244 static void kill_css(struct cgroup_subsys_state *css);
245 static int cgroup_addrm_files(struct cgroup_subsys_state *css,
501 	struct cgroup_subsys_state *css;  in cgroup_tryget_css()  local
504 	css = cgroup_css(cgrp, ss);  in cgroup_tryget_css()
505 	if (css && !css_tryget_online(css))  in cgroup_tryget_css()
506 		css = NULL;  in cgroup_tryget_css()
509 	return css;  in cgroup_tryget_css()
559 	struct cgroup_subsys_state *css;  in cgroup_e_css()  local
565 		css = cgroup_css(cgrp, ss);  in cgroup_e_css()
567 		if (css)  in cgroup_e_css()
568 			return css;  in cgroup_e_css()
589 	struct cgroup_subsys_state *css;  in cgroup_get_e_css()  local
597 		css = cgroup_css(cgrp, ss);  in cgroup_get_e_css()
599 		if (css && css_tryget_online(css))  in cgroup_get_e_css()
604 	css = init_css_set.subsys[ss->id];  in cgroup_get_e_css()
605 	css_get(css);  in cgroup_get_e_css()
608 	return css;  in cgroup_get_e_css()
679 #define for_each_css(css, ssid, cgrp)					\  argument
681 		if (!((css) = rcu_dereference_check(			\
694 #define for_each_e_css(css, ssid, cgrp)					    \  argument
696 		if (!((css) = cgroup_e_css_by_mask(cgrp,		    \
941 static unsigned long css_set_hash(struct cgroup_subsys_state *css[])  in css_set_hash()  argument
948 		key += (unsigned long)css[i];  in css_set_hash()
1268 		struct cgroup_subsys_state *css = cset->subsys[ssid];  in find_css_set()  local
1271 			      &css->cgroup->e_csets[ssid]);  in find_css_set()
1272 		css_get(css);  in find_css_set()
1652 		struct cgroup_subsys_state *css = cgroup_css(cgrp, cft->ss);  in cgroup_rm_file()  local
1653 		struct cgroup_file *cfile = (void *)css + cft->file_offset;  in cgroup_rm_file()
1669 static void css_clear_dir(struct cgroup_subsys_state *css)  in css_clear_dir()  argument
1671 	struct cgroup *cgrp = css->cgroup;  in css_clear_dir()
1674 	if (!(css->flags & CSS_VISIBLE))  in css_clear_dir()
1677 	css->flags &= ~CSS_VISIBLE;  in css_clear_dir()
1679 	if (!css->ss) {  in css_clear_dir()
1685 		cgroup_addrm_files(css, cgrp, cfts, false);  in css_clear_dir()
1687 		list_for_each_entry(cfts, &css->ss->cfts, node)  in css_clear_dir()
1688 			cgroup_addrm_files(css, cgrp, cfts, false);  in css_clear_dir()
1698 static int css_populate_dir(struct cgroup_subsys_state *css)  in css_populate_dir()  argument
1700 	struct cgroup *cgrp = css->cgroup;  in css_populate_dir()
1704 	if ((css->flags & CSS_VISIBLE) || !cgrp->kn)  in css_populate_dir()
1707 	if (!css->ss) {  in css_populate_dir()
1717 		list_for_each_entry(cfts, &css->ss->cfts, node) {  in css_populate_dir()
1718 			ret = cgroup_addrm_files(css, cgrp, cfts, true);  in css_populate_dir()
1726 	css->flags |= CSS_VISIBLE;  in css_populate_dir()
1730 	list_for_each_entry(cfts, &css->ss->cfts, node) {  in css_populate_dir()
1733 		cgroup_addrm_files(css, cgrp, cfts, false);  in css_populate_dir()
1764 		struct cgroup_subsys_state *css = cgroup_css(scgrp, ss);  in rebind_subsystems()  local
1767 		WARN_ON(!css || cgroup_css(dcgrp, ss));  in rebind_subsystems()
1776 		rcu_assign_pointer(dcgrp->subsys[ssid], css);  in rebind_subsystems()
1778 		css->cgroup = dcgrp;  in rebind_subsystems()
1787 			list_del_rcu(&css->rstat_css_node);  in rebind_subsystems()
1788 			list_add_rcu(&css->rstat_css_node,  in rebind_subsystems()
1807 			ss->bind(css);  in rebind_subsystems()
2979 			struct cgroup_subsys_state *css = cgroup_css(dsct, ss);  in cgroup_lock_and_drain_offline()  local
2982 			if (!css || !percpu_ref_is_dying(&css->refcnt))  in cgroup_lock_and_drain_offline()
3060 static bool css_visible(struct cgroup_subsys_state *css)  in css_visible()  argument
3062 	struct cgroup_subsys *ss = css->ss;  in css_visible()
3063 	struct cgroup *cgrp = css->cgroup;  in css_visible()
3094 			struct cgroup_subsys_state *css = cgroup_css(dsct, ss);  in cgroup_apply_control_enable()  local
3099 			if (!css) {  in cgroup_apply_control_enable()
3100 				css = css_create(dsct, ss);  in cgroup_apply_control_enable()
3101 				if (IS_ERR(css))  in cgroup_apply_control_enable()
3102 					return PTR_ERR(css);  in cgroup_apply_control_enable()
3105 			WARN_ON_ONCE(percpu_ref_is_dying(&css->refcnt));  in cgroup_apply_control_enable()
3107 			if (css_visible(css)) {  in cgroup_apply_control_enable()
3108 				ret = css_populate_dir(css);  in cgroup_apply_control_enable()
3140 			struct cgroup_subsys_state *css = cgroup_css(dsct, ss);  in cgroup_apply_control_disable()  local
3142 			if (!css)  in cgroup_apply_control_disable()
3145 			WARN_ON_ONCE(percpu_ref_is_dying(&css->refcnt));  in cgroup_apply_control_disable()
3147 			if (css->parent &&  in cgroup_apply_control_disable()
3149 				kill_css(css);  in cgroup_apply_control_disable()
3150 			} else if (!css_visible(css)) {  in cgroup_apply_control_disable()
3151 				css_clear_dir(css);  in cgroup_apply_control_disable()
3153 					ss->css_reset(css);  in cgroup_apply_control_disable()
3557 	struct cgroup_subsys_state *css;  in cgroup_extra_stat_show()  local
3563 	css = cgroup_tryget_css(cgrp, ss);  in cgroup_extra_stat_show()
3564 	if (!css)  in cgroup_extra_stat_show()
3567 	ret = ss->css_extra_stat_show(seq, css);  in cgroup_extra_stat_show()
3568 	css_put(css);  in cgroup_extra_stat_show()
3746 	struct cgroup_subsys_state *css;  in cgroup_kill()  local
3751 	cgroup_for_each_live_descendant_pre(dsct, css, cgrp)  in cgroup_kill()
3811 	struct cgroup_subsys_state *css;  in cgroup_file_write()  local
3838 	css = cgroup_css(cgrp, cft->ss);  in cgroup_file_write()
3845 			ret = cft->write_u64(css, cft, v);  in cgroup_file_write()
3850 			ret = cft->write_s64(css, cft, v);  in cgroup_file_write()
3887 	struct cgroup_subsys_state *css = seq_css(m);  in cgroup_seqfile_show()  local
3893 		seq_printf(m, "%llu\n", cft->read_u64(css, cft));  in cgroup_seqfile_show()
3895 		seq_printf(m, "%lld\n", cft->read_s64(css, cft));  in cgroup_seqfile_show()
3942 static int cgroup_add_file(struct cgroup_subsys_state *css, struct cgroup *cgrp,  in cgroup_add_file()  argument
3968 		struct cgroup_file *cfile = (void *)css + cft->file_offset;  in cgroup_add_file()
3990 static int cgroup_addrm_files(struct cgroup_subsys_state *css,  in cgroup_addrm_files()  argument
4015 			ret = cgroup_add_file(css, cgrp, cft);  in cgroup_addrm_files()
4034 	struct cgroup_subsys_state *css;  in cgroup_apply_cftypes()  local
4040 	css_for_each_descendant_pre(css, cgroup_css(root, ss)) {  in cgroup_apply_cftypes()
4041 		struct cgroup *cgrp = css->cgroup;  in cgroup_apply_cftypes()
4043 		if (!(css->flags & CSS_VISIBLE))  in cgroup_apply_cftypes()
4046 		ret = cgroup_addrm_files(css, cgrp, cfts, is_add);  in cgroup_apply_cftypes()
4454 bool css_has_online_children(struct cgroup_subsys_state *css)  in css_has_online_children()  argument
4460 	css_for_each_child(child, css) {  in css_has_online_children()
4652 void css_task_iter_start(struct cgroup_subsys_state *css, unsigned int flags,  in css_task_iter_start()  argument
4659 	it->ss = css->ss;  in css_task_iter_start()
4663 		it->cset_pos = &css->cgroup->e_csets[css->ss->id];  in css_task_iter_start()
4665 		it->cset_pos = &css->cgroup->cset_links;  in css_task_iter_start()
5047 	struct cgroup_subsys_state *css = container_of(to_rcu_work(work),  in css_free_rwork_fn()  local
5049 	struct cgroup_subsys *ss = css->ss;  in css_free_rwork_fn()
5050 	struct cgroup *cgrp = css->cgroup;  in css_free_rwork_fn()
5052 	percpu_ref_exit(&css->refcnt);  in css_free_rwork_fn()
5056 		struct cgroup_subsys_state *parent = css->parent;  in css_free_rwork_fn()
5057 		int id = css->id;  in css_free_rwork_fn()
5059 		ss->css_free(css);  in css_free_rwork_fn()
5096 	struct cgroup_subsys_state *css =  in css_release_work_fn()  local
5098 	struct cgroup_subsys *ss = css->ss;  in css_release_work_fn()
5099 	struct cgroup *cgrp = css->cgroup;  in css_release_work_fn()
5103 	css->flags |= CSS_RELEASED;  in css_release_work_fn()
5104 	list_del_rcu(&css->sibling);  in css_release_work_fn()
5108 		if (!list_empty(&css->rstat_css_node)) {  in css_release_work_fn()
5110 			list_del_rcu(&css->rstat_css_node);  in css_release_work_fn()
5113 		cgroup_idr_replace(&ss->css_idr, NULL, css->id);  in css_release_work_fn()
5115 			ss->css_released(css);  in css_release_work_fn()
5144 	INIT_RCU_WORK(&css->destroy_rwork, css_free_rwork_fn);  in css_release_work_fn()
5145 	queue_rcu_work(cgroup_destroy_wq, &css->destroy_rwork);  in css_release_work_fn()
5150 	struct cgroup_subsys_state *css =  in css_release()  local
5153 	INIT_WORK(&css->destroy_work, css_release_work_fn);  in css_release()
5154 	queue_work(cgroup_destroy_wq, &css->destroy_work);  in css_release()
5157 static void init_and_link_css(struct cgroup_subsys_state *css,  in init_and_link_css()  argument
5164 	memset(css, 0, sizeof(*css));  in init_and_link_css()
5165 	css->cgroup = cgrp;  in init_and_link_css()
5166 	css->ss = ss;  in init_and_link_css()
5167 	css->id = -1;  in init_and_link_css()
5168 	INIT_LIST_HEAD(&css->sibling);  in init_and_link_css()
5169 	INIT_LIST_HEAD(&css->children);  in init_and_link_css()
5170 	INIT_LIST_HEAD(&css->rstat_css_node);  in init_and_link_css()
5171 	css->serial_nr = css_serial_nr_next++;  in init_and_link_css()
5172 	atomic_set(&css->online_cnt, 0);  in init_and_link_css()
5175 		css->parent = cgroup_css(cgroup_parent(cgrp), ss);  in init_and_link_css()
5176 		css_get(css->parent);  in init_and_link_css()
5180 		list_add_rcu(&css->rstat_css_node, &cgrp->rstat_css_list);  in init_and_link_css()
5186 static int online_css(struct cgroup_subsys_state *css)  in online_css()  argument
5188 	struct cgroup_subsys *ss = css->ss;  in online_css()
5194 		ret = ss->css_online(css);  in online_css()
5196 		css->flags |= CSS_ONLINE;  in online_css()
5197 		rcu_assign_pointer(css->cgroup->subsys[ss->id], css);  in online_css()
5199 		atomic_inc(&css->online_cnt);  in online_css()
5200 		if (css->parent)  in online_css()
5201 			atomic_inc(&css->parent->online_cnt);  in online_css()
5207 static void offline_css(struct cgroup_subsys_state *css)  in offline_css()  argument
5209 	struct cgroup_subsys *ss = css->ss;  in offline_css()
5213 	if (!(css->flags & CSS_ONLINE))  in offline_css()
5217 		ss->css_offline(css);  in offline_css()
5219 	css->flags &= ~CSS_ONLINE;  in offline_css()
5220 	RCU_INIT_POINTER(css->cgroup->subsys[ss->id], NULL);  in offline_css()
5222 	wake_up_all(&css->cgroup->offline_waitq);  in offline_css()
5239 	struct cgroup_subsys_state *css;  in css_create()  local
5244 	css = ss->css_alloc(parent_css);  in css_create()
5245 	if (!css)  in css_create()
5246 		css = ERR_PTR(-ENOMEM);  in css_create()
5247 	if (IS_ERR(css))  in css_create()
5248 		return css;  in css_create()
5250 	init_and_link_css(css, ss, cgrp);  in css_create()
5252 	err = percpu_ref_init(&css->refcnt, css_release, 0, GFP_KERNEL);  in css_create()
5259 	css->id = err;  in css_create()
5262 	list_add_tail_rcu(&css->sibling, &parent_css->children);  in css_create()
5263 	cgroup_idr_replace(&ss->css_idr, css, css->id);  in css_create()
5265 	err = online_css(css);  in css_create()
5269 	return css;  in css_create()
5272 	list_del_rcu(&css->sibling);  in css_create()
5274 	list_del_rcu(&css->rstat_css_node);  in css_create()
5275 	INIT_RCU_WORK(&css->destroy_rwork, css_free_rwork_fn);  in css_create()
5276 	queue_rcu_work(cgroup_destroy_wq, &css->destroy_rwork);  in css_create()
5488 	struct cgroup_subsys_state *css =  in css_killed_work_fn()  local
5494 		offline_css(css);  in css_killed_work_fn()
5495 		css_put(css);  in css_killed_work_fn()
5497 		css = css->parent;  in css_killed_work_fn()
5498 	} while (css && atomic_dec_and_test(&css->online_cnt));  in css_killed_work_fn()
5506 	struct cgroup_subsys_state *css =  in css_killed_ref_fn()  local
5509 	if (atomic_dec_and_test(&css->online_cnt)) {  in css_killed_ref_fn()
5510 		INIT_WORK(&css->destroy_work, css_killed_work_fn);  in css_killed_ref_fn()
5511 		queue_work(cgroup_destroy_wq, &css->destroy_work);  in css_killed_ref_fn()
5524 static void kill_css(struct cgroup_subsys_state *css)  in kill_css()  argument
5528 	if (css->flags & CSS_DYING)  in kill_css()
5531 	css->flags |= CSS_DYING;  in kill_css()
5537 	css_clear_dir(css);  in kill_css()
5543 	css_get(css);  in kill_css()
5555 	percpu_ref_kill_and_confirm(&css->refcnt, css_killed_ref_fn);  in kill_css()
5586 	struct cgroup_subsys_state *css;  in cgroup_destroy_locked()  local
5621 	for_each_css(css, ssid, cgrp)  in cgroup_destroy_locked()
5622 		kill_css(css);  in cgroup_destroy_locked()
5680 	struct cgroup_subsys_state *css;  in cgroup_init_subsys()  local
5691 	css = ss->css_alloc(cgroup_css(&cgrp_dfl_root.cgrp, ss));  in cgroup_init_subsys()
5693 	BUG_ON(IS_ERR(css));  in cgroup_init_subsys()
5694 	init_and_link_css(css, ss, &cgrp_dfl_root.cgrp);  in cgroup_init_subsys()
5700 	css->flags |= CSS_NO_REF;  in cgroup_init_subsys()
5704 		css->id = 1;  in cgroup_init_subsys()
5706 		css->id = cgroup_idr_alloc(&ss->css_idr, css, 1, 2, GFP_KERNEL);  in cgroup_init_subsys()
5707 		BUG_ON(css->id < 0);  in cgroup_init_subsys()
5714 	init_css_set.subsys[ss->id] = css;  in cgroup_init_subsys()
5726 	BUG_ON(online_css(css));  in cgroup_init_subsys()
5808 			struct cgroup_subsys_state *css =  in cgroup_init()  local
5811 			css->id = cgroup_idr_alloc(&ss->css_idr, css, 1, 2,  in cgroup_init()
5813 			BUG_ON(css->id < 0);  in cgroup_init()
6022 	struct cgroup_subsys_state *css;  in cgroup_get_from_file()  local
6025 	css = css_tryget_online_from_dir(f->f_path.dentry, NULL);  in cgroup_get_from_file()
6026 	if (IS_ERR(css))  in cgroup_get_from_file()
6027 		return ERR_CAST(css);  in cgroup_get_from_file()
6029 	cgrp = css->cgroup;  in cgroup_get_from_file()
6431 	struct cgroup_subsys_state *css = NULL;  in css_tryget_online_from_dir()  local
6448 		css = cgroup_css(cgrp, ss);  in css_tryget_online_from_dir()
6450 	if (!css || !css_tryget_online(css))  in css_tryget_online_from_dir()
6451 		css = ERR_PTR(-ENOENT);  in css_tryget_online_from_dir()
6454 	return css;  in css_tryget_online_from_dir()