Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756853AbcDLSOu (ORCPT ); Tue, 12 Apr 2016 14:14:50 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:49028 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966185AbcDLSIL (ORCPT ); Tue, 12 Apr 2016 14:08:11 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: "David S. Miller" , Moritz Muehlenhoff , Luis Henriques Subject: [PATCH 3.16.y-ckt 01/17] ipv4: Don't do expensive useless work during inetdev destroy. Date: Tue, 12 Apr 2016 19:07:48 +0100 Message-Id: <1460484484-22395-2-git-send-email-luis.henriques@canonical.com> In-Reply-To: <1460484484-22395-1-git-send-email-luis.henriques@canonical.com> References: <1460484484-22395-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3518 Lines: 101 3.16.7-ckt27 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: "David S. Miller" commit fbd40ea0180a2d328c5adc61414dc8bab9335ce2 upstream. When an inetdev is destroyed, every address assigned to the interface is removed. And in this scenerio we do two pointless things which can be very expensive if the number of assigned interfaces is large: 1) Address promotion. We are deleting all addresses, so there is no point in doing this. 2) A full nf conntrack table purge for every address. We only need to do this once, as is already caught by the existing masq_dev_notifier so masq_inet_event() can skip this. Reported-by: Solar Designer Signed-off-by: David S. Miller Tested-by: Cyrill Gorcunov Cc: Moritz Muehlenhoff [ luis: backported to 3.16: - file rename: nf_nat_masquerade_ipv4.c -> ipt_MASQUERADE.c ] Signed-off-by: Luis Henriques --- net/ipv4/devinet.c | 4 ++++ net/ipv4/fib_frontend.c | 4 ++++ net/ipv4/netfilter/ipt_MASQUERADE.c | 12 ++++++++++-- 3 files changed, 18 insertions(+), 2 deletions(-) diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c index aa4b9990dd7a..710fe64fb2f7 100644 --- a/net/ipv4/devinet.c +++ b/net/ipv4/devinet.c @@ -326,6 +326,9 @@ static void __inet_del_ifa(struct in_device *in_dev, struct in_ifaddr **ifap, ASSERT_RTNL(); + if (in_dev->dead) + goto no_promotions; + /* 1. Deleting primary ifaddr forces deletion all secondaries * unless alias promotion is set **/ @@ -372,6 +375,7 @@ static void __inet_del_ifa(struct in_device *in_dev, struct in_ifaddr **ifap, fib_del_ifaddr(ifa, ifa1); } +no_promotions: /* 2. Unlink it */ *ifap = ifa1->ifa_next; diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c index 255aa9946fe7..7d736cd3ee91 100644 --- a/net/ipv4/fib_frontend.c +++ b/net/ipv4/fib_frontend.c @@ -812,6 +812,9 @@ void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim) subnet = 1; } + if (in_dev->dead) + goto no_promotions; + /* Deletion is more complicated than add. * We should take care of not to delete too much :-) * @@ -887,6 +890,7 @@ void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim) } } +no_promotions: if (!(ok & BRD_OK)) fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim); if (subnet && ifa->ifa_prefixlen < 31) { diff --git a/net/ipv4/netfilter/ipt_MASQUERADE.c b/net/ipv4/netfilter/ipt_MASQUERADE.c index 00352ce0f0de..3bc1c98aa2f0 100644 --- a/net/ipv4/netfilter/ipt_MASQUERADE.c +++ b/net/ipv4/netfilter/ipt_MASQUERADE.c @@ -128,10 +128,18 @@ static int masq_inet_event(struct notifier_block *this, unsigned long event, void *ptr) { - struct net_device *dev = ((struct in_ifaddr *)ptr)->ifa_dev->dev; + struct in_device *idev = ((struct in_ifaddr *)ptr)->ifa_dev; struct netdev_notifier_info info; - netdev_notifier_info_init(&info, dev); + /* The masq_dev_notifier will catch the case of the device going + * down. So if the inetdev is dead and being destroyed we have + * no work to do. Otherwise this is an individual address removal + * and we have to perform the flush. + */ + if (idev->dead) + return NOTIFY_DONE; + + netdev_notifier_info_init(&info, idev->dev); return masq_device_event(this, event, &info); }