From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 28FB6C433E0 for ; Tue, 23 Jun 2020 17:44:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 00AA2207FB for ; Tue, 23 Jun 2020 17:44:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592934289; bh=JC1anIg52iQ91nUX1Wg98PfJNloEzw3qVno1XsNiYWw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=AzxY8e6OnyWbwT4GwC8U7RGkJHG9ukX7hXGjTVp6e85c5n1Zyzt8sc5TgXxQzb4Qa t3VLNcfRx2/D3vZU8qgeJwTlRMLlUERKY/cRcBXHISIyFlcAUiYvZ7MUT8zJPtlqpD fsxZcTO5QAXiGt1Q8Flsi3m9zF2GeWa0homRW8Tk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387730AbgFWRos (ORCPT ); Tue, 23 Jun 2020 13:44:48 -0400 Received: from mail.kernel.org ([198.145.29.99]:41668 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733128AbgFWRor (ORCPT ); Tue, 23 Jun 2020 13:44:47 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 41C8F20781; Tue, 23 Jun 2020 17:44:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592934286; bh=JC1anIg52iQ91nUX1Wg98PfJNloEzw3qVno1XsNiYWw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=YZWrI/QitWzGnGPSnQLXIqts5kkAGXsuaNjAxawvXLMzL9ZfUGvzeBLdoe9YGcX2g Vrlyda2Qka/ozFLaZEFFjNBFenUhiP52Ff+cZmzI+A2sWsL3NNZXdrofLhTKUliTSs wcGV1j22wIorEAoqgr8Gfwq8OZaa4yWylrevSKaM= Date: Tue, 23 Jun 2020 19:44:46 +0200 From: Greg KH To: Toke =?iso-8859-1?Q?H=F8iland-J=F8rgensen?= Cc: stable@vger.kernel.org, Eric Dumazet , "David S . Miller" Subject: Re: [PATCH 4.4] net: Revert "pkt_sched: fq: use proper locking in fq_dump_stats()" Message-ID: <20200623174446.GA17865@kroah.com> References: <20200623150053.272985-1-toke@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20200623150053.272985-1-toke@redhat.com> Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Tue, Jun 23, 2020 at 05:00:53PM +0200, Toke Høiland-Jørgensen wrote: > This reverts commit 191cf872190de28a92e1bd2b56d8860e37e07443. > > That commit should never have been backported since it relies on a change in > locking semantics that was introduced in v4.8 and not backported. Because of > this, the backported commit to sch_fq leads to lockups because of the double > locking. > > Signed-off-by: Toke Høiland-Jørgensen > --- > net/sched/sch_fq.c | 32 ++++++++++++++------------------ > 1 file changed, 14 insertions(+), 18 deletions(-) > > diff --git a/net/sched/sch_fq.c b/net/sched/sch_fq.c > index f4aa2ab4713a..eb814ffc0902 100644 > --- a/net/sched/sch_fq.c > +++ b/net/sched/sch_fq.c > @@ -830,24 +830,20 @@ nla_put_failure: > static int fq_dump_stats(struct Qdisc *sch, struct gnet_dump *d) > { > struct fq_sched_data *q = qdisc_priv(sch); > - struct tc_fq_qd_stats st; > - > - sch_tree_lock(sch); > - > - st.gc_flows = q->stat_gc_flows; > - st.highprio_packets = q->stat_internal_packets; > - st.tcp_retrans = q->stat_tcp_retrans; > - st.throttled = q->stat_throttled; > - st.flows_plimit = q->stat_flows_plimit; > - st.pkts_too_long = q->stat_pkts_too_long; > - st.allocation_errors = q->stat_allocation_errors; > - st.time_next_delayed_flow = q->time_next_delayed_flow - ktime_get_ns(); > - st.flows = q->flows; > - st.inactive_flows = q->inactive_flows; > - st.throttled_flows = q->throttled_flows; > - st.pad = 0; > - > - sch_tree_unlock(sch); > + u64 now = ktime_get_ns(); > + struct tc_fq_qd_stats st = { > + .gc_flows = q->stat_gc_flows, > + .highprio_packets = q->stat_internal_packets, > + .tcp_retrans = q->stat_tcp_retrans, > + .throttled = q->stat_throttled, > + .flows_plimit = q->stat_flows_plimit, > + .pkts_too_long = q->stat_pkts_too_long, > + .allocation_errors = q->stat_allocation_errors, > + .flows = q->flows, > + .inactive_flows = q->inactive_flows, > + .throttled_flows = q->throttled_flows, > + .time_next_delayed_flow = q->time_next_delayed_flow - now, > + }; > > return gnet_stats_copy_app(d, &st, sizeof(st)); > } > -- > 2.27.0 > Thanks, now applied. greg k-h