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8e274523 LP |
1 | /*-*- Mode: C; c-basic-offset: 8 -*-*/ |
2 | ||
3 | /*** | |
4 | This file is part of systemd. | |
5 | ||
6 | Copyright 2010 Lennart Poettering | |
7 | ||
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. | |
12 | ||
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. | |
17 | ||
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/>. | |
20 | ***/ | |
21 | ||
22 | #include <errno.h> | |
23 | #include <assert.h> | |
24 | #include <unistd.h> | |
25 | #include <sys/types.h> | |
26 | #include <signal.h> | |
27 | #include <sys/mount.h> | |
28 | ||
29 | #include "cgroup.h" | |
30 | #include "log.h" | |
31 | ||
32 | static int translate_error(int error, int _errno) { | |
33 | ||
34 | switch (error) { | |
35 | ||
36 | case ECGROUPNOTCOMPILED: | |
37 | case ECGROUPNOTMOUNTED: | |
38 | case ECGROUPNOTEXIST: | |
39 | case ECGROUPNOTCREATED: | |
40 | return -ENOENT; | |
41 | ||
42 | case ECGINVAL: | |
43 | return -EINVAL; | |
44 | ||
45 | case ECGROUPNOTALLOWED: | |
46 | return -EPERM; | |
47 | ||
48 | case ECGOTHER: | |
49 | return -_errno; | |
50 | } | |
51 | ||
52 | return -EIO; | |
53 | } | |
54 | ||
55 | int cgroup_bonding_realize(CGroupBonding *b) { | |
56 | int r; | |
57 | ||
58 | assert(b); | |
59 | assert(b->path); | |
60 | assert(b->controller); | |
61 | ||
62 | if (b->cgroup) | |
63 | return 0; | |
64 | ||
65 | if (!(b->cgroup = cgroup_new_cgroup(b->path))) | |
66 | return -ENOMEM; | |
67 | ||
68 | if (!cgroup_add_controller(b->cgroup, b->controller)) { | |
69 | r = -ENOMEM; | |
70 | goto fail; | |
71 | } | |
72 | ||
73 | if (b->inherit) | |
74 | r = cgroup_create_cgroup_from_parent(b->cgroup, true); | |
75 | else | |
76 | r = cgroup_create_cgroup(b->cgroup, true); | |
77 | ||
78 | if (r != 0) { | |
79 | r = translate_error(r, errno); | |
80 | goto fail; | |
81 | } | |
82 | ||
83 | return 0; | |
84 | ||
85 | fail: | |
86 | cgroup_free(&b->cgroup); | |
87 | b->cgroup = NULL; | |
88 | return r; | |
89 | } | |
90 | ||
91 | int cgroup_bonding_realize_list(CGroupBonding *first) { | |
92 | CGroupBonding *b; | |
93 | ||
94 | LIST_FOREACH(by_unit, b, first) { | |
95 | int r; | |
96 | ||
97 | if ((r = cgroup_bonding_realize(b)) < 0) | |
98 | return r; | |
99 | } | |
100 | ||
101 | return 0; | |
102 | } | |
103 | ||
104 | void cgroup_bonding_free(CGroupBonding *b) { | |
105 | assert(b); | |
106 | ||
107 | if (b->unit) { | |
108 | CGroupBonding *f; | |
109 | ||
110 | LIST_REMOVE(CGroupBonding, by_unit, b->unit->meta.cgroup_bondings, b); | |
111 | ||
112 | assert_se(f = hashmap_get(b->unit->meta.manager->cgroup_bondings, b->path)); | |
113 | LIST_REMOVE(CGroupBonding, by_path, f, b); | |
114 | ||
115 | if (f) | |
116 | hashmap_replace(b->unit->meta.manager->cgroup_bondings, b->path, f); | |
117 | else | |
118 | hashmap_remove(b->unit->meta.manager->cgroup_bondings, b->path); | |
119 | } | |
120 | ||
8e274523 | 121 | if (b->cgroup) { |
c9106f61 LP |
122 | if (b->only_us && b->clean_up && cgroup_bonding_is_empty(b) > 0) |
123 | cgroup_delete_cgroup_ext(b->cgroup, true); | |
8e274523 LP |
124 | |
125 | cgroup_free(&b->cgroup); | |
126 | } | |
127 | ||
c9106f61 LP |
128 | free(b->controller); |
129 | free(b->path); | |
8e274523 LP |
130 | free(b); |
131 | } | |
132 | ||
133 | void cgroup_bonding_free_list(CGroupBonding *first) { | |
134 | CGroupBonding *b, *n; | |
135 | ||
136 | LIST_FOREACH_SAFE(by_unit, b, n, first) | |
137 | cgroup_bonding_free(b); | |
138 | } | |
139 | ||
140 | int cgroup_bonding_install(CGroupBonding *b, pid_t pid) { | |
141 | int r; | |
142 | ||
143 | assert(b); | |
144 | assert(pid >= 0); | |
145 | ||
146 | if (pid == 0) | |
147 | pid = getpid(); | |
148 | ||
149 | if (!b->cgroup) | |
150 | return -ENOENT; | |
151 | ||
152 | if ((r = cgroup_attach_task_pid(b->cgroup, pid))) | |
153 | return translate_error(r, errno); | |
154 | ||
155 | return 0; | |
156 | } | |
157 | ||
158 | int cgroup_bonding_install_list(CGroupBonding *first, pid_t pid) { | |
159 | CGroupBonding *b; | |
160 | ||
161 | LIST_FOREACH(by_unit, b, first) { | |
162 | int r; | |
163 | ||
164 | if ((r = cgroup_bonding_install(b, pid)) < 0) | |
165 | return r; | |
166 | } | |
167 | ||
168 | return 0; | |
169 | } | |
170 | ||
171 | int cgroup_bonding_kill(CGroupBonding *b, int sig) { | |
172 | int r; | |
173 | Set *s; | |
174 | bool done; | |
50159e6a | 175 | bool killed = false; |
8e274523 LP |
176 | |
177 | assert(b); | |
178 | assert(sig > 0); | |
179 | ||
50159e6a LP |
180 | if (!b->only_us) |
181 | return -EAGAIN; | |
182 | ||
8e274523 LP |
183 | if (!(s = set_new(trivial_hash_func, trivial_compare_func))) |
184 | return -ENOMEM; | |
185 | ||
186 | do { | |
187 | void *iterator; | |
188 | pid_t pid; | |
189 | ||
190 | done = true; | |
191 | ||
192 | if ((r = cgroup_get_task_begin(b->path, b->controller, &iterator, &pid)) != 0) { | |
193 | if (r == ECGEOF) { | |
194 | r = 0; | |
195 | goto kill_done; | |
196 | } else { | |
197 | r = translate_error(r, errno); | |
198 | break; | |
199 | } | |
200 | } | |
201 | ||
202 | for (;;) { | |
203 | if (set_get(s, INT_TO_PTR(pid)) != INT_TO_PTR(pid)) { | |
204 | ||
205 | /* If we haven't killed this process | |
206 | * yet, kill it */ | |
207 | ||
208 | if (kill(pid, sig) < 0 && errno != ESRCH) { | |
209 | r = -errno; | |
210 | break; | |
211 | } | |
212 | ||
50159e6a | 213 | killed = true; |
8e274523 LP |
214 | done = false; |
215 | ||
216 | if ((r = set_put(s, INT_TO_PTR(pid))) < 0) | |
217 | break; | |
218 | } | |
219 | ||
220 | if ((r = cgroup_get_task_next(&iterator, &pid)) != 0) { | |
221 | ||
222 | if (r == ECGEOF) | |
223 | r = 0; | |
224 | else | |
225 | r = translate_error(r, errno); | |
226 | ||
227 | break; | |
228 | } | |
229 | } | |
230 | ||
231 | kill_done: | |
232 | assert_se(cgroup_get_task_end(&iterator) == 0); | |
233 | ||
234 | /* To avoid racing against processes which fork | |
235 | * quicker than we can kill them we repeat this until | |
236 | * no new pids need to be killed. */ | |
237 | ||
238 | } while (!done && r >= 0); | |
239 | ||
240 | set_free(s); | |
50159e6a LP |
241 | |
242 | if (r < 0) | |
243 | return r; | |
244 | ||
245 | return killed ? 0 : -ESRCH; | |
8e274523 LP |
246 | } |
247 | ||
248 | int cgroup_bonding_kill_list(CGroupBonding *first, int sig) { | |
249 | CGroupBonding *b; | |
50159e6a | 250 | int r = -EAGAIN; |
8e274523 LP |
251 | |
252 | LIST_FOREACH(by_unit, b, first) { | |
50159e6a LP |
253 | if ((r = cgroup_bonding_kill(b, sig)) < 0) { |
254 | if (r == -EAGAIN || -ESRCH) | |
255 | continue; | |
8e274523 | 256 | |
8e274523 | 257 | return r; |
50159e6a LP |
258 | } |
259 | ||
260 | return 0; | |
8e274523 LP |
261 | } |
262 | ||
50159e6a | 263 | return r; |
8e274523 LP |
264 | } |
265 | ||
266 | /* Returns 1 if the group is empty, 0 if it is not, -EAGAIN if we | |
267 | * cannot know */ | |
268 | int cgroup_bonding_is_empty(CGroupBonding *b) { | |
269 | void *iterator; | |
270 | pid_t pid; | |
271 | int r; | |
272 | ||
273 | assert(b); | |
274 | ||
275 | r = cgroup_get_task_begin(b->path, b->controller, &iterator, &pid); | |
276 | ||
277 | if (r == 0 || r == ECGEOF) | |
278 | cgroup_get_task_end(&iterator); | |
279 | ||
280 | /* Hmm, no PID in this group? Then it is definitely empty */ | |
281 | if (r == ECGEOF) | |
282 | return 1; | |
283 | ||
284 | /* Some error? Let's return it */ | |
285 | if (r != 0) | |
286 | return translate_error(r, errno); | |
287 | ||
288 | /* It's not empty, and we are the only user, then it is | |
289 | * definitely not empty */ | |
290 | if (b->only_us) | |
291 | return 0; | |
292 | ||
293 | /* There are PIDs in the group but we aren't the only users, | |
294 | * hence we cannot say */ | |
295 | return -EAGAIN; | |
296 | } | |
297 | ||
298 | int cgroup_bonding_is_empty_list(CGroupBonding *first) { | |
299 | CGroupBonding *b; | |
300 | ||
301 | LIST_FOREACH(by_unit, b, first) { | |
302 | int r; | |
303 | ||
304 | if ((r = cgroup_bonding_is_empty(b)) < 0) { | |
305 | /* If this returned -EAGAIN, then we don't know if the | |
306 | * group is empty, so let's see if another group can | |
307 | * tell us */ | |
308 | ||
309 | if (r != -EAGAIN) | |
310 | return r; | |
311 | } else | |
312 | return r; | |
313 | } | |
314 | ||
315 | return -EAGAIN; | |
316 | } | |
317 | ||
318 | static int install_release_agent(Manager *m, const char *mount_point) { | |
319 | char *p, *c, *sc; | |
320 | int r; | |
321 | ||
322 | assert(m); | |
323 | assert(mount_point); | |
324 | ||
325 | if (asprintf(&p, "%s/release_agent", mount_point) < 0) | |
326 | return -ENOMEM; | |
327 | ||
328 | if ((r = read_one_line_file(p, &c)) < 0) { | |
329 | free(p); | |
330 | return r; | |
331 | } | |
332 | ||
333 | sc = strstrip(c); | |
334 | ||
335 | if (sc[0] == 0) { | |
336 | if ((r = write_one_line_file(p, CGROUP_AGENT_PATH "\n" )) < 0) { | |
337 | free(p); | |
338 | free(c); | |
339 | return r; | |
340 | } | |
341 | } else if (!streq(sc, CGROUP_AGENT_PATH)) { | |
342 | free(p); | |
343 | free(c); | |
344 | return -EEXIST; | |
345 | } | |
346 | ||
347 | free(c); | |
348 | free(p); | |
349 | ||
350 | if (asprintf(&p, "%s/notify_on_release", mount_point) < 0) | |
351 | return -ENOMEM; | |
352 | ||
353 | if ((r = read_one_line_file(p, &c)) < 0) { | |
354 | free(p); | |
355 | return r; | |
356 | } | |
357 | ||
358 | sc = strstrip(c); | |
359 | ||
360 | if (streq(sc, "0")) { | |
361 | if ((r = write_one_line_file(p, "1\n")) < 0) { | |
362 | free(p); | |
363 | free(c); | |
364 | return r; | |
365 | } | |
366 | } else if (!streq(sc, "1")) { | |
367 | free(p); | |
368 | free(c); | |
369 | return -EIO; | |
370 | } | |
371 | ||
58783cda LP |
372 | free(p); |
373 | free(c); | |
374 | ||
8e274523 LP |
375 | return 0; |
376 | } | |
377 | ||
378 | static int create_hierarchy_cgroup(Manager *m) { | |
379 | struct cgroup *cg; | |
380 | int r; | |
381 | ||
382 | assert(m); | |
383 | ||
384 | if (!(cg = cgroup_new_cgroup(m->cgroup_hierarchy))) | |
385 | return -ENOMEM; | |
386 | ||
387 | if (!(cgroup_add_controller(cg, m->cgroup_controller))) { | |
388 | r = -ENOMEM; | |
389 | goto finish; | |
390 | } | |
391 | ||
392 | if ((r = cgroup_create_cgroup(cg, true)) != 0) { | |
393 | log_error("Failed to create cgroup hierarchy group: %s", cgroup_strerror(r)); | |
394 | r = translate_error(r, errno); | |
395 | goto finish; | |
396 | } | |
397 | ||
398 | if ((r = cgroup_attach_task(cg)) != 0) { | |
399 | log_error("Failed to add ourselves to hierarchy group: %s", cgroup_strerror(r)); | |
400 | r = translate_error(r, errno); | |
401 | goto finish; | |
402 | } | |
403 | ||
404 | r = 0; | |
405 | ||
406 | finish: | |
407 | cgroup_free(&cg); | |
408 | return r; | |
409 | } | |
410 | ||
411 | int manager_setup_cgroup(Manager *m) { | |
412 | char *mp, *cp; | |
413 | int r; | |
414 | pid_t pid; | |
7ccfb64a | 415 | char suffix[32]; |
8e274523 LP |
416 | |
417 | assert(m); | |
418 | ||
419 | if ((r = cgroup_init()) != 0) { | |
420 | log_error("Failed to initialize libcg: %s", cgroup_strerror(r)); | |
421 | return translate_error(r, errno); | |
422 | } | |
423 | ||
424 | free(m->cgroup_controller); | |
425 | if (!(m->cgroup_controller = strdup("debug"))) | |
426 | return -ENOMEM; | |
427 | ||
428 | if ((r = cgroup_get_subsys_mount_point(m->cgroup_controller, &mp))) | |
429 | return translate_error(r, errno); | |
430 | ||
431 | pid = getpid(); | |
432 | ||
433 | if ((r = cgroup_get_current_controller_path(pid, m->cgroup_controller, &cp))) { | |
434 | free(mp); | |
435 | return translate_error(r, errno); | |
436 | } | |
437 | ||
7ccfb64a LP |
438 | snprintf(suffix, sizeof(suffix), "/systemd-%u", (unsigned) pid); |
439 | char_array_0(suffix); | |
440 | ||
8e274523 | 441 | free(m->cgroup_hierarchy); |
7ccfb64a LP |
442 | |
443 | if (endswith(cp, suffix)) | |
444 | /* We probably got reexecuted and can continue to use our root cgroup */ | |
445 | m->cgroup_hierarchy = cp; | |
446 | else { | |
447 | /* We need a new root cgroup */ | |
448 | ||
449 | m->cgroup_hierarchy = NULL; | |
450 | r = asprintf(&m->cgroup_hierarchy, "%s%s", streq(cp, "/") ? "" : cp, suffix); | |
8e274523 | 451 | free(cp); |
7ccfb64a LP |
452 | |
453 | if (r < 0) { | |
454 | free(mp); | |
455 | return -ENOMEM; | |
456 | } | |
8e274523 LP |
457 | } |
458 | ||
459 | log_info("Using cgroup controller <%s>, hierarchy mounted at <%s>, using root group <%s>.", | |
460 | m->cgroup_controller, | |
461 | mp, | |
462 | m->cgroup_hierarchy); | |
463 | ||
464 | if ((r = install_release_agent(m, mp)) < 0) | |
465 | log_warning("Failed to install release agent, ignoring: %s", strerror(-r)); | |
466 | else | |
467 | log_info("Installed release agent, or already installed."); | |
468 | ||
469 | free(mp); | |
8e274523 LP |
470 | |
471 | if ((r = create_hierarchy_cgroup(m)) < 0) | |
472 | log_error("Failed to create root cgroup hierarchy: %s", strerror(-r)); | |
473 | else | |
474 | log_info("Created root group."); | |
475 | ||
476 | return r; | |
477 | } | |
478 | ||
a16e1123 | 479 | int manager_shutdown_cgroup(Manager *m, bool delete) { |
8e274523 LP |
480 | struct cgroup *cg; |
481 | int r; | |
482 | ||
483 | assert(m); | |
484 | ||
485 | if (!m->cgroup_hierarchy) | |
486 | return 0; | |
487 | ||
488 | if (!(cg = cgroup_new_cgroup(m->cgroup_hierarchy))) | |
489 | return -ENOMEM; | |
490 | ||
491 | if (!(cgroup_add_controller(cg, m->cgroup_controller))) { | |
492 | r = -ENOMEM; | |
493 | goto finish; | |
494 | } | |
495 | ||
a16e1123 LP |
496 | /* Often enough we won't be able to delete the cgroup we |
497 | * ourselves are in, hence ignore all errors here */ | |
498 | if (delete) | |
499 | cgroup_delete_cgroup_ext(cg, CGFLAG_DELETE_IGNORE_MIGRATION|CGFLAG_DELETE_RECURSIVE); | |
8e274523 LP |
500 | r = 0; |
501 | ||
502 | finish: | |
503 | cgroup_free(&cg); | |
504 | return r; | |
505 | ||
506 | } | |
507 | ||
508 | int cgroup_notify_empty(Manager *m, const char *group) { | |
509 | CGroupBonding *l, *b; | |
510 | ||
511 | assert(m); | |
512 | assert(group); | |
513 | ||
514 | if (!(l = hashmap_get(m->cgroup_bondings, group))) | |
515 | return 0; | |
516 | ||
517 | LIST_FOREACH(by_path, b, l) { | |
518 | int t; | |
519 | ||
520 | if (!b->unit) | |
521 | continue; | |
522 | ||
523 | if ((t = cgroup_bonding_is_empty_list(b)) < 0) { | |
524 | ||
525 | /* If we don't know, we don't know */ | |
526 | if (t != -EAGAIN) | |
527 | log_warning("Failed to check whether cgroup is empty: %s", strerror(errno)); | |
528 | ||
529 | continue; | |
530 | } | |
531 | ||
532 | if (t > 0) | |
533 | if (UNIT_VTABLE(b->unit)->cgroup_notify_empty) | |
534 | UNIT_VTABLE(b->unit)->cgroup_notify_empty(b->unit); | |
535 | } | |
536 | ||
537 | return 0; | |
538 | } | |
539 | ||
540 | CGroupBonding *cgroup_bonding_find_list(CGroupBonding *first, const char *controller) { | |
541 | CGroupBonding *b; | |
542 | ||
543 | assert(controller); | |
544 | ||
545 | LIST_FOREACH(by_unit, b, first) | |
546 | if (streq(b->controller, controller)) | |
547 | return b; | |
548 | ||
549 | return NULL; | |
550 | } | |
6dde1f33 LP |
551 | |
552 | char *cgroup_bonding_to_string(CGroupBonding *b) { | |
553 | char *r; | |
554 | ||
555 | assert(b); | |
556 | ||
557 | if (asprintf(&r, "%s:%s", b->controller, b->path) < 0) | |
558 | return NULL; | |
559 | ||
560 | return r; | |
561 | } |