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core: undo the dependency inversion between unit.h and all unit types
[thirdparty/systemd.git] / src / core / swap.c
1 /* SPDX-License-Identifier: LGPL-2.1+ */
2 /***
3 This file is part of systemd.
4
5 Copyright 2010 Lennart Poettering
6 ***/
7
8 #include <errno.h>
9 #include <sys/epoll.h>
10 #include <sys/stat.h>
11 #include <unistd.h>
12
13 #include "libudev.h"
14
15 #include "alloc-util.h"
16 #include "dbus-swap.h"
17 #include "device.h"
18 #include "escape.h"
19 #include "exit-status.h"
20 #include "fd-util.h"
21 #include "format-util.h"
22 #include "fstab-util.h"
23 #include "parse-util.h"
24 #include "path-util.h"
25 #include "process-util.h"
26 #include "special.h"
27 #include "string-table.h"
28 #include "string-util.h"
29 #include "swap.h"
30 #include "udev-util.h"
31 #include "unit-name.h"
32 #include "unit.h"
33 #include "virt.h"
34
35 static const UnitActiveState state_translation_table[_SWAP_STATE_MAX] = {
36 [SWAP_DEAD] = UNIT_INACTIVE,
37 [SWAP_ACTIVATING] = UNIT_ACTIVATING,
38 [SWAP_ACTIVATING_DONE] = UNIT_ACTIVE,
39 [SWAP_ACTIVE] = UNIT_ACTIVE,
40 [SWAP_DEACTIVATING] = UNIT_DEACTIVATING,
41 [SWAP_DEACTIVATING_SIGTERM] = UNIT_DEACTIVATING,
42 [SWAP_DEACTIVATING_SIGKILL] = UNIT_DEACTIVATING,
43 [SWAP_FAILED] = UNIT_FAILED
44 };
45
46 static int swap_dispatch_timer(sd_event_source *source, usec_t usec, void *userdata);
47 static int swap_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata);
48
49 static bool SWAP_STATE_WITH_PROCESS(SwapState state) {
50 return IN_SET(state,
51 SWAP_ACTIVATING,
52 SWAP_ACTIVATING_DONE,
53 SWAP_DEACTIVATING,
54 SWAP_DEACTIVATING_SIGTERM,
55 SWAP_DEACTIVATING_SIGKILL);
56 }
57
58 static void swap_unset_proc_swaps(Swap *s) {
59 assert(s);
60
61 if (!s->from_proc_swaps)
62 return;
63
64 s->parameters_proc_swaps.what = mfree(s->parameters_proc_swaps.what);
65
66 s->from_proc_swaps = false;
67 }
68
69 static int swap_set_devnode(Swap *s, const char *devnode) {
70 Hashmap *swaps;
71 Swap *first;
72 int r;
73
74 assert(s);
75
76 r = hashmap_ensure_allocated(&UNIT(s)->manager->swaps_by_devnode, &path_hash_ops);
77 if (r < 0)
78 return r;
79
80 swaps = UNIT(s)->manager->swaps_by_devnode;
81
82 if (s->devnode) {
83 first = hashmap_get(swaps, s->devnode);
84
85 LIST_REMOVE(same_devnode, first, s);
86 if (first)
87 hashmap_replace(swaps, first->devnode, first);
88 else
89 hashmap_remove(swaps, s->devnode);
90
91 s->devnode = mfree(s->devnode);
92 }
93
94 if (devnode) {
95 s->devnode = strdup(devnode);
96 if (!s->devnode)
97 return -ENOMEM;
98
99 first = hashmap_get(swaps, s->devnode);
100 LIST_PREPEND(same_devnode, first, s);
101
102 return hashmap_replace(swaps, first->devnode, first);
103 }
104
105 return 0;
106 }
107
108 static void swap_init(Unit *u) {
109 Swap *s = SWAP(u);
110
111 assert(s);
112 assert(UNIT(s)->load_state == UNIT_STUB);
113
114 s->timeout_usec = u->manager->default_timeout_start_usec;
115
116 s->exec_context.std_output = u->manager->default_std_output;
117 s->exec_context.std_error = u->manager->default_std_error;
118
119 s->parameters_proc_swaps.priority = s->parameters_fragment.priority = -1;
120
121 s->control_command_id = _SWAP_EXEC_COMMAND_INVALID;
122
123 u->ignore_on_isolate = true;
124 }
125
126 static void swap_unwatch_control_pid(Swap *s) {
127 assert(s);
128
129 if (s->control_pid <= 0)
130 return;
131
132 unit_unwatch_pid(UNIT(s), s->control_pid);
133 s->control_pid = 0;
134 }
135
136 static void swap_done(Unit *u) {
137 Swap *s = SWAP(u);
138
139 assert(s);
140
141 swap_unset_proc_swaps(s);
142 swap_set_devnode(s, NULL);
143
144 s->what = mfree(s->what);
145 s->parameters_fragment.what = mfree(s->parameters_fragment.what);
146 s->parameters_fragment.options = mfree(s->parameters_fragment.options);
147
148 s->exec_runtime = exec_runtime_unref(s->exec_runtime, false);
149 exec_command_done_array(s->exec_command, _SWAP_EXEC_COMMAND_MAX);
150 s->control_command = NULL;
151
152 dynamic_creds_unref(&s->dynamic_creds);
153
154 swap_unwatch_control_pid(s);
155
156 s->timer_event_source = sd_event_source_unref(s->timer_event_source);
157 }
158
159 static int swap_arm_timer(Swap *s, usec_t usec) {
160 int r;
161
162 assert(s);
163
164 if (s->timer_event_source) {
165 r = sd_event_source_set_time(s->timer_event_source, usec);
166 if (r < 0)
167 return r;
168
169 return sd_event_source_set_enabled(s->timer_event_source, SD_EVENT_ONESHOT);
170 }
171
172 if (usec == USEC_INFINITY)
173 return 0;
174
175 r = sd_event_add_time(
176 UNIT(s)->manager->event,
177 &s->timer_event_source,
178 CLOCK_MONOTONIC,
179 usec, 0,
180 swap_dispatch_timer, s);
181 if (r < 0)
182 return r;
183
184 (void) sd_event_source_set_description(s->timer_event_source, "swap-timer");
185
186 return 0;
187 }
188
189 static int swap_add_device_dependencies(Swap *s) {
190 assert(s);
191
192 if (!s->what)
193 return 0;
194
195 if (!s->from_fragment)
196 return 0;
197
198 if (is_device_path(s->what))
199 return unit_add_node_dependency(UNIT(s), s->what, MANAGER_IS_SYSTEM(UNIT(s)->manager), UNIT_BINDS_TO, UNIT_DEPENDENCY_FILE);
200 else
201 /* File based swap devices need to be ordered after
202 * systemd-remount-fs.service, since they might need a
203 * writable file system. */
204 return unit_add_dependency_by_name(UNIT(s), UNIT_AFTER, SPECIAL_REMOUNT_FS_SERVICE, NULL, true, UNIT_DEPENDENCY_FILE);
205 }
206
207 static int swap_add_default_dependencies(Swap *s) {
208 int r;
209
210 assert(s);
211
212 if (!UNIT(s)->default_dependencies)
213 return 0;
214
215 if (!MANAGER_IS_SYSTEM(UNIT(s)->manager))
216 return 0;
217
218 if (detect_container() > 0)
219 return 0;
220
221 /* swap units generated for the swap dev links are missing the
222 * ordering dep against the swap target. */
223 r = unit_add_dependency_by_name(UNIT(s), UNIT_BEFORE, SPECIAL_SWAP_TARGET, NULL, true, UNIT_DEPENDENCY_DEFAULT);
224 if (r < 0)
225 return r;
226
227 return unit_add_two_dependencies_by_name(UNIT(s), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_UMOUNT_TARGET, NULL, true, UNIT_DEPENDENCY_DEFAULT);
228 }
229
230 static int swap_verify(Swap *s) {
231 _cleanup_free_ char *e = NULL;
232 int r;
233
234 if (UNIT(s)->load_state != UNIT_LOADED)
235 return 0;
236
237 r = unit_name_from_path(s->what, ".swap", &e);
238 if (r < 0)
239 return log_unit_error_errno(UNIT(s), r, "Failed to generate unit name from path: %m");
240
241 if (!unit_has_name(UNIT(s), e)) {
242 log_unit_error(UNIT(s), "Value of What= and unit name do not match, not loading.");
243 return -EINVAL;
244 }
245
246 if (s->exec_context.pam_name && s->kill_context.kill_mode != KILL_CONTROL_GROUP) {
247 log_unit_error(UNIT(s), "Unit has PAM enabled. Kill mode must be set to 'control-group'. Refusing to load.");
248 return -EINVAL;
249 }
250
251 return 0;
252 }
253
254 static int swap_load_devnode(Swap *s) {
255 _cleanup_(udev_device_unrefp) struct udev_device *d = NULL;
256 struct stat st;
257 const char *p;
258
259 assert(s);
260
261 if (stat(s->what, &st) < 0 || !S_ISBLK(st.st_mode))
262 return 0;
263
264 d = udev_device_new_from_devnum(UNIT(s)->manager->udev, 'b', st.st_rdev);
265 if (!d)
266 return 0;
267
268 p = udev_device_get_devnode(d);
269 if (!p)
270 return 0;
271
272 return swap_set_devnode(s, p);
273 }
274
275 static int swap_load(Unit *u) {
276 int r;
277 Swap *s = SWAP(u);
278
279 assert(s);
280 assert(u->load_state == UNIT_STUB);
281
282 /* Load a .swap file */
283 if (SWAP(u)->from_proc_swaps)
284 r = unit_load_fragment_and_dropin_optional(u);
285 else
286 r = unit_load_fragment_and_dropin(u);
287 if (r < 0)
288 return r;
289
290 if (u->load_state == UNIT_LOADED) {
291
292 if (UNIT(s)->fragment_path)
293 s->from_fragment = true;
294
295 if (!s->what) {
296 if (s->parameters_fragment.what)
297 s->what = strdup(s->parameters_fragment.what);
298 else if (s->parameters_proc_swaps.what)
299 s->what = strdup(s->parameters_proc_swaps.what);
300 else {
301 r = unit_name_to_path(u->id, &s->what);
302 if (r < 0)
303 return r;
304 }
305
306 if (!s->what)
307 return -ENOMEM;
308 }
309
310 path_kill_slashes(s->what);
311
312 if (!UNIT(s)->description) {
313 r = unit_set_description(u, s->what);
314 if (r < 0)
315 return r;
316 }
317
318 r = unit_require_mounts_for(UNIT(s), s->what, UNIT_DEPENDENCY_IMPLICIT);
319 if (r < 0)
320 return r;
321
322 r = swap_add_device_dependencies(s);
323 if (r < 0)
324 return r;
325
326 r = swap_load_devnode(s);
327 if (r < 0)
328 return r;
329
330 r = unit_patch_contexts(u);
331 if (r < 0)
332 return r;
333
334 r = unit_add_exec_dependencies(u, &s->exec_context);
335 if (r < 0)
336 return r;
337
338 r = unit_set_default_slice(u);
339 if (r < 0)
340 return r;
341
342 r = swap_add_default_dependencies(s);
343 if (r < 0)
344 return r;
345 }
346
347 return swap_verify(s);
348 }
349
350 static int swap_setup_unit(
351 Manager *m,
352 const char *what,
353 const char *what_proc_swaps,
354 int priority,
355 bool set_flags) {
356
357 _cleanup_free_ char *e = NULL;
358 bool delete = false;
359 Unit *u = NULL;
360 int r;
361 SwapParameters *p;
362
363 assert(m);
364 assert(what);
365 assert(what_proc_swaps);
366
367 r = unit_name_from_path(what, ".swap", &e);
368 if (r < 0)
369 return log_unit_error_errno(u, r, "Failed to generate unit name from path: %m");
370
371 u = manager_get_unit(m, e);
372
373 if (u &&
374 SWAP(u)->from_proc_swaps &&
375 !path_equal(SWAP(u)->parameters_proc_swaps.what, what_proc_swaps)) {
376 log_error("Swap %s appeared twice with different device paths %s and %s", e, SWAP(u)->parameters_proc_swaps.what, what_proc_swaps);
377 return -EEXIST;
378 }
379
380 if (!u) {
381 delete = true;
382
383 r = unit_new_for_name(m, sizeof(Swap), e, &u);
384 if (r < 0)
385 goto fail;
386
387 SWAP(u)->what = strdup(what);
388 if (!SWAP(u)->what) {
389 r = -ENOMEM;
390 goto fail;
391 }
392
393 unit_add_to_load_queue(u);
394 } else
395 delete = false;
396
397 p = &SWAP(u)->parameters_proc_swaps;
398
399 if (!p->what) {
400 p->what = strdup(what_proc_swaps);
401 if (!p->what) {
402 r = -ENOMEM;
403 goto fail;
404 }
405 }
406
407 if (set_flags) {
408 SWAP(u)->is_active = true;
409 SWAP(u)->just_activated = !SWAP(u)->from_proc_swaps;
410 }
411
412 SWAP(u)->from_proc_swaps = true;
413
414 p->priority = priority;
415
416 unit_add_to_dbus_queue(u);
417 return 0;
418
419 fail:
420 log_unit_warning_errno(u, r, "Failed to load swap unit: %m");
421
422 if (delete)
423 unit_free(u);
424
425 return r;
426 }
427
428 static int swap_process_new(Manager *m, const char *device, int prio, bool set_flags) {
429 _cleanup_(udev_device_unrefp) struct udev_device *d = NULL;
430 struct udev_list_entry *item = NULL, *first = NULL;
431 const char *dn;
432 struct stat st;
433 int r;
434
435 assert(m);
436
437 r = swap_setup_unit(m, device, device, prio, set_flags);
438 if (r < 0)
439 return r;
440
441 /* If this is a block device, then let's add duplicates for
442 * all other names of this block device */
443 if (stat(device, &st) < 0 || !S_ISBLK(st.st_mode))
444 return 0;
445
446 d = udev_device_new_from_devnum(m->udev, 'b', st.st_rdev);
447 if (!d)
448 return 0;
449
450 /* Add the main device node */
451 dn = udev_device_get_devnode(d);
452 if (dn && !streq(dn, device))
453 swap_setup_unit(m, dn, device, prio, set_flags);
454
455 /* Add additional units for all symlinks */
456 first = udev_device_get_devlinks_list_entry(d);
457 udev_list_entry_foreach(item, first) {
458 const char *p;
459
460 /* Don't bother with the /dev/block links */
461 p = udev_list_entry_get_name(item);
462
463 if (streq(p, device))
464 continue;
465
466 if (path_startswith(p, "/dev/block/"))
467 continue;
468
469 if (stat(p, &st) >= 0)
470 if (!S_ISBLK(st.st_mode) ||
471 st.st_rdev != udev_device_get_devnum(d))
472 continue;
473
474 swap_setup_unit(m, p, device, prio, set_flags);
475 }
476
477 return r;
478 }
479
480 static void swap_set_state(Swap *s, SwapState state) {
481 SwapState old_state;
482 Swap *other;
483
484 assert(s);
485
486 old_state = s->state;
487 s->state = state;
488
489 if (!SWAP_STATE_WITH_PROCESS(state)) {
490 s->timer_event_source = sd_event_source_unref(s->timer_event_source);
491 swap_unwatch_control_pid(s);
492 s->control_command = NULL;
493 s->control_command_id = _SWAP_EXEC_COMMAND_INVALID;
494 }
495
496 if (state != old_state)
497 log_unit_debug(UNIT(s), "Changed %s -> %s", swap_state_to_string(old_state), swap_state_to_string(state));
498
499 unit_notify(UNIT(s), state_translation_table[old_state], state_translation_table[state], true);
500
501 /* If there other units for the same device node have a job
502 queued it might be worth checking again if it is runnable
503 now. This is necessary, since swap_start() refuses
504 operation with EAGAIN if there's already another job for
505 the same device node queued. */
506 LIST_FOREACH_OTHERS(same_devnode, other, s)
507 if (UNIT(other)->job)
508 job_add_to_run_queue(UNIT(other)->job);
509 }
510
511 static int swap_coldplug(Unit *u) {
512 Swap *s = SWAP(u);
513 SwapState new_state = SWAP_DEAD;
514 int r;
515
516 assert(s);
517 assert(s->state == SWAP_DEAD);
518
519 if (s->deserialized_state != s->state)
520 new_state = s->deserialized_state;
521 else if (s->from_proc_swaps)
522 new_state = SWAP_ACTIVE;
523
524 if (new_state == s->state)
525 return 0;
526
527 if (s->control_pid > 0 &&
528 pid_is_unwaited(s->control_pid) &&
529 SWAP_STATE_WITH_PROCESS(new_state)) {
530
531 r = unit_watch_pid(UNIT(s), s->control_pid);
532 if (r < 0)
533 return r;
534
535 r = swap_arm_timer(s, usec_add(u->state_change_timestamp.monotonic, s->timeout_usec));
536 if (r < 0)
537 return r;
538 }
539
540 if (!IN_SET(new_state, SWAP_DEAD, SWAP_FAILED)) {
541 (void) unit_setup_dynamic_creds(u);
542 (void) unit_setup_exec_runtime(u);
543 }
544
545 swap_set_state(s, new_state);
546 return 0;
547 }
548
549 static void swap_dump(Unit *u, FILE *f, const char *prefix) {
550 char buf[FORMAT_TIMESPAN_MAX];
551 Swap *s = SWAP(u);
552 SwapParameters *p;
553
554 assert(s);
555 assert(f);
556
557 if (s->from_proc_swaps)
558 p = &s->parameters_proc_swaps;
559 else if (s->from_fragment)
560 p = &s->parameters_fragment;
561 else
562 p = NULL;
563
564 fprintf(f,
565 "%sSwap State: %s\n"
566 "%sResult: %s\n"
567 "%sWhat: %s\n"
568 "%sFrom /proc/swaps: %s\n"
569 "%sFrom fragment: %s\n",
570 prefix, swap_state_to_string(s->state),
571 prefix, swap_result_to_string(s->result),
572 prefix, s->what,
573 prefix, yes_no(s->from_proc_swaps),
574 prefix, yes_no(s->from_fragment));
575
576 if (s->devnode)
577 fprintf(f, "%sDevice Node: %s\n", prefix, s->devnode);
578
579 if (p)
580 fprintf(f,
581 "%sPriority: %i\n"
582 "%sOptions: %s\n",
583 prefix, p->priority,
584 prefix, strempty(p->options));
585
586 fprintf(f,
587 "%sTimeoutSec: %s\n",
588 prefix, format_timespan(buf, sizeof(buf), s->timeout_usec, USEC_PER_SEC));
589
590 if (s->control_pid > 0)
591 fprintf(f,
592 "%sControl PID: "PID_FMT"\n",
593 prefix, s->control_pid);
594
595 exec_context_dump(&s->exec_context, f, prefix);
596 kill_context_dump(&s->kill_context, f, prefix);
597 cgroup_context_dump(&s->cgroup_context, f, prefix);
598 }
599
600 static int swap_spawn(Swap *s, ExecCommand *c, pid_t *_pid) {
601
602 ExecParameters exec_params = {
603 .flags = EXEC_APPLY_SANDBOXING|EXEC_APPLY_CHROOT|EXEC_APPLY_TTY_STDIN,
604 .stdin_fd = -1,
605 .stdout_fd = -1,
606 .stderr_fd = -1,
607 };
608 pid_t pid;
609 int r;
610
611 assert(s);
612 assert(c);
613 assert(_pid);
614
615 r = unit_prepare_exec(UNIT(s));
616 if (r < 0)
617 return r;
618
619 r = swap_arm_timer(s, usec_add(now(CLOCK_MONOTONIC), s->timeout_usec));
620 if (r < 0)
621 goto fail;
622
623 unit_set_exec_params(UNIT(s), &exec_params);
624
625 r = exec_spawn(UNIT(s),
626 c,
627 &s->exec_context,
628 &exec_params,
629 s->exec_runtime,
630 &s->dynamic_creds,
631 &pid);
632 if (r < 0)
633 goto fail;
634
635 r = unit_watch_pid(UNIT(s), pid);
636 if (r < 0)
637 /* FIXME: we need to do something here */
638 goto fail;
639
640 *_pid = pid;
641
642 return 0;
643
644 fail:
645 s->timer_event_source = sd_event_source_unref(s->timer_event_source);
646
647 return r;
648 }
649
650 static void swap_enter_dead(Swap *s, SwapResult f) {
651 assert(s);
652
653 if (s->result == SWAP_SUCCESS)
654 s->result = f;
655
656 if (s->result != SWAP_SUCCESS)
657 log_unit_warning(UNIT(s), "Failed with result '%s'.", swap_result_to_string(s->result));
658
659 swap_set_state(s, s->result != SWAP_SUCCESS ? SWAP_FAILED : SWAP_DEAD);
660
661 s->exec_runtime = exec_runtime_unref(s->exec_runtime, true);
662
663 exec_context_destroy_runtime_directory(&s->exec_context, UNIT(s)->manager->prefix[EXEC_DIRECTORY_RUNTIME]);
664
665 unit_unref_uid_gid(UNIT(s), true);
666
667 dynamic_creds_destroy(&s->dynamic_creds);
668 }
669
670 static void swap_enter_active(Swap *s, SwapResult f) {
671 assert(s);
672
673 if (s->result == SWAP_SUCCESS)
674 s->result = f;
675
676 swap_set_state(s, SWAP_ACTIVE);
677 }
678
679 static void swap_enter_dead_or_active(Swap *s, SwapResult f) {
680 assert(s);
681
682 if (s->from_proc_swaps)
683 swap_enter_active(s, f);
684 else
685 swap_enter_dead(s, f);
686 }
687
688 static void swap_enter_signal(Swap *s, SwapState state, SwapResult f) {
689 int r;
690 KillOperation kop;
691
692 assert(s);
693
694 if (s->result == SWAP_SUCCESS)
695 s->result = f;
696
697 if (state == SWAP_DEACTIVATING_SIGTERM)
698 kop = KILL_TERMINATE;
699 else
700 kop = KILL_KILL;
701
702 r = unit_kill_context(UNIT(s), &s->kill_context, kop, -1, s->control_pid, false);
703 if (r < 0)
704 goto fail;
705
706 if (r > 0) {
707 r = swap_arm_timer(s, usec_add(now(CLOCK_MONOTONIC), s->timeout_usec));
708 if (r < 0)
709 goto fail;
710
711 swap_set_state(s, state);
712 } else if (state == SWAP_DEACTIVATING_SIGTERM && s->kill_context.send_sigkill)
713 swap_enter_signal(s, SWAP_DEACTIVATING_SIGKILL, SWAP_SUCCESS);
714 else
715 swap_enter_dead_or_active(s, SWAP_SUCCESS);
716
717 return;
718
719 fail:
720 log_unit_warning_errno(UNIT(s), r, "Failed to kill processes: %m");
721 swap_enter_dead_or_active(s, SWAP_FAILURE_RESOURCES);
722 }
723
724 static void swap_enter_activating(Swap *s) {
725 _cleanup_free_ char *opts = NULL;
726 int r;
727
728 assert(s);
729
730 unit_warn_leftover_processes(UNIT(s));
731
732 s->control_command_id = SWAP_EXEC_ACTIVATE;
733 s->control_command = s->exec_command + SWAP_EXEC_ACTIVATE;
734
735 if (s->from_fragment) {
736 int priority = -1;
737
738 r = fstab_find_pri(s->parameters_fragment.options, &priority);
739 if (r < 0)
740 log_warning_errno(r, "Failed to parse swap priority \"%s\", ignoring: %m", s->parameters_fragment.options);
741 else if (r == 1 && s->parameters_fragment.priority >= 0)
742 log_warning("Duplicate swap priority configuration by Priority and Options fields.");
743
744 if (r <= 0 && s->parameters_fragment.priority >= 0) {
745 if (s->parameters_fragment.options)
746 r = asprintf(&opts, "%s,pri=%i", s->parameters_fragment.options, s->parameters_fragment.priority);
747 else
748 r = asprintf(&opts, "pri=%i", s->parameters_fragment.priority);
749 if (r < 0)
750 goto fail;
751 }
752 }
753
754 r = exec_command_set(s->control_command, "/sbin/swapon", NULL);
755 if (r < 0)
756 goto fail;
757
758 if (s->parameters_fragment.options || opts) {
759 r = exec_command_append(s->control_command, "-o",
760 opts ? : s->parameters_fragment.options, NULL);
761 if (r < 0)
762 goto fail;
763 }
764
765 r = exec_command_append(s->control_command, s->what, NULL);
766 if (r < 0)
767 goto fail;
768
769 swap_unwatch_control_pid(s);
770
771 r = swap_spawn(s, s->control_command, &s->control_pid);
772 if (r < 0)
773 goto fail;
774
775 swap_set_state(s, SWAP_ACTIVATING);
776
777 return;
778
779 fail:
780 log_unit_warning_errno(UNIT(s), r, "Failed to run 'swapon' task: %m");
781 swap_enter_dead_or_active(s, SWAP_FAILURE_RESOURCES);
782 }
783
784 static void swap_enter_deactivating(Swap *s) {
785 int r;
786
787 assert(s);
788
789 s->control_command_id = SWAP_EXEC_DEACTIVATE;
790 s->control_command = s->exec_command + SWAP_EXEC_DEACTIVATE;
791
792 r = exec_command_set(s->control_command,
793 "/sbin/swapoff",
794 s->what,
795 NULL);
796 if (r < 0)
797 goto fail;
798
799 swap_unwatch_control_pid(s);
800
801 r = swap_spawn(s, s->control_command, &s->control_pid);
802 if (r < 0)
803 goto fail;
804
805 swap_set_state(s, SWAP_DEACTIVATING);
806
807 return;
808
809 fail:
810 log_unit_warning_errno(UNIT(s), r, "Failed to run 'swapoff' task: %m");
811 swap_enter_dead_or_active(s, SWAP_FAILURE_RESOURCES);
812 }
813
814 static int swap_start(Unit *u) {
815 Swap *s = SWAP(u), *other;
816 int r;
817
818 assert(s);
819
820 /* We cannot fulfill this request right now, try again later please! */
821 if (IN_SET(s->state,
822 SWAP_DEACTIVATING,
823 SWAP_DEACTIVATING_SIGTERM,
824 SWAP_DEACTIVATING_SIGKILL))
825 return -EAGAIN;
826
827 /* Already on it! */
828 if (s->state == SWAP_ACTIVATING)
829 return 0;
830
831 assert(IN_SET(s->state, SWAP_DEAD, SWAP_FAILED));
832
833 if (detect_container() > 0)
834 return -EPERM;
835
836 /* If there's a job for another swap unit for the same node
837 * running, then let's not dispatch this one for now, and wait
838 * until that other job has finished. */
839 LIST_FOREACH_OTHERS(same_devnode, other, s)
840 if (UNIT(other)->job && UNIT(other)->job->state == JOB_RUNNING)
841 return -EAGAIN;
842
843 r = unit_start_limit_test(u);
844 if (r < 0) {
845 swap_enter_dead(s, SWAP_FAILURE_START_LIMIT_HIT);
846 return r;
847 }
848
849 r = unit_acquire_invocation_id(u);
850 if (r < 0)
851 return r;
852
853 s->result = SWAP_SUCCESS;
854
855 u->reset_accounting = true;
856
857 swap_enter_activating(s);
858 return 1;
859 }
860
861 static int swap_stop(Unit *u) {
862 Swap *s = SWAP(u);
863
864 assert(s);
865
866 switch (s->state) {
867
868 case SWAP_DEACTIVATING:
869 case SWAP_DEACTIVATING_SIGTERM:
870 case SWAP_DEACTIVATING_SIGKILL:
871 /* Already on it */
872 return 0;
873
874 case SWAP_ACTIVATING:
875 case SWAP_ACTIVATING_DONE:
876 /* There's a control process pending, directly enter kill mode */
877 swap_enter_signal(s, SWAP_DEACTIVATING_SIGTERM, SWAP_SUCCESS);
878 return 0;
879
880 case SWAP_ACTIVE:
881 if (detect_container() > 0)
882 return -EPERM;
883
884 swap_enter_deactivating(s);
885 return 1;
886
887 default:
888 assert_not_reached("Unexpected state.");
889 }
890 }
891
892 static int swap_serialize(Unit *u, FILE *f, FDSet *fds) {
893 Swap *s = SWAP(u);
894
895 assert(s);
896 assert(f);
897 assert(fds);
898
899 unit_serialize_item(u, f, "state", swap_state_to_string(s->state));
900 unit_serialize_item(u, f, "result", swap_result_to_string(s->result));
901
902 if (s->control_pid > 0)
903 unit_serialize_item_format(u, f, "control-pid", PID_FMT, s->control_pid);
904
905 if (s->control_command_id >= 0)
906 unit_serialize_item(u, f, "control-command", swap_exec_command_to_string(s->control_command_id));
907
908 return 0;
909 }
910
911 static int swap_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
912 Swap *s = SWAP(u);
913
914 assert(s);
915 assert(fds);
916
917 if (streq(key, "state")) {
918 SwapState state;
919
920 state = swap_state_from_string(value);
921 if (state < 0)
922 log_unit_debug(u, "Failed to parse state value: %s", value);
923 else
924 s->deserialized_state = state;
925 } else if (streq(key, "result")) {
926 SwapResult f;
927
928 f = swap_result_from_string(value);
929 if (f < 0)
930 log_unit_debug(u, "Failed to parse result value: %s", value);
931 else if (f != SWAP_SUCCESS)
932 s->result = f;
933 } else if (streq(key, "control-pid")) {
934 pid_t pid;
935
936 if (parse_pid(value, &pid) < 0)
937 log_unit_debug(u, "Failed to parse control-pid value: %s", value);
938 else
939 s->control_pid = pid;
940
941 } else if (streq(key, "control-command")) {
942 SwapExecCommand id;
943
944 id = swap_exec_command_from_string(value);
945 if (id < 0)
946 log_unit_debug(u, "Failed to parse exec-command value: %s", value);
947 else {
948 s->control_command_id = id;
949 s->control_command = s->exec_command + id;
950 }
951 } else
952 log_unit_debug(u, "Unknown serialization key: %s", key);
953
954 return 0;
955 }
956
957 _pure_ static UnitActiveState swap_active_state(Unit *u) {
958 assert(u);
959
960 return state_translation_table[SWAP(u)->state];
961 }
962
963 _pure_ static const char *swap_sub_state_to_string(Unit *u) {
964 assert(u);
965
966 return swap_state_to_string(SWAP(u)->state);
967 }
968
969 _pure_ static bool swap_may_gc(Unit *u) {
970 Swap *s = SWAP(u);
971
972 assert(s);
973
974 if (s->from_proc_swaps)
975 return false;
976
977 return true;
978 }
979
980 static void swap_sigchld_event(Unit *u, pid_t pid, int code, int status) {
981 Swap *s = SWAP(u);
982 SwapResult f;
983
984 assert(s);
985 assert(pid >= 0);
986
987 if (pid != s->control_pid)
988 return;
989
990 s->control_pid = 0;
991
992 if (is_clean_exit(code, status, EXIT_CLEAN_COMMAND, NULL))
993 f = SWAP_SUCCESS;
994 else if (code == CLD_EXITED)
995 f = SWAP_FAILURE_EXIT_CODE;
996 else if (code == CLD_KILLED)
997 f = SWAP_FAILURE_SIGNAL;
998 else if (code == CLD_DUMPED)
999 f = SWAP_FAILURE_CORE_DUMP;
1000 else
1001 assert_not_reached("Unknown code");
1002
1003 if (s->result == SWAP_SUCCESS)
1004 s->result = f;
1005
1006 if (s->control_command) {
1007 exec_status_exit(&s->control_command->exec_status, &s->exec_context, pid, code, status);
1008
1009 s->control_command = NULL;
1010 s->control_command_id = _SWAP_EXEC_COMMAND_INVALID;
1011 }
1012
1013 log_unit_full(u, f == SWAP_SUCCESS ? LOG_DEBUG : LOG_NOTICE, 0,
1014 "Swap process exited, code=%s status=%i", sigchld_code_to_string(code), status);
1015
1016 switch (s->state) {
1017
1018 case SWAP_ACTIVATING:
1019 case SWAP_ACTIVATING_DONE:
1020
1021 if (f == SWAP_SUCCESS || s->from_proc_swaps)
1022 swap_enter_active(s, f);
1023 else
1024 swap_enter_dead(s, f);
1025 break;
1026
1027 case SWAP_DEACTIVATING:
1028 case SWAP_DEACTIVATING_SIGKILL:
1029 case SWAP_DEACTIVATING_SIGTERM:
1030
1031 swap_enter_dead_or_active(s, f);
1032 break;
1033
1034 default:
1035 assert_not_reached("Uh, control process died at wrong time.");
1036 }
1037
1038 /* Notify clients about changed exit status */
1039 unit_add_to_dbus_queue(u);
1040 }
1041
1042 static int swap_dispatch_timer(sd_event_source *source, usec_t usec, void *userdata) {
1043 Swap *s = SWAP(userdata);
1044
1045 assert(s);
1046 assert(s->timer_event_source == source);
1047
1048 switch (s->state) {
1049
1050 case SWAP_ACTIVATING:
1051 case SWAP_ACTIVATING_DONE:
1052 log_unit_warning(UNIT(s), "Activation timed out. Stopping.");
1053 swap_enter_signal(s, SWAP_DEACTIVATING_SIGTERM, SWAP_FAILURE_TIMEOUT);
1054 break;
1055
1056 case SWAP_DEACTIVATING:
1057 log_unit_warning(UNIT(s), "Deactivation timed out. Stopping.");
1058 swap_enter_signal(s, SWAP_DEACTIVATING_SIGTERM, SWAP_FAILURE_TIMEOUT);
1059 break;
1060
1061 case SWAP_DEACTIVATING_SIGTERM:
1062 if (s->kill_context.send_sigkill) {
1063 log_unit_warning(UNIT(s), "Swap process timed out. Killing.");
1064 swap_enter_signal(s, SWAP_DEACTIVATING_SIGKILL, SWAP_FAILURE_TIMEOUT);
1065 } else {
1066 log_unit_warning(UNIT(s), "Swap process timed out. Skipping SIGKILL. Ignoring.");
1067 swap_enter_dead_or_active(s, SWAP_FAILURE_TIMEOUT);
1068 }
1069 break;
1070
1071 case SWAP_DEACTIVATING_SIGKILL:
1072 log_unit_warning(UNIT(s), "Swap process still around after SIGKILL. Ignoring.");
1073 swap_enter_dead_or_active(s, SWAP_FAILURE_TIMEOUT);
1074 break;
1075
1076 default:
1077 assert_not_reached("Timeout at wrong time.");
1078 }
1079
1080 return 0;
1081 }
1082
1083 static int swap_load_proc_swaps(Manager *m, bool set_flags) {
1084 unsigned i;
1085 int r = 0;
1086
1087 assert(m);
1088
1089 rewind(m->proc_swaps);
1090
1091 (void) fscanf(m->proc_swaps, "%*s %*s %*s %*s %*s\n");
1092
1093 for (i = 1;; i++) {
1094 _cleanup_free_ char *dev = NULL, *d = NULL;
1095 int prio = 0, k;
1096
1097 k = fscanf(m->proc_swaps,
1098 "%ms " /* device/file */
1099 "%*s " /* type of swap */
1100 "%*s " /* swap size */
1101 "%*s " /* used */
1102 "%i\n", /* priority */
1103 &dev, &prio);
1104 if (k != 2) {
1105 if (k == EOF)
1106 break;
1107
1108 log_warning("Failed to parse /proc/swaps:%u.", i);
1109 continue;
1110 }
1111
1112 if (cunescape(dev, UNESCAPE_RELAX, &d) < 0)
1113 return log_oom();
1114
1115 device_found_node(m, d, true, DEVICE_FOUND_SWAP, set_flags);
1116
1117 k = swap_process_new(m, d, prio, set_flags);
1118 if (k < 0)
1119 r = k;
1120 }
1121
1122 return r;
1123 }
1124
1125 static int swap_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
1126 Manager *m = userdata;
1127 Unit *u;
1128 int r;
1129
1130 assert(m);
1131 assert(revents & EPOLLPRI);
1132
1133 r = swap_load_proc_swaps(m, true);
1134 if (r < 0) {
1135 log_error_errno(r, "Failed to reread /proc/swaps: %m");
1136
1137 /* Reset flags, just in case, for late calls */
1138 LIST_FOREACH(units_by_type, u, m->units_by_type[UNIT_SWAP]) {
1139 Swap *swap = SWAP(u);
1140
1141 swap->is_active = swap->just_activated = false;
1142 }
1143
1144 return 0;
1145 }
1146
1147 manager_dispatch_load_queue(m);
1148
1149 LIST_FOREACH(units_by_type, u, m->units_by_type[UNIT_SWAP]) {
1150 Swap *swap = SWAP(u);
1151
1152 if (!swap->is_active) {
1153 /* This has just been deactivated */
1154
1155 swap_unset_proc_swaps(swap);
1156
1157 switch (swap->state) {
1158
1159 case SWAP_ACTIVE:
1160 swap_enter_dead(swap, SWAP_SUCCESS);
1161 break;
1162
1163 default:
1164 /* Fire again */
1165 swap_set_state(swap, swap->state);
1166 break;
1167 }
1168
1169 if (swap->what)
1170 device_found_node(m, swap->what, false, DEVICE_FOUND_SWAP, true);
1171
1172 } else if (swap->just_activated) {
1173
1174 /* New swap entry */
1175
1176 switch (swap->state) {
1177
1178 case SWAP_DEAD:
1179 case SWAP_FAILED:
1180 (void) unit_acquire_invocation_id(UNIT(swap));
1181 swap_enter_active(swap, SWAP_SUCCESS);
1182 break;
1183
1184 case SWAP_ACTIVATING:
1185 swap_set_state(swap, SWAP_ACTIVATING_DONE);
1186 break;
1187
1188 default:
1189 /* Nothing really changed, but let's
1190 * issue an notification call
1191 * nonetheless, in case somebody is
1192 * waiting for this. */
1193 swap_set_state(swap, swap->state);
1194 break;
1195 }
1196 }
1197
1198 /* Reset the flags for later calls */
1199 swap->is_active = swap->just_activated = false;
1200 }
1201
1202 return 1;
1203 }
1204
1205 static Unit *swap_following(Unit *u) {
1206 Swap *s = SWAP(u);
1207 Swap *other, *first = NULL;
1208
1209 assert(s);
1210
1211 /* If the user configured the swap through /etc/fstab or
1212 * a device unit, follow that. */
1213
1214 if (s->from_fragment)
1215 return NULL;
1216
1217 LIST_FOREACH_OTHERS(same_devnode, other, s)
1218 if (other->from_fragment)
1219 return UNIT(other);
1220
1221 /* Otherwise, make everybody follow the unit that's named after
1222 * the swap device in the kernel */
1223
1224 if (streq_ptr(s->what, s->devnode))
1225 return NULL;
1226
1227 LIST_FOREACH_AFTER(same_devnode, other, s)
1228 if (streq_ptr(other->what, other->devnode))
1229 return UNIT(other);
1230
1231 LIST_FOREACH_BEFORE(same_devnode, other, s) {
1232 if (streq_ptr(other->what, other->devnode))
1233 return UNIT(other);
1234
1235 first = other;
1236 }
1237
1238 /* Fall back to the first on the list */
1239 return UNIT(first);
1240 }
1241
1242 static int swap_following_set(Unit *u, Set **_set) {
1243 Swap *s = SWAP(u), *other;
1244 _cleanup_set_free_ Set *set = NULL;
1245 int r;
1246
1247 assert(s);
1248 assert(_set);
1249
1250 if (LIST_JUST_US(same_devnode, s)) {
1251 *_set = NULL;
1252 return 0;
1253 }
1254
1255 set = set_new(NULL);
1256 if (!set)
1257 return -ENOMEM;
1258
1259 LIST_FOREACH_OTHERS(same_devnode, other, s) {
1260 r = set_put(set, other);
1261 if (r < 0)
1262 return r;
1263 }
1264
1265 *_set = TAKE_PTR(set);
1266 return 1;
1267 }
1268
1269 static void swap_shutdown(Manager *m) {
1270 assert(m);
1271
1272 m->swap_event_source = sd_event_source_unref(m->swap_event_source);
1273
1274 m->proc_swaps = safe_fclose(m->proc_swaps);
1275
1276 m->swaps_by_devnode = hashmap_free(m->swaps_by_devnode);
1277 }
1278
1279 static void swap_enumerate(Manager *m) {
1280 int r;
1281
1282 assert(m);
1283
1284 if (!m->proc_swaps) {
1285 m->proc_swaps = fopen("/proc/swaps", "re");
1286 if (!m->proc_swaps) {
1287 if (errno == ENOENT)
1288 log_debug("Not swap enabled, skipping enumeration");
1289 else
1290 log_error_errno(errno, "Failed to open /proc/swaps: %m");
1291
1292 return;
1293 }
1294
1295 r = sd_event_add_io(m->event, &m->swap_event_source, fileno(m->proc_swaps), EPOLLPRI, swap_dispatch_io, m);
1296 if (r < 0) {
1297 log_error_errno(r, "Failed to watch /proc/swaps: %m");
1298 goto fail;
1299 }
1300
1301 /* Dispatch this before we dispatch SIGCHLD, so that
1302 * we always get the events from /proc/swaps before
1303 * the SIGCHLD of /sbin/swapon. */
1304 r = sd_event_source_set_priority(m->swap_event_source, SD_EVENT_PRIORITY_NORMAL-10);
1305 if (r < 0) {
1306 log_error_errno(r, "Failed to change /proc/swaps priority: %m");
1307 goto fail;
1308 }
1309
1310 (void) sd_event_source_set_description(m->swap_event_source, "swap-proc");
1311 }
1312
1313 r = swap_load_proc_swaps(m, false);
1314 if (r < 0)
1315 goto fail;
1316
1317 return;
1318
1319 fail:
1320 swap_shutdown(m);
1321 }
1322
1323 int swap_process_device_new(Manager *m, struct udev_device *dev) {
1324 struct udev_list_entry *item = NULL, *first = NULL;
1325 _cleanup_free_ char *e = NULL;
1326 const char *dn;
1327 Unit *u;
1328 int r = 0;
1329
1330 assert(m);
1331 assert(dev);
1332
1333 dn = udev_device_get_devnode(dev);
1334 if (!dn)
1335 return 0;
1336
1337 r = unit_name_from_path(dn, ".swap", &e);
1338 if (r < 0)
1339 return r;
1340
1341 u = manager_get_unit(m, e);
1342 if (u)
1343 r = swap_set_devnode(SWAP(u), dn);
1344
1345 first = udev_device_get_devlinks_list_entry(dev);
1346 udev_list_entry_foreach(item, first) {
1347 _cleanup_free_ char *n = NULL;
1348 int q;
1349
1350 q = unit_name_from_path(udev_list_entry_get_name(item), ".swap", &n);
1351 if (q < 0)
1352 return q;
1353
1354 u = manager_get_unit(m, n);
1355 if (u) {
1356 q = swap_set_devnode(SWAP(u), dn);
1357 if (q < 0)
1358 r = q;
1359 }
1360 }
1361
1362 return r;
1363 }
1364
1365 int swap_process_device_remove(Manager *m, struct udev_device *dev) {
1366 const char *dn;
1367 int r = 0;
1368 Swap *s;
1369
1370 dn = udev_device_get_devnode(dev);
1371 if (!dn)
1372 return 0;
1373
1374 while ((s = hashmap_get(m->swaps_by_devnode, dn))) {
1375 int q;
1376
1377 q = swap_set_devnode(s, NULL);
1378 if (q < 0)
1379 r = q;
1380 }
1381
1382 return r;
1383 }
1384
1385 static void swap_reset_failed(Unit *u) {
1386 Swap *s = SWAP(u);
1387
1388 assert(s);
1389
1390 if (s->state == SWAP_FAILED)
1391 swap_set_state(s, SWAP_DEAD);
1392
1393 s->result = SWAP_SUCCESS;
1394 }
1395
1396 static int swap_kill(Unit *u, KillWho who, int signo, sd_bus_error *error) {
1397 return unit_kill_common(u, who, signo, -1, SWAP(u)->control_pid, error);
1398 }
1399
1400 static int swap_get_timeout(Unit *u, usec_t *timeout) {
1401 Swap *s = SWAP(u);
1402 usec_t t;
1403 int r;
1404
1405 if (!s->timer_event_source)
1406 return 0;
1407
1408 r = sd_event_source_get_time(s->timer_event_source, &t);
1409 if (r < 0)
1410 return r;
1411 if (t == USEC_INFINITY)
1412 return 0;
1413
1414 *timeout = t;
1415 return 1;
1416 }
1417
1418 static bool swap_supported(void) {
1419 static int supported = -1;
1420
1421 /* If swap support is not available in the kernel, or we are
1422 * running in a container we don't support swap units, and any
1423 * attempts to starting one should fail immediately. */
1424
1425 if (supported < 0)
1426 supported =
1427 access("/proc/swaps", F_OK) >= 0 &&
1428 detect_container() <= 0;
1429
1430 return supported;
1431 }
1432
1433 static int swap_control_pid(Unit *u) {
1434 Swap *s = SWAP(u);
1435
1436 assert(s);
1437
1438 return s->control_pid;
1439 }
1440
1441 static const char* const swap_exec_command_table[_SWAP_EXEC_COMMAND_MAX] = {
1442 [SWAP_EXEC_ACTIVATE] = "ExecActivate",
1443 [SWAP_EXEC_DEACTIVATE] = "ExecDeactivate",
1444 };
1445
1446 DEFINE_STRING_TABLE_LOOKUP(swap_exec_command, SwapExecCommand);
1447
1448 static const char* const swap_result_table[_SWAP_RESULT_MAX] = {
1449 [SWAP_SUCCESS] = "success",
1450 [SWAP_FAILURE_RESOURCES] = "resources",
1451 [SWAP_FAILURE_TIMEOUT] = "timeout",
1452 [SWAP_FAILURE_EXIT_CODE] = "exit-code",
1453 [SWAP_FAILURE_SIGNAL] = "signal",
1454 [SWAP_FAILURE_CORE_DUMP] = "core-dump",
1455 [SWAP_FAILURE_START_LIMIT_HIT] = "start-limit-hit",
1456 };
1457
1458 DEFINE_STRING_TABLE_LOOKUP(swap_result, SwapResult);
1459
1460 const UnitVTable swap_vtable = {
1461 .object_size = sizeof(Swap),
1462 .exec_context_offset = offsetof(Swap, exec_context),
1463 .cgroup_context_offset = offsetof(Swap, cgroup_context),
1464 .kill_context_offset = offsetof(Swap, kill_context),
1465 .exec_runtime_offset = offsetof(Swap, exec_runtime),
1466 .dynamic_creds_offset = offsetof(Swap, dynamic_creds),
1467
1468 .sections =
1469 "Unit\0"
1470 "Swap\0"
1471 "Install\0",
1472 .private_section = "Swap",
1473
1474 .init = swap_init,
1475 .load = swap_load,
1476 .done = swap_done,
1477
1478 .coldplug = swap_coldplug,
1479
1480 .dump = swap_dump,
1481
1482 .start = swap_start,
1483 .stop = swap_stop,
1484
1485 .kill = swap_kill,
1486
1487 .get_timeout = swap_get_timeout,
1488
1489 .serialize = swap_serialize,
1490 .deserialize_item = swap_deserialize_item,
1491
1492 .active_state = swap_active_state,
1493 .sub_state_to_string = swap_sub_state_to_string,
1494
1495 .may_gc = swap_may_gc,
1496
1497 .sigchld_event = swap_sigchld_event,
1498
1499 .reset_failed = swap_reset_failed,
1500
1501 .control_pid = swap_control_pid,
1502
1503 .bus_vtable = bus_swap_vtable,
1504 .bus_set_property = bus_swap_set_property,
1505 .bus_commit_properties = bus_swap_commit_properties,
1506
1507 .following = swap_following,
1508 .following_set = swap_following_set,
1509
1510 .enumerate = swap_enumerate,
1511 .shutdown = swap_shutdown,
1512 .supported = swap_supported,
1513
1514 .status_message_formats = {
1515 .starting_stopping = {
1516 [0] = "Activating swap %s...",
1517 [1] = "Deactivating swap %s...",
1518 },
1519 .finished_start_job = {
1520 [JOB_DONE] = "Activated swap %s.",
1521 [JOB_FAILED] = "Failed to activate swap %s.",
1522 [JOB_TIMEOUT] = "Timed out activating swap %s.",
1523 },
1524 .finished_stop_job = {
1525 [JOB_DONE] = "Deactivated swap %s.",
1526 [JOB_FAILED] = "Failed deactivating swap %s.",
1527 [JOB_TIMEOUT] = "Timed out deactivating swap %s.",
1528 },
1529 },
1530 };
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