From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [RFC PATCH 06/10] ipv6: Avoid deleting RTF_CACHE route from ip6_route_del() Date: Mon, 20 Apr 2015 15:37:18 -0400 (EDT) Message-ID: <20150420.153718.918911597668800943.davem@davemloft.net> References: <1428717253-1006248-7-git-send-email-kafai@fb.com> <20150420.142305.507346652058648202.davem@davemloft.net> <20150420193304.GD2416462@devbig242.prn2.facebook.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, hannes@stressinduktion.org, kernel-team@fb.com To: kafai@fb.com Return-path: Received: from shards.monkeyblade.net ([149.20.54.216]:46633 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751255AbbDTThU (ORCPT ); Mon, 20 Apr 2015 15:37:20 -0400 In-Reply-To: <20150420193304.GD2416462@devbig242.prn2.facebook.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Martin KaFai Lau Date: Mon, 20 Apr 2015 12:33:05 -0700 > On Mon, Apr 20, 2015 at 02:23:05PM -0400, David Miller wrote: >> From: Martin KaFai Lau >> Date: Fri, 10 Apr 2015 18:54:09 -0700 >> >> > Before patch 'Allow pmtu update on /128 via gateway route', >> > RTF_CACHE route was not created for DST_HOST. It also requires changes on both >> > delete code path and rt6_select() code patch. >> > >> > This patch fixes the delete code path to avoid deleting the RTF_CACHE >> > route by 'ip -6 r del...' >> > >> > Signed-off-by: Martin KaFai Lau >> > Reviewed-by: Hannes Frederic Sowa >> >> If a cached route was created in response to say a PMTU event, and >> it's a clone/copy/cow of the route we are being asked to delete, >> it absolutely should be removed. >> >> In fact this is a critically important aspect of removing routes >> from the table. > When a non-clone routes are removed, its clones are removed together by > fib6_prune_clones() in fib6_del(). > > Hence, 'ip -6 r del' will remove a route and its clones. > 'ip -6 r flush table cache will only remove RTF_CACHE routes. > > I will fix up the commit message. Ok, thanks.