From: Maxim Mikityanskiy maximmi@nvidia.com
[ 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 maximmi@nvidia.com Reviewed-by: Tariq Toukan tariqt@nvidia.com Link: https://lore.kernel.org/r/20210826115425.1744053-1-maximmi@nvidia.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- .../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 b0424c36cf7f..814ff51db1a5 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c @@ -3447,8 +3447,7 @@ 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 ec7823921bd2..b420f905f4f6 100644 --- a/include/net/pkt_cls.h +++ b/include/net/pkt_cls.h @@ -820,10 +820,9 @@ 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 8827987ba903..11bc6bf35f84 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]; @@ -1376,24 +1377,47 @@ 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, @@ -1407,10 +1431,8 @@ 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, @@ -1479,6 +1501,8 @@ 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, @@ -1499,6 +1523,7 @@ 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; @@ -1507,16 +1532,15 @@ 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; @@ -1535,18 +1559,17 @@ 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; @@ -1669,9 +1692,11 @@ 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); @@ -1843,7 +1868,7 @@ 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) { @@ -1900,6 +1925,8 @@ 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;