mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
961 lines
29 KiB
961 lines
29 KiB
/* SPDX-License-Identifier: GPL-2.0 */ |
|
#ifndef _LINUX_CGROUP_H |
|
#define _LINUX_CGROUP_H |
|
/* |
|
* cgroup interface |
|
* |
|
* Copyright (C) 2003 BULL SA |
|
* Copyright (C) 2004-2006 Silicon Graphics, Inc. |
|
* |
|
*/ |
|
|
|
#include <linux/sched.h> |
|
#include <linux/cpumask.h> |
|
#include <linux/nodemask.h> |
|
#include <linux/rculist.h> |
|
#include <linux/cgroupstats.h> |
|
#include <linux/fs.h> |
|
#include <linux/seq_file.h> |
|
#include <linux/kernfs.h> |
|
#include <linux/jump_label.h> |
|
#include <linux/types.h> |
|
#include <linux/ns_common.h> |
|
#include <linux/nsproxy.h> |
|
#include <linux/user_namespace.h> |
|
#include <linux/refcount.h> |
|
#include <linux/kernel_stat.h> |
|
|
|
#include <linux/cgroup-defs.h> |
|
|
|
struct kernel_clone_args; |
|
|
|
#ifdef CONFIG_CGROUPS |
|
|
|
/* |
|
* All weight knobs on the default hierarhcy should use the following min, |
|
* default and max values. The default value is the logarithmic center of |
|
* MIN and MAX and allows 100x to be expressed in both directions. |
|
*/ |
|
#define CGROUP_WEIGHT_MIN 1 |
|
#define CGROUP_WEIGHT_DFL 100 |
|
#define CGROUP_WEIGHT_MAX 10000 |
|
|
|
/* walk only threadgroup leaders */ |
|
#define CSS_TASK_ITER_PROCS (1U << 0) |
|
/* walk all threaded css_sets in the domain */ |
|
#define CSS_TASK_ITER_THREADED (1U << 1) |
|
|
|
/* internal flags */ |
|
#define CSS_TASK_ITER_SKIPPED (1U << 16) |
|
|
|
/* a css_task_iter should be treated as an opaque object */ |
|
struct css_task_iter { |
|
struct cgroup_subsys *ss; |
|
unsigned int flags; |
|
|
|
struct list_head *cset_pos; |
|
struct list_head *cset_head; |
|
|
|
struct list_head *tcset_pos; |
|
struct list_head *tcset_head; |
|
|
|
struct list_head *task_pos; |
|
|
|
struct list_head *cur_tasks_head; |
|
struct css_set *cur_cset; |
|
struct css_set *cur_dcset; |
|
struct task_struct *cur_task; |
|
struct list_head iters_node; /* css_set->task_iters */ |
|
}; |
|
|
|
extern struct cgroup_root cgrp_dfl_root; |
|
extern struct css_set init_css_set; |
|
|
|
#define SUBSYS(_x) extern struct cgroup_subsys _x ## _cgrp_subsys; |
|
#include <linux/cgroup_subsys.h> |
|
#undef SUBSYS |
|
|
|
#define SUBSYS(_x) \ |
|
extern struct static_key_true _x ## _cgrp_subsys_enabled_key; \ |
|
extern struct static_key_true _x ## _cgrp_subsys_on_dfl_key; |
|
#include <linux/cgroup_subsys.h> |
|
#undef SUBSYS |
|
|
|
/** |
|
* cgroup_subsys_enabled - fast test on whether a subsys is enabled |
|
* @ss: subsystem in question |
|
*/ |
|
#define cgroup_subsys_enabled(ss) \ |
|
static_branch_likely(&ss ## _enabled_key) |
|
|
|
/** |
|
* cgroup_subsys_on_dfl - fast test on whether a subsys is on default hierarchy |
|
* @ss: subsystem in question |
|
*/ |
|
#define cgroup_subsys_on_dfl(ss) \ |
|
static_branch_likely(&ss ## _on_dfl_key) |
|
|
|
bool css_has_online_children(struct cgroup_subsys_state *css); |
|
struct cgroup_subsys_state *css_from_id(int id, struct cgroup_subsys *ss); |
|
struct cgroup_subsys_state *cgroup_e_css(struct cgroup *cgroup, |
|
struct cgroup_subsys *ss); |
|
struct cgroup_subsys_state *cgroup_get_e_css(struct cgroup *cgroup, |
|
struct cgroup_subsys *ss); |
|
struct cgroup_subsys_state *css_tryget_online_from_dir(struct dentry *dentry, |
|
struct cgroup_subsys *ss); |
|
|
|
struct cgroup *cgroup_get_from_path(const char *path); |
|
struct cgroup *cgroup_get_from_fd(int fd); |
|
|
|
int cgroup_attach_task_all(struct task_struct *from, struct task_struct *); |
|
int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from); |
|
|
|
int cgroup_add_dfl_cftypes(struct cgroup_subsys *ss, struct cftype *cfts); |
|
int cgroup_add_legacy_cftypes(struct cgroup_subsys *ss, struct cftype *cfts); |
|
int cgroup_rm_cftypes(struct cftype *cfts); |
|
void cgroup_file_notify(struct cgroup_file *cfile); |
|
|
|
int task_cgroup_path(struct task_struct *task, char *buf, size_t buflen); |
|
int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry); |
|
int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns, |
|
struct pid *pid, struct task_struct *tsk); |
|
|
|
void cgroup_fork(struct task_struct *p); |
|
extern int cgroup_can_fork(struct task_struct *p, |
|
struct kernel_clone_args *kargs); |
|
extern void cgroup_cancel_fork(struct task_struct *p, |
|
struct kernel_clone_args *kargs); |
|
extern void cgroup_post_fork(struct task_struct *p, |
|
struct kernel_clone_args *kargs); |
|
void cgroup_exit(struct task_struct *p); |
|
void cgroup_release(struct task_struct *p); |
|
void cgroup_free(struct task_struct *p); |
|
|
|
int cgroup_init_early(void); |
|
int cgroup_init(void); |
|
|
|
int cgroup_parse_float(const char *input, unsigned dec_shift, s64 *v); |
|
|
|
/* |
|
* Iteration helpers and macros. |
|
*/ |
|
|
|
struct cgroup_subsys_state *css_next_child(struct cgroup_subsys_state *pos, |
|
struct cgroup_subsys_state *parent); |
|
struct cgroup_subsys_state *css_next_descendant_pre(struct cgroup_subsys_state *pos, |
|
struct cgroup_subsys_state *css); |
|
struct cgroup_subsys_state *css_rightmost_descendant(struct cgroup_subsys_state *pos); |
|
struct cgroup_subsys_state *css_next_descendant_post(struct cgroup_subsys_state *pos, |
|
struct cgroup_subsys_state *css); |
|
|
|
struct task_struct *cgroup_taskset_first(struct cgroup_taskset *tset, |
|
struct cgroup_subsys_state **dst_cssp); |
|
struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset, |
|
struct cgroup_subsys_state **dst_cssp); |
|
|
|
void css_task_iter_start(struct cgroup_subsys_state *css, unsigned int flags, |
|
struct css_task_iter *it); |
|
struct task_struct *css_task_iter_next(struct css_task_iter *it); |
|
void css_task_iter_end(struct css_task_iter *it); |
|
|
|
/** |
|
* css_for_each_child - iterate through children of a css |
|
* @pos: the css * to use as the loop cursor |
|
* @parent: css whose children to walk |
|
* |
|
* Walk @parent's children. Must be called under rcu_read_lock(). |
|
* |
|
* If a subsystem synchronizes ->css_online() and the start of iteration, a |
|
* css which finished ->css_online() is guaranteed to be visible in the |
|
* future iterations and will stay visible until the last reference is put. |
|
* A css which hasn't finished ->css_online() or already finished |
|
* ->css_offline() may show up during traversal. It's each subsystem's |
|
* responsibility to synchronize against on/offlining. |
|
* |
|
* It is allowed to temporarily drop RCU read lock during iteration. The |
|
* caller is responsible for ensuring that @pos remains accessible until |
|
* the start of the next iteration by, for example, bumping the css refcnt. |
|
*/ |
|
#define css_for_each_child(pos, parent) \ |
|
for ((pos) = css_next_child(NULL, (parent)); (pos); \ |
|
(pos) = css_next_child((pos), (parent))) |
|
|
|
/** |
|
* css_for_each_descendant_pre - pre-order walk of a css's descendants |
|
* @pos: the css * to use as the loop cursor |
|
* @root: css whose descendants to walk |
|
* |
|
* Walk @root's descendants. @root is included in the iteration and the |
|
* first node to be visited. Must be called under rcu_read_lock(). |
|
* |
|
* If a subsystem synchronizes ->css_online() and the start of iteration, a |
|
* css which finished ->css_online() is guaranteed to be visible in the |
|
* future iterations and will stay visible until the last reference is put. |
|
* A css which hasn't finished ->css_online() or already finished |
|
* ->css_offline() may show up during traversal. It's each subsystem's |
|
* responsibility to synchronize against on/offlining. |
|
* |
|
* For example, the following guarantees that a descendant can't escape |
|
* state updates of its ancestors. |
|
* |
|
* my_online(@css) |
|
* { |
|
* Lock @css's parent and @css; |
|
* Inherit state from the parent; |
|
* Unlock both. |
|
* } |
|
* |
|
* my_update_state(@css) |
|
* { |
|
* css_for_each_descendant_pre(@pos, @css) { |
|
* Lock @pos; |
|
* if (@pos == @css) |
|
* Update @css's state; |
|
* else |
|
* Verify @pos is alive and inherit state from its parent; |
|
* Unlock @pos; |
|
* } |
|
* } |
|
* |
|
* As long as the inheriting step, including checking the parent state, is |
|
* enclosed inside @pos locking, double-locking the parent isn't necessary |
|
* while inheriting. The state update to the parent is guaranteed to be |
|
* visible by walking order and, as long as inheriting operations to the |
|
* same @pos are atomic to each other, multiple updates racing each other |
|
* still result in the correct state. It's guaranateed that at least one |
|
* inheritance happens for any css after the latest update to its parent. |
|
* |
|
* If checking parent's state requires locking the parent, each inheriting |
|
* iteration should lock and unlock both @pos->parent and @pos. |
|
* |
|
* Alternatively, a subsystem may choose to use a single global lock to |
|
* synchronize ->css_online() and ->css_offline() against tree-walking |
|
* operations. |
|
* |
|
* It is allowed to temporarily drop RCU read lock during iteration. The |
|
* caller is responsible for ensuring that @pos remains accessible until |
|
* the start of the next iteration by, for example, bumping the css refcnt. |
|
*/ |
|
#define css_for_each_descendant_pre(pos, css) \ |
|
for ((pos) = css_next_descendant_pre(NULL, (css)); (pos); \ |
|
(pos) = css_next_descendant_pre((pos), (css))) |
|
|
|
/** |
|
* css_for_each_descendant_post - post-order walk of a css's descendants |
|
* @pos: the css * to use as the loop cursor |
|
* @css: css whose descendants to walk |
|
* |
|
* Similar to css_for_each_descendant_pre() but performs post-order |
|
* traversal instead. @root is included in the iteration and the last |
|
* node to be visited. |
|
* |
|
* If a subsystem synchronizes ->css_online() and the start of iteration, a |
|
* css which finished ->css_online() is guaranteed to be visible in the |
|
* future iterations and will stay visible until the last reference is put. |
|
* A css which hasn't finished ->css_online() or already finished |
|
* ->css_offline() may show up during traversal. It's each subsystem's |
|
* responsibility to synchronize against on/offlining. |
|
* |
|
* Note that the walk visibility guarantee example described in pre-order |
|
* walk doesn't apply the same to post-order walks. |
|
*/ |
|
#define css_for_each_descendant_post(pos, css) \ |
|
for ((pos) = css_next_descendant_post(NULL, (css)); (pos); \ |
|
(pos) = css_next_descendant_post((pos), (css))) |
|
|
|
/** |
|
* cgroup_taskset_for_each - iterate cgroup_taskset |
|
* @task: the loop cursor |
|
* @dst_css: the destination css |
|
* @tset: taskset to iterate |
|
* |
|
* @tset may contain multiple tasks and they may belong to multiple |
|
* processes. |
|
* |
|
* On the v2 hierarchy, there may be tasks from multiple processes and they |
|
* may not share the source or destination csses. |
|
* |
|
* On traditional hierarchies, when there are multiple tasks in @tset, if a |
|
* task of a process is in @tset, all tasks of the process are in @tset. |
|
* Also, all are guaranteed to share the same source and destination csses. |
|
* |
|
* Iteration is not in any specific order. |
|
*/ |
|
#define cgroup_taskset_for_each(task, dst_css, tset) \ |
|
for ((task) = cgroup_taskset_first((tset), &(dst_css)); \ |
|
(task); \ |
|
(task) = cgroup_taskset_next((tset), &(dst_css))) |
|
|
|
/** |
|
* cgroup_taskset_for_each_leader - iterate group leaders in a cgroup_taskset |
|
* @leader: the loop cursor |
|
* @dst_css: the destination css |
|
* @tset: taskset to iterate |
|
* |
|
* Iterate threadgroup leaders of @tset. For single-task migrations, @tset |
|
* may not contain any. |
|
*/ |
|
#define cgroup_taskset_for_each_leader(leader, dst_css, tset) \ |
|
for ((leader) = cgroup_taskset_first((tset), &(dst_css)); \ |
|
(leader); \ |
|
(leader) = cgroup_taskset_next((tset), &(dst_css))) \ |
|
if ((leader) != (leader)->group_leader) \ |
|
; \ |
|
else |
|
|
|
/* |
|
* Inline functions. |
|
*/ |
|
|
|
static inline u64 cgroup_id(const struct cgroup *cgrp) |
|
{ |
|
return cgrp->kn->id; |
|
} |
|
|
|
/** |
|
* css_get - obtain a reference on the specified css |
|
* @css: target css |
|
* |
|
* The caller must already have a reference. |
|
*/ |
|
static inline void css_get(struct cgroup_subsys_state *css) |
|
{ |
|
if (!(css->flags & CSS_NO_REF)) |
|
percpu_ref_get(&css->refcnt); |
|
} |
|
|
|
/** |
|
* css_get_many - obtain references on the specified css |
|
* @css: target css |
|
* @n: number of references to get |
|
* |
|
* The caller must already have a reference. |
|
*/ |
|
static inline void css_get_many(struct cgroup_subsys_state *css, unsigned int n) |
|
{ |
|
if (!(css->flags & CSS_NO_REF)) |
|
percpu_ref_get_many(&css->refcnt, n); |
|
} |
|
|
|
/** |
|
* css_tryget - try to obtain a reference on the specified css |
|
* @css: target css |
|
* |
|
* Obtain a reference on @css unless it already has reached zero and is |
|
* being released. This function doesn't care whether @css is on or |
|
* offline. The caller naturally needs to ensure that @css is accessible |
|
* but doesn't have to be holding a reference on it - IOW, RCU protected |
|
* access is good enough for this function. Returns %true if a reference |
|
* count was successfully obtained; %false otherwise. |
|
*/ |
|
static inline bool css_tryget(struct cgroup_subsys_state *css) |
|
{ |
|
if (!(css->flags & CSS_NO_REF)) |
|
return percpu_ref_tryget(&css->refcnt); |
|
return true; |
|
} |
|
|
|
/** |
|
* css_tryget_online - try to obtain a reference on the specified css if online |
|
* @css: target css |
|
* |
|
* Obtain a reference on @css if it's online. The caller naturally needs |
|
* to ensure that @css is accessible but doesn't have to be holding a |
|
* reference on it - IOW, RCU protected access is good enough for this |
|
* function. Returns %true if a reference count was successfully obtained; |
|
* %false otherwise. |
|
*/ |
|
static inline bool css_tryget_online(struct cgroup_subsys_state *css) |
|
{ |
|
if (!(css->flags & CSS_NO_REF)) |
|
return percpu_ref_tryget_live(&css->refcnt); |
|
return true; |
|
} |
|
|
|
/** |
|
* css_is_dying - test whether the specified css is dying |
|
* @css: target css |
|
* |
|
* Test whether @css is in the process of offlining or already offline. In |
|
* most cases, ->css_online() and ->css_offline() callbacks should be |
|
* enough; however, the actual offline operations are RCU delayed and this |
|
* test returns %true also when @css is scheduled to be offlined. |
|
* |
|
* This is useful, for example, when the use case requires synchronous |
|
* behavior with respect to cgroup removal. cgroup removal schedules css |
|
* offlining but the css can seem alive while the operation is being |
|
* delayed. If the delay affects user visible semantics, this test can be |
|
* used to resolve the situation. |
|
*/ |
|
static inline bool css_is_dying(struct cgroup_subsys_state *css) |
|
{ |
|
return !(css->flags & CSS_NO_REF) && percpu_ref_is_dying(&css->refcnt); |
|
} |
|
|
|
/** |
|
* css_put - put a css reference |
|
* @css: target css |
|
* |
|
* Put a reference obtained via css_get() and css_tryget_online(). |
|
*/ |
|
static inline void css_put(struct cgroup_subsys_state *css) |
|
{ |
|
if (!(css->flags & CSS_NO_REF)) |
|
percpu_ref_put(&css->refcnt); |
|
} |
|
|
|
/** |
|
* css_put_many - put css references |
|
* @css: target css |
|
* @n: number of references to put |
|
* |
|
* Put references obtained via css_get() and css_tryget_online(). |
|
*/ |
|
static inline void css_put_many(struct cgroup_subsys_state *css, unsigned int n) |
|
{ |
|
if (!(css->flags & CSS_NO_REF)) |
|
percpu_ref_put_many(&css->refcnt, n); |
|
} |
|
|
|
static inline void cgroup_get(struct cgroup *cgrp) |
|
{ |
|
css_get(&cgrp->self); |
|
} |
|
|
|
static inline bool cgroup_tryget(struct cgroup *cgrp) |
|
{ |
|
return css_tryget(&cgrp->self); |
|
} |
|
|
|
static inline void cgroup_put(struct cgroup *cgrp) |
|
{ |
|
css_put(&cgrp->self); |
|
} |
|
|
|
/** |
|
* task_css_set_check - obtain a task's css_set with extra access conditions |
|
* @task: the task to obtain css_set for |
|
* @__c: extra condition expression to be passed to rcu_dereference_check() |
|
* |
|
* A task's css_set is RCU protected, initialized and exited while holding |
|
* task_lock(), and can only be modified while holding both cgroup_mutex |
|
* and task_lock() while the task is alive. This macro verifies that the |
|
* caller is inside proper critical section and returns @task's css_set. |
|
* |
|
* The caller can also specify additional allowed conditions via @__c, such |
|
* as locks used during the cgroup_subsys::attach() methods. |
|
*/ |
|
#ifdef CONFIG_PROVE_RCU |
|
extern struct mutex cgroup_mutex; |
|
extern spinlock_t css_set_lock; |
|
#define task_css_set_check(task, __c) \ |
|
rcu_dereference_check((task)->cgroups, \ |
|
lockdep_is_held(&cgroup_mutex) || \ |
|
lockdep_is_held(&css_set_lock) || \ |
|
((task)->flags & PF_EXITING) || (__c)) |
|
#else |
|
#define task_css_set_check(task, __c) \ |
|
rcu_dereference((task)->cgroups) |
|
#endif |
|
|
|
/** |
|
* task_css_check - obtain css for (task, subsys) w/ extra access conds |
|
* @task: the target task |
|
* @subsys_id: the target subsystem ID |
|
* @__c: extra condition expression to be passed to rcu_dereference_check() |
|
* |
|
* Return the cgroup_subsys_state for the (@task, @subsys_id) pair. The |
|
* synchronization rules are the same as task_css_set_check(). |
|
*/ |
|
#define task_css_check(task, subsys_id, __c) \ |
|
task_css_set_check((task), (__c))->subsys[(subsys_id)] |
|
|
|
/** |
|
* task_css_set - obtain a task's css_set |
|
* @task: the task to obtain css_set for |
|
* |
|
* See task_css_set_check(). |
|
*/ |
|
static inline struct css_set *task_css_set(struct task_struct *task) |
|
{ |
|
return task_css_set_check(task, false); |
|
} |
|
|
|
/** |
|
* task_css - obtain css for (task, subsys) |
|
* @task: the target task |
|
* @subsys_id: the target subsystem ID |
|
* |
|
* See task_css_check(). |
|
*/ |
|
static inline struct cgroup_subsys_state *task_css(struct task_struct *task, |
|
int subsys_id) |
|
{ |
|
return task_css_check(task, subsys_id, false); |
|
} |
|
|
|
/** |
|
* task_get_css - find and get the css for (task, subsys) |
|
* @task: the target task |
|
* @subsys_id: the target subsystem ID |
|
* |
|
* Find the css for the (@task, @subsys_id) combination, increment a |
|
* reference on and return it. This function is guaranteed to return a |
|
* valid css. The returned css may already have been offlined. |
|
*/ |
|
static inline struct cgroup_subsys_state * |
|
task_get_css(struct task_struct *task, int subsys_id) |
|
{ |
|
struct cgroup_subsys_state *css; |
|
|
|
rcu_read_lock(); |
|
while (true) { |
|
css = task_css(task, subsys_id); |
|
/* |
|
* Can't use css_tryget_online() here. A task which has |
|
* PF_EXITING set may stay associated with an offline css. |
|
* If such task calls this function, css_tryget_online() |
|
* will keep failing. |
|
*/ |
|
if (likely(css_tryget(css))) |
|
break; |
|
cpu_relax(); |
|
} |
|
rcu_read_unlock(); |
|
return css; |
|
} |
|
|
|
/** |
|
* task_css_is_root - test whether a task belongs to the root css |
|
* @task: the target task |
|
* @subsys_id: the target subsystem ID |
|
* |
|
* Test whether @task belongs to the root css on the specified subsystem. |
|
* May be invoked in any context. |
|
*/ |
|
static inline bool task_css_is_root(struct task_struct *task, int subsys_id) |
|
{ |
|
return task_css_check(task, subsys_id, true) == |
|
init_css_set.subsys[subsys_id]; |
|
} |
|
|
|
static inline struct cgroup *task_cgroup(struct task_struct *task, |
|
int subsys_id) |
|
{ |
|
return task_css(task, subsys_id)->cgroup; |
|
} |
|
|
|
static inline struct cgroup *task_dfl_cgroup(struct task_struct *task) |
|
{ |
|
return task_css_set(task)->dfl_cgrp; |
|
} |
|
|
|
static inline struct cgroup *cgroup_parent(struct cgroup *cgrp) |
|
{ |
|
struct cgroup_subsys_state *parent_css = cgrp->self.parent; |
|
|
|
if (parent_css) |
|
return container_of(parent_css, struct cgroup, self); |
|
return NULL; |
|
} |
|
|
|
/** |
|
* cgroup_is_descendant - test ancestry |
|
* @cgrp: the cgroup to be tested |
|
* @ancestor: possible ancestor of @cgrp |
|
* |
|
* Test whether @cgrp is a descendant of @ancestor. It also returns %true |
|
* if @cgrp == @ancestor. This function is safe to call as long as @cgrp |
|
* and @ancestor are accessible. |
|
*/ |
|
static inline bool cgroup_is_descendant(struct cgroup *cgrp, |
|
struct cgroup *ancestor) |
|
{ |
|
if (cgrp->root != ancestor->root || cgrp->level < ancestor->level) |
|
return false; |
|
return cgrp->ancestor_ids[ancestor->level] == cgroup_id(ancestor); |
|
} |
|
|
|
/** |
|
* cgroup_ancestor - find ancestor of cgroup |
|
* @cgrp: cgroup to find ancestor of |
|
* @ancestor_level: level of ancestor to find starting from root |
|
* |
|
* Find ancestor of cgroup at specified level starting from root if it exists |
|
* and return pointer to it. Return NULL if @cgrp doesn't have ancestor at |
|
* @ancestor_level. |
|
* |
|
* This function is safe to call as long as @cgrp is accessible. |
|
*/ |
|
static inline struct cgroup *cgroup_ancestor(struct cgroup *cgrp, |
|
int ancestor_level) |
|
{ |
|
if (cgrp->level < ancestor_level) |
|
return NULL; |
|
while (cgrp && cgrp->level > ancestor_level) |
|
cgrp = cgroup_parent(cgrp); |
|
return cgrp; |
|
} |
|
|
|
/** |
|
* task_under_cgroup_hierarchy - test task's membership of cgroup ancestry |
|
* @task: the task to be tested |
|
* @ancestor: possible ancestor of @task's cgroup |
|
* |
|
* Tests whether @task's default cgroup hierarchy is a descendant of @ancestor. |
|
* It follows all the same rules as cgroup_is_descendant, and only applies |
|
* to the default hierarchy. |
|
*/ |
|
static inline bool task_under_cgroup_hierarchy(struct task_struct *task, |
|
struct cgroup *ancestor) |
|
{ |
|
struct css_set *cset = task_css_set(task); |
|
|
|
return cgroup_is_descendant(cset->dfl_cgrp, ancestor); |
|
} |
|
|
|
/* no synchronization, the result can only be used as a hint */ |
|
static inline bool cgroup_is_populated(struct cgroup *cgrp) |
|
{ |
|
return cgrp->nr_populated_csets + cgrp->nr_populated_domain_children + |
|
cgrp->nr_populated_threaded_children; |
|
} |
|
|
|
/* returns ino associated with a cgroup */ |
|
static inline ino_t cgroup_ino(struct cgroup *cgrp) |
|
{ |
|
return kernfs_ino(cgrp->kn); |
|
} |
|
|
|
/* cft/css accessors for cftype->write() operation */ |
|
static inline struct cftype *of_cft(struct kernfs_open_file *of) |
|
{ |
|
return of->kn->priv; |
|
} |
|
|
|
struct cgroup_subsys_state *of_css(struct kernfs_open_file *of); |
|
|
|
/* cft/css accessors for cftype->seq_*() operations */ |
|
static inline struct cftype *seq_cft(struct seq_file *seq) |
|
{ |
|
return of_cft(seq->private); |
|
} |
|
|
|
static inline struct cgroup_subsys_state *seq_css(struct seq_file *seq) |
|
{ |
|
return of_css(seq->private); |
|
} |
|
|
|
/* |
|
* Name / path handling functions. All are thin wrappers around the kernfs |
|
* counterparts and can be called under any context. |
|
*/ |
|
|
|
static inline int cgroup_name(struct cgroup *cgrp, char *buf, size_t buflen) |
|
{ |
|
return kernfs_name(cgrp->kn, buf, buflen); |
|
} |
|
|
|
static inline int cgroup_path(struct cgroup *cgrp, char *buf, size_t buflen) |
|
{ |
|
return kernfs_path(cgrp->kn, buf, buflen); |
|
} |
|
|
|
static inline void pr_cont_cgroup_name(struct cgroup *cgrp) |
|
{ |
|
pr_cont_kernfs_name(cgrp->kn); |
|
} |
|
|
|
static inline void pr_cont_cgroup_path(struct cgroup *cgrp) |
|
{ |
|
pr_cont_kernfs_path(cgrp->kn); |
|
} |
|
|
|
static inline struct psi_group *cgroup_psi(struct cgroup *cgrp) |
|
{ |
|
return &cgrp->psi; |
|
} |
|
|
|
static inline void cgroup_init_kthreadd(void) |
|
{ |
|
/* |
|
* kthreadd is inherited by all kthreads, keep it in the root so |
|
* that the new kthreads are guaranteed to stay in the root until |
|
* initialization is finished. |
|
*/ |
|
current->no_cgroup_migration = 1; |
|
} |
|
|
|
static inline void cgroup_kthread_ready(void) |
|
{ |
|
/* |
|
* This kthread finished initialization. The creator should have |
|
* set PF_NO_SETAFFINITY if this kthread should stay in the root. |
|
*/ |
|
current->no_cgroup_migration = 0; |
|
} |
|
|
|
void cgroup_path_from_kernfs_id(u64 id, char *buf, size_t buflen); |
|
#else /* !CONFIG_CGROUPS */ |
|
|
|
struct cgroup_subsys_state; |
|
struct cgroup; |
|
|
|
static inline u64 cgroup_id(const struct cgroup *cgrp) { return 1; } |
|
static inline void css_get(struct cgroup_subsys_state *css) {} |
|
static inline void css_put(struct cgroup_subsys_state *css) {} |
|
static inline int cgroup_attach_task_all(struct task_struct *from, |
|
struct task_struct *t) { return 0; } |
|
static inline int cgroupstats_build(struct cgroupstats *stats, |
|
struct dentry *dentry) { return -EINVAL; } |
|
|
|
static inline void cgroup_fork(struct task_struct *p) {} |
|
static inline int cgroup_can_fork(struct task_struct *p, |
|
struct kernel_clone_args *kargs) { return 0; } |
|
static inline void cgroup_cancel_fork(struct task_struct *p, |
|
struct kernel_clone_args *kargs) {} |
|
static inline void cgroup_post_fork(struct task_struct *p, |
|
struct kernel_clone_args *kargs) {} |
|
static inline void cgroup_exit(struct task_struct *p) {} |
|
static inline void cgroup_release(struct task_struct *p) {} |
|
static inline void cgroup_free(struct task_struct *p) {} |
|
|
|
static inline int cgroup_init_early(void) { return 0; } |
|
static inline int cgroup_init(void) { return 0; } |
|
static inline void cgroup_init_kthreadd(void) {} |
|
static inline void cgroup_kthread_ready(void) {} |
|
|
|
static inline struct cgroup *cgroup_parent(struct cgroup *cgrp) |
|
{ |
|
return NULL; |
|
} |
|
|
|
static inline struct psi_group *cgroup_psi(struct cgroup *cgrp) |
|
{ |
|
return NULL; |
|
} |
|
|
|
static inline bool task_under_cgroup_hierarchy(struct task_struct *task, |
|
struct cgroup *ancestor) |
|
{ |
|
return true; |
|
} |
|
|
|
static inline void cgroup_path_from_kernfs_id(u64 id, char *buf, size_t buflen) |
|
{} |
|
#endif /* !CONFIG_CGROUPS */ |
|
|
|
#ifdef CONFIG_CGROUPS |
|
/* |
|
* cgroup scalable recursive statistics. |
|
*/ |
|
void cgroup_rstat_updated(struct cgroup *cgrp, int cpu); |
|
void cgroup_rstat_flush(struct cgroup *cgrp); |
|
void cgroup_rstat_flush_irqsafe(struct cgroup *cgrp); |
|
void cgroup_rstat_flush_hold(struct cgroup *cgrp); |
|
void cgroup_rstat_flush_release(void); |
|
|
|
/* |
|
* Basic resource stats. |
|
*/ |
|
#ifdef CONFIG_CGROUP_CPUACCT |
|
void cpuacct_charge(struct task_struct *tsk, u64 cputime); |
|
void cpuacct_account_field(struct task_struct *tsk, int index, u64 val); |
|
#else |
|
static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {} |
|
static inline void cpuacct_account_field(struct task_struct *tsk, int index, |
|
u64 val) {} |
|
#endif |
|
|
|
void __cgroup_account_cputime(struct cgroup *cgrp, u64 delta_exec); |
|
void __cgroup_account_cputime_field(struct cgroup *cgrp, |
|
enum cpu_usage_stat index, u64 delta_exec); |
|
|
|
static inline void cgroup_account_cputime(struct task_struct *task, |
|
u64 delta_exec) |
|
{ |
|
struct cgroup *cgrp; |
|
|
|
cpuacct_charge(task, delta_exec); |
|
|
|
rcu_read_lock(); |
|
cgrp = task_dfl_cgroup(task); |
|
if (cgroup_parent(cgrp)) |
|
__cgroup_account_cputime(cgrp, delta_exec); |
|
rcu_read_unlock(); |
|
} |
|
|
|
static inline void cgroup_account_cputime_field(struct task_struct *task, |
|
enum cpu_usage_stat index, |
|
u64 delta_exec) |
|
{ |
|
struct cgroup *cgrp; |
|
|
|
cpuacct_account_field(task, index, delta_exec); |
|
|
|
rcu_read_lock(); |
|
cgrp = task_dfl_cgroup(task); |
|
if (cgroup_parent(cgrp)) |
|
__cgroup_account_cputime_field(cgrp, index, delta_exec); |
|
rcu_read_unlock(); |
|
} |
|
|
|
#else /* CONFIG_CGROUPS */ |
|
|
|
static inline void cgroup_account_cputime(struct task_struct *task, |
|
u64 delta_exec) {} |
|
static inline void cgroup_account_cputime_field(struct task_struct *task, |
|
enum cpu_usage_stat index, |
|
u64 delta_exec) {} |
|
|
|
#endif /* CONFIG_CGROUPS */ |
|
|
|
/* |
|
* sock->sk_cgrp_data handling. For more info, see sock_cgroup_data |
|
* definition in cgroup-defs.h. |
|
*/ |
|
#ifdef CONFIG_SOCK_CGROUP_DATA |
|
|
|
#if defined(CONFIG_CGROUP_NET_PRIO) || defined(CONFIG_CGROUP_NET_CLASSID) |
|
extern spinlock_t cgroup_sk_update_lock; |
|
#endif |
|
|
|
void cgroup_sk_alloc_disable(void); |
|
void cgroup_sk_alloc(struct sock_cgroup_data *skcd); |
|
void cgroup_sk_clone(struct sock_cgroup_data *skcd); |
|
void cgroup_sk_free(struct sock_cgroup_data *skcd); |
|
|
|
static inline struct cgroup *sock_cgroup_ptr(struct sock_cgroup_data *skcd) |
|
{ |
|
#if defined(CONFIG_CGROUP_NET_PRIO) || defined(CONFIG_CGROUP_NET_CLASSID) |
|
unsigned long v; |
|
|
|
/* |
|
* @skcd->val is 64bit but the following is safe on 32bit too as we |
|
* just need the lower ulong to be written and read atomically. |
|
*/ |
|
v = READ_ONCE(skcd->val); |
|
|
|
if (v & 3) |
|
return &cgrp_dfl_root.cgrp; |
|
|
|
return (struct cgroup *)(unsigned long)v ?: &cgrp_dfl_root.cgrp; |
|
#else |
|
return (struct cgroup *)(unsigned long)skcd->val; |
|
#endif |
|
} |
|
|
|
#else /* CONFIG_CGROUP_DATA */ |
|
|
|
static inline void cgroup_sk_alloc(struct sock_cgroup_data *skcd) {} |
|
static inline void cgroup_sk_clone(struct sock_cgroup_data *skcd) {} |
|
static inline void cgroup_sk_free(struct sock_cgroup_data *skcd) {} |
|
|
|
#endif /* CONFIG_CGROUP_DATA */ |
|
|
|
struct cgroup_namespace { |
|
struct ns_common ns; |
|
struct user_namespace *user_ns; |
|
struct ucounts *ucounts; |
|
struct css_set *root_cset; |
|
}; |
|
|
|
extern struct cgroup_namespace init_cgroup_ns; |
|
|
|
#ifdef CONFIG_CGROUPS |
|
|
|
void free_cgroup_ns(struct cgroup_namespace *ns); |
|
|
|
struct cgroup_namespace *copy_cgroup_ns(unsigned long flags, |
|
struct user_namespace *user_ns, |
|
struct cgroup_namespace *old_ns); |
|
|
|
int cgroup_path_ns(struct cgroup *cgrp, char *buf, size_t buflen, |
|
struct cgroup_namespace *ns); |
|
|
|
#else /* !CONFIG_CGROUPS */ |
|
|
|
static inline void free_cgroup_ns(struct cgroup_namespace *ns) { } |
|
static inline struct cgroup_namespace * |
|
copy_cgroup_ns(unsigned long flags, struct user_namespace *user_ns, |
|
struct cgroup_namespace *old_ns) |
|
{ |
|
return old_ns; |
|
} |
|
|
|
#endif /* !CONFIG_CGROUPS */ |
|
|
|
static inline void get_cgroup_ns(struct cgroup_namespace *ns) |
|
{ |
|
if (ns) |
|
refcount_inc(&ns->ns.count); |
|
} |
|
|
|
static inline void put_cgroup_ns(struct cgroup_namespace *ns) |
|
{ |
|
if (ns && refcount_dec_and_test(&ns->ns.count)) |
|
free_cgroup_ns(ns); |
|
} |
|
|
|
#ifdef CONFIG_CGROUPS |
|
|
|
void cgroup_enter_frozen(void); |
|
void cgroup_leave_frozen(bool always_leave); |
|
void cgroup_update_frozen(struct cgroup *cgrp); |
|
void cgroup_freeze(struct cgroup *cgrp, bool freeze); |
|
void cgroup_freezer_migrate_task(struct task_struct *task, struct cgroup *src, |
|
struct cgroup *dst); |
|
|
|
static inline bool cgroup_task_freeze(struct task_struct *task) |
|
{ |
|
bool ret; |
|
|
|
if (task->flags & PF_KTHREAD) |
|
return false; |
|
|
|
rcu_read_lock(); |
|
ret = test_bit(CGRP_FREEZE, &task_dfl_cgroup(task)->flags); |
|
rcu_read_unlock(); |
|
|
|
return ret; |
|
} |
|
|
|
static inline bool cgroup_task_frozen(struct task_struct *task) |
|
{ |
|
return task->frozen; |
|
} |
|
|
|
#else /* !CONFIG_CGROUPS */ |
|
|
|
static inline void cgroup_enter_frozen(void) { } |
|
static inline void cgroup_leave_frozen(bool always_leave) { } |
|
static inline bool cgroup_task_freeze(struct task_struct *task) |
|
{ |
|
return false; |
|
} |
|
static inline bool cgroup_task_frozen(struct task_struct *task) |
|
{ |
|
return false; |
|
} |
|
|
|
#endif /* !CONFIG_CGROUPS */ |
|
|
|
#ifdef CONFIG_CGROUP_BPF |
|
static inline void cgroup_bpf_get(struct cgroup *cgrp) |
|
{ |
|
percpu_ref_get(&cgrp->bpf.refcnt); |
|
} |
|
|
|
static inline void cgroup_bpf_put(struct cgroup *cgrp) |
|
{ |
|
percpu_ref_put(&cgrp->bpf.refcnt); |
|
} |
|
|
|
#else /* CONFIG_CGROUP_BPF */ |
|
|
|
static inline void cgroup_bpf_get(struct cgroup *cgrp) {} |
|
static inline void cgroup_bpf_put(struct cgroup *cgrp) {} |
|
|
|
#endif /* CONFIG_CGROUP_BPF */ |
|
|
|
#endif /* _LINUX_CGROUP_H */
|
|
|