1 /*-*- Mode: C; c-basic-offset: 8 -*-*/
4 This file is part of systemd.
6 Copyright 2010 Lennart Poettering
8 systemd is free software; you can redistribute it and/or modify it
9 under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 systemd is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with systemd; If not, see <http://www.gnu.org/licenses/>.
25 #include <sys/types.h>
27 #include <sys/mount.h>
32 static int translate_error(int error, int _errno) {
36 case ECGROUPNOTCOMPILED:
37 case ECGROUPNOTMOUNTED:
39 case ECGROUPNOTCREATED:
45 case ECGROUPNOTALLOWED:
55 int cgroup_bonding_realize(CGroupBonding *b) {
60 assert(b->controller);
65 if (!(b->cgroup = cgroup_new_cgroup(b->path)))
68 if (!cgroup_add_controller(b->cgroup, b->controller)) {
73 if ((r = cgroup_create_cgroup(b->cgroup, true)) != 0) {
74 r = translate_error(r, errno);
81 cgroup_free(&b->cgroup);
86 int cgroup_bonding_realize_list(CGroupBonding *first) {
89 LIST_FOREACH(by_unit, b, first) {
92 if ((r = cgroup_bonding_realize(b)) < 0)
99 void cgroup_bonding_free(CGroupBonding *b) {
105 LIST_REMOVE(CGroupBonding, by_unit, b->unit->meta.cgroup_bondings, b);
107 assert_se(f = hashmap_get(b->unit->meta.manager->cgroup_bondings, b->path));
108 LIST_REMOVE(CGroupBonding, by_path, f, b);
111 hashmap_replace(b->unit->meta.manager->cgroup_bondings, b->path, f);
113 hashmap_remove(b->unit->meta.manager->cgroup_bondings, b->path);
117 if (b->only_us && b->clean_up && cgroup_bonding_is_empty(b) > 0)
118 cgroup_delete_cgroup_ext(b->cgroup, true);
120 cgroup_free(&b->cgroup);
128 void cgroup_bonding_free_list(CGroupBonding *first) {
129 CGroupBonding *b, *n;
131 LIST_FOREACH_SAFE(by_unit, b, n, first)
132 cgroup_bonding_free(b);
135 int cgroup_bonding_install(CGroupBonding *b, pid_t pid) {
147 if ((r = cgroup_attach_task_pid(b->cgroup, pid)))
148 return translate_error(r, errno);
153 int cgroup_bonding_install_list(CGroupBonding *first, pid_t pid) {
156 LIST_FOREACH(by_unit, b, first) {
159 if ((r = cgroup_bonding_install(b, pid)) < 0)
166 int cgroup_bonding_kill(CGroupBonding *b, int sig) {
178 if (!(s = set_new(trivial_hash_func, trivial_compare_func)))
187 if ((r = cgroup_get_task_begin(b->path, b->controller, &iterator, &pid)) != 0) {
192 if (r == ECGOTHER && errno == ENOENT)
195 r = translate_error(r, errno);
201 if (set_get(s, INT_TO_PTR(pid)) != INT_TO_PTR(pid)) {
203 /* If we haven't killed this process
206 if (kill(pid, sig) < 0 && errno != ESRCH) {
214 if ((r = set_put(s, INT_TO_PTR(pid))) < 0)
218 if ((r = cgroup_get_task_next(&iterator, &pid)) != 0) {
223 r = translate_error(r, errno);
230 assert_se(cgroup_get_task_end(&iterator) == 0);
232 /* To avoid racing against processes which fork
233 * quicker than we can kill them we repeat this until
234 * no new pids need to be killed. */
236 } while (!done && r >= 0);
243 return killed ? 0 : -ESRCH;
246 int cgroup_bonding_kill_list(CGroupBonding *first, int sig) {
250 LIST_FOREACH(by_unit, b, first) {
251 if ((r = cgroup_bonding_kill(b, sig)) < 0) {
252 if (r == -EAGAIN || -ESRCH)
264 /* Returns 1 if the group is empty, 0 if it is not, -EAGAIN if we
266 int cgroup_bonding_is_empty(CGroupBonding *b) {
273 r = cgroup_get_task_begin(b->path, b->controller, &iterator, &pid);
275 if (r == 0 || r == ECGEOF)
276 cgroup_get_task_end(&iterator);
278 /* Hmm, no PID in this group? Then it is definitely empty */
282 /* Some error? Let's return it */
284 return translate_error(r, errno);
286 /* It's not empty, and we are the only user, then it is
287 * definitely not empty */
291 /* There are PIDs in the group but we aren't the only users,
292 * hence we cannot say */
296 int cgroup_bonding_is_empty_list(CGroupBonding *first) {
299 LIST_FOREACH(by_unit, b, first) {
302 if ((r = cgroup_bonding_is_empty(b)) < 0) {
303 /* If this returned -EAGAIN, then we don't know if the
304 * group is empty, so let's see if another group can
316 static int install_release_agent(Manager *m, const char *mount_point) {
323 if (asprintf(&p, "%s/release_agent", mount_point) < 0)
326 if ((r = read_one_line_file(p, &c)) < 0) {
334 if ((r = write_one_line_file(p, CGROUP_AGENT_PATH "\n" )) < 0) {
339 } else if (!streq(sc, CGROUP_AGENT_PATH)) {
348 if (asprintf(&p, "%s/notify_on_release", mount_point) < 0)
351 if ((r = read_one_line_file(p, &c)) < 0) {
358 if (streq(sc, "0")) {
359 if ((r = write_one_line_file(p, "1\n")) < 0) {
364 } else if (!streq(sc, "1")) {
376 static int create_hierarchy_cgroup(Manager *m) {
382 if (!(cg = cgroup_new_cgroup(m->cgroup_hierarchy)))
385 if (!(cgroup_add_controller(cg, m->cgroup_controller))) {
390 if ((r = cgroup_create_cgroup(cg, true)) != 0) {
391 log_error("Failed to create cgroup hierarchy group: %s", cgroup_strerror(r));
392 r = translate_error(r, errno);
396 if ((r = cgroup_attach_task(cg)) != 0) {
397 log_error("Failed to add ourselves to hierarchy group: %s", cgroup_strerror(r));
398 r = translate_error(r, errno);
409 int manager_setup_cgroup(Manager *m) {
417 if ((r = cgroup_init()) != 0) {
418 log_error("Failed to initialize libcg: %s", cgroup_strerror(r));
419 return translate_error(r, errno);
422 free(m->cgroup_controller);
423 if (!(m->cgroup_controller = strdup("name=systemd")))
426 if ((r = cgroup_get_subsys_mount_point(m->cgroup_controller, &mp)))
427 return translate_error(r, errno);
431 if ((r = cgroup_get_current_controller_path(pid, m->cgroup_controller, &cp))) {
433 return translate_error(r, errno);
436 snprintf(suffix, sizeof(suffix), "/systemd-%u", (unsigned) pid);
437 char_array_0(suffix);
439 free(m->cgroup_hierarchy);
441 if (endswith(cp, suffix))
442 /* We probably got reexecuted and can continue to use our root cgroup */
443 m->cgroup_hierarchy = cp;
445 /* We need a new root cgroup */
447 m->cgroup_hierarchy = NULL;
448 r = asprintf(&m->cgroup_hierarchy, "%s%s", streq(cp, "/") ? "" : cp, suffix);
457 log_debug("Using cgroup controller <%s>, hierarchy mounted at <%s>, using root group <%s>.",
458 m->cgroup_controller,
460 m->cgroup_hierarchy);
462 if ((r = install_release_agent(m, mp)) < 0)
463 log_warning("Failed to install release agent, ignoring: %s", strerror(-r));
465 log_debug("Installed release agent, or already installed.");
469 if ((r = create_hierarchy_cgroup(m)) < 0)
470 log_error("Failed to create root cgroup hierarchy: %s", strerror(-r));
472 log_debug("Created root group.");
477 int manager_shutdown_cgroup(Manager *m, bool delete) {
483 if (!m->cgroup_hierarchy)
486 if (!(cg = cgroup_new_cgroup(m->cgroup_hierarchy)))
489 if (!(cgroup_add_controller(cg, m->cgroup_controller))) {
494 /* Often enough we won't be able to delete the cgroup we
495 * ourselves are in, hence ignore all errors here */
497 cgroup_delete_cgroup_ext(cg, CGFLAG_DELETE_IGNORE_MIGRATION|CGFLAG_DELETE_RECURSIVE);
506 int cgroup_notify_empty(Manager *m, const char *group) {
507 CGroupBonding *l, *b;
512 if (!(l = hashmap_get(m->cgroup_bondings, group)))
515 LIST_FOREACH(by_path, b, l) {
521 if ((t = cgroup_bonding_is_empty_list(b)) < 0) {
523 /* If we don't know, we don't know */
525 log_warning("Failed to check whether cgroup is empty: %s", strerror(errno));
531 if (UNIT_VTABLE(b->unit)->cgroup_notify_empty)
532 UNIT_VTABLE(b->unit)->cgroup_notify_empty(b->unit);
538 Unit* cgroup_unit_by_pid(Manager *m, pid_t pid) {
539 CGroupBonding *l, *b;
548 if ((r = cgroup_get_current_controller_path(pid, m->cgroup_controller, &group)))
551 l = hashmap_get(m->cgroup_bondings, group);
557 LIST_FOREACH(by_path, b, l) {
569 CGroupBonding *cgroup_bonding_find_list(CGroupBonding *first, const char *controller) {
574 LIST_FOREACH(by_unit, b, first)
575 if (streq(b->controller, controller))
581 char *cgroup_bonding_to_string(CGroupBonding *b) {
586 if (asprintf(&r, "%s:%s", b->controller, b->path) < 0)