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1 : : /* SPDX-License-Identifier: GPL-2.0 */
2 : : #ifndef _LINUX_CGROUP_H
3 : : #define _LINUX_CGROUP_H
4 : : /*
5 : : * cgroup interface
6 : : *
7 : : * Copyright (C) 2003 BULL SA
8 : : * Copyright (C) 2004-2006 Silicon Graphics, Inc.
9 : : *
10 : : */
11 : :
12 : : #include <linux/sched.h>
13 : : #include <linux/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 : : #ifdef CONFIG_CGROUPS
31 : :
32 : : /*
33 : : * All weight knobs on the default hierarhcy should use the following min,
34 : : * default and max values. The default value is the logarithmic center of
35 : : * MIN and MAX and allows 100x to be expressed in both directions.
36 : : */
37 : : #define CGROUP_WEIGHT_MIN 1
38 : : #define CGROUP_WEIGHT_DFL 100
39 : : #define CGROUP_WEIGHT_MAX 10000
40 : :
41 : : /* walk only threadgroup leaders */
42 : : #define CSS_TASK_ITER_PROCS (1U << 0)
43 : : /* walk all threaded css_sets in the domain */
44 : : #define CSS_TASK_ITER_THREADED (1U << 1)
45 : :
46 : : /* internal flags */
47 : : #define CSS_TASK_ITER_SKIPPED (1U << 16)
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 : : struct list_head *tasks_head;
62 : : struct list_head *mg_tasks_head;
63 : : struct list_head *dying_tasks_head;
64 : :
65 : : struct list_head *cur_tasks_head;
66 : : struct css_set *cur_cset;
67 : : struct css_set *cur_dcset;
68 : : struct task_struct *cur_task;
69 : : struct list_head iters_node; /* css_set->task_iters */
70 : : };
71 : :
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 : :
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 : :
119 : : int task_cgroup_path(struct task_struct *task, char *buf, size_t buflen);
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 : : extern void cgroup_cancel_fork(struct task_struct *p);
127 : : extern void cgroup_post_fork(struct task_struct *p);
128 : : void cgroup_exit(struct task_struct *p);
129 : : void cgroup_release(struct task_struct *p);
130 : : void cgroup_free(struct task_struct *p);
131 : :
132 : : int cgroup_init_early(void);
133 : : int cgroup_init(void);
134 : :
135 : : int cgroup_parse_float(const char *input, unsigned dec_shift, s64 *v);
136 : :
137 : : /*
138 : : * Iteration helpers and macros.
139 : : */
140 : :
141 : : struct cgroup_subsys_state *css_next_child(struct cgroup_subsys_state *pos,
142 : : struct cgroup_subsys_state *parent);
143 : : struct cgroup_subsys_state *css_next_descendant_pre(struct cgroup_subsys_state *pos,
144 : : struct cgroup_subsys_state *css);
145 : : struct cgroup_subsys_state *css_rightmost_descendant(struct cgroup_subsys_state *pos);
146 : : struct cgroup_subsys_state *css_next_descendant_post(struct cgroup_subsys_state *pos,
147 : : struct cgroup_subsys_state *css);
148 : :
149 : : struct task_struct *cgroup_taskset_first(struct cgroup_taskset *tset,
150 : : struct cgroup_subsys_state **dst_cssp);
151 : : struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset,
152 : : struct cgroup_subsys_state **dst_cssp);
153 : :
154 : : void css_task_iter_start(struct cgroup_subsys_state *css, unsigned int flags,
155 : : struct css_task_iter *it);
156 : : struct task_struct *css_task_iter_next(struct css_task_iter *it);
157 : : void css_task_iter_end(struct css_task_iter *it);
158 : :
159 : : /**
160 : : * css_for_each_child - iterate through children of a css
161 : : * @pos: the css * to use as the loop cursor
162 : : * @parent: css whose children to walk
163 : : *
164 : : * Walk @parent's children. Must be called under rcu_read_lock().
165 : : *
166 : : * If a subsystem synchronizes ->css_online() and the start of iteration, a
167 : : * css which finished ->css_online() is guaranteed to be visible in the
168 : : * future iterations and will stay visible until the last reference is put.
169 : : * A css which hasn't finished ->css_online() or already finished
170 : : * ->css_offline() may show up during traversal. It's each subsystem's
171 : : * responsibility to synchronize against on/offlining.
172 : : *
173 : : * It is allowed to temporarily drop RCU read lock during iteration. The
174 : : * caller is responsible for ensuring that @pos remains accessible until
175 : : * the start of the next iteration by, for example, bumping the css refcnt.
176 : : */
177 : : #define css_for_each_child(pos, parent) \
178 : : for ((pos) = css_next_child(NULL, (parent)); (pos); \
179 : : (pos) = css_next_child((pos), (parent)))
180 : :
181 : : /**
182 : : * css_for_each_descendant_pre - pre-order walk of a css's descendants
183 : : * @pos: the css * to use as the loop cursor
184 : : * @root: css whose descendants to walk
185 : : *
186 : : * Walk @root's descendants. @root is included in the iteration and the
187 : : * first node to be visited. Must be called under rcu_read_lock().
188 : : *
189 : : * If a subsystem synchronizes ->css_online() and the start of iteration, a
190 : : * css which finished ->css_online() is guaranteed to be visible in the
191 : : * future iterations and will stay visible until the last reference is put.
192 : : * A css which hasn't finished ->css_online() or already finished
193 : : * ->css_offline() may show up during traversal. It's each subsystem's
194 : : * responsibility to synchronize against on/offlining.
195 : : *
196 : : * For example, the following guarantees that a descendant can't escape
197 : : * state updates of its ancestors.
198 : : *
199 : : * my_online(@css)
200 : : * {
201 : : * Lock @css's parent and @css;
202 : : * Inherit state from the parent;
203 : : * Unlock both.
204 : : * }
205 : : *
206 : : * my_update_state(@css)
207 : : * {
208 : : * css_for_each_descendant_pre(@pos, @css) {
209 : : * Lock @pos;
210 : : * if (@pos == @css)
211 : : * Update @css's state;
212 : : * else
213 : : * Verify @pos is alive and inherit state from its parent;
214 : : * Unlock @pos;
215 : : * }
216 : : * }
217 : : *
218 : : * As long as the inheriting step, including checking the parent state, is
219 : : * enclosed inside @pos locking, double-locking the parent isn't necessary
220 : : * while inheriting. The state update to the parent is guaranteed to be
221 : : * visible by walking order and, as long as inheriting operations to the
222 : : * same @pos are atomic to each other, multiple updates racing each other
223 : : * still result in the correct state. It's guaranateed that at least one
224 : : * inheritance happens for any css after the latest update to its parent.
225 : : *
226 : : * If checking parent's state requires locking the parent, each inheriting
227 : : * iteration should lock and unlock both @pos->parent and @pos.
228 : : *
229 : : * Alternatively, a subsystem may choose to use a single global lock to
230 : : * synchronize ->css_online() and ->css_offline() against tree-walking
231 : : * operations.
232 : : *
233 : : * It is allowed to temporarily drop RCU read lock during iteration. The
234 : : * caller is responsible for ensuring that @pos remains accessible until
235 : : * the start of the next iteration by, for example, bumping the css refcnt.
236 : : */
237 : : #define css_for_each_descendant_pre(pos, css) \
238 : : for ((pos) = css_next_descendant_pre(NULL, (css)); (pos); \
239 : : (pos) = css_next_descendant_pre((pos), (css)))
240 : :
241 : : /**
242 : : * css_for_each_descendant_post - post-order walk of a css's descendants
243 : : * @pos: the css * to use as the loop cursor
244 : : * @css: css whose descendants to walk
245 : : *
246 : : * Similar to css_for_each_descendant_pre() but performs post-order
247 : : * traversal instead. @root is included in the iteration and the last
248 : : * node to be visited.
249 : : *
250 : : * If a subsystem synchronizes ->css_online() and the start of iteration, a
251 : : * css which finished ->css_online() is guaranteed to be visible in the
252 : : * future iterations and will stay visible until the last reference is put.
253 : : * A css which hasn't finished ->css_online() or already finished
254 : : * ->css_offline() may show up during traversal. It's each subsystem's
255 : : * responsibility to synchronize against on/offlining.
256 : : *
257 : : * Note that the walk visibility guarantee example described in pre-order
258 : : * walk doesn't apply the same to post-order walks.
259 : : */
260 : : #define css_for_each_descendant_post(pos, css) \
261 : : for ((pos) = css_next_descendant_post(NULL, (css)); (pos); \
262 : : (pos) = css_next_descendant_post((pos), (css)))
263 : :
264 : : /**
265 : : * cgroup_taskset_for_each - iterate cgroup_taskset
266 : : * @task: the loop cursor
267 : : * @dst_css: the destination css
268 : : * @tset: taskset to iterate
269 : : *
270 : : * @tset may contain multiple tasks and they may belong to multiple
271 : : * processes.
272 : : *
273 : : * On the v2 hierarchy, there may be tasks from multiple processes and they
274 : : * may not share the source or destination csses.
275 : : *
276 : : * On traditional hierarchies, when there are multiple tasks in @tset, if a
277 : : * task of a process is in @tset, all tasks of the process are in @tset.
278 : : * Also, all are guaranteed to share the same source and destination csses.
279 : : *
280 : : * Iteration is not in any specific order.
281 : : */
282 : : #define cgroup_taskset_for_each(task, dst_css, tset) \
283 : : for ((task) = cgroup_taskset_first((tset), &(dst_css)); \
284 : : (task); \
285 : : (task) = cgroup_taskset_next((tset), &(dst_css)))
286 : :
287 : : /**
288 : : * cgroup_taskset_for_each_leader - iterate group leaders in a cgroup_taskset
289 : : * @leader: the loop cursor
290 : : * @dst_css: the destination css
291 : : * @tset: taskset to iterate
292 : : *
293 : : * Iterate threadgroup leaders of @tset. For single-task migrations, @tset
294 : : * may not contain any.
295 : : */
296 : : #define cgroup_taskset_for_each_leader(leader, dst_css, tset) \
297 : : for ((leader) = cgroup_taskset_first((tset), &(dst_css)); \
298 : : (leader); \
299 : : (leader) = cgroup_taskset_next((tset), &(dst_css))) \
300 : : if ((leader) != (leader)->group_leader) \
301 : : ; \
302 : : else
303 : :
304 : : /*
305 : : * Inline functions.
306 : : */
307 : :
308 : 1140 : static inline u64 cgroup_id(struct cgroup *cgrp)
309 : : {
310 [ + + - - : 543 : return cgrp->kn->id;
- - ]
311 : : }
312 : :
313 : : /**
314 : : * css_get - obtain a reference on the specified css
315 : : * @css: target css
316 : : *
317 : : * The caller must already have a reference.
318 : : */
319 : 1200 : static inline void css_get(struct cgroup_subsys_state *css)
320 : : {
321 [ - - - - : 1200 : if (!(css->flags & CSS_NO_REF))
- + + + -
- ]
322 : 507 : percpu_ref_get(&css->refcnt);
323 : : }
324 : :
325 : : /**
326 : : * css_get_many - obtain references on the specified css
327 : : * @css: target css
328 : : * @n: number of references to get
329 : : *
330 : : * The caller must already have a reference.
331 : : */
332 : : static inline void css_get_many(struct cgroup_subsys_state *css, unsigned int n)
333 : : {
334 : : if (!(css->flags & CSS_NO_REF))
335 : : percpu_ref_get_many(&css->refcnt, n);
336 : : }
337 : :
338 : : /**
339 : : * css_tryget - try to obtain a reference on the specified css
340 : : * @css: target css
341 : : *
342 : : * Obtain a reference on @css unless it already has reached zero and is
343 : : * being released. This function doesn't care whether @css is on or
344 : : * offline. The caller naturally needs to ensure that @css is accessible
345 : : * but doesn't have to be holding a reference on it - IOW, RCU protected
346 : : * access is good enough for this function. Returns %true if a reference
347 : : * count was successfully obtained; %false otherwise.
348 : : */
349 : 690 : static inline bool css_tryget(struct cgroup_subsys_state *css)
350 : : {
351 : 690 : if (!(css->flags & CSS_NO_REF))
352 : 684 : return percpu_ref_tryget(&css->refcnt);
353 : : return true;
354 : : }
355 : :
356 : : /**
357 : : * css_tryget_online - try to obtain a reference on the specified css if online
358 : : * @css: target css
359 : : *
360 : : * Obtain a reference on @css if it's online. The caller naturally needs
361 : : * to ensure that @css is accessible but doesn't have to be holding a
362 : : * reference on it - IOW, RCU protected access is good enough for this
363 : : * function. Returns %true if a reference count was successfully obtained;
364 : : * %false otherwise.
365 : : */
366 : 0 : static inline bool css_tryget_online(struct cgroup_subsys_state *css)
367 : : {
368 [ # # # # : 0 : if (!(css->flags & CSS_NO_REF))
# # ]
369 : 0 : return percpu_ref_tryget_live(&css->refcnt);
370 : : return true;
371 : : }
372 : :
373 : : /**
374 : : * css_is_dying - test whether the specified css is dying
375 : : * @css: target css
376 : : *
377 : : * Test whether @css is in the process of offlining or already offline. In
378 : : * most cases, ->css_online() and ->css_offline() callbacks should be
379 : : * enough; however, the actual offline operations are RCU delayed and this
380 : : * test returns %true also when @css is scheduled to be offlined.
381 : : *
382 : : * This is useful, for example, when the use case requires synchronous
383 : : * behavior with respect to cgroup removal. cgroup removal schedules css
384 : : * offlining but the css can seem alive while the operation is being
385 : : * delayed. If the delay affects user visible semantics, this test can be
386 : : * used to resolve the situation.
387 : : */
388 : 0 : static inline bool css_is_dying(struct cgroup_subsys_state *css)
389 : : {
390 [ # # # # : 0 : return !(css->flags & CSS_NO_REF) && percpu_ref_is_dying(&css->refcnt);
# # ]
391 : : }
392 : :
393 : : /**
394 : : * css_put - put a css reference
395 : : * @css: target css
396 : : *
397 : : * Put a reference obtained via css_get() and css_tryget_online().
398 : : */
399 : 1635 : static inline void css_put(struct cgroup_subsys_state *css)
400 : : {
401 [ - - - - : 576 : if (!(css->flags & CSS_NO_REF))
- - - + #
# # # #
# ]
402 : 1053 : percpu_ref_put(&css->refcnt);
403 : : }
404 : :
405 : : /**
406 : : * css_put_many - put css references
407 : : * @css: target css
408 : : * @n: number of references to put
409 : : *
410 : : * Put references obtained via css_get() and css_tryget_online().
411 : : */
412 : : static inline void css_put_many(struct cgroup_subsys_state *css, unsigned int n)
413 : : {
414 : : if (!(css->flags & CSS_NO_REF))
415 : : percpu_ref_put_many(&css->refcnt, n);
416 : : }
417 : :
418 : : static inline void cgroup_get(struct cgroup *cgrp)
419 : : {
420 : : css_get(&cgrp->self);
421 : : }
422 : :
423 : 690 : static inline bool cgroup_tryget(struct cgroup *cgrp)
424 : : {
425 [ + + ]: 690 : return css_tryget(&cgrp->self);
426 : : }
427 : :
428 : 1059 : static inline void cgroup_put(struct cgroup *cgrp)
429 : : {
430 [ - - - - : 975 : css_put(&cgrp->self);
- - - - -
- + + +
- ]
431 : : }
432 : :
433 : : /**
434 : : * task_css_set_check - obtain a task's css_set with extra access conditions
435 : : * @task: the task to obtain css_set for
436 : : * @__c: extra condition expression to be passed to rcu_dereference_check()
437 : : *
438 : : * A task's css_set is RCU protected, initialized and exited while holding
439 : : * task_lock(), and can only be modified while holding both cgroup_mutex
440 : : * and task_lock() while the task is alive. This macro verifies that the
441 : : * caller is inside proper critical section and returns @task's css_set.
442 : : *
443 : : * The caller can also specify additional allowed conditions via @__c, such
444 : : * as locks used during the cgroup_subsys::attach() methods.
445 : : */
446 : : #ifdef CONFIG_PROVE_RCU
447 : : extern struct mutex cgroup_mutex;
448 : : extern spinlock_t css_set_lock;
449 : : #define task_css_set_check(task, __c) \
450 : : rcu_dereference_check((task)->cgroups, \
451 : : lockdep_is_held(&cgroup_mutex) || \
452 : : lockdep_is_held(&css_set_lock) || \
453 : : ((task)->flags & PF_EXITING) || (__c))
454 : : #else
455 : : #define task_css_set_check(task, __c) \
456 : : rcu_dereference((task)->cgroups)
457 : : #endif
458 : :
459 : : /**
460 : : * task_css_check - obtain css for (task, subsys) w/ extra access conds
461 : : * @task: the target task
462 : : * @subsys_id: the target subsystem ID
463 : : * @__c: extra condition expression to be passed to rcu_dereference_check()
464 : : *
465 : : * Return the cgroup_subsys_state for the (@task, @subsys_id) pair. The
466 : : * synchronization rules are the same as task_css_set_check().
467 : : */
468 : : #define task_css_check(task, subsys_id, __c) \
469 : : task_css_set_check((task), (__c))->subsys[(subsys_id)]
470 : :
471 : : /**
472 : : * task_css_set - obtain a task's css_set
473 : : * @task: the task to obtain css_set for
474 : : *
475 : : * See task_css_set_check().
476 : : */
477 : 68720 : static inline struct css_set *task_css_set(struct task_struct *task)
478 : : {
479 [ + + ]: 64892 : return task_css_set_check(task, false);
480 : : }
481 : :
482 : : /**
483 : : * task_css - obtain css for (task, subsys)
484 : : * @task: the target task
485 : : * @subsys_id: the target subsystem ID
486 : : *
487 : : * See task_css_check().
488 : : */
489 : 54629 : static inline struct cgroup_subsys_state *task_css(struct task_struct *task,
490 : : int subsys_id)
491 : : {
492 [ - + - + : 54629 : return task_css_check(task, subsys_id, false);
- - - - -
- - - - -
- + ]
493 : : }
494 : :
495 : : /**
496 : : * task_get_css - find and get the css for (task, subsys)
497 : : * @task: the target task
498 : : * @subsys_id: the target subsystem ID
499 : : *
500 : : * Find the css for the (@task, @subsys_id) combination, increment a
501 : : * reference on and return it. This function is guaranteed to return a
502 : : * valid css. The returned css may already have been offlined.
503 : : */
504 : : static inline struct cgroup_subsys_state *
505 : 0 : task_get_css(struct task_struct *task, int subsys_id)
506 : : {
507 : 0 : struct cgroup_subsys_state *css;
508 : :
509 : 0 : rcu_read_lock();
510 : 0 : while (true) {
511 [ # # ]: 0 : css = task_css(task, subsys_id);
512 : : /*
513 : : * Can't use css_tryget_online() here. A task which has
514 : : * PF_EXITING set may stay associated with an offline css.
515 : : * If such task calls this function, css_tryget_online()
516 : : * will keep failing.
517 : : */
518 [ # # # # ]: 0 : if (likely(css_tryget(css)))
519 : : break;
520 : 0 : cpu_relax();
521 : : }
522 : 0 : rcu_read_unlock();
523 : 0 : return css;
524 : : }
525 : :
526 : : /**
527 : : * task_css_is_root - test whether a task belongs to the root css
528 : : * @task: the target task
529 : : * @subsys_id: the target subsystem ID
530 : : *
531 : : * Test whether @task belongs to the root css on the specified subsystem.
532 : : * May be invoked in any context.
533 : : */
534 : 4564 : static inline bool task_css_is_root(struct task_struct *task, int subsys_id)
535 : : {
536 [ - + ]: 4564 : return task_css_check(task, subsys_id, true) ==
537 [ - + ]: 4564 : init_css_set.subsys[subsys_id];
538 : : }
539 : :
540 : : static inline struct cgroup *task_cgroup(struct task_struct *task,
541 : : int subsys_id)
542 : : {
543 : : return task_css(task, subsys_id)->cgroup;
544 : : }
545 : :
546 : 57779 : static inline struct cgroup *task_dfl_cgroup(struct task_struct *task)
547 : : {
548 [ # # ]: 53951 : return task_css_set(task)->dfl_cgrp;
549 : : }
550 : :
551 : 94078 : static inline struct cgroup *cgroup_parent(struct cgroup *cgrp)
552 : : {
553 : 94078 : struct cgroup_subsys_state *parent_css = cgrp->self.parent;
554 : :
555 [ + - + - : 93484 : if (parent_css)
+ + + + +
+ + - + +
- - - + -
- + - + +
+ - + - +
- + + + +
- - - - -
- - - + +
+ + + - +
- + + + +
+ + - - -
- - - - +
+ + + + +
+ ]
556 [ - - + - : 64027 : return container_of(parent_css, struct cgroup, self);
- - - - -
- - - - +
- + + - +
- - - + +
+ - ]
557 : : return NULL;
558 : : }
559 : :
560 : : /**
561 : : * cgroup_is_descendant - test ancestry
562 : : * @cgrp: the cgroup to be tested
563 : : * @ancestor: possible ancestor of @cgrp
564 : : *
565 : : * Test whether @cgrp is a descendant of @ancestor. It also returns %true
566 : : * if @cgrp == @ancestor. This function is safe to call as long as @cgrp
567 : : * and @ancestor are accessible.
568 : : */
569 : 597 : static inline bool cgroup_is_descendant(struct cgroup *cgrp,
570 : : struct cgroup *ancestor)
571 : : {
572 [ - + - + : 597 : if (cgrp->root != ancestor->root || cgrp->level < ancestor->level)
+ - + - +
- + - ]
573 : : return false;
574 [ + + + - : 597 : return cgrp->ancestor_ids[ancestor->level] == cgroup_id(ancestor);
- + ]
575 : : }
576 : :
577 : : /**
578 : : * cgroup_ancestor - find ancestor of cgroup
579 : : * @cgrp: cgroup to find ancestor of
580 : : * @ancestor_level: level of ancestor to find starting from root
581 : : *
582 : : * Find ancestor of cgroup at specified level starting from root if it exists
583 : : * and return pointer to it. Return NULL if @cgrp doesn't have ancestor at
584 : : * @ancestor_level.
585 : : *
586 : : * This function is safe to call as long as @cgrp is accessible.
587 : : */
588 : : static inline struct cgroup *cgroup_ancestor(struct cgroup *cgrp,
589 : : int ancestor_level)
590 : : {
591 : : if (cgrp->level < ancestor_level)
592 : : return NULL;
593 : : while (cgrp && cgrp->level > ancestor_level)
594 : : cgrp = cgroup_parent(cgrp);
595 : : return cgrp;
596 : : }
597 : :
598 : : /**
599 : : * task_under_cgroup_hierarchy - test task's membership of cgroup ancestry
600 : : * @task: the task to be tested
601 : : * @ancestor: possible ancestor of @task's cgroup
602 : : *
603 : : * Tests whether @task's default cgroup hierarchy is a descendant of @ancestor.
604 : : * It follows all the same rules as cgroup_is_descendant, and only applies
605 : : * to the default hierarchy.
606 : : */
607 : : static inline bool task_under_cgroup_hierarchy(struct task_struct *task,
608 : : struct cgroup *ancestor)
609 : : {
610 : : struct css_set *cset = task_css_set(task);
611 : :
612 : : return cgroup_is_descendant(cset->dfl_cgrp, ancestor);
613 : : }
614 : :
615 : : /* no synchronization, the result can only be used as a hint */
616 : 4051 : static inline bool cgroup_is_populated(struct cgroup *cgrp)
617 : : {
618 : 4051 : return cgrp->nr_populated_csets + cgrp->nr_populated_domain_children +
619 [ + - - - : 4051 : cgrp->nr_populated_threaded_children;
+ + + + ]
620 : : }
621 : :
622 : : /* returns ino associated with a cgroup */
623 : 15 : static inline ino_t cgroup_ino(struct cgroup *cgrp)
624 : : {
625 [ - + ]: 15 : return kernfs_ino(cgrp->kn);
626 : : }
627 : :
628 : : /* cft/css accessors for cftype->write() operation */
629 : 687 : static inline struct cftype *of_cft(struct kernfs_open_file *of)
630 : : {
631 [ - + - - : 172 : return of->kn->priv;
- - - - -
+ - - - -
- - - - -
- - - ]
632 : : }
633 : :
634 : : struct cgroup_subsys_state *of_css(struct kernfs_open_file *of);
635 : :
636 : : /* cft/css accessors for cftype->seq_*() operations */
637 : 515 : static inline struct cftype *seq_cft(struct seq_file *seq)
638 : : {
639 [ - + - + ]: 515 : return of_cft(seq->private);
640 : : }
641 : :
642 : 385 : static inline struct cgroup_subsys_state *seq_css(struct seq_file *seq)
643 : : {
644 [ - + - + : 385 : return of_css(seq->private);
- - - - -
- - + - -
- - - - -
- - - ]
645 : : }
646 : :
647 : : /*
648 : : * Name / path handling functions. All are thin wrappers around the kernfs
649 : : * counterparts and can be called under any context.
650 : : */
651 : :
652 : : static inline int cgroup_name(struct cgroup *cgrp, char *buf, size_t buflen)
653 : : {
654 : : return kernfs_name(cgrp->kn, buf, buflen);
655 : : }
656 : :
657 : 0 : static inline int cgroup_path(struct cgroup *cgrp, char *buf, size_t buflen)
658 : : {
659 : 0 : return kernfs_path(cgrp->kn, buf, buflen);
660 : : }
661 : :
662 : 0 : static inline void pr_cont_cgroup_name(struct cgroup *cgrp)
663 : : {
664 : 0 : pr_cont_kernfs_name(cgrp->kn);
665 : : }
666 : :
667 : : static inline void pr_cont_cgroup_path(struct cgroup *cgrp)
668 : : {
669 : : pr_cont_kernfs_path(cgrp->kn);
670 : : }
671 : :
672 : : static inline struct psi_group *cgroup_psi(struct cgroup *cgrp)
673 : : {
674 : : return &cgrp->psi;
675 : : }
676 : :
677 : 3 : static inline void cgroup_init_kthreadd(void)
678 : : {
679 : : /*
680 : : * kthreadd is inherited by all kthreads, keep it in the root so
681 : : * that the new kthreads are guaranteed to stay in the root until
682 : : * initialization is finished.
683 : : */
684 : 3 : current->no_cgroup_migration = 1;
685 : 3 : }
686 : :
687 : 206 : static inline void cgroup_kthread_ready(void)
688 : : {
689 : : /*
690 : : * This kthread finished initialization. The creator should have
691 : : * set PF_NO_SETAFFINITY if this kthread should stay in the root.
692 : : */
693 : 206 : current->no_cgroup_migration = 0;
694 : : }
695 : :
696 : : void cgroup_path_from_kernfs_id(u64 id, char *buf, size_t buflen);
697 : : #else /* !CONFIG_CGROUPS */
698 : :
699 : : struct cgroup_subsys_state;
700 : : struct cgroup;
701 : :
702 : : static inline u64 cgroup_id(struct cgroup *cgrp) { return 1; }
703 : : static inline void css_get(struct cgroup_subsys_state *css) {}
704 : : static inline void css_put(struct cgroup_subsys_state *css) {}
705 : : static inline int cgroup_attach_task_all(struct task_struct *from,
706 : : struct task_struct *t) { return 0; }
707 : : static inline int cgroupstats_build(struct cgroupstats *stats,
708 : : struct dentry *dentry) { return -EINVAL; }
709 : :
710 : : static inline void cgroup_fork(struct task_struct *p) {}
711 : : static inline int cgroup_can_fork(struct task_struct *p) { return 0; }
712 : : static inline void cgroup_cancel_fork(struct task_struct *p) {}
713 : : static inline void cgroup_post_fork(struct task_struct *p) {}
714 : : static inline void cgroup_exit(struct task_struct *p) {}
715 : : static inline void cgroup_release(struct task_struct *p) {}
716 : : static inline void cgroup_free(struct task_struct *p) {}
717 : :
718 : : static inline int cgroup_init_early(void) { return 0; }
719 : : static inline int cgroup_init(void) { return 0; }
720 : : static inline void cgroup_init_kthreadd(void) {}
721 : : static inline void cgroup_kthread_ready(void) {}
722 : :
723 : : static inline struct cgroup *cgroup_parent(struct cgroup *cgrp)
724 : : {
725 : : return NULL;
726 : : }
727 : :
728 : : static inline struct psi_group *cgroup_psi(struct cgroup *cgrp)
729 : : {
730 : : return NULL;
731 : : }
732 : :
733 : : static inline bool task_under_cgroup_hierarchy(struct task_struct *task,
734 : : struct cgroup *ancestor)
735 : : {
736 : : return true;
737 : : }
738 : :
739 : : static inline void cgroup_path_from_kernfs_id(u64 id, char *buf, size_t buflen)
740 : : {}
741 : : #endif /* !CONFIG_CGROUPS */
742 : :
743 : : #ifdef CONFIG_CGROUPS
744 : : /*
745 : : * cgroup scalable recursive statistics.
746 : : */
747 : : void cgroup_rstat_updated(struct cgroup *cgrp, int cpu);
748 : : void cgroup_rstat_flush(struct cgroup *cgrp);
749 : : void cgroup_rstat_flush_irqsafe(struct cgroup *cgrp);
750 : : void cgroup_rstat_flush_hold(struct cgroup *cgrp);
751 : : void cgroup_rstat_flush_release(void);
752 : :
753 : : /*
754 : : * Basic resource stats.
755 : : */
756 : : #ifdef CONFIG_CGROUP_CPUACCT
757 : : void cpuacct_charge(struct task_struct *tsk, u64 cputime);
758 : : void cpuacct_account_field(struct task_struct *tsk, int index, u64 val);
759 : : #else
760 : : static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {}
761 : : static inline void cpuacct_account_field(struct task_struct *tsk, int index,
762 : : u64 val) {}
763 : : #endif
764 : :
765 : : void __cgroup_account_cputime(struct cgroup *cgrp, u64 delta_exec);
766 : : void __cgroup_account_cputime_field(struct cgroup *cgrp,
767 : : enum cpu_usage_stat index, u64 delta_exec);
768 : :
769 : 47414 : static inline void cgroup_account_cputime(struct task_struct *task,
770 : : u64 delta_exec)
771 : : {
772 : 47414 : struct cgroup *cgrp;
773 : :
774 : 47414 : cpuacct_charge(task, delta_exec);
775 : :
776 : 47414 : rcu_read_lock();
777 [ + + ]: 47414 : cgrp = task_dfl_cgroup(task);
778 [ + + ]: 47414 : if (cgroup_parent(cgrp))
779 : 24542 : __cgroup_account_cputime(cgrp, delta_exec);
780 : 47414 : rcu_read_unlock();
781 : 47414 : }
782 : :
783 : 6537 : static inline void cgroup_account_cputime_field(struct task_struct *task,
784 : : enum cpu_usage_stat index,
785 : : u64 delta_exec)
786 : : {
787 : 6537 : struct cgroup *cgrp;
788 : :
789 : 6537 : cpuacct_account_field(task, index, delta_exec);
790 : :
791 : 6537 : rcu_read_lock();
792 [ + + ]: 6537 : cgrp = task_dfl_cgroup(task);
793 [ + + ]: 6537 : if (cgroup_parent(cgrp))
794 : 3714 : __cgroup_account_cputime_field(cgrp, index, delta_exec);
795 : 6537 : rcu_read_unlock();
796 : 6537 : }
797 : :
798 : : #else /* CONFIG_CGROUPS */
799 : :
800 : : static inline void cgroup_account_cputime(struct task_struct *task,
801 : : u64 delta_exec) {}
802 : : static inline void cgroup_account_cputime_field(struct task_struct *task,
803 : : enum cpu_usage_stat index,
804 : : u64 delta_exec) {}
805 : :
806 : : #endif /* CONFIG_CGROUPS */
807 : :
808 : : /*
809 : : * sock->sk_cgrp_data handling. For more info, see sock_cgroup_data
810 : : * definition in cgroup-defs.h.
811 : : */
812 : : #ifdef CONFIG_SOCK_CGROUP_DATA
813 : :
814 : : #if defined(CONFIG_CGROUP_NET_PRIO) || defined(CONFIG_CGROUP_NET_CLASSID)
815 : : extern spinlock_t cgroup_sk_update_lock;
816 : : #endif
817 : :
818 : : void cgroup_sk_alloc_disable(void);
819 : : void cgroup_sk_alloc(struct sock_cgroup_data *skcd);
820 : : void cgroup_sk_free(struct sock_cgroup_data *skcd);
821 : :
822 : : static inline struct cgroup *sock_cgroup_ptr(struct sock_cgroup_data *skcd)
823 : : {
824 : : #if defined(CONFIG_CGROUP_NET_PRIO) || defined(CONFIG_CGROUP_NET_CLASSID)
825 : : unsigned long v;
826 : :
827 : : /*
828 : : * @skcd->val is 64bit but the following is safe on 32bit too as we
829 : : * just need the lower ulong to be written and read atomically.
830 : : */
831 : : v = READ_ONCE(skcd->val);
832 : :
833 : : if (v & 1)
834 : : return &cgrp_dfl_root.cgrp;
835 : :
836 : : return (struct cgroup *)(unsigned long)v ?: &cgrp_dfl_root.cgrp;
837 : : #else
838 : : return (struct cgroup *)(unsigned long)skcd->val;
839 : : #endif
840 : : }
841 : :
842 : : #else /* CONFIG_CGROUP_DATA */
843 : :
844 : 1284 : static inline void cgroup_sk_alloc(struct sock_cgroup_data *skcd) {}
845 : : static inline void cgroup_sk_free(struct sock_cgroup_data *skcd) {}
846 : :
847 : : #endif /* CONFIG_CGROUP_DATA */
848 : :
849 : : struct cgroup_namespace {
850 : : refcount_t count;
851 : : struct ns_common ns;
852 : : struct user_namespace *user_ns;
853 : : struct ucounts *ucounts;
854 : : struct css_set *root_cset;
855 : : };
856 : :
857 : : extern struct cgroup_namespace init_cgroup_ns;
858 : :
859 : : #ifdef CONFIG_CGROUPS
860 : :
861 : : void free_cgroup_ns(struct cgroup_namespace *ns);
862 : :
863 : : struct cgroup_namespace *copy_cgroup_ns(unsigned long flags,
864 : : struct user_namespace *user_ns,
865 : : struct cgroup_namespace *old_ns);
866 : :
867 : : int cgroup_path_ns(struct cgroup *cgrp, char *buf, size_t buflen,
868 : : struct cgroup_namespace *ns);
869 : :
870 : : #else /* !CONFIG_CGROUPS */
871 : :
872 : : static inline void free_cgroup_ns(struct cgroup_namespace *ns) { }
873 : : static inline struct cgroup_namespace *
874 : : copy_cgroup_ns(unsigned long flags, struct user_namespace *user_ns,
875 : : struct cgroup_namespace *old_ns)
876 : : {
877 : : return old_ns;
878 : : }
879 : :
880 : : #endif /* !CONFIG_CGROUPS */
881 : :
882 : 24 : static inline void get_cgroup_ns(struct cgroup_namespace *ns)
883 : : {
884 [ + - - - : 24 : if (ns)
+ - ]
885 : 24 : refcount_inc(&ns->count);
886 : : }
887 : :
888 : 15 : static inline void put_cgroup_ns(struct cgroup_namespace *ns)
889 : : {
890 [ + - - + ]: 15 : if (ns && refcount_dec_and_test(&ns->count))
891 : 0 : free_cgroup_ns(ns);
892 : 15 : }
893 : :
894 : : #ifdef CONFIG_CGROUPS
895 : :
896 : : void cgroup_enter_frozen(void);
897 : : void cgroup_leave_frozen(bool always_leave);
898 : : void cgroup_update_frozen(struct cgroup *cgrp);
899 : : void cgroup_freeze(struct cgroup *cgrp, bool freeze);
900 : : void cgroup_freezer_migrate_task(struct task_struct *task, struct cgroup *src,
901 : : struct cgroup *dst);
902 : :
903 : 4283 : static inline bool cgroup_task_freeze(struct task_struct *task)
904 : : {
905 : 4283 : bool ret;
906 : :
907 [ + + ]: 4283 : if (task->flags & PF_KTHREAD)
908 : : return false;
909 : :
910 : 3828 : rcu_read_lock();
911 : 3828 : ret = test_bit(CGRP_FREEZE, &task_dfl_cgroup(task)->flags);
912 : 3828 : rcu_read_unlock();
913 : :
914 : 3828 : return ret;
915 : : }
916 : :
917 : 19385 : static inline bool cgroup_task_frozen(struct task_struct *task)
918 : : {
919 [ - + - - : 19385 : return task->frozen;
- + ]
920 : : }
921 : :
922 : : #else /* !CONFIG_CGROUPS */
923 : :
924 : : static inline void cgroup_enter_frozen(void) { }
925 : : static inline void cgroup_leave_frozen(bool always_leave) { }
926 : : static inline bool cgroup_task_freeze(struct task_struct *task)
927 : : {
928 : : return false;
929 : : }
930 : : static inline bool cgroup_task_frozen(struct task_struct *task)
931 : : {
932 : : return false;
933 : : }
934 : :
935 : : #endif /* !CONFIG_CGROUPS */
936 : :
937 : : #ifdef CONFIG_CGROUP_BPF
938 : : static inline void cgroup_bpf_get(struct cgroup *cgrp)
939 : : {
940 : : percpu_ref_get(&cgrp->bpf.refcnt);
941 : : }
942 : :
943 : : static inline void cgroup_bpf_put(struct cgroup *cgrp)
944 : : {
945 : : percpu_ref_put(&cgrp->bpf.refcnt);
946 : : }
947 : :
948 : : #else /* CONFIG_CGROUP_BPF */
949 : :
950 : : static inline void cgroup_bpf_get(struct cgroup *cgrp) {}
951 : : static inline void cgroup_bpf_put(struct cgroup *cgrp) {}
952 : :
953 : : #endif /* CONFIG_CGROUP_BPF */
954 : :
955 : : #endif /* _LINUX_CGROUP_H */
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