linux/net/sched/sch_drr.c
Michal Koutný 241a94abcf net/sched: Add module aliases for cls_,sch_,act_ modules
No functional change intended, aliases will be used in followup commits.
Note for backporters: you may need to add aliases also for modules that
are already removed in mainline kernel but still in your version.

Patches were generated with the help of Coccinelle scripts like:

cat >scripts/coccinelle/misc/tcf_alias.cocci <<EOD
virtual patch
virtual report

@ haskernel @
@@

@ tcf_has_kind depends on report && haskernel @
identifier ops;
constant K;
@@

  static struct tcf_proto_ops ops = {
    .kind = K,
    ...
  };
+char module_alias = K;
EOD

/usr/bin/spatch -D report --cocci-file scripts/coccinelle/misc/tcf_alias.cocci \
        --dir . \
        -I ./arch/x86/include -I ./arch/x86/include/generated -I ./include \
        -I ./arch/x86/include/uapi -I ./arch/x86/include/generated/uapi \
        -I ./include/uapi -I ./include/generated/uapi \
        --include ./include/linux/compiler-version.h --include ./include/linux/kconfig.h \
        --jobs 8 --chunksize 1 2>/dev/null | \
        sed 's/char module_alias = "\([^"]*\)";/MODULE_ALIAS_NET_CLS("\1");/'

And analogously for:

  static struct tc_action_ops ops = {
    .kind = K,

  static struct Qdisc_ops ops = {
    .id = K,

(Someone familiar would be able to fit those into one .cocci file
without sed post processing.)

Signed-off-by: Michal Koutný <mkoutny@suse.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20240201130943.19536-3-mkoutny@suse.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-02-02 10:57:55 -08:00

500 lines
11 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* net/sched/sch_drr.c Deficit Round Robin scheduler
*
* Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
*/
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/netdevice.h>
#include <linux/pkt_sched.h>
#include <net/sch_generic.h>
#include <net/pkt_sched.h>
#include <net/pkt_cls.h>
struct drr_class {
struct Qdisc_class_common common;
struct gnet_stats_basic_sync bstats;
struct gnet_stats_queue qstats;
struct net_rate_estimator __rcu *rate_est;
struct list_head alist;
struct Qdisc *qdisc;
u32 quantum;
u32 deficit;
};
struct drr_sched {
struct list_head active;
struct tcf_proto __rcu *filter_list;
struct tcf_block *block;
struct Qdisc_class_hash clhash;
};
static struct drr_class *drr_find_class(struct Qdisc *sch, u32 classid)
{
struct drr_sched *q = qdisc_priv(sch);
struct Qdisc_class_common *clc;
clc = qdisc_class_find(&q->clhash, classid);
if (clc == NULL)
return NULL;
return container_of(clc, struct drr_class, common);
}
static const struct nla_policy drr_policy[TCA_DRR_MAX + 1] = {
[TCA_DRR_QUANTUM] = { .type = NLA_U32 },
};
static int drr_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
struct nlattr **tca, unsigned long *arg,
struct netlink_ext_ack *extack)
{
struct drr_sched *q = qdisc_priv(sch);
struct drr_class *cl = (struct drr_class *)*arg;
struct nlattr *opt = tca[TCA_OPTIONS];
struct nlattr *tb[TCA_DRR_MAX + 1];
u32 quantum;
int err;
if (!opt) {
NL_SET_ERR_MSG(extack, "DRR options are required for this operation");
return -EINVAL;
}
err = nla_parse_nested_deprecated(tb, TCA_DRR_MAX, opt, drr_policy,
extack);
if (err < 0)
return err;
if (tb[TCA_DRR_QUANTUM]) {
quantum = nla_get_u32(tb[TCA_DRR_QUANTUM]);
if (quantum == 0) {
NL_SET_ERR_MSG(extack, "Specified DRR quantum cannot be zero");
return -EINVAL;
}
} else
quantum = psched_mtu(qdisc_dev(sch));
if (cl != NULL) {
if (tca[TCA_RATE]) {
err = gen_replace_estimator(&cl->bstats, NULL,
&cl->rate_est,
NULL, true,
tca[TCA_RATE]);
if (err) {
NL_SET_ERR_MSG(extack, "Failed to replace estimator");
return err;
}
}
sch_tree_lock(sch);
if (tb[TCA_DRR_QUANTUM])
cl->quantum = quantum;
sch_tree_unlock(sch);
return 0;
}
cl = kzalloc(sizeof(struct drr_class), GFP_KERNEL);
if (cl == NULL)
return -ENOBUFS;
gnet_stats_basic_sync_init(&cl->bstats);
cl->common.classid = classid;
cl->quantum = quantum;
cl->qdisc = qdisc_create_dflt(sch->dev_queue,
&pfifo_qdisc_ops, classid,
NULL);
if (cl->qdisc == NULL)
cl->qdisc = &noop_qdisc;
else
qdisc_hash_add(cl->qdisc, true);
if (tca[TCA_RATE]) {
err = gen_replace_estimator(&cl->bstats, NULL, &cl->rate_est,
NULL, true, tca[TCA_RATE]);
if (err) {
NL_SET_ERR_MSG(extack, "Failed to replace estimator");
qdisc_put(cl->qdisc);
kfree(cl);
return err;
}
}
sch_tree_lock(sch);
qdisc_class_hash_insert(&q->clhash, &cl->common);
sch_tree_unlock(sch);
qdisc_class_hash_grow(sch, &q->clhash);
*arg = (unsigned long)cl;
return 0;
}
static void drr_destroy_class(struct Qdisc *sch, struct drr_class *cl)
{
gen_kill_estimator(&cl->rate_est);
qdisc_put(cl->qdisc);
kfree(cl);
}
static int drr_delete_class(struct Qdisc *sch, unsigned long arg,
struct netlink_ext_ack *extack)
{
struct drr_sched *q = qdisc_priv(sch);
struct drr_class *cl = (struct drr_class *)arg;
if (qdisc_class_in_use(&cl->common)) {
NL_SET_ERR_MSG(extack, "DRR class is in use");
return -EBUSY;
}
sch_tree_lock(sch);
qdisc_purge_queue(cl->qdisc);
qdisc_class_hash_remove(&q->clhash, &cl->common);
sch_tree_unlock(sch);
drr_destroy_class(sch, cl);
return 0;
}
static unsigned long drr_search_class(struct Qdisc *sch, u32 classid)
{
return (unsigned long)drr_find_class(sch, classid);
}
static struct tcf_block *drr_tcf_block(struct Qdisc *sch, unsigned long cl,
struct netlink_ext_ack *extack)
{
struct drr_sched *q = qdisc_priv(sch);
if (cl) {
NL_SET_ERR_MSG(extack, "DRR classid must be zero");
return NULL;
}
return q->block;
}
static unsigned long drr_bind_tcf(struct Qdisc *sch, unsigned long parent,
u32 classid)
{
struct drr_class *cl = drr_find_class(sch, classid);
if (cl)
qdisc_class_get(&cl->common);
return (unsigned long)cl;
}
static void drr_unbind_tcf(struct Qdisc *sch, unsigned long arg)
{
struct drr_class *cl = (struct drr_class *)arg;
qdisc_class_put(&cl->common);
}
static int drr_graft_class(struct Qdisc *sch, unsigned long arg,
struct Qdisc *new, struct Qdisc **old,
struct netlink_ext_ack *extack)
{
struct drr_class *cl = (struct drr_class *)arg;
if (new == NULL) {
new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
cl->common.classid, NULL);
if (new == NULL)
new = &noop_qdisc;
}
*old = qdisc_replace(sch, new, &cl->qdisc);
return 0;
}
static struct Qdisc *drr_class_leaf(struct Qdisc *sch, unsigned long arg)
{
struct drr_class *cl = (struct drr_class *)arg;
return cl->qdisc;
}
static void drr_qlen_notify(struct Qdisc *csh, unsigned long arg)
{
struct drr_class *cl = (struct drr_class *)arg;
list_del(&cl->alist);
}
static int drr_dump_class(struct Qdisc *sch, unsigned long arg,
struct sk_buff *skb, struct tcmsg *tcm)
{
struct drr_class *cl = (struct drr_class *)arg;
struct nlattr *nest;
tcm->tcm_parent = TC_H_ROOT;
tcm->tcm_handle = cl->common.classid;
tcm->tcm_info = cl->qdisc->handle;
nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
if (nest == NULL)
goto nla_put_failure;
if (nla_put_u32(skb, TCA_DRR_QUANTUM, cl->quantum))
goto nla_put_failure;
return nla_nest_end(skb, nest);
nla_put_failure:
nla_nest_cancel(skb, nest);
return -EMSGSIZE;
}
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 = qdisc_qlen_sum(cl->qdisc);
struct Qdisc *cl_q = cl->qdisc;
struct tc_drr_stats xstats;
memset(&xstats, 0, sizeof(xstats));
if (qlen)
xstats.deficit = cl->deficit;
if (gnet_stats_copy_basic(d, NULL, &cl->bstats, true) < 0 ||
gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
gnet_stats_copy_queue(d, cl_q->cpu_qstats, &cl_q->qstats, qlen) < 0)
return -1;
return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
}
static void drr_walk(struct Qdisc *sch, struct qdisc_walker *arg)
{
struct drr_sched *q = qdisc_priv(sch);
struct drr_class *cl;
unsigned int i;
if (arg->stop)
return;
for (i = 0; i < q->clhash.hashsize; i++) {
hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
if (!tc_qdisc_stats_dump(sch, (unsigned long)cl, arg))
return;
}
}
}
static struct drr_class *drr_classify(struct sk_buff *skb, struct Qdisc *sch,
int *qerr)
{
struct drr_sched *q = qdisc_priv(sch);
struct drr_class *cl;
struct tcf_result res;
struct tcf_proto *fl;
int result;
if (TC_H_MAJ(skb->priority ^ sch->handle) == 0) {
cl = drr_find_class(sch, skb->priority);
if (cl != NULL)
return cl;
}
*qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
fl = rcu_dereference_bh(q->filter_list);
result = tcf_classify(skb, NULL, fl, &res, false);
if (result >= 0) {
#ifdef CONFIG_NET_CLS_ACT
switch (result) {
case TC_ACT_QUEUED:
case TC_ACT_STOLEN:
case TC_ACT_TRAP:
*qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
fallthrough;
case TC_ACT_SHOT:
return NULL;
}
#endif
cl = (struct drr_class *)res.class;
if (cl == NULL)
cl = drr_find_class(sch, res.classid);
return cl;
}
return NULL;
}
static int drr_enqueue(struct sk_buff *skb, struct Qdisc *sch,
struct sk_buff **to_free)
{
unsigned int len = qdisc_pkt_len(skb);
struct drr_sched *q = qdisc_priv(sch);
struct drr_class *cl;
int err = 0;
bool first;
cl = drr_classify(skb, sch, &err);
if (cl == NULL) {
if (err & __NET_XMIT_BYPASS)
qdisc_qstats_drop(sch);
__qdisc_drop(skb, to_free);
return err;
}
first = !cl->qdisc->q.qlen;
err = qdisc_enqueue(skb, cl->qdisc, to_free);
if (unlikely(err != NET_XMIT_SUCCESS)) {
if (net_xmit_drop_count(err)) {
cl->qstats.drops++;
qdisc_qstats_drop(sch);
}
return err;
}
if (first) {
list_add_tail(&cl->alist, &q->active);
cl->deficit = cl->quantum;
}
sch->qstats.backlog += len;
sch->q.qlen++;
return err;
}
static struct sk_buff *drr_dequeue(struct Qdisc *sch)
{
struct drr_sched *q = qdisc_priv(sch);
struct drr_class *cl;
struct sk_buff *skb;
unsigned int len;
if (list_empty(&q->active))
goto out;
while (1) {
cl = list_first_entry(&q->active, struct drr_class, alist);
skb = cl->qdisc->ops->peek(cl->qdisc);
if (skb == NULL) {
qdisc_warn_nonwc(__func__, cl->qdisc);
goto out;
}
len = qdisc_pkt_len(skb);
if (len <= cl->deficit) {
cl->deficit -= len;
skb = qdisc_dequeue_peeked(cl->qdisc);
if (unlikely(skb == NULL))
goto out;
if (cl->qdisc->q.qlen == 0)
list_del(&cl->alist);
bstats_update(&cl->bstats, skb);
qdisc_bstats_update(sch, skb);
qdisc_qstats_backlog_dec(sch, skb);
sch->q.qlen--;
return skb;
}
cl->deficit += cl->quantum;
list_move_tail(&cl->alist, &q->active);
}
out:
return NULL;
}
static int drr_init_qdisc(struct Qdisc *sch, struct nlattr *opt,
struct netlink_ext_ack *extack)
{
struct drr_sched *q = qdisc_priv(sch);
int err;
err = tcf_block_get(&q->block, &q->filter_list, sch, extack);
if (err)
return err;
err = qdisc_class_hash_init(&q->clhash);
if (err < 0)
return err;
INIT_LIST_HEAD(&q->active);
return 0;
}
static void drr_reset_qdisc(struct Qdisc *sch)
{
struct drr_sched *q = qdisc_priv(sch);
struct drr_class *cl;
unsigned int i;
for (i = 0; i < q->clhash.hashsize; i++) {
hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
if (cl->qdisc->q.qlen)
list_del(&cl->alist);
qdisc_reset(cl->qdisc);
}
}
}
static void drr_destroy_qdisc(struct Qdisc *sch)
{
struct drr_sched *q = qdisc_priv(sch);
struct drr_class *cl;
struct hlist_node *next;
unsigned int i;
tcf_block_put(q->block);
for (i = 0; i < q->clhash.hashsize; i++) {
hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i],
common.hnode)
drr_destroy_class(sch, cl);
}
qdisc_class_hash_destroy(&q->clhash);
}
static const struct Qdisc_class_ops drr_class_ops = {
.change = drr_change_class,
.delete = drr_delete_class,
.find = drr_search_class,
.tcf_block = drr_tcf_block,
.bind_tcf = drr_bind_tcf,
.unbind_tcf = drr_unbind_tcf,
.graft = drr_graft_class,
.leaf = drr_class_leaf,
.qlen_notify = drr_qlen_notify,
.dump = drr_dump_class,
.dump_stats = drr_dump_class_stats,
.walk = drr_walk,
};
static struct Qdisc_ops drr_qdisc_ops __read_mostly = {
.cl_ops = &drr_class_ops,
.id = "drr",
.priv_size = sizeof(struct drr_sched),
.enqueue = drr_enqueue,
.dequeue = drr_dequeue,
.peek = qdisc_peek_dequeued,
.init = drr_init_qdisc,
.reset = drr_reset_qdisc,
.destroy = drr_destroy_qdisc,
.owner = THIS_MODULE,
};
MODULE_ALIAS_NET_SCH("drr");
static int __init drr_init(void)
{
return register_qdisc(&drr_qdisc_ops);
}
static void __exit drr_exit(void)
{
unregister_qdisc(&drr_qdisc_ops);
}
module_init(drr_init);
module_exit(drr_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Deficit Round Robin scheduler");