net: sched: Convert timers to use timer_setup()

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly. Add pointer back to Qdisc.

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/sch_sfq.c b/net/sched/sch_sfq.c
index 123a53a..5a9c951 100644
--- a/net/sched/sch_sfq.c
+++ b/net/sched/sch_sfq.c
@@ -145,6 +145,7 @@ struct sfq_sched_data {
 	int		perturb_period;
 	unsigned int	quantum;	/* Allotment per round: MUST BE >= MTU */
 	struct timer_list perturb_timer;
+	struct Qdisc	*sch;
 };
 
 /*
@@ -604,10 +605,10 @@ static void sfq_rehash(struct Qdisc *sch)
 	qdisc_tree_reduce_backlog(sch, dropped, drop_len);
 }
 
-static void sfq_perturbation(unsigned long arg)
+static void sfq_perturbation(struct timer_list *t)
 {
-	struct Qdisc *sch = (struct Qdisc *)arg;
-	struct sfq_sched_data *q = qdisc_priv(sch);
+	struct sfq_sched_data *q = from_timer(q, t, perturb_timer);
+	struct Qdisc *sch = q->sch;
 	spinlock_t *root_lock = qdisc_lock(qdisc_root_sleeping(sch));
 
 	spin_lock(root_lock);
@@ -722,8 +723,7 @@ static int sfq_init(struct Qdisc *sch, struct nlattr *opt)
 	int i;
 	int err;
 
-	setup_deferrable_timer(&q->perturb_timer, sfq_perturbation,
-			       (unsigned long)sch);
+	timer_setup(&q->perturb_timer, sfq_perturbation, TIMER_DEFERRABLE);
 
 	err = tcf_block_get(&q->block, &q->filter_list, sch);
 	if (err)