From patchwork Thu Jan 7 09:49:40 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vladimir Oltean X-Patchwork-Id: 12003457 X-Patchwork-Delegate: kuba@kernel.org 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 E433FC43217 for ; Thu, 7 Jan 2021 09:52:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C3CE92333D for ; Thu, 7 Jan 2021 09:52:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725900AbhAGJwd (ORCPT ); Thu, 7 Jan 2021 04:52:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41022 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727329AbhAGJvm (ORCPT ); Thu, 7 Jan 2021 04:51:42 -0500 Received: from mail-ej1-x632.google.com (mail-ej1-x632.google.com [IPv6:2a00:1450:4864:20::632]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 77CE3C0612F6 for ; Thu, 7 Jan 2021 01:51:05 -0800 (PST) Received: by mail-ej1-x632.google.com with SMTP id lt17so8899239ejb.3 for ; Thu, 07 Jan 2021 01:51:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=UPJmR7uMHRCatZTn33/yNFiM8glq727qCmvqZpOn3zs=; b=Az/V5u34trbHgkuL5m9yqK6UvJTVOcQBxq9rdw1WLdtZG971Tc/9Wa6WTSTQQlRRet TPxzWENy8dTLr3wfSKG6FPLGTBI6TvNmDt+NMSOuybDd3RQBj9YLMfaLi2x3H+6Fr+mn hPuptCUx0901e7ryCNh95uf1J6JLHSn7fdMA19SIhZVD85HxYtmLM7Ay9C/2p+MfKWrh jlRiAhe+qd0F+vJ4Zm/B/xdUa2OGAxA8srbaDirOLFxenJ+zWsVd5yfup8ZO07YrSG1K 2vAx7USUgEeEAd7hfynLMs5dbUiXcUvca62GwlsW6GFJcYTqAV9X1VZ5iaqCaYyFlvk/ RJiA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=UPJmR7uMHRCatZTn33/yNFiM8glq727qCmvqZpOn3zs=; b=FW+kgIkqP+fZYT9AeS1Zbc7FzcKcpP/su3Ds9pUV5S6cBNcD/nBgUnCDjedwyNERsJ RsyEyer0qA9P4FrZH/NB3eWxpz9X/wXULglnqaYayQyzph0pLwSL4F4PWV1ciJmwN8tp dzgs03jU2PXbNjnn7hwHirxtjeh8o0k54X9t3FxIvha98OciQk0M6zV/TpEPcHrTObNF /txHLJxtXLSeu7Jq/RAILSwyxEQF4lFTvIN1O2nPzR2FLachbICWOBxFrE1bJ3DIhcnD pAONV+tWLq4Aw3a5g4kBq/smqYpvv57BXtrlrdSZDKkp7BkXqX/SygtAQZipGMzGBQUU TD/Q== X-Gm-Message-State: AOAM533uHG1rR1iTd1Cbot6pLMVPGyXbv1ANWl6lkldKAUgc+GhQalr9 umdGAG+rVyaWt/VD6kB7+gE= X-Google-Smtp-Source: ABdhPJxSPlTcYnCi5P73Yz7hHDCLMIZN3hTILn9yPM6gkLkhbQFqmnzj78mNEG/sXiWVF3PsJZDzVg== X-Received: by 2002:a17:906:451:: with SMTP id e17mr5559149eja.228.1610013064166; Thu, 07 Jan 2021 01:51:04 -0800 (PST) Received: from localhost.localdomain (5-12-227-87.residential.rdsnet.ro. [5.12.227.87]) by smtp.gmail.com with ESMTPSA id k15sm2251571ejc.79.2021.01.07.01.51.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 Jan 2021 01:51:03 -0800 (PST) From: Vladimir Oltean To: "David S . Miller" , Jakub Kicinski Cc: netdev@vger.kernel.org, Andrew Lunn , Florian Fainelli , Cong Wang , Stephen Hemminger , Eric Dumazet , George McCollister , Oleksij Rempel , Jay Vosburgh , Veaceslav Falico , Andy Gospodarek , Arnd Bergmann , Taehee Yoo , Jiri Pirko , Florian Westphal Subject: [PATCH v3 net-next 01/12] net: mark dev_base_lock for deprecation Date: Thu, 7 Jan 2021 11:49:40 +0200 Message-Id: <20210107094951.1772183-2-olteanv@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210107094951.1772183-1-olteanv@gmail.com> References: <20210107094951.1772183-1-olteanv@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Vladimir Oltean There is a movement to eliminate the usage of dev_base_lock, which exists since as far as I could track the kernel history down (the "7a2deb329241 Import changeset" commit from the bitkeeper branch). The dev_base_lock approach has multiple issues: - It is global and not per netns. - Its meaning has mutated over the years and the vast majority of current users is using it to protect against changes of network device state, as opposed to changes of the interface list. - It is overlapping with other protection mechanisms introduced in the meantime, which have higher performance for readers, like RCU introduced in 2009 by Eric Dumazet for kernel 2.6. The old comment that I just deleted made this distinction: writers protect only against readers by holding dev_base_lock, whereas they need to protect against other writers by holding the RTNL mutex. This is slightly confusing/incorrect, since a rwlock_t cannot have more than one concurrently running writer, so that explanation does not justify why the RTNL mutex would be necessary. Instead, Stephen Hemminger makes this clarification here: https://lore.kernel.org/netdev/20201129211230.4d704931@hermes.local/T/#u | There are really two different domains being covered by locks here. | | The first area is change of state of network devices. This has traditionally | been covered by RTNL because there are places that depend on coordinating | state between multiple devices. RTNL is too big and held too long but getting | rid of it is hard because there are corner cases (like state changes from userspace | for VPN devices). | | The other area is code that wants to do read access to look at list of devices. | These pure readers can/should be converted to RCU by now. Writers should hold RTNL. This patch edits the comment for dev_base_lock, minimizing its role in the protection of network interface lists, and clarifies that it is has other purposes as well. Signed-off-by: Vladimir Oltean --- Changes in v3: None. Changes in v2: None. net/core/dev.c | 33 ++++++++++++++++----------------- 1 file changed, 16 insertions(+), 17 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index 8fa739259041..67d912745e5c 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -169,23 +169,22 @@ static int call_netdevice_notifiers_extack(unsigned long val, static struct napi_struct *napi_by_id(unsigned int napi_id); /* - * The @dev_base_head list is protected by @dev_base_lock and the rtnl - * semaphore. - * - * Pure readers hold dev_base_lock for reading, or rcu_read_lock() - * - * Writers must hold the rtnl semaphore while they loop through the - * dev_base_head list, and hold dev_base_lock for writing when they do the - * actual updates. This allows pure readers to access the list even - * while a writer is preparing to update it. - * - * To put it another way, dev_base_lock is held for writing only to - * protect against pure readers; the rtnl semaphore provides the - * protection against other writers. - * - * See, for example usages, register_netdevice() and - * unregister_netdevice(), which must be called with the rtnl - * semaphore held. + * The network interface list of a netns (@net->dev_base_head) and the hash + * tables per ifindex (@net->dev_index_head) and per name (@net->dev_name_head) + * are protected using the following rules: + * + * Pure readers should hold rcu_read_lock() which should protect them against + * concurrent changes to the interface lists made by the writers. Pure writers + * must serialize by holding the RTNL mutex while they loop through the list + * and make changes to it. + * + * It is also possible to hold the global rwlock_t @dev_base_lock for + * protection (holding its read side as an alternative to rcu_read_lock, and + * its write side as an alternative to the RTNL mutex), however this should not + * be done in new code, since it is deprecated and pending removal. + * + * One other role of @dev_base_lock is to protect against changes in the + * operational state of a network interface. */ DEFINE_RWLOCK(dev_base_lock); EXPORT_SYMBOL(dev_base_lock); From patchwork Thu Jan 7 09:49:41 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vladimir Oltean X-Patchwork-Id: 12003453 X-Patchwork-Delegate: kuba@kernel.org 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 CDE0DC43333 for ; Thu, 7 Jan 2021 09:52:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AF6FC2333F for ; Thu, 7 Jan 2021 09:52:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728018AbhAGJw1 (ORCPT ); Thu, 7 Jan 2021 04:52:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41032 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725900AbhAGJvn (ORCPT ); Thu, 7 Jan 2021 04:51:43 -0500 Received: from mail-ed1-x532.google.com (mail-ed1-x532.google.com [IPv6:2a00:1450:4864:20::532]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 05574C0612FB for ; Thu, 7 Jan 2021 01:51:07 -0800 (PST) Received: by mail-ed1-x532.google.com with SMTP id r5so7092606eda.12 for ; Thu, 07 Jan 2021 01:51:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=Xb/5C7dw8P0ak9NdfRuUfvNNfG6Axg/WzAUkD8IrScM=; b=oHEfgKcWaAg906Lur7v1v5iMN2S2TcA+jJVuE4mx8NTcUdpYlFyoPyDRJpt3EiwsYZ K132F8lfbE9DSsfXcoyU3ZRCNhh+L5BfO/FCb8WF/w4o4PRu7t5QLEWDrLIBAvOiGnlO oJD4LhPcdt9qxgVx7vC/AQebh9Ng/5y0NpZEhbmZ3sMRvW/6gplj/genyvrP20iINDEH tIpcZQy0TUpc18xv6kz/w9avMzycJlD1olpRq0Mt9N4qZhbx/qhmTrAQkL99H6g0K8MR 1580ZuBD4pTO8c690j/zy73pF+T7T/rjM+BCrpUWlinc/4xT29Lqway/gPVAEs+7jS7b zenA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=Xb/5C7dw8P0ak9NdfRuUfvNNfG6Axg/WzAUkD8IrScM=; b=Pf1/HQEBXrUsfeu2BBqnCozbudk6Gl0mvF6lzj0/SGLoo4ahIr6HpV2gsA4CSoEpmI so1Q7OFZeAXcjOhNtHXQCmvWQ1+zHnJR1HuYLF0tK01StU3UGe6NDrrNVvrlCklmkazr ABy/bROqhP/ZpNNM2Zgp4OW1yNApOlVlIAE1rKiRd0KiXApYi4P+tOXX+fnrFkFwqEnv hz09bSd7UOz++RcCLXD9Nogg8sWLq+RPVQSUKwlbikmLtv6tbQhHI6IYQbX42F8/ivqb bIFzomEh7kP5QvxwXoWTObcF514nnJS3fKhyBOvbDFEoG0itx2TXdBax7ylExHiNHbnR 9yAw== X-Gm-Message-State: AOAM533Zmn8PFA/T+aWggNIEoNGpL71Nvefuh8M3UJKYCZMNLs/cGLF3 1FmE/97UGatDq20OK3jElbE= X-Google-Smtp-Source: ABdhPJw/X0K77UZxFK5v7HPcxd0n9neucNt8TTMZH0caAofdUbtQD2VnWZ2Dw0OcCSOtL4XNb0mxQw== X-Received: by 2002:a05:6402:a53:: with SMTP id bt19mr1117575edb.104.1610013065662; Thu, 07 Jan 2021 01:51:05 -0800 (PST) Received: from localhost.localdomain (5-12-227-87.residential.rdsnet.ro. [5.12.227.87]) by smtp.gmail.com with ESMTPSA id k15sm2251571ejc.79.2021.01.07.01.51.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 Jan 2021 01:51:05 -0800 (PST) From: Vladimir Oltean To: "David S . Miller" , Jakub Kicinski Cc: netdev@vger.kernel.org, Andrew Lunn , Florian Fainelli , Cong Wang , Stephen Hemminger , Eric Dumazet , George McCollister , Oleksij Rempel , Jay Vosburgh , Veaceslav Falico , Andy Gospodarek , Arnd Bergmann , Taehee Yoo , Jiri Pirko , Florian Westphal Subject: [PATCH v3 net-next 02/12] net: introduce a mutex for the netns interface lists Date: Thu, 7 Jan 2021 11:49:41 +0200 Message-Id: <20210107094951.1772183-3-olteanv@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210107094951.1772183-1-olteanv@gmail.com> References: <20210107094951.1772183-1-olteanv@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Vladimir Oltean Currently, any writer that wants to alter the lists of network interfaces (either the plain list net->dev_base_head, or the hash tables net->dev_index_head and net->dev_name_head) can keep other writers at bay using the RTNL mutex. However, the RTNL mutex has become a very contended resource over the years, so there is a movement to do finer grained locking. This patch adds one more way for writers to the network interface lists to serialize themselves. We assume that all writers to the network interface lists are easily identifiable because the write side of dev_base_lock also needs to be held (note that some instances of that were deliberately skipped, since they only dealt with protecting the operational state of the netdev). Holding the RTNL mutex is now optional for new code that alters the lists, since all relevant writers were made to also hold the new lock. Signed-off-by: Vladimir Oltean --- Changes in v3: None. Changes in v2: - Renamed from netdev_lists_lock to netif_lists_lock. - Created some helper functions netif_lists_lock() and netif_lists_unlock(). include/linux/netdevice.h | 10 +++++++++ include/net/net_namespace.h | 6 +++++ net/core/dev.c | 44 +++++++++++++++++++++++++------------ 3 files changed, 46 insertions(+), 14 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 259be67644e3..2cc4800238bd 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -4393,6 +4393,16 @@ static inline void netif_addr_unlock_bh(struct net_device *dev) spin_unlock_bh(&dev->addr_list_lock); } +static inline void netif_lists_lock(struct net *net) +{ + mutex_lock(&net->netif_lists_lock); +} + +static inline void netif_lists_unlock(struct net *net) +{ + mutex_unlock(&net->netif_lists_lock); +} + /* * dev_addrs walker. Should be used only for read access. Call with * rcu_read_lock held. diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h index 29567875f428..cac64c3c7ce0 100644 --- a/include/net/net_namespace.h +++ b/include/net/net_namespace.h @@ -183,6 +183,12 @@ struct net { struct sock *crypto_nlsk; #endif struct sock *diag_nlsk; + + /* Serializes writers to @dev_base_head, @dev_name_head and + * @dev_index_head. It does _not_ protect the netif adjacency lists + * (struct net_device::adj_list). + */ + struct mutex netif_lists_lock; } __randomize_layout; #include diff --git a/net/core/dev.c b/net/core/dev.c index 67d912745e5c..49963aaf12b5 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -175,13 +175,16 @@ static struct napi_struct *napi_by_id(unsigned int napi_id); * * Pure readers should hold rcu_read_lock() which should protect them against * concurrent changes to the interface lists made by the writers. Pure writers - * must serialize by holding the RTNL mutex while they loop through the list - * and make changes to it. + * must serialize by holding the @net->netif_lists_lock mutex while they loop + * through the list and make changes to it. + * + * It is possible to hold the RTNL mutex for serializing the writers too, but + * this should be avoided in new code due to lock contention. * * It is also possible to hold the global rwlock_t @dev_base_lock for * protection (holding its read side as an alternative to rcu_read_lock, and - * its write side as an alternative to the RTNL mutex), however this should not - * be done in new code, since it is deprecated and pending removal. + * its write side as an alternative to @net->netif_lists_lock), however this + * should not be done in new code, since it is deprecated and pending removal. * * One other role of @dev_base_lock is to protect against changes in the * operational state of a network interface. @@ -360,12 +363,14 @@ static void list_netdevice(struct net_device *dev) ASSERT_RTNL(); + netif_lists_lock(net); write_lock_bh(&dev_base_lock); list_add_tail_rcu(&dev->dev_list, &net->dev_base_head); netdev_name_node_add(net, dev->name_node); hlist_add_head_rcu(&dev->index_hlist, dev_index_hash(net, dev->ifindex)); write_unlock_bh(&dev_base_lock); + netif_lists_unlock(net); dev_base_seq_inc(net); } @@ -375,16 +380,20 @@ static void list_netdevice(struct net_device *dev) */ static void unlist_netdevice(struct net_device *dev) { + struct net *net = dev_net(dev); + ASSERT_RTNL(); /* Unlink dev from the device chain */ + netif_lists_lock(net); write_lock_bh(&dev_base_lock); list_del_rcu(&dev->dev_list); netdev_name_node_del(dev->name_node); hlist_del_rcu(&dev->index_hlist); write_unlock_bh(&dev_base_lock); + netif_lists_unlock(net); - dev_base_seq_inc(dev_net(dev)); + dev_base_seq_inc(net); } /* @@ -850,11 +859,11 @@ EXPORT_SYMBOL_GPL(dev_fill_metadata_dst); * @net: the applicable net namespace * @name: name to find * - * Find an interface by name. Must be called under RTNL semaphore - * or @dev_base_lock. If the name is found a pointer to the device - * is returned. If the name is not found then %NULL is returned. The - * reference counters are not incremented so the caller must be - * careful with locks. + * Find an interface by name. Must be called under RTNL semaphore, + * @net->netif_lists_lock or @dev_base_lock. If the name is found, + * a pointer to the device is returned. If the name is not found then + * %NULL is returned. The reference counters are not incremented so the + * caller must be careful with locks. */ struct net_device *__dev_get_by_name(struct net *net, const char *name) @@ -920,8 +929,8 @@ EXPORT_SYMBOL(dev_get_by_name); * Search for an interface by index. Returns %NULL if the device * is not found or a pointer to the device. The device has not * had its reference counter increased so the caller must be careful - * about locking. The caller must hold either the RTNL semaphore - * or @dev_base_lock. + * about locking. The caller must hold either the RTNL semaphore, + * @net->netif_lists_lock or @dev_base_lock. */ struct net_device *__dev_get_by_index(struct net *net, int ifindex) @@ -1330,15 +1339,19 @@ int dev_change_name(struct net_device *dev, const char *newname) netdev_adjacent_rename_links(dev, oldname); + netif_lists_lock(net); write_lock_bh(&dev_base_lock); netdev_name_node_del(dev->name_node); write_unlock_bh(&dev_base_lock); + netif_lists_unlock(net); synchronize_rcu(); + netif_lists_lock(net); write_lock_bh(&dev_base_lock); netdev_name_node_add(net, dev->name_node); write_unlock_bh(&dev_base_lock); + netif_lists_unlock(net); ret = call_netdevice_notifiers(NETDEV_CHANGENAME, dev); ret = notifier_to_errno(ret); @@ -9415,8 +9428,9 @@ int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack, * @net: the applicable net namespace * * Returns a suitable unique value for a new device interface - * number. The caller must hold the rtnl semaphore or the - * dev_base_lock to be sure it remains unique. + * number. + * The caller must hold the rtnl semaphore, @net->netif_lists_lock or the + * @dev_base_lock to be sure it remains unique. */ static int dev_new_index(struct net *net) { @@ -10999,6 +11013,8 @@ static int __net_init netdev_init(struct net *net) if (net->dev_index_head == NULL) goto err_idx; + mutex_init(&net->netif_lists_lock); + RAW_INIT_NOTIFIER_HEAD(&net->netdev_chain); return 0; From patchwork Thu Jan 7 09:49:42 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vladimir Oltean X-Patchwork-Id: 12003417 X-Patchwork-Delegate: kuba@kernel.org 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 E4E3DC433E6 for ; Thu, 7 Jan 2021 09:52:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B1B072333D for ; Thu, 7 Jan 2021 09:52:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727932AbhAGJvv (ORCPT ); Thu, 7 Jan 2021 04:51:51 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41030 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727283AbhAGJvq (ORCPT ); Thu, 7 Jan 2021 04:51:46 -0500 Received: from mail-ed1-x534.google.com (mail-ed1-x534.google.com [IPv6:2a00:1450:4864:20::534]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 518A0C0612A1 for ; Thu, 7 Jan 2021 01:51:08 -0800 (PST) Received: by mail-ed1-x534.google.com with SMTP id y24so7125403edt.10 for ; Thu, 07 Jan 2021 01:51:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=pnRhj7MGrAFks0sNbh9iopBOpkA/i+Ed1RPw6h3LoTY=; b=c2I3RWLFfRCzkfKscd+p2mP6zbJsfQnzi/+2b4DQGjOyQv9Ea9kX7une3hm4bMePEB afkV0umzXsqgecJjImPh75jdCuVF+2o7hXw2shCKQMtBQC1fy4hLm1+oXo5E16s2zW6q VzraX3tx0OYcTb2KVQkWkv3jW3GGqmJmytD+LsfJwSKnU1EEzeQiwx2NCXij4iyDLhoc oK2rxFEfxnOD210F2iOpu1AwtkmBZAFOrF1JK85I3ntvGC/gaJFTsgL7JDZRWpf8Vpn9 DoAp0q+bqMSi9hBH4GlUgstTu73ImCNSLKIB9rP4otIhyzPRgIpmZHigBpIsto4Xyi8A eirQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=pnRhj7MGrAFks0sNbh9iopBOpkA/i+Ed1RPw6h3LoTY=; b=D+Bc2Y2L1OixgkW/qekkWMu3XOvZm4mdnqPOrITzeTP25+IfGE3mRJUXjfe7NKnJBg KeHT5Dyh5ruFv0fCQVc/AFpEGgFF88WP0CJSe3ry2OBxcW8cXiX0HagvKTILOStnD1jy GQ6+07qPEcKouFhb5gyKIQqrWYMhUkyj2XvnmFJD0l9hWtj7QyX+iXHXC7smPKkCgPWT pH2y8AeCJLzbinI4cBSbknh61QdbsvHj3mhxHuQ0Vl/LysNkX1I1xnSwlDiVyH1VtnYk ZtNJSRGbjPB+/9WkWWcAhqKT0dNpLHkMkklztjivKeMAoCzBQ3c+iUWRrAH6YDTPY3Kr /24Q== X-Gm-Message-State: AOAM531Gsvmk0mkINU4eUrsloPWA12cbfHha7Vpn8hNKMlj/NKxdwIoX ZZ8kXhu6YjLoG9TZuDa3wlE= X-Google-Smtp-Source: ABdhPJy8ZjDcb77QCvpbasYGt76R8EePoY3CYN7OgM/cRCdlakkn+Du+AxHyLjVvkUTLuu1I+RWdiQ== X-Received: by 2002:a05:6402:c83:: with SMTP id cm3mr1058183edb.189.1610013067105; Thu, 07 Jan 2021 01:51:07 -0800 (PST) Received: from localhost.localdomain (5-12-227-87.residential.rdsnet.ro. [5.12.227.87]) by smtp.gmail.com with ESMTPSA id k15sm2251571ejc.79.2021.01.07.01.51.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 Jan 2021 01:51:06 -0800 (PST) From: Vladimir Oltean To: "David S . Miller" , Jakub Kicinski Cc: netdev@vger.kernel.org, Andrew Lunn , Florian Fainelli , Cong Wang , Stephen Hemminger , Eric Dumazet , George McCollister , Oleksij Rempel , Jay Vosburgh , Veaceslav Falico , Andy Gospodarek , Arnd Bergmann , Taehee Yoo , Jiri Pirko , Florian Westphal Subject: [PATCH v3 net-next 03/12] net: procfs: hold netif_lists_lock when retrieving device statistics Date: Thu, 7 Jan 2021 11:49:42 +0200 Message-Id: <20210107094951.1772183-4-olteanv@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210107094951.1772183-1-olteanv@gmail.com> References: <20210107094951.1772183-1-olteanv@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Vladimir Oltean In the effort of making .ndo_get_stats64 be able to sleep, we need to ensure the callers of dev_get_stats do not use atomic context. The /proc/net/dev file uses an RCU read-side critical section to ensure the integrity of the list of network interfaces, because it iterates through all net devices in the netns to show their statistics. To offer the equivalent protection against an interface registering or deregistering, while also remaining in sleepable context, we can use the netns mutex for the interface lists. Cc: Cong Wang Cc: Eric Dumazet Signed-off-by: Vladimir Oltean --- Changes in v3: None. Changes in v2: None. net/core/net-procfs.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/net/core/net-procfs.c b/net/core/net-procfs.c index c714e6a9dad4..4784703c1e39 100644 --- a/net/core/net-procfs.c +++ b/net/core/net-procfs.c @@ -21,7 +21,7 @@ static inline struct net_device *dev_from_same_bucket(struct seq_file *seq, loff unsigned int count = 0, offset = get_offset(*pos); h = &net->dev_index_head[get_bucket(*pos)]; - hlist_for_each_entry_rcu(dev, h, index_hlist) { + hlist_for_each_entry(dev, h, index_hlist) { if (++count == offset) return dev; } @@ -51,9 +51,11 @@ static inline struct net_device *dev_from_bucket(struct seq_file *seq, loff_t *p * in detail. */ static void *dev_seq_start(struct seq_file *seq, loff_t *pos) - __acquires(RCU) { - rcu_read_lock(); + struct net *net = seq_file_net(seq); + + netif_lists_lock(net); + if (!*pos) return SEQ_START_TOKEN; @@ -70,9 +72,10 @@ static void *dev_seq_next(struct seq_file *seq, void *v, loff_t *pos) } static void dev_seq_stop(struct seq_file *seq, void *v) - __releases(RCU) { - rcu_read_unlock(); + struct net *net = seq_file_net(seq); + + netif_lists_unlock(net); } static void dev_seq_printf_stats(struct seq_file *seq, struct net_device *dev) From patchwork Thu Jan 7 09:49:43 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vladimir Oltean X-Patchwork-Id: 12003441 X-Patchwork-Delegate: kuba@kernel.org 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 9C192C433DB for ; Thu, 7 Jan 2021 09:52:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5BF852333D for ; Thu, 7 Jan 2021 09:52:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727914AbhAGJvu (ORCPT ); Thu, 7 Jan 2021 04:51:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41036 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727902AbhAGJvq (ORCPT ); Thu, 7 Jan 2021 04:51:46 -0500 Received: from mail-ej1-x62a.google.com (mail-ej1-x62a.google.com [IPv6:2a00:1450:4864:20::62a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ECAA2C0612A2 for ; Thu, 7 Jan 2021 01:51:09 -0800 (PST) Received: by mail-ej1-x62a.google.com with SMTP id jx16so8785442ejb.10 for ; Thu, 07 Jan 2021 01:51:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=Y7uWbEbsBXF1F/7KTwfTITzqENv+hT1Vv+Tffl7XOas=; b=ETy99AdZ/mJWPRKQFR7xqYZIbb71D6nz346zTPW1YqzdAWA6xBwfQvofu/UvU1IwSo U11AauqptZqYNE6sBMQh9aIEQO+caTutKVDorKbAAubC9x8SduQs6iumsAHvnrDlmL/5 H+1pmScT30t5kP/MX0ziMYQjFCgcdTnmSUnt0R2zPBbTzg39BTDRku04Y1ivyjnKL6np fvTFqRy/o+S8A9eM7qo1VLyilJiJpxGds1OSUw0vGXkXKLL/aP5BepdnQ864z2Mwj01z hELiRJNL5557032D/9PnXPPy08QOh2cgsVGOT+ai8w+nJAUa7NVmmz9e8+qp1s00XxMl JfLA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=Y7uWbEbsBXF1F/7KTwfTITzqENv+hT1Vv+Tffl7XOas=; b=pdwP4Bad7aogdJ5+u+q3dSmCc3g+WmaPeZ457sQ15MlDX3z51aQm/YlqH+u2eCBKPx 6vOom7XGcPmKw+CzA2fTIOF/f7qNUyz8jiALO5ygT2lDxfOk3wA+MeY5WRvRcOeDnSAw mZ4GQR/+OsC0LngI6+TDyH4pu9O7vsGgRBbPR2Limb6PXMOclsrifXiptTXTGNnos8gU AoMpMmIIPEx/QezB3wAp+AN+dJqRnrlw3IqzicKf3Cn1x3v4Ic8mJycZwTC2sdzzfISQ sIAU1hVuk4vHpMN5JZ2Iq779e6bikFXHj0cCCGaL1iKZ+W3TWWKByLrUstmfQ/im0tt6 bUQQ== X-Gm-Message-State: AOAM531nwLdOfyQxnBxnpI6bsPsAqn/rE4po5k7Ui5WVyGfT76w9yx2+ OgOV/IfgFmvWfR/XhFHOyg0= X-Google-Smtp-Source: ABdhPJyYAXwiQBpgQwBRgp0KNcDktY0u+M7P6NA0yHOkxdggKlQOHXQj+Xhsd7qalbebt6zrryygYQ== X-Received: by 2002:a17:906:1a01:: with SMTP id i1mr5747698ejf.315.1610013068671; Thu, 07 Jan 2021 01:51:08 -0800 (PST) Received: from localhost.localdomain (5-12-227-87.residential.rdsnet.ro. [5.12.227.87]) by smtp.gmail.com with ESMTPSA id k15sm2251571ejc.79.2021.01.07.01.51.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 Jan 2021 01:51:08 -0800 (PST) From: Vladimir Oltean To: "David S . Miller" , Jakub Kicinski Cc: netdev@vger.kernel.org, Andrew Lunn , Florian Fainelli , Cong Wang , Stephen Hemminger , Eric Dumazet , George McCollister , Oleksij Rempel , Jay Vosburgh , Veaceslav Falico , Andy Gospodarek , Arnd Bergmann , Taehee Yoo , Jiri Pirko , Florian Westphal Subject: [PATCH v3 net-next 04/12] net: sysfs: don't hold dev_base_lock while retrieving device statistics Date: Thu, 7 Jan 2021 11:49:43 +0200 Message-Id: <20210107094951.1772183-5-olteanv@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210107094951.1772183-1-olteanv@gmail.com> References: <20210107094951.1772183-1-olteanv@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Vladimir Oltean In the effort of making .ndo_get_stats64 be able to sleep, we need to ensure the callers of dev_get_stats do not use atomic context. I need to preface this by saying that I have no idea why netstat_show takes the dev_base_lock rwlock. Two things can be observed: (a) it does not appear to be due to dev_isalive requiring it for some reason, because broadcast_show() also calls dev_isalive() and has had no problem existing since the beginning of git. (b) the dev_get_stats function definitely does not need dev_base_lock protection either. In fact, holding the dev_base_lock is the entire problem here, because we want to make dev_get_stats sleepable, and holding a rwlock gives us atomic context. So since no protection seems to be necessary, just run unlocked while retrieving the /sys/class/net/eth0/statistics/* values. Cc: Christian Brauner Cc: Eric Dumazet Signed-off-by: Vladimir Oltean --- Changes in v3: None. Changes in v2: None. net/core/net-sysfs.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index daf502c13d6d..8604183678fc 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -585,14 +585,13 @@ static ssize_t netstat_show(const struct device *d, WARN_ON(offset > sizeof(struct rtnl_link_stats64) || offset % sizeof(u64) != 0); - read_lock(&dev_base_lock); if (dev_isalive(dev)) { struct rtnl_link_stats64 temp; const struct rtnl_link_stats64 *stats = dev_get_stats(dev, &temp); ret = sprintf(buf, fmt_u64, *(u64 *)(((u8 *)stats) + offset)); } - read_unlock(&dev_base_lock); + return ret; } From patchwork Thu Jan 7 09:49:44 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vladimir Oltean X-Patchwork-Id: 12003413 X-Patchwork-Delegate: kuba@kernel.org 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 B4999C433DB for ; Thu, 7 Jan 2021 09:52:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 85DD62333E for ; Thu, 7 Jan 2021 09:52:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727925AbhAGJvu (ORCPT ); Thu, 7 Jan 2021 04:51:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41034 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727903AbhAGJvq (ORCPT ); Thu, 7 Jan 2021 04:51:46 -0500 Received: from mail-ej1-x62a.google.com (mail-ej1-x62a.google.com [IPv6:2a00:1450:4864:20::62a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6B22BC061257 for ; Thu, 7 Jan 2021 01:51:11 -0800 (PST) Received: by mail-ej1-x62a.google.com with SMTP id g20so8937147ejb.1 for ; Thu, 07 Jan 2021 01:51:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=0lIb6M9mgiYZY3hRKhHnSuCWG9h9HMO9fL86gPEBXrk=; b=WxvOVyjpUGzb2w35wYJGGUpLJ/e6rgZHMPza23pE2a5jOMUomQt6SarMAshUbmDmCt jKOztPdRw1oSLDD/kQ9GGOWmvcXgyux9KX46EEZj4bYRnsINRncR1m/Pq+NMoPHNlB8Y izlSacERS5Nlp6r8hckhTWqYgwozgVNNKVDz6s6ankBIiD2P0c2CwVNqjaEXds/1azft Rd9II9fbn1hl5V+8lCCFCV73A5sz1dks0hgf5U5+LKRLmoywRie+/jgMQgLYr1C9fLme s9OxQrhFWROZO2LJA1g4C9PHELdSF4PibUq1GVs9PtzebC+zrY0+chZ89gejGUg5VAdt DubQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=0lIb6M9mgiYZY3hRKhHnSuCWG9h9HMO9fL86gPEBXrk=; b=BUg7JZBwGUiXQmTvEpH+LAAOZ15xDpft9aQd39gyfUtj9nof80P9K2Nk8NxCN8edPZ 2/hvfL9hScj/SnTGhEDrHfnpj4MIO9HHOVmMj5lCcuCMN48LU8jc1gGrCBLyPIg8DQ8s kDUZsHKjTCR9sVBSHvNYcMrGfKGYR0CQ3WAKyBCpE+qgZxC1blpDEyXZIjUgyMuDekQR 5ZwFSt+DhCKjBFQcZ11OsL6zzfgS7yzF0FtFt5Js/fMW4B47yowR5M6jX9w6zMv445UY nkpiG3YwewtEwhpUodi2X0VSaAYRGEbnJnV8AAKjUkadUB6tbpsdQmTxb9wg+VTrqzjy p3cA== X-Gm-Message-State: AOAM531e01WoSKIYXmuoNF5APBjdNke/GLOeUIvVke22m2aYhUP1hsv8 MhQwyD/aEdSAwC/8W3ZaE8g= X-Google-Smtp-Source: ABdhPJxy43sPMdDo4ftMVGMLK1FBqpRFE28YB0T+rAgSZaq1RJNqoYU4CcqYdAHKzpr4Jmk0JvcIlw== X-Received: by 2002:a17:906:9382:: with SMTP id l2mr6013251ejx.162.1610013070160; Thu, 07 Jan 2021 01:51:10 -0800 (PST) Received: from localhost.localdomain (5-12-227-87.residential.rdsnet.ro. [5.12.227.87]) by smtp.gmail.com with ESMTPSA id k15sm2251571ejc.79.2021.01.07.01.51.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 Jan 2021 01:51:09 -0800 (PST) From: Vladimir Oltean To: "David S . Miller" , Jakub Kicinski Cc: netdev@vger.kernel.org, Andrew Lunn , Florian Fainelli , Cong Wang , Stephen Hemminger , Eric Dumazet , George McCollister , Oleksij Rempel , Jay Vosburgh , Veaceslav Falico , Andy Gospodarek , Arnd Bergmann , Taehee Yoo , Jiri Pirko , Florian Westphal Subject: [PATCH v3 net-next 05/12] s390/appldata_net_sum: hold the netdev lists lock when retrieving device statistics Date: Thu, 7 Jan 2021 11:49:44 +0200 Message-Id: <20210107094951.1772183-6-olteanv@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210107094951.1772183-1-olteanv@gmail.com> References: <20210107094951.1772183-1-olteanv@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Vladimir Oltean In the effort of making .ndo_get_stats64 be able to sleep, we need to ensure the callers of dev_get_stats do not use atomic context. In the case of the appldata driver, an RCU read-side critical section is used to ensure the integrity of the list of network interfaces, because the driver iterates through all net devices in the netns to aggregate statistics. We still need some protection against an interface registering or deregistering, and the writer-side lock, the netns's mutex, is fine for that, because it offers sleepable context. The ops->callback function is called from under appldata_ops_mutex protection, so this is proof that the context is sleepable and holding a mutex is therefore fine. Cc: Heiko Carstens Cc: Vasily Gorbik Cc: linux-s390@vger.kernel.org Signed-off-by: Vladimir Oltean --- Changes in v3: None. Changes in v2: None. arch/s390/appldata/appldata_net_sum.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/arch/s390/appldata/appldata_net_sum.c b/arch/s390/appldata/appldata_net_sum.c index 59c282ca002f..4db886980cba 100644 --- a/arch/s390/appldata/appldata_net_sum.c +++ b/arch/s390/appldata/appldata_net_sum.c @@ -78,8 +78,9 @@ static void appldata_get_net_sum_data(void *data) tx_dropped = 0; collisions = 0; - rcu_read_lock(); - for_each_netdev_rcu(&init_net, dev) { + netif_lists_lock(&init_net); + + for_each_netdev(&init_net, dev) { const struct rtnl_link_stats64 *stats; struct rtnl_link_stats64 temp; @@ -95,7 +96,8 @@ static void appldata_get_net_sum_data(void *data) collisions += stats->collisions; i++; } - rcu_read_unlock(); + + netif_lists_unlock(&init_net); net_data->nr_interfaces = i; net_data->rx_packets = rx_packets; From patchwork Thu Jan 7 09:49:45 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vladimir Oltean X-Patchwork-Id: 12003445 X-Patchwork-Delegate: kuba@kernel.org 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 3562DC43381 for ; Thu, 7 Jan 2021 09:52:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E99762333E for ; Thu, 7 Jan 2021 09:52:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728003AbhAGJwP (ORCPT ); Thu, 7 Jan 2021 04:52:15 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40938 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727905AbhAGJvr (ORCPT ); Thu, 7 Jan 2021 04:51:47 -0500 Received: from mail-ej1-x62f.google.com (mail-ej1-x62f.google.com [IPv6:2a00:1450:4864:20::62f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F3C81C0612FC for ; Thu, 7 Jan 2021 01:51:12 -0800 (PST) Received: by mail-ej1-x62f.google.com with SMTP id n26so8850699eju.6 for ; Thu, 07 Jan 2021 01:51:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=UgBhBVpzz6m5FwdjCW5WUOkWO3FR/vyy7c45RHmTols=; b=GrWdCYXFw/CxDEhhIsLb/y4hC63LQ5zFthNin1HkzlYR6kET6fnohgx/MwALBxPihF 6rfBP9MWT9NSJqIkqdOxLmUMgV5wIPvq89t0aEmcsoBICRM12Gz4Iqx3xkbhfhYrx/S0 OHO+0d60fFr0bB1u+YFSxPEYwA7en6Gs9GP5saAmXSfN4Sho5tX/6ErEzmvg9I8bKcwV 5yID9czjqiUuKAiePCTJrRKx21ryEzd/QpWWY0b+VeFWaOhPqzPq5he4jv7djy+1YzkQ SP4LmvrZjwOiQ26VS6bGKoxLzXpNxaq0z1p7mK11Zre72KJFkZTah1LlWioMy3rImRXE o5Gg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=UgBhBVpzz6m5FwdjCW5WUOkWO3FR/vyy7c45RHmTols=; b=e0X8Jx0zlkivTTwzlVJKmPTCkZf8L7FdXRyi9fjbVCnfPiYTd417lMTeNmlY0TKz2e fYlUjtUB04gOQRQXokYmsqlPgYVfDv1gzptNFCWUbs84XMwsqfB9xio3jCYPpHJ1SsZU 3zZB1eHeYx6/kBipI8MEllsKMkVU1jl7dCtE6c9zwNy7Rj4ITC15XZvDAelb0dcOuPX6 QmYo1nMKdsqctGmfqMBJef5JHUUYXJUjbv8Ku39N+ZzEx6tptEM53YBQXuD4RRg6JpcU ql5E+pUwh7Wq4QEw+bseIk51S0mM1NT15l0h2ogGlZ1mNx7geu5ozfk8HOh+/19okNat CWug== X-Gm-Message-State: AOAM530z0OwVMXHxxC4jQiag/zRklhrq/I10DIW4oAufmp2MQRF56Tr0 cRF6bRpdM0hLz4LMh5P7EY0= X-Google-Smtp-Source: ABdhPJx3EDiVZs9u5xtTHQLV9r9T+7dUZo4LQMRe1iWkqpXy8xblsKTvM5Hwlxd0yKn+810KQ2h1xQ== X-Received: by 2002:a17:906:d146:: with SMTP id br6mr5629615ejb.331.1610013071776; Thu, 07 Jan 2021 01:51:11 -0800 (PST) Received: from localhost.localdomain (5-12-227-87.residential.rdsnet.ro. [5.12.227.87]) by smtp.gmail.com with ESMTPSA id k15sm2251571ejc.79.2021.01.07.01.51.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 Jan 2021 01:51:11 -0800 (PST) From: Vladimir Oltean To: "David S . Miller" , Jakub Kicinski Cc: netdev@vger.kernel.org, Andrew Lunn , Florian Fainelli , Cong Wang , Stephen Hemminger , Eric Dumazet , George McCollister , Oleksij Rempel , Jay Vosburgh , Veaceslav Falico , Andy Gospodarek , Arnd Bergmann , Taehee Yoo , Jiri Pirko , Florian Westphal Subject: [PATCH v3 net-next 06/12] parisc/led: reindent the code that gathers device statistics Date: Thu, 7 Jan 2021 11:49:45 +0200 Message-Id: <20210107094951.1772183-7-olteanv@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210107094951.1772183-1-olteanv@gmail.com> References: <20210107094951.1772183-1-olteanv@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Vladimir Oltean The standard in the Linux kernel is to use one tab character per indentation level. Cc: "James E.J. Bottomley" Cc: Helge Deller Cc: linux-parisc@vger.kernel.org Signed-off-by: Vladimir Oltean --- Changes in v3: None. Changes in v2: None. drivers/parisc/led.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) diff --git a/drivers/parisc/led.c b/drivers/parisc/led.c index 36c6613f7a36..3cada632a4be 100644 --- a/drivers/parisc/led.c +++ b/drivers/parisc/led.c @@ -359,16 +359,19 @@ static __inline__ int led_get_net_activity(void) /* we are running as a workqueue task, so we can use an RCU lookup */ rcu_read_lock(); for_each_netdev_rcu(&init_net, dev) { - const struct rtnl_link_stats64 *stats; - struct rtnl_link_stats64 temp; - struct in_device *in_dev = __in_dev_get_rcu(dev); - if (!in_dev || !in_dev->ifa_list) - continue; - if (ipv4_is_loopback(in_dev->ifa_list->ifa_local)) - continue; - stats = dev_get_stats(dev, &temp); - rx_total += stats->rx_packets; - tx_total += stats->tx_packets; + const struct rtnl_link_stats64 *stats; + struct rtnl_link_stats64 temp; + struct in_device *in_dev = __in_dev_get_rcu(dev); + + if (!in_dev || !in_dev->ifa_list) + continue; + + if (ipv4_is_loopback(in_dev->ifa_list->ifa_local)) + continue; + + stats = dev_get_stats(dev, &temp); + rx_total += stats->rx_packets; + tx_total += stats->tx_packets; } rcu_read_unlock(); From patchwork Thu Jan 7 09:49:46 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vladimir Oltean X-Patchwork-Id: 12003415 X-Patchwork-Delegate: kuba@kernel.org 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 0F93FC43381 for ; Thu, 7 Jan 2021 09:52:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CEC5C2333E for ; Thu, 7 Jan 2021 09:52:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727944AbhAGJvx (ORCPT ); Thu, 7 Jan 2021 04:51:53 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40940 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727906AbhAGJvr (ORCPT ); Thu, 7 Jan 2021 04:51:47 -0500 Received: from mail-ej1-x62c.google.com (mail-ej1-x62c.google.com [IPv6:2a00:1450:4864:20::62c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 62CB4C0612FD for ; Thu, 7 Jan 2021 01:51:14 -0800 (PST) Received: by mail-ej1-x62c.google.com with SMTP id d17so8807108ejy.9 for ; Thu, 07 Jan 2021 01:51:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=ZY8ji9fFG08blymAp9Y+P4geDkhw8vQUxrybxWKW3qs=; b=GEJ1kf+Ks1TUZNQcMn67KWGzsLJSAspBL/9c1SwcRXezRM/W134BYJLbqxkMBn6fUU aYmq7+k50UhlrD3gwzyWXFxCECIjyeDAp2Rf7Cla9MTSOs6QOLkpOW7lpce5l5/y/ZKN GlBp+pJ6LxzmkfGNBb49+YxMtpDBS/O7dXM+JZzvvcg+FtEHYk8+f8VZAKrLK61juAfB vDXhWaH2BA/56KHTDlczed0zsK1gGgxmtFKJ+Kn0/sR8SoKigcU6Oqtr4w2DSoIIJIGC z2v5OhN0oVz7S31kGviDUGlFctAJJh7tVh6bnGJdsRMjKFF3/Ir03ElNQXqwv06LJIxw jxYQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=ZY8ji9fFG08blymAp9Y+P4geDkhw8vQUxrybxWKW3qs=; b=Z/cd7ue3L/P5Gk3oPuHysL+E/hDkc1hOQjafipy872YskcZSDsw2yl2fZU9AtZw7Zx L11IaPh5gImAWgjHLJOHZwgpsCQ9pA86rNSsWek8UBBJOmXdAwMjkh0q+8UBnLmw6ywo ZRsw6rD0xJ8ANYVHLy7xP6tmNqG7GmaWUZxpdLg29gATkH4K1q5R4wbzAvc5wGnmiDdx yiMEGxuXReXV3RxmGSky+D4NXSsECCGWqpq1UuVLjbEWXn3lO1D2eoEUmzQ3qRAQyiLi 4aZZl3KK2ALRj94tJex6/1Ov2pDZz4ukOudsvqXZ+6jRQGXGC1ypYTWfg0ZXaoPePFiN KmzQ== X-Gm-Message-State: AOAM530jhAW7j+RSOkMr6fPq1a5a8JJsaWG07M/z3+T6xWf1RJZ6Rl7b 6vdqdY4MlKR428ki06HXmw4= X-Google-Smtp-Source: ABdhPJyA1behA7NXwJ0YIyS1peKH1CCoP6WXTV5ZK39bP3NiTOffT6hW+PaWZvK8S+0fZRRpTQX74w== X-Received: by 2002:a17:906:3a98:: with SMTP id y24mr5319017ejd.436.1610013073187; Thu, 07 Jan 2021 01:51:13 -0800 (PST) Received: from localhost.localdomain (5-12-227-87.residential.rdsnet.ro. [5.12.227.87]) by smtp.gmail.com with ESMTPSA id k15sm2251571ejc.79.2021.01.07.01.51.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 Jan 2021 01:51:12 -0800 (PST) From: Vladimir Oltean To: "David S . Miller" , Jakub Kicinski Cc: netdev@vger.kernel.org, Andrew Lunn , Florian Fainelli , Cong Wang , Stephen Hemminger , Eric Dumazet , George McCollister , Oleksij Rempel , Jay Vosburgh , Veaceslav Falico , Andy Gospodarek , Arnd Bergmann , Taehee Yoo , Jiri Pirko , Florian Westphal Subject: [PATCH v3 net-next 07/12] parisc/led: hold the netdev lists lock when retrieving device statistics Date: Thu, 7 Jan 2021 11:49:46 +0200 Message-Id: <20210107094951.1772183-8-olteanv@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210107094951.1772183-1-olteanv@gmail.com> References: <20210107094951.1772183-1-olteanv@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Vladimir Oltean In the effort of making .ndo_get_stats64 be able to sleep, we need to ensure the callers of dev_get_stats do not use atomic context. The LED driver for HP-PARISC workstations uses a workqueue to periodically check for updates in network interface statistics, and flicker when those have changed (i.e. there has been activity on the line). Ignoring the fact that this driver is completely duplicating drivers/leds/trigger/ledtrig-netdev.c, there is an even bigger problem. Now, the dev_get_stats call can sleep, and iterating through the list of network interfaces still needs to ensure the integrity of list of network interfaces. So that leaves us only one locking option given the current design of the network stack, and that is the netns mutex. Cc: "James E.J. Bottomley" Cc: Helge Deller Cc: linux-parisc@vger.kernel.org Signed-off-by: Vladimir Oltean --- Changes in v3: None. Changes in v2: None. drivers/parisc/led.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) diff --git a/drivers/parisc/led.c b/drivers/parisc/led.c index 3cada632a4be..c8c6b2301dc9 100644 --- a/drivers/parisc/led.c +++ b/drivers/parisc/led.c @@ -38,7 +38,6 @@ #include #include #include -#include #include #include #include @@ -355,25 +354,29 @@ static __inline__ int led_get_net_activity(void) int retval; rx_total = tx_total = 0; - - /* we are running as a workqueue task, so we can use an RCU lookup */ - rcu_read_lock(); - for_each_netdev_rcu(&init_net, dev) { + + /* we are running as a workqueue task, so we can sleep */ + netif_lists_lock(&init_net); + + for_each_netdev(&init_net, dev) { + struct in_device *in_dev = in_dev_get(dev); const struct rtnl_link_stats64 *stats; struct rtnl_link_stats64 temp; - struct in_device *in_dev = __in_dev_get_rcu(dev); - if (!in_dev || !in_dev->ifa_list) + if (!in_dev || !in_dev->ifa_list || + ipv4_is_loopback(in_dev->ifa_list->ifa_local)) { + in_dev_put(in_dev); continue; + } - if (ipv4_is_loopback(in_dev->ifa_list->ifa_local)) - continue; + in_dev_put(in_dev); stats = dev_get_stats(dev, &temp); rx_total += stats->rx_packets; tx_total += stats->tx_packets; } - rcu_read_unlock(); + + netif_lists_unlock(&init_net); retval = 0; From patchwork Thu Jan 7 09:49:47 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vladimir Oltean X-Patchwork-Id: 12003421 X-Patchwork-Delegate: kuba@kernel.org 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 D3092C432C3 for ; Thu, 7 Jan 2021 09:52:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9E4932333E for ; Thu, 7 Jan 2021 09:52:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727970AbhAGJwA (ORCPT ); Thu, 7 Jan 2021 04:52:00 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41074 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727701AbhAGJv6 (ORCPT ); Thu, 7 Jan 2021 04:51:58 -0500 Received: from mail-ej1-x634.google.com (mail-ej1-x634.google.com [IPv6:2a00:1450:4864:20::634]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 24A25C0612FE for ; Thu, 7 Jan 2021 01:51:16 -0800 (PST) Received: by mail-ej1-x634.google.com with SMTP id q22so8912030eja.2 for ; Thu, 07 Jan 2021 01:51:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=snsqN/paMNG2EA66Ha/NW5YR31/RfmYco0nTbNO8fB4=; b=BIcMSYFvVna55psXrKexo4owY+kyPteyTHANF3SuyLT2lljhB4WgkEskshTFNwbkKX HSOv4cIY/S6E0w83jwN8sAKOacLeNKSNKWQL4tsLD6AELYSIGD46Gi/U6hwOv1n113k4 Z+xhKKOHa4zJ8jlE3PJXu6uw2BXGwD1NxVId1GTgbSZ6EbN19a/jbOSo8TKXK0dXL70G uU283Z9OvJJPy+saAEoOKSc/v0uqDOqIpqP+gzjU3CLglfx3dnWNRth88ZNl69EmBaOv 16mtpzchdY8+imzIQLEldipKM6YBISUed+h+49yfOwUYUNh1XQPMY20CZUARx4A1Q5LI LEhw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=snsqN/paMNG2EA66Ha/NW5YR31/RfmYco0nTbNO8fB4=; b=n42iKV+Bmxd4hpMZNhwUjoN128CNja0VyYERdhIv1ob8VWBnq0ry6jLsMIL64xEy7u 5SA5t/2UGn3lKqiBGo0cChcIZrZGfPn2qeXnFNbCNaz7x+ZgksO+dW/rWU4YBm2BIEMe NvjcAa+Yegf/bIsbv07Mr2GIpvGtP5GDKf7ZfIzMsLHNjAZ0pfvKwY5gSoxIynLrIbWx xa2jZFbFf+fT8bj9OCNF80dOOxt6edTVmzR/rwBjKUkL5ekTZ9VEpcVb1VxPHrbOy9lj BLd/isFPrOacWiE9vKykDSHx/aBnUgh6iXORyUaRoeSRnj+nSomaR8mDh4OS8Tupl3Se yHTA== X-Gm-Message-State: AOAM530MPew5XdsWQdB0RwoLkaAQcFnvYQQKMJLjlCrJM7RwQtgSjdro kXb4i3GbH8LSi2fF8rrSR7M= X-Google-Smtp-Source: ABdhPJyjn5/e5Rjfzpia+QUm8EB+wd2ZKYxNG+SYDzqqTlgxBCCMfy2IETgXpj1vkciwdaPMP+BjFA== X-Received: by 2002:a17:906:8617:: with SMTP id o23mr5771033ejx.274.1610013074694; Thu, 07 Jan 2021 01:51:14 -0800 (PST) Received: from localhost.localdomain (5-12-227-87.residential.rdsnet.ro. [5.12.227.87]) by smtp.gmail.com with ESMTPSA id k15sm2251571ejc.79.2021.01.07.01.51.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 Jan 2021 01:51:14 -0800 (PST) From: Vladimir Oltean To: "David S . Miller" , Jakub Kicinski Cc: netdev@vger.kernel.org, Andrew Lunn , Florian Fainelli , Cong Wang , Stephen Hemminger , Eric Dumazet , George McCollister , Oleksij Rempel , Jay Vosburgh , Veaceslav Falico , Andy Gospodarek , Arnd Bergmann , Taehee Yoo , Jiri Pirko , Florian Westphal Subject: [PATCH v3 net-next 08/12] net: make dev_get_stats return void Date: Thu, 7 Jan 2021 11:49:47 +0200 Message-Id: <20210107094951.1772183-9-olteanv@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210107094951.1772183-1-olteanv@gmail.com> References: <20210107094951.1772183-1-olteanv@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Vladimir Oltean After commit 28172739f0a2 ("net: fix 64 bit counters on 32 bit arches"), dev_get_stats got an additional argument for storage of statistics. At this point, dev_get_stats could return either the passed "storage" argument, or the output of .ndo_get_stats64. Then commit caf586e5f23c ("net: add a core netdev->rx_dropped counter") came, and the output of .ndo_get_stats64 (still returning a pointer to struct rtnl_link_stats64) started being ignored. Then came commit bc1f44709cf2 ("net: make ndo_get_stats64 a void function") which made .ndo_get_stats64 stop returning anything. So now, dev_get_stats always reports the "storage" pointer received as argument. This is useless. Some drivers are dealing with unnecessary complexity due to this, so refactor them to ignore the return value completely. Signed-off-by: Vladimir Oltean Reported-by: kernel test robot --- Changes in v3: None. Changes in v2: Patch is new. arch/s390/appldata/appldata_net_sum.c | 25 +++++---- drivers/leds/trigger/ledtrig-netdev.c | 9 ++-- drivers/net/bonding/bond_main.c | 7 ++- .../net/ethernet/hisilicon/hns/hns_ethtool.c | 51 +++++++++---------- .../net/ethernet/intel/ixgbe/ixgbe_ethtool.c | 7 ++- drivers/net/ethernet/intel/ixgbevf/ethtool.c | 7 ++- drivers/net/net_failover.c | 13 +++-- drivers/parisc/led.c | 9 ++-- drivers/scsi/fcoe/fcoe_transport.c | 6 +-- drivers/usb/gadget/function/rndis.c | 45 ++++++---------- include/linux/netdevice.h | 3 +- net/8021q/vlanproc.c | 15 +++--- net/core/dev.c | 6 +-- net/core/net-procfs.c | 35 ++++++------- net/core/net-sysfs.c | 7 +-- net/openvswitch/vport.c | 25 +++++---- 16 files changed, 123 insertions(+), 147 deletions(-) diff --git a/arch/s390/appldata/appldata_net_sum.c b/arch/s390/appldata/appldata_net_sum.c index 4db886980cba..6146606ac9a3 100644 --- a/arch/s390/appldata/appldata_net_sum.c +++ b/arch/s390/appldata/appldata_net_sum.c @@ -81,19 +81,18 @@ static void appldata_get_net_sum_data(void *data) netif_lists_lock(&init_net); for_each_netdev(&init_net, dev) { - const struct rtnl_link_stats64 *stats; - struct rtnl_link_stats64 temp; - - stats = dev_get_stats(dev, &temp); - rx_packets += stats->rx_packets; - tx_packets += stats->tx_packets; - rx_bytes += stats->rx_bytes; - tx_bytes += stats->tx_bytes; - rx_errors += stats->rx_errors; - tx_errors += stats->tx_errors; - rx_dropped += stats->rx_dropped; - tx_dropped += stats->tx_dropped; - collisions += stats->collisions; + struct rtnl_link_stats64 stats; + + dev_get_stats(dev, &stats); + rx_packets += stats.rx_packets; + tx_packets += stats.tx_packets; + rx_bytes += stats.rx_bytes; + tx_bytes += stats.tx_bytes; + rx_errors += stats.rx_errors; + tx_errors += stats.tx_errors; + rx_dropped += stats.rx_dropped; + tx_dropped += stats.tx_dropped; + collisions += stats.collisions; i++; } diff --git a/drivers/leds/trigger/ledtrig-netdev.c b/drivers/leds/trigger/ledtrig-netdev.c index d5e774d83021..4382ee278309 100644 --- a/drivers/leds/trigger/ledtrig-netdev.c +++ b/drivers/leds/trigger/ledtrig-netdev.c @@ -347,9 +347,8 @@ static void netdev_trig_work(struct work_struct *work) { struct led_netdev_data *trigger_data = container_of(work, struct led_netdev_data, work.work); - struct rtnl_link_stats64 *dev_stats; + struct rtnl_link_stats64 dev_stats; unsigned int new_activity; - struct rtnl_link_stats64 temp; unsigned long interval; int invert; @@ -364,12 +363,12 @@ static void netdev_trig_work(struct work_struct *work) !test_bit(NETDEV_LED_RX, &trigger_data->mode)) return; - dev_stats = dev_get_stats(trigger_data->net_dev, &temp); + dev_get_stats(trigger_data->net_dev, &dev_stats); new_activity = (test_bit(NETDEV_LED_TX, &trigger_data->mode) ? - dev_stats->tx_packets : 0) + + dev_stats.tx_packets : 0) + (test_bit(NETDEV_LED_RX, &trigger_data->mode) ? - dev_stats->rx_packets : 0); + dev_stats.rx_packets : 0); if (trigger_data->last_activity != new_activity) { led_stop_software_blink(trigger_data->led_cdev); diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 5fe5232cc3f3..714aa0e5d041 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -3753,13 +3753,12 @@ static void bond_get_stats(struct net_device *bond_dev, memcpy(stats, &bond->bond_stats, sizeof(*stats)); bond_for_each_slave_rcu(bond, slave, iter) { - const struct rtnl_link_stats64 *new = - dev_get_stats(slave->dev, &temp); + dev_get_stats(slave->dev, &temp); - bond_fold_stats(stats, new, &slave->slave_stats); + bond_fold_stats(stats, &temp, &slave->slave_stats); /* save off the slave stats for the next run */ - memcpy(&slave->slave_stats, new, sizeof(*new)); + memcpy(&slave->slave_stats, &temp, sizeof(temp)); } memcpy(&bond->bond_stats, stats, sizeof(*stats)); diff --git a/drivers/net/ethernet/hisilicon/hns/hns_ethtool.c b/drivers/net/ethernet/hisilicon/hns/hns_ethtool.c index a6e3f07caf99..ee2172011051 100644 --- a/drivers/net/ethernet/hisilicon/hns/hns_ethtool.c +++ b/drivers/net/ethernet/hisilicon/hns/hns_ethtool.c @@ -839,8 +839,7 @@ static void hns_get_ethtool_stats(struct net_device *netdev, u64 *p = data; struct hns_nic_priv *priv = netdev_priv(netdev); struct hnae_handle *h = priv->ae_handle; - const struct rtnl_link_stats64 *net_stats; - struct rtnl_link_stats64 temp; + struct rtnl_link_stats64 net_stats; if (!h->dev->ops->get_stats || !h->dev->ops->update_stats) { netdev_err(netdev, "get_stats or update_stats is null!\n"); @@ -849,32 +848,32 @@ static void hns_get_ethtool_stats(struct net_device *netdev, h->dev->ops->update_stats(h, &netdev->stats); - net_stats = dev_get_stats(netdev, &temp); + dev_get_stats(netdev, &net_stats); /* get netdev statistics */ - p[0] = net_stats->rx_packets; - p[1] = net_stats->tx_packets; - p[2] = net_stats->rx_bytes; - p[3] = net_stats->tx_bytes; - p[4] = net_stats->rx_errors; - p[5] = net_stats->tx_errors; - p[6] = net_stats->rx_dropped; - p[7] = net_stats->tx_dropped; - p[8] = net_stats->multicast; - p[9] = net_stats->collisions; - p[10] = net_stats->rx_over_errors; - p[11] = net_stats->rx_crc_errors; - p[12] = net_stats->rx_frame_errors; - p[13] = net_stats->rx_fifo_errors; - p[14] = net_stats->rx_missed_errors; - p[15] = net_stats->tx_aborted_errors; - p[16] = net_stats->tx_carrier_errors; - p[17] = net_stats->tx_fifo_errors; - p[18] = net_stats->tx_heartbeat_errors; - p[19] = net_stats->rx_length_errors; - p[20] = net_stats->tx_window_errors; - p[21] = net_stats->rx_compressed; - p[22] = net_stats->tx_compressed; + p[0] = net_stats.rx_packets; + p[1] = net_stats.tx_packets; + p[2] = net_stats.rx_bytes; + p[3] = net_stats.tx_bytes; + p[4] = net_stats.rx_errors; + p[5] = net_stats.tx_errors; + p[6] = net_stats.rx_dropped; + p[7] = net_stats.tx_dropped; + p[8] = net_stats.multicast; + p[9] = net_stats.collisions; + p[10] = net_stats.rx_over_errors; + p[11] = net_stats.rx_crc_errors; + p[12] = net_stats.rx_frame_errors; + p[13] = net_stats.rx_fifo_errors; + p[14] = net_stats.rx_missed_errors; + p[15] = net_stats.tx_aborted_errors; + p[16] = net_stats.tx_carrier_errors; + p[17] = net_stats.tx_fifo_errors; + p[18] = net_stats.tx_heartbeat_errors; + p[19] = net_stats.rx_length_errors; + p[20] = net_stats.tx_window_errors; + p[21] = net_stats.rx_compressed; + p[22] = net_stats.tx_compressed; p[23] = netdev->rx_dropped.counter; p[24] = netdev->tx_dropped.counter; diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c index a280aa34ca1d..2b8084664403 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c @@ -1295,19 +1295,18 @@ static void ixgbe_get_ethtool_stats(struct net_device *netdev, struct ethtool_stats *stats, u64 *data) { struct ixgbe_adapter *adapter = netdev_priv(netdev); - struct rtnl_link_stats64 temp; - const struct rtnl_link_stats64 *net_stats; + struct rtnl_link_stats64 net_stats; unsigned int start; struct ixgbe_ring *ring; int i, j; char *p = NULL; ixgbe_update_stats(adapter); - net_stats = dev_get_stats(netdev, &temp); + dev_get_stats(netdev, &net_stats); for (i = 0; i < IXGBE_GLOBAL_STATS_LEN; i++) { switch (ixgbe_gstrings_stats[i].type) { case NETDEV_STATS: - p = (char *) net_stats + + p = (char *) &net_stats + ixgbe_gstrings_stats[i].stat_offset; break; case IXGBE_STATS: diff --git a/drivers/net/ethernet/intel/ixgbevf/ethtool.c b/drivers/net/ethernet/intel/ixgbevf/ethtool.c index e49fb1cd9a99..3b9b7e5c2998 100644 --- a/drivers/net/ethernet/intel/ixgbevf/ethtool.c +++ b/drivers/net/ethernet/intel/ixgbevf/ethtool.c @@ -420,19 +420,18 @@ static void ixgbevf_get_ethtool_stats(struct net_device *netdev, struct ethtool_stats *stats, u64 *data) { struct ixgbevf_adapter *adapter = netdev_priv(netdev); - struct rtnl_link_stats64 temp; - const struct rtnl_link_stats64 *net_stats; + struct rtnl_link_stats64 net_stats; unsigned int start; struct ixgbevf_ring *ring; int i, j; char *p; ixgbevf_update_stats(adapter); - net_stats = dev_get_stats(netdev, &temp); + dev_get_stats(netdev, &net_stats); for (i = 0; i < IXGBEVF_GLOBAL_STATS_LEN; i++) { switch (ixgbevf_gstrings_stats[i].type) { case NETDEV_STATS: - p = (char *)net_stats + + p = (char *)&net_stats + ixgbevf_gstrings_stats[i].stat_offset; break; case IXGBEVF_STATS: diff --git a/drivers/net/net_failover.c b/drivers/net/net_failover.c index 2a4892402ed8..4f83165412bd 100644 --- a/drivers/net/net_failover.c +++ b/drivers/net/net_failover.c @@ -183,7 +183,6 @@ static void net_failover_get_stats(struct net_device *dev, struct rtnl_link_stats64 *stats) { struct net_failover_info *nfo_info = netdev_priv(dev); - const struct rtnl_link_stats64 *new; struct rtnl_link_stats64 temp; struct net_device *slave_dev; @@ -194,16 +193,16 @@ static void net_failover_get_stats(struct net_device *dev, slave_dev = rcu_dereference(nfo_info->primary_dev); if (slave_dev) { - new = dev_get_stats(slave_dev, &temp); - net_failover_fold_stats(stats, new, &nfo_info->primary_stats); - memcpy(&nfo_info->primary_stats, new, sizeof(*new)); + dev_get_stats(slave_dev, &temp); + net_failover_fold_stats(stats, &temp, &nfo_info->primary_stats); + memcpy(&nfo_info->primary_stats, &temp, sizeof(temp)); } slave_dev = rcu_dereference(nfo_info->standby_dev); if (slave_dev) { - new = dev_get_stats(slave_dev, &temp); - net_failover_fold_stats(stats, new, &nfo_info->standby_stats); - memcpy(&nfo_info->standby_stats, new, sizeof(*new)); + dev_get_stats(slave_dev, &temp); + net_failover_fold_stats(stats, &temp, &nfo_info->standby_stats); + memcpy(&nfo_info->standby_stats, &temp, sizeof(temp)); } rcu_read_unlock(); diff --git a/drivers/parisc/led.c b/drivers/parisc/led.c index c8c6b2301dc9..cc6108785323 100644 --- a/drivers/parisc/led.c +++ b/drivers/parisc/led.c @@ -360,8 +360,7 @@ static __inline__ int led_get_net_activity(void) for_each_netdev(&init_net, dev) { struct in_device *in_dev = in_dev_get(dev); - const struct rtnl_link_stats64 *stats; - struct rtnl_link_stats64 temp; + struct rtnl_link_stats64 stats; if (!in_dev || !in_dev->ifa_list || ipv4_is_loopback(in_dev->ifa_list->ifa_local)) { @@ -371,9 +370,9 @@ static __inline__ int led_get_net_activity(void) in_dev_put(in_dev); - stats = dev_get_stats(dev, &temp); - rx_total += stats->rx_packets; - tx_total += stats->tx_packets; + dev_get_stats(dev, &stats); + rx_total += stats.rx_packets; + tx_total += stats.tx_packets; } netif_lists_unlock(&init_net); diff --git a/drivers/scsi/fcoe/fcoe_transport.c b/drivers/scsi/fcoe/fcoe_transport.c index b927b3d84523..f8ba6495e745 100644 --- a/drivers/scsi/fcoe/fcoe_transport.c +++ b/drivers/scsi/fcoe/fcoe_transport.c @@ -170,11 +170,11 @@ void __fcoe_get_lesb(struct fc_lport *lport, struct fc_els_lesb *fc_lesb, struct net_device *netdev) { + struct rtnl_link_stats64 stats; unsigned int cpu; u32 lfc, vlfc, mdac; struct fc_stats *stats; struct fcoe_fc_els_lesb *lesb; - struct rtnl_link_stats64 temp; lfc = 0; vlfc = 0; @@ -190,8 +190,8 @@ void __fcoe_get_lesb(struct fc_lport *lport, lesb->lesb_link_fail = htonl(lfc); lesb->lesb_vlink_fail = htonl(vlfc); lesb->lesb_miss_fka = htonl(mdac); - lesb->lesb_fcs_error = - htonl(dev_get_stats(netdev, &temp)->rx_crc_errors); + dev_get_stats(netdev, &stats); + lesb->lesb_fcs_error = htonl(stats.rx_crc_errors); } EXPORT_SYMBOL_GPL(__fcoe_get_lesb); diff --git a/drivers/usb/gadget/function/rndis.c b/drivers/usb/gadget/function/rndis.c index 64de9f1b874c..7ec29e007ae9 100644 --- a/drivers/usb/gadget/function/rndis.c +++ b/drivers/usb/gadget/function/rndis.c @@ -169,14 +169,13 @@ static const u32 oid_supported_list[] = { static int gen_ndis_query_resp(struct rndis_params *params, u32 OID, u8 *buf, unsigned buf_len, rndis_resp_t *r) { + struct rtnl_link_stats64 stats; int retval = -ENOTSUPP; u32 length = 4; /* usually */ __le32 *outbuf; int i, count; rndis_query_cmplt_type *resp; struct net_device *net; - struct rtnl_link_stats64 temp; - const struct rtnl_link_stats64 *stats; if (!r) return -ENOMEM; resp = (rndis_query_cmplt_type *)r->buf; @@ -199,7 +198,7 @@ static int gen_ndis_query_resp(struct rndis_params *params, u32 OID, u8 *buf, resp->InformationBufferOffset = cpu_to_le32(16); net = params->dev; - stats = dev_get_stats(net, &temp); + dev_get_stats(net, &stats); switch (OID) { @@ -353,51 +352,41 @@ static int gen_ndis_query_resp(struct rndis_params *params, u32 OID, u8 *buf, case RNDIS_OID_GEN_XMIT_OK: if (rndis_debug > 1) pr_debug("%s: RNDIS_OID_GEN_XMIT_OK\n", __func__); - if (stats) { - *outbuf = cpu_to_le32(stats->tx_packets - - stats->tx_errors - stats->tx_dropped); - retval = 0; - } + *outbuf = cpu_to_le32(stats.tx_packets - stats.tx_errors - + stats.tx_dropped); + retval = 0; break; /* mandatory */ case RNDIS_OID_GEN_RCV_OK: if (rndis_debug > 1) pr_debug("%s: RNDIS_OID_GEN_RCV_OK\n", __func__); - if (stats) { - *outbuf = cpu_to_le32(stats->rx_packets - - stats->rx_errors - stats->rx_dropped); - retval = 0; - } + *outbuf = cpu_to_le32(stats.rx_packets - stats.rx_errors - + stats.rx_dropped); + retval = 0; break; /* mandatory */ case RNDIS_OID_GEN_XMIT_ERROR: if (rndis_debug > 1) pr_debug("%s: RNDIS_OID_GEN_XMIT_ERROR\n", __func__); - if (stats) { - *outbuf = cpu_to_le32(stats->tx_errors); - retval = 0; - } + *outbuf = cpu_to_le32(stats.tx_errors); + retval = 0; break; /* mandatory */ case RNDIS_OID_GEN_RCV_ERROR: if (rndis_debug > 1) pr_debug("%s: RNDIS_OID_GEN_RCV_ERROR\n", __func__); - if (stats) { - *outbuf = cpu_to_le32(stats->rx_errors); - retval = 0; - } + *outbuf = cpu_to_le32(stats.rx_errors); + retval = 0; break; /* mandatory */ case RNDIS_OID_GEN_RCV_NO_BUFFER: pr_debug("%s: RNDIS_OID_GEN_RCV_NO_BUFFER\n", __func__); - if (stats) { - *outbuf = cpu_to_le32(stats->rx_dropped); - retval = 0; - } + *outbuf = cpu_to_le32(stats.rx_dropped); + retval = 0; break; /* ieee802.3 OIDs (table 4-3) */ @@ -449,10 +438,8 @@ static int gen_ndis_query_resp(struct rndis_params *params, u32 OID, u8 *buf, /* mandatory */ case RNDIS_OID_802_3_RCV_ERROR_ALIGNMENT: pr_debug("%s: RNDIS_OID_802_3_RCV_ERROR_ALIGNMENT\n", __func__); - if (stats) { - *outbuf = cpu_to_le32(stats->rx_frame_errors); - retval = 0; - } + *outbuf = cpu_to_le32(stats.rx_frame_errors); + retval = 0; break; /* mandatory */ diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 2cc4800238bd..7075a6e94486 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -4562,8 +4562,7 @@ void netdev_notify_peers(struct net_device *dev); void netdev_features_change(struct net_device *dev); /* Load a device via the kmod */ void dev_load(struct net *net, const char *name); -struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev, - struct rtnl_link_stats64 *storage); +void dev_get_stats(struct net_device *dev, struct rtnl_link_stats64 *storage); void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64, const struct net_device_stats *netdev_stats); void dev_fetch_sw_netstats(struct rtnl_link_stats64 *s, diff --git a/net/8021q/vlanproc.c b/net/8021q/vlanproc.c index ec87dea23719..3a6682d79630 100644 --- a/net/8021q/vlanproc.c +++ b/net/8021q/vlanproc.c @@ -242,26 +242,25 @@ static int vlandev_seq_show(struct seq_file *seq, void *offset) { struct net_device *vlandev = (struct net_device *) seq->private; const struct vlan_dev_priv *vlan = vlan_dev_priv(vlandev); - struct rtnl_link_stats64 temp; - const struct rtnl_link_stats64 *stats; static const char fmt64[] = "%30s %12llu\n"; + struct rtnl_link_stats64 stats; int i; if (!is_vlan_dev(vlandev)) return 0; - stats = dev_get_stats(vlandev, &temp); + dev_get_stats(vlandev, &stats); seq_printf(seq, "%s VID: %d REORDER_HDR: %i dev->priv_flags: %hx\n", vlandev->name, vlan->vlan_id, (int)(vlan->flags & 1), vlandev->priv_flags); - seq_printf(seq, fmt64, "total frames received", stats->rx_packets); - seq_printf(seq, fmt64, "total bytes received", stats->rx_bytes); - seq_printf(seq, fmt64, "Broadcast/Multicast Rcvd", stats->multicast); + seq_printf(seq, fmt64, "total frames received", stats.rx_packets); + seq_printf(seq, fmt64, "total bytes received", stats.rx_bytes); + seq_printf(seq, fmt64, "Broadcast/Multicast Rcvd", stats.multicast); seq_puts(seq, "\n"); - seq_printf(seq, fmt64, "total frames transmitted", stats->tx_packets); - seq_printf(seq, fmt64, "total bytes transmitted", stats->tx_bytes); + seq_printf(seq, fmt64, "total frames transmitted", stats.tx_packets); + seq_printf(seq, fmt64, "total bytes transmitted", stats.tx_bytes); seq_printf(seq, "Device: %s", vlan->real_dev->name); /* now show all PRIORITY mappings relating to this VLAN */ seq_printf(seq, "\nINGRESS priority mappings: " diff --git a/net/core/dev.c b/net/core/dev.c index 49963aaf12b5..93618300ac90 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -10398,13 +10398,12 @@ EXPORT_SYMBOL(netdev_stats_to_stats64); * @dev: device to get statistics from * @storage: place to store stats * - * Get network statistics from device. Return @storage. + * Get network statistics from device. * The device driver may provide its own method by setting * dev->netdev_ops->get_stats64 or dev->netdev_ops->get_stats; * otherwise the internal statistics structure is used. */ -struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev, - struct rtnl_link_stats64 *storage) +void dev_get_stats(struct net_device *dev, struct rtnl_link_stats64 *storage) { const struct net_device_ops *ops = dev->netdev_ops; @@ -10419,7 +10418,6 @@ struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev, storage->rx_dropped += (unsigned long)atomic_long_read(&dev->rx_dropped); storage->tx_dropped += (unsigned long)atomic_long_read(&dev->tx_dropped); storage->rx_nohandler += (unsigned long)atomic_long_read(&dev->rx_nohandler); - return storage; } EXPORT_SYMBOL(dev_get_stats); diff --git a/net/core/net-procfs.c b/net/core/net-procfs.c index 4784703c1e39..64666ba7ccab 100644 --- a/net/core/net-procfs.c +++ b/net/core/net-procfs.c @@ -80,26 +80,27 @@ static void dev_seq_stop(struct seq_file *seq, void *v) static void dev_seq_printf_stats(struct seq_file *seq, struct net_device *dev) { - struct rtnl_link_stats64 temp; - const struct rtnl_link_stats64 *stats = dev_get_stats(dev, &temp); + struct rtnl_link_stats64 stats; + + dev_get_stats(dev, &stats); seq_printf(seq, "%6s: %7llu %7llu %4llu %4llu %4llu %5llu %10llu %9llu " "%8llu %7llu %4llu %4llu %4llu %5llu %7llu %10llu\n", - dev->name, stats->rx_bytes, stats->rx_packets, - stats->rx_errors, - stats->rx_dropped + stats->rx_missed_errors, - stats->rx_fifo_errors, - stats->rx_length_errors + stats->rx_over_errors + - stats->rx_crc_errors + stats->rx_frame_errors, - stats->rx_compressed, stats->multicast, - stats->tx_bytes, stats->tx_packets, - stats->tx_errors, stats->tx_dropped, - stats->tx_fifo_errors, stats->collisions, - stats->tx_carrier_errors + - stats->tx_aborted_errors + - stats->tx_window_errors + - stats->tx_heartbeat_errors, - stats->tx_compressed); + dev->name, stats.rx_bytes, stats.rx_packets, + stats.rx_errors, + stats.rx_dropped + stats.rx_missed_errors, + stats.rx_fifo_errors, + stats.rx_length_errors + stats.rx_over_errors + + stats.rx_crc_errors + stats.rx_frame_errors, + stats.rx_compressed, stats.multicast, + stats.tx_bytes, stats.tx_packets, + stats.tx_errors, stats.tx_dropped, + stats.tx_fifo_errors, stats.collisions, + stats.tx_carrier_errors + + stats.tx_aborted_errors + + stats.tx_window_errors + + stats.tx_heartbeat_errors, + stats.tx_compressed); } /* diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index 8604183678fc..5d89c85b42d4 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -586,10 +586,11 @@ static ssize_t netstat_show(const struct device *d, offset % sizeof(u64) != 0); if (dev_isalive(dev)) { - struct rtnl_link_stats64 temp; - const struct rtnl_link_stats64 *stats = dev_get_stats(dev, &temp); + struct rtnl_link_stats64 stats; - ret = sprintf(buf, fmt_u64, *(u64 *)(((u8 *)stats) + offset)); + dev_get_stats(dev, &stats); + + ret = sprintf(buf, fmt_u64, *(u64 *)(((u8 *)&stats) + offset)); } return ret; diff --git a/net/openvswitch/vport.c b/net/openvswitch/vport.c index 4ed7e52c7012..215a818bf9ce 100644 --- a/net/openvswitch/vport.c +++ b/net/openvswitch/vport.c @@ -269,19 +269,18 @@ void ovs_vport_del(struct vport *vport) */ void ovs_vport_get_stats(struct vport *vport, struct ovs_vport_stats *stats) { - const struct rtnl_link_stats64 *dev_stats; - struct rtnl_link_stats64 temp; - - dev_stats = dev_get_stats(vport->dev, &temp); - stats->rx_errors = dev_stats->rx_errors; - stats->tx_errors = dev_stats->tx_errors; - stats->tx_dropped = dev_stats->tx_dropped; - stats->rx_dropped = dev_stats->rx_dropped; - - stats->rx_bytes = dev_stats->rx_bytes; - stats->rx_packets = dev_stats->rx_packets; - stats->tx_bytes = dev_stats->tx_bytes; - stats->tx_packets = dev_stats->tx_packets; + struct rtnl_link_stats64 dev_stats; + + dev_get_stats(vport->dev, &dev_stats); + stats->rx_errors = dev_stats.rx_errors; + stats->tx_errors = dev_stats.tx_errors; + stats->tx_dropped = dev_stats.tx_dropped; + stats->rx_dropped = dev_stats.rx_dropped; + + stats->rx_bytes = dev_stats.rx_bytes; + stats->rx_packets = dev_stats.rx_packets; + stats->tx_bytes = dev_stats.tx_bytes; + stats->tx_packets = dev_stats.tx_packets; } /** From patchwork Thu Jan 7 09:49:48 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vladimir Oltean X-Patchwork-Id: 12003451 X-Patchwork-Delegate: kuba@kernel.org 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 D47FEC433E6 for ; Thu, 7 Jan 2021 09:52:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A24682333F for ; Thu, 7 Jan 2021 09:52:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727989AbhAGJwG (ORCPT ); Thu, 7 Jan 2021 04:52:06 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41018 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727961AbhAGJv7 (ORCPT ); Thu, 7 Jan 2021 04:51:59 -0500 Received: from mail-ej1-x632.google.com (mail-ej1-x632.google.com [IPv6:2a00:1450:4864:20::632]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 78DBAC0612FF for ; Thu, 7 Jan 2021 01:51:17 -0800 (PST) Received: by mail-ej1-x632.google.com with SMTP id qw4so8759405ejb.12 for ; Thu, 07 Jan 2021 01:51:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=Nem25OmsmkjNSBbvqZ41iqgC+QLTepbfzN5gUedefIM=; b=QTQfk6NwC9aHiSW6tnJLMlXC49jVo3IefyXWD0DWThFSllY63Yv3fUoW+YjVwpt25i uCA+UqbZKtGMIlv1RSc5ftENwzGJvR9YNjMSt4ZHkvYyRpDufgt15CSN+rnjiVZjjfDW 3wJfv2FZmNhs8vELqjCL12M/iDl9SKTnjpqUkpID2HEQONSpiy/Oz3vkiJOZFjgn3QSU 6BCew6hQqi9Xd+3p4evemicLXAhzqpZxuIUFhEvxhPPaRs3YI7Hoy/62Zwj+1apUox+m 9BXQsF36qHS4Y4gQuB2RCbljS642phou8/u9B2AWWkD5lvtGeBZyAe7jc8Ww2w/Y8IxY TMUQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=Nem25OmsmkjNSBbvqZ41iqgC+QLTepbfzN5gUedefIM=; b=HiteX04TuyXY0PzPmJ0qHfPRDZSkpxKWDBRi0Fh2p16KLITd/flpfJmLANMbYfhx/7 SfZR4yO9E/fDedAs229TUmJV6I025+y/1d5JOlYCcZyUwHLDwesPM7g8m3Ijt4HFwyh9 plIAFxEerIGnDFmgVYN+wMnDvOCIYHt5E0OypSoLtFGJXMOs+fMm7VEJdTzR6mCIsxQq e1AKsX7A0YAVmJXCbUIzuoq9k9dX/qLEGIZ60jxSVIyMF28Hux19syz/zi9RL7qiU574 u83fJ9JMsTJCx+8AmwByB86DRNKqJ0afWrE4mGVJdG1oD2tIFVbjHk1XQvRm6tN9vCvx c5vA== X-Gm-Message-State: AOAM532vXVUN7CwT2VPfFLqDPFVGe1MiLtzHzSlkJgpOoZnch8O2+QQw aWXXx1hN9Snj9g62dyxwUtqEU9DvbkgFNA== X-Google-Smtp-Source: ABdhPJywu7JlHdM+ODHSPcaQ4L3iYf8jBzPnnhNkefzoyske7RnJ1LBa0+3vUVnll1dtMJPUMiu18w== X-Received: by 2002:a17:906:c097:: with SMTP id f23mr5909527ejz.136.1610013076245; Thu, 07 Jan 2021 01:51:16 -0800 (PST) Received: from localhost.localdomain (5-12-227-87.residential.rdsnet.ro. [5.12.227.87]) by smtp.gmail.com with ESMTPSA id k15sm2251571ejc.79.2021.01.07.01.51.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 Jan 2021 01:51:15 -0800 (PST) From: Vladimir Oltean To: "David S . Miller" , Jakub Kicinski Cc: netdev@vger.kernel.org, Andrew Lunn , Florian Fainelli , Cong Wang , Stephen Hemminger , Eric Dumazet , George McCollister , Oleksij Rempel , Jay Vosburgh , Veaceslav Falico , Andy Gospodarek , Arnd Bergmann , Taehee Yoo , Jiri Pirko , Florian Westphal Subject: [PATCH v3 net-next 09/12] net: net_failover: ensure .ndo_get_stats64 can sleep Date: Thu, 7 Jan 2021 11:49:48 +0200 Message-Id: <20210107094951.1772183-10-olteanv@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210107094951.1772183-1-olteanv@gmail.com> References: <20210107094951.1772183-1-olteanv@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Vladimir Oltean The failover framework sets up a virtio_net interface [ when it has the VIRTIO_NET_F_STANDBY feature ] and a VF interface, having the same MAC address, in a standby/active relationship. When the active VF is unplugged, the standby virtio_net temporarily kicks in. The failover framework registers a common upper for the active and the standby interface, which is what the application layer uses. This is similar to bonding/team. The statistics of the upper interface are the sum of the statistics of the active and of the standby interface. There is an effort to convert .ndo_get_stats64 to sleepable context, and for that to work, we need to prevent callers of dev_get_stats from using atomic locking. The failover driver needs protection via an RCU read-side critical section to access the standby and the active interface. This has two features: - It is atomic: this needs to change. - It is reentrant: this is ok, because generally speaking, dev_get_stats is recursive, and taking global locks is a bad thing from a recursive context. A better locking architecture would be to do what the team driver does. Instead of using something as broad as the rtnl_mutex to ensure serialization of updates, it should use something more specific, like a private mutex. This patch adds that and names it slaves_lock. The slaves_lock now protects the only updater, the rcu_assign_pointer sections from net_failover_slave_register. In the team driver, a separate lockdep class is created for each team lock, to account for possible nesting (team over team over ...). For the net_failover driver, we can do something simpler, which is to just not hold any lock while we call dev_get_stats recursively. We can "cheat" and use dev_hold to take a reference on the active and backup interfaces, and netdev_wait_allrefs() will just have to wait until we finish. Signed-off-by: Vladimir Oltean --- Changes in v3: None. Changes in v2: Switched to the new scheme of holding just a refcnt to the slave interfaces while recursing with dev_get_stats. drivers/net/net_failover.c | 62 +++++++++++++++++++++++++++----------- include/net/net_failover.h | 9 ++++-- 2 files changed, 52 insertions(+), 19 deletions(-) diff --git a/drivers/net/net_failover.c b/drivers/net/net_failover.c index 4f83165412bd..c83066b0ef70 100644 --- a/drivers/net/net_failover.c +++ b/drivers/net/net_failover.c @@ -27,6 +27,9 @@ #include #include +#define nfo_dereference(nfo_info, p) \ + rcu_dereference_protected(p, lockdep_is_held(&nfo_info->slaves_lock)) + static bool net_failover_xmit_ready(struct net_device *dev) { return netif_running(dev) && netif_carrier_ok(dev); @@ -183,32 +186,48 @@ static void net_failover_get_stats(struct net_device *dev, struct rtnl_link_stats64 *stats) { struct net_failover_info *nfo_info = netdev_priv(dev); - struct rtnl_link_stats64 temp; - struct net_device *slave_dev; + struct rtnl_link_stats64 primary_stats; + struct rtnl_link_stats64 standby_stats; + struct net_device *primary_dev; + struct net_device *standby_dev; - spin_lock(&nfo_info->stats_lock); - memcpy(stats, &nfo_info->failover_stats, sizeof(*stats)); + mutex_lock(&nfo_info->slaves_lock); - rcu_read_lock(); + primary_dev = nfo_dereference(nfo_info, nfo_info->primary_dev); + if (primary_dev) + dev_hold(primary_dev); - slave_dev = rcu_dereference(nfo_info->primary_dev); - if (slave_dev) { - dev_get_stats(slave_dev, &temp); - net_failover_fold_stats(stats, &temp, &nfo_info->primary_stats); - memcpy(&nfo_info->primary_stats, &temp, sizeof(temp)); + standby_dev = nfo_dereference(nfo_info, nfo_info->standby_dev); + if (standby_dev) + dev_hold(standby_dev); + + mutex_unlock(&nfo_info->slaves_lock); + + /* Don't hold slaves_lock while calling dev_get_stats, just a + * reference to ensure they won't get unregistered. + */ + if (primary_dev) { + dev_get_stats(primary_dev, &primary_stats); + dev_put(primary_dev); } - slave_dev = rcu_dereference(nfo_info->standby_dev); - if (slave_dev) { - dev_get_stats(slave_dev, &temp); - net_failover_fold_stats(stats, &temp, &nfo_info->standby_stats); - memcpy(&nfo_info->standby_stats, &temp, sizeof(temp)); + if (standby_dev) { + dev_get_stats(standby_dev, &standby_stats); + dev_put(standby_dev); } - rcu_read_unlock(); + mutex_lock(&nfo_info->stats_lock); + + memcpy(stats, &nfo_info->failover_stats, sizeof(*stats)); + + net_failover_fold_stats(stats, &primary_stats, &nfo_info->primary_stats); + memcpy(&nfo_info->primary_stats, &primary_stats, sizeof(primary_stats)); + net_failover_fold_stats(stats, &standby_stats, &nfo_info->standby_stats); + memcpy(&nfo_info->standby_stats, &standby_stats, sizeof(standby_stats)); memcpy(&nfo_info->failover_stats, stats, sizeof(*stats)); - spin_unlock(&nfo_info->stats_lock); + + mutex_unlock(&nfo_info->stats_lock); } static int net_failover_change_mtu(struct net_device *dev, int new_mtu) @@ -540,6 +559,8 @@ static int net_failover_slave_register(struct net_device *slave_dev, primary_dev = rtnl_dereference(nfo_info->primary_dev); slave_is_standby = slave_dev->dev.parent == failover_dev->dev.parent; + mutex_lock(&nfo_info->slaves_lock); + if (slave_is_standby) { rcu_assign_pointer(nfo_info->standby_dev, slave_dev); standby_dev = slave_dev; @@ -552,6 +573,8 @@ static int net_failover_slave_register(struct net_device *slave_dev, failover_dev->max_mtu = slave_dev->max_mtu; } + mutex_unlock(&nfo_info->slaves_lock); + net_failover_lower_state_changed(slave_dev, primary_dev, standby_dev); net_failover_compute_features(failover_dev); @@ -709,6 +732,7 @@ static struct failover_ops net_failover_ops = { struct failover *net_failover_create(struct net_device *standby_dev) { struct device *dev = standby_dev->dev.parent; + struct net_failover_info *nfo_info; struct net_device *failover_dev; struct failover *failover; int err; @@ -753,6 +777,10 @@ struct failover *net_failover_create(struct net_device *standby_dev) failover_dev->min_mtu = standby_dev->min_mtu; failover_dev->max_mtu = standby_dev->max_mtu; + nfo_info = netdev_priv(failover_dev); + mutex_init(&nfo_info->slaves_lock); + mutex_init(&nfo_info->stats_lock); + err = register_netdev(failover_dev); if (err) { dev_err(dev, "Unable to register failover_dev!\n"); diff --git a/include/net/net_failover.h b/include/net/net_failover.h index b12a1c469d1c..988cdfaf14ca 100644 --- a/include/net/net_failover.h +++ b/include/net/net_failover.h @@ -23,8 +23,13 @@ struct net_failover_info { /* aggregated stats */ struct rtnl_link_stats64 failover_stats; - /* spinlock while updating stats */ - spinlock_t stats_lock; + /* lock for updating stats */ + struct mutex stats_lock; + + /* lock for protecting lower interfaces. + * TODO: convert all rtnl_dereference instances to nfo_dereference + */ + struct mutex slaves_lock; }; struct failover *net_failover_create(struct net_device *standby_dev); From patchwork Thu Jan 7 09:49:49 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vladimir Oltean X-Patchwork-Id: 12003423 X-Patchwork-Delegate: kuba@kernel.org 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 DD141C43333 for ; Thu, 7 Jan 2021 09:52:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C2B9E2333D for ; Thu, 7 Jan 2021 09:52:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727977AbhAGJwC (ORCPT ); Thu, 7 Jan 2021 04:52:02 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41116 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727957AbhAGJv7 (ORCPT ); Thu, 7 Jan 2021 04:51:59 -0500 Received: from mail-ej1-x62b.google.com (mail-ej1-x62b.google.com [IPv6:2a00:1450:4864:20::62b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E91E6C061285 for ; Thu, 7 Jan 2021 01:51:18 -0800 (PST) Received: by mail-ej1-x62b.google.com with SMTP id g20so8937642ejb.1 for ; Thu, 07 Jan 2021 01:51:18 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=rrVC3mmeskMWF5wSTd77r+DBVddBmm9itzymiAtQXiI=; b=OjypJGlPC67dx3VlsmlyqUDvXk+D0l2Kq8Q8X7rVnmYIAXzSKAKg9aGjQEjKmUt8ES stig7EyEuuSSGlqXDBNsrj78nB1uzdji2ZKXZYp+VFG1kXh0TEXCeGku2lNwmH6W4dJW Bxfb/6M4xsbRP1E2/dz68+pF3KgK2gZkSTZvf1LvtTxWbH3eCyXC6i6KO0UArVkyJOPD /M3onrvzMDmLeYvq94uNNmttArDWMp1MR3hjYKVV77SEuzSPA701rDnex8ExCy+gX0Hc TqjwjC39QwhdYbcmnTaHP1mZ5lRdR2+aU0ce/L7Fhsu0bWTQvqErg35wQWvql1/GHGDk Q+NQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=rrVC3mmeskMWF5wSTd77r+DBVddBmm9itzymiAtQXiI=; b=ubsqGE/2pmUD08OeWeclcuBW1iwtARCxVgLIt0ExEef/OaPCJWyd6jZbp8tlWdBTX0 z1gwUsM5kDCJPm9RmlL6R4ziPw7E0ZjMFoEKq0773nxEMOadfd/eLiQJaX89mHgAce6a 8qS9R9Cy0A6ZnVg4f+IhEuwcW8pBvLnJ3Y1RILNxjpM/4hQXz1ZJrVfOmavfAfXnnw58 dU2Z23Ov8ukypedXJl/kfcpgxJTb3piIAj1QTLtf+RZraXx5ubPJsBBjluCv2Gyt5BE9 6ZFzOHHIeHFhgIjlXQYxUyoCaS/W6UQSa+F9JKEEuvcAbtVoK9ywRs7xZS/2fh4UDv6H EZmQ== X-Gm-Message-State: AOAM532aNpLBjCp9icMkJk/HIgPl0MpsZ79HOb+ezXdNcYSFz7nAn/C7 JyX11dAtW2NLscPssuNXFOA= X-Google-Smtp-Source: ABdhPJweFJlAc+TwAyxWNg/q4RUJVAlDM/DU67T2hXKGSTdBVWN5RRYeoyL144RPfsxx9FnU82RuvQ== X-Received: by 2002:a17:906:f949:: with SMTP id ld9mr5817617ejb.401.1610013077659; Thu, 07 Jan 2021 01:51:17 -0800 (PST) Received: from localhost.localdomain (5-12-227-87.residential.rdsnet.ro. [5.12.227.87]) by smtp.gmail.com with ESMTPSA id k15sm2251571ejc.79.2021.01.07.01.51.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 Jan 2021 01:51:17 -0800 (PST) From: Vladimir Oltean To: "David S . Miller" , Jakub Kicinski Cc: netdev@vger.kernel.org, Andrew Lunn , Florian Fainelli , Cong Wang , Stephen Hemminger , Eric Dumazet , George McCollister , Oleksij Rempel , Jay Vosburgh , Veaceslav Falico , Andy Gospodarek , Arnd Bergmann , Taehee Yoo , Jiri Pirko , Florian Westphal Subject: [PATCH v3 net-next 10/12] net: bonding: ensure .ndo_get_stats64 can sleep Date: Thu, 7 Jan 2021 11:49:49 +0200 Message-Id: <20210107094951.1772183-11-olteanv@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210107094951.1772183-1-olteanv@gmail.com> References: <20210107094951.1772183-1-olteanv@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Vladimir Oltean There is an effort to convert .ndo_get_stats64 to sleepable context, and for that to work, we need to prevent callers of dev_get_stats from using atomic locking. The bonding driver retrieves its statistics recursively from its lower interfaces, with additional care to only count packets sent/received while those lowers were actually enslaved to the bond - see commit 5f0c5f73e5ef ("bonding: make global bonding stats more reliable"). Since commit 87163ef9cda7 ("bonding: remove last users of bond->lock and bond->lock itself"), the bonding driver uses the following protection for its array of slaves: RCU for readers and rtnl_mutex for updaters. This is not great because there is another movement [ somehow simultaneous with the one to make .ndo_get_stats64 sleepable ] to reduce driver usage of rtnl_mutex. This makes sense, because the rtnl_mutex has become a very contended resource. The aforementioned commit removed an interesting comment: /* [...] we can't hold bond->lock [...] because we'll * deadlock. The only solution is to rely on the fact * that we're under rtnl_lock here, and the slaves * list won't change. This doesn't solve the problem * of setting the slave's MTU while it is * transmitting, but the assumption is that the base * driver can handle that. * * TODO: figure out a way to safely iterate the slaves * list, but without holding a lock around the actual * call to the base driver. */ The above summarizes pretty well the challenges we have with nested bonding interfaces (bond over bond over bond over...), which need to be addressed by a better locking scheme that also not relies on the bloated rtnl_mutex. Instead of using something as broad as the rtnl_mutex to ensure serialization of updates to the slave array, we can reintroduce a private mutex in the bonding driver, called slaves_lock. This mutex circles the only updater, bond_update_slave_arr, and ensures that whatever other readers want to see a consistent slave array, they don't need to hold the rtnl_mutex for that. Now _of_course_ I did not convert the entire driver to use bond_for_each_slave protected by the bond->slaves_lock, and rtnl_dereference to bond_dereference. I just started that process by converting the one reader I needed: ndo_get_stats64. Not only is it nice to not hold rtnl_mutex in .ndo_get_stats64, but it is also in fact forbidden to do so (since top-level callers may hold netif_lists_lock, which is a sub-lock of the rtnl_mutex, and therefore this would cause a lock inversion and a deadlock). To solve the nesting problem, the simple way is to not hold any locks when recursing into the slave netdev operation, which is exactly the approach that we take. We can "cheat" and use dev_hold to take a reference on the slave net_device, which is enough to ensure that netdev_wait_allrefs() waits until we finish, and the kernel won't fault. However, the slave structure might no longer be valid, just its associated net_device. That isn't a biggie. We just need to do some more work to ensure that the slave exists after we took the statistics, and if it still does, reapply the logic from Andy's commit 5f0c5f73e5ef. Signed-off-by: Vladimir Oltean --- Changes in v3: - Added kfree(dev_stats); - Removed the now useless stats_lock (bond->bond_stats and slave->slave_stats are now protected by bond->slaves_lock) Changes in v2: Switched to the new scheme of holding just a refcnt to the slave interfaces while recursing with dev_get_stats. drivers/net/bonding/bond_main.c | 118 +++++++++++++++----------------- include/net/bonding.h | 49 ++++++++++++- 2 files changed, 104 insertions(+), 63 deletions(-) diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 714aa0e5d041..6e38079ea66d 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -3693,77 +3693,64 @@ static void bond_fold_stats(struct rtnl_link_stats64 *_res, } } -#ifdef CONFIG_LOCKDEP -static int bond_get_lowest_level_rcu(struct net_device *dev) -{ - struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1]; - struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1]; - int cur = 0, max = 0; - - now = dev; - iter = &dev->adj_list.lower; - - while (1) { - next = NULL; - while (1) { - ldev = netdev_next_lower_dev_rcu(now, &iter); - if (!ldev) - break; - - next = ldev; - niter = &ldev->adj_list.lower; - dev_stack[cur] = now; - iter_stack[cur++] = iter; - if (max <= cur) - max = cur; - break; - } - - if (!next) { - if (!cur) - return max; - next = dev_stack[--cur]; - niter = iter_stack[cur]; - } - - now = next; - iter = niter; - } - - return max; -} -#endif - static void bond_get_stats(struct net_device *bond_dev, struct rtnl_link_stats64 *stats) { struct bonding *bond = netdev_priv(bond_dev); - struct rtnl_link_stats64 temp; - struct list_head *iter; - struct slave *slave; - int nest_level = 0; + struct rtnl_link_stats64 *dev_stats; + struct net_device **slaves; + int i, res, num_slaves; + res = bond_get_slave_arr(bond, &slaves, &num_slaves); + if (res) { + netdev_err(bond->dev, + "failed to allocate memory for slave array\n"); + return; + } - rcu_read_lock(); -#ifdef CONFIG_LOCKDEP - nest_level = bond_get_lowest_level_rcu(bond_dev); -#endif + dev_stats = kcalloc(num_slaves, sizeof(*dev_stats), GFP_KERNEL); + if (!dev_stats) { + netdev_err(bond->dev, + "failed to allocate memory for slave stats\n"); + bond_put_slave_arr(slaves, num_slaves); + return; + } + + /* Recurse with no locks taken */ + for (i = 0; i < num_slaves; i++) + dev_get_stats(slaves[i], &dev_stats[i]); + + /* When taking the slaves lock again, the new slave array might be + * different from the original one. + */ + mutex_lock(&bond->slaves_lock); - spin_lock_nested(&bond->stats_lock, nest_level); memcpy(stats, &bond->bond_stats, sizeof(*stats)); - bond_for_each_slave_rcu(bond, slave, iter) { - dev_get_stats(slave->dev, &temp); + for (i = 0; i < num_slaves; i++) { + struct list_head *iter; + struct slave *slave; - bond_fold_stats(stats, &temp, &slave->slave_stats); + bond_for_each_slave(bond, slave, iter) { + if (slave->dev != slaves[i]) + continue; - /* save off the slave stats for the next run */ - memcpy(&slave->slave_stats, &temp, sizeof(temp)); + bond_fold_stats(stats, &dev_stats[i], + &slave->slave_stats); + + /* save off the slave stats for the next run */ + memcpy(&slave->slave_stats, &dev_stats[i], + sizeof(dev_stats[i])); + break; + } } memcpy(&bond->bond_stats, stats, sizeof(*stats)); - spin_unlock(&bond->stats_lock); - rcu_read_unlock(); + + mutex_unlock(&bond->slaves_lock); + + kfree(dev_stats); + bond_put_slave_arr(slaves, num_slaves); } static int bond_do_ioctl(struct net_device *bond_dev, struct ifreq *ifr, int cmd) @@ -4287,11 +4274,11 @@ static void bond_set_slave_arr(struct bonding *bond, { struct bond_up_slave *usable, *all; - usable = rtnl_dereference(bond->usable_slaves); + usable = bond_dereference(bond, bond->usable_slaves); rcu_assign_pointer(bond->usable_slaves, usable_slaves); kfree_rcu(usable, rcu); - all = rtnl_dereference(bond->all_slaves); + all = bond_dereference(bond, bond->all_slaves); rcu_assign_pointer(bond->all_slaves, all_slaves); kfree_rcu(all, rcu); } @@ -4333,6 +4320,8 @@ int bond_update_slave_arr(struct bonding *bond, struct slave *skipslave) WARN_ON(lockdep_is_held(&bond->mode_lock)); #endif + mutex_lock(&bond->slaves_lock); + usable_slaves = kzalloc(struct_size(usable_slaves, arr, bond->slave_cnt), GFP_KERNEL); all_slaves = kzalloc(struct_size(all_slaves, arr, @@ -4376,17 +4365,22 @@ int bond_update_slave_arr(struct bonding *bond, struct slave *skipslave) } bond_set_slave_arr(bond, usable_slaves, all_slaves); + + mutex_unlock(&bond->slaves_lock); + return ret; out: if (ret != 0 && skipslave) { - bond_skip_slave(rtnl_dereference(bond->all_slaves), + bond_skip_slave(bond_dereference(bond, bond->all_slaves), skipslave); - bond_skip_slave(rtnl_dereference(bond->usable_slaves), + bond_skip_slave(bond_dereference(bond, bond->usable_slaves), skipslave); } kfree_rcu(all_slaves, rcu); kfree_rcu(usable_slaves, rcu); + mutex_unlock(&bond->slaves_lock); + return ret; } @@ -4699,6 +4693,7 @@ void bond_setup(struct net_device *bond_dev) { struct bonding *bond = netdev_priv(bond_dev); + mutex_init(&bond->slaves_lock); spin_lock_init(&bond->mode_lock); bond->params = bonding_defaults; @@ -5189,7 +5184,6 @@ static int bond_init(struct net_device *bond_dev) if (!bond->wq) return -ENOMEM; - spin_lock_init(&bond->stats_lock); netdev_lockdep_set_classes(bond_dev); list_add_tail(&bond->bond_list, &bn->dev_list); diff --git a/include/net/bonding.h b/include/net/bonding.h index adc3da776970..146b46d276c0 100644 --- a/include/net/bonding.h +++ b/include/net/bonding.h @@ -222,7 +222,6 @@ struct bonding { * ALB mode (6) - to sync the use and modifications of its hash table */ spinlock_t mode_lock; - spinlock_t stats_lock; u8 send_peer_notif; u8 igmp_retrans; #ifdef CONFIG_PROC_FS @@ -249,6 +248,11 @@ struct bonding { #ifdef CONFIG_XFRM_OFFLOAD struct xfrm_state *xs; #endif /* CONFIG_XFRM_OFFLOAD */ + + /* Protects the slave array. TODO: convert all instances of + * rtnl_dereference to bond_dereference + */ + struct mutex slaves_lock; }; #define bond_slave_get_rcu(dev) \ @@ -257,6 +261,9 @@ struct bonding { #define bond_slave_get_rtnl(dev) \ ((struct slave *) rtnl_dereference(dev->rx_handler_data)) +#define bond_dereference(bond, p) \ + rcu_dereference_protected(p, lockdep_is_held(&(bond)->slaves_lock)) + void bond_queue_slave_event(struct slave *slave); void bond_lower_state_changed(struct slave *slave); @@ -449,6 +456,46 @@ static inline void bond_hw_addr_copy(u8 *dst, const u8 *src, unsigned int len) memcpy(dst, src, len); } +static inline int bond_get_slave_arr(struct bonding *bond, + struct net_device ***slaves, + int *num_slaves) +{ + struct net *net = dev_net(bond->dev); + struct list_head *iter; + struct slave *slave; + int i = 0; + + mutex_lock(&bond->slaves_lock); + + *slaves = kcalloc(bond->slave_cnt, sizeof(*slaves), GFP_KERNEL); + if (!(*slaves)) { + netif_lists_unlock(net); + return -ENOMEM; + } + + bond_for_each_slave(bond, slave, iter) { + dev_hold(slave->dev); + *slaves[i++] = slave->dev; + } + + *num_slaves = bond->slave_cnt; + + mutex_unlock(&bond->slaves_lock); + + return 0; +} + +static inline void bond_put_slave_arr(struct net_device **slaves, + int num_slaves) +{ + int i; + + for (i = 0; i < num_slaves; i++) + dev_put(slaves[i]); + + kfree(slaves); +} + #define BOND_PRI_RESELECT_ALWAYS 0 #define BOND_PRI_RESELECT_BETTER 1 #define BOND_PRI_RESELECT_FAILURE 2 From patchwork Thu Jan 7 09:49:50 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vladimir Oltean X-Patchwork-Id: 12003447 X-Patchwork-Delegate: kuba@kernel.org 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 EEF4FC433E9 for ; Thu, 7 Jan 2021 09:52:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C1C0D2333D for ; Thu, 7 Jan 2021 09:52:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727997AbhAGJwI (ORCPT ); Thu, 7 Jan 2021 04:52:08 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41114 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727959AbhAGJv7 (ORCPT ); Thu, 7 Jan 2021 04:51:59 -0500 Received: from mail-ej1-x632.google.com (mail-ej1-x632.google.com [IPv6:2a00:1450:4864:20::632]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 56FACC061290 for ; Thu, 7 Jan 2021 01:51:20 -0800 (PST) Received: by mail-ej1-x632.google.com with SMTP id jx16so8786052ejb.10 for ; Thu, 07 Jan 2021 01:51:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=s6/KSwpYaFicCBOmHGp8olwhxQfTeT9BvGFmL3TZtU0=; b=k4srG0hUz3ymRjl2O61v8y2Ij5FqmVzgBT99dg0biEI3M4W0wvYtyYCLMwYQjVwUfC 9fHUe/YR5e3Z1YoGzKYkZL7vWG+Qh4JLZvUiNX3jCVvdzRm/4IxEoU82qWt9pXJeTQwJ 5HCznBH1nGj9+ZAvcTuw97BQ4LBHCYWgN2dvBBqwTWkdmLg0UI3jl0F96tQ+xnGo6LTA 2l8GMxiEGeFt/f61qg8eCOeanBolv6R1aGsAzgCOekniV7s+JB3+o3wWHP3GXaRwWTGm HSHczR9dBbfdNSw/OYHZ87J84D3JtnJShvm8Juk+K1GMUHDyG5jtNxCObpCWxcTtG6cL ubsQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=s6/KSwpYaFicCBOmHGp8olwhxQfTeT9BvGFmL3TZtU0=; b=nwHYXI5swf3oAyq/NqYyGbHu5pXWTJ5Q18sHD2UxQ4gMM1S3PC/+HFWkpTn/bXM5a/ Ca2ZrXbgTTuGDE5CGPDkzt+2aY8oYjHyNnoA+olpsfGZcDytlHecoLV7O37xFabiFxGU m4CPcH1jvnXkVlQUR3PLXuiye6nNpj3C7tAmfcd2s0/2ievYzKiPpadRdy+iVoOHPaFO 1j3Gs3ScrZkH0wtFpccP5OxvJk1e72c/zJZ9Ri8UsZ8C6euIQWeebtISsYcuPVjE6QkQ yiDWNCJ0o/8qOVd81qTbDX3q9iDjXfpK64vScq++fjcFz5NwkHIDW9XYwZCK/rsE381R HwLA== X-Gm-Message-State: AOAM5302pzR2+0vPZzRy+CAnCd9kRTBpN3hyMwHlh+tnR98Nj1hEFp2T DqS2lce09dVjJnocvdh+gs0= X-Google-Smtp-Source: ABdhPJwMHXEemzYTsIss0OBGFMrA2zcrhE44kmejdeBnjaIpJ1sAnBL6wgsSDptH8pFcr6GKddrmPA== X-Received: by 2002:a17:906:2499:: with SMTP id e25mr5713103ejb.446.1610013079060; Thu, 07 Jan 2021 01:51:19 -0800 (PST) Received: from localhost.localdomain (5-12-227-87.residential.rdsnet.ro. [5.12.227.87]) by smtp.gmail.com with ESMTPSA id k15sm2251571ejc.79.2021.01.07.01.51.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 Jan 2021 01:51:18 -0800 (PST) From: Vladimir Oltean To: "David S . Miller" , Jakub Kicinski Cc: netdev@vger.kernel.org, Andrew Lunn , Florian Fainelli , Cong Wang , Stephen Hemminger , Eric Dumazet , George McCollister , Oleksij Rempel , Jay Vosburgh , Veaceslav Falico , Andy Gospodarek , Arnd Bergmann , Taehee Yoo , Jiri Pirko , Florian Westphal Subject: [PATCH v3 net-next 11/12] net: mark ndo_get_stats64 as being able to sleep Date: Thu, 7 Jan 2021 11:49:50 +0200 Message-Id: <20210107094951.1772183-12-olteanv@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210107094951.1772183-1-olteanv@gmail.com> References: <20210107094951.1772183-1-olteanv@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Vladimir Oltean Now that all callers have been converted to not use atomic context when calling dev_get_stats, it is time to update the documentation and put a notice in the function that it expects process context. Signed-off-by: Vladimir Oltean --- Changes in v3: None. Changes in v2: Updated the documentation. Documentation/networking/netdevices.rst | 8 ++++++-- Documentation/networking/statistics.rst | 9 ++++----- net/core/dev.c | 2 ++ 3 files changed, 12 insertions(+), 7 deletions(-) diff --git a/Documentation/networking/netdevices.rst b/Documentation/networking/netdevices.rst index 5a85fcc80c76..944599722c76 100644 --- a/Documentation/networking/netdevices.rst +++ b/Documentation/networking/netdevices.rst @@ -64,8 +64,12 @@ ndo_do_ioctl: Context: process ndo_get_stats: - Synchronization: dev_base_lock rwlock. - Context: nominally process, but don't sleep inside an rwlock + Synchronization: + none. netif_lists_lock(net) might be held, but not guaranteed. + It is illegal to hold rtnl_lock() in this method, since it will + cause a lock inversion with netif_lists_lock and a deadlock. + Context: + process ndo_start_xmit: Synchronization: __netif_tx_lock spinlock. diff --git a/Documentation/networking/statistics.rst b/Documentation/networking/statistics.rst index 234abedc29b2..ad3e353df0dd 100644 --- a/Documentation/networking/statistics.rst +++ b/Documentation/networking/statistics.rst @@ -155,11 +155,10 @@ Drivers must ensure best possible compliance with Please note for example that detailed error statistics must be added into the general `rx_error` / `tx_error` counters. -The `.ndo_get_stats64` callback can not sleep because of accesses -via `/proc/net/dev`. If driver may sleep when retrieving the statistics -from the device it should do so periodically asynchronously and only return -a recent copy from `.ndo_get_stats64`. Ethtool interrupt coalescing interface -allows setting the frequency of refreshing statistics, if needed. +Drivers may sleep when retrieving the statistics from the device, or they might +read the counters periodically and only return in `.ndo_get_stats64` a recent +copy collected asynchronously. In the latter case, the ethtool interrupt +coalescing interface allows setting the frequency of refreshing statistics. Retrieving ethtool statistics is a multi-syscall process, drivers are advised to keep the number of statistics constant to avoid race conditions with diff --git a/net/core/dev.c b/net/core/dev.c index 93618300ac90..ccb31a52e514 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -10407,6 +10407,8 @@ void dev_get_stats(struct net_device *dev, struct rtnl_link_stats64 *storage) { const struct net_device_ops *ops = dev->netdev_ops; + might_sleep(); + if (ops->ndo_get_stats64) { memset(storage, 0, sizeof(*storage)); ops->ndo_get_stats64(dev, storage); From patchwork Thu Jan 7 09:49:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vladimir Oltean X-Patchwork-Id: 12003443 X-Patchwork-Delegate: kuba@kernel.org 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 BAFBDC433E0 for ; Thu, 7 Jan 2021 09:52:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7FE0D2333E for ; Thu, 7 Jan 2021 09:52:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727983AbhAGJwF (ORCPT ); Thu, 7 Jan 2021 04:52:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41020 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727962AbhAGJv7 (ORCPT ); Thu, 7 Jan 2021 04:51:59 -0500 Received: from mail-ej1-x62a.google.com (mail-ej1-x62a.google.com [IPv6:2a00:1450:4864:20::62a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C5677C0612A0 for ; Thu, 7 Jan 2021 01:51:21 -0800 (PST) Received: by mail-ej1-x62a.google.com with SMTP id 6so8858495ejz.5 for ; Thu, 07 Jan 2021 01:51:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=PoqSBxPScrFd49HRen6PJJlMx5D97p4DjodtTjMvHqQ=; b=jA8DAiV6jAxFdO+Z1RFOzWlPl5Sk+pWfHmlHbcan+f98fA9EEYh1Do5QkWSXkgVezP CU5+Q1N25frOSbI+Dy8Wu87ML8BCiYcJouNDoklQStXBlXPxGYGXMnJf5VQQJgSYRRxh SE9dzzGXyC2dCQcJHFWOi3Ymu3K9czsgHBQKs5/aq7LHScl64nvgLgUAAQ1Bv/6EZWCW 5FQKCmvfq+7ESziaRgLDMPVxp2yjNO++RZKVi12omSfhKiYJlYONL2ZeO+Yr8mnqMJZG y27w8muhGy4iaXtcvaglsdAryEO5qvTWr6g/cun95uCxZR2vc/mNpc3FOTdZA90Ooun0 zprQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=PoqSBxPScrFd49HRen6PJJlMx5D97p4DjodtTjMvHqQ=; b=sDpYUr6Dg8f7A4583PuT6fy4/zeRaSbdgOBiQpq1rKFuJIRsXneO3BBwni965Blr+q ZxyJfvPJy0Hmy5s1Ue6Ws9oCONS+hQlCCyG2+bRh9uxD5C+qiZMUx3S7chwkHbH5uYQI KwgzjtbwFtaKKJkkffF812MocphX/lsv+i7noxmHoDk6aDrlHWIfUQG/MQG3BOuzfyhm 0dujC8Q3amffy4xUoPD6hE07OTEs3X2y7d6Juh8KFocBDOz6BXgM/+O+A8Ovd3/5NAWq WHCObCygcoYQnT90ia2hG9qnd13fUdhc2+EtOIff9P5R37+24s2h6bbfe5Q13QTC4W0P HdLQ== X-Gm-Message-State: AOAM5310muhZ7Czeu107eKFMud3RHZqbxJOay039PquO4RGoDIC/clSr 2cAwRHL4t+8j/DarCYnw4Oo= X-Google-Smtp-Source: ABdhPJycVd91GlMHzPs3txSIm1KLwT5PWdTw1HNI7IVLvJhk8O6RUIr3t5ZQc9SmDvwLpN8cQorjng== X-Received: by 2002:a17:906:90d6:: with SMTP id v22mr5801709ejw.88.1610013080557; Thu, 07 Jan 2021 01:51:20 -0800 (PST) Received: from localhost.localdomain (5-12-227-87.residential.rdsnet.ro. [5.12.227.87]) by smtp.gmail.com with ESMTPSA id k15sm2251571ejc.79.2021.01.07.01.51.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 Jan 2021 01:51:20 -0800 (PST) From: Vladimir Oltean To: "David S . Miller" , Jakub Kicinski Cc: netdev@vger.kernel.org, Andrew Lunn , Florian Fainelli , Cong Wang , Stephen Hemminger , Eric Dumazet , George McCollister , Oleksij Rempel , Jay Vosburgh , Veaceslav Falico , Andy Gospodarek , Arnd Bergmann , Taehee Yoo , Jiri Pirko , Florian Westphal Subject: [PATCH v3 net-next 12/12] net: remove obsolete comments about ndo_get_stats64 context from eth drivers Date: Thu, 7 Jan 2021 11:49:51 +0200 Message-Id: <20210107094951.1772183-13-olteanv@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210107094951.1772183-1-olteanv@gmail.com> References: <20210107094951.1772183-1-olteanv@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Vladimir Oltean Now that we have a good summary in Documentation/networking/netdevices.rst, these comments serve no purpose and are actually distracting/confusing. Signed-off-by: Vladimir Oltean --- Changes in v3: None. Changes in v2: None. drivers/net/ethernet/cisco/enic/enic_main.c | 1 - drivers/net/ethernet/nvidia/forcedeth.c | 2 -- drivers/net/ethernet/sfc/efx_common.c | 1 - drivers/net/ethernet/sfc/falcon/efx.c | 1 - 4 files changed, 5 deletions(-) diff --git a/drivers/net/ethernet/cisco/enic/enic_main.c b/drivers/net/ethernet/cisco/enic/enic_main.c index fb269d587b74..7425f94f9091 100644 --- a/drivers/net/ethernet/cisco/enic/enic_main.c +++ b/drivers/net/ethernet/cisco/enic/enic_main.c @@ -870,7 +870,6 @@ static netdev_tx_t enic_hard_start_xmit(struct sk_buff *skb, return NETDEV_TX_OK; } -/* dev_base_lock rwlock held, nominally process context */ static void enic_get_stats(struct net_device *netdev, struct rtnl_link_stats64 *net_stats) { diff --git a/drivers/net/ethernet/nvidia/forcedeth.c b/drivers/net/ethernet/nvidia/forcedeth.c index 8724d6a9ed02..8fa254dc64e9 100644 --- a/drivers/net/ethernet/nvidia/forcedeth.c +++ b/drivers/net/ethernet/nvidia/forcedeth.c @@ -1761,8 +1761,6 @@ static void nv_get_stats(int cpu, struct fe_priv *np, /* * nv_get_stats64: dev->ndo_get_stats64 function * Get latest stats value from the nic. - * Called with read_lock(&dev_base_lock) held for read - - * only synchronized against unregister_netdevice. */ static void nv_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *storage) diff --git a/drivers/net/ethernet/sfc/efx_common.c b/drivers/net/ethernet/sfc/efx_common.c index de797e1ac5a9..4d8047b35fb2 100644 --- a/drivers/net/ethernet/sfc/efx_common.c +++ b/drivers/net/ethernet/sfc/efx_common.c @@ -596,7 +596,6 @@ void efx_stop_all(struct efx_nic *efx) efx_stop_datapath(efx); } -/* Context: process, dev_base_lock or RTNL held, non-blocking. */ void efx_net_stats(struct net_device *net_dev, struct rtnl_link_stats64 *stats) { struct efx_nic *efx = netdev_priv(net_dev); diff --git a/drivers/net/ethernet/sfc/falcon/efx.c b/drivers/net/ethernet/sfc/falcon/efx.c index f8979991970e..6db2b6583dec 100644 --- a/drivers/net/ethernet/sfc/falcon/efx.c +++ b/drivers/net/ethernet/sfc/falcon/efx.c @@ -2096,7 +2096,6 @@ int ef4_net_stop(struct net_device *net_dev) return 0; } -/* Context: process, dev_base_lock or RTNL held, non-blocking. */ static void ef4_net_stats(struct net_device *net_dev, struct rtnl_link_stats64 *stats) {