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1/* SPDX-License-Identifier: GPL-2.0 */ 2#ifndef _LINUX_CGROUP_H 3#define _LINUX_CGROUP_H 4/* 5 * cgroup interface 6 * 7 * Copyright (C) 2003 BULL SA 8 * Copyright (C) 2004-2006 Silicon Graphics, Inc. 9 * 10 */ 11 12#include <linux/sched.h> 13#include <linux/nodemask.h> 14#include <linux/list.h> 15#include <linux/rculist.h> 16#include <linux/cgroupstats.h> 17#include <linux/fs.h> 18#include <linux/seq_file.h> 19#include <linux/kernfs.h> 20#include <linux/jump_label.h> 21#include <linux/types.h> 22#include <linux/ns_common.h> 23#include <linux/nsproxy.h> 24#include <linux/user_namespace.h> 25#include <linux/refcount.h> 26#include <linux/kernel_stat.h> 27 28#include <linux/cgroup-defs.h> 29 30struct kernel_clone_args; 31 32/* 33 * All weight knobs on the default hierarchy should use the following min, 34 * default and max values. The default value is the logarithmic center of 35 * MIN and MAX and allows 100x to be expressed in both directions. 36 */ 37#define CGROUP_WEIGHT_MIN 1 38#define CGROUP_WEIGHT_DFL 100 39#define CGROUP_WEIGHT_MAX 10000 40 41#ifdef CONFIG_CGROUPS 42 43enum { 44 CSS_TASK_ITER_PROCS = (1U << 0), /* walk only threadgroup leaders */ 45 CSS_TASK_ITER_THREADED = (1U << 1), /* walk all threaded css_sets in the domain */ 46 CSS_TASK_ITER_SKIPPED = (1U << 16), /* internal flags */ 47}; 48 49/* a css_task_iter should be treated as an opaque object */ 50struct css_task_iter { 51 struct cgroup_subsys *ss; 52 unsigned int flags; 53 54 struct list_head *cset_pos; 55 struct list_head *cset_head; 56 57 struct list_head *tcset_pos; 58 struct list_head *tcset_head; 59 60 struct list_head *task_pos; 61 62 struct list_head *cur_tasks_head; 63 struct css_set *cur_cset; 64 struct css_set *cur_dcset; 65 struct task_struct *cur_task; 66 struct list_head iters_node; /* css_set->task_iters */ 67}; 68 69extern struct file_system_type cgroup_fs_type; 70extern struct cgroup_root cgrp_dfl_root; 71extern struct css_set init_css_set; 72extern spinlock_t css_set_lock; 73 74#define SUBSYS(_x) extern struct cgroup_subsys _x ## _cgrp_subsys; 75#include <linux/cgroup_subsys.h> 76#undef SUBSYS 77 78#define SUBSYS(_x) \ 79 extern struct static_key_true _x ## _cgrp_subsys_enabled_key; \ 80 extern struct static_key_true _x ## _cgrp_subsys_on_dfl_key; 81#include <linux/cgroup_subsys.h> 82#undef SUBSYS 83 84/** 85 * cgroup_subsys_enabled - fast test on whether a subsys is enabled 86 * @ss: subsystem in question 87 */ 88#define cgroup_subsys_enabled(ss) \ 89 static_branch_likely(&ss ## _enabled_key) 90 91/** 92 * cgroup_subsys_on_dfl - fast test on whether a subsys is on default hierarchy 93 * @ss: subsystem in question 94 */ 95#define cgroup_subsys_on_dfl(ss) \ 96 static_branch_likely(&ss ## _on_dfl_key) 97 98bool css_has_online_children(struct cgroup_subsys_state *css); 99struct cgroup_subsys_state *css_from_id(int id, struct cgroup_subsys *ss); 100struct cgroup_subsys_state *cgroup_e_css(struct cgroup *cgroup, 101 struct cgroup_subsys *ss); 102struct cgroup_subsys_state *cgroup_get_e_css(struct cgroup *cgroup, 103 struct cgroup_subsys *ss); 104struct cgroup_subsys_state *css_tryget_online_from_dir(struct dentry *dentry, 105 struct cgroup_subsys *ss); 106 107struct cgroup *cgroup_get_from_path(const char *path); 108struct cgroup *cgroup_get_from_fd(int fd); 109struct cgroup *cgroup_v1v2_get_from_fd(int fd); 110 111int cgroup_attach_task_all(struct task_struct *from, struct task_struct *); 112int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from); 113 114int cgroup_add_dfl_cftypes(struct cgroup_subsys *ss, struct cftype *cfts); 115int cgroup_add_legacy_cftypes(struct cgroup_subsys *ss, struct cftype *cfts); 116int cgroup_add_cftypes(struct cgroup_subsys *ss, struct cftype *cfts); 117int cgroup_rm_cftypes(struct cftype *cfts); 118void cgroup_file_notify(struct cgroup_file *cfile); 119void cgroup_file_show(struct cgroup_file *cfile, bool show); 120 121int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry); 122int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns, 123 struct pid *pid, struct task_struct *tsk); 124 125void cgroup_fork(struct task_struct *p); 126extern int cgroup_can_fork(struct task_struct *p, 127 struct kernel_clone_args *kargs); 128extern void cgroup_cancel_fork(struct task_struct *p, 129 struct kernel_clone_args *kargs); 130extern void cgroup_post_fork(struct task_struct *p, 131 struct kernel_clone_args *kargs); 132void cgroup_exit(struct task_struct *p); 133void cgroup_release(struct task_struct *p); 134void cgroup_free(struct task_struct *p); 135 136int cgroup_init_early(void); 137int cgroup_init(void); 138 139int cgroup_parse_float(const char *input, unsigned dec_shift, s64 *v); 140 141/* 142 * Iteration helpers and macros. 143 */ 144 145struct cgroup_subsys_state *css_next_child(struct cgroup_subsys_state *pos, 146 struct cgroup_subsys_state *parent); 147struct cgroup_subsys_state *css_next_descendant_pre(struct cgroup_subsys_state *pos, 148 struct cgroup_subsys_state *css); 149struct cgroup_subsys_state *css_rightmost_descendant(struct cgroup_subsys_state *pos); 150struct cgroup_subsys_state *css_next_descendant_post(struct cgroup_subsys_state *pos, 151 struct cgroup_subsys_state *css); 152 153struct task_struct *cgroup_taskset_first(struct cgroup_taskset *tset, 154 struct cgroup_subsys_state **dst_cssp); 155struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset, 156 struct cgroup_subsys_state **dst_cssp); 157 158void css_task_iter_start(struct cgroup_subsys_state *css, unsigned int flags, 159 struct css_task_iter *it); 160struct task_struct *css_task_iter_next(struct css_task_iter *it); 161void css_task_iter_end(struct css_task_iter *it); 162 163/** 164 * css_for_each_child - iterate through children of a css 165 * @pos: the css * to use as the loop cursor 166 * @parent: css whose children to walk 167 * 168 * Walk @parent's children. Must be called under rcu_read_lock(). 169 * 170 * If a subsystem synchronizes ->css_online() and the start of iteration, a 171 * css which finished ->css_online() is guaranteed to be visible in the 172 * future iterations and will stay visible until the last reference is put. 173 * A css which hasn't finished ->css_online() or already finished 174 * ->css_offline() may show up during traversal. It's each subsystem's 175 * responsibility to synchronize against on/offlining. 176 * 177 * It is allowed to temporarily drop RCU read lock during iteration. The 178 * caller is responsible for ensuring that @pos remains accessible until 179 * the start of the next iteration by, for example, bumping the css refcnt. 180 */ 181#define css_for_each_child(pos, parent) \ 182 for ((pos) = css_next_child(NULL, (parent)); (pos); \ 183 (pos) = css_next_child((pos), (parent))) 184 185/** 186 * css_for_each_descendant_pre - pre-order walk of a css's descendants 187 * @pos: the css * to use as the loop cursor 188 * @root: css whose descendants to walk 189 * 190 * Walk @root's descendants. @root is included in the iteration and the 191 * first node to be visited. Must be called under rcu_read_lock(). 192 * 193 * If a subsystem synchronizes ->css_online() and the start of iteration, a 194 * css which finished ->css_online() is guaranteed to be visible in the 195 * future iterations and will stay visible until the last reference is put. 196 * A css which hasn't finished ->css_online() or already finished 197 * ->css_offline() may show up during traversal. It's each subsystem's 198 * responsibility to synchronize against on/offlining. 199 * 200 * For example, the following guarantees that a descendant can't escape 201 * state updates of its ancestors. 202 * 203 * my_online(@css) 204 * { 205 * Lock @css's parent and @css; 206 * Inherit state from the parent; 207 * Unlock both. 208 * } 209 * 210 * my_update_state(@css) 211 * { 212 * css_for_each_descendant_pre(@pos, @css) { 213 * Lock @pos; 214 * if (@pos == @css) 215 * Update @css's state; 216 * else 217 * Verify @pos is alive and inherit state from its parent; 218 * Unlock @pos; 219 * } 220 * } 221 * 222 * As long as the inheriting step, including checking the parent state, is 223 * enclosed inside @pos locking, double-locking the parent isn't necessary 224 * while inheriting. The state update to the parent is guaranteed to be 225 * visible by walking order and, as long as inheriting operations to the 226 * same @pos are atomic to each other, multiple updates racing each other 227 * still result in the correct state. It's guaranateed that at least one 228 * inheritance happens for any css after the latest update to its parent. 229 * 230 * If checking parent's state requires locking the parent, each inheriting 231 * iteration should lock and unlock both @pos->parent and @pos. 232 * 233 * Alternatively, a subsystem may choose to use a single global lock to 234 * synchronize ->css_online() and ->css_offline() against tree-walking 235 * operations. 236 * 237 * It is allowed to temporarily drop RCU read lock during iteration. The 238 * caller is responsible for ensuring that @pos remains accessible until 239 * the start of the next iteration by, for example, bumping the css refcnt. 240 */ 241#define css_for_each_descendant_pre(pos, css) \ 242 for ((pos) = css_next_descendant_pre(NULL, (css)); (pos); \ 243 (pos) = css_next_descendant_pre((pos), (css))) 244 245/** 246 * css_for_each_descendant_post - post-order walk of a css's descendants 247 * @pos: the css * to use as the loop cursor 248 * @css: css whose descendants to walk 249 * 250 * Similar to css_for_each_descendant_pre() but performs post-order 251 * traversal instead. @root is included in the iteration and the last 252 * node to be visited. 253 * 254 * If a subsystem synchronizes ->css_online() and the start of iteration, a 255 * css which finished ->css_online() is guaranteed to be visible in the 256 * future iterations and will stay visible until the last reference is put. 257 * A css which hasn't finished ->css_online() or already finished 258 * ->css_offline() may show up during traversal. It's each subsystem's 259 * responsibility to synchronize against on/offlining. 260 * 261 * Note that the walk visibility guarantee example described in pre-order 262 * walk doesn't apply the same to post-order walks. 263 */ 264#define css_for_each_descendant_post(pos, css) \ 265 for ((pos) = css_next_descendant_post(NULL, (css)); (pos); \ 266 (pos) = css_next_descendant_post((pos), (css))) 267 268/** 269 * cgroup_taskset_for_each - iterate cgroup_taskset 270 * @task: the loop cursor 271 * @dst_css: the destination css 272 * @tset: taskset to iterate 273 * 274 * @tset may contain multiple tasks and they may belong to multiple 275 * processes. 276 * 277 * On the v2 hierarchy, there may be tasks from multiple processes and they 278 * may not share the source or destination csses. 279 * 280 * On traditional hierarchies, when there are multiple tasks in @tset, if a 281 * task of a process is in @tset, all tasks of the process are in @tset. 282 * Also, all are guaranteed to share the same source and destination csses. 283 * 284 * Iteration is not in any specific order. 285 */ 286#define cgroup_taskset_for_each(task, dst_css, tset) \ 287 for ((task) = cgroup_taskset_first((tset), &(dst_css)); \ 288 (task); \ 289 (task) = cgroup_taskset_next((tset), &(dst_css))) 290 291/** 292 * cgroup_taskset_for_each_leader - iterate group leaders in a cgroup_taskset 293 * @leader: the loop cursor 294 * @dst_css: the destination css 295 * @tset: taskset to iterate 296 * 297 * Iterate threadgroup leaders of @tset. For single-task migrations, @tset 298 * may not contain any. 299 */ 300#define cgroup_taskset_for_each_leader(leader, dst_css, tset) \ 301 for ((leader) = cgroup_taskset_first((tset), &(dst_css)); \ 302 (leader); \ 303 (leader) = cgroup_taskset_next((tset), &(dst_css))) \ 304 if ((leader) != (leader)->group_leader) \ 305 ; \ 306 else 307 308/* 309 * Inline functions. 310 */ 311 312#ifdef CONFIG_DEBUG_CGROUP_REF 313void css_get(struct cgroup_subsys_state *css); 314void css_get_many(struct cgroup_subsys_state *css, unsigned int n); 315bool css_tryget(struct cgroup_subsys_state *css); 316bool css_tryget_online(struct cgroup_subsys_state *css); 317void css_put(struct cgroup_subsys_state *css); 318void css_put_many(struct cgroup_subsys_state *css, unsigned int n); 319#else 320#define CGROUP_REF_FN_ATTRS static inline 321#define CGROUP_REF_EXPORT(fn) 322#include <linux/cgroup_refcnt.h> 323#endif 324 325static inline u64 cgroup_id(const struct cgroup *cgrp) 326{ 327 return cgrp->kn->id; 328} 329 330/** 331 * css_is_dying - test whether the specified css is dying 332 * @css: target css 333 * 334 * Test whether @css is in the process of offlining or already offline. In 335 * most cases, ->css_online() and ->css_offline() callbacks should be 336 * enough; however, the actual offline operations are RCU delayed and this 337 * test returns %true also when @css is scheduled to be offlined. 338 * 339 * This is useful, for example, when the use case requires synchronous 340 * behavior with respect to cgroup removal. cgroup removal schedules css 341 * offlining but the css can seem alive while the operation is being 342 * delayed. If the delay affects user visible semantics, this test can be 343 * used to resolve the situation. 344 */ 345static inline bool css_is_dying(struct cgroup_subsys_state *css) 346{ 347 return css->flags & CSS_DYING; 348} 349 350static inline void cgroup_get(struct cgroup *cgrp) 351{ 352 css_get(&cgrp->self); 353} 354 355static inline bool cgroup_tryget(struct cgroup *cgrp) 356{ 357 return css_tryget(&cgrp->self); 358} 359 360static inline void cgroup_put(struct cgroup *cgrp) 361{ 362 css_put(&cgrp->self); 363} 364 365extern struct mutex cgroup_mutex; 366 367static inline void cgroup_lock(void) 368{ 369 mutex_lock(&cgroup_mutex); 370} 371 372static inline void cgroup_unlock(void) 373{ 374 mutex_unlock(&cgroup_mutex); 375} 376 377/** 378 * task_css_set_check - obtain a task's css_set with extra access conditions 379 * @task: the task to obtain css_set for 380 * @__c: extra condition expression to be passed to rcu_dereference_check() 381 * 382 * A task's css_set is RCU protected, initialized and exited while holding 383 * task_lock(), and can only be modified while holding both cgroup_mutex 384 * and task_lock() while the task is alive. This macro verifies that the 385 * caller is inside proper critical section and returns @task's css_set. 386 * 387 * The caller can also specify additional allowed conditions via @__c, such 388 * as locks used during the cgroup_subsys::attach() methods. 389 */ 390#ifdef CONFIG_PROVE_RCU 391#define task_css_set_check(task, __c) \ 392 rcu_dereference_check((task)->cgroups, \ 393 rcu_read_lock_sched_held() || \ 394 lockdep_is_held(&cgroup_mutex) || \ 395 lockdep_is_held(&css_set_lock) || \ 396 ((task)->flags & PF_EXITING) || (__c)) 397#else 398#define task_css_set_check(task, __c) \ 399 rcu_dereference((task)->cgroups) 400#endif 401 402/** 403 * task_css_check - obtain css for (task, subsys) w/ extra access conds 404 * @task: the target task 405 * @subsys_id: the target subsystem ID 406 * @__c: extra condition expression to be passed to rcu_dereference_check() 407 * 408 * Return the cgroup_subsys_state for the (@task, @subsys_id) pair. The 409 * synchronization rules are the same as task_css_set_check(). 410 */ 411#define task_css_check(task, subsys_id, __c) \ 412 task_css_set_check((task), (__c))->subsys[(subsys_id)] 413 414/** 415 * task_css_set - obtain a task's css_set 416 * @task: the task to obtain css_set for 417 * 418 * See task_css_set_check(). 419 */ 420static inline struct css_set *task_css_set(struct task_struct *task) 421{ 422 return task_css_set_check(task, false); 423} 424 425/** 426 * task_css - obtain css for (task, subsys) 427 * @task: the target task 428 * @subsys_id: the target subsystem ID 429 * 430 * See task_css_check(). 431 */ 432static inline struct cgroup_subsys_state *task_css(struct task_struct *task, 433 int subsys_id) 434{ 435 return task_css_check(task, subsys_id, false); 436} 437 438/** 439 * task_get_css - find and get the css for (task, subsys) 440 * @task: the target task 441 * @subsys_id: the target subsystem ID 442 * 443 * Find the css for the (@task, @subsys_id) combination, increment a 444 * reference on and return it. This function is guaranteed to return a 445 * valid css. The returned css may already have been offlined. 446 */ 447static inline struct cgroup_subsys_state * 448task_get_css(struct task_struct *task, int subsys_id) 449{ 450 struct cgroup_subsys_state *css; 451 452 rcu_read_lock(); 453 while (true) { 454 css = task_css(task, subsys_id); 455 /* 456 * Can't use css_tryget_online() here. A task which has 457 * PF_EXITING set may stay associated with an offline css. 458 * If such task calls this function, css_tryget_online() 459 * will keep failing. 460 */ 461 if (likely(css_tryget(css))) 462 break; 463 cpu_relax(); 464 } 465 rcu_read_unlock(); 466 return css; 467} 468 469/** 470 * task_css_is_root - test whether a task belongs to the root css 471 * @task: the target task 472 * @subsys_id: the target subsystem ID 473 * 474 * Test whether @task belongs to the root css on the specified subsystem. 475 * May be invoked in any context. 476 */ 477static inline bool task_css_is_root(struct task_struct *task, int subsys_id) 478{ 479 return task_css_check(task, subsys_id, true) == 480 init_css_set.subsys[subsys_id]; 481} 482 483static inline struct cgroup *task_cgroup(struct task_struct *task, 484 int subsys_id) 485{ 486 return task_css(task, subsys_id)->cgroup; 487} 488 489static inline struct cgroup *task_dfl_cgroup(struct task_struct *task) 490{ 491 return task_css_set(task)->dfl_cgrp; 492} 493 494static inline struct cgroup *cgroup_parent(struct cgroup *cgrp) 495{ 496 struct cgroup_subsys_state *parent_css = cgrp->self.parent; 497 498 if (parent_css) 499 return container_of(parent_css, struct cgroup, self); 500 return NULL; 501} 502 503/** 504 * cgroup_is_descendant - test ancestry 505 * @cgrp: the cgroup to be tested 506 * @ancestor: possible ancestor of @cgrp 507 * 508 * Test whether @cgrp is a descendant of @ancestor. It also returns %true 509 * if @cgrp == @ancestor. This function is safe to call as long as @cgrp 510 * and @ancestor are accessible. 511 */ 512static inline bool cgroup_is_descendant(struct cgroup *cgrp, 513 struct cgroup *ancestor) 514{ 515 if (cgrp->root != ancestor->root || cgrp->level < ancestor->level) 516 return false; 517 return cgrp->ancestors[ancestor->level] == ancestor; 518} 519 520/** 521 * cgroup_ancestor - find ancestor of cgroup 522 * @cgrp: cgroup to find ancestor of 523 * @ancestor_level: level of ancestor to find starting from root 524 * 525 * Find ancestor of cgroup at specified level starting from root if it exists 526 * and return pointer to it. Return NULL if @cgrp doesn't have ancestor at 527 * @ancestor_level. 528 * 529 * This function is safe to call as long as @cgrp is accessible. 530 */ 531static inline struct cgroup *cgroup_ancestor(struct cgroup *cgrp, 532 int ancestor_level) 533{ 534 if (ancestor_level < 0 || ancestor_level > cgrp->level) 535 return NULL; 536 return cgrp->ancestors[ancestor_level]; 537} 538 539/** 540 * task_under_cgroup_hierarchy - test task's membership of cgroup ancestry 541 * @task: the task to be tested 542 * @ancestor: possible ancestor of @task's cgroup 543 * 544 * Tests whether @task's default cgroup hierarchy is a descendant of @ancestor. 545 * It follows all the same rules as cgroup_is_descendant, and only applies 546 * to the default hierarchy. 547 */ 548static inline bool task_under_cgroup_hierarchy(struct task_struct *task, 549 struct cgroup *ancestor) 550{ 551 struct css_set *cset = task_css_set(task); 552 553 return cgroup_is_descendant(cset->dfl_cgrp, ancestor); 554} 555 556/* no synchronization, the result can only be used as a hint */ 557static inline bool cgroup_is_populated(struct cgroup *cgrp) 558{ 559 return cgrp->nr_populated_csets + cgrp->nr_populated_domain_children + 560 cgrp->nr_populated_threaded_children; 561} 562 563/* returns ino associated with a cgroup */ 564static inline ino_t cgroup_ino(struct cgroup *cgrp) 565{ 566 return kernfs_ino(cgrp->kn); 567} 568 569/* cft/css accessors for cftype->write() operation */ 570static inline struct cftype *of_cft(struct kernfs_open_file *of) 571{ 572 return of->kn->priv; 573} 574 575struct cgroup_subsys_state *of_css(struct kernfs_open_file *of); 576 577/* cft/css accessors for cftype->seq_*() operations */ 578static inline struct cftype *seq_cft(struct seq_file *seq) 579{ 580 return of_cft(seq->private); 581} 582 583static inline struct cgroup_subsys_state *seq_css(struct seq_file *seq) 584{ 585 return of_css(seq->private); 586} 587 588/* 589 * Name / path handling functions. All are thin wrappers around the kernfs 590 * counterparts and can be called under any context. 591 */ 592 593static inline int cgroup_name(struct cgroup *cgrp, char *buf, size_t buflen) 594{ 595 return kernfs_name(cgrp->kn, buf, buflen); 596} 597 598static inline int cgroup_path(struct cgroup *cgrp, char *buf, size_t buflen) 599{ 600 return kernfs_path(cgrp->kn, buf, buflen); 601} 602 603static inline void pr_cont_cgroup_name(struct cgroup *cgrp) 604{ 605 pr_cont_kernfs_name(cgrp->kn); 606} 607 608static inline void pr_cont_cgroup_path(struct cgroup *cgrp) 609{ 610 pr_cont_kernfs_path(cgrp->kn); 611} 612 613bool cgroup_psi_enabled(void); 614 615static inline void cgroup_init_kthreadd(void) 616{ 617 /* 618 * kthreadd is inherited by all kthreads, keep it in the root so 619 * that the new kthreads are guaranteed to stay in the root until 620 * initialization is finished. 621 */ 622 current->no_cgroup_migration = 1; 623} 624 625static inline void cgroup_kthread_ready(void) 626{ 627 /* 628 * This kthread finished initialization. The creator should have 629 * set PF_NO_SETAFFINITY if this kthread should stay in the root. 630 */ 631 current->no_cgroup_migration = 0; 632} 633 634void cgroup_path_from_kernfs_id(u64 id, char *buf, size_t buflen); 635struct cgroup *cgroup_get_from_id(u64 id); 636#else /* !CONFIG_CGROUPS */ 637 638struct cgroup_subsys_state; 639struct cgroup; 640 641static inline u64 cgroup_id(const struct cgroup *cgrp) { return 1; } 642static inline void css_get(struct cgroup_subsys_state *css) {} 643static inline void css_put(struct cgroup_subsys_state *css) {} 644static inline void cgroup_lock(void) {} 645static inline void cgroup_unlock(void) {} 646static inline int cgroup_attach_task_all(struct task_struct *from, 647 struct task_struct *t) { return 0; } 648static inline int cgroupstats_build(struct cgroupstats *stats, 649 struct dentry *dentry) { return -EINVAL; } 650 651static inline void cgroup_fork(struct task_struct *p) {} 652static inline int cgroup_can_fork(struct task_struct *p, 653 struct kernel_clone_args *kargs) { return 0; } 654static inline void cgroup_cancel_fork(struct task_struct *p, 655 struct kernel_clone_args *kargs) {} 656static inline void cgroup_post_fork(struct task_struct *p, 657 struct kernel_clone_args *kargs) {} 658static inline void cgroup_exit(struct task_struct *p) {} 659static inline void cgroup_release(struct task_struct *p) {} 660static inline void cgroup_free(struct task_struct *p) {} 661 662static inline int cgroup_init_early(void) { return 0; } 663static inline int cgroup_init(void) { return 0; } 664static inline void cgroup_init_kthreadd(void) {} 665static inline void cgroup_kthread_ready(void) {} 666 667static inline struct cgroup *cgroup_parent(struct cgroup *cgrp) 668{ 669 return NULL; 670} 671 672static inline bool cgroup_psi_enabled(void) 673{ 674 return false; 675} 676 677static inline bool task_under_cgroup_hierarchy(struct task_struct *task, 678 struct cgroup *ancestor) 679{ 680 return true; 681} 682 683static inline void cgroup_path_from_kernfs_id(u64 id, char *buf, size_t buflen) 684{} 685#endif /* !CONFIG_CGROUPS */ 686 687#ifdef CONFIG_CGROUPS 688/* 689 * cgroup scalable recursive statistics. 690 */ 691void cgroup_rstat_updated(struct cgroup *cgrp, int cpu); 692void cgroup_rstat_flush(struct cgroup *cgrp); 693 694/* 695 * Basic resource stats. 696 */ 697#ifdef CONFIG_CGROUP_CPUACCT 698void cpuacct_charge(struct task_struct *tsk, u64 cputime); 699void cpuacct_account_field(struct task_struct *tsk, int index, u64 val); 700#else 701static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {} 702static inline void cpuacct_account_field(struct task_struct *tsk, int index, 703 u64 val) {} 704#endif 705 706void __cgroup_account_cputime(struct cgroup *cgrp, u64 delta_exec); 707void __cgroup_account_cputime_field(struct cgroup *cgrp, 708 enum cpu_usage_stat index, u64 delta_exec); 709 710static inline void cgroup_account_cputime(struct task_struct *task, 711 u64 delta_exec) 712{ 713 struct cgroup *cgrp; 714 715 cpuacct_charge(task, delta_exec); 716 717 cgrp = task_dfl_cgroup(task); 718 if (cgroup_parent(cgrp)) 719 __cgroup_account_cputime(cgrp, delta_exec); 720} 721 722static inline void cgroup_account_cputime_field(struct task_struct *task, 723 enum cpu_usage_stat index, 724 u64 delta_exec) 725{ 726 struct cgroup *cgrp; 727 728 cpuacct_account_field(task, index, delta_exec); 729 730 cgrp = task_dfl_cgroup(task); 731 if (cgroup_parent(cgrp)) 732 __cgroup_account_cputime_field(cgrp, index, delta_exec); 733} 734 735#else /* CONFIG_CGROUPS */ 736 737static inline void cgroup_account_cputime(struct task_struct *task, 738 u64 delta_exec) {} 739static inline void cgroup_account_cputime_field(struct task_struct *task, 740 enum cpu_usage_stat index, 741 u64 delta_exec) {} 742 743#endif /* CONFIG_CGROUPS */ 744 745/* 746 * sock->sk_cgrp_data handling. For more info, see sock_cgroup_data 747 * definition in cgroup-defs.h. 748 */ 749#ifdef CONFIG_SOCK_CGROUP_DATA 750 751void cgroup_sk_alloc(struct sock_cgroup_data *skcd); 752void cgroup_sk_clone(struct sock_cgroup_data *skcd); 753void cgroup_sk_free(struct sock_cgroup_data *skcd); 754 755static inline struct cgroup *sock_cgroup_ptr(struct sock_cgroup_data *skcd) 756{ 757 return skcd->cgroup; 758} 759 760#else /* CONFIG_CGROUP_DATA */ 761 762static inline void cgroup_sk_alloc(struct sock_cgroup_data *skcd) {} 763static inline void cgroup_sk_clone(struct sock_cgroup_data *skcd) {} 764static inline void cgroup_sk_free(struct sock_cgroup_data *skcd) {} 765 766#endif /* CONFIG_CGROUP_DATA */ 767 768struct cgroup_namespace { 769 struct ns_common ns; 770 struct user_namespace *user_ns; 771 struct ucounts *ucounts; 772 struct css_set *root_cset; 773}; 774 775extern struct cgroup_namespace init_cgroup_ns; 776 777#ifdef CONFIG_CGROUPS 778 779void free_cgroup_ns(struct cgroup_namespace *ns); 780 781struct cgroup_namespace *copy_cgroup_ns(unsigned long flags, 782 struct user_namespace *user_ns, 783 struct cgroup_namespace *old_ns); 784 785int cgroup_path_ns(struct cgroup *cgrp, char *buf, size_t buflen, 786 struct cgroup_namespace *ns); 787 788#else /* !CONFIG_CGROUPS */ 789 790static inline void free_cgroup_ns(struct cgroup_namespace *ns) { } 791static inline struct cgroup_namespace * 792copy_cgroup_ns(unsigned long flags, struct user_namespace *user_ns, 793 struct cgroup_namespace *old_ns) 794{ 795 return old_ns; 796} 797 798#endif /* !CONFIG_CGROUPS */ 799 800static inline void get_cgroup_ns(struct cgroup_namespace *ns) 801{ 802 if (ns) 803 refcount_inc(&ns->ns.count); 804} 805 806static inline void put_cgroup_ns(struct cgroup_namespace *ns) 807{ 808 if (ns && refcount_dec_and_test(&ns->ns.count)) 809 free_cgroup_ns(ns); 810} 811 812#ifdef CONFIG_CGROUPS 813 814void cgroup_enter_frozen(void); 815void cgroup_leave_frozen(bool always_leave); 816void cgroup_update_frozen(struct cgroup *cgrp); 817void cgroup_freeze(struct cgroup *cgrp, bool freeze); 818void cgroup_freezer_migrate_task(struct task_struct *task, struct cgroup *src, 819 struct cgroup *dst); 820 821static inline bool cgroup_task_frozen(struct task_struct *task) 822{ 823 return task->frozen; 824} 825 826#else /* !CONFIG_CGROUPS */ 827 828static inline void cgroup_enter_frozen(void) { } 829static inline void cgroup_leave_frozen(bool always_leave) { } 830static inline bool cgroup_task_frozen(struct task_struct *task) 831{ 832 return false; 833} 834 835#endif /* !CONFIG_CGROUPS */ 836 837#ifdef CONFIG_CGROUP_BPF 838static inline void cgroup_bpf_get(struct cgroup *cgrp) 839{ 840 percpu_ref_get(&cgrp->bpf.refcnt); 841} 842 843static inline void cgroup_bpf_put(struct cgroup *cgrp) 844{ 845 percpu_ref_put(&cgrp->bpf.refcnt); 846} 847 848#else /* CONFIG_CGROUP_BPF */ 849 850static inline void cgroup_bpf_get(struct cgroup *cgrp) {} 851static inline void cgroup_bpf_put(struct cgroup *cgrp) {} 852 853#endif /* CONFIG_CGROUP_BPF */ 854 855struct cgroup *task_get_cgroup1(struct task_struct *tsk, int hierarchy_id); 856 857struct cgroup_of_peak *of_peak(struct kernfs_open_file *of); 858 859#endif /* _LINUX_CGROUP_H */