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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 | ||
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; | |
44 | }; | |
ddbcc7e8 | 45 | |
c326aa2b TH |
46 | extern struct cgroup_root cgrp_dfl_root; |
47 | extern struct css_set init_css_set; | |
a424316c | 48 | |
c326aa2b | 49 | #define SUBSYS(_x) extern struct cgroup_subsys _x ## _cgrp_subsys; |
817929ec | 50 | #include <linux/cgroup_subsys.h> |
817929ec PM |
51 | #undef SUBSYS |
52 | ||
c326aa2b TH |
53 | bool css_has_online_children(struct cgroup_subsys_state *css); |
54 | struct cgroup_subsys_state *css_from_id(int id, struct cgroup_subsys *ss); | |
55 | struct cgroup_subsys_state *cgroup_get_e_css(struct cgroup *cgroup, | |
56 | struct cgroup_subsys *ss); | |
57 | struct cgroup_subsys_state *css_tryget_online_from_dir(struct dentry *dentry, | |
58 | struct cgroup_subsys *ss); | |
59 | ||
60 | bool cgroup_is_descendant(struct cgroup *cgrp, struct cgroup *ancestor); | |
61 | int cgroup_attach_task_all(struct task_struct *from, struct task_struct *); | |
62 | int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from); | |
63 | ||
64 | int cgroup_add_dfl_cftypes(struct cgroup_subsys *ss, struct cftype *cfts); | |
65 | int cgroup_add_legacy_cftypes(struct cgroup_subsys *ss, struct cftype *cfts); | |
66 | int cgroup_rm_cftypes(struct cftype *cfts); | |
67 | ||
68 | char *task_cgroup_path(struct task_struct *task, char *buf, size_t buflen); | |
69 | int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry); | |
70 | int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns, | |
71 | struct pid *pid, struct task_struct *tsk); | |
72 | ||
73 | void cgroup_fork(struct task_struct *p); | |
7e47682e AS |
74 | extern int cgroup_can_fork(struct task_struct *p, |
75 | void *ss_priv[CGROUP_CANFORK_COUNT]); | |
76 | extern void cgroup_cancel_fork(struct task_struct *p, | |
77 | void *ss_priv[CGROUP_CANFORK_COUNT]); | |
78 | extern void cgroup_post_fork(struct task_struct *p, | |
79 | void *old_ss_priv[CGROUP_CANFORK_COUNT]); | |
c326aa2b TH |
80 | void cgroup_exit(struct task_struct *p); |
81 | ||
82 | int cgroup_init_early(void); | |
83 | int cgroup_init(void); | |
84 | ||
5c9d535b | 85 | /* |
c326aa2b TH |
86 | * Iteration helpers and macros. |
87 | */ | |
88 | ||
89 | struct cgroup_subsys_state *css_next_child(struct cgroup_subsys_state *pos, | |
90 | struct cgroup_subsys_state *parent); | |
91 | struct cgroup_subsys_state *css_next_descendant_pre(struct cgroup_subsys_state *pos, | |
92 | struct cgroup_subsys_state *css); | |
93 | struct cgroup_subsys_state *css_rightmost_descendant(struct cgroup_subsys_state *pos); | |
94 | struct cgroup_subsys_state *css_next_descendant_post(struct cgroup_subsys_state *pos, | |
95 | struct cgroup_subsys_state *css); | |
96 | ||
97 | struct task_struct *cgroup_taskset_first(struct cgroup_taskset *tset); | |
98 | struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset); | |
99 | ||
100 | void css_task_iter_start(struct cgroup_subsys_state *css, | |
101 | struct css_task_iter *it); | |
102 | struct task_struct *css_task_iter_next(struct css_task_iter *it); | |
103 | void css_task_iter_end(struct css_task_iter *it); | |
104 | ||
105 | /** | |
106 | * css_for_each_child - iterate through children of a css | |
107 | * @pos: the css * to use as the loop cursor | |
108 | * @parent: css whose children to walk | |
109 | * | |
110 | * Walk @parent's children. Must be called under rcu_read_lock(). | |
111 | * | |
112 | * If a subsystem synchronizes ->css_online() and the start of iteration, a | |
113 | * css which finished ->css_online() is guaranteed to be visible in the | |
114 | * future iterations and will stay visible until the last reference is put. | |
115 | * A css which hasn't finished ->css_online() or already finished | |
116 | * ->css_offline() may show up during traversal. It's each subsystem's | |
117 | * responsibility to synchronize against on/offlining. | |
5c9d535b | 118 | * |
c326aa2b TH |
119 | * It is allowed to temporarily drop RCU read lock during iteration. The |
120 | * caller is responsible for ensuring that @pos remains accessible until | |
121 | * the start of the next iteration by, for example, bumping the css refcnt. | |
5c9d535b | 122 | */ |
c326aa2b TH |
123 | #define css_for_each_child(pos, parent) \ |
124 | for ((pos) = css_next_child(NULL, (parent)); (pos); \ | |
125 | (pos) = css_next_child((pos), (parent))) | |
ddbcc7e8 | 126 | |
c326aa2b TH |
127 | /** |
128 | * css_for_each_descendant_pre - pre-order walk of a css's descendants | |
129 | * @pos: the css * to use as the loop cursor | |
130 | * @root: css whose descendants to walk | |
131 | * | |
132 | * Walk @root's descendants. @root is included in the iteration and the | |
133 | * first node to be visited. Must be called under rcu_read_lock(). | |
134 | * | |
135 | * If a subsystem synchronizes ->css_online() and the start of iteration, a | |
136 | * css which finished ->css_online() is guaranteed to be visible in the | |
137 | * future iterations and will stay visible until the last reference is put. | |
138 | * A css which hasn't finished ->css_online() or already finished | |
139 | * ->css_offline() may show up during traversal. It's each subsystem's | |
140 | * responsibility to synchronize against on/offlining. | |
141 | * | |
142 | * For example, the following guarantees that a descendant can't escape | |
143 | * state updates of its ancestors. | |
144 | * | |
145 | * my_online(@css) | |
146 | * { | |
147 | * Lock @css's parent and @css; | |
148 | * Inherit state from the parent; | |
149 | * Unlock both. | |
150 | * } | |
151 | * | |
152 | * my_update_state(@css) | |
153 | * { | |
154 | * css_for_each_descendant_pre(@pos, @css) { | |
155 | * Lock @pos; | |
156 | * if (@pos == @css) | |
157 | * Update @css's state; | |
158 | * else | |
159 | * Verify @pos is alive and inherit state from its parent; | |
160 | * Unlock @pos; | |
161 | * } | |
162 | * } | |
163 | * | |
164 | * As long as the inheriting step, including checking the parent state, is | |
165 | * enclosed inside @pos locking, double-locking the parent isn't necessary | |
166 | * while inheriting. The state update to the parent is guaranteed to be | |
167 | * visible by walking order and, as long as inheriting operations to the | |
168 | * same @pos are atomic to each other, multiple updates racing each other | |
169 | * still result in the correct state. It's guaranateed that at least one | |
170 | * inheritance happens for any css after the latest update to its parent. | |
171 | * | |
172 | * If checking parent's state requires locking the parent, each inheriting | |
173 | * iteration should lock and unlock both @pos->parent and @pos. | |
174 | * | |
175 | * Alternatively, a subsystem may choose to use a single global lock to | |
176 | * synchronize ->css_online() and ->css_offline() against tree-walking | |
177 | * operations. | |
178 | * | |
179 | * It is allowed to temporarily drop RCU read lock during iteration. The | |
180 | * caller is responsible for ensuring that @pos remains accessible until | |
181 | * the start of the next iteration by, for example, bumping the css refcnt. | |
182 | */ | |
183 | #define css_for_each_descendant_pre(pos, css) \ | |
184 | for ((pos) = css_next_descendant_pre(NULL, (css)); (pos); \ | |
185 | (pos) = css_next_descendant_pre((pos), (css))) | |
186 | ||
187 | /** | |
188 | * css_for_each_descendant_post - post-order walk of a css's descendants | |
189 | * @pos: the css * to use as the loop cursor | |
190 | * @css: css whose descendants to walk | |
191 | * | |
192 | * Similar to css_for_each_descendant_pre() but performs post-order | |
193 | * traversal instead. @root is included in the iteration and the last | |
194 | * node to be visited. | |
195 | * | |
196 | * If a subsystem synchronizes ->css_online() and the start of iteration, a | |
197 | * css which finished ->css_online() is guaranteed to be visible in the | |
198 | * future iterations and will stay visible until the last reference is put. | |
199 | * A css which hasn't finished ->css_online() or already finished | |
200 | * ->css_offline() may show up during traversal. It's each subsystem's | |
201 | * responsibility to synchronize against on/offlining. | |
202 | * | |
203 | * Note that the walk visibility guarantee example described in pre-order | |
204 | * walk doesn't apply the same to post-order walks. | |
205 | */ | |
206 | #define css_for_each_descendant_post(pos, css) \ | |
207 | for ((pos) = css_next_descendant_post(NULL, (css)); (pos); \ | |
208 | (pos) = css_next_descendant_post((pos), (css))) | |
209 | ||
210 | /** | |
211 | * cgroup_taskset_for_each - iterate cgroup_taskset | |
212 | * @task: the loop cursor | |
213 | * @tset: taskset to iterate | |
214 | */ | |
215 | #define cgroup_taskset_for_each(task, tset) \ | |
216 | for ((task) = cgroup_taskset_first((tset)); (task); \ | |
217 | (task) = cgroup_taskset_next((tset))) | |
ddbcc7e8 | 218 | |
c326aa2b TH |
219 | /* |
220 | * Inline functions. | |
221 | */ | |
ddbcc7e8 | 222 | |
5de0107e TH |
223 | /** |
224 | * css_get - obtain a reference on the specified css | |
225 | * @css: target css | |
226 | * | |
227 | * The caller must already have a reference. | |
ddbcc7e8 | 228 | */ |
ddbcc7e8 PM |
229 | static inline void css_get(struct cgroup_subsys_state *css) |
230 | { | |
3b514d24 TH |
231 | if (!(css->flags & CSS_NO_REF)) |
232 | percpu_ref_get(&css->refcnt); | |
ddbcc7e8 | 233 | } |
e7c5ec91 | 234 | |
e8ea14cc JW |
235 | /** |
236 | * css_get_many - obtain references on the specified css | |
237 | * @css: target css | |
238 | * @n: number of references to get | |
239 | * | |
240 | * The caller must already have a reference. | |
241 | */ | |
242 | static inline void css_get_many(struct cgroup_subsys_state *css, unsigned int n) | |
243 | { | |
244 | if (!(css->flags & CSS_NO_REF)) | |
245 | percpu_ref_get_many(&css->refcnt, n); | |
246 | } | |
247 | ||
6f4524d3 TH |
248 | /** |
249 | * css_tryget - try to obtain a reference on the specified css | |
250 | * @css: target css | |
251 | * | |
252 | * Obtain a reference on @css unless it already has reached zero and is | |
253 | * being released. This function doesn't care whether @css is on or | |
254 | * offline. The caller naturally needs to ensure that @css is accessible | |
255 | * but doesn't have to be holding a reference on it - IOW, RCU protected | |
256 | * access is good enough for this function. Returns %true if a reference | |
257 | * count was successfully obtained; %false otherwise. | |
258 | */ | |
259 | static inline bool css_tryget(struct cgroup_subsys_state *css) | |
260 | { | |
261 | if (!(css->flags & CSS_NO_REF)) | |
262 | return percpu_ref_tryget(&css->refcnt); | |
263 | return true; | |
264 | } | |
265 | ||
5de0107e | 266 | /** |
ec903c0c | 267 | * css_tryget_online - try to obtain a reference on the specified css if online |
5de0107e TH |
268 | * @css: target css |
269 | * | |
ec903c0c TH |
270 | * Obtain a reference on @css if it's online. The caller naturally needs |
271 | * to ensure that @css is accessible but doesn't have to be holding a | |
5de0107e TH |
272 | * reference on it - IOW, RCU protected access is good enough for this |
273 | * function. Returns %true if a reference count was successfully obtained; | |
274 | * %false otherwise. | |
275 | */ | |
ec903c0c | 276 | static inline bool css_tryget_online(struct cgroup_subsys_state *css) |
e7c5ec91 | 277 | { |
3b514d24 TH |
278 | if (!(css->flags & CSS_NO_REF)) |
279 | return percpu_ref_tryget_live(&css->refcnt); | |
280 | return true; | |
e7c5ec91 | 281 | } |
2f7ee569 TH |
282 | |
283 | /** | |
5de0107e TH |
284 | * css_put - put a css reference |
285 | * @css: target css | |
286 | * | |
ec903c0c | 287 | * Put a reference obtained via css_get() and css_tryget_online(). |
2f7ee569 | 288 | */ |
ddbcc7e8 PM |
289 | static inline void css_put(struct cgroup_subsys_state *css) |
290 | { | |
3b514d24 TH |
291 | if (!(css->flags & CSS_NO_REF)) |
292 | percpu_ref_put(&css->refcnt); | |
ddbcc7e8 | 293 | } |
2f7ee569 | 294 | |
e8ea14cc JW |
295 | /** |
296 | * css_put_many - put css references | |
297 | * @css: target css | |
298 | * @n: number of references to put | |
299 | * | |
300 | * Put references obtained via css_get() and css_tryget_online(). | |
21acb9ca | 301 | */ |
e8ea14cc JW |
302 | static inline void css_put_many(struct cgroup_subsys_state *css, unsigned int n) |
303 | { | |
304 | if (!(css->flags & CSS_NO_REF)) | |
305 | percpu_ref_put_many(&css->refcnt, n); | |
306 | } | |
ddbcc7e8 | 307 | |
14611e51 TH |
308 | /** |
309 | * task_css_set_check - obtain a task's css_set with extra access conditions | |
310 | * @task: the task to obtain css_set for | |
311 | * @__c: extra condition expression to be passed to rcu_dereference_check() | |
312 | * | |
313 | * A task's css_set is RCU protected, initialized and exited while holding | |
314 | * task_lock(), and can only be modified while holding both cgroup_mutex | |
315 | * and task_lock() while the task is alive. This macro verifies that the | |
316 | * caller is inside proper critical section and returns @task's css_set. | |
317 | * | |
318 | * The caller can also specify additional allowed conditions via @__c, such | |
319 | * as locks used during the cgroup_subsys::attach() methods. | |
dc61b1d6 | 320 | */ |
2219449a TH |
321 | #ifdef CONFIG_PROVE_RCU |
322 | extern struct mutex cgroup_mutex; | |
0e1d768f | 323 | extern struct rw_semaphore css_set_rwsem; |
14611e51 TH |
324 | #define task_css_set_check(task, __c) \ |
325 | rcu_dereference_check((task)->cgroups, \ | |
0e1d768f TH |
326 | lockdep_is_held(&cgroup_mutex) || \ |
327 | lockdep_is_held(&css_set_rwsem) || \ | |
328 | ((task)->flags & PF_EXITING) || (__c)) | |
2219449a | 329 | #else |
14611e51 TH |
330 | #define task_css_set_check(task, __c) \ |
331 | rcu_dereference((task)->cgroups) | |
2219449a | 332 | #endif |
dc61b1d6 | 333 | |
14611e51 | 334 | /** |
8af01f56 | 335 | * task_css_check - obtain css for (task, subsys) w/ extra access conds |
14611e51 TH |
336 | * @task: the target task |
337 | * @subsys_id: the target subsystem ID | |
338 | * @__c: extra condition expression to be passed to rcu_dereference_check() | |
339 | * | |
340 | * Return the cgroup_subsys_state for the (@task, @subsys_id) pair. The | |
341 | * synchronization rules are the same as task_css_set_check(). | |
342 | */ | |
8af01f56 | 343 | #define task_css_check(task, subsys_id, __c) \ |
14611e51 TH |
344 | task_css_set_check((task), (__c))->subsys[(subsys_id)] |
345 | ||
346 | /** | |
347 | * task_css_set - obtain a task's css_set | |
348 | * @task: the task to obtain css_set for | |
349 | * | |
350 | * See task_css_set_check(). | |
351 | */ | |
352 | static inline struct css_set *task_css_set(struct task_struct *task) | |
353 | { | |
354 | return task_css_set_check(task, false); | |
355 | } | |
356 | ||
357 | /** | |
8af01f56 | 358 | * task_css - obtain css for (task, subsys) |
14611e51 TH |
359 | * @task: the target task |
360 | * @subsys_id: the target subsystem ID | |
361 | * | |
8af01f56 | 362 | * See task_css_check(). |
14611e51 | 363 | */ |
8af01f56 TH |
364 | static inline struct cgroup_subsys_state *task_css(struct task_struct *task, |
365 | int subsys_id) | |
ddbcc7e8 | 366 | { |
8af01f56 | 367 | return task_css_check(task, subsys_id, false); |
ddbcc7e8 PM |
368 | } |
369 | ||
ec438699 TH |
370 | /** |
371 | * task_get_css - find and get the css for (task, subsys) | |
372 | * @task: the target task | |
373 | * @subsys_id: the target subsystem ID | |
374 | * | |
375 | * Find the css for the (@task, @subsys_id) combination, increment a | |
376 | * reference on and return it. This function is guaranteed to return a | |
377 | * valid css. | |
378 | */ | |
379 | static inline struct cgroup_subsys_state * | |
380 | task_get_css(struct task_struct *task, int subsys_id) | |
381 | { | |
382 | struct cgroup_subsys_state *css; | |
383 | ||
384 | rcu_read_lock(); | |
385 | while (true) { | |
386 | css = task_css(task, subsys_id); | |
387 | if (likely(css_tryget_online(css))) | |
388 | break; | |
389 | cpu_relax(); | |
390 | } | |
391 | rcu_read_unlock(); | |
392 | return css; | |
393 | } | |
394 | ||
5024ae29 TH |
395 | /** |
396 | * task_css_is_root - test whether a task belongs to the root css | |
397 | * @task: the target task | |
398 | * @subsys_id: the target subsystem ID | |
399 | * | |
400 | * Test whether @task belongs to the root css on the specified subsystem. | |
401 | * May be invoked in any context. | |
402 | */ | |
403 | static inline bool task_css_is_root(struct task_struct *task, int subsys_id) | |
404 | { | |
405 | return task_css_check(task, subsys_id, true) == | |
406 | init_css_set.subsys[subsys_id]; | |
407 | } | |
408 | ||
8af01f56 TH |
409 | static inline struct cgroup *task_cgroup(struct task_struct *task, |
410 | int subsys_id) | |
ddbcc7e8 | 411 | { |
8af01f56 | 412 | return task_css(task, subsys_id)->cgroup; |
ddbcc7e8 PM |
413 | } |
414 | ||
574bd9f7 | 415 | /** |
aa6ec29b TH |
416 | * cgroup_on_dfl - test whether a cgroup is on the default hierarchy |
417 | * @cgrp: the cgroup of interest | |
574bd9f7 | 418 | * |
aa6ec29b TH |
419 | * The default hierarchy is the v2 interface of cgroup and this function |
420 | * can be used to test whether a cgroup is on the default hierarchy for | |
421 | * cases where a subsystem should behave differnetly depending on the | |
422 | * interface version. | |
574bd9f7 | 423 | * |
aa6ec29b TH |
424 | * The set of behaviors which change on the default hierarchy are still |
425 | * being determined and the mount option is prefixed with __DEVEL__. | |
75501a6d | 426 | * |
aa6ec29b | 427 | * List of changed behaviors: |
574bd9f7 | 428 | * |
aa6ec29b TH |
429 | * - Mount options "noprefix", "xattr", "clone_children", "release_agent" |
430 | * and "name" are disallowed. | |
574bd9f7 | 431 | * |
aa6ec29b | 432 | * - When mounting an existing superblock, mount options should match. |
574bd9f7 | 433 | * |
aa6ec29b | 434 | * - Remount is disallowed. |
574bd9f7 | 435 | * |
aa6ec29b | 436 | * - rename(2) is disallowed. |
574bd9f7 | 437 | * |
aa6ec29b TH |
438 | * - "tasks" is removed. Everything should be at process granularity. Use |
439 | * "cgroup.procs" instead. | |
574bd9f7 | 440 | * |
aa6ec29b TH |
441 | * - "cgroup.procs" is not sorted. pids will be unique unless they got |
442 | * recycled inbetween reads. | |
574bd9f7 | 443 | * |
aa6ec29b TH |
444 | * - "release_agent" and "notify_on_release" are removed. Replacement |
445 | * notification mechanism will be implemented. | |
574bd9f7 | 446 | * |
aa6ec29b | 447 | * - "cgroup.clone_children" is removed. |
75501a6d | 448 | * |
aa6ec29b TH |
449 | * - "cgroup.subtree_populated" is available. Its value is 0 if the cgroup |
450 | * and its descendants contain no task; otherwise, 1. The file also | |
451 | * generates kernfs notification which can be monitored through poll and | |
452 | * [di]notify when the value of the file changes. | |
574bd9f7 | 453 | * |
aa6ec29b TH |
454 | * - cpuset: tasks will be kept in empty cpusets when hotplug happens and |
455 | * take masks of ancestors with non-empty cpus/mems, instead of being | |
456 | * moved to an ancestor. | |
c2931b70 | 457 | * |
aa6ec29b TH |
458 | * - cpuset: a task can be moved into an empty cpuset, and again it takes |
459 | * masks of ancestors. | |
c2931b70 | 460 | * |
aa6ec29b TH |
461 | * - memcg: use_hierarchy is on by default and the cgroup file for the flag |
462 | * is not created. | |
463 | * | |
464 | * - blkcg: blk-throttle becomes properly hierarchical. | |
465 | * | |
466 | * - debug: disallowed on the default hierarchy. | |
574bd9f7 | 467 | */ |
a2dd4247 TH |
468 | static inline bool cgroup_on_dfl(const struct cgroup *cgrp) |
469 | { | |
470 | return cgrp->root == &cgrp_dfl_root; | |
471 | } | |
574bd9f7 | 472 | |
07bc356e TH |
473 | /* no synchronization, the result can only be used as a hint */ |
474 | static inline bool cgroup_has_tasks(struct cgroup *cgrp) | |
475 | { | |
476 | return !list_empty(&cgrp->cset_links); | |
477 | } | |
f3d46500 | 478 | |
f29374b1 | 479 | /* returns ino associated with a cgroup */ |
b1664924 TH |
480 | static inline ino_t cgroup_ino(struct cgroup *cgrp) |
481 | { | |
f29374b1 | 482 | return cgrp->kn->ino; |
b1664924 | 483 | } |
3ebb2b6e | 484 | |
b4168640 TH |
485 | /* cft/css accessors for cftype->write() operation */ |
486 | static inline struct cftype *of_cft(struct kernfs_open_file *of) | |
7da11279 | 487 | { |
2bd59d48 | 488 | return of->kn->priv; |
7da11279 | 489 | } |
0f0a2b4f | 490 | |
b4168640 | 491 | struct cgroup_subsys_state *of_css(struct kernfs_open_file *of); |
817929ec | 492 | |
b4168640 TH |
493 | /* cft/css accessors for cftype->seq_*() operations */ |
494 | static inline struct cftype *seq_cft(struct seq_file *seq) | |
495 | { | |
496 | return of_cft(seq->private); | |
497 | } | |
e535837b | 498 | |
b4168640 TH |
499 | static inline struct cgroup_subsys_state *seq_css(struct seq_file *seq) |
500 | { | |
501 | return of_css(seq->private); | |
502 | } | |
31583bb0 | 503 | |
e61734c5 TH |
504 | /* |
505 | * Name / path handling functions. All are thin wrappers around the kernfs | |
506 | * counterparts and can be called under any context. | |
507 | */ | |
38460b48 | 508 | |
e61734c5 TH |
509 | static inline int cgroup_name(struct cgroup *cgrp, char *buf, size_t buflen) |
510 | { | |
fdce6bf8 | 511 | return kernfs_name(cgrp->kn, buf, buflen); |
e61734c5 | 512 | } |
ddbcc7e8 | 513 | |
e61734c5 TH |
514 | static inline char * __must_check cgroup_path(struct cgroup *cgrp, char *buf, |
515 | size_t buflen) | |
516 | { | |
fdce6bf8 | 517 | return kernfs_path(cgrp->kn, buf, buflen); |
e61734c5 | 518 | } |
f3ba5380 | 519 | |
e61734c5 TH |
520 | static inline void pr_cont_cgroup_name(struct cgroup *cgrp) |
521 | { | |
fdce6bf8 | 522 | pr_cont_kernfs_name(cgrp->kn); |
e61734c5 | 523 | } |
ddbcc7e8 | 524 | |
e61734c5 | 525 | static inline void pr_cont_cgroup_path(struct cgroup *cgrp) |
846c7bb0 | 526 | { |
fdce6bf8 | 527 | pr_cont_kernfs_path(cgrp->kn); |
846c7bb0 | 528 | } |
ddbcc7e8 | 529 | |
ddbcc7e8 PM |
530 | #else /* !CONFIG_CGROUPS */ |
531 | ||
f3ba5380 | 532 | struct cgroup_subsys_state; |
f3ba5380 | 533 | |
c326aa2b | 534 | static inline void css_put(struct cgroup_subsys_state *css) {} |
31583bb0 | 535 | static inline int cgroup_attach_task_all(struct task_struct *from, |
c326aa2b TH |
536 | struct task_struct *t) { return 0; } |
537 | static inline int cgroupstats_build(struct cgroupstats *stats, | |
538 | struct dentry *dentry) { return -EINVAL; } | |
539 | ||
b4f48b63 | 540 | static inline void cgroup_fork(struct task_struct *p) {} |
7e47682e AS |
541 | static inline int cgroup_can_fork(struct task_struct *p, |
542 | void *ss_priv[CGROUP_CANFORK_COUNT]) | |
543 | { return 0; } | |
544 | static inline void cgroup_cancel_fork(struct task_struct *p, | |
545 | void *ss_priv[CGROUP_CANFORK_COUNT]) {} | |
546 | static inline void cgroup_post_fork(struct task_struct *p, | |
547 | void *ss_priv[CGROUP_CANFORK_COUNT]) {} | |
1ec41830 | 548 | static inline void cgroup_exit(struct task_struct *p) {} |
ddbcc7e8 | 549 | |
c326aa2b TH |
550 | static inline int cgroup_init_early(void) { return 0; } |
551 | static inline int cgroup_init(void) { return 0; } | |
d7926ee3 | 552 | |
ddbcc7e8 PM |
553 | #endif /* !CONFIG_CGROUPS */ |
554 | ||
555 | #endif /* _LINUX_CGROUP_H */ |