1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_CGROUP_H
3 #define _LINUX_CGROUP_H
7 * Copyright (C) 2003 BULL SA
8 * Copyright (C) 2004-2006 Silicon Graphics, Inc.
12 #include <linux/sched.h>
13 #include <linux/cpumask.h>
14 #include <linux/nodemask.h>
15 #include <linux/rculist.h>
16 #include <linux/cgroupstats.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>
27 #include <linux/cgroup-defs.h>
32 * All weight knobs on the default hierarhcy should use the following min,
33 * default and max values. The default value is the logarithmic center of
34 * MIN and MAX and allows 100x to be expressed in both directions.
36 #define CGROUP_WEIGHT_MIN 1
37 #define CGROUP_WEIGHT_DFL 100
38 #define CGROUP_WEIGHT_MAX 10000
40 /* walk only threadgroup leaders */
41 #define CSS_TASK_ITER_PROCS (1U << 0)
42 /* walk all threaded css_sets in the domain */
43 #define CSS_TASK_ITER_THREADED (1U << 1)
45 /* a css_task_iter should be treated as an opaque object */
46 struct css_task_iter
{
47 struct cgroup_subsys
*ss
;
50 struct list_head
*cset_pos
;
51 struct list_head
*cset_head
;
53 struct list_head
*tcset_pos
;
54 struct list_head
*tcset_head
;
56 struct list_head
*task_pos
;
57 struct list_head
*tasks_head
;
58 struct list_head
*mg_tasks_head
;
60 struct css_set
*cur_cset
;
61 struct css_set
*cur_dcset
;
62 struct task_struct
*cur_task
;
63 struct list_head iters_node
; /* css_set->task_iters */
66 extern struct cgroup_root cgrp_dfl_root
;
67 extern struct css_set init_css_set
;
69 #define SUBSYS(_x) extern struct cgroup_subsys _x ## _cgrp_subsys;
70 #include <linux/cgroup_subsys.h>
74 extern struct static_key_true _x ## _cgrp_subsys_enabled_key; \
75 extern struct static_key_true _x ## _cgrp_subsys_on_dfl_key;
76 #include <linux/cgroup_subsys.h>
80 * cgroup_subsys_enabled - fast test on whether a subsys is enabled
81 * @ss: subsystem in question
83 #define cgroup_subsys_enabled(ss) \
84 static_branch_likely(&ss ## _enabled_key)
87 * cgroup_subsys_on_dfl - fast test on whether a subsys is on default hierarchy
88 * @ss: subsystem in question
90 #define cgroup_subsys_on_dfl(ss) \
91 static_branch_likely(&ss ## _on_dfl_key)
93 bool css_has_online_children(struct cgroup_subsys_state
*css
);
94 struct cgroup_subsys_state
*css_from_id(int id
, struct cgroup_subsys
*ss
);
95 struct cgroup_subsys_state
*cgroup_get_e_css(struct cgroup
*cgroup
,
96 struct cgroup_subsys
*ss
);
97 struct cgroup_subsys_state
*css_tryget_online_from_dir(struct dentry
*dentry
,
98 struct cgroup_subsys
*ss
);
100 struct cgroup
*cgroup_get_from_path(const char *path
);
101 struct cgroup
*cgroup_get_from_fd(int fd
);
103 int cgroup_attach_task_all(struct task_struct
*from
, struct task_struct
*);
104 int cgroup_transfer_tasks(struct cgroup
*to
, struct cgroup
*from
);
106 int cgroup_add_dfl_cftypes(struct cgroup_subsys
*ss
, struct cftype
*cfts
);
107 int cgroup_add_legacy_cftypes(struct cgroup_subsys
*ss
, struct cftype
*cfts
);
108 int cgroup_rm_cftypes(struct cftype
*cfts
);
109 void cgroup_file_notify(struct cgroup_file
*cfile
);
111 int task_cgroup_path(struct task_struct
*task
, char *buf
, size_t buflen
);
112 int cgroupstats_build(struct cgroupstats
*stats
, struct dentry
*dentry
);
113 int proc_cgroup_show(struct seq_file
*m
, struct pid_namespace
*ns
,
114 struct pid
*pid
, struct task_struct
*tsk
);
116 void cgroup_fork(struct task_struct
*p
);
117 extern int cgroup_can_fork(struct task_struct
*p
);
118 extern void cgroup_cancel_fork(struct task_struct
*p
);
119 extern void cgroup_post_fork(struct task_struct
*p
);
120 void cgroup_exit(struct task_struct
*p
);
121 void cgroup_free(struct task_struct
*p
);
123 int cgroup_init_early(void);
124 int cgroup_init(void);
127 * Iteration helpers and macros.
130 struct cgroup_subsys_state
*css_next_child(struct cgroup_subsys_state
*pos
,
131 struct cgroup_subsys_state
*parent
);
132 struct cgroup_subsys_state
*css_next_descendant_pre(struct cgroup_subsys_state
*pos
,
133 struct cgroup_subsys_state
*css
);
134 struct cgroup_subsys_state
*css_rightmost_descendant(struct cgroup_subsys_state
*pos
);
135 struct cgroup_subsys_state
*css_next_descendant_post(struct cgroup_subsys_state
*pos
,
136 struct cgroup_subsys_state
*css
);
138 struct task_struct
*cgroup_taskset_first(struct cgroup_taskset
*tset
,
139 struct cgroup_subsys_state
**dst_cssp
);
140 struct task_struct
*cgroup_taskset_next(struct cgroup_taskset
*tset
,
141 struct cgroup_subsys_state
**dst_cssp
);
143 void css_task_iter_start(struct cgroup_subsys_state
*css
, unsigned int flags
,
144 struct css_task_iter
*it
);
145 struct task_struct
*css_task_iter_next(struct css_task_iter
*it
);
146 void css_task_iter_end(struct css_task_iter
*it
);
149 * css_for_each_child - iterate through children of a css
150 * @pos: the css * to use as the loop cursor
151 * @parent: css whose children to walk
153 * Walk @parent's children. Must be called under rcu_read_lock().
155 * If a subsystem synchronizes ->css_online() and the start of iteration, a
156 * css which finished ->css_online() is guaranteed to be visible in the
157 * future iterations and will stay visible until the last reference is put.
158 * A css which hasn't finished ->css_online() or already finished
159 * ->css_offline() may show up during traversal. It's each subsystem's
160 * responsibility to synchronize against on/offlining.
162 * It is allowed to temporarily drop RCU read lock during iteration. The
163 * caller is responsible for ensuring that @pos remains accessible until
164 * the start of the next iteration by, for example, bumping the css refcnt.
166 #define css_for_each_child(pos, parent) \
167 for ((pos) = css_next_child(NULL, (parent)); (pos); \
168 (pos) = css_next_child((pos), (parent)))
171 * css_for_each_descendant_pre - pre-order walk of a css's descendants
172 * @pos: the css * to use as the loop cursor
173 * @root: css whose descendants to walk
175 * Walk @root's descendants. @root is included in the iteration and the
176 * first node to be visited. Must be called under rcu_read_lock().
178 * If a subsystem synchronizes ->css_online() and the start of iteration, a
179 * css which finished ->css_online() is guaranteed to be visible in the
180 * future iterations and will stay visible until the last reference is put.
181 * A css which hasn't finished ->css_online() or already finished
182 * ->css_offline() may show up during traversal. It's each subsystem's
183 * responsibility to synchronize against on/offlining.
185 * For example, the following guarantees that a descendant can't escape
186 * state updates of its ancestors.
190 * Lock @css's parent and @css;
191 * Inherit state from the parent;
195 * my_update_state(@css)
197 * css_for_each_descendant_pre(@pos, @css) {
200 * Update @css's state;
202 * Verify @pos is alive and inherit state from its parent;
207 * As long as the inheriting step, including checking the parent state, is
208 * enclosed inside @pos locking, double-locking the parent isn't necessary
209 * while inheriting. The state update to the parent is guaranteed to be
210 * visible by walking order and, as long as inheriting operations to the
211 * same @pos are atomic to each other, multiple updates racing each other
212 * still result in the correct state. It's guaranateed that at least one
213 * inheritance happens for any css after the latest update to its parent.
215 * If checking parent's state requires locking the parent, each inheriting
216 * iteration should lock and unlock both @pos->parent and @pos.
218 * Alternatively, a subsystem may choose to use a single global lock to
219 * synchronize ->css_online() and ->css_offline() against tree-walking
222 * It is allowed to temporarily drop RCU read lock during iteration. The
223 * caller is responsible for ensuring that @pos remains accessible until
224 * the start of the next iteration by, for example, bumping the css refcnt.
226 #define css_for_each_descendant_pre(pos, css) \
227 for ((pos) = css_next_descendant_pre(NULL, (css)); (pos); \
228 (pos) = css_next_descendant_pre((pos), (css)))
231 * css_for_each_descendant_post - post-order walk of a css's descendants
232 * @pos: the css * to use as the loop cursor
233 * @css: css whose descendants to walk
235 * Similar to css_for_each_descendant_pre() but performs post-order
236 * traversal instead. @root is included in the iteration and the last
237 * node to be visited.
239 * If a subsystem synchronizes ->css_online() and the start of iteration, a
240 * css which finished ->css_online() is guaranteed to be visible in the
241 * future iterations and will stay visible until the last reference is put.
242 * A css which hasn't finished ->css_online() or already finished
243 * ->css_offline() may show up during traversal. It's each subsystem's
244 * responsibility to synchronize against on/offlining.
246 * Note that the walk visibility guarantee example described in pre-order
247 * walk doesn't apply the same to post-order walks.
249 #define css_for_each_descendant_post(pos, css) \
250 for ((pos) = css_next_descendant_post(NULL, (css)); (pos); \
251 (pos) = css_next_descendant_post((pos), (css)))
254 * cgroup_taskset_for_each - iterate cgroup_taskset
255 * @task: the loop cursor
256 * @dst_css: the destination css
257 * @tset: taskset to iterate
259 * @tset may contain multiple tasks and they may belong to multiple
262 * On the v2 hierarchy, there may be tasks from multiple processes and they
263 * may not share the source or destination csses.
265 * On traditional hierarchies, when there are multiple tasks in @tset, if a
266 * task of a process is in @tset, all tasks of the process are in @tset.
267 * Also, all are guaranteed to share the same source and destination csses.
269 * Iteration is not in any specific order.
271 #define cgroup_taskset_for_each(task, dst_css, tset) \
272 for ((task) = cgroup_taskset_first((tset), &(dst_css)); \
274 (task) = cgroup_taskset_next((tset), &(dst_css)))
277 * cgroup_taskset_for_each_leader - iterate group leaders in a cgroup_taskset
278 * @leader: the loop cursor
279 * @dst_css: the destination css
280 * @tset: taskset to iterate
282 * Iterate threadgroup leaders of @tset. For single-task migrations, @tset
283 * may not contain any.
285 #define cgroup_taskset_for_each_leader(leader, dst_css, tset) \
286 for ((leader) = cgroup_taskset_first((tset), &(dst_css)); \
288 (leader) = cgroup_taskset_next((tset), &(dst_css))) \
289 if ((leader) != (leader)->group_leader) \
298 * css_get - obtain a reference on the specified css
301 * The caller must already have a reference.
303 static inline void css_get(struct cgroup_subsys_state
*css
)
305 if (!(css
->flags
& CSS_NO_REF
))
306 percpu_ref_get(&css
->refcnt
);
310 * css_get_many - obtain references on the specified css
312 * @n: number of references to get
314 * The caller must already have a reference.
316 static inline void css_get_many(struct cgroup_subsys_state
*css
, unsigned int n
)
318 if (!(css
->flags
& CSS_NO_REF
))
319 percpu_ref_get_many(&css
->refcnt
, n
);
323 * css_tryget - try to obtain a reference on the specified css
326 * Obtain a reference on @css unless it already has reached zero and is
327 * being released. This function doesn't care whether @css is on or
328 * offline. The caller naturally needs to ensure that @css is accessible
329 * but doesn't have to be holding a reference on it - IOW, RCU protected
330 * access is good enough for this function. Returns %true if a reference
331 * count was successfully obtained; %false otherwise.
333 static inline bool css_tryget(struct cgroup_subsys_state
*css
)
335 if (!(css
->flags
& CSS_NO_REF
))
336 return percpu_ref_tryget(&css
->refcnt
);
341 * css_tryget_online - try to obtain a reference on the specified css if online
344 * Obtain a reference on @css if it's online. The caller naturally needs
345 * to ensure that @css is accessible but doesn't have to be holding a
346 * reference on it - IOW, RCU protected access is good enough for this
347 * function. Returns %true if a reference count was successfully obtained;
350 static inline bool css_tryget_online(struct cgroup_subsys_state
*css
)
352 if (!(css
->flags
& CSS_NO_REF
))
353 return percpu_ref_tryget_live(&css
->refcnt
);
358 * css_is_dying - test whether the specified css is dying
361 * Test whether @css is in the process of offlining or already offline. In
362 * most cases, ->css_online() and ->css_offline() callbacks should be
363 * enough; however, the actual offline operations are RCU delayed and this
364 * test returns %true also when @css is scheduled to be offlined.
366 * This is useful, for example, when the use case requires synchronous
367 * behavior with respect to cgroup removal. cgroup removal schedules css
368 * offlining but the css can seem alive while the operation is being
369 * delayed. If the delay affects user visible semantics, this test can be
370 * used to resolve the situation.
372 static inline bool css_is_dying(struct cgroup_subsys_state
*css
)
374 return !(css
->flags
& CSS_NO_REF
) && percpu_ref_is_dying(&css
->refcnt
);
378 * css_put - put a css reference
381 * Put a reference obtained via css_get() and css_tryget_online().
383 static inline void css_put(struct cgroup_subsys_state
*css
)
385 if (!(css
->flags
& CSS_NO_REF
))
386 percpu_ref_put(&css
->refcnt
);
390 * css_put_many - put css references
392 * @n: number of references to put
394 * Put references obtained via css_get() and css_tryget_online().
396 static inline void css_put_many(struct cgroup_subsys_state
*css
, unsigned int n
)
398 if (!(css
->flags
& CSS_NO_REF
))
399 percpu_ref_put_many(&css
->refcnt
, n
);
402 static inline void cgroup_get(struct cgroup
*cgrp
)
404 css_get(&cgrp
->self
);
407 static inline bool cgroup_tryget(struct cgroup
*cgrp
)
409 return css_tryget(&cgrp
->self
);
412 static inline void cgroup_put(struct cgroup
*cgrp
)
414 css_put(&cgrp
->self
);
418 * task_css_set_check - obtain a task's css_set with extra access conditions
419 * @task: the task to obtain css_set for
420 * @__c: extra condition expression to be passed to rcu_dereference_check()
422 * A task's css_set is RCU protected, initialized and exited while holding
423 * task_lock(), and can only be modified while holding both cgroup_mutex
424 * and task_lock() while the task is alive. This macro verifies that the
425 * caller is inside proper critical section and returns @task's css_set.
427 * The caller can also specify additional allowed conditions via @__c, such
428 * as locks used during the cgroup_subsys::attach() methods.
430 #ifdef CONFIG_PROVE_RCU
431 extern struct mutex cgroup_mutex
;
432 extern spinlock_t css_set_lock
;
433 #define task_css_set_check(task, __c) \
434 rcu_dereference_check((task)->cgroups, \
435 lockdep_is_held(&cgroup_mutex) || \
436 lockdep_is_held(&css_set_lock) || \
437 ((task)->flags & PF_EXITING) || (__c))
439 #define task_css_set_check(task, __c) \
440 rcu_dereference((task)->cgroups)
444 * task_css_check - obtain css for (task, subsys) w/ extra access conds
445 * @task: the target task
446 * @subsys_id: the target subsystem ID
447 * @__c: extra condition expression to be passed to rcu_dereference_check()
449 * Return the cgroup_subsys_state for the (@task, @subsys_id) pair. The
450 * synchronization rules are the same as task_css_set_check().
452 #define task_css_check(task, subsys_id, __c) \
453 task_css_set_check((task), (__c))->subsys[(subsys_id)]
456 * task_css_set - obtain a task's css_set
457 * @task: the task to obtain css_set for
459 * See task_css_set_check().
461 static inline struct css_set
*task_css_set(struct task_struct
*task
)
463 return task_css_set_check(task
, false);
467 * task_css - obtain css for (task, subsys)
468 * @task: the target task
469 * @subsys_id: the target subsystem ID
471 * See task_css_check().
473 static inline struct cgroup_subsys_state
*task_css(struct task_struct
*task
,
476 return task_css_check(task
, subsys_id
, false);
480 * task_get_css - find and get the css for (task, subsys)
481 * @task: the target task
482 * @subsys_id: the target subsystem ID
484 * Find the css for the (@task, @subsys_id) combination, increment a
485 * reference on and return it. This function is guaranteed to return a
488 static inline struct cgroup_subsys_state
*
489 task_get_css(struct task_struct
*task
, int subsys_id
)
491 struct cgroup_subsys_state
*css
;
495 css
= task_css(task
, subsys_id
);
496 if (likely(css_tryget_online(css
)))
505 * task_css_is_root - test whether a task belongs to the root css
506 * @task: the target task
507 * @subsys_id: the target subsystem ID
509 * Test whether @task belongs to the root css on the specified subsystem.
510 * May be invoked in any context.
512 static inline bool task_css_is_root(struct task_struct
*task
, int subsys_id
)
514 return task_css_check(task
, subsys_id
, true) ==
515 init_css_set
.subsys
[subsys_id
];
518 static inline struct cgroup
*task_cgroup(struct task_struct
*task
,
521 return task_css(task
, subsys_id
)->cgroup
;
524 static inline struct cgroup
*task_dfl_cgroup(struct task_struct
*task
)
526 return task_css_set(task
)->dfl_cgrp
;
529 static inline struct cgroup
*cgroup_parent(struct cgroup
*cgrp
)
531 struct cgroup_subsys_state
*parent_css
= cgrp
->self
.parent
;
534 return container_of(parent_css
, struct cgroup
, self
);
539 * cgroup_is_descendant - test ancestry
540 * @cgrp: the cgroup to be tested
541 * @ancestor: possible ancestor of @cgrp
543 * Test whether @cgrp is a descendant of @ancestor. It also returns %true
544 * if @cgrp == @ancestor. This function is safe to call as long as @cgrp
545 * and @ancestor are accessible.
547 static inline bool cgroup_is_descendant(struct cgroup
*cgrp
,
548 struct cgroup
*ancestor
)
550 if (cgrp
->root
!= ancestor
->root
|| cgrp
->level
< ancestor
->level
)
552 return cgrp
->ancestor_ids
[ancestor
->level
] == ancestor
->id
;
556 * task_under_cgroup_hierarchy - test task's membership of cgroup ancestry
557 * @task: the task to be tested
558 * @ancestor: possible ancestor of @task's cgroup
560 * Tests whether @task's default cgroup hierarchy is a descendant of @ancestor.
561 * It follows all the same rules as cgroup_is_descendant, and only applies
562 * to the default hierarchy.
564 static inline bool task_under_cgroup_hierarchy(struct task_struct
*task
,
565 struct cgroup
*ancestor
)
567 struct css_set
*cset
= task_css_set(task
);
569 return cgroup_is_descendant(cset
->dfl_cgrp
, ancestor
);
572 /* no synchronization, the result can only be used as a hint */
573 static inline bool cgroup_is_populated(struct cgroup
*cgrp
)
575 return cgrp
->nr_populated_csets
+ cgrp
->nr_populated_domain_children
+
576 cgrp
->nr_populated_threaded_children
;
579 /* returns ino associated with a cgroup */
580 static inline ino_t
cgroup_ino(struct cgroup
*cgrp
)
582 return cgrp
->kn
->id
.ino
;
585 /* cft/css accessors for cftype->write() operation */
586 static inline struct cftype
*of_cft(struct kernfs_open_file
*of
)
591 struct cgroup_subsys_state
*of_css(struct kernfs_open_file
*of
);
593 /* cft/css accessors for cftype->seq_*() operations */
594 static inline struct cftype
*seq_cft(struct seq_file
*seq
)
596 return of_cft(seq
->private);
599 static inline struct cgroup_subsys_state
*seq_css(struct seq_file
*seq
)
601 return of_css(seq
->private);
605 * Name / path handling functions. All are thin wrappers around the kernfs
606 * counterparts and can be called under any context.
609 static inline int cgroup_name(struct cgroup
*cgrp
, char *buf
, size_t buflen
)
611 return kernfs_name(cgrp
->kn
, buf
, buflen
);
614 static inline int cgroup_path(struct cgroup
*cgrp
, char *buf
, size_t buflen
)
616 return kernfs_path(cgrp
->kn
, buf
, buflen
);
619 static inline void pr_cont_cgroup_name(struct cgroup
*cgrp
)
621 pr_cont_kernfs_name(cgrp
->kn
);
624 static inline void pr_cont_cgroup_path(struct cgroup
*cgrp
)
626 pr_cont_kernfs_path(cgrp
->kn
);
629 static inline void cgroup_init_kthreadd(void)
632 * kthreadd is inherited by all kthreads, keep it in the root so
633 * that the new kthreads are guaranteed to stay in the root until
634 * initialization is finished.
636 current
->no_cgroup_migration
= 1;
639 static inline void cgroup_kthread_ready(void)
642 * This kthread finished initialization. The creator should have
643 * set PF_NO_SETAFFINITY if this kthread should stay in the root.
645 current
->no_cgroup_migration
= 0;
648 static inline union kernfs_node_id
*cgroup_get_kernfs_id(struct cgroup
*cgrp
)
650 return &cgrp
->kn
->id
;
653 void cgroup_path_from_kernfs_id(const union kernfs_node_id
*id
,
654 char *buf
, size_t buflen
);
655 #else /* !CONFIG_CGROUPS */
657 struct cgroup_subsys_state
;
660 static inline void css_put(struct cgroup_subsys_state
*css
) {}
661 static inline int cgroup_attach_task_all(struct task_struct
*from
,
662 struct task_struct
*t
) { return 0; }
663 static inline int cgroupstats_build(struct cgroupstats
*stats
,
664 struct dentry
*dentry
) { return -EINVAL
; }
666 static inline void cgroup_fork(struct task_struct
*p
) {}
667 static inline int cgroup_can_fork(struct task_struct
*p
) { return 0; }
668 static inline void cgroup_cancel_fork(struct task_struct
*p
) {}
669 static inline void cgroup_post_fork(struct task_struct
*p
) {}
670 static inline void cgroup_exit(struct task_struct
*p
) {}
671 static inline void cgroup_free(struct task_struct
*p
) {}
673 static inline int cgroup_init_early(void) { return 0; }
674 static inline int cgroup_init(void) { return 0; }
675 static inline void cgroup_init_kthreadd(void) {}
676 static inline void cgroup_kthread_ready(void) {}
677 static inline union kernfs_node_id
*cgroup_get_kernfs_id(struct cgroup
*cgrp
)
682 static inline bool task_under_cgroup_hierarchy(struct task_struct
*task
,
683 struct cgroup
*ancestor
)
688 static inline void cgroup_path_from_kernfs_id(const union kernfs_node_id
*id
,
689 char *buf
, size_t buflen
) {}
690 #endif /* !CONFIG_CGROUPS */
693 * sock->sk_cgrp_data handling. For more info, see sock_cgroup_data
694 * definition in cgroup-defs.h.
696 #ifdef CONFIG_SOCK_CGROUP_DATA
698 #if defined(CONFIG_CGROUP_NET_PRIO) || defined(CONFIG_CGROUP_NET_CLASSID)
699 extern spinlock_t cgroup_sk_update_lock
;
702 void cgroup_sk_alloc_disable(void);
703 void cgroup_sk_alloc(struct sock_cgroup_data
*skcd
);
704 void cgroup_sk_free(struct sock_cgroup_data
*skcd
);
706 static inline struct cgroup
*sock_cgroup_ptr(struct sock_cgroup_data
*skcd
)
708 #if defined(CONFIG_CGROUP_NET_PRIO) || defined(CONFIG_CGROUP_NET_CLASSID)
712 * @skcd->val is 64bit but the following is safe on 32bit too as we
713 * just need the lower ulong to be written and read atomically.
715 v
= READ_ONCE(skcd
->val
);
718 return &cgrp_dfl_root
.cgrp
;
720 return (struct cgroup
*)(unsigned long)v
?: &cgrp_dfl_root
.cgrp
;
722 return (struct cgroup
*)(unsigned long)skcd
->val
;
726 #else /* CONFIG_CGROUP_DATA */
728 static inline void cgroup_sk_alloc(struct sock_cgroup_data
*skcd
) {}
729 static inline void cgroup_sk_free(struct sock_cgroup_data
*skcd
) {}
731 #endif /* CONFIG_CGROUP_DATA */
733 struct cgroup_namespace
{
736 struct user_namespace
*user_ns
;
737 struct ucounts
*ucounts
;
738 struct css_set
*root_cset
;
741 extern struct cgroup_namespace init_cgroup_ns
;
743 #ifdef CONFIG_CGROUPS
745 void free_cgroup_ns(struct cgroup_namespace
*ns
);
747 struct cgroup_namespace
*copy_cgroup_ns(unsigned long flags
,
748 struct user_namespace
*user_ns
,
749 struct cgroup_namespace
*old_ns
);
751 int cgroup_path_ns(struct cgroup
*cgrp
, char *buf
, size_t buflen
,
752 struct cgroup_namespace
*ns
);
754 #else /* !CONFIG_CGROUPS */
756 static inline void free_cgroup_ns(struct cgroup_namespace
*ns
) { }
757 static inline struct cgroup_namespace
*
758 copy_cgroup_ns(unsigned long flags
, struct user_namespace
*user_ns
,
759 struct cgroup_namespace
*old_ns
)
764 #endif /* !CONFIG_CGROUPS */
766 static inline void get_cgroup_ns(struct cgroup_namespace
*ns
)
769 refcount_inc(&ns
->count
);
772 static inline void put_cgroup_ns(struct cgroup_namespace
*ns
)
774 if (ns
&& refcount_dec_and_test(&ns
->count
))
778 #endif /* _LINUX_CGROUP_H */