m_specific.net_frag_header_len = 0; + + tcpv6_prot_override = tcpv6_prot; + tcpv6_prot_override.release_cb = tcp_release_cb_override; #endif mptcp_diag_subflow_init(&subflow_ulp_ops);