net: sched: restrict use of qstats qlen

This removes the use of qstats->qlen variable from the classifiers
and makes it an explicit argument to gnet_stats_copy_queue().

The qlen represents the qdisc queue length and is packed into
the qstats at the last moment before passnig to user space. By
handling it explicitely we avoid, in the percpu stats case, having
to figure out which per_cpu variable to put it in.

It would probably be best to remove it from qstats completely
but qstats is a user space ABI and can't be broken. A future
patch could make an internal only qstats structure that would
avoid having to allocate an additional u32 variable on the
Qdisc struct. This would make the qstats struct 128bits instead
of 128+32.

Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/gen_stats.h b/include/net/gen_stats.h
index ce3c1281f2a0ea74d9672f3d90741208d2cedb14..de9b3dd5750e006a926092917e582c9f57676341 100644 (file)
--- a/include/net/gen_stats.h
+++ b/include/net/gen_stats.h
@@ -40,7 +40,8 @@ void __gnet_stats_copy_basic(struct gnet_stats_basic_packed *bstats,
 int gnet_stats_copy_rate_est(struct gnet_dump *d,
                             const struct gnet_stats_basic_packed *b,
                             struct gnet_stats_rate_est64 *r);
-int gnet_stats_copy_queue(struct gnet_dump *d, struct gnet_stats_queue *q);
+int gnet_stats_copy_queue(struct gnet_dump *d,
+                         struct gnet_stats_queue *q, __u32 len);
 int gnet_stats_copy_app(struct gnet_dump *d, void *st, int len);
 
 int gnet_stats_finish_copy(struct gnet_dump *d);

diff --git a/net/core/gen_stats.c b/net/core/gen_stats.c
index 5ff8e80fe0bb11fc0c34b9f6ef24cd50a3256d1d..ad3ecb6ba835ceffecbe1a89e53df7387a8011df 100644 (file)
--- a/net/core/gen_stats.c
+++ b/net/core/gen_stats.c
@@ -219,6 +219,7 @@ EXPORT_SYMBOL(gnet_stats_copy_rate_est);
  * gnet_stats_copy_queue - copy queue statistics into statistics TLV
  * @d: dumping handle
  * @q: queue statistics
+ * @qlen: queue length statistics
  *
  * Appends the queue statistics to the top level TLV created by
  * gnet_stats_start_copy().
@@ -227,8 +228,11 @@ EXPORT_SYMBOL(gnet_stats_copy_rate_est);
  * if the room in the socket buffer was not sufficient.
  */
 int
-gnet_stats_copy_queue(struct gnet_dump *d, struct gnet_stats_queue *q)
+gnet_stats_copy_queue(struct gnet_dump *d,
+                     struct gnet_stats_queue *q, __u32 qlen)
 {
+       q->qlen = qlen;
+
        if (d->compat_tc_stats) {
                d->tc_stats.drops = q->drops;
                d->tc_stats.qlen = q->qlen;

diff --git a/net/sched/act_api.c b/net/sched/act_api.c
index eca4cf9ece2f12b2c2f6133375dd8012719ed60d..2e134093b8eccca95d5540da742021f209ef7847 100644 (file)
--- a/net/sched/act_api.c
+++ b/net/sched/act_api.c
@@ -623,7 +623,9 @@ int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
        if (gnet_stats_copy_basic(&d, NULL, &p->tcfc_bstats) < 0 ||
            gnet_stats_copy_rate_est(&d, &p->tcfc_bstats,
                                     &p->tcfc_rate_est) < 0 ||
-           gnet_stats_copy_queue(&d, &p->tcfc_qstats) < 0)
+           gnet_stats_copy_queue(&d,
+                                 &p->tcfc_qstats,
+                                 p->tcfc_qstats.qlen) < 0)
                goto errout;
 
        if (gnet_stats_finish_copy(&d) < 0)

diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 2862bc61a358b4e0e6313c132e05fdf25732f453..ca00ea8e84dc1f04e5b65be5656d30a018557030 100644 (file)
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -1318,6 +1318,7 @@ static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
        unsigned char *b = skb_tail_pointer(skb);
        struct gnet_dump d;
        struct qdisc_size_table *stab;
+       __u32 qlen;
 
        cond_resched();
        nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
@@ -1335,7 +1336,7 @@ static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
                goto nla_put_failure;
        if (q->ops->dump && q->ops->dump(q, skb) < 0)
                goto nla_put_failure;
-       q->qstats.qlen = q->q.qlen;
+       qlen = q->q.qlen;
 
        stab = rtnl_dereference(q->stab);
        if (stab && qdisc_dump_stab(skb, stab) < 0)
@@ -1353,7 +1354,7 @@ static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
 
        if (gnet_stats_copy_basic(&d, cpu_bstats, &q->bstats) < 0 ||
            gnet_stats_copy_rate_est(&d, &q->bstats, &q->rate_est) < 0 ||
-           gnet_stats_copy_queue(&d, &q->qstats) < 0)
+           gnet_stats_copy_queue(&d, &q->qstats, qlen) < 0)
                goto nla_put_failure;
 
        if (gnet_stats_finish_copy(&d) < 0)

diff --git a/net/sched/sch_atm.c b/net/sched/sch_atm.c
index 040212cab9886ff277ce872edd2f47f4afb7c1b3..c145eb6279cc323768bcafe7537799d0e430403f 100644 (file)
--- a/net/sched/sch_atm.c
+++ b/net/sched/sch_atm.c
@@ -637,10 +637,8 @@ atm_tc_dump_class_stats(struct Qdisc *sch, unsigned long arg,
 {
        struct atm_flow_data *flow = (struct atm_flow_data *)arg;
 
-       flow->qstats.qlen = flow->q->q.qlen;
-
        if (gnet_stats_copy_basic(d, NULL, &flow->bstats) < 0 ||
-           gnet_stats_copy_queue(d, &flow->qstats) < 0)
+           gnet_stats_copy_queue(d, &flow->qstats, flow->q->q.qlen) < 0)
                return -1;
 
        return 0;

diff --git a/net/sched/sch_cbq.c b/net/sched/sch_cbq.c
index 60432c3d3cd4f09df2d9d5691fedf50f43562e02..c610081ffba53846a3585bc80d898e0506567d88 100644 (file)
--- a/net/sched/sch_cbq.c
+++ b/net/sched/sch_cbq.c
@@ -1594,7 +1594,6 @@ cbq_dump_class_stats(struct Qdisc *sch, unsigned long arg,
        struct cbq_sched_data *q = qdisc_priv(sch);
        struct cbq_class *cl = (struct cbq_class *)arg;
 
-       cl->qstats.qlen = cl->q->q.qlen;
        cl->xstats.avgidle = cl->avgidle;
        cl->xstats.undertime = 0;
 
@@ -1603,7 +1602,7 @@ cbq_dump_class_stats(struct Qdisc *sch, unsigned long arg,
 
        if (gnet_stats_copy_basic(d, NULL, &cl->bstats) < 0 ||
            gnet_stats_copy_rate_est(d, &cl->bstats, &cl->rate_est) < 0 ||
-           gnet_stats_copy_queue(d, &cl->qstats) < 0)
+           gnet_stats_copy_queue(d, &cl->qstats, cl->q->q.qlen) < 0)
                return -1;
 
        return gnet_stats_copy_app(d, &cl->xstats, sizeof(cl->xstats));

diff --git a/net/sched/sch_drr.c b/net/sched/sch_drr.c
index 907b12fd6825184d0e6b9c13fa7bf1e65042c415..5835a93905b16cc7684a1e1266e6df71257fd70b 100644 (file)
--- a/net/sched/sch_drr.c
+++ b/net/sched/sch_drr.c
@@ -275,17 +275,16 @@ static int drr_dump_class_stats(struct Qdisc *sch, unsigned long arg,
                                struct gnet_dump *d)
 {
        struct drr_class *cl = (struct drr_class *)arg;
+       __u32 qlen = cl->qdisc->q.qlen;
        struct tc_drr_stats xstats;
 
        memset(&xstats, 0, sizeof(xstats));
-       if (cl->qdisc->q.qlen) {
+       if (qlen)
                xstats.deficit = cl->deficit;
-               cl->qdisc->qstats.qlen = cl->qdisc->q.qlen;
-       }
 
        if (gnet_stats_copy_basic(d, NULL, &cl->bstats) < 0 ||
            gnet_stats_copy_rate_est(d, &cl->bstats, &cl->rate_est) < 0 ||
-           gnet_stats_copy_queue(d, &cl->qdisc->qstats) < 0)
+           gnet_stats_copy_queue(d, &cl->qdisc->qstats, qlen) < 0)
                return -1;
 
        return gnet_stats_copy_app(d, &xstats, sizeof(xstats));

diff --git a/net/sched/sch_fq_codel.c b/net/sched/sch_fq_codel.c
index 9270e1b2f25da5282b56026b977f64bf2e60c447..226d7359753998b26fccdb01fdaffaeed8b940e9 100644 (file)
--- a/net/sched/sch_fq_codel.c
+++ b/net/sched/sch_fq_codel.c
@@ -550,7 +550,7 @@ static int fq_codel_dump_class_stats(struct Qdisc *sch, unsigned long cl,
                qs.backlog = q->backlogs[idx];
                qs.drops = flow->dropped;
        }
-       if (gnet_stats_copy_queue(d, &qs) < 0)
+       if (gnet_stats_copy_queue(d, &qs, 0) < 0)
                return -1;
        if (idx < q->flows_cnt)
                return gnet_stats_copy_app(d, &xstats, sizeof(xstats));

diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c
index ad278251d81168340c6c088005467a93c7fb2670..d364acb2ad07ff6a1791aa2dcfb177bb7a1894b0 100644 (file)
--- a/net/sched/sch_hfsc.c
+++ b/net/sched/sch_hfsc.c
@@ -1370,7 +1370,6 @@ hfsc_dump_class_stats(struct Qdisc *sch, unsigned long arg,
        struct hfsc_class *cl = (struct hfsc_class *)arg;
        struct tc_hfsc_stats xstats;
 
-       cl->qstats.qlen = cl->qdisc->q.qlen;
        cl->qstats.backlog = cl->qdisc->qstats.backlog;
        xstats.level   = cl->level;
        xstats.period  = cl->cl_vtperiod;
@@ -1379,7 +1378,7 @@ hfsc_dump_class_stats(struct Qdisc *sch, unsigned long arg,
 
        if (gnet_stats_copy_basic(d, NULL, &cl->bstats) < 0 ||
            gnet_stats_copy_rate_est(d, &cl->bstats, &cl->rate_est) < 0 ||
-           gnet_stats_copy_queue(d, &cl->qstats) < 0)
+           gnet_stats_copy_queue(d, &cl->qstats, cl->qdisc->q.qlen) < 0)
                return -1;
 
        return gnet_stats_copy_app(d, &xstats, sizeof(xstats));

diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
index c40ab7a98c50819f73b1edd4037c4f43147e011c..3a691fd88f9935bf0f9a0e4f009babdfcedbd06f 100644 (file)
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -1138,15 +1138,16 @@ static int
 htb_dump_class_stats(struct Qdisc *sch, unsigned long arg, struct gnet_dump *d)
 {
        struct htb_class *cl = (struct htb_class *)arg;
+       __u32 qlen = 0;
 
        if (!cl->level && cl->un.leaf.q)
-               cl->qstats.qlen = cl->un.leaf.q->q.qlen;
+               qlen = cl->un.leaf.q->q.qlen;
        cl->xstats.tokens = PSCHED_NS2TICKS(cl->tokens);
        cl->xstats.ctokens = PSCHED_NS2TICKS(cl->ctokens);
 
        if (gnet_stats_copy_basic(d, NULL, &cl->bstats) < 0 ||
            gnet_stats_copy_rate_est(d, NULL, &cl->rate_est) < 0 ||
-           gnet_stats_copy_queue(d, &cl->qstats) < 0)
+           gnet_stats_copy_queue(d, &cl->qstats, qlen) < 0)
                return -1;
 
        return gnet_stats_copy_app(d, &cl->xstats, sizeof(cl->xstats));

diff --git a/net/sched/sch_mq.c b/net/sched/sch_mq.c
index d3a27fb607af762681cf9af8b43be765137bc832..6416a69420620c564d40cfd3db5fa82df9bd3010 100644 (file)
--- a/net/sched/sch_mq.c
+++ b/net/sched/sch_mq.c
@@ -112,7 +112,6 @@ static int mq_dump(struct Qdisc *sch, struct sk_buff *skb)
                sch->q.qlen             += qdisc->q.qlen;
                sch->bstats.bytes       += qdisc->bstats.bytes;
                sch->bstats.packets     += qdisc->bstats.packets;
-               sch->qstats.qlen        += qdisc->qstats.qlen;
                sch->qstats.backlog     += qdisc->qstats.backlog;
                sch->qstats.drops       += qdisc->qstats.drops;
                sch->qstats.requeues    += qdisc->qstats.requeues;
@@ -200,9 +199,8 @@ static int mq_dump_class_stats(struct Qdisc *sch, unsigned long cl,
        struct netdev_queue *dev_queue = mq_queue_get(sch, cl);
 
        sch = dev_queue->qdisc_sleeping;
-       sch->qstats.qlen = sch->q.qlen;
        if (gnet_stats_copy_basic(d, NULL, &sch->bstats) < 0 ||
-           gnet_stats_copy_queue(d, &sch->qstats) < 0)
+           gnet_stats_copy_queue(d, &sch->qstats, sch->q.qlen) < 0)
                return -1;
        return 0;
 }

diff --git a/net/sched/sch_mqprio.c b/net/sched/sch_mqprio.c
index 8917372fddc69858c9344dc730b24f3ba8581de4..03dbeb5e81816d8f0d224c264a7c035125c3af4f 100644 (file)
--- a/net/sched/sch_mqprio.c
+++ b/net/sched/sch_mqprio.c
@@ -236,7 +236,6 @@ static int mqprio_dump(struct Qdisc *sch, struct sk_buff *skb)
                sch->q.qlen             += qdisc->q.qlen;
                sch->bstats.bytes       += qdisc->bstats.bytes;
                sch->bstats.packets     += qdisc->bstats.packets;
-               sch->qstats.qlen        += qdisc->qstats.qlen;
                sch->qstats.backlog     += qdisc->qstats.backlog;
                sch->qstats.drops       += qdisc->qstats.drops;
                sch->qstats.requeues    += qdisc->qstats.requeues;
@@ -327,6 +326,7 @@ static int mqprio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
 
        if (cl <= netdev_get_num_tc(dev)) {
                int i;
+               __u32 qlen = 0;
                struct Qdisc *qdisc;
                struct gnet_stats_queue qstats = {0};
                struct gnet_stats_basic_packed bstats = {0};
@@ -344,9 +344,9 @@ static int mqprio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
 
                        qdisc = rtnl_dereference(q->qdisc);
                        spin_lock_bh(qdisc_lock(qdisc));
+                       qlen              += qdisc->q.qlen;
                        bstats.bytes      += qdisc->bstats.bytes;
                        bstats.packets    += qdisc->bstats.packets;
-                       qstats.qlen       += qdisc->qstats.qlen;
                        qstats.backlog    += qdisc->qstats.backlog;
                        qstats.drops      += qdisc->qstats.drops;
                        qstats.requeues   += qdisc->qstats.requeues;
@@ -356,15 +356,14 @@ static int mqprio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
                /* Reclaim root sleeping lock before completing stats */
                spin_lock_bh(d->lock);
                if (gnet_stats_copy_basic(d, NULL, &bstats) < 0 ||
-                   gnet_stats_copy_queue(d, &qstats) < 0)
+                   gnet_stats_copy_queue(d, &qstats, qlen) < 0)
                        return -1;
        } else {
                struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
 
                sch = dev_queue->qdisc_sleeping;
-               sch->qstats.qlen = sch->q.qlen;
                if (gnet_stats_copy_basic(d, NULL, &sch->bstats) < 0 ||
-                   gnet_stats_copy_queue(d, &sch->qstats) < 0)
+                   gnet_stats_copy_queue(d, &sch->qstats, sch->q.qlen) < 0)
                        return -1;
        }
        return 0;

diff --git a/net/sched/sch_multiq.c b/net/sched/sch_multiq.c
index 7f4e1d8504b0e829554ac93bbfb18610d1c9476f..53357b368bffde6041eff145b87261c346e018f5 100644 (file)
--- a/net/sched/sch_multiq.c
+++ b/net/sched/sch_multiq.c
@@ -360,9 +360,8 @@ static int multiq_dump_class_stats(struct Qdisc *sch, unsigned long cl,
        struct Qdisc *cl_q;
 
        cl_q = q->queues[cl - 1];
-       cl_q->qstats.qlen = cl_q->q.qlen;
        if (gnet_stats_copy_basic(d, NULL, &cl_q->bstats) < 0 ||
-           gnet_stats_copy_queue(d, &cl_q->qstats) < 0)
+           gnet_stats_copy_queue(d, &cl_q->qstats, cl_q->q.qlen) < 0)
                return -1;
 
        return 0;

diff --git a/net/sched/sch_prio.c b/net/sched/sch_prio.c
index b411e78a02fc8902c972ebc661a43b0f37c0e5ab..4644f55242d2f8aa648f10e48f4b26caa2126255 100644 (file)
--- a/net/sched/sch_prio.c
+++ b/net/sched/sch_prio.c
@@ -324,9 +324,8 @@ static int prio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
        struct Qdisc *cl_q;
 
        cl_q = q->queues[cl - 1];
-       cl_q->qstats.qlen = cl_q->q.qlen;
        if (gnet_stats_copy_basic(d, NULL, &cl_q->bstats) < 0 ||
-           gnet_stats_copy_queue(d, &cl_q->qstats) < 0)
+           gnet_stats_copy_queue(d, &cl_q->qstats, cl_q->q.qlen) < 0)
                return -1;
 
        return 0;

diff --git a/net/sched/sch_qfq.c b/net/sched/sch_qfq.c
index 3fb26555c79bb7e735cf4563d12baba4f1aff8e7..66df9d9e301afa82a17b315b98413c9a22c2da5e 100644 (file)
--- a/net/sched/sch_qfq.c
+++ b/net/sched/sch_qfq.c
@@ -664,14 +664,13 @@ static int qfq_dump_class_stats(struct Qdisc *sch, unsigned long arg,
        struct tc_qfq_stats xstats;
 
        memset(&xstats, 0, sizeof(xstats));
-       cl->qdisc->qstats.qlen = cl->qdisc->q.qlen;
 
        xstats.weight = cl->agg->class_weight;
        xstats.lmax = cl->agg->lmax;
 
        if (gnet_stats_copy_basic(d, NULL, &cl->bstats) < 0 ||
            gnet_stats_copy_rate_est(d, &cl->bstats, &cl->rate_est) < 0 ||
-           gnet_stats_copy_queue(d, &cl->qdisc->qstats) < 0)
+           gnet_stats_copy_queue(d, &cl->qdisc->qstats, cl->qdisc->q.qlen) < 0)
                return -1;
 
        return gnet_stats_copy_app(d, &xstats, sizeof(xstats));

diff --git a/net/sched/sch_sfq.c b/net/sched/sch_sfq.c
index 158dfa641d18ab060c6a14d4c88e7378b208c012..d4afcbc1c6f7d6fe2d7bbbe7fc586695ab3f5e87 100644 (file)
--- a/net/sched/sch_sfq.c
+++ b/net/sched/sch_sfq.c
@@ -871,7 +871,7 @@ static int sfq_dump_class_stats(struct Qdisc *sch, unsigned long cl,
                qs.qlen = slot->qlen;
                qs.backlog = slot->backlog;
        }
-       if (gnet_stats_copy_queue(d, &qs) < 0)
+       if (gnet_stats_copy_queue(d, &qs, qs.qlen) < 0)
                return -1;
        return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
 }