From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 19C1B352FC7; Tue, 26 Aug 2025 14:01:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756216870; cv=none; b=IOlBn4KWaxyeDt4F4PIXHmyl6JqANy6N/jMov0Dc9cDAKHrY+XzzukPAQUnUjaKqJq+ulriMTrmMM1TKG3CUVOpW1PfhvuI2I42/HmqlgeNIYjjV18i5kKWp3lERAfvQcundaG5DlO/jjZ05hw8F+/ceyx7d8H355b1Ter1+PBM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756216870; c=relaxed/simple; bh=ibmhUqpCmqgneio3Dq5qwsdl+MPjTdgHSpa7s/DpQxs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=vAPnbDZwYmZ6KI84PFMxbGMHkZMwoqKUak9WK4SXqta2OIsSTSc0XiRLVO90PRwN14tuoZynVXP594usc2OTwvZ9M/GgqNd0d7ZP0iy2ea6/+M1CgiXghP2myMk43OXgbTV1aFILbnPcDW7L1febAchY6SK/cf3IpKsw3qU2WIM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=N+ihDsKj; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="N+ihDsKj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 60384C4CEF1; Tue, 26 Aug 2025 14:01:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1756216869; bh=ibmhUqpCmqgneio3Dq5qwsdl+MPjTdgHSpa7s/DpQxs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=N+ihDsKjVxP5q2abZDRD3FsEcxmgROjsRnOhLxehgMz7zV0d3rAasmk3jnDZYqChm OFEZSS5BZroEyCqRv7Q3somC9C5AkvHF2o7E475RreQxnmTv1ndiBVClXTUi06OYRo TifrdgAr4S6ZOn+ihp4ocdS0IYY3zi6THALaTGHU= 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 5.15 542/644] net_sched: sch_ets: implement lockless ets_dump() Date: Tue, 26 Aug 2025 13:10:33 +0200 Message-ID: <20250826110959.950302446@linuxfoundation.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250826110946.507083938@linuxfoundation.org> References: <20250826110946.507083938@linuxfoundation.org> User-Agent: quilt/0.68 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 c5f1dde7f731e7bf2e7c169ca42cb4989fc2f8b9 ] Instead of relying on RTNL, ets_dump() can use READ_ONCE() annotations, paired with WRITE_ONCE() ones in ets_change(). Signed-off-by: Eric Dumazet Reviewed-by: Simon Horman Signed-off-by: David S. Miller Stable-dep-of: 87c6efc5ce9c ("net/sched: ets: use old 'nbands' while purging unused classes") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- net/sched/sch_ets.c | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-) --- a/net/sched/sch_ets.c +++ b/net/sched/sch_ets.c @@ -664,7 +664,7 @@ static int ets_qdisc_change(struct Qdisc sch_tree_lock(sch); - q->nbands = nbands; + WRITE_ONCE(q->nbands, nbands); for (i = nstrict; i < q->nstrict; i++) { if (q->classes[i].qdisc->q.qlen) { list_add_tail(&q->classes[i].alist, &q->active); @@ -676,11 +676,11 @@ static int ets_qdisc_change(struct Qdisc list_del_init(&q->classes[i].alist); qdisc_purge_queue(q->classes[i].qdisc); } - q->nstrict = nstrict; + WRITE_ONCE(q->nstrict, nstrict); memcpy(q->prio2band, priomap, sizeof(priomap)); for (i = 0; i < q->nbands; i++) - q->classes[i].quantum = quanta[i]; + WRITE_ONCE(q->classes[i].quantum, quanta[i]); for (i = oldbands; i < q->nbands; i++) { q->classes[i].qdisc = queues[i]; @@ -694,7 +694,7 @@ static int ets_qdisc_change(struct Qdisc for (i = q->nbands; i < oldbands; i++) { qdisc_put(q->classes[i].qdisc); q->classes[i].qdisc = NULL; - q->classes[i].quantum = 0; + WRITE_ONCE(q->classes[i].quantum, 0); q->classes[i].deficit = 0; memset(&q->classes[i].bstats, 0, sizeof(q->classes[i].bstats)); memset(&q->classes[i].qstats, 0, sizeof(q->classes[i].qstats)); @@ -751,6 +751,7 @@ static int ets_qdisc_dump(struct Qdisc * struct ets_sched *q = qdisc_priv(sch); struct nlattr *opts; struct nlattr *nest; + u8 nbands, nstrict; int band; int prio; int err; @@ -763,21 +764,22 @@ static int ets_qdisc_dump(struct Qdisc * if (!opts) goto nla_err; - if (nla_put_u8(skb, TCA_ETS_NBANDS, q->nbands)) + nbands = READ_ONCE(q->nbands); + if (nla_put_u8(skb, TCA_ETS_NBANDS, nbands)) goto nla_err; - if (q->nstrict && - nla_put_u8(skb, TCA_ETS_NSTRICT, q->nstrict)) + nstrict = READ_ONCE(q->nstrict); + if (nstrict && nla_put_u8(skb, TCA_ETS_NSTRICT, nstrict)) goto nla_err; - if (q->nbands > q->nstrict) { + if (nbands > nstrict) { nest = nla_nest_start(skb, TCA_ETS_QUANTA); if (!nest) goto nla_err; - for (band = q->nstrict; band < q->nbands; band++) { + for (band = nstrict; band < nbands; band++) { if (nla_put_u32(skb, TCA_ETS_QUANTA_BAND, - q->classes[band].quantum)) + READ_ONCE(q->classes[band].quantum))) goto nla_err; } @@ -789,7 +791,8 @@ static int ets_qdisc_dump(struct Qdisc * goto nla_err; for (prio = 0; prio <= TC_PRIO_MAX; prio++) { - if (nla_put_u8(skb, TCA_ETS_PRIOMAP_BAND, q->prio2band[prio])) + if (nla_put_u8(skb, TCA_ETS_PRIOMAP_BAND, + READ_ONCE(q->prio2band[prio]))) goto nla_err; }