From patchwork Fri May 29 05:12:36 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roopa Prabhu X-Patchwork-Id: 218237 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=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY,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 BE6F1C433DF for ; Fri, 29 May 2020 05:12:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8E03F2075A for ; Fri, 29 May 2020 05:12:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=cumulusnetworks.com header.i=@cumulusnetworks.com header.b="aQtshDYE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725922AbgE2FMq (ORCPT ); Fri, 29 May 2020 01:12:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38634 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725775AbgE2FMp (ORCPT ); Fri, 29 May 2020 01:12:45 -0400 Received: from mail-pf1-x443.google.com (mail-pf1-x443.google.com [IPv6:2607:f8b0:4864:20::443]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D9194C08C5C6 for ; Thu, 28 May 2020 22:12:44 -0700 (PDT) Received: by mail-pf1-x443.google.com with SMTP id d66so677483pfd.6 for ; Thu, 28 May 2020 22:12:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cumulusnetworks.com; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=QQuE+DBZlLqSBcSGuHdf8Whpv1PGyDsHzi+wuEr71ZM=; b=aQtshDYEEuhW80F0i5xpsESZt9xJeWzwKhJ0+hmtFJ7h03eNQ8j542BfGNVBToSY8q KusnRAEkltcvVT+nU81xQ8S834ebUNgB+1vXDEwPHrDWRQa5suWishaX59RYHsaVF8wC RGeYLKKJoL/56BpyOlzS9SlfFm+VX/Az7d5Ew= 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; bh=QQuE+DBZlLqSBcSGuHdf8Whpv1PGyDsHzi+wuEr71ZM=; b=hefLYzYT1KPkQx1xP9OK6hl+hA5E7acDkmD/D4cc7fuJJz9/BmVoPyvdeEu5I1M9lS a/DoFw1PkiM3yj9H2qczSIcW440QDxZROJudVFXbOlMuk8dhgIecnVvBRT5H3hNxV4Q3 EvJsZodUbFhPk7jZiUfjNhULSGy1h+RB1Xcnzm5YevclTQJKXLCj4aK3/f6aIhl2fS78 fXIpia8kRSpIahj4Zub/GcJoATXllOFLvYIcP5DiVwNg8pz3jD6Ic0ok9Xk8BZhx4jYO 1Nh2f0WXFQINJPOzPSSI5lZpExy0b+qjSv2JMMTELNXArswv1s23TfrHjT2QkSnzg4W0 BxFw== X-Gm-Message-State: AOAM5330HADoc7W3h/F1+bp/Jl/CGRr8zuGOC4mpmvpeg5su9TTofRXJ KqgMpfpqRgqrfq/GQrh0i8mxtgXD+Os= X-Google-Smtp-Source: ABdhPJzLdLf9eY4v9VqDI4NIwQl8uLX3a3Zrtt7h3HQUmiWunGSkVM7oh0lkvfF1pYBYuwo6JMo3TA== X-Received: by 2002:a63:482:: with SMTP id 124mr6561564pge.169.1590729164370; Thu, 28 May 2020 22:12:44 -0700 (PDT) Received: from monster-08.mvlab.cumulusnetworks.com. (fw.cumulusnetworks.com. [216.129.126.126]) by smtp.googlemail.com with ESMTPSA id z20sm6935634pjn.53.2020.05.28.22.12.43 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 28 May 2020 22:12:43 -0700 (PDT) From: Roopa Prabhu X-Google-Original-From: Roopa Prabhu To: davem@davemloft.net, kuba@kernel.org Cc: netdev@vger.kernel.org, dsahern@gmail.com, nikolay@cumulusnetworks.com, jiri@mellanox.com, idosch@mellanox.com, petrm@mellanox.com Subject: [PATCH net-next 2/2] vxlan: few locking fixes in nexthop event handler Date: Thu, 28 May 2020 22:12:36 -0700 Message-Id: <1590729156-35543-3-git-send-email-roopa@cumulusnetworks.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1590729156-35543-1-git-send-email-roopa@cumulusnetworks.com> References: <1590729156-35543-1-git-send-email-roopa@cumulusnetworks.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Roopa Prabhu - remove fdb from nh_list before the rcu grace period - protect fdb->vdev with rcu - hold spin lock before destroying fdb Fixes: c7cdbe2efc40 ("vxlan: support for nexthop notifiers") Signed-off-by: Roopa Prabhu Reviewed-by: Nikolay Aleksandrov --- drivers/net/vxlan.c | 32 +++++++++++++++++++++++++------- 1 file changed, 25 insertions(+), 7 deletions(-) diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c index fe606c6..39bc10a 100644 --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -81,7 +81,7 @@ struct vxlan_fdb { u16 flags; /* see ndm_flags and below */ struct list_head nh_list; struct nexthop __rcu *nh; - struct vxlan_dev *vdev; + struct vxlan_dev __rcu *vdev; }; #define NTF_VXLAN_ADDED_BY_USER 0x100 @@ -837,7 +837,7 @@ static struct vxlan_fdb *vxlan_fdb_alloc(struct vxlan_dev *vxlan, const u8 *mac, f->updated = f->used = jiffies; f->vni = src_vni; f->nh = NULL; - f->vdev = vxlan; + RCU_INIT_POINTER(f->vdev, vxlan); INIT_LIST_HEAD(&f->nh_list); INIT_LIST_HEAD(&f->remotes); memcpy(f->eth_addr, mac, ETH_ALEN); @@ -963,7 +963,7 @@ static void __vxlan_fdb_free(struct vxlan_fdb *f) nh = rcu_dereference_raw(f->nh); if (nh) { rcu_assign_pointer(f->nh, NULL); - list_del_rcu(&f->nh_list); + rcu_assign_pointer(f->vdev, NULL); nexthop_put(nh); } @@ -1000,7 +1000,7 @@ static void vxlan_fdb_destroy(struct vxlan_dev *vxlan, struct vxlan_fdb *f, } hlist_del_rcu(&f->hlist); - f->vdev = NULL; + list_del_rcu(&f->nh_list); call_rcu(&f->rcu, vxlan_fdb_free); } @@ -4615,17 +4615,35 @@ static struct notifier_block vxlan_switchdev_notifier_block __read_mostly = { .notifier_call = vxlan_switchdev_event, }; +static void vxlan_fdb_nh_flush(struct nexthop *nh) +{ + struct vxlan_fdb *fdb; + struct vxlan_dev *vxlan; + u32 hash_index; + + rcu_read_lock(); + list_for_each_entry_rcu(fdb, &nh->fdb_list, nh_list) { + vxlan = rcu_dereference(fdb->vdev); + WARN_ON(!vxlan); + hash_index = fdb_head_index(vxlan, fdb->eth_addr, + vxlan->default_dst.remote_vni); + spin_lock_bh(&vxlan->hash_lock[hash_index]); + if (!hlist_unhashed(&fdb->hlist)) + vxlan_fdb_destroy(vxlan, fdb, false, false); + spin_unlock_bh(&vxlan->hash_lock[hash_index]); + } + rcu_read_unlock(); +} + static int vxlan_nexthop_event(struct notifier_block *nb, unsigned long event, void *ptr) { struct nexthop *nh = ptr; - struct vxlan_fdb *fdb, *tmp; if (!nh || event != NEXTHOP_EVENT_DEL) return NOTIFY_DONE; - list_for_each_entry_safe(fdb, tmp, &nh->fdb_list, nh_list) - vxlan_fdb_destroy(fdb->vdev, fdb, false, false); + vxlan_fdb_nh_flush(nh); return NOTIFY_DONE; }