297 	return cgrp->root == &cgrp_dfl_root;  in cgroup_on_dfl()
379 	if (!(cgrp->root->subsys_mask & (1 << ss->id)))  in cgroup_e_css()
549 #define for_each_root(root)						\  argument
550 	list_for_each_entry((root), &cgroup_roots, root_list)
857 		BUG_ON(cgrp1->root != cgrp2->root);  in compare_css_sets()
866 		if (cgrp1->root == new_cgrp->root) {  in compare_css_sets()
887 	struct cgroup_root *root = cgrp->root;  in find_existing_css_set()  local
899 		if (root->subsys_mask & (1UL << i)) {  in find_existing_css_set()
1054 		if (c->root == cgrp->root)  in find_css_set()
1084 	return root_cgrp->root;  in cgroup_root_from_kf()
1087 static int cgroup_init_root_id(struct cgroup_root *root)  in cgroup_init_root_id()  argument
1093 	id = idr_alloc_cyclic(&cgroup_hierarchy_idr, root, 0, 0, GFP_KERNEL);  in cgroup_init_root_id()
1097 	root->hierarchy_id = id;  in cgroup_init_root_id()
1101 static void cgroup_exit_root_id(struct cgroup_root *root)  in cgroup_exit_root_id()  argument
1105 	if (root->hierarchy_id) {  in cgroup_exit_root_id()
1106 		idr_remove(&cgroup_hierarchy_idr, root->hierarchy_id);  in cgroup_exit_root_id()
1107 		root->hierarchy_id = 0;  in cgroup_exit_root_id()
1111 static void cgroup_free_root(struct cgroup_root *root)  in cgroup_free_root()  argument
1113 	if (root) {  in cgroup_free_root()
1115 		WARN_ON_ONCE(root->hierarchy_id);  in cgroup_free_root()
1117 		idr_destroy(&root->cgroup_idr);  in cgroup_free_root()
1118 		kfree(root);  in cgroup_free_root()
1122 static void cgroup_destroy_root(struct cgroup_root *root)  in cgroup_destroy_root()  argument
1124 	struct cgroup *cgrp = &root->cgrp;  in cgroup_destroy_root()
1129 	BUG_ON(atomic_read(&root->nr_cgrps));  in cgroup_destroy_root()
1133 	rebind_subsystems(&cgrp_dfl_root, root->subsys_mask);  in cgroup_destroy_root()
1149 	if (!list_empty(&root->root_list)) {  in cgroup_destroy_root()
1150 		list_del(&root->root_list);  in cgroup_destroy_root()
1154 	cgroup_exit_root_id(root);  in cgroup_destroy_root()
1158 	kernfs_destroy_root(root->kf_root);  in cgroup_destroy_root()
1159 	cgroup_free_root(root);  in cgroup_destroy_root()
1164 					    struct cgroup_root *root)  in cset_cgroup_from_root()  argument
1172 		res = &root->cgrp;  in cset_cgroup_from_root()
1179 			if (c->root == root) {  in cset_cgroup_from_root()
1195 					    struct cgroup_root *root)  in task_cgroup_from_root()  argument
1202 	return cset_cgroup_from_root(task_css_set(task), root);  in task_cgroup_from_root()
1240 	    !(cgrp->root->flags & CGRP_ROOT_NOPREFIX))  in cgroup_file_name()
1312 			new_ss_mask &= cgrp->root->subsys_mask;  in cgroup_calc_child_subsys_mask()
1488 		if (css_next_child(NULL, cgroup_css(&ss->root->cgrp, ss)))  in rebind_subsystems()
1492 		if (ss->root != &cgrp_dfl_root && dst_root != &cgrp_dfl_root)  in rebind_subsystems()
1502 		struct cgroup *scgrp = &ss->root->cgrp;  in rebind_subsystems()
1537 		struct cgroup_root *src_root = ss->root;  in rebind_subsystems()
1548 		ss->root = dst_root;  in rebind_subsystems()
1582 	struct cgroup_root *root = cgroup_root_from_kf(kf_root);  in cgroup_show_options()  local
1586 	if (root != &cgrp_dfl_root)  in cgroup_show_options()
1588 			if (root->subsys_mask & (1 << ssid))  in cgroup_show_options()
1590 	if (root->flags & CGRP_ROOT_NOPREFIX)  in cgroup_show_options()
1592 	if (root->flags & CGRP_ROOT_XATTR)  in cgroup_show_options()
1596 	if (strlen(root->release_agent_path))  in cgroup_show_options()
1598 				root->release_agent_path);  in cgroup_show_options()
1601 	if (test_bit(CGRP_CPUSET_CLONE_CHILDREN, &root->cgrp.flags))  in cgroup_show_options()
1603 	if (strlen(root->name))  in cgroup_show_options()
1604 		seq_show_option(seq, "name", root->name);  in cgroup_show_options()
1764 	struct cgroup_root *root = cgroup_root_from_kf(kf_root);  in cgroup_remount()  local
1768 	if (root == &cgrp_dfl_root) {  in cgroup_remount()
1780 	if (opts.subsys_mask != root->subsys_mask || opts.release_agent)  in cgroup_remount()
1784 	added_mask = opts.subsys_mask & ~root->subsys_mask;  in cgroup_remount()
1785 	removed_mask = root->subsys_mask & ~opts.subsys_mask;  in cgroup_remount()
1788 	if ((opts.flags ^ root->flags) ||  in cgroup_remount()
1789 	    (opts.name && strcmp(opts.name, root->name))) {  in cgroup_remount()
1791 		       opts.flags, opts.name ?: "", root->flags, root->name);  in cgroup_remount()
1797 	if (!list_empty(&root->cgrp.self.children)) {  in cgroup_remount()
1802 	ret = rebind_subsystems(root, added_mask);  in cgroup_remount()
1810 		strcpy(root->release_agent_path, opts.release_agent);  in cgroup_remount()
1894 static void init_cgroup_root(struct cgroup_root *root,  in init_cgroup_root()  argument
1897 	struct cgroup *cgrp = &root->cgrp;  in init_cgroup_root()
1899 	INIT_LIST_HEAD(&root->root_list);  in init_cgroup_root()
1900 	atomic_set(&root->nr_cgrps, 1);  in init_cgroup_root()
1901 	cgrp->root = root;  in init_cgroup_root()
1903 	idr_init(&root->cgroup_idr);  in init_cgroup_root()
1905 	root->flags = opts->flags;  in init_cgroup_root()
1907 		strcpy(root->release_agent_path, opts->release_agent);  in init_cgroup_root()
1909 		strcpy(root->name, opts->name);  in init_cgroup_root()
1911 		set_bit(CGRP_CPUSET_CLONE_CHILDREN, &root->cgrp.flags);  in init_cgroup_root()
1914 static int cgroup_setup_root(struct cgroup_root *root, unsigned long ss_mask)  in cgroup_setup_root()  argument
1917 	struct cgroup *root_cgrp = &root->cgrp;  in cgroup_setup_root()
1923 	ret = cgroup_idr_alloc(&root->cgroup_idr, root_cgrp, 1, 2, GFP_KERNEL);  in cgroup_setup_root()
1943 	ret = cgroup_init_root_id(root);  in cgroup_setup_root()
1947 	root->kf_root = kernfs_create_root(&cgroup_kf_syscall_ops,  in cgroup_setup_root()
1950 	if (IS_ERR(root->kf_root)) {  in cgroup_setup_root()
1951 		ret = PTR_ERR(root->kf_root);  in cgroup_setup_root()
1954 	root_cgrp->kn = root->kf_root->kn;  in cgroup_setup_root()
1960 	ret = rebind_subsystems(root, ss_mask);  in cgroup_setup_root()
1969 	list_add(&root->root_list, &cgroup_roots);  in cgroup_setup_root()
1985 	BUG_ON(atomic_read(&root->nr_cgrps) != 1);  in cgroup_setup_root()
1992 	kernfs_destroy_root(root->kf_root);  in cgroup_setup_root()
1993 	root->kf_root = NULL;  in cgroup_setup_root()
1995 	cgroup_exit_root_id(root);  in cgroup_setup_root()
2009 	struct cgroup_root *root;  in cgroup_mount()  local
2033 		root = &cgrp_dfl_root;  in cgroup_mount()
2034 		cgroup_get(&root->cgrp);  in cgroup_mount()
2048 		    ss->root == &cgrp_dfl_root)  in cgroup_mount()
2051 		if (!percpu_ref_tryget_live(&ss->root->cgrp.self.refcnt)) {  in cgroup_mount()
2057 		cgroup_put(&ss->root->cgrp);  in cgroup_mount()
2060 	for_each_root(root) {  in cgroup_mount()
2063 		if (root == &cgrp_dfl_root)  in cgroup_mount()
2072 			if (strcmp(opts.name, root->name))  in cgroup_mount()
2082 		    (opts.subsys_mask != root->subsys_mask)) {  in cgroup_mount()
2089 		if (root->flags ^ opts.flags)  in cgroup_mount()
2104 		pinned_sb = kernfs_pin_sb(root->kf_root, NULL);  in cgroup_mount()
2106 		    !percpu_ref_tryget_live(&root->cgrp.self.refcnt)) {  in cgroup_mount()
2129 	root = kzalloc(sizeof(*root), GFP_KERNEL);  in cgroup_mount()
2130 	if (!root) {  in cgroup_mount()
2135 	init_cgroup_root(root, &opts);  in cgroup_mount()
2137 	ret = cgroup_setup_root(root, opts.subsys_mask);  in cgroup_mount()
2139 		cgroup_free_root(root);  in cgroup_mount()
2150 	dentry = kernfs_mount(fs_type, flags, root->kf_root,  in cgroup_mount()
2153 		cgroup_put(&root->cgrp);  in cgroup_mount()
2170 	struct cgroup_root *root = cgroup_root_from_kf(kf_root);  in cgroup_kill_sb()  local
2179 	if (!list_empty(&root->cgrp.self.children) ||  in cgroup_kill_sb()
2180 	    root == &cgrp_dfl_root)  in cgroup_kill_sb()
2181 		cgroup_put(&root->cgrp);  in cgroup_kill_sb()
2183 		percpu_ref_kill(&root->cgrp.self.refcnt);  in cgroup_kill_sb()
2209 	struct cgroup_root *root;  in task_cgroup_path()  local
2217 	root = idr_get_next(&cgroup_hierarchy_idr, &hierarchy_id);  in task_cgroup_path()
2219 	if (root) {  in task_cgroup_path()
2220 		cgrp = task_cgroup_from_root(task, root);  in task_cgroup_path()
2509 	src_cgrp = cset_cgroup_from_root(src_cset, dst_cgrp->root);  in cgroup_migrate_add_src()
2789 	struct cgroup_root *root;  in cgroup_attach_task_all()  local
2793 	for_each_root(root) {  in cgroup_attach_task_all()
2796 		if (root == &cgrp_dfl_root)  in cgroup_attach_task_all()
2800 		from_cgrp = task_cgroup_from_root(from, root);  in cgroup_attach_task_all()
2830 	BUILD_BUG_ON(sizeof(cgrp->root->release_agent_path) < PATH_MAX);  in cgroup_release_agent_write()
2836 	strlcpy(cgrp->root->release_agent_path, strstrip(buf),  in cgroup_release_agent_write()
2837 		sizeof(cgrp->root->release_agent_path));  in cgroup_release_agent_write()
2848 	seq_puts(seq, cgrp->root->release_agent_path);  in cgroup_release_agent_show()
2881 	cgroup_print_ss_mask(seq, cgrp->root->subsys_mask &  in cgroup_root_controllers_show()
3433 	struct cgroup *root = &ss->root->cgrp;  in cgroup_apply_cftypes()  local
3440 	css_for_each_descendant_pre(css, cgroup_css(root, ss)) {  in cgroup_apply_cftypes()
3452 		kernfs_activate(root->kn);  in cgroup_apply_cftypes()
3733 			struct cgroup_subsys_state *root)  in css_next_descendant_pre()  argument
3741 		return root;  in css_next_descendant_pre()
3749 	while (pos != root) {  in css_next_descendant_pre()
3827 			 struct cgroup_subsys_state *root)  in css_next_descendant_post()  argument
3835 		return css_leftmost_descendant(root);  in css_next_descendant_post()
3838 	if (pos == root)  in css_next_descendant_post()
4706 		atomic_dec(&cgrp->root->nr_cgrps);  in css_free_work_fn()
4726 			cgroup_destroy_root(cgrp->root);  in css_free_work_fn()
4759 		cgroup_idr_remove(&cgrp->root->cgroup_idr, cgrp->id);  in css_release_work_fn()
4925 	struct cgroup_root *root;  in cgroup_mkdir()  local
4938 	root = parent->root;  in cgroup_mkdir()
4955 	cgrp->id = cgroup_idr_alloc(&root->cgroup_idr, NULL, 2, 0, GFP_KERNEL);  in cgroup_mkdir()
4964 	cgrp->root = root;  in cgroup_mkdir()
4990 	atomic_inc(&root->nr_cgrps);  in cgroup_mkdir()
4997 	cgroup_idr_replace(&root->cgroup_idr, cgrp, cgrp->id);  in cgroup_mkdir()
5032 	cgroup_idr_remove(&root->cgroup_idr, cgrp->id);  in cgroup_mkdir()
5232 	ss->root = &cgrp_dfl_root;  in cgroup_init_subsys()
5422 	struct cgroup_root *root;  in proc_cgroup_show()  local
5432 	for_each_root(root) {  in proc_cgroup_show()
5437 		if (root == &cgrp_dfl_root && !cgrp_dfl_root_visible)  in proc_cgroup_show()
5440 		seq_printf(m, "%d:", root->hierarchy_id);  in proc_cgroup_show()
5441 		if (root != &cgrp_dfl_root)  in proc_cgroup_show()
5443 				if (root->subsys_mask & (1 << ssid))  in proc_cgroup_show()
5446 		if (strlen(root->name))  in proc_cgroup_show()
5448 				   root->name);  in proc_cgroup_show()
5451 		cgrp = task_cgroup_from_root(tsk, root);  in proc_cgroup_show()
5505 			   ss->legacy_name, ss->root->hierarchy_id,  in proc_cgroupstats_show()
5506 			   atomic_read(&ss->root->nr_cgrps),  in proc_cgroupstats_show()
5757 	agentbuf = kstrdup(cgrp->root->release_agent_path, GFP_KERNEL);  in cgroup_release_agent()
5916 			   c->root->hierarchy_id, name_buf);  in current_css_set_cg_links_read()