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ddbcc7e8 PM |
1 | #ifndef _LINUX_CGROUP_H |
2 | #define _LINUX_CGROUP_H | |
3 | /* | |
4 | * cgroup interface | |
5 | * | |
6 | * Copyright (C) 2003 BULL SA | |
7 | * Copyright (C) 2004-2006 Silicon Graphics, Inc. | |
8 | * | |
9 | */ | |
10 | ||
11 | #include <linux/sched.h> | |
ddbcc7e8 PM |
12 | #include <linux/cpumask.h> |
13 | #include <linux/nodemask.h> | |
eb6fd504 | 14 | #include <linux/rculist.h> |
846c7bb0 | 15 | #include <linux/cgroupstats.h> |
25a7e684 | 16 | #include <linux/fs.h> |
7da11279 | 17 | #include <linux/seq_file.h> |
2bd59d48 | 18 | #include <linux/kernfs.h> |
49d1dc4b | 19 | #include <linux/jump_label.h> |
ddbcc7e8 | 20 | |
b4a04ab7 | 21 | #include <linux/cgroup-defs.h> |
ddbcc7e8 PM |
22 | |
23 | #ifdef CONFIG_CGROUPS | |
24 | ||
6abc8ca1 TH |
25 | /* |
26 | * All weight knobs on the default hierarhcy should use the following min, | |
27 | * default and max values. The default value is the logarithmic center of | |
28 | * MIN and MAX and allows 100x to be expressed in both directions. | |
29 | */ | |
30 | #define CGROUP_WEIGHT_MIN 1 | |
31 | #define CGROUP_WEIGHT_DFL 100 | |
32 | #define CGROUP_WEIGHT_MAX 10000 | |
33 | ||
c326aa2b TH |
34 | /* a css_task_iter should be treated as an opaque object */ |
35 | struct css_task_iter { | |
36 | struct cgroup_subsys *ss; | |
37 | ||
38 | struct list_head *cset_pos; | |
39 | struct list_head *cset_head; | |
ddbcc7e8 | 40 | |
c326aa2b TH |
41 | struct list_head *task_pos; |
42 | struct list_head *tasks_head; | |
43 | struct list_head *mg_tasks_head; | |
ed27b9f7 TH |
44 | |
45 | struct css_set *cur_cset; | |
46 | struct task_struct *cur_task; | |
47 | struct list_head iters_node; /* css_set->task_iters */ | |
c326aa2b | 48 | }; |
ddbcc7e8 | 49 | |
c326aa2b TH |
50 | extern struct cgroup_root cgrp_dfl_root; |
51 | extern struct css_set init_css_set; | |
a424316c | 52 | |
c326aa2b | 53 | #define SUBSYS(_x) extern struct cgroup_subsys _x ## _cgrp_subsys; |
817929ec | 54 | #include <linux/cgroup_subsys.h> |
817929ec PM |
55 | #undef SUBSYS |
56 | ||
49d1dc4b TH |
57 | #define SUBSYS(_x) \ |
58 | extern struct static_key_true _x ## _cgrp_subsys_enabled_key; \ | |
59 | extern struct static_key_true _x ## _cgrp_subsys_on_dfl_key; | |
60 | #include <linux/cgroup_subsys.h> | |
61 | #undef SUBSYS | |
62 | ||
63 | /** | |
64 | * cgroup_subsys_enabled - fast test on whether a subsys is enabled | |
65 | * @ss: subsystem in question | |
66 | */ | |
67 | #define cgroup_subsys_enabled(ss) \ | |
68 | static_branch_likely(&ss ## _enabled_key) | |
69 | ||
70 | /** | |
71 | * cgroup_subsys_on_dfl - fast test on whether a subsys is on default hierarchy | |
72 | * @ss: subsystem in question | |
73 | */ | |
74 | #define cgroup_subsys_on_dfl(ss) \ | |
75 | static_branch_likely(&ss ## _on_dfl_key) | |
76 | ||
c326aa2b TH |
77 | bool css_has_online_children(struct cgroup_subsys_state *css); |
78 | struct cgroup_subsys_state *css_from_id(int id, struct cgroup_subsys *ss); | |
79 | struct cgroup_subsys_state *cgroup_get_e_css(struct cgroup *cgroup, | |
80 | struct cgroup_subsys *ss); | |
81 | struct cgroup_subsys_state *css_tryget_online_from_dir(struct dentry *dentry, | |
82 | struct cgroup_subsys *ss); | |
83 | ||
16af4396 TH |
84 | struct cgroup *cgroup_get_from_path(const char *path); |
85 | ||
c326aa2b TH |
86 | int cgroup_attach_task_all(struct task_struct *from, struct task_struct *); |
87 | int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from); | |
88 | ||
89 | int cgroup_add_dfl_cftypes(struct cgroup_subsys *ss, struct cftype *cfts); | |
90 | int cgroup_add_legacy_cftypes(struct cgroup_subsys *ss, struct cftype *cfts); | |
91 | int cgroup_rm_cftypes(struct cftype *cfts); | |
34c06254 | 92 | void cgroup_file_notify(struct cgroup_file *cfile); |
c326aa2b TH |
93 | |
94 | char *task_cgroup_path(struct task_struct *task, char *buf, size_t buflen); | |
95 | int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry); | |
96 | int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns, | |
97 | struct pid *pid, struct task_struct *tsk); | |
98 | ||
99 | void cgroup_fork(struct task_struct *p); | |
b53202e6 ON |
100 | extern int cgroup_can_fork(struct task_struct *p); |
101 | extern void cgroup_cancel_fork(struct task_struct *p); | |
102 | extern void cgroup_post_fork(struct task_struct *p); | |
c326aa2b | 103 | void cgroup_exit(struct task_struct *p); |
2e91fa7f | 104 | void cgroup_free(struct task_struct *p); |
c326aa2b TH |
105 | |
106 | int cgroup_init_early(void); | |
107 | int cgroup_init(void); | |
108 | ||
5c9d535b | 109 | /* |
c326aa2b TH |
110 | * Iteration helpers and macros. |
111 | */ | |
112 | ||
113 | struct cgroup_subsys_state *css_next_child(struct cgroup_subsys_state *pos, | |
114 | struct cgroup_subsys_state *parent); | |
115 | struct cgroup_subsys_state *css_next_descendant_pre(struct cgroup_subsys_state *pos, | |
116 | struct cgroup_subsys_state *css); | |
117 | struct cgroup_subsys_state *css_rightmost_descendant(struct cgroup_subsys_state *pos); | |
118 | struct cgroup_subsys_state *css_next_descendant_post(struct cgroup_subsys_state *pos, | |
119 | struct cgroup_subsys_state *css); | |
120 | ||
1f7dd3e5 TH |
121 | struct task_struct *cgroup_taskset_first(struct cgroup_taskset *tset, |
122 | struct cgroup_subsys_state **dst_cssp); | |
123 | struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset, | |
124 | struct cgroup_subsys_state **dst_cssp); | |
c326aa2b TH |
125 | |
126 | void css_task_iter_start(struct cgroup_subsys_state *css, | |
127 | struct css_task_iter *it); | |
128 | struct task_struct *css_task_iter_next(struct css_task_iter *it); | |
129 | void css_task_iter_end(struct css_task_iter *it); | |
130 | ||
131 | /** | |
132 | * css_for_each_child - iterate through children of a css | |
133 | * @pos: the css * to use as the loop cursor | |
134 | * @parent: css whose children to walk | |
135 | * | |
136 | * Walk @parent's children. Must be called under rcu_read_lock(). | |
137 | * | |
138 | * If a subsystem synchronizes ->css_online() and the start of iteration, a | |
139 | * css which finished ->css_online() is guaranteed to be visible in the | |
140 | * future iterations and will stay visible until the last reference is put. | |
141 | * A css which hasn't finished ->css_online() or already finished | |
142 | * ->css_offline() may show up during traversal. It's each subsystem's | |
143 | * responsibility to synchronize against on/offlining. | |
5c9d535b | 144 | * |
c326aa2b TH |
145 | * It is allowed to temporarily drop RCU read lock during iteration. The |
146 | * caller is responsible for ensuring that @pos remains accessible until | |
147 | * the start of the next iteration by, for example, bumping the css refcnt. | |
5c9d535b | 148 | */ |
c326aa2b TH |
149 | #define css_for_each_child(pos, parent) \ |
150 | for ((pos) = css_next_child(NULL, (parent)); (pos); \ | |
151 | (pos) = css_next_child((pos), (parent))) | |
ddbcc7e8 | 152 | |
c326aa2b TH |
153 | /** |
154 | * css_for_each_descendant_pre - pre-order walk of a css's descendants | |
155 | * @pos: the css * to use as the loop cursor | |
156 | * @root: css whose descendants to walk | |
157 | * | |
158 | * Walk @root's descendants. @root is included in the iteration and the | |
159 | * first node to be visited. Must be called under rcu_read_lock(). | |
160 | * | |
161 | * If a subsystem synchronizes ->css_online() and the start of iteration, a | |
162 | * css which finished ->css_online() is guaranteed to be visible in the | |
163 | * future iterations and will stay visible until the last reference is put. | |
164 | * A css which hasn't finished ->css_online() or already finished | |
165 | * ->css_offline() may show up during traversal. It's each subsystem's | |
166 | * responsibility to synchronize against on/offlining. | |
167 | * | |
168 | * For example, the following guarantees that a descendant can't escape | |
169 | * state updates of its ancestors. | |
170 | * | |
171 | * my_online(@css) | |
172 | * { | |
173 | * Lock @css's parent and @css; | |
174 | * Inherit state from the parent; | |
175 | * Unlock both. | |
176 | * } | |
177 | * | |
178 | * my_update_state(@css) | |
179 | * { | |
180 | * css_for_each_descendant_pre(@pos, @css) { | |
181 | * Lock @pos; | |
182 | * if (@pos == @css) | |
183 | * Update @css's state; | |
184 | * else | |
185 | * Verify @pos is alive and inherit state from its parent; | |
186 | * Unlock @pos; | |
187 | * } | |
188 | * } | |
189 | * | |
190 | * As long as the inheriting step, including checking the parent state, is | |
191 | * enclosed inside @pos locking, double-locking the parent isn't necessary | |
192 | * while inheriting. The state update to the parent is guaranteed to be | |
193 | * visible by walking order and, as long as inheriting operations to the | |
194 | * same @pos are atomic to each other, multiple updates racing each other | |
195 | * still result in the correct state. It's guaranateed that at least one | |
196 | * inheritance happens for any css after the latest update to its parent. | |
197 | * | |
198 | * If checking parent's state requires locking the parent, each inheriting | |
199 | * iteration should lock and unlock both @pos->parent and @pos. | |
200 | * | |
201 | * Alternatively, a subsystem may choose to use a single global lock to | |
202 | * synchronize ->css_online() and ->css_offline() against tree-walking | |
203 | * operations. | |
204 | * | |
205 | * It is allowed to temporarily drop RCU read lock during iteration. The | |
206 | * caller is responsible for ensuring that @pos remains accessible until | |
207 | * the start of the next iteration by, for example, bumping the css refcnt. | |
208 | */ | |
209 | #define css_for_each_descendant_pre(pos, css) \ | |
210 | for ((pos) = css_next_descendant_pre(NULL, (css)); (pos); \ | |
211 | (pos) = css_next_descendant_pre((pos), (css))) | |
212 | ||
213 | /** | |
214 | * css_for_each_descendant_post - post-order walk of a css's descendants | |
215 | * @pos: the css * to use as the loop cursor | |
216 | * @css: css whose descendants to walk | |
217 | * | |
218 | * Similar to css_for_each_descendant_pre() but performs post-order | |
219 | * traversal instead. @root is included in the iteration and the last | |
220 | * node to be visited. | |
221 | * | |
222 | * If a subsystem synchronizes ->css_online() and the start of iteration, a | |
223 | * css which finished ->css_online() is guaranteed to be visible in the | |
224 | * future iterations and will stay visible until the last reference is put. | |
225 | * A css which hasn't finished ->css_online() or already finished | |
226 | * ->css_offline() may show up during traversal. It's each subsystem's | |
227 | * responsibility to synchronize against on/offlining. | |
228 | * | |
229 | * Note that the walk visibility guarantee example described in pre-order | |
230 | * walk doesn't apply the same to post-order walks. | |
231 | */ | |
232 | #define css_for_each_descendant_post(pos, css) \ | |
233 | for ((pos) = css_next_descendant_post(NULL, (css)); (pos); \ | |
234 | (pos) = css_next_descendant_post((pos), (css))) | |
235 | ||
236 | /** | |
237 | * cgroup_taskset_for_each - iterate cgroup_taskset | |
238 | * @task: the loop cursor | |
1f7dd3e5 | 239 | * @dst_css: the destination css |
c326aa2b | 240 | * @tset: taskset to iterate |
4530eddb TH |
241 | * |
242 | * @tset may contain multiple tasks and they may belong to multiple | |
1f7dd3e5 TH |
243 | * processes. |
244 | * | |
245 | * On the v2 hierarchy, there may be tasks from multiple processes and they | |
246 | * may not share the source or destination csses. | |
247 | * | |
248 | * On traditional hierarchies, when there are multiple tasks in @tset, if a | |
249 | * task of a process is in @tset, all tasks of the process are in @tset. | |
250 | * Also, all are guaranteed to share the same source and destination csses. | |
4530eddb TH |
251 | * |
252 | * Iteration is not in any specific order. | |
c326aa2b | 253 | */ |
1f7dd3e5 TH |
254 | #define cgroup_taskset_for_each(task, dst_css, tset) \ |
255 | for ((task) = cgroup_taskset_first((tset), &(dst_css)); \ | |
256 | (task); \ | |
257 | (task) = cgroup_taskset_next((tset), &(dst_css))) | |
ddbcc7e8 | 258 | |
4530eddb TH |
259 | /** |
260 | * cgroup_taskset_for_each_leader - iterate group leaders in a cgroup_taskset | |
261 | * @leader: the loop cursor | |
1f7dd3e5 | 262 | * @dst_css: the destination css |
4530eddb TH |
263 | * @tset: takset to iterate |
264 | * | |
265 | * Iterate threadgroup leaders of @tset. For single-task migrations, @tset | |
266 | * may not contain any. | |
267 | */ | |
1f7dd3e5 TH |
268 | #define cgroup_taskset_for_each_leader(leader, dst_css, tset) \ |
269 | for ((leader) = cgroup_taskset_first((tset), &(dst_css)); \ | |
270 | (leader); \ | |
271 | (leader) = cgroup_taskset_next((tset), &(dst_css))) \ | |
4530eddb TH |
272 | if ((leader) != (leader)->group_leader) \ |
273 | ; \ | |
274 | else | |
275 | ||
c326aa2b TH |
276 | /* |
277 | * Inline functions. | |
278 | */ | |
ddbcc7e8 | 279 | |
5de0107e TH |
280 | /** |
281 | * css_get - obtain a reference on the specified css | |
282 | * @css: target css | |
283 | * | |
284 | * The caller must already have a reference. | |
ddbcc7e8 | 285 | */ |
ddbcc7e8 PM |
286 | static inline void css_get(struct cgroup_subsys_state *css) |
287 | { | |
3b514d24 TH |
288 | if (!(css->flags & CSS_NO_REF)) |
289 | percpu_ref_get(&css->refcnt); | |
ddbcc7e8 | 290 | } |
e7c5ec91 | 291 | |
e8ea14cc JW |
292 | /** |
293 | * css_get_many - obtain references on the specified css | |
294 | * @css: target css | |
295 | * @n: number of references to get | |
296 | * | |
297 | * The caller must already have a reference. | |
298 | */ | |
299 | static inline void css_get_many(struct cgroup_subsys_state *css, unsigned int n) | |
300 | { | |
301 | if (!(css->flags & CSS_NO_REF)) | |
302 | percpu_ref_get_many(&css->refcnt, n); | |
303 | } | |
304 | ||
6f4524d3 TH |
305 | /** |
306 | * css_tryget - try to obtain a reference on the specified css | |
307 | * @css: target css | |
308 | * | |
309 | * Obtain a reference on @css unless it already has reached zero and is | |
310 | * being released. This function doesn't care whether @css is on or | |
311 | * offline. The caller naturally needs to ensure that @css is accessible | |
312 | * but doesn't have to be holding a reference on it - IOW, RCU protected | |
313 | * access is good enough for this function. Returns %true if a reference | |
314 | * count was successfully obtained; %false otherwise. | |
315 | */ | |
316 | static inline bool css_tryget(struct cgroup_subsys_state *css) | |
317 | { | |
318 | if (!(css->flags & CSS_NO_REF)) | |
319 | return percpu_ref_tryget(&css->refcnt); | |
320 | return true; | |
321 | } | |
322 | ||
5de0107e | 323 | /** |
ec903c0c | 324 | * css_tryget_online - try to obtain a reference on the specified css if online |
5de0107e TH |
325 | * @css: target css |
326 | * | |
ec903c0c TH |
327 | * Obtain a reference on @css if it's online. The caller naturally needs |
328 | * to ensure that @css is accessible but doesn't have to be holding a | |
5de0107e TH |
329 | * reference on it - IOW, RCU protected access is good enough for this |
330 | * function. Returns %true if a reference count was successfully obtained; | |
331 | * %false otherwise. | |
332 | */ | |
ec903c0c | 333 | static inline bool css_tryget_online(struct cgroup_subsys_state *css) |
e7c5ec91 | 334 | { |
3b514d24 TH |
335 | if (!(css->flags & CSS_NO_REF)) |
336 | return percpu_ref_tryget_live(&css->refcnt); | |
337 | return true; | |
e7c5ec91 | 338 | } |
2f7ee569 TH |
339 | |
340 | /** | |
5de0107e TH |
341 | * css_put - put a css reference |
342 | * @css: target css | |
343 | * | |
ec903c0c | 344 | * Put a reference obtained via css_get() and css_tryget_online(). |
2f7ee569 | 345 | */ |
ddbcc7e8 PM |
346 | static inline void css_put(struct cgroup_subsys_state *css) |
347 | { | |
3b514d24 TH |
348 | if (!(css->flags & CSS_NO_REF)) |
349 | percpu_ref_put(&css->refcnt); | |
ddbcc7e8 | 350 | } |
2f7ee569 | 351 | |
e8ea14cc JW |
352 | /** |
353 | * css_put_many - put css references | |
354 | * @css: target css | |
355 | * @n: number of references to put | |
356 | * | |
357 | * Put references obtained via css_get() and css_tryget_online(). | |
21acb9ca | 358 | */ |
e8ea14cc JW |
359 | static inline void css_put_many(struct cgroup_subsys_state *css, unsigned int n) |
360 | { | |
361 | if (!(css->flags & CSS_NO_REF)) | |
362 | percpu_ref_put_many(&css->refcnt, n); | |
363 | } | |
ddbcc7e8 | 364 | |
16af4396 TH |
365 | static inline void cgroup_put(struct cgroup *cgrp) |
366 | { | |
367 | css_put(&cgrp->self); | |
368 | } | |
369 | ||
14611e51 TH |
370 | /** |
371 | * task_css_set_check - obtain a task's css_set with extra access conditions | |
372 | * @task: the task to obtain css_set for | |
373 | * @__c: extra condition expression to be passed to rcu_dereference_check() | |
374 | * | |
375 | * A task's css_set is RCU protected, initialized and exited while holding | |
376 | * task_lock(), and can only be modified while holding both cgroup_mutex | |
377 | * and task_lock() while the task is alive. This macro verifies that the | |
378 | * caller is inside proper critical section and returns @task's css_set. | |
379 | * | |
380 | * The caller can also specify additional allowed conditions via @__c, such | |
381 | * as locks used during the cgroup_subsys::attach() methods. | |
dc61b1d6 | 382 | */ |
2219449a TH |
383 | #ifdef CONFIG_PROVE_RCU |
384 | extern struct mutex cgroup_mutex; | |
f0d9a5f1 | 385 | extern spinlock_t css_set_lock; |
14611e51 TH |
386 | #define task_css_set_check(task, __c) \ |
387 | rcu_dereference_check((task)->cgroups, \ | |
0e1d768f | 388 | lockdep_is_held(&cgroup_mutex) || \ |
f0d9a5f1 | 389 | lockdep_is_held(&css_set_lock) || \ |
0e1d768f | 390 | ((task)->flags & PF_EXITING) || (__c)) |
2219449a | 391 | #else |
14611e51 TH |
392 | #define task_css_set_check(task, __c) \ |
393 | rcu_dereference((task)->cgroups) | |
2219449a | 394 | #endif |
dc61b1d6 | 395 | |
14611e51 | 396 | /** |
8af01f56 | 397 | * task_css_check - obtain css for (task, subsys) w/ extra access conds |
14611e51 TH |
398 | * @task: the target task |
399 | * @subsys_id: the target subsystem ID | |
400 | * @__c: extra condition expression to be passed to rcu_dereference_check() | |
401 | * | |
402 | * Return the cgroup_subsys_state for the (@task, @subsys_id) pair. The | |
403 | * synchronization rules are the same as task_css_set_check(). | |
404 | */ | |
8af01f56 | 405 | #define task_css_check(task, subsys_id, __c) \ |
14611e51 TH |
406 | task_css_set_check((task), (__c))->subsys[(subsys_id)] |
407 | ||
408 | /** | |
409 | * task_css_set - obtain a task's css_set | |
410 | * @task: the task to obtain css_set for | |
411 | * | |
412 | * See task_css_set_check(). | |
413 | */ | |
414 | static inline struct css_set *task_css_set(struct task_struct *task) | |
415 | { | |
416 | return task_css_set_check(task, false); | |
417 | } | |
418 | ||
419 | /** | |
8af01f56 | 420 | * task_css - obtain css for (task, subsys) |
14611e51 TH |
421 | * @task: the target task |
422 | * @subsys_id: the target subsystem ID | |
423 | * | |
8af01f56 | 424 | * See task_css_check(). |
14611e51 | 425 | */ |
8af01f56 TH |
426 | static inline struct cgroup_subsys_state *task_css(struct task_struct *task, |
427 | int subsys_id) | |
ddbcc7e8 | 428 | { |
8af01f56 | 429 | return task_css_check(task, subsys_id, false); |
ddbcc7e8 PM |
430 | } |
431 | ||
ec438699 TH |
432 | /** |
433 | * task_get_css - find and get the css for (task, subsys) | |
434 | * @task: the target task | |
435 | * @subsys_id: the target subsystem ID | |
436 | * | |
437 | * Find the css for the (@task, @subsys_id) combination, increment a | |
438 | * reference on and return it. This function is guaranteed to return a | |
439 | * valid css. | |
440 | */ | |
441 | static inline struct cgroup_subsys_state * | |
442 | task_get_css(struct task_struct *task, int subsys_id) | |
443 | { | |
444 | struct cgroup_subsys_state *css; | |
445 | ||
446 | rcu_read_lock(); | |
447 | while (true) { | |
448 | css = task_css(task, subsys_id); | |
449 | if (likely(css_tryget_online(css))) | |
450 | break; | |
451 | cpu_relax(); | |
452 | } | |
453 | rcu_read_unlock(); | |
454 | return css; | |
455 | } | |
456 | ||
5024ae29 TH |
457 | /** |
458 | * task_css_is_root - test whether a task belongs to the root css | |
459 | * @task: the target task | |
460 | * @subsys_id: the target subsystem ID | |
461 | * | |
462 | * Test whether @task belongs to the root css on the specified subsystem. | |
463 | * May be invoked in any context. | |
464 | */ | |
465 | static inline bool task_css_is_root(struct task_struct *task, int subsys_id) | |
466 | { | |
467 | return task_css_check(task, subsys_id, true) == | |
468 | init_css_set.subsys[subsys_id]; | |
469 | } | |
470 | ||
8af01f56 TH |
471 | static inline struct cgroup *task_cgroup(struct task_struct *task, |
472 | int subsys_id) | |
ddbcc7e8 | 473 | { |
8af01f56 | 474 | return task_css(task, subsys_id)->cgroup; |
ddbcc7e8 PM |
475 | } |
476 | ||
b11cfb58 TH |
477 | /** |
478 | * cgroup_is_descendant - test ancestry | |
479 | * @cgrp: the cgroup to be tested | |
480 | * @ancestor: possible ancestor of @cgrp | |
481 | * | |
482 | * Test whether @cgrp is a descendant of @ancestor. It also returns %true | |
483 | * if @cgrp == @ancestor. This function is safe to call as long as @cgrp | |
484 | * and @ancestor are accessible. | |
485 | */ | |
486 | static inline bool cgroup_is_descendant(struct cgroup *cgrp, | |
487 | struct cgroup *ancestor) | |
488 | { | |
489 | if (cgrp->root != ancestor->root || cgrp->level < ancestor->level) | |
490 | return false; | |
491 | return cgrp->ancestor_ids[ancestor->level] == ancestor->id; | |
492 | } | |
493 | ||
07bc356e | 494 | /* no synchronization, the result can only be used as a hint */ |
27bd4dbb | 495 | static inline bool cgroup_is_populated(struct cgroup *cgrp) |
07bc356e | 496 | { |
27bd4dbb | 497 | return cgrp->populated_cnt; |
07bc356e | 498 | } |
f3d46500 | 499 | |
f29374b1 | 500 | /* returns ino associated with a cgroup */ |
b1664924 TH |
501 | static inline ino_t cgroup_ino(struct cgroup *cgrp) |
502 | { | |
f29374b1 | 503 | return cgrp->kn->ino; |
b1664924 | 504 | } |
3ebb2b6e | 505 | |
b4168640 TH |
506 | /* cft/css accessors for cftype->write() operation */ |
507 | static inline struct cftype *of_cft(struct kernfs_open_file *of) | |
7da11279 | 508 | { |
2bd59d48 | 509 | return of->kn->priv; |
7da11279 | 510 | } |
0f0a2b4f | 511 | |
b4168640 | 512 | struct cgroup_subsys_state *of_css(struct kernfs_open_file *of); |
817929ec | 513 | |
b4168640 TH |
514 | /* cft/css accessors for cftype->seq_*() operations */ |
515 | static inline struct cftype *seq_cft(struct seq_file *seq) | |
516 | { | |
517 | return of_cft(seq->private); | |
518 | } | |
e535837b | 519 | |
b4168640 TH |
520 | static inline struct cgroup_subsys_state *seq_css(struct seq_file *seq) |
521 | { | |
522 | return of_css(seq->private); | |
523 | } | |
31583bb0 | 524 | |
e61734c5 TH |
525 | /* |
526 | * Name / path handling functions. All are thin wrappers around the kernfs | |
527 | * counterparts and can be called under any context. | |
528 | */ | |
38460b48 | 529 | |
e61734c5 TH |
530 | static inline int cgroup_name(struct cgroup *cgrp, char *buf, size_t buflen) |
531 | { | |
fdce6bf8 | 532 | return kernfs_name(cgrp->kn, buf, buflen); |
e61734c5 | 533 | } |
ddbcc7e8 | 534 | |
e61734c5 TH |
535 | static inline char * __must_check cgroup_path(struct cgroup *cgrp, char *buf, |
536 | size_t buflen) | |
537 | { | |
fdce6bf8 | 538 | return kernfs_path(cgrp->kn, buf, buflen); |
e61734c5 | 539 | } |
f3ba5380 | 540 | |
e61734c5 TH |
541 | static inline void pr_cont_cgroup_name(struct cgroup *cgrp) |
542 | { | |
fdce6bf8 | 543 | pr_cont_kernfs_name(cgrp->kn); |
e61734c5 | 544 | } |
ddbcc7e8 | 545 | |
e61734c5 | 546 | static inline void pr_cont_cgroup_path(struct cgroup *cgrp) |
846c7bb0 | 547 | { |
fdce6bf8 | 548 | pr_cont_kernfs_path(cgrp->kn); |
846c7bb0 | 549 | } |
ddbcc7e8 | 550 | |
ddbcc7e8 PM |
551 | #else /* !CONFIG_CGROUPS */ |
552 | ||
f3ba5380 | 553 | struct cgroup_subsys_state; |
f3ba5380 | 554 | |
c326aa2b | 555 | static inline void css_put(struct cgroup_subsys_state *css) {} |
31583bb0 | 556 | static inline int cgroup_attach_task_all(struct task_struct *from, |
c326aa2b TH |
557 | struct task_struct *t) { return 0; } |
558 | static inline int cgroupstats_build(struct cgroupstats *stats, | |
559 | struct dentry *dentry) { return -EINVAL; } | |
560 | ||
b4f48b63 | 561 | static inline void cgroup_fork(struct task_struct *p) {} |
b53202e6 ON |
562 | static inline int cgroup_can_fork(struct task_struct *p) { return 0; } |
563 | static inline void cgroup_cancel_fork(struct task_struct *p) {} | |
564 | static inline void cgroup_post_fork(struct task_struct *p) {} | |
1ec41830 | 565 | static inline void cgroup_exit(struct task_struct *p) {} |
2e91fa7f | 566 | static inline void cgroup_free(struct task_struct *p) {} |
ddbcc7e8 | 567 | |
c326aa2b TH |
568 | static inline int cgroup_init_early(void) { return 0; } |
569 | static inline int cgroup_init(void) { return 0; } | |
d7926ee3 | 570 | |
ddbcc7e8 PM |
571 | #endif /* !CONFIG_CGROUPS */ |
572 | ||
bd1060a1 TH |
573 | /* |
574 | * sock->sk_cgrp_data handling. For more info, see sock_cgroup_data | |
575 | * definition in cgroup-defs.h. | |
576 | */ | |
577 | #ifdef CONFIG_SOCK_CGROUP_DATA | |
578 | ||
579 | #if defined(CONFIG_CGROUP_NET_PRIO) || defined(CONFIG_CGROUP_NET_CLASSID) | |
580 | extern spinlock_t cgroup_sk_update_lock; | |
581 | #endif | |
582 | ||
583 | void cgroup_sk_alloc_disable(void); | |
584 | void cgroup_sk_alloc(struct sock_cgroup_data *skcd); | |
585 | void cgroup_sk_free(struct sock_cgroup_data *skcd); | |
586 | ||
587 | static inline struct cgroup *sock_cgroup_ptr(struct sock_cgroup_data *skcd) | |
588 | { | |
589 | #if defined(CONFIG_CGROUP_NET_PRIO) || defined(CONFIG_CGROUP_NET_CLASSID) | |
590 | unsigned long v; | |
591 | ||
592 | /* | |
593 | * @skcd->val is 64bit but the following is safe on 32bit too as we | |
594 | * just need the lower ulong to be written and read atomically. | |
595 | */ | |
596 | v = READ_ONCE(skcd->val); | |
597 | ||
598 | if (v & 1) | |
599 | return &cgrp_dfl_root.cgrp; | |
600 | ||
601 | return (struct cgroup *)(unsigned long)v ?: &cgrp_dfl_root.cgrp; | |
602 | #else | |
603 | return (struct cgroup *)(unsigned long)skcd->val; | |
604 | #endif | |
605 | } | |
606 | ||
607 | #else /* CONFIG_CGROUP_DATA */ | |
608 | ||
609 | static inline void cgroup_sk_alloc(struct sock_cgroup_data *skcd) {} | |
610 | static inline void cgroup_sk_free(struct sock_cgroup_data *skcd) {} | |
611 | ||
612 | #endif /* CONFIG_CGROUP_DATA */ | |
613 | ||
ddbcc7e8 | 614 | #endif /* _LINUX_CGROUP_H */ |