mirror of
https://github.com/torvalds/linux.git
synced 2024-11-12 15:11:50 +00:00
68d47a137c
Pull cgroup hierarchy update from Tejun Heo: "Currently, different cgroup subsystems handle nested cgroups completely differently. There's no consistency among subsystems and the behaviors often are outright broken. People at least seem to agree that the broken hierarhcy behaviors need to be weeded out if any progress is gonna be made on this front and that the fallouts from deprecating the broken behaviors should be acceptable especially given that the current behaviors don't make much sense when nested. This patch makes cgroup emit warning messages if cgroups for subsystems with broken hierarchy behavior are nested to prepare for fixing them in the future. This was put in a separate branch because more related changes were expected (didn't make it this round) and the memory cgroup wanted to pull in this and make changes on top." * 'for-3.7-hierarchy' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: mark subsystems with broken hierarchy support and whine if cgroups are nested for them
311 lines
6.9 KiB
C
311 lines
6.9 KiB
C
/*
|
|
* net/sched/cls_cgroup.c Control Group Classifier
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*
|
|
* Authors: Thomas Graf <tgraf@suug.ch>
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/types.h>
|
|
#include <linux/string.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/skbuff.h>
|
|
#include <linux/cgroup.h>
|
|
#include <linux/rcupdate.h>
|
|
#include <net/rtnetlink.h>
|
|
#include <net/pkt_cls.h>
|
|
#include <net/sock.h>
|
|
#include <net/cls_cgroup.h>
|
|
|
|
static inline struct cgroup_cls_state *cgrp_cls_state(struct cgroup *cgrp)
|
|
{
|
|
return container_of(cgroup_subsys_state(cgrp, net_cls_subsys_id),
|
|
struct cgroup_cls_state, css);
|
|
}
|
|
|
|
static inline struct cgroup_cls_state *task_cls_state(struct task_struct *p)
|
|
{
|
|
return container_of(task_subsys_state(p, net_cls_subsys_id),
|
|
struct cgroup_cls_state, css);
|
|
}
|
|
|
|
static struct cgroup_subsys_state *cgrp_create(struct cgroup *cgrp)
|
|
{
|
|
struct cgroup_cls_state *cs;
|
|
|
|
cs = kzalloc(sizeof(*cs), GFP_KERNEL);
|
|
if (!cs)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
if (cgrp->parent)
|
|
cs->classid = cgrp_cls_state(cgrp->parent)->classid;
|
|
|
|
return &cs->css;
|
|
}
|
|
|
|
static void cgrp_destroy(struct cgroup *cgrp)
|
|
{
|
|
kfree(cgrp_cls_state(cgrp));
|
|
}
|
|
|
|
static u64 read_classid(struct cgroup *cgrp, struct cftype *cft)
|
|
{
|
|
return cgrp_cls_state(cgrp)->classid;
|
|
}
|
|
|
|
static int write_classid(struct cgroup *cgrp, struct cftype *cft, u64 value)
|
|
{
|
|
cgrp_cls_state(cgrp)->classid = (u32) value;
|
|
return 0;
|
|
}
|
|
|
|
static struct cftype ss_files[] = {
|
|
{
|
|
.name = "classid",
|
|
.read_u64 = read_classid,
|
|
.write_u64 = write_classid,
|
|
},
|
|
{ } /* terminate */
|
|
};
|
|
|
|
struct cgroup_subsys net_cls_subsys = {
|
|
.name = "net_cls",
|
|
.create = cgrp_create,
|
|
.destroy = cgrp_destroy,
|
|
.subsys_id = net_cls_subsys_id,
|
|
.base_cftypes = ss_files,
|
|
.module = THIS_MODULE,
|
|
|
|
/*
|
|
* While net_cls cgroup has the rudimentary hierarchy support of
|
|
* inheriting the parent's classid on cgroup creation, it doesn't
|
|
* properly propagates config changes in ancestors to their
|
|
* descendents. A child should follow the parent's configuration
|
|
* but be allowed to override it. Fix it and remove the following.
|
|
*/
|
|
.broken_hierarchy = true,
|
|
};
|
|
|
|
struct cls_cgroup_head {
|
|
u32 handle;
|
|
struct tcf_exts exts;
|
|
struct tcf_ematch_tree ematches;
|
|
};
|
|
|
|
static int cls_cgroup_classify(struct sk_buff *skb, const struct tcf_proto *tp,
|
|
struct tcf_result *res)
|
|
{
|
|
struct cls_cgroup_head *head = tp->root;
|
|
u32 classid;
|
|
|
|
rcu_read_lock();
|
|
classid = task_cls_state(current)->classid;
|
|
rcu_read_unlock();
|
|
|
|
/*
|
|
* Due to the nature of the classifier it is required to ignore all
|
|
* packets originating from softirq context as accessing `current'
|
|
* would lead to false results.
|
|
*
|
|
* This test assumes that all callers of dev_queue_xmit() explicitely
|
|
* disable bh. Knowing this, it is possible to detect softirq based
|
|
* calls by looking at the number of nested bh disable calls because
|
|
* softirqs always disables bh.
|
|
*/
|
|
if (in_serving_softirq()) {
|
|
/* If there is an sk_classid we'll use that. */
|
|
if (!skb->sk)
|
|
return -1;
|
|
classid = skb->sk->sk_classid;
|
|
}
|
|
|
|
if (!classid)
|
|
return -1;
|
|
|
|
if (!tcf_em_tree_match(skb, &head->ematches, NULL))
|
|
return -1;
|
|
|
|
res->classid = classid;
|
|
res->class = 0;
|
|
return tcf_exts_exec(skb, &head->exts, res);
|
|
}
|
|
|
|
static unsigned long cls_cgroup_get(struct tcf_proto *tp, u32 handle)
|
|
{
|
|
return 0UL;
|
|
}
|
|
|
|
static void cls_cgroup_put(struct tcf_proto *tp, unsigned long f)
|
|
{
|
|
}
|
|
|
|
static int cls_cgroup_init(struct tcf_proto *tp)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static const struct tcf_ext_map cgroup_ext_map = {
|
|
.action = TCA_CGROUP_ACT,
|
|
.police = TCA_CGROUP_POLICE,
|
|
};
|
|
|
|
static const struct nla_policy cgroup_policy[TCA_CGROUP_MAX + 1] = {
|
|
[TCA_CGROUP_EMATCHES] = { .type = NLA_NESTED },
|
|
};
|
|
|
|
static int cls_cgroup_change(struct tcf_proto *tp, unsigned long base,
|
|
u32 handle, struct nlattr **tca,
|
|
unsigned long *arg)
|
|
{
|
|
struct nlattr *tb[TCA_CGROUP_MAX + 1];
|
|
struct cls_cgroup_head *head = tp->root;
|
|
struct tcf_ematch_tree t;
|
|
struct tcf_exts e;
|
|
int err;
|
|
|
|
if (!tca[TCA_OPTIONS])
|
|
return -EINVAL;
|
|
|
|
if (head == NULL) {
|
|
if (!handle)
|
|
return -EINVAL;
|
|
|
|
head = kzalloc(sizeof(*head), GFP_KERNEL);
|
|
if (head == NULL)
|
|
return -ENOBUFS;
|
|
|
|
head->handle = handle;
|
|
|
|
tcf_tree_lock(tp);
|
|
tp->root = head;
|
|
tcf_tree_unlock(tp);
|
|
}
|
|
|
|
if (handle != head->handle)
|
|
return -ENOENT;
|
|
|
|
err = nla_parse_nested(tb, TCA_CGROUP_MAX, tca[TCA_OPTIONS],
|
|
cgroup_policy);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
err = tcf_exts_validate(tp, tb, tca[TCA_RATE], &e, &cgroup_ext_map);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
err = tcf_em_tree_validate(tp, tb[TCA_CGROUP_EMATCHES], &t);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
tcf_exts_change(tp, &head->exts, &e);
|
|
tcf_em_tree_change(tp, &head->ematches, &t);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void cls_cgroup_destroy(struct tcf_proto *tp)
|
|
{
|
|
struct cls_cgroup_head *head = tp->root;
|
|
|
|
if (head) {
|
|
tcf_exts_destroy(tp, &head->exts);
|
|
tcf_em_tree_destroy(tp, &head->ematches);
|
|
kfree(head);
|
|
}
|
|
}
|
|
|
|
static int cls_cgroup_delete(struct tcf_proto *tp, unsigned long arg)
|
|
{
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
static void cls_cgroup_walk(struct tcf_proto *tp, struct tcf_walker *arg)
|
|
{
|
|
struct cls_cgroup_head *head = tp->root;
|
|
|
|
if (arg->count < arg->skip)
|
|
goto skip;
|
|
|
|
if (arg->fn(tp, (unsigned long) head, arg) < 0) {
|
|
arg->stop = 1;
|
|
return;
|
|
}
|
|
skip:
|
|
arg->count++;
|
|
}
|
|
|
|
static int cls_cgroup_dump(struct tcf_proto *tp, unsigned long fh,
|
|
struct sk_buff *skb, struct tcmsg *t)
|
|
{
|
|
struct cls_cgroup_head *head = tp->root;
|
|
unsigned char *b = skb_tail_pointer(skb);
|
|
struct nlattr *nest;
|
|
|
|
t->tcm_handle = head->handle;
|
|
|
|
nest = nla_nest_start(skb, TCA_OPTIONS);
|
|
if (nest == NULL)
|
|
goto nla_put_failure;
|
|
|
|
if (tcf_exts_dump(skb, &head->exts, &cgroup_ext_map) < 0 ||
|
|
tcf_em_tree_dump(skb, &head->ematches, TCA_CGROUP_EMATCHES) < 0)
|
|
goto nla_put_failure;
|
|
|
|
nla_nest_end(skb, nest);
|
|
|
|
if (tcf_exts_dump_stats(skb, &head->exts, &cgroup_ext_map) < 0)
|
|
goto nla_put_failure;
|
|
|
|
return skb->len;
|
|
|
|
nla_put_failure:
|
|
nlmsg_trim(skb, b);
|
|
return -1;
|
|
}
|
|
|
|
static struct tcf_proto_ops cls_cgroup_ops __read_mostly = {
|
|
.kind = "cgroup",
|
|
.init = cls_cgroup_init,
|
|
.change = cls_cgroup_change,
|
|
.classify = cls_cgroup_classify,
|
|
.destroy = cls_cgroup_destroy,
|
|
.get = cls_cgroup_get,
|
|
.put = cls_cgroup_put,
|
|
.delete = cls_cgroup_delete,
|
|
.walk = cls_cgroup_walk,
|
|
.dump = cls_cgroup_dump,
|
|
.owner = THIS_MODULE,
|
|
};
|
|
|
|
static int __init init_cgroup_cls(void)
|
|
{
|
|
int ret;
|
|
|
|
ret = cgroup_load_subsys(&net_cls_subsys);
|
|
if (ret)
|
|
goto out;
|
|
|
|
ret = register_tcf_proto_ops(&cls_cgroup_ops);
|
|
if (ret)
|
|
cgroup_unload_subsys(&net_cls_subsys);
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static void __exit exit_cgroup_cls(void)
|
|
{
|
|
unregister_tcf_proto_ops(&cls_cgroup_ops);
|
|
|
|
cgroup_unload_subsys(&net_cls_subsys);
|
|
}
|
|
|
|
module_init(init_cgroup_cls);
|
|
module_exit(exit_cgroup_cls);
|
|
MODULE_LICENSE("GPL");
|