src/swap.c

   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 General Public License as published by
  10   the Free Software Foundation; either version 2 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   General Public License for more details.
  17
  18   You should have received a copy of the GNU General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <errno.h>
  23 #include <limits.h>
  24 #include <unistd.h>
  25 #include <fcntl.h>
  26 #include <sys/epoll.h>
  27 #include <sys/stat.h>
  28 #include <sys/swap.h>
  29 #include <libudev.h>
  30
  31 #include "unit.h"
  32 #include "swap.h"
  33 #include "load-fragment.h"
  34 #include "load-dropin.h"
  35 #include "unit-name.h"
  36 #include "dbus-swap.h"
  37 #include "special.h"
  38 #include "bus-errors.h"
  39 #include "exit-status.h"
  40
  41 static const UnitActiveState state_translation_table[_SWAP_STATE_MAX] = {
  42         [SWAP_DEAD] = UNIT_INACTIVE,
  43         [SWAP_ACTIVATING] = UNIT_ACTIVATING,
  44         [SWAP_ACTIVE] = UNIT_ACTIVE,
  45         [SWAP_DEACTIVATING] = UNIT_DEACTIVATING,
  46         [SWAP_ACTIVATING_SIGTERM] = UNIT_DEACTIVATING,
  47         [SWAP_ACTIVATING_SIGKILL] = UNIT_DEACTIVATING,
  48         [SWAP_DEACTIVATING_SIGTERM] = UNIT_DEACTIVATING,
  49         [SWAP_DEACTIVATING_SIGKILL] = UNIT_DEACTIVATING,
  50         [SWAP_FAILED] = UNIT_FAILED
  51 };
  52
  53 static void swap_unset_proc_swaps(Swap *s) {
  54         Swap *first;
  55
  56         assert(s);
  57
  58         if (!s->parameters_proc_swaps.what)
  59                 return;
  60
  61         /* Remove this unit from the chain of swaps which share the
  62          * same kernel swap device. */
  63
  64         first = hashmap_get(s->meta.manager->swaps_by_proc_swaps, s->parameters_proc_swaps.what);
  65         LIST_REMOVE(Swap, same_proc_swaps, first, s);
  66
  67         if (first)
  68                 hashmap_remove_and_replace(s->meta.manager->swaps_by_proc_swaps, s->parameters_proc_swaps.what, first->parameters_proc_swaps.what, first);
  69         else
  70                 hashmap_remove(s->meta.manager->swaps_by_proc_swaps, s->parameters_proc_swaps.what);
  71
  72         free(s->parameters_proc_swaps.what);
  73         s->parameters_proc_swaps.what = NULL;
  74 }
  75
  76  static void swap_init(Unit *u) {
  77         Swap *s = SWAP(u);
  78
  79         assert(s);
  80         assert(s->meta.load_state == UNIT_STUB);
  81
  82         s->timeout_usec = DEFAULT_TIMEOUT_USEC;
  83
  84         exec_context_init(&s->exec_context);
  85
  86         s->parameters_etc_fstab.priority = s->parameters_proc_swaps.priority = s->parameters_fragment.priority = -1;
  87
  88         s->timer_watch.type = WATCH_INVALID;
  89
  90         s->control_command_id = _MOUNT_EXEC_COMMAND_INVALID;
  91 }
  92
  93 static void swap_unwatch_control_pid(Swap *s) {
  94         assert(s);
  95
  96         if (s->control_pid <= 0)
  97                 return;
  98
  99         unit_unwatch_pid(UNIT(s), s->control_pid);
 100         s->control_pid = 0;
 101 }
 102
 103 static void swap_done(Unit *u) {
 104         Swap *s = SWAP(u);
 105
 106         assert(s);
 107
 108         swap_unset_proc_swaps(s);
 109
 110         free(s->what);
 111         s->what = NULL;
 112
 113         free(s->parameters_etc_fstab.what);
 114         free(s->parameters_fragment.what);
 115         s->parameters_etc_fstab.what = s->parameters_fragment.what = NULL;
 116
 117         exec_context_done(&s->exec_context);
 118         exec_command_done_array(s->exec_command, _SWAP_EXEC_COMMAND_MAX);
 119         s->control_command = NULL;
 120
 121         swap_unwatch_control_pid(s);
 122
 123         unit_unwatch_timer(u, &s->timer_watch);
 124 }
 125
 126 int swap_add_one_mount_link(Swap *s, Mount *m) {
 127          int r;
 128
 129         assert(s);
 130         assert(m);
 131
 132         if (s->meta.load_state != UNIT_LOADED ||
 133             m->meta.load_state != UNIT_LOADED)
 134                 return 0;
 135
 136         if (is_device_path(s->what))
 137                 return 0;
 138
 139         if (!path_startswith(s->what, m->where))
 140                 return 0;
 141
 142         if ((r = unit_add_two_dependencies(UNIT(s), UNIT_AFTER, UNIT_REQUIRES, UNIT(m), true)) < 0)
 143                 return r;
 144
 145         return 0;
 146 }
 147
 148 static int swap_add_mount_links(Swap *s) {
 149         Meta *other;
 150         int r;
 151
 152         assert(s);
 153
 154         LIST_FOREACH(units_per_type, other, s->meta.manager->units_per_type[UNIT_MOUNT])
 155                 if ((r = swap_add_one_mount_link(s, (Mount*) other)) < 0)
 156                         return r;
 157
 158         return 0;
 159 }
 160
 161 static int swap_add_target_links(Swap *s) {
 162         Unit *tu;
 163         SwapParameters *p;
 164         int r;
 165
 166         assert(s);
 167
 168         if (s->from_fragment)
 169                 p = &s->parameters_fragment;
 170         else if (s->from_etc_fstab)
 171                 p = &s->parameters_etc_fstab;
 172         else
 173                 return 0;
 174
 175         if ((r = manager_load_unit(s->meta.manager, SPECIAL_SWAP_TARGET, NULL, NULL, &tu)) < 0)
 176                 return r;
 177
 178         if (!p->noauto &&
 179             (p->handle || s->meta.manager->swap_auto) &&
 180             s->from_etc_fstab &&
 181             s->meta.manager->running_as == MANAGER_SYSTEM)
 182                 if ((r = unit_add_dependency(tu, UNIT_WANTS, UNIT(s), true)) < 0)
 183                         return r;
 184
 185         return unit_add_dependency(UNIT(s), UNIT_BEFORE, tu, true);
 186 }
 187
 188 static int swap_add_device_links(Swap *s) {
 189         SwapParameters *p;
 190
 191         assert(s);
 192
 193         if (!s->what)
 194                 return 0;
 195
 196         if (s->from_fragment)
 197                 p = &s->parameters_fragment;
 198         else if (s->from_etc_fstab)
 199                 p = &s->parameters_etc_fstab;
 200         else
 201                 return 0;
 202
 203         if (is_device_path(s->what))
 204                 return unit_add_node_link(UNIT(s), s->what,
 205                                           !p->noauto && p->nofail &&
 206                                           s->meta.manager->running_as == MANAGER_SYSTEM);
 207         else
 208                 /* File based swap devices need to be ordered after
 209                  * remount-rootfs.service, since they might need a
 210                  * writable file system. */
 211                 return unit_add_dependency_by_name(UNIT(s), UNIT_AFTER, SPECIAL_REMOUNT_ROOTFS_SERVICE, NULL, true);
 212 }
 213
 214 static int swap_add_default_dependencies(Swap *s) {
 215         int r;
 216
 217         assert(s);
 218
 219         if (s->meta.manager->running_as == MANAGER_SYSTEM) {
 220
 221                 if ((r = unit_add_two_dependencies_by_name(UNIT(s), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_UMOUNT_TARGET, NULL, true)) < 0)
 222                         return r;
 223         }
 224
 225         return 0;
 226 }
 227
 228 static int swap_verify(Swap *s) {
 229         bool b;
 230         char *e;
 231
 232         if (s->meta.load_state != UNIT_LOADED)
 233                   return 0;
 234
 235         if (!(e = unit_name_from_path(s->what, ".swap")))
 236                   return -ENOMEM;
 237
 238         b = unit_has_name(UNIT(s), e);
 239         free(e);
 240
 241         if (!b) {
 242                 log_error("%s: Value of \"What\" and unit name do not match, not loading.\n", s->meta.id);
 243                 return -EINVAL;
 244         }
 245
 246         if (s->exec_context.pam_name && s->exec_context.kill_mode != KILL_CONTROL_GROUP) {
 247                 log_error("%s has PAM enabled. Kill mode must be set to 'control-group'. Refusing.", s->meta.id);
 248                 return -EINVAL;
 249         }
 250
 251         return 0;
 252 }
 253
 254 static int swap_load(Unit *u) {
 255         int r;
 256         Swap *s = SWAP(u);
 257
 258         assert(s);
 259         assert(u->meta.load_state == UNIT_STUB);
 260
 261         /* Load a .swap file */
 262         if ((r = unit_load_fragment_and_dropin_optional(u)) < 0)
 263                 return r;
 264
 265         if (u->meta.load_state == UNIT_LOADED) {
 266
 267                 if (s->meta.fragment_path)
 268                         s->from_fragment = true;
 269
 270                 if (!s->what) {
 271                         if (s->parameters_fragment.what)
 272                                 s->what = strdup(s->parameters_fragment.what);
 273                         else if (s->parameters_etc_fstab.what)
 274                                 s->what = strdup(s->parameters_etc_fstab.what);
 275                         else if (s->parameters_proc_swaps.what)
 276                                 s->what = strdup(s->parameters_proc_swaps.what);
 277                         else
 278                                 s->what = unit_name_to_path(u->meta.id);
 279
 280                         if (!s->what)
 281                                 return -ENOMEM;
 282                 }
 283
 284                 path_kill_slashes(s->what);
 285
 286                 if (!s->meta.description)
 287                         if ((r = unit_set_description(u, s->what)) < 0)
 288                                 return r;
 289
 290                 if ((r = swap_add_device_links(s)) < 0)
 291                         return r;
 292
 293                 if ((r = swap_add_mount_links(s)) < 0)
 294                         return r;
 295
 296                 if ((r = swap_add_target_links(s)) < 0)
 297                         return r;
 298
 299                 if ((r = unit_add_default_cgroups(u)) < 0)
 300                         return r;
 301
 302                 if (s->meta.default_dependencies)
 303                         if ((r = swap_add_default_dependencies(s)) < 0)
 304                                 return r;
 305         }
 306
 307         return swap_verify(s);
 308 }
 309
 310 int swap_add_one(
 311                 Manager *m,
 312                 const char *what,
 313                 const char *what_proc_swaps,
 314                 int priority,
 315                 bool noauto,
 316                 bool nofail,
 317                 bool handle,
 318                 bool set_flags) {
 319
 320         Unit *u = NULL;
 321         char *e = NULL, *wp = NULL;
 322         bool delete = false;
 323         int r;
 324         SwapParameters *p;
 325
 326         assert(m);
 327         assert(what);
 328
 329         if (!(e = unit_name_from_path(what, ".swap")))
 330                 return -ENOMEM;
 331
 332         u = manager_get_unit(m, e);
 333
 334         if (what_proc_swaps &&
 335             u &&
 336             SWAP(u)->from_proc_swaps &&
 337             !path_equal(SWAP(u)->parameters_proc_swaps.what, what_proc_swaps))
 338                 return -EEXIST;
 339
 340         if (!u) {
 341                 delete = true;
 342
 343                 if (!(u = unit_new(m))) {
 344                         free(e);
 345                         return -ENOMEM;
 346                 }
 347
 348                 if ((r = unit_add_name(u, e)) < 0)
 349                         goto fail;
 350
 351                 if (!(SWAP(u)->what = strdup(what))) {
 352                         r = -ENOMEM;
 353                         goto fail;
 354                 }
 355
 356                 unit_add_to_load_queue(u);
 357         } else
 358                 delete = false;
 359
 360         if (what_proc_swaps) {
 361                 Swap *first;
 362
 363                 p = &SWAP(u)->parameters_proc_swaps;
 364
 365                 if (!p->what) {
 366                         if (!(wp = strdup(what_proc_swaps))) {
 367                                 r = -ENOMEM;
 368                                 goto fail;
 369                         }
 370
 371                         if (!m->swaps_by_proc_swaps)
 372                                 if (!(m->swaps_by_proc_swaps = hashmap_new(string_hash_func, string_compare_func))) {
 373                                         r = -ENOMEM;
 374                                         goto fail;
 375                                 }
 376
 377                         free(p->what);
 378                         p->what = wp;
 379
 380                         first = hashmap_get(m->swaps_by_proc_swaps, wp);
 381                         LIST_PREPEND(Swap, same_proc_swaps, first, SWAP(u));
 382
 383                         if ((r = hashmap_replace(m->swaps_by_proc_swaps, wp, first)) < 0)
 384                                 goto fail;
 385                 }
 386
 387                 if (set_flags) {
 388                         SWAP(u)->is_active = true;
 389                         SWAP(u)->just_activated = !SWAP(u)->from_proc_swaps;
 390                 }
 391
 392                 SWAP(u)->from_proc_swaps = true;
 393
 394         } else {
 395                 p = &SWAP(u)->parameters_etc_fstab;
 396
 397                 if (!(wp = strdup(what))) {
 398                         r = -ENOMEM;
 399                         goto fail;
 400                 }
 401
 402                 free(p->what);
 403                 p->what = wp;
 404
 405                 SWAP(u)->from_etc_fstab = true;
 406         }
 407
 408         p->priority = priority;
 409         p->noauto = noauto;
 410         p->nofail = nofail;
 411         p->handle = handle;
 412
 413         unit_add_to_dbus_queue(u);
 414
 415         free(e);
 416
 417         return 0;
 418
 419 fail:
 420         log_warning("Failed to load swap unit: %s", strerror(-r));
 421
 422         free(wp);
 423         free(e);
 424
 425         if (delete && u)
 426                 unit_free(u);
 427
 428         return r;
 429 }
 430
 431 static int swap_process_new_swap(Manager *m, const char *device, int prio, bool set_flags) {
 432         struct stat st;
 433         int r = 0, k;
 434
 435         assert(m);
 436
 437         if (stat(device, &st) >= 0 && S_ISBLK(st.st_mode)) {
 438                 struct udev_device *d;
 439                 const char *dn;
 440                 struct udev_list_entry *item = NULL, *first = NULL;
 441
 442                 /* So this is a proper swap device. Create swap units
 443                  * for all names this swap device is known under */
 444
 445                 if (!(d = udev_device_new_from_devnum(m->udev, 'b', st.st_rdev)))
 446                         return -ENOMEM;
 447
 448                 if ((dn = udev_device_get_devnode(d)))
 449                         r = swap_add_one(m, dn, device, prio, false, false, false, set_flags);
 450
 451                 /* Add additional units for all symlinks */
 452                 first = udev_device_get_devlinks_list_entry(d);
 453                 udev_list_entry_foreach(item, first) {
 454                         const char *p;
 455
 456                         /* Don't bother with the /dev/block links */
 457                         p = udev_list_entry_get_name(item);
 458
 459                         if (path_startswith(p, "/dev/block/"))
 460                                 continue;
 461
 462                         if (stat(p, &st) >= 0)
 463                                 if ((!S_ISBLK(st.st_mode)) || st.st_rdev != udev_device_get_devnum(d))
 464                                         continue;
 465
 466                         if ((k = swap_add_one(m, p, device, prio, false, false, false, set_flags)) < 0)
 467                                 r = k;
 468                 }
 469
 470                 udev_device_unref(d);
 471         }
 472
 473         if ((k = swap_add_one(m, device, device, prio, false, false, false, set_flags)) < 0)
 474                 r = k;
 475
 476         return r;
 477 }
 478
 479 static void swap_set_state(Swap *s, SwapState state) {
 480         SwapState old_state;
 481
 482         assert(s);
 483
 484         old_state = s->state;
 485         s->state = state;
 486
 487         if (state != SWAP_ACTIVATING &&
 488             state != SWAP_ACTIVATING_SIGTERM &&
 489             state != SWAP_ACTIVATING_SIGKILL &&
 490             state != SWAP_DEACTIVATING &&
 491             state != SWAP_DEACTIVATING_SIGTERM &&
 492             state != SWAP_DEACTIVATING_SIGKILL) {
 493                 unit_unwatch_timer(UNIT(s), &s->timer_watch);
 494                 swap_unwatch_control_pid(s);
 495                 s->control_command = NULL;
 496                 s->control_command_id = _SWAP_EXEC_COMMAND_INVALID;
 497         }
 498
 499         if (state != old_state)
 500                 log_debug("%s changed %s -> %s",
 501                           s->meta.id,
 502                           swap_state_to_string(old_state),
 503                           swap_state_to_string(state));
 504
 505         unit_notify(UNIT(s), state_translation_table[old_state], state_translation_table[state], true);
 506 }
 507
 508 static int swap_coldplug(Unit *u) {
 509         Swap *s = SWAP(u);
 510         SwapState new_state = SWAP_DEAD;
 511         int r;
 512
 513         assert(s);
 514         assert(s->state == SWAP_DEAD);
 515
 516         if (s->deserialized_state != s->state)
 517                 new_state = s->deserialized_state;
 518         else if (s->from_proc_swaps)
 519                 new_state = SWAP_ACTIVE;
 520
 521         if (new_state != s->state) {
 522
 523                 if (new_state == SWAP_ACTIVATING ||
 524                     new_state == SWAP_ACTIVATING_SIGTERM ||
 525                     new_state == SWAP_ACTIVATING_SIGKILL ||
 526                     new_state == SWAP_DEACTIVATING ||
 527                     new_state == SWAP_DEACTIVATING_SIGTERM ||
 528                     new_state == SWAP_DEACTIVATING_SIGKILL) {
 529
 530                         if (s->control_pid <= 0)
 531                                 return -EBADMSG;
 532
 533                         if ((r = unit_watch_pid(UNIT(s), s->control_pid)) < 0)
 534                                 return r;
 535
 536                         if ((r = unit_watch_timer(UNIT(s), s->timeout_usec, &s->timer_watch)) < 0)
 537                                 return r;
 538                 }
 539
 540                 swap_set_state(s, new_state);
 541         }
 542
 543         return 0;
 544 }
 545
 546 static void swap_dump(Unit *u, FILE *f, const char *prefix) {
 547         Swap *s = SWAP(u);
 548         SwapParameters *p;
 549
 550         assert(s);
 551         assert(f);
 552
 553         if (s->from_proc_swaps)
 554                 p = &s->parameters_proc_swaps;
 555         else if (s->from_fragment)
 556                 p = &s->parameters_fragment;
 557         else
 558                 p = &s->parameters_etc_fstab;
 559
 560         fprintf(f,
 561                 "%sSwap State: %s\n"
 562                 "%sWhat: %s\n"
 563                 "%sPriority: %i\n"
 564                 "%sNoAuto: %s\n"
 565                 "%sNoFail: %s\n"
 566                 "%sHandle: %s\n"
 567                 "%sFrom /etc/fstab: %s\n"
 568                 "%sFrom /proc/swaps: %s\n"
 569                 "%sFrom fragment: %s\n",
 570                 prefix, swap_state_to_string(s->state),
 571                 prefix, s->what,
 572                 prefix, p->priority,
 573                 prefix, yes_no(p->noauto),
 574                 prefix, yes_no(p->nofail),
 575                 prefix, yes_no(p->handle),
 576                 prefix, yes_no(s->from_etc_fstab),
 577                 prefix, yes_no(s->from_proc_swaps),
 578                 prefix, yes_no(s->from_fragment));
 579
 580         if (s->control_pid > 0)
 581                 fprintf(f,
 582                         "%sControl PID: %lu\n",
 583                         prefix, (unsigned long) s->control_pid);
 584
 585         exec_context_dump(&s->exec_context, f, prefix);
 586 }
 587
 588 static int swap_spawn(Swap *s, ExecCommand *c, pid_t *_pid) {
 589         pid_t pid;
 590         int r;
 591
 592         assert(s);
 593         assert(c);
 594         assert(_pid);
 595
 596         if ((r = unit_watch_timer(UNIT(s), s->timeout_usec, &s->timer_watch)) < 0)
 597                 goto fail;
 598
 599         if ((r = exec_spawn(c,
 600                             NULL,
 601                             &s->exec_context,
 602                             NULL, 0,
 603                             s->meta.manager->environment,
 604                             true,
 605                             true,
 606                             true,
 607                             s->meta.manager->confirm_spawn,
 608                             s->meta.cgroup_bondings,
 609                             &pid)) < 0)
 610                 goto fail;
 611
 612         if ((r = unit_watch_pid(UNIT(s), pid)) < 0)
 613                 /* FIXME: we need to do something here */
 614                 goto fail;
 615
 616         *_pid = pid;
 617
 618         return 0;
 619
 620 fail:
 621         unit_unwatch_timer(UNIT(s), &s->timer_watch);
 622
 623         return r;
 624 }
 625
 626 static void swap_enter_dead(Swap *s, bool success) {
 627         assert(s);
 628
 629         if (!success)
 630                 s->failure = true;
 631
 632         swap_set_state(s, s->failure ? SWAP_FAILED : SWAP_DEAD);
 633 }
 634
 635 static void swap_enter_active(Swap *s, bool success) {
 636         assert(s);
 637
 638         if (!success)
 639                 s->failure = true;
 640
 641         swap_set_state(s, SWAP_ACTIVE);
 642 }
 643
 644 static void swap_enter_signal(Swap *s, SwapState state, bool success) {
 645         int r;
 646         Set *pid_set = NULL;
 647         bool wait_for_exit = false;
 648
 649         assert(s);
 650
 651         if (!success)
 652                 s->failure = true;
 653
 654         if (s->exec_context.kill_mode != KILL_NONE) {
 655                 int sig = (state == SWAP_ACTIVATING_SIGTERM ||
 656                            state == SWAP_DEACTIVATING_SIGTERM) ? s->exec_context.kill_signal : SIGKILL;
 657
 658                 if (s->control_pid > 0) {
 659                         if (kill(s->exec_context.kill_mode == KILL_PROCESS_GROUP ?
 660                                  -s->control_pid :
 661                                  s->control_pid, sig) < 0 && errno != ESRCH)
 662
 663                                 log_warning("Failed to kill control process %li: %m", (long) s->control_pid);
 664                         else
 665                                 wait_for_exit = true;
 666                 }
 667
 668                 if (s->exec_context.kill_mode == KILL_CONTROL_GROUP) {
 669
 670                         if (!(pid_set = set_new(trivial_hash_func, trivial_compare_func))) {
 671                                 r = -ENOMEM;
 672                                 goto fail;
 673                         }
 674
 675                         /* Exclude the control pid from being killed via the cgroup */
 676                         if (s->control_pid > 0)
 677                                 if ((r = set_put(pid_set, LONG_TO_PTR(s->control_pid))) < 0)
 678                                         goto fail;
 679
 680                         if ((r = cgroup_bonding_kill_list(s->meta.cgroup_bondings, sig, pid_set)) < 0) {
 681                                 if (r != -EAGAIN && r != -ESRCH && r != -ENOENT)
 682                                         log_warning("Failed to kill control group: %s", strerror(-r));
 683                         } else if (r > 0)
 684                                 wait_for_exit = true;
 685
 686                         set_free(pid_set);
 687                 }
 688         }
 689
 690         if (wait_for_exit) {
 691                 if ((r = unit_watch_timer(UNIT(s), s->timeout_usec, &s->timer_watch)) < 0)
 692                         goto fail;
 693
 694                 swap_set_state(s, state);
 695         } else
 696                 swap_enter_dead(s, true);
 697
 698         return;
 699
 700 fail:
 701         log_warning("%s failed to kill processes: %s", s->meta.id, strerror(-r));
 702
 703         swap_enter_dead(s, false);
 704
 705         if (pid_set)
 706                 set_free(pid_set);
 707 }
 708
 709 static void swap_enter_activating(Swap *s) {
 710         int r, priority;
 711
 712         assert(s);
 713
 714         s->control_command_id = SWAP_EXEC_ACTIVATE;
 715         s->control_command = s->exec_command + SWAP_EXEC_ACTIVATE;
 716
 717         if (s->from_fragment)
 718                 priority = s->parameters_fragment.priority;
 719         else if (s->from_etc_fstab)
 720                 priority = s->parameters_etc_fstab.priority;
 721         else
 722                 priority = -1;
 723
 724         if (priority >= 0) {
 725                 char p[LINE_MAX];
 726
 727                 snprintf(p, sizeof(p), "%i", priority);
 728                 char_array_0(p);
 729
 730                 r = exec_command_set(
 731                                 s->control_command,
 732                                 "/sbin/swapon",
 733                                 "-p",
 734                                 p,
 735                                 s->what,
 736                                 NULL);
 737         } else
 738                 r = exec_command_set(
 739                                 s->control_command,
 740                                 "/sbin/swapon",
 741                                 s->what,
 742                                 NULL);
 743
 744         if (r < 0)
 745                 goto fail;
 746
 747         swap_unwatch_control_pid(s);
 748
 749         if ((r = swap_spawn(s, s->control_command, &s->control_pid)) < 0)
 750                 goto fail;
 751
 752         swap_set_state(s, SWAP_ACTIVATING);
 753
 754         return;
 755
 756 fail:
 757         log_warning("%s failed to run 'swapon' task: %s", s->meta.id, strerror(-r));
 758         swap_enter_dead(s, false);
 759 }
 760
 761 static void swap_enter_deactivating(Swap *s, bool success) {
 762         int r;
 763
 764         assert(s);
 765
 766         if (!success)
 767                 s->failure = true;
 768
 769         s->control_command_id = SWAP_EXEC_DEACTIVATE;
 770         s->control_command = s->exec_command + SWAP_EXEC_DEACTIVATE;
 771
 772         if ((r = exec_command_set(
 773                              s->control_command,
 774                              "/sbin/swapoff",
 775                              s->what,
 776                              NULL)) < 0)
 777                 goto fail;
 778
 779         swap_unwatch_control_pid(s);
 780
 781         if ((r = swap_spawn(s, s->control_command, &s->control_pid)) < 0)
 782                 goto fail;
 783
 784         swap_set_state(s, SWAP_DEACTIVATING);
 785
 786         return;
 787
 788 fail:
 789         log_warning("%s failed to run 'swapoff' task: %s", s->meta.id, strerror(-r));
 790         swap_enter_active(s, false);
 791 }
 792
 793 static int swap_start(Unit *u) {
 794         Swap *s = SWAP(u);
 795
 796         assert(s);
 797
 798         /* We cannot fulfill this request right now, try again later
 799          * please! */
 800
 801         if (s->state == SWAP_DEACTIVATING ||
 802             s->state == SWAP_DEACTIVATING_SIGTERM ||
 803             s->state == SWAP_DEACTIVATING_SIGKILL ||
 804             s->state == SWAP_ACTIVATING_SIGTERM ||
 805             s->state == SWAP_ACTIVATING_SIGKILL)
 806                 return -EAGAIN;
 807
 808         if (s->state == SWAP_ACTIVATING)
 809                 return 0;
 810
 811         assert(s->state == SWAP_DEAD || s->state == SWAP_FAILED);
 812
 813         s->failure = false;
 814         swap_enter_activating(s);
 815         return 0;
 816 }
 817
 818 static int swap_stop(Unit *u) {
 819         Swap *s = SWAP(u);
 820
 821         assert(s);
 822
 823         if (s->state == SWAP_DEACTIVATING ||
 824             s->state == SWAP_DEACTIVATING_SIGTERM ||
 825             s->state == SWAP_DEACTIVATING_SIGKILL ||
 826             s->state == SWAP_ACTIVATING_SIGTERM ||
 827             s->state == SWAP_ACTIVATING_SIGKILL)
 828                 return 0;
 829
 830         assert(s->state == SWAP_ACTIVATING ||
 831                s->state == SWAP_ACTIVE);
 832
 833         swap_enter_deactivating(s, true);
 834         return 0;
 835 }
 836
 837 static int swap_serialize(Unit *u, FILE *f, FDSet *fds) {
 838         Swap *s = SWAP(u);
 839
 840         assert(s);
 841         assert(f);
 842         assert(fds);
 843
 844         unit_serialize_item(u, f, "state", swap_state_to_string(s->state));
 845         unit_serialize_item(u, f, "failure", yes_no(s->failure));
 846
 847         if (s->control_pid > 0)
 848                 unit_serialize_item_format(u, f, "control-pid", "%lu", (unsigned long) s->control_pid);
 849
 850         if (s->control_command_id >= 0)
 851                 unit_serialize_item(u, f, "control-command", swap_exec_command_to_string(s->control_command_id));
 852
 853         return 0;
 854 }
 855
 856 static int swap_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 857         Swap *s = SWAP(u);
 858
 859         assert(s);
 860         assert(fds);
 861
 862         if (streq(key, "state")) {
 863                 SwapState state;
 864
 865                 if ((state = swap_state_from_string(value)) < 0)
 866                         log_debug("Failed to parse state value %s", value);
 867                 else
 868                         s->deserialized_state = state;
 869         } else if (streq(key, "failure")) {
 870                 int b;
 871
 872                 if ((b = parse_boolean(value)) < 0)
 873                         log_debug("Failed to parse failure value %s", value);
 874                 else
 875                         s->failure = b || s->failure;
 876
 877         } else if (streq(key, "control-pid")) {
 878                 pid_t pid;
 879
 880                 if (parse_pid(value, &pid) < 0)
 881                         log_debug("Failed to parse control-pid value %s", value);
 882                 else
 883                         s->control_pid = pid;
 884
 885         } else if (streq(key, "control-command")) {
 886                 SwapExecCommand id;
 887
 888                 if ((id = swap_exec_command_from_string(value)) < 0)
 889                         log_debug("Failed to parse exec-command value %s", value);
 890                 else {
 891                         s->control_command_id = id;
 892                         s->control_command = s->exec_command + id;
 893                 }
 894
 895         } else
 896                 log_debug("Unknown serialization key '%s'", key);
 897
 898         return 0;
 899 }
 900
 901 static UnitActiveState swap_active_state(Unit *u) {
 902         assert(u);
 903
 904         return state_translation_table[SWAP(u)->state];
 905 }
 906
 907 static const char *swap_sub_state_to_string(Unit *u) {
 908         assert(u);
 909
 910         return swap_state_to_string(SWAP(u)->state);
 911 }
 912
 913 static bool swap_check_gc(Unit *u) {
 914         Swap *s = SWAP(u);
 915
 916         assert(s);
 917
 918         return s->from_etc_fstab || s->from_proc_swaps;
 919 }
 920
 921 static void swap_sigchld_event(Unit *u, pid_t pid, int code, int status) {
 922         Swap *s = SWAP(u);
 923         bool success;
 924
 925         assert(s);
 926         assert(pid >= 0);
 927
 928         if (pid != s->control_pid)
 929                 return;
 930
 931         s->control_pid = 0;
 932
 933         success = is_clean_exit(code, status);
 934         s->failure = s->failure || !success;
 935
 936         if (s->control_command) {
 937                 exec_status_exit(&s->control_command->exec_status, pid, code, status, s->exec_context.utmp_id);
 938                 s->control_command = NULL;
 939                 s->control_command_id = _SWAP_EXEC_COMMAND_INVALID;
 940         }
 941
 942         log_full(success ? LOG_DEBUG : LOG_NOTICE,
 943                  "%s swap process exited, code=%s status=%i", u->meta.id, sigchld_code_to_string(code), status);
 944
 945         switch (s->state) {
 946
 947         case SWAP_ACTIVATING:
 948         case SWAP_ACTIVATING_SIGTERM:
 949         case SWAP_ACTIVATING_SIGKILL:
 950
 951                 if (success)
 952                         swap_enter_active(s, true);
 953                 else
 954                         swap_enter_dead(s, false);
 955                 break;
 956
 957         case SWAP_DEACTIVATING:
 958         case SWAP_DEACTIVATING_SIGKILL:
 959         case SWAP_DEACTIVATING_SIGTERM:
 960
 961                 if (success)
 962                         swap_enter_dead(s, true);
 963                 else
 964                         swap_enter_dead(s, false);
 965                 break;
 966
 967         default:
 968                 assert_not_reached("Uh, control process died at wrong time.");
 969         }
 970
 971         /* Notify clients about changed exit status */
 972         unit_add_to_dbus_queue(u);
 973
 974         /* Request a reload of /proc/swaps, so that following units
 975          * can follow our state change */
 976         u->meta.manager->request_reload = true;
 977 }
 978
 979 static void swap_timer_event(Unit *u, uint64_t elapsed, Watch *w) {
 980         Swap *s = SWAP(u);
 981
 982         assert(s);
 983         assert(elapsed == 1);
 984         assert(w == &s->timer_watch);
 985
 986         switch (s->state) {
 987
 988         case SWAP_ACTIVATING:
 989                 log_warning("%s activation timed out. Stopping.", u->meta.id);
 990                 swap_enter_signal(s, SWAP_ACTIVATING_SIGTERM, false);
 991                 break;
 992
 993         case SWAP_DEACTIVATING:
 994                 log_warning("%s deactivation timed out. Stopping.", u->meta.id);
 995                 swap_enter_signal(s, SWAP_DEACTIVATING_SIGTERM, false);
 996                 break;
 997
 998         case SWAP_ACTIVATING_SIGTERM:
 999                 if (s->exec_context.send_sigkill) {
1000                         log_warning("%s activation timed out. Killing.", u->meta.id);
1001                         swap_enter_signal(s, SWAP_ACTIVATING_SIGKILL, false);
1002                 } else {
1003                         log_warning("%s activation timed out. Skipping SIGKILL. Ignoring.", u->meta.id);
1004                         swap_enter_dead(s, false);
1005                 }
1006                 break;
1007
1008         case SWAP_DEACTIVATING_SIGTERM:
1009                 if (s->exec_context.send_sigkill) {
1010                         log_warning("%s deactivation timed out. Killing.", u->meta.id);
1011                         swap_enter_signal(s, SWAP_DEACTIVATING_SIGKILL, false);
1012                 } else {
1013                         log_warning("%s deactivation timed out. Skipping SIGKILL. Ignoring.", u->meta.id);
1014                         swap_enter_dead(s, false);
1015                 }
1016                 break;
1017
1018         case SWAP_ACTIVATING_SIGKILL:
1019         case SWAP_DEACTIVATING_SIGKILL:
1020                 log_warning("%s swap process still around after SIGKILL. Ignoring.", u->meta.id);
1021                 swap_enter_dead(s, false);
1022                 break;
1023
1024         default:
1025                 assert_not_reached("Timeout at wrong time.");
1026         }
1027 }
1028
1029 static int swap_load_proc_swaps(Manager *m, bool set_flags) {
1030         unsigned i;
1031         int r = 0;
1032
1033         assert(m);
1034
1035         rewind(m->proc_swaps);
1036
1037         (void) fscanf(m->proc_swaps, "%*s %*s %*s %*s %*s\n");
1038
1039         for (i = 1;; i++) {
1040                 char *dev = NULL, *d;
1041                 int prio = 0, k;
1042
1043                 if ((k = fscanf(m->proc_swaps,
1044                                 "%ms "  /* device/file */
1045                                 "%*s "  /* type of swap */
1046                                 "%*s "  /* swap size */
1047                                 "%*s "  /* used */
1048                                 "%i\n", /* priority */
1049                                 &dev, &prio)) != 2) {
1050
1051                         if (k == EOF)
1052                                 break;
1053
1054                         log_warning("Failed to parse /proc/swaps:%u.", i);
1055                         free(dev);
1056                         continue;
1057                 }
1058
1059                 d = cunescape(dev);
1060                 free(dev);
1061
1062                 if (!d)
1063                         return -ENOMEM;
1064
1065                 k = swap_process_new_swap(m, d, prio, set_flags);
1066                 free(d);
1067
1068                 if (k < 0)
1069                         r = k;
1070         }
1071
1072         return r;
1073 }
1074
1075 int swap_dispatch_reload(Manager *m) {
1076         /* This function should go as soon as the kernel properly notifies us */
1077
1078         if (_likely_(!m->request_reload))
1079                 return 0;
1080
1081         m->request_reload = false;
1082
1083         return swap_fd_event(m, EPOLLPRI);
1084 }
1085
1086 int swap_fd_event(Manager *m, int events) {
1087         Meta *meta;
1088         int r;
1089
1090         assert(m);
1091         assert(events & EPOLLPRI);
1092
1093         if ((r = swap_load_proc_swaps(m, true)) < 0) {
1094                 log_error("Failed to reread /proc/swaps: %s", strerror(-r));
1095
1096                 /* Reset flags, just in case, for late calls */
1097                 LIST_FOREACH(units_per_type, meta, m->units_per_type[UNIT_SWAP]) {
1098                         Swap *swap = (Swap*) meta;
1099
1100                         swap->is_active = swap->just_activated = false;
1101                 }
1102
1103                 return 0;
1104         }
1105
1106         manager_dispatch_load_queue(m);
1107
1108         LIST_FOREACH(units_per_type, meta, m->units_per_type[UNIT_SWAP]) {
1109                 Swap *swap = (Swap*) meta;
1110
1111                 if (!swap->is_active) {
1112                         /* This has just been deactivated */
1113
1114                         swap->from_proc_swaps = false;
1115                         swap_unset_proc_swaps(swap);
1116
1117                         switch (swap->state) {
1118
1119                         case SWAP_ACTIVE:
1120                                 swap_enter_dead(swap, true);
1121                                 break;
1122
1123                         default:
1124                                 swap_set_state(swap, swap->state);
1125                                 break;
1126                         }
1127
1128                 } else if (swap->just_activated) {
1129
1130                         /* New swap entry */
1131
1132                         switch (swap->state) {
1133
1134                         case SWAP_DEAD:
1135                         case SWAP_FAILED:
1136                                 swap_enter_active(swap, true);
1137                                 break;
1138
1139                         default:
1140                                 /* Nothing really changed, but let's
1141                                  * issue an notification call
1142                                  * nonetheless, in case somebody is
1143                                  * waiting for this. */
1144                                 swap_set_state(swap, swap->state);
1145                                 break;
1146                         }
1147                 }
1148
1149                 /* Reset the flags for later calls */
1150                 swap->is_active = swap->just_activated = false;
1151         }
1152
1153         return 1;
1154 }
1155
1156 static Unit *swap_following(Unit *u) {
1157         Swap *s = SWAP(u);
1158         Swap *other, *first = NULL;
1159
1160         assert(s);
1161
1162         if (streq_ptr(s->what, s->parameters_proc_swaps.what))
1163                 return NULL;
1164
1165         /* Make everybody follow the unit that's named after the swap
1166          * device in the kernel */
1167
1168         LIST_FOREACH_AFTER(same_proc_swaps, other, s)
1169                 if (streq_ptr(other->what, other->parameters_proc_swaps.what))
1170                         return UNIT(other);
1171
1172         LIST_FOREACH_BEFORE(same_proc_swaps, other, s) {
1173                 if (streq_ptr(other->what, other->parameters_proc_swaps.what))
1174                         return UNIT(other);
1175
1176                 first = other;
1177         }
1178
1179         return UNIT(first);
1180 }
1181
1182 static int swap_following_set(Unit *u, Set **_set) {
1183         Swap *s = SWAP(u);
1184         Swap *other;
1185         Set *set;
1186         int r;
1187
1188         assert(s);
1189         assert(_set);
1190
1191         if (LIST_JUST_US(same_proc_swaps, s)) {
1192                 *_set = NULL;
1193                 return 0;
1194         }
1195
1196         if (!(set = set_new(NULL, NULL)))
1197                 return -ENOMEM;
1198
1199         LIST_FOREACH_AFTER(same_proc_swaps, other, s)
1200                 if ((r = set_put(set, other)) < 0)
1201                         goto fail;
1202
1203         LIST_FOREACH_BEFORE(same_proc_swaps, other, s)
1204                 if ((r = set_put(set, other)) < 0)
1205                         goto fail;
1206
1207         *_set = set;
1208         return 1;
1209
1210 fail:
1211         set_free(set);
1212         return r;
1213 }
1214
1215 static void swap_shutdown(Manager *m) {
1216         assert(m);
1217
1218         if (m->proc_swaps) {
1219                 fclose(m->proc_swaps);
1220                 m->proc_swaps = NULL;
1221         }
1222
1223         hashmap_free(m->swaps_by_proc_swaps);
1224         m->swaps_by_proc_swaps = NULL;
1225 }
1226
1227 static int swap_enumerate(Manager *m) {
1228         int r;
1229         struct epoll_event ev;
1230         assert(m);
1231
1232         if (!m->proc_swaps) {
1233                 if (!(m->proc_swaps = fopen("/proc/swaps", "re")))
1234                         return -errno;
1235
1236                 m->swap_watch.type = WATCH_SWAP;
1237                 m->swap_watch.fd = fileno(m->proc_swaps);
1238
1239                 zero(ev);
1240                 ev.events = EPOLLPRI;
1241                 ev.data.ptr = &m->swap_watch;
1242
1243                 if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->swap_watch.fd, &ev) < 0)
1244                         return -errno;
1245         }
1246
1247         /* We rely on mount.c to load /etc/fstab for us */
1248
1249         if ((r = swap_load_proc_swaps(m, false)) < 0)
1250                 swap_shutdown(m);
1251
1252         return r;
1253 }
1254
1255 static void swap_reset_failed(Unit *u) {
1256         Swap *s = SWAP(u);
1257
1258         assert(s);
1259
1260         if (s->state == SWAP_FAILED)
1261                 swap_set_state(s, SWAP_DEAD);
1262
1263         s->failure = false;
1264 }
1265
1266 static int swap_kill(Unit *u, KillWho who, KillMode mode, int signo, DBusError *error) {
1267         Swap *s = SWAP(u);
1268         int r = 0;
1269         Set *pid_set = NULL;
1270
1271         assert(s);
1272
1273         if (who == KILL_MAIN) {
1274                 dbus_set_error(error, BUS_ERROR_NO_SUCH_PROCESS, "Swap units have no main processes");
1275                 return -EINVAL;
1276         }
1277
1278         if (s->control_pid <= 0 && who == KILL_CONTROL) {
1279                 dbus_set_error(error, BUS_ERROR_NO_SUCH_PROCESS, "No control process to kill");
1280                 return -ENOENT;
1281         }
1282
1283         if (s->control_pid > 0)
1284                 if (kill(mode == KILL_PROCESS_GROUP ? -s->control_pid : s->control_pid, signo) < 0)
1285                         r = -errno;
1286
1287         if (mode == KILL_CONTROL_GROUP) {
1288                 int q;
1289
1290                 if (!(pid_set = set_new(trivial_hash_func, trivial_compare_func)))
1291                         return -ENOMEM;
1292
1293                 /* Exclude the control pid from being killed via the cgroup */
1294                 if (s->control_pid > 0)
1295                         if ((q = set_put(pid_set, LONG_TO_PTR(s->control_pid))) < 0) {
1296                                 r = q;
1297                                 goto finish;
1298                         }
1299
1300                 if ((q = cgroup_bonding_kill_list(s->meta.cgroup_bondings, signo, pid_set)) < 0)
1301                         if (r != -EAGAIN && r != -ESRCH && r != -ENOENT)
1302                                 r = q;
1303         }
1304
1305 finish:
1306         if (pid_set)
1307                 set_free(pid_set);
1308
1309         return r;
1310 }
1311
1312 static const char* const swap_state_table[_SWAP_STATE_MAX] = {
1313         [SWAP_DEAD] = "dead",
1314         [SWAP_ACTIVATING] = "activating",
1315         [SWAP_ACTIVE] = "active",
1316         [SWAP_DEACTIVATING] = "deactivating",
1317         [SWAP_ACTIVATING_SIGTERM] = "activating-sigterm",
1318         [SWAP_ACTIVATING_SIGKILL] = "activating-sigkill",
1319         [SWAP_DEACTIVATING_SIGTERM] = "deactivating-sigterm",
1320         [SWAP_DEACTIVATING_SIGKILL] = "deactivating-sigkill",
1321         [SWAP_FAILED] = "failed"
1322 };
1323
1324 DEFINE_STRING_TABLE_LOOKUP(swap_state, SwapState);
1325
1326 static const char* const swap_exec_command_table[_SWAP_EXEC_COMMAND_MAX] = {
1327         [SWAP_EXEC_ACTIVATE] = "ExecActivate",
1328         [SWAP_EXEC_DEACTIVATE] = "ExecDeactivate",
1329 };
1330
1331 DEFINE_STRING_TABLE_LOOKUP(swap_exec_command, SwapExecCommand);
1332
1333 const UnitVTable swap_vtable = {
1334         .suffix = ".swap",
1335
1336         .no_alias = true,
1337         .no_instances = true,
1338         .no_isolate = true,
1339         .show_status = true,
1340
1341         .init = swap_init,
1342         .load = swap_load,
1343         .done = swap_done,
1344
1345         .coldplug = swap_coldplug,
1346
1347         .dump = swap_dump,
1348
1349         .start = swap_start,
1350         .stop = swap_stop,
1351
1352         .kill = swap_kill,
1353
1354         .serialize = swap_serialize,
1355         .deserialize_item = swap_deserialize_item,
1356
1357         .active_state = swap_active_state,
1358         .sub_state_to_string = swap_sub_state_to_string,
1359
1360         .check_gc = swap_check_gc,
1361
1362         .sigchld_event = swap_sigchld_event,
1363         .timer_event = swap_timer_event,
1364
1365         .reset_failed = swap_reset_failed,
1366
1367         .bus_interface = "org.freedesktop.systemd1.Swap",
1368         .bus_message_handler = bus_swap_message_handler,
1369         .bus_invalidating_properties =  bus_swap_invalidating_properties,
1370
1371         .following = swap_following,
1372         .following_set = swap_following_set,
1373
1374         .enumerate = swap_enumerate,
1375         .shutdown = swap_shutdown
1376 };