[PKT_SCHED]: Convert sch_red to a classful qdisc
Convert sch_red to a classful qdisc. All qdiscs that maintain accurate
backlog counters are eligible as child qdiscs. When a queue limit larger
than zero is given, a bfifo qdisc is used for backwards compatibility.
Current versions of tc enforce a limit larger than zero, other users
can avoid creating the default qdisc by using zero.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Acked-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/sch_red.c b/net/sched/sch_red.c
index dccfa44..2be563c 100644
--- a/net/sched/sch_red.c
+++ b/net/sched/sch_red.c
@@ -44,6 +44,7 @@
unsigned char flags;
struct red_parms parms;
struct red_stats stats;
+ struct Qdisc *qdisc;
};
static inline int red_use_ecn(struct red_sched_data *q)
@@ -59,8 +60,10 @@
static int red_enqueue(struct sk_buff *skb, struct Qdisc* sch)
{
struct red_sched_data *q = qdisc_priv(sch);
+ struct Qdisc *child = q->qdisc;
+ int ret;
- q->parms.qavg = red_calc_qavg(&q->parms, sch->qstats.backlog);
+ q->parms.qavg = red_calc_qavg(&q->parms, child->qstats.backlog);
if (red_is_idling(&q->parms))
red_end_of_idle_period(&q->parms);
@@ -91,11 +94,16 @@
break;
}
- if (sch->qstats.backlog + skb->len <= q->limit)
- return qdisc_enqueue_tail(skb, sch);
-
- q->stats.pdrop++;
- return qdisc_drop(skb, sch);
+ ret = child->enqueue(skb, child);
+ if (likely(ret == NET_XMIT_SUCCESS)) {
+ sch->bstats.bytes += skb->len;
+ sch->bstats.packets++;
+ sch->q.qlen++;
+ } else {
+ q->stats.pdrop++;
+ sch->qstats.drops++;
+ }
+ return ret;
congestion_drop:
qdisc_drop(skb, sch);
@@ -105,21 +113,30 @@
static int red_requeue(struct sk_buff *skb, struct Qdisc* sch)
{
struct red_sched_data *q = qdisc_priv(sch);
+ struct Qdisc *child = q->qdisc;
+ int ret;
if (red_is_idling(&q->parms))
red_end_of_idle_period(&q->parms);
- return qdisc_requeue(skb, sch);
+ ret = child->ops->requeue(skb, child);
+ if (likely(ret == NET_XMIT_SUCCESS)) {
+ sch->qstats.requeues++;
+ sch->q.qlen++;
+ }
+ return ret;
}
static struct sk_buff * red_dequeue(struct Qdisc* sch)
{
struct sk_buff *skb;
struct red_sched_data *q = qdisc_priv(sch);
+ struct Qdisc *child = q->qdisc;
- skb = qdisc_dequeue_head(sch);
-
- if (skb == NULL && !red_is_idling(&q->parms))
+ skb = child->dequeue(child);
+ if (skb)
+ sch->q.qlen--;
+ else if (!red_is_idling(&q->parms))
red_start_of_idle_period(&q->parms);
return skb;
@@ -127,14 +144,14 @@
static unsigned int red_drop(struct Qdisc* sch)
{
- struct sk_buff *skb;
struct red_sched_data *q = qdisc_priv(sch);
+ struct Qdisc *child = q->qdisc;
+ unsigned int len;
- skb = qdisc_dequeue_tail(sch);
- if (skb) {
- unsigned int len = skb->len;
+ if (child->ops->drop && (len = child->ops->drop(child)) > 0) {
q->stats.other++;
- qdisc_drop(skb, sch);
+ sch->qstats.drops++;
+ sch->q.qlen--;
return len;
}
@@ -148,15 +165,48 @@
{
struct red_sched_data *q = qdisc_priv(sch);
- qdisc_reset_queue(sch);
+ qdisc_reset(q->qdisc);
+ sch->q.qlen = 0;
red_restart(&q->parms);
}
+static void red_destroy(struct Qdisc *sch)
+{
+ struct red_sched_data *q = qdisc_priv(sch);
+ qdisc_destroy(q->qdisc);
+}
+
+static struct Qdisc *red_create_dflt(struct net_device *dev, u32 limit)
+{
+ struct Qdisc *q = qdisc_create_dflt(dev, &bfifo_qdisc_ops);
+ struct rtattr *rta;
+ int ret;
+
+ if (q) {
+ rta = kmalloc(RTA_LENGTH(sizeof(struct tc_fifo_qopt)),
+ GFP_KERNEL);
+ if (rta) {
+ rta->rta_type = RTM_NEWQDISC;
+ rta->rta_len = RTA_LENGTH(sizeof(struct tc_fifo_qopt));
+ ((struct tc_fifo_qopt *)RTA_DATA(rta))->limit = limit;
+
+ ret = q->ops->change(q, rta);
+ kfree(rta);
+
+ if (ret == 0)
+ return q;
+ }
+ qdisc_destroy(q);
+ }
+ return NULL;
+}
+
static int red_change(struct Qdisc *sch, struct rtattr *opt)
{
struct red_sched_data *q = qdisc_priv(sch);
struct rtattr *tb[TCA_RED_MAX];
struct tc_red_qopt *ctl;
+ struct Qdisc *child = NULL;
if (opt == NULL || rtattr_parse_nested(tb, TCA_RED_MAX, opt))
return -EINVAL;
@@ -169,9 +219,17 @@
ctl = RTA_DATA(tb[TCA_RED_PARMS-1]);
+ if (ctl->limit > 0) {
+ child = red_create_dflt(sch->dev, ctl->limit);
+ if (child == NULL)
+ return -ENOMEM;
+ }
+
sch_tree_lock(sch);
q->flags = ctl->flags;
q->limit = ctl->limit;
+ if (child)
+ qdisc_destroy(xchg(&q->qdisc, child));
red_set_parms(&q->parms, ctl->qth_min, ctl->qth_max, ctl->Wlog,
ctl->Plog, ctl->Scell_log,
@@ -186,6 +244,9 @@
static int red_init(struct Qdisc* sch, struct rtattr *opt)
{
+ struct red_sched_data *q = qdisc_priv(sch);
+
+ q->qdisc = &noop_qdisc;
return red_change(sch, opt);
}
@@ -224,15 +285,101 @@
return gnet_stats_copy_app(d, &st, sizeof(st));
}
+static int red_dump_class(struct Qdisc *sch, unsigned long cl,
+ struct sk_buff *skb, struct tcmsg *tcm)
+{
+ struct red_sched_data *q = qdisc_priv(sch);
+
+ if (cl != 1)
+ return -ENOENT;
+ tcm->tcm_handle |= TC_H_MIN(1);
+ tcm->tcm_info = q->qdisc->handle;
+ return 0;
+}
+
+static int red_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
+ struct Qdisc **old)
+{
+ struct red_sched_data *q = qdisc_priv(sch);
+
+ if (new == NULL)
+ new = &noop_qdisc;
+
+ sch_tree_lock(sch);
+ *old = xchg(&q->qdisc, new);
+ qdisc_reset(*old);
+ sch->q.qlen = 0;
+ sch_tree_unlock(sch);
+ return 0;
+}
+
+static struct Qdisc *red_leaf(struct Qdisc *sch, unsigned long arg)
+{
+ struct red_sched_data *q = qdisc_priv(sch);
+ return q->qdisc;
+}
+
+static unsigned long red_get(struct Qdisc *sch, u32 classid)
+{
+ return 1;
+}
+
+static void red_put(struct Qdisc *sch, unsigned long arg)
+{
+ return;
+}
+
+static int red_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
+ struct rtattr **tca, unsigned long *arg)
+{
+ return -ENOSYS;
+}
+
+static int red_delete(struct Qdisc *sch, unsigned long cl)
+{
+ return -ENOSYS;
+}
+
+static void red_walk(struct Qdisc *sch, struct qdisc_walker *walker)
+{
+ if (!walker->stop) {
+ if (walker->count >= walker->skip)
+ if (walker->fn(sch, 1, walker) < 0) {
+ walker->stop = 1;
+ return;
+ }
+ walker->count++;
+ }
+}
+
+static struct tcf_proto **red_find_tcf(struct Qdisc *sch, unsigned long cl)
+{
+ return NULL;
+}
+
+static struct Qdisc_class_ops red_class_ops = {
+ .graft = red_graft,
+ .leaf = red_leaf,
+ .get = red_get,
+ .put = red_put,
+ .change = red_change_class,
+ .delete = red_delete,
+ .walk = red_walk,
+ .tcf_chain = red_find_tcf,
+ .dump = red_dump_class,
+};
+
static struct Qdisc_ops red_qdisc_ops = {
.id = "red",
.priv_size = sizeof(struct red_sched_data),
+ .cl_ops = &red_class_ops,
.enqueue = red_enqueue,
.dequeue = red_dequeue,
.requeue = red_requeue,
.drop = red_drop,
.init = red_init,
.reset = red_reset,
+ .destroy = red_destroy,
.change = red_change,
.dump = red_dump,
.dump_stats = red_dump_stats,