Merge branch 'net-sched-do-not-drop-root-lock-in-tcf_qevent_handle'

Petr Machata says:

====================
net: sched: Do not drop root lock in tcf_qevent_handle()

Mirred currently does not mix well with blocks executed after the qdisc
root lock is taken. This includes classification blocks (such as in PRIO,
ETS, DRR qdiscs) and qevents. The locking caused by the packet mirrored by
mirred can cause deadlocks: either when the thread of execution attempts to
take the lock a second time, or when two threads end up waiting on each
other's locks.

The qevent patchset attempted to not introduce further badness of this
sort, and dropped the lock before executing the qevent block. However this
lead to too little locking and races between qdisc configuration and packet
enqueue in the RED qdisc.

Before the deadlock issues are solved in a way that can be applied across
many qdiscs reasonably easily, do for qevents what is done for the
classification blocks and just keep holding the root lock.

That is done in patch #1. Patch #2 then drops the now unnecessary root_lock
argument from Qdisc_ops.enqueue.
====================

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

37 files changed, 77 insertions, 85 deletions

diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
index 690a7f49c8f9..d4d461236351 100644
--- a/include/net/pkt_cls.h
+++ b/include/net/pkt_cls.h
@@ -568,7 +568,7 @@ void tcf_qevent_destroy(struct tcf_qevent *qe, struct Qdisc *sch);
 int tcf_qevent_validate_change(struct tcf_qevent *qe, struct nlattr *block_index_attr,
 			       struct netlink_ext_ack *extack);
 struct sk_buff *tcf_qevent_handle(struct tcf_qevent *qe, struct Qdisc *sch, struct sk_buff *skb,
-				  spinlock_t *root_lock, struct sk_buff **to_free, int *ret);
+				  struct sk_buff **to_free, int *ret);
 int tcf_qevent_dump(struct sk_buff *skb, int attr_name, struct tcf_qevent *qe);
 #else
 static inline int tcf_qevent_init(struct tcf_qevent *qe, struct Qdisc *sch,
@@ -591,7 +591,7 @@ static inline int tcf_qevent_validate_change(struct tcf_qevent *qe, struct nlatt
 
 static inline struct sk_buff *
 tcf_qevent_handle(struct tcf_qevent *qe, struct Qdisc *sch, struct sk_buff *skb,
-		  spinlock_t *root_lock, struct sk_buff **to_free, int *ret)
+		  struct sk_buff **to_free, int *ret)
 {
 	return skb;
 }
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index fceb3d63c925..c510b03b9751 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -57,7 +57,6 @@ struct qdisc_skb_head {
 struct Qdisc {
 	int 			(*enqueue)(struct sk_buff *skb,
 					   struct Qdisc *sch,
-					   spinlock_t *root_lock,
 					   struct sk_buff **to_free);
 	struct sk_buff *	(*dequeue)(struct Qdisc *sch);
 	unsigned int		flags;
@@ -242,7 +241,6 @@ struct Qdisc_ops {
 
 	int 			(*enqueue)(struct sk_buff *skb,
 					   struct Qdisc *sch,
-					   spinlock_t *root_lock,
 					   struct sk_buff **to_free);
 	struct sk_buff *	(*dequeue)(struct Qdisc *);
 	struct sk_buff *	(*peek)(struct Qdisc *);
@@ -790,11 +788,11 @@ static inline void qdisc_calculate_pkt_len(struct sk_buff *skb,
 #endif
 }
 
-static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 				struct sk_buff **to_free)
 {
 	qdisc_calculate_pkt_len(skb, sch);
-	return sch->enqueue(skb, sch, root_lock, to_free);
+	return sch->enqueue(skb, sch, to_free);
 }
 
 static inline void _bstats_update(struct gnet_stats_basic_packed *bstats,
diff --git a/net/core/dev.c b/net/core/dev.c
index b61075828358..062a00fdca9b 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3749,7 +3749,7 @@ static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
 	qdisc_calculate_pkt_len(skb, q);
 
 	if (q->flags & TCQ_F_NOLOCK) {
-		rc = q->enqueue(skb, q, NULL, &to_free) & NET_XMIT_MASK;
+		rc = q->enqueue(skb, q, &to_free) & NET_XMIT_MASK;
 		qdisc_run(q);
 
 		if (unlikely(to_free))
@@ -3792,7 +3792,7 @@ static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
 		qdisc_run_end(q);
 		rc = NET_XMIT_SUCCESS;
 	} else {
-		rc = q->enqueue(skb, q, root_lock, &to_free) & NET_XMIT_MASK;
+		rc = q->enqueue(skb, q, &to_free) & NET_XMIT_MASK;
 		if (qdisc_run_begin(q)) {
 			if (unlikely(contended)) {
 				spin_unlock(&q->busylock);
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 322b279154de..b2b7440c2ae7 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -3822,7 +3822,7 @@ int tcf_qevent_validate_change(struct tcf_qevent *qe, struct nlattr *block_index
 EXPORT_SYMBOL(tcf_qevent_validate_change);
 
 struct sk_buff *tcf_qevent_handle(struct tcf_qevent *qe, struct Qdisc *sch, struct sk_buff *skb,
-				  spinlock_t *root_lock, struct sk_buff **to_free, int *ret)
+				  struct sk_buff **to_free, int *ret)
 {
 	struct tcf_result cl_res;
 	struct tcf_proto *fl;
@@ -3832,9 +3832,6 @@ struct sk_buff *tcf_qevent_handle(struct tcf_qevent *qe, struct Qdisc *sch, stru
 
 	fl = rcu_dereference_bh(qe->filter_chain);
 
-	if (root_lock)
-		spin_unlock(root_lock);
-
 	switch (tcf_classify(skb, fl, &cl_res, false)) {
 	case TC_ACT_SHOT:
 		qdisc_qstats_drop(sch);
@@ -3853,9 +3850,6 @@ struct sk_buff *tcf_qevent_handle(struct tcf_qevent *qe, struct Qdisc *sch, stru
 		return NULL;
 	}
 
-	if (root_lock)
-		spin_lock(root_lock);
-
 	return skb;
 }
 EXPORT_SYMBOL(tcf_qevent_handle);
diff --git a/net/sched/sch_atm.c b/net/sched/sch_atm.c
index 1d5e422d9be2..1c281cc81f57 100644
--- a/net/sched/sch_atm.c
+++ b/net/sched/sch_atm.c
@@ -374,7 +374,7 @@ static struct tcf_block *atm_tc_tcf_block(struct Qdisc *sch, unsigned long cl,
 
 /* --------------------------- Qdisc operations ---------------------------- */
 
-static int atm_tc_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+static int atm_tc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 			  struct sk_buff **to_free)
 {
 	struct atm_qdisc_data *p = qdisc_priv(sch);
@@ -432,7 +432,7 @@ done:
 #endif
 	}
 
-	ret = qdisc_enqueue(skb, flow->q, root_lock, to_free);
+	ret = qdisc_enqueue(skb, flow->q, to_free);
 	if (ret != NET_XMIT_SUCCESS) {
 drop: __maybe_unused
 		if (net_xmit_drop_count(ret)) {
diff --git a/net/sched/sch_blackhole.c b/net/sched/sch_blackhole.c
index 187644657c4f..a7f7667ae984 100644
--- a/net/sched/sch_blackhole.c
+++ b/net/sched/sch_blackhole.c
@@ -13,7 +13,7 @@
 #include <linux/skbuff.h>
 #include <net/pkt_sched.h>
 
-static int blackhole_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+static int blackhole_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 			     struct sk_buff **to_free)
 {
 	qdisc_drop(skb, sch, to_free);
diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
index b3cdcd86cbfd..561d20c9adca 100644
--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
@@ -1687,7 +1687,7 @@ hash:
 
 static void cake_reconfigure(struct Qdisc *sch);
 
-static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 			struct sk_buff **to_free)
 {
 	struct cake_sched_data *q = qdisc_priv(sch);
diff --git a/net/sched/sch_cbq.c b/net/sched/sch_cbq.c
index 9e16fdf47fe7..b2130df933a7 100644
--- a/net/sched/sch_cbq.c
+++ b/net/sched/sch_cbq.c
@@ -356,7 +356,7 @@ cbq_mark_toplevel(struct cbq_sched_data *q, struct cbq_class *cl)
 }
 
 static int
-cbq_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+cbq_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 	    struct sk_buff **to_free)
 {
 	struct cbq_sched_data *q = qdisc_priv(sch);
@@ -373,7 +373,7 @@ cbq_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
 		return ret;
 	}
 
-	ret = qdisc_enqueue(skb, cl->q, root_lock, to_free);
+	ret = qdisc_enqueue(skb, cl->q, to_free);
 	if (ret == NET_XMIT_SUCCESS) {
 		sch->q.qlen++;
 		cbq_mark_toplevel(q, cl);
diff --git a/net/sched/sch_cbs.c b/net/sched/sch_cbs.c
index 7af15ebe07f7..2eaac2ff380f 100644
--- a/net/sched/sch_cbs.c
+++ b/net/sched/sch_cbs.c
@@ -77,7 +77,7 @@ struct cbs_sched_data {
 	s64 sendslope; /* in bytes/s */
 	s64 idleslope; /* in bytes/s */
 	struct qdisc_watchdog watchdog;
-	int (*enqueue)(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+	int (*enqueue)(struct sk_buff *skb, struct Qdisc *sch,
 		       struct sk_buff **to_free);
 	struct sk_buff *(*dequeue)(struct Qdisc *sch);
 	struct Qdisc *qdisc;
@@ -85,13 +85,13 @@ struct cbs_sched_data {
 };
 
 static int cbs_child_enqueue(struct sk_buff *skb, struct Qdisc *sch,
-			     struct Qdisc *child, spinlock_t *root_lock,
+			     struct Qdisc *child,
 			     struct sk_buff **to_free)
 {
 	unsigned int len = qdisc_pkt_len(skb);
 	int err;
 
-	err = child->ops->enqueue(skb, child, root_lock, to_free);
+	err = child->ops->enqueue(skb, child, to_free);
 	if (err != NET_XMIT_SUCCESS)
 		return err;
 
@@ -101,16 +101,16 @@ static int cbs_child_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 	return NET_XMIT_SUCCESS;
 }
 
-static int cbs_enqueue_offload(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+static int cbs_enqueue_offload(struct sk_buff *skb, struct Qdisc *sch,
 			       struct sk_buff **to_free)
 {
 	struct cbs_sched_data *q = qdisc_priv(sch);
 	struct Qdisc *qdisc = q->qdisc;
 
-	return cbs_child_enqueue(skb, sch, qdisc, root_lock, to_free);
+	return cbs_child_enqueue(skb, sch, qdisc, to_free);
 }
 
-static int cbs_enqueue_soft(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+static int cbs_enqueue_soft(struct sk_buff *skb, struct Qdisc *sch,
 			    struct sk_buff **to_free)
 {
 	struct cbs_sched_data *q = qdisc_priv(sch);
@@ -124,15 +124,15 @@ static int cbs_enqueue_soft(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *
 		q->last = ktime_get_ns();
 	}
 
-	return cbs_child_enqueue(skb, sch, qdisc, root_lock, to_free);
+	return cbs_child_enqueue(skb, sch, qdisc, to_free);
 }
 
-static int cbs_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+static int cbs_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 		       struct sk_buff **to_free)
 {
 	struct cbs_sched_data *q = qdisc_priv(sch);
 
-	return q->enqueue(skb, sch, root_lock, to_free);
+	return q->enqueue(skb, sch, to_free);
 }
 
 /* timediff is in ns, slope is in bytes/s */
diff --git a/net/sched/sch_choke.c b/net/sched/sch_choke.c
index baf3faee31aa..bd618b00d319 100644
--- a/net/sched/sch_choke.c
+++ b/net/sched/sch_choke.c
@@ -210,7 +210,7 @@ static bool choke_match_random(const struct choke_sched_data *q,
 	return choke_match_flow(oskb, nskb);
 }
 
-static int choke_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+static int choke_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 			 struct sk_buff **to_free)
 {
 	struct choke_sched_data *q = qdisc_priv(sch);
diff --git a/net/sched/sch_codel.c b/net/sched/sch_codel.c
index 1d94837abdd8..30169b3adbbb 100644
--- a/net/sched/sch_codel.c
+++ b/net/sched/sch_codel.c
@@ -108,7 +108,7 @@ static struct sk_buff *codel_qdisc_dequeue(struct Qdisc *sch)
 	return skb;
 }
 
-static int codel_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+static int codel_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 			       struct sk_buff **to_free)
 {
 	struct codel_sched_data *q;
diff --git a/net/sched/sch_drr.c b/net/sched/sch_drr.c
index ad14df2ecf3a..dde564670ad8 100644
--- a/net/sched/sch_drr.c
+++ b/net/sched/sch_drr.c
@@ -337,7 +337,7 @@ static struct drr_class *drr_classify(struct sk_buff *skb, struct Qdisc *sch,
 	return NULL;
 }
 
-static int drr_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+static int drr_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 		       struct sk_buff **to_free)
 {
 	unsigned int len = qdisc_pkt_len(skb);
@@ -355,7 +355,7 @@ static int drr_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_
 	}
 
 	first = !cl->qdisc->q.qlen;
-	err = qdisc_enqueue(skb, cl->qdisc, root_lock, to_free);
+	err = qdisc_enqueue(skb, cl->qdisc, to_free);
 	if (unlikely(err != NET_XMIT_SUCCESS)) {
 		if (net_xmit_drop_count(err)) {
 			cl->qstats.drops++;
diff --git a/net/sched/sch_dsmark.c b/net/sched/sch_dsmark.c
index 76a9c4f277f2..2b88710994d7 100644
--- a/net/sched/sch_dsmark.c
+++ b/net/sched/sch_dsmark.c
@@ -198,7 +198,7 @@ static struct tcf_block *dsmark_tcf_block(struct Qdisc *sch, unsigned long cl,
 
 /* --------------------------- Qdisc operations ---------------------------- */
 
-static int dsmark_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+static int dsmark_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 			  struct sk_buff **to_free)
 {
 	unsigned int len = qdisc_pkt_len(skb);
@@ -267,7 +267,7 @@ static int dsmark_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *ro
 		}
 	}
 
-	err = qdisc_enqueue(skb, p->q, root_lock, to_free);
+	err = qdisc_enqueue(skb, p->q, to_free);
 	if (err != NET_XMIT_SUCCESS) {
 		if (net_xmit_drop_count(err))
 			qdisc_qstats_drop(sch);
diff --git a/net/sched/sch_etf.c b/net/sched/sch_etf.c
index 7a7c50a68115..c48f91075b5c 100644
--- a/net/sched/sch_etf.c
+++ b/net/sched/sch_etf.c
@@ -160,7 +160,7 @@ static void report_sock_error(struct sk_buff *skb, u32 err, u8 code)
 }
 
 static int etf_enqueue_timesortedlist(struct sk_buff *nskb, struct Qdisc *sch,
-				      spinlock_t *root_lock, struct sk_buff **to_free)
+				      struct sk_buff **to_free)
 {
 	struct etf_sched_data *q = qdisc_priv(sch);
 	struct rb_node **p = &q->head.rb_root.rb_node, *parent = NULL;
diff --git a/net/sched/sch_ets.c b/net/sched/sch_ets.c
index 1af86f30b18e..c1e84d1eeaba 100644
--- a/net/sched/sch_ets.c
+++ b/net/sched/sch_ets.c
@@ -415,7 +415,7 @@ static struct ets_class *ets_classify(struct sk_buff *skb, struct Qdisc *sch,
 	return &q->classes[band];
 }
 
-static int ets_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+static int ets_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 			     struct sk_buff **to_free)
 {
 	unsigned int len = qdisc_pkt_len(skb);
@@ -433,7 +433,7 @@ static int ets_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t
 	}
 
 	first = !cl->qdisc->q.qlen;
-	err = qdisc_enqueue(skb, cl->qdisc, root_lock, to_free);
+	err = qdisc_enqueue(skb, cl->qdisc, to_free);
 	if (unlikely(err != NET_XMIT_SUCCESS)) {
 		if (net_xmit_drop_count(err)) {
 			cl->qstats.drops++;
diff --git a/net/sched/sch_fifo.c b/net/sched/sch_fifo.c
index b4da5b624ad8..a579a4131d22 100644
--- a/net/sched/sch_fifo.c
+++ b/net/sched/sch_fifo.c
@@ -16,7 +16,7 @@
 
 /* 1 band FIFO pseudo-"scheduler" */
 
-static int bfifo_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+static int bfifo_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 			 struct sk_buff **to_free)
 {
 	if (likely(sch->qstats.backlog + qdisc_pkt_len(skb) <= sch->limit))
@@ -25,7 +25,7 @@ static int bfifo_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *roo
 	return qdisc_drop(skb, sch, to_free);
 }
 
-static int pfifo_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+static int pfifo_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 			 struct sk_buff **to_free)
 {
 	if (likely(sch->q.qlen < sch->limit))
@@ -34,7 +34,7 @@ static int pfifo_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *roo
 	return qdisc_drop(skb, sch, to_free);
 }
 
-static int pfifo_tail_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+static int pfifo_tail_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 			      struct sk_buff **to_free)
 {
 	unsigned int prev_backlog;
diff --git a/net/sched/sch_fq.c b/net/sched/sch_fq.c
index a90d745c41e0..2fb76fc0cc31 100644
--- a/net/sched/sch_fq.c
+++ b/net/sched/sch_fq.c
@@ -439,7 +439,7 @@ static bool fq_packet_beyond_horizon(const struct sk_buff *skb,
 	return unlikely((s64)skb->tstamp > (s64)(q->ktime_cache + q->horizon));
 }
 
-static int fq_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+static int fq_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 		      struct sk_buff **to_free)
 {
 	struct fq_sched_data *q = qdisc_priv(sch);
diff --git a/net/sched/sch_fq_codel.c b/net/sched/sch_fq_codel.c
index bca016ffc069..3106653c17f3 100644
--- a/net/sched/sch_fq_codel.c
+++ b/net/sched/sch_fq_codel.c
@@ -181,7 +181,7 @@ static unsigned int fq_codel_drop(struct Qdisc *sch, unsigned int max_packets,
 	return idx;
 }
 
-static int fq_codel_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+static int fq_codel_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 			    struct sk_buff **to_free)
 {
 	struct fq_codel_sched_data *q = qdisc_priv(sch);
diff --git a/net/sched/sch_fq_pie.c b/net/sched/sch_fq_pie.c
index 741840b9994f..f98c74018805 100644
--- a/net/sched/sch_fq_pie.c
+++ b/net/sched/sch_fq_pie.c
@@ -125,7 +125,7 @@ static inline void flow_queue_add(struct fq_pie_flow *flow,
 	skb->next = NULL;
 }
 
-static int fq_pie_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+static int fq_pie_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 				struct sk_buff **to_free)
 {
 	struct fq_pie_sched_data *q = qdisc_priv(sch);
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 715cde1df9e4..265a61d011df 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -520,7 +520,7 @@ EXPORT_SYMBOL(netif_carrier_off);
    cheaper.
  */
 
-static int noop_enqueue(struct sk_buff *skb, struct Qdisc *qdisc, spinlock_t *root_lock,
+static int noop_enqueue(struct sk_buff *skb, struct Qdisc *qdisc,
 			struct sk_buff **to_free)
 {
 	__qdisc_drop(skb, to_free);
@@ -614,7 +614,7 @@ static inline struct skb_array *band2list(struct pfifo_fast_priv *priv,
 	return &priv->q[band];
 }
 
-static int pfifo_fast_enqueue(struct sk_buff *skb, struct Qdisc *qdisc, spinlock_t *root_lock,
+static int pfifo_fast_enqueue(struct sk_buff *skb, struct Qdisc *qdisc,
 			      struct sk_buff **to_free)
 {
 	int band = prio2band[skb->priority & TC_PRIO_MAX];
diff --git a/net/sched/sch_gred.c b/net/sched/sch_gred.c
index 7d67c6cd6605..8599c6f31b05 100644
--- a/net/sched/sch_gred.c
+++ b/net/sched/sch_gred.c
@@ -161,7 +161,7 @@ static bool gred_per_vq_red_flags_used(struct gred_sched *table)
 	return false;
 }
 
-static int gred_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+static int gred_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 			struct sk_buff **to_free)
 {
 	struct gred_sched_data *q = NULL;
diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c
index 13ba8648bb63..0f5f121404f3 100644
--- a/net/sched/sch_hfsc.c
+++ b/net/sched/sch_hfsc.c
@@ -1528,8 +1528,8 @@ hfsc_dump_qdisc(struct Qdisc *sch, struct sk_buff *skb)
 	return -1;
 }
 
-static int hfsc_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
-			struct sk_buff **to_free)
+static int
+hfsc_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free)
 {
 	unsigned int len = qdisc_pkt_len(skb);
 	struct hfsc_class *cl;
@@ -1545,7 +1545,7 @@ static int hfsc_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root
 	}
 
 	first = !cl->qdisc->q.qlen;
-	err = qdisc_enqueue(skb, cl->qdisc, root_lock, to_free);
+	err = qdisc_enqueue(skb, cl->qdisc, to_free);
 	if (unlikely(err != NET_XMIT_SUCCESS)) {
 		if (net_xmit_drop_count(err)) {
 			cl->qstats.drops++;
diff --git a/net/sched/sch_hhf.c b/net/sched/sch_hhf.c
index ddc6bf1d85d0..420ede875322 100644
--- a/net/sched/sch_hhf.c
+++ b/net/sched/sch_hhf.c
@@ -368,7 +368,7 @@ static unsigned int hhf_drop(struct Qdisc *sch, struct sk_buff **to_free)
 	return bucket - q->buckets;
 }
 
-static int hhf_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+static int hhf_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 		       struct sk_buff **to_free)
 {
 	struct hhf_sched_data *q = qdisc_priv(sch);
diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
index b07f29059f47..ba37defaca7a 100644
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -576,7 +576,7 @@ static inline void htb_deactivate(struct htb_sched *q, struct htb_class *cl)
 	cl->prio_activity = 0;
 }
 
-static int htb_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+static int htb_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 		       struct sk_buff **to_free)
 {
 	int uninitialized_var(ret);
@@ -599,7 +599,7 @@ static int htb_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_
 		__qdisc_drop(skb, to_free);
 		return ret;
 #endif
-	} else if ((ret = qdisc_enqueue(skb, cl->leaf.q, root_lock,
+	} else if ((ret = qdisc_enqueue(skb, cl->leaf.q,
 					to_free)) != NET_XMIT_SUCCESS) {
 		if (net_xmit_drop_count(ret)) {
 			qdisc_qstats_drop(sch);
diff --git a/net/sched/sch_multiq.c b/net/sched/sch_multiq.c
index 56bdc4bcdc63..5c27b4270b90 100644
--- a/net/sched/sch_multiq.c
+++ b/net/sched/sch_multiq.c
@@ -57,7 +57,7 @@ multiq_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
 }
 
 static int
-multiq_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+multiq_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 	       struct sk_buff **to_free)
 {
 	struct Qdisc *qdisc;
@@ -74,7 +74,7 @@ multiq_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
 	}
 #endif
 
-	ret = qdisc_enqueue(skb, qdisc, root_lock, to_free);
+	ret = qdisc_enqueue(skb, qdisc, to_free);
 	if (ret == NET_XMIT_SUCCESS) {
 		sch->q.qlen++;
 		return NET_XMIT_SUCCESS;
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index 8fb17483a34f..84f82771cdf5 100644
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -431,7 +431,7 @@ static struct sk_buff *netem_segment(struct sk_buff *skb, struct Qdisc *sch,
  * 	NET_XMIT_DROP: queue length didn't change.
  *      NET_XMIT_SUCCESS: one skb was queued.
  */
-static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 			 struct sk_buff **to_free)
 {
 	struct netem_sched_data *q = qdisc_priv(sch);
@@ -480,7 +480,7 @@ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *roo
 		u32 dupsave = q->duplicate; /* prevent duplicating a dup... */
 
 		q->duplicate = 0;
-		rootq->enqueue(skb2, rootq, root_lock, to_free);
+		rootq->enqueue(skb2, rootq, to_free);
 		q->duplicate = dupsave;
 		rc_drop = NET_XMIT_SUCCESS;
 	}
@@ -604,7 +604,7 @@ finish_segs:
 			skb_mark_not_on_list(segs);
 			qdisc_skb_cb(segs)->pkt_len = segs->len;
 			last_len = segs->len;
-			rc = qdisc_enqueue(segs, sch, root_lock, to_free);
+			rc = qdisc_enqueue(segs, sch, to_free);
 			if (rc != NET_XMIT_SUCCESS) {
 				if (net_xmit_drop_count(rc))
 					qdisc_qstats_drop(sch);
@@ -720,7 +720,7 @@ deliver:
 				struct sk_buff *to_free = NULL;
 				int err;
 
-				err = qdisc_enqueue(skb, q->qdisc, NULL, &to_free);
+				err = qdisc_enqueue(skb, q->qdisc, &to_free);
 				kfree_skb_list(to_free);
 				if (err != NET_XMIT_SUCCESS &&
 				    net_xmit_drop_count(err)) {
diff --git a/net/sched/sch_pie.c b/net/sched/sch_pie.c
index b305313b64e3..c65077f0c0f3 100644
--- a/net/sched/sch_pie.c
+++ b/net/sched/sch_pie.c
@@ -82,7 +82,7 @@ bool pie_drop_early(struct Qdisc *sch, struct pie_params *params,
 }
 EXPORT_SYMBOL_GPL(pie_drop_early);
 
-static int pie_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+static int pie_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 			     struct sk_buff **to_free)
 {
 	struct pie_sched_data *q = qdisc_priv(sch);
diff --git a/net/sched/sch_plug.c b/net/sched/sch_plug.c
index e5f8b4769b4d..cbc2ebca4548 100644
--- a/net/sched/sch_plug.c
+++ b/net/sched/sch_plug.c
@@ -84,7 +84,7 @@ struct plug_sched_data {
 	u32 pkts_to_release;
 };
 
-static int plug_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+static int plug_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 			struct sk_buff **to_free)
 {
 	struct plug_sched_data *q = qdisc_priv(sch);
diff --git a/net/sched/sch_prio.c b/net/sched/sch_prio.c
index 46b7ce81c6e3..3eabb871a1d5 100644
--- a/net/sched/sch_prio.c
+++ b/net/sched/sch_prio.c
@@ -65,8 +65,8 @@ prio_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
 	return q->queues[band];
 }
 
-static int prio_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
-			struct sk_buff **to_free)
+static int
+prio_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free)
 {
 	unsigned int len = qdisc_pkt_len(skb);
 	struct Qdisc *qdisc;
@@ -83,7 +83,7 @@ static int prio_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root
 	}
 #endif
 
-	ret = qdisc_enqueue(skb, qdisc, root_lock, to_free);
+	ret = qdisc_enqueue(skb, qdisc, to_free);
 	if (ret == NET_XMIT_SUCCESS) {
 		sch->qstats.backlog += len;
 		sch->q.qlen++;
diff --git a/net/sched/sch_qfq.c b/net/sched/sch_qfq.c
index 3cfe6262eb00..6335230a971e 100644
--- a/net/sched/sch_qfq.c
+++ b/net/sched/sch_qfq.c
@@ -1194,7 +1194,7 @@ static struct qfq_aggregate *qfq_choose_next_agg(struct qfq_sched *q)
 	return agg;
 }
 
-static int qfq_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+static int qfq_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 		       struct sk_buff **to_free)
 {
 	unsigned int len = qdisc_pkt_len(skb), gso_segs;
@@ -1225,7 +1225,7 @@ static int qfq_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_
 
 	gso_segs = skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1;
 	first = !cl->qdisc->q.qlen;
-	err = qdisc_enqueue(skb, cl->qdisc, root_lock, to_free);
+	err = qdisc_enqueue(skb, cl->qdisc, to_free);
 	if (unlikely(err != NET_XMIT_SUCCESS)) {
 		pr_debug("qfq_enqueue: enqueue failed %d\n", err);
 		if (net_xmit_drop_count(err)) {
diff --git a/net/sched/sch_red.c b/net/sched/sch_red.c
index de2be4d04ed6..4cc0ad0b1189 100644
--- a/net/sched/sch_red.c
+++ b/net/sched/sch_red.c
@@ -67,7 +67,7 @@ static int red_use_nodrop(struct red_sched_data *q)
 	return q->flags & TC_RED_NODROP;
 }
 
-static int red_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+static int red_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 		       struct sk_buff **to_free)
 {
 	struct red_sched_data *q = qdisc_priv(sch);
@@ -94,7 +94,7 @@ static int red_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_
 
 		if (INET_ECN_set_ce(skb)) {
 			q->stats.prob_mark++;
-			skb = tcf_qevent_handle(&q->qe_mark, sch, skb, root_lock, to_free, &ret);
+			skb = tcf_qevent_handle(&q->qe_mark, sch, skb, to_free, &ret);
 			if (!skb)
 				return NET_XMIT_CN | ret;
 		} else if (!red_use_nodrop(q)) {
@@ -114,7 +114,7 @@ static int red_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_
 
 		if (INET_ECN_set_ce(skb)) {
 			q->stats.forced_mark++;
-			skb = tcf_qevent_handle(&q->qe_mark, sch, skb, root_lock, to_free, &ret);
+			skb = tcf_qevent_handle(&q->qe_mark, sch, skb, to_free, &ret);
 			if (!skb)
 				return NET_XMIT_CN | ret;
 		} else if (!red_use_nodrop(q)) {
@@ -126,7 +126,7 @@ static int red_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_
 		break;
 	}
 
-	ret = qdisc_enqueue(skb, child, root_lock, to_free);
+	ret = qdisc_enqueue(skb, child, to_free);
 	if (likely(ret == NET_XMIT_SUCCESS)) {
 		qdisc_qstats_backlog_inc(sch, skb);
 		sch->q.qlen++;
@@ -137,7 +137,7 @@ static int red_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_
 	return ret;
 
 congestion_drop:
-	skb = tcf_qevent_handle(&q->qe_early_drop, sch, skb, root_lock, to_free, &ret);
+	skb = tcf_qevent_handle(&q->qe_early_drop, sch, skb, to_free, &ret);
 	if (!skb)
 		return NET_XMIT_CN | ret;
 
diff --git a/net/sched/sch_sfb.c b/net/sched/sch_sfb.c
index 356f6d1d30db..da047a37a3bf 100644
--- a/net/sched/sch_sfb.c
+++ b/net/sched/sch_sfb.c
@@ -276,7 +276,7 @@ static bool sfb_classify(struct sk_buff *skb, struct tcf_proto *fl,
 	return false;
 }
 
-static int sfb_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+static int sfb_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 		       struct sk_buff **to_free)
 {
 
@@ -399,7 +399,7 @@ static int sfb_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_
 	}
 
 enqueue:
-	ret = qdisc_enqueue(skb, child, root_lock, to_free);
+	ret = qdisc_enqueue(skb, child, to_free);
 	if (likely(ret == NET_XMIT_SUCCESS)) {
 		qdisc_qstats_backlog_inc(sch, skb);
 		sch->q.qlen++;
diff --git a/net/sched/sch_sfq.c b/net/sched/sch_sfq.c
index a1314510dc69..cae5dbbadc1c 100644
--- a/net/sched/sch_sfq.c
+++ b/net/sched/sch_sfq.c
@@ -343,7 +343,7 @@ static int sfq_headdrop(const struct sfq_sched_data *q)
 }
 
 static int
-sfq_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock, struct sk_buff **to_free)
+sfq_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free)
 {
 	struct sfq_sched_data *q = qdisc_priv(sch);
 	unsigned int hash, dropped;
diff --git a/net/sched/sch_skbprio.c b/net/sched/sch_skbprio.c
index f75f237c4436..7a5e4c454715 100644
--- a/net/sched/sch_skbprio.c
+++ b/net/sched/sch_skbprio.c
@@ -65,7 +65,7 @@ static u16 calc_new_low_prio(const struct skbprio_sched_data *q)
 	return SKBPRIO_MAX_PRIORITY - 1;
 }
 
-static int skbprio_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+static int skbprio_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 			  struct sk_buff **to_free)
 {
 	const unsigned int max_priority = SKBPRIO_MAX_PRIORITY - 1;
diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c
index daef2ff60a98..e981992634dd 100644
--- a/net/sched/sch_taprio.c
+++ b/net/sched/sch_taprio.c
@@ -410,7 +410,7 @@ done:
 	return txtime;
 }
 
-static int taprio_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+static int taprio_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 			  struct sk_buff **to_free)
 {
 	struct taprio_sched *q = qdisc_priv(sch);
@@ -435,7 +435,7 @@ static int taprio_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *ro
 	qdisc_qstats_backlog_inc(sch, skb);
 	sch->q.qlen++;
 
-	return qdisc_enqueue(skb, child, root_lock, to_free);
+	return qdisc_enqueue(skb, child, to_free);
 }
 
 static struct sk_buff *taprio_peek_soft(struct Qdisc *sch)
diff --git a/net/sched/sch_tbf.c b/net/sched/sch_tbf.c
index c3eb5cdb83a8..78e79029dc63 100644
--- a/net/sched/sch_tbf.c
+++ b/net/sched/sch_tbf.c
@@ -187,7 +187,7 @@ static int tbf_offload_dump(struct Qdisc *sch)
 /* GSO packet is too big, segment it so that tbf can transmit
  * each segment in time
  */
-static int tbf_segment(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+static int tbf_segment(struct sk_buff *skb, struct Qdisc *sch,
 		       struct sk_buff **to_free)
 {
 	struct tbf_sched_data *q = qdisc_priv(sch);
@@ -206,7 +206,7 @@ static int tbf_segment(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_
 		skb_mark_not_on_list(segs);
 		qdisc_skb_cb(segs)->pkt_len = segs->len;
 		len += segs->len;
-		ret = qdisc_enqueue(segs, q->qdisc, root_lock, to_free);
+		ret = qdisc_enqueue(segs, q->qdisc, to_free);
 		if (ret != NET_XMIT_SUCCESS) {
 			if (net_xmit_drop_count(ret))
 				qdisc_qstats_drop(sch);
@@ -221,7 +221,7 @@ static int tbf_segment(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_
 	return nb > 0 ? NET_XMIT_SUCCESS : NET_XMIT_DROP;
 }
 
-static int tbf_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
+static int tbf_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 		       struct sk_buff **to_free)
 {
 	struct tbf_sched_data *q = qdisc_priv(sch);
@@ -231,10 +231,10 @@ static int tbf_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_
 	if (qdisc_pkt_len(skb) > q->max_size) {
 		if (skb_is_gso(skb) &&
 		    skb_gso_validate_mac_len(skb, q->max_size))
-			return tbf_segment(skb, sch, root_lock, to_free);
+			return tbf_segment(skb, sch, to_free);
 		return qdisc_drop(skb, sch, to_free);
 	}
-	ret = qdisc_enqueue(skb, q->qdisc, root_lock, to_free);
+	ret = qdisc_enqueue(skb, q->qdisc, to_free);
 	if (ret != NET_XMIT_SUCCESS) {
 		if (net_xmit_drop_count(ret))
 			qdisc_qstats_drop(sch);
diff --git a/net/sched/sch_teql.c b/net/sched/sch_teql.c
index b586eec2eaeb..2f1f0a378408 100644
--- a/net/sched/sch_teql.c
+++ b/net/sched/sch_teql.c
@@ -72,8 +72,8 @@ struct teql_sched_data {
 
 /* "teql*" qdisc routines */
 
-static int teql_enqueue(struct sk_buff *skb, struct Qdisc *sch, spinlock_t *root_lock,
-			struct sk_buff **to_free)
+static int
+teql_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free)
 {
 	struct net_device *dev = qdisc_dev(sch);
 	struct teql_sched_data *q = qdisc_priv(sch);