linux/net/sched/sch_gred.c
Jakub Kicinski 339346d49a net: sched: gred: prevent races when adding offloads to stats
Naresh reports seeing a warning that gred is calling
u64_stats_update_begin() with preemption enabled.
Arnd points out it's coming from _bstats_update().

We should be holding the qdisc lock when writing
to stats, they are also updated from the datapath.

Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
Link: https://lore.kernel.org/all/CA+G9fYsTr9_r893+62u6UGD3dVaCE-kN9C-Apmb2m=hxjc1Cqg@mail.gmail.com/
Fixes: e49efd5288 ("net: sched: gred: support reporting stats from offloads")
Link: https://lore.kernel.org/r/20230113044137.1383067-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-01-18 20:28:25 -08:00

948 lines
23 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* net/sched/sch_gred.c Generic Random Early Detection queue.
*
* Authors: J Hadi Salim (hadi@cyberus.ca) 1998-2002
*
* 991129: - Bug fix with grio mode
* - a better sing. AvgQ mode with Grio(WRED)
* - A finer grained VQ dequeue based on suggestion
* from Ren Liu
* - More error checks
*
* For all the glorious comments look at include/net/red.h
*/
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <net/pkt_cls.h>
#include <net/pkt_sched.h>
#include <net/red.h>
#define GRED_DEF_PRIO (MAX_DPs / 2)
#define GRED_VQ_MASK (MAX_DPs - 1)
#define GRED_VQ_RED_FLAGS (TC_RED_ECN | TC_RED_HARDDROP)
struct gred_sched_data;
struct gred_sched;
struct gred_sched_data {
u32 limit; /* HARD maximal queue length */
u32 DP; /* the drop parameters */
u32 red_flags; /* virtualQ version of red_flags */
u64 bytesin; /* bytes seen on virtualQ so far*/
u32 packetsin; /* packets seen on virtualQ so far*/
u32 backlog; /* bytes on the virtualQ */
u8 prio; /* the prio of this vq */
struct red_parms parms;
struct red_vars vars;
struct red_stats stats;
};
enum {
GRED_WRED_MODE = 1,
GRED_RIO_MODE,
};
struct gred_sched {
struct gred_sched_data *tab[MAX_DPs];
unsigned long flags;
u32 red_flags;
u32 DPs;
u32 def;
struct red_vars wred_set;
struct tc_gred_qopt_offload *opt;
};
static inline int gred_wred_mode(struct gred_sched *table)
{
return test_bit(GRED_WRED_MODE, &table->flags);
}
static inline void gred_enable_wred_mode(struct gred_sched *table)
{
__set_bit(GRED_WRED_MODE, &table->flags);
}
static inline void gred_disable_wred_mode(struct gred_sched *table)
{
__clear_bit(GRED_WRED_MODE, &table->flags);
}
static inline int gred_rio_mode(struct gred_sched *table)
{
return test_bit(GRED_RIO_MODE, &table->flags);
}
static inline void gred_enable_rio_mode(struct gred_sched *table)
{
__set_bit(GRED_RIO_MODE, &table->flags);
}
static inline void gred_disable_rio_mode(struct gred_sched *table)
{
__clear_bit(GRED_RIO_MODE, &table->flags);
}
static inline int gred_wred_mode_check(struct Qdisc *sch)
{
struct gred_sched *table = qdisc_priv(sch);
int i;
/* Really ugly O(n^2) but shouldn't be necessary too frequent. */
for (i = 0; i < table->DPs; i++) {
struct gred_sched_data *q = table->tab[i];
int n;
if (q == NULL)
continue;
for (n = i + 1; n < table->DPs; n++)
if (table->tab[n] && table->tab[n]->prio == q->prio)
return 1;
}
return 0;
}
static inline unsigned int gred_backlog(struct gred_sched *table,
struct gred_sched_data *q,
struct Qdisc *sch)
{
if (gred_wred_mode(table))
return sch->qstats.backlog;
else
return q->backlog;
}
static inline u16 tc_index_to_dp(struct sk_buff *skb)
{
return skb->tc_index & GRED_VQ_MASK;
}
static inline void gred_load_wred_set(const struct gred_sched *table,
struct gred_sched_data *q)
{
q->vars.qavg = table->wred_set.qavg;
q->vars.qidlestart = table->wred_set.qidlestart;
}
static inline void gred_store_wred_set(struct gred_sched *table,
struct gred_sched_data *q)
{
table->wred_set.qavg = q->vars.qavg;
table->wred_set.qidlestart = q->vars.qidlestart;
}
static int gred_use_ecn(struct gred_sched_data *q)
{
return q->red_flags & TC_RED_ECN;
}
static int gred_use_harddrop(struct gred_sched_data *q)
{
return q->red_flags & TC_RED_HARDDROP;
}
static bool gred_per_vq_red_flags_used(struct gred_sched *table)
{
unsigned int i;
/* Local per-vq flags couldn't have been set unless global are 0 */
if (table->red_flags)
return false;
for (i = 0; i < MAX_DPs; i++)
if (table->tab[i] && table->tab[i]->red_flags)
return true;
return false;
}
static int gred_enqueue(struct sk_buff *skb, struct Qdisc *sch,
struct sk_buff **to_free)
{
struct gred_sched_data *q = NULL;
struct gred_sched *t = qdisc_priv(sch);
unsigned long qavg = 0;
u16 dp = tc_index_to_dp(skb);
if (dp >= t->DPs || (q = t->tab[dp]) == NULL) {
dp = t->def;
q = t->tab[dp];
if (!q) {
/* Pass through packets not assigned to a DP
* if no default DP has been configured. This
* allows for DP flows to be left untouched.
*/
if (likely(sch->qstats.backlog + qdisc_pkt_len(skb) <=
sch->limit))
return qdisc_enqueue_tail(skb, sch);
else
goto drop;
}
/* fix tc_index? --could be controversial but needed for
requeueing */
skb->tc_index = (skb->tc_index & ~GRED_VQ_MASK) | dp;
}
/* sum up all the qaves of prios < ours to get the new qave */
if (!gred_wred_mode(t) && gred_rio_mode(t)) {
int i;
for (i = 0; i < t->DPs; i++) {
if (t->tab[i] && t->tab[i]->prio < q->prio &&
!red_is_idling(&t->tab[i]->vars))
qavg += t->tab[i]->vars.qavg;
}
}
q->packetsin++;
q->bytesin += qdisc_pkt_len(skb);
if (gred_wred_mode(t))
gred_load_wred_set(t, q);
q->vars.qavg = red_calc_qavg(&q->parms,
&q->vars,
gred_backlog(t, q, sch));
if (red_is_idling(&q->vars))
red_end_of_idle_period(&q->vars);
if (gred_wred_mode(t))
gred_store_wred_set(t, q);
switch (red_action(&q->parms, &q->vars, q->vars.qavg + qavg)) {
case RED_DONT_MARK:
break;
case RED_PROB_MARK:
qdisc_qstats_overlimit(sch);
if (!gred_use_ecn(q) || !INET_ECN_set_ce(skb)) {
q->stats.prob_drop++;
goto congestion_drop;
}
q->stats.prob_mark++;
break;
case RED_HARD_MARK:
qdisc_qstats_overlimit(sch);
if (gred_use_harddrop(q) || !gred_use_ecn(q) ||
!INET_ECN_set_ce(skb)) {
q->stats.forced_drop++;
goto congestion_drop;
}
q->stats.forced_mark++;
break;
}
if (gred_backlog(t, q, sch) + qdisc_pkt_len(skb) <= q->limit) {
q->backlog += qdisc_pkt_len(skb);
return qdisc_enqueue_tail(skb, sch);
}
q->stats.pdrop++;
drop:
return qdisc_drop(skb, sch, to_free);
congestion_drop:
qdisc_drop(skb, sch, to_free);
return NET_XMIT_CN;
}
static struct sk_buff *gred_dequeue(struct Qdisc *sch)
{
struct sk_buff *skb;
struct gred_sched *t = qdisc_priv(sch);
skb = qdisc_dequeue_head(sch);
if (skb) {
struct gred_sched_data *q;
u16 dp = tc_index_to_dp(skb);
if (dp >= t->DPs || (q = t->tab[dp]) == NULL) {
net_warn_ratelimited("GRED: Unable to relocate VQ 0x%x after dequeue, screwing up backlog\n",
tc_index_to_dp(skb));
} else {
q->backlog -= qdisc_pkt_len(skb);
if (gred_wred_mode(t)) {
if (!sch->qstats.backlog)
red_start_of_idle_period(&t->wred_set);
} else {
if (!q->backlog)
red_start_of_idle_period(&q->vars);
}
}
return skb;
}
return NULL;
}
static void gred_reset(struct Qdisc *sch)
{
int i;
struct gred_sched *t = qdisc_priv(sch);
qdisc_reset_queue(sch);
for (i = 0; i < t->DPs; i++) {
struct gred_sched_data *q = t->tab[i];
if (!q)
continue;
red_restart(&q->vars);
q->backlog = 0;
}
}
static void gred_offload(struct Qdisc *sch, enum tc_gred_command command)
{
struct gred_sched *table = qdisc_priv(sch);
struct net_device *dev = qdisc_dev(sch);
struct tc_gred_qopt_offload *opt = table->opt;
if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
return;
memset(opt, 0, sizeof(*opt));
opt->command = command;
opt->handle = sch->handle;
opt->parent = sch->parent;
if (command == TC_GRED_REPLACE) {
unsigned int i;
opt->set.grio_on = gred_rio_mode(table);
opt->set.wred_on = gred_wred_mode(table);
opt->set.dp_cnt = table->DPs;
opt->set.dp_def = table->def;
for (i = 0; i < table->DPs; i++) {
struct gred_sched_data *q = table->tab[i];
if (!q)
continue;
opt->set.tab[i].present = true;
opt->set.tab[i].limit = q->limit;
opt->set.tab[i].prio = q->prio;
opt->set.tab[i].min = q->parms.qth_min >> q->parms.Wlog;
opt->set.tab[i].max = q->parms.qth_max >> q->parms.Wlog;
opt->set.tab[i].is_ecn = gred_use_ecn(q);
opt->set.tab[i].is_harddrop = gred_use_harddrop(q);
opt->set.tab[i].probability = q->parms.max_P;
opt->set.tab[i].backlog = &q->backlog;
}
opt->set.qstats = &sch->qstats;
}
dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_GRED, opt);
}
static int gred_offload_dump_stats(struct Qdisc *sch)
{
struct gred_sched *table = qdisc_priv(sch);
struct tc_gred_qopt_offload *hw_stats;
u64 bytes = 0, packets = 0;
unsigned int i;
int ret;
hw_stats = kzalloc(sizeof(*hw_stats), GFP_KERNEL);
if (!hw_stats)
return -ENOMEM;
hw_stats->command = TC_GRED_STATS;
hw_stats->handle = sch->handle;
hw_stats->parent = sch->parent;
for (i = 0; i < MAX_DPs; i++) {
gnet_stats_basic_sync_init(&hw_stats->stats.bstats[i]);
if (table->tab[i])
hw_stats->stats.xstats[i] = &table->tab[i]->stats;
}
ret = qdisc_offload_dump_helper(sch, TC_SETUP_QDISC_GRED, hw_stats);
/* Even if driver returns failure adjust the stats - in case offload
* ended but driver still wants to adjust the values.
*/
sch_tree_lock(sch);
for (i = 0; i < MAX_DPs; i++) {
if (!table->tab[i])
continue;
table->tab[i]->packetsin += u64_stats_read(&hw_stats->stats.bstats[i].packets);
table->tab[i]->bytesin += u64_stats_read(&hw_stats->stats.bstats[i].bytes);
table->tab[i]->backlog += hw_stats->stats.qstats[i].backlog;
bytes += u64_stats_read(&hw_stats->stats.bstats[i].bytes);
packets += u64_stats_read(&hw_stats->stats.bstats[i].packets);
sch->qstats.qlen += hw_stats->stats.qstats[i].qlen;
sch->qstats.backlog += hw_stats->stats.qstats[i].backlog;
sch->qstats.drops += hw_stats->stats.qstats[i].drops;
sch->qstats.requeues += hw_stats->stats.qstats[i].requeues;
sch->qstats.overlimits += hw_stats->stats.qstats[i].overlimits;
}
_bstats_update(&sch->bstats, bytes, packets);
sch_tree_unlock(sch);
kfree(hw_stats);
return ret;
}
static inline void gred_destroy_vq(struct gred_sched_data *q)
{
kfree(q);
}
static int gred_change_table_def(struct Qdisc *sch, struct nlattr *dps,
struct netlink_ext_ack *extack)
{
struct gred_sched *table = qdisc_priv(sch);
struct tc_gred_sopt *sopt;
bool red_flags_changed;
int i;
if (!dps)
return -EINVAL;
sopt = nla_data(dps);
if (sopt->DPs > MAX_DPs) {
NL_SET_ERR_MSG_MOD(extack, "number of virtual queues too high");
return -EINVAL;
}
if (sopt->DPs == 0) {
NL_SET_ERR_MSG_MOD(extack,
"number of virtual queues can't be 0");
return -EINVAL;
}
if (sopt->def_DP >= sopt->DPs) {
NL_SET_ERR_MSG_MOD(extack, "default virtual queue above virtual queue count");
return -EINVAL;
}
if (sopt->flags && gred_per_vq_red_flags_used(table)) {
NL_SET_ERR_MSG_MOD(extack, "can't set per-Qdisc RED flags when per-virtual queue flags are used");
return -EINVAL;
}
sch_tree_lock(sch);
table->DPs = sopt->DPs;
table->def = sopt->def_DP;
red_flags_changed = table->red_flags != sopt->flags;
table->red_flags = sopt->flags;
/*
* Every entry point to GRED is synchronized with the above code
* and the DP is checked against DPs, i.e. shadowed VQs can no
* longer be found so we can unlock right here.
*/
sch_tree_unlock(sch);
if (sopt->grio) {
gred_enable_rio_mode(table);
gred_disable_wred_mode(table);
if (gred_wred_mode_check(sch))
gred_enable_wred_mode(table);
} else {
gred_disable_rio_mode(table);
gred_disable_wred_mode(table);
}
if (red_flags_changed)
for (i = 0; i < table->DPs; i++)
if (table->tab[i])
table->tab[i]->red_flags =
table->red_flags & GRED_VQ_RED_FLAGS;
for (i = table->DPs; i < MAX_DPs; i++) {
if (table->tab[i]) {
pr_warn("GRED: Warning: Destroying shadowed VQ 0x%x\n",
i);
gred_destroy_vq(table->tab[i]);
table->tab[i] = NULL;
}
}
gred_offload(sch, TC_GRED_REPLACE);
return 0;
}
static inline int gred_change_vq(struct Qdisc *sch, int dp,
struct tc_gred_qopt *ctl, int prio,
u8 *stab, u32 max_P,
struct gred_sched_data **prealloc,
struct netlink_ext_ack *extack)
{
struct gred_sched *table = qdisc_priv(sch);
struct gred_sched_data *q = table->tab[dp];
if (!red_check_params(ctl->qth_min, ctl->qth_max, ctl->Wlog, ctl->Scell_log, stab)) {
NL_SET_ERR_MSG_MOD(extack, "invalid RED parameters");
return -EINVAL;
}
if (!q) {
table->tab[dp] = q = *prealloc;
*prealloc = NULL;
if (!q)
return -ENOMEM;
q->red_flags = table->red_flags & GRED_VQ_RED_FLAGS;
}
q->DP = dp;
q->prio = prio;
if (ctl->limit > sch->limit)
q->limit = sch->limit;
else
q->limit = ctl->limit;
if (q->backlog == 0)
red_end_of_idle_period(&q->vars);
red_set_parms(&q->parms,
ctl->qth_min, ctl->qth_max, ctl->Wlog, ctl->Plog,
ctl->Scell_log, stab, max_P);
red_set_vars(&q->vars);
return 0;
}
static const struct nla_policy gred_vq_policy[TCA_GRED_VQ_MAX + 1] = {
[TCA_GRED_VQ_DP] = { .type = NLA_U32 },
[TCA_GRED_VQ_FLAGS] = { .type = NLA_U32 },
};
static const struct nla_policy gred_vqe_policy[TCA_GRED_VQ_ENTRY_MAX + 1] = {
[TCA_GRED_VQ_ENTRY] = { .type = NLA_NESTED },
};
static const struct nla_policy gred_policy[TCA_GRED_MAX + 1] = {
[TCA_GRED_PARMS] = { .len = sizeof(struct tc_gred_qopt) },
[TCA_GRED_STAB] = { .len = 256 },
[TCA_GRED_DPS] = { .len = sizeof(struct tc_gred_sopt) },
[TCA_GRED_MAX_P] = { .type = NLA_U32 },
[TCA_GRED_LIMIT] = { .type = NLA_U32 },
[TCA_GRED_VQ_LIST] = { .type = NLA_NESTED },
};
static void gred_vq_apply(struct gred_sched *table, const struct nlattr *entry)
{
struct nlattr *tb[TCA_GRED_VQ_MAX + 1];
u32 dp;
nla_parse_nested_deprecated(tb, TCA_GRED_VQ_MAX, entry,
gred_vq_policy, NULL);
dp = nla_get_u32(tb[TCA_GRED_VQ_DP]);
if (tb[TCA_GRED_VQ_FLAGS])
table->tab[dp]->red_flags = nla_get_u32(tb[TCA_GRED_VQ_FLAGS]);
}
static void gred_vqs_apply(struct gred_sched *table, struct nlattr *vqs)
{
const struct nlattr *attr;
int rem;
nla_for_each_nested(attr, vqs, rem) {
switch (nla_type(attr)) {
case TCA_GRED_VQ_ENTRY:
gred_vq_apply(table, attr);
break;
}
}
}
static int gred_vq_validate(struct gred_sched *table, u32 cdp,
const struct nlattr *entry,
struct netlink_ext_ack *extack)
{
struct nlattr *tb[TCA_GRED_VQ_MAX + 1];
int err;
u32 dp;
err = nla_parse_nested_deprecated(tb, TCA_GRED_VQ_MAX, entry,
gred_vq_policy, extack);
if (err < 0)
return err;
if (!tb[TCA_GRED_VQ_DP]) {
NL_SET_ERR_MSG_MOD(extack, "Virtual queue with no index specified");
return -EINVAL;
}
dp = nla_get_u32(tb[TCA_GRED_VQ_DP]);
if (dp >= table->DPs) {
NL_SET_ERR_MSG_MOD(extack, "Virtual queue with index out of bounds");
return -EINVAL;
}
if (dp != cdp && !table->tab[dp]) {
NL_SET_ERR_MSG_MOD(extack, "Virtual queue not yet instantiated");
return -EINVAL;
}
if (tb[TCA_GRED_VQ_FLAGS]) {
u32 red_flags = nla_get_u32(tb[TCA_GRED_VQ_FLAGS]);
if (table->red_flags && table->red_flags != red_flags) {
NL_SET_ERR_MSG_MOD(extack, "can't change per-virtual queue RED flags when per-Qdisc flags are used");
return -EINVAL;
}
if (red_flags & ~GRED_VQ_RED_FLAGS) {
NL_SET_ERR_MSG_MOD(extack,
"invalid RED flags specified");
return -EINVAL;
}
}
return 0;
}
static int gred_vqs_validate(struct gred_sched *table, u32 cdp,
struct nlattr *vqs, struct netlink_ext_ack *extack)
{
const struct nlattr *attr;
int rem, err;
err = nla_validate_nested_deprecated(vqs, TCA_GRED_VQ_ENTRY_MAX,
gred_vqe_policy, extack);
if (err < 0)
return err;
nla_for_each_nested(attr, vqs, rem) {
switch (nla_type(attr)) {
case TCA_GRED_VQ_ENTRY:
err = gred_vq_validate(table, cdp, attr, extack);
if (err)
return err;
break;
default:
NL_SET_ERR_MSG_MOD(extack, "GRED_VQ_LIST can contain only entry attributes");
return -EINVAL;
}
}
if (rem > 0) {
NL_SET_ERR_MSG_MOD(extack, "Trailing data after parsing virtual queue list");
return -EINVAL;
}
return 0;
}
static int gred_change(struct Qdisc *sch, struct nlattr *opt,
struct netlink_ext_ack *extack)
{
struct gred_sched *table = qdisc_priv(sch);
struct tc_gred_qopt *ctl;
struct nlattr *tb[TCA_GRED_MAX + 1];
int err, prio = GRED_DEF_PRIO;
u8 *stab;
u32 max_P;
struct gred_sched_data *prealloc;
err = nla_parse_nested_deprecated(tb, TCA_GRED_MAX, opt, gred_policy,
extack);
if (err < 0)
return err;
if (tb[TCA_GRED_PARMS] == NULL && tb[TCA_GRED_STAB] == NULL) {
if (tb[TCA_GRED_LIMIT] != NULL)
sch->limit = nla_get_u32(tb[TCA_GRED_LIMIT]);
return gred_change_table_def(sch, tb[TCA_GRED_DPS], extack);
}
if (tb[TCA_GRED_PARMS] == NULL ||
tb[TCA_GRED_STAB] == NULL ||
tb[TCA_GRED_LIMIT] != NULL) {
NL_SET_ERR_MSG_MOD(extack, "can't configure Qdisc and virtual queue at the same time");
return -EINVAL;
}
max_P = tb[TCA_GRED_MAX_P] ? nla_get_u32(tb[TCA_GRED_MAX_P]) : 0;
ctl = nla_data(tb[TCA_GRED_PARMS]);
stab = nla_data(tb[TCA_GRED_STAB]);
if (ctl->DP >= table->DPs) {
NL_SET_ERR_MSG_MOD(extack, "virtual queue index above virtual queue count");
return -EINVAL;
}
if (tb[TCA_GRED_VQ_LIST]) {
err = gred_vqs_validate(table, ctl->DP, tb[TCA_GRED_VQ_LIST],
extack);
if (err)
return err;
}
if (gred_rio_mode(table)) {
if (ctl->prio == 0) {
int def_prio = GRED_DEF_PRIO;
if (table->tab[table->def])
def_prio = table->tab[table->def]->prio;
printk(KERN_DEBUG "GRED: DP %u does not have a prio "
"setting default to %d\n", ctl->DP, def_prio);
prio = def_prio;
} else
prio = ctl->prio;
}
prealloc = kzalloc(sizeof(*prealloc), GFP_KERNEL);
sch_tree_lock(sch);
err = gred_change_vq(sch, ctl->DP, ctl, prio, stab, max_P, &prealloc,
extack);
if (err < 0)
goto err_unlock_free;
if (tb[TCA_GRED_VQ_LIST])
gred_vqs_apply(table, tb[TCA_GRED_VQ_LIST]);
if (gred_rio_mode(table)) {
gred_disable_wred_mode(table);
if (gred_wred_mode_check(sch))
gred_enable_wred_mode(table);
}
sch_tree_unlock(sch);
kfree(prealloc);
gred_offload(sch, TC_GRED_REPLACE);
return 0;
err_unlock_free:
sch_tree_unlock(sch);
kfree(prealloc);
return err;
}
static int gred_init(struct Qdisc *sch, struct nlattr *opt,
struct netlink_ext_ack *extack)
{
struct gred_sched *table = qdisc_priv(sch);
struct nlattr *tb[TCA_GRED_MAX + 1];
int err;
if (!opt)
return -EINVAL;
err = nla_parse_nested_deprecated(tb, TCA_GRED_MAX, opt, gred_policy,
extack);
if (err < 0)
return err;
if (tb[TCA_GRED_PARMS] || tb[TCA_GRED_STAB]) {
NL_SET_ERR_MSG_MOD(extack,
"virtual queue configuration can't be specified at initialization time");
return -EINVAL;
}
if (tb[TCA_GRED_LIMIT])
sch->limit = nla_get_u32(tb[TCA_GRED_LIMIT]);
else
sch->limit = qdisc_dev(sch)->tx_queue_len
* psched_mtu(qdisc_dev(sch));
if (qdisc_dev(sch)->netdev_ops->ndo_setup_tc) {
table->opt = kzalloc(sizeof(*table->opt), GFP_KERNEL);
if (!table->opt)
return -ENOMEM;
}
return gred_change_table_def(sch, tb[TCA_GRED_DPS], extack);
}
static int gred_dump(struct Qdisc *sch, struct sk_buff *skb)
{
struct gred_sched *table = qdisc_priv(sch);
struct nlattr *parms, *vqs, *opts = NULL;
int i;
u32 max_p[MAX_DPs];
struct tc_gred_sopt sopt = {
.DPs = table->DPs,
.def_DP = table->def,
.grio = gred_rio_mode(table),
.flags = table->red_flags,
};
if (gred_offload_dump_stats(sch))
goto nla_put_failure;
opts = nla_nest_start_noflag(skb, TCA_OPTIONS);
if (opts == NULL)
goto nla_put_failure;
if (nla_put(skb, TCA_GRED_DPS, sizeof(sopt), &sopt))
goto nla_put_failure;
for (i = 0; i < MAX_DPs; i++) {
struct gred_sched_data *q = table->tab[i];
max_p[i] = q ? q->parms.max_P : 0;
}
if (nla_put(skb, TCA_GRED_MAX_P, sizeof(max_p), max_p))
goto nla_put_failure;
if (nla_put_u32(skb, TCA_GRED_LIMIT, sch->limit))
goto nla_put_failure;
/* Old style all-in-one dump of VQs */
parms = nla_nest_start_noflag(skb, TCA_GRED_PARMS);
if (parms == NULL)
goto nla_put_failure;
for (i = 0; i < MAX_DPs; i++) {
struct gred_sched_data *q = table->tab[i];
struct tc_gred_qopt opt;
unsigned long qavg;
memset(&opt, 0, sizeof(opt));
if (!q) {
/* hack -- fix at some point with proper message
This is how we indicate to tc that there is no VQ
at this DP */
opt.DP = MAX_DPs + i;
goto append_opt;
}
opt.limit = q->limit;
opt.DP = q->DP;
opt.backlog = gred_backlog(table, q, sch);
opt.prio = q->prio;
opt.qth_min = q->parms.qth_min >> q->parms.Wlog;
opt.qth_max = q->parms.qth_max >> q->parms.Wlog;
opt.Wlog = q->parms.Wlog;
opt.Plog = q->parms.Plog;
opt.Scell_log = q->parms.Scell_log;
opt.early = q->stats.prob_drop;
opt.forced = q->stats.forced_drop;
opt.pdrop = q->stats.pdrop;
opt.packets = q->packetsin;
opt.bytesin = q->bytesin;
if (gred_wred_mode(table))
gred_load_wred_set(table, q);
qavg = red_calc_qavg(&q->parms, &q->vars,
q->vars.qavg >> q->parms.Wlog);
opt.qave = qavg >> q->parms.Wlog;
append_opt:
if (nla_append(skb, sizeof(opt), &opt) < 0)
goto nla_put_failure;
}
nla_nest_end(skb, parms);
/* Dump the VQs again, in more structured way */
vqs = nla_nest_start_noflag(skb, TCA_GRED_VQ_LIST);
if (!vqs)
goto nla_put_failure;
for (i = 0; i < MAX_DPs; i++) {
struct gred_sched_data *q = table->tab[i];
struct nlattr *vq;
if (!q)
continue;
vq = nla_nest_start_noflag(skb, TCA_GRED_VQ_ENTRY);
if (!vq)
goto nla_put_failure;
if (nla_put_u32(skb, TCA_GRED_VQ_DP, q->DP))
goto nla_put_failure;
if (nla_put_u32(skb, TCA_GRED_VQ_FLAGS, q->red_flags))
goto nla_put_failure;
/* Stats */
if (nla_put_u64_64bit(skb, TCA_GRED_VQ_STAT_BYTES, q->bytesin,
TCA_GRED_VQ_PAD))
goto nla_put_failure;
if (nla_put_u32(skb, TCA_GRED_VQ_STAT_PACKETS, q->packetsin))
goto nla_put_failure;
if (nla_put_u32(skb, TCA_GRED_VQ_STAT_BACKLOG,
gred_backlog(table, q, sch)))
goto nla_put_failure;
if (nla_put_u32(skb, TCA_GRED_VQ_STAT_PROB_DROP,
q->stats.prob_drop))
goto nla_put_failure;
if (nla_put_u32(skb, TCA_GRED_VQ_STAT_PROB_MARK,
q->stats.prob_mark))
goto nla_put_failure;
if (nla_put_u32(skb, TCA_GRED_VQ_STAT_FORCED_DROP,
q->stats.forced_drop))
goto nla_put_failure;
if (nla_put_u32(skb, TCA_GRED_VQ_STAT_FORCED_MARK,
q->stats.forced_mark))
goto nla_put_failure;
if (nla_put_u32(skb, TCA_GRED_VQ_STAT_PDROP, q->stats.pdrop))
goto nla_put_failure;
nla_nest_end(skb, vq);
}
nla_nest_end(skb, vqs);
return nla_nest_end(skb, opts);
nla_put_failure:
nla_nest_cancel(skb, opts);
return -EMSGSIZE;
}
static void gred_destroy(struct Qdisc *sch)
{
struct gred_sched *table = qdisc_priv(sch);
int i;
for (i = 0; i < table->DPs; i++)
gred_destroy_vq(table->tab[i]);
gred_offload(sch, TC_GRED_DESTROY);
kfree(table->opt);
}
static struct Qdisc_ops gred_qdisc_ops __read_mostly = {
.id = "gred",
.priv_size = sizeof(struct gred_sched),
.enqueue = gred_enqueue,
.dequeue = gred_dequeue,
.peek = qdisc_peek_head,
.init = gred_init,
.reset = gred_reset,
.destroy = gred_destroy,
.change = gred_change,
.dump = gred_dump,
.owner = THIS_MODULE,
};
static int __init gred_module_init(void)
{
return register_qdisc(&gred_qdisc_ops);
}
static void __exit gred_module_exit(void)
{
unregister_qdisc(&gred_qdisc_ops);
}
module_init(gred_module_init)
module_exit(gred_module_exit)
MODULE_LICENSE("GPL");