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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 | ||
84 | bool cgroup_is_descendant(struct cgroup *cgrp, struct cgroup *ancestor); | |
85 | int cgroup_attach_task_all(struct task_struct *from, struct task_struct *); | |
86 | int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from); | |
87 | ||
88 | int cgroup_add_dfl_cftypes(struct cgroup_subsys *ss, struct cftype *cfts); | |
89 | int cgroup_add_legacy_cftypes(struct cgroup_subsys *ss, struct cftype *cfts); | |
90 | int cgroup_rm_cftypes(struct cftype *cfts); | |
34c06254 | 91 | void cgroup_file_notify(struct cgroup_file *cfile); |
c326aa2b TH |
92 | |
93 | char *task_cgroup_path(struct task_struct *task, char *buf, size_t buflen); | |
94 | int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry); | |
95 | int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns, | |
96 | struct pid *pid, struct task_struct *tsk); | |
97 | ||
98 | void cgroup_fork(struct task_struct *p); | |
b53202e6 ON |
99 | extern int cgroup_can_fork(struct task_struct *p); |
100 | extern void cgroup_cancel_fork(struct task_struct *p); | |
101 | extern void cgroup_post_fork(struct task_struct *p); | |
c326aa2b | 102 | void cgroup_exit(struct task_struct *p); |
2e91fa7f | 103 | void cgroup_free(struct task_struct *p); |
c326aa2b TH |
104 | |
105 | int cgroup_init_early(void); | |
106 | int cgroup_init(void); | |
107 | ||
5c9d535b | 108 | /* |
c326aa2b TH |
109 | * Iteration helpers and macros. |
110 | */ | |
111 | ||
112 | struct cgroup_subsys_state *css_next_child(struct cgroup_subsys_state *pos, | |
113 | struct cgroup_subsys_state *parent); | |
114 | struct cgroup_subsys_state *css_next_descendant_pre(struct cgroup_subsys_state *pos, | |
115 | struct cgroup_subsys_state *css); | |
116 | struct cgroup_subsys_state *css_rightmost_descendant(struct cgroup_subsys_state *pos); | |
117 | struct cgroup_subsys_state *css_next_descendant_post(struct cgroup_subsys_state *pos, | |
118 | struct cgroup_subsys_state *css); | |
119 | ||
1f7dd3e5 TH |
120 | struct task_struct *cgroup_taskset_first(struct cgroup_taskset *tset, |
121 | struct cgroup_subsys_state **dst_cssp); | |
122 | struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset, | |
123 | struct cgroup_subsys_state **dst_cssp); | |
c326aa2b TH |
124 | |
125 | void css_task_iter_start(struct cgroup_subsys_state *css, | |
126 | struct css_task_iter *it); | |
127 | struct task_struct *css_task_iter_next(struct css_task_iter *it); | |
128 | void css_task_iter_end(struct css_task_iter *it); | |
129 | ||
130 | /** | |
131 | * css_for_each_child - iterate through children of a css | |
132 | * @pos: the css * to use as the loop cursor | |
133 | * @parent: css whose children to walk | |
134 | * | |
135 | * Walk @parent's children. Must be called under rcu_read_lock(). | |
136 | * | |
137 | * If a subsystem synchronizes ->css_online() and the start of iteration, a | |
138 | * css which finished ->css_online() is guaranteed to be visible in the | |
139 | * future iterations and will stay visible until the last reference is put. | |
140 | * A css which hasn't finished ->css_online() or already finished | |
141 | * ->css_offline() may show up during traversal. It's each subsystem's | |
142 | * responsibility to synchronize against on/offlining. | |
5c9d535b | 143 | * |
c326aa2b TH |
144 | * It is allowed to temporarily drop RCU read lock during iteration. The |
145 | * caller is responsible for ensuring that @pos remains accessible until | |
146 | * the start of the next iteration by, for example, bumping the css refcnt. | |
5c9d535b | 147 | */ |
c326aa2b TH |
148 | #define css_for_each_child(pos, parent) \ |
149 | for ((pos) = css_next_child(NULL, (parent)); (pos); \ | |
150 | (pos) = css_next_child((pos), (parent))) | |
ddbcc7e8 | 151 | |
c326aa2b TH |
152 | /** |
153 | * css_for_each_descendant_pre - pre-order walk of a css's descendants | |
154 | * @pos: the css * to use as the loop cursor | |
155 | * @root: css whose descendants to walk | |
156 | * | |
157 | * Walk @root's descendants. @root is included in the iteration and the | |
158 | * first node to be visited. Must be called under rcu_read_lock(). | |
159 | * | |
160 | * If a subsystem synchronizes ->css_online() and the start of iteration, a | |
161 | * css which finished ->css_online() is guaranteed to be visible in the | |
162 | * future iterations and will stay visible until the last reference is put. | |
163 | * A css which hasn't finished ->css_online() or already finished | |
164 | * ->css_offline() may show up during traversal. It's each subsystem's | |
165 | * responsibility to synchronize against on/offlining. | |
166 | * | |
167 | * For example, the following guarantees that a descendant can't escape | |
168 | * state updates of its ancestors. | |
169 | * | |
170 | * my_online(@css) | |
171 | * { | |
172 | * Lock @css's parent and @css; | |
173 | * Inherit state from the parent; | |
174 | * Unlock both. | |
175 | * } | |
176 | * | |
177 | * my_update_state(@css) | |
178 | * { | |
179 | * css_for_each_descendant_pre(@pos, @css) { | |
180 | * Lock @pos; | |
181 | * if (@pos == @css) | |
182 | * Update @css's state; | |
183 | * else | |
184 | * Verify @pos is alive and inherit state from its parent; | |
185 | * Unlock @pos; | |
186 | * } | |
187 | * } | |
188 | * | |
189 | * As long as the inheriting step, including checking the parent state, is | |
190 | * enclosed inside @pos locking, double-locking the parent isn't necessary | |
191 | * while inheriting. The state update to the parent is guaranteed to be | |
192 | * visible by walking order and, as long as inheriting operations to the | |
193 | * same @pos are atomic to each other, multiple updates racing each other | |
194 | * still result in the correct state. It's guaranateed that at least one | |
195 | * inheritance happens for any css after the latest update to its parent. | |
196 | * | |
197 | * If checking parent's state requires locking the parent, each inheriting | |
198 | * iteration should lock and unlock both @pos->parent and @pos. | |
199 | * | |
200 | * Alternatively, a subsystem may choose to use a single global lock to | |
201 | * synchronize ->css_online() and ->css_offline() against tree-walking | |
202 | * operations. | |
203 | * | |
204 | * It is allowed to temporarily drop RCU read lock during iteration. The | |
205 | * caller is responsible for ensuring that @pos remains accessible until | |
206 | * the start of the next iteration by, for example, bumping the css refcnt. | |
207 | */ | |
208 | #define css_for_each_descendant_pre(pos, css) \ | |
209 | for ((pos) = css_next_descendant_pre(NULL, (css)); (pos); \ | |
210 | (pos) = css_next_descendant_pre((pos), (css))) | |
211 | ||
212 | /** | |
213 | * css_for_each_descendant_post - post-order walk of a css's descendants | |
214 | * @pos: the css * to use as the loop cursor | |
215 | * @css: css whose descendants to walk | |
216 | * | |
217 | * Similar to css_for_each_descendant_pre() but performs post-order | |
218 | * traversal instead. @root is included in the iteration and the last | |
219 | * node to be visited. | |
220 | * | |
221 | * If a subsystem synchronizes ->css_online() and the start of iteration, a | |
222 | * css which finished ->css_online() is guaranteed to be visible in the | |
223 | * future iterations and will stay visible until the last reference is put. | |
224 | * A css which hasn't finished ->css_online() or already finished | |
225 | * ->css_offline() may show up during traversal. It's each subsystem's | |
226 | * responsibility to synchronize against on/offlining. | |
227 | * | |
228 | * Note that the walk visibility guarantee example described in pre-order | |
229 | * walk doesn't apply the same to post-order walks. | |
230 | */ | |
231 | #define css_for_each_descendant_post(pos, css) \ | |
232 | for ((pos) = css_next_descendant_post(NULL, (css)); (pos); \ | |
233 | (pos) = css_next_descendant_post((pos), (css))) | |
234 | ||
235 | /** | |
236 | * cgroup_taskset_for_each - iterate cgroup_taskset | |
237 | * @task: the loop cursor | |
1f7dd3e5 | 238 | * @dst_css: the destination css |
c326aa2b | 239 | * @tset: taskset to iterate |
4530eddb TH |
240 | * |
241 | * @tset may contain multiple tasks and they may belong to multiple | |
1f7dd3e5 TH |
242 | * processes. |
243 | * | |
244 | * On the v2 hierarchy, there may be tasks from multiple processes and they | |
245 | * may not share the source or destination csses. | |
246 | * | |
247 | * On traditional hierarchies, when there are multiple tasks in @tset, if a | |
248 | * task of a process is in @tset, all tasks of the process are in @tset. | |
249 | * Also, all are guaranteed to share the same source and destination csses. | |
4530eddb TH |
250 | * |
251 | * Iteration is not in any specific order. | |
c326aa2b | 252 | */ |
1f7dd3e5 TH |
253 | #define cgroup_taskset_for_each(task, dst_css, tset) \ |
254 | for ((task) = cgroup_taskset_first((tset), &(dst_css)); \ | |
255 | (task); \ | |
256 | (task) = cgroup_taskset_next((tset), &(dst_css))) | |
ddbcc7e8 | 257 | |
4530eddb TH |
258 | /** |
259 | * cgroup_taskset_for_each_leader - iterate group leaders in a cgroup_taskset | |
260 | * @leader: the loop cursor | |
1f7dd3e5 | 261 | * @dst_css: the destination css |
4530eddb TH |
262 | * @tset: takset to iterate |
263 | * | |
264 | * Iterate threadgroup leaders of @tset. For single-task migrations, @tset | |
265 | * may not contain any. | |
266 | */ | |
1f7dd3e5 TH |
267 | #define cgroup_taskset_for_each_leader(leader, dst_css, tset) \ |
268 | for ((leader) = cgroup_taskset_first((tset), &(dst_css)); \ | |
269 | (leader); \ | |
270 | (leader) = cgroup_taskset_next((tset), &(dst_css))) \ | |
4530eddb TH |
271 | if ((leader) != (leader)->group_leader) \ |
272 | ; \ | |
273 | else | |
274 | ||
c326aa2b TH |
275 | /* |
276 | * Inline functions. | |
277 | */ | |
ddbcc7e8 | 278 | |
5de0107e TH |
279 | /** |
280 | * css_get - obtain a reference on the specified css | |
281 | * @css: target css | |
282 | * | |
283 | * The caller must already have a reference. | |
ddbcc7e8 | 284 | */ |
ddbcc7e8 PM |
285 | static inline void css_get(struct cgroup_subsys_state *css) |
286 | { | |
3b514d24 TH |
287 | if (!(css->flags & CSS_NO_REF)) |
288 | percpu_ref_get(&css->refcnt); | |
ddbcc7e8 | 289 | } |
e7c5ec91 | 290 | |
e8ea14cc JW |
291 | /** |
292 | * css_get_many - obtain references on the specified css | |
293 | * @css: target css | |
294 | * @n: number of references to get | |
295 | * | |
296 | * The caller must already have a reference. | |
297 | */ | |
298 | static inline void css_get_many(struct cgroup_subsys_state *css, unsigned int n) | |
299 | { | |
300 | if (!(css->flags & CSS_NO_REF)) | |
301 | percpu_ref_get_many(&css->refcnt, n); | |
302 | } | |
303 | ||
6f4524d3 TH |
304 | /** |
305 | * css_tryget - try to obtain a reference on the specified css | |
306 | * @css: target css | |
307 | * | |
308 | * Obtain a reference on @css unless it already has reached zero and is | |
309 | * being released. This function doesn't care whether @css is on or | |
310 | * offline. The caller naturally needs to ensure that @css is accessible | |
311 | * but doesn't have to be holding a reference on it - IOW, RCU protected | |
312 | * access is good enough for this function. Returns %true if a reference | |
313 | * count was successfully obtained; %false otherwise. | |
314 | */ | |
315 | static inline bool css_tryget(struct cgroup_subsys_state *css) | |
316 | { | |
317 | if (!(css->flags & CSS_NO_REF)) | |
318 | return percpu_ref_tryget(&css->refcnt); | |
319 | return true; | |
320 | } | |
321 | ||
5de0107e | 322 | /** |
ec903c0c | 323 | * css_tryget_online - try to obtain a reference on the specified css if online |
5de0107e TH |
324 | * @css: target css |
325 | * | |
ec903c0c TH |
326 | * Obtain a reference on @css if it's online. The caller naturally needs |
327 | * to ensure that @css is accessible but doesn't have to be holding a | |
5de0107e TH |
328 | * reference on it - IOW, RCU protected access is good enough for this |
329 | * function. Returns %true if a reference count was successfully obtained; | |
330 | * %false otherwise. | |
331 | */ | |
ec903c0c | 332 | static inline bool css_tryget_online(struct cgroup_subsys_state *css) |
e7c5ec91 | 333 | { |
3b514d24 TH |
334 | if (!(css->flags & CSS_NO_REF)) |
335 | return percpu_ref_tryget_live(&css->refcnt); | |
336 | return true; | |
e7c5ec91 | 337 | } |
2f7ee569 TH |
338 | |
339 | /** | |
5de0107e TH |
340 | * css_put - put a css reference |
341 | * @css: target css | |
342 | * | |
ec903c0c | 343 | * Put a reference obtained via css_get() and css_tryget_online(). |
2f7ee569 | 344 | */ |
ddbcc7e8 PM |
345 | static inline void css_put(struct cgroup_subsys_state *css) |
346 | { | |
3b514d24 TH |
347 | if (!(css->flags & CSS_NO_REF)) |
348 | percpu_ref_put(&css->refcnt); | |
ddbcc7e8 | 349 | } |
2f7ee569 | 350 | |
e8ea14cc JW |
351 | /** |
352 | * css_put_many - put css references | |
353 | * @css: target css | |
354 | * @n: number of references to put | |
355 | * | |
356 | * Put references obtained via css_get() and css_tryget_online(). | |
21acb9ca | 357 | */ |
e8ea14cc JW |
358 | static inline void css_put_many(struct cgroup_subsys_state *css, unsigned int n) |
359 | { | |
360 | if (!(css->flags & CSS_NO_REF)) | |
361 | percpu_ref_put_many(&css->refcnt, n); | |
362 | } | |
ddbcc7e8 | 363 | |
14611e51 TH |
364 | /** |
365 | * task_css_set_check - obtain a task's css_set with extra access conditions | |
366 | * @task: the task to obtain css_set for | |
367 | * @__c: extra condition expression to be passed to rcu_dereference_check() | |
368 | * | |
369 | * A task's css_set is RCU protected, initialized and exited while holding | |
370 | * task_lock(), and can only be modified while holding both cgroup_mutex | |
371 | * and task_lock() while the task is alive. This macro verifies that the | |
372 | * caller is inside proper critical section and returns @task's css_set. | |
373 | * | |
374 | * The caller can also specify additional allowed conditions via @__c, such | |
375 | * as locks used during the cgroup_subsys::attach() methods. | |
dc61b1d6 | 376 | */ |
2219449a TH |
377 | #ifdef CONFIG_PROVE_RCU |
378 | extern struct mutex cgroup_mutex; | |
f0d9a5f1 | 379 | extern spinlock_t css_set_lock; |
14611e51 TH |
380 | #define task_css_set_check(task, __c) \ |
381 | rcu_dereference_check((task)->cgroups, \ | |
0e1d768f | 382 | lockdep_is_held(&cgroup_mutex) || \ |
f0d9a5f1 | 383 | lockdep_is_held(&css_set_lock) || \ |
0e1d768f | 384 | ((task)->flags & PF_EXITING) || (__c)) |
2219449a | 385 | #else |
14611e51 TH |
386 | #define task_css_set_check(task, __c) \ |
387 | rcu_dereference((task)->cgroups) | |
2219449a | 388 | #endif |
dc61b1d6 | 389 | |
14611e51 | 390 | /** |
8af01f56 | 391 | * task_css_check - obtain css for (task, subsys) w/ extra access conds |
14611e51 TH |
392 | * @task: the target task |
393 | * @subsys_id: the target subsystem ID | |
394 | * @__c: extra condition expression to be passed to rcu_dereference_check() | |
395 | * | |
396 | * Return the cgroup_subsys_state for the (@task, @subsys_id) pair. The | |
397 | * synchronization rules are the same as task_css_set_check(). | |
398 | */ | |
8af01f56 | 399 | #define task_css_check(task, subsys_id, __c) \ |
14611e51 TH |
400 | task_css_set_check((task), (__c))->subsys[(subsys_id)] |
401 | ||
402 | /** | |
403 | * task_css_set - obtain a task's css_set | |
404 | * @task: the task to obtain css_set for | |
405 | * | |
406 | * See task_css_set_check(). | |
407 | */ | |
408 | static inline struct css_set *task_css_set(struct task_struct *task) | |
409 | { | |
410 | return task_css_set_check(task, false); | |
411 | } | |
412 | ||
413 | /** | |
8af01f56 | 414 | * task_css - obtain css for (task, subsys) |
14611e51 TH |
415 | * @task: the target task |
416 | * @subsys_id: the target subsystem ID | |
417 | * | |
8af01f56 | 418 | * See task_css_check(). |
14611e51 | 419 | */ |
8af01f56 TH |
420 | static inline struct cgroup_subsys_state *task_css(struct task_struct *task, |
421 | int subsys_id) | |
ddbcc7e8 | 422 | { |
8af01f56 | 423 | return task_css_check(task, subsys_id, false); |
ddbcc7e8 PM |
424 | } |
425 | ||
ec438699 TH |
426 | /** |
427 | * task_get_css - find and get the css for (task, subsys) | |
428 | * @task: the target task | |
429 | * @subsys_id: the target subsystem ID | |
430 | * | |
431 | * Find the css for the (@task, @subsys_id) combination, increment a | |
432 | * reference on and return it. This function is guaranteed to return a | |
433 | * valid css. | |
434 | */ | |
435 | static inline struct cgroup_subsys_state * | |
436 | task_get_css(struct task_struct *task, int subsys_id) | |
437 | { | |
438 | struct cgroup_subsys_state *css; | |
439 | ||
440 | rcu_read_lock(); | |
441 | while (true) { | |
442 | css = task_css(task, subsys_id); | |
443 | if (likely(css_tryget_online(css))) | |
444 | break; | |
445 | cpu_relax(); | |
446 | } | |
447 | rcu_read_unlock(); | |
448 | return css; | |
449 | } | |
450 | ||
5024ae29 TH |
451 | /** |
452 | * task_css_is_root - test whether a task belongs to the root css | |
453 | * @task: the target task | |
454 | * @subsys_id: the target subsystem ID | |
455 | * | |
456 | * Test whether @task belongs to the root css on the specified subsystem. | |
457 | * May be invoked in any context. | |
458 | */ | |
459 | static inline bool task_css_is_root(struct task_struct *task, int subsys_id) | |
460 | { | |
461 | return task_css_check(task, subsys_id, true) == | |
462 | init_css_set.subsys[subsys_id]; | |
463 | } | |
464 | ||
8af01f56 TH |
465 | static inline struct cgroup *task_cgroup(struct task_struct *task, |
466 | int subsys_id) | |
ddbcc7e8 | 467 | { |
8af01f56 | 468 | return task_css(task, subsys_id)->cgroup; |
ddbcc7e8 PM |
469 | } |
470 | ||
07bc356e | 471 | /* no synchronization, the result can only be used as a hint */ |
27bd4dbb | 472 | static inline bool cgroup_is_populated(struct cgroup *cgrp) |
07bc356e | 473 | { |
27bd4dbb | 474 | return cgrp->populated_cnt; |
07bc356e | 475 | } |
f3d46500 | 476 | |
f29374b1 | 477 | /* returns ino associated with a cgroup */ |
b1664924 TH |
478 | static inline ino_t cgroup_ino(struct cgroup *cgrp) |
479 | { | |
f29374b1 | 480 | return cgrp->kn->ino; |
b1664924 | 481 | } |
3ebb2b6e | 482 | |
b4168640 TH |
483 | /* cft/css accessors for cftype->write() operation */ |
484 | static inline struct cftype *of_cft(struct kernfs_open_file *of) | |
7da11279 | 485 | { |
2bd59d48 | 486 | return of->kn->priv; |
7da11279 | 487 | } |
0f0a2b4f | 488 | |
b4168640 | 489 | struct cgroup_subsys_state *of_css(struct kernfs_open_file *of); |
817929ec | 490 | |
b4168640 TH |
491 | /* cft/css accessors for cftype->seq_*() operations */ |
492 | static inline struct cftype *seq_cft(struct seq_file *seq) | |
493 | { | |
494 | return of_cft(seq->private); | |
495 | } | |
e535837b | 496 | |
b4168640 TH |
497 | static inline struct cgroup_subsys_state *seq_css(struct seq_file *seq) |
498 | { | |
499 | return of_css(seq->private); | |
500 | } | |
31583bb0 | 501 | |
e61734c5 TH |
502 | /* |
503 | * Name / path handling functions. All are thin wrappers around the kernfs | |
504 | * counterparts and can be called under any context. | |
505 | */ | |
38460b48 | 506 | |
e61734c5 TH |
507 | static inline int cgroup_name(struct cgroup *cgrp, char *buf, size_t buflen) |
508 | { | |
fdce6bf8 | 509 | return kernfs_name(cgrp->kn, buf, buflen); |
e61734c5 | 510 | } |
ddbcc7e8 | 511 | |
e61734c5 TH |
512 | static inline char * __must_check cgroup_path(struct cgroup *cgrp, char *buf, |
513 | size_t buflen) | |
514 | { | |
fdce6bf8 | 515 | return kernfs_path(cgrp->kn, buf, buflen); |
e61734c5 | 516 | } |
f3ba5380 | 517 | |
e61734c5 TH |
518 | static inline void pr_cont_cgroup_name(struct cgroup *cgrp) |
519 | { | |
fdce6bf8 | 520 | pr_cont_kernfs_name(cgrp->kn); |
e61734c5 | 521 | } |
ddbcc7e8 | 522 | |
e61734c5 | 523 | static inline void pr_cont_cgroup_path(struct cgroup *cgrp) |
846c7bb0 | 524 | { |
fdce6bf8 | 525 | pr_cont_kernfs_path(cgrp->kn); |
6f60eade TH |
526 | } |
527 | ||
ddbcc7e8 PM |
528 | #else /* !CONFIG_CGROUPS */ |
529 | ||
f3ba5380 | 530 | struct cgroup_subsys_state; |
f3ba5380 | 531 | |
c326aa2b | 532 | static inline void css_put(struct cgroup_subsys_state *css) {} |
31583bb0 | 533 | static inline int cgroup_attach_task_all(struct task_struct *from, |
c326aa2b TH |
534 | struct task_struct *t) { return 0; } |
535 | static inline int cgroupstats_build(struct cgroupstats *stats, | |
536 | struct dentry *dentry) { return -EINVAL; } | |
537 | ||
b4f48b63 | 538 | static inline void cgroup_fork(struct task_struct *p) {} |
b53202e6 ON |
539 | static inline int cgroup_can_fork(struct task_struct *p) { return 0; } |
540 | static inline void cgroup_cancel_fork(struct task_struct *p) {} | |
541 | static inline void cgroup_post_fork(struct task_struct *p) {} | |
1ec41830 | 542 | static inline void cgroup_exit(struct task_struct *p) {} |
2e91fa7f | 543 | static inline void cgroup_free(struct task_struct *p) {} |
ddbcc7e8 | 544 | |
c326aa2b TH |
545 | static inline int cgroup_init_early(void) { return 0; } |
546 | static inline int cgroup_init(void) { return 0; } | |
d7926ee3 | 547 | |
ddbcc7e8 PM |
548 | #endif /* !CONFIG_CGROUPS */ |
549 | ||
550 | #endif /* _LINUX_CGROUP_H */ |