3b13758f51
The classid of a process is changed either when a process is moved to or from a cgroup or when the net_cls.classid file is updated. Previously net_cls only supported propogating these changes to the cgroup's related sockets when a process was added or removed from the cgroup. This means it was neccessary to remove and re-add all processes to a cgroup in order to update its classid. This change introduces support for doing this dynamically - i.e. when the value is changed in the net_cls_classid file, this will also trigger an update to the classid associated with all sockets controlled by the cgroup. This mimics the behaviour of other cgroup subsystems. net_prio circumvents this issue by storing an index into a table with each socket (and so any updates to the table, don't require updating the value associated with the socket). net_cls, however, passes the socket the classid directly, and so this additional step is needed. Signed-off-by: Nina Schiff <ninasc@fb.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
123 lines
2.8 KiB
C
123 lines
2.8 KiB
C
/*
|
|
* net/core/netclassid_cgroup.c Classid Cgroupfs Handling
|
|
*
|
|
* 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/cgroup.h>
|
|
#include <linux/fdtable.h>
|
|
#include <net/cls_cgroup.h>
|
|
#include <net/sock.h>
|
|
|
|
static inline struct cgroup_cls_state *css_cls_state(struct cgroup_subsys_state *css)
|
|
{
|
|
return css ? container_of(css, struct cgroup_cls_state, css) : NULL;
|
|
}
|
|
|
|
struct cgroup_cls_state *task_cls_state(struct task_struct *p)
|
|
{
|
|
return css_cls_state(task_css_check(p, net_cls_cgrp_id,
|
|
rcu_read_lock_bh_held()));
|
|
}
|
|
EXPORT_SYMBOL_GPL(task_cls_state);
|
|
|
|
static struct cgroup_subsys_state *
|
|
cgrp_css_alloc(struct cgroup_subsys_state *parent_css)
|
|
{
|
|
struct cgroup_cls_state *cs;
|
|
|
|
cs = kzalloc(sizeof(*cs), GFP_KERNEL);
|
|
if (!cs)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
return &cs->css;
|
|
}
|
|
|
|
static int cgrp_css_online(struct cgroup_subsys_state *css)
|
|
{
|
|
struct cgroup_cls_state *cs = css_cls_state(css);
|
|
struct cgroup_cls_state *parent = css_cls_state(css->parent);
|
|
|
|
if (parent)
|
|
cs->classid = parent->classid;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void cgrp_css_free(struct cgroup_subsys_state *css)
|
|
{
|
|
kfree(css_cls_state(css));
|
|
}
|
|
|
|
static int update_classid_sock(const void *v, struct file *file, unsigned n)
|
|
{
|
|
int err;
|
|
struct socket *sock = sock_from_file(file, &err);
|
|
|
|
if (sock)
|
|
sock->sk->sk_classid = (u32)(unsigned long)v;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void update_classid(struct cgroup_subsys_state *css, void *v)
|
|
{
|
|
struct css_task_iter it;
|
|
struct task_struct *p;
|
|
|
|
css_task_iter_start(css, &it);
|
|
while ((p = css_task_iter_next(&it))) {
|
|
task_lock(p);
|
|
iterate_fd(p->files, 0, update_classid_sock, v);
|
|
task_unlock(p);
|
|
}
|
|
css_task_iter_end(&it);
|
|
}
|
|
|
|
static void cgrp_attach(struct cgroup_subsys_state *css,
|
|
struct cgroup_taskset *tset)
|
|
{
|
|
update_classid(css,
|
|
(void *)(unsigned long)css_cls_state(css)->classid);
|
|
}
|
|
|
|
static u64 read_classid(struct cgroup_subsys_state *css, struct cftype *cft)
|
|
{
|
|
return css_cls_state(css)->classid;
|
|
}
|
|
|
|
static int write_classid(struct cgroup_subsys_state *css, struct cftype *cft,
|
|
u64 value)
|
|
{
|
|
struct cgroup_cls_state *cs = css_cls_state(css);
|
|
|
|
cs->classid = (u32)value;
|
|
|
|
update_classid(css, (void *)(unsigned long)cs->classid);
|
|
return 0;
|
|
}
|
|
|
|
static struct cftype ss_files[] = {
|
|
{
|
|
.name = "classid",
|
|
.read_u64 = read_classid,
|
|
.write_u64 = write_classid,
|
|
},
|
|
{ } /* terminate */
|
|
};
|
|
|
|
struct cgroup_subsys net_cls_cgrp_subsys = {
|
|
.css_alloc = cgrp_css_alloc,
|
|
.css_online = cgrp_css_online,
|
|
.css_free = cgrp_css_free,
|
|
.attach = cgrp_attach,
|
|
.legacy_cftypes = ss_files,
|
|
};
|