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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 | ||
121 | free(b->controller); | |
122 | free(b->path); | |
123 | ||
124 | if (b->cgroup) { | |
125 | ||
126 | if (b->only_us && b->clean_up) | |
127 | cgroup_delete_cgroup(b->cgroup, true); | |
128 | ||
129 | cgroup_free(&b->cgroup); | |
130 | } | |
131 | ||
132 | free(b); | |
133 | } | |
134 | ||
135 | void cgroup_bonding_free_list(CGroupBonding *first) { | |
136 | CGroupBonding *b, *n; | |
137 | ||
138 | LIST_FOREACH_SAFE(by_unit, b, n, first) | |
139 | cgroup_bonding_free(b); | |
140 | } | |
141 | ||
142 | int cgroup_bonding_install(CGroupBonding *b, pid_t pid) { | |
143 | int r; | |
144 | ||
145 | assert(b); | |
146 | assert(pid >= 0); | |
147 | ||
148 | if (pid == 0) | |
149 | pid = getpid(); | |
150 | ||
151 | if (!b->cgroup) | |
152 | return -ENOENT; | |
153 | ||
154 | if ((r = cgroup_attach_task_pid(b->cgroup, pid))) | |
155 | return translate_error(r, errno); | |
156 | ||
157 | return 0; | |
158 | } | |
159 | ||
160 | int cgroup_bonding_install_list(CGroupBonding *first, pid_t pid) { | |
161 | CGroupBonding *b; | |
162 | ||
163 | LIST_FOREACH(by_unit, b, first) { | |
164 | int r; | |
165 | ||
166 | if ((r = cgroup_bonding_install(b, pid)) < 0) | |
167 | return r; | |
168 | } | |
169 | ||
170 | return 0; | |
171 | } | |
172 | ||
173 | int cgroup_bonding_kill(CGroupBonding *b, int sig) { | |
174 | int r; | |
175 | Set *s; | |
176 | bool done; | |
177 | ||
178 | assert(b); | |
179 | assert(sig > 0); | |
180 | ||
181 | if (!(s = set_new(trivial_hash_func, trivial_compare_func))) | |
182 | return -ENOMEM; | |
183 | ||
184 | do { | |
185 | void *iterator; | |
186 | pid_t pid; | |
187 | ||
188 | done = true; | |
189 | ||
190 | if ((r = cgroup_get_task_begin(b->path, b->controller, &iterator, &pid)) != 0) { | |
191 | if (r == ECGEOF) { | |
192 | r = 0; | |
193 | goto kill_done; | |
194 | } else { | |
195 | r = translate_error(r, errno); | |
196 | break; | |
197 | } | |
198 | } | |
199 | ||
200 | for (;;) { | |
201 | if (set_get(s, INT_TO_PTR(pid)) != INT_TO_PTR(pid)) { | |
202 | ||
203 | /* If we haven't killed this process | |
204 | * yet, kill it */ | |
205 | ||
206 | if (kill(pid, sig) < 0 && errno != ESRCH) { | |
207 | r = -errno; | |
208 | break; | |
209 | } | |
210 | ||
211 | done = false; | |
212 | ||
213 | if ((r = set_put(s, INT_TO_PTR(pid))) < 0) | |
214 | break; | |
215 | } | |
216 | ||
217 | if ((r = cgroup_get_task_next(&iterator, &pid)) != 0) { | |
218 | ||
219 | if (r == ECGEOF) | |
220 | r = 0; | |
221 | else | |
222 | r = translate_error(r, errno); | |
223 | ||
224 | break; | |
225 | } | |
226 | } | |
227 | ||
228 | kill_done: | |
229 | assert_se(cgroup_get_task_end(&iterator) == 0); | |
230 | ||
231 | /* To avoid racing against processes which fork | |
232 | * quicker than we can kill them we repeat this until | |
233 | * no new pids need to be killed. */ | |
234 | ||
235 | } while (!done && r >= 0); | |
236 | ||
237 | set_free(s); | |
238 | return r; | |
239 | } | |
240 | ||
241 | int cgroup_bonding_kill_list(CGroupBonding *first, int sig) { | |
242 | CGroupBonding *b; | |
243 | ||
244 | LIST_FOREACH(by_unit, b, first) { | |
245 | int r; | |
246 | ||
247 | if ((r = cgroup_bonding_kill(b, sig)) < 0) | |
248 | return r; | |
249 | } | |
250 | ||
251 | return 0; | |
252 | } | |
253 | ||
254 | /* Returns 1 if the group is empty, 0 if it is not, -EAGAIN if we | |
255 | * cannot know */ | |
256 | int cgroup_bonding_is_empty(CGroupBonding *b) { | |
257 | void *iterator; | |
258 | pid_t pid; | |
259 | int r; | |
260 | ||
261 | assert(b); | |
262 | ||
263 | r = cgroup_get_task_begin(b->path, b->controller, &iterator, &pid); | |
264 | ||
265 | if (r == 0 || r == ECGEOF) | |
266 | cgroup_get_task_end(&iterator); | |
267 | ||
268 | /* Hmm, no PID in this group? Then it is definitely empty */ | |
269 | if (r == ECGEOF) | |
270 | return 1; | |
271 | ||
272 | /* Some error? Let's return it */ | |
273 | if (r != 0) | |
274 | return translate_error(r, errno); | |
275 | ||
276 | /* It's not empty, and we are the only user, then it is | |
277 | * definitely not empty */ | |
278 | if (b->only_us) | |
279 | return 0; | |
280 | ||
281 | /* There are PIDs in the group but we aren't the only users, | |
282 | * hence we cannot say */ | |
283 | return -EAGAIN; | |
284 | } | |
285 | ||
286 | int cgroup_bonding_is_empty_list(CGroupBonding *first) { | |
287 | CGroupBonding *b; | |
288 | ||
289 | LIST_FOREACH(by_unit, b, first) { | |
290 | int r; | |
291 | ||
292 | if ((r = cgroup_bonding_is_empty(b)) < 0) { | |
293 | /* If this returned -EAGAIN, then we don't know if the | |
294 | * group is empty, so let's see if another group can | |
295 | * tell us */ | |
296 | ||
297 | if (r != -EAGAIN) | |
298 | return r; | |
299 | } else | |
300 | return r; | |
301 | } | |
302 | ||
303 | return -EAGAIN; | |
304 | } | |
305 | ||
306 | static int install_release_agent(Manager *m, const char *mount_point) { | |
307 | char *p, *c, *sc; | |
308 | int r; | |
309 | ||
310 | assert(m); | |
311 | assert(mount_point); | |
312 | ||
313 | if (asprintf(&p, "%s/release_agent", mount_point) < 0) | |
314 | return -ENOMEM; | |
315 | ||
316 | if ((r = read_one_line_file(p, &c)) < 0) { | |
317 | free(p); | |
318 | return r; | |
319 | } | |
320 | ||
321 | sc = strstrip(c); | |
322 | ||
323 | if (sc[0] == 0) { | |
324 | if ((r = write_one_line_file(p, CGROUP_AGENT_PATH "\n" )) < 0) { | |
325 | free(p); | |
326 | free(c); | |
327 | return r; | |
328 | } | |
329 | } else if (!streq(sc, CGROUP_AGENT_PATH)) { | |
330 | free(p); | |
331 | free(c); | |
332 | return -EEXIST; | |
333 | } | |
334 | ||
335 | free(c); | |
336 | free(p); | |
337 | ||
338 | if (asprintf(&p, "%s/notify_on_release", mount_point) < 0) | |
339 | return -ENOMEM; | |
340 | ||
341 | if ((r = read_one_line_file(p, &c)) < 0) { | |
342 | free(p); | |
343 | return r; | |
344 | } | |
345 | ||
346 | sc = strstrip(c); | |
347 | ||
348 | if (streq(sc, "0")) { | |
349 | if ((r = write_one_line_file(p, "1\n")) < 0) { | |
350 | free(p); | |
351 | free(c); | |
352 | return r; | |
353 | } | |
354 | } else if (!streq(sc, "1")) { | |
355 | free(p); | |
356 | free(c); | |
357 | return -EIO; | |
358 | } | |
359 | ||
58783cda LP |
360 | free(p); |
361 | free(c); | |
362 | ||
8e274523 LP |
363 | return 0; |
364 | } | |
365 | ||
366 | static int create_hierarchy_cgroup(Manager *m) { | |
367 | struct cgroup *cg; | |
368 | int r; | |
369 | ||
370 | assert(m); | |
371 | ||
372 | if (!(cg = cgroup_new_cgroup(m->cgroup_hierarchy))) | |
373 | return -ENOMEM; | |
374 | ||
375 | if (!(cgroup_add_controller(cg, m->cgroup_controller))) { | |
376 | r = -ENOMEM; | |
377 | goto finish; | |
378 | } | |
379 | ||
380 | if ((r = cgroup_create_cgroup(cg, true)) != 0) { | |
381 | log_error("Failed to create cgroup hierarchy group: %s", cgroup_strerror(r)); | |
382 | r = translate_error(r, errno); | |
383 | goto finish; | |
384 | } | |
385 | ||
386 | if ((r = cgroup_attach_task(cg)) != 0) { | |
387 | log_error("Failed to add ourselves to hierarchy group: %s", cgroup_strerror(r)); | |
388 | r = translate_error(r, errno); | |
389 | goto finish; | |
390 | } | |
391 | ||
392 | r = 0; | |
393 | ||
394 | finish: | |
395 | cgroup_free(&cg); | |
396 | return r; | |
397 | } | |
398 | ||
399 | int manager_setup_cgroup(Manager *m) { | |
400 | char *mp, *cp; | |
401 | int r; | |
402 | pid_t pid; | |
403 | ||
404 | assert(m); | |
405 | ||
406 | if ((r = cgroup_init()) != 0) { | |
407 | log_error("Failed to initialize libcg: %s", cgroup_strerror(r)); | |
408 | return translate_error(r, errno); | |
409 | } | |
410 | ||
411 | free(m->cgroup_controller); | |
412 | if (!(m->cgroup_controller = strdup("debug"))) | |
413 | return -ENOMEM; | |
414 | ||
415 | if ((r = cgroup_get_subsys_mount_point(m->cgroup_controller, &mp))) | |
416 | return translate_error(r, errno); | |
417 | ||
418 | pid = getpid(); | |
419 | ||
420 | if ((r = cgroup_get_current_controller_path(pid, m->cgroup_controller, &cp))) { | |
421 | free(mp); | |
422 | return translate_error(r, errno); | |
423 | } | |
424 | ||
425 | free(m->cgroup_hierarchy); | |
426 | m->cgroup_hierarchy = NULL; | |
427 | if (asprintf(&m->cgroup_hierarchy, "%s/systemd-%llu", strcmp(cp, "/") == 0 ? "" : cp, (unsigned long long) pid) < 0) { | |
428 | free(cp); | |
429 | free(mp); | |
430 | return -ENOMEM; | |
431 | } | |
432 | ||
433 | log_info("Using cgroup controller <%s>, hierarchy mounted at <%s>, using root group <%s>.", | |
434 | m->cgroup_controller, | |
435 | mp, | |
436 | m->cgroup_hierarchy); | |
437 | ||
438 | if ((r = install_release_agent(m, mp)) < 0) | |
439 | log_warning("Failed to install release agent, ignoring: %s", strerror(-r)); | |
440 | else | |
441 | log_info("Installed release agent, or already installed."); | |
442 | ||
443 | free(mp); | |
444 | free(cp); | |
445 | ||
446 | if ((r = create_hierarchy_cgroup(m)) < 0) | |
447 | log_error("Failed to create root cgroup hierarchy: %s", strerror(-r)); | |
448 | else | |
449 | log_info("Created root group."); | |
450 | ||
451 | return r; | |
452 | } | |
453 | ||
454 | int manager_shutdown_cgroup(Manager *m) { | |
455 | struct cgroup *cg; | |
456 | int r; | |
457 | ||
458 | assert(m); | |
459 | ||
460 | if (!m->cgroup_hierarchy) | |
461 | return 0; | |
462 | ||
463 | if (!(cg = cgroup_new_cgroup(m->cgroup_hierarchy))) | |
464 | return -ENOMEM; | |
465 | ||
466 | if (!(cgroup_add_controller(cg, m->cgroup_controller))) { | |
467 | r = -ENOMEM; | |
468 | goto finish; | |
469 | } | |
470 | ||
471 | if ((r = cgroup_delete_cgroup_ext(cg, CGFLAG_DELETE_IGNORE_MIGRATION|CGFLAG_DELETE_RECURSIVE)) != 0) { | |
472 | log_error("Failed to delete cgroup hierarchy group: %s", cgroup_strerror(r)); | |
473 | r = translate_error(r, errno); | |
474 | goto finish; | |
475 | } | |
476 | r = 0; | |
477 | ||
478 | finish: | |
479 | cgroup_free(&cg); | |
480 | return r; | |
481 | ||
482 | } | |
483 | ||
484 | int cgroup_notify_empty(Manager *m, const char *group) { | |
485 | CGroupBonding *l, *b; | |
486 | ||
487 | assert(m); | |
488 | assert(group); | |
489 | ||
490 | if (!(l = hashmap_get(m->cgroup_bondings, group))) | |
491 | return 0; | |
492 | ||
493 | LIST_FOREACH(by_path, b, l) { | |
494 | int t; | |
495 | ||
496 | if (!b->unit) | |
497 | continue; | |
498 | ||
499 | if ((t = cgroup_bonding_is_empty_list(b)) < 0) { | |
500 | ||
501 | /* If we don't know, we don't know */ | |
502 | if (t != -EAGAIN) | |
503 | log_warning("Failed to check whether cgroup is empty: %s", strerror(errno)); | |
504 | ||
505 | continue; | |
506 | } | |
507 | ||
508 | if (t > 0) | |
509 | if (UNIT_VTABLE(b->unit)->cgroup_notify_empty) | |
510 | UNIT_VTABLE(b->unit)->cgroup_notify_empty(b->unit); | |
511 | } | |
512 | ||
513 | return 0; | |
514 | } | |
515 | ||
516 | CGroupBonding *cgroup_bonding_find_list(CGroupBonding *first, const char *controller) { | |
517 | CGroupBonding *b; | |
518 | ||
519 | assert(controller); | |
520 | ||
521 | LIST_FOREACH(by_unit, b, first) | |
522 | if (streq(b->controller, controller)) | |
523 | return b; | |
524 | ||
525 | return NULL; | |
526 | } |