1#include "cgroup-internal.h"
2
3#include <linux/ctype.h>
4#include <linux/kmod.h>
5#include <linux/sort.h>
6#include <linux/delay.h>
7#include <linux/mm.h>
8#include <linux/sched/signal.h>
9#include <linux/sched/task.h>
10#include <linux/magic.h>
11#include <linux/slab.h>
12#include <linux/vmalloc.h>
13#include <linux/delayacct.h>
14#include <linux/pid_namespace.h>
15#include <linux/cgroupstats.h>
16
17#include <trace/events/cgroup.h>
18
19
20
21
22
23
24
25#define CGROUP_PIDLIST_DESTROY_DELAY HZ
26
27
28static u16 cgroup_no_v1_mask;
29
30
31
32
33
34static struct workqueue_struct *cgroup_pidlist_destroy_wq;
35
36
37
38
39
40static DEFINE_SPINLOCK(release_agent_path_lock);
41
42bool cgroup1_ssid_disabled(int ssid)
43{
44 return cgroup_no_v1_mask & (1 << ssid);
45}
46
47
48
49
50
51
52int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk)
53{
54 struct cgroup_root *root;
55 int retval = 0;
56
57 mutex_lock(&cgroup_mutex);
58 percpu_down_write(&cgroup_threadgroup_rwsem);
59 for_each_root(root) {
60 struct cgroup *from_cgrp;
61
62 if (root == &cgrp_dfl_root)
63 continue;
64
65 spin_lock_irq(&css_set_lock);
66 from_cgrp = task_cgroup_from_root(from, root);
67 spin_unlock_irq(&css_set_lock);
68
69 retval = cgroup_attach_task(from_cgrp, tsk, false);
70 if (retval)
71 break;
72 }
73 percpu_up_write(&cgroup_threadgroup_rwsem);
74 mutex_unlock(&cgroup_mutex);
75
76 return retval;
77}
78EXPORT_SYMBOL_GPL(cgroup_attach_task_all);
79
80
81
82
83
84
85
86
87
88
89
90
91int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from)
92{
93 DEFINE_CGROUP_MGCTX(mgctx);
94 struct cgrp_cset_link *link;
95 struct css_task_iter it;
96 struct task_struct *task;
97 int ret;
98
99 if (cgroup_on_dfl(to))
100 return -EINVAL;
101
102 if (!cgroup_may_migrate_to(to))
103 return -EBUSY;
104
105 mutex_lock(&cgroup_mutex);
106
107 percpu_down_write(&cgroup_threadgroup_rwsem);
108
109
110 spin_lock_irq(&css_set_lock);
111 list_for_each_entry(link, &from->cset_links, cset_link)
112 cgroup_migrate_add_src(link->cset, to, &mgctx);
113 spin_unlock_irq(&css_set_lock);
114
115 ret = cgroup_migrate_prepare_dst(&mgctx);
116 if (ret)
117 goto out_err;
118
119
120
121
122
123 do {
124 css_task_iter_start(&from->self, &it);
125 task = css_task_iter_next(&it);
126 if (task)
127 get_task_struct(task);
128 css_task_iter_end(&it);
129
130 if (task) {
131 ret = cgroup_migrate(task, false, &mgctx);
132 if (!ret)
133 trace_cgroup_transfer_tasks(to, task, false);
134 put_task_struct(task);
135 }
136 } while (task && !ret);
137out_err:
138 cgroup_migrate_finish(&mgctx);
139 percpu_up_write(&cgroup_threadgroup_rwsem);
140 mutex_unlock(&cgroup_mutex);
141 return ret;
142}
143
144
145
146
147
148
149
150
151
152
153
154
155enum cgroup_filetype {
156 CGROUP_FILE_PROCS,
157 CGROUP_FILE_TASKS,
158};
159
160
161
162
163
164
165
166struct cgroup_pidlist {
167
168
169
170
171 struct { enum cgroup_filetype type; struct pid_namespace *ns; } key;
172
173 pid_t *list;
174
175 int length;
176
177 struct list_head links;
178
179 struct cgroup *owner;
180
181 struct delayed_work destroy_dwork;
182};
183
184
185
186
187
188
189#define PIDLIST_TOO_LARGE(c) ((c) * sizeof(pid_t) > (PAGE_SIZE * 2))
190static void *pidlist_allocate(int count)
191{
192 if (PIDLIST_TOO_LARGE(count))
193 return vmalloc(count * sizeof(pid_t));
194 else
195 return kmalloc(count * sizeof(pid_t), GFP_KERNEL);
196}
197
198static void pidlist_free(void *p)
199{
200 kvfree(p);
201}
202
203
204
205
206
207void cgroup1_pidlist_destroy_all(struct cgroup *cgrp)
208{
209 struct cgroup_pidlist *l, *tmp_l;
210
211 mutex_lock(&cgrp->pidlist_mutex);
212 list_for_each_entry_safe(l, tmp_l, &cgrp->pidlists, links)
213 mod_delayed_work(cgroup_pidlist_destroy_wq, &l->destroy_dwork, 0);
214 mutex_unlock(&cgrp->pidlist_mutex);
215
216 flush_workqueue(cgroup_pidlist_destroy_wq);
217 BUG_ON(!list_empty(&cgrp->pidlists));
218}
219
220static void cgroup_pidlist_destroy_work_fn(struct work_struct *work)
221{
222 struct delayed_work *dwork = to_delayed_work(work);
223 struct cgroup_pidlist *l = container_of(dwork, struct cgroup_pidlist,
224 destroy_dwork);
225 struct cgroup_pidlist *tofree = NULL;
226
227 mutex_lock(&l->owner->pidlist_mutex);
228
229
230
231
232
233 if (!delayed_work_pending(dwork)) {
234 list_del(&l->links);
235 pidlist_free(l->list);
236 put_pid_ns(l->key.ns);
237 tofree = l;
238 }
239
240 mutex_unlock(&l->owner->pidlist_mutex);
241 kfree(tofree);
242}
243
244
245
246
247
248static int pidlist_uniq(pid_t *list, int length)
249{
250 int src, dest = 1;
251
252
253
254
255
256 if (length == 0 || length == 1)
257 return length;
258
259 for (src = 1; src < length; src++) {
260
261 while (list[src] == list[src-1]) {
262 src++;
263 if (src == length)
264 goto after;
265 }
266
267 list[dest] = list[src];
268 dest++;
269 }
270after:
271 return dest;
272}
273
274
275
276
277
278
279
280
281
282
283static int cmppid(const void *a, const void *b)
284{
285 return *(pid_t *)a - *(pid_t *)b;
286}
287
288static struct cgroup_pidlist *cgroup_pidlist_find(struct cgroup *cgrp,
289 enum cgroup_filetype type)
290{
291 struct cgroup_pidlist *l;
292
293 struct pid_namespace *ns = task_active_pid_ns(current);
294
295 lockdep_assert_held(&cgrp->pidlist_mutex);
296
297 list_for_each_entry(l, &cgrp->pidlists, links)
298 if (l->key.type == type && l->key.ns == ns)
299 return l;
300 return NULL;
301}
302
303
304
305
306
307
308
309static struct cgroup_pidlist *cgroup_pidlist_find_create(struct cgroup *cgrp,
310 enum cgroup_filetype type)
311{
312 struct cgroup_pidlist *l;
313
314 lockdep_assert_held(&cgrp->pidlist_mutex);
315
316 l = cgroup_pidlist_find(cgrp, type);
317 if (l)
318 return l;
319
320
321 l = kzalloc(sizeof(struct cgroup_pidlist), GFP_KERNEL);
322 if (!l)
323 return l;
324
325 INIT_DELAYED_WORK(&l->destroy_dwork, cgroup_pidlist_destroy_work_fn);
326 l->key.type = type;
327
328 l->key.ns = get_pid_ns(task_active_pid_ns(current));
329 l->owner = cgrp;
330 list_add(&l->links, &cgrp->pidlists);
331 return l;
332}
333
334
335
336
337
338int cgroup_task_count(const struct cgroup *cgrp)
339{
340 int count = 0;
341 struct cgrp_cset_link *link;
342
343 spin_lock_irq(&css_set_lock);
344 list_for_each_entry(link, &cgrp->cset_links, cset_link)
345 count += link->cset->nr_tasks;
346 spin_unlock_irq(&css_set_lock);
347 return count;
348}
349
350
351
352
353static int pidlist_array_load(struct cgroup *cgrp, enum cgroup_filetype type,
354 struct cgroup_pidlist **lp)
355{
356 pid_t *array;
357 int length;
358 int pid, n = 0;
359 struct css_task_iter it;
360 struct task_struct *tsk;
361 struct cgroup_pidlist *l;
362
363 lockdep_assert_held(&cgrp->pidlist_mutex);
364
365
366
367
368
369
370
371 length = cgroup_task_count(cgrp);
372 array = pidlist_allocate(length);
373 if (!array)
374 return -ENOMEM;
375
376 css_task_iter_start(&cgrp->self, &it);
377 while ((tsk = css_task_iter_next(&it))) {
378 if (unlikely(n == length))
379 break;
380
381 if (type == CGROUP_FILE_PROCS)
382 pid = task_tgid_vnr(tsk);
383 else
384 pid = task_pid_vnr(tsk);
385 if (pid > 0)
386 array[n++] = pid;
387 }
388 css_task_iter_end(&it);
389 length = n;
390
391 sort(array, length, sizeof(pid_t), cmppid, NULL);
392 if (type == CGROUP_FILE_PROCS)
393 length = pidlist_uniq(array, length);
394
395 l = cgroup_pidlist_find_create(cgrp, type);
396 if (!l) {
397 pidlist_free(array);
398 return -ENOMEM;
399 }
400
401
402 pidlist_free(l->list);
403 l->list = array;
404 l->length = length;
405 *lp = l;
406 return 0;
407}
408
409
410
411
412
413
414
415static void *cgroup_pidlist_start(struct seq_file *s, loff_t *pos)
416{
417
418
419
420
421
422
423 struct kernfs_open_file *of = s->private;
424 struct cgroup *cgrp = seq_css(s)->cgroup;
425 struct cgroup_pidlist *l;
426 enum cgroup_filetype type = seq_cft(s)->private;
427 int index = 0, pid = *pos;
428 int *iter, ret;
429
430 mutex_lock(&cgrp->pidlist_mutex);
431
432
433
434
435
436
437
438 if (of->priv)
439 of->priv = cgroup_pidlist_find(cgrp, type);
440
441
442
443
444
445 if (!of->priv) {
446 ret = pidlist_array_load(cgrp, type,
447 (struct cgroup_pidlist **)&of->priv);
448 if (ret)
449 return ERR_PTR(ret);
450 }
451 l = of->priv;
452
453 if (pid) {
454 int end = l->length;
455
456 while (index < end) {
457 int mid = (index + end) / 2;
458 if (l->list[mid] == pid) {
459 index = mid;
460 break;
461 } else if (l->list[mid] <= pid)
462 index = mid + 1;
463 else
464 end = mid;
465 }
466 }
467
468 if (index >= l->length)
469 return NULL;
470
471 iter = l->list + index;
472 *pos = *iter;
473 return iter;
474}
475
476static void cgroup_pidlist_stop(struct seq_file *s, void *v)
477{
478 struct kernfs_open_file *of = s->private;
479 struct cgroup_pidlist *l = of->priv;
480
481 if (l)
482 mod_delayed_work(cgroup_pidlist_destroy_wq, &l->destroy_dwork,
483 CGROUP_PIDLIST_DESTROY_DELAY);
484 mutex_unlock(&seq_css(s)->cgroup->pidlist_mutex);
485}
486
487static void *cgroup_pidlist_next(struct seq_file *s, void *v, loff_t *pos)
488{
489 struct kernfs_open_file *of = s->private;
490 struct cgroup_pidlist *l = of->priv;
491 pid_t *p = v;
492 pid_t *end = l->list + l->length;
493
494
495
496
497 p++;
498 if (p >= end) {
499 return NULL;
500 } else {
501 *pos = *p;
502 return p;
503 }
504}
505
506static int cgroup_pidlist_show(struct seq_file *s, void *v)
507{
508 seq_printf(s, "%d\n", *(int *)v);
509
510 return 0;
511}
512
513static ssize_t cgroup_tasks_write(struct kernfs_open_file *of,
514 char *buf, size_t nbytes, loff_t off)
515{
516 return __cgroup_procs_write(of, buf, nbytes, off, false);
517}
518
519static ssize_t cgroup_release_agent_write(struct kernfs_open_file *of,
520 char *buf, size_t nbytes, loff_t off)
521{
522 struct cgroup *cgrp;
523
524 BUILD_BUG_ON(sizeof(cgrp->root->release_agent_path) < PATH_MAX);
525
526 cgrp = cgroup_kn_lock_live(of->kn, false);
527 if (!cgrp)
528 return -ENODEV;
529 spin_lock(&release_agent_path_lock);
530 strlcpy(cgrp->root->release_agent_path, strstrip(buf),
531 sizeof(cgrp->root->release_agent_path));
532 spin_unlock(&release_agent_path_lock);
533 cgroup_kn_unlock(of->kn);
534 return nbytes;
535}
536
537static int cgroup_release_agent_show(struct seq_file *seq, void *v)
538{
539 struct cgroup *cgrp = seq_css(seq)->cgroup;
540
541 spin_lock(&release_agent_path_lock);
542 seq_puts(seq, cgrp->root->release_agent_path);
543 spin_unlock(&release_agent_path_lock);
544 seq_putc(seq, '\n');
545 return 0;
546}
547
548static int cgroup_sane_behavior_show(struct seq_file *seq, void *v)
549{
550 seq_puts(seq, "0\n");
551 return 0;
552}
553
554static u64 cgroup_read_notify_on_release(struct cgroup_subsys_state *css,
555 struct cftype *cft)
556{
557 return notify_on_release(css->cgroup);
558}
559
560static int cgroup_write_notify_on_release(struct cgroup_subsys_state *css,
561 struct cftype *cft, u64 val)
562{
563 if (val)
564 set_bit(CGRP_NOTIFY_ON_RELEASE, &css->cgroup->flags);
565 else
566 clear_bit(CGRP_NOTIFY_ON_RELEASE, &css->cgroup->flags);
567 return 0;
568}
569
570static u64 cgroup_clone_children_read(struct cgroup_subsys_state *css,
571 struct cftype *cft)
572{
573 return test_bit(CGRP_CPUSET_CLONE_CHILDREN, &css->cgroup->flags);
574}
575
576static int cgroup_clone_children_write(struct cgroup_subsys_state *css,
577 struct cftype *cft, u64 val)
578{
579 if (val)
580 set_bit(CGRP_CPUSET_CLONE_CHILDREN, &css->cgroup->flags);
581 else
582 clear_bit(CGRP_CPUSET_CLONE_CHILDREN, &css->cgroup->flags);
583 return 0;
584}
585
586
587struct cftype cgroup1_base_files[] = {
588 {
589 .name = "cgroup.procs",
590 .seq_start = cgroup_pidlist_start,
591 .seq_next = cgroup_pidlist_next,
592 .seq_stop = cgroup_pidlist_stop,
593 .seq_show = cgroup_pidlist_show,
594 .private = CGROUP_FILE_PROCS,
595 .write = cgroup_procs_write,
596 },
597 {
598 .name = "cgroup.clone_children",
599 .read_u64 = cgroup_clone_children_read,
600 .write_u64 = cgroup_clone_children_write,
601 },
602 {
603 .name = "cgroup.sane_behavior",
604 .flags = CFTYPE_ONLY_ON_ROOT,
605 .seq_show = cgroup_sane_behavior_show,
606 },
607 {
608 .name = "tasks",
609 .seq_start = cgroup_pidlist_start,
610 .seq_next = cgroup_pidlist_next,
611 .seq_stop = cgroup_pidlist_stop,
612 .seq_show = cgroup_pidlist_show,
613 .private = CGROUP_FILE_TASKS,
614 .write = cgroup_tasks_write,
615 },
616 {
617 .name = "notify_on_release",
618 .read_u64 = cgroup_read_notify_on_release,
619 .write_u64 = cgroup_write_notify_on_release,
620 },
621 {
622 .name = "release_agent",
623 .flags = CFTYPE_ONLY_ON_ROOT,
624 .seq_show = cgroup_release_agent_show,
625 .write = cgroup_release_agent_write,
626 .max_write_len = PATH_MAX - 1,
627 },
628 { }
629};
630
631
632static int proc_cgroupstats_show(struct seq_file *m, void *v)
633{
634 struct cgroup_subsys *ss;
635 int i;
636
637 seq_puts(m, "#subsys_name\thierarchy\tnum_cgroups\tenabled\n");
638
639
640
641
642
643 mutex_lock(&cgroup_mutex);
644
645 for_each_subsys(ss, i)
646 seq_printf(m, "%s\t%d\t%d\t%d\n",
647 ss->legacy_name, ss->root->hierarchy_id,
648 atomic_read(&ss->root->nr_cgrps),
649 cgroup_ssid_enabled(i));
650
651 mutex_unlock(&cgroup_mutex);
652 return 0;
653}
654
655static int cgroupstats_open(struct inode *inode, struct file *file)
656{
657 return single_open(file, proc_cgroupstats_show, NULL);
658}
659
660const struct file_operations proc_cgroupstats_operations = {
661 .open = cgroupstats_open,
662 .read = seq_read,
663 .llseek = seq_lseek,
664 .release = single_release,
665};
666
667
668
669
670
671
672
673
674
675
676int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry)
677{
678 struct kernfs_node *kn = kernfs_node_from_dentry(dentry);
679 struct cgroup *cgrp;
680 struct css_task_iter it;
681 struct task_struct *tsk;
682
683
684 if (dentry->d_sb->s_type != &cgroup_fs_type || !kn ||
685 kernfs_type(kn) != KERNFS_DIR)
686 return -EINVAL;
687
688 mutex_lock(&cgroup_mutex);
689
690
691
692
693
694
695 rcu_read_lock();
696 cgrp = rcu_dereference(*(void __rcu __force **)&kn->priv);
697 if (!cgrp || cgroup_is_dead(cgrp)) {
698 rcu_read_unlock();
699 mutex_unlock(&cgroup_mutex);
700 return -ENOENT;
701 }
702 rcu_read_unlock();
703
704 css_task_iter_start(&cgrp->self, &it);
705 while ((tsk = css_task_iter_next(&it))) {
706 switch (tsk->state) {
707 case TASK_RUNNING:
708 stats->nr_running++;
709 break;
710 case TASK_INTERRUPTIBLE:
711 stats->nr_sleeping++;
712 break;
713 case TASK_UNINTERRUPTIBLE:
714 stats->nr_uninterruptible++;
715 break;
716 case TASK_STOPPED:
717 stats->nr_stopped++;
718 break;
719 default:
720 if (delayacct_is_task_waiting_on_io(tsk))
721 stats->nr_io_wait++;
722 break;
723 }
724 }
725 css_task_iter_end(&it);
726
727 mutex_unlock(&cgroup_mutex);
728 return 0;
729}
730
731void cgroup1_check_for_release(struct cgroup *cgrp)
732{
733 if (notify_on_release(cgrp) && !cgroup_is_populated(cgrp) &&
734 !css_has_online_children(&cgrp->self) && !cgroup_is_dead(cgrp))
735 schedule_work(&cgrp->release_agent_work);
736}
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761void cgroup1_release_agent(struct work_struct *work)
762{
763 struct cgroup *cgrp =
764 container_of(work, struct cgroup, release_agent_work);
765 char *pathbuf = NULL, *agentbuf = NULL;
766 char *argv[3], *envp[3];
767 int ret;
768
769 mutex_lock(&cgroup_mutex);
770
771 pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);
772 agentbuf = kstrdup(cgrp->root->release_agent_path, GFP_KERNEL);
773 if (!pathbuf || !agentbuf)
774 goto out;
775
776 spin_lock_irq(&css_set_lock);
777 ret = cgroup_path_ns_locked(cgrp, pathbuf, PATH_MAX, &init_cgroup_ns);
778 spin_unlock_irq(&css_set_lock);
779 if (ret < 0 || ret >= PATH_MAX)
780 goto out;
781
782 argv[0] = agentbuf;
783 argv[1] = pathbuf;
784 argv[2] = NULL;
785
786
787 envp[0] = "HOME=/";
788 envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
789 envp[2] = NULL;
790
791 mutex_unlock(&cgroup_mutex);
792 call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC);
793 goto out_free;
794out:
795 mutex_unlock(&cgroup_mutex);
796out_free:
797 kfree(agentbuf);
798 kfree(pathbuf);
799}
800
801
802
803
804static int cgroup1_rename(struct kernfs_node *kn, struct kernfs_node *new_parent,
805 const char *new_name_str)
806{
807 struct cgroup *cgrp = kn->priv;
808 int ret;
809
810 if (kernfs_type(kn) != KERNFS_DIR)
811 return -ENOTDIR;
812 if (kn->parent != new_parent)
813 return -EIO;
814
815
816
817
818
819
820 kernfs_break_active_protection(new_parent);
821 kernfs_break_active_protection(kn);
822
823 mutex_lock(&cgroup_mutex);
824
825 ret = kernfs_rename(kn, new_parent, new_name_str);
826 if (!ret)
827 trace_cgroup_rename(cgrp);
828
829 mutex_unlock(&cgroup_mutex);
830
831 kernfs_unbreak_active_protection(kn);
832 kernfs_unbreak_active_protection(new_parent);
833 return ret;
834}
835
836static int cgroup1_show_options(struct seq_file *seq, struct kernfs_root *kf_root)
837{
838 struct cgroup_root *root = cgroup_root_from_kf(kf_root);
839 struct cgroup_subsys *ss;
840 int ssid;
841
842 for_each_subsys(ss, ssid)
843 if (root->subsys_mask & (1 << ssid))
844 seq_show_option(seq, ss->legacy_name, NULL);
845 if (root->flags & CGRP_ROOT_NOPREFIX)
846 seq_puts(seq, ",noprefix");
847 if (root->flags & CGRP_ROOT_XATTR)
848 seq_puts(seq, ",xattr");
849
850 spin_lock(&release_agent_path_lock);
851 if (strlen(root->release_agent_path))
852 seq_show_option(seq, "release_agent",
853 root->release_agent_path);
854 spin_unlock(&release_agent_path_lock);
855
856 if (test_bit(CGRP_CPUSET_CLONE_CHILDREN, &root->cgrp.flags))
857 seq_puts(seq, ",clone_children");
858 if (strlen(root->name))
859 seq_show_option(seq, "name", root->name);
860 return 0;
861}
862
863static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
864{
865 char *token, *o = data;
866 bool all_ss = false, one_ss = false;
867 u16 mask = U16_MAX;
868 struct cgroup_subsys *ss;
869 int nr_opts = 0;
870 int i;
871
872#ifdef CONFIG_CPUSETS
873 mask = ~((u16)1 << cpuset_cgrp_id);
874#endif
875
876 memset(opts, 0, sizeof(*opts));
877
878 while ((token = strsep(&o, ",")) != NULL) {
879 nr_opts++;
880
881 if (!*token)
882 return -EINVAL;
883 if (!strcmp(token, "none")) {
884
885 opts->none = true;
886 continue;
887 }
888 if (!strcmp(token, "all")) {
889
890 if (one_ss)
891 return -EINVAL;
892 all_ss = true;
893 continue;
894 }
895 if (!strcmp(token, "noprefix")) {
896 opts->flags |= CGRP_ROOT_NOPREFIX;
897 continue;
898 }
899 if (!strcmp(token, "clone_children")) {
900 opts->cpuset_clone_children = true;
901 continue;
902 }
903 if (!strcmp(token, "xattr")) {
904 opts->flags |= CGRP_ROOT_XATTR;
905 continue;
906 }
907 if (!strncmp(token, "release_agent=", 14)) {
908
909 if (opts->release_agent)
910 return -EINVAL;
911 opts->release_agent =
912 kstrndup(token + 14, PATH_MAX - 1, GFP_KERNEL);
913 if (!opts->release_agent)
914 return -ENOMEM;
915 continue;
916 }
917 if (!strncmp(token, "name=", 5)) {
918 const char *name = token + 5;
919
920 if (!strlen(name))
921 return -EINVAL;
922
923 for (i = 0; i < strlen(name); i++) {
924 char c = name[i];
925 if (isalnum(c))
926 continue;
927 if ((c == '.') || (c == '-') || (c == '_'))
928 continue;
929 return -EINVAL;
930 }
931
932 if (opts->name)
933 return -EINVAL;
934 opts->name = kstrndup(name,
935 MAX_CGROUP_ROOT_NAMELEN - 1,
936 GFP_KERNEL);
937 if (!opts->name)
938 return -ENOMEM;
939
940 continue;
941 }
942
943 for_each_subsys(ss, i) {
944 if (strcmp(token, ss->legacy_name))
945 continue;
946 if (!cgroup_ssid_enabled(i))
947 continue;
948 if (cgroup1_ssid_disabled(i))
949 continue;
950
951
952 if (all_ss)
953 return -EINVAL;
954 opts->subsys_mask |= (1 << i);
955 one_ss = true;
956
957 break;
958 }
959 if (i == CGROUP_SUBSYS_COUNT)
960 return -ENOENT;
961 }
962
963
964
965
966
967
968 if (all_ss || (!one_ss && !opts->none && !opts->name))
969 for_each_subsys(ss, i)
970 if (cgroup_ssid_enabled(i) && !cgroup1_ssid_disabled(i))
971 opts->subsys_mask |= (1 << i);
972
973
974
975
976
977 if (!opts->subsys_mask && !opts->name)
978 return -EINVAL;
979
980
981
982
983
984
985 if ((opts->flags & CGRP_ROOT_NOPREFIX) && (opts->subsys_mask & mask))
986 return -EINVAL;
987
988
989 if (opts->subsys_mask && opts->none)
990 return -EINVAL;
991
992 return 0;
993}
994
995static int cgroup1_remount(struct kernfs_root *kf_root, int *flags, char *data)
996{
997 int ret = 0;
998 struct cgroup_root *root = cgroup_root_from_kf(kf_root);
999 struct cgroup_sb_opts opts;
1000 u16 added_mask, removed_mask;
1001
1002 cgroup_lock_and_drain_offline(&cgrp_dfl_root.cgrp);
1003
1004
1005 ret = parse_cgroupfs_options(data, &opts);
1006 if (ret)
1007 goto out_unlock;
1008
1009 if (opts.subsys_mask != root->subsys_mask || opts.release_agent)
1010 pr_warn("option changes via remount are deprecated (pid=%d comm=%s)\n",
1011 task_tgid_nr(current), current->comm);
1012
1013 added_mask = opts.subsys_mask & ~root->subsys_mask;
1014 removed_mask = root->subsys_mask & ~opts.subsys_mask;
1015
1016
1017 if ((opts.flags ^ root->flags) ||
1018 (opts.name && strcmp(opts.name, root->name))) {
1019 pr_err("option or name mismatch, new: 0x%x \"%s\", old: 0x%x \"%s\"\n",
1020 opts.flags, opts.name ?: "", root->flags, root->name);
1021 ret = -EINVAL;
1022 goto out_unlock;
1023 }
1024
1025
1026 if (!list_empty(&root->cgrp.self.children)) {
1027 ret = -EBUSY;
1028 goto out_unlock;
1029 }
1030
1031 ret = rebind_subsystems(root, added_mask);
1032 if (ret)
1033 goto out_unlock;
1034
1035 WARN_ON(rebind_subsystems(&cgrp_dfl_root, removed_mask));
1036
1037 if (opts.release_agent) {
1038 spin_lock(&release_agent_path_lock);
1039 strcpy(root->release_agent_path, opts.release_agent);
1040 spin_unlock(&release_agent_path_lock);
1041 }
1042
1043 trace_cgroup_remount(root);
1044
1045 out_unlock:
1046 kfree(opts.release_agent);
1047 kfree(opts.name);
1048 mutex_unlock(&cgroup_mutex);
1049 return ret;
1050}
1051
1052struct kernfs_syscall_ops cgroup1_kf_syscall_ops = {
1053 .rename = cgroup1_rename,
1054 .show_options = cgroup1_show_options,
1055 .remount_fs = cgroup1_remount,
1056 .mkdir = cgroup_mkdir,
1057 .rmdir = cgroup_rmdir,
1058 .show_path = cgroup_show_path,
1059};
1060
1061struct dentry *cgroup1_mount(struct file_system_type *fs_type, int flags,
1062 void *data, unsigned long magic,
1063 struct cgroup_namespace *ns)
1064{
1065 struct super_block *pinned_sb = NULL;
1066 struct cgroup_sb_opts opts;
1067 struct cgroup_root *root;
1068 struct cgroup_subsys *ss;
1069 struct dentry *dentry;
1070 int i, ret;
1071 bool new_root = false;
1072
1073 cgroup_lock_and_drain_offline(&cgrp_dfl_root.cgrp);
1074
1075
1076 ret = parse_cgroupfs_options(data, &opts);
1077 if (ret)
1078 goto out_unlock;
1079
1080
1081
1082
1083
1084
1085
1086
1087 for_each_subsys(ss, i) {
1088 if (!(opts.subsys_mask & (1 << i)) ||
1089 ss->root == &cgrp_dfl_root)
1090 continue;
1091
1092 if (!percpu_ref_tryget_live(&ss->root->cgrp.self.refcnt)) {
1093 mutex_unlock(&cgroup_mutex);
1094 msleep(10);
1095 ret = restart_syscall();
1096 goto out_free;
1097 }
1098 cgroup_put(&ss->root->cgrp);
1099 }
1100
1101 for_each_root(root) {
1102 bool name_match = false;
1103
1104 if (root == &cgrp_dfl_root)
1105 continue;
1106
1107
1108
1109
1110
1111
1112 if (opts.name) {
1113 if (strcmp(opts.name, root->name))
1114 continue;
1115 name_match = true;
1116 }
1117
1118
1119
1120
1121
1122 if ((opts.subsys_mask || opts.none) &&
1123 (opts.subsys_mask != root->subsys_mask)) {
1124 if (!name_match)
1125 continue;
1126 ret = -EBUSY;
1127 goto out_unlock;
1128 }
1129
1130 if (root->flags ^ opts.flags)
1131 pr_warn("new mount options do not match the existing superblock, will be ignored\n");
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145 pinned_sb = kernfs_pin_sb(root->kf_root, NULL);
1146 if (IS_ERR(pinned_sb) ||
1147 !percpu_ref_tryget_live(&root->cgrp.self.refcnt)) {
1148 mutex_unlock(&cgroup_mutex);
1149 if (!IS_ERR_OR_NULL(pinned_sb))
1150 deactivate_super(pinned_sb);
1151 msleep(10);
1152 ret = restart_syscall();
1153 goto out_free;
1154 }
1155
1156 ret = 0;
1157 goto out_unlock;
1158 }
1159
1160
1161
1162
1163
1164
1165 if (!opts.subsys_mask && !opts.none) {
1166 ret = -EINVAL;
1167 goto out_unlock;
1168 }
1169
1170
1171 if (ns != &init_cgroup_ns) {
1172 ret = -EPERM;
1173 goto out_unlock;
1174 }
1175
1176 root = kzalloc(sizeof(*root), GFP_KERNEL);
1177 if (!root) {
1178 ret = -ENOMEM;
1179 goto out_unlock;
1180 }
1181 new_root = true;
1182
1183 init_cgroup_root(root, &opts);
1184
1185 ret = cgroup_setup_root(root, opts.subsys_mask, PERCPU_REF_INIT_DEAD);
1186 if (ret)
1187 cgroup_free_root(root);
1188
1189out_unlock:
1190 mutex_unlock(&cgroup_mutex);
1191out_free:
1192 kfree(opts.release_agent);
1193 kfree(opts.name);
1194
1195 if (ret)
1196 return ERR_PTR(ret);
1197
1198 dentry = cgroup_do_mount(&cgroup_fs_type, flags, root,
1199 CGROUP_SUPER_MAGIC, ns);
1200
1201
1202
1203
1204
1205
1206
1207 if (new_root) {
1208 mutex_lock(&cgroup_mutex);
1209 percpu_ref_reinit(&root->cgrp.self.refcnt);
1210 mutex_unlock(&cgroup_mutex);
1211 }
1212
1213
1214
1215
1216
1217 if (pinned_sb)
1218 deactivate_super(pinned_sb);
1219
1220 return dentry;
1221}
1222
1223static int __init cgroup1_wq_init(void)
1224{
1225
1226
1227
1228
1229 cgroup_pidlist_destroy_wq = alloc_workqueue("cgroup_pidlist_destroy",
1230 0, 1);
1231 BUG_ON(!cgroup_pidlist_destroy_wq);
1232 return 0;
1233}
1234core_initcall(cgroup1_wq_init);
1235
1236static int __init cgroup_no_v1(char *str)
1237{
1238 struct cgroup_subsys *ss;
1239 char *token;
1240 int i;
1241
1242 while ((token = strsep(&str, ",")) != NULL) {
1243 if (!*token)
1244 continue;
1245
1246 if (!strcmp(token, "all")) {
1247 cgroup_no_v1_mask = U16_MAX;
1248 break;
1249 }
1250
1251 for_each_subsys(ss, i) {
1252 if (strcmp(token, ss->name) &&
1253 strcmp(token, ss->legacy_name))
1254 continue;
1255
1256 cgroup_no_v1_mask |= 1 << i;
1257 }
1258 }
1259 return 1;
1260}
1261__setup("cgroup_no_v1=", cgroup_no_v1);
1262