| /* SPDX-License-Identifier: GPL-2.0 */ |
| #ifndef __CGROUP_INTERNAL_H |
| #define __CGROUP_INTERNAL_H |
| |
| #include <linux/cgroup.h> |
| #include <linux/kernfs.h> |
| #include <linux/workqueue.h> |
| #include <linux/list.h> |
| #include <linux/refcount.h> |
| |
| #define TRACE_CGROUP_PATH_LEN 1024 |
| extern spinlock_t trace_cgroup_path_lock; |
| extern char trace_cgroup_path[TRACE_CGROUP_PATH_LEN]; |
| |
| /* |
| * cgroup_path() takes a spin lock. It is good practice not to take |
| * spin locks within trace point handlers, as they are mostly hidden |
| * from normal view. As cgroup_path() can take the kernfs_rename_lock |
| * spin lock, it is best to not call that function from the trace event |
| * handler. |
| * |
| * Note: trace_cgroup_##type##_enabled() is a static branch that will only |
| * be set when the trace event is enabled. |
| */ |
| #define TRACE_CGROUP_PATH(type, cgrp, ...) \ |
| do { \ |
| if (trace_cgroup_##type##_enabled()) { \ |
| spin_lock(&trace_cgroup_path_lock); \ |
| cgroup_path(cgrp, trace_cgroup_path, \ |
| TRACE_CGROUP_PATH_LEN); \ |
| trace_cgroup_##type(cgrp, trace_cgroup_path, \ |
| ##__VA_ARGS__); \ |
| spin_unlock(&trace_cgroup_path_lock); \ |
| } \ |
| } while (0) |
| |
| /* |
| * A cgroup can be associated with multiple css_sets as different tasks may |
| * belong to different cgroups on different hierarchies. In the other |
| * direction, a css_set is naturally associated with multiple cgroups. |
| * This M:N relationship is represented by the following link structure |
| * which exists for each association and allows traversing the associations |
| * from both sides. |
| */ |
| struct cgrp_cset_link { |
| /* the cgroup and css_set this link associates */ |
| struct cgroup *cgrp; |
| struct css_set *cset; |
| |
| /* list of cgrp_cset_links anchored at cgrp->cset_links */ |
| struct list_head cset_link; |
| |
| /* list of cgrp_cset_links anchored at css_set->cgrp_links */ |
| struct list_head cgrp_link; |
| }; |
| |
| /* used to track tasks and csets during migration */ |
| struct cgroup_taskset { |
| /* the src and dst cset list running through cset->mg_node */ |
| struct list_head src_csets; |
| struct list_head dst_csets; |
| |
| /* the number of tasks in the set */ |
| int nr_tasks; |
| |
| /* the subsys currently being processed */ |
| int ssid; |
| |
| /* |
| * Fields for cgroup_taskset_*() iteration. |
| * |
| * Before migration is committed, the target migration tasks are on |
| * ->mg_tasks of the csets on ->src_csets. After, on ->mg_tasks of |
| * the csets on ->dst_csets. ->csets point to either ->src_csets |
| * or ->dst_csets depending on whether migration is committed. |
| * |
| * ->cur_csets and ->cur_task point to the current task position |
| * during iteration. |
| */ |
| struct list_head *csets; |
| struct css_set *cur_cset; |
| struct task_struct *cur_task; |
| }; |
| |
| /* migration context also tracks preloading */ |
| struct cgroup_mgctx { |
| /* |
| * Preloaded source and destination csets. Used to guarantee |
| * atomic success or failure on actual migration. |
| */ |
| struct list_head preloaded_src_csets; |
| struct list_head preloaded_dst_csets; |
| |
| /* tasks and csets to migrate */ |
| struct cgroup_taskset tset; |
| |
| /* subsystems affected by migration */ |
| u16 ss_mask; |
| }; |
| |
| #define CGROUP_TASKSET_INIT(tset) \ |
| { \ |
| .src_csets = LIST_HEAD_INIT(tset.src_csets), \ |
| .dst_csets = LIST_HEAD_INIT(tset.dst_csets), \ |
| .csets = &tset.src_csets, \ |
| } |
| |
| #define CGROUP_MGCTX_INIT(name) \ |
| { \ |
| LIST_HEAD_INIT(name.preloaded_src_csets), \ |
| LIST_HEAD_INIT(name.preloaded_dst_csets), \ |
| CGROUP_TASKSET_INIT(name.tset), \ |
| } |
| |
| #define DEFINE_CGROUP_MGCTX(name) \ |
| struct cgroup_mgctx name = CGROUP_MGCTX_INIT(name) |
| |
| struct cgroup_sb_opts { |
| u16 subsys_mask; |
| unsigned int flags; |
| char *release_agent; |
| bool cpuset_clone_children; |
| char *name; |
| /* User explicitly requested empty subsystem */ |
| bool none; |
| }; |
| |
| extern struct mutex cgroup_mutex; |
| extern spinlock_t css_set_lock; |
| extern struct cgroup_subsys *cgroup_subsys[]; |
| extern struct list_head cgroup_roots; |
| extern struct file_system_type cgroup_fs_type; |
| |
| /* iterate across the hierarchies */ |
| #define for_each_root(root) \ |
| list_for_each_entry((root), &cgroup_roots, root_list) |
| |
| /** |
| * for_each_subsys - iterate all enabled cgroup subsystems |
| * @ss: the iteration cursor |
| * @ssid: the index of @ss, CGROUP_SUBSYS_COUNT after reaching the end |
| */ |
| #define for_each_subsys(ss, ssid) \ |
| for ((ssid) = 0; (ssid) < CGROUP_SUBSYS_COUNT && \ |
| (((ss) = cgroup_subsys[ssid]) || true); (ssid)++) |
| |
| static inline bool cgroup_is_dead(const struct cgroup *cgrp) |
| { |
| return !(cgrp->self.flags & CSS_ONLINE); |
| } |
| |
| static inline bool notify_on_release(const struct cgroup *cgrp) |
| { |
| return test_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags); |
| } |
| |
| void put_css_set_locked(struct css_set *cset); |
| |
| static inline void put_css_set(struct css_set *cset) |
| { |
| unsigned long flags; |
| |
| /* |
| * Ensure that the refcount doesn't hit zero while any readers |
| * can see it. Similar to atomic_dec_and_lock(), but for an |
| * rwlock |
| */ |
| if (refcount_dec_not_one(&cset->refcount)) |
| return; |
| |
| spin_lock_irqsave(&css_set_lock, flags); |
| put_css_set_locked(cset); |
| spin_unlock_irqrestore(&css_set_lock, flags); |
| } |
| |
| /* |
| * refcounted get/put for css_set objects |
| */ |
| static inline void get_css_set(struct css_set *cset) |
| { |
| refcount_inc(&cset->refcount); |
| } |
| |
| bool cgroup_ssid_enabled(int ssid); |
| bool cgroup_on_dfl(const struct cgroup *cgrp); |
| bool cgroup_is_thread_root(struct cgroup *cgrp); |
| bool cgroup_is_threaded(struct cgroup *cgrp); |
| |
| struct cgroup_root *cgroup_root_from_kf(struct kernfs_root *kf_root); |
| struct cgroup *task_cgroup_from_root(struct task_struct *task, |
| struct cgroup_root *root); |
| struct cgroup *cgroup_kn_lock_live(struct kernfs_node *kn, bool drain_offline); |
| void cgroup_kn_unlock(struct kernfs_node *kn); |
| int cgroup_path_ns_locked(struct cgroup *cgrp, char *buf, size_t buflen, |
| struct cgroup_namespace *ns); |
| |
| void cgroup_free_root(struct cgroup_root *root); |
| void init_cgroup_root(struct cgroup_root *root, struct cgroup_sb_opts *opts); |
| int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask); |
| int rebind_subsystems(struct cgroup_root *dst_root, u16 ss_mask); |
| struct dentry *cgroup_do_mount(struct file_system_type *fs_type, int flags, |
| struct cgroup_root *root, unsigned long magic, |
| struct cgroup_namespace *ns); |
| |
| int cgroup_migrate_vet_dst(struct cgroup *dst_cgrp); |
| void cgroup_migrate_finish(struct cgroup_mgctx *mgctx); |
| void cgroup_migrate_add_src(struct css_set *src_cset, struct cgroup *dst_cgrp, |
| struct cgroup_mgctx *mgctx); |
| int cgroup_migrate_prepare_dst(struct cgroup_mgctx *mgctx); |
| int cgroup_migrate(struct task_struct *leader, bool threadgroup, |
| struct cgroup_mgctx *mgctx); |
| |
| int cgroup_attach_task(struct cgroup *dst_cgrp, struct task_struct *leader, |
| bool threadgroup); |
| struct task_struct *cgroup_procs_write_start(char *buf, bool threadgroup) |
| __acquires(&cgroup_threadgroup_rwsem); |
| void cgroup_procs_write_finish(struct task_struct *task) |
| __releases(&cgroup_threadgroup_rwsem); |
| |
| void cgroup_lock_and_drain_offline(struct cgroup *cgrp); |
| |
| int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name, umode_t mode); |
| int cgroup_rmdir(struct kernfs_node *kn); |
| int cgroup_show_path(struct seq_file *sf, struct kernfs_node *kf_node, |
| struct kernfs_root *kf_root); |
| |
| int __cgroup_task_count(const struct cgroup *cgrp); |
| int cgroup_task_count(const struct cgroup *cgrp); |
| |
| /* |
| * rstat.c |
| */ |
| int cgroup_rstat_init(struct cgroup *cgrp); |
| void cgroup_rstat_exit(struct cgroup *cgrp); |
| void cgroup_rstat_boot(void); |
| void cgroup_base_stat_cputime_show(struct seq_file *seq); |
| |
| /* |
| * namespace.c |
| */ |
| extern const struct proc_ns_operations cgroupns_operations; |
| |
| /* |
| * cgroup-v1.c |
| */ |
| extern struct cftype cgroup1_base_files[]; |
| extern struct kernfs_syscall_ops cgroup1_kf_syscall_ops; |
| |
| int proc_cgroupstats_show(struct seq_file *m, void *v); |
| bool cgroup1_ssid_disabled(int ssid); |
| void cgroup1_pidlist_destroy_all(struct cgroup *cgrp); |
| void cgroup1_release_agent(struct work_struct *work); |
| void cgroup1_check_for_release(struct cgroup *cgrp); |
| struct dentry *cgroup1_mount(struct file_system_type *fs_type, int flags, |
| void *data, unsigned long magic, |
| struct cgroup_namespace *ns); |
| |
| #endif /* __CGROUP_INTERNAL_H */ |