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