From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 319A8503918; Wed, 30 Sep 2026 18:04:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790791481; cv=none; b=d1pstXVb/RgNryvCWoOo1y3cnkHEpM62yBwWWXJHfeA7+Df6WQOJ2XYwDp2fKPxLGAy4DN6UQ+szisfo17obDIJYH7rQmWzrn7WFGoemqmzCz7z2aAstZc2XX3Nl0ASlvesMnc2wzFrnC/fmndTUy0LohzG1ZInZhgtds/qY4/Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790791481; c=relaxed/simple; bh=FsfyTYndM1sGWorivn9BYFGiSr09vfhCqBRF9mD6Wd8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=KZpJOj8XbnoFK7qvXkLZMVoruDMSiBbZinduoILtX0tiW6ipAJnmnJdwigjLxjK1vTSZmPEku316YE1zXh64XD4AxKJlu0Hv9fbFFEof+cRpzlSrGWQ3PA5PeAwDdrhkT8Sk9AqjYrvrDSmp8nBllnbExFpknrumzFgXZRRpPK4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=a7FOzHv7; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="a7FOzHv7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8612A1F000FF; Wed, 30 Sep 2026 18:04:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790791480; bh=NwC1JoSuSBXADzIvkcwk9UKDJsunEagvN6G/Coa569A=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=a7FOzHv7umKpy0/JKisVFWOyxOkYQdq1jOBO0/EDzoKFFqLq+rVF9gcrkbEGLw6FO biIys+N7ewg5kkRskO29kcNRYJIdZ0md3YsysfFXCpELQpX2bDrzlE7gJMDSuJ+/Vm lZIs/gx6K+QPN93Hqf0npZ+g8rqHpuu+LCJn8YDU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Dumazet , Simon Horman , "David S. Miller" , Sasha Levin Subject: [PATCH 5.15 315/752] net_sched: sch_fq_pie: implement lockless fq_pie_dump() Date: Wed, 30 Sep 2026 17:23:05 +0200 Message-ID: <20260930152405.114180868@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152358.131179731@linuxfoundation.org> References: <20260930152358.131179731@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit 13a9965de32457d59aa3162d657aa4c5e512c146 ] Instead of relying on RTNL, fq_pie_dump() can use READ_ONCE() annotations, paired with WRITE_ONCE() ones in fq_pie_change(). Signed-off-by: Eric Dumazet Reviewed-by: Simon Horman Signed-off-by: David S. Miller Stable-dep-of: 4864f58c53eb ("net/sched: fq_pie: clamp quantum in change path") Signed-off-by: Sasha Levin --- net/sched/sch_fq_pie.c | 61 +++++++++++++++++++++++------------------- 1 file changed, 34 insertions(+), 27 deletions(-) diff --git a/net/sched/sch_fq_pie.c b/net/sched/sch_fq_pie.c index 33ec3aefde39a..e3d9a92a1ba68 100644 --- a/net/sched/sch_fq_pie.c +++ b/net/sched/sch_fq_pie.c @@ -301,8 +301,8 @@ static int fq_pie_change(struct Qdisc *sch, struct nlattr *opt, if (tb[TCA_FQ_PIE_LIMIT]) { u32 limit = nla_get_u32(tb[TCA_FQ_PIE_LIMIT]); - q->p_params.limit = limit; - sch->limit = limit; + WRITE_ONCE(q->p_params.limit, limit); + WRITE_ONCE(sch->limit, limit); } if (tb[TCA_FQ_PIE_FLOWS]) { if (q->flows) { @@ -324,39 +324,45 @@ static int fq_pie_change(struct Qdisc *sch, struct nlattr *opt, u32 target = nla_get_u32(tb[TCA_FQ_PIE_TARGET]); /* convert to pschedtime */ - q->p_params.target = - PSCHED_NS2TICKS((u64)target * NSEC_PER_USEC); + WRITE_ONCE(q->p_params.target, + PSCHED_NS2TICKS((u64)target * NSEC_PER_USEC)); } /* tupdate is in jiffies */ if (tb[TCA_FQ_PIE_TUPDATE]) - q->p_params.tupdate = - usecs_to_jiffies(nla_get_u32(tb[TCA_FQ_PIE_TUPDATE])); + WRITE_ONCE(q->p_params.tupdate, + usecs_to_jiffies(nla_get_u32(tb[TCA_FQ_PIE_TUPDATE]))); if (tb[TCA_FQ_PIE_ALPHA]) - q->p_params.alpha = nla_get_u32(tb[TCA_FQ_PIE_ALPHA]); + WRITE_ONCE(q->p_params.alpha, + nla_get_u32(tb[TCA_FQ_PIE_ALPHA])); if (tb[TCA_FQ_PIE_BETA]) - q->p_params.beta = nla_get_u32(tb[TCA_FQ_PIE_BETA]); + WRITE_ONCE(q->p_params.beta, + nla_get_u32(tb[TCA_FQ_PIE_BETA])); if (tb[TCA_FQ_PIE_QUANTUM]) - q->quantum = nla_get_u32(tb[TCA_FQ_PIE_QUANTUM]); + WRITE_ONCE(q->quantum, nla_get_u32(tb[TCA_FQ_PIE_QUANTUM])); if (tb[TCA_FQ_PIE_MEMORY_LIMIT]) - q->memory_limit = nla_get_u32(tb[TCA_FQ_PIE_MEMORY_LIMIT]); + WRITE_ONCE(q->memory_limit, + nla_get_u32(tb[TCA_FQ_PIE_MEMORY_LIMIT])); if (tb[TCA_FQ_PIE_ECN_PROB]) - q->ecn_prob = nla_get_u32(tb[TCA_FQ_PIE_ECN_PROB]); + WRITE_ONCE(q->ecn_prob, + nla_get_u32(tb[TCA_FQ_PIE_ECN_PROB])); if (tb[TCA_FQ_PIE_ECN]) - q->p_params.ecn = nla_get_u32(tb[TCA_FQ_PIE_ECN]); + WRITE_ONCE(q->p_params.ecn, + nla_get_u32(tb[TCA_FQ_PIE_ECN])); if (tb[TCA_FQ_PIE_BYTEMODE]) - q->p_params.bytemode = nla_get_u32(tb[TCA_FQ_PIE_BYTEMODE]); + WRITE_ONCE(q->p_params.bytemode, + nla_get_u32(tb[TCA_FQ_PIE_BYTEMODE])); if (tb[TCA_FQ_PIE_DQ_RATE_ESTIMATOR]) - q->p_params.dq_rate_estimator = - nla_get_u32(tb[TCA_FQ_PIE_DQ_RATE_ESTIMATOR]); + WRITE_ONCE(q->p_params.dq_rate_estimator, + nla_get_u32(tb[TCA_FQ_PIE_DQ_RATE_ESTIMATOR])); /* Drop excess packets if new limit is lower */ while (sch->q.qlen > sch->limit) { @@ -472,22 +478,23 @@ static int fq_pie_dump(struct Qdisc *sch, struct sk_buff *skb) return -EMSGSIZE; /* convert target from pschedtime to us */ - if (nla_put_u32(skb, TCA_FQ_PIE_LIMIT, sch->limit) || - nla_put_u32(skb, TCA_FQ_PIE_FLOWS, q->flows_cnt) || + if (nla_put_u32(skb, TCA_FQ_PIE_LIMIT, READ_ONCE(sch->limit)) || + nla_put_u32(skb, TCA_FQ_PIE_FLOWS, READ_ONCE(q->flows_cnt)) || nla_put_u32(skb, TCA_FQ_PIE_TARGET, - ((u32)PSCHED_TICKS2NS(q->p_params.target)) / + ((u32)PSCHED_TICKS2NS(READ_ONCE(q->p_params.target))) / NSEC_PER_USEC) || nla_put_u32(skb, TCA_FQ_PIE_TUPDATE, - jiffies_to_usecs(q->p_params.tupdate)) || - nla_put_u32(skb, TCA_FQ_PIE_ALPHA, q->p_params.alpha) || - nla_put_u32(skb, TCA_FQ_PIE_BETA, q->p_params.beta) || - nla_put_u32(skb, TCA_FQ_PIE_QUANTUM, q->quantum) || - nla_put_u32(skb, TCA_FQ_PIE_MEMORY_LIMIT, q->memory_limit) || - nla_put_u32(skb, TCA_FQ_PIE_ECN_PROB, q->ecn_prob) || - nla_put_u32(skb, TCA_FQ_PIE_ECN, q->p_params.ecn) || - nla_put_u32(skb, TCA_FQ_PIE_BYTEMODE, q->p_params.bytemode) || + jiffies_to_usecs(READ_ONCE(q->p_params.tupdate))) || + nla_put_u32(skb, TCA_FQ_PIE_ALPHA, READ_ONCE(q->p_params.alpha)) || + nla_put_u32(skb, TCA_FQ_PIE_BETA, READ_ONCE(q->p_params.beta)) || + nla_put_u32(skb, TCA_FQ_PIE_QUANTUM, READ_ONCE(q->quantum)) || + nla_put_u32(skb, TCA_FQ_PIE_MEMORY_LIMIT, + READ_ONCE(q->memory_limit)) || + nla_put_u32(skb, TCA_FQ_PIE_ECN_PROB, READ_ONCE(q->ecn_prob)) || + nla_put_u32(skb, TCA_FQ_PIE_ECN, READ_ONCE(q->p_params.ecn)) || + nla_put_u32(skb, TCA_FQ_PIE_BYTEMODE, READ_ONCE(q->p_params.bytemode)) || nla_put_u32(skb, TCA_FQ_PIE_DQ_RATE_ESTIMATOR, - q->p_params.dq_rate_estimator)) + READ_ONCE(q->p_params.dq_rate_estimator))) goto nla_put_failure; return nla_nest_end(skb, opts); -- 2.53.0