1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_CGROUP_H
3#define _LINUX_CGROUP_H
4/*
5 * cgroup interface
6 *
7 * Copyright (C) 2003 BULL SA
8 * Copyright (C) 2004-2006 Silicon Graphics, Inc.
9 *
10 */
11
12#include <linux/sched.h>
13#include <linux/cpumask.h>
14#include <linux/nodemask.h>
15#include <linux/rculist.h>
16#include <linux/cgroupstats.h>
17#include <linux/fs.h>
18#include <linux/seq_file.h>
19#include <linux/kernfs.h>
20#include <linux/jump_label.h>
21#include <linux/types.h>
22#include <linux/ns_common.h>
23#include <linux/nsproxy.h>
24#include <linux/user_namespace.h>
25#include <linux/refcount.h>
26#include <linux/kernel_stat.h>
27
28#include <linux/cgroup-defs.h>
29
30struct kernel_clone_args;
31
32#ifdef CONFIG_CGROUPS
33
34/*
35 * All weight knobs on the default hierarchy should use the following min,
36 * default and max values. The default value is the logarithmic center of
37 * MIN and MAX and allows 100x to be expressed in both directions.
38 */
39#define CGROUP_WEIGHT_MIN 1
40#define CGROUP_WEIGHT_DFL 100
41#define CGROUP_WEIGHT_MAX 10000
42
43enum {
44 CSS_TASK_ITER_PROCS = (1U << 0), /* walk only threadgroup leaders */
45 CSS_TASK_ITER_THREADED = (1U << 1), /* walk all threaded css_sets in the domain */
46 CSS_TASK_ITER_SKIPPED = (1U << 16), /* internal flags */
47};
48
49/* a css_task_iter should be treated as an opaque object */
50struct css_task_iter {
51 struct cgroup_subsys *ss;
52 unsigned int flags;
53
54 struct list_head *cset_pos;
55 struct list_head *cset_head;
56
57 struct list_head *tcset_pos;
58 struct list_head *tcset_head;
59
60 struct list_head *task_pos;
61
62 struct list_head *cur_tasks_head;
63 struct css_set *cur_cset;
64 struct css_set *cur_dcset;
65 struct task_struct *cur_task;
66 struct list_head iters_node; /* css_set->task_iters */
67};
68
69extern struct file_system_type cgroup_fs_type;
70extern struct cgroup_root cgrp_dfl_root;
71extern struct css_set init_css_set;
72
73#define SUBSYS(_x) extern struct cgroup_subsys _x ## _cgrp_subsys;
74#include <linux/cgroup_subsys.h>
75#undef SUBSYS
76
77#define SUBSYS(_x) \
78 extern struct static_key_true _x ## _cgrp_subsys_enabled_key; \
79 extern struct static_key_true _x ## _cgrp_subsys_on_dfl_key;
80#include <linux/cgroup_subsys.h>
81#undef SUBSYS
82
83/**
84 * cgroup_subsys_enabled - fast test on whether a subsys is enabled
85 * @ss: subsystem in question
86 */
87#define cgroup_subsys_enabled(ss) \
88 static_branch_likely(&ss ## _enabled_key)
89
90/**
91 * cgroup_subsys_on_dfl - fast test on whether a subsys is on default hierarchy
92 * @ss: subsystem in question
93 */
94#define cgroup_subsys_on_dfl(ss) \
95 static_branch_likely(&ss ## _on_dfl_key)
96
97bool css_has_online_children(struct cgroup_subsys_state *css);
98struct cgroup_subsys_state *css_from_id(int id, struct cgroup_subsys *ss);
99struct cgroup_subsys_state *cgroup_e_css(struct cgroup *cgroup,
100 struct cgroup_subsys *ss);
101struct cgroup_subsys_state *cgroup_get_e_css(struct cgroup *cgroup,
102 struct cgroup_subsys *ss);
103struct cgroup_subsys_state *css_tryget_online_from_dir(struct dentry *dentry,
104 struct cgroup_subsys *ss);
105
106struct cgroup *cgroup_get_from_path(const char *path);
107struct cgroup *cgroup_get_from_fd(int fd);
108struct cgroup *cgroup_v1v2_get_from_fd(int fd);
109
110int cgroup_attach_task_all(struct task_struct *from, struct task_struct *);
111int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from);
112
113int cgroup_add_dfl_cftypes(struct cgroup_subsys *ss, struct cftype *cfts);
114int cgroup_add_legacy_cftypes(struct cgroup_subsys *ss, struct cftype *cfts);
115int cgroup_rm_cftypes(struct cftype *cfts);
116void cgroup_file_notify(struct cgroup_file *cfile);
117void cgroup_file_show(struct cgroup_file *cfile, bool show);
118
119int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry);
120int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns,
121 struct pid *pid, struct task_struct *tsk);
122
123void cgroup_fork(struct task_struct *p);
124extern int cgroup_can_fork(struct task_struct *p,
125 struct kernel_clone_args *kargs);
126extern void cgroup_cancel_fork(struct task_struct *p,
127 struct kernel_clone_args *kargs);
128extern void cgroup_post_fork(struct task_struct *p,
129 struct kernel_clone_args *kargs);
130void cgroup_exit(struct task_struct *p);
131void cgroup_release(struct task_struct *p);
132void cgroup_free(struct task_struct *p);
133
134int cgroup_init_early(void);
135int cgroup_init(void);
136
137int cgroup_parse_float(const char *input, unsigned dec_shift, s64 *v);
138
139/*
140 * Iteration helpers and macros.
141 */
142
143struct cgroup_subsys_state *css_next_child(struct cgroup_subsys_state *pos,
144 struct cgroup_subsys_state *parent);
145struct cgroup_subsys_state *css_next_descendant_pre(struct cgroup_subsys_state *pos,
146 struct cgroup_subsys_state *css);
147struct cgroup_subsys_state *css_rightmost_descendant(struct cgroup_subsys_state *pos);
148struct cgroup_subsys_state *css_next_descendant_post(struct cgroup_subsys_state *pos,
149 struct cgroup_subsys_state *css);
150
151struct task_struct *cgroup_taskset_first(struct cgroup_taskset *tset,
152 struct cgroup_subsys_state **dst_cssp);
153struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset,
154 struct cgroup_subsys_state **dst_cssp);
155
156void css_task_iter_start(struct cgroup_subsys_state *css, unsigned int flags,
157 struct css_task_iter *it);
158struct task_struct *css_task_iter_next(struct css_task_iter *it);
159void css_task_iter_end(struct css_task_iter *it);
160
161/**
162 * css_for_each_child - iterate through children of a css
163 * @pos: the css * to use as the loop cursor
164 * @parent: css whose children to walk
165 *
166 * Walk @parent's children. Must be called under rcu_read_lock().
167 *
168 * If a subsystem synchronizes ->css_online() and the start of iteration, a
169 * css which finished ->css_online() is guaranteed to be visible in the
170 * future iterations and will stay visible until the last reference is put.
171 * A css which hasn't finished ->css_online() or already finished
172 * ->css_offline() may show up during traversal. It's each subsystem's
173 * responsibility to synchronize against on/offlining.
174 *
175 * It is allowed to temporarily drop RCU read lock during iteration. The
176 * caller is responsible for ensuring that @pos remains accessible until
177 * the start of the next iteration by, for example, bumping the css refcnt.
178 */
179#define css_for_each_child(pos, parent) \
180 for ((pos) = css_next_child(NULL, (parent)); (pos); \
181 (pos) = css_next_child((pos), (parent)))
182
183/**
184 * css_for_each_descendant_pre - pre-order walk of a css's descendants
185 * @pos: the css * to use as the loop cursor
186 * @root: css whose descendants to walk
187 *
188 * Walk @root's descendants. @root is included in the iteration and the
189 * first node to be visited. Must be called under rcu_read_lock().
190 *
191 * If a subsystem synchronizes ->css_online() and the start of iteration, a
192 * css which finished ->css_online() is guaranteed to be visible in the
193 * future iterations and will stay visible until the last reference is put.
194 * A css which hasn't finished ->css_online() or already finished
195 * ->css_offline() may show up during traversal. It's each subsystem's
196 * responsibility to synchronize against on/offlining.
197 *
198 * For example, the following guarantees that a descendant can't escape
199 * state updates of its ancestors.
200 *
201 * my_online(@css)
202 * {
203 * Lock @css's parent and @css;
204 * Inherit state from the parent;
205 * Unlock both.
206 * }
207 *
208 * my_update_state(@css)
209 * {
210 * css_for_each_descendant_pre(@pos, @css) {
211 * Lock @pos;
212 * if (@pos == @css)
213 * Update @css's state;
214 * else
215 * Verify @pos is alive and inherit state from its parent;
216 * Unlock @pos;
217 * }
218 * }
219 *
220 * As long as the inheriting step, including checking the parent state, is
221 * enclosed inside @pos locking, double-locking the parent isn't necessary
222 * while inheriting. The state update to the parent is guaranteed to be
223 * visible by walking order and, as long as inheriting operations to the
224 * same @pos are atomic to each other, multiple updates racing each other
225 * still result in the correct state. It's guaranateed that at least one
226 * inheritance happens for any css after the latest update to its parent.
227 *
228 * If checking parent's state requires locking the parent, each inheriting
229 * iteration should lock and unlock both @pos->parent and @pos.
230 *
231 * Alternatively, a subsystem may choose to use a single global lock to
232 * synchronize ->css_online() and ->css_offline() against tree-walking
233 * operations.
234 *
235 * It is allowed to temporarily drop RCU read lock during iteration. The
236 * caller is responsible for ensuring that @pos remains accessible until
237 * the start of the next iteration by, for example, bumping the css refcnt.
238 */
239#define css_for_each_descendant_pre(pos, css) \
240 for ((pos) = css_next_descendant_pre(NULL, (css)); (pos); \
241 (pos) = css_next_descendant_pre((pos), (css)))
242
243/**
244 * css_for_each_descendant_post - post-order walk of a css's descendants
245 * @pos: the css * to use as the loop cursor
246 * @css: css whose descendants to walk
247 *
248 * Similar to css_for_each_descendant_pre() but performs post-order
249 * traversal instead. @root is included in the iteration and the last
250 * node to be visited.
251 *
252 * If a subsystem synchronizes ->css_online() and the start of iteration, a
253 * css which finished ->css_online() is guaranteed to be visible in the
254 * future iterations and will stay visible until the last reference is put.
255 * A css which hasn't finished ->css_online() or already finished
256 * ->css_offline() may show up during traversal. It's each subsystem's
257 * responsibility to synchronize against on/offlining.
258 *
259 * Note that the walk visibility guarantee example described in pre-order
260 * walk doesn't apply the same to post-order walks.
261 */
262#define css_for_each_descendant_post(pos, css) \
263 for ((pos) = css_next_descendant_post(NULL, (css)); (pos); \
264 (pos) = css_next_descendant_post((pos), (css)))
265
266/**
267 * cgroup_taskset_for_each - iterate cgroup_taskset
268 * @task: the loop cursor
269 * @dst_css: the destination css
270 * @tset: taskset to iterate
271 *
272 * @tset may contain multiple tasks and they may belong to multiple
273 * processes.
274 *
275 * On the v2 hierarchy, there may be tasks from multiple processes and they
276 * may not share the source or destination csses.
277 *
278 * On traditional hierarchies, when there are multiple tasks in @tset, if a
279 * task of a process is in @tset, all tasks of the process are in @tset.
280 * Also, all are guaranteed to share the same source and destination csses.
281 *
282 * Iteration is not in any specific order.
283 */
284#define cgroup_taskset_for_each(task, dst_css, tset) \
285 for ((task) = cgroup_taskset_first((tset), &(dst_css)); \
286 (task); \
287 (task) = cgroup_taskset_next((tset), &(dst_css)))
288
289/**
290 * cgroup_taskset_for_each_leader - iterate group leaders in a cgroup_taskset
291 * @leader: the loop cursor
292 * @dst_css: the destination css
293 * @tset: taskset to iterate
294 *
295 * Iterate threadgroup leaders of @tset. For single-task migrations, @tset
296 * may not contain any.
297 */
298#define cgroup_taskset_for_each_leader(leader, dst_css, tset) \
299 for ((leader) = cgroup_taskset_first((tset), &(dst_css)); \
300 (leader); \
301 (leader) = cgroup_taskset_next((tset), &(dst_css))) \
302 if ((leader) != (leader)->group_leader) \
303 ; \
304 else
305
306/*
307 * Inline functions.
308 */
309
310#ifdef CONFIG_DEBUG_CGROUP_REF
311void css_get(struct cgroup_subsys_state *css);
312void css_get_many(struct cgroup_subsys_state *css, unsigned int n);
313bool css_tryget(struct cgroup_subsys_state *css);
314bool css_tryget_online(struct cgroup_subsys_state *css);
315void css_put(struct cgroup_subsys_state *css);
316void css_put_many(struct cgroup_subsys_state *css, unsigned int n);
317#else
318#define CGROUP_REF_FN_ATTRS static inline
319#define CGROUP_REF_EXPORT(fn)
320#include <linux/cgroup_refcnt.h>
321#endif
322
323static inline u64 cgroup_id(const struct cgroup *cgrp)
324{
325 return cgrp->kn->id;
326}
327
328/**
329 * css_is_dying - test whether the specified css is dying
330 * @css: target css
331 *
332 * Test whether @css is in the process of offlining or already offline. In
333 * most cases, ->css_online() and ->css_offline() callbacks should be
334 * enough; however, the actual offline operations are RCU delayed and this
335 * test returns %true also when @css is scheduled to be offlined.
336 *
337 * This is useful, for example, when the use case requires synchronous
338 * behavior with respect to cgroup removal. cgroup removal schedules css
339 * offlining but the css can seem alive while the operation is being
340 * delayed. If the delay affects user visible semantics, this test can be
341 * used to resolve the situation.
342 */
343static inline bool css_is_dying(struct cgroup_subsys_state *css)
344{
345 return !(css->flags & CSS_NO_REF) && percpu_ref_is_dying(ref: &css->refcnt);
346}
347
348static inline void cgroup_get(struct cgroup *cgrp)
349{
350 css_get(css: &cgrp->self);
351}
352
353static inline bool cgroup_tryget(struct cgroup *cgrp)
354{
355 return css_tryget(css: &cgrp->self);
356}
357
358static inline void cgroup_put(struct cgroup *cgrp)
359{
360 css_put(css: &cgrp->self);
361}
362
363extern struct mutex cgroup_mutex;
364
365static inline void cgroup_lock(void)
366{
367 mutex_lock(&cgroup_mutex);
368}
369
370static inline void cgroup_unlock(void)
371{
372 mutex_unlock(lock: &cgroup_mutex);
373}
374
375/**
376 * task_css_set_check - obtain a task's css_set with extra access conditions
377 * @task: the task to obtain css_set for
378 * @__c: extra condition expression to be passed to rcu_dereference_check()
379 *
380 * A task's css_set is RCU protected, initialized and exited while holding
381 * task_lock(), and can only be modified while holding both cgroup_mutex
382 * and task_lock() while the task is alive. This macro verifies that the
383 * caller is inside proper critical section and returns @task's css_set.
384 *
385 * The caller can also specify additional allowed conditions via @__c, such
386 * as locks used during the cgroup_subsys::attach() methods.
387 */
388#ifdef CONFIG_PROVE_RCU
389extern spinlock_t css_set_lock;
390#define task_css_set_check(task, __c) \
391 rcu_dereference_check((task)->cgroups, \
392 rcu_read_lock_sched_held() || \
393 lockdep_is_held(&cgroup_mutex) || \
394 lockdep_is_held(&css_set_lock) || \
395 ((task)->flags & PF_EXITING) || (__c))
396#else
397#define task_css_set_check(task, __c) \
398 rcu_dereference((task)->cgroups)
399#endif
400
401/**
402 * task_css_check - obtain css for (task, subsys) w/ extra access conds
403 * @task: the target task
404 * @subsys_id: the target subsystem ID
405 * @__c: extra condition expression to be passed to rcu_dereference_check()
406 *
407 * Return the cgroup_subsys_state for the (@task, @subsys_id) pair. The
408 * synchronization rules are the same as task_css_set_check().
409 */
410#define task_css_check(task, subsys_id, __c) \
411 task_css_set_check((task), (__c))->subsys[(subsys_id)]
412
413/**
414 * task_css_set - obtain a task's css_set
415 * @task: the task to obtain css_set for
416 *
417 * See task_css_set_check().
418 */
419static inline struct css_set *task_css_set(struct task_struct *task)
420{
421 return task_css_set_check(task, false);
422}
423
424/**
425 * task_css - obtain css for (task, subsys)
426 * @task: the target task
427 * @subsys_id: the target subsystem ID
428 *
429 * See task_css_check().
430 */
431static inline struct cgroup_subsys_state *task_css(struct task_struct *task,
432 int subsys_id)
433{
434 return task_css_check(task, subsys_id, false);
435}
436
437/**
438 * task_get_css - find and get the css for (task, subsys)
439 * @task: the target task
440 * @subsys_id: the target subsystem ID
441 *
442 * Find the css for the (@task, @subsys_id) combination, increment a
443 * reference on and return it. This function is guaranteed to return a
444 * valid css. The returned css may already have been offlined.
445 */
446static inline struct cgroup_subsys_state *
447task_get_css(struct task_struct *task, int subsys_id)
448{
449 struct cgroup_subsys_state *css;
450
451 rcu_read_lock();
452 while (true) {
453 css = task_css(task, subsys_id);
454 /*
455 * Can't use css_tryget_online() here. A task which has
456 * PF_EXITING set may stay associated with an offline css.
457 * If such task calls this function, css_tryget_online()
458 * will keep failing.
459 */
460 if (likely(css_tryget(css)))
461 break;
462 cpu_relax();
463 }
464 rcu_read_unlock();
465 return css;
466}
467
468/**
469 * task_css_is_root - test whether a task belongs to the root css
470 * @task: the target task
471 * @subsys_id: the target subsystem ID
472 *
473 * Test whether @task belongs to the root css on the specified subsystem.
474 * May be invoked in any context.
475 */
476static inline bool task_css_is_root(struct task_struct *task, int subsys_id)
477{
478 return task_css_check(task, subsys_id, true) ==
479 init_css_set.subsys[subsys_id];
480}
481
482static inline struct cgroup *task_cgroup(struct task_struct *task,
483 int subsys_id)
484{
485 return task_css(task, subsys_id)->cgroup;
486}
487
488static inline struct cgroup *task_dfl_cgroup(struct task_struct *task)
489{
490 return task_css_set(task)->dfl_cgrp;
491}
492
493static inline struct cgroup *cgroup_parent(struct cgroup *cgrp)
494{
495 struct cgroup_subsys_state *parent_css = cgrp->self.parent;
496
497 if (parent_css)
498 return container_of(parent_css, struct cgroup, self);
499 return NULL;
500}
501
502/**
503 * cgroup_is_descendant - test ancestry
504 * @cgrp: the cgroup to be tested
505 * @ancestor: possible ancestor of @cgrp
506 *
507 * Test whether @cgrp is a descendant of @ancestor. It also returns %true
508 * if @cgrp == @ancestor. This function is safe to call as long as @cgrp
509 * and @ancestor are accessible.
510 */
511static inline bool cgroup_is_descendant(struct cgroup *cgrp,
512 struct cgroup *ancestor)
513{
514 if (cgrp->root != ancestor->root || cgrp->level < ancestor->level)
515 return false;
516 return cgrp->ancestors[ancestor->level] == ancestor;
517}
518
519/**
520 * cgroup_ancestor - find ancestor of cgroup
521 * @cgrp: cgroup to find ancestor of
522 * @ancestor_level: level of ancestor to find starting from root
523 *
524 * Find ancestor of cgroup at specified level starting from root if it exists
525 * and return pointer to it. Return NULL if @cgrp doesn't have ancestor at
526 * @ancestor_level.
527 *
528 * This function is safe to call as long as @cgrp is accessible.
529 */
530static inline struct cgroup *cgroup_ancestor(struct cgroup *cgrp,
531 int ancestor_level)
532{
533 if (ancestor_level < 0 || ancestor_level > cgrp->level)
534 return NULL;
535 return cgrp->ancestors[ancestor_level];
536}
537
538/**
539 * task_under_cgroup_hierarchy - test task's membership of cgroup ancestry
540 * @task: the task to be tested
541 * @ancestor: possible ancestor of @task's cgroup
542 *
543 * Tests whether @task's default cgroup hierarchy is a descendant of @ancestor.
544 * It follows all the same rules as cgroup_is_descendant, and only applies
545 * to the default hierarchy.
546 */
547static inline bool task_under_cgroup_hierarchy(struct task_struct *task,
548 struct cgroup *ancestor)
549{
550 struct css_set *cset = task_css_set(task);
551
552 return cgroup_is_descendant(cgrp: cset->dfl_cgrp, ancestor);
553}
554
555/* no synchronization, the result can only be used as a hint */
556static inline bool cgroup_is_populated(struct cgroup *cgrp)
557{
558 return cgrp->nr_populated_csets + cgrp->nr_populated_domain_children +
559 cgrp->nr_populated_threaded_children;
560}
561
562/* returns ino associated with a cgroup */
563static inline ino_t cgroup_ino(struct cgroup *cgrp)
564{
565 return kernfs_ino(kn: cgrp->kn);
566}
567
568/* cft/css accessors for cftype->write() operation */
569static inline struct cftype *of_cft(struct kernfs_open_file *of)
570{
571 return of->kn->priv;
572}
573
574struct cgroup_subsys_state *of_css(struct kernfs_open_file *of);
575
576/* cft/css accessors for cftype->seq_*() operations */
577static inline struct cftype *seq_cft(struct seq_file *seq)
578{
579 return of_cft(of: seq->private);
580}
581
582static inline struct cgroup_subsys_state *seq_css(struct seq_file *seq)
583{
584 return of_css(of: seq->private);
585}
586
587/*
588 * Name / path handling functions. All are thin wrappers around the kernfs
589 * counterparts and can be called under any context.
590 */
591
592static inline int cgroup_name(struct cgroup *cgrp, char *buf, size_t buflen)
593{
594 return kernfs_name(kn: cgrp->kn, buf, buflen);
595}
596
597static inline int cgroup_path(struct cgroup *cgrp, char *buf, size_t buflen)
598{
599 return kernfs_path(kn: cgrp->kn, buf, buflen);
600}
601
602static inline void pr_cont_cgroup_name(struct cgroup *cgrp)
603{
604 pr_cont_kernfs_name(kn: cgrp->kn);
605}
606
607static inline void pr_cont_cgroup_path(struct cgroup *cgrp)
608{
609 pr_cont_kernfs_path(kn: cgrp->kn);
610}
611
612bool cgroup_psi_enabled(void);
613
614static inline void cgroup_init_kthreadd(void)
615{
616 /*
617 * kthreadd is inherited by all kthreads, keep it in the root so
618 * that the new kthreads are guaranteed to stay in the root until
619 * initialization is finished.
620 */
621 current->no_cgroup_migration = 1;
622}
623
624static inline void cgroup_kthread_ready(void)
625{
626 /*
627 * This kthread finished initialization. The creator should have
628 * set PF_NO_SETAFFINITY if this kthread should stay in the root.
629 */
630 current->no_cgroup_migration = 0;
631}
632
633void cgroup_path_from_kernfs_id(u64 id, char *buf, size_t buflen);
634struct cgroup *cgroup_get_from_id(u64 id);
635#else /* !CONFIG_CGROUPS */
636
637struct cgroup_subsys_state;
638struct cgroup;
639
640static inline u64 cgroup_id(const struct cgroup *cgrp) { return 1; }
641static inline void css_get(struct cgroup_subsys_state *css) {}
642static inline void css_put(struct cgroup_subsys_state *css) {}
643static inline void cgroup_lock(void) {}
644static inline void cgroup_unlock(void) {}
645static inline int cgroup_attach_task_all(struct task_struct *from,
646 struct task_struct *t) { return 0; }
647static inline int cgroupstats_build(struct cgroupstats *stats,
648 struct dentry *dentry) { return -EINVAL; }
649
650static inline void cgroup_fork(struct task_struct *p) {}
651static inline int cgroup_can_fork(struct task_struct *p,
652 struct kernel_clone_args *kargs) { return 0; }
653static inline void cgroup_cancel_fork(struct task_struct *p,
654 struct kernel_clone_args *kargs) {}
655static inline void cgroup_post_fork(struct task_struct *p,
656 struct kernel_clone_args *kargs) {}
657static inline void cgroup_exit(struct task_struct *p) {}
658static inline void cgroup_release(struct task_struct *p) {}
659static inline void cgroup_free(struct task_struct *p) {}
660
661static inline int cgroup_init_early(void) { return 0; }
662static inline int cgroup_init(void) { return 0; }
663static inline void cgroup_init_kthreadd(void) {}
664static inline void cgroup_kthread_ready(void) {}
665
666static inline struct cgroup *cgroup_parent(struct cgroup *cgrp)
667{
668 return NULL;
669}
670
671static inline bool cgroup_psi_enabled(void)
672{
673 return false;
674}
675
676static inline bool task_under_cgroup_hierarchy(struct task_struct *task,
677 struct cgroup *ancestor)
678{
679 return true;
680}
681
682static inline void cgroup_path_from_kernfs_id(u64 id, char *buf, size_t buflen)
683{}
684#endif /* !CONFIG_CGROUPS */
685
686#ifdef CONFIG_CGROUPS
687/*
688 * cgroup scalable recursive statistics.
689 */
690void cgroup_rstat_updated(struct cgroup *cgrp, int cpu);
691void cgroup_rstat_flush(struct cgroup *cgrp);
692void cgroup_rstat_flush_hold(struct cgroup *cgrp);
693void cgroup_rstat_flush_release(void);
694
695/*
696 * Basic resource stats.
697 */
698#ifdef CONFIG_CGROUP_CPUACCT
699void cpuacct_charge(struct task_struct *tsk, u64 cputime);
700void cpuacct_account_field(struct task_struct *tsk, int index, u64 val);
701#else
702static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {}
703static inline void cpuacct_account_field(struct task_struct *tsk, int index,
704 u64 val) {}
705#endif
706
707void __cgroup_account_cputime(struct cgroup *cgrp, u64 delta_exec);
708void __cgroup_account_cputime_field(struct cgroup *cgrp,
709 enum cpu_usage_stat index, u64 delta_exec);
710
711static inline void cgroup_account_cputime(struct task_struct *task,
712 u64 delta_exec)
713{
714 struct cgroup *cgrp;
715
716 cpuacct_charge(tsk: task, cputime: delta_exec);
717
718 cgrp = task_dfl_cgroup(task);
719 if (cgroup_parent(cgrp))
720 __cgroup_account_cputime(cgrp, delta_exec);
721}
722
723static inline void cgroup_account_cputime_field(struct task_struct *task,
724 enum cpu_usage_stat index,
725 u64 delta_exec)
726{
727 struct cgroup *cgrp;
728
729 cpuacct_account_field(tsk: task, index, val: delta_exec);
730
731 cgrp = task_dfl_cgroup(task);
732 if (cgroup_parent(cgrp))
733 __cgroup_account_cputime_field(cgrp, index, delta_exec);
734}
735
736#else /* CONFIG_CGROUPS */
737
738static inline void cgroup_account_cputime(struct task_struct *task,
739 u64 delta_exec) {}
740static inline void cgroup_account_cputime_field(struct task_struct *task,
741 enum cpu_usage_stat index,
742 u64 delta_exec) {}
743
744#endif /* CONFIG_CGROUPS */
745
746/*
747 * sock->sk_cgrp_data handling. For more info, see sock_cgroup_data
748 * definition in cgroup-defs.h.
749 */
750#ifdef CONFIG_SOCK_CGROUP_DATA
751
752void cgroup_sk_alloc(struct sock_cgroup_data *skcd);
753void cgroup_sk_clone(struct sock_cgroup_data *skcd);
754void cgroup_sk_free(struct sock_cgroup_data *skcd);
755
756static inline struct cgroup *sock_cgroup_ptr(struct sock_cgroup_data *skcd)
757{
758 return skcd->cgroup;
759}
760
761#else /* CONFIG_CGROUP_DATA */
762
763static inline void cgroup_sk_alloc(struct sock_cgroup_data *skcd) {}
764static inline void cgroup_sk_clone(struct sock_cgroup_data *skcd) {}
765static inline void cgroup_sk_free(struct sock_cgroup_data *skcd) {}
766
767#endif /* CONFIG_CGROUP_DATA */
768
769struct cgroup_namespace {
770 struct ns_common ns;
771 struct user_namespace *user_ns;
772 struct ucounts *ucounts;
773 struct css_set *root_cset;
774};
775
776extern struct cgroup_namespace init_cgroup_ns;
777
778#ifdef CONFIG_CGROUPS
779
780void free_cgroup_ns(struct cgroup_namespace *ns);
781
782struct cgroup_namespace *copy_cgroup_ns(unsigned long flags,
783 struct user_namespace *user_ns,
784 struct cgroup_namespace *old_ns);
785
786int cgroup_path_ns(struct cgroup *cgrp, char *buf, size_t buflen,
787 struct cgroup_namespace *ns);
788
789#else /* !CONFIG_CGROUPS */
790
791static inline void free_cgroup_ns(struct cgroup_namespace *ns) { }
792static inline struct cgroup_namespace *
793copy_cgroup_ns(unsigned long flags, struct user_namespace *user_ns,
794 struct cgroup_namespace *old_ns)
795{
796 return old_ns;
797}
798
799#endif /* !CONFIG_CGROUPS */
800
801static inline void get_cgroup_ns(struct cgroup_namespace *ns)
802{
803 if (ns)
804 refcount_inc(r: &ns->ns.count);
805}
806
807static inline void put_cgroup_ns(struct cgroup_namespace *ns)
808{
809 if (ns && refcount_dec_and_test(r: &ns->ns.count))
810 free_cgroup_ns(ns);
811}
812
813#ifdef CONFIG_CGROUPS
814
815void cgroup_enter_frozen(void);
816void cgroup_leave_frozen(bool always_leave);
817void cgroup_update_frozen(struct cgroup *cgrp);
818void cgroup_freeze(struct cgroup *cgrp, bool freeze);
819void cgroup_freezer_migrate_task(struct task_struct *task, struct cgroup *src,
820 struct cgroup *dst);
821
822static inline bool cgroup_task_frozen(struct task_struct *task)
823{
824 return task->frozen;
825}
826
827#else /* !CONFIG_CGROUPS */
828
829static inline void cgroup_enter_frozen(void) { }
830static inline void cgroup_leave_frozen(bool always_leave) { }
831static inline bool cgroup_task_frozen(struct task_struct *task)
832{
833 return false;
834}
835
836#endif /* !CONFIG_CGROUPS */
837
838#ifdef CONFIG_CGROUP_BPF
839static inline void cgroup_bpf_get(struct cgroup *cgrp)
840{
841 percpu_ref_get(ref: &cgrp->bpf.refcnt);
842}
843
844static inline void cgroup_bpf_put(struct cgroup *cgrp)
845{
846 percpu_ref_put(ref: &cgrp->bpf.refcnt);
847}
848
849#else /* CONFIG_CGROUP_BPF */
850
851static inline void cgroup_bpf_get(struct cgroup *cgrp) {}
852static inline void cgroup_bpf_put(struct cgroup *cgrp) {}
853
854#endif /* CONFIG_CGROUP_BPF */
855
856#endif /* _LINUX_CGROUP_H */
857

source code of linux/include/linux/cgroup.h