| /* 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/cgroup-defs.h> |
| |
| #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 *tasks_head; |
| struct list_head *mg_tasks_head; |
| struct list_head *dying_tasks_head; |
| |
| 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_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); |
| extern void cgroup_cancel_fork(struct task_struct *p); |
| extern void cgroup_post_fork(struct task_struct *p); |
| 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); |
| |
| /* |
| * 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. |
| */ |
| |
| /** |
| * 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] == ancestor->id; |
| } |
| |
| /** |
| * 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 cgrp->kn->id.ino; |
| } |
| |
| /* 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 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; |
| } |
| |
| static inline union kernfs_node_id *cgroup_get_kernfs_id(struct cgroup *cgrp) |
| { |
| return &cgrp->kn->id; |
| } |
| |
| void cgroup_path_from_kernfs_id(const union kernfs_node_id *id, |
| char *buf, size_t buflen); |
| #else /* !CONFIG_CGROUPS */ |
| |
| struct cgroup_subsys_state; |
| struct cgroup; |
| |
| 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) { return 0; } |
| static inline void cgroup_cancel_fork(struct task_struct *p) {} |
| static inline void cgroup_post_fork(struct task_struct *p) {} |
| 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 union kernfs_node_id *cgroup_get_kernfs_id(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(const union kernfs_node_id *id, |
| char *buf, size_t buflen) {} |
| #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 { |
| refcount_t count; |
| 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->count); |
| } |
| |
| static inline void put_cgroup_ns(struct cgroup_namespace *ns) |
| { |
| if (ns && refcount_dec_and_test(&ns->count)) |
| free_cgroup_ns(ns); |
| } |
| |
| #endif /* _LINUX_CGROUP_H */ |