job.c

   1 /*-*- Mode: C; c-basic-offset: 8 -*-*/
   2
   3 #include <assert.h>
   4 #include <errno.h>
   5
   6 #include "set.h"
   7 #include "unit.h"
   8 #include "macro.h"
   9 #include "strv.h"
  10 #include "load-fragment.h"
  11 #include "load-dropin.h"
  12 #include "log.h"
  13
  14 Job* job_new(Manager *m, JobType type, Unit *unit) {
  15         Job *j;
  16
  17         assert(m);
  18         assert(type < _JOB_TYPE_MAX);
  19         assert(unit);
  20
  21         if (!(j = new0(Job, 1)))
  22                 return NULL;
  23
  24         j->manager = m;
  25         j->id = m->current_job_id++;
  26         j->type = type;
  27         j->unit = unit;
  28
  29         /* We don't link it here, that's what job_dependency() is for */
  30
  31         return j;
  32 }
  33
  34 void job_free(Job *j) {
  35         assert(j);
  36
  37         /* Detach from next 'bigger' objects */
  38         if (j->installed) {
  39                 if (j->unit->meta.job == j)
  40                         j->unit->meta.job = NULL;
  41
  42                 hashmap_remove(j->manager->jobs, UINT32_TO_PTR(j->id));
  43                 j->installed = false;
  44         }
  45
  46         /* Detach from next 'smaller' objects */
  47         manager_transaction_unlink_job(j->manager, j);
  48
  49         free(j);
  50 }
  51
  52 JobDependency* job_dependency_new(Job *subject, Job *object, bool matters) {
  53         JobDependency *l;
  54
  55         assert(object);
  56
  57         /* Adds a new job link, which encodes that the 'subject' job
  58          * needs the 'object' job in some way. If 'subject' is NULL
  59          * this means the 'anchor' job (i.e. the one the user
  60          * explcitily asked for) is the requester. */
  61
  62         if (!(l = new0(JobDependency, 1)))
  63                 return NULL;
  64
  65         l->subject = subject;
  66         l->object = object;
  67         l->matters = matters;
  68
  69         if (subject)
  70                 LIST_PREPEND(JobDependency, subject, subject->subject_list, l);
  71         else
  72                 LIST_PREPEND(JobDependency, subject, object->manager->transaction_anchor, l);
  73
  74         LIST_PREPEND(JobDependency, object, object->object_list, l);
  75
  76         return l;
  77 }
  78
  79 void job_dependency_free(JobDependency *l) {
  80         assert(l);
  81
  82         if (l->subject)
  83                 LIST_REMOVE(JobDependency, subject, l->subject->subject_list, l);
  84         else
  85                 LIST_REMOVE(JobDependency, subject, l->object->manager->transaction_anchor, l);
  86
  87         LIST_REMOVE(JobDependency, object, l->object->object_list, l);
  88
  89         free(l);
  90 }
  91
  92 void job_dependency_delete(Job *subject, Job *object, bool *matters) {
  93         JobDependency *l;
  94
  95         assert(object);
  96
  97         LIST_FOREACH(object, l, object->object_list) {
  98                 assert(l->object == object);
  99
 100                 if (l->subject == subject)
 101                         break;
 102         }
 103
 104         if (!l) {
 105                 if (matters)
 106                         *matters = false;
 107                 return;
 108         }
 109
 110         if (matters)
 111                 *matters = l->matters;
 112
 113         job_dependency_free(l);
 114 }
 115
 116 void job_dump(Job *j, FILE*f, const char *prefix) {
 117
 118
 119         assert(j);
 120         assert(f);
 121
 122         fprintf(f,
 123                 "%s→ Job %u:\n"
 124                 "%s\tAction: %s → %s\n"
 125                 "%s\tState: %s\n"
 126                 "%s\tForced: %s\n",
 127                 prefix, j->id,
 128                 prefix, unit_id(j->unit), job_type_to_string(j->type),
 129                 prefix, job_state_to_string(j->state),
 130                 prefix, yes_no(j->forced));
 131 }
 132
 133 bool job_is_anchor(Job *j) {
 134         JobDependency *l;
 135
 136         assert(j);
 137
 138         LIST_FOREACH(object, l, j->object_list)
 139                 if (!l->subject)
 140                         return true;
 141
 142         return false;
 143 }
 144
 145 static bool types_match(JobType a, JobType b, JobType c, JobType d) {
 146         return
 147                 (a == c && b == d) ||
 148                 (a == d && b == c);
 149 }
 150
 151 int job_type_merge(JobType *a, JobType b) {
 152         if (*a == b)
 153                 return 0;
 154
 155         /* Merging is associative! a merged with b merged with c is
 156          * the same as a merged with c merged with b. */
 157
 158         /* Mergeability is transitive! if a can be merged with b and b
 159          * with c then a also with c */
 160
 161         /* Also, if a merged with b cannot be merged with c, then
 162          * either a or b cannot be merged with c either */
 163
 164         if (types_match(*a, b, JOB_START, JOB_VERIFY_ACTIVE))
 165                 *a = JOB_START;
 166         else if (types_match(*a, b, JOB_START, JOB_RELOAD) ||
 167                  types_match(*a, b, JOB_START, JOB_RELOAD_OR_START) ||
 168                  types_match(*a, b, JOB_VERIFY_ACTIVE, JOB_RELOAD_OR_START) ||
 169                  types_match(*a, b, JOB_RELOAD, JOB_RELOAD_OR_START))
 170                 *a = JOB_RELOAD_OR_START;
 171         else if (types_match(*a, b, JOB_START, JOB_RESTART) ||
 172                  types_match(*a, b, JOB_START, JOB_TRY_RESTART) ||
 173                  types_match(*a, b, JOB_VERIFY_ACTIVE, JOB_RESTART) ||
 174                  types_match(*a, b, JOB_RELOAD, JOB_RESTART) ||
 175                  types_match(*a, b, JOB_RELOAD_OR_START, JOB_RESTART) ||
 176                  types_match(*a, b, JOB_RELOAD_OR_START, JOB_TRY_RESTART) ||
 177                  types_match(*a, b, JOB_RESTART, JOB_TRY_RESTART))
 178                 *a = JOB_RESTART;
 179         else if (types_match(*a, b, JOB_VERIFY_ACTIVE, JOB_RELOAD))
 180                 *a = JOB_RELOAD;
 181         else if (types_match(*a, b, JOB_VERIFY_ACTIVE, JOB_TRY_RESTART) ||
 182                  types_match(*a, b, JOB_RELOAD, JOB_TRY_RESTART))
 183                 *a = JOB_TRY_RESTART;
 184         else
 185                 return -EEXIST;
 186
 187         return 0;
 188 }
 189
 190 bool job_type_is_mergeable(JobType a, JobType b) {
 191         return job_type_merge(&a, b) >= 0;
 192 }
 193
 194 bool job_type_is_superset(JobType a, JobType b) {
 195
 196         /* Checks whether operation a is a "superset" of b in its
 197          * actions */
 198
 199         if (a == b)
 200                 return true;
 201
 202         switch (a) {
 203                 case JOB_START:
 204                         return b == JOB_VERIFY_ACTIVE;
 205
 206                 case JOB_RELOAD:
 207                         return
 208                                 b == JOB_VERIFY_ACTIVE;
 209
 210                 case JOB_RELOAD_OR_START:
 211                         return
 212                                 b == JOB_RELOAD ||
 213                                 b == JOB_START ||
 214                                 b == JOB_VERIFY_ACTIVE;
 215
 216                 case JOB_RESTART:
 217                         return
 218                                 b == JOB_START ||
 219                                 b == JOB_VERIFY_ACTIVE ||
 220                                 b == JOB_RELOAD ||
 221                                 b == JOB_RELOAD_OR_START ||
 222                                 b == JOB_TRY_RESTART;
 223
 224                 case JOB_TRY_RESTART:
 225                         return
 226                                 b == JOB_VERIFY_ACTIVE ||
 227                                 b == JOB_RELOAD;
 228                 default:
 229                         return false;
 230
 231         }
 232 }
 233
 234 bool job_type_is_conflicting(JobType a, JobType b) {
 235         assert(a >= 0 && a < _JOB_TYPE_MAX);
 236         assert(b >= 0 && b < _JOB_TYPE_MAX);
 237
 238         return (a == JOB_STOP) != (b == JOB_STOP);
 239 }
 240
 241 bool job_is_runnable(Job *j) {
 242         Iterator i;
 243         Unit *other;
 244
 245         assert(j);
 246         assert(j->installed);
 247
 248         /* Checks whether there is any job running for the units this
 249          * job needs to be running after (in the case of a 'positive'
 250          * job type) or before (in the case of a 'negative' job type
 251          * . */
 252
 253         if (j->type == JOB_START ||
 254             j->type == JOB_VERIFY_ACTIVE ||
 255             j->type == JOB_RELOAD ||
 256             j->type == JOB_RELOAD_OR_START) {
 257
 258                 /* Immediate result is that the job is or might be
 259                  * started. In this case lets wait for the
 260                  * dependencies, regardless whether they are
 261                  * starting or stopping something. */
 262
 263                 SET_FOREACH(other, j->unit->meta.dependencies[UNIT_AFTER], i)
 264                         if (other->meta.job)
 265                                 return false;
 266         }
 267
 268         /* Also, if something else is being stopped and we should
 269          * change state after it, then lets wait. */
 270
 271         SET_FOREACH(other, j->unit->meta.dependencies[UNIT_BEFORE], i)
 272                 if (other->meta.job &&
 273                     (other->meta.job->type == JOB_STOP ||
 274                      other->meta.job->type == JOB_RESTART ||
 275                      other->meta.job->type == JOB_TRY_RESTART))
 276                         return false;
 277
 278         /* This means that for a service a and a service b where b
 279          * shall be started after a:
 280          *
 281          *  start a + start b → 1st step start a, 2nd step start b
 282          *  start a + stop b  → 1st step stop b,  2nd step start a
 283          *  stop a  + start b → 1st step stop a,  2nd step start b
 284          *  stop a  + stop b  → 1st step stop b,  2nd step stop a
 285          *
 286          *  This has the side effect that restarts are properly
 287          *  synchronized too. */
 288
 289         return true;
 290 }
 291
 292 int job_run_and_invalidate(Job *j) {
 293         int r;
 294
 295         assert(j);
 296         assert(j->installed);
 297
 298         if (j->in_run_queue) {
 299                 LIST_REMOVE(Job, run_queue, j->manager->run_queue, j);
 300                 j->in_run_queue = false;
 301         }
 302
 303         if (j->state != JOB_WAITING)
 304                 return 0;
 305
 306         if (!job_is_runnable(j))
 307                 return -EAGAIN;
 308
 309         j->state = JOB_RUNNING;
 310
 311         switch (j->type) {
 312
 313                 case JOB_START:
 314                         r = unit_start(j->unit);
 315                         if (r == -EBADR)
 316                                 r = 0;
 317                         break;
 318
 319                 case JOB_VERIFY_ACTIVE: {
 320                         UnitActiveState t = unit_active_state(j->unit);
 321                         if (UNIT_IS_ACTIVE_OR_RELOADING(t))
 322                                 r = -EALREADY;
 323                         else if (t == UNIT_ACTIVATING)
 324                                 r = -EAGAIN;
 325                         else
 326                                 r = -ENOEXEC;
 327                         break;
 328                 }
 329
 330                 case JOB_STOP:
 331                         r = unit_stop(j->unit);
 332                         break;
 333
 334                 case JOB_RELOAD:
 335                         r = unit_reload(j->unit);
 336                         break;
 337
 338                 case JOB_RELOAD_OR_START:
 339                         if (unit_active_state(j->unit) == UNIT_ACTIVE)
 340                                 r = unit_reload(j->unit);
 341                         else
 342                                 r = unit_start(j->unit);
 343                         break;
 344
 345                 case JOB_RESTART: {
 346                         UnitActiveState t = unit_active_state(j->unit);
 347                         if (t == UNIT_INACTIVE || t == UNIT_ACTIVATING) {
 348                                 j->type = JOB_START;
 349                                 r = unit_start(j->unit);
 350                         } else
 351                                 r = unit_stop(j->unit);
 352                         break;
 353                 }
 354
 355                 case JOB_TRY_RESTART: {
 356                         UnitActiveState t = unit_active_state(j->unit);
 357                         if (t == UNIT_INACTIVE || t == UNIT_DEACTIVATING)
 358                                 r = -ENOEXEC;
 359                         else if (t == UNIT_ACTIVATING) {
 360                                 j->type = JOB_START;
 361                                 r = unit_start(j->unit);
 362                         } else
 363                                 r = unit_stop(j->unit);
 364                         break;
 365                 }
 366
 367                 default:
 368                         assert_not_reached("Unknown job type");
 369         }
 370
 371         if (r == -EALREADY)
 372                 r = job_finish_and_invalidate(j, true);
 373         else if (r == -EAGAIN) {
 374                 j->state = JOB_WAITING;
 375                 return -EAGAIN;
 376         } else if (r < 0)
 377                 r = job_finish_and_invalidate(j, false);
 378
 379         return r;
 380 }
 381
 382 int job_finish_and_invalidate(Job *j, bool success) {
 383         Unit *u;
 384         Unit *other;
 385         UnitType t;
 386         Iterator i;
 387
 388         assert(j);
 389         assert(j->installed);
 390
 391         log_debug("Job %s/%s finished, success=%s", unit_id(j->unit), job_type_to_string(j->type), yes_no(success));
 392
 393         /* Patch restart jobs so that they become normal start jobs */
 394         if (success && (j->type == JOB_RESTART || j->type == JOB_TRY_RESTART)) {
 395
 396                 log_debug("Converting job %s/%s → %s/%s",
 397                           unit_id(j->unit), job_type_to_string(j->type),
 398                           unit_id(j->unit), job_type_to_string(JOB_START));
 399
 400                 j->state = JOB_RUNNING;
 401                 j->type = JOB_START;
 402
 403                 job_schedule_run(j);
 404                 return 0;
 405         }
 406
 407         u = j->unit;
 408         t = j->type;
 409         job_free(j);
 410
 411         /* Fail depending jobs on failure */
 412         if (!success) {
 413
 414                 if (t == JOB_START ||
 415                     t == JOB_VERIFY_ACTIVE ||
 416                     t == JOB_RELOAD_OR_START) {
 417
 418                         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY], i)
 419                                 if (other->meta.job &&
 420                                     (other->meta.type == JOB_START ||
 421                                      other->meta.type == JOB_VERIFY_ACTIVE ||
 422                                      other->meta.type == JOB_RELOAD_OR_START))
 423                                         job_finish_and_invalidate(other->meta.job, false);
 424
 425                         SET_FOREACH(other, u->meta.dependencies[UNIT_SOFT_REQUIRED_BY], i)
 426                                 if (other->meta.job &&
 427                                     !other->meta.job->forced &&
 428                                     (other->meta.type == JOB_START ||
 429                                      other->meta.type == JOB_VERIFY_ACTIVE ||
 430                                      other->meta.type == JOB_RELOAD_OR_START))
 431                                         job_finish_and_invalidate(other->meta.job, false);
 432
 433                 } else if (t == JOB_STOP) {
 434
 435                         SET_FOREACH(other, u->meta.dependencies[UNIT_CONFLICTS], i)
 436                                 if (other->meta.job &&
 437                                     (t == JOB_START ||
 438                                      t == JOB_VERIFY_ACTIVE ||
 439                                      t == JOB_RELOAD_OR_START))
 440                                         job_finish_and_invalidate(other->meta.job, false);
 441                 }
 442         }
 443
 444         /* Try to start the next jobs that can be started */
 445         SET_FOREACH(other, u->meta.dependencies[UNIT_AFTER], i)
 446                 if (other->meta.job)
 447                         job_schedule_run(other->meta.job);
 448         SET_FOREACH(other, u->meta.dependencies[UNIT_BEFORE], i)
 449                 if (other->meta.job)
 450                         job_schedule_run(other->meta.job);
 451
 452         return 0;
 453 }
 454
 455 void job_schedule_run(Job *j) {
 456         assert(j);
 457         assert(j->installed);
 458
 459         if (j->in_run_queue)
 460                 return;
 461
 462         LIST_PREPEND(Job, run_queue, j->manager->run_queue, j);
 463         j->in_run_queue = true;
 464 }
 465
 466 char *job_dbus_path(Job *j) {
 467         char *p;
 468
 469         assert(j);
 470
 471         if (asprintf(&p, "/org/freedesktop/systemd1/job/%lu", (unsigned long) j->id) < 0)
 472                 return NULL;
 473
 474         return p;
 475 }
 476
 477 static const char* const job_state_table[_JOB_STATE_MAX] = {
 478         [JOB_WAITING] = "waiting",
 479         [JOB_RUNNING] = "running"
 480 };
 481
 482 DEFINE_STRING_TABLE_LOOKUP(job_state, JobState);
 483
 484 static const char* const job_type_table[_JOB_TYPE_MAX] = {
 485         [JOB_START] = "start",
 486         [JOB_VERIFY_ACTIVE] = "verify-active",
 487         [JOB_STOP] = "stop",
 488         [JOB_RELOAD] = "reload",
 489         [JOB_RELOAD_OR_START] = "reload-or-start",
 490         [JOB_RESTART] = "restart",
 491         [JOB_TRY_RESTART] = "try-restart",
 492 };
 493
 494 DEFINE_STRING_TABLE_LOOKUP(job_type, JobType);