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 #include "def.h"
  41
  42 static const UnitActiveState state_translation_table[_SWAP_STATE_MAX] = {
  43         [SWAP_DEAD] = UNIT_INACTIVE,
  44         [SWAP_ACTIVATING] = UNIT_ACTIVATING,
  45         [SWAP_ACTIVE] = UNIT_ACTIVE,
  46         [SWAP_DEACTIVATING] = UNIT_DEACTIVATING,
  47         [SWAP_ACTIVATING_SIGTERM] = UNIT_DEACTIVATING,
  48         [SWAP_ACTIVATING_SIGKILL] = UNIT_DEACTIVATING,
  49         [SWAP_DEACTIVATING_SIGTERM] = UNIT_DEACTIVATING,
  50         [SWAP_DEACTIVATING_SIGKILL] = UNIT_DEACTIVATING,
  51         [SWAP_FAILED] = UNIT_FAILED
  52 };
  53
  54 static void swap_unset_proc_swaps(Swap *s) {
  55         Swap *first;
  56
  57         assert(s);
  58
  59         if (!s->parameters_proc_swaps.what)
  60                 return;
  61
  62         /* Remove this unit from the chain of swaps which share the
  63          * same kernel swap device. */
  64
  65         first = hashmap_get(s->meta.manager->swaps_by_proc_swaps, s->parameters_proc_swaps.what);
  66         LIST_REMOVE(Swap, same_proc_swaps, first, s);
  67
  68         if (first)
  69                 hashmap_remove_and_replace(s->meta.manager->swaps_by_proc_swaps, s->parameters_proc_swaps.what, first->parameters_proc_swaps.what, first);
  70         else
  71                 hashmap_remove(s->meta.manager->swaps_by_proc_swaps, s->parameters_proc_swaps.what);
  72
  73         free(s->parameters_proc_swaps.what);
  74         s->parameters_proc_swaps.what = NULL;
  75 }
  76
  77  static void swap_init(Unit *u) {
  78         Swap *s = SWAP(u);
  79
  80         assert(s);
  81         assert(s->meta.load_state == UNIT_STUB);
  82
  83         s->timeout_usec = DEFAULT_TIMEOUT_USEC;
  84
  85         exec_context_init(&s->exec_context);
  86         s->exec_context.std_output = EXEC_OUTPUT_KMSG;
  87
  88         s->parameters_etc_fstab.priority = s->parameters_proc_swaps.priority = s->parameters_fragment.priority = -1;
  89
  90         s->timer_watch.type = WATCH_INVALID;
  91
  92         s->control_command_id = _MOUNT_EXEC_COMMAND_INVALID;
  93 }
  94
  95 static void swap_unwatch_control_pid(Swap *s) {
  96         assert(s);
  97
  98         if (s->control_pid <= 0)
  99                 return;
 100
 101         unit_unwatch_pid(UNIT(s), s->control_pid);
 102         s->control_pid = 0;
 103 }
 104
 105 static void swap_done(Unit *u) {
 106         Swap *s = SWAP(u);
 107
 108         assert(s);
 109
 110         swap_unset_proc_swaps(s);
 111
 112         free(s->what);
 113         s->what = NULL;
 114
 115         free(s->parameters_etc_fstab.what);
 116         free(s->parameters_fragment.what);
 117         s->parameters_etc_fstab.what = s->parameters_fragment.what = NULL;
 118
 119         exec_context_done(&s->exec_context);
 120         exec_command_done_array(s->exec_command, _SWAP_EXEC_COMMAND_MAX);
 121         s->control_command = NULL;
 122
 123         swap_unwatch_control_pid(s);
 124
 125         unit_unwatch_timer(u, &s->timer_watch);
 126 }
 127
 128 int swap_add_one_mount_link(Swap *s, Mount *m) {
 129          int r;
 130
 131         assert(s);
 132         assert(m);
 133
 134         if (s->meta.load_state != UNIT_LOADED ||
 135             m->meta.load_state != UNIT_LOADED)
 136                 return 0;
 137
 138         if (is_device_path(s->what))
 139                 return 0;
 140
 141         if (!path_startswith(s->what, m->where))
 142                 return 0;
 143
 144         if ((r = unit_add_two_dependencies(UNIT(s), UNIT_AFTER, UNIT_REQUIRES, UNIT(m), true)) < 0)
 145                 return r;
 146
 147         return 0;
 148 }
 149
 150 static int swap_add_mount_links(Swap *s) {
 151         Meta *other;
 152         int r;
 153
 154         assert(s);
 155
 156         LIST_FOREACH(units_per_type, other, s->meta.manager->units_per_type[UNIT_MOUNT])
 157                 if ((r = swap_add_one_mount_link(s, (Mount*) other)) < 0)
 158                         return r;
 159
 160         return 0;
 161 }
 162
 163 static int swap_add_target_links(Swap *s) {
 164         Unit *tu;
 165         SwapParameters *p;
 166         int r;
 167
 168         assert(s);
 169
 170         if (s->from_fragment)
 171                 p = &s->parameters_fragment;
 172         else if (s->from_etc_fstab)
 173                 p = &s->parameters_etc_fstab;
 174         else
 175                 return 0;
 176
 177         if ((r = manager_load_unit(s->meta.manager, SPECIAL_SWAP_TARGET, NULL, NULL, &tu)) < 0)
 178                 return r;
 179
 180         if (!p->noauto &&
 181             !p->nofail &&
 182             (p->handle || s->meta.manager->swap_auto) &&
 183             s->from_etc_fstab &&
 184             s->meta.manager->running_as == MANAGER_SYSTEM)
 185                 if ((r = unit_add_dependency(tu, UNIT_WANTS, UNIT(s), true)) < 0)
 186                         return r;
 187
 188         return unit_add_dependency(UNIT(s), UNIT_BEFORE, tu, true);
 189 }
 190
 191 static int swap_add_device_links(Swap *s) {
 192         SwapParameters *p;
 193
 194         assert(s);
 195
 196         if (!s->what)
 197                 return 0;
 198
 199         if (s->from_fragment)
 200                 p = &s->parameters_fragment;
 201         else if (s->from_etc_fstab)
 202                 p = &s->parameters_etc_fstab;
 203         else
 204                 return 0;
 205
 206         if (is_device_path(s->what))
 207                 return unit_add_node_link(UNIT(s), s->what,
 208                                           !p->noauto && p->nofail &&
 209                                           s->meta.manager->running_as == MANAGER_SYSTEM);
 210         else
 211                 /* File based swap devices need to be ordered after
 212                  * remount-rootfs.service, since they might need a
 213                  * writable file system. */
 214                 return unit_add_dependency_by_name(UNIT(s), UNIT_AFTER, SPECIAL_REMOUNT_ROOTFS_SERVICE, NULL, true);
 215 }
 216
 217 static int swap_add_default_dependencies(Swap *s) {
 218         int r;
 219
 220         assert(s);
 221
 222         if (s->meta.manager->running_as == MANAGER_SYSTEM) {
 223
 224                 if ((r = unit_add_two_dependencies_by_name(UNIT(s), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_UMOUNT_TARGET, NULL, true)) < 0)
 225                         return r;
 226         }
 227
 228         return 0;
 229 }
 230
 231 static int swap_verify(Swap *s) {
 232         bool b;
 233         char *e;
 234
 235         if (s->meta.load_state != UNIT_LOADED)
 236                   return 0;
 237
 238         if (!(e = unit_name_from_path(s->what, ".swap")))
 239                   return -ENOMEM;
 240
 241         b = unit_has_name(UNIT(s), e);
 242         free(e);
 243
 244         if (!b) {
 245                 log_error("%s: Value of \"What\" and unit name do not match, not loading.\n", s->meta.id);
 246                 return -EINVAL;
 247         }
 248
 249         if (s->exec_context.pam_name && s->exec_context.kill_mode != KILL_CONTROL_GROUP) {
 250                 log_error("%s has PAM enabled. Kill mode must be set to 'control-group'. Refusing.", s->meta.id);
 251                 return -EINVAL;
 252         }
 253
 254         return 0;
 255 }
 256
 257 static int swap_load(Unit *u) {
 258         int r;
 259         Swap *s = SWAP(u);
 260
 261         assert(s);
 262         assert(u->meta.load_state == UNIT_STUB);
 263
 264         /* Load a .swap file */
 265         if ((r = unit_load_fragment_and_dropin_optional(u)) < 0)
 266                 return r;
 267
 268         if (u->meta.load_state == UNIT_LOADED) {
 269                 if ((r = unit_add_exec_dependencies(u, &s->exec_context)) < 0)
 270                         return r;
 271
 272                 if (s->meta.fragment_path)
 273                         s->from_fragment = true;
 274
 275                 if (!s->what) {
 276                         if (s->parameters_fragment.what)
 277                                 s->what = strdup(s->parameters_fragment.what);
 278                         else if (s->parameters_etc_fstab.what)
 279                                 s->what = strdup(s->parameters_etc_fstab.what);
 280                         else if (s->parameters_proc_swaps.what)
 281                                 s->what = strdup(s->parameters_proc_swaps.what);
 282                         else
 283                                 s->what = unit_name_to_path(u->meta.id);
 284
 285                         if (!s->what)
 286                                 return -ENOMEM;
 287                 }
 288
 289                 path_kill_slashes(s->what);
 290
 291                 if (!s->meta.description)
 292                         if ((r = unit_set_description(u, s->what)) < 0)
 293                                 return r;
 294
 295                 if ((r = swap_add_device_links(s)) < 0)
 296                         return r;
 297
 298                 if ((r = swap_add_mount_links(s)) < 0)
 299                         return r;
 300
 301                 if ((r = swap_add_target_links(s)) < 0)
 302                         return r;
 303
 304                 if ((r = unit_add_default_cgroups(u)) < 0)
 305                         return r;
 306
 307                 if (s->meta.default_dependencies)
 308                         if ((r = swap_add_default_dependencies(s)) < 0)
 309                                 return r;
 310         }
 311
 312         return swap_verify(s);
 313 }
 314
 315 int swap_add_one(
 316                 Manager *m,
 317                 const char *what,
 318                 const char *what_proc_swaps,
 319                 int priority,
 320                 bool noauto,
 321                 bool nofail,
 322                 bool handle,
 323                 bool set_flags) {
 324
 325         Unit *u = NULL;
 326         char *e = NULL, *wp = NULL;
 327         bool delete = false;
 328         int r;
 329         SwapParameters *p;
 330
 331         assert(m);
 332         assert(what);
 333
 334         if (!(e = unit_name_from_path(what, ".swap")))
 335                 return -ENOMEM;
 336
 337         u = manager_get_unit(m, e);
 338
 339         if (what_proc_swaps &&
 340             u &&
 341             SWAP(u)->from_proc_swaps &&
 342             !path_equal(SWAP(u)->parameters_proc_swaps.what, what_proc_swaps))
 343                 return -EEXIST;
 344
 345         if (!u) {
 346                 delete = true;
 347
 348                 if (!(u = unit_new(m))) {
 349                         free(e);
 350                         return -ENOMEM;
 351                 }
 352
 353                 if ((r = unit_add_name(u, e)) < 0)
 354                         goto fail;
 355
 356                 if (!(SWAP(u)->what = strdup(what))) {
 357                         r = -ENOMEM;
 358                         goto fail;
 359                 }
 360
 361                 unit_add_to_load_queue(u);
 362         } else
 363                 delete = false;
 364
 365         if (what_proc_swaps) {
 366                 Swap *first;
 367
 368                 p = &SWAP(u)->parameters_proc_swaps;
 369
 370                 if (!p->what) {
 371                         if (!(wp = strdup(what_proc_swaps))) {
 372                                 r = -ENOMEM;
 373                                 goto fail;
 374                         }
 375
 376                         if (!m->swaps_by_proc_swaps)
 377                                 if (!(m->swaps_by_proc_swaps = hashmap_new(string_hash_func, string_compare_func))) {
 378                                         r = -ENOMEM;
 379                                         goto fail;
 380                                 }
 381
 382                         free(p->what);
 383                         p->what = wp;
 384
 385                         first = hashmap_get(m->swaps_by_proc_swaps, wp);
 386                         LIST_PREPEND(Swap, same_proc_swaps, first, SWAP(u));
 387
 388                         if ((r = hashmap_replace(m->swaps_by_proc_swaps, wp, first)) < 0)
 389                                 goto fail;
 390                 }
 391
 392                 if (set_flags) {
 393                         SWAP(u)->is_active = true;
 394                         SWAP(u)->just_activated = !SWAP(u)->from_proc_swaps;
 395                 }
 396
 397                 SWAP(u)->from_proc_swaps = true;
 398
 399         } else {
 400                 p = &SWAP(u)->parameters_etc_fstab;
 401
 402                 if (!(wp = strdup(what))) {
 403                         r = -ENOMEM;
 404                         goto fail;
 405                 }
 406
 407                 free(p->what);
 408                 p->what = wp;
 409
 410                 SWAP(u)->from_etc_fstab = true;
 411         }
 412
 413         p->priority = priority;
 414         p->noauto = noauto;
 415         p->nofail = nofail;
 416         p->handle = handle;
 417
 418         unit_add_to_dbus_queue(u);
 419
 420         free(e);
 421
 422         return 0;
 423
 424 fail:
 425         log_warning("Failed to load swap unit: %s", strerror(-r));
 426
 427         free(wp);
 428         free(e);
 429
 430         if (delete && u)
 431                 unit_free(u);
 432
 433         return r;
 434 }
 435
 436 static int swap_process_new_swap(Manager *m, const char *device, int prio, bool set_flags) {
 437         struct stat st;
 438         int r = 0, k;
 439
 440         assert(m);
 441
 442         if (stat(device, &st) >= 0 && S_ISBLK(st.st_mode)) {
 443                 struct udev_device *d;
 444                 const char *dn;
 445                 struct udev_list_entry *item = NULL, *first = NULL;
 446
 447                 /* So this is a proper swap device. Create swap units
 448                  * for all names this swap device is known under */
 449
 450                 if (!(d = udev_device_new_from_devnum(m->udev, 'b', st.st_rdev)))
 451                         return -ENOMEM;
 452
 453                 if ((dn = udev_device_get_devnode(d)))
 454                         r = swap_add_one(m, dn, device, prio, false, false, false, set_flags);
 455
 456                 /* Add additional units for all symlinks */
 457                 first = udev_device_get_devlinks_list_entry(d);
 458                 udev_list_entry_foreach(item, first) {
 459                         const char *p;
 460
 461                         /* Don't bother with the /dev/block links */
 462                         p = udev_list_entry_get_name(item);
 463
 464                         if (path_startswith(p, "/dev/block/"))
 465                                 continue;
 466
 467                         if (stat(p, &st) >= 0)
 468                                 if ((!S_ISBLK(st.st_mode)) || st.st_rdev != udev_device_get_devnum(d))
 469                                         continue;
 470
 471                         if ((k = swap_add_one(m, p, device, prio, false, false, false, set_flags)) < 0)
 472                                 r = k;
 473                 }
 474
 475                 udev_device_unref(d);
 476         }
 477
 478         if ((k = swap_add_one(m, device, device, prio, false, false, false, set_flags)) < 0)
 479                 r = k;
 480
 481         return r;
 482 }
 483
 484 static void swap_set_state(Swap *s, SwapState state) {
 485         SwapState old_state;
 486
 487         assert(s);
 488
 489         old_state = s->state;
 490         s->state = state;
 491
 492         if (state != SWAP_ACTIVATING &&
 493             state != SWAP_ACTIVATING_SIGTERM &&
 494             state != SWAP_ACTIVATING_SIGKILL &&
 495             state != SWAP_DEACTIVATING &&
 496             state != SWAP_DEACTIVATING_SIGTERM &&
 497             state != SWAP_DEACTIVATING_SIGKILL) {
 498                 unit_unwatch_timer(UNIT(s), &s->timer_watch);
 499                 swap_unwatch_control_pid(s);
 500                 s->control_command = NULL;
 501                 s->control_command_id = _SWAP_EXEC_COMMAND_INVALID;
 502         }
 503
 504         if (state != old_state)
 505                 log_debug("%s changed %s -> %s",
 506                           s->meta.id,
 507                           swap_state_to_string(old_state),
 508                           swap_state_to_string(state));
 509
 510         unit_notify(UNIT(s), state_translation_table[old_state], state_translation_table[state], true);
 511 }
 512
 513 static int swap_coldplug(Unit *u) {
 514         Swap *s = SWAP(u);
 515         SwapState new_state = SWAP_DEAD;
 516         int r;
 517
 518         assert(s);
 519         assert(s->state == SWAP_DEAD);
 520
 521         if (s->deserialized_state != s->state)
 522                 new_state = s->deserialized_state;
 523         else if (s->from_proc_swaps)
 524                 new_state = SWAP_ACTIVE;
 525
 526         if (new_state != s->state) {
 527
 528                 if (new_state == SWAP_ACTIVATING ||
 529                     new_state == SWAP_ACTIVATING_SIGTERM ||
 530                     new_state == SWAP_ACTIVATING_SIGKILL ||
 531                     new_state == SWAP_DEACTIVATING ||
 532                     new_state == SWAP_DEACTIVATING_SIGTERM ||
 533                     new_state == SWAP_DEACTIVATING_SIGKILL) {
 534
 535                         if (s->control_pid <= 0)
 536                                 return -EBADMSG;
 537
 538                         if ((r = unit_watch_pid(UNIT(s), s->control_pid)) < 0)
 539                                 return r;
 540
 541                         if ((r = unit_watch_timer(UNIT(s), s->timeout_usec, &s->timer_watch)) < 0)
 542                                 return r;
 543                 }
 544
 545                 swap_set_state(s, new_state);
 546         }
 547
 548         return 0;
 549 }
 550
 551 static void swap_dump(Unit *u, FILE *f, const char *prefix) {
 552         Swap *s = SWAP(u);
 553         SwapParameters *p;
 554
 555         assert(s);
 556         assert(f);
 557
 558         if (s->from_proc_swaps)
 559                 p = &s->parameters_proc_swaps;
 560         else if (s->from_fragment)
 561                 p = &s->parameters_fragment;
 562         else
 563                 p = &s->parameters_etc_fstab;
 564
 565         fprintf(f,
 566                 "%sSwap State: %s\n"
 567                 "%sWhat: %s\n"
 568                 "%sPriority: %i\n"
 569                 "%sNoAuto: %s\n"
 570                 "%sNoFail: %s\n"
 571                 "%sHandle: %s\n"
 572                 "%sFrom /etc/fstab: %s\n"
 573                 "%sFrom /proc/swaps: %s\n"
 574                 "%sFrom fragment: %s\n",
 575                 prefix, swap_state_to_string(s->state),
 576                 prefix, s->what,
 577                 prefix, p->priority,
 578                 prefix, yes_no(p->noauto),
 579                 prefix, yes_no(p->nofail),
 580                 prefix, yes_no(p->handle),
 581                 prefix, yes_no(s->from_etc_fstab),
 582                 prefix, yes_no(s->from_proc_swaps),
 583                 prefix, yes_no(s->from_fragment));
 584
 585         if (s->control_pid > 0)
 586                 fprintf(f,
 587                         "%sControl PID: %lu\n",
 588                         prefix, (unsigned long) s->control_pid);
 589
 590         exec_context_dump(&s->exec_context, f, prefix);
 591 }
 592
 593 static int swap_spawn(Swap *s, ExecCommand *c, pid_t *_pid) {
 594         pid_t pid;
 595         int r;
 596
 597         assert(s);
 598         assert(c);
 599         assert(_pid);
 600
 601         if ((r = unit_watch_timer(UNIT(s), s->timeout_usec, &s->timer_watch)) < 0)
 602                 goto fail;
 603
 604         if ((r = exec_spawn(c,
 605                             NULL,
 606                             &s->exec_context,
 607                             NULL, 0,
 608                             s->meta.manager->environment,
 609                             true,
 610                             true,
 611                             true,
 612                             s->meta.manager->confirm_spawn,
 613                             s->meta.cgroup_bondings,
 614                             &pid)) < 0)
 615                 goto fail;
 616
 617         if ((r = unit_watch_pid(UNIT(s), pid)) < 0)
 618                 /* FIXME: we need to do something here */
 619                 goto fail;
 620
 621         *_pid = pid;
 622
 623         return 0;
 624
 625 fail:
 626         unit_unwatch_timer(UNIT(s), &s->timer_watch);
 627
 628         return r;
 629 }
 630
 631 static void swap_enter_dead(Swap *s, bool success) {
 632         assert(s);
 633
 634         if (!success)
 635                 s->failure = true;
 636
 637         swap_set_state(s, s->failure ? SWAP_FAILED : SWAP_DEAD);
 638 }
 639
 640 static void swap_enter_active(Swap *s, bool success) {
 641         assert(s);
 642
 643         if (!success)
 644                 s->failure = true;
 645
 646         swap_set_state(s, SWAP_ACTIVE);
 647 }
 648
 649 static void swap_enter_signal(Swap *s, SwapState state, bool success) {
 650         int r;
 651         Set *pid_set = NULL;
 652         bool wait_for_exit = false;
 653
 654         assert(s);
 655
 656         if (!success)
 657                 s->failure = true;
 658
 659         if (s->exec_context.kill_mode != KILL_NONE) {
 660                 int sig = (state == SWAP_ACTIVATING_SIGTERM ||
 661                            state == SWAP_DEACTIVATING_SIGTERM) ? s->exec_context.kill_signal : SIGKILL;
 662
 663                 if (s->control_pid > 0) {
 664                         if (kill_and_sigcont(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, true, 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                         pid_set = NULL;
 691                 }
 692         }
 693
 694         if (wait_for_exit) {
 695                 if ((r = unit_watch_timer(UNIT(s), s->timeout_usec, &s->timer_watch)) < 0)
 696                         goto fail;
 697
 698                 swap_set_state(s, state);
 699         } else
 700                 swap_enter_dead(s, true);
 701
 702         return;
 703
 704 fail:
 705         log_warning("%s failed to kill processes: %s", s->meta.id, strerror(-r));
 706
 707         swap_enter_dead(s, false);
 708
 709         if (pid_set)
 710                 set_free(pid_set);
 711 }
 712
 713 static void swap_enter_activating(Swap *s) {
 714         int r, priority;
 715
 716         assert(s);
 717
 718         s->control_command_id = SWAP_EXEC_ACTIVATE;
 719         s->control_command = s->exec_command + SWAP_EXEC_ACTIVATE;
 720
 721         if (s->from_fragment)
 722                 priority = s->parameters_fragment.priority;
 723         else if (s->from_etc_fstab)
 724                 priority = s->parameters_etc_fstab.priority;
 725         else
 726                 priority = -1;
 727
 728         if (priority >= 0) {
 729                 char p[LINE_MAX];
 730
 731                 snprintf(p, sizeof(p), "%i", priority);
 732                 char_array_0(p);
 733
 734                 r = exec_command_set(
 735                                 s->control_command,
 736                                 "/sbin/swapon",
 737                                 "-p",
 738                                 p,
 739                                 s->what,
 740                                 NULL);
 741         } else
 742                 r = exec_command_set(
 743                                 s->control_command,
 744                                 "/sbin/swapon",
 745                                 s->what,
 746                                 NULL);
 747
 748         if (r < 0)
 749                 goto fail;
 750
 751         swap_unwatch_control_pid(s);
 752
 753         if ((r = swap_spawn(s, s->control_command, &s->control_pid)) < 0)
 754                 goto fail;
 755
 756         swap_set_state(s, SWAP_ACTIVATING);
 757
 758         return;
 759
 760 fail:
 761         log_warning("%s failed to run 'swapon' task: %s", s->meta.id, strerror(-r));
 762         swap_enter_dead(s, false);
 763 }
 764
 765 static void swap_enter_deactivating(Swap *s, bool success) {
 766         int r;
 767
 768         assert(s);
 769
 770         if (!success)
 771                 s->failure = true;
 772
 773         s->control_command_id = SWAP_EXEC_DEACTIVATE;
 774         s->control_command = s->exec_command + SWAP_EXEC_DEACTIVATE;
 775
 776         if ((r = exec_command_set(
 777                              s->control_command,
 778                              "/sbin/swapoff",
 779                              s->what,
 780                              NULL)) < 0)
 781                 goto fail;
 782
 783         swap_unwatch_control_pid(s);
 784
 785         if ((r = swap_spawn(s, s->control_command, &s->control_pid)) < 0)
 786                 goto fail;
 787
 788         swap_set_state(s, SWAP_DEACTIVATING);
 789
 790         return;
 791
 792 fail:
 793         log_warning("%s failed to run 'swapoff' task: %s", s->meta.id, strerror(-r));
 794         swap_enter_active(s, false);
 795 }
 796
 797 static int swap_start(Unit *u) {
 798         Swap *s = SWAP(u);
 799
 800         assert(s);
 801
 802         /* We cannot fulfill this request right now, try again later
 803          * please! */
 804
 805         if (s->state == SWAP_DEACTIVATING ||
 806             s->state == SWAP_DEACTIVATING_SIGTERM ||
 807             s->state == SWAP_DEACTIVATING_SIGKILL ||
 808             s->state == SWAP_ACTIVATING_SIGTERM ||
 809             s->state == SWAP_ACTIVATING_SIGKILL)
 810                 return -EAGAIN;
 811
 812         if (s->state == SWAP_ACTIVATING)
 813                 return 0;
 814
 815         assert(s->state == SWAP_DEAD || s->state == SWAP_FAILED);
 816
 817         s->failure = false;
 818         swap_enter_activating(s);
 819         return 0;
 820 }
 821
 822 static int swap_stop(Unit *u) {
 823         Swap *s = SWAP(u);
 824
 825         assert(s);
 826
 827         if (s->state == SWAP_DEACTIVATING ||
 828             s->state == SWAP_DEACTIVATING_SIGTERM ||
 829             s->state == SWAP_DEACTIVATING_SIGKILL ||
 830             s->state == SWAP_ACTIVATING_SIGTERM ||
 831             s->state == SWAP_ACTIVATING_SIGKILL)
 832                 return 0;
 833
 834         assert(s->state == SWAP_ACTIVATING ||
 835                s->state == SWAP_ACTIVE);
 836
 837         swap_enter_deactivating(s, true);
 838         return 0;
 839 }
 840
 841 static int swap_serialize(Unit *u, FILE *f, FDSet *fds) {
 842         Swap *s = SWAP(u);
 843
 844         assert(s);
 845         assert(f);
 846         assert(fds);
 847
 848         unit_serialize_item(u, f, "state", swap_state_to_string(s->state));
 849         unit_serialize_item(u, f, "failure", yes_no(s->failure));
 850
 851         if (s->control_pid > 0)
 852                 unit_serialize_item_format(u, f, "control-pid", "%lu", (unsigned long) s->control_pid);
 853
 854         if (s->control_command_id >= 0)
 855                 unit_serialize_item(u, f, "control-command", swap_exec_command_to_string(s->control_command_id));
 856
 857         return 0;
 858 }
 859
 860 static int swap_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 861         Swap *s = SWAP(u);
 862
 863         assert(s);
 864         assert(fds);
 865
 866         if (streq(key, "state")) {
 867                 SwapState state;
 868
 869                 if ((state = swap_state_from_string(value)) < 0)
 870                         log_debug("Failed to parse state value %s", value);
 871                 else
 872                         s->deserialized_state = state;
 873         } else if (streq(key, "failure")) {
 874                 int b;
 875
 876                 if ((b = parse_boolean(value)) < 0)
 877                         log_debug("Failed to parse failure value %s", value);
 878                 else
 879                         s->failure = b || s->failure;
 880
 881         } else if (streq(key, "control-pid")) {
 882                 pid_t pid;
 883
 884                 if (parse_pid(value, &pid) < 0)
 885                         log_debug("Failed to parse control-pid value %s", value);
 886                 else
 887                         s->control_pid = pid;
 888
 889         } else if (streq(key, "control-command")) {
 890                 SwapExecCommand id;
 891
 892                 if ((id = swap_exec_command_from_string(value)) < 0)
 893                         log_debug("Failed to parse exec-command value %s", value);
 894                 else {
 895                         s->control_command_id = id;
 896                         s->control_command = s->exec_command + id;
 897                 }
 898
 899         } else
 900                 log_debug("Unknown serialization key '%s'", key);
 901
 902         return 0;
 903 }
 904
 905 static UnitActiveState swap_active_state(Unit *u) {
 906         assert(u);
 907
 908         return state_translation_table[SWAP(u)->state];
 909 }
 910
 911 static const char *swap_sub_state_to_string(Unit *u) {
 912         assert(u);
 913
 914         return swap_state_to_string(SWAP(u)->state);
 915 }
 916
 917 static bool swap_check_gc(Unit *u) {
 918         Swap *s = SWAP(u);
 919
 920         assert(s);
 921
 922         return s->from_etc_fstab || s->from_proc_swaps;
 923 }
 924
 925 static void swap_sigchld_event(Unit *u, pid_t pid, int code, int status) {
 926         Swap *s = SWAP(u);
 927         bool success;
 928
 929         assert(s);
 930         assert(pid >= 0);
 931
 932         if (pid != s->control_pid)
 933                 return;
 934
 935         s->control_pid = 0;
 936
 937         success = is_clean_exit(code, status);
 938         s->failure = s->failure || !success;
 939
 940         if (s->control_command) {
 941                 exec_status_exit(&s->control_command->exec_status, pid, code, status, s->exec_context.utmp_id);
 942                 s->control_command = NULL;
 943                 s->control_command_id = _SWAP_EXEC_COMMAND_INVALID;
 944         }
 945
 946         log_full(success ? LOG_DEBUG : LOG_NOTICE,
 947                  "%s swap process exited, code=%s status=%i", u->meta.id, sigchld_code_to_string(code), status);
 948
 949         switch (s->state) {
 950
 951         case SWAP_ACTIVATING:
 952         case SWAP_ACTIVATING_SIGTERM:
 953         case SWAP_ACTIVATING_SIGKILL:
 954
 955                 if (success)
 956                         swap_enter_active(s, true);
 957                 else
 958                         swap_enter_dead(s, false);
 959                 break;
 960
 961         case SWAP_DEACTIVATING:
 962         case SWAP_DEACTIVATING_SIGKILL:
 963         case SWAP_DEACTIVATING_SIGTERM:
 964
 965                 if (success)
 966                         swap_enter_dead(s, true);
 967                 else
 968                         swap_enter_dead(s, false);
 969                 break;
 970
 971         default:
 972                 assert_not_reached("Uh, control process died at wrong time.");
 973         }
 974
 975         /* Notify clients about changed exit status */
 976         unit_add_to_dbus_queue(u);
 977
 978         /* Request a reload of /proc/swaps, so that following units
 979          * can follow our state change */
 980         u->meta.manager->request_reload = true;
 981 }
 982
 983 static void swap_timer_event(Unit *u, uint64_t elapsed, Watch *w) {
 984         Swap *s = SWAP(u);
 985
 986         assert(s);
 987         assert(elapsed == 1);
 988         assert(w == &s->timer_watch);
 989
 990         switch (s->state) {
 991
 992         case SWAP_ACTIVATING:
 993                 log_warning("%s activation timed out. Stopping.", u->meta.id);
 994                 swap_enter_signal(s, SWAP_ACTIVATING_SIGTERM, false);
 995                 break;
 996
 997         case SWAP_DEACTIVATING:
 998                 log_warning("%s deactivation timed out. Stopping.", u->meta.id);
 999                 swap_enter_signal(s, SWAP_DEACTIVATING_SIGTERM, false);
1000                 break;
1001
1002         case SWAP_ACTIVATING_SIGTERM:
1003                 if (s->exec_context.send_sigkill) {
1004                         log_warning("%s activation timed out. Killing.", u->meta.id);
1005                         swap_enter_signal(s, SWAP_ACTIVATING_SIGKILL, false);
1006                 } else {
1007                         log_warning("%s activation timed out. Skipping SIGKILL. Ignoring.", u->meta.id);
1008                         swap_enter_dead(s, false);
1009                 }
1010                 break;
1011
1012         case SWAP_DEACTIVATING_SIGTERM:
1013                 if (s->exec_context.send_sigkill) {
1014                         log_warning("%s deactivation timed out. Killing.", u->meta.id);
1015                         swap_enter_signal(s, SWAP_DEACTIVATING_SIGKILL, false);
1016                 } else {
1017                         log_warning("%s deactivation timed out. Skipping SIGKILL. Ignoring.", u->meta.id);
1018                         swap_enter_dead(s, false);
1019                 }
1020                 break;
1021
1022         case SWAP_ACTIVATING_SIGKILL:
1023         case SWAP_DEACTIVATING_SIGKILL:
1024                 log_warning("%s swap process still around after SIGKILL. Ignoring.", u->meta.id);
1025                 swap_enter_dead(s, false);
1026                 break;
1027
1028         default:
1029                 assert_not_reached("Timeout at wrong time.");
1030         }
1031 }
1032
1033 static int swap_load_proc_swaps(Manager *m, bool set_flags) {
1034         unsigned i;
1035         int r = 0;
1036
1037         assert(m);
1038
1039         rewind(m->proc_swaps);
1040
1041         (void) fscanf(m->proc_swaps, "%*s %*s %*s %*s %*s\n");
1042
1043         for (i = 1;; i++) {
1044                 char *dev = NULL, *d;
1045                 int prio = 0, k;
1046
1047                 if ((k = fscanf(m->proc_swaps,
1048                                 "%ms "  /* device/file */
1049                                 "%*s "  /* type of swap */
1050                                 "%*s "  /* swap size */
1051                                 "%*s "  /* used */
1052                                 "%i\n", /* priority */
1053                                 &dev, &prio)) != 2) {
1054
1055                         if (k == EOF)
1056                                 break;
1057
1058                         log_warning("Failed to parse /proc/swaps:%u.", i);
1059                         free(dev);
1060                         continue;
1061                 }
1062
1063                 d = cunescape(dev);
1064                 free(dev);
1065
1066                 if (!d)
1067                         return -ENOMEM;
1068
1069                 k = swap_process_new_swap(m, d, prio, set_flags);
1070                 free(d);
1071
1072                 if (k < 0)
1073                         r = k;
1074         }
1075
1076         return r;
1077 }
1078
1079 int swap_dispatch_reload(Manager *m) {
1080         /* This function should go as soon as the kernel properly notifies us */
1081
1082         if (_likely_(!m->request_reload))
1083                 return 0;
1084
1085         m->request_reload = false;
1086
1087         return swap_fd_event(m, EPOLLPRI);
1088 }
1089
1090 int swap_fd_event(Manager *m, int events) {
1091         Meta *meta;
1092         int r;
1093
1094         assert(m);
1095         assert(events & EPOLLPRI);
1096
1097         if ((r = swap_load_proc_swaps(m, true)) < 0) {
1098                 log_error("Failed to reread /proc/swaps: %s", strerror(-r));
1099
1100                 /* Reset flags, just in case, for late calls */
1101                 LIST_FOREACH(units_per_type, meta, m->units_per_type[UNIT_SWAP]) {
1102                         Swap *swap = (Swap*) meta;
1103
1104                         swap->is_active = swap->just_activated = false;
1105                 }
1106
1107                 return 0;
1108         }
1109
1110         manager_dispatch_load_queue(m);
1111
1112         LIST_FOREACH(units_per_type, meta, m->units_per_type[UNIT_SWAP]) {
1113                 Swap *swap = (Swap*) meta;
1114
1115                 if (!swap->is_active) {
1116                         /* This has just been deactivated */
1117
1118                         swap->from_proc_swaps = false;
1119                         swap_unset_proc_swaps(swap);
1120
1121                         switch (swap->state) {
1122
1123                         case SWAP_ACTIVE:
1124                                 swap_enter_dead(swap, true);
1125                                 break;
1126
1127                         default:
1128                                 swap_set_state(swap, swap->state);
1129                                 break;
1130                         }
1131
1132                 } else if (swap->just_activated) {
1133
1134                         /* New swap entry */
1135
1136                         switch (swap->state) {
1137
1138                         case SWAP_DEAD:
1139                         case SWAP_FAILED:
1140                                 swap_enter_active(swap, true);
1141                                 break;
1142
1143                         default:
1144                                 /* Nothing really changed, but let's
1145                                  * issue an notification call
1146                                  * nonetheless, in case somebody is
1147                                  * waiting for this. */
1148                                 swap_set_state(swap, swap->state);
1149                                 break;
1150                         }
1151                 }
1152
1153                 /* Reset the flags for later calls */
1154                 swap->is_active = swap->just_activated = false;
1155         }
1156
1157         return 1;
1158 }
1159
1160 static Unit *swap_following(Unit *u) {
1161         Swap *s = SWAP(u);
1162         Swap *other, *first = NULL;
1163
1164         assert(s);
1165
1166         if (streq_ptr(s->what, s->parameters_proc_swaps.what))
1167                 return NULL;
1168
1169         /* Make everybody follow the unit that's named after the swap
1170          * device in the kernel */
1171
1172         LIST_FOREACH_AFTER(same_proc_swaps, other, s)
1173                 if (streq_ptr(other->what, other->parameters_proc_swaps.what))
1174                         return UNIT(other);
1175
1176         LIST_FOREACH_BEFORE(same_proc_swaps, other, s) {
1177                 if (streq_ptr(other->what, other->parameters_proc_swaps.what))
1178                         return UNIT(other);
1179
1180                 first = other;
1181         }
1182
1183         return UNIT(first);
1184 }
1185
1186 static int swap_following_set(Unit *u, Set **_set) {
1187         Swap *s = SWAP(u);
1188         Swap *other;
1189         Set *set;
1190         int r;
1191
1192         assert(s);
1193         assert(_set);
1194
1195         if (LIST_JUST_US(same_proc_swaps, s)) {
1196                 *_set = NULL;
1197                 return 0;
1198         }
1199
1200         if (!(set = set_new(NULL, NULL)))
1201                 return -ENOMEM;
1202
1203         LIST_FOREACH_AFTER(same_proc_swaps, other, s)
1204                 if ((r = set_put(set, other)) < 0)
1205                         goto fail;
1206
1207         LIST_FOREACH_BEFORE(same_proc_swaps, other, s)
1208                 if ((r = set_put(set, other)) < 0)
1209                         goto fail;
1210
1211         *_set = set;
1212         return 1;
1213
1214 fail:
1215         set_free(set);
1216         return r;
1217 }
1218
1219 static void swap_shutdown(Manager *m) {
1220         assert(m);
1221
1222         if (m->proc_swaps) {
1223                 fclose(m->proc_swaps);
1224                 m->proc_swaps = NULL;
1225         }
1226
1227         hashmap_free(m->swaps_by_proc_swaps);
1228         m->swaps_by_proc_swaps = NULL;
1229 }
1230
1231 static int swap_enumerate(Manager *m) {
1232         int r;
1233         struct epoll_event ev;
1234         assert(m);
1235
1236         if (!m->proc_swaps) {
1237                 if (!(m->proc_swaps = fopen("/proc/swaps", "re")))
1238                         return -errno;
1239
1240                 m->swap_watch.type = WATCH_SWAP;
1241                 m->swap_watch.fd = fileno(m->proc_swaps);
1242
1243                 zero(ev);
1244                 ev.events = EPOLLPRI;
1245                 ev.data.ptr = &m->swap_watch;
1246
1247                 if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->swap_watch.fd, &ev) < 0)
1248                         return -errno;
1249         }
1250
1251         /* We rely on mount.c to load /etc/fstab for us */
1252
1253         if ((r = swap_load_proc_swaps(m, false)) < 0)
1254                 swap_shutdown(m);
1255
1256         return r;
1257 }
1258
1259 static void swap_reset_failed(Unit *u) {
1260         Swap *s = SWAP(u);
1261
1262         assert(s);
1263
1264         if (s->state == SWAP_FAILED)
1265                 swap_set_state(s, SWAP_DEAD);
1266
1267         s->failure = false;
1268 }
1269
1270 static int swap_kill(Unit *u, KillWho who, KillMode mode, int signo, DBusError *error) {
1271         Swap *s = SWAP(u);
1272         int r = 0;
1273         Set *pid_set = NULL;
1274
1275         assert(s);
1276
1277         if (who == KILL_MAIN) {
1278                 dbus_set_error(error, BUS_ERROR_NO_SUCH_PROCESS, "Swap units have no main processes");
1279                 return -EINVAL;
1280         }
1281
1282         if (s->control_pid <= 0 && who == KILL_CONTROL) {
1283                 dbus_set_error(error, BUS_ERROR_NO_SUCH_PROCESS, "No control process to kill");
1284                 return -ENOENT;
1285         }
1286
1287         if (s->control_pid > 0)
1288                 if (kill(s->control_pid, signo) < 0)
1289                         r = -errno;
1290
1291         if (mode == KILL_CONTROL_GROUP) {
1292                 int q;
1293
1294                 if (!(pid_set = set_new(trivial_hash_func, trivial_compare_func)))
1295                         return -ENOMEM;
1296
1297                 /* Exclude the control pid from being killed via the cgroup */
1298                 if (s->control_pid > 0)
1299                         if ((q = set_put(pid_set, LONG_TO_PTR(s->control_pid))) < 0) {
1300                                 r = q;
1301                                 goto finish;
1302                         }
1303
1304                 if ((q = cgroup_bonding_kill_list(s->meta.cgroup_bondings, signo, false, pid_set)) < 0)
1305                         if (r != -EAGAIN && r != -ESRCH && r != -ENOENT)
1306                                 r = q;
1307         }
1308
1309 finish:
1310         if (pid_set)
1311                 set_free(pid_set);
1312
1313         return r;
1314 }
1315
1316 static const char* const swap_state_table[_SWAP_STATE_MAX] = {
1317         [SWAP_DEAD] = "dead",
1318         [SWAP_ACTIVATING] = "activating",
1319         [SWAP_ACTIVE] = "active",
1320         [SWAP_DEACTIVATING] = "deactivating",
1321         [SWAP_ACTIVATING_SIGTERM] = "activating-sigterm",
1322         [SWAP_ACTIVATING_SIGKILL] = "activating-sigkill",
1323         [SWAP_DEACTIVATING_SIGTERM] = "deactivating-sigterm",
1324         [SWAP_DEACTIVATING_SIGKILL] = "deactivating-sigkill",
1325         [SWAP_FAILED] = "failed"
1326 };
1327
1328 DEFINE_STRING_TABLE_LOOKUP(swap_state, SwapState);
1329
1330 static const char* const swap_exec_command_table[_SWAP_EXEC_COMMAND_MAX] = {
1331         [SWAP_EXEC_ACTIVATE] = "ExecActivate",
1332         [SWAP_EXEC_DEACTIVATE] = "ExecDeactivate",
1333 };
1334
1335 DEFINE_STRING_TABLE_LOOKUP(swap_exec_command, SwapExecCommand);
1336
1337 const UnitVTable swap_vtable = {
1338         .suffix = ".swap",
1339
1340         .no_alias = true,
1341         .no_instances = true,
1342         .no_isolate = true,
1343         .show_status = true,
1344
1345         .init = swap_init,
1346         .load = swap_load,
1347         .done = swap_done,
1348
1349         .coldplug = swap_coldplug,
1350
1351         .dump = swap_dump,
1352
1353         .start = swap_start,
1354         .stop = swap_stop,
1355
1356         .kill = swap_kill,
1357
1358         .serialize = swap_serialize,
1359         .deserialize_item = swap_deserialize_item,
1360
1361         .active_state = swap_active_state,
1362         .sub_state_to_string = swap_sub_state_to_string,
1363
1364         .check_gc = swap_check_gc,
1365
1366         .sigchld_event = swap_sigchld_event,
1367         .timer_event = swap_timer_event,
1368
1369         .reset_failed = swap_reset_failed,
1370
1371         .bus_interface = "org.freedesktop.systemd1.Swap",
1372         .bus_message_handler = bus_swap_message_handler,
1373         .bus_invalidating_properties =  bus_swap_invalidating_properties,
1374
1375         .following = swap_following,
1376         .following_set = swap_following_set,
1377
1378         .enumerate = swap_enumerate,
1379         .shutdown = swap_shutdown
1380 };