Line data Source code
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 :
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 : */
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 :
350 : static inline void cgroup_get(struct cgroup *cgrp)
351 : {
352 : css_get(&cgrp->self);
353 : }
354 :
355 : static inline bool cgroup_tryget(struct cgroup *cgrp)
356 : {
357 : return css_tryget(&cgrp->self);
358 : }
359 :
360 : static inline void cgroup_put(struct cgroup *cgrp)
361 : {
362 : css_put(&cgrp->self);
363 : }
364 :
365 : extern struct mutex cgroup_mutex;
366 :
367 : static inline void cgroup_lock(void)
368 : {
369 : mutex_lock(&cgroup_mutex);
370 : }
371 :
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 : */
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 : */
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 *
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 : */
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 :
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 :
490 : static inline struct cgroup *task_dfl_cgroup(struct task_struct *task)
491 : {
492 : return task_css_set(task)->dfl_cgrp;
493 : }
494 :
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 : */
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 : */
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 : */
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 */
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 */
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 */
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 */
579 : static inline struct cftype *seq_cft(struct seq_file *seq)
580 : {
581 : return of_cft(seq->private);
582 : }
583 :
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 :
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 :
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 :
604 : static inline void pr_cont_cgroup_name(struct cgroup *cgrp)
605 : {
606 : pr_cont_kernfs_name(cgrp->kn);
607 : }
608 :
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 :
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 :
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 :
642 : static inline u64 cgroup_id(const struct cgroup *cgrp) { return 1; }
643 : static inline void css_get(struct cgroup_subsys_state *css) {}
644 : static inline void css_put(struct cgroup_subsys_state *css) {}
645 : static inline void cgroup_lock(void) {}
646 : static inline void cgroup_unlock(void) {}
647 : static inline int cgroup_attach_task_all(struct task_struct *from,
648 : struct task_struct *t) { return 0; }
649 : static inline int cgroupstats_build(struct cgroupstats *stats,
650 : struct dentry *dentry) { return -EINVAL; }
651 :
652 : static inline void cgroup_fork(struct task_struct *p) {}
653 : static inline int cgroup_can_fork(struct task_struct *p,
654 : struct kernel_clone_args *kargs) { return 0; }
655 : static inline void cgroup_cancel_fork(struct task_struct *p,
656 : struct kernel_clone_args *kargs) {}
657 : static inline void cgroup_post_fork(struct task_struct *p,
658 : struct kernel_clone_args *kargs) {}
659 : static inline void cgroup_exit(struct task_struct *p) {}
660 : static inline void cgroup_release(struct task_struct *p) {}
661 : static inline void cgroup_free(struct task_struct *p) {}
662 :
663 : static inline int cgroup_init_early(void) { return 0; }
664 : static inline int cgroup_init(void) { return 0; }
665 : static inline void cgroup_init_kthreadd(void) {}
666 : static inline void cgroup_kthread_ready(void) {}
667 :
668 : static inline struct cgroup *cgroup_parent(struct cgroup *cgrp)
669 : {
670 : return NULL;
671 : }
672 :
673 : static inline bool cgroup_psi_enabled(void)
674 : {
675 : return false;
676 : }
677 :
678 : static inline bool task_under_cgroup_hierarchy(struct task_struct *task,
679 : struct cgroup *ancestor)
680 : {
681 : return true;
682 : }
683 :
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
704 : static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {}
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 :
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 :
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 :
740 : static inline void cgroup_account_cputime(struct task_struct *task,
741 : 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 :
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 :
765 : static inline void cgroup_sk_alloc(struct sock_cgroup_data *skcd) {}
766 : static inline void cgroup_sk_clone(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 :
793 : static inline void free_cgroup_ns(struct cgroup_namespace *ns) { }
794 : static inline struct cgroup_namespace *
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 :
803 : static inline void get_cgroup_ns(struct cgroup_namespace *ns)
804 : {
805 : if (ns)
806 : refcount_inc(&ns->ns.count);
807 : }
808 :
809 : static inline void put_cgroup_ns(struct cgroup_namespace *ns)
810 : {
811 0 : 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 :
824 : static inline bool cgroup_task_frozen(struct task_struct *task)
825 : {
826 : return task->frozen;
827 : }
828 :
829 : #else /* !CONFIG_CGROUPS */
830 :
831 : static inline void cgroup_enter_frozen(void) { }
832 : static inline void cgroup_leave_frozen(bool always_leave) { }
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
841 : static inline void cgroup_bpf_get(struct cgroup *cgrp)
842 : {
843 : percpu_ref_get(&cgrp->bpf.refcnt);
844 : }
845 :
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 :
853 : static inline void cgroup_bpf_get(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 */
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