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