src/core/transaction.c

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