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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
ddbcc7e8 PM |
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> | |
ddbcc7e8 PM |
13 | #include <linux/cpumask.h> |
14 | #include <linux/nodemask.h> | |
eb6fd504 | 15 | #include <linux/rculist.h> |
846c7bb0 | 16 | #include <linux/cgroupstats.h> |
25a7e684 | 17 | #include <linux/fs.h> |
7da11279 | 18 | #include <linux/seq_file.h> |
2bd59d48 | 19 | #include <linux/kernfs.h> |
49d1dc4b | 20 | #include <linux/jump_label.h> |
a79a908f AK |
21 | #include <linux/types.h> |
22 | #include <linux/ns_common.h> | |
23 | #include <linux/nsproxy.h> | |
24 | #include <linux/user_namespace.h> | |
387ad967 | 25 | #include <linux/refcount.h> |
d2cc5ed6 | 26 | #include <linux/kernel_stat.h> |
ddbcc7e8 | 27 | |
b4a04ab7 | 28 | #include <linux/cgroup-defs.h> |
ddbcc7e8 PM |
29 | |
30 | #ifdef CONFIG_CGROUPS | |
31 | ||
6abc8ca1 TH |
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 | ||
bc2fb7ed TH |
41 | /* walk only threadgroup leaders */ |
42 | #define CSS_TASK_ITER_PROCS (1U << 0) | |
450ee0c1 TH |
43 | /* walk all threaded css_sets in the domain */ |
44 | #define CSS_TASK_ITER_THREADED (1U << 1) | |
bc2fb7ed | 45 | |
b636fd38 TH |
46 | /* internal flags */ |
47 | #define CSS_TASK_ITER_SKIPPED (1U << 16) | |
48 | ||
c326aa2b TH |
49 | /* a css_task_iter should be treated as an opaque object */ |
50 | struct css_task_iter { | |
51 | struct cgroup_subsys *ss; | |
bc2fb7ed | 52 | unsigned int flags; |
c326aa2b TH |
53 | |
54 | struct list_head *cset_pos; | |
55 | struct list_head *cset_head; | |
ddbcc7e8 | 56 | |
450ee0c1 TH |
57 | struct list_head *tcset_pos; |
58 | struct list_head *tcset_head; | |
59 | ||
c326aa2b TH |
60 | struct list_head *task_pos; |
61 | struct list_head *tasks_head; | |
62 | struct list_head *mg_tasks_head; | |
c03cd773 | 63 | struct list_head *dying_tasks_head; |
ed27b9f7 | 64 | |
d27c8baa | 65 | struct list_head *cur_tasks_head; |
ed27b9f7 | 66 | struct css_set *cur_cset; |
450ee0c1 | 67 | struct css_set *cur_dcset; |
ed27b9f7 TH |
68 | struct task_struct *cur_task; |
69 | struct list_head iters_node; /* css_set->task_iters */ | |
c326aa2b | 70 | }; |
ddbcc7e8 | 71 | |
c326aa2b TH |
72 | extern struct cgroup_root cgrp_dfl_root; |
73 | extern struct css_set init_css_set; | |
a424316c | 74 | |
c326aa2b | 75 | #define SUBSYS(_x) extern struct cgroup_subsys _x ## _cgrp_subsys; |
817929ec | 76 | #include <linux/cgroup_subsys.h> |
817929ec PM |
77 | #undef SUBSYS |
78 | ||
49d1dc4b TH |
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 | ||
c326aa2b TH |
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); | |
fc5a828b DZ |
101 | struct cgroup_subsys_state *cgroup_e_css(struct cgroup *cgroup, |
102 | struct cgroup_subsys *ss); | |
c326aa2b TH |
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 | ||
16af4396 | 108 | struct cgroup *cgroup_get_from_path(const char *path); |
1f3fe7eb | 109 | struct cgroup *cgroup_get_from_fd(int fd); |
16af4396 | 110 | |
c326aa2b TH |
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); | |
34c06254 | 117 | void cgroup_file_notify(struct cgroup_file *cfile); |
c326aa2b | 118 | |
4c737b41 | 119 | int task_cgroup_path(struct task_struct *task, char *buf, size_t buflen); |
c326aa2b TH |
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); | |
b53202e6 ON |
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); | |
c326aa2b | 128 | void cgroup_exit(struct task_struct *p); |
51bee5ab | 129 | void cgroup_release(struct task_struct *p); |
2e91fa7f | 130 | void cgroup_free(struct task_struct *p); |
c326aa2b TH |
131 | |
132 | int cgroup_init_early(void); | |
133 | int cgroup_init(void); | |
134 | ||
a5e112e6 TH |
135 | int cgroup_parse_float(const char *input, unsigned dec_shift, s64 *v); |
136 | ||
5c9d535b | 137 | /* |
c326aa2b TH |
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 | ||
1f7dd3e5 TH |
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); | |
c326aa2b | 153 | |
f9a25f77 | 154 | void cgroup_enable_task_cg_lists(void); |
bc2fb7ed | 155 | void css_task_iter_start(struct cgroup_subsys_state *css, unsigned int flags, |
c326aa2b TH |
156 | struct css_task_iter *it); |
157 | struct task_struct *css_task_iter_next(struct css_task_iter *it); | |
158 | void css_task_iter_end(struct css_task_iter *it); | |
159 | ||
160 | /** | |
161 | * css_for_each_child - iterate through children of a css | |
162 | * @pos: the css * to use as the loop cursor | |
163 | * @parent: css whose children to walk | |
164 | * | |
165 | * Walk @parent's children. Must be called under rcu_read_lock(). | |
166 | * | |
167 | * If a subsystem synchronizes ->css_online() and the start of iteration, a | |
168 | * css which finished ->css_online() is guaranteed to be visible in the | |
169 | * future iterations and will stay visible until the last reference is put. | |
170 | * A css which hasn't finished ->css_online() or already finished | |
171 | * ->css_offline() may show up during traversal. It's each subsystem's | |
172 | * responsibility to synchronize against on/offlining. | |
5c9d535b | 173 | * |
c326aa2b TH |
174 | * It is allowed to temporarily drop RCU read lock during iteration. The |
175 | * caller is responsible for ensuring that @pos remains accessible until | |
176 | * the start of the next iteration by, for example, bumping the css refcnt. | |
5c9d535b | 177 | */ |
c326aa2b TH |
178 | #define css_for_each_child(pos, parent) \ |
179 | for ((pos) = css_next_child(NULL, (parent)); (pos); \ | |
180 | (pos) = css_next_child((pos), (parent))) | |
ddbcc7e8 | 181 | |
c326aa2b TH |
182 | /** |
183 | * css_for_each_descendant_pre - pre-order walk of a css's descendants | |
184 | * @pos: the css * to use as the loop cursor | |
185 | * @root: css whose descendants to walk | |
186 | * | |
187 | * Walk @root's descendants. @root is included in the iteration and the | |
188 | * first node to be visited. Must be called under rcu_read_lock(). | |
189 | * | |
190 | * If a subsystem synchronizes ->css_online() and the start of iteration, a | |
191 | * css which finished ->css_online() is guaranteed to be visible in the | |
192 | * future iterations and will stay visible until the last reference is put. | |
193 | * A css which hasn't finished ->css_online() or already finished | |
194 | * ->css_offline() may show up during traversal. It's each subsystem's | |
195 | * responsibility to synchronize against on/offlining. | |
196 | * | |
197 | * For example, the following guarantees that a descendant can't escape | |
198 | * state updates of its ancestors. | |
199 | * | |
200 | * my_online(@css) | |
201 | * { | |
202 | * Lock @css's parent and @css; | |
203 | * Inherit state from the parent; | |
204 | * Unlock both. | |
205 | * } | |
206 | * | |
207 | * my_update_state(@css) | |
208 | * { | |
209 | * css_for_each_descendant_pre(@pos, @css) { | |
210 | * Lock @pos; | |
211 | * if (@pos == @css) | |
212 | * Update @css's state; | |
213 | * else | |
214 | * Verify @pos is alive and inherit state from its parent; | |
215 | * Unlock @pos; | |
216 | * } | |
217 | * } | |
218 | * | |
219 | * As long as the inheriting step, including checking the parent state, is | |
220 | * enclosed inside @pos locking, double-locking the parent isn't necessary | |
221 | * while inheriting. The state update to the parent is guaranteed to be | |
222 | * visible by walking order and, as long as inheriting operations to the | |
223 | * same @pos are atomic to each other, multiple updates racing each other | |
224 | * still result in the correct state. It's guaranateed that at least one | |
225 | * inheritance happens for any css after the latest update to its parent. | |
226 | * | |
227 | * If checking parent's state requires locking the parent, each inheriting | |
228 | * iteration should lock and unlock both @pos->parent and @pos. | |
229 | * | |
230 | * Alternatively, a subsystem may choose to use a single global lock to | |
231 | * synchronize ->css_online() and ->css_offline() against tree-walking | |
232 | * operations. | |
233 | * | |
234 | * It is allowed to temporarily drop RCU read lock during iteration. The | |
235 | * caller is responsible for ensuring that @pos remains accessible until | |
236 | * the start of the next iteration by, for example, bumping the css refcnt. | |
237 | */ | |
238 | #define css_for_each_descendant_pre(pos, css) \ | |
239 | for ((pos) = css_next_descendant_pre(NULL, (css)); (pos); \ | |
240 | (pos) = css_next_descendant_pre((pos), (css))) | |
241 | ||
242 | /** | |
243 | * css_for_each_descendant_post - post-order walk of a css's descendants | |
244 | * @pos: the css * to use as the loop cursor | |
245 | * @css: css whose descendants to walk | |
246 | * | |
247 | * Similar to css_for_each_descendant_pre() but performs post-order | |
248 | * traversal instead. @root is included in the iteration and the last | |
249 | * node to be visited. | |
250 | * | |
251 | * If a subsystem synchronizes ->css_online() and the start of iteration, a | |
252 | * css which finished ->css_online() is guaranteed to be visible in the | |
253 | * future iterations and will stay visible until the last reference is put. | |
254 | * A css which hasn't finished ->css_online() or already finished | |
255 | * ->css_offline() may show up during traversal. It's each subsystem's | |
256 | * responsibility to synchronize against on/offlining. | |
257 | * | |
258 | * Note that the walk visibility guarantee example described in pre-order | |
259 | * walk doesn't apply the same to post-order walks. | |
260 | */ | |
261 | #define css_for_each_descendant_post(pos, css) \ | |
262 | for ((pos) = css_next_descendant_post(NULL, (css)); (pos); \ | |
263 | (pos) = css_next_descendant_post((pos), (css))) | |
264 | ||
265 | /** | |
266 | * cgroup_taskset_for_each - iterate cgroup_taskset | |
267 | * @task: the loop cursor | |
1f7dd3e5 | 268 | * @dst_css: the destination css |
c326aa2b | 269 | * @tset: taskset to iterate |
4530eddb TH |
270 | * |
271 | * @tset may contain multiple tasks and they may belong to multiple | |
1f7dd3e5 TH |
272 | * processes. |
273 | * | |
274 | * On the v2 hierarchy, there may be tasks from multiple processes and they | |
275 | * may not share the source or destination csses. | |
276 | * | |
277 | * On traditional hierarchies, when there are multiple tasks in @tset, if a | |
278 | * task of a process is in @tset, all tasks of the process are in @tset. | |
279 | * Also, all are guaranteed to share the same source and destination csses. | |
4530eddb TH |
280 | * |
281 | * Iteration is not in any specific order. | |
c326aa2b | 282 | */ |
1f7dd3e5 TH |
283 | #define cgroup_taskset_for_each(task, dst_css, tset) \ |
284 | for ((task) = cgroup_taskset_first((tset), &(dst_css)); \ | |
285 | (task); \ | |
286 | (task) = cgroup_taskset_next((tset), &(dst_css))) | |
ddbcc7e8 | 287 | |
4530eddb TH |
288 | /** |
289 | * cgroup_taskset_for_each_leader - iterate group leaders in a cgroup_taskset | |
290 | * @leader: the loop cursor | |
1f7dd3e5 | 291 | * @dst_css: the destination css |
7b4632f0 | 292 | * @tset: taskset to iterate |
4530eddb TH |
293 | * |
294 | * Iterate threadgroup leaders of @tset. For single-task migrations, @tset | |
295 | * may not contain any. | |
296 | */ | |
1f7dd3e5 TH |
297 | #define cgroup_taskset_for_each_leader(leader, dst_css, tset) \ |
298 | for ((leader) = cgroup_taskset_first((tset), &(dst_css)); \ | |
299 | (leader); \ | |
300 | (leader) = cgroup_taskset_next((tset), &(dst_css))) \ | |
4530eddb TH |
301 | if ((leader) != (leader)->group_leader) \ |
302 | ; \ | |
303 | else | |
304 | ||
c326aa2b TH |
305 | /* |
306 | * Inline functions. | |
307 | */ | |
ddbcc7e8 | 308 | |
5de0107e TH |
309 | /** |
310 | * css_get - obtain a reference on the specified css | |
311 | * @css: target css | |
312 | * | |
313 | * The caller must already have a reference. | |
ddbcc7e8 | 314 | */ |
ddbcc7e8 PM |
315 | static inline void css_get(struct cgroup_subsys_state *css) |
316 | { | |
3b514d24 TH |
317 | if (!(css->flags & CSS_NO_REF)) |
318 | percpu_ref_get(&css->refcnt); | |
ddbcc7e8 | 319 | } |
e7c5ec91 | 320 | |
e8ea14cc JW |
321 | /** |
322 | * css_get_many - obtain references on the specified css | |
323 | * @css: target css | |
324 | * @n: number of references to get | |
325 | * | |
326 | * The caller must already have a reference. | |
327 | */ | |
328 | static inline void css_get_many(struct cgroup_subsys_state *css, unsigned int n) | |
329 | { | |
330 | if (!(css->flags & CSS_NO_REF)) | |
331 | percpu_ref_get_many(&css->refcnt, n); | |
332 | } | |
333 | ||
6f4524d3 TH |
334 | /** |
335 | * css_tryget - try to obtain a reference on the specified css | |
336 | * @css: target css | |
337 | * | |
338 | * Obtain a reference on @css unless it already has reached zero and is | |
339 | * being released. This function doesn't care whether @css is on or | |
340 | * offline. The caller naturally needs to ensure that @css is accessible | |
341 | * but doesn't have to be holding a reference on it - IOW, RCU protected | |
342 | * access is good enough for this function. Returns %true if a reference | |
343 | * count was successfully obtained; %false otherwise. | |
344 | */ | |
345 | static inline bool css_tryget(struct cgroup_subsys_state *css) | |
346 | { | |
347 | if (!(css->flags & CSS_NO_REF)) | |
348 | return percpu_ref_tryget(&css->refcnt); | |
349 | return true; | |
350 | } | |
351 | ||
5de0107e | 352 | /** |
ec903c0c | 353 | * css_tryget_online - try to obtain a reference on the specified css if online |
5de0107e TH |
354 | * @css: target css |
355 | * | |
ec903c0c TH |
356 | * Obtain a reference on @css if it's online. The caller naturally needs |
357 | * to ensure that @css is accessible but doesn't have to be holding a | |
5de0107e TH |
358 | * reference on it - IOW, RCU protected access is good enough for this |
359 | * function. Returns %true if a reference count was successfully obtained; | |
360 | * %false otherwise. | |
361 | */ | |
ec903c0c | 362 | static inline bool css_tryget_online(struct cgroup_subsys_state *css) |
e7c5ec91 | 363 | { |
3b514d24 TH |
364 | if (!(css->flags & CSS_NO_REF)) |
365 | return percpu_ref_tryget_live(&css->refcnt); | |
366 | return true; | |
e7c5ec91 | 367 | } |
2f7ee569 | 368 | |
41c25707 TH |
369 | /** |
370 | * css_is_dying - test whether the specified css is dying | |
371 | * @css: target css | |
372 | * | |
373 | * Test whether @css is in the process of offlining or already offline. In | |
374 | * most cases, ->css_online() and ->css_offline() callbacks should be | |
375 | * enough; however, the actual offline operations are RCU delayed and this | |
376 | * test returns %true also when @css is scheduled to be offlined. | |
377 | * | |
378 | * This is useful, for example, when the use case requires synchronous | |
379 | * behavior with respect to cgroup removal. cgroup removal schedules css | |
380 | * offlining but the css can seem alive while the operation is being | |
381 | * delayed. If the delay affects user visible semantics, this test can be | |
382 | * used to resolve the situation. | |
383 | */ | |
384 | static inline bool css_is_dying(struct cgroup_subsys_state *css) | |
385 | { | |
386 | return !(css->flags & CSS_NO_REF) && percpu_ref_is_dying(&css->refcnt); | |
387 | } | |
388 | ||
2f7ee569 | 389 | /** |
5de0107e TH |
390 | * css_put - put a css reference |
391 | * @css: target css | |
392 | * | |
ec903c0c | 393 | * Put a reference obtained via css_get() and css_tryget_online(). |
2f7ee569 | 394 | */ |
ddbcc7e8 PM |
395 | static inline void css_put(struct cgroup_subsys_state *css) |
396 | { | |
3b514d24 TH |
397 | if (!(css->flags & CSS_NO_REF)) |
398 | percpu_ref_put(&css->refcnt); | |
ddbcc7e8 | 399 | } |
2f7ee569 | 400 | |
e8ea14cc JW |
401 | /** |
402 | * css_put_many - put css references | |
403 | * @css: target css | |
404 | * @n: number of references to put | |
405 | * | |
406 | * Put references obtained via css_get() and css_tryget_online(). | |
21acb9ca | 407 | */ |
e8ea14cc JW |
408 | static inline void css_put_many(struct cgroup_subsys_state *css, unsigned int n) |
409 | { | |
410 | if (!(css->flags & CSS_NO_REF)) | |
411 | percpu_ref_put_many(&css->refcnt, n); | |
412 | } | |
ddbcc7e8 | 413 | |
3e48930c TH |
414 | static inline void cgroup_get(struct cgroup *cgrp) |
415 | { | |
416 | css_get(&cgrp->self); | |
417 | } | |
418 | ||
419 | static inline bool cgroup_tryget(struct cgroup *cgrp) | |
420 | { | |
421 | return css_tryget(&cgrp->self); | |
422 | } | |
423 | ||
16af4396 TH |
424 | static inline void cgroup_put(struct cgroup *cgrp) |
425 | { | |
426 | css_put(&cgrp->self); | |
427 | } | |
428 | ||
14611e51 TH |
429 | /** |
430 | * task_css_set_check - obtain a task's css_set with extra access conditions | |
431 | * @task: the task to obtain css_set for | |
432 | * @__c: extra condition expression to be passed to rcu_dereference_check() | |
433 | * | |
434 | * A task's css_set is RCU protected, initialized and exited while holding | |
435 | * task_lock(), and can only be modified while holding both cgroup_mutex | |
436 | * and task_lock() while the task is alive. This macro verifies that the | |
437 | * caller is inside proper critical section and returns @task's css_set. | |
438 | * | |
439 | * The caller can also specify additional allowed conditions via @__c, such | |
440 | * as locks used during the cgroup_subsys::attach() methods. | |
dc61b1d6 | 441 | */ |
2219449a TH |
442 | #ifdef CONFIG_PROVE_RCU |
443 | extern struct mutex cgroup_mutex; | |
f0d9a5f1 | 444 | extern spinlock_t css_set_lock; |
14611e51 TH |
445 | #define task_css_set_check(task, __c) \ |
446 | rcu_dereference_check((task)->cgroups, \ | |
0e1d768f | 447 | lockdep_is_held(&cgroup_mutex) || \ |
f0d9a5f1 | 448 | lockdep_is_held(&css_set_lock) || \ |
0e1d768f | 449 | ((task)->flags & PF_EXITING) || (__c)) |
2219449a | 450 | #else |
14611e51 TH |
451 | #define task_css_set_check(task, __c) \ |
452 | rcu_dereference((task)->cgroups) | |
2219449a | 453 | #endif |
dc61b1d6 | 454 | |
14611e51 | 455 | /** |
8af01f56 | 456 | * task_css_check - obtain css for (task, subsys) w/ extra access conds |
14611e51 TH |
457 | * @task: the target task |
458 | * @subsys_id: the target subsystem ID | |
459 | * @__c: extra condition expression to be passed to rcu_dereference_check() | |
460 | * | |
461 | * Return the cgroup_subsys_state for the (@task, @subsys_id) pair. The | |
462 | * synchronization rules are the same as task_css_set_check(). | |
463 | */ | |
8af01f56 | 464 | #define task_css_check(task, subsys_id, __c) \ |
14611e51 TH |
465 | task_css_set_check((task), (__c))->subsys[(subsys_id)] |
466 | ||
467 | /** | |
468 | * task_css_set - obtain a task's css_set | |
469 | * @task: the task to obtain css_set for | |
470 | * | |
471 | * See task_css_set_check(). | |
472 | */ | |
473 | static inline struct css_set *task_css_set(struct task_struct *task) | |
474 | { | |
475 | return task_css_set_check(task, false); | |
476 | } | |
477 | ||
478 | /** | |
8af01f56 | 479 | * task_css - obtain css for (task, subsys) |
14611e51 TH |
480 | * @task: the target task |
481 | * @subsys_id: the target subsystem ID | |
482 | * | |
8af01f56 | 483 | * See task_css_check(). |
14611e51 | 484 | */ |
8af01f56 TH |
485 | static inline struct cgroup_subsys_state *task_css(struct task_struct *task, |
486 | int subsys_id) | |
ddbcc7e8 | 487 | { |
8af01f56 | 488 | return task_css_check(task, subsys_id, false); |
ddbcc7e8 PM |
489 | } |
490 | ||
ec438699 TH |
491 | /** |
492 | * task_get_css - find and get the css for (task, subsys) | |
493 | * @task: the target task | |
494 | * @subsys_id: the target subsystem ID | |
495 | * | |
496 | * Find the css for the (@task, @subsys_id) combination, increment a | |
497 | * reference on and return it. This function is guaranteed to return a | |
18fa84a2 | 498 | * valid css. The returned css may already have been offlined. |
ec438699 TH |
499 | */ |
500 | static inline struct cgroup_subsys_state * | |
501 | task_get_css(struct task_struct *task, int subsys_id) | |
502 | { | |
503 | struct cgroup_subsys_state *css; | |
504 | ||
505 | rcu_read_lock(); | |
506 | while (true) { | |
507 | css = task_css(task, subsys_id); | |
18fa84a2 TH |
508 | /* |
509 | * Can't use css_tryget_online() here. A task which has | |
510 | * PF_EXITING set may stay associated with an offline css. | |
511 | * If such task calls this function, css_tryget_online() | |
512 | * will keep failing. | |
513 | */ | |
514 | if (likely(css_tryget(css))) | |
ec438699 TH |
515 | break; |
516 | cpu_relax(); | |
517 | } | |
518 | rcu_read_unlock(); | |
519 | return css; | |
520 | } | |
521 | ||
5024ae29 TH |
522 | /** |
523 | * task_css_is_root - test whether a task belongs to the root css | |
524 | * @task: the target task | |
525 | * @subsys_id: the target subsystem ID | |
526 | * | |
527 | * Test whether @task belongs to the root css on the specified subsystem. | |
528 | * May be invoked in any context. | |
529 | */ | |
530 | static inline bool task_css_is_root(struct task_struct *task, int subsys_id) | |
531 | { | |
532 | return task_css_check(task, subsys_id, true) == | |
533 | init_css_set.subsys[subsys_id]; | |
534 | } | |
535 | ||
8af01f56 TH |
536 | static inline struct cgroup *task_cgroup(struct task_struct *task, |
537 | int subsys_id) | |
ddbcc7e8 | 538 | { |
8af01f56 | 539 | return task_css(task, subsys_id)->cgroup; |
ddbcc7e8 PM |
540 | } |
541 | ||
3e48930c TH |
542 | static inline struct cgroup *task_dfl_cgroup(struct task_struct *task) |
543 | { | |
544 | return task_css_set(task)->dfl_cgrp; | |
545 | } | |
546 | ||
547 | static inline struct cgroup *cgroup_parent(struct cgroup *cgrp) | |
548 | { | |
549 | struct cgroup_subsys_state *parent_css = cgrp->self.parent; | |
550 | ||
551 | if (parent_css) | |
552 | return container_of(parent_css, struct cgroup, self); | |
553 | return NULL; | |
554 | } | |
555 | ||
b11cfb58 TH |
556 | /** |
557 | * cgroup_is_descendant - test ancestry | |
558 | * @cgrp: the cgroup to be tested | |
559 | * @ancestor: possible ancestor of @cgrp | |
560 | * | |
561 | * Test whether @cgrp is a descendant of @ancestor. It also returns %true | |
562 | * if @cgrp == @ancestor. This function is safe to call as long as @cgrp | |
563 | * and @ancestor are accessible. | |
564 | */ | |
565 | static inline bool cgroup_is_descendant(struct cgroup *cgrp, | |
566 | struct cgroup *ancestor) | |
567 | { | |
568 | if (cgrp->root != ancestor->root || cgrp->level < ancestor->level) | |
569 | return false; | |
570 | return cgrp->ancestor_ids[ancestor->level] == ancestor->id; | |
571 | } | |
572 | ||
77236281 AI |
573 | /** |
574 | * cgroup_ancestor - find ancestor of cgroup | |
575 | * @cgrp: cgroup to find ancestor of | |
576 | * @ancestor_level: level of ancestor to find starting from root | |
577 | * | |
578 | * Find ancestor of cgroup at specified level starting from root if it exists | |
579 | * and return pointer to it. Return NULL if @cgrp doesn't have ancestor at | |
580 | * @ancestor_level. | |
581 | * | |
582 | * This function is safe to call as long as @cgrp is accessible. | |
583 | */ | |
584 | static inline struct cgroup *cgroup_ancestor(struct cgroup *cgrp, | |
585 | int ancestor_level) | |
586 | { | |
77236281 AI |
587 | if (cgrp->level < ancestor_level) |
588 | return NULL; | |
808c43b7 AI |
589 | while (cgrp && cgrp->level > ancestor_level) |
590 | cgrp = cgroup_parent(cgrp); | |
591 | return cgrp; | |
77236281 AI |
592 | } |
593 | ||
aed704b7 SD |
594 | /** |
595 | * task_under_cgroup_hierarchy - test task's membership of cgroup ancestry | |
596 | * @task: the task to be tested | |
597 | * @ancestor: possible ancestor of @task's cgroup | |
598 | * | |
599 | * Tests whether @task's default cgroup hierarchy is a descendant of @ancestor. | |
600 | * It follows all the same rules as cgroup_is_descendant, and only applies | |
601 | * to the default hierarchy. | |
602 | */ | |
603 | static inline bool task_under_cgroup_hierarchy(struct task_struct *task, | |
604 | struct cgroup *ancestor) | |
605 | { | |
606 | struct css_set *cset = task_css_set(task); | |
607 | ||
608 | return cgroup_is_descendant(cset->dfl_cgrp, ancestor); | |
609 | } | |
610 | ||
07bc356e | 611 | /* no synchronization, the result can only be used as a hint */ |
27bd4dbb | 612 | static inline bool cgroup_is_populated(struct cgroup *cgrp) |
07bc356e | 613 | { |
454000ad TH |
614 | return cgrp->nr_populated_csets + cgrp->nr_populated_domain_children + |
615 | cgrp->nr_populated_threaded_children; | |
07bc356e | 616 | } |
f3d46500 | 617 | |
f29374b1 | 618 | /* returns ino associated with a cgroup */ |
b1664924 TH |
619 | static inline ino_t cgroup_ino(struct cgroup *cgrp) |
620 | { | |
c53cd490 | 621 | return cgrp->kn->id.ino; |
b1664924 | 622 | } |
3ebb2b6e | 623 | |
b4168640 TH |
624 | /* cft/css accessors for cftype->write() operation */ |
625 | static inline struct cftype *of_cft(struct kernfs_open_file *of) | |
7da11279 | 626 | { |
2bd59d48 | 627 | return of->kn->priv; |
7da11279 | 628 | } |
0f0a2b4f | 629 | |
b4168640 | 630 | struct cgroup_subsys_state *of_css(struct kernfs_open_file *of); |
817929ec | 631 | |
b4168640 TH |
632 | /* cft/css accessors for cftype->seq_*() operations */ |
633 | static inline struct cftype *seq_cft(struct seq_file *seq) | |
634 | { | |
635 | return of_cft(seq->private); | |
636 | } | |
e535837b | 637 | |
b4168640 TH |
638 | static inline struct cgroup_subsys_state *seq_css(struct seq_file *seq) |
639 | { | |
640 | return of_css(seq->private); | |
641 | } | |
31583bb0 | 642 | |
e61734c5 TH |
643 | /* |
644 | * Name / path handling functions. All are thin wrappers around the kernfs | |
645 | * counterparts and can be called under any context. | |
646 | */ | |
38460b48 | 647 | |
e61734c5 TH |
648 | static inline int cgroup_name(struct cgroup *cgrp, char *buf, size_t buflen) |
649 | { | |
fdce6bf8 | 650 | return kernfs_name(cgrp->kn, buf, buflen); |
e61734c5 | 651 | } |
ddbcc7e8 | 652 | |
4c737b41 | 653 | static inline int cgroup_path(struct cgroup *cgrp, char *buf, size_t buflen) |
e61734c5 | 654 | { |
fdce6bf8 | 655 | return kernfs_path(cgrp->kn, buf, buflen); |
e61734c5 | 656 | } |
f3ba5380 | 657 | |
e61734c5 TH |
658 | static inline void pr_cont_cgroup_name(struct cgroup *cgrp) |
659 | { | |
fdce6bf8 | 660 | pr_cont_kernfs_name(cgrp->kn); |
e61734c5 | 661 | } |
ddbcc7e8 | 662 | |
e61734c5 | 663 | static inline void pr_cont_cgroup_path(struct cgroup *cgrp) |
846c7bb0 | 664 | { |
fdce6bf8 | 665 | pr_cont_kernfs_path(cgrp->kn); |
846c7bb0 | 666 | } |
ddbcc7e8 | 667 | |
2ce7135a JW |
668 | static inline struct psi_group *cgroup_psi(struct cgroup *cgrp) |
669 | { | |
670 | return &cgrp->psi; | |
671 | } | |
672 | ||
77f88796 TH |
673 | static inline void cgroup_init_kthreadd(void) |
674 | { | |
675 | /* | |
676 | * kthreadd is inherited by all kthreads, keep it in the root so | |
677 | * that the new kthreads are guaranteed to stay in the root until | |
678 | * initialization is finished. | |
679 | */ | |
680 | current->no_cgroup_migration = 1; | |
681 | } | |
682 | ||
683 | static inline void cgroup_kthread_ready(void) | |
684 | { | |
685 | /* | |
686 | * This kthread finished initialization. The creator should have | |
687 | * set PF_NO_SETAFFINITY if this kthread should stay in the root. | |
688 | */ | |
689 | current->no_cgroup_migration = 0; | |
690 | } | |
691 | ||
121508df SL |
692 | static inline union kernfs_node_id *cgroup_get_kernfs_id(struct cgroup *cgrp) |
693 | { | |
694 | return &cgrp->kn->id; | |
695 | } | |
69fd5c39 SL |
696 | |
697 | void cgroup_path_from_kernfs_id(const union kernfs_node_id *id, | |
698 | char *buf, size_t buflen); | |
ddbcc7e8 PM |
699 | #else /* !CONFIG_CGROUPS */ |
700 | ||
f3ba5380 | 701 | struct cgroup_subsys_state; |
aed704b7 | 702 | struct cgroup; |
f3ba5380 | 703 | |
9b0eb69b | 704 | static inline void css_get(struct cgroup_subsys_state *css) {} |
c326aa2b | 705 | static inline void css_put(struct cgroup_subsys_state *css) {} |
31583bb0 | 706 | static inline int cgroup_attach_task_all(struct task_struct *from, |
c326aa2b TH |
707 | struct task_struct *t) { return 0; } |
708 | static inline int cgroupstats_build(struct cgroupstats *stats, | |
709 | struct dentry *dentry) { return -EINVAL; } | |
710 | ||
b4f48b63 | 711 | static inline void cgroup_fork(struct task_struct *p) {} |
b53202e6 ON |
712 | static inline int cgroup_can_fork(struct task_struct *p) { return 0; } |
713 | static inline void cgroup_cancel_fork(struct task_struct *p) {} | |
714 | static inline void cgroup_post_fork(struct task_struct *p) {} | |
1ec41830 | 715 | static inline void cgroup_exit(struct task_struct *p) {} |
51bee5ab | 716 | static inline void cgroup_release(struct task_struct *p) {} |
2e91fa7f | 717 | static inline void cgroup_free(struct task_struct *p) {} |
ddbcc7e8 | 718 | |
c326aa2b TH |
719 | static inline int cgroup_init_early(void) { return 0; } |
720 | static inline int cgroup_init(void) { return 0; } | |
77f88796 TH |
721 | static inline void cgroup_init_kthreadd(void) {} |
722 | static inline void cgroup_kthread_ready(void) {} | |
121508df SL |
723 | static inline union kernfs_node_id *cgroup_get_kernfs_id(struct cgroup *cgrp) |
724 | { | |
725 | return NULL; | |
726 | } | |
d7926ee3 | 727 | |
2ce7135a JW |
728 | static inline struct cgroup *cgroup_parent(struct cgroup *cgrp) |
729 | { | |
730 | return NULL; | |
731 | } | |
732 | ||
733 | static inline struct psi_group *cgroup_psi(struct cgroup *cgrp) | |
734 | { | |
735 | return NULL; | |
736 | } | |
737 | ||
aed704b7 SD |
738 | static inline bool task_under_cgroup_hierarchy(struct task_struct *task, |
739 | struct cgroup *ancestor) | |
740 | { | |
741 | return true; | |
742 | } | |
69fd5c39 SL |
743 | |
744 | static inline void cgroup_path_from_kernfs_id(const union kernfs_node_id *id, | |
745 | char *buf, size_t buflen) {} | |
ddbcc7e8 PM |
746 | #endif /* !CONFIG_CGROUPS */ |
747 | ||
6162cef0 | 748 | #ifdef CONFIG_CGROUPS |
d2cc5ed6 | 749 | /* |
6162cef0 | 750 | * cgroup scalable recursive statistics. |
d2cc5ed6 | 751 | */ |
6162cef0 TH |
752 | void cgroup_rstat_updated(struct cgroup *cgrp, int cpu); |
753 | void cgroup_rstat_flush(struct cgroup *cgrp); | |
0fa294fb | 754 | void cgroup_rstat_flush_irqsafe(struct cgroup *cgrp); |
6162cef0 TH |
755 | void cgroup_rstat_flush_hold(struct cgroup *cgrp); |
756 | void cgroup_rstat_flush_release(void); | |
d2cc5ed6 | 757 | |
6162cef0 TH |
758 | /* |
759 | * Basic resource stats. | |
760 | */ | |
d2cc5ed6 TH |
761 | #ifdef CONFIG_CGROUP_CPUACCT |
762 | void cpuacct_charge(struct task_struct *tsk, u64 cputime); | |
763 | void cpuacct_account_field(struct task_struct *tsk, int index, u64 val); | |
764 | #else | |
765 | static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {} | |
766 | static inline void cpuacct_account_field(struct task_struct *tsk, int index, | |
767 | u64 val) {} | |
768 | #endif | |
769 | ||
041cd640 TH |
770 | void __cgroup_account_cputime(struct cgroup *cgrp, u64 delta_exec); |
771 | void __cgroup_account_cputime_field(struct cgroup *cgrp, | |
772 | enum cpu_usage_stat index, u64 delta_exec); | |
773 | ||
d2cc5ed6 TH |
774 | static inline void cgroup_account_cputime(struct task_struct *task, |
775 | u64 delta_exec) | |
776 | { | |
041cd640 TH |
777 | struct cgroup *cgrp; |
778 | ||
d2cc5ed6 | 779 | cpuacct_charge(task, delta_exec); |
041cd640 TH |
780 | |
781 | rcu_read_lock(); | |
782 | cgrp = task_dfl_cgroup(task); | |
783 | if (cgroup_parent(cgrp)) | |
784 | __cgroup_account_cputime(cgrp, delta_exec); | |
785 | rcu_read_unlock(); | |
d2cc5ed6 TH |
786 | } |
787 | ||
788 | static inline void cgroup_account_cputime_field(struct task_struct *task, | |
789 | enum cpu_usage_stat index, | |
790 | u64 delta_exec) | |
791 | { | |
041cd640 TH |
792 | struct cgroup *cgrp; |
793 | ||
d2cc5ed6 | 794 | cpuacct_account_field(task, index, delta_exec); |
041cd640 TH |
795 | |
796 | rcu_read_lock(); | |
797 | cgrp = task_dfl_cgroup(task); | |
798 | if (cgroup_parent(cgrp)) | |
799 | __cgroup_account_cputime_field(cgrp, index, delta_exec); | |
800 | rcu_read_unlock(); | |
d2cc5ed6 TH |
801 | } |
802 | ||
803 | #else /* CONFIG_CGROUPS */ | |
804 | ||
805 | static inline void cgroup_account_cputime(struct task_struct *task, | |
806 | u64 delta_exec) {} | |
807 | static inline void cgroup_account_cputime_field(struct task_struct *task, | |
808 | enum cpu_usage_stat index, | |
809 | u64 delta_exec) {} | |
810 | ||
811 | #endif /* CONFIG_CGROUPS */ | |
812 | ||
bd1060a1 TH |
813 | /* |
814 | * sock->sk_cgrp_data handling. For more info, see sock_cgroup_data | |
815 | * definition in cgroup-defs.h. | |
816 | */ | |
817 | #ifdef CONFIG_SOCK_CGROUP_DATA | |
818 | ||
819 | #if defined(CONFIG_CGROUP_NET_PRIO) || defined(CONFIG_CGROUP_NET_CLASSID) | |
820 | extern spinlock_t cgroup_sk_update_lock; | |
821 | #endif | |
822 | ||
823 | void cgroup_sk_alloc_disable(void); | |
824 | void cgroup_sk_alloc(struct sock_cgroup_data *skcd); | |
a5d0cb57 | 825 | void cgroup_sk_clone(struct sock_cgroup_data *skcd); |
bd1060a1 TH |
826 | void cgroup_sk_free(struct sock_cgroup_data *skcd); |
827 | ||
828 | static inline struct cgroup *sock_cgroup_ptr(struct sock_cgroup_data *skcd) | |
829 | { | |
830 | #if defined(CONFIG_CGROUP_NET_PRIO) || defined(CONFIG_CGROUP_NET_CLASSID) | |
831 | unsigned long v; | |
832 | ||
833 | /* | |
834 | * @skcd->val is 64bit but the following is safe on 32bit too as we | |
835 | * just need the lower ulong to be written and read atomically. | |
836 | */ | |
837 | v = READ_ONCE(skcd->val); | |
838 | ||
a5d0cb57 | 839 | if (v & 3) |
bd1060a1 TH |
840 | return &cgrp_dfl_root.cgrp; |
841 | ||
842 | return (struct cgroup *)(unsigned long)v ?: &cgrp_dfl_root.cgrp; | |
843 | #else | |
844 | return (struct cgroup *)(unsigned long)skcd->val; | |
845 | #endif | |
846 | } | |
847 | ||
848 | #else /* CONFIG_CGROUP_DATA */ | |
849 | ||
850 | static inline void cgroup_sk_alloc(struct sock_cgroup_data *skcd) {} | |
a5d0cb57 | 851 | static inline void cgroup_sk_clone(struct sock_cgroup_data *skcd) {} |
bd1060a1 TH |
852 | static inline void cgroup_sk_free(struct sock_cgroup_data *skcd) {} |
853 | ||
854 | #endif /* CONFIG_CGROUP_DATA */ | |
855 | ||
a79a908f | 856 | struct cgroup_namespace { |
387ad967 | 857 | refcount_t count; |
a79a908f AK |
858 | struct ns_common ns; |
859 | struct user_namespace *user_ns; | |
d08311dd | 860 | struct ucounts *ucounts; |
a79a908f AK |
861 | struct css_set *root_cset; |
862 | }; | |
863 | ||
864 | extern struct cgroup_namespace init_cgroup_ns; | |
865 | ||
866 | #ifdef CONFIG_CGROUPS | |
867 | ||
868 | void free_cgroup_ns(struct cgroup_namespace *ns); | |
869 | ||
870 | struct cgroup_namespace *copy_cgroup_ns(unsigned long flags, | |
871 | struct user_namespace *user_ns, | |
872 | struct cgroup_namespace *old_ns); | |
873 | ||
4c737b41 TH |
874 | int cgroup_path_ns(struct cgroup *cgrp, char *buf, size_t buflen, |
875 | struct cgroup_namespace *ns); | |
a79a908f AK |
876 | |
877 | #else /* !CONFIG_CGROUPS */ | |
878 | ||
879 | static inline void free_cgroup_ns(struct cgroup_namespace *ns) { } | |
880 | static inline struct cgroup_namespace * | |
881 | copy_cgroup_ns(unsigned long flags, struct user_namespace *user_ns, | |
882 | struct cgroup_namespace *old_ns) | |
883 | { | |
884 | return old_ns; | |
885 | } | |
886 | ||
887 | #endif /* !CONFIG_CGROUPS */ | |
888 | ||
889 | static inline void get_cgroup_ns(struct cgroup_namespace *ns) | |
890 | { | |
891 | if (ns) | |
387ad967 | 892 | refcount_inc(&ns->count); |
a79a908f AK |
893 | } |
894 | ||
895 | static inline void put_cgroup_ns(struct cgroup_namespace *ns) | |
896 | { | |
387ad967 | 897 | if (ns && refcount_dec_and_test(&ns->count)) |
a79a908f AK |
898 | free_cgroup_ns(ns); |
899 | } | |
900 | ||
76f969e8 RG |
901 | #ifdef CONFIG_CGROUPS |
902 | ||
903 | void cgroup_enter_frozen(void); | |
904 | void cgroup_leave_frozen(bool always_leave); | |
905 | void cgroup_update_frozen(struct cgroup *cgrp); | |
906 | void cgroup_freeze(struct cgroup *cgrp, bool freeze); | |
907 | void cgroup_freezer_migrate_task(struct task_struct *task, struct cgroup *src, | |
908 | struct cgroup *dst); | |
96b9c592 | 909 | |
76f969e8 RG |
910 | static inline bool cgroup_task_freeze(struct task_struct *task) |
911 | { | |
912 | bool ret; | |
913 | ||
914 | if (task->flags & PF_KTHREAD) | |
915 | return false; | |
916 | ||
917 | rcu_read_lock(); | |
918 | ret = test_bit(CGRP_FREEZE, &task_dfl_cgroup(task)->flags); | |
919 | rcu_read_unlock(); | |
920 | ||
921 | return ret; | |
922 | } | |
923 | ||
924 | static inline bool cgroup_task_frozen(struct task_struct *task) | |
925 | { | |
926 | return task->frozen; | |
927 | } | |
928 | ||
929 | #else /* !CONFIG_CGROUPS */ | |
930 | ||
931 | static inline void cgroup_enter_frozen(void) { } | |
932 | static inline void cgroup_leave_frozen(bool always_leave) { } | |
933 | static inline bool cgroup_task_freeze(struct task_struct *task) | |
934 | { | |
935 | return false; | |
936 | } | |
937 | static inline bool cgroup_task_frozen(struct task_struct *task) | |
938 | { | |
939 | return false; | |
940 | } | |
941 | ||
942 | #endif /* !CONFIG_CGROUPS */ | |
943 | ||
4bfc0bb2 RG |
944 | #ifdef CONFIG_CGROUP_BPF |
945 | static inline void cgroup_bpf_get(struct cgroup *cgrp) | |
946 | { | |
947 | percpu_ref_get(&cgrp->bpf.refcnt); | |
948 | } | |
949 | ||
950 | static inline void cgroup_bpf_put(struct cgroup *cgrp) | |
951 | { | |
952 | percpu_ref_put(&cgrp->bpf.refcnt); | |
953 | } | |
954 | ||
955 | #else /* CONFIG_CGROUP_BPF */ | |
956 | ||
957 | static inline void cgroup_bpf_get(struct cgroup *cgrp) {} | |
958 | static inline void cgroup_bpf_put(struct cgroup *cgrp) {} | |
959 | ||
960 | #endif /* CONFIG_CGROUP_BPF */ | |
961 | ||
ddbcc7e8 | 962 | #endif /* _LINUX_CGROUP_H */ |