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         s->exec_context.std_output = EXEC_OUTPUT_KMSG;
  86
  87         s->parameters_etc_fstab.priority = s->parameters_proc_swaps.priority = s->parameters_fragment.priority = -1;
  88
  89         s->timer_watch.type = WATCH_INVALID;
  90
  91         s->control_command_id = _MOUNT_EXEC_COMMAND_INVALID;
  92 }
  93
  94 static void swap_unwatch_control_pid(Swap *s) {
  95         assert(s);
  96
  97         if (s->control_pid <= 0)
  98                 return;
  99
 100         unit_unwatch_pid(UNIT(s), s->control_pid);
 101         s->control_pid = 0;
 102 }
 103
 104 static void swap_done(Unit *u) {
 105         Swap *s = SWAP(u);
 106
 107         assert(s);
 108
 109         swap_unset_proc_swaps(s);
 110
 111         free(s->what);
 112         s->what = NULL;
 113
 114         free(s->parameters_etc_fstab.what);
 115         free(s->parameters_fragment.what);
 116         s->parameters_etc_fstab.what = s->parameters_fragment.what = NULL;
 117
 118         exec_context_done(&s->exec_context);
 119         exec_command_done_array(s->exec_command, _SWAP_EXEC_COMMAND_MAX);
 120         s->control_command = NULL;
 121
 122         swap_unwatch_control_pid(s);
 123
 124         unit_unwatch_timer(u, &s->timer_watch);
 125 }
 126
 127 int swap_add_one_mount_link(Swap *s, Mount *m) {
 128          int r;
 129
 130         assert(s);
 131         assert(m);
 132
 133         if (s->meta.load_state != UNIT_LOADED ||
 134             m->meta.load_state != UNIT_LOADED)
 135                 return 0;
 136
 137         if (is_device_path(s->what))
 138                 return 0;
 139
 140         if (!path_startswith(s->what, m->where))
 141                 return 0;
 142
 143         if ((r = unit_add_two_dependencies(UNIT(s), UNIT_AFTER, UNIT_REQUIRES, UNIT(m), true)) < 0)
 144                 return r;
 145
 146         return 0;
 147 }
 148
 149 static int swap_add_mount_links(Swap *s) {
 150         Meta *other;
 151         int r;
 152
 153         assert(s);
 154
 155         LIST_FOREACH(units_per_type, other, s->meta.manager->units_per_type[UNIT_MOUNT])
 156                 if ((r = swap_add_one_mount_link(s, (Mount*) other)) < 0)
 157                         return r;
 158
 159         return 0;
 160 }
 161
 162 static int swap_add_target_links(Swap *s) {
 163         Unit *tu;
 164         SwapParameters *p;
 165         int r;
 166
 167         assert(s);
 168
 169         if (s->from_fragment)
 170                 p = &s->parameters_fragment;
 171         else if (s->from_etc_fstab)
 172                 p = &s->parameters_etc_fstab;
 173         else
 174                 return 0;
 175
 176         if ((r = manager_load_unit(s->meta.manager, SPECIAL_SWAP_TARGET, NULL, NULL, &tu)) < 0)
 177                 return r;
 178
 179         if (!p->noauto &&
 180             (p->handle || s->meta.manager->swap_auto) &&
 181             s->from_etc_fstab &&
 182             s->meta.manager->running_as == MANAGER_SYSTEM)
 183                 if ((r = unit_add_dependency(tu, UNIT_WANTS, UNIT(s), true)) < 0)
 184                         return r;
 185
 186         return unit_add_dependency(UNIT(s), UNIT_BEFORE, tu, true);
 187 }
 188
 189 static int swap_add_device_links(Swap *s) {
 190         SwapParameters *p;
 191
 192         assert(s);
 193
 194         if (!s->what)
 195                 return 0;
 196
 197         if (s->from_fragment)
 198                 p = &s->parameters_fragment;
 199         else if (s->from_etc_fstab)
 200                 p = &s->parameters_etc_fstab;
 201         else
 202                 return 0;
 203
 204         if (is_device_path(s->what))
 205                 return unit_add_node_link(UNIT(s), s->what,
 206                                           !p->noauto && p->nofail &&
 207                                           s->meta.manager->running_as == MANAGER_SYSTEM);
 208         else
 209                 /* File based swap devices need to be ordered after
 210                  * remount-rootfs.service, since they might need a
 211                  * writable file system. */
 212                 return unit_add_dependency_by_name(UNIT(s), UNIT_AFTER, SPECIAL_REMOUNT_ROOTFS_SERVICE, NULL, true);
 213 }
 214
 215 static int swap_add_default_dependencies(Swap *s) {
 216         int r;
 217
 218         assert(s);
 219
 220         if (s->meta.manager->running_as == MANAGER_SYSTEM) {
 221
 222                 if ((r = unit_add_two_dependencies_by_name(UNIT(s), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_UMOUNT_TARGET, NULL, true)) < 0)
 223                         return r;
 224         }
 225
 226         return 0;
 227 }
 228
 229 static int swap_verify(Swap *s) {
 230         bool b;
 231         char *e;
 232
 233         if (s->meta.load_state != UNIT_LOADED)
 234                   return 0;
 235
 236         if (!(e = unit_name_from_path(s->what, ".swap")))
 237                   return -ENOMEM;
 238
 239         b = unit_has_name(UNIT(s), e);
 240         free(e);
 241
 242         if (!b) {
 243                 log_error("%s: Value of \"What\" and unit name do not match, not loading.\n", s->meta.id);
 244                 return -EINVAL;
 245         }
 246
 247         if (s->exec_context.pam_name && s->exec_context.kill_mode != KILL_CONTROL_GROUP) {
 248                 log_error("%s has PAM enabled. Kill mode must be set to 'control-group'. Refusing.", s->meta.id);
 249                 return -EINVAL;
 250         }
 251
 252         return 0;
 253 }
 254
 255 static int swap_load(Unit *u) {
 256         int r;
 257         Swap *s = SWAP(u);
 258
 259         assert(s);
 260         assert(u->meta.load_state == UNIT_STUB);
 261
 262         /* Load a .swap file */
 263         if ((r = unit_load_fragment_and_dropin_optional(u)) < 0)
 264                 return r;
 265
 266         if (u->meta.load_state == UNIT_LOADED) {
 267                 if ((r = unit_add_exec_dependencies(u, &s->exec_context)) < 0)
 268                         return r;
 269
 270                 if (s->meta.fragment_path)
 271                         s->from_fragment = true;
 272
 273                 if (!s->what) {
 274                         if (s->parameters_fragment.what)
 275                                 s->what = strdup(s->parameters_fragment.what);
 276                         else if (s->parameters_etc_fstab.what)
 277                                 s->what = strdup(s->parameters_etc_fstab.what);
 278                         else if (s->parameters_proc_swaps.what)
 279                                 s->what = strdup(s->parameters_proc_swaps.what);
 280                         else
 281                                 s->what = unit_name_to_path(u->meta.id);
 282
 283                         if (!s->what)
 284                                 return -ENOMEM;
 285                 }
 286
 287                 path_kill_slashes(s->what);
 288
 289                 if (!s->meta.description)
 290                         if ((r = unit_set_description(u, s->what)) < 0)
 291                                 return r;
 292
 293                 if ((r = swap_add_device_links(s)) < 0)
 294                         return r;
 295
 296                 if ((r = swap_add_mount_links(s)) < 0)
 297                         return r;
 298
 299                 if ((r = swap_add_target_links(s)) < 0)
 300                         return r;
 301
 302                 if ((r = unit_add_default_cgroups(u)) < 0)
 303                         return r;
 304
 305                 if (s->meta.default_dependencies)
 306                         if ((r = swap_add_default_dependencies(s)) < 0)
 307                                 return r;
 308         }
 309
 310         return swap_verify(s);
 311 }
 312
 313 int swap_add_one(
 314                 Manager *m,
 315                 const char *what,
 316                 const char *what_proc_swaps,
 317                 int priority,
 318                 bool noauto,
 319                 bool nofail,
 320                 bool handle,
 321                 bool set_flags) {
 322
 323         Unit *u = NULL;
 324         char *e = NULL, *wp = NULL;
 325         bool delete = false;
 326         int r;
 327         SwapParameters *p;
 328
 329         assert(m);
 330         assert(what);
 331
 332         if (!(e = unit_name_from_path(what, ".swap")))
 333                 return -ENOMEM;
 334
 335         u = manager_get_unit(m, e);
 336
 337         if (what_proc_swaps &&
 338             u &&
 339             SWAP(u)->from_proc_swaps &&
 340             !path_equal(SWAP(u)->parameters_proc_swaps.what, what_proc_swaps))
 341                 return -EEXIST;
 342
 343         if (!u) {
 344                 delete = true;
 345
 346                 if (!(u = unit_new(m))) {
 347                         free(e);
 348                         return -ENOMEM;
 349                 }
 350
 351                 if ((r = unit_add_name(u, e)) < 0)
 352                         goto fail;
 353
 354                 if (!(SWAP(u)->what = strdup(what))) {
 355                         r = -ENOMEM;
 356                         goto fail;
 357                 }
 358
 359                 unit_add_to_load_queue(u);
 360         } else
 361                 delete = false;
 362
 363         if (what_proc_swaps) {
 364                 Swap *first;
 365
 366                 p = &SWAP(u)->parameters_proc_swaps;
 367
 368                 if (!p->what) {
 369                         if (!(wp = strdup(what_proc_swaps))) {
 370                                 r = -ENOMEM;
 371                                 goto fail;
 372                         }
 373
 374                         if (!m->swaps_by_proc_swaps)
 375                                 if (!(m->swaps_by_proc_swaps = hashmap_new(string_hash_func, string_compare_func))) {
 376                                         r = -ENOMEM;
 377                                         goto fail;
 378                                 }
 379
 380                         free(p->what);
 381                         p->what = wp;
 382
 383                         first = hashmap_get(m->swaps_by_proc_swaps, wp);
 384                         LIST_PREPEND(Swap, same_proc_swaps, first, SWAP(u));
 385
 386                         if ((r = hashmap_replace(m->swaps_by_proc_swaps, wp, first)) < 0)
 387                                 goto fail;
 388                 }
 389
 390                 if (set_flags) {
 391                         SWAP(u)->is_active = true;
 392                         SWAP(u)->just_activated = !SWAP(u)->from_proc_swaps;
 393                 }
 394
 395                 SWAP(u)->from_proc_swaps = true;
 396
 397         } else {
 398                 p = &SWAP(u)->parameters_etc_fstab;
 399
 400                 if (!(wp = strdup(what))) {
 401                         r = -ENOMEM;
 402                         goto fail;
 403                 }
 404
 405                 free(p->what);
 406                 p->what = wp;
 407
 408                 SWAP(u)->from_etc_fstab = true;
 409         }
 410
 411         p->priority = priority;
 412         p->noauto = noauto;
 413         p->nofail = nofail;
 414         p->handle = handle;
 415
 416         unit_add_to_dbus_queue(u);
 417
 418         free(e);
 419
 420         return 0;
 421
 422 fail:
 423         log_warning("Failed to load swap unit: %s", strerror(-r));
 424
 425         free(wp);
 426         free(e);
 427
 428         if (delete && u)
 429                 unit_free(u);
 430
 431         return r;
 432 }
 433
 434 static int swap_process_new_swap(Manager *m, const char *device, int prio, bool set_flags) {
 435         struct stat st;
 436         int r = 0, k;
 437
 438         assert(m);
 439
 440         if (stat(device, &st) >= 0 && S_ISBLK(st.st_mode)) {
 441                 struct udev_device *d;
 442                 const char *dn;
 443                 struct udev_list_entry *item = NULL, *first = NULL;
 444
 445                 /* So this is a proper swap device. Create swap units
 446                  * for all names this swap device is known under */
 447
 448                 if (!(d = udev_device_new_from_devnum(m->udev, 'b', st.st_rdev)))
 449                         return -ENOMEM;
 450
 451                 if ((dn = udev_device_get_devnode(d)))
 452                         r = swap_add_one(m, dn, device, prio, false, false, false, set_flags);
 453
 454                 /* Add additional units for all symlinks */
 455                 first = udev_device_get_devlinks_list_entry(d);
 456                 udev_list_entry_foreach(item, first) {
 457                         const char *p;
 458
 459                         /* Don't bother with the /dev/block links */
 460                         p = udev_list_entry_get_name(item);
 461
 462                         if (path_startswith(p, "/dev/block/"))
 463                                 continue;
 464
 465                         if (stat(p, &st) >= 0)
 466                                 if ((!S_ISBLK(st.st_mode)) || st.st_rdev != udev_device_get_devnum(d))
 467                                         continue;
 468
 469                         if ((k = swap_add_one(m, p, device, prio, false, false, false, set_flags)) < 0)
 470                                 r = k;
 471                 }
 472
 473                 udev_device_unref(d);
 474         }
 475
 476         if ((k = swap_add_one(m, device, device, prio, false, false, false, set_flags)) < 0)
 477                 r = k;
 478
 479         return r;
 480 }
 481
 482 static void swap_set_state(Swap *s, SwapState state) {
 483         SwapState old_state;
 484
 485         assert(s);
 486
 487         old_state = s->state;
 488         s->state = state;
 489
 490         if (state != SWAP_ACTIVATING &&
 491             state != SWAP_ACTIVATING_SIGTERM &&
 492             state != SWAP_ACTIVATING_SIGKILL &&
 493             state != SWAP_DEACTIVATING &&
 494             state != SWAP_DEACTIVATING_SIGTERM &&
 495             state != SWAP_DEACTIVATING_SIGKILL) {
 496                 unit_unwatch_timer(UNIT(s), &s->timer_watch);
 497                 swap_unwatch_control_pid(s);
 498                 s->control_command = NULL;
 499                 s->control_command_id = _SWAP_EXEC_COMMAND_INVALID;
 500         }
 501
 502         if (state != old_state)
 503                 log_debug("%s changed %s -> %s",
 504                           s->meta.id,
 505                           swap_state_to_string(old_state),
 506                           swap_state_to_string(state));
 507
 508         unit_notify(UNIT(s), state_translation_table[old_state], state_translation_table[state], true);
 509 }
 510
 511 static int swap_coldplug(Unit *u) {
 512         Swap *s = SWAP(u);
 513         SwapState new_state = SWAP_DEAD;
 514         int r;
 515
 516         assert(s);
 517         assert(s->state == SWAP_DEAD);
 518
 519         if (s->deserialized_state != s->state)
 520                 new_state = s->deserialized_state;
 521         else if (s->from_proc_swaps)
 522                 new_state = SWAP_ACTIVE;
 523
 524         if (new_state != s->state) {
 525
 526                 if (new_state == SWAP_ACTIVATING ||
 527                     new_state == SWAP_ACTIVATING_SIGTERM ||
 528                     new_state == SWAP_ACTIVATING_SIGKILL ||
 529                     new_state == SWAP_DEACTIVATING ||
 530                     new_state == SWAP_DEACTIVATING_SIGTERM ||
 531                     new_state == SWAP_DEACTIVATING_SIGKILL) {
 532
 533                         if (s->control_pid <= 0)
 534                                 return -EBADMSG;
 535
 536                         if ((r = unit_watch_pid(UNIT(s), s->control_pid)) < 0)
 537                                 return r;
 538
 539                         if ((r = unit_watch_timer(UNIT(s), s->timeout_usec, &s->timer_watch)) < 0)
 540                                 return r;
 541                 }
 542
 543                 swap_set_state(s, new_state);
 544         }
 545
 546         return 0;
 547 }
 548
 549 static void swap_dump(Unit *u, FILE *f, const char *prefix) {
 550         Swap *s = SWAP(u);
 551         SwapParameters *p;
 552
 553         assert(s);
 554         assert(f);
 555
 556         if (s->from_proc_swaps)
 557                 p = &s->parameters_proc_swaps;
 558         else if (s->from_fragment)
 559                 p = &s->parameters_fragment;
 560         else
 561                 p = &s->parameters_etc_fstab;
 562
 563         fprintf(f,
 564                 "%sSwap State: %s\n"
 565                 "%sWhat: %s\n"
 566                 "%sPriority: %i\n"
 567                 "%sNoAuto: %s\n"
 568                 "%sNoFail: %s\n"
 569                 "%sHandle: %s\n"
 570                 "%sFrom /etc/fstab: %s\n"
 571                 "%sFrom /proc/swaps: %s\n"
 572                 "%sFrom fragment: %s\n",
 573                 prefix, swap_state_to_string(s->state),
 574                 prefix, s->what,
 575                 prefix, p->priority,
 576                 prefix, yes_no(p->noauto),
 577                 prefix, yes_no(p->nofail),
 578                 prefix, yes_no(p->handle),
 579                 prefix, yes_no(s->from_etc_fstab),
 580                 prefix, yes_no(s->from_proc_swaps),
 581                 prefix, yes_no(s->from_fragment));
 582
 583         if (s->control_pid > 0)
 584                 fprintf(f,
 585                         "%sControl PID: %lu\n",
 586                         prefix, (unsigned long) s->control_pid);
 587
 588         exec_context_dump(&s->exec_context, f, prefix);
 589 }
 590
 591 static int swap_spawn(Swap *s, ExecCommand *c, pid_t *_pid) {
 592         pid_t pid;
 593         int r;
 594
 595         assert(s);
 596         assert(c);
 597         assert(_pid);
 598
 599         if ((r = unit_watch_timer(UNIT(s), s->timeout_usec, &s->timer_watch)) < 0)
 600                 goto fail;
 601
 602         if ((r = exec_spawn(c,
 603                             NULL,
 604                             &s->exec_context,
 605                             NULL, 0,
 606                             s->meta.manager->environment,
 607                             true,
 608                             true,
 609                             true,
 610                             s->meta.manager->confirm_spawn,
 611                             s->meta.cgroup_bondings,
 612                             &pid)) < 0)
 613                 goto fail;
 614
 615         if ((r = unit_watch_pid(UNIT(s), pid)) < 0)
 616                 /* FIXME: we need to do something here */
 617                 goto fail;
 618
 619         *_pid = pid;
 620
 621         return 0;
 622
 623 fail:
 624         unit_unwatch_timer(UNIT(s), &s->timer_watch);
 625
 626         return r;
 627 }
 628
 629 static void swap_enter_dead(Swap *s, bool success) {
 630         assert(s);
 631
 632         if (!success)
 633                 s->failure = true;
 634
 635         swap_set_state(s, s->failure ? SWAP_FAILED : SWAP_DEAD);
 636 }
 637
 638 static void swap_enter_active(Swap *s, bool success) {
 639         assert(s);
 640
 641         if (!success)
 642                 s->failure = true;
 643
 644         swap_set_state(s, SWAP_ACTIVE);
 645 }
 646
 647 static void swap_enter_signal(Swap *s, SwapState state, bool success) {
 648         int r;
 649         Set *pid_set = NULL;
 650         bool wait_for_exit = false;
 651
 652         assert(s);
 653
 654         if (!success)
 655                 s->failure = true;
 656
 657         if (s->exec_context.kill_mode != KILL_NONE) {
 658                 int sig = (state == SWAP_ACTIVATING_SIGTERM ||
 659                            state == SWAP_DEACTIVATING_SIGTERM) ? s->exec_context.kill_signal : SIGKILL;
 660
 661                 if (s->control_pid > 0) {
 662                         if (kill(s->exec_context.kill_mode == KILL_PROCESS_GROUP ?
 663                                  -s->control_pid :
 664                                  s->control_pid, sig) < 0 && errno != ESRCH)
 665
 666                                 log_warning("Failed to kill control process %li: %m", (long) s->control_pid);
 667                         else
 668                                 wait_for_exit = true;
 669                 }
 670
 671                 if (s->exec_context.kill_mode == KILL_CONTROL_GROUP) {
 672
 673                         if (!(pid_set = set_new(trivial_hash_func, trivial_compare_func))) {
 674                                 r = -ENOMEM;
 675                                 goto fail;
 676                         }
 677
 678                         /* Exclude the control pid from being killed via the cgroup */
 679                         if (s->control_pid > 0)
 680                                 if ((r = set_put(pid_set, LONG_TO_PTR(s->control_pid))) < 0)
 681                                         goto fail;
 682
 683                         if ((r = cgroup_bonding_kill_list(s->meta.cgroup_bondings, sig, pid_set)) < 0) {
 684                                 if (r != -EAGAIN && r != -ESRCH && r != -ENOENT)
 685                                         log_warning("Failed to kill control group: %s", strerror(-r));
 686                         } else if (r > 0)
 687                                 wait_for_exit = true;
 688
 689                         set_free(pid_set);
 690                 }
 691         }
 692
 693         if (wait_for_exit) {
 694                 if ((r = unit_watch_timer(UNIT(s), s->timeout_usec, &s->timer_watch)) < 0)
 695                         goto fail;
 696
 697                 swap_set_state(s, state);
 698         } else
 699                 swap_enter_dead(s, true);
 700
 701         return;
 702
 703 fail:
 704         log_warning("%s failed to kill processes: %s", s->meta.id, strerror(-r));
 705
 706         swap_enter_dead(s, false);
 707
 708         if (pid_set)
 709                 set_free(pid_set);
 710 }
 711
 712 static void swap_enter_activating(Swap *s) {
 713         int r, priority;
 714
 715         assert(s);
 716
 717         s->control_command_id = SWAP_EXEC_ACTIVATE;
 718         s->control_command = s->exec_command + SWAP_EXEC_ACTIVATE;
 719
 720         if (s->from_fragment)
 721                 priority = s->parameters_fragment.priority;
 722         else if (s->from_etc_fstab)
 723                 priority = s->parameters_etc_fstab.priority;
 724         else
 725                 priority = -1;
 726
 727         if (priority >= 0) {
 728                 char p[LINE_MAX];
 729
 730                 snprintf(p, sizeof(p), "%i", priority);
 731                 char_array_0(p);
 732
 733                 r = exec_command_set(
 734                                 s->control_command,
 735                                 "/sbin/swapon",
 736                                 "-p",
 737                                 p,
 738                                 s->what,
 739                                 NULL);
 740         } else
 741                 r = exec_command_set(
 742                                 s->control_command,
 743                                 "/sbin/swapon",
 744                                 s->what,
 745                                 NULL);
 746
 747         if (r < 0)
 748                 goto fail;
 749
 750         swap_unwatch_control_pid(s);
 751
 752         if ((r = swap_spawn(s, s->control_command, &s->control_pid)) < 0)
 753                 goto fail;
 754
 755         swap_set_state(s, SWAP_ACTIVATING);
 756
 757         return;
 758
 759 fail:
 760         log_warning("%s failed to run 'swapon' task: %s", s->meta.id, strerror(-r));
 761         swap_enter_dead(s, false);
 762 }
 763
 764 static void swap_enter_deactivating(Swap *s, bool success) {
 765         int r;
 766
 767         assert(s);
 768
 769         if (!success)
 770                 s->failure = true;
 771
 772         s->control_command_id = SWAP_EXEC_DEACTIVATE;
 773         s->control_command = s->exec_command + SWAP_EXEC_DEACTIVATE;
 774
 775         if ((r = exec_command_set(
 776                              s->control_command,
 777                              "/sbin/swapoff",
 778                              s->what,
 779                              NULL)) < 0)
 780                 goto fail;
 781
 782         swap_unwatch_control_pid(s);
 783
 784         if ((r = swap_spawn(s, s->control_command, &s->control_pid)) < 0)
 785                 goto fail;
 786
 787         swap_set_state(s, SWAP_DEACTIVATING);
 788
 789         return;
 790
 791 fail:
 792         log_warning("%s failed to run 'swapoff' task: %s", s->meta.id, strerror(-r));
 793         swap_enter_active(s, false);
 794 }
 795
 796 static int swap_start(Unit *u) {
 797         Swap *s = SWAP(u);
 798
 799         assert(s);
 800
 801         /* We cannot fulfill this request right now, try again later
 802          * please! */
 803
 804         if (s->state == SWAP_DEACTIVATING ||
 805             s->state == SWAP_DEACTIVATING_SIGTERM ||
 806             s->state == SWAP_DEACTIVATING_SIGKILL ||
 807             s->state == SWAP_ACTIVATING_SIGTERM ||
 808             s->state == SWAP_ACTIVATING_SIGKILL)
 809                 return -EAGAIN;
 810
 811         if (s->state == SWAP_ACTIVATING)
 812                 return 0;
 813
 814         assert(s->state == SWAP_DEAD || s->state == SWAP_FAILED);
 815
 816         s->failure = false;
 817         swap_enter_activating(s);
 818         return 0;
 819 }
 820
 821 static int swap_stop(Unit *u) {
 822         Swap *s = SWAP(u);
 823
 824         assert(s);
 825
 826         if (s->state == SWAP_DEACTIVATING ||
 827             s->state == SWAP_DEACTIVATING_SIGTERM ||
 828             s->state == SWAP_DEACTIVATING_SIGKILL ||
 829             s->state == SWAP_ACTIVATING_SIGTERM ||
 830             s->state == SWAP_ACTIVATING_SIGKILL)
 831                 return 0;
 832
 833         assert(s->state == SWAP_ACTIVATING ||
 834                s->state == SWAP_ACTIVE);
 835
 836         swap_enter_deactivating(s, true);
 837         return 0;
 838 }
 839
 840 static int swap_serialize(Unit *u, FILE *f, FDSet *fds) {
 841         Swap *s = SWAP(u);
 842
 843         assert(s);
 844         assert(f);
 845         assert(fds);
 846
 847         unit_serialize_item(u, f, "state", swap_state_to_string(s->state));
 848         unit_serialize_item(u, f, "failure", yes_no(s->failure));
 849
 850         if (s->control_pid > 0)
 851                 unit_serialize_item_format(u, f, "control-pid", "%lu", (unsigned long) s->control_pid);
 852
 853         if (s->control_command_id >= 0)
 854                 unit_serialize_item(u, f, "control-command", swap_exec_command_to_string(s->control_command_id));
 855
 856         return 0;
 857 }
 858
 859 static int swap_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 860         Swap *s = SWAP(u);
 861
 862         assert(s);
 863         assert(fds);
 864
 865         if (streq(key, "state")) {
 866                 SwapState state;
 867
 868                 if ((state = swap_state_from_string(value)) < 0)
 869                         log_debug("Failed to parse state value %s", value);
 870                 else
 871                         s->deserialized_state = state;
 872         } else if (streq(key, "failure")) {
 873                 int b;
 874
 875                 if ((b = parse_boolean(value)) < 0)
 876                         log_debug("Failed to parse failure value %s", value);
 877                 else
 878                         s->failure = b || s->failure;
 879
 880         } else if (streq(key, "control-pid")) {
 881                 pid_t pid;
 882
 883                 if (parse_pid(value, &pid) < 0)
 884                         log_debug("Failed to parse control-pid value %s", value);
 885                 else
 886                         s->control_pid = pid;
 887
 888         } else if (streq(key, "control-command")) {
 889                 SwapExecCommand id;
 890
 891                 if ((id = swap_exec_command_from_string(value)) < 0)
 892                         log_debug("Failed to parse exec-command value %s", value);
 893                 else {
 894                         s->control_command_id = id;
 895                         s->control_command = s->exec_command + id;
 896                 }
 897
 898         } else
 899                 log_debug("Unknown serialization key '%s'", key);
 900
 901         return 0;
 902 }
 903
 904 static UnitActiveState swap_active_state(Unit *u) {
 905         assert(u);
 906
 907         return state_translation_table[SWAP(u)->state];
 908 }
 909
 910 static const char *swap_sub_state_to_string(Unit *u) {
 911         assert(u);
 912
 913         return swap_state_to_string(SWAP(u)->state);
 914 }
 915
 916 static bool swap_check_gc(Unit *u) {
 917         Swap *s = SWAP(u);
 918
 919         assert(s);
 920
 921         return s->from_etc_fstab || s->from_proc_swaps;
 922 }
 923
 924 static void swap_sigchld_event(Unit *u, pid_t pid, int code, int status) {
 925         Swap *s = SWAP(u);
 926         bool success;
 927
 928         assert(s);
 929         assert(pid >= 0);
 930
 931         if (pid != s->control_pid)
 932                 return;
 933
 934         s->control_pid = 0;
 935
 936         success = is_clean_exit(code, status);
 937         s->failure = s->failure || !success;
 938
 939         if (s->control_command) {
 940                 exec_status_exit(&s->control_command->exec_status, pid, code, status, s->exec_context.utmp_id);
 941                 s->control_command = NULL;
 942                 s->control_command_id = _SWAP_EXEC_COMMAND_INVALID;
 943         }
 944
 945         log_full(success ? LOG_DEBUG : LOG_NOTICE,
 946                  "%s swap process exited, code=%s status=%i", u->meta.id, sigchld_code_to_string(code), status);
 947
 948         switch (s->state) {
 949
 950         case SWAP_ACTIVATING:
 951         case SWAP_ACTIVATING_SIGTERM:
 952         case SWAP_ACTIVATING_SIGKILL:
 953
 954                 if (success)
 955                         swap_enter_active(s, true);
 956                 else
 957                         swap_enter_dead(s, false);
 958                 break;
 959
 960         case SWAP_DEACTIVATING:
 961         case SWAP_DEACTIVATING_SIGKILL:
 962         case SWAP_DEACTIVATING_SIGTERM:
 963
 964                 if (success)
 965                         swap_enter_dead(s, true);
 966                 else
 967                         swap_enter_dead(s, false);
 968                 break;
 969
 970         default:
 971                 assert_not_reached("Uh, control process died at wrong time.");
 972         }
 973
 974         /* Notify clients about changed exit status */
 975         unit_add_to_dbus_queue(u);
 976
 977         /* Request a reload of /proc/swaps, so that following units
 978          * can follow our state change */
 979         u->meta.manager->request_reload = true;
 980 }
 981
 982 static void swap_timer_event(Unit *u, uint64_t elapsed, Watch *w) {
 983         Swap *s = SWAP(u);
 984
 985         assert(s);
 986         assert(elapsed == 1);
 987         assert(w == &s->timer_watch);
 988
 989         switch (s->state) {
 990
 991         case SWAP_ACTIVATING:
 992                 log_warning("%s activation timed out. Stopping.", u->meta.id);
 993                 swap_enter_signal(s, SWAP_ACTIVATING_SIGTERM, false);
 994                 break;
 995
 996         case SWAP_DEACTIVATING:
 997                 log_warning("%s deactivation timed out. Stopping.", u->meta.id);
 998                 swap_enter_signal(s, SWAP_DEACTIVATING_SIGTERM, false);
 999                 break;
1000
1001         case SWAP_ACTIVATING_SIGTERM:
1002                 if (s->exec_context.send_sigkill) {
1003                         log_warning("%s activation timed out. Killing.", u->meta.id);
1004                         swap_enter_signal(s, SWAP_ACTIVATING_SIGKILL, false);
1005                 } else {
1006                         log_warning("%s activation timed out. Skipping SIGKILL. Ignoring.", u->meta.id);
1007                         swap_enter_dead(s, false);
1008                 }
1009                 break;
1010
1011         case SWAP_DEACTIVATING_SIGTERM:
1012                 if (s->exec_context.send_sigkill) {
1013                         log_warning("%s deactivation timed out. Killing.", u->meta.id);
1014                         swap_enter_signal(s, SWAP_DEACTIVATING_SIGKILL, false);
1015                 } else {
1016                         log_warning("%s deactivation timed out. Skipping SIGKILL. Ignoring.", u->meta.id);
1017                         swap_enter_dead(s, false);
1018                 }
1019                 break;
1020
1021         case SWAP_ACTIVATING_SIGKILL:
1022         case SWAP_DEACTIVATING_SIGKILL:
1023                 log_warning("%s swap process still around after SIGKILL. Ignoring.", u->meta.id);
1024                 swap_enter_dead(s, false);
1025                 break;
1026
1027         default:
1028                 assert_not_reached("Timeout at wrong time.");
1029         }
1030 }
1031
1032 static int swap_load_proc_swaps(Manager *m, bool set_flags) {
1033         unsigned i;
1034         int r = 0;
1035
1036         assert(m);
1037
1038         rewind(m->proc_swaps);
1039
1040         (void) fscanf(m->proc_swaps, "%*s %*s %*s %*s %*s\n");
1041
1042         for (i = 1;; i++) {
1043                 char *dev = NULL, *d;
1044                 int prio = 0, k;
1045
1046                 if ((k = fscanf(m->proc_swaps,
1047                                 "%ms "  /* device/file */
1048                                 "%*s "  /* type of swap */
1049                                 "%*s "  /* swap size */
1050                                 "%*s "  /* used */
1051                                 "%i\n", /* priority */
1052                                 &dev, &prio)) != 2) {
1053
1054                         if (k == EOF)
1055                                 break;
1056
1057                         log_warning("Failed to parse /proc/swaps:%u.", i);
1058                         free(dev);
1059                         continue;
1060                 }
1061
1062                 d = cunescape(dev);
1063                 free(dev);
1064
1065                 if (!d)
1066                         return -ENOMEM;
1067
1068                 k = swap_process_new_swap(m, d, prio, set_flags);
1069                 free(d);
1070
1071                 if (k < 0)
1072                         r = k;
1073         }
1074
1075         return r;
1076 }
1077
1078 int swap_dispatch_reload(Manager *m) {
1079         /* This function should go as soon as the kernel properly notifies us */
1080
1081         if (_likely_(!m->request_reload))
1082                 return 0;
1083
1084         m->request_reload = false;
1085
1086         return swap_fd_event(m, EPOLLPRI);
1087 }
1088
1089 int swap_fd_event(Manager *m, int events) {
1090         Meta *meta;
1091         int r;
1092
1093         assert(m);
1094         assert(events & EPOLLPRI);
1095
1096         if ((r = swap_load_proc_swaps(m, true)) < 0) {
1097                 log_error("Failed to reread /proc/swaps: %s", strerror(-r));
1098
1099                 /* Reset flags, just in case, for late calls */
1100                 LIST_FOREACH(units_per_type, meta, m->units_per_type[UNIT_SWAP]) {
1101                         Swap *swap = (Swap*) meta;
1102
1103                         swap->is_active = swap->just_activated = false;
1104                 }
1105
1106                 return 0;
1107         }
1108
1109         manager_dispatch_load_queue(m);
1110
1111         LIST_FOREACH(units_per_type, meta, m->units_per_type[UNIT_SWAP]) {
1112                 Swap *swap = (Swap*) meta;
1113
1114                 if (!swap->is_active) {
1115                         /* This has just been deactivated */
1116
1117                         swap->from_proc_swaps = false;
1118                         swap_unset_proc_swaps(swap);
1119
1120                         switch (swap->state) {
1121
1122                         case SWAP_ACTIVE:
1123                                 swap_enter_dead(swap, true);
1124                                 break;
1125
1126                         default:
1127                                 swap_set_state(swap, swap->state);
1128                                 break;
1129                         }
1130
1131                 } else if (swap->just_activated) {
1132
1133                         /* New swap entry */
1134
1135                         switch (swap->state) {
1136
1137                         case SWAP_DEAD:
1138                         case SWAP_FAILED:
1139                                 swap_enter_active(swap, true);
1140                                 break;
1141
1142                         default:
1143                                 /* Nothing really changed, but let's
1144                                  * issue an notification call
1145                                  * nonetheless, in case somebody is
1146                                  * waiting for this. */
1147                                 swap_set_state(swap, swap->state);
1148                                 break;
1149                         }
1150                 }
1151
1152                 /* Reset the flags for later calls */
1153                 swap->is_active = swap->just_activated = false;
1154         }
1155
1156         return 1;
1157 }
1158
1159 static Unit *swap_following(Unit *u) {
1160         Swap *s = SWAP(u);
1161         Swap *other, *first = NULL;
1162
1163         assert(s);
1164
1165         if (streq_ptr(s->what, s->parameters_proc_swaps.what))
1166                 return NULL;
1167
1168         /* Make everybody follow the unit that's named after the swap
1169          * device in the kernel */
1170
1171         LIST_FOREACH_AFTER(same_proc_swaps, other, s)
1172                 if (streq_ptr(other->what, other->parameters_proc_swaps.what))
1173                         return UNIT(other);
1174
1175         LIST_FOREACH_BEFORE(same_proc_swaps, other, s) {
1176                 if (streq_ptr(other->what, other->parameters_proc_swaps.what))
1177                         return UNIT(other);
1178
1179                 first = other;
1180         }
1181
1182         return UNIT(first);
1183 }
1184
1185 static int swap_following_set(Unit *u, Set **_set) {
1186         Swap *s = SWAP(u);
1187         Swap *other;
1188         Set *set;
1189         int r;
1190
1191         assert(s);
1192         assert(_set);
1193
1194         if (LIST_JUST_US(same_proc_swaps, s)) {
1195                 *_set = NULL;
1196                 return 0;
1197         }
1198
1199         if (!(set = set_new(NULL, NULL)))
1200                 return -ENOMEM;
1201
1202         LIST_FOREACH_AFTER(same_proc_swaps, other, s)
1203                 if ((r = set_put(set, other)) < 0)
1204                         goto fail;
1205
1206         LIST_FOREACH_BEFORE(same_proc_swaps, other, s)
1207                 if ((r = set_put(set, other)) < 0)
1208                         goto fail;
1209
1210         *_set = set;
1211         return 1;
1212
1213 fail:
1214         set_free(set);
1215         return r;
1216 }
1217
1218 static void swap_shutdown(Manager *m) {
1219         assert(m);
1220
1221         if (m->proc_swaps) {
1222                 fclose(m->proc_swaps);
1223                 m->proc_swaps = NULL;
1224         }
1225
1226         hashmap_free(m->swaps_by_proc_swaps);
1227         m->swaps_by_proc_swaps = NULL;
1228 }
1229
1230 static int swap_enumerate(Manager *m) {
1231         int r;
1232         struct epoll_event ev;
1233         assert(m);
1234
1235         if (!m->proc_swaps) {
1236                 if (!(m->proc_swaps = fopen("/proc/swaps", "re")))
1237                         return -errno;
1238
1239                 m->swap_watch.type = WATCH_SWAP;
1240                 m->swap_watch.fd = fileno(m->proc_swaps);
1241
1242                 zero(ev);
1243                 ev.events = EPOLLPRI;
1244                 ev.data.ptr = &m->swap_watch;
1245
1246                 if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->swap_watch.fd, &ev) < 0)
1247                         return -errno;
1248         }
1249
1250         /* We rely on mount.c to load /etc/fstab for us */
1251
1252         if ((r = swap_load_proc_swaps(m, false)) < 0)
1253                 swap_shutdown(m);
1254
1255         return r;
1256 }
1257
1258 static void swap_reset_failed(Unit *u) {
1259         Swap *s = SWAP(u);
1260
1261         assert(s);
1262
1263         if (s->state == SWAP_FAILED)
1264                 swap_set_state(s, SWAP_DEAD);
1265
1266         s->failure = false;
1267 }
1268
1269 static int swap_kill(Unit *u, KillWho who, KillMode mode, int signo, DBusError *error) {
1270         Swap *s = SWAP(u);
1271         int r = 0;
1272         Set *pid_set = NULL;
1273
1274         assert(s);
1275
1276         if (who == KILL_MAIN) {
1277                 dbus_set_error(error, BUS_ERROR_NO_SUCH_PROCESS, "Swap units have no main processes");
1278                 return -EINVAL;
1279         }
1280
1281         if (s->control_pid <= 0 && who == KILL_CONTROL) {
1282                 dbus_set_error(error, BUS_ERROR_NO_SUCH_PROCESS, "No control process to kill");
1283                 return -ENOENT;
1284         }
1285
1286         if (s->control_pid > 0)
1287                 if (kill(mode == KILL_PROCESS_GROUP ? -s->control_pid : s->control_pid, signo) < 0)
1288                         r = -errno;
1289
1290         if (mode == KILL_CONTROL_GROUP) {
1291                 int q;
1292
1293                 if (!(pid_set = set_new(trivial_hash_func, trivial_compare_func)))
1294                         return -ENOMEM;
1295
1296                 /* Exclude the control pid from being killed via the cgroup */
1297                 if (s->control_pid > 0)
1298                         if ((q = set_put(pid_set, LONG_TO_PTR(s->control_pid))) < 0) {
1299                                 r = q;
1300                                 goto finish;
1301                         }
1302
1303                 if ((q = cgroup_bonding_kill_list(s->meta.cgroup_bondings, signo, pid_set)) < 0)
1304                         if (r != -EAGAIN && r != -ESRCH && r != -ENOENT)
1305                                 r = q;
1306         }
1307
1308 finish:
1309         if (pid_set)
1310                 set_free(pid_set);
1311
1312         return r;
1313 }
1314
1315 static const char* const swap_state_table[_SWAP_STATE_MAX] = {
1316         [SWAP_DEAD] = "dead",
1317         [SWAP_ACTIVATING] = "activating",
1318         [SWAP_ACTIVE] = "active",
1319         [SWAP_DEACTIVATING] = "deactivating",
1320         [SWAP_ACTIVATING_SIGTERM] = "activating-sigterm",
1321         [SWAP_ACTIVATING_SIGKILL] = "activating-sigkill",
1322         [SWAP_DEACTIVATING_SIGTERM] = "deactivating-sigterm",
1323         [SWAP_DEACTIVATING_SIGKILL] = "deactivating-sigkill",
1324         [SWAP_FAILED] = "failed"
1325 };
1326
1327 DEFINE_STRING_TABLE_LOOKUP(swap_state, SwapState);
1328
1329 static const char* const swap_exec_command_table[_SWAP_EXEC_COMMAND_MAX] = {
1330         [SWAP_EXEC_ACTIVATE] = "ExecActivate",
1331         [SWAP_EXEC_DEACTIVATE] = "ExecDeactivate",
1332 };
1333
1334 DEFINE_STRING_TABLE_LOOKUP(swap_exec_command, SwapExecCommand);
1335
1336 const UnitVTable swap_vtable = {
1337         .suffix = ".swap",
1338
1339         .no_alias = true,
1340         .no_instances = true,
1341         .no_isolate = true,
1342         .show_status = true,
1343
1344         .init = swap_init,
1345         .load = swap_load,
1346         .done = swap_done,
1347
1348         .coldplug = swap_coldplug,
1349
1350         .dump = swap_dump,
1351
1352         .start = swap_start,
1353         .stop = swap_stop,
1354
1355         .kill = swap_kill,
1356
1357         .serialize = swap_serialize,
1358         .deserialize_item = swap_deserialize_item,
1359
1360         .active_state = swap_active_state,
1361         .sub_state_to_string = swap_sub_state_to_string,
1362
1363         .check_gc = swap_check_gc,
1364
1365         .sigchld_event = swap_sigchld_event,
1366         .timer_event = swap_timer_event,
1367
1368         .reset_failed = swap_reset_failed,
1369
1370         .bus_interface = "org.freedesktop.systemd1.Swap",
1371         .bus_message_handler = bus_swap_message_handler,
1372         .bus_invalidating_properties =  bus_swap_invalidating_properties,
1373
1374         .following = swap_following,
1375         .following_set = swap_following_set,
1376
1377         .enumerate = swap_enumerate,
1378         .shutdown = swap_shutdown
1379 };