2 * net/core/netclassid_cgroup.c Classid Cgroupfs Handling
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
9 * Authors: Thomas Graf <tgraf@suug.ch>
12 #include <linux/slab.h>
13 #include <linux/cgroup.h>
14 #include <linux/fdtable.h>
15 #include <net/cls_cgroup.h>
18 static inline struct cgroup_cls_state *css_cls_state(struct cgroup_subsys_state *css)
20 return css ? container_of(css, struct cgroup_cls_state, css) : NULL;
23 struct cgroup_cls_state *task_cls_state(struct task_struct *p)
25 return css_cls_state(task_css_check(p, net_cls_cgrp_id,
26 rcu_read_lock_bh_held()));
28 EXPORT_SYMBOL_GPL(task_cls_state);
30 static struct cgroup_subsys_state *
31 cgrp_css_alloc(struct cgroup_subsys_state *parent_css)
33 struct cgroup_cls_state *cs;
35 cs = kzalloc(sizeof(*cs), GFP_KERNEL);
37 return ERR_PTR(-ENOMEM);
42 static int cgrp_css_online(struct cgroup_subsys_state *css)
44 struct cgroup_cls_state *cs = css_cls_state(css);
45 struct cgroup_cls_state *parent = css_cls_state(css->parent);
48 cs->classid = parent->classid;
53 static void cgrp_css_free(struct cgroup_subsys_state *css)
55 kfree(css_cls_state(css));
59 * To avoid freezing of sockets creation for tasks with big number of threads
60 * and opened sockets lets release file_lock every 1000 iterated descriptors.
61 * New sockets will already have been created with new classid.
64 struct update_classid_context {
69 #define UPDATE_CLASSID_BATCH 1000
71 static int update_classid_sock(const void *v, struct file *file, unsigned n)
74 struct update_classid_context *ctx = (void *)v;
75 struct socket *sock = sock_from_file(file, &err);
78 spin_lock(&cgroup_sk_update_lock);
79 sock_cgroup_set_classid(&sock->sk->sk_cgrp_data, ctx->classid);
80 spin_unlock(&cgroup_sk_update_lock);
82 if (--ctx->batch == 0) {
83 ctx->batch = UPDATE_CLASSID_BATCH;
89 static void update_classid_task(struct task_struct *p, u32 classid)
91 struct update_classid_context ctx = {
93 .batch = UPDATE_CLASSID_BATCH
99 fd = iterate_fd(p->files, fd, update_classid_sock, &ctx);
105 static void cgrp_attach(struct cgroup_taskset *tset)
107 struct cgroup_subsys_state *css;
108 struct task_struct *p;
110 cgroup_taskset_for_each(p, css, tset) {
111 update_classid_task(p, css_cls_state(css)->classid);
115 static u64 read_classid(struct cgroup_subsys_state *css, struct cftype *cft)
117 return css_cls_state(css)->classid;
120 static int write_classid(struct cgroup_subsys_state *css, struct cftype *cft,
123 struct cgroup_cls_state *cs = css_cls_state(css);
124 struct css_task_iter it;
125 struct task_struct *p;
127 cgroup_sk_alloc_disable();
129 cs->classid = (u32)value;
131 css_task_iter_start(css, &it);
132 while ((p = css_task_iter_next(&it))) {
133 update_classid_task(p, cs->classid);
136 css_task_iter_end(&it);
141 static struct cftype ss_files[] = {
144 .read_u64 = read_classid,
145 .write_u64 = write_classid,
150 struct cgroup_subsys net_cls_cgrp_subsys = {
151 .css_alloc = cgrp_css_alloc,
152 .css_online = cgrp_css_online,
153 .css_free = cgrp_css_free,
154 .attach = cgrp_attach,
155 .legacy_cftypes = ss_files,