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1 | /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
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 Lesser General Public License as published by | |
10 | the Free Software Foundation; either version 2.1 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 | Lesser General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU Lesser General Public License | |
19 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
20 | ***/ | |
21 | ||
f2b68789 LP |
22 | #include <unistd.h> |
23 | #include <fcntl.h> | |
24 | ||
75778e21 MS |
25 | #include "transaction.h" |
26 | #include "bus-errors.h" | |
27 | ||
28 | static void transaction_unlink_job(Transaction *tr, Job *j, bool delete_dependencies); | |
29 | ||
30 | static void transaction_delete_job(Transaction *tr, Job *j, bool delete_dependencies) { | |
31 | assert(tr); | |
32 | assert(j); | |
33 | ||
34 | /* Deletes one job from the transaction */ | |
35 | ||
36 | transaction_unlink_job(tr, j, delete_dependencies); | |
37 | ||
d6a093d0 | 38 | job_free(j); |
75778e21 MS |
39 | } |
40 | ||
41 | static void transaction_delete_unit(Transaction *tr, Unit *u) { | |
42 | Job *j; | |
43 | ||
44 | /* Deletes all jobs associated with a certain unit from the | |
45 | * transaction */ | |
46 | ||
47 | while ((j = hashmap_get(tr->jobs, u))) | |
48 | transaction_delete_job(tr, j, true); | |
49 | } | |
50 | ||
51 | void transaction_abort(Transaction *tr) { | |
52 | Job *j; | |
53 | ||
54 | assert(tr); | |
55 | ||
56 | while ((j = hashmap_first(tr->jobs))) | |
1b9cea0c | 57 | transaction_delete_job(tr, j, false); |
75778e21 MS |
58 | |
59 | assert(hashmap_isempty(tr->jobs)); | |
75778e21 MS |
60 | } |
61 | ||
0d9989aa | 62 | static void transaction_find_jobs_that_matter_to_anchor(Job *j, unsigned generation) { |
75778e21 MS |
63 | JobDependency *l; |
64 | ||
75778e21 MS |
65 | /* A recursive sweep through the graph that marks all units |
66 | * that matter to the anchor job, i.e. are directly or | |
67 | * indirectly a dependency of the anchor job via paths that | |
68 | * are fully marked as mattering. */ | |
69 | ||
0d9989aa MS |
70 | j->matters_to_anchor = true; |
71 | j->generation = generation; | |
75778e21 | 72 | |
0d9989aa | 73 | LIST_FOREACH(subject, l, j->subject_list) { |
75778e21 MS |
74 | |
75 | /* This link does not matter */ | |
76 | if (!l->matters) | |
77 | continue; | |
78 | ||
79 | /* This unit has already been marked */ | |
80 | if (l->object->generation == generation) | |
81 | continue; | |
82 | ||
0d9989aa | 83 | transaction_find_jobs_that_matter_to_anchor(l->object, generation); |
75778e21 MS |
84 | } |
85 | } | |
86 | ||
87 | static void transaction_merge_and_delete_job(Transaction *tr, Job *j, Job *other, JobType t) { | |
88 | JobDependency *l, *last; | |
89 | ||
90 | assert(j); | |
91 | assert(other); | |
92 | assert(j->unit == other->unit); | |
93 | assert(!j->installed); | |
94 | ||
95 | /* Merges 'other' into 'j' and then deletes 'other'. */ | |
96 | ||
97 | j->type = t; | |
98 | j->state = JOB_WAITING; | |
99 | j->override = j->override || other->override; | |
100 | ||
101 | j->matters_to_anchor = j->matters_to_anchor || other->matters_to_anchor; | |
102 | ||
103 | /* Patch us in as new owner of the JobDependency objects */ | |
104 | last = NULL; | |
105 | LIST_FOREACH(subject, l, other->subject_list) { | |
106 | assert(l->subject == other); | |
107 | l->subject = j; | |
108 | last = l; | |
109 | } | |
110 | ||
111 | /* Merge both lists */ | |
112 | if (last) { | |
113 | last->subject_next = j->subject_list; | |
114 | if (j->subject_list) | |
115 | j->subject_list->subject_prev = last; | |
116 | j->subject_list = other->subject_list; | |
117 | } | |
118 | ||
119 | /* Patch us in as new owner of the JobDependency objects */ | |
120 | last = NULL; | |
121 | LIST_FOREACH(object, l, other->object_list) { | |
122 | assert(l->object == other); | |
123 | l->object = j; | |
124 | last = l; | |
125 | } | |
126 | ||
127 | /* Merge both lists */ | |
128 | if (last) { | |
129 | last->object_next = j->object_list; | |
130 | if (j->object_list) | |
131 | j->object_list->object_prev = last; | |
132 | j->object_list = other->object_list; | |
133 | } | |
134 | ||
135 | /* Kill the other job */ | |
136 | other->subject_list = NULL; | |
137 | other->object_list = NULL; | |
138 | transaction_delete_job(tr, other, true); | |
139 | } | |
140 | ||
141 | static bool job_is_conflicted_by(Job *j) { | |
142 | JobDependency *l; | |
143 | ||
144 | assert(j); | |
145 | ||
146 | /* Returns true if this job is pulled in by a least one | |
147 | * ConflictedBy dependency. */ | |
148 | ||
149 | LIST_FOREACH(object, l, j->object_list) | |
150 | if (l->conflicts) | |
151 | return true; | |
152 | ||
153 | return false; | |
154 | } | |
155 | ||
156 | static int delete_one_unmergeable_job(Transaction *tr, Job *j) { | |
157 | Job *k; | |
158 | ||
159 | assert(j); | |
160 | ||
161 | /* Tries to delete one item in the linked list | |
162 | * j->transaction_next->transaction_next->... that conflicts | |
163 | * with another one, in an attempt to make an inconsistent | |
164 | * transaction work. */ | |
165 | ||
166 | /* We rely here on the fact that if a merged with b does not | |
167 | * merge with c, either a or b merge with c neither */ | |
168 | LIST_FOREACH(transaction, j, j) | |
169 | LIST_FOREACH(transaction, k, j->transaction_next) { | |
170 | Job *d; | |
171 | ||
172 | /* Is this one mergeable? Then skip it */ | |
173 | if (job_type_is_mergeable(j->type, k->type)) | |
174 | continue; | |
175 | ||
176 | /* Ok, we found two that conflict, let's see if we can | |
177 | * drop one of them */ | |
178 | if (!j->matters_to_anchor && !k->matters_to_anchor) { | |
179 | ||
180 | /* Both jobs don't matter, so let's | |
181 | * find the one that is smarter to | |
182 | * remove. Let's think positive and | |
183 | * rather remove stops then starts -- | |
184 | * except if something is being | |
185 | * stopped because it is conflicted by | |
186 | * another unit in which case we | |
187 | * rather remove the start. */ | |
188 | ||
189 | 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))); | |
190 | 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))); | |
191 | ||
192 | if (j->type == JOB_STOP) { | |
193 | ||
194 | if (job_is_conflicted_by(j)) | |
195 | d = k; | |
196 | else | |
197 | d = j; | |
198 | ||
199 | } else if (k->type == JOB_STOP) { | |
200 | ||
201 | if (job_is_conflicted_by(k)) | |
202 | d = j; | |
203 | else | |
204 | d = k; | |
205 | } else | |
206 | d = j; | |
207 | ||
208 | } else if (!j->matters_to_anchor) | |
209 | d = j; | |
210 | else if (!k->matters_to_anchor) | |
211 | d = k; | |
212 | else | |
213 | return -ENOEXEC; | |
214 | ||
215 | /* Ok, we can drop one, so let's do so. */ | |
216 | log_debug("Fixing conflicting jobs by deleting job %s/%s", d->unit->id, job_type_to_string(d->type)); | |
217 | transaction_delete_job(tr, d, true); | |
218 | return 0; | |
219 | } | |
220 | ||
221 | return -EINVAL; | |
222 | } | |
223 | ||
224 | static int transaction_merge_jobs(Transaction *tr, DBusError *e) { | |
225 | Job *j; | |
226 | Iterator i; | |
227 | int r; | |
228 | ||
229 | assert(tr); | |
230 | ||
231 | /* First step, check whether any of the jobs for one specific | |
232 | * task conflict. If so, try to drop one of them. */ | |
233 | HASHMAP_FOREACH(j, tr->jobs, i) { | |
234 | JobType t; | |
235 | Job *k; | |
236 | ||
237 | t = j->type; | |
238 | LIST_FOREACH(transaction, k, j->transaction_next) { | |
e0209d83 | 239 | if (job_type_merge_and_collapse(&t, k->type, j->unit) >= 0) |
75778e21 MS |
240 | continue; |
241 | ||
242 | /* OK, we could not merge all jobs for this | |
243 | * action. Let's see if we can get rid of one | |
244 | * of them */ | |
245 | ||
246 | r = delete_one_unmergeable_job(tr, j); | |
247 | if (r >= 0) | |
248 | /* Ok, we managed to drop one, now | |
249 | * let's ask our callers to call us | |
250 | * again after garbage collecting */ | |
251 | return -EAGAIN; | |
252 | ||
253 | /* We couldn't merge anything. Failure */ | |
254 | dbus_set_error(e, BUS_ERROR_TRANSACTION_JOBS_CONFLICTING, "Transaction contains conflicting jobs '%s' and '%s' for %s. Probably contradicting requirement dependencies configured.", | |
255 | job_type_to_string(t), job_type_to_string(k->type), k->unit->id); | |
256 | return r; | |
257 | } | |
258 | } | |
259 | ||
260 | /* Second step, merge the jobs. */ | |
261 | HASHMAP_FOREACH(j, tr->jobs, i) { | |
262 | JobType t = j->type; | |
263 | Job *k; | |
264 | ||
e0209d83 | 265 | /* Merge all transaction jobs for j->unit */ |
75778e21 | 266 | LIST_FOREACH(transaction, k, j->transaction_next) |
e0209d83 | 267 | assert_se(job_type_merge_and_collapse(&t, k->type, j->unit) == 0); |
75778e21 | 268 | |
75778e21 | 269 | while ((k = j->transaction_next)) { |
656bbffc | 270 | if (tr->anchor_job == k) { |
75778e21 MS |
271 | transaction_merge_and_delete_job(tr, k, j, t); |
272 | j = k; | |
273 | } else | |
274 | transaction_merge_and_delete_job(tr, j, k, t); | |
275 | } | |
276 | ||
75778e21 MS |
277 | assert(!j->transaction_next); |
278 | assert(!j->transaction_prev); | |
279 | } | |
280 | ||
281 | return 0; | |
282 | } | |
283 | ||
284 | static void transaction_drop_redundant(Transaction *tr) { | |
055163ad MS |
285 | Job *j; |
286 | Iterator i; | |
75778e21 | 287 | |
055163ad MS |
288 | /* Goes through the transaction and removes all jobs of the units |
289 | * whose jobs are all noops. If not all of a unit's jobs are | |
290 | * redundant, they are kept. */ | |
75778e21 | 291 | |
055163ad | 292 | assert(tr); |
75778e21 | 293 | |
055163ad MS |
294 | rescan: |
295 | HASHMAP_FOREACH(j, tr->jobs, i) { | |
296 | Job *k; | |
75778e21 | 297 | |
055163ad | 298 | LIST_FOREACH(transaction, k, j) { |
75778e21 | 299 | |
055163ad MS |
300 | if (tr->anchor_job == k || |
301 | !job_type_is_redundant(k->type, unit_active_state(k->unit)) || | |
302 | (k->unit->job && job_type_is_conflicting(k->type, k->unit->job->type))) | |
303 | goto next_unit; | |
75778e21 MS |
304 | } |
305 | ||
055163ad MS |
306 | /* log_debug("Found redundant job %s/%s, dropping.", j->unit->id, job_type_to_string(j->type)); */ |
307 | transaction_delete_job(tr, j, false); | |
308 | goto rescan; | |
309 | next_unit:; | |
310 | } | |
75778e21 MS |
311 | } |
312 | ||
313 | static bool unit_matters_to_anchor(Unit *u, Job *j) { | |
314 | assert(u); | |
315 | assert(!j->transaction_prev); | |
316 | ||
317 | /* Checks whether at least one of the jobs for this unit | |
318 | * matters to the anchor. */ | |
319 | ||
320 | LIST_FOREACH(transaction, j, j) | |
321 | if (j->matters_to_anchor) | |
322 | return true; | |
323 | ||
324 | return false; | |
325 | } | |
326 | ||
327 | static int transaction_verify_order_one(Transaction *tr, Job *j, Job *from, unsigned generation, DBusError *e) { | |
328 | Iterator i; | |
329 | Unit *u; | |
330 | int r; | |
331 | ||
332 | assert(tr); | |
333 | assert(j); | |
334 | assert(!j->transaction_prev); | |
335 | ||
336 | /* Does a recursive sweep through the ordering graph, looking | |
337 | * for a cycle. If we find cycle we try to break it. */ | |
338 | ||
339 | /* Have we seen this before? */ | |
340 | if (j->generation == generation) { | |
341 | Job *k, *delete; | |
342 | ||
343 | /* If the marker is NULL we have been here already and | |
344 | * decided the job was loop-free from here. Hence | |
345 | * shortcut things and return right-away. */ | |
346 | if (!j->marker) | |
347 | return 0; | |
348 | ||
349 | /* So, the marker is not NULL and we already have been | |
350 | * here. We have a cycle. Let's try to break it. We go | |
351 | * backwards in our path and try to find a suitable | |
352 | * job to remove. We use the marker to find our way | |
353 | * back, since smart how we are we stored our way back | |
354 | * in there. */ | |
355 | log_warning("Found ordering cycle on %s/%s", j->unit->id, job_type_to_string(j->type)); | |
356 | ||
357 | delete = NULL; | |
358 | for (k = from; k; k = ((k->generation == generation && k->marker != k) ? k->marker : NULL)) { | |
359 | ||
360 | log_info("Walked on cycle path to %s/%s", k->unit->id, job_type_to_string(k->type)); | |
361 | ||
362 | if (!delete && | |
75778e21 MS |
363 | !unit_matters_to_anchor(k->unit, k)) { |
364 | /* Ok, we can drop this one, so let's | |
365 | * do so. */ | |
366 | delete = k; | |
367 | } | |
368 | ||
369 | /* Check if this in fact was the beginning of | |
370 | * the cycle */ | |
371 | if (k == j) | |
372 | break; | |
373 | } | |
374 | ||
375 | ||
376 | if (delete) { | |
377 | log_warning("Breaking ordering cycle by deleting job %s/%s", delete->unit->id, job_type_to_string(delete->type)); | |
378 | transaction_delete_unit(tr, delete->unit); | |
379 | return -EAGAIN; | |
380 | } | |
381 | ||
382 | log_error("Unable to break cycle"); | |
383 | ||
384 | dbus_set_error(e, BUS_ERROR_TRANSACTION_ORDER_IS_CYCLIC, "Transaction order is cyclic. See system logs for details."); | |
385 | return -ENOEXEC; | |
386 | } | |
387 | ||
388 | /* Make the marker point to where we come from, so that we can | |
389 | * find our way backwards if we want to break a cycle. We use | |
390 | * a special marker for the beginning: we point to | |
391 | * ourselves. */ | |
392 | j->marker = from ? from : j; | |
393 | j->generation = generation; | |
394 | ||
395 | /* We assume that the the dependencies are bidirectional, and | |
396 | * hence can ignore UNIT_AFTER */ | |
397 | SET_FOREACH(u, j->unit->dependencies[UNIT_BEFORE], i) { | |
398 | Job *o; | |
399 | ||
400 | /* Is there a job for this unit? */ | |
401 | o = hashmap_get(tr->jobs, u); | |
402 | if (!o) { | |
403 | /* Ok, there is no job for this in the | |
404 | * transaction, but maybe there is already one | |
405 | * running? */ | |
406 | o = u->job; | |
407 | if (!o) | |
408 | continue; | |
409 | } | |
410 | ||
411 | r = transaction_verify_order_one(tr, o, j, generation, e); | |
412 | if (r < 0) | |
413 | return r; | |
414 | } | |
415 | ||
416 | /* Ok, let's backtrack, and remember that this entry is not on | |
417 | * our path anymore. */ | |
418 | j->marker = NULL; | |
419 | ||
420 | return 0; | |
421 | } | |
422 | ||
423 | static int transaction_verify_order(Transaction *tr, unsigned *generation, DBusError *e) { | |
424 | Job *j; | |
425 | int r; | |
426 | Iterator i; | |
427 | unsigned g; | |
428 | ||
429 | assert(tr); | |
430 | assert(generation); | |
431 | ||
432 | /* Check if the ordering graph is cyclic. If it is, try to fix | |
433 | * that up by dropping one of the jobs. */ | |
434 | ||
435 | g = (*generation)++; | |
436 | ||
437 | HASHMAP_FOREACH(j, tr->jobs, i) | |
438 | if ((r = transaction_verify_order_one(tr, j, NULL, g, e)) < 0) | |
439 | return r; | |
440 | ||
441 | return 0; | |
442 | } | |
443 | ||
444 | static void transaction_collect_garbage(Transaction *tr) { | |
055163ad MS |
445 | Iterator i; |
446 | Job *j; | |
75778e21 MS |
447 | |
448 | assert(tr); | |
449 | ||
450 | /* Drop jobs that are not required by any other job */ | |
451 | ||
055163ad MS |
452 | rescan: |
453 | HASHMAP_FOREACH(j, tr->jobs, i) { | |
454 | if (tr->anchor_job == j || j->object_list) { | |
455 | /* log_debug("Keeping job %s/%s because of %s/%s", */ | |
456 | /* j->unit->id, job_type_to_string(j->type), */ | |
457 | /* j->object_list->subject ? j->object_list->subject->unit->id : "root", */ | |
458 | /* j->object_list->subject ? job_type_to_string(j->object_list->subject->type) : "root"); */ | |
459 | continue; | |
75778e21 MS |
460 | } |
461 | ||
055163ad MS |
462 | /* log_debug("Garbage collecting job %s/%s", j->unit->id, job_type_to_string(j->type)); */ |
463 | transaction_delete_job(tr, j, true); | |
464 | goto rescan; | |
465 | } | |
75778e21 MS |
466 | } |
467 | ||
468 | static int transaction_is_destructive(Transaction *tr, DBusError *e) { | |
469 | Iterator i; | |
470 | Job *j; | |
471 | ||
472 | assert(tr); | |
473 | ||
474 | /* Checks whether applying this transaction means that | |
475 | * existing jobs would be replaced */ | |
476 | ||
477 | HASHMAP_FOREACH(j, tr->jobs, i) { | |
478 | ||
479 | /* Assume merged */ | |
480 | assert(!j->transaction_prev); | |
481 | assert(!j->transaction_next); | |
482 | ||
483 | if (j->unit->job && | |
75778e21 MS |
484 | !job_type_is_superset(j->type, j->unit->job->type)) { |
485 | ||
486 | dbus_set_error(e, BUS_ERROR_TRANSACTION_IS_DESTRUCTIVE, "Transaction is destructive."); | |
487 | return -EEXIST; | |
488 | } | |
489 | } | |
490 | ||
491 | return 0; | |
492 | } | |
493 | ||
494 | static void transaction_minimize_impact(Transaction *tr) { | |
055163ad MS |
495 | Job *j; |
496 | Iterator i; | |
497 | ||
75778e21 MS |
498 | assert(tr); |
499 | ||
500 | /* Drops all unnecessary jobs that reverse already active jobs | |
501 | * or that stop a running service. */ | |
502 | ||
055163ad MS |
503 | rescan: |
504 | HASHMAP_FOREACH(j, tr->jobs, i) { | |
505 | LIST_FOREACH(transaction, j, j) { | |
506 | bool stops_running_service, changes_existing_job; | |
75778e21 | 507 | |
055163ad MS |
508 | /* If it matters, we shouldn't drop it */ |
509 | if (j->matters_to_anchor) | |
510 | continue; | |
75778e21 | 511 | |
055163ad MS |
512 | /* Would this stop a running service? |
513 | * Would this change an existing job? | |
514 | * If so, let's drop this entry */ | |
75778e21 | 515 | |
055163ad MS |
516 | stops_running_service = |
517 | j->type == JOB_STOP && UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(j->unit)); | |
75778e21 | 518 | |
055163ad MS |
519 | changes_existing_job = |
520 | j->unit->job && | |
521 | job_type_is_conflicting(j->type, j->unit->job->type); | |
75778e21 | 522 | |
055163ad MS |
523 | if (!stops_running_service && !changes_existing_job) |
524 | continue; | |
75778e21 | 525 | |
055163ad MS |
526 | if (stops_running_service) |
527 | log_debug("%s/%s would stop a running service.", j->unit->id, job_type_to_string(j->type)); | |
75778e21 | 528 | |
055163ad MS |
529 | if (changes_existing_job) |
530 | log_debug("%s/%s would change existing job.", j->unit->id, job_type_to_string(j->type)); | |
75778e21 | 531 | |
055163ad MS |
532 | /* Ok, let's get rid of this */ |
533 | log_debug("Deleting %s/%s to minimize impact.", j->unit->id, job_type_to_string(j->type)); | |
75778e21 | 534 | |
055163ad MS |
535 | transaction_delete_job(tr, j, true); |
536 | goto rescan; | |
75778e21 | 537 | } |
055163ad | 538 | } |
75778e21 MS |
539 | } |
540 | ||
541 | static int transaction_apply(Transaction *tr, Manager *m, JobMode mode) { | |
542 | Iterator i; | |
543 | Job *j; | |
544 | int r; | |
545 | ||
546 | /* Moves the transaction jobs to the set of active jobs */ | |
547 | ||
548 | if (mode == JOB_ISOLATE) { | |
549 | ||
550 | /* When isolating first kill all installed jobs which | |
551 | * aren't part of the new transaction */ | |
75778e21 MS |
552 | HASHMAP_FOREACH(j, m->jobs, i) { |
553 | assert(j->installed); | |
554 | ||
555 | if (hashmap_get(tr->jobs, j->unit)) | |
556 | continue; | |
557 | ||
5273510e MS |
558 | /* Not invalidating recursively. Avoids triggering |
559 | * OnFailure= actions of dependent jobs. Also avoids | |
560 | * invalidating our iterator. */ | |
561 | job_finish_and_invalidate(j, JOB_CANCELED, false); | |
75778e21 MS |
562 | } |
563 | } | |
564 | ||
565 | HASHMAP_FOREACH(j, tr->jobs, i) { | |
566 | /* Assume merged */ | |
567 | assert(!j->transaction_prev); | |
568 | assert(!j->transaction_next); | |
569 | ||
75778e21 MS |
570 | r = hashmap_put(m->jobs, UINT32_TO_PTR(j->id), j); |
571 | if (r < 0) | |
572 | goto rollback; | |
573 | } | |
574 | ||
575 | while ((j = hashmap_steal_first(tr->jobs))) { | |
656bbffc MS |
576 | Job *installed_job; |
577 | ||
75778e21 MS |
578 | /* Clean the job dependencies */ |
579 | transaction_unlink_job(tr, j, false); | |
580 | ||
656bbffc MS |
581 | installed_job = job_install(j); |
582 | if (installed_job != j) { | |
583 | /* j has been merged into a previously installed job */ | |
584 | if (tr->anchor_job == j) | |
585 | tr->anchor_job = installed_job; | |
586 | hashmap_remove(m->jobs, UINT32_TO_PTR(j->id)); | |
587 | job_free(j); | |
588 | j = installed_job; | |
589 | } | |
05d576f1 | 590 | |
75778e21 MS |
591 | job_add_to_run_queue(j); |
592 | job_add_to_dbus_queue(j); | |
593 | job_start_timer(j); | |
75778e21 MS |
594 | } |
595 | ||
75778e21 MS |
596 | return 0; |
597 | ||
598 | rollback: | |
599 | ||
d6a093d0 | 600 | HASHMAP_FOREACH(j, tr->jobs, i) |
75778e21 | 601 | hashmap_remove(m->jobs, UINT32_TO_PTR(j->id)); |
75778e21 MS |
602 | |
603 | return r; | |
604 | } | |
605 | ||
606 | int transaction_activate(Transaction *tr, Manager *m, JobMode mode, DBusError *e) { | |
4e7bd268 MS |
607 | Iterator i; |
608 | Job *j; | |
75778e21 MS |
609 | int r; |
610 | unsigned generation = 1; | |
611 | ||
612 | assert(tr); | |
613 | ||
614 | /* This applies the changes recorded in tr->jobs to | |
615 | * the actual list of jobs, if possible. */ | |
616 | ||
4e7bd268 MS |
617 | /* Reset the generation counter of all installed jobs. The detection of cycles |
618 | * looks at installed jobs. If they had a non-zero generation from some previous | |
619 | * walk of the graph, the algorithm would break. */ | |
620 | HASHMAP_FOREACH(j, m->jobs, i) | |
621 | j->generation = 0; | |
622 | ||
75778e21 | 623 | /* First step: figure out which jobs matter */ |
0d9989aa | 624 | transaction_find_jobs_that_matter_to_anchor(tr->anchor_job, generation++); |
75778e21 MS |
625 | |
626 | /* Second step: Try not to stop any running services if | |
627 | * we don't have to. Don't try to reverse running | |
628 | * jobs if we don't have to. */ | |
629 | if (mode == JOB_FAIL) | |
630 | transaction_minimize_impact(tr); | |
631 | ||
632 | /* Third step: Drop redundant jobs */ | |
633 | transaction_drop_redundant(tr); | |
634 | ||
635 | for (;;) { | |
636 | /* Fourth step: Let's remove unneeded jobs that might | |
637 | * be lurking. */ | |
638 | if (mode != JOB_ISOLATE) | |
639 | transaction_collect_garbage(tr); | |
640 | ||
641 | /* Fifth step: verify order makes sense and correct | |
642 | * cycles if necessary and possible */ | |
643 | r = transaction_verify_order(tr, &generation, e); | |
644 | if (r >= 0) | |
645 | break; | |
646 | ||
647 | if (r != -EAGAIN) { | |
648 | log_warning("Requested transaction contains an unfixable cyclic ordering dependency: %s", bus_error(e, r)); | |
649 | return r; | |
650 | } | |
651 | ||
652 | /* Let's see if the resulting transaction ordering | |
653 | * graph is still cyclic... */ | |
654 | } | |
655 | ||
656 | for (;;) { | |
657 | /* Sixth step: let's drop unmergeable entries if | |
658 | * necessary and possible, merge entries we can | |
659 | * merge */ | |
660 | r = transaction_merge_jobs(tr, e); | |
661 | if (r >= 0) | |
662 | break; | |
663 | ||
664 | if (r != -EAGAIN) { | |
665 | log_warning("Requested transaction contains unmergeable jobs: %s", bus_error(e, r)); | |
666 | return r; | |
667 | } | |
668 | ||
669 | /* Seventh step: an entry got dropped, let's garbage | |
670 | * collect its dependencies. */ | |
671 | if (mode != JOB_ISOLATE) | |
672 | transaction_collect_garbage(tr); | |
673 | ||
674 | /* Let's see if the resulting transaction still has | |
675 | * unmergeable entries ... */ | |
676 | } | |
677 | ||
678 | /* Eights step: Drop redundant jobs again, if the merging now allows us to drop more. */ | |
679 | transaction_drop_redundant(tr); | |
680 | ||
681 | /* Ninth step: check whether we can actually apply this */ | |
682 | if (mode == JOB_FAIL) { | |
683 | r = transaction_is_destructive(tr, e); | |
684 | if (r < 0) { | |
685 | log_notice("Requested transaction contradicts existing jobs: %s", bus_error(e, r)); | |
686 | return r; | |
687 | } | |
688 | } | |
689 | ||
690 | /* Tenth step: apply changes */ | |
691 | r = transaction_apply(tr, m, mode); | |
692 | if (r < 0) { | |
693 | log_warning("Failed to apply transaction: %s", strerror(-r)); | |
694 | return r; | |
695 | } | |
696 | ||
697 | assert(hashmap_isempty(tr->jobs)); | |
75778e21 | 698 | |
f2b68789 LP |
699 | if (!hashmap_isempty(m->jobs)) { |
700 | /* Are there any jobs now? Then make sure we have the | |
701 | * idle pipe around. We don't really care too much | |
702 | * whether this works or not, as the idle pipe is a | |
703 | * feature for cosmetics, not actually useful for | |
704 | * anything beyond that. */ | |
705 | ||
706 | if (m->idle_pipe[0] < 0 && m->idle_pipe[1] < 0) | |
707 | pipe2(m->idle_pipe, O_NONBLOCK|O_CLOEXEC); | |
708 | } | |
709 | ||
75778e21 MS |
710 | return 0; |
711 | } | |
712 | ||
713 | static Job* transaction_add_one_job(Transaction *tr, JobType type, Unit *unit, bool override, bool *is_new) { | |
714 | Job *j, *f; | |
715 | ||
716 | assert(tr); | |
717 | assert(unit); | |
718 | ||
719 | /* Looks for an existing prospective job and returns that. If | |
720 | * it doesn't exist it is created and added to the prospective | |
721 | * jobs list. */ | |
722 | ||
723 | f = hashmap_get(tr->jobs, unit); | |
724 | ||
725 | LIST_FOREACH(transaction, j, f) { | |
726 | assert(j->unit == unit); | |
727 | ||
728 | if (j->type == type) { | |
729 | if (is_new) | |
730 | *is_new = false; | |
731 | return j; | |
732 | } | |
733 | } | |
734 | ||
3c956cfe MS |
735 | j = job_new(unit, type); |
736 | if (!j) | |
737 | return NULL; | |
75778e21 MS |
738 | |
739 | j->generation = 0; | |
740 | j->marker = NULL; | |
741 | j->matters_to_anchor = false; | |
742 | j->override = override; | |
743 | ||
744 | LIST_PREPEND(Job, transaction, f, j); | |
745 | ||
746 | if (hashmap_replace(tr->jobs, unit, f) < 0) { | |
747 | LIST_REMOVE(Job, transaction, f, j); | |
748 | job_free(j); | |
749 | return NULL; | |
750 | } | |
751 | ||
752 | if (is_new) | |
753 | *is_new = true; | |
754 | ||
755 | /* log_debug("Added job %s/%s to transaction.", unit->id, job_type_to_string(type)); */ | |
756 | ||
757 | return j; | |
758 | } | |
759 | ||
760 | static void transaction_unlink_job(Transaction *tr, Job *j, bool delete_dependencies) { | |
761 | assert(tr); | |
762 | assert(j); | |
763 | ||
764 | if (j->transaction_prev) | |
765 | j->transaction_prev->transaction_next = j->transaction_next; | |
766 | else if (j->transaction_next) | |
767 | hashmap_replace(tr->jobs, j->unit, j->transaction_next); | |
768 | else | |
769 | hashmap_remove_value(tr->jobs, j->unit, j); | |
770 | ||
771 | if (j->transaction_next) | |
772 | j->transaction_next->transaction_prev = j->transaction_prev; | |
773 | ||
774 | j->transaction_prev = j->transaction_next = NULL; | |
775 | ||
776 | while (j->subject_list) | |
e6eda1f2 | 777 | job_dependency_free(j->subject_list); |
75778e21 MS |
778 | |
779 | while (j->object_list) { | |
780 | Job *other = j->object_list->matters ? j->object_list->subject : NULL; | |
781 | ||
e6eda1f2 | 782 | job_dependency_free(j->object_list); |
75778e21 MS |
783 | |
784 | if (other && delete_dependencies) { | |
785 | log_debug("Deleting job %s/%s as dependency of job %s/%s", | |
786 | other->unit->id, job_type_to_string(other->type), | |
787 | j->unit->id, job_type_to_string(j->type)); | |
788 | transaction_delete_job(tr, other, delete_dependencies); | |
789 | } | |
790 | } | |
791 | } | |
792 | ||
793 | int transaction_add_job_and_dependencies( | |
794 | Transaction *tr, | |
795 | JobType type, | |
796 | Unit *unit, | |
797 | Job *by, | |
798 | bool matters, | |
799 | bool override, | |
800 | bool conflicts, | |
801 | bool ignore_requirements, | |
802 | bool ignore_order, | |
b94fbd30 | 803 | DBusError *e) { |
75778e21 MS |
804 | Job *ret; |
805 | Iterator i; | |
806 | Unit *dep; | |
807 | int r; | |
808 | bool is_new; | |
809 | ||
810 | assert(tr); | |
811 | assert(type < _JOB_TYPE_MAX); | |
e0209d83 | 812 | assert(type < _JOB_TYPE_MAX_IN_TRANSACTION); |
75778e21 MS |
813 | assert(unit); |
814 | ||
815 | /* log_debug("Pulling in %s/%s from %s/%s", */ | |
816 | /* unit->id, job_type_to_string(type), */ | |
817 | /* by ? by->unit->id : "NA", */ | |
818 | /* by ? job_type_to_string(by->type) : "NA"); */ | |
819 | ||
820 | if (unit->load_state != UNIT_LOADED && | |
821 | unit->load_state != UNIT_ERROR && | |
822 | unit->load_state != UNIT_MASKED) { | |
823 | dbus_set_error(e, BUS_ERROR_LOAD_FAILED, "Unit %s is not loaded properly.", unit->id); | |
824 | return -EINVAL; | |
825 | } | |
826 | ||
827 | if (type != JOB_STOP && unit->load_state == UNIT_ERROR) { | |
828 | dbus_set_error(e, BUS_ERROR_LOAD_FAILED, | |
829 | "Unit %s failed to load: %s. " | |
830 | "See system logs and 'systemctl status %s' for details.", | |
831 | unit->id, | |
832 | strerror(-unit->load_error), | |
833 | unit->id); | |
834 | return -EINVAL; | |
835 | } | |
836 | ||
837 | if (type != JOB_STOP && unit->load_state == UNIT_MASKED) { | |
838 | dbus_set_error(e, BUS_ERROR_MASKED, "Unit %s is masked.", unit->id); | |
59e132a7 | 839 | return -EADDRNOTAVAIL; |
75778e21 MS |
840 | } |
841 | ||
842 | if (!unit_job_is_applicable(unit, type)) { | |
843 | 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); | |
844 | return -EBADR; | |
845 | } | |
846 | ||
847 | /* First add the job. */ | |
848 | ret = transaction_add_one_job(tr, type, unit, override, &is_new); | |
849 | if (!ret) | |
850 | return -ENOMEM; | |
851 | ||
852 | ret->ignore_order = ret->ignore_order || ignore_order; | |
853 | ||
854 | /* Then, add a link to the job. */ | |
e6eda1f2 MS |
855 | if (by) { |
856 | if (!job_dependency_new(by, ret, matters, conflicts)) | |
857 | return -ENOMEM; | |
858 | } else { | |
859 | /* If the job has no parent job, it is the anchor job. */ | |
4483f694 MS |
860 | assert(!tr->anchor_job); |
861 | tr->anchor_job = ret; | |
b94fbd30 | 862 | } |
e0209d83 MS |
863 | |
864 | if (is_new && !ignore_requirements && type != JOB_NOP) { | |
75778e21 MS |
865 | Set *following; |
866 | ||
867 | /* If we are following some other unit, make sure we | |
868 | * add all dependencies of everybody following. */ | |
869 | if (unit_following_set(ret->unit, &following) > 0) { | |
870 | SET_FOREACH(dep, following, i) { | |
b94fbd30 | 871 | r = transaction_add_job_and_dependencies(tr, type, dep, ret, false, override, false, false, ignore_order, e); |
75778e21 MS |
872 | if (r < 0) { |
873 | log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->id, bus_error(e, r)); | |
874 | ||
875 | if (e) | |
876 | dbus_error_free(e); | |
877 | } | |
878 | } | |
879 | ||
880 | set_free(following); | |
881 | } | |
882 | ||
883 | /* Finally, recursively add in all dependencies. */ | |
e0209d83 | 884 | if (type == JOB_START || type == JOB_RESTART) { |
75778e21 | 885 | SET_FOREACH(dep, ret->unit->dependencies[UNIT_REQUIRES], i) { |
b94fbd30 | 886 | r = transaction_add_job_and_dependencies(tr, JOB_START, dep, ret, true, override, false, false, ignore_order, e); |
75778e21 MS |
887 | if (r < 0) { |
888 | if (r != -EBADR) | |
889 | goto fail; | |
890 | ||
891 | if (e) | |
892 | dbus_error_free(e); | |
893 | } | |
894 | } | |
895 | ||
7f2cddae | 896 | SET_FOREACH(dep, ret->unit->dependencies[UNIT_BINDS_TO], i) { |
b94fbd30 | 897 | r = transaction_add_job_and_dependencies(tr, JOB_START, dep, ret, true, override, false, false, ignore_order, e); |
75778e21 MS |
898 | if (r < 0) { |
899 | if (r != -EBADR) | |
900 | goto fail; | |
901 | ||
902 | if (e) | |
903 | dbus_error_free(e); | |
904 | } | |
905 | } | |
906 | ||
907 | SET_FOREACH(dep, ret->unit->dependencies[UNIT_REQUIRES_OVERRIDABLE], i) { | |
b94fbd30 | 908 | r = transaction_add_job_and_dependencies(tr, JOB_START, dep, ret, !override, override, false, false, ignore_order, e); |
75778e21 | 909 | if (r < 0) { |
59e132a7 LP |
910 | log_full(r == -EADDRNOTAVAIL ? LOG_DEBUG : LOG_WARNING, |
911 | "Cannot add dependency job for unit %s, ignoring: %s", dep->id, bus_error(e, r)); | |
75778e21 MS |
912 | |
913 | if (e) | |
914 | dbus_error_free(e); | |
915 | } | |
916 | } | |
917 | ||
918 | SET_FOREACH(dep, ret->unit->dependencies[UNIT_WANTS], i) { | |
b94fbd30 | 919 | r = transaction_add_job_and_dependencies(tr, JOB_START, dep, ret, false, false, false, false, ignore_order, e); |
75778e21 | 920 | if (r < 0) { |
59e132a7 LP |
921 | log_full(r == -EADDRNOTAVAIL ? LOG_DEBUG : LOG_WARNING, |
922 | "Cannot add dependency job for unit %s, ignoring: %s", dep->id, bus_error(e, r)); | |
75778e21 MS |
923 | |
924 | if (e) | |
925 | dbus_error_free(e); | |
926 | } | |
927 | } | |
928 | ||
929 | SET_FOREACH(dep, ret->unit->dependencies[UNIT_REQUISITE], i) { | |
b94fbd30 | 930 | r = transaction_add_job_and_dependencies(tr, JOB_VERIFY_ACTIVE, dep, ret, true, override, false, false, ignore_order, e); |
75778e21 MS |
931 | if (r < 0) { |
932 | if (r != -EBADR) | |
933 | goto fail; | |
934 | ||
935 | if (e) | |
936 | dbus_error_free(e); | |
937 | } | |
938 | } | |
939 | ||
940 | SET_FOREACH(dep, ret->unit->dependencies[UNIT_REQUISITE_OVERRIDABLE], i) { | |
b94fbd30 | 941 | r = transaction_add_job_and_dependencies(tr, JOB_VERIFY_ACTIVE, dep, ret, !override, override, false, false, ignore_order, e); |
75778e21 | 942 | if (r < 0) { |
59e132a7 LP |
943 | log_full(r == -EADDRNOTAVAIL ? LOG_DEBUG : LOG_WARNING, |
944 | "Cannot add dependency job for unit %s, ignoring: %s", dep->id, bus_error(e, r)); | |
75778e21 MS |
945 | |
946 | if (e) | |
947 | dbus_error_free(e); | |
948 | } | |
949 | } | |
950 | ||
951 | SET_FOREACH(dep, ret->unit->dependencies[UNIT_CONFLICTS], i) { | |
b94fbd30 | 952 | r = transaction_add_job_and_dependencies(tr, JOB_STOP, dep, ret, true, override, true, false, ignore_order, e); |
75778e21 MS |
953 | if (r < 0) { |
954 | if (r != -EBADR) | |
955 | goto fail; | |
956 | ||
957 | if (e) | |
958 | dbus_error_free(e); | |
959 | } | |
960 | } | |
961 | ||
962 | SET_FOREACH(dep, ret->unit->dependencies[UNIT_CONFLICTED_BY], i) { | |
b94fbd30 | 963 | r = transaction_add_job_and_dependencies(tr, JOB_STOP, dep, ret, false, override, false, false, ignore_order, e); |
75778e21 MS |
964 | if (r < 0) { |
965 | log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->id, bus_error(e, r)); | |
966 | ||
967 | if (e) | |
968 | dbus_error_free(e); | |
969 | } | |
970 | } | |
971 | ||
972 | } | |
973 | ||
e0209d83 | 974 | if (type == JOB_STOP || type == JOB_RESTART) { |
75778e21 MS |
975 | |
976 | SET_FOREACH(dep, ret->unit->dependencies[UNIT_REQUIRED_BY], i) { | |
b94fbd30 | 977 | r = transaction_add_job_and_dependencies(tr, type, dep, ret, true, override, false, false, ignore_order, e); |
75778e21 MS |
978 | if (r < 0) { |
979 | if (r != -EBADR) | |
980 | goto fail; | |
981 | ||
982 | if (e) | |
983 | dbus_error_free(e); | |
984 | } | |
985 | } | |
986 | ||
987 | SET_FOREACH(dep, ret->unit->dependencies[UNIT_BOUND_BY], i) { | |
b94fbd30 | 988 | r = transaction_add_job_and_dependencies(tr, type, dep, ret, true, override, false, false, ignore_order, e); |
75778e21 MS |
989 | if (r < 0) { |
990 | if (r != -EBADR) | |
991 | goto fail; | |
992 | ||
993 | if (e) | |
994 | dbus_error_free(e); | |
995 | } | |
996 | } | |
85e9a101 MS |
997 | |
998 | SET_FOREACH(dep, ret->unit->dependencies[UNIT_CONSISTS_OF], i) { | |
999 | r = transaction_add_job_and_dependencies(tr, type, dep, ret, true, override, false, false, ignore_order, e); | |
1000 | if (r < 0) { | |
1001 | if (r != -EBADR) | |
1002 | goto fail; | |
1003 | ||
1004 | if (e) | |
1005 | dbus_error_free(e); | |
1006 | } | |
1007 | } | |
1008 | ||
75778e21 MS |
1009 | } |
1010 | ||
e0209d83 | 1011 | if (type == JOB_RELOAD) { |
75778e21 | 1012 | |
7f2cddae | 1013 | SET_FOREACH(dep, ret->unit->dependencies[UNIT_PROPAGATES_RELOAD_TO], i) { |
b94fbd30 | 1014 | r = transaction_add_job_and_dependencies(tr, JOB_RELOAD, dep, ret, false, override, false, false, ignore_order, e); |
75778e21 MS |
1015 | if (r < 0) { |
1016 | log_warning("Cannot add dependency reload job for unit %s, ignoring: %s", dep->id, bus_error(e, r)); | |
1017 | ||
1018 | if (e) | |
1019 | dbus_error_free(e); | |
1020 | } | |
1021 | } | |
1022 | } | |
1023 | ||
e0209d83 | 1024 | /* JOB_VERIFY_STARTED require no dependency handling */ |
75778e21 MS |
1025 | } |
1026 | ||
75778e21 MS |
1027 | return 0; |
1028 | ||
1029 | fail: | |
1030 | return r; | |
1031 | } | |
1032 | ||
1033 | int transaction_add_isolate_jobs(Transaction *tr, Manager *m) { | |
1034 | Iterator i; | |
1035 | Unit *u; | |
1036 | char *k; | |
1037 | int r; | |
1038 | ||
1039 | assert(tr); | |
1040 | assert(m); | |
1041 | ||
1042 | HASHMAP_FOREACH_KEY(u, k, m->units, i) { | |
1043 | ||
1044 | /* ignore aliases */ | |
1045 | if (u->id != k) | |
1046 | continue; | |
1047 | ||
1048 | if (u->ignore_on_isolate) | |
1049 | continue; | |
1050 | ||
1051 | /* No need to stop inactive jobs */ | |
1052 | if (UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(u)) && !u->job) | |
1053 | continue; | |
1054 | ||
1055 | /* Is there already something listed for this? */ | |
1056 | if (hashmap_get(tr->jobs, u)) | |
1057 | continue; | |
1058 | ||
4483f694 | 1059 | r = transaction_add_job_and_dependencies(tr, JOB_STOP, u, tr->anchor_job, true, false, false, false, false, NULL); |
75778e21 MS |
1060 | if (r < 0) |
1061 | log_warning("Cannot add isolate job for unit %s, ignoring: %s", u->id, strerror(-r)); | |
1062 | } | |
1063 | ||
1064 | return 0; | |
1065 | } | |
1066 | ||
1067 | Transaction *transaction_new(void) { | |
1068 | Transaction *tr; | |
1069 | ||
1070 | tr = new0(Transaction, 1); | |
1071 | if (!tr) | |
1072 | return NULL; | |
1073 | ||
1074 | tr->jobs = hashmap_new(trivial_hash_func, trivial_compare_func); | |
1075 | if (!tr->jobs) { | |
1076 | free(tr); | |
1077 | return NULL; | |
1078 | } | |
1079 | ||
1080 | return tr; | |
1081 | } | |
1082 | ||
1083 | void transaction_free(Transaction *tr) { | |
1084 | assert(hashmap_isempty(tr->jobs)); | |
1085 | hashmap_free(tr->jobs); | |
1086 | free(tr); | |
1087 | } |