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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 CF7E0C433EF for ; Mon, 13 Sep 2021 14:46:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B7CEC60FC0 for ; Mon, 13 Sep 2021 14:46:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346489AbhIMOsB (ORCPT ); Mon, 13 Sep 2021 10:48:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:58824 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345614AbhIMOmY (ORCPT ); Mon, 13 Sep 2021 10:42:24 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id D671361004; Mon, 13 Sep 2021 13:56:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1631541409; bh=ADolzZ/a6d+r1ZgaXKhMKsA92fhmcxoPDcdrZNovPIQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PNeai3d2EqD6vJbXj1P63IUlcrbkxeePpURhqfiMVy2hu6O4SaJlxVUlzkkaGOd0O 12EfEUkmryaAhwAFLqDxOCwx/oaPsBJ9fsfZ8xrXNUUPjJ6+LYfLd7ec5+itnlIuRB u/b0aVtFSkIfUOR2a0ffU0OKCamiFbigirqk/Qus= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Maxim Mikityanskiy , Tariq Toukan , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.14 287/334] sch_htb: Fix inconsistency when leaf qdisc creation fails Date: Mon, 13 Sep 2021 15:15:41 +0200 Message-Id: <20210913131123.129930592@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210913131113.390368911@linuxfoundation.org> References: <20210913131113.390368911@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Maxim Mikityanskiy [ Upstream commit ca49bfd90a9dde175d2929dc1544b54841e33804 ] In HTB offload mode, qdiscs of leaf classes are grafted to netdev queues. sch_htb expects the dev_queue field of these qdiscs to point to the corresponding queues. However, qdisc creation may fail, and in that case noop_qdisc is used instead. Its dev_queue doesn't point to the right queue, so sch_htb can lose track of used netdev queues, which will cause internal inconsistencies. This commit fixes this bug by keeping track of the netdev queue inside struct htb_class. All reads of cl->leaf.q->dev_queue are replaced by the new field, the two values are synced on writes, and WARNs are added to assert equality of the two values. The driver API has changed: when TC_HTB_LEAF_DEL needs to move a queue, the driver used to pass the old and new queue IDs to sch_htb. Now that there is a new field (offload_queue) in struct htb_class that needs to be updated on this operation, the driver will pass the old class ID to sch_htb instead (it already knows the new class ID). Fixes: d03b195b5aa0 ("sch_htb: Hierarchical QoS hardware offload") Signed-off-by: Maxim Mikityanskiy Reviewed-by: Tariq Toukan Link: https://lore.kernel.org/r/20210826115425.1744053-1-maximmi@nvidia.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- .../net/ethernet/mellanox/mlx5/core/en/qos.c | 15 ++- .../net/ethernet/mellanox/mlx5/core/en/qos.h | 4 +- .../net/ethernet/mellanox/mlx5/core/en_main.c | 3 +- include/net/pkt_cls.h | 3 +- net/sched/sch_htb.c | 97 ++++++++++++------- 5 files changed, 72 insertions(+), 50 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/qos.c b/drivers/net/ethernet/mellanox/mlx5/core/en/qos.c index 5efe3278b0f6..1fd8baf19829 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en/qos.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en/qos.c @@ -733,8 +733,8 @@ static void mlx5e_reset_qdisc(struct net_device *dev, u16 qid) spin_unlock_bh(qdisc_lock(qdisc)); } -int mlx5e_htb_leaf_del(struct mlx5e_priv *priv, u16 classid, u16 *old_qid, - u16 *new_qid, struct netlink_ext_ack *extack) +int mlx5e_htb_leaf_del(struct mlx5e_priv *priv, u16 *classid, + struct netlink_ext_ack *extack) { struct mlx5e_qos_node *node; struct netdev_queue *txq; @@ -742,11 +742,9 @@ int mlx5e_htb_leaf_del(struct mlx5e_priv *priv, u16 classid, u16 *old_qid, bool opened; int err; - qos_dbg(priv->mdev, "TC_HTB_LEAF_DEL classid %04x\n", classid); - - *old_qid = *new_qid = 0; + qos_dbg(priv->mdev, "TC_HTB_LEAF_DEL classid %04x\n", *classid); - node = mlx5e_sw_node_find(priv, classid); + node = mlx5e_sw_node_find(priv, *classid); if (!node) return -ENOENT; @@ -764,7 +762,7 @@ int mlx5e_htb_leaf_del(struct mlx5e_priv *priv, u16 classid, u16 *old_qid, err = mlx5_qos_destroy_node(priv->mdev, node->hw_id); if (err) /* Not fatal. */ qos_warn(priv->mdev, "Failed to destroy leaf node %u (class %04x), err = %d\n", - node->hw_id, classid, err); + node->hw_id, *classid, err); mlx5e_sw_node_delete(priv, node); @@ -826,8 +824,7 @@ int mlx5e_htb_leaf_del(struct mlx5e_priv *priv, u16 classid, u16 *old_qid, if (opened) mlx5e_reactivate_qos_sq(priv, moved_qid, txq); - *old_qid = mlx5e_qid_from_qos(&priv->channels, moved_qid); - *new_qid = mlx5e_qid_from_qos(&priv->channels, qid); + *classid = node->classid; return 0; } diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/qos.h b/drivers/net/ethernet/mellanox/mlx5/core/en/qos.h index 5af7991fcd19..757682b7c0e0 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en/qos.h +++ b/drivers/net/ethernet/mellanox/mlx5/core/en/qos.h @@ -34,8 +34,8 @@ int mlx5e_htb_leaf_alloc_queue(struct mlx5e_priv *priv, u16 classid, struct netlink_ext_ack *extack); int mlx5e_htb_leaf_to_inner(struct mlx5e_priv *priv, u16 classid, u16 child_classid, u64 rate, u64 ceil, struct netlink_ext_ack *extack); -int mlx5e_htb_leaf_del(struct mlx5e_priv *priv, u16 classid, u16 *old_qid, - u16 *new_qid, struct netlink_ext_ack *extack); +int mlx5e_htb_leaf_del(struct mlx5e_priv *priv, u16 *classid, + struct netlink_ext_ack *extack); int mlx5e_htb_leaf_del_last(struct mlx5e_priv *priv, u16 classid, bool force, struct netlink_ext_ack *extack); int mlx5e_htb_node_modify(struct mlx5e_priv *priv, u16 classid, u64 rate, u64 ceil, diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c index b7be1ef4cbb2..2d53eaf3b924 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c @@ -3453,8 +3453,7 @@ static int mlx5e_setup_tc_htb(struct mlx5e_priv *priv, struct tc_htb_qopt_offloa return mlx5e_htb_leaf_to_inner(priv, htb->parent_classid, htb->classid, htb->rate, htb->ceil, htb->extack); case TC_HTB_LEAF_DEL: - return mlx5e_htb_leaf_del(priv, htb->classid, &htb->moved_qid, &htb->qid, - htb->extack); + return mlx5e_htb_leaf_del(priv, &htb->classid, htb->extack); case TC_HTB_LEAF_DEL_LAST: case TC_HTB_LEAF_DEL_LAST_FORCE: return mlx5e_htb_leaf_del_last(priv, htb->classid, diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h index 298a8d10168b..fb34b66aefa7 100644 --- a/include/net/pkt_cls.h +++ b/include/net/pkt_cls.h @@ -824,10 +824,9 @@ enum tc_htb_command { struct tc_htb_qopt_offload { struct netlink_ext_ack *extack; enum tc_htb_command command; - u16 classid; u32 parent_classid; + u16 classid; u16 qid; - u16 moved_qid; u64 rate; u64 ceil; }; diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c index 5f7ac27a5264..f22d26a2c89f 100644 --- a/net/sched/sch_htb.c +++ b/net/sched/sch_htb.c @@ -125,6 +125,7 @@ struct htb_class { struct htb_class_leaf { int deficit[TC_HTB_MAXDEPTH]; struct Qdisc *q; + struct netdev_queue *offload_queue; } leaf; struct htb_class_inner { struct htb_prio clprio[TC_HTB_NUMPRIO]; @@ -1411,24 +1412,47 @@ htb_graft_helper(struct netdev_queue *dev_queue, struct Qdisc *new_q) return old_q; } -static void htb_offload_move_qdisc(struct Qdisc *sch, u16 qid_old, u16 qid_new) +static struct netdev_queue *htb_offload_get_queue(struct htb_class *cl) +{ + struct netdev_queue *queue; + + queue = cl->leaf.offload_queue; + if (!(cl->leaf.q->flags & TCQ_F_BUILTIN)) + WARN_ON(cl->leaf.q->dev_queue != queue); + + return queue; +} + +static void htb_offload_move_qdisc(struct Qdisc *sch, struct htb_class *cl_old, + struct htb_class *cl_new, bool destroying) { struct netdev_queue *queue_old, *queue_new; struct net_device *dev = qdisc_dev(sch); - struct Qdisc *qdisc; - queue_old = netdev_get_tx_queue(dev, qid_old); - queue_new = netdev_get_tx_queue(dev, qid_new); + queue_old = htb_offload_get_queue(cl_old); + queue_new = htb_offload_get_queue(cl_new); - if (dev->flags & IFF_UP) - dev_deactivate(dev); - qdisc = dev_graft_qdisc(queue_old, NULL); - qdisc->dev_queue = queue_new; - qdisc = dev_graft_qdisc(queue_new, qdisc); - if (dev->flags & IFF_UP) - dev_activate(dev); + if (!destroying) { + struct Qdisc *qdisc; - WARN_ON(!(qdisc->flags & TCQ_F_BUILTIN)); + if (dev->flags & IFF_UP) + dev_deactivate(dev); + qdisc = dev_graft_qdisc(queue_old, NULL); + WARN_ON(qdisc != cl_old->leaf.q); + } + + if (!(cl_old->leaf.q->flags & TCQ_F_BUILTIN)) + cl_old->leaf.q->dev_queue = queue_new; + cl_old->leaf.offload_queue = queue_new; + + if (!destroying) { + struct Qdisc *qdisc; + + qdisc = dev_graft_qdisc(queue_new, cl_old->leaf.q); + if (dev->flags & IFF_UP) + dev_activate(dev); + WARN_ON(!(qdisc->flags & TCQ_F_BUILTIN)); + } } static int htb_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, @@ -1442,10 +1466,8 @@ static int htb_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, if (cl->level) return -EINVAL; - if (q->offload) { - dev_queue = new->dev_queue; - WARN_ON(dev_queue != cl->leaf.q->dev_queue); - } + if (q->offload) + dev_queue = htb_offload_get_queue(cl); if (!new) { new = qdisc_create_dflt(dev_queue, &pfifo_qdisc_ops, @@ -1514,6 +1536,8 @@ static void htb_parent_to_leaf(struct Qdisc *sch, struct htb_class *cl, parent->ctokens = parent->cbuffer; parent->t_c = ktime_get_ns(); parent->cmode = HTB_CAN_SEND; + if (q->offload) + parent->leaf.offload_queue = cl->leaf.offload_queue; } static void htb_parent_to_leaf_offload(struct Qdisc *sch, @@ -1534,6 +1558,7 @@ static int htb_destroy_class_offload(struct Qdisc *sch, struct htb_class *cl, struct netlink_ext_ack *extack) { struct tc_htb_qopt_offload offload_opt; + struct netdev_queue *dev_queue; struct Qdisc *q = cl->leaf.q; struct Qdisc *old = NULL; int err; @@ -1542,16 +1567,15 @@ static int htb_destroy_class_offload(struct Qdisc *sch, struct htb_class *cl, return -EINVAL; WARN_ON(!q); - if (!destroying) { - /* On destroy of HTB, two cases are possible: - * 1. q is a normal qdisc, but q->dev_queue has noop qdisc. - * 2. q is a noop qdisc (for nodes that were inner), - * q->dev_queue is noop_netdev_queue. + dev_queue = htb_offload_get_queue(cl); + old = htb_graft_helper(dev_queue, NULL); + if (destroying) + /* Before HTB is destroyed, the kernel grafts noop_qdisc to + * all queues. */ - old = htb_graft_helper(q->dev_queue, NULL); - WARN_ON(!old); + WARN_ON(!(old->flags & TCQ_F_BUILTIN)); + else WARN_ON(old != q); - } if (cl->parent) { cl->parent->bstats_bias.bytes += q->bstats.bytes; @@ -1570,18 +1594,17 @@ static int htb_destroy_class_offload(struct Qdisc *sch, struct htb_class *cl, if (!err || destroying) qdisc_put(old); else - htb_graft_helper(q->dev_queue, old); + htb_graft_helper(dev_queue, old); if (last_child) return err; - if (!err && offload_opt.moved_qid != 0) { - if (destroying) - q->dev_queue = netdev_get_tx_queue(qdisc_dev(sch), - offload_opt.qid); - else - htb_offload_move_qdisc(sch, offload_opt.moved_qid, - offload_opt.qid); + if (!err && offload_opt.classid != TC_H_MIN(cl->common.classid)) { + u32 classid = TC_H_MAJ(sch->handle) | + TC_H_MIN(offload_opt.classid); + struct htb_class *moved_cl = htb_find(classid, sch); + + htb_offload_move_qdisc(sch, moved_cl, cl, destroying); } return err; @@ -1704,9 +1727,11 @@ static int htb_delete(struct Qdisc *sch, unsigned long arg, } if (last_child) { - struct netdev_queue *dev_queue; + struct netdev_queue *dev_queue = sch->dev_queue; + + if (q->offload) + dev_queue = htb_offload_get_queue(cl); - dev_queue = q->offload ? cl->leaf.q->dev_queue : sch->dev_queue; new_q = qdisc_create_dflt(dev_queue, &pfifo_qdisc_ops, cl->parent->common.classid, NULL); @@ -1878,7 +1903,7 @@ static int htb_change_class(struct Qdisc *sch, u32 classid, } dev_queue = netdev_get_tx_queue(dev, offload_opt.qid); } else { /* First child. */ - dev_queue = parent->leaf.q->dev_queue; + dev_queue = htb_offload_get_queue(parent); old_q = htb_graft_helper(dev_queue, NULL); WARN_ON(old_q != parent->leaf.q); offload_opt = (struct tc_htb_qopt_offload) { @@ -1935,6 +1960,8 @@ static int htb_change_class(struct Qdisc *sch, u32 classid, /* leaf (we) needs elementary qdisc */ cl->leaf.q = new_q ? new_q : &noop_qdisc; + if (q->offload) + cl->leaf.offload_queue = dev_queue; cl->parent = parent; -- 2.30.2