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75778e21 MS |
1 | #include "transaction.h" |
2 | #include "bus-errors.h" | |
3 | ||
4 | static void transaction_unlink_job(Transaction *tr, Job *j, bool delete_dependencies); | |
5 | ||
6 | static void transaction_delete_job(Transaction *tr, Job *j, bool delete_dependencies) { | |
7 | assert(tr); | |
8 | assert(j); | |
9 | ||
10 | /* Deletes one job from the transaction */ | |
11 | ||
12 | transaction_unlink_job(tr, j, delete_dependencies); | |
13 | ||
14 | if (!j->installed) | |
15 | job_free(j); | |
16 | } | |
17 | ||
18 | static void transaction_delete_unit(Transaction *tr, Unit *u) { | |
19 | Job *j; | |
20 | ||
21 | /* Deletes all jobs associated with a certain unit from the | |
22 | * transaction */ | |
23 | ||
24 | while ((j = hashmap_get(tr->jobs, u))) | |
25 | transaction_delete_job(tr, j, true); | |
26 | } | |
27 | ||
28 | void transaction_abort(Transaction *tr) { | |
29 | Job *j; | |
30 | ||
31 | assert(tr); | |
32 | ||
33 | while ((j = hashmap_first(tr->jobs))) | |
34 | transaction_delete_job(tr, j, true); | |
35 | ||
36 | assert(hashmap_isempty(tr->jobs)); | |
37 | ||
38 | assert(!tr->anchor); | |
39 | } | |
40 | ||
0d9989aa | 41 | static void transaction_find_jobs_that_matter_to_anchor(Job *j, unsigned generation) { |
75778e21 MS |
42 | JobDependency *l; |
43 | ||
75778e21 MS |
44 | /* A recursive sweep through the graph that marks all units |
45 | * that matter to the anchor job, i.e. are directly or | |
46 | * indirectly a dependency of the anchor job via paths that | |
47 | * are fully marked as mattering. */ | |
48 | ||
0d9989aa MS |
49 | j->matters_to_anchor = true; |
50 | j->generation = generation; | |
75778e21 | 51 | |
0d9989aa | 52 | LIST_FOREACH(subject, l, j->subject_list) { |
75778e21 MS |
53 | |
54 | /* This link does not matter */ | |
55 | if (!l->matters) | |
56 | continue; | |
57 | ||
58 | /* This unit has already been marked */ | |
59 | if (l->object->generation == generation) | |
60 | continue; | |
61 | ||
0d9989aa | 62 | transaction_find_jobs_that_matter_to_anchor(l->object, generation); |
75778e21 MS |
63 | } |
64 | } | |
65 | ||
66 | static void transaction_merge_and_delete_job(Transaction *tr, Job *j, Job *other, JobType t) { | |
67 | JobDependency *l, *last; | |
68 | ||
69 | assert(j); | |
70 | assert(other); | |
71 | assert(j->unit == other->unit); | |
72 | assert(!j->installed); | |
73 | ||
74 | /* Merges 'other' into 'j' and then deletes 'other'. */ | |
75 | ||
76 | j->type = t; | |
77 | j->state = JOB_WAITING; | |
78 | j->override = j->override || other->override; | |
79 | ||
80 | j->matters_to_anchor = j->matters_to_anchor || other->matters_to_anchor; | |
81 | ||
82 | /* Patch us in as new owner of the JobDependency objects */ | |
83 | last = NULL; | |
84 | LIST_FOREACH(subject, l, other->subject_list) { | |
85 | assert(l->subject == other); | |
86 | l->subject = j; | |
87 | last = l; | |
88 | } | |
89 | ||
90 | /* Merge both lists */ | |
91 | if (last) { | |
92 | last->subject_next = j->subject_list; | |
93 | if (j->subject_list) | |
94 | j->subject_list->subject_prev = last; | |
95 | j->subject_list = other->subject_list; | |
96 | } | |
97 | ||
98 | /* Patch us in as new owner of the JobDependency objects */ | |
99 | last = NULL; | |
100 | LIST_FOREACH(object, l, other->object_list) { | |
101 | assert(l->object == other); | |
102 | l->object = j; | |
103 | last = l; | |
104 | } | |
105 | ||
106 | /* Merge both lists */ | |
107 | if (last) { | |
108 | last->object_next = j->object_list; | |
109 | if (j->object_list) | |
110 | j->object_list->object_prev = last; | |
111 | j->object_list = other->object_list; | |
112 | } | |
113 | ||
114 | /* Kill the other job */ | |
115 | other->subject_list = NULL; | |
116 | other->object_list = NULL; | |
117 | transaction_delete_job(tr, other, true); | |
118 | } | |
119 | ||
120 | static bool job_is_conflicted_by(Job *j) { | |
121 | JobDependency *l; | |
122 | ||
123 | assert(j); | |
124 | ||
125 | /* Returns true if this job is pulled in by a least one | |
126 | * ConflictedBy dependency. */ | |
127 | ||
128 | LIST_FOREACH(object, l, j->object_list) | |
129 | if (l->conflicts) | |
130 | return true; | |
131 | ||
132 | return false; | |
133 | } | |
134 | ||
135 | static int delete_one_unmergeable_job(Transaction *tr, Job *j) { | |
136 | Job *k; | |
137 | ||
138 | assert(j); | |
139 | ||
140 | /* Tries to delete one item in the linked list | |
141 | * j->transaction_next->transaction_next->... that conflicts | |
142 | * with another one, in an attempt to make an inconsistent | |
143 | * transaction work. */ | |
144 | ||
145 | /* We rely here on the fact that if a merged with b does not | |
146 | * merge with c, either a or b merge with c neither */ | |
147 | LIST_FOREACH(transaction, j, j) | |
148 | LIST_FOREACH(transaction, k, j->transaction_next) { | |
149 | Job *d; | |
150 | ||
151 | /* Is this one mergeable? Then skip it */ | |
152 | if (job_type_is_mergeable(j->type, k->type)) | |
153 | continue; | |
154 | ||
155 | /* Ok, we found two that conflict, let's see if we can | |
156 | * drop one of them */ | |
157 | if (!j->matters_to_anchor && !k->matters_to_anchor) { | |
158 | ||
159 | /* Both jobs don't matter, so let's | |
160 | * find the one that is smarter to | |
161 | * remove. Let's think positive and | |
162 | * rather remove stops then starts -- | |
163 | * except if something is being | |
164 | * stopped because it is conflicted by | |
165 | * another unit in which case we | |
166 | * rather remove the start. */ | |
167 | ||
168 | log_debug("Looking at job %s/%s conflicted_by=%s", j->unit->id, job_type_to_string(j->type), yes_no(j->type == JOB_STOP && job_is_conflicted_by(j))); | |
169 | log_debug("Looking at job %s/%s conflicted_by=%s", k->unit->id, job_type_to_string(k->type), yes_no(k->type == JOB_STOP && job_is_conflicted_by(k))); | |
170 | ||
171 | if (j->type == JOB_STOP) { | |
172 | ||
173 | if (job_is_conflicted_by(j)) | |
174 | d = k; | |
175 | else | |
176 | d = j; | |
177 | ||
178 | } else if (k->type == JOB_STOP) { | |
179 | ||
180 | if (job_is_conflicted_by(k)) | |
181 | d = j; | |
182 | else | |
183 | d = k; | |
184 | } else | |
185 | d = j; | |
186 | ||
187 | } else if (!j->matters_to_anchor) | |
188 | d = j; | |
189 | else if (!k->matters_to_anchor) | |
190 | d = k; | |
191 | else | |
192 | return -ENOEXEC; | |
193 | ||
194 | /* Ok, we can drop one, so let's do so. */ | |
195 | log_debug("Fixing conflicting jobs by deleting job %s/%s", d->unit->id, job_type_to_string(d->type)); | |
196 | transaction_delete_job(tr, d, true); | |
197 | return 0; | |
198 | } | |
199 | ||
200 | return -EINVAL; | |
201 | } | |
202 | ||
203 | static int transaction_merge_jobs(Transaction *tr, DBusError *e) { | |
204 | Job *j; | |
205 | Iterator i; | |
206 | int r; | |
207 | ||
208 | assert(tr); | |
209 | ||
210 | /* First step, check whether any of the jobs for one specific | |
211 | * task conflict. If so, try to drop one of them. */ | |
212 | HASHMAP_FOREACH(j, tr->jobs, i) { | |
213 | JobType t; | |
214 | Job *k; | |
215 | ||
216 | t = j->type; | |
217 | LIST_FOREACH(transaction, k, j->transaction_next) { | |
218 | if (job_type_merge(&t, k->type) >= 0) | |
219 | continue; | |
220 | ||
221 | /* OK, we could not merge all jobs for this | |
222 | * action. Let's see if we can get rid of one | |
223 | * of them */ | |
224 | ||
225 | r = delete_one_unmergeable_job(tr, j); | |
226 | if (r >= 0) | |
227 | /* Ok, we managed to drop one, now | |
228 | * let's ask our callers to call us | |
229 | * again after garbage collecting */ | |
230 | return -EAGAIN; | |
231 | ||
232 | /* We couldn't merge anything. Failure */ | |
233 | dbus_set_error(e, BUS_ERROR_TRANSACTION_JOBS_CONFLICTING, "Transaction contains conflicting jobs '%s' and '%s' for %s. Probably contradicting requirement dependencies configured.", | |
234 | job_type_to_string(t), job_type_to_string(k->type), k->unit->id); | |
235 | return r; | |
236 | } | |
237 | } | |
238 | ||
239 | /* Second step, merge the jobs. */ | |
240 | HASHMAP_FOREACH(j, tr->jobs, i) { | |
241 | JobType t = j->type; | |
242 | Job *k; | |
243 | ||
244 | /* Merge all transactions */ | |
245 | LIST_FOREACH(transaction, k, j->transaction_next) | |
246 | assert_se(job_type_merge(&t, k->type) == 0); | |
247 | ||
248 | /* If an active job is mergeable, merge it too */ | |
249 | if (j->unit->job) | |
250 | job_type_merge(&t, j->unit->job->type); /* Might fail. Which is OK */ | |
251 | ||
252 | while ((k = j->transaction_next)) { | |
253 | if (j->installed) { | |
254 | transaction_merge_and_delete_job(tr, k, j, t); | |
255 | j = k; | |
256 | } else | |
257 | transaction_merge_and_delete_job(tr, j, k, t); | |
258 | } | |
259 | ||
260 | if (j->unit->job && !j->installed) | |
261 | transaction_merge_and_delete_job(tr, j, j->unit->job, t); | |
262 | ||
263 | assert(!j->transaction_next); | |
264 | assert(!j->transaction_prev); | |
265 | } | |
266 | ||
267 | return 0; | |
268 | } | |
269 | ||
270 | static void transaction_drop_redundant(Transaction *tr) { | |
271 | bool again; | |
272 | ||
273 | assert(tr); | |
274 | ||
275 | /* Goes through the transaction and removes all jobs that are | |
276 | * a noop */ | |
277 | ||
278 | do { | |
279 | Job *j; | |
280 | Iterator i; | |
281 | ||
282 | again = false; | |
283 | ||
284 | HASHMAP_FOREACH(j, tr->jobs, i) { | |
285 | bool changes_something = false; | |
286 | Job *k; | |
287 | ||
288 | LIST_FOREACH(transaction, k, j) { | |
289 | ||
290 | if (!job_is_anchor(k) && | |
291 | (k->installed || job_type_is_redundant(k->type, unit_active_state(k->unit))) && | |
292 | (!k->unit->job || !job_type_is_conflicting(k->type, k->unit->job->type))) | |
293 | continue; | |
294 | ||
295 | changes_something = true; | |
296 | break; | |
297 | } | |
298 | ||
299 | if (changes_something) | |
300 | continue; | |
301 | ||
302 | /* log_debug("Found redundant job %s/%s, dropping.", j->unit->id, job_type_to_string(j->type)); */ | |
303 | transaction_delete_job(tr, j, false); | |
304 | again = true; | |
305 | break; | |
306 | } | |
307 | ||
308 | } while (again); | |
309 | } | |
310 | ||
311 | static bool unit_matters_to_anchor(Unit *u, Job *j) { | |
312 | assert(u); | |
313 | assert(!j->transaction_prev); | |
314 | ||
315 | /* Checks whether at least one of the jobs for this unit | |
316 | * matters to the anchor. */ | |
317 | ||
318 | LIST_FOREACH(transaction, j, j) | |
319 | if (j->matters_to_anchor) | |
320 | return true; | |
321 | ||
322 | return false; | |
323 | } | |
324 | ||
325 | static int transaction_verify_order_one(Transaction *tr, Job *j, Job *from, unsigned generation, DBusError *e) { | |
326 | Iterator i; | |
327 | Unit *u; | |
328 | int r; | |
329 | ||
330 | assert(tr); | |
331 | assert(j); | |
332 | assert(!j->transaction_prev); | |
333 | ||
334 | /* Does a recursive sweep through the ordering graph, looking | |
335 | * for a cycle. If we find cycle we try to break it. */ | |
336 | ||
337 | /* Have we seen this before? */ | |
338 | if (j->generation == generation) { | |
339 | Job *k, *delete; | |
340 | ||
341 | /* If the marker is NULL we have been here already and | |
342 | * decided the job was loop-free from here. Hence | |
343 | * shortcut things and return right-away. */ | |
344 | if (!j->marker) | |
345 | return 0; | |
346 | ||
347 | /* So, the marker is not NULL and we already have been | |
348 | * here. We have a cycle. Let's try to break it. We go | |
349 | * backwards in our path and try to find a suitable | |
350 | * job to remove. We use the marker to find our way | |
351 | * back, since smart how we are we stored our way back | |
352 | * in there. */ | |
353 | log_warning("Found ordering cycle on %s/%s", j->unit->id, job_type_to_string(j->type)); | |
354 | ||
355 | delete = NULL; | |
356 | for (k = from; k; k = ((k->generation == generation && k->marker != k) ? k->marker : NULL)) { | |
357 | ||
358 | log_info("Walked on cycle path to %s/%s", k->unit->id, job_type_to_string(k->type)); | |
359 | ||
360 | if (!delete && | |
361 | !k->installed && | |
362 | !unit_matters_to_anchor(k->unit, k)) { | |
363 | /* Ok, we can drop this one, so let's | |
364 | * do so. */ | |
365 | delete = k; | |
366 | } | |
367 | ||
368 | /* Check if this in fact was the beginning of | |
369 | * the cycle */ | |
370 | if (k == j) | |
371 | break; | |
372 | } | |
373 | ||
374 | ||
375 | if (delete) { | |
376 | log_warning("Breaking ordering cycle by deleting job %s/%s", delete->unit->id, job_type_to_string(delete->type)); | |
377 | transaction_delete_unit(tr, delete->unit); | |
378 | return -EAGAIN; | |
379 | } | |
380 | ||
381 | log_error("Unable to break cycle"); | |
382 | ||
383 | dbus_set_error(e, BUS_ERROR_TRANSACTION_ORDER_IS_CYCLIC, "Transaction order is cyclic. See system logs for details."); | |
384 | return -ENOEXEC; | |
385 | } | |
386 | ||
387 | /* Make the marker point to where we come from, so that we can | |
388 | * find our way backwards if we want to break a cycle. We use | |
389 | * a special marker for the beginning: we point to | |
390 | * ourselves. */ | |
391 | j->marker = from ? from : j; | |
392 | j->generation = generation; | |
393 | ||
394 | /* We assume that the the dependencies are bidirectional, and | |
395 | * hence can ignore UNIT_AFTER */ | |
396 | SET_FOREACH(u, j->unit->dependencies[UNIT_BEFORE], i) { | |
397 | Job *o; | |
398 | ||
399 | /* Is there a job for this unit? */ | |
400 | o = hashmap_get(tr->jobs, u); | |
401 | if (!o) { | |
402 | /* Ok, there is no job for this in the | |
403 | * transaction, but maybe there is already one | |
404 | * running? */ | |
405 | o = u->job; | |
406 | if (!o) | |
407 | continue; | |
408 | } | |
409 | ||
410 | r = transaction_verify_order_one(tr, o, j, generation, e); | |
411 | if (r < 0) | |
412 | return r; | |
413 | } | |
414 | ||
415 | /* Ok, let's backtrack, and remember that this entry is not on | |
416 | * our path anymore. */ | |
417 | j->marker = NULL; | |
418 | ||
419 | return 0; | |
420 | } | |
421 | ||
422 | static int transaction_verify_order(Transaction *tr, unsigned *generation, DBusError *e) { | |
423 | Job *j; | |
424 | int r; | |
425 | Iterator i; | |
426 | unsigned g; | |
427 | ||
428 | assert(tr); | |
429 | assert(generation); | |
430 | ||
431 | /* Check if the ordering graph is cyclic. If it is, try to fix | |
432 | * that up by dropping one of the jobs. */ | |
433 | ||
434 | g = (*generation)++; | |
435 | ||
436 | HASHMAP_FOREACH(j, tr->jobs, i) | |
437 | if ((r = transaction_verify_order_one(tr, j, NULL, g, e)) < 0) | |
438 | return r; | |
439 | ||
440 | return 0; | |
441 | } | |
442 | ||
443 | static void transaction_collect_garbage(Transaction *tr) { | |
444 | bool again; | |
445 | ||
446 | assert(tr); | |
447 | ||
448 | /* Drop jobs that are not required by any other job */ | |
449 | ||
450 | do { | |
451 | Iterator i; | |
452 | Job *j; | |
453 | ||
454 | again = false; | |
455 | ||
456 | HASHMAP_FOREACH(j, tr->jobs, i) { | |
38809d9d | 457 | if (tr->anchor_job == j || j->object_list) { |
75778e21 MS |
458 | /* log_debug("Keeping job %s/%s because of %s/%s", */ |
459 | /* j->unit->id, job_type_to_string(j->type), */ | |
460 | /* j->object_list->subject ? j->object_list->subject->unit->id : "root", */ | |
461 | /* j->object_list->subject ? job_type_to_string(j->object_list->subject->type) : "root"); */ | |
462 | continue; | |
463 | } | |
464 | ||
465 | /* log_debug("Garbage collecting job %s/%s", j->unit->id, job_type_to_string(j->type)); */ | |
466 | transaction_delete_job(tr, j, true); | |
467 | again = true; | |
468 | break; | |
469 | } | |
470 | ||
471 | } while (again); | |
472 | } | |
473 | ||
474 | static int transaction_is_destructive(Transaction *tr, DBusError *e) { | |
475 | Iterator i; | |
476 | Job *j; | |
477 | ||
478 | assert(tr); | |
479 | ||
480 | /* Checks whether applying this transaction means that | |
481 | * existing jobs would be replaced */ | |
482 | ||
483 | HASHMAP_FOREACH(j, tr->jobs, i) { | |
484 | ||
485 | /* Assume merged */ | |
486 | assert(!j->transaction_prev); | |
487 | assert(!j->transaction_next); | |
488 | ||
489 | if (j->unit->job && | |
490 | j->unit->job != j && | |
491 | !job_type_is_superset(j->type, j->unit->job->type)) { | |
492 | ||
493 | dbus_set_error(e, BUS_ERROR_TRANSACTION_IS_DESTRUCTIVE, "Transaction is destructive."); | |
494 | return -EEXIST; | |
495 | } | |
496 | } | |
497 | ||
498 | return 0; | |
499 | } | |
500 | ||
501 | static void transaction_minimize_impact(Transaction *tr) { | |
502 | bool again; | |
503 | assert(tr); | |
504 | ||
505 | /* Drops all unnecessary jobs that reverse already active jobs | |
506 | * or that stop a running service. */ | |
507 | ||
508 | do { | |
509 | Job *j; | |
510 | Iterator i; | |
511 | ||
512 | again = false; | |
513 | ||
514 | HASHMAP_FOREACH(j, tr->jobs, i) { | |
515 | LIST_FOREACH(transaction, j, j) { | |
516 | bool stops_running_service, changes_existing_job; | |
517 | ||
518 | /* If it matters, we shouldn't drop it */ | |
519 | if (j->matters_to_anchor) | |
520 | continue; | |
521 | ||
522 | /* Would this stop a running service? | |
523 | * Would this change an existing job? | |
524 | * If so, let's drop this entry */ | |
525 | ||
526 | stops_running_service = | |
527 | j->type == JOB_STOP && UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(j->unit)); | |
528 | ||
529 | changes_existing_job = | |
530 | j->unit->job && | |
531 | job_type_is_conflicting(j->type, j->unit->job->type); | |
532 | ||
533 | if (!stops_running_service && !changes_existing_job) | |
534 | continue; | |
535 | ||
536 | if (stops_running_service) | |
537 | log_debug("%s/%s would stop a running service.", j->unit->id, job_type_to_string(j->type)); | |
538 | ||
539 | if (changes_existing_job) | |
540 | log_debug("%s/%s would change existing job.", j->unit->id, job_type_to_string(j->type)); | |
541 | ||
542 | /* Ok, let's get rid of this */ | |
543 | log_debug("Deleting %s/%s to minimize impact.", j->unit->id, job_type_to_string(j->type)); | |
544 | ||
545 | transaction_delete_job(tr, j, true); | |
546 | again = true; | |
547 | break; | |
548 | } | |
549 | ||
550 | if (again) | |
551 | break; | |
552 | } | |
553 | ||
554 | } while (again); | |
555 | } | |
556 | ||
557 | static int transaction_apply(Transaction *tr, Manager *m, JobMode mode) { | |
558 | Iterator i; | |
559 | Job *j; | |
560 | int r; | |
561 | ||
562 | /* Moves the transaction jobs to the set of active jobs */ | |
563 | ||
564 | if (mode == JOB_ISOLATE) { | |
565 | ||
566 | /* When isolating first kill all installed jobs which | |
567 | * aren't part of the new transaction */ | |
568 | rescan: | |
569 | HASHMAP_FOREACH(j, m->jobs, i) { | |
570 | assert(j->installed); | |
571 | ||
572 | if (hashmap_get(tr->jobs, j->unit)) | |
573 | continue; | |
574 | ||
575 | /* 'j' itself is safe to remove, but if other jobs | |
576 | are invalidated recursively, our iterator may become | |
577 | invalid and we need to start over. */ | |
578 | if (job_finish_and_invalidate(j, JOB_CANCELED) > 0) | |
579 | goto rescan; | |
580 | } | |
581 | } | |
582 | ||
583 | HASHMAP_FOREACH(j, tr->jobs, i) { | |
584 | /* Assume merged */ | |
585 | assert(!j->transaction_prev); | |
586 | assert(!j->transaction_next); | |
587 | ||
588 | if (j->installed) | |
589 | continue; | |
590 | ||
591 | r = hashmap_put(m->jobs, UINT32_TO_PTR(j->id), j); | |
592 | if (r < 0) | |
593 | goto rollback; | |
594 | } | |
595 | ||
596 | while ((j = hashmap_steal_first(tr->jobs))) { | |
597 | Job *uj; | |
598 | if (j->installed) { | |
599 | /* log_debug("Skipping already installed job %s/%s as %u", j->unit->id, job_type_to_string(j->type), (unsigned) j->id); */ | |
600 | continue; | |
601 | } | |
602 | ||
603 | uj = j->unit->job; | |
604 | if (uj) { | |
605 | job_uninstall(uj); | |
606 | job_free(uj); | |
607 | } | |
608 | ||
609 | j->unit->job = j; | |
610 | j->installed = true; | |
611 | m->n_installed_jobs ++; | |
612 | ||
613 | /* We're fully installed. Now let's free data we don't | |
614 | * need anymore. */ | |
615 | ||
616 | assert(!j->transaction_next); | |
617 | assert(!j->transaction_prev); | |
618 | ||
619 | /* Clean the job dependencies */ | |
620 | transaction_unlink_job(tr, j, false); | |
621 | ||
622 | job_add_to_run_queue(j); | |
623 | job_add_to_dbus_queue(j); | |
624 | job_start_timer(j); | |
625 | ||
626 | log_debug("Installed new job %s/%s as %u", j->unit->id, job_type_to_string(j->type), (unsigned) j->id); | |
627 | } | |
628 | ||
629 | assert(!tr->anchor); | |
630 | ||
631 | return 0; | |
632 | ||
633 | rollback: | |
634 | ||
635 | HASHMAP_FOREACH(j, tr->jobs, i) { | |
636 | if (j->installed) | |
637 | continue; | |
638 | ||
639 | hashmap_remove(m->jobs, UINT32_TO_PTR(j->id)); | |
640 | } | |
641 | ||
642 | return r; | |
643 | } | |
644 | ||
645 | int transaction_activate(Transaction *tr, Manager *m, JobMode mode, DBusError *e) { | |
646 | int r; | |
647 | unsigned generation = 1; | |
648 | ||
649 | assert(tr); | |
650 | ||
651 | /* This applies the changes recorded in tr->jobs to | |
652 | * the actual list of jobs, if possible. */ | |
653 | ||
654 | /* First step: figure out which jobs matter */ | |
0d9989aa | 655 | transaction_find_jobs_that_matter_to_anchor(tr->anchor_job, generation++); |
75778e21 MS |
656 | |
657 | /* Second step: Try not to stop any running services if | |
658 | * we don't have to. Don't try to reverse running | |
659 | * jobs if we don't have to. */ | |
660 | if (mode == JOB_FAIL) | |
661 | transaction_minimize_impact(tr); | |
662 | ||
663 | /* Third step: Drop redundant jobs */ | |
664 | transaction_drop_redundant(tr); | |
665 | ||
666 | for (;;) { | |
667 | /* Fourth step: Let's remove unneeded jobs that might | |
668 | * be lurking. */ | |
669 | if (mode != JOB_ISOLATE) | |
670 | transaction_collect_garbage(tr); | |
671 | ||
672 | /* Fifth step: verify order makes sense and correct | |
673 | * cycles if necessary and possible */ | |
674 | r = transaction_verify_order(tr, &generation, e); | |
675 | if (r >= 0) | |
676 | break; | |
677 | ||
678 | if (r != -EAGAIN) { | |
679 | log_warning("Requested transaction contains an unfixable cyclic ordering dependency: %s", bus_error(e, r)); | |
680 | return r; | |
681 | } | |
682 | ||
683 | /* Let's see if the resulting transaction ordering | |
684 | * graph is still cyclic... */ | |
685 | } | |
686 | ||
687 | for (;;) { | |
688 | /* Sixth step: let's drop unmergeable entries if | |
689 | * necessary and possible, merge entries we can | |
690 | * merge */ | |
691 | r = transaction_merge_jobs(tr, e); | |
692 | if (r >= 0) | |
693 | break; | |
694 | ||
695 | if (r != -EAGAIN) { | |
696 | log_warning("Requested transaction contains unmergeable jobs: %s", bus_error(e, r)); | |
697 | return r; | |
698 | } | |
699 | ||
700 | /* Seventh step: an entry got dropped, let's garbage | |
701 | * collect its dependencies. */ | |
702 | if (mode != JOB_ISOLATE) | |
703 | transaction_collect_garbage(tr); | |
704 | ||
705 | /* Let's see if the resulting transaction still has | |
706 | * unmergeable entries ... */ | |
707 | } | |
708 | ||
709 | /* Eights step: Drop redundant jobs again, if the merging now allows us to drop more. */ | |
710 | transaction_drop_redundant(tr); | |
711 | ||
712 | /* Ninth step: check whether we can actually apply this */ | |
713 | if (mode == JOB_FAIL) { | |
714 | r = transaction_is_destructive(tr, e); | |
715 | if (r < 0) { | |
716 | log_notice("Requested transaction contradicts existing jobs: %s", bus_error(e, r)); | |
717 | return r; | |
718 | } | |
719 | } | |
720 | ||
721 | /* Tenth step: apply changes */ | |
722 | r = transaction_apply(tr, m, mode); | |
723 | if (r < 0) { | |
724 | log_warning("Failed to apply transaction: %s", strerror(-r)); | |
725 | return r; | |
726 | } | |
727 | ||
728 | assert(hashmap_isempty(tr->jobs)); | |
729 | assert(!tr->anchor); | |
730 | ||
731 | return 0; | |
732 | } | |
733 | ||
734 | static Job* transaction_add_one_job(Transaction *tr, JobType type, Unit *unit, bool override, bool *is_new) { | |
735 | Job *j, *f; | |
736 | ||
737 | assert(tr); | |
738 | assert(unit); | |
739 | ||
740 | /* Looks for an existing prospective job and returns that. If | |
741 | * it doesn't exist it is created and added to the prospective | |
742 | * jobs list. */ | |
743 | ||
744 | f = hashmap_get(tr->jobs, unit); | |
745 | ||
746 | LIST_FOREACH(transaction, j, f) { | |
747 | assert(j->unit == unit); | |
748 | ||
749 | if (j->type == type) { | |
750 | if (is_new) | |
751 | *is_new = false; | |
752 | return j; | |
753 | } | |
754 | } | |
755 | ||
3c956cfe MS |
756 | j = job_new(unit, type); |
757 | if (!j) | |
758 | return NULL; | |
75778e21 MS |
759 | |
760 | j->generation = 0; | |
761 | j->marker = NULL; | |
762 | j->matters_to_anchor = false; | |
763 | j->override = override; | |
764 | ||
765 | LIST_PREPEND(Job, transaction, f, j); | |
766 | ||
767 | if (hashmap_replace(tr->jobs, unit, f) < 0) { | |
768 | LIST_REMOVE(Job, transaction, f, j); | |
769 | job_free(j); | |
770 | return NULL; | |
771 | } | |
772 | ||
773 | if (is_new) | |
774 | *is_new = true; | |
775 | ||
776 | /* log_debug("Added job %s/%s to transaction.", unit->id, job_type_to_string(type)); */ | |
777 | ||
778 | return j; | |
779 | } | |
780 | ||
1da4264f MS |
781 | static void transaction_job_dependency_free(Transaction *tr, JobDependency *l) { |
782 | if (!l->subject) | |
783 | LIST_REMOVE(JobDependency, subject, tr->anchor, l); | |
784 | job_dependency_free(l); | |
785 | } | |
786 | ||
75778e21 MS |
787 | static void transaction_unlink_job(Transaction *tr, Job *j, bool delete_dependencies) { |
788 | assert(tr); | |
789 | assert(j); | |
790 | ||
791 | if (j->transaction_prev) | |
792 | j->transaction_prev->transaction_next = j->transaction_next; | |
793 | else if (j->transaction_next) | |
794 | hashmap_replace(tr->jobs, j->unit, j->transaction_next); | |
795 | else | |
796 | hashmap_remove_value(tr->jobs, j->unit, j); | |
797 | ||
798 | if (j->transaction_next) | |
799 | j->transaction_next->transaction_prev = j->transaction_prev; | |
800 | ||
801 | j->transaction_prev = j->transaction_next = NULL; | |
802 | ||
803 | while (j->subject_list) | |
1da4264f | 804 | transaction_job_dependency_free(tr, j->subject_list); |
75778e21 MS |
805 | |
806 | while (j->object_list) { | |
807 | Job *other = j->object_list->matters ? j->object_list->subject : NULL; | |
808 | ||
1da4264f | 809 | transaction_job_dependency_free(tr, j->object_list); |
75778e21 MS |
810 | |
811 | if (other && delete_dependencies) { | |
812 | log_debug("Deleting job %s/%s as dependency of job %s/%s", | |
813 | other->unit->id, job_type_to_string(other->type), | |
814 | j->unit->id, job_type_to_string(j->type)); | |
815 | transaction_delete_job(tr, other, delete_dependencies); | |
816 | } | |
817 | } | |
818 | } | |
819 | ||
820 | int transaction_add_job_and_dependencies( | |
821 | Transaction *tr, | |
822 | JobType type, | |
823 | Unit *unit, | |
824 | Job *by, | |
825 | bool matters, | |
826 | bool override, | |
827 | bool conflicts, | |
828 | bool ignore_requirements, | |
829 | bool ignore_order, | |
b94fbd30 | 830 | DBusError *e) { |
75778e21 | 831 | Job *ret; |
1da4264f | 832 | JobDependency *l; |
75778e21 MS |
833 | Iterator i; |
834 | Unit *dep; | |
835 | int r; | |
836 | bool is_new; | |
837 | ||
838 | assert(tr); | |
839 | assert(type < _JOB_TYPE_MAX); | |
840 | assert(unit); | |
841 | ||
842 | /* log_debug("Pulling in %s/%s from %s/%s", */ | |
843 | /* unit->id, job_type_to_string(type), */ | |
844 | /* by ? by->unit->id : "NA", */ | |
845 | /* by ? job_type_to_string(by->type) : "NA"); */ | |
846 | ||
847 | if (unit->load_state != UNIT_LOADED && | |
848 | unit->load_state != UNIT_ERROR && | |
849 | unit->load_state != UNIT_MASKED) { | |
850 | dbus_set_error(e, BUS_ERROR_LOAD_FAILED, "Unit %s is not loaded properly.", unit->id); | |
851 | return -EINVAL; | |
852 | } | |
853 | ||
854 | if (type != JOB_STOP && unit->load_state == UNIT_ERROR) { | |
855 | dbus_set_error(e, BUS_ERROR_LOAD_FAILED, | |
856 | "Unit %s failed to load: %s. " | |
857 | "See system logs and 'systemctl status %s' for details.", | |
858 | unit->id, | |
859 | strerror(-unit->load_error), | |
860 | unit->id); | |
861 | return -EINVAL; | |
862 | } | |
863 | ||
864 | if (type != JOB_STOP && unit->load_state == UNIT_MASKED) { | |
865 | dbus_set_error(e, BUS_ERROR_MASKED, "Unit %s is masked.", unit->id); | |
866 | return -EINVAL; | |
867 | } | |
868 | ||
869 | if (!unit_job_is_applicable(unit, type)) { | |
870 | dbus_set_error(e, BUS_ERROR_JOB_TYPE_NOT_APPLICABLE, "Job type %s is not applicable for unit %s.", job_type_to_string(type), unit->id); | |
871 | return -EBADR; | |
872 | } | |
873 | ||
874 | /* First add the job. */ | |
875 | ret = transaction_add_one_job(tr, type, unit, override, &is_new); | |
876 | if (!ret) | |
877 | return -ENOMEM; | |
878 | ||
879 | ret->ignore_order = ret->ignore_order || ignore_order; | |
880 | ||
881 | /* Then, add a link to the job. */ | |
1da4264f MS |
882 | l = job_dependency_new(by, ret, matters, conflicts); |
883 | if (!l) | |
75778e21 MS |
884 | return -ENOMEM; |
885 | ||
1da4264f | 886 | /* If the link has no subject job, it's the anchor link. */ |
b94fbd30 | 887 | if (!by) { |
1da4264f | 888 | LIST_PREPEND(JobDependency, subject, tr->anchor, l); |
4483f694 MS |
889 | assert(!tr->anchor_job); |
890 | tr->anchor_job = ret; | |
b94fbd30 | 891 | } |
1da4264f | 892 | |
75778e21 MS |
893 | if (is_new && !ignore_requirements) { |
894 | Set *following; | |
895 | ||
896 | /* If we are following some other unit, make sure we | |
897 | * add all dependencies of everybody following. */ | |
898 | if (unit_following_set(ret->unit, &following) > 0) { | |
899 | SET_FOREACH(dep, following, i) { | |
b94fbd30 | 900 | r = transaction_add_job_and_dependencies(tr, type, dep, ret, false, override, false, false, ignore_order, e); |
75778e21 MS |
901 | if (r < 0) { |
902 | log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->id, bus_error(e, r)); | |
903 | ||
904 | if (e) | |
905 | dbus_error_free(e); | |
906 | } | |
907 | } | |
908 | ||
909 | set_free(following); | |
910 | } | |
911 | ||
912 | /* Finally, recursively add in all dependencies. */ | |
913 | if (type == JOB_START || type == JOB_RELOAD_OR_START) { | |
914 | SET_FOREACH(dep, ret->unit->dependencies[UNIT_REQUIRES], i) { | |
b94fbd30 | 915 | r = transaction_add_job_and_dependencies(tr, JOB_START, dep, ret, true, override, false, false, ignore_order, e); |
75778e21 MS |
916 | if (r < 0) { |
917 | if (r != -EBADR) | |
918 | goto fail; | |
919 | ||
920 | if (e) | |
921 | dbus_error_free(e); | |
922 | } | |
923 | } | |
924 | ||
925 | SET_FOREACH(dep, ret->unit->dependencies[UNIT_BIND_TO], i) { | |
b94fbd30 | 926 | r = transaction_add_job_and_dependencies(tr, JOB_START, dep, ret, true, override, false, false, ignore_order, e); |
75778e21 MS |
927 | if (r < 0) { |
928 | if (r != -EBADR) | |
929 | goto fail; | |
930 | ||
931 | if (e) | |
932 | dbus_error_free(e); | |
933 | } | |
934 | } | |
935 | ||
936 | SET_FOREACH(dep, ret->unit->dependencies[UNIT_REQUIRES_OVERRIDABLE], i) { | |
b94fbd30 | 937 | r = transaction_add_job_and_dependencies(tr, JOB_START, dep, ret, !override, override, false, false, ignore_order, e); |
75778e21 MS |
938 | if (r < 0) { |
939 | log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->id, bus_error(e, r)); | |
940 | ||
941 | if (e) | |
942 | dbus_error_free(e); | |
943 | } | |
944 | } | |
945 | ||
946 | SET_FOREACH(dep, ret->unit->dependencies[UNIT_WANTS], i) { | |
b94fbd30 | 947 | r = transaction_add_job_and_dependencies(tr, JOB_START, dep, ret, false, false, false, false, ignore_order, e); |
75778e21 MS |
948 | if (r < 0) { |
949 | log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->id, bus_error(e, r)); | |
950 | ||
951 | if (e) | |
952 | dbus_error_free(e); | |
953 | } | |
954 | } | |
955 | ||
956 | SET_FOREACH(dep, ret->unit->dependencies[UNIT_REQUISITE], i) { | |
b94fbd30 | 957 | r = transaction_add_job_and_dependencies(tr, JOB_VERIFY_ACTIVE, dep, ret, true, override, false, false, ignore_order, e); |
75778e21 MS |
958 | if (r < 0) { |
959 | if (r != -EBADR) | |
960 | goto fail; | |
961 | ||
962 | if (e) | |
963 | dbus_error_free(e); | |
964 | } | |
965 | } | |
966 | ||
967 | SET_FOREACH(dep, ret->unit->dependencies[UNIT_REQUISITE_OVERRIDABLE], i) { | |
b94fbd30 | 968 | r = transaction_add_job_and_dependencies(tr, JOB_VERIFY_ACTIVE, dep, ret, !override, override, false, false, ignore_order, e); |
75778e21 MS |
969 | if (r < 0) { |
970 | log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->id, bus_error(e, r)); | |
971 | ||
972 | if (e) | |
973 | dbus_error_free(e); | |
974 | } | |
975 | } | |
976 | ||
977 | SET_FOREACH(dep, ret->unit->dependencies[UNIT_CONFLICTS], i) { | |
b94fbd30 | 978 | r = transaction_add_job_and_dependencies(tr, JOB_STOP, dep, ret, true, override, true, false, ignore_order, e); |
75778e21 MS |
979 | if (r < 0) { |
980 | if (r != -EBADR) | |
981 | goto fail; | |
982 | ||
983 | if (e) | |
984 | dbus_error_free(e); | |
985 | } | |
986 | } | |
987 | ||
988 | SET_FOREACH(dep, ret->unit->dependencies[UNIT_CONFLICTED_BY], i) { | |
b94fbd30 | 989 | r = transaction_add_job_and_dependencies(tr, JOB_STOP, dep, ret, false, override, false, false, ignore_order, e); |
75778e21 MS |
990 | if (r < 0) { |
991 | log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->id, bus_error(e, r)); | |
992 | ||
993 | if (e) | |
994 | dbus_error_free(e); | |
995 | } | |
996 | } | |
997 | ||
998 | } | |
999 | ||
1000 | if (type == JOB_STOP || type == JOB_RESTART || type == JOB_TRY_RESTART) { | |
1001 | ||
1002 | SET_FOREACH(dep, ret->unit->dependencies[UNIT_REQUIRED_BY], i) { | |
b94fbd30 | 1003 | r = transaction_add_job_and_dependencies(tr, type, dep, ret, true, override, false, false, ignore_order, e); |
75778e21 MS |
1004 | if (r < 0) { |
1005 | if (r != -EBADR) | |
1006 | goto fail; | |
1007 | ||
1008 | if (e) | |
1009 | dbus_error_free(e); | |
1010 | } | |
1011 | } | |
1012 | ||
1013 | SET_FOREACH(dep, ret->unit->dependencies[UNIT_BOUND_BY], i) { | |
b94fbd30 | 1014 | r = transaction_add_job_and_dependencies(tr, type, dep, ret, true, override, false, false, ignore_order, e); |
75778e21 MS |
1015 | if (r < 0) { |
1016 | if (r != -EBADR) | |
1017 | goto fail; | |
1018 | ||
1019 | if (e) | |
1020 | dbus_error_free(e); | |
1021 | } | |
1022 | } | |
1023 | } | |
1024 | ||
1025 | if (type == JOB_RELOAD || type == JOB_RELOAD_OR_START) { | |
1026 | ||
1027 | SET_FOREACH(dep, ret->unit->dependencies[UNIT_PROPAGATE_RELOAD_TO], i) { | |
b94fbd30 | 1028 | r = transaction_add_job_and_dependencies(tr, JOB_RELOAD, dep, ret, false, override, false, false, ignore_order, e); |
75778e21 MS |
1029 | if (r < 0) { |
1030 | log_warning("Cannot add dependency reload job for unit %s, ignoring: %s", dep->id, bus_error(e, r)); | |
1031 | ||
1032 | if (e) | |
1033 | dbus_error_free(e); | |
1034 | } | |
1035 | } | |
1036 | } | |
1037 | ||
1038 | /* JOB_VERIFY_STARTED, JOB_RELOAD require no dependency handling */ | |
1039 | } | |
1040 | ||
75778e21 MS |
1041 | return 0; |
1042 | ||
1043 | fail: | |
1044 | return r; | |
1045 | } | |
1046 | ||
1047 | int transaction_add_isolate_jobs(Transaction *tr, Manager *m) { | |
1048 | Iterator i; | |
1049 | Unit *u; | |
1050 | char *k; | |
1051 | int r; | |
1052 | ||
1053 | assert(tr); | |
1054 | assert(m); | |
1055 | ||
1056 | HASHMAP_FOREACH_KEY(u, k, m->units, i) { | |
1057 | ||
1058 | /* ignore aliases */ | |
1059 | if (u->id != k) | |
1060 | continue; | |
1061 | ||
1062 | if (u->ignore_on_isolate) | |
1063 | continue; | |
1064 | ||
1065 | /* No need to stop inactive jobs */ | |
1066 | if (UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(u)) && !u->job) | |
1067 | continue; | |
1068 | ||
1069 | /* Is there already something listed for this? */ | |
1070 | if (hashmap_get(tr->jobs, u)) | |
1071 | continue; | |
1072 | ||
4483f694 | 1073 | r = transaction_add_job_and_dependencies(tr, JOB_STOP, u, tr->anchor_job, true, false, false, false, false, NULL); |
75778e21 MS |
1074 | if (r < 0) |
1075 | log_warning("Cannot add isolate job for unit %s, ignoring: %s", u->id, strerror(-r)); | |
1076 | } | |
1077 | ||
1078 | return 0; | |
1079 | } | |
1080 | ||
1081 | Transaction *transaction_new(void) { | |
1082 | Transaction *tr; | |
1083 | ||
1084 | tr = new0(Transaction, 1); | |
1085 | if (!tr) | |
1086 | return NULL; | |
1087 | ||
1088 | tr->jobs = hashmap_new(trivial_hash_func, trivial_compare_func); | |
1089 | if (!tr->jobs) { | |
1090 | free(tr); | |
1091 | return NULL; | |
1092 | } | |
1093 | ||
1094 | return tr; | |
1095 | } | |
1096 | ||
1097 | void transaction_free(Transaction *tr) { | |
1098 | assert(hashmap_isempty(tr->jobs)); | |
1099 | hashmap_free(tr->jobs); | |
1100 | free(tr); | |
1101 | } |