1 // SPDX-License-Identifier: GPL-2.0
12 #include "cgroup-internal.h"
20 		return ERR_PTR(-ENOMEM);  in debug_css_alloc()
31  * debug_taskcount_read - return the number of tasks in a cgroup.
37 	return cgroup_task_count(css->cgroup);  in debug_taskcount_read()
42 	struct kernfs_open_file *of = seq->private;  in current_css_set_read()
48 	if (!cgroup_kn_lock_live(of->kn, false))  in current_css_set_read()
49 		return -ENODEV;  in current_css_set_read()
54 	refcnt = refcount_read(&cset->refcount);  in current_css_set_read()
55 	seq_printf(seq, "css_set %pK %d", cset, refcnt);  in current_css_set_read()
56 	if (refcnt > cset->nr_tasks)  in current_css_set_read()
57 		seq_printf(seq, " +%d", refcnt - cset->nr_tasks);  in current_css_set_read()
64 		css = cset->subsys[ss->id];  in current_css_set_read()
67 		seq_printf(seq, "%2d: %-4s\t- %p[%d]\n", ss->id, ss->name,  in current_css_set_read()
68 			  css, css->id);  in current_css_set_read()
72 	cgroup_kn_unlock(of->kn);  in current_css_set_read()
82 	count = refcount_read(&task_css_set(current)->refcount);  in current_css_set_refcount_read()
95 		return -ENOMEM;  in current_css_set_cg_links_read()
100 	list_for_each_entry(link, &cset->cgrp_links, cgrp_link) {  in current_css_set_cg_links_read()
101 		struct cgroup *c = link->cgrp;  in current_css_set_cg_links_read()
105 			   c->root->hierarchy_id, name_buf);  in current_css_set_cg_links_read()
122 	list_for_each_entry(link, &css->cgroup->cset_links, cset_link) {  in cgroup_css_links_read()
123 		struct css_set *cset = link->cset;  in cgroup_css_links_read()
126 		int refcnt = refcount_read(&cset->refcount);  in cgroup_css_links_read()
132 		seq_printf(seq, "css_set %pK", cset);  in cgroup_css_links_read()
133 		if (rcu_dereference_protected(cset->dom_cset, 1) != cset) {  in cgroup_css_links_read()
135 			seq_printf(seq, "=>%pK", cset->dom_cset);  in cgroup_css_links_read()
137 		if (!list_empty(&cset->threaded_csets)) {  in cgroup_css_links_read()
141 			list_for_each_entry(tcset, &cset->threaded_csets,  in cgroup_css_links_read()
144 				seq_printf(seq, "%pK", tcset);  in cgroup_css_links_read()
149 			if (refcnt - cset->nr_tasks > 0) {  in cgroup_css_links_read()
150 				int extra = refcnt - cset->nr_tasks;  in cgroup_css_links_read()
158 					extra--;  in cgroup_css_links_read()
164 		list_for_each_entry(task, &cset->tasks, cg_list) {  in cgroup_css_links_read()
170 		list_for_each_entry(task, &cset->mg_tasks, cg_list) {  in cgroup_css_links_read()
178 				   count - MAX_TASKS_SHOWN_PER_CSS);  in cgroup_css_links_read()
180 		if (cset->dead) {  in cgroup_css_links_read()
185 		WARN_ON(count != cset->nr_tasks);  in cgroup_css_links_read()
205 	struct kernfs_open_file *of = seq->private;  in cgroup_subsys_states_read()
212 	cgrp = cgroup_kn_lock_live(of->kn, false);  in cgroup_subsys_states_read()
214 		return -ENODEV;  in cgroup_subsys_states_read()
217 		css = rcu_dereference_check(cgrp->subsys[ss->id], true);  in cgroup_subsys_states_read()
224 		if (css->parent)  in cgroup_subsys_states_read()
225 			snprintf(pbuf, sizeof(pbuf) - 1, " P=%d",  in cgroup_subsys_states_read()
226 				 css->parent->id);  in cgroup_subsys_states_read()
227 		seq_printf(seq, "%2d: %-4s\t- %p[%d] %d%s\n", ss->id, ss->name,  in cgroup_subsys_states_read()
228 			  css, css->id,  in cgroup_subsys_states_read()
229 			  atomic_read(&css->online_cnt), pbuf);  in cgroup_subsys_states_read()
232 	cgroup_kn_unlock(of->kn);  in cgroup_subsys_states_read()
243 	seq_printf(seq, "%-17s: ", name);  in cgroup_masks_read_one()
249 		seq_puts(seq, ss->name);  in cgroup_masks_read_one()
257 	struct kernfs_open_file *of = seq->private;  in cgroup_masks_read()
260 	cgrp = cgroup_kn_lock_live(of->kn, false);  in cgroup_masks_read()
262 		return -ENODEV;  in cgroup_masks_read()
264 	cgroup_masks_read_one(seq, "subtree_control", cgrp->subtree_control);  in cgroup_masks_read()
265 	cgroup_masks_read_one(seq, "subtree_ss_mask", cgrp->subtree_ss_mask);  in cgroup_masks_read()
267 	cgroup_kn_unlock(of->kn);  in cgroup_masks_read()
273 	return (!cgroup_is_populated(css->cgroup) &&  in releasable_read()
274 		!css_has_online_children(&css->cgroup->self));  in releasable_read()