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         s->meta.ignore_on_isolate = true;
  95 }
  96
  97 static void swap_unwatch_control_pid(Swap *s) {
  98         assert(s);
  99
 100         if (s->control_pid <= 0)
 101                 return;
 102
 103         unit_unwatch_pid(UNIT(s), s->control_pid);
 104         s->control_pid = 0;
 105 }
 106
 107 static void swap_done(Unit *u) {
 108         Swap *s = SWAP(u);
 109
 110         assert(s);
 111
 112         swap_unset_proc_swaps(s);
 113
 114         free(s->what);
 115         s->what = NULL;
 116
 117         free(s->parameters_etc_fstab.what);
 118         free(s->parameters_fragment.what);
 119         s->parameters_etc_fstab.what = s->parameters_fragment.what = NULL;
 120
 121         exec_context_done(&s->exec_context);
 122         exec_command_done_array(s->exec_command, _SWAP_EXEC_COMMAND_MAX);
 123         s->control_command = NULL;
 124
 125         swap_unwatch_control_pid(s);
 126
 127         unit_unwatch_timer(u, &s->timer_watch);
 128 }
 129
 130 int swap_add_one_mount_link(Swap *s, Mount *m) {
 131          int r;
 132
 133         assert(s);
 134         assert(m);
 135
 136         if (s->meta.load_state != UNIT_LOADED ||
 137             m->meta.load_state != UNIT_LOADED)
 138                 return 0;
 139
 140         if (is_device_path(s->what))
 141                 return 0;
 142
 143         if (!path_startswith(s->what, m->where))
 144                 return 0;
 145
 146         if ((r = unit_add_two_dependencies(UNIT(s), UNIT_AFTER, UNIT_REQUIRES, UNIT(m), true)) < 0)
 147                 return r;
 148
 149         return 0;
 150 }
 151
 152 static int swap_add_mount_links(Swap *s) {
 153         Meta *other;
 154         int r;
 155
 156         assert(s);
 157
 158         LIST_FOREACH(units_by_type, other, s->meta.manager->units_by_type[UNIT_MOUNT])
 159                 if ((r = swap_add_one_mount_link(s, (Mount*) other)) < 0)
 160                         return r;
 161
 162         return 0;
 163 }
 164
 165 static int swap_add_target_links(Swap *s) {
 166         Unit *tu;
 167         SwapParameters *p;
 168         int r;
 169
 170         assert(s);
 171
 172         if (s->from_fragment)
 173                 p = &s->parameters_fragment;
 174         else if (s->from_etc_fstab)
 175                 p = &s->parameters_etc_fstab;
 176         else
 177                 return 0;
 178
 179         if ((r = manager_load_unit(s->meta.manager, SPECIAL_SWAP_TARGET, NULL, NULL, &tu)) < 0)
 180                 return r;
 181
 182         if (!p->noauto &&
 183             !p->nofail &&
 184             (p->handle || s->meta.manager->swap_auto) &&
 185             s->from_etc_fstab &&
 186             s->meta.manager->running_as == MANAGER_SYSTEM)
 187                 if ((r = unit_add_dependency(tu, UNIT_WANTS, UNIT(s), true)) < 0)
 188                         return r;
 189
 190         return unit_add_dependency(UNIT(s), UNIT_BEFORE, tu, true);
 191 }
 192
 193 static int swap_add_device_links(Swap *s) {
 194         SwapParameters *p;
 195
 196         assert(s);
 197
 198         if (!s->what)
 199                 return 0;
 200
 201         if (s->from_fragment)
 202                 p = &s->parameters_fragment;
 203         else if (s->from_etc_fstab)
 204                 p = &s->parameters_etc_fstab;
 205         else
 206                 return 0;
 207
 208         if (is_device_path(s->what))
 209                 return unit_add_node_link(UNIT(s), s->what,
 210                                           !p->noauto && p->nofail &&
 211                                           s->meta.manager->running_as == MANAGER_SYSTEM);
 212         else
 213                 /* File based swap devices need to be ordered after
 214                  * remount-rootfs.service, since they might need a
 215                  * writable file system. */
 216                 return unit_add_dependency_by_name(UNIT(s), UNIT_AFTER, SPECIAL_REMOUNT_ROOTFS_SERVICE, NULL, true);
 217 }
 218
 219 static int swap_add_default_dependencies(Swap *s) {
 220         int r;
 221
 222         assert(s);
 223
 224         if (s->meta.manager->running_as == MANAGER_SYSTEM) {
 225
 226                 if ((r = unit_add_two_dependencies_by_name(UNIT(s), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_UMOUNT_TARGET, NULL, true)) < 0)
 227                         return r;
 228         }
 229
 230         return 0;
 231 }
 232
 233 static int swap_verify(Swap *s) {
 234         bool b;
 235         char *e;
 236
 237         if (s->meta.load_state != UNIT_LOADED)
 238                   return 0;
 239
 240         if (!(e = unit_name_from_path(s->what, ".swap")))
 241                   return -ENOMEM;
 242
 243         b = unit_has_name(UNIT(s), e);
 244         free(e);
 245
 246         if (!b) {
 247                 log_error("%s: Value of \"What\" and unit name do not match, not loading.\n", s->meta.id);
 248                 return -EINVAL;
 249         }
 250
 251         if (s->exec_context.pam_name && s->exec_context.kill_mode != KILL_CONTROL_GROUP) {
 252                 log_error("%s has PAM enabled. Kill mode must be set to 'control-group'. Refusing.", s->meta.id);
 253                 return -EINVAL;
 254         }
 255
 256         return 0;
 257 }
 258
 259 static int swap_load(Unit *u) {
 260         int r;
 261         Swap *s = SWAP(u);
 262
 263         assert(s);
 264         assert(u->meta.load_state == UNIT_STUB);
 265
 266         /* Load a .swap file */
 267         if ((r = unit_load_fragment_and_dropin_optional(u)) < 0)
 268                 return r;
 269
 270         if (u->meta.load_state == UNIT_LOADED) {
 271                 if ((r = unit_add_exec_dependencies(u, &s->exec_context)) < 0)
 272                         return r;
 273
 274                 if (s->meta.fragment_path)
 275                         s->from_fragment = true;
 276
 277                 if (!s->what) {
 278                         if (s->parameters_fragment.what)
 279                                 s->what = strdup(s->parameters_fragment.what);
 280                         else if (s->parameters_etc_fstab.what)
 281                                 s->what = strdup(s->parameters_etc_fstab.what);
 282                         else if (s->parameters_proc_swaps.what)
 283                                 s->what = strdup(s->parameters_proc_swaps.what);
 284                         else
 285                                 s->what = unit_name_to_path(u->meta.id);
 286
 287                         if (!s->what)
 288                                 return -ENOMEM;
 289                 }
 290
 291                 path_kill_slashes(s->what);
 292
 293                 if (!s->meta.description)
 294                         if ((r = unit_set_description(u, s->what)) < 0)
 295                                 return r;
 296
 297                 if ((r = swap_add_device_links(s)) < 0)
 298                         return r;
 299
 300                 if ((r = swap_add_mount_links(s)) < 0)
 301                         return r;
 302
 303                 if ((r = swap_add_target_links(s)) < 0)
 304                         return r;
 305
 306                 if ((r = unit_add_default_cgroups(u)) < 0)
 307                         return r;
 308
 309                 if (s->meta.default_dependencies)
 310                         if ((r = swap_add_default_dependencies(s)) < 0)
 311                                 return r;
 312         }
 313
 314         return swap_verify(s);
 315 }
 316
 317 int swap_add_one(
 318                 Manager *m,
 319                 const char *what,
 320                 const char *what_proc_swaps,
 321                 int priority,
 322                 bool noauto,
 323                 bool nofail,
 324                 bool handle,
 325                 bool set_flags) {
 326
 327         Unit *u = NULL;
 328         char *e = NULL, *wp = NULL;
 329         bool delete = false;
 330         int r;
 331         SwapParameters *p;
 332
 333         assert(m);
 334         assert(what);
 335
 336         if (!(e = unit_name_from_path(what, ".swap")))
 337                 return -ENOMEM;
 338
 339         u = manager_get_unit(m, e);
 340
 341         if (what_proc_swaps &&
 342             u &&
 343             SWAP(u)->from_proc_swaps &&
 344             !path_equal(SWAP(u)->parameters_proc_swaps.what, what_proc_swaps))
 345                 return -EEXIST;
 346
 347         if (!u) {
 348                 delete = true;
 349
 350                 if (!(u = unit_new(m))) {
 351                         free(e);
 352                         return -ENOMEM;
 353                 }
 354
 355                 if ((r = unit_add_name(u, e)) < 0)
 356                         goto fail;
 357
 358                 if (!(SWAP(u)->what = strdup(what))) {
 359                         r = -ENOMEM;
 360                         goto fail;
 361                 }
 362
 363                 unit_add_to_load_queue(u);
 364         } else
 365                 delete = false;
 366
 367         if (what_proc_swaps) {
 368                 Swap *first;
 369
 370                 p = &SWAP(u)->parameters_proc_swaps;
 371
 372                 if (!p->what) {
 373                         if (!(wp = strdup(what_proc_swaps))) {
 374                                 r = -ENOMEM;
 375                                 goto fail;
 376                         }
 377
 378                         if (!m->swaps_by_proc_swaps)
 379                                 if (!(m->swaps_by_proc_swaps = hashmap_new(string_hash_func, string_compare_func))) {
 380                                         r = -ENOMEM;
 381                                         goto fail;
 382                                 }
 383
 384                         free(p->what);
 385                         p->what = wp;
 386
 387                         first = hashmap_get(m->swaps_by_proc_swaps, wp);
 388                         LIST_PREPEND(Swap, same_proc_swaps, first, SWAP(u));
 389
 390                         if ((r = hashmap_replace(m->swaps_by_proc_swaps, wp, first)) < 0)
 391                                 goto fail;
 392                 }
 393
 394                 if (set_flags) {
 395                         SWAP(u)->is_active = true;
 396                         SWAP(u)->just_activated = !SWAP(u)->from_proc_swaps;
 397                 }
 398
 399                 SWAP(u)->from_proc_swaps = true;
 400
 401         } else {
 402                 p = &SWAP(u)->parameters_etc_fstab;
 403
 404                 if (!(wp = strdup(what))) {
 405                         r = -ENOMEM;
 406                         goto fail;
 407                 }
 408
 409                 free(p->what);
 410                 p->what = wp;
 411
 412                 SWAP(u)->from_etc_fstab = true;
 413         }
 414
 415         p->priority = priority;
 416         p->noauto = noauto;
 417         p->nofail = nofail;
 418         p->handle = handle;
 419
 420         unit_add_to_dbus_queue(u);
 421
 422         free(e);
 423
 424         return 0;
 425
 426 fail:
 427         log_warning("Failed to load swap unit: %s", strerror(-r));
 428
 429         free(wp);
 430         free(e);
 431
 432         if (delete && u)
 433                 unit_free(u);
 434
 435         return r;
 436 }
 437
 438 static int swap_process_new_swap(Manager *m, const char *device, int prio, bool set_flags) {
 439         struct stat st;
 440         int r = 0, k;
 441
 442         assert(m);
 443
 444         if (stat(device, &st) >= 0 && S_ISBLK(st.st_mode)) {
 445                 struct udev_device *d;
 446                 const char *dn;
 447                 struct udev_list_entry *item = NULL, *first = NULL;
 448
 449                 /* So this is a proper swap device. Create swap units
 450                  * for all names this swap device is known under */
 451
 452                 if (!(d = udev_device_new_from_devnum(m->udev, 'b', st.st_rdev)))
 453                         return -ENOMEM;
 454
 455                 if ((dn = udev_device_get_devnode(d)))
 456                         r = swap_add_one(m, dn, device, prio, false, false, false, set_flags);
 457
 458                 /* Add additional units for all symlinks */
 459                 first = udev_device_get_devlinks_list_entry(d);
 460                 udev_list_entry_foreach(item, first) {
 461                         const char *p;
 462
 463                         /* Don't bother with the /dev/block links */
 464                         p = udev_list_entry_get_name(item);
 465
 466                         if (path_startswith(p, "/dev/block/"))
 467                                 continue;
 468
 469                         if (stat(p, &st) >= 0)
 470                                 if ((!S_ISBLK(st.st_mode)) || st.st_rdev != udev_device_get_devnum(d))
 471                                         continue;
 472
 473                         if ((k = swap_add_one(m, p, device, prio, false, false, false, set_flags)) < 0)
 474                                 r = k;
 475                 }
 476
 477                 udev_device_unref(d);
 478         }
 479
 480         if ((k = swap_add_one(m, device, device, prio, false, false, false, set_flags)) < 0)
 481                 r = k;
 482
 483         return r;
 484 }
 485
 486 static void swap_set_state(Swap *s, SwapState state) {
 487         SwapState old_state;
 488
 489         assert(s);
 490
 491         old_state = s->state;
 492         s->state = state;
 493
 494         if (state != SWAP_ACTIVATING &&
 495             state != SWAP_ACTIVATING_SIGTERM &&
 496             state != SWAP_ACTIVATING_SIGKILL &&
 497             state != SWAP_DEACTIVATING &&
 498             state != SWAP_DEACTIVATING_SIGTERM &&
 499             state != SWAP_DEACTIVATING_SIGKILL) {
 500                 unit_unwatch_timer(UNIT(s), &s->timer_watch);
 501                 swap_unwatch_control_pid(s);
 502                 s->control_command = NULL;
 503                 s->control_command_id = _SWAP_EXEC_COMMAND_INVALID;
 504         }
 505
 506         if (state != old_state)
 507                 log_debug("%s changed %s -> %s",
 508                           s->meta.id,
 509                           swap_state_to_string(old_state),
 510                           swap_state_to_string(state));
 511
 512         unit_notify(UNIT(s), state_translation_table[old_state], state_translation_table[state], true);
 513 }
 514
 515 static int swap_coldplug(Unit *u) {
 516         Swap *s = SWAP(u);
 517         SwapState new_state = SWAP_DEAD;
 518         int r;
 519
 520         assert(s);
 521         assert(s->state == SWAP_DEAD);
 522
 523         if (s->deserialized_state != s->state)
 524                 new_state = s->deserialized_state;
 525         else if (s->from_proc_swaps)
 526                 new_state = SWAP_ACTIVE;
 527
 528         if (new_state != s->state) {
 529
 530                 if (new_state == SWAP_ACTIVATING ||
 531                     new_state == SWAP_ACTIVATING_SIGTERM ||
 532                     new_state == SWAP_ACTIVATING_SIGKILL ||
 533                     new_state == SWAP_DEACTIVATING ||
 534                     new_state == SWAP_DEACTIVATING_SIGTERM ||
 535                     new_state == SWAP_DEACTIVATING_SIGKILL) {
 536
 537                         if (s->control_pid <= 0)
 538                                 return -EBADMSG;
 539
 540                         if ((r = unit_watch_pid(UNIT(s), s->control_pid)) < 0)
 541                                 return r;
 542
 543                         if ((r = unit_watch_timer(UNIT(s), s->timeout_usec, &s->timer_watch)) < 0)
 544                                 return r;
 545                 }
 546
 547                 swap_set_state(s, new_state);
 548         }
 549
 550         return 0;
 551 }
 552
 553 static void swap_dump(Unit *u, FILE *f, const char *prefix) {
 554         Swap *s = SWAP(u);
 555         SwapParameters *p;
 556
 557         assert(s);
 558         assert(f);
 559
 560         if (s->from_proc_swaps)
 561                 p = &s->parameters_proc_swaps;
 562         else if (s->from_fragment)
 563                 p = &s->parameters_fragment;
 564         else
 565                 p = &s->parameters_etc_fstab;
 566
 567         fprintf(f,
 568                 "%sSwap State: %s\n"
 569                 "%sWhat: %s\n"
 570                 "%sPriority: %i\n"
 571                 "%sNoAuto: %s\n"
 572                 "%sNoFail: %s\n"
 573                 "%sHandle: %s\n"
 574                 "%sFrom /etc/fstab: %s\n"
 575                 "%sFrom /proc/swaps: %s\n"
 576                 "%sFrom fragment: %s\n",
 577                 prefix, swap_state_to_string(s->state),
 578                 prefix, s->what,
 579                 prefix, p->priority,
 580                 prefix, yes_no(p->noauto),
 581                 prefix, yes_no(p->nofail),
 582                 prefix, yes_no(p->handle),
 583                 prefix, yes_no(s->from_etc_fstab),
 584                 prefix, yes_no(s->from_proc_swaps),
 585                 prefix, yes_no(s->from_fragment));
 586
 587         if (s->control_pid > 0)
 588                 fprintf(f,
 589                         "%sControl PID: %lu\n",
 590                         prefix, (unsigned long) s->control_pid);
 591
 592         exec_context_dump(&s->exec_context, f, prefix);
 593 }
 594
 595 static int swap_spawn(Swap *s, ExecCommand *c, pid_t *_pid) {
 596         pid_t pid;
 597         int r;
 598
 599         assert(s);
 600         assert(c);
 601         assert(_pid);
 602
 603         if ((r = unit_watch_timer(UNIT(s), s->timeout_usec, &s->timer_watch)) < 0)
 604                 goto fail;
 605
 606         if ((r = exec_spawn(c,
 607                             NULL,
 608                             &s->exec_context,
 609                             NULL, 0,
 610                             s->meta.manager->environment,
 611                             true,
 612                             true,
 613                             true,
 614                             s->meta.manager->confirm_spawn,
 615                             s->meta.cgroup_bondings,
 616                             s->meta.cgroup_attributes,
 617                             &pid)) < 0)
 618                 goto fail;
 619
 620         if ((r = unit_watch_pid(UNIT(s), pid)) < 0)
 621                 /* FIXME: we need to do something here */
 622                 goto fail;
 623
 624         *_pid = pid;
 625
 626         return 0;
 627
 628 fail:
 629         unit_unwatch_timer(UNIT(s), &s->timer_watch);
 630
 631         return r;
 632 }
 633
 634 static void swap_enter_dead(Swap *s, bool success) {
 635         assert(s);
 636
 637         if (!success)
 638                 s->failure = true;
 639
 640         swap_set_state(s, s->failure ? SWAP_FAILED : SWAP_DEAD);
 641 }
 642
 643 static void swap_enter_active(Swap *s, bool success) {
 644         assert(s);
 645
 646         if (!success)
 647                 s->failure = true;
 648
 649         swap_set_state(s, SWAP_ACTIVE);
 650 }
 651
 652 static void swap_enter_signal(Swap *s, SwapState state, bool success) {
 653         int r;
 654         Set *pid_set = NULL;
 655         bool wait_for_exit = false;
 656
 657         assert(s);
 658
 659         if (!success)
 660                 s->failure = true;
 661
 662         if (s->exec_context.kill_mode != KILL_NONE) {
 663                 int sig = (state == SWAP_ACTIVATING_SIGTERM ||
 664                            state == SWAP_DEACTIVATING_SIGTERM) ? s->exec_context.kill_signal : SIGKILL;
 665
 666                 if (s->control_pid > 0) {
 667                         if (kill_and_sigcont(s->control_pid, sig) < 0 && errno != ESRCH)
 668
 669                                 log_warning("Failed to kill control process %li: %m", (long) s->control_pid);
 670                         else
 671                                 wait_for_exit = true;
 672                 }
 673
 674                 if (s->exec_context.kill_mode == KILL_CONTROL_GROUP) {
 675
 676                         if (!(pid_set = set_new(trivial_hash_func, trivial_compare_func))) {
 677                                 r = -ENOMEM;
 678                                 goto fail;
 679                         }
 680
 681                         /* Exclude the control pid from being killed via the cgroup */
 682                         if (s->control_pid > 0)
 683                                 if ((r = set_put(pid_set, LONG_TO_PTR(s->control_pid))) < 0)
 684                                         goto fail;
 685
 686                         if ((r = cgroup_bonding_kill_list(s->meta.cgroup_bondings, sig, true, pid_set)) < 0) {
 687                                 if (r != -EAGAIN && r != -ESRCH && r != -ENOENT)
 688                                         log_warning("Failed to kill control group: %s", strerror(-r));
 689                         } else if (r > 0)
 690                                 wait_for_exit = true;
 691
 692                         set_free(pid_set);
 693                         pid_set = NULL;
 694                 }
 695         }
 696
 697         if (wait_for_exit) {
 698                 if ((r = unit_watch_timer(UNIT(s), s->timeout_usec, &s->timer_watch)) < 0)
 699                         goto fail;
 700
 701                 swap_set_state(s, state);
 702         } else
 703                 swap_enter_dead(s, true);
 704
 705         return;
 706
 707 fail:
 708         log_warning("%s failed to kill processes: %s", s->meta.id, strerror(-r));
 709
 710         swap_enter_dead(s, false);
 711
 712         if (pid_set)
 713                 set_free(pid_set);
 714 }
 715
 716 static void swap_enter_activating(Swap *s) {
 717         int r, priority;
 718
 719         assert(s);
 720
 721         s->control_command_id = SWAP_EXEC_ACTIVATE;
 722         s->control_command = s->exec_command + SWAP_EXEC_ACTIVATE;
 723
 724         if (s->from_fragment)
 725                 priority = s->parameters_fragment.priority;
 726         else if (s->from_etc_fstab)
 727                 priority = s->parameters_etc_fstab.priority;
 728         else
 729                 priority = -1;
 730
 731         if (priority >= 0) {
 732                 char p[LINE_MAX];
 733
 734                 snprintf(p, sizeof(p), "%i", priority);
 735                 char_array_0(p);
 736
 737                 r = exec_command_set(
 738                                 s->control_command,
 739                                 "/sbin/swapon",
 740                                 "-p",
 741                                 p,
 742                                 s->what,
 743                                 NULL);
 744         } else
 745                 r = exec_command_set(
 746                                 s->control_command,
 747                                 "/sbin/swapon",
 748                                 s->what,
 749                                 NULL);
 750
 751         if (r < 0)
 752                 goto fail;
 753
 754         swap_unwatch_control_pid(s);
 755
 756         if ((r = swap_spawn(s, s->control_command, &s->control_pid)) < 0)
 757                 goto fail;
 758
 759         swap_set_state(s, SWAP_ACTIVATING);
 760
 761         return;
 762
 763 fail:
 764         log_warning("%s failed to run 'swapon' task: %s", s->meta.id, strerror(-r));
 765         swap_enter_dead(s, false);
 766 }
 767
 768 static void swap_enter_deactivating(Swap *s, bool success) {
 769         int r;
 770
 771         assert(s);
 772
 773         if (!success)
 774                 s->failure = true;
 775
 776         s->control_command_id = SWAP_EXEC_DEACTIVATE;
 777         s->control_command = s->exec_command + SWAP_EXEC_DEACTIVATE;
 778
 779         if ((r = exec_command_set(
 780                              s->control_command,
 781                              "/sbin/swapoff",
 782                              s->what,
 783                              NULL)) < 0)
 784                 goto fail;
 785
 786         swap_unwatch_control_pid(s);
 787
 788         if ((r = swap_spawn(s, s->control_command, &s->control_pid)) < 0)
 789                 goto fail;
 790
 791         swap_set_state(s, SWAP_DEACTIVATING);
 792
 793         return;
 794
 795 fail:
 796         log_warning("%s failed to run 'swapoff' task: %s", s->meta.id, strerror(-r));
 797         swap_enter_active(s, false);
 798 }
 799
 800 static int swap_start(Unit *u) {
 801         Swap *s = SWAP(u);
 802
 803         assert(s);
 804
 805         /* We cannot fulfill this request right now, try again later
 806          * please! */
 807
 808         if (s->state == SWAP_DEACTIVATING ||
 809             s->state == SWAP_DEACTIVATING_SIGTERM ||
 810             s->state == SWAP_DEACTIVATING_SIGKILL ||
 811             s->state == SWAP_ACTIVATING_SIGTERM ||
 812             s->state == SWAP_ACTIVATING_SIGKILL)
 813                 return -EAGAIN;
 814
 815         if (s->state == SWAP_ACTIVATING)
 816                 return 0;
 817
 818         assert(s->state == SWAP_DEAD || s->state == SWAP_FAILED);
 819
 820         s->failure = false;
 821         swap_enter_activating(s);
 822         return 0;
 823 }
 824
 825 static int swap_stop(Unit *u) {
 826         Swap *s = SWAP(u);
 827
 828         assert(s);
 829
 830         if (s->state == SWAP_DEACTIVATING ||
 831             s->state == SWAP_DEACTIVATING_SIGTERM ||
 832             s->state == SWAP_DEACTIVATING_SIGKILL ||
 833             s->state == SWAP_ACTIVATING_SIGTERM ||
 834             s->state == SWAP_ACTIVATING_SIGKILL)
 835                 return 0;
 836
 837         assert(s->state == SWAP_ACTIVATING ||
 838                s->state == SWAP_ACTIVE);
 839
 840         swap_enter_deactivating(s, true);
 841         return 0;
 842 }
 843
 844 static int swap_serialize(Unit *u, FILE *f, FDSet *fds) {
 845         Swap *s = SWAP(u);
 846
 847         assert(s);
 848         assert(f);
 849         assert(fds);
 850
 851         unit_serialize_item(u, f, "state", swap_state_to_string(s->state));
 852         unit_serialize_item(u, f, "failure", yes_no(s->failure));
 853
 854         if (s->control_pid > 0)
 855                 unit_serialize_item_format(u, f, "control-pid", "%lu", (unsigned long) s->control_pid);
 856
 857         if (s->control_command_id >= 0)
 858                 unit_serialize_item(u, f, "control-command", swap_exec_command_to_string(s->control_command_id));
 859
 860         return 0;
 861 }
 862
 863 static int swap_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 864         Swap *s = SWAP(u);
 865
 866         assert(s);
 867         assert(fds);
 868
 869         if (streq(key, "state")) {
 870                 SwapState state;
 871
 872                 if ((state = swap_state_from_string(value)) < 0)
 873                         log_debug("Failed to parse state value %s", value);
 874                 else
 875                         s->deserialized_state = state;
 876         } else if (streq(key, "failure")) {
 877                 int b;
 878
 879                 if ((b = parse_boolean(value)) < 0)
 880                         log_debug("Failed to parse failure value %s", value);
 881                 else
 882                         s->failure = b || s->failure;
 883
 884         } else if (streq(key, "control-pid")) {
 885                 pid_t pid;
 886
 887                 if (parse_pid(value, &pid) < 0)
 888                         log_debug("Failed to parse control-pid value %s", value);
 889                 else
 890                         s->control_pid = pid;
 891
 892         } else if (streq(key, "control-command")) {
 893                 SwapExecCommand id;
 894
 895                 if ((id = swap_exec_command_from_string(value)) < 0)
 896                         log_debug("Failed to parse exec-command value %s", value);
 897                 else {
 898                         s->control_command_id = id;
 899                         s->control_command = s->exec_command + id;
 900                 }
 901
 902         } else
 903                 log_debug("Unknown serialization key '%s'", key);
 904
 905         return 0;
 906 }
 907
 908 static UnitActiveState swap_active_state(Unit *u) {
 909         assert(u);
 910
 911         return state_translation_table[SWAP(u)->state];
 912 }
 913
 914 static const char *swap_sub_state_to_string(Unit *u) {
 915         assert(u);
 916
 917         return swap_state_to_string(SWAP(u)->state);
 918 }
 919
 920 static bool swap_check_gc(Unit *u) {
 921         Swap *s = SWAP(u);
 922
 923         assert(s);
 924
 925         return s->from_etc_fstab || s->from_proc_swaps;
 926 }
 927
 928 static void swap_sigchld_event(Unit *u, pid_t pid, int code, int status) {
 929         Swap *s = SWAP(u);
 930         bool success;
 931
 932         assert(s);
 933         assert(pid >= 0);
 934
 935         if (pid != s->control_pid)
 936                 return;
 937
 938         s->control_pid = 0;
 939
 940         success = is_clean_exit(code, status);
 941         s->failure = s->failure || !success;
 942
 943         if (s->control_command) {
 944                 exec_status_exit(&s->control_command->exec_status, &s->exec_context, pid, code, status);
 945                 s->control_command = NULL;
 946                 s->control_command_id = _SWAP_EXEC_COMMAND_INVALID;
 947         }
 948
 949         log_full(success ? LOG_DEBUG : LOG_NOTICE,
 950                  "%s swap process exited, code=%s status=%i", u->meta.id, sigchld_code_to_string(code), status);
 951
 952         switch (s->state) {
 953
 954         case SWAP_ACTIVATING:
 955         case SWAP_ACTIVATING_SIGTERM:
 956         case SWAP_ACTIVATING_SIGKILL:
 957
 958                 if (success)
 959                         swap_enter_active(s, true);
 960                 else
 961                         swap_enter_dead(s, false);
 962                 break;
 963
 964         case SWAP_DEACTIVATING:
 965         case SWAP_DEACTIVATING_SIGKILL:
 966         case SWAP_DEACTIVATING_SIGTERM:
 967
 968                 if (success)
 969                         swap_enter_dead(s, true);
 970                 else
 971                         swap_enter_dead(s, false);
 972                 break;
 973
 974         default:
 975                 assert_not_reached("Uh, control process died at wrong time.");
 976         }
 977
 978         /* Notify clients about changed exit status */
 979         unit_add_to_dbus_queue(u);
 980
 981         /* Request a reload of /proc/swaps, so that following units
 982          * can follow our state change */
 983         u->meta.manager->request_reload = true;
 984 }
 985
 986 static void swap_timer_event(Unit *u, uint64_t elapsed, Watch *w) {
 987         Swap *s = SWAP(u);
 988
 989         assert(s);
 990         assert(elapsed == 1);
 991         assert(w == &s->timer_watch);
 992
 993         switch (s->state) {
 994
 995         case SWAP_ACTIVATING:
 996                 log_warning("%s activation timed out. Stopping.", u->meta.id);
 997                 swap_enter_signal(s, SWAP_ACTIVATING_SIGTERM, false);
 998                 break;
 999
1000         case SWAP_DEACTIVATING:
1001                 log_warning("%s deactivation timed out. Stopping.", u->meta.id);
1002                 swap_enter_signal(s, SWAP_DEACTIVATING_SIGTERM, false);
1003                 break;
1004
1005         case SWAP_ACTIVATING_SIGTERM:
1006                 if (s->exec_context.send_sigkill) {
1007                         log_warning("%s activation timed out. Killing.", u->meta.id);
1008                         swap_enter_signal(s, SWAP_ACTIVATING_SIGKILL, false);
1009                 } else {
1010                         log_warning("%s activation timed out. Skipping SIGKILL. Ignoring.", u->meta.id);
1011                         swap_enter_dead(s, false);
1012                 }
1013                 break;
1014
1015         case SWAP_DEACTIVATING_SIGTERM:
1016                 if (s->exec_context.send_sigkill) {
1017                         log_warning("%s deactivation timed out. Killing.", u->meta.id);
1018                         swap_enter_signal(s, SWAP_DEACTIVATING_SIGKILL, false);
1019                 } else {
1020                         log_warning("%s deactivation timed out. Skipping SIGKILL. Ignoring.", u->meta.id);
1021                         swap_enter_dead(s, false);
1022                 }
1023                 break;
1024
1025         case SWAP_ACTIVATING_SIGKILL:
1026         case SWAP_DEACTIVATING_SIGKILL:
1027                 log_warning("%s swap process still around after SIGKILL. Ignoring.", u->meta.id);
1028                 swap_enter_dead(s, false);
1029                 break;
1030
1031         default:
1032                 assert_not_reached("Timeout at wrong time.");
1033         }
1034 }
1035
1036 static int swap_load_proc_swaps(Manager *m, bool set_flags) {
1037         unsigned i;
1038         int r = 0;
1039
1040         assert(m);
1041
1042         rewind(m->proc_swaps);
1043
1044         (void) fscanf(m->proc_swaps, "%*s %*s %*s %*s %*s\n");
1045
1046         for (i = 1;; i++) {
1047                 char *dev = NULL, *d;
1048                 int prio = 0, k;
1049
1050                 if ((k = fscanf(m->proc_swaps,
1051                                 "%ms "  /* device/file */
1052                                 "%*s "  /* type of swap */
1053                                 "%*s "  /* swap size */
1054                                 "%*s "  /* used */
1055                                 "%i\n", /* priority */
1056                                 &dev, &prio)) != 2) {
1057
1058                         if (k == EOF)
1059                                 break;
1060
1061                         log_warning("Failed to parse /proc/swaps:%u.", i);
1062                         free(dev);
1063                         continue;
1064                 }
1065
1066                 d = cunescape(dev);
1067                 free(dev);
1068
1069                 if (!d)
1070                         return -ENOMEM;
1071
1072                 k = swap_process_new_swap(m, d, prio, set_flags);
1073                 free(d);
1074
1075                 if (k < 0)
1076                         r = k;
1077         }
1078
1079         return r;
1080 }
1081
1082 int swap_dispatch_reload(Manager *m) {
1083         /* This function should go as soon as the kernel properly notifies us */
1084
1085         if (_likely_(!m->request_reload))
1086                 return 0;
1087
1088         m->request_reload = false;
1089
1090         return swap_fd_event(m, EPOLLPRI);
1091 }
1092
1093 int swap_fd_event(Manager *m, int events) {
1094         Meta *meta;
1095         int r;
1096
1097         assert(m);
1098         assert(events & EPOLLPRI);
1099
1100         if ((r = swap_load_proc_swaps(m, true)) < 0) {
1101                 log_error("Failed to reread /proc/swaps: %s", strerror(-r));
1102
1103                 /* Reset flags, just in case, for late calls */
1104                 LIST_FOREACH(units_by_type, meta, m->units_by_type[UNIT_SWAP]) {
1105                         Swap *swap = (Swap*) meta;
1106
1107                         swap->is_active = swap->just_activated = false;
1108                 }
1109
1110                 return 0;
1111         }
1112
1113         manager_dispatch_load_queue(m);
1114
1115         LIST_FOREACH(units_by_type, meta, m->units_by_type[UNIT_SWAP]) {
1116                 Swap *swap = (Swap*) meta;
1117
1118                 if (!swap->is_active) {
1119                         /* This has just been deactivated */
1120
1121                         swap->from_proc_swaps = false;
1122                         swap_unset_proc_swaps(swap);
1123
1124                         switch (swap->state) {
1125
1126                         case SWAP_ACTIVE:
1127                                 swap_enter_dead(swap, true);
1128                                 break;
1129
1130                         default:
1131                                 swap_set_state(swap, swap->state);
1132                                 break;
1133                         }
1134
1135                 } else if (swap->just_activated) {
1136
1137                         /* New swap entry */
1138
1139                         switch (swap->state) {
1140
1141                         case SWAP_DEAD:
1142                         case SWAP_FAILED:
1143                                 swap_enter_active(swap, true);
1144                                 break;
1145
1146                         default:
1147                                 /* Nothing really changed, but let's
1148                                  * issue an notification call
1149                                  * nonetheless, in case somebody is
1150                                  * waiting for this. */
1151                                 swap_set_state(swap, swap->state);
1152                                 break;
1153                         }
1154                 }
1155
1156                 /* Reset the flags for later calls */
1157                 swap->is_active = swap->just_activated = false;
1158         }
1159
1160         return 1;
1161 }
1162
1163 static Unit *swap_following(Unit *u) {
1164         Swap *s = SWAP(u);
1165         Swap *other, *first = NULL;
1166
1167         assert(s);
1168
1169         if (streq_ptr(s->what, s->parameters_proc_swaps.what))
1170                 return NULL;
1171
1172         /* Make everybody follow the unit that's named after the swap
1173          * device in the kernel */
1174
1175         LIST_FOREACH_AFTER(same_proc_swaps, other, s)
1176                 if (streq_ptr(other->what, other->parameters_proc_swaps.what))
1177                         return UNIT(other);
1178
1179         LIST_FOREACH_BEFORE(same_proc_swaps, other, s) {
1180                 if (streq_ptr(other->what, other->parameters_proc_swaps.what))
1181                         return UNIT(other);
1182
1183                 first = other;
1184         }
1185
1186         return UNIT(first);
1187 }
1188
1189 static int swap_following_set(Unit *u, Set **_set) {
1190         Swap *s = SWAP(u);
1191         Swap *other;
1192         Set *set;
1193         int r;
1194
1195         assert(s);
1196         assert(_set);
1197
1198         if (LIST_JUST_US(same_proc_swaps, s)) {
1199                 *_set = NULL;
1200                 return 0;
1201         }
1202
1203         if (!(set = set_new(NULL, NULL)))
1204                 return -ENOMEM;
1205
1206         LIST_FOREACH_AFTER(same_proc_swaps, other, s)
1207                 if ((r = set_put(set, other)) < 0)
1208                         goto fail;
1209
1210         LIST_FOREACH_BEFORE(same_proc_swaps, other, s)
1211                 if ((r = set_put(set, other)) < 0)
1212                         goto fail;
1213
1214         *_set = set;
1215         return 1;
1216
1217 fail:
1218         set_free(set);
1219         return r;
1220 }
1221
1222 static void swap_shutdown(Manager *m) {
1223         assert(m);
1224
1225         if (m->proc_swaps) {
1226                 fclose(m->proc_swaps);
1227                 m->proc_swaps = NULL;
1228         }
1229
1230         hashmap_free(m->swaps_by_proc_swaps);
1231         m->swaps_by_proc_swaps = NULL;
1232 }
1233
1234 static int swap_enumerate(Manager *m) {
1235         int r;
1236         struct epoll_event ev;
1237         assert(m);
1238
1239         if (!m->proc_swaps) {
1240                 if (!(m->proc_swaps = fopen("/proc/swaps", "re")))
1241                         return (errno == ENOENT) ? 0 : -errno;
1242
1243                 m->swap_watch.type = WATCH_SWAP;
1244                 m->swap_watch.fd = fileno(m->proc_swaps);
1245
1246                 zero(ev);
1247                 ev.events = EPOLLPRI;
1248                 ev.data.ptr = &m->swap_watch;
1249
1250                 if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->swap_watch.fd, &ev) < 0)
1251                         return -errno;
1252         }
1253
1254         /* We rely on mount.c to load /etc/fstab for us */
1255
1256         if ((r = swap_load_proc_swaps(m, false)) < 0)
1257                 swap_shutdown(m);
1258
1259         return r;
1260 }
1261
1262 static void swap_reset_failed(Unit *u) {
1263         Swap *s = SWAP(u);
1264
1265         assert(s);
1266
1267         if (s->state == SWAP_FAILED)
1268                 swap_set_state(s, SWAP_DEAD);
1269
1270         s->failure = false;
1271 }
1272
1273 static int swap_kill(Unit *u, KillWho who, KillMode mode, int signo, DBusError *error) {
1274         Swap *s = SWAP(u);
1275         int r = 0;
1276         Set *pid_set = NULL;
1277
1278         assert(s);
1279
1280         if (who == KILL_MAIN) {
1281                 dbus_set_error(error, BUS_ERROR_NO_SUCH_PROCESS, "Swap units have no main processes");
1282                 return -ESRCH;
1283         }
1284
1285         if (s->control_pid <= 0 && who == KILL_CONTROL) {
1286                 dbus_set_error(error, BUS_ERROR_NO_SUCH_PROCESS, "No control process to kill");
1287                 return -ESRCH;
1288         }
1289
1290         if (who == KILL_CONTROL || who == KILL_ALL)
1291                 if (s->control_pid > 0)
1292                         if (kill(s->control_pid, signo) < 0)
1293                                 r = -errno;
1294
1295         if (who == KILL_ALL && mode == KILL_CONTROL_GROUP) {
1296                 int q;
1297
1298                 if (!(pid_set = set_new(trivial_hash_func, trivial_compare_func)))
1299                         return -ENOMEM;
1300
1301                 /* Exclude the control pid from being killed via the cgroup */
1302                 if (s->control_pid > 0)
1303                         if ((q = set_put(pid_set, LONG_TO_PTR(s->control_pid))) < 0) {
1304                                 r = q;
1305                                 goto finish;
1306                         }
1307
1308                 if ((q = cgroup_bonding_kill_list(s->meta.cgroup_bondings, signo, false, pid_set)) < 0)
1309                         if (q != -EAGAIN && q != -ESRCH && q != -ENOENT)
1310                                 r = q;
1311         }
1312
1313 finish:
1314         if (pid_set)
1315                 set_free(pid_set);
1316
1317         return r;
1318 }
1319
1320 static const char* const swap_state_table[_SWAP_STATE_MAX] = {
1321         [SWAP_DEAD] = "dead",
1322         [SWAP_ACTIVATING] = "activating",
1323         [SWAP_ACTIVE] = "active",
1324         [SWAP_DEACTIVATING] = "deactivating",
1325         [SWAP_ACTIVATING_SIGTERM] = "activating-sigterm",
1326         [SWAP_ACTIVATING_SIGKILL] = "activating-sigkill",
1327         [SWAP_DEACTIVATING_SIGTERM] = "deactivating-sigterm",
1328         [SWAP_DEACTIVATING_SIGKILL] = "deactivating-sigkill",
1329         [SWAP_FAILED] = "failed"
1330 };
1331
1332 DEFINE_STRING_TABLE_LOOKUP(swap_state, SwapState);
1333
1334 static const char* const swap_exec_command_table[_SWAP_EXEC_COMMAND_MAX] = {
1335         [SWAP_EXEC_ACTIVATE] = "ExecActivate",
1336         [SWAP_EXEC_DEACTIVATE] = "ExecDeactivate",
1337 };
1338
1339 DEFINE_STRING_TABLE_LOOKUP(swap_exec_command, SwapExecCommand);
1340
1341 const UnitVTable swap_vtable = {
1342         .suffix = ".swap",
1343         .sections =
1344                 "Unit\0"
1345                 "Swap\0"
1346                 "Install\0",
1347
1348         .no_alias = true,
1349         .no_instances = true,
1350         .show_status = true,
1351
1352         .init = swap_init,
1353         .load = swap_load,
1354         .done = swap_done,
1355
1356         .coldplug = swap_coldplug,
1357
1358         .dump = swap_dump,
1359
1360         .start = swap_start,
1361         .stop = swap_stop,
1362
1363         .kill = swap_kill,
1364
1365         .serialize = swap_serialize,
1366         .deserialize_item = swap_deserialize_item,
1367
1368         .active_state = swap_active_state,
1369         .sub_state_to_string = swap_sub_state_to_string,
1370
1371         .check_gc = swap_check_gc,
1372
1373         .sigchld_event = swap_sigchld_event,
1374         .timer_event = swap_timer_event,
1375
1376         .reset_failed = swap_reset_failed,
1377
1378         .bus_interface = "org.freedesktop.systemd1.Swap",
1379         .bus_message_handler = bus_swap_message_handler,
1380         .bus_invalidating_properties =  bus_swap_invalidating_properties,
1381
1382         .following = swap_following,
1383         .following_set = swap_following_set,
1384
1385         .enumerate = swap_enumerate,
1386         .shutdown = swap_shutdown
1387 };