From mboxrd@z Thu Jan 1 00:00:00 1970 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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 8331DC33CAF for ; Thu, 16 Jan 2020 19:02:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 52C5E2073A for ; Thu, 16 Jan 2020 19:02:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579201333; bh=e/9Z3XcsxP40y7lkufZoExY3PVKO3rkQTP7TqxKknR0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=i4CIfHW/QVmNpIiur2v1TP5i79cEK2rwf617MTMhg0WL7plGr8r+sUcch73HUTlHT CcFpwcNHsI9YXC7lIHdYPIR6bTxJTKLIC1Opfy4bg0r02HEqEIUuPlRdJGW4ancALK 2k5YIq5rBgvxd7KZDOKlCHiRCEdh5fP2cQ8hx9k8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2437267AbgAPTCM (ORCPT ); Thu, 16 Jan 2020 14:02:12 -0500 Received: from mail.kernel.org ([198.145.29.99]:34832 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388687AbgAPRFm (ORCPT ); Thu, 16 Jan 2020 12:05:42 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id DD2DC24653; Thu, 16 Jan 2020 17:05:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579194341; bh=e/9Z3XcsxP40y7lkufZoExY3PVKO3rkQTP7TqxKknR0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=t2vd60uSVs2suaqcBHY0TGtKsswcWQp/8qeHS5uN4GNQRnj1Kz2rVUlbR8T0e0FuA NdlywprSF0Ynpie+IU2P1CGlgX6ZuRm3ZSWvtOim2cpezS1Pl5ZEX62qs5pRe2k84k W7hMNFoSPi3cvm2i4jL+VjM7aNdIlm8Vg3MS5JgM= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Leandro Dorileo , Vedang Patel , "David S . Miller" , Sasha Levin , netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 284/671] net/sched: cbs: fix port_rate miscalculation Date: Thu, 16 Jan 2020 11:58:42 -0500 Message-Id: <20200116170509.12787-21-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200116170509.12787-1-sashal@kernel.org> References: <20200116170509.12787-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Leandro Dorileo [ Upstream commit e0a7683d30e91e30ee6cf96314ae58a0314a095e ] The Credit Based Shaper heavily depends on link speed to calculate the scheduling credits, we can't properly calculate the credits if the device has failed to report the link speed. In that case we can't dequeue packets assuming a wrong port rate that will result into an inconsistent credit distribution. This patch makes sure we fail to dequeue case: 1) __ethtool_get_link_ksettings() reports error or 2) the ethernet driver failed to set the ksettings' speed value (setting link speed to SPEED_UNKNOWN). Additionally we properly re calculate the port rate whenever the link speed is changed. Fixes: 3d0bd028ffb4a ("net/sched: Add support for HW offloading for CBS") Signed-off-by: Leandro Dorileo Reviewed-by: Vedang Patel Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/sched/sch_cbs.c | 98 ++++++++++++++++++++++++++++++++++++++------- 1 file changed, 84 insertions(+), 14 deletions(-) diff --git a/net/sched/sch_cbs.c b/net/sched/sch_cbs.c index e26a24017faa..81f84cb5dd23 100644 --- a/net/sched/sch_cbs.c +++ b/net/sched/sch_cbs.c @@ -61,16 +61,20 @@ #include #include #include +#include #include #include #include +static LIST_HEAD(cbs_list); +static DEFINE_SPINLOCK(cbs_list_lock); + #define BYTES_PER_KBIT (1000LL / 8) struct cbs_sched_data { bool offload; int queue; - s64 port_rate; /* in bytes/s */ + atomic64_t port_rate; /* in bytes/s */ s64 last; /* timestamp in ns */ s64 credits; /* in bytes */ s32 locredit; /* in bytes */ @@ -82,6 +86,7 @@ struct cbs_sched_data { struct sk_buff **to_free); struct sk_buff *(*dequeue)(struct Qdisc *sch); struct Qdisc *qdisc; + struct list_head cbs_list; }; static int cbs_child_enqueue(struct sk_buff *skb, struct Qdisc *sch, @@ -180,6 +185,11 @@ static struct sk_buff *cbs_dequeue_soft(struct Qdisc *sch) s64 credits; int len; + if (atomic64_read(&q->port_rate) == -1) { + WARN_ONCE(1, "cbs: dequeue() called with unknown port rate."); + return NULL; + } + if (q->credits < 0) { credits = timediff_to_credits(now - q->last, q->idleslope); @@ -206,7 +216,8 @@ static struct sk_buff *cbs_dequeue_soft(struct Qdisc *sch) /* As sendslope is a negative number, this will decrease the * amount of q->credits. */ - credits = credits_from_len(len, q->sendslope, q->port_rate); + credits = credits_from_len(len, q->sendslope, + atomic64_read(&q->port_rate)); credits += q->credits; q->credits = max_t(s64, credits, q->locredit); @@ -293,6 +304,50 @@ static int cbs_enable_offload(struct net_device *dev, struct cbs_sched_data *q, return 0; } +static void cbs_set_port_rate(struct net_device *dev, struct cbs_sched_data *q) +{ + struct ethtool_link_ksettings ecmd; + int port_rate = -1; + + if (!__ethtool_get_link_ksettings(dev, &ecmd) && + ecmd.base.speed != SPEED_UNKNOWN) + port_rate = ecmd.base.speed * 1000 * BYTES_PER_KBIT; + + atomic64_set(&q->port_rate, port_rate); + netdev_dbg(dev, "cbs: set %s's port_rate to: %lld, linkspeed: %d\n", + dev->name, (long long)atomic64_read(&q->port_rate), + ecmd.base.speed); +} + +static int cbs_dev_notifier(struct notifier_block *nb, unsigned long event, + void *ptr) +{ + struct net_device *dev = netdev_notifier_info_to_dev(ptr); + struct cbs_sched_data *q; + struct net_device *qdev; + bool found = false; + + ASSERT_RTNL(); + + if (event != NETDEV_UP && event != NETDEV_CHANGE) + return NOTIFY_DONE; + + spin_lock(&cbs_list_lock); + list_for_each_entry(q, &cbs_list, cbs_list) { + qdev = qdisc_dev(q->qdisc); + if (qdev == dev) { + found = true; + break; + } + } + spin_unlock(&cbs_list_lock); + + if (found) + cbs_set_port_rate(dev, q); + + return NOTIFY_DONE; +} + static int cbs_change(struct Qdisc *sch, struct nlattr *opt, struct netlink_ext_ack *extack) { @@ -314,16 +369,7 @@ static int cbs_change(struct Qdisc *sch, struct nlattr *opt, qopt = nla_data(tb[TCA_CBS_PARMS]); if (!qopt->offload) { - struct ethtool_link_ksettings ecmd; - s64 link_speed; - - if (!__ethtool_get_link_ksettings(dev, &ecmd)) - link_speed = ecmd.base.speed; - else - link_speed = SPEED_1000; - - q->port_rate = link_speed * 1000 * BYTES_PER_KBIT; - + cbs_set_port_rate(dev, q); cbs_disable_offload(dev, q); } else { err = cbs_enable_offload(dev, q, qopt, extack); @@ -346,6 +392,7 @@ static int cbs_init(struct Qdisc *sch, struct nlattr *opt, { struct cbs_sched_data *q = qdisc_priv(sch); struct net_device *dev = qdisc_dev(sch); + int err; if (!opt) { NL_SET_ERR_MSG(extack, "Missing CBS qdisc options which are mandatory"); @@ -366,7 +413,17 @@ static int cbs_init(struct Qdisc *sch, struct nlattr *opt, qdisc_watchdog_init(&q->watchdog, sch); - return cbs_change(sch, opt, extack); + err = cbs_change(sch, opt, extack); + if (err) + return err; + + if (!q->offload) { + spin_lock(&cbs_list_lock); + list_add(&q->cbs_list, &cbs_list); + spin_unlock(&cbs_list_lock); + } + + return 0; } static void cbs_destroy(struct Qdisc *sch) @@ -374,8 +431,11 @@ static void cbs_destroy(struct Qdisc *sch) struct cbs_sched_data *q = qdisc_priv(sch); struct net_device *dev = qdisc_dev(sch); - qdisc_watchdog_cancel(&q->watchdog); + spin_lock(&cbs_list_lock); + list_del(&q->cbs_list); + spin_unlock(&cbs_list_lock); + qdisc_watchdog_cancel(&q->watchdog); cbs_disable_offload(dev, q); if (q->qdisc) @@ -486,14 +546,24 @@ static struct Qdisc_ops cbs_qdisc_ops __read_mostly = { .owner = THIS_MODULE, }; +static struct notifier_block cbs_device_notifier = { + .notifier_call = cbs_dev_notifier, +}; + static int __init cbs_module_init(void) { + int err = register_netdevice_notifier(&cbs_device_notifier); + + if (err) + return err; + return register_qdisc(&cbs_qdisc_ops); } static void __exit cbs_module_exit(void) { unregister_qdisc(&cbs_qdisc_ops); + unregister_netdevice_notifier(&cbs_device_notifier); } module_init(cbs_module_init) module_exit(cbs_module_exit) -- 2.20.1