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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> |
cc31edce | 16 | #include <linux/rwsem.h> |
25a7e684 | 17 | #include <linux/fs.h> |
7da11279 | 18 | #include <linux/seq_file.h> |
2bd59d48 | 19 | #include <linux/kernfs.h> |
ddbcc7e8 | 20 | |
b4a04ab7 | 21 | #include <linux/cgroup-defs.h> |
ddbcc7e8 PM |
22 | |
23 | #ifdef CONFIG_CGROUPS | |
24 | ||
c326aa2b TH |
25 | /* a css_task_iter should be treated as an opaque object */ |
26 | struct css_task_iter { | |
27 | struct cgroup_subsys *ss; | |
28 | ||
29 | struct list_head *cset_pos; | |
30 | struct list_head *cset_head; | |
ddbcc7e8 | 31 | |
c326aa2b TH |
32 | struct list_head *task_pos; |
33 | struct list_head *tasks_head; | |
34 | struct list_head *mg_tasks_head; | |
35 | }; | |
ddbcc7e8 | 36 | |
c326aa2b TH |
37 | extern struct cgroup_root cgrp_dfl_root; |
38 | extern struct css_set init_css_set; | |
a424316c | 39 | |
c326aa2b | 40 | #define SUBSYS(_x) extern struct cgroup_subsys _x ## _cgrp_subsys; |
817929ec | 41 | #include <linux/cgroup_subsys.h> |
817929ec PM |
42 | #undef SUBSYS |
43 | ||
c326aa2b TH |
44 | bool css_has_online_children(struct cgroup_subsys_state *css); |
45 | struct cgroup_subsys_state *css_from_id(int id, struct cgroup_subsys *ss); | |
46 | struct cgroup_subsys_state *cgroup_get_e_css(struct cgroup *cgroup, | |
47 | struct cgroup_subsys *ss); | |
48 | struct cgroup_subsys_state *css_tryget_online_from_dir(struct dentry *dentry, | |
49 | struct cgroup_subsys *ss); | |
50 | ||
51 | bool cgroup_is_descendant(struct cgroup *cgrp, struct cgroup *ancestor); | |
52 | int cgroup_attach_task_all(struct task_struct *from, struct task_struct *); | |
53 | int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from); | |
54 | ||
55 | int cgroup_add_dfl_cftypes(struct cgroup_subsys *ss, struct cftype *cfts); | |
56 | int cgroup_add_legacy_cftypes(struct cgroup_subsys *ss, struct cftype *cfts); | |
57 | int cgroup_rm_cftypes(struct cftype *cfts); | |
58 | ||
59 | char *task_cgroup_path(struct task_struct *task, char *buf, size_t buflen); | |
60 | int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry); | |
61 | int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns, | |
62 | struct pid *pid, struct task_struct *tsk); | |
63 | ||
64 | void cgroup_fork(struct task_struct *p); | |
65 | void cgroup_post_fork(struct task_struct *p); | |
66 | void cgroup_exit(struct task_struct *p); | |
67 | ||
68 | int cgroup_init_early(void); | |
69 | int cgroup_init(void); | |
70 | ||
5c9d535b | 71 | /* |
c326aa2b TH |
72 | * Iteration helpers and macros. |
73 | */ | |
74 | ||
75 | struct cgroup_subsys_state *css_next_child(struct cgroup_subsys_state *pos, | |
76 | struct cgroup_subsys_state *parent); | |
77 | struct cgroup_subsys_state *css_next_descendant_pre(struct cgroup_subsys_state *pos, | |
78 | struct cgroup_subsys_state *css); | |
79 | struct cgroup_subsys_state *css_rightmost_descendant(struct cgroup_subsys_state *pos); | |
80 | struct cgroup_subsys_state *css_next_descendant_post(struct cgroup_subsys_state *pos, | |
81 | struct cgroup_subsys_state *css); | |
82 | ||
83 | struct task_struct *cgroup_taskset_first(struct cgroup_taskset *tset); | |
84 | struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset); | |
85 | ||
86 | void css_task_iter_start(struct cgroup_subsys_state *css, | |
87 | struct css_task_iter *it); | |
88 | struct task_struct *css_task_iter_next(struct css_task_iter *it); | |
89 | void css_task_iter_end(struct css_task_iter *it); | |
90 | ||
91 | /** | |
92 | * css_for_each_child - iterate through children of a css | |
93 | * @pos: the css * to use as the loop cursor | |
94 | * @parent: css whose children to walk | |
95 | * | |
96 | * Walk @parent's children. Must be called under rcu_read_lock(). | |
97 | * | |
98 | * If a subsystem synchronizes ->css_online() and the start of iteration, a | |
99 | * css which finished ->css_online() is guaranteed to be visible in the | |
100 | * future iterations and will stay visible until the last reference is put. | |
101 | * A css which hasn't finished ->css_online() or already finished | |
102 | * ->css_offline() may show up during traversal. It's each subsystem's | |
103 | * responsibility to synchronize against on/offlining. | |
5c9d535b | 104 | * |
c326aa2b TH |
105 | * It is allowed to temporarily drop RCU read lock during iteration. The |
106 | * caller is responsible for ensuring that @pos remains accessible until | |
107 | * the start of the next iteration by, for example, bumping the css refcnt. | |
5c9d535b | 108 | */ |
c326aa2b TH |
109 | #define css_for_each_child(pos, parent) \ |
110 | for ((pos) = css_next_child(NULL, (parent)); (pos); \ | |
111 | (pos) = css_next_child((pos), (parent))) | |
ddbcc7e8 | 112 | |
c326aa2b TH |
113 | /** |
114 | * css_for_each_descendant_pre - pre-order walk of a css's descendants | |
115 | * @pos: the css * to use as the loop cursor | |
116 | * @root: css whose descendants to walk | |
117 | * | |
118 | * Walk @root's descendants. @root is included in the iteration and the | |
119 | * first node to be visited. Must be called under rcu_read_lock(). | |
120 | * | |
121 | * If a subsystem synchronizes ->css_online() and the start of iteration, a | |
122 | * css which finished ->css_online() is guaranteed to be visible in the | |
123 | * future iterations and will stay visible until the last reference is put. | |
124 | * A css which hasn't finished ->css_online() or already finished | |
125 | * ->css_offline() may show up during traversal. It's each subsystem's | |
126 | * responsibility to synchronize against on/offlining. | |
127 | * | |
128 | * For example, the following guarantees that a descendant can't escape | |
129 | * state updates of its ancestors. | |
130 | * | |
131 | * my_online(@css) | |
132 | * { | |
133 | * Lock @css's parent and @css; | |
134 | * Inherit state from the parent; | |
135 | * Unlock both. | |
136 | * } | |
137 | * | |
138 | * my_update_state(@css) | |
139 | * { | |
140 | * css_for_each_descendant_pre(@pos, @css) { | |
141 | * Lock @pos; | |
142 | * if (@pos == @css) | |
143 | * Update @css's state; | |
144 | * else | |
145 | * Verify @pos is alive and inherit state from its parent; | |
146 | * Unlock @pos; | |
147 | * } | |
148 | * } | |
149 | * | |
150 | * As long as the inheriting step, including checking the parent state, is | |
151 | * enclosed inside @pos locking, double-locking the parent isn't necessary | |
152 | * while inheriting. The state update to the parent is guaranteed to be | |
153 | * visible by walking order and, as long as inheriting operations to the | |
154 | * same @pos are atomic to each other, multiple updates racing each other | |
155 | * still result in the correct state. It's guaranateed that at least one | |
156 | * inheritance happens for any css after the latest update to its parent. | |
157 | * | |
158 | * If checking parent's state requires locking the parent, each inheriting | |
159 | * iteration should lock and unlock both @pos->parent and @pos. | |
160 | * | |
161 | * Alternatively, a subsystem may choose to use a single global lock to | |
162 | * synchronize ->css_online() and ->css_offline() against tree-walking | |
163 | * operations. | |
164 | * | |
165 | * It is allowed to temporarily drop RCU read lock during iteration. The | |
166 | * caller is responsible for ensuring that @pos remains accessible until | |
167 | * the start of the next iteration by, for example, bumping the css refcnt. | |
168 | */ | |
169 | #define css_for_each_descendant_pre(pos, css) \ | |
170 | for ((pos) = css_next_descendant_pre(NULL, (css)); (pos); \ | |
171 | (pos) = css_next_descendant_pre((pos), (css))) | |
172 | ||
173 | /** | |
174 | * css_for_each_descendant_post - post-order walk of a css's descendants | |
175 | * @pos: the css * to use as the loop cursor | |
176 | * @css: css whose descendants to walk | |
177 | * | |
178 | * Similar to css_for_each_descendant_pre() but performs post-order | |
179 | * traversal instead. @root is included in the iteration and the last | |
180 | * node to be visited. | |
181 | * | |
182 | * If a subsystem synchronizes ->css_online() and the start of iteration, a | |
183 | * css which finished ->css_online() is guaranteed to be visible in the | |
184 | * future iterations and will stay visible until the last reference is put. | |
185 | * A css which hasn't finished ->css_online() or already finished | |
186 | * ->css_offline() may show up during traversal. It's each subsystem's | |
187 | * responsibility to synchronize against on/offlining. | |
188 | * | |
189 | * Note that the walk visibility guarantee example described in pre-order | |
190 | * walk doesn't apply the same to post-order walks. | |
191 | */ | |
192 | #define css_for_each_descendant_post(pos, css) \ | |
193 | for ((pos) = css_next_descendant_post(NULL, (css)); (pos); \ | |
194 | (pos) = css_next_descendant_post((pos), (css))) | |
195 | ||
196 | /** | |
197 | * cgroup_taskset_for_each - iterate cgroup_taskset | |
198 | * @task: the loop cursor | |
199 | * @tset: taskset to iterate | |
200 | */ | |
201 | #define cgroup_taskset_for_each(task, tset) \ | |
202 | for ((task) = cgroup_taskset_first((tset)); (task); \ | |
203 | (task) = cgroup_taskset_next((tset))) | |
ddbcc7e8 | 204 | |
c326aa2b TH |
205 | /* |
206 | * Inline functions. | |
207 | */ | |
ddbcc7e8 | 208 | |
5de0107e TH |
209 | /** |
210 | * css_get - obtain a reference on the specified css | |
211 | * @css: target css | |
212 | * | |
213 | * The caller must already have a reference. | |
ddbcc7e8 | 214 | */ |
ddbcc7e8 PM |
215 | static inline void css_get(struct cgroup_subsys_state *css) |
216 | { | |
3b514d24 TH |
217 | if (!(css->flags & CSS_NO_REF)) |
218 | percpu_ref_get(&css->refcnt); | |
ddbcc7e8 | 219 | } |
e7c5ec91 | 220 | |
e8ea14cc JW |
221 | /** |
222 | * css_get_many - obtain references on the specified css | |
223 | * @css: target css | |
224 | * @n: number of references to get | |
225 | * | |
226 | * The caller must already have a reference. | |
227 | */ | |
228 | static inline void css_get_many(struct cgroup_subsys_state *css, unsigned int n) | |
229 | { | |
230 | if (!(css->flags & CSS_NO_REF)) | |
231 | percpu_ref_get_many(&css->refcnt, n); | |
232 | } | |
233 | ||
6f4524d3 TH |
234 | /** |
235 | * css_tryget - try to obtain a reference on the specified css | |
236 | * @css: target css | |
237 | * | |
238 | * Obtain a reference on @css unless it already has reached zero and is | |
239 | * being released. This function doesn't care whether @css is on or | |
240 | * offline. The caller naturally needs to ensure that @css is accessible | |
241 | * but doesn't have to be holding a reference on it - IOW, RCU protected | |
242 | * access is good enough for this function. Returns %true if a reference | |
243 | * count was successfully obtained; %false otherwise. | |
244 | */ | |
245 | static inline bool css_tryget(struct cgroup_subsys_state *css) | |
246 | { | |
247 | if (!(css->flags & CSS_NO_REF)) | |
248 | return percpu_ref_tryget(&css->refcnt); | |
249 | return true; | |
250 | } | |
251 | ||
5de0107e | 252 | /** |
ec903c0c | 253 | * css_tryget_online - try to obtain a reference on the specified css if online |
5de0107e TH |
254 | * @css: target css |
255 | * | |
ec903c0c TH |
256 | * Obtain a reference on @css if it's online. The caller naturally needs |
257 | * to ensure that @css is accessible but doesn't have to be holding a | |
5de0107e TH |
258 | * reference on it - IOW, RCU protected access is good enough for this |
259 | * function. Returns %true if a reference count was successfully obtained; | |
260 | * %false otherwise. | |
261 | */ | |
ec903c0c | 262 | static inline bool css_tryget_online(struct cgroup_subsys_state *css) |
e7c5ec91 | 263 | { |
3b514d24 TH |
264 | if (!(css->flags & CSS_NO_REF)) |
265 | return percpu_ref_tryget_live(&css->refcnt); | |
266 | return true; | |
e7c5ec91 | 267 | } |
2f7ee569 TH |
268 | |
269 | /** | |
5de0107e TH |
270 | * css_put - put a css reference |
271 | * @css: target css | |
272 | * | |
ec903c0c | 273 | * Put a reference obtained via css_get() and css_tryget_online(). |
2f7ee569 | 274 | */ |
ddbcc7e8 PM |
275 | static inline void css_put(struct cgroup_subsys_state *css) |
276 | { | |
3b514d24 TH |
277 | if (!(css->flags & CSS_NO_REF)) |
278 | percpu_ref_put(&css->refcnt); | |
ddbcc7e8 | 279 | } |
2f7ee569 | 280 | |
e8ea14cc JW |
281 | /** |
282 | * css_put_many - put css references | |
283 | * @css: target css | |
284 | * @n: number of references to put | |
285 | * | |
286 | * Put references obtained via css_get() and css_tryget_online(). | |
21acb9ca | 287 | */ |
e8ea14cc JW |
288 | static inline void css_put_many(struct cgroup_subsys_state *css, unsigned int n) |
289 | { | |
290 | if (!(css->flags & CSS_NO_REF)) | |
291 | percpu_ref_put_many(&css->refcnt, n); | |
292 | } | |
ddbcc7e8 | 293 | |
14611e51 TH |
294 | /** |
295 | * task_css_set_check - obtain a task's css_set with extra access conditions | |
296 | * @task: the task to obtain css_set for | |
297 | * @__c: extra condition expression to be passed to rcu_dereference_check() | |
298 | * | |
299 | * A task's css_set is RCU protected, initialized and exited while holding | |
300 | * task_lock(), and can only be modified while holding both cgroup_mutex | |
301 | * and task_lock() while the task is alive. This macro verifies that the | |
302 | * caller is inside proper critical section and returns @task's css_set. | |
303 | * | |
304 | * The caller can also specify additional allowed conditions via @__c, such | |
305 | * as locks used during the cgroup_subsys::attach() methods. | |
dc61b1d6 | 306 | */ |
2219449a TH |
307 | #ifdef CONFIG_PROVE_RCU |
308 | extern struct mutex cgroup_mutex; | |
0e1d768f | 309 | extern struct rw_semaphore css_set_rwsem; |
14611e51 TH |
310 | #define task_css_set_check(task, __c) \ |
311 | rcu_dereference_check((task)->cgroups, \ | |
0e1d768f TH |
312 | lockdep_is_held(&cgroup_mutex) || \ |
313 | lockdep_is_held(&css_set_rwsem) || \ | |
314 | ((task)->flags & PF_EXITING) || (__c)) | |
2219449a | 315 | #else |
14611e51 TH |
316 | #define task_css_set_check(task, __c) \ |
317 | rcu_dereference((task)->cgroups) | |
2219449a | 318 | #endif |
dc61b1d6 | 319 | |
14611e51 | 320 | /** |
8af01f56 | 321 | * task_css_check - obtain css for (task, subsys) w/ extra access conds |
14611e51 TH |
322 | * @task: the target task |
323 | * @subsys_id: the target subsystem ID | |
324 | * @__c: extra condition expression to be passed to rcu_dereference_check() | |
325 | * | |
326 | * Return the cgroup_subsys_state for the (@task, @subsys_id) pair. The | |
327 | * synchronization rules are the same as task_css_set_check(). | |
328 | */ | |
8af01f56 | 329 | #define task_css_check(task, subsys_id, __c) \ |
14611e51 TH |
330 | task_css_set_check((task), (__c))->subsys[(subsys_id)] |
331 | ||
332 | /** | |
333 | * task_css_set - obtain a task's css_set | |
334 | * @task: the task to obtain css_set for | |
335 | * | |
336 | * See task_css_set_check(). | |
337 | */ | |
338 | static inline struct css_set *task_css_set(struct task_struct *task) | |
339 | { | |
340 | return task_css_set_check(task, false); | |
341 | } | |
342 | ||
343 | /** | |
8af01f56 | 344 | * task_css - obtain css for (task, subsys) |
14611e51 TH |
345 | * @task: the target task |
346 | * @subsys_id: the target subsystem ID | |
347 | * | |
8af01f56 | 348 | * See task_css_check(). |
14611e51 | 349 | */ |
8af01f56 TH |
350 | static inline struct cgroup_subsys_state *task_css(struct task_struct *task, |
351 | int subsys_id) | |
ddbcc7e8 | 352 | { |
8af01f56 | 353 | return task_css_check(task, subsys_id, false); |
ddbcc7e8 PM |
354 | } |
355 | ||
ec438699 TH |
356 | /** |
357 | * task_get_css - find and get the css for (task, subsys) | |
358 | * @task: the target task | |
359 | * @subsys_id: the target subsystem ID | |
360 | * | |
361 | * Find the css for the (@task, @subsys_id) combination, increment a | |
362 | * reference on and return it. This function is guaranteed to return a | |
363 | * valid css. | |
364 | */ | |
365 | static inline struct cgroup_subsys_state * | |
366 | task_get_css(struct task_struct *task, int subsys_id) | |
367 | { | |
368 | struct cgroup_subsys_state *css; | |
369 | ||
370 | rcu_read_lock(); | |
371 | while (true) { | |
372 | css = task_css(task, subsys_id); | |
373 | if (likely(css_tryget_online(css))) | |
374 | break; | |
375 | cpu_relax(); | |
376 | } | |
377 | rcu_read_unlock(); | |
378 | return css; | |
379 | } | |
380 | ||
5024ae29 TH |
381 | /** |
382 | * task_css_is_root - test whether a task belongs to the root css | |
383 | * @task: the target task | |
384 | * @subsys_id: the target subsystem ID | |
385 | * | |
386 | * Test whether @task belongs to the root css on the specified subsystem. | |
387 | * May be invoked in any context. | |
388 | */ | |
389 | static inline bool task_css_is_root(struct task_struct *task, int subsys_id) | |
390 | { | |
391 | return task_css_check(task, subsys_id, true) == | |
392 | init_css_set.subsys[subsys_id]; | |
393 | } | |
394 | ||
8af01f56 TH |
395 | static inline struct cgroup *task_cgroup(struct task_struct *task, |
396 | int subsys_id) | |
ddbcc7e8 | 397 | { |
8af01f56 | 398 | return task_css(task, subsys_id)->cgroup; |
ddbcc7e8 PM |
399 | } |
400 | ||
574bd9f7 | 401 | /** |
aa6ec29b TH |
402 | * cgroup_on_dfl - test whether a cgroup is on the default hierarchy |
403 | * @cgrp: the cgroup of interest | |
574bd9f7 | 404 | * |
aa6ec29b TH |
405 | * The default hierarchy is the v2 interface of cgroup and this function |
406 | * can be used to test whether a cgroup is on the default hierarchy for | |
407 | * cases where a subsystem should behave differnetly depending on the | |
408 | * interface version. | |
574bd9f7 | 409 | * |
aa6ec29b TH |
410 | * The set of behaviors which change on the default hierarchy are still |
411 | * being determined and the mount option is prefixed with __DEVEL__. | |
75501a6d | 412 | * |
aa6ec29b | 413 | * List of changed behaviors: |
574bd9f7 | 414 | * |
aa6ec29b TH |
415 | * - Mount options "noprefix", "xattr", "clone_children", "release_agent" |
416 | * and "name" are disallowed. | |
574bd9f7 | 417 | * |
aa6ec29b | 418 | * - When mounting an existing superblock, mount options should match. |
574bd9f7 | 419 | * |
aa6ec29b | 420 | * - Remount is disallowed. |
574bd9f7 | 421 | * |
aa6ec29b | 422 | * - rename(2) is disallowed. |
574bd9f7 | 423 | * |
aa6ec29b TH |
424 | * - "tasks" is removed. Everything should be at process granularity. Use |
425 | * "cgroup.procs" instead. | |
574bd9f7 | 426 | * |
aa6ec29b TH |
427 | * - "cgroup.procs" is not sorted. pids will be unique unless they got |
428 | * recycled inbetween reads. | |
574bd9f7 | 429 | * |
aa6ec29b TH |
430 | * - "release_agent" and "notify_on_release" are removed. Replacement |
431 | * notification mechanism will be implemented. | |
574bd9f7 | 432 | * |
aa6ec29b | 433 | * - "cgroup.clone_children" is removed. |
75501a6d | 434 | * |
aa6ec29b TH |
435 | * - "cgroup.subtree_populated" is available. Its value is 0 if the cgroup |
436 | * and its descendants contain no task; otherwise, 1. The file also | |
437 | * generates kernfs notification which can be monitored through poll and | |
438 | * [di]notify when the value of the file changes. | |
574bd9f7 | 439 | * |
aa6ec29b TH |
440 | * - cpuset: tasks will be kept in empty cpusets when hotplug happens and |
441 | * take masks of ancestors with non-empty cpus/mems, instead of being | |
442 | * moved to an ancestor. | |
c2931b70 | 443 | * |
aa6ec29b TH |
444 | * - cpuset: a task can be moved into an empty cpuset, and again it takes |
445 | * masks of ancestors. | |
c2931b70 | 446 | * |
aa6ec29b TH |
447 | * - memcg: use_hierarchy is on by default and the cgroup file for the flag |
448 | * is not created. | |
449 | * | |
450 | * - blkcg: blk-throttle becomes properly hierarchical. | |
451 | * | |
452 | * - debug: disallowed on the default hierarchy. | |
574bd9f7 | 453 | */ |
a2dd4247 TH |
454 | static inline bool cgroup_on_dfl(const struct cgroup *cgrp) |
455 | { | |
456 | return cgrp->root == &cgrp_dfl_root; | |
457 | } | |
574bd9f7 | 458 | |
07bc356e TH |
459 | /* no synchronization, the result can only be used as a hint */ |
460 | static inline bool cgroup_has_tasks(struct cgroup *cgrp) | |
461 | { | |
462 | return !list_empty(&cgrp->cset_links); | |
463 | } | |
f3d46500 | 464 | |
f29374b1 | 465 | /* returns ino associated with a cgroup */ |
b1664924 TH |
466 | static inline ino_t cgroup_ino(struct cgroup *cgrp) |
467 | { | |
f29374b1 | 468 | return cgrp->kn->ino; |
b1664924 | 469 | } |
3ebb2b6e | 470 | |
b4168640 TH |
471 | /* cft/css accessors for cftype->write() operation */ |
472 | static inline struct cftype *of_cft(struct kernfs_open_file *of) | |
7da11279 | 473 | { |
2bd59d48 | 474 | return of->kn->priv; |
7da11279 | 475 | } |
0f0a2b4f | 476 | |
b4168640 | 477 | struct cgroup_subsys_state *of_css(struct kernfs_open_file *of); |
817929ec | 478 | |
b4168640 TH |
479 | /* cft/css accessors for cftype->seq_*() operations */ |
480 | static inline struct cftype *seq_cft(struct seq_file *seq) | |
481 | { | |
482 | return of_cft(seq->private); | |
483 | } | |
e535837b | 484 | |
b4168640 TH |
485 | static inline struct cgroup_subsys_state *seq_css(struct seq_file *seq) |
486 | { | |
487 | return of_css(seq->private); | |
488 | } | |
31583bb0 | 489 | |
e61734c5 TH |
490 | /* |
491 | * Name / path handling functions. All are thin wrappers around the kernfs | |
492 | * counterparts and can be called under any context. | |
493 | */ | |
38460b48 | 494 | |
e61734c5 TH |
495 | static inline int cgroup_name(struct cgroup *cgrp, char *buf, size_t buflen) |
496 | { | |
fdce6bf8 | 497 | return kernfs_name(cgrp->kn, buf, buflen); |
e61734c5 | 498 | } |
ddbcc7e8 | 499 | |
e61734c5 TH |
500 | static inline char * __must_check cgroup_path(struct cgroup *cgrp, char *buf, |
501 | size_t buflen) | |
502 | { | |
fdce6bf8 | 503 | return kernfs_path(cgrp->kn, buf, buflen); |
e61734c5 | 504 | } |
f3ba5380 | 505 | |
e61734c5 TH |
506 | static inline void pr_cont_cgroup_name(struct cgroup *cgrp) |
507 | { | |
fdce6bf8 | 508 | pr_cont_kernfs_name(cgrp->kn); |
e61734c5 | 509 | } |
ddbcc7e8 | 510 | |
e61734c5 | 511 | static inline void pr_cont_cgroup_path(struct cgroup *cgrp) |
846c7bb0 | 512 | { |
fdce6bf8 | 513 | pr_cont_kernfs_path(cgrp->kn); |
846c7bb0 | 514 | } |
ddbcc7e8 | 515 | |
ddbcc7e8 PM |
516 | #else /* !CONFIG_CGROUPS */ |
517 | ||
f3ba5380 | 518 | struct cgroup_subsys_state; |
f3ba5380 | 519 | |
c326aa2b | 520 | static inline void css_put(struct cgroup_subsys_state *css) {} |
31583bb0 | 521 | static inline int cgroup_attach_task_all(struct task_struct *from, |
c326aa2b TH |
522 | struct task_struct *t) { return 0; } |
523 | static inline int cgroupstats_build(struct cgroupstats *stats, | |
524 | struct dentry *dentry) { return -EINVAL; } | |
525 | ||
b4f48b63 | 526 | static inline void cgroup_fork(struct task_struct *p) {} |
817929ec | 527 | static inline void cgroup_post_fork(struct task_struct *p) {} |
1ec41830 | 528 | static inline void cgroup_exit(struct task_struct *p) {} |
ddbcc7e8 | 529 | |
c326aa2b TH |
530 | static inline int cgroup_init_early(void) { return 0; } |
531 | static inline int cgroup_init(void) { return 0; } | |
d7926ee3 | 532 | |
ddbcc7e8 PM |
533 | #endif /* !CONFIG_CGROUPS */ |
534 | ||
535 | #endif /* _LINUX_CGROUP_H */ |