Commit | Line | Data |
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dc52ddc0 MH |
1 | /* |
2 | * cgroup_freezer.c - control group freezer subsystem | |
3 | * | |
4 | * Copyright IBM Corporation, 2007 | |
5 | * | |
6 | * Author : Cedric Le Goater <clg@fr.ibm.com> | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify it | |
9 | * under the terms of version 2.1 of the GNU Lesser General Public License | |
10 | * as published by the Free Software Foundation. | |
11 | * | |
12 | * This program is distributed in the hope that it would be useful, but | |
13 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. | |
15 | */ | |
16 | ||
9984de1a | 17 | #include <linux/export.h> |
5a0e3ad6 | 18 | #include <linux/slab.h> |
dc52ddc0 MH |
19 | #include <linux/cgroup.h> |
20 | #include <linux/fs.h> | |
21 | #include <linux/uaccess.h> | |
22 | #include <linux/freezer.h> | |
23 | #include <linux/seq_file.h> | |
24 | ||
ef9fe980 TH |
25 | /* |
26 | * A cgroup is freezing if any FREEZING flags are set. FREEZING_SELF is | |
27 | * set if "FROZEN" is written to freezer.state cgroupfs file, and cleared | |
28 | * for "THAWED". FREEZING_PARENT is set if the parent freezer is FREEZING | |
29 | * for whatever reason. IOW, a cgroup has FREEZING_PARENT set if one of | |
30 | * its ancestors has FREEZING_SELF set. | |
31 | */ | |
d6a2fe13 | 32 | enum freezer_state_flags { |
5300a9b3 | 33 | CGROUP_FREEZER_ONLINE = (1 << 0), /* freezer is fully online */ |
a2252180 TH |
34 | CGROUP_FREEZING_SELF = (1 << 1), /* this freezer is freezing */ |
35 | CGROUP_FREEZING_PARENT = (1 << 2), /* the parent freezer is freezing */ | |
d6a2fe13 | 36 | CGROUP_FROZEN = (1 << 3), /* this and its descendants frozen */ |
a2252180 TH |
37 | |
38 | /* mask for all FREEZING flags */ | |
39 | CGROUP_FREEZING = CGROUP_FREEZING_SELF | CGROUP_FREEZING_PARENT, | |
dc52ddc0 MH |
40 | }; |
41 | ||
42 | struct freezer { | |
bcd66c89 | 43 | struct cgroup_subsys_state css; |
d6a2fe13 | 44 | unsigned int state; |
bcd66c89 | 45 | spinlock_t lock; |
dc52ddc0 MH |
46 | }; |
47 | ||
a7c6d554 TH |
48 | static inline struct freezer *css_freezer(struct cgroup_subsys_state *css) |
49 | { | |
50 | return css ? container_of(css, struct freezer, css) : NULL; | |
51 | } | |
52 | ||
dc52ddc0 MH |
53 | static inline struct freezer *task_freezer(struct task_struct *task) |
54 | { | |
073219e9 | 55 | return css_freezer(task_css(task, freezer_cgrp_id)); |
dc52ddc0 MH |
56 | } |
57 | ||
ef9fe980 TH |
58 | static struct freezer *parent_freezer(struct freezer *freezer) |
59 | { | |
63876986 | 60 | return css_freezer(css_parent(&freezer->css)); |
ef9fe980 TH |
61 | } |
62 | ||
22b4e111 | 63 | bool cgroup_freezing(struct task_struct *task) |
dc52ddc0 | 64 | { |
22b4e111 | 65 | bool ret; |
dc52ddc0 | 66 | |
22b4e111 | 67 | rcu_read_lock(); |
d6a2fe13 | 68 | ret = task_freezer(task)->state & CGROUP_FREEZING; |
22b4e111 TH |
69 | rcu_read_unlock(); |
70 | ||
71 | return ret; | |
dc52ddc0 MH |
72 | } |
73 | ||
74 | /* | |
75 | * cgroups_write_string() limits the size of freezer state strings to | |
76 | * CGROUP_LOCAL_BUFFER_SIZE | |
77 | */ | |
d6a2fe13 TH |
78 | static const char *freezer_state_strs(unsigned int state) |
79 | { | |
80 | if (state & CGROUP_FROZEN) | |
81 | return "FROZEN"; | |
82 | if (state & CGROUP_FREEZING) | |
83 | return "FREEZING"; | |
84 | return "THAWED"; | |
dc52ddc0 MH |
85 | }; |
86 | ||
eb95419b TH |
87 | static struct cgroup_subsys_state * |
88 | freezer_css_alloc(struct cgroup_subsys_state *parent_css) | |
dc52ddc0 MH |
89 | { |
90 | struct freezer *freezer; | |
91 | ||
92 | freezer = kzalloc(sizeof(struct freezer), GFP_KERNEL); | |
93 | if (!freezer) | |
94 | return ERR_PTR(-ENOMEM); | |
95 | ||
96 | spin_lock_init(&freezer->lock); | |
dc52ddc0 MH |
97 | return &freezer->css; |
98 | } | |
99 | ||
5300a9b3 | 100 | /** |
eb95419b TH |
101 | * freezer_css_online - commit creation of a freezer css |
102 | * @css: css being created | |
5300a9b3 | 103 | * |
eb95419b | 104 | * We're committing to creation of @css. Mark it online and inherit |
ef9fe980 TH |
105 | * parent's freezing state while holding both parent's and our |
106 | * freezer->lock. | |
5300a9b3 | 107 | */ |
eb95419b | 108 | static int freezer_css_online(struct cgroup_subsys_state *css) |
dc52ddc0 | 109 | { |
eb95419b | 110 | struct freezer *freezer = css_freezer(css); |
ef9fe980 TH |
111 | struct freezer *parent = parent_freezer(freezer); |
112 | ||
113 | /* | |
114 | * The following double locking and freezing state inheritance | |
115 | * guarantee that @cgroup can never escape ancestors' freezing | |
492eb21b | 116 | * states. See css_for_each_descendant_pre() for details. |
ef9fe980 TH |
117 | */ |
118 | if (parent) | |
119 | spin_lock_irq(&parent->lock); | |
120 | spin_lock_nested(&freezer->lock, SINGLE_DEPTH_NESTING); | |
a3201227 | 121 | |
5300a9b3 | 122 | freezer->state |= CGROUP_FREEZER_ONLINE; |
ef9fe980 TH |
123 | |
124 | if (parent && (parent->state & CGROUP_FREEZING)) { | |
125 | freezer->state |= CGROUP_FREEZING_PARENT | CGROUP_FROZEN; | |
126 | atomic_inc(&system_freezing_cnt); | |
127 | } | |
128 | ||
129 | spin_unlock(&freezer->lock); | |
130 | if (parent) | |
131 | spin_unlock_irq(&parent->lock); | |
b1929db4 TH |
132 | |
133 | return 0; | |
5300a9b3 TH |
134 | } |
135 | ||
136 | /** | |
eb95419b TH |
137 | * freezer_css_offline - initiate destruction of a freezer css |
138 | * @css: css being destroyed | |
5300a9b3 | 139 | * |
eb95419b TH |
140 | * @css is going away. Mark it dead and decrement system_freezing_count if |
141 | * it was holding one. | |
5300a9b3 | 142 | */ |
eb95419b | 143 | static void freezer_css_offline(struct cgroup_subsys_state *css) |
5300a9b3 | 144 | { |
eb95419b | 145 | struct freezer *freezer = css_freezer(css); |
5300a9b3 TH |
146 | |
147 | spin_lock_irq(&freezer->lock); | |
148 | ||
d6a2fe13 | 149 | if (freezer->state & CGROUP_FREEZING) |
a3201227 | 150 | atomic_dec(&system_freezing_cnt); |
5300a9b3 TH |
151 | |
152 | freezer->state = 0; | |
153 | ||
154 | spin_unlock_irq(&freezer->lock); | |
155 | } | |
156 | ||
eb95419b | 157 | static void freezer_css_free(struct cgroup_subsys_state *css) |
5300a9b3 | 158 | { |
eb95419b | 159 | kfree(css_freezer(css)); |
dc52ddc0 MH |
160 | } |
161 | ||
957a4eea | 162 | /* |
ead5c473 TH |
163 | * Tasks can be migrated into a different freezer anytime regardless of its |
164 | * current state. freezer_attach() is responsible for making new tasks | |
165 | * conform to the current state. | |
166 | * | |
167 | * Freezer state changes and task migration are synchronized via | |
168 | * @freezer->lock. freezer_attach() makes the new tasks conform to the | |
169 | * current state and all following state changes can see the new tasks. | |
957a4eea | 170 | */ |
eb95419b TH |
171 | static void freezer_attach(struct cgroup_subsys_state *new_css, |
172 | struct cgroup_taskset *tset) | |
dc52ddc0 | 173 | { |
eb95419b | 174 | struct freezer *freezer = css_freezer(new_css); |
bb9d97b6 | 175 | struct task_struct *task; |
ef9fe980 | 176 | bool clear_frozen = false; |
957a4eea | 177 | |
8755ade6 TH |
178 | spin_lock_irq(&freezer->lock); |
179 | ||
80a6a2cf | 180 | /* |
eb95419b | 181 | * Make the new tasks conform to the current state of @new_css. |
8755ade6 TH |
182 | * For simplicity, when migrating any task to a FROZEN cgroup, we |
183 | * revert it to FREEZING and let update_if_frozen() determine the | |
184 | * correct state later. | |
185 | * | |
eb95419b | 186 | * Tasks in @tset are on @new_css but may not conform to its |
8755ade6 TH |
187 | * current state before executing the following - !frozen tasks may |
188 | * be visible in a FROZEN cgroup and frozen tasks in a THAWED one. | |
80a6a2cf | 189 | */ |
924f0d9a | 190 | cgroup_taskset_for_each(task, tset) { |
d6a2fe13 | 191 | if (!(freezer->state & CGROUP_FREEZING)) { |
8755ade6 TH |
192 | __thaw_task(task); |
193 | } else { | |
194 | freeze_task(task); | |
d6a2fe13 | 195 | freezer->state &= ~CGROUP_FROZEN; |
ef9fe980 | 196 | clear_frozen = true; |
8755ade6 TH |
197 | } |
198 | } | |
dc52ddc0 | 199 | |
8755ade6 | 200 | spin_unlock_irq(&freezer->lock); |
ef9fe980 TH |
201 | |
202 | /* | |
203 | * Propagate FROZEN clearing upwards. We may race with | |
204 | * update_if_frozen(), but as long as both work bottom-up, either | |
205 | * update_if_frozen() sees child's FROZEN cleared or we clear the | |
206 | * parent's FROZEN later. No parent w/ !FROZEN children can be | |
207 | * left FROZEN. | |
208 | */ | |
209 | while (clear_frozen && (freezer = parent_freezer(freezer))) { | |
210 | spin_lock_irq(&freezer->lock); | |
211 | freezer->state &= ~CGROUP_FROZEN; | |
212 | clear_frozen = freezer->state & CGROUP_FREEZING; | |
213 | spin_unlock_irq(&freezer->lock); | |
214 | } | |
f780bdb7 BB |
215 | } |
216 | ||
a60bed29 TH |
217 | /** |
218 | * freezer_fork - cgroup post fork callback | |
219 | * @task: a task which has just been forked | |
220 | * | |
221 | * @task has just been created and should conform to the current state of | |
222 | * the cgroup_freezer it belongs to. This function may race against | |
223 | * freezer_attach(). Losing to freezer_attach() means that we don't have | |
224 | * to do anything as freezer_attach() will put @task into the appropriate | |
225 | * state. | |
226 | */ | |
761b3ef5 | 227 | static void freezer_fork(struct task_struct *task) |
dc52ddc0 MH |
228 | { |
229 | struct freezer *freezer; | |
230 | ||
8b46f880 | 231 | rcu_read_lock(); |
dc52ddc0 | 232 | freezer = task_freezer(task); |
dc52ddc0 | 233 | |
3b1b3f6e | 234 | /* |
a60bed29 TH |
235 | * The root cgroup is non-freezable, so we can skip locking the |
236 | * freezer. This is safe regardless of race with task migration. | |
237 | * If we didn't race or won, skipping is obviously the right thing | |
238 | * to do. If we lost and root is the new cgroup, noop is still the | |
239 | * right thing to do. | |
3b1b3f6e | 240 | */ |
63876986 | 241 | if (!parent_freezer(freezer)) |
5edee61e | 242 | goto out; |
3b1b3f6e | 243 | |
a60bed29 TH |
244 | /* |
245 | * Grab @freezer->lock and freeze @task after verifying @task still | |
246 | * belongs to @freezer and it's freezing. The former is for the | |
247 | * case where we have raced against task migration and lost and | |
248 | * @task is already in a different cgroup which may not be frozen. | |
249 | * This isn't strictly necessary as freeze_task() is allowed to be | |
250 | * called spuriously but let's do it anyway for, if nothing else, | |
251 | * documentation. | |
252 | */ | |
dc52ddc0 | 253 | spin_lock_irq(&freezer->lock); |
a60bed29 | 254 | if (freezer == task_freezer(task) && (freezer->state & CGROUP_FREEZING)) |
839e3407 | 255 | freeze_task(task); |
dc52ddc0 | 256 | spin_unlock_irq(&freezer->lock); |
5edee61e TH |
257 | out: |
258 | rcu_read_unlock(); | |
dc52ddc0 MH |
259 | } |
260 | ||
ef9fe980 TH |
261 | /** |
262 | * update_if_frozen - update whether a cgroup finished freezing | |
182446d0 | 263 | * @css: css of interest |
ef9fe980 TH |
264 | * |
265 | * Once FREEZING is initiated, transition to FROZEN is lazily updated by | |
266 | * calling this function. If the current state is FREEZING but not FROZEN, | |
267 | * this function checks whether all tasks of this cgroup and the descendant | |
268 | * cgroups finished freezing and, if so, sets FROZEN. | |
269 | * | |
270 | * The caller is responsible for grabbing RCU read lock and calling | |
271 | * update_if_frozen() on all descendants prior to invoking this function. | |
b4d18311 TH |
272 | * |
273 | * Task states and freezer state might disagree while tasks are being | |
182446d0 | 274 | * migrated into or out of @css, so we can't verify task states against |
ead5c473 | 275 | * @freezer state here. See freezer_attach() for details. |
dc52ddc0 | 276 | */ |
182446d0 | 277 | static void update_if_frozen(struct cgroup_subsys_state *css) |
dc52ddc0 | 278 | { |
182446d0 | 279 | struct freezer *freezer = css_freezer(css); |
492eb21b | 280 | struct cgroup_subsys_state *pos; |
72ec7029 | 281 | struct css_task_iter it; |
dc52ddc0 | 282 | struct task_struct *task; |
b4d18311 | 283 | |
ef9fe980 TH |
284 | WARN_ON_ONCE(!rcu_read_lock_held()); |
285 | ||
286 | spin_lock_irq(&freezer->lock); | |
287 | ||
d6a2fe13 TH |
288 | if (!(freezer->state & CGROUP_FREEZING) || |
289 | (freezer->state & CGROUP_FROZEN)) | |
ef9fe980 TH |
290 | goto out_unlock; |
291 | ||
292 | /* are all (live) children frozen? */ | |
492eb21b TH |
293 | css_for_each_child(pos, css) { |
294 | struct freezer *child = css_freezer(pos); | |
dc52ddc0 | 295 | |
ef9fe980 TH |
296 | if ((child->state & CGROUP_FREEZER_ONLINE) && |
297 | !(child->state & CGROUP_FROZEN)) | |
298 | goto out_unlock; | |
299 | } | |
300 | ||
301 | /* are all tasks frozen? */ | |
72ec7029 | 302 | css_task_iter_start(css, &it); |
b4d18311 | 303 | |
72ec7029 | 304 | while ((task = css_task_iter_next(&it))) { |
3c426d5e | 305 | if (freezing(task)) { |
3c426d5e TH |
306 | /* |
307 | * freezer_should_skip() indicates that the task | |
308 | * should be skipped when determining freezing | |
309 | * completion. Consider it frozen in addition to | |
310 | * the usual frozen condition. | |
311 | */ | |
5d8f72b5 | 312 | if (!frozen(task) && !freezer_should_skip(task)) |
ef9fe980 | 313 | goto out_iter_end; |
3c426d5e | 314 | } |
dc52ddc0 MH |
315 | } |
316 | ||
d6a2fe13 | 317 | freezer->state |= CGROUP_FROZEN; |
ef9fe980 | 318 | out_iter_end: |
72ec7029 | 319 | css_task_iter_end(&it); |
ef9fe980 TH |
320 | out_unlock: |
321 | spin_unlock_irq(&freezer->lock); | |
dc52ddc0 MH |
322 | } |
323 | ||
2da8ca82 | 324 | static int freezer_read(struct seq_file *m, void *v) |
dc52ddc0 | 325 | { |
2da8ca82 | 326 | struct cgroup_subsys_state *css = seq_css(m), *pos; |
dc52ddc0 | 327 | |
ef9fe980 | 328 | rcu_read_lock(); |
dc52ddc0 | 329 | |
ef9fe980 | 330 | /* update states bottom-up */ |
492eb21b TH |
331 | css_for_each_descendant_post(pos, css) |
332 | update_if_frozen(pos); | |
ef9fe980 TH |
333 | |
334 | rcu_read_unlock(); | |
335 | ||
182446d0 | 336 | seq_puts(m, freezer_state_strs(css_freezer(css)->state)); |
dc52ddc0 MH |
337 | seq_putc(m, '\n'); |
338 | return 0; | |
339 | } | |
340 | ||
bcd66c89 | 341 | static void freeze_cgroup(struct freezer *freezer) |
dc52ddc0 | 342 | { |
72ec7029 | 343 | struct css_task_iter it; |
dc52ddc0 | 344 | struct task_struct *task; |
dc52ddc0 | 345 | |
72ec7029 TH |
346 | css_task_iter_start(&freezer->css, &it); |
347 | while ((task = css_task_iter_next(&it))) | |
51f246ed | 348 | freeze_task(task); |
72ec7029 | 349 | css_task_iter_end(&it); |
dc52ddc0 MH |
350 | } |
351 | ||
bcd66c89 | 352 | static void unfreeze_cgroup(struct freezer *freezer) |
dc52ddc0 | 353 | { |
72ec7029 | 354 | struct css_task_iter it; |
dc52ddc0 MH |
355 | struct task_struct *task; |
356 | ||
72ec7029 TH |
357 | css_task_iter_start(&freezer->css, &it); |
358 | while ((task = css_task_iter_next(&it))) | |
a5be2d0d | 359 | __thaw_task(task); |
72ec7029 | 360 | css_task_iter_end(&it); |
dc52ddc0 MH |
361 | } |
362 | ||
04a4ec32 TH |
363 | /** |
364 | * freezer_apply_state - apply state change to a single cgroup_freezer | |
365 | * @freezer: freezer to apply state change to | |
366 | * @freeze: whether to freeze or unfreeze | |
a2252180 TH |
367 | * @state: CGROUP_FREEZING_* flag to set or clear |
368 | * | |
369 | * Set or clear @state on @cgroup according to @freeze, and perform | |
370 | * freezing or thawing as necessary. | |
04a4ec32 | 371 | */ |
a2252180 TH |
372 | static void freezer_apply_state(struct freezer *freezer, bool freeze, |
373 | unsigned int state) | |
dc52ddc0 | 374 | { |
ead5c473 | 375 | /* also synchronizes against task migration, see freezer_attach() */ |
04a4ec32 | 376 | lockdep_assert_held(&freezer->lock); |
51308ee5 | 377 | |
5300a9b3 TH |
378 | if (!(freezer->state & CGROUP_FREEZER_ONLINE)) |
379 | return; | |
380 | ||
04a4ec32 | 381 | if (freeze) { |
d6a2fe13 | 382 | if (!(freezer->state & CGROUP_FREEZING)) |
a3201227 | 383 | atomic_inc(&system_freezing_cnt); |
a2252180 | 384 | freezer->state |= state; |
bcd66c89 | 385 | freeze_cgroup(freezer); |
04a4ec32 | 386 | } else { |
a2252180 TH |
387 | bool was_freezing = freezer->state & CGROUP_FREEZING; |
388 | ||
389 | freezer->state &= ~state; | |
390 | ||
391 | if (!(freezer->state & CGROUP_FREEZING)) { | |
392 | if (was_freezing) | |
393 | atomic_dec(&system_freezing_cnt); | |
394 | freezer->state &= ~CGROUP_FROZEN; | |
395 | unfreeze_cgroup(freezer); | |
396 | } | |
dc52ddc0 | 397 | } |
04a4ec32 | 398 | } |
22b4e111 | 399 | |
04a4ec32 TH |
400 | /** |
401 | * freezer_change_state - change the freezing state of a cgroup_freezer | |
402 | * @freezer: freezer of interest | |
403 | * @freeze: whether to freeze or thaw | |
404 | * | |
ef9fe980 TH |
405 | * Freeze or thaw @freezer according to @freeze. The operations are |
406 | * recursive - all descendants of @freezer will be affected. | |
04a4ec32 TH |
407 | */ |
408 | static void freezer_change_state(struct freezer *freezer, bool freeze) | |
409 | { | |
492eb21b | 410 | struct cgroup_subsys_state *pos; |
ef9fe980 | 411 | |
ef9fe980 TH |
412 | /* |
413 | * Update all its descendants in pre-order traversal. Each | |
414 | * descendant will try to inherit its parent's FREEZING state as | |
415 | * CGROUP_FREEZING_PARENT. | |
416 | */ | |
417 | rcu_read_lock(); | |
492eb21b TH |
418 | css_for_each_descendant_pre(pos, &freezer->css) { |
419 | struct freezer *pos_f = css_freezer(pos); | |
ef9fe980 TH |
420 | struct freezer *parent = parent_freezer(pos_f); |
421 | ||
ef9fe980 | 422 | spin_lock_irq(&pos_f->lock); |
bd8815a6 TH |
423 | |
424 | if (pos_f == freezer) { | |
425 | freezer_apply_state(pos_f, freeze, | |
426 | CGROUP_FREEZING_SELF); | |
427 | } else { | |
428 | /* | |
429 | * Our update to @parent->state is already visible | |
430 | * which is all we need. No need to lock @parent. | |
431 | * For more info on synchronization, see | |
432 | * freezer_post_create(). | |
433 | */ | |
434 | freezer_apply_state(pos_f, | |
435 | parent->state & CGROUP_FREEZING, | |
436 | CGROUP_FREEZING_PARENT); | |
437 | } | |
438 | ||
ef9fe980 TH |
439 | spin_unlock_irq(&pos_f->lock); |
440 | } | |
441 | rcu_read_unlock(); | |
dc52ddc0 MH |
442 | } |
443 | ||
182446d0 | 444 | static int freezer_write(struct cgroup_subsys_state *css, struct cftype *cft, |
4d3bb511 | 445 | char *buffer) |
dc52ddc0 | 446 | { |
04a4ec32 | 447 | bool freeze; |
dc52ddc0 | 448 | |
d6a2fe13 | 449 | if (strcmp(buffer, freezer_state_strs(0)) == 0) |
04a4ec32 | 450 | freeze = false; |
d6a2fe13 | 451 | else if (strcmp(buffer, freezer_state_strs(CGROUP_FROZEN)) == 0) |
04a4ec32 | 452 | freeze = true; |
dc52ddc0 | 453 | else |
3b1b3f6e | 454 | return -EINVAL; |
dc52ddc0 | 455 | |
182446d0 | 456 | freezer_change_state(css_freezer(css), freeze); |
51f246ed | 457 | return 0; |
dc52ddc0 MH |
458 | } |
459 | ||
182446d0 TH |
460 | static u64 freezer_self_freezing_read(struct cgroup_subsys_state *css, |
461 | struct cftype *cft) | |
a2252180 | 462 | { |
182446d0 | 463 | struct freezer *freezer = css_freezer(css); |
a2252180 TH |
464 | |
465 | return (bool)(freezer->state & CGROUP_FREEZING_SELF); | |
466 | } | |
467 | ||
182446d0 TH |
468 | static u64 freezer_parent_freezing_read(struct cgroup_subsys_state *css, |
469 | struct cftype *cft) | |
a2252180 | 470 | { |
182446d0 | 471 | struct freezer *freezer = css_freezer(css); |
a2252180 TH |
472 | |
473 | return (bool)(freezer->state & CGROUP_FREEZING_PARENT); | |
474 | } | |
475 | ||
dc52ddc0 MH |
476 | static struct cftype files[] = { |
477 | { | |
478 | .name = "state", | |
4baf6e33 | 479 | .flags = CFTYPE_NOT_ON_ROOT, |
2da8ca82 | 480 | .seq_show = freezer_read, |
dc52ddc0 MH |
481 | .write_string = freezer_write, |
482 | }, | |
a2252180 TH |
483 | { |
484 | .name = "self_freezing", | |
485 | .flags = CFTYPE_NOT_ON_ROOT, | |
486 | .read_u64 = freezer_self_freezing_read, | |
487 | }, | |
488 | { | |
489 | .name = "parent_freezing", | |
490 | .flags = CFTYPE_NOT_ON_ROOT, | |
491 | .read_u64 = freezer_parent_freezing_read, | |
492 | }, | |
4baf6e33 | 493 | { } /* terminate */ |
dc52ddc0 MH |
494 | }; |
495 | ||
073219e9 | 496 | struct cgroup_subsys freezer_cgrp_subsys = { |
92fb9748 TH |
497 | .css_alloc = freezer_css_alloc, |
498 | .css_online = freezer_css_online, | |
499 | .css_offline = freezer_css_offline, | |
500 | .css_free = freezer_css_free, | |
8755ade6 | 501 | .attach = freezer_attach, |
dc52ddc0 | 502 | .fork = freezer_fork, |
4baf6e33 | 503 | .base_cftypes = files, |
dc52ddc0 | 504 | }; |