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
30 struct 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
43 /* walk only threadgroup leaders */
44 #define CSS_TASK_ITER_PROCS (1U << 0)
45 /* walk all threaded css_sets in the domain */
46 #define CSS_TASK_ITER_THREADED (1U << 1)
47
48 /* internal flags */
49 #define CSS_TASK_ITER_SKIPPED (1U << 16)
50
51 /* a css_task_iter should be treated as an opaque object */
52 struct css_task_iter {
53 struct cgroup_subsys *ss;
54 unsigned int flags;
55
56 struct list_head *cset_pos;
57 struct list_head *cset_head;
58
59 struct list_head *tcset_pos;
60 struct list_head *tcset_head;
61
62 struct list_head *task_pos;
63
64 struct list_head *cur_tasks_head;
65 struct css_set *cur_cset;
66 struct css_set *cur_dcset;
67 struct task_struct *cur_task;
68 struct list_head iters_node; /* css_set->task_iters */
69 };
70
71 extern struct file_system_type cgroup_fs_type;
72 extern struct cgroup_root cgrp_dfl_root;
73 extern struct css_set init_css_set;
74
75 #define SUBSYS(_x) extern struct cgroup_subsys _x ## _cgrp_subsys;
76 #include <linux/cgroup_subsys.h>
77 #undef SUBSYS
78
79 #define SUBSYS(_x) \
80 extern struct static_key_true _x ## _cgrp_subsys_enabled_key; \
81 extern struct static_key_true _x ## _cgrp_subsys_on_dfl_key;
82 #include <linux/cgroup_subsys.h>
83 #undef SUBSYS
84
85 /**
86 * cgroup_subsys_enabled - fast test on whether a subsys is enabled
87 * @ss: subsystem in question
88 */
89 #define cgroup_subsys_enabled(ss) \
90 static_branch_likely(&ss ## _enabled_key)
91
92 /**
93 * cgroup_subsys_on_dfl - fast test on whether a subsys is on default hierarchy
94 * @ss: subsystem in question
95 */
96 #define cgroup_subsys_on_dfl(ss) \
97 static_branch_likely(&ss ## _on_dfl_key)
98
99 bool css_has_online_children(struct cgroup_subsys_state *css);
100 struct cgroup_subsys_state *css_from_id(int id, struct cgroup_subsys *ss);
101 struct cgroup_subsys_state *cgroup_e_css(struct cgroup *cgroup,
102 struct cgroup_subsys *ss);
103 struct cgroup_subsys_state *cgroup_get_e_css(struct cgroup *cgroup,
104 struct cgroup_subsys *ss);
105 struct cgroup_subsys_state *css_tryget_online_from_dir(struct dentry *dentry,
106 struct cgroup_subsys *ss);
107
108 struct cgroup *cgroup_get_from_path(const char *path);
109 struct cgroup *cgroup_get_from_fd(int fd);
110 struct cgroup *cgroup_v1v2_get_from_fd(int fd);
111
112 int cgroup_attach_task_all(struct task_struct *from, struct task_struct *);
113 int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from);
114
115 int cgroup_add_dfl_cftypes(struct cgroup_subsys *ss, struct cftype *cfts);
116 int cgroup_add_legacy_cftypes(struct cgroup_subsys *ss, struct cftype *cfts);
117 int cgroup_rm_cftypes(struct cftype *cfts);
118 void cgroup_file_notify(struct cgroup_file *cfile);
119 void cgroup_file_show(struct cgroup_file *cfile, bool show);
120
121 int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry);
122 int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns,
123 struct pid *pid, struct task_struct *tsk);
124
125 void cgroup_fork(struct task_struct *p);
126 extern int cgroup_can_fork(struct task_struct *p,
127 struct kernel_clone_args *kargs);
128 extern void cgroup_cancel_fork(struct task_struct *p,
129 struct kernel_clone_args *kargs);
130 extern void cgroup_post_fork(struct task_struct *p,
131 struct kernel_clone_args *kargs);
132 void cgroup_exit(struct task_struct *p);
133 void cgroup_release(struct task_struct *p);
134 void cgroup_free(struct task_struct *p);
135
136 int cgroup_init_early(void);
137 int cgroup_init(void);
138
139 int cgroup_parse_float(const char *input, unsigned dec_shift, s64 *v);
140
141 /*
142 * Iteration helpers and macros.
143 */
144
145 struct cgroup_subsys_state *css_next_child(struct cgroup_subsys_state *pos,
146 struct cgroup_subsys_state *parent);
147 struct cgroup_subsys_state *css_next_descendant_pre(struct cgroup_subsys_state *pos,
148 struct cgroup_subsys_state *css);
149 struct cgroup_subsys_state *css_rightmost_descendant(struct cgroup_subsys_state *pos);
150 struct cgroup_subsys_state *css_next_descendant_post(struct cgroup_subsys_state *pos,
151 struct cgroup_subsys_state *css);
152
153 struct task_struct *cgroup_taskset_first(struct cgroup_taskset *tset,
154 struct cgroup_subsys_state **dst_cssp);
155 struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset,
156 struct cgroup_subsys_state **dst_cssp);
157
158 void css_task_iter_start(struct cgroup_subsys_state *css, unsigned int flags,
159 struct css_task_iter *it);
160 struct task_struct *css_task_iter_next(struct css_task_iter *it);
161 void 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
313 void css_get(struct cgroup_subsys_state *css);
314 void css_get_many(struct cgroup_subsys_state *css, unsigned int n);
315 bool css_tryget(struct cgroup_subsys_state *css);
316 bool css_tryget_online(struct cgroup_subsys_state *css);
317 void css_put(struct cgroup_subsys_state *css);
318 void 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
cgroup_id(const struct cgroup * cgrp)325 static 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 */
css_is_dying(struct cgroup_subsys_state * css)345 static inline bool css_is_dying(struct cgroup_subsys_state *css)
346 {
347 return !(css->flags & CSS_NO_REF) && percpu_ref_is_dying(&css->refcnt);
348 }
349
cgroup_get(struct cgroup * cgrp)350 static inline void cgroup_get(struct cgroup *cgrp)
351 {
352 css_get(&cgrp->self);
353 }
354
cgroup_tryget(struct cgroup * cgrp)355 static inline bool cgroup_tryget(struct cgroup *cgrp)
356 {
357 return css_tryget(&cgrp->self);
358 }
359
cgroup_put(struct cgroup * cgrp)360 static inline void cgroup_put(struct cgroup *cgrp)
361 {
362 css_put(&cgrp->self);
363 }
364
365 extern struct mutex cgroup_mutex;
366
cgroup_lock(void)367 static inline void cgroup_lock(void)
368 {
369 mutex_lock(&cgroup_mutex);
370 }
371
cgroup_unlock(void)372 static 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 extern spinlock_t css_set_lock;
392 #define task_css_set_check(task, __c) \
393 rcu_dereference_check((task)->cgroups, \
394 rcu_read_lock_sched_held() || \
395 lockdep_is_held(&cgroup_mutex) || \
396 lockdep_is_held(&css_set_lock) || \
397 ((task)->flags & PF_EXITING) || (__c))
398 #else
399 #define task_css_set_check(task, __c) \
400 rcu_dereference((task)->cgroups)
401 #endif
402
403 /**
404 * task_css_check - obtain css for (task, subsys) w/ extra access conds
405 * @task: the target task
406 * @subsys_id: the target subsystem ID
407 * @__c: extra condition expression to be passed to rcu_dereference_check()
408 *
409 * Return the cgroup_subsys_state for the (@task, @subsys_id) pair. The
410 * synchronization rules are the same as task_css_set_check().
411 */
412 #define task_css_check(task, subsys_id, __c) \
413 task_css_set_check((task), (__c))->subsys[(subsys_id)]
414
415 /**
416 * task_css_set - obtain a task's css_set
417 * @task: the task to obtain css_set for
418 *
419 * See task_css_set_check().
420 */
task_css_set(struct task_struct * task)421 static inline struct css_set *task_css_set(struct task_struct *task)
422 {
423 return task_css_set_check(task, false);
424 }
425
426 /**
427 * task_css - obtain css for (task, subsys)
428 * @task: the target task
429 * @subsys_id: the target subsystem ID
430 *
431 * See task_css_check().
432 */
task_css(struct task_struct * task,int subsys_id)433 static inline struct cgroup_subsys_state *task_css(struct task_struct *task,
434 int subsys_id)
435 {
436 return task_css_check(task, subsys_id, false);
437 }
438
439 /**
440 * task_get_css - find and get the css for (task, subsys)
441 * @task: the target task
442 * @subsys_id: the target subsystem ID
443 *
444 * Find the css for the (@task, @subsys_id) combination, increment a
445 * reference on and return it. This function is guaranteed to return a
446 * valid css. The returned css may already have been offlined.
447 */
448 static inline struct cgroup_subsys_state *
task_get_css(struct task_struct * task,int subsys_id)449 task_get_css(struct task_struct *task, int subsys_id)
450 {
451 struct cgroup_subsys_state *css;
452
453 rcu_read_lock();
454 while (true) {
455 css = task_css(task, subsys_id);
456 /*
457 * Can't use css_tryget_online() here. A task which has
458 * PF_EXITING set may stay associated with an offline css.
459 * If such task calls this function, css_tryget_online()
460 * will keep failing.
461 */
462 if (likely(css_tryget(css)))
463 break;
464 cpu_relax();
465 }
466 rcu_read_unlock();
467 return css;
468 }
469
470 /**
471 * task_css_is_root - test whether a task belongs to the root css
472 * @task: the target task
473 * @subsys_id: the target subsystem ID
474 *
475 * Test whether @task belongs to the root css on the specified subsystem.
476 * May be invoked in any context.
477 */
task_css_is_root(struct task_struct * task,int subsys_id)478 static inline bool task_css_is_root(struct task_struct *task, int subsys_id)
479 {
480 return task_css_check(task, subsys_id, true) ==
481 init_css_set.subsys[subsys_id];
482 }
483
task_cgroup(struct task_struct * task,int subsys_id)484 static inline struct cgroup *task_cgroup(struct task_struct *task,
485 int subsys_id)
486 {
487 return task_css(task, subsys_id)->cgroup;
488 }
489
task_dfl_cgroup(struct task_struct * task)490 static inline struct cgroup *task_dfl_cgroup(struct task_struct *task)
491 {
492 return task_css_set(task)->dfl_cgrp;
493 }
494
cgroup_parent(struct cgroup * cgrp)495 static inline struct cgroup *cgroup_parent(struct cgroup *cgrp)
496 {
497 struct cgroup_subsys_state *parent_css = cgrp->self.parent;
498
499 if (parent_css)
500 return container_of(parent_css, struct cgroup, self);
501 return NULL;
502 }
503
504 /**
505 * cgroup_is_descendant - test ancestry
506 * @cgrp: the cgroup to be tested
507 * @ancestor: possible ancestor of @cgrp
508 *
509 * Test whether @cgrp is a descendant of @ancestor. It also returns %true
510 * if @cgrp == @ancestor. This function is safe to call as long as @cgrp
511 * and @ancestor are accessible.
512 */
cgroup_is_descendant(struct cgroup * cgrp,struct cgroup * ancestor)513 static inline bool cgroup_is_descendant(struct cgroup *cgrp,
514 struct cgroup *ancestor)
515 {
516 if (cgrp->root != ancestor->root || cgrp->level < ancestor->level)
517 return false;
518 return cgrp->ancestors[ancestor->level] == ancestor;
519 }
520
521 /**
522 * cgroup_ancestor - find ancestor of cgroup
523 * @cgrp: cgroup to find ancestor of
524 * @ancestor_level: level of ancestor to find starting from root
525 *
526 * Find ancestor of cgroup at specified level starting from root if it exists
527 * and return pointer to it. Return NULL if @cgrp doesn't have ancestor at
528 * @ancestor_level.
529 *
530 * This function is safe to call as long as @cgrp is accessible.
531 */
cgroup_ancestor(struct cgroup * cgrp,int ancestor_level)532 static inline struct cgroup *cgroup_ancestor(struct cgroup *cgrp,
533 int ancestor_level)
534 {
535 if (ancestor_level < 0 || ancestor_level > cgrp->level)
536 return NULL;
537 return cgrp->ancestors[ancestor_level];
538 }
539
540 /**
541 * task_under_cgroup_hierarchy - test task's membership of cgroup ancestry
542 * @task: the task to be tested
543 * @ancestor: possible ancestor of @task's cgroup
544 *
545 * Tests whether @task's default cgroup hierarchy is a descendant of @ancestor.
546 * It follows all the same rules as cgroup_is_descendant, and only applies
547 * to the default hierarchy.
548 */
task_under_cgroup_hierarchy(struct task_struct * task,struct cgroup * ancestor)549 static inline bool task_under_cgroup_hierarchy(struct task_struct *task,
550 struct cgroup *ancestor)
551 {
552 struct css_set *cset = task_css_set(task);
553
554 return cgroup_is_descendant(cset->dfl_cgrp, ancestor);
555 }
556
557 /* no synchronization, the result can only be used as a hint */
cgroup_is_populated(struct cgroup * cgrp)558 static inline bool cgroup_is_populated(struct cgroup *cgrp)
559 {
560 return cgrp->nr_populated_csets + cgrp->nr_populated_domain_children +
561 cgrp->nr_populated_threaded_children;
562 }
563
564 /* returns ino associated with a cgroup */
cgroup_ino(struct cgroup * cgrp)565 static inline ino_t cgroup_ino(struct cgroup *cgrp)
566 {
567 return kernfs_ino(cgrp->kn);
568 }
569
570 /* cft/css accessors for cftype->write() operation */
of_cft(struct kernfs_open_file * of)571 static inline struct cftype *of_cft(struct kernfs_open_file *of)
572 {
573 return of->kn->priv;
574 }
575
576 struct cgroup_subsys_state *of_css(struct kernfs_open_file *of);
577
578 /* cft/css accessors for cftype->seq_*() operations */
seq_cft(struct seq_file * seq)579 static inline struct cftype *seq_cft(struct seq_file *seq)
580 {
581 return of_cft(seq->private);
582 }
583
seq_css(struct seq_file * seq)584 static inline struct cgroup_subsys_state *seq_css(struct seq_file *seq)
585 {
586 return of_css(seq->private);
587 }
588
589 /*
590 * Name / path handling functions. All are thin wrappers around the kernfs
591 * counterparts and can be called under any context.
592 */
593
cgroup_name(struct cgroup * cgrp,char * buf,size_t buflen)594 static inline int cgroup_name(struct cgroup *cgrp, char *buf, size_t buflen)
595 {
596 return kernfs_name(cgrp->kn, buf, buflen);
597 }
598
cgroup_path(struct cgroup * cgrp,char * buf,size_t buflen)599 static inline int cgroup_path(struct cgroup *cgrp, char *buf, size_t buflen)
600 {
601 return kernfs_path(cgrp->kn, buf, buflen);
602 }
603
pr_cont_cgroup_name(struct cgroup * cgrp)604 static inline void pr_cont_cgroup_name(struct cgroup *cgrp)
605 {
606 pr_cont_kernfs_name(cgrp->kn);
607 }
608
pr_cont_cgroup_path(struct cgroup * cgrp)609 static inline void pr_cont_cgroup_path(struct cgroup *cgrp)
610 {
611 pr_cont_kernfs_path(cgrp->kn);
612 }
613
614 bool cgroup_psi_enabled(void);
615
cgroup_init_kthreadd(void)616 static inline void cgroup_init_kthreadd(void)
617 {
618 /*
619 * kthreadd is inherited by all kthreads, keep it in the root so
620 * that the new kthreads are guaranteed to stay in the root until
621 * initialization is finished.
622 */
623 current->no_cgroup_migration = 1;
624 }
625
cgroup_kthread_ready(void)626 static inline void cgroup_kthread_ready(void)
627 {
628 /*
629 * This kthread finished initialization. The creator should have
630 * set PF_NO_SETAFFINITY if this kthread should stay in the root.
631 */
632 current->no_cgroup_migration = 0;
633 }
634
635 void cgroup_path_from_kernfs_id(u64 id, char *buf, size_t buflen);
636 struct cgroup *cgroup_get_from_id(u64 id);
637 #else /* !CONFIG_CGROUPS */
638
639 struct cgroup_subsys_state;
640 struct cgroup;
641
cgroup_id(const struct cgroup * cgrp)642 static inline u64 cgroup_id(const struct cgroup *cgrp) { return 1; }
css_get(struct cgroup_subsys_state * css)643 static inline void css_get(struct cgroup_subsys_state *css) {}
css_put(struct cgroup_subsys_state * css)644 static inline void css_put(struct cgroup_subsys_state *css) {}
cgroup_lock(void)645 static inline void cgroup_lock(void) {}
cgroup_unlock(void)646 static inline void cgroup_unlock(void) {}
cgroup_attach_task_all(struct task_struct * from,struct task_struct * t)647 static inline int cgroup_attach_task_all(struct task_struct *from,
648 struct task_struct *t) { return 0; }
cgroupstats_build(struct cgroupstats * stats,struct dentry * dentry)649 static inline int cgroupstats_build(struct cgroupstats *stats,
650 struct dentry *dentry) { return -EINVAL; }
651
cgroup_fork(struct task_struct * p)652 static inline void cgroup_fork(struct task_struct *p) {}
cgroup_can_fork(struct task_struct * p,struct kernel_clone_args * kargs)653 static inline int cgroup_can_fork(struct task_struct *p,
654 struct kernel_clone_args *kargs) { return 0; }
cgroup_cancel_fork(struct task_struct * p,struct kernel_clone_args * kargs)655 static inline void cgroup_cancel_fork(struct task_struct *p,
656 struct kernel_clone_args *kargs) {}
cgroup_post_fork(struct task_struct * p,struct kernel_clone_args * kargs)657 static inline void cgroup_post_fork(struct task_struct *p,
658 struct kernel_clone_args *kargs) {}
cgroup_exit(struct task_struct * p)659 static inline void cgroup_exit(struct task_struct *p) {}
cgroup_release(struct task_struct * p)660 static inline void cgroup_release(struct task_struct *p) {}
cgroup_free(struct task_struct * p)661 static inline void cgroup_free(struct task_struct *p) {}
662
cgroup_init_early(void)663 static inline int cgroup_init_early(void) { return 0; }
cgroup_init(void)664 static inline int cgroup_init(void) { return 0; }
cgroup_init_kthreadd(void)665 static inline void cgroup_init_kthreadd(void) {}
cgroup_kthread_ready(void)666 static inline void cgroup_kthread_ready(void) {}
667
cgroup_parent(struct cgroup * cgrp)668 static inline struct cgroup *cgroup_parent(struct cgroup *cgrp)
669 {
670 return NULL;
671 }
672
cgroup_psi_enabled(void)673 static inline bool cgroup_psi_enabled(void)
674 {
675 return false;
676 }
677
task_under_cgroup_hierarchy(struct task_struct * task,struct cgroup * ancestor)678 static inline bool task_under_cgroup_hierarchy(struct task_struct *task,
679 struct cgroup *ancestor)
680 {
681 return true;
682 }
683
cgroup_path_from_kernfs_id(u64 id,char * buf,size_t buflen)684 static inline void cgroup_path_from_kernfs_id(u64 id, char *buf, size_t buflen)
685 {}
686 #endif /* !CONFIG_CGROUPS */
687
688 #ifdef CONFIG_CGROUPS
689 /*
690 * cgroup scalable recursive statistics.
691 */
692 void cgroup_rstat_updated(struct cgroup *cgrp, int cpu);
693 void cgroup_rstat_flush(struct cgroup *cgrp);
694 void cgroup_rstat_flush_hold(struct cgroup *cgrp);
695 void cgroup_rstat_flush_release(void);
696
697 /*
698 * Basic resource stats.
699 */
700 #ifdef CONFIG_CGROUP_CPUACCT
701 void cpuacct_charge(struct task_struct *tsk, u64 cputime);
702 void cpuacct_account_field(struct task_struct *tsk, int index, u64 val);
703 #else
cpuacct_charge(struct task_struct * tsk,u64 cputime)704 static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {}
cpuacct_account_field(struct task_struct * tsk,int index,u64 val)705 static inline void cpuacct_account_field(struct task_struct *tsk, int index,
706 u64 val) {}
707 #endif
708
709 void __cgroup_account_cputime(struct cgroup *cgrp, u64 delta_exec);
710 void __cgroup_account_cputime_field(struct cgroup *cgrp,
711 enum cpu_usage_stat index, u64 delta_exec);
712
cgroup_account_cputime(struct task_struct * task,u64 delta_exec)713 static inline void cgroup_account_cputime(struct task_struct *task,
714 u64 delta_exec)
715 {
716 struct cgroup *cgrp;
717
718 cpuacct_charge(task, delta_exec);
719
720 cgrp = task_dfl_cgroup(task);
721 if (cgroup_parent(cgrp))
722 __cgroup_account_cputime(cgrp, delta_exec);
723 }
724
cgroup_account_cputime_field(struct task_struct * task,enum cpu_usage_stat index,u64 delta_exec)725 static inline void cgroup_account_cputime_field(struct task_struct *task,
726 enum cpu_usage_stat index,
727 u64 delta_exec)
728 {
729 struct cgroup *cgrp;
730
731 cpuacct_account_field(task, index, delta_exec);
732
733 cgrp = task_dfl_cgroup(task);
734 if (cgroup_parent(cgrp))
735 __cgroup_account_cputime_field(cgrp, index, delta_exec);
736 }
737
738 #else /* CONFIG_CGROUPS */
739
cgroup_account_cputime(struct task_struct * task,u64 delta_exec)740 static inline void cgroup_account_cputime(struct task_struct *task,
741 u64 delta_exec) {}
cgroup_account_cputime_field(struct task_struct * task,enum cpu_usage_stat index,u64 delta_exec)742 static inline void cgroup_account_cputime_field(struct task_struct *task,
743 enum cpu_usage_stat index,
744 u64 delta_exec) {}
745
746 #endif /* CONFIG_CGROUPS */
747
748 /*
749 * sock->sk_cgrp_data handling. For more info, see sock_cgroup_data
750 * definition in cgroup-defs.h.
751 */
752 #ifdef CONFIG_SOCK_CGROUP_DATA
753
754 void cgroup_sk_alloc(struct sock_cgroup_data *skcd);
755 void cgroup_sk_clone(struct sock_cgroup_data *skcd);
756 void cgroup_sk_free(struct sock_cgroup_data *skcd);
757
sock_cgroup_ptr(struct sock_cgroup_data * skcd)758 static inline struct cgroup *sock_cgroup_ptr(struct sock_cgroup_data *skcd)
759 {
760 return skcd->cgroup;
761 }
762
763 #else /* CONFIG_CGROUP_DATA */
764
cgroup_sk_alloc(struct sock_cgroup_data * skcd)765 static inline void cgroup_sk_alloc(struct sock_cgroup_data *skcd) {}
cgroup_sk_clone(struct sock_cgroup_data * skcd)766 static inline void cgroup_sk_clone(struct sock_cgroup_data *skcd) {}
cgroup_sk_free(struct sock_cgroup_data * skcd)767 static inline void cgroup_sk_free(struct sock_cgroup_data *skcd) {}
768
769 #endif /* CONFIG_CGROUP_DATA */
770
771 struct cgroup_namespace {
772 struct ns_common ns;
773 struct user_namespace *user_ns;
774 struct ucounts *ucounts;
775 struct css_set *root_cset;
776 };
777
778 extern struct cgroup_namespace init_cgroup_ns;
779
780 #ifdef CONFIG_CGROUPS
781
782 void free_cgroup_ns(struct cgroup_namespace *ns);
783
784 struct cgroup_namespace *copy_cgroup_ns(unsigned long flags,
785 struct user_namespace *user_ns,
786 struct cgroup_namespace *old_ns);
787
788 int cgroup_path_ns(struct cgroup *cgrp, char *buf, size_t buflen,
789 struct cgroup_namespace *ns);
790
791 #else /* !CONFIG_CGROUPS */
792
free_cgroup_ns(struct cgroup_namespace * ns)793 static inline void free_cgroup_ns(struct cgroup_namespace *ns) { }
794 static inline struct cgroup_namespace *
copy_cgroup_ns(unsigned long flags,struct user_namespace * user_ns,struct cgroup_namespace * old_ns)795 copy_cgroup_ns(unsigned long flags, struct user_namespace *user_ns,
796 struct cgroup_namespace *old_ns)
797 {
798 return old_ns;
799 }
800
801 #endif /* !CONFIG_CGROUPS */
802
get_cgroup_ns(struct cgroup_namespace * ns)803 static inline void get_cgroup_ns(struct cgroup_namespace *ns)
804 {
805 if (ns)
806 refcount_inc(&ns->ns.count);
807 }
808
put_cgroup_ns(struct cgroup_namespace * ns)809 static inline void put_cgroup_ns(struct cgroup_namespace *ns)
810 {
811 if (ns && refcount_dec_and_test(&ns->ns.count))
812 free_cgroup_ns(ns);
813 }
814
815 #ifdef CONFIG_CGROUPS
816
817 void cgroup_enter_frozen(void);
818 void cgroup_leave_frozen(bool always_leave);
819 void cgroup_update_frozen(struct cgroup *cgrp);
820 void cgroup_freeze(struct cgroup *cgrp, bool freeze);
821 void cgroup_freezer_migrate_task(struct task_struct *task, struct cgroup *src,
822 struct cgroup *dst);
823
cgroup_task_frozen(struct task_struct * task)824 static inline bool cgroup_task_frozen(struct task_struct *task)
825 {
826 return task->frozen;
827 }
828
829 #else /* !CONFIG_CGROUPS */
830
cgroup_enter_frozen(void)831 static inline void cgroup_enter_frozen(void) { }
cgroup_leave_frozen(bool always_leave)832 static inline void cgroup_leave_frozen(bool always_leave) { }
cgroup_task_frozen(struct task_struct * task)833 static inline bool cgroup_task_frozen(struct task_struct *task)
834 {
835 return false;
836 }
837
838 #endif /* !CONFIG_CGROUPS */
839
840 #ifdef CONFIG_CGROUP_BPF
cgroup_bpf_get(struct cgroup * cgrp)841 static inline void cgroup_bpf_get(struct cgroup *cgrp)
842 {
843 percpu_ref_get(&cgrp->bpf.refcnt);
844 }
845
cgroup_bpf_put(struct cgroup * cgrp)846 static inline void cgroup_bpf_put(struct cgroup *cgrp)
847 {
848 percpu_ref_put(&cgrp->bpf.refcnt);
849 }
850
851 #else /* CONFIG_CGROUP_BPF */
852
cgroup_bpf_get(struct cgroup * cgrp)853 static inline void cgroup_bpf_get(struct cgroup *cgrp) {}
cgroup_bpf_put(struct cgroup * cgrp)854 static inline void cgroup_bpf_put(struct cgroup *cgrp) {}
855
856 #endif /* CONFIG_CGROUP_BPF */
857
858 #endif /* _LINUX_CGROUP_H */
859