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 | enum { |
44 | CSS_TASK_ITER_PROCS = (1U << 0), /* walk only threadgroup leaders */ |
45 | CSS_TASK_ITER_THREADED = (1U << 1), /* walk all threaded css_sets in the domain */ |
46 | CSS_TASK_ITER_SKIPPED = (1U << 16), /* internal flags */ |
47 | }; |
48 | |
49 | /* a css_task_iter should be treated as an opaque object */ |
50 | struct css_task_iter { |
51 | struct cgroup_subsys *ss; |
52 | unsigned int flags; |
53 | |
54 | struct list_head *cset_pos; |
55 | struct list_head *cset_head; |
56 | |
57 | struct list_head *tcset_pos; |
58 | struct list_head *tcset_head; |
59 | |
60 | struct list_head *task_pos; |
61 | |
62 | struct list_head *cur_tasks_head; |
63 | struct css_set *cur_cset; |
64 | struct css_set *cur_dcset; |
65 | struct task_struct *cur_task; |
66 | struct list_head iters_node; /* css_set->task_iters */ |
67 | }; |
68 | |
69 | extern struct file_system_type cgroup_fs_type; |
70 | extern struct cgroup_root cgrp_dfl_root; |
71 | extern struct css_set init_css_set; |
72 | extern spinlock_t css_set_lock; |
73 | |
74 | #define SUBSYS(_x) extern struct cgroup_subsys _x ## _cgrp_subsys; |
75 | #include <linux/cgroup_subsys.h> |
76 | #undef SUBSYS |
77 | |
78 | #define SUBSYS(_x) \ |
79 | extern struct static_key_true _x ## _cgrp_subsys_enabled_key; \ |
80 | extern struct static_key_true _x ## _cgrp_subsys_on_dfl_key; |
81 | #include <linux/cgroup_subsys.h> |
82 | #undef SUBSYS |
83 | |
84 | /** |
85 | * cgroup_subsys_enabled - fast test on whether a subsys is enabled |
86 | * @ss: subsystem in question |
87 | */ |
88 | #define cgroup_subsys_enabled(ss) \ |
89 | static_branch_likely(&ss ## _enabled_key) |
90 | |
91 | /** |
92 | * cgroup_subsys_on_dfl - fast test on whether a subsys is on default hierarchy |
93 | * @ss: subsystem in question |
94 | */ |
95 | #define cgroup_subsys_on_dfl(ss) \ |
96 | static_branch_likely(&ss ## _on_dfl_key) |
97 | |
98 | bool css_has_online_children(struct cgroup_subsys_state *css); |
99 | struct cgroup_subsys_state *css_from_id(int id, struct cgroup_subsys *ss); |
100 | struct cgroup_subsys_state *cgroup_e_css(struct cgroup *cgroup, |
101 | struct cgroup_subsys *ss); |
102 | struct cgroup_subsys_state *cgroup_get_e_css(struct cgroup *cgroup, |
103 | struct cgroup_subsys *ss); |
104 | struct cgroup_subsys_state *css_tryget_online_from_dir(struct dentry *dentry, |
105 | struct cgroup_subsys *ss); |
106 | |
107 | struct cgroup *cgroup_get_from_path(const char *path); |
108 | struct cgroup *cgroup_get_from_fd(int fd); |
109 | struct cgroup *cgroup_v1v2_get_from_fd(int fd); |
110 | |
111 | int cgroup_attach_task_all(struct task_struct *from, struct task_struct *); |
112 | int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from); |
113 | |
114 | int cgroup_add_dfl_cftypes(struct cgroup_subsys *ss, struct cftype *cfts); |
115 | int cgroup_add_legacy_cftypes(struct cgroup_subsys *ss, struct cftype *cfts); |
116 | int cgroup_rm_cftypes(struct cftype *cfts); |
117 | void cgroup_file_notify(struct cgroup_file *cfile); |
118 | void cgroup_file_show(struct cgroup_file *cfile, bool show); |
119 | |
120 | int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry); |
121 | int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns, |
122 | struct pid *pid, struct task_struct *tsk); |
123 | |
124 | void cgroup_fork(struct task_struct *p); |
125 | extern int cgroup_can_fork(struct task_struct *p, |
126 | struct kernel_clone_args *kargs); |
127 | extern void cgroup_cancel_fork(struct task_struct *p, |
128 | struct kernel_clone_args *kargs); |
129 | extern void cgroup_post_fork(struct task_struct *p, |
130 | struct kernel_clone_args *kargs); |
131 | void cgroup_exit(struct task_struct *p); |
132 | void cgroup_release(struct task_struct *p); |
133 | void cgroup_free(struct task_struct *p); |
134 | |
135 | int cgroup_init_early(void); |
136 | int cgroup_init(void); |
137 | |
138 | int cgroup_parse_float(const char *input, unsigned dec_shift, s64 *v); |
139 | |
140 | /* |
141 | * Iteration helpers and macros. |
142 | */ |
143 | |
144 | struct cgroup_subsys_state *css_next_child(struct cgroup_subsys_state *pos, |
145 | struct cgroup_subsys_state *parent); |
146 | struct cgroup_subsys_state *css_next_descendant_pre(struct cgroup_subsys_state *pos, |
147 | struct cgroup_subsys_state *css); |
148 | struct cgroup_subsys_state *css_rightmost_descendant(struct cgroup_subsys_state *pos); |
149 | struct cgroup_subsys_state *css_next_descendant_post(struct cgroup_subsys_state *pos, |
150 | struct cgroup_subsys_state *css); |
151 | |
152 | struct task_struct *cgroup_taskset_first(struct cgroup_taskset *tset, |
153 | struct cgroup_subsys_state **dst_cssp); |
154 | struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset, |
155 | struct cgroup_subsys_state **dst_cssp); |
156 | |
157 | void css_task_iter_start(struct cgroup_subsys_state *css, unsigned int flags, |
158 | struct css_task_iter *it); |
159 | struct task_struct *css_task_iter_next(struct css_task_iter *it); |
160 | void css_task_iter_end(struct css_task_iter *it); |
161 | |
162 | /** |
163 | * css_for_each_child - iterate through children of a css |
164 | * @pos: the css * to use as the loop cursor |
165 | * @parent: css whose children to walk |
166 | * |
167 | * Walk @parent's children. Must be called under rcu_read_lock(). |
168 | * |
169 | * If a subsystem synchronizes ->css_online() and the start of iteration, a |
170 | * css which finished ->css_online() is guaranteed to be visible in the |
171 | * future iterations and will stay visible until the last reference is put. |
172 | * A css which hasn't finished ->css_online() or already finished |
173 | * ->css_offline() may show up during traversal. It's each subsystem's |
174 | * responsibility to synchronize against on/offlining. |
175 | * |
176 | * It is allowed to temporarily drop RCU read lock during iteration. The |
177 | * caller is responsible for ensuring that @pos remains accessible until |
178 | * the start of the next iteration by, for example, bumping the css refcnt. |
179 | */ |
180 | #define css_for_each_child(pos, parent) \ |
181 | for ((pos) = css_next_child(NULL, (parent)); (pos); \ |
182 | (pos) = css_next_child((pos), (parent))) |
183 | |
184 | /** |
185 | * css_for_each_descendant_pre - pre-order walk of a css's descendants |
186 | * @pos: the css * to use as the loop cursor |
187 | * @root: css whose descendants to walk |
188 | * |
189 | * Walk @root's descendants. @root is included in the iteration and the |
190 | * first node to be visited. Must be called under rcu_read_lock(). |
191 | * |
192 | * If a subsystem synchronizes ->css_online() and the start of iteration, a |
193 | * css which finished ->css_online() is guaranteed to be visible in the |
194 | * future iterations and will stay visible until the last reference is put. |
195 | * A css which hasn't finished ->css_online() or already finished |
196 | * ->css_offline() may show up during traversal. It's each subsystem's |
197 | * responsibility to synchronize against on/offlining. |
198 | * |
199 | * For example, the following guarantees that a descendant can't escape |
200 | * state updates of its ancestors. |
201 | * |
202 | * my_online(@css) |
203 | * { |
204 | * Lock @css's parent and @css; |
205 | * Inherit state from the parent; |
206 | * Unlock both. |
207 | * } |
208 | * |
209 | * my_update_state(@css) |
210 | * { |
211 | * css_for_each_descendant_pre(@pos, @css) { |
212 | * Lock @pos; |
213 | * if (@pos == @css) |
214 | * Update @css's state; |
215 | * else |
216 | * Verify @pos is alive and inherit state from its parent; |
217 | * Unlock @pos; |
218 | * } |
219 | * } |
220 | * |
221 | * As long as the inheriting step, including checking the parent state, is |
222 | * enclosed inside @pos locking, double-locking the parent isn't necessary |
223 | * while inheriting. The state update to the parent is guaranteed to be |
224 | * visible by walking order and, as long as inheriting operations to the |
225 | * same @pos are atomic to each other, multiple updates racing each other |
226 | * still result in the correct state. It's guaranateed that at least one |
227 | * inheritance happens for any css after the latest update to its parent. |
228 | * |
229 | * If checking parent's state requires locking the parent, each inheriting |
230 | * iteration should lock and unlock both @pos->parent and @pos. |
231 | * |
232 | * Alternatively, a subsystem may choose to use a single global lock to |
233 | * synchronize ->css_online() and ->css_offline() against tree-walking |
234 | * operations. |
235 | * |
236 | * It is allowed to temporarily drop RCU read lock during iteration. The |
237 | * caller is responsible for ensuring that @pos remains accessible until |
238 | * the start of the next iteration by, for example, bumping the css refcnt. |
239 | */ |
240 | #define css_for_each_descendant_pre(pos, css) \ |
241 | for ((pos) = css_next_descendant_pre(NULL, (css)); (pos); \ |
242 | (pos) = css_next_descendant_pre((pos), (css))) |
243 | |
244 | /** |
245 | * css_for_each_descendant_post - post-order walk of a css's descendants |
246 | * @pos: the css * to use as the loop cursor |
247 | * @css: css whose descendants to walk |
248 | * |
249 | * Similar to css_for_each_descendant_pre() but performs post-order |
250 | * traversal instead. @root is included in the iteration and the last |
251 | * node to be visited. |
252 | * |
253 | * If a subsystem synchronizes ->css_online() and the start of iteration, a |
254 | * css which finished ->css_online() is guaranteed to be visible in the |
255 | * future iterations and will stay visible until the last reference is put. |
256 | * A css which hasn't finished ->css_online() or already finished |
257 | * ->css_offline() may show up during traversal. It's each subsystem's |
258 | * responsibility to synchronize against on/offlining. |
259 | * |
260 | * Note that the walk visibility guarantee example described in pre-order |
261 | * walk doesn't apply the same to post-order walks. |
262 | */ |
263 | #define css_for_each_descendant_post(pos, css) \ |
264 | for ((pos) = css_next_descendant_post(NULL, (css)); (pos); \ |
265 | (pos) = css_next_descendant_post((pos), (css))) |
266 | |
267 | /** |
268 | * cgroup_taskset_for_each - iterate cgroup_taskset |
269 | * @task: the loop cursor |
270 | * @dst_css: the destination css |
271 | * @tset: taskset to iterate |
272 | * |
273 | * @tset may contain multiple tasks and they may belong to multiple |
274 | * processes. |
275 | * |
276 | * On the v2 hierarchy, there may be tasks from multiple processes and they |
277 | * may not share the source or destination csses. |
278 | * |
279 | * On traditional hierarchies, when there are multiple tasks in @tset, if a |
280 | * task of a process is in @tset, all tasks of the process are in @tset. |
281 | * Also, all are guaranteed to share the same source and destination csses. |
282 | * |
283 | * Iteration is not in any specific order. |
284 | */ |
285 | #define cgroup_taskset_for_each(task, dst_css, tset) \ |
286 | for ((task) = cgroup_taskset_first((tset), &(dst_css)); \ |
287 | (task); \ |
288 | (task) = cgroup_taskset_next((tset), &(dst_css))) |
289 | |
290 | /** |
291 | * cgroup_taskset_for_each_leader - iterate group leaders in a cgroup_taskset |
292 | * @leader: the loop cursor |
293 | * @dst_css: the destination css |
294 | * @tset: taskset to iterate |
295 | * |
296 | * Iterate threadgroup leaders of @tset. For single-task migrations, @tset |
297 | * may not contain any. |
298 | */ |
299 | #define cgroup_taskset_for_each_leader(leader, dst_css, tset) \ |
300 | for ((leader) = cgroup_taskset_first((tset), &(dst_css)); \ |
301 | (leader); \ |
302 | (leader) = cgroup_taskset_next((tset), &(dst_css))) \ |
303 | if ((leader) != (leader)->group_leader) \ |
304 | ; \ |
305 | else |
306 | |
307 | /* |
308 | * Inline functions. |
309 | */ |
310 | |
311 | #ifdef CONFIG_DEBUG_CGROUP_REF |
312 | void css_get(struct cgroup_subsys_state *css); |
313 | void css_get_many(struct cgroup_subsys_state *css, unsigned int n); |
314 | bool css_tryget(struct cgroup_subsys_state *css); |
315 | bool css_tryget_online(struct cgroup_subsys_state *css); |
316 | void css_put(struct cgroup_subsys_state *css); |
317 | void css_put_many(struct cgroup_subsys_state *css, unsigned int n); |
318 | #else |
319 | #define CGROUP_REF_FN_ATTRS static inline |
320 | #define CGROUP_REF_EXPORT(fn) |
321 | #include <linux/cgroup_refcnt.h> |
322 | #endif |
323 | |
324 | static inline u64 cgroup_id(const struct cgroup *cgrp) |
325 | { |
326 | return cgrp->kn->id; |
327 | } |
328 | |
329 | /** |
330 | * css_is_dying - test whether the specified css is dying |
331 | * @css: target css |
332 | * |
333 | * Test whether @css is in the process of offlining or already offline. In |
334 | * most cases, ->css_online() and ->css_offline() callbacks should be |
335 | * enough; however, the actual offline operations are RCU delayed and this |
336 | * test returns %true also when @css is scheduled to be offlined. |
337 | * |
338 | * This is useful, for example, when the use case requires synchronous |
339 | * behavior with respect to cgroup removal. cgroup removal schedules css |
340 | * offlining but the css can seem alive while the operation is being |
341 | * delayed. If the delay affects user visible semantics, this test can be |
342 | * used to resolve the situation. |
343 | */ |
344 | static inline bool css_is_dying(struct cgroup_subsys_state *css) |
345 | { |
346 | return !(css->flags & CSS_NO_REF) && percpu_ref_is_dying(ref: &css->refcnt); |
347 | } |
348 | |
349 | static inline void cgroup_get(struct cgroup *cgrp) |
350 | { |
351 | css_get(css: &cgrp->self); |
352 | } |
353 | |
354 | static inline bool cgroup_tryget(struct cgroup *cgrp) |
355 | { |
356 | return css_tryget(css: &cgrp->self); |
357 | } |
358 | |
359 | static inline void cgroup_put(struct cgroup *cgrp) |
360 | { |
361 | css_put(css: &cgrp->self); |
362 | } |
363 | |
364 | extern struct mutex cgroup_mutex; |
365 | |
366 | static inline void cgroup_lock(void) |
367 | { |
368 | mutex_lock(&cgroup_mutex); |
369 | } |
370 | |
371 | static inline void cgroup_unlock(void) |
372 | { |
373 | mutex_unlock(lock: &cgroup_mutex); |
374 | } |
375 | |
376 | /** |
377 | * task_css_set_check - obtain a task's css_set with extra access conditions |
378 | * @task: the task to obtain css_set for |
379 | * @__c: extra condition expression to be passed to rcu_dereference_check() |
380 | * |
381 | * A task's css_set is RCU protected, initialized and exited while holding |
382 | * task_lock(), and can only be modified while holding both cgroup_mutex |
383 | * and task_lock() while the task is alive. This macro verifies that the |
384 | * caller is inside proper critical section and returns @task's css_set. |
385 | * |
386 | * The caller can also specify additional allowed conditions via @__c, such |
387 | * as locks used during the cgroup_subsys::attach() methods. |
388 | */ |
389 | #ifdef CONFIG_PROVE_RCU |
390 | #define task_css_set_check(task, __c) \ |
391 | rcu_dereference_check((task)->cgroups, \ |
392 | rcu_read_lock_sched_held() || \ |
393 | lockdep_is_held(&cgroup_mutex) || \ |
394 | lockdep_is_held(&css_set_lock) || \ |
395 | ((task)->flags & PF_EXITING) || (__c)) |
396 | #else |
397 | #define task_css_set_check(task, __c) \ |
398 | rcu_dereference((task)->cgroups) |
399 | #endif |
400 | |
401 | /** |
402 | * task_css_check - obtain css for (task, subsys) w/ extra access conds |
403 | * @task: the target task |
404 | * @subsys_id: the target subsystem ID |
405 | * @__c: extra condition expression to be passed to rcu_dereference_check() |
406 | * |
407 | * Return the cgroup_subsys_state for the (@task, @subsys_id) pair. The |
408 | * synchronization rules are the same as task_css_set_check(). |
409 | */ |
410 | #define task_css_check(task, subsys_id, __c) \ |
411 | task_css_set_check((task), (__c))->subsys[(subsys_id)] |
412 | |
413 | /** |
414 | * task_css_set - obtain a task's css_set |
415 | * @task: the task to obtain css_set for |
416 | * |
417 | * See task_css_set_check(). |
418 | */ |
419 | static inline struct css_set *task_css_set(struct task_struct *task) |
420 | { |
421 | return task_css_set_check(task, false); |
422 | } |
423 | |
424 | /** |
425 | * task_css - obtain css for (task, subsys) |
426 | * @task: the target task |
427 | * @subsys_id: the target subsystem ID |
428 | * |
429 | * See task_css_check(). |
430 | */ |
431 | static inline struct cgroup_subsys_state *task_css(struct task_struct *task, |
432 | int subsys_id) |
433 | { |
434 | return task_css_check(task, subsys_id, false); |
435 | } |
436 | |
437 | /** |
438 | * task_get_css - find and get the css for (task, subsys) |
439 | * @task: the target task |
440 | * @subsys_id: the target subsystem ID |
441 | * |
442 | * Find the css for the (@task, @subsys_id) combination, increment a |
443 | * reference on and return it. This function is guaranteed to return a |
444 | * valid css. The returned css may already have been offlined. |
445 | */ |
446 | static inline struct cgroup_subsys_state * |
447 | task_get_css(struct task_struct *task, int subsys_id) |
448 | { |
449 | struct cgroup_subsys_state *css; |
450 | |
451 | rcu_read_lock(); |
452 | while (true) { |
453 | css = task_css(task, subsys_id); |
454 | /* |
455 | * Can't use css_tryget_online() here. A task which has |
456 | * PF_EXITING set may stay associated with an offline css. |
457 | * If such task calls this function, css_tryget_online() |
458 | * will keep failing. |
459 | */ |
460 | if (likely(css_tryget(css))) |
461 | break; |
462 | cpu_relax(); |
463 | } |
464 | rcu_read_unlock(); |
465 | return css; |
466 | } |
467 | |
468 | /** |
469 | * task_css_is_root - test whether a task belongs to the root css |
470 | * @task: the target task |
471 | * @subsys_id: the target subsystem ID |
472 | * |
473 | * Test whether @task belongs to the root css on the specified subsystem. |
474 | * May be invoked in any context. |
475 | */ |
476 | static inline bool task_css_is_root(struct task_struct *task, int subsys_id) |
477 | { |
478 | return task_css_check(task, subsys_id, true) == |
479 | init_css_set.subsys[subsys_id]; |
480 | } |
481 | |
482 | static inline struct cgroup *task_cgroup(struct task_struct *task, |
483 | int subsys_id) |
484 | { |
485 | return task_css(task, subsys_id)->cgroup; |
486 | } |
487 | |
488 | static inline struct cgroup *task_dfl_cgroup(struct task_struct *task) |
489 | { |
490 | return task_css_set(task)->dfl_cgrp; |
491 | } |
492 | |
493 | static inline struct cgroup *cgroup_parent(struct cgroup *cgrp) |
494 | { |
495 | struct cgroup_subsys_state *parent_css = cgrp->self.parent; |
496 | |
497 | if (parent_css) |
498 | return container_of(parent_css, struct cgroup, self); |
499 | return NULL; |
500 | } |
501 | |
502 | /** |
503 | * cgroup_is_descendant - test ancestry |
504 | * @cgrp: the cgroup to be tested |
505 | * @ancestor: possible ancestor of @cgrp |
506 | * |
507 | * Test whether @cgrp is a descendant of @ancestor. It also returns %true |
508 | * if @cgrp == @ancestor. This function is safe to call as long as @cgrp |
509 | * and @ancestor are accessible. |
510 | */ |
511 | static inline bool cgroup_is_descendant(struct cgroup *cgrp, |
512 | struct cgroup *ancestor) |
513 | { |
514 | if (cgrp->root != ancestor->root || cgrp->level < ancestor->level) |
515 | return false; |
516 | return cgrp->ancestors[ancestor->level] == ancestor; |
517 | } |
518 | |
519 | /** |
520 | * cgroup_ancestor - find ancestor of cgroup |
521 | * @cgrp: cgroup to find ancestor of |
522 | * @ancestor_level: level of ancestor to find starting from root |
523 | * |
524 | * Find ancestor of cgroup at specified level starting from root if it exists |
525 | * and return pointer to it. Return NULL if @cgrp doesn't have ancestor at |
526 | * @ancestor_level. |
527 | * |
528 | * This function is safe to call as long as @cgrp is accessible. |
529 | */ |
530 | static inline struct cgroup *cgroup_ancestor(struct cgroup *cgrp, |
531 | int ancestor_level) |
532 | { |
533 | if (ancestor_level < 0 || ancestor_level > cgrp->level) |
534 | return NULL; |
535 | return cgrp->ancestors[ancestor_level]; |
536 | } |
537 | |
538 | /** |
539 | * task_under_cgroup_hierarchy - test task's membership of cgroup ancestry |
540 | * @task: the task to be tested |
541 | * @ancestor: possible ancestor of @task's cgroup |
542 | * |
543 | * Tests whether @task's default cgroup hierarchy is a descendant of @ancestor. |
544 | * It follows all the same rules as cgroup_is_descendant, and only applies |
545 | * to the default hierarchy. |
546 | */ |
547 | static inline bool task_under_cgroup_hierarchy(struct task_struct *task, |
548 | struct cgroup *ancestor) |
549 | { |
550 | struct css_set *cset = task_css_set(task); |
551 | |
552 | return cgroup_is_descendant(cgrp: cset->dfl_cgrp, ancestor); |
553 | } |
554 | |
555 | /* no synchronization, the result can only be used as a hint */ |
556 | static inline bool cgroup_is_populated(struct cgroup *cgrp) |
557 | { |
558 | return cgrp->nr_populated_csets + cgrp->nr_populated_domain_children + |
559 | cgrp->nr_populated_threaded_children; |
560 | } |
561 | |
562 | /* returns ino associated with a cgroup */ |
563 | static inline ino_t cgroup_ino(struct cgroup *cgrp) |
564 | { |
565 | return kernfs_ino(kn: cgrp->kn); |
566 | } |
567 | |
568 | /* cft/css accessors for cftype->write() operation */ |
569 | static inline struct cftype *of_cft(struct kernfs_open_file *of) |
570 | { |
571 | return of->kn->priv; |
572 | } |
573 | |
574 | struct cgroup_subsys_state *of_css(struct kernfs_open_file *of); |
575 | |
576 | /* cft/css accessors for cftype->seq_*() operations */ |
577 | static inline struct cftype *seq_cft(struct seq_file *seq) |
578 | { |
579 | return of_cft(of: seq->private); |
580 | } |
581 | |
582 | static inline struct cgroup_subsys_state *seq_css(struct seq_file *seq) |
583 | { |
584 | return of_css(of: seq->private); |
585 | } |
586 | |
587 | /* |
588 | * Name / path handling functions. All are thin wrappers around the kernfs |
589 | * counterparts and can be called under any context. |
590 | */ |
591 | |
592 | static inline int cgroup_name(struct cgroup *cgrp, char *buf, size_t buflen) |
593 | { |
594 | return kernfs_name(kn: cgrp->kn, buf, buflen); |
595 | } |
596 | |
597 | static inline int cgroup_path(struct cgroup *cgrp, char *buf, size_t buflen) |
598 | { |
599 | return kernfs_path(kn: cgrp->kn, buf, buflen); |
600 | } |
601 | |
602 | static inline void pr_cont_cgroup_name(struct cgroup *cgrp) |
603 | { |
604 | pr_cont_kernfs_name(kn: cgrp->kn); |
605 | } |
606 | |
607 | static inline void pr_cont_cgroup_path(struct cgroup *cgrp) |
608 | { |
609 | pr_cont_kernfs_path(kn: cgrp->kn); |
610 | } |
611 | |
612 | bool cgroup_psi_enabled(void); |
613 | |
614 | static inline void cgroup_init_kthreadd(void) |
615 | { |
616 | /* |
617 | * kthreadd is inherited by all kthreads, keep it in the root so |
618 | * that the new kthreads are guaranteed to stay in the root until |
619 | * initialization is finished. |
620 | */ |
621 | current->no_cgroup_migration = 1; |
622 | } |
623 | |
624 | static inline void cgroup_kthread_ready(void) |
625 | { |
626 | /* |
627 | * This kthread finished initialization. The creator should have |
628 | * set PF_NO_SETAFFINITY if this kthread should stay in the root. |
629 | */ |
630 | current->no_cgroup_migration = 0; |
631 | } |
632 | |
633 | void cgroup_path_from_kernfs_id(u64 id, char *buf, size_t buflen); |
634 | struct cgroup *cgroup_get_from_id(u64 id); |
635 | #else /* !CONFIG_CGROUPS */ |
636 | |
637 | struct cgroup_subsys_state; |
638 | struct cgroup; |
639 | |
640 | static inline u64 cgroup_id(const struct cgroup *cgrp) { return 1; } |
641 | static inline void css_get(struct cgroup_subsys_state *css) {} |
642 | static inline void css_put(struct cgroup_subsys_state *css) {} |
643 | static inline void cgroup_lock(void) {} |
644 | static inline void cgroup_unlock(void) {} |
645 | static inline int cgroup_attach_task_all(struct task_struct *from, |
646 | struct task_struct *t) { return 0; } |
647 | static inline int cgroupstats_build(struct cgroupstats *stats, |
648 | struct dentry *dentry) { return -EINVAL; } |
649 | |
650 | static inline void cgroup_fork(struct task_struct *p) {} |
651 | static inline int cgroup_can_fork(struct task_struct *p, |
652 | struct kernel_clone_args *kargs) { return 0; } |
653 | static inline void cgroup_cancel_fork(struct task_struct *p, |
654 | struct kernel_clone_args *kargs) {} |
655 | static inline void cgroup_post_fork(struct task_struct *p, |
656 | struct kernel_clone_args *kargs) {} |
657 | static inline void cgroup_exit(struct task_struct *p) {} |
658 | static inline void cgroup_release(struct task_struct *p) {} |
659 | static inline void cgroup_free(struct task_struct *p) {} |
660 | |
661 | static inline int cgroup_init_early(void) { return 0; } |
662 | static inline int cgroup_init(void) { return 0; } |
663 | static inline void cgroup_init_kthreadd(void) {} |
664 | static inline void cgroup_kthread_ready(void) {} |
665 | |
666 | static inline struct cgroup *cgroup_parent(struct cgroup *cgrp) |
667 | { |
668 | return NULL; |
669 | } |
670 | |
671 | static inline bool cgroup_psi_enabled(void) |
672 | { |
673 | return false; |
674 | } |
675 | |
676 | static inline bool task_under_cgroup_hierarchy(struct task_struct *task, |
677 | struct cgroup *ancestor) |
678 | { |
679 | return true; |
680 | } |
681 | |
682 | static inline void cgroup_path_from_kernfs_id(u64 id, char *buf, size_t buflen) |
683 | {} |
684 | #endif /* !CONFIG_CGROUPS */ |
685 | |
686 | #ifdef CONFIG_CGROUPS |
687 | /* |
688 | * cgroup scalable recursive statistics. |
689 | */ |
690 | void cgroup_rstat_updated(struct cgroup *cgrp, int cpu); |
691 | void cgroup_rstat_flush(struct cgroup *cgrp); |
692 | void cgroup_rstat_flush_hold(struct cgroup *cgrp); |
693 | void cgroup_rstat_flush_release(void); |
694 | |
695 | /* |
696 | * Basic resource stats. |
697 | */ |
698 | #ifdef CONFIG_CGROUP_CPUACCT |
699 | void cpuacct_charge(struct task_struct *tsk, u64 cputime); |
700 | void cpuacct_account_field(struct task_struct *tsk, int index, u64 val); |
701 | #else |
702 | static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {} |
703 | static inline void cpuacct_account_field(struct task_struct *tsk, int index, |
704 | u64 val) {} |
705 | #endif |
706 | |
707 | void __cgroup_account_cputime(struct cgroup *cgrp, u64 delta_exec); |
708 | void __cgroup_account_cputime_field(struct cgroup *cgrp, |
709 | enum cpu_usage_stat index, u64 delta_exec); |
710 | |
711 | static inline void cgroup_account_cputime(struct task_struct *task, |
712 | u64 delta_exec) |
713 | { |
714 | struct cgroup *cgrp; |
715 | |
716 | cpuacct_charge(tsk: task, cputime: delta_exec); |
717 | |
718 | cgrp = task_dfl_cgroup(task); |
719 | if (cgroup_parent(cgrp)) |
720 | __cgroup_account_cputime(cgrp, delta_exec); |
721 | } |
722 | |
723 | static inline void cgroup_account_cputime_field(struct task_struct *task, |
724 | enum cpu_usage_stat index, |
725 | u64 delta_exec) |
726 | { |
727 | struct cgroup *cgrp; |
728 | |
729 | cpuacct_account_field(tsk: task, index, val: delta_exec); |
730 | |
731 | cgrp = task_dfl_cgroup(task); |
732 | if (cgroup_parent(cgrp)) |
733 | __cgroup_account_cputime_field(cgrp, index, delta_exec); |
734 | } |
735 | |
736 | #else /* CONFIG_CGROUPS */ |
737 | |
738 | static inline void cgroup_account_cputime(struct task_struct *task, |
739 | u64 delta_exec) {} |
740 | static inline void cgroup_account_cputime_field(struct task_struct *task, |
741 | enum cpu_usage_stat index, |
742 | u64 delta_exec) {} |
743 | |
744 | #endif /* CONFIG_CGROUPS */ |
745 | |
746 | /* |
747 | * sock->sk_cgrp_data handling. For more info, see sock_cgroup_data |
748 | * definition in cgroup-defs.h. |
749 | */ |
750 | #ifdef CONFIG_SOCK_CGROUP_DATA |
751 | |
752 | void cgroup_sk_alloc(struct sock_cgroup_data *skcd); |
753 | void cgroup_sk_clone(struct sock_cgroup_data *skcd); |
754 | void cgroup_sk_free(struct sock_cgroup_data *skcd); |
755 | |
756 | static inline struct cgroup *sock_cgroup_ptr(struct sock_cgroup_data *skcd) |
757 | { |
758 | return skcd->cgroup; |
759 | } |
760 | |
761 | #else /* CONFIG_CGROUP_DATA */ |
762 | |
763 | static inline void cgroup_sk_alloc(struct sock_cgroup_data *skcd) {} |
764 | static inline void cgroup_sk_clone(struct sock_cgroup_data *skcd) {} |
765 | static inline void cgroup_sk_free(struct sock_cgroup_data *skcd) {} |
766 | |
767 | #endif /* CONFIG_CGROUP_DATA */ |
768 | |
769 | struct cgroup_namespace { |
770 | struct ns_common ns; |
771 | struct user_namespace *user_ns; |
772 | struct ucounts *ucounts; |
773 | struct css_set *root_cset; |
774 | }; |
775 | |
776 | extern struct cgroup_namespace init_cgroup_ns; |
777 | |
778 | #ifdef CONFIG_CGROUPS |
779 | |
780 | void free_cgroup_ns(struct cgroup_namespace *ns); |
781 | |
782 | struct cgroup_namespace *copy_cgroup_ns(unsigned long flags, |
783 | struct user_namespace *user_ns, |
784 | struct cgroup_namespace *old_ns); |
785 | |
786 | int cgroup_path_ns(struct cgroup *cgrp, char *buf, size_t buflen, |
787 | struct cgroup_namespace *ns); |
788 | |
789 | #else /* !CONFIG_CGROUPS */ |
790 | |
791 | static inline void free_cgroup_ns(struct cgroup_namespace *ns) { } |
792 | static inline struct cgroup_namespace * |
793 | copy_cgroup_ns(unsigned long flags, struct user_namespace *user_ns, |
794 | struct cgroup_namespace *old_ns) |
795 | { |
796 | return old_ns; |
797 | } |
798 | |
799 | #endif /* !CONFIG_CGROUPS */ |
800 | |
801 | static inline void get_cgroup_ns(struct cgroup_namespace *ns) |
802 | { |
803 | if (ns) |
804 | refcount_inc(r: &ns->ns.count); |
805 | } |
806 | |
807 | static inline void put_cgroup_ns(struct cgroup_namespace *ns) |
808 | { |
809 | if (ns && refcount_dec_and_test(r: &ns->ns.count)) |
810 | free_cgroup_ns(ns); |
811 | } |
812 | |
813 | #ifdef CONFIG_CGROUPS |
814 | |
815 | void cgroup_enter_frozen(void); |
816 | void cgroup_leave_frozen(bool always_leave); |
817 | void cgroup_update_frozen(struct cgroup *cgrp); |
818 | void cgroup_freeze(struct cgroup *cgrp, bool freeze); |
819 | void cgroup_freezer_migrate_task(struct task_struct *task, struct cgroup *src, |
820 | struct cgroup *dst); |
821 | |
822 | static inline bool cgroup_task_frozen(struct task_struct *task) |
823 | { |
824 | return task->frozen; |
825 | } |
826 | |
827 | #else /* !CONFIG_CGROUPS */ |
828 | |
829 | static inline void cgroup_enter_frozen(void) { } |
830 | static inline void cgroup_leave_frozen(bool always_leave) { } |
831 | static inline bool cgroup_task_frozen(struct task_struct *task) |
832 | { |
833 | return false; |
834 | } |
835 | |
836 | #endif /* !CONFIG_CGROUPS */ |
837 | |
838 | #ifdef CONFIG_CGROUP_BPF |
839 | static inline void cgroup_bpf_get(struct cgroup *cgrp) |
840 | { |
841 | percpu_ref_get(ref: &cgrp->bpf.refcnt); |
842 | } |
843 | |
844 | static inline void cgroup_bpf_put(struct cgroup *cgrp) |
845 | { |
846 | percpu_ref_put(ref: &cgrp->bpf.refcnt); |
847 | } |
848 | |
849 | #else /* CONFIG_CGROUP_BPF */ |
850 | |
851 | static inline void cgroup_bpf_get(struct cgroup *cgrp) {} |
852 | static inline void cgroup_bpf_put(struct cgroup *cgrp) {} |
853 | |
854 | #endif /* CONFIG_CGROUP_BPF */ |
855 | |
856 | struct cgroup *task_get_cgroup1(struct task_struct *tsk, int hierarchy_id); |
857 | |
858 | #endif /* _LINUX_CGROUP_H */ |
859 | |