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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> | |
12 | #include <linux/kref.h> | |
13 | #include <linux/cpumask.h> | |
14 | #include <linux/nodemask.h> | |
15 | #include <linux/rcupdate.h> | |
846c7bb0 | 16 | #include <linux/cgroupstats.h> |
31a7df01 | 17 | #include <linux/prio_heap.h> |
ddbcc7e8 PM |
18 | |
19 | #ifdef CONFIG_CGROUPS | |
20 | ||
21 | struct cgroupfs_root; | |
22 | struct cgroup_subsys; | |
23 | struct inode; | |
84eea842 | 24 | struct cgroup; |
ddbcc7e8 PM |
25 | |
26 | extern int cgroup_init_early(void); | |
27 | extern int cgroup_init(void); | |
28 | extern void cgroup_init_smp(void); | |
29 | extern void cgroup_lock(void); | |
84eea842 | 30 | extern bool cgroup_lock_live_group(struct cgroup *cgrp); |
ddbcc7e8 | 31 | extern void cgroup_unlock(void); |
b4f48b63 PM |
32 | extern void cgroup_fork(struct task_struct *p); |
33 | extern void cgroup_fork_callbacks(struct task_struct *p); | |
817929ec | 34 | extern void cgroup_post_fork(struct task_struct *p); |
b4f48b63 | 35 | extern void cgroup_exit(struct task_struct *p, int run_callbacks); |
846c7bb0 BS |
36 | extern int cgroupstats_build(struct cgroupstats *stats, |
37 | struct dentry *dentry); | |
ddbcc7e8 | 38 | |
a424316c PM |
39 | extern struct file_operations proc_cgroup_operations; |
40 | ||
817929ec PM |
41 | /* Define the enumeration of all cgroup subsystems */ |
42 | #define SUBSYS(_x) _x ## _subsys_id, | |
43 | enum cgroup_subsys_id { | |
44 | #include <linux/cgroup_subsys.h> | |
45 | CGROUP_SUBSYS_COUNT | |
46 | }; | |
47 | #undef SUBSYS | |
48 | ||
ddbcc7e8 PM |
49 | /* Per-subsystem/per-cgroup state maintained by the system. */ |
50 | struct cgroup_subsys_state { | |
51 | /* The cgroup that this subsystem is attached to. Useful | |
52 | * for subsystems that want to know about the cgroup | |
53 | * hierarchy structure */ | |
54 | struct cgroup *cgroup; | |
55 | ||
56 | /* State maintained by the cgroup system to allow | |
57 | * subsystems to be "busy". Should be accessed via css_get() | |
58 | * and css_put() */ | |
59 | ||
60 | atomic_t refcnt; | |
61 | ||
62 | unsigned long flags; | |
63 | }; | |
64 | ||
65 | /* bits in struct cgroup_subsys_state flags field */ | |
66 | enum { | |
67 | CSS_ROOT, /* This CSS is the root of the subsystem */ | |
68 | }; | |
69 | ||
70 | /* | |
71 | * Call css_get() to hold a reference on the cgroup; | |
72 | * | |
73 | */ | |
74 | ||
75 | static inline void css_get(struct cgroup_subsys_state *css) | |
76 | { | |
77 | /* We don't need to reference count the root state */ | |
78 | if (!test_bit(CSS_ROOT, &css->flags)) | |
79 | atomic_inc(&css->refcnt); | |
80 | } | |
81 | /* | |
82 | * css_put() should be called to release a reference taken by | |
83 | * css_get() | |
84 | */ | |
85 | ||
81a6a5cd | 86 | extern void __css_put(struct cgroup_subsys_state *css); |
ddbcc7e8 PM |
87 | static inline void css_put(struct cgroup_subsys_state *css) |
88 | { | |
89 | if (!test_bit(CSS_ROOT, &css->flags)) | |
81a6a5cd | 90 | __css_put(css); |
ddbcc7e8 PM |
91 | } |
92 | ||
3116f0e3 PM |
93 | /* bits in struct cgroup flags field */ |
94 | enum { | |
95 | /* Control Group is dead */ | |
96 | CGRP_REMOVED, | |
97 | /* Control Group has previously had a child cgroup or a task, | |
98 | * but no longer (only if CGRP_NOTIFY_ON_RELEASE is set) */ | |
99 | CGRP_RELEASABLE, | |
100 | /* Control Group requires release notifications to userspace */ | |
101 | CGRP_NOTIFY_ON_RELEASE, | |
102 | }; | |
103 | ||
ddbcc7e8 PM |
104 | struct cgroup { |
105 | unsigned long flags; /* "unsigned long" so bitops work */ | |
106 | ||
107 | /* count users of this cgroup. >0 means busy, but doesn't | |
108 | * necessarily indicate the number of tasks in the | |
109 | * cgroup */ | |
110 | atomic_t count; | |
111 | ||
112 | /* | |
113 | * We link our 'sibling' struct into our parent's 'children'. | |
114 | * Our children link their 'sibling' into our 'children'. | |
115 | */ | |
116 | struct list_head sibling; /* my parent's children */ | |
117 | struct list_head children; /* my children */ | |
118 | ||
119 | struct cgroup *parent; /* my parent */ | |
120 | struct dentry *dentry; /* cgroup fs entry */ | |
121 | ||
122 | /* Private pointers for each registered subsystem */ | |
123 | struct cgroup_subsys_state *subsys[CGROUP_SUBSYS_COUNT]; | |
124 | ||
125 | struct cgroupfs_root *root; | |
126 | struct cgroup *top_cgroup; | |
817929ec PM |
127 | |
128 | /* | |
129 | * List of cg_cgroup_links pointing at css_sets with | |
130 | * tasks in this cgroup. Protected by css_set_lock | |
131 | */ | |
132 | struct list_head css_sets; | |
81a6a5cd PM |
133 | |
134 | /* | |
135 | * Linked list running through all cgroups that can | |
136 | * potentially be reaped by the release agent. Protected by | |
137 | * release_list_lock | |
138 | */ | |
139 | struct list_head release_list; | |
817929ec PM |
140 | }; |
141 | ||
142 | /* A css_set is a structure holding pointers to a set of | |
143 | * cgroup_subsys_state objects. This saves space in the task struct | |
144 | * object and speeds up fork()/exit(), since a single inc/dec and a | |
145 | * list_add()/del() can bump the reference count on the entire | |
146 | * cgroup set for a task. | |
147 | */ | |
148 | ||
149 | struct css_set { | |
150 | ||
151 | /* Reference count */ | |
152 | struct kref ref; | |
153 | ||
472b1053 LZ |
154 | /* |
155 | * List running through all cgroup groups in the same hash | |
156 | * slot. Protected by css_set_lock | |
157 | */ | |
158 | struct hlist_node hlist; | |
159 | ||
817929ec PM |
160 | /* |
161 | * List running through all tasks using this cgroup | |
162 | * group. Protected by css_set_lock | |
163 | */ | |
164 | struct list_head tasks; | |
165 | ||
166 | /* | |
167 | * List of cg_cgroup_link objects on link chains from | |
168 | * cgroups referenced from this css_set. Protected by | |
169 | * css_set_lock | |
170 | */ | |
171 | struct list_head cg_links; | |
172 | ||
173 | /* | |
174 | * Set of subsystem states, one for each subsystem. This array | |
175 | * is immutable after creation apart from the init_css_set | |
176 | * during subsystem registration (at boot time). | |
177 | */ | |
178 | struct cgroup_subsys_state *subsys[CGROUP_SUBSYS_COUNT]; | |
ddbcc7e8 PM |
179 | }; |
180 | ||
91796569 PM |
181 | /* |
182 | * cgroup_map_cb is an abstract callback API for reporting map-valued | |
183 | * control files | |
184 | */ | |
185 | ||
186 | struct cgroup_map_cb { | |
187 | int (*fill)(struct cgroup_map_cb *cb, const char *key, u64 value); | |
188 | void *state; | |
189 | }; | |
190 | ||
ddbcc7e8 PM |
191 | /* struct cftype: |
192 | * | |
193 | * The files in the cgroup filesystem mostly have a very simple read/write | |
194 | * handling, some common function will take care of it. Nevertheless some cases | |
195 | * (read tasks) are special and therefore I define this structure for every | |
196 | * kind of file. | |
197 | * | |
198 | * | |
199 | * When reading/writing to a file: | |
a043e3b2 | 200 | * - the cgroup to use is file->f_dentry->d_parent->d_fsdata |
ddbcc7e8 PM |
201 | * - the 'cftype' of the file is file->f_dentry->d_fsdata |
202 | */ | |
203 | ||
204 | #define MAX_CFTYPE_NAME 64 | |
205 | struct cftype { | |
206 | /* By convention, the name should begin with the name of the | |
207 | * subsystem, followed by a period */ | |
208 | char name[MAX_CFTYPE_NAME]; | |
209 | int private; | |
db3b1497 PM |
210 | |
211 | /* | |
212 | * If non-zero, defines the maximum length of string that can | |
213 | * be passed to write_string; defaults to 64 | |
214 | */ | |
215 | size_t max_write_len; | |
216 | ||
ce16b49d PM |
217 | int (*open)(struct inode *inode, struct file *file); |
218 | ssize_t (*read)(struct cgroup *cgrp, struct cftype *cft, | |
219 | struct file *file, | |
220 | char __user *buf, size_t nbytes, loff_t *ppos); | |
ddbcc7e8 | 221 | /* |
f4c753b7 | 222 | * read_u64() is a shortcut for the common case of returning a |
ddbcc7e8 PM |
223 | * single integer. Use it in place of read() |
224 | */ | |
ce16b49d | 225 | u64 (*read_u64)(struct cgroup *cgrp, struct cftype *cft); |
e73d2c61 PM |
226 | /* |
227 | * read_s64() is a signed version of read_u64() | |
228 | */ | |
ce16b49d | 229 | s64 (*read_s64)(struct cgroup *cgrp, struct cftype *cft); |
91796569 PM |
230 | /* |
231 | * read_map() is used for defining a map of key/value | |
232 | * pairs. It should call cb->fill(cb, key, value) for each | |
233 | * entry. The key/value pairs (and their ordering) should not | |
234 | * change between reboots. | |
235 | */ | |
ce16b49d PM |
236 | int (*read_map)(struct cgroup *cont, struct cftype *cft, |
237 | struct cgroup_map_cb *cb); | |
29486df3 SH |
238 | /* |
239 | * read_seq_string() is used for outputting a simple sequence | |
240 | * using seqfile. | |
241 | */ | |
ce16b49d PM |
242 | int (*read_seq_string)(struct cgroup *cont, struct cftype *cft, |
243 | struct seq_file *m); | |
91796569 | 244 | |
ce16b49d PM |
245 | ssize_t (*write)(struct cgroup *cgrp, struct cftype *cft, |
246 | struct file *file, | |
247 | const char __user *buf, size_t nbytes, loff_t *ppos); | |
355e0c48 PM |
248 | |
249 | /* | |
f4c753b7 | 250 | * write_u64() is a shortcut for the common case of accepting |
355e0c48 PM |
251 | * a single integer (as parsed by simple_strtoull) from |
252 | * userspace. Use in place of write(); return 0 or error. | |
253 | */ | |
ce16b49d | 254 | int (*write_u64)(struct cgroup *cgrp, struct cftype *cft, u64 val); |
e73d2c61 PM |
255 | /* |
256 | * write_s64() is a signed version of write_u64() | |
257 | */ | |
ce16b49d | 258 | int (*write_s64)(struct cgroup *cgrp, struct cftype *cft, s64 val); |
355e0c48 | 259 | |
db3b1497 PM |
260 | /* |
261 | * write_string() is passed a nul-terminated kernelspace | |
262 | * buffer of maximum length determined by max_write_len. | |
263 | * Returns 0 or -ve error code. | |
264 | */ | |
265 | int (*write_string)(struct cgroup *cgrp, struct cftype *cft, | |
266 | const char *buffer); | |
d447ea2f PE |
267 | /* |
268 | * trigger() callback can be used to get some kick from the | |
269 | * userspace, when the actual string written is not important | |
270 | * at all. The private field can be used to determine the | |
271 | * kick type for multiplexing. | |
272 | */ | |
273 | int (*trigger)(struct cgroup *cgrp, unsigned int event); | |
274 | ||
ce16b49d | 275 | int (*release)(struct inode *inode, struct file *file); |
ddbcc7e8 PM |
276 | }; |
277 | ||
31a7df01 CW |
278 | struct cgroup_scanner { |
279 | struct cgroup *cg; | |
280 | int (*test_task)(struct task_struct *p, struct cgroup_scanner *scan); | |
281 | void (*process_task)(struct task_struct *p, | |
282 | struct cgroup_scanner *scan); | |
283 | struct ptr_heap *heap; | |
284 | }; | |
285 | ||
ddbcc7e8 PM |
286 | /* Add a new file to the given cgroup directory. Should only be |
287 | * called by subsystems from within a populate() method */ | |
ffd2d883 | 288 | int cgroup_add_file(struct cgroup *cgrp, struct cgroup_subsys *subsys, |
ddbcc7e8 PM |
289 | const struct cftype *cft); |
290 | ||
291 | /* Add a set of new files to the given cgroup directory. Should | |
292 | * only be called by subsystems from within a populate() method */ | |
ffd2d883 | 293 | int cgroup_add_files(struct cgroup *cgrp, |
ddbcc7e8 PM |
294 | struct cgroup_subsys *subsys, |
295 | const struct cftype cft[], | |
296 | int count); | |
297 | ||
ffd2d883 | 298 | int cgroup_is_removed(const struct cgroup *cgrp); |
ddbcc7e8 | 299 | |
ffd2d883 | 300 | int cgroup_path(const struct cgroup *cgrp, char *buf, int buflen); |
ddbcc7e8 | 301 | |
ffd2d883 | 302 | int cgroup_task_count(const struct cgroup *cgrp); |
bbcb81d0 | 303 | |
ddbcc7e8 | 304 | /* Return true if the cgroup is a descendant of the current cgroup */ |
ffd2d883 | 305 | int cgroup_is_descendant(const struct cgroup *cgrp); |
ddbcc7e8 PM |
306 | |
307 | /* Control Group subsystem type. See Documentation/cgroups.txt for details */ | |
308 | ||
309 | struct cgroup_subsys { | |
310 | struct cgroup_subsys_state *(*create)(struct cgroup_subsys *ss, | |
ffd2d883 LZ |
311 | struct cgroup *cgrp); |
312 | void (*pre_destroy)(struct cgroup_subsys *ss, struct cgroup *cgrp); | |
313 | void (*destroy)(struct cgroup_subsys *ss, struct cgroup *cgrp); | |
ddbcc7e8 | 314 | int (*can_attach)(struct cgroup_subsys *ss, |
ffd2d883 LZ |
315 | struct cgroup *cgrp, struct task_struct *tsk); |
316 | void (*attach)(struct cgroup_subsys *ss, struct cgroup *cgrp, | |
317 | struct cgroup *old_cgrp, struct task_struct *tsk); | |
ddbcc7e8 PM |
318 | void (*fork)(struct cgroup_subsys *ss, struct task_struct *task); |
319 | void (*exit)(struct cgroup_subsys *ss, struct task_struct *task); | |
320 | int (*populate)(struct cgroup_subsys *ss, | |
ffd2d883 LZ |
321 | struct cgroup *cgrp); |
322 | void (*post_clone)(struct cgroup_subsys *ss, struct cgroup *cgrp); | |
ddbcc7e8 | 323 | void (*bind)(struct cgroup_subsys *ss, struct cgroup *root); |
cf475ad2 BS |
324 | /* |
325 | * This routine is called with the task_lock of mm->owner held | |
326 | */ | |
327 | void (*mm_owner_changed)(struct cgroup_subsys *ss, | |
328 | struct cgroup *old, | |
329 | struct cgroup *new); | |
ddbcc7e8 PM |
330 | int subsys_id; |
331 | int active; | |
8bab8dde | 332 | int disabled; |
ddbcc7e8 PM |
333 | int early_init; |
334 | #define MAX_CGROUP_TYPE_NAMELEN 32 | |
335 | const char *name; | |
336 | ||
337 | /* Protected by RCU */ | |
338 | struct cgroupfs_root *root; | |
339 | ||
340 | struct list_head sibling; | |
341 | ||
342 | void *private; | |
343 | }; | |
344 | ||
345 | #define SUBSYS(_x) extern struct cgroup_subsys _x ## _subsys; | |
346 | #include <linux/cgroup_subsys.h> | |
347 | #undef SUBSYS | |
348 | ||
349 | static inline struct cgroup_subsys_state *cgroup_subsys_state( | |
ffd2d883 | 350 | struct cgroup *cgrp, int subsys_id) |
ddbcc7e8 | 351 | { |
ffd2d883 | 352 | return cgrp->subsys[subsys_id]; |
ddbcc7e8 PM |
353 | } |
354 | ||
355 | static inline struct cgroup_subsys_state *task_subsys_state( | |
356 | struct task_struct *task, int subsys_id) | |
357 | { | |
817929ec | 358 | return rcu_dereference(task->cgroups->subsys[subsys_id]); |
ddbcc7e8 PM |
359 | } |
360 | ||
361 | static inline struct cgroup* task_cgroup(struct task_struct *task, | |
362 | int subsys_id) | |
363 | { | |
364 | return task_subsys_state(task, subsys_id)->cgroup; | |
365 | } | |
366 | ||
e885dcde SH |
367 | int cgroup_clone(struct task_struct *tsk, struct cgroup_subsys *ss, |
368 | char *nodename); | |
697f4161 | 369 | |
817929ec PM |
370 | /* A cgroup_iter should be treated as an opaque object */ |
371 | struct cgroup_iter { | |
372 | struct list_head *cg_link; | |
373 | struct list_head *task; | |
374 | }; | |
375 | ||
376 | /* To iterate across the tasks in a cgroup: | |
377 | * | |
378 | * 1) call cgroup_iter_start to intialize an iterator | |
379 | * | |
380 | * 2) call cgroup_iter_next() to retrieve member tasks until it | |
381 | * returns NULL or until you want to end the iteration | |
382 | * | |
383 | * 3) call cgroup_iter_end() to destroy the iterator. | |
31a7df01 CW |
384 | * |
385 | * Or, call cgroup_scan_tasks() to iterate through every task in a cpuset. | |
386 | * - cgroup_scan_tasks() holds the css_set_lock when calling the test_task() | |
387 | * callback, but not while calling the process_task() callback. | |
817929ec | 388 | */ |
ffd2d883 LZ |
389 | void cgroup_iter_start(struct cgroup *cgrp, struct cgroup_iter *it); |
390 | struct task_struct *cgroup_iter_next(struct cgroup *cgrp, | |
817929ec | 391 | struct cgroup_iter *it); |
ffd2d883 | 392 | void cgroup_iter_end(struct cgroup *cgrp, struct cgroup_iter *it); |
31a7df01 | 393 | int cgroup_scan_tasks(struct cgroup_scanner *scan); |
956db3ca | 394 | int cgroup_attach_task(struct cgroup *, struct task_struct *); |
817929ec | 395 | |
ddbcc7e8 PM |
396 | #else /* !CONFIG_CGROUPS */ |
397 | ||
398 | static inline int cgroup_init_early(void) { return 0; } | |
399 | static inline int cgroup_init(void) { return 0; } | |
400 | static inline void cgroup_init_smp(void) {} | |
b4f48b63 PM |
401 | static inline void cgroup_fork(struct task_struct *p) {} |
402 | static inline void cgroup_fork_callbacks(struct task_struct *p) {} | |
817929ec | 403 | static inline void cgroup_post_fork(struct task_struct *p) {} |
b4f48b63 | 404 | static inline void cgroup_exit(struct task_struct *p, int callbacks) {} |
ddbcc7e8 PM |
405 | |
406 | static inline void cgroup_lock(void) {} | |
407 | static inline void cgroup_unlock(void) {} | |
846c7bb0 BS |
408 | static inline int cgroupstats_build(struct cgroupstats *stats, |
409 | struct dentry *dentry) | |
410 | { | |
411 | return -EINVAL; | |
412 | } | |
ddbcc7e8 PM |
413 | |
414 | #endif /* !CONFIG_CGROUPS */ | |
415 | ||
cf475ad2 BS |
416 | #ifdef CONFIG_MM_OWNER |
417 | extern void | |
418 | cgroup_mm_owner_callbacks(struct task_struct *old, struct task_struct *new); | |
419 | #else /* !CONFIG_MM_OWNER */ | |
420 | static inline void | |
421 | cgroup_mm_owner_callbacks(struct task_struct *old, struct task_struct *new) | |
422 | { | |
423 | } | |
424 | #endif /* CONFIG_MM_OWNER */ | |
ddbcc7e8 | 425 | #endif /* _LINUX_CGROUP_H */ |