/* 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>#include <linux/fs_parser.h> #define TRACE_CGROUP_PATH_LEN 1024extern spinlock_t trace_cgroup_path_lock;extern char trace_cgroup_path[TRACE_CGROUP_PATH_LEN];extern void __init enable_debug_cgroup(void); /* * 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()) {			\			unsigned long flags;				\			spin_lock_irqsave(&trace_cgroup_path_lock,	\					  flags);			\			cgroup_path(cgrp, trace_cgroup_path,		\				    TRACE_CGROUP_PATH_LEN);		\			trace_cgroup_##type(cgrp, trace_cgroup_path,	\					    ##__VA_ARGS__);		\			spin_unlock_irqrestore(&trace_cgroup_path_lock, \					       flags);			\		}							\	} while (0) /* * The cgroup filesystem superblock creation/mount context. */struct cgroup_fs_context {	struct kernfs_fs_context kfc;	struct cgroup_root	*root;	struct cgroup_namespace	*ns;	unsigned int	flags;			/* CGRP_ROOT_* flags */ 	/* cgroup1 bits */	bool		cpuset_clone_children;	bool		none;			/* User explicitly requested empty subsystem */	bool		all_ss;			/* Seen 'all' option */	u32		subsys_mask;		/* Selected subsystems */	char		*name;			/* Hierarchy name */	char		*release_agent;		/* Path for release notifications */}; static inline struct cgroup_fs_context *cgroup_fc2context(struct fs_context *fc){	struct kernfs_fs_context *kfc = fc->fs_private; 	return container_of(kfc, struct cgroup_fs_context, kfc);} struct cgroup_pidlist; struct cgroup_file_ctx {	struct cgroup_namespace	*ns; 	struct {		void			*trigger;	} psi; 	struct {		bool			started;		struct css_task_iter	iter;	} procs; 	struct {		struct cgroup_pidlist	*pidlist;	} procs1; 	struct cgroup_of_peak peak;}; /* * 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 */	u32			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) extern struct cgroup_subsys *cgroup_subsys[];extern struct list_head cgroup_roots;extern bool cgrp_dfl_visible; /* iterate across the hierarchies */#define for_each_root(root)						\	list_for_each_entry_rcu((root), &cgroup_roots, root_list,	\				lockdep_is_held(&cgroup_mutex)) /** * 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 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); 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_favor_dynmods(struct cgroup_root *root, bool favor);void cgroup_free_root(struct cgroup_root *root);void init_cgroup_root(struct cgroup_fs_context *ctx);int cgroup_setup_root(struct cgroup_root *root, u32 ss_mask);int rebind_subsystems(struct cgroup_root *dst_root, u32 ss_mask);int cgroup_do_get_tree(struct fs_context *fc); 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);void cgroup_attach_lock(enum cgroup_attach_lock_mode lock_mode,			struct task_struct *tsk);void cgroup_attach_unlock(enum cgroup_attach_lock_mode lock_mode,			  struct task_struct *tsk);struct task_struct *cgroup_procs_write_start(char *buf, bool threadgroup,					     enum cgroup_attach_lock_mode *lock_mode)	__acquires(&cgroup_threadgroup_rwsem);void cgroup_procs_write_finish(struct task_struct *task,			       enum cgroup_attach_lock_mode lock_mode)	__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 css_rstat_init(struct cgroup_subsys_state *css);void css_rstat_exit(struct cgroup_subsys_state *css);int ss_rstat_init(struct cgroup_subsys *ss);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;extern const struct fs_parameter_spec cgroup1_fs_parameters[]; 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);int cgroup1_parse_param(struct fs_context *fc, struct fs_parameter *param);int cgroup1_get_tree(struct fs_context *fc);int cgroup1_reconfigure(struct fs_context *ctx); #endif /* __CGROUP_INTERNAL_H */