18 files changed, 156 insertions, 115 deletions
diff --git a/net/sched/Kconfig b/net/sched/Kconfig
index 8180d0c12fce..a800127effcd 100644
--- a/net/sched/Kconfig
+++ b/net/sched/Kconfig
@@ -784,7 +784,7 @@ config NET_ACT_SKBEDIT
 config NET_ACT_CSUM
 	tristate "Checksum Updating"
 	depends on NET_CLS_ACT && INET
-	select LIBCRC32C
+	select CRC32
 	help
 	  Say Y here to update some common checksum after some direct
 	  packet alterations.
diff --git a/net/sched/act_tunnel_key.c b/net/sched/act_tunnel_key.c
index ae5dea7c48a8..2cef4b08befb 100644
--- a/net/sched/act_tunnel_key.c
+++ b/net/sched/act_tunnel_key.c
@@ -68,7 +68,7 @@ geneve_opt_policy[TCA_TUNNEL_KEY_ENC_OPT_GENEVE_MAX + 1] = {
 	[TCA_TUNNEL_KEY_ENC_OPT_GENEVE_CLASS]	   = { .type = NLA_U16 },
 	[TCA_TUNNEL_KEY_ENC_OPT_GENEVE_TYPE]	   = { .type = NLA_U8 },
 	[TCA_TUNNEL_KEY_ENC_OPT_GENEVE_DATA]	   = { .type = NLA_BINARY,
-						       .len = 128 },
+						       .len = 127 },
 };
 
 static const struct nla_policy
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 4f648af8cfaa..ecec0a1e1c1a 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -2057,6 +2057,7 @@ static int tcf_fill_node(struct net *net, struct sk_buff *skb,
 	struct tcmsg *tcm;
 	struct nlmsghdr  *nlh;
 	unsigned char *b = skb_tail_pointer(skb);
+	int ret = -EMSGSIZE;
 
 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
 	if (!nlh)
@@ -2101,11 +2102,45 @@ static int tcf_fill_node(struct net *net, struct sk_buff *skb,
 
 	return skb->len;
 
+cls_op_not_supp:
+	ret = -EOPNOTSUPP;
 out_nlmsg_trim:
 nla_put_failure:
-cls_op_not_supp:
 	nlmsg_trim(skb, b);
-	return -1;
+	return ret;
+}
+
+static struct sk_buff *tfilter_notify_prep(struct net *net,
+					   struct sk_buff *oskb,
+					   struct nlmsghdr *n,
+					   struct tcf_proto *tp,
+					   struct tcf_block *block,
+					   struct Qdisc *q, u32 parent,
+					   void *fh, int event,
+					   u32 portid, bool rtnl_held,
+					   struct netlink_ext_ack *extack)
+{
+	unsigned int size = oskb ? max(NLMSG_GOODSIZE, oskb->len) : NLMSG_GOODSIZE;
+	struct sk_buff *skb;
+	int ret;
+
+retry:
+	skb = alloc_skb(size, GFP_KERNEL);
+	if (!skb)
+		return ERR_PTR(-ENOBUFS);
+
+	ret = tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
+			    n->nlmsg_seq, n->nlmsg_flags, event, false,
+			    rtnl_held, extack);
+	if (ret <= 0) {
+		kfree_skb(skb);
+		if (ret == -EMSGSIZE) {
+			size += NLMSG_GOODSIZE;
+			goto retry;
+		}
+		return ERR_PTR(-EINVAL);
+	}
+	return skb;
 }
 
 static int tfilter_notify(struct net *net, struct sk_buff *oskb,
@@ -2121,16 +2156,10 @@ static int tfilter_notify(struct net *net, struct sk_buff *oskb,
 	if (!unicast && !rtnl_notify_needed(net, n->nlmsg_flags, RTNLGRP_TC))
 		return 0;
 
-	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
-	if (!skb)
-		return -ENOBUFS;
-
-	if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
-			  n->nlmsg_seq, n->nlmsg_flags, event,
-			  false, rtnl_held, extack) <= 0) {
-		kfree_skb(skb);
-		return -EINVAL;
-	}
+	skb = tfilter_notify_prep(net, oskb, n, tp, block, q, parent, fh, event,
+				  portid, rtnl_held, extack);
+	if (IS_ERR(skb))
+		return PTR_ERR(skb);
 
 	if (unicast)
 		err = rtnl_unicast(skb, net, portid);
@@ -2153,16 +2182,11 @@ static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
 	if (!rtnl_notify_needed(net, n->nlmsg_flags, RTNLGRP_TC))
 		return tp->ops->delete(tp, fh, last, rtnl_held, extack);
 
-	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
-	if (!skb)
-		return -ENOBUFS;
-
-	if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
-			  n->nlmsg_seq, n->nlmsg_flags, RTM_DELTFILTER,
-			  false, rtnl_held, extack) <= 0) {
+	skb = tfilter_notify_prep(net, oskb, n, tp, block, q, parent, fh,
+				  RTM_DELTFILTER, portid, rtnl_held, extack);
+	if (IS_ERR(skb)) {
 		NL_SET_ERR_MSG(extack, "Failed to build del event notification");
-		kfree_skb(skb);
-		return -EINVAL;
+		return PTR_ERR(skb);
 	}
 
 	err = tp->ops->delete(tp, fh, last, rtnl_held, extack);
diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index 03505673d523..099ff6a3e1f5 100644
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -766,7 +766,7 @@ geneve_opt_policy[TCA_FLOWER_KEY_ENC_OPT_GENEVE_MAX + 1] = {
 	[TCA_FLOWER_KEY_ENC_OPT_GENEVE_CLASS]      = { .type = NLA_U16 },
 	[TCA_FLOWER_KEY_ENC_OPT_GENEVE_TYPE]       = { .type = NLA_U8 },
 	[TCA_FLOWER_KEY_ENC_OPT_GENEVE_DATA]       = { .type = NLA_BINARY,
-						       .len = 128 },
+						       .len = 127 },
 };
 
 static const struct nla_policy
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index defb05c1fba4..f74a097f54ae 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -1267,38 +1267,8 @@ static struct Qdisc *qdisc_create(struct net_device *dev,
 	struct qdisc_size_table *stab;
 
 	ops = qdisc_lookup_ops(kind);
-#ifdef CONFIG_MODULES
-	if (ops == NULL && kind != NULL) {
-		char name[IFNAMSIZ];
-		if (nla_strscpy(name, kind, IFNAMSIZ) >= 0) {
-			/* We dropped the RTNL semaphore in order to
-			 * perform the module load.  So, even if we
-			 * succeeded in loading the module we have to
-			 * tell the caller to replay the request.  We
-			 * indicate this using -EAGAIN.
-			 * We replay the request because the device may
-			 * go away in the mean time.
-			 */
-			netdev_unlock_ops(dev);
-			rtnl_unlock();
-			request_module(NET_SCH_ALIAS_PREFIX "%s", name);
-			rtnl_lock();
-			netdev_lock_ops(dev);
-			ops = qdisc_lookup_ops(kind);
-			if (ops != NULL) {
-				/* We will try again qdisc_lookup_ops,
-				 * so don't keep a reference.
-				 */
-				module_put(ops->owner);
-				err = -EAGAIN;
-				goto err_out;
-			}
-		}
-	}
-#endif
-
-	err = -ENOENT;
 	if (!ops) {
+		err = -ENOENT;
 		NL_SET_ERR_MSG(extack, "Specified qdisc kind is unknown");
 		goto err_out;
 	}
@@ -1623,8 +1593,7 @@ static int __tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n,
 			     struct netlink_ext_ack *extack,
 			     struct net_device *dev,
 			     struct nlattr *tca[TCA_MAX + 1],
-			     struct tcmsg *tcm,
-			     bool *replay)
+			     struct tcmsg *tcm)
 {
 	struct Qdisc *q = NULL;
 	struct Qdisc *p = NULL;
@@ -1789,13 +1758,8 @@ create_n_graft2:
 				 tcm->tcm_parent, tcm->tcm_handle,
 				 tca, &err, extack);
 	}
-	if (q == NULL) {
-		if (err == -EAGAIN) {
-			*replay = true;
-			return 0;
-		}
+	if (!q)
 		return err;
-	}
 
 graft:
 	err = qdisc_graft(dev, p, skb, n, clid, q, NULL, extack);
@@ -1808,6 +1772,27 @@ graft:
 	return 0;
 }
 
+static void request_qdisc_module(struct nlattr *kind)
+{
+	struct Qdisc_ops *ops;
+	char name[IFNAMSIZ];
+
+	if (!kind)
+		return;
+
+	ops = qdisc_lookup_ops(kind);
+	if (ops) {
+		module_put(ops->owner);
+		return;
+	}
+
+	if (nla_strscpy(name, kind, IFNAMSIZ) >= 0) {
+		rtnl_unlock();
+		request_module(NET_SCH_ALIAS_PREFIX "%s", name);
+		rtnl_lock();
+	}
+}
+
 /*
  * Create/change qdisc.
  */
@@ -1818,27 +1803,23 @@ static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n,
 	struct nlattr *tca[TCA_MAX + 1];
 	struct net_device *dev;
 	struct tcmsg *tcm;
-	bool replay;
 	int err;
 
-replay:
-	/* Reinit, just in case something touches this. */
 	err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX,
 				     rtm_tca_policy, extack);
 	if (err < 0)
 		return err;
 
+	request_qdisc_module(tca[TCA_KIND]);
+
 	tcm = nlmsg_data(n);
 	dev = __dev_get_by_index(net, tcm->tcm_ifindex);
 	if (!dev)
 		return -ENODEV;
 
-	replay = false;
 	netdev_lock_ops(dev);
-	err = __tc_modify_qdisc(skb, n, extack, dev, tca, tcm, &replay);
+	err = __tc_modify_qdisc(skb, n, extack, dev, tca, tcm);
 	netdev_unlock_ops(dev);
-	if (replay)
-		goto replay;
 
 	return err;
 }
diff --git a/net/sched/sch_codel.c b/net/sched/sch_codel.c
index 81189d02fee7..12dd71139da3 100644
--- a/net/sched/sch_codel.c
+++ b/net/sched/sch_codel.c
@@ -65,10 +65,7 @@ static struct sk_buff *codel_qdisc_dequeue(struct Qdisc *sch)
 			    &q->stats, qdisc_pkt_len, codel_get_enqueue_time,
 			    drop_func, dequeue_func);
 
-	/* We cant call qdisc_tree_reduce_backlog() if our qlen is 0,
-	 * or HTB crashes. Defer it for next round.
-	 */
-	if (q->stats.drop_count && sch->q.qlen) {
+	if (q->stats.drop_count) {
 		qdisc_tree_reduce_backlog(sch, q->stats.drop_count, q->stats.drop_len);
 		q->stats.drop_count = 0;
 		q->stats.drop_len = 0;
diff --git a/net/sched/sch_drr.c b/net/sched/sch_drr.c
index c69b999fae17..e0a81d313aa7 100644
--- a/net/sched/sch_drr.c
+++ b/net/sched/sch_drr.c
@@ -105,6 +105,7 @@ static int drr_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
 		return -ENOBUFS;
 
 	gnet_stats_basic_sync_init(&cl->bstats);
+	INIT_LIST_HEAD(&cl->alist);
 	cl->common.classid = classid;
 	cl->quantum	   = quantum;
 	cl->qdisc	   = qdisc_create_dflt(sch->dev_queue,
@@ -229,7 +230,7 @@ static void drr_qlen_notify(struct Qdisc *csh, unsigned long arg)
 {
 	struct drr_class *cl = (struct drr_class *)arg;
 
-	list_del(&cl->alist);
+	list_del_init(&cl->alist);
 }
 
 static int drr_dump_class(struct Qdisc *sch, unsigned long arg,
@@ -390,7 +391,7 @@ static struct sk_buff *drr_dequeue(struct Qdisc *sch)
 			if (unlikely(skb == NULL))
 				goto out;
 			if (cl->qdisc->q.qlen == 0)
-				list_del(&cl->alist);
+				list_del_init(&cl->alist);
 
 			bstats_update(&cl->bstats, skb);
 			qdisc_bstats_update(sch, skb);
@@ -431,7 +432,7 @@ static void drr_reset_qdisc(struct Qdisc *sch)
 	for (i = 0; i < q->clhash.hashsize; i++) {
 		hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
 			if (cl->qdisc->q.qlen)
-				list_del(&cl->alist);
+				list_del_init(&cl->alist);
 			qdisc_reset(cl->qdisc);
 		}
 	}
diff --git a/net/sched/sch_ets.c b/net/sched/sch_ets.c
index 516038a44163..c3bdeb14185b 100644
--- a/net/sched/sch_ets.c
+++ b/net/sched/sch_ets.c
@@ -293,7 +293,7 @@ static void ets_class_qlen_notify(struct Qdisc *sch, unsigned long arg)
 	 * to remove them.
 	 */
 	if (!ets_class_is_strict(q, cl) && sch->q.qlen)
-		list_del(&cl->alist);
+		list_del_init(&cl->alist);
 }
 
 static int ets_class_dump(struct Qdisc *sch, unsigned long arg,
@@ -488,7 +488,7 @@ static struct sk_buff *ets_qdisc_dequeue(struct Qdisc *sch)
 			if (unlikely(!skb))
 				goto out;
 			if (cl->qdisc->q.qlen == 0)
-				list_del(&cl->alist);
+				list_del_init(&cl->alist);
 			return ets_qdisc_dequeue_skb(sch, skb);
 		}
 
@@ -657,7 +657,7 @@ static int ets_qdisc_change(struct Qdisc *sch, struct nlattr *opt,
 	}
 	for (i = q->nbands; i < oldbands; i++) {
 		if (i >= q->nstrict && q->classes[i].qdisc->q.qlen)
-			list_del(&q->classes[i].alist);
+			list_del_init(&q->classes[i].alist);
 		qdisc_tree_flush_backlog(q->classes[i].qdisc);
 	}
 	WRITE_ONCE(q->nstrict, nstrict);
@@ -713,7 +713,7 @@ static void ets_qdisc_reset(struct Qdisc *sch)
 
 	for (band = q->nstrict; band < q->nbands; band++) {
 		if (q->classes[band].qdisc->q.qlen)
-			list_del(&q->classes[band].alist);
+			list_del_init(&q->classes[band].alist);
 	}
 	for (band = 0; band < q->nbands; band++)
 		qdisc_reset(q->classes[band].qdisc);
diff --git a/net/sched/sch_fq_codel.c b/net/sched/sch_fq_codel.c
index 799f5397ad4c..6c9029f71e88 100644
--- a/net/sched/sch_fq_codel.c
+++ b/net/sched/sch_fq_codel.c
@@ -315,10 +315,8 @@ begin:
 	}
 	qdisc_bstats_update(sch, skb);
 	flow->deficit -= qdisc_pkt_len(skb);
-	/* We cant call qdisc_tree_reduce_backlog() if our qlen is 0,
-	 * or HTB crashes. Defer it for next round.
-	 */
-	if (q->cstats.drop_count && sch->q.qlen) {
+
+	if (q->cstats.drop_count) {
 		qdisc_tree_reduce_backlog(sch, q->cstats.drop_count,
 					  q->cstats.drop_len);
 		q->cstats.drop_count = 0;
diff --git a/net/sched/sch_fq_pie.c b/net/sched/sch_fq_pie.c
index 93c36afbf576..f3b8203d3e85 100644
--- a/net/sched/sch_fq_pie.c
+++ b/net/sched/sch_fq_pie.c
@@ -555,7 +555,7 @@ static void fq_pie_destroy(struct Qdisc *sch)
 
 	tcf_block_put(q->block);
 	q->p_params.tupdate = 0;
-	del_timer_sync(&q->adapt_timer);
+	timer_delete_sync(&q->adapt_timer);
 	kvfree(q->flows);
 }
 
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 14ab2f4c190a..514b1b6ac681 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -567,7 +567,7 @@ EXPORT_SYMBOL_GPL(netdev_watchdog_up);
 static void netdev_watchdog_down(struct net_device *dev)
 {
 	netif_tx_lock_bh(dev);
-	if (del_timer(&dev->watchdog_timer))
+	if (timer_delete(&dev->watchdog_timer))
 		netdev_put(dev, &dev->watchdog_dev_tracker);
 	netif_tx_unlock_bh(dev);
 }
diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c
index c287bf8423b4..ce5045eea065 100644
--- a/net/sched/sch_hfsc.c
+++ b/net/sched/sch_hfsc.c
@@ -203,7 +203,10 @@ eltree_insert(struct hfsc_class *cl)
 static inline void
 eltree_remove(struct hfsc_class *cl)
 {
-	rb_erase(&cl->el_node, &cl->sched->eligible);
+	if (!RB_EMPTY_NODE(&cl->el_node)) {
+		rb_erase(&cl->el_node, &cl->sched->eligible);
+		RB_CLEAR_NODE(&cl->el_node);
+	}
 }
 
 static inline void
@@ -1220,7 +1223,8 @@ hfsc_qlen_notify(struct Qdisc *sch, unsigned long arg)
 	/* vttree is now handled in update_vf() so that update_vf(cl, 0, 0)
 	 * needs to be called explicitly to remove a class from vttree.
 	 */
-	update_vf(cl, 0, 0);
+	if (cl->cl_nactive)
+		update_vf(cl, 0, 0);
 	if (cl->cl_flags & HFSC_RSC)
 		eltree_remove(cl);
 }
diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
index c31bc5489bdd..4b9a639b642e 100644
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -1485,6 +1485,8 @@ static void htb_qlen_notify(struct Qdisc *sch, unsigned long arg)
 {
 	struct htb_class *cl = (struct htb_class *)arg;
 
+	if (!cl->prio_activity)
+		return;
 	htb_deactivate(qdisc_priv(sch), cl);
 }
 
diff --git a/net/sched/sch_pie.c b/net/sched/sch_pie.c
index bb1fa9aa530b..3771d000b30d 100644
--- a/net/sched/sch_pie.c
+++ b/net/sched/sch_pie.c
@@ -545,7 +545,7 @@ static void pie_destroy(struct Qdisc *sch)
 	struct pie_sched_data *q = qdisc_priv(sch);
 
 	q->params.tupdate = 0;
-	del_timer_sync(&q->adapt_timer);
+	timer_delete_sync(&q->adapt_timer);
 }
 
 static struct Qdisc_ops pie_qdisc_ops __read_mostly = {
diff --git a/net/sched/sch_qfq.c b/net/sched/sch_qfq.c
index 2cfbc977fe6d..687a932eb9b2 100644
--- a/net/sched/sch_qfq.c
+++ b/net/sched/sch_qfq.c
@@ -347,7 +347,7 @@ static void qfq_deactivate_class(struct qfq_sched *q, struct qfq_class *cl)
 	struct qfq_aggregate *agg = cl->agg;
 
 
-	list_del(&cl->alist); /* remove from RR queue of the aggregate */
+	list_del_init(&cl->alist); /* remove from RR queue of the aggregate */
 	if (list_empty(&agg->active)) /* agg is now inactive */
 		qfq_deactivate_agg(q, agg);
 }
@@ -474,6 +474,7 @@ static int qfq_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
 	gnet_stats_basic_sync_init(&cl->bstats);
 	cl->common.classid = classid;
 	cl->deficit = lmax;
+	INIT_LIST_HEAD(&cl->alist);
 
 	cl->qdisc = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
 				      classid, NULL);
@@ -982,7 +983,7 @@ static struct sk_buff *agg_dequeue(struct qfq_aggregate *agg,
 	cl->deficit -= (int) len;
 
 	if (cl->qdisc->q.qlen == 0) /* no more packets, remove from list */
-		list_del(&cl->alist);
+		list_del_init(&cl->alist);
 	else if (cl->deficit < qdisc_pkt_len(cl->qdisc->ops->peek(cl->qdisc))) {
 		cl->deficit += agg->lmax;
 		list_move_tail(&cl->alist, &agg->active);
@@ -1415,6 +1416,8 @@ static void qfq_qlen_notify(struct Qdisc *sch, unsigned long arg)
 	struct qfq_sched *q = qdisc_priv(sch);
 	struct qfq_class *cl = (struct qfq_class *)arg;
 
+	if (list_empty(&cl->alist))
+		return;
 	qfq_deactivate_class(q, cl);
 }
 
diff --git a/net/sched/sch_red.c b/net/sched/sch_red.c
index ef8a2afed26b..1ba3e0bba54f 100644
--- a/net/sched/sch_red.c
+++ b/net/sched/sch_red.c
@@ -218,7 +218,7 @@ static void red_destroy(struct Qdisc *sch)
 
 	tcf_qevent_destroy(&q->qe_mark, sch);
 	tcf_qevent_destroy(&q->qe_early_drop, sch);
-	del_timer_sync(&q->adapt_timer);
+	timer_delete_sync(&q->adapt_timer);
 	red_offload(sch, false);
 	qdisc_put(q->qdisc);
 }
@@ -297,7 +297,7 @@ static int __red_change(struct Qdisc *sch, struct nlattr **tb,
 		      max_P);
 	red_set_vars(&q->vars);
 
-	del_timer(&q->adapt_timer);
+	timer_delete(&q->adapt_timer);
 	if (ctl->flags & TC_RED_ADAPTATIVE)
 		mod_timer(&q->adapt_timer, jiffies + HZ/2);
 
diff --git a/net/sched/sch_sfq.c b/net/sched/sch_sfq.c
index 65d5b59da583..b912ad99aa15 100644
--- a/net/sched/sch_sfq.c
+++ b/net/sched/sch_sfq.c
@@ -631,6 +631,15 @@ static int sfq_change(struct Qdisc *sch, struct nlattr *opt,
 	struct red_parms *p = NULL;
 	struct sk_buff *to_free = NULL;
 	struct sk_buff *tail = NULL;
+	unsigned int maxflows;
+	unsigned int quantum;
+	unsigned int divisor;
+	int perturb_period;
+	u8 headdrop;
+	u8 maxdepth;
+	int limit;
+	u8 flags;
+
 
 	if (opt->nla_len < nla_attr_size(sizeof(*ctl)))
 		return -EINVAL;
@@ -652,39 +661,64 @@ static int sfq_change(struct Qdisc *sch, struct nlattr *opt,
 		if (!p)
 			return -ENOMEM;
 	}
-	if (ctl->limit == 1) {
-		NL_SET_ERR_MSG_MOD(extack, "invalid limit");
-		return -EINVAL;
-	}
+
 	sch_tree_lock(sch);
+
+	limit = q->limit;
+	divisor = q->divisor;
+	headdrop = q->headdrop;
+	maxdepth = q->maxdepth;
+	maxflows = q->maxflows;
+	perturb_period = q->perturb_period;
+	quantum = q->quantum;
+	flags = q->flags;
+
+	/* update and validate configuration */
 	if (ctl->quantum)
-		q->quantum = ctl->quantum;
-	WRITE_ONCE(q->perturb_period, ctl->perturb_period * HZ);
+		quantum = ctl->quantum;
+	perturb_period = ctl->perturb_period * HZ;
 	if (ctl->flows)
-		q->maxflows = min_t(u32, ctl->flows, SFQ_MAX_FLOWS);
+		maxflows = min_t(u32, ctl->flows, SFQ_MAX_FLOWS);
 	if (ctl->divisor) {
-		q->divisor = ctl->divisor;
-		q->maxflows = min_t(u32, q->maxflows, q->divisor);
+		divisor = ctl->divisor;
+		maxflows = min_t(u32, maxflows, divisor);
 	}
 	if (ctl_v1) {
 		if (ctl_v1->depth)
-			q->maxdepth = min_t(u32, ctl_v1->depth, SFQ_MAX_DEPTH);
+			maxdepth = min_t(u32, ctl_v1->depth, SFQ_MAX_DEPTH);
 		if (p) {
-			swap(q->red_parms, p);
-			red_set_parms(q->red_parms,
+			red_set_parms(p,
 				      ctl_v1->qth_min, ctl_v1->qth_max,
 				      ctl_v1->Wlog,
 				      ctl_v1->Plog, ctl_v1->Scell_log,
 				      NULL,
 				      ctl_v1->max_P);
 		}
-		q->flags = ctl_v1->flags;
-		q->headdrop = ctl_v1->headdrop;
+		flags = ctl_v1->flags;
+		headdrop = ctl_v1->headdrop;
 	}
 	if (ctl->limit) {
-		q->limit = min_t(u32, ctl->limit, q->maxdepth * q->maxflows);
-		q->maxflows = min_t(u32, q->maxflows, q->limit);
+		limit = min_t(u32, ctl->limit, maxdepth * maxflows);
+		maxflows = min_t(u32, maxflows, limit);
 	}
+	if (limit == 1) {
+		sch_tree_unlock(sch);
+		kfree(p);
+		NL_SET_ERR_MSG_MOD(extack, "invalid limit");
+		return -EINVAL;
+	}
+
+	/* commit configuration */
+	q->limit = limit;
+	q->divisor = divisor;
+	q->headdrop = headdrop;
+	q->maxdepth = maxdepth;
+	q->maxflows = maxflows;
+	WRITE_ONCE(q->perturb_period, perturb_period);
+	q->quantum = quantum;
+	q->flags = flags;
+	if (p)
+		swap(q->red_parms, p);
 
 	qlen = sch->q.qlen;
 	while (sch->q.qlen > q->limit) {
@@ -696,7 +730,7 @@ static int sfq_change(struct Qdisc *sch, struct nlattr *opt,
 	rtnl_kfree_skbs(to_free, tail);
 	qdisc_tree_reduce_backlog(sch, qlen - sch->q.qlen, dropped);
 
-	del_timer(&q->perturb_timer);
+	timer_delete(&q->perturb_timer);
 	if (q->perturb_period) {
 		mod_timer(&q->perturb_timer, jiffies + q->perturb_period);
 		get_random_bytes(&q->perturbation, sizeof(q->perturbation));
@@ -722,7 +756,7 @@ static void sfq_destroy(struct Qdisc *sch)
 
 	tcf_block_put(q->block);
 	WRITE_ONCE(q->perturb_period, 0);
-	del_timer_sync(&q->perturb_timer);
+	timer_delete_sync(&q->perturb_timer);
 	sfq_free(q->ht);
 	sfq_free(q->slots);
 	kfree(q->red_parms);
diff --git a/net/sched/sch_skbprio.c b/net/sched/sch_skbprio.c
index 20ff7386b74b..f485f62ab721 100644
--- a/net/sched/sch_skbprio.c
+++ b/net/sched/sch_skbprio.c
@@ -123,8 +123,6 @@ static int skbprio_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 	/* Check to update highest and lowest priorities. */
 	if (skb_queue_empty(lp_qdisc)) {
 		if (q->lowest_prio == q->highest_prio) {
-			/* The incoming packet is the only packet in queue. */
-			BUG_ON(sch->q.qlen != 1);
 			q->lowest_prio = prio;
 			q->highest_prio = prio;
 		} else {
@@ -156,7 +154,6 @@ static struct sk_buff *skbprio_dequeue(struct Qdisc *sch)
 	/* Update highest priority field. */
 	if (skb_queue_empty(hpq)) {
 		if (q->lowest_prio == q->highest_prio) {
-			BUG_ON(sch->q.qlen);
 			q->highest_prio = 0;
 			q->lowest_prio = SKBPRIO_MAX_PRIORITY - 1;
 		} else {