Linux kernel mirror (for testing)
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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/nodemask.h>
14#include <linux/list.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/*
33 * All weight knobs on the default hierarchy should use the following min,
34 * default and max values. The default value is the logarithmic center of
35 * MIN and MAX and allows 100x to be expressed in both directions.
36 */
37#define CGROUP_WEIGHT_MIN 1
38#define CGROUP_WEIGHT_DFL 100
39#define CGROUP_WEIGHT_MAX 10000
40
41#ifdef CONFIG_CGROUPS
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;
72extern spinlock_t css_set_lock;
73
74#define SUBSYS(_x) extern struct cgroup_subsys _x ## _cgrp_subsys;
75#include <linux/cgroup_subsys.h>
76#undef SUBSYS
77
78#define SUBSYS(_x) \
79 extern struct static_key_true _x ## _cgrp_subsys_enabled_key; \
80 extern struct static_key_true _x ## _cgrp_subsys_on_dfl_key;
81#include <linux/cgroup_subsys.h>
82#undef SUBSYS
83
84/**
85 * cgroup_subsys_enabled - fast test on whether a subsys is enabled
86 * @ss: subsystem in question
87 */
88#define cgroup_subsys_enabled(ss) \
89 static_branch_likely(&ss ## _enabled_key)
90
91/**
92 * cgroup_subsys_on_dfl - fast test on whether a subsys is on default hierarchy
93 * @ss: subsystem in question
94 */
95#define cgroup_subsys_on_dfl(ss) \
96 static_branch_likely(&ss ## _on_dfl_key)
97
98bool css_has_online_children(struct cgroup_subsys_state *css);
99struct cgroup_subsys_state *css_from_id(int id, struct cgroup_subsys *ss);
100struct cgroup_subsys_state *cgroup_e_css(struct cgroup *cgroup,
101 struct cgroup_subsys *ss);
102struct cgroup_subsys_state *cgroup_get_e_css(struct cgroup *cgroup,
103 struct cgroup_subsys *ss);
104struct cgroup_subsys_state *css_tryget_online_from_dir(struct dentry *dentry,
105 struct cgroup_subsys *ss);
106
107struct cgroup *cgroup_get_from_path(const char *path);
108struct cgroup *cgroup_get_from_fd(int fd);
109struct cgroup *cgroup_v1v2_get_from_fd(int fd);
110
111int cgroup_attach_task_all(struct task_struct *from, struct task_struct *);
112int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from);
113
114int cgroup_add_dfl_cftypes(struct cgroup_subsys *ss, struct cftype *cfts);
115int cgroup_add_legacy_cftypes(struct cgroup_subsys *ss, struct cftype *cfts);
116int cgroup_add_cftypes(struct cgroup_subsys *ss, struct cftype *cfts);
117int cgroup_rm_cftypes(struct cftype *cfts);
118void cgroup_file_notify(struct cgroup_file *cfile);
119void cgroup_file_show(struct cgroup_file *cfile, bool show);
120
121int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry);
122int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns,
123 struct pid *pid, struct task_struct *tsk);
124
125void cgroup_fork(struct task_struct *p);
126extern int cgroup_can_fork(struct task_struct *p,
127 struct kernel_clone_args *kargs);
128extern void cgroup_cancel_fork(struct task_struct *p,
129 struct kernel_clone_args *kargs);
130extern void cgroup_post_fork(struct task_struct *p,
131 struct kernel_clone_args *kargs);
132void cgroup_exit(struct task_struct *p);
133void cgroup_release(struct task_struct *p);
134void cgroup_free(struct task_struct *p);
135
136int cgroup_init_early(void);
137int cgroup_init(void);
138
139int cgroup_parse_float(const char *input, unsigned dec_shift, s64 *v);
140
141/*
142 * Iteration helpers and macros.
143 */
144
145struct cgroup_subsys_state *css_next_child(struct cgroup_subsys_state *pos,
146 struct cgroup_subsys_state *parent);
147struct cgroup_subsys_state *css_next_descendant_pre(struct cgroup_subsys_state *pos,
148 struct cgroup_subsys_state *css);
149struct cgroup_subsys_state *css_rightmost_descendant(struct cgroup_subsys_state *pos);
150struct cgroup_subsys_state *css_next_descendant_post(struct cgroup_subsys_state *pos,
151 struct cgroup_subsys_state *css);
152
153struct task_struct *cgroup_taskset_first(struct cgroup_taskset *tset,
154 struct cgroup_subsys_state **dst_cssp);
155struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset,
156 struct cgroup_subsys_state **dst_cssp);
157
158void css_task_iter_start(struct cgroup_subsys_state *css, unsigned int flags,
159 struct css_task_iter *it);
160struct task_struct *css_task_iter_next(struct css_task_iter *it);
161void css_task_iter_end(struct css_task_iter *it);
162
163/**
164 * css_for_each_child - iterate through children of a css
165 * @pos: the css * to use as the loop cursor
166 * @parent: css whose children to walk
167 *
168 * Walk @parent's children. Must be called under rcu_read_lock().
169 *
170 * If a subsystem synchronizes ->css_online() and the start of iteration, a
171 * css which finished ->css_online() is guaranteed to be visible in the
172 * future iterations and will stay visible until the last reference is put.
173 * A css which hasn't finished ->css_online() or already finished
174 * ->css_offline() may show up during traversal. It's each subsystem's
175 * responsibility to synchronize against on/offlining.
176 *
177 * It is allowed to temporarily drop RCU read lock during iteration. The
178 * caller is responsible for ensuring that @pos remains accessible until
179 * the start of the next iteration by, for example, bumping the css refcnt.
180 */
181#define css_for_each_child(pos, parent) \
182 for ((pos) = css_next_child(NULL, (parent)); (pos); \
183 (pos) = css_next_child((pos), (parent)))
184
185/**
186 * css_for_each_descendant_pre - pre-order walk of a css's descendants
187 * @pos: the css * to use as the loop cursor
188 * @root: css whose descendants to walk
189 *
190 * Walk @root's descendants. @root is included in the iteration and the
191 * first node to be visited. Must be called under rcu_read_lock().
192 *
193 * If a subsystem synchronizes ->css_online() and the start of iteration, a
194 * css which finished ->css_online() is guaranteed to be visible in the
195 * future iterations and will stay visible until the last reference is put.
196 * A css which hasn't finished ->css_online() or already finished
197 * ->css_offline() may show up during traversal. It's each subsystem's
198 * responsibility to synchronize against on/offlining.
199 *
200 * For example, the following guarantees that a descendant can't escape
201 * state updates of its ancestors.
202 *
203 * my_online(@css)
204 * {
205 * Lock @css's parent and @css;
206 * Inherit state from the parent;
207 * Unlock both.
208 * }
209 *
210 * my_update_state(@css)
211 * {
212 * css_for_each_descendant_pre(@pos, @css) {
213 * Lock @pos;
214 * if (@pos == @css)
215 * Update @css's state;
216 * else
217 * Verify @pos is alive and inherit state from its parent;
218 * Unlock @pos;
219 * }
220 * }
221 *
222 * As long as the inheriting step, including checking the parent state, is
223 * enclosed inside @pos locking, double-locking the parent isn't necessary
224 * while inheriting. The state update to the parent is guaranteed to be
225 * visible by walking order and, as long as inheriting operations to the
226 * same @pos are atomic to each other, multiple updates racing each other
227 * still result in the correct state. It's guaranateed that at least one
228 * inheritance happens for any css after the latest update to its parent.
229 *
230 * If checking parent's state requires locking the parent, each inheriting
231 * iteration should lock and unlock both @pos->parent and @pos.
232 *
233 * Alternatively, a subsystem may choose to use a single global lock to
234 * synchronize ->css_online() and ->css_offline() against tree-walking
235 * operations.
236 *
237 * It is allowed to temporarily drop RCU read lock during iteration. The
238 * caller is responsible for ensuring that @pos remains accessible until
239 * the start of the next iteration by, for example, bumping the css refcnt.
240 */
241#define css_for_each_descendant_pre(pos, css) \
242 for ((pos) = css_next_descendant_pre(NULL, (css)); (pos); \
243 (pos) = css_next_descendant_pre((pos), (css)))
244
245/**
246 * css_for_each_descendant_post - post-order walk of a css's descendants
247 * @pos: the css * to use as the loop cursor
248 * @css: css whose descendants to walk
249 *
250 * Similar to css_for_each_descendant_pre() but performs post-order
251 * traversal instead. @root is included in the iteration and the last
252 * node to be visited.
253 *
254 * If a subsystem synchronizes ->css_online() and the start of iteration, a
255 * css which finished ->css_online() is guaranteed to be visible in the
256 * future iterations and will stay visible until the last reference is put.
257 * A css which hasn't finished ->css_online() or already finished
258 * ->css_offline() may show up during traversal. It's each subsystem's
259 * responsibility to synchronize against on/offlining.
260 *
261 * Note that the walk visibility guarantee example described in pre-order
262 * walk doesn't apply the same to post-order walks.
263 */
264#define css_for_each_descendant_post(pos, css) \
265 for ((pos) = css_next_descendant_post(NULL, (css)); (pos); \
266 (pos) = css_next_descendant_post((pos), (css)))
267
268/**
269 * cgroup_taskset_for_each - iterate cgroup_taskset
270 * @task: the loop cursor
271 * @dst_css: the destination css
272 * @tset: taskset to iterate
273 *
274 * @tset may contain multiple tasks and they may belong to multiple
275 * processes.
276 *
277 * On the v2 hierarchy, there may be tasks from multiple processes and they
278 * may not share the source or destination csses.
279 *
280 * On traditional hierarchies, when there are multiple tasks in @tset, if a
281 * task of a process is in @tset, all tasks of the process are in @tset.
282 * Also, all are guaranteed to share the same source and destination csses.
283 *
284 * Iteration is not in any specific order.
285 */
286#define cgroup_taskset_for_each(task, dst_css, tset) \
287 for ((task) = cgroup_taskset_first((tset), &(dst_css)); \
288 (task); \
289 (task) = cgroup_taskset_next((tset), &(dst_css)))
290
291/**
292 * cgroup_taskset_for_each_leader - iterate group leaders in a cgroup_taskset
293 * @leader: the loop cursor
294 * @dst_css: the destination css
295 * @tset: taskset to iterate
296 *
297 * Iterate threadgroup leaders of @tset. For single-task migrations, @tset
298 * may not contain any.
299 */
300#define cgroup_taskset_for_each_leader(leader, dst_css, tset) \
301 for ((leader) = cgroup_taskset_first((tset), &(dst_css)); \
302 (leader); \
303 (leader) = cgroup_taskset_next((tset), &(dst_css))) \
304 if ((leader) != (leader)->group_leader) \
305 ; \
306 else
307
308/*
309 * Inline functions.
310 */
311
312#ifdef CONFIG_DEBUG_CGROUP_REF
313void css_get(struct cgroup_subsys_state *css);
314void css_get_many(struct cgroup_subsys_state *css, unsigned int n);
315bool css_tryget(struct cgroup_subsys_state *css);
316bool css_tryget_online(struct cgroup_subsys_state *css);
317void css_put(struct cgroup_subsys_state *css);
318void css_put_many(struct cgroup_subsys_state *css, unsigned int n);
319#else
320#define CGROUP_REF_FN_ATTRS static inline
321#define CGROUP_REF_EXPORT(fn)
322#include <linux/cgroup_refcnt.h>
323#endif
324
325static inline u64 cgroup_id(const struct cgroup *cgrp)
326{
327 return cgrp->kn->id;
328}
329
330/**
331 * css_is_dying - test whether the specified css is dying
332 * @css: target css
333 *
334 * Test whether @css is in the process of offlining or already offline. In
335 * most cases, ->css_online() and ->css_offline() callbacks should be
336 * enough; however, the actual offline operations are RCU delayed and this
337 * test returns %true also when @css is scheduled to be offlined.
338 *
339 * This is useful, for example, when the use case requires synchronous
340 * behavior with respect to cgroup removal. cgroup removal schedules css
341 * offlining but the css can seem alive while the operation is being
342 * delayed. If the delay affects user visible semantics, this test can be
343 * used to resolve the situation.
344 */
345static inline bool css_is_dying(struct cgroup_subsys_state *css)
346{
347 return css->flags & CSS_DYING;
348}
349
350static inline void cgroup_get(struct cgroup *cgrp)
351{
352 css_get(&cgrp->self);
353}
354
355static inline bool cgroup_tryget(struct cgroup *cgrp)
356{
357 return css_tryget(&cgrp->self);
358}
359
360static inline void cgroup_put(struct cgroup *cgrp)
361{
362 css_put(&cgrp->self);
363}
364
365extern struct mutex cgroup_mutex;
366
367static inline void cgroup_lock(void)
368{
369 mutex_lock(&cgroup_mutex);
370}
371
372static inline void cgroup_unlock(void)
373{
374 mutex_unlock(&cgroup_mutex);
375}
376
377/**
378 * task_css_set_check - obtain a task's css_set with extra access conditions
379 * @task: the task to obtain css_set for
380 * @__c: extra condition expression to be passed to rcu_dereference_check()
381 *
382 * A task's css_set is RCU protected, initialized and exited while holding
383 * task_lock(), and can only be modified while holding both cgroup_mutex
384 * and task_lock() while the task is alive. This macro verifies that the
385 * caller is inside proper critical section and returns @task's css_set.
386 *
387 * The caller can also specify additional allowed conditions via @__c, such
388 * as locks used during the cgroup_subsys::attach() methods.
389 */
390#ifdef CONFIG_PROVE_RCU
391#define task_css_set_check(task, __c) \
392 rcu_dereference_check((task)->cgroups, \
393 rcu_read_lock_sched_held() || \
394 lockdep_is_held(&cgroup_mutex) || \
395 lockdep_is_held(&css_set_lock) || \
396 ((task)->flags & PF_EXITING) || (__c))
397#else
398#define task_css_set_check(task, __c) \
399 rcu_dereference((task)->cgroups)
400#endif
401
402/**
403 * task_css_check - obtain css for (task, subsys) w/ extra access conds
404 * @task: the target task
405 * @subsys_id: the target subsystem ID
406 * @__c: extra condition expression to be passed to rcu_dereference_check()
407 *
408 * Return the cgroup_subsys_state for the (@task, @subsys_id) pair. The
409 * synchronization rules are the same as task_css_set_check().
410 */
411#define task_css_check(task, subsys_id, __c) \
412 task_css_set_check((task), (__c))->subsys[(subsys_id)]
413
414/**
415 * task_css_set - obtain a task's css_set
416 * @task: the task to obtain css_set for
417 *
418 * See task_css_set_check().
419 */
420static inline struct css_set *task_css_set(struct task_struct *task)
421{
422 return task_css_set_check(task, false);
423}
424
425/**
426 * task_css - obtain css for (task, subsys)
427 * @task: the target task
428 * @subsys_id: the target subsystem ID
429 *
430 * See task_css_check().
431 */
432static inline struct cgroup_subsys_state *task_css(struct task_struct *task,
433 int subsys_id)
434{
435 return task_css_check(task, subsys_id, false);
436}
437
438/**
439 * task_get_css - find and get the css for (task, subsys)
440 * @task: the target task
441 * @subsys_id: the target subsystem ID
442 *
443 * Find the css for the (@task, @subsys_id) combination, increment a
444 * reference on and return it. This function is guaranteed to return a
445 * valid css. The returned css may already have been offlined.
446 */
447static inline struct cgroup_subsys_state *
448task_get_css(struct task_struct *task, int subsys_id)
449{
450 struct cgroup_subsys_state *css;
451
452 rcu_read_lock();
453 while (true) {
454 css = task_css(task, subsys_id);
455 /*
456 * Can't use css_tryget_online() here. A task which has
457 * PF_EXITING set may stay associated with an offline css.
458 * If such task calls this function, css_tryget_online()
459 * will keep failing.
460 */
461 if (likely(css_tryget(css)))
462 break;
463 cpu_relax();
464 }
465 rcu_read_unlock();
466 return css;
467}
468
469/**
470 * task_css_is_root - test whether a task belongs to the root css
471 * @task: the target task
472 * @subsys_id: the target subsystem ID
473 *
474 * Test whether @task belongs to the root css on the specified subsystem.
475 * May be invoked in any context.
476 */
477static inline bool task_css_is_root(struct task_struct *task, int subsys_id)
478{
479 return task_css_check(task, subsys_id, true) ==
480 init_css_set.subsys[subsys_id];
481}
482
483static inline struct cgroup *task_cgroup(struct task_struct *task,
484 int subsys_id)
485{
486 return task_css(task, subsys_id)->cgroup;
487}
488
489static inline struct cgroup *task_dfl_cgroup(struct task_struct *task)
490{
491 return task_css_set(task)->dfl_cgrp;
492}
493
494static inline struct cgroup *cgroup_parent(struct cgroup *cgrp)
495{
496 struct cgroup_subsys_state *parent_css = cgrp->self.parent;
497
498 if (parent_css)
499 return container_of(parent_css, struct cgroup, self);
500 return NULL;
501}
502
503/**
504 * cgroup_is_descendant - test ancestry
505 * @cgrp: the cgroup to be tested
506 * @ancestor: possible ancestor of @cgrp
507 *
508 * Test whether @cgrp is a descendant of @ancestor. It also returns %true
509 * if @cgrp == @ancestor. This function is safe to call as long as @cgrp
510 * and @ancestor are accessible.
511 */
512static inline bool cgroup_is_descendant(struct cgroup *cgrp,
513 struct cgroup *ancestor)
514{
515 if (cgrp->root != ancestor->root || cgrp->level < ancestor->level)
516 return false;
517 return cgrp->ancestors[ancestor->level] == ancestor;
518}
519
520/**
521 * cgroup_ancestor - find ancestor of cgroup
522 * @cgrp: cgroup to find ancestor of
523 * @ancestor_level: level of ancestor to find starting from root
524 *
525 * Find ancestor of cgroup at specified level starting from root if it exists
526 * and return pointer to it. Return NULL if @cgrp doesn't have ancestor at
527 * @ancestor_level.
528 *
529 * This function is safe to call as long as @cgrp is accessible.
530 */
531static inline struct cgroup *cgroup_ancestor(struct cgroup *cgrp,
532 int ancestor_level)
533{
534 if (ancestor_level < 0 || ancestor_level > cgrp->level)
535 return NULL;
536 return cgrp->ancestors[ancestor_level];
537}
538
539/**
540 * task_under_cgroup_hierarchy - test task's membership of cgroup ancestry
541 * @task: the task to be tested
542 * @ancestor: possible ancestor of @task's cgroup
543 *
544 * Tests whether @task's default cgroup hierarchy is a descendant of @ancestor.
545 * It follows all the same rules as cgroup_is_descendant, and only applies
546 * to the default hierarchy.
547 */
548static inline bool task_under_cgroup_hierarchy(struct task_struct *task,
549 struct cgroup *ancestor)
550{
551 struct css_set *cset = task_css_set(task);
552
553 return cgroup_is_descendant(cset->dfl_cgrp, ancestor);
554}
555
556/* no synchronization, the result can only be used as a hint */
557static inline bool cgroup_is_populated(struct cgroup *cgrp)
558{
559 return cgrp->nr_populated_csets + cgrp->nr_populated_domain_children +
560 cgrp->nr_populated_threaded_children;
561}
562
563/* returns ino associated with a cgroup */
564static inline ino_t cgroup_ino(struct cgroup *cgrp)
565{
566 return kernfs_ino(cgrp->kn);
567}
568
569/* cft/css accessors for cftype->write() operation */
570static inline struct cftype *of_cft(struct kernfs_open_file *of)
571{
572 return of->kn->priv;
573}
574
575struct cgroup_subsys_state *of_css(struct kernfs_open_file *of);
576
577/* cft/css accessors for cftype->seq_*() operations */
578static inline struct cftype *seq_cft(struct seq_file *seq)
579{
580 return of_cft(seq->private);
581}
582
583static inline struct cgroup_subsys_state *seq_css(struct seq_file *seq)
584{
585 return of_css(seq->private);
586}
587
588/*
589 * Name / path handling functions. All are thin wrappers around the kernfs
590 * counterparts and can be called under any context.
591 */
592
593static inline int cgroup_name(struct cgroup *cgrp, char *buf, size_t buflen)
594{
595 return kernfs_name(cgrp->kn, buf, buflen);
596}
597
598static inline int cgroup_path(struct cgroup *cgrp, char *buf, size_t buflen)
599{
600 return kernfs_path(cgrp->kn, buf, buflen);
601}
602
603static inline void pr_cont_cgroup_name(struct cgroup *cgrp)
604{
605 pr_cont_kernfs_name(cgrp->kn);
606}
607
608static inline void pr_cont_cgroup_path(struct cgroup *cgrp)
609{
610 pr_cont_kernfs_path(cgrp->kn);
611}
612
613bool cgroup_psi_enabled(void);
614
615static inline void cgroup_init_kthreadd(void)
616{
617 /*
618 * kthreadd is inherited by all kthreads, keep it in the root so
619 * that the new kthreads are guaranteed to stay in the root until
620 * initialization is finished.
621 */
622 current->no_cgroup_migration = 1;
623}
624
625static inline void cgroup_kthread_ready(void)
626{
627 /*
628 * This kthread finished initialization. The creator should have
629 * set PF_NO_SETAFFINITY if this kthread should stay in the root.
630 */
631 current->no_cgroup_migration = 0;
632}
633
634void cgroup_path_from_kernfs_id(u64 id, char *buf, size_t buflen);
635struct cgroup *cgroup_get_from_id(u64 id);
636#else /* !CONFIG_CGROUPS */
637
638struct cgroup_subsys_state;
639struct cgroup;
640
641static inline u64 cgroup_id(const struct cgroup *cgrp) { return 1; }
642static inline void css_get(struct cgroup_subsys_state *css) {}
643static inline void css_put(struct cgroup_subsys_state *css) {}
644static inline void cgroup_lock(void) {}
645static inline void cgroup_unlock(void) {}
646static inline int cgroup_attach_task_all(struct task_struct *from,
647 struct task_struct *t) { return 0; }
648static inline int cgroupstats_build(struct cgroupstats *stats,
649 struct dentry *dentry) { return -EINVAL; }
650
651static inline void cgroup_fork(struct task_struct *p) {}
652static inline int cgroup_can_fork(struct task_struct *p,
653 struct kernel_clone_args *kargs) { return 0; }
654static inline void cgroup_cancel_fork(struct task_struct *p,
655 struct kernel_clone_args *kargs) {}
656static inline void cgroup_post_fork(struct task_struct *p,
657 struct kernel_clone_args *kargs) {}
658static inline void cgroup_exit(struct task_struct *p) {}
659static inline void cgroup_release(struct task_struct *p) {}
660static inline void cgroup_free(struct task_struct *p) {}
661
662static inline int cgroup_init_early(void) { return 0; }
663static inline int cgroup_init(void) { return 0; }
664static inline void cgroup_init_kthreadd(void) {}
665static inline void cgroup_kthread_ready(void) {}
666
667static inline struct cgroup *cgroup_parent(struct cgroup *cgrp)
668{
669 return NULL;
670}
671
672static inline bool cgroup_psi_enabled(void)
673{
674 return false;
675}
676
677static inline bool task_under_cgroup_hierarchy(struct task_struct *task,
678 struct cgroup *ancestor)
679{
680 return true;
681}
682
683static inline void cgroup_path_from_kernfs_id(u64 id, char *buf, size_t buflen)
684{}
685#endif /* !CONFIG_CGROUPS */
686
687#ifdef CONFIG_CGROUPS
688/*
689 * cgroup scalable recursive statistics.
690 */
691void cgroup_rstat_updated(struct cgroup *cgrp, int cpu);
692void cgroup_rstat_flush(struct cgroup *cgrp);
693
694/*
695 * Basic resource stats.
696 */
697#ifdef CONFIG_CGROUP_CPUACCT
698void cpuacct_charge(struct task_struct *tsk, u64 cputime);
699void cpuacct_account_field(struct task_struct *tsk, int index, u64 val);
700#else
701static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {}
702static inline void cpuacct_account_field(struct task_struct *tsk, int index,
703 u64 val) {}
704#endif
705
706void __cgroup_account_cputime(struct cgroup *cgrp, u64 delta_exec);
707void __cgroup_account_cputime_field(struct cgroup *cgrp,
708 enum cpu_usage_stat index, u64 delta_exec);
709
710static inline void cgroup_account_cputime(struct task_struct *task,
711 u64 delta_exec)
712{
713 struct cgroup *cgrp;
714
715 cpuacct_charge(task, delta_exec);
716
717 cgrp = task_dfl_cgroup(task);
718 if (cgroup_parent(cgrp))
719 __cgroup_account_cputime(cgrp, delta_exec);
720}
721
722static inline void cgroup_account_cputime_field(struct task_struct *task,
723 enum cpu_usage_stat index,
724 u64 delta_exec)
725{
726 struct cgroup *cgrp;
727
728 cpuacct_account_field(task, index, delta_exec);
729
730 cgrp = task_dfl_cgroup(task);
731 if (cgroup_parent(cgrp))
732 __cgroup_account_cputime_field(cgrp, index, delta_exec);
733}
734
735#else /* CONFIG_CGROUPS */
736
737static inline void cgroup_account_cputime(struct task_struct *task,
738 u64 delta_exec) {}
739static inline void cgroup_account_cputime_field(struct task_struct *task,
740 enum cpu_usage_stat index,
741 u64 delta_exec) {}
742
743#endif /* CONFIG_CGROUPS */
744
745/*
746 * sock->sk_cgrp_data handling. For more info, see sock_cgroup_data
747 * definition in cgroup-defs.h.
748 */
749#ifdef CONFIG_SOCK_CGROUP_DATA
750
751void cgroup_sk_alloc(struct sock_cgroup_data *skcd);
752void cgroup_sk_clone(struct sock_cgroup_data *skcd);
753void cgroup_sk_free(struct sock_cgroup_data *skcd);
754
755static inline struct cgroup *sock_cgroup_ptr(struct sock_cgroup_data *skcd)
756{
757 return skcd->cgroup;
758}
759
760#else /* CONFIG_CGROUP_DATA */
761
762static inline void cgroup_sk_alloc(struct sock_cgroup_data *skcd) {}
763static inline void cgroup_sk_clone(struct sock_cgroup_data *skcd) {}
764static inline void cgroup_sk_free(struct sock_cgroup_data *skcd) {}
765
766#endif /* CONFIG_CGROUP_DATA */
767
768struct cgroup_namespace {
769 struct ns_common ns;
770 struct user_namespace *user_ns;
771 struct ucounts *ucounts;
772 struct css_set *root_cset;
773};
774
775extern struct cgroup_namespace init_cgroup_ns;
776
777#ifdef CONFIG_CGROUPS
778
779void free_cgroup_ns(struct cgroup_namespace *ns);
780
781struct cgroup_namespace *copy_cgroup_ns(unsigned long flags,
782 struct user_namespace *user_ns,
783 struct cgroup_namespace *old_ns);
784
785int cgroup_path_ns(struct cgroup *cgrp, char *buf, size_t buflen,
786 struct cgroup_namespace *ns);
787
788#else /* !CONFIG_CGROUPS */
789
790static inline void free_cgroup_ns(struct cgroup_namespace *ns) { }
791static inline struct cgroup_namespace *
792copy_cgroup_ns(unsigned long flags, struct user_namespace *user_ns,
793 struct cgroup_namespace *old_ns)
794{
795 return old_ns;
796}
797
798#endif /* !CONFIG_CGROUPS */
799
800static inline void get_cgroup_ns(struct cgroup_namespace *ns)
801{
802 if (ns)
803 refcount_inc(&ns->ns.count);
804}
805
806static inline void put_cgroup_ns(struct cgroup_namespace *ns)
807{
808 if (ns && refcount_dec_and_test(&ns->ns.count))
809 free_cgroup_ns(ns);
810}
811
812#ifdef CONFIG_CGROUPS
813
814void cgroup_enter_frozen(void);
815void cgroup_leave_frozen(bool always_leave);
816void cgroup_update_frozen(struct cgroup *cgrp);
817void cgroup_freeze(struct cgroup *cgrp, bool freeze);
818void cgroup_freezer_migrate_task(struct task_struct *task, struct cgroup *src,
819 struct cgroup *dst);
820
821static inline bool cgroup_task_frozen(struct task_struct *task)
822{
823 return task->frozen;
824}
825
826#else /* !CONFIG_CGROUPS */
827
828static inline void cgroup_enter_frozen(void) { }
829static inline void cgroup_leave_frozen(bool always_leave) { }
830static inline bool cgroup_task_frozen(struct task_struct *task)
831{
832 return false;
833}
834
835#endif /* !CONFIG_CGROUPS */
836
837#ifdef CONFIG_CGROUP_BPF
838static inline void cgroup_bpf_get(struct cgroup *cgrp)
839{
840 percpu_ref_get(&cgrp->bpf.refcnt);
841}
842
843static inline void cgroup_bpf_put(struct cgroup *cgrp)
844{
845 percpu_ref_put(&cgrp->bpf.refcnt);
846}
847
848#else /* CONFIG_CGROUP_BPF */
849
850static inline void cgroup_bpf_get(struct cgroup *cgrp) {}
851static inline void cgroup_bpf_put(struct cgroup *cgrp) {}
852
853#endif /* CONFIG_CGROUP_BPF */
854
855struct cgroup *task_get_cgroup1(struct task_struct *tsk, int hierarchy_id);
856
857struct cgroup_of_peak *of_peak(struct kernfs_open_file *of);
858
859#endif /* _LINUX_CGROUP_H */