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(UNIT(s)->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(UNIT(s)->manager->swaps_by_proc_swaps, s->parameters_proc_swaps.what, first->parameters_proc_swaps.what, first);
  70         else
  71                 hashmap_remove(UNIT(s)->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(UNIT(s)->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 = u->manager->default_std_output;
  87         s->exec_context.std_error = u->manager->default_std_error;
  88
  89         s->parameters_etc_fstab.priority = s->parameters_proc_swaps.priority = s->parameters_fragment.priority = -1;
  90
  91         s->timer_watch.type = WATCH_INVALID;
  92
  93         s->control_command_id = _MOUNT_EXEC_COMMAND_INVALID;
  94
  95         UNIT(s)->ignore_on_isolate = true;
  96 }
  97
  98 static void swap_unwatch_control_pid(Swap *s) {
  99         assert(s);
 100
 101         if (s->control_pid <= 0)
 102                 return;
 103
 104         unit_unwatch_pid(UNIT(s), s->control_pid);
 105         s->control_pid = 0;
 106 }
 107
 108 static void swap_done(Unit *u) {
 109         Swap *s = SWAP(u);
 110
 111         assert(s);
 112
 113         swap_unset_proc_swaps(s);
 114
 115         free(s->what);
 116         s->what = NULL;
 117
 118         free(s->parameters_etc_fstab.what);
 119         free(s->parameters_fragment.what);
 120         s->parameters_etc_fstab.what = s->parameters_fragment.what = NULL;
 121
 122         exec_context_done(&s->exec_context);
 123         exec_command_done_array(s->exec_command, _SWAP_EXEC_COMMAND_MAX);
 124         s->control_command = NULL;
 125
 126         swap_unwatch_control_pid(s);
 127
 128         unit_unwatch_timer(u, &s->timer_watch);
 129 }
 130
 131 int swap_add_one_mount_link(Swap *s, Mount *m) {
 132          int r;
 133
 134         assert(s);
 135         assert(m);
 136
 137         if (UNIT(s)->load_state != UNIT_LOADED ||
 138             UNIT(m)->load_state != UNIT_LOADED)
 139                 return 0;
 140
 141         if (is_device_path(s->what))
 142                 return 0;
 143
 144         if (!path_startswith(s->what, m->where))
 145                 return 0;
 146
 147         if ((r = unit_add_two_dependencies(UNIT(s), UNIT_AFTER, UNIT_REQUIRES, UNIT(m), true)) < 0)
 148                 return r;
 149
 150         return 0;
 151 }
 152
 153 static int swap_add_mount_links(Swap *s) {
 154         Unit *other;
 155         int r;
 156
 157         assert(s);
 158
 159         LIST_FOREACH(units_by_type, other, UNIT(s)->manager->units_by_type[UNIT_MOUNT])
 160                 if ((r = swap_add_one_mount_link(s, (Mount*) other)) < 0)
 161                         return r;
 162
 163         return 0;
 164 }
 165
 166 static int swap_add_target_links(Swap *s) {
 167         Unit *tu;
 168         SwapParameters *p;
 169         int r;
 170
 171         assert(s);
 172
 173         if (s->from_fragment)
 174                 p = &s->parameters_fragment;
 175         else if (s->from_etc_fstab)
 176                 p = &s->parameters_etc_fstab;
 177         else
 178                 return 0;
 179
 180         if ((r = manager_load_unit(UNIT(s)->manager, SPECIAL_SWAP_TARGET, NULL, NULL, &tu)) < 0)
 181                 return r;
 182
 183         if (!p->noauto &&
 184             !p->nofail &&
 185             (p->handle || UNIT(s)->manager->swap_auto) &&
 186             s->from_etc_fstab &&
 187             UNIT(s)->manager->running_as == MANAGER_SYSTEM)
 188                 if ((r = unit_add_dependency(tu, UNIT_WANTS, UNIT(s), true)) < 0)
 189                         return r;
 190
 191         return unit_add_dependency(UNIT(s), UNIT_BEFORE, tu, true);
 192 }
 193
 194 static int swap_add_device_links(Swap *s) {
 195         SwapParameters *p;
 196
 197         assert(s);
 198
 199         if (!s->what)
 200                 return 0;
 201
 202         if (s->from_fragment)
 203                 p = &s->parameters_fragment;
 204         else if (s->from_etc_fstab)
 205                 p = &s->parameters_etc_fstab;
 206         else
 207                 return 0;
 208
 209         if (is_device_path(s->what))
 210                 return unit_add_node_link(UNIT(s), s->what,
 211                                           !p->noauto && p->nofail &&
 212                                           UNIT(s)->manager->running_as == MANAGER_SYSTEM);
 213         else
 214                 /* File based swap devices need to be ordered after
 215                  * remount-rootfs.service, since they might need a
 216                  * writable file system. */
 217                 return unit_add_dependency_by_name(UNIT(s), UNIT_AFTER, SPECIAL_REMOUNT_ROOTFS_SERVICE, NULL, true);
 218 }
 219
 220 static int swap_add_default_dependencies(Swap *s) {
 221         int r;
 222
 223         assert(s);
 224
 225         if (UNIT(s)->manager->running_as == MANAGER_SYSTEM) {
 226
 227                 if ((r = unit_add_two_dependencies_by_name(UNIT(s), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_UMOUNT_TARGET, NULL, true)) < 0)
 228                         return r;
 229         }
 230
 231         return 0;
 232 }
 233
 234 static int swap_verify(Swap *s) {
 235         bool b;
 236         char *e;
 237
 238         if (UNIT(s)->load_state != UNIT_LOADED)
 239                   return 0;
 240
 241         if (!(e = unit_name_from_path(s->what, ".swap")))
 242                   return -ENOMEM;
 243
 244         b = unit_has_name(UNIT(s), e);
 245         free(e);
 246
 247         if (!b) {
 248                 log_error("%s: Value of \"What\" and unit name do not match, not loading.\n", UNIT(s)->id);
 249                 return -EINVAL;
 250         }
 251
 252         if (s->exec_context.pam_name && s->exec_context.kill_mode != KILL_CONTROL_GROUP) {
 253                 log_error("%s has PAM enabled. Kill mode must be set to 'control-group'. Refusing.", UNIT(s)->id);
 254                 return -EINVAL;
 255         }
 256
 257         return 0;
 258 }
 259
 260 static int swap_load(Unit *u) {
 261         int r;
 262         Swap *s = SWAP(u);
 263
 264         assert(s);
 265         assert(u->load_state == UNIT_STUB);
 266
 267         /* Load a .swap file */
 268         if ((r = unit_load_fragment_and_dropin_optional(u)) < 0)
 269                 return r;
 270
 271         if (u->load_state == UNIT_LOADED) {
 272                 if ((r = unit_add_exec_dependencies(u, &s->exec_context)) < 0)
 273                         return r;
 274
 275                 if (UNIT(s)->fragment_path)
 276                         s->from_fragment = true;
 277
 278                 if (!s->what) {
 279                         if (s->parameters_fragment.what)
 280                                 s->what = strdup(s->parameters_fragment.what);
 281                         else if (s->parameters_etc_fstab.what)
 282                                 s->what = strdup(s->parameters_etc_fstab.what);
 283                         else if (s->parameters_proc_swaps.what)
 284                                 s->what = strdup(s->parameters_proc_swaps.what);
 285                         else
 286                                 s->what = unit_name_to_path(u->id);
 287
 288                         if (!s->what)
 289                                 return -ENOMEM;
 290                 }
 291
 292                 path_kill_slashes(s->what);
 293
 294                 if (!UNIT(s)->description)
 295                         if ((r = unit_set_description(u, s->what)) < 0)
 296                                 return r;
 297
 298                 if ((r = swap_add_device_links(s)) < 0)
 299                         return r;
 300
 301                 if ((r = swap_add_mount_links(s)) < 0)
 302                         return r;
 303
 304                 if ((r = swap_add_target_links(s)) < 0)
 305                         return r;
 306
 307                 if ((r = unit_add_default_cgroups(u)) < 0)
 308                         return r;
 309
 310                 if (UNIT(s)->default_dependencies)
 311                         if ((r = swap_add_default_dependencies(s)) < 0)
 312                                 return r;
 313         }
 314
 315         return swap_verify(s);
 316 }
 317
 318 int swap_add_one(
 319                 Manager *m,
 320                 const char *what,
 321                 const char *what_proc_swaps,
 322                 int priority,
 323                 bool noauto,
 324                 bool nofail,
 325                 bool handle,
 326                 bool set_flags) {
 327
 328         Unit *u = NULL;
 329         char *e = NULL, *wp = NULL;
 330         bool delete = false;
 331         int r;
 332         SwapParameters *p;
 333
 334         assert(m);
 335         assert(what);
 336
 337         e = unit_name_from_path(what, ".swap");
 338         if (!e)
 339                 return -ENOMEM;
 340
 341         u = manager_get_unit(m, e);
 342
 343         if (what_proc_swaps &&
 344             u &&
 345             SWAP(u)->from_proc_swaps &&
 346             !path_equal(SWAP(u)->parameters_proc_swaps.what, what_proc_swaps))
 347                 return -EEXIST;
 348
 349         if (!u) {
 350                 delete = true;
 351
 352                 u = unit_new(m, sizeof(Swap));
 353                 if (!u) {
 354                         free(e);
 355                         return -ENOMEM;
 356                 }
 357
 358                 r = unit_add_name(u, e);
 359                 if (r < 0)
 360                         goto fail;
 361
 362                 SWAP(u)->what = strdup(what);
 363                 if (!SWAP(u)->what) {
 364                         r = -ENOMEM;
 365                         goto fail;
 366                 }
 367
 368                 unit_add_to_load_queue(u);
 369         } else
 370                 delete = false;
 371
 372         if (what_proc_swaps) {
 373                 Swap *first;
 374
 375                 p = &SWAP(u)->parameters_proc_swaps;
 376
 377                 if (!p->what) {
 378                         if (!(wp = strdup(what_proc_swaps))) {
 379                                 r = -ENOMEM;
 380                                 goto fail;
 381                         }
 382
 383                         if (!m->swaps_by_proc_swaps)
 384                                 if (!(m->swaps_by_proc_swaps = hashmap_new(string_hash_func, string_compare_func))) {
 385                                         r = -ENOMEM;
 386                                         goto fail;
 387                                 }
 388
 389                         free(p->what);
 390                         p->what = wp;
 391
 392                         first = hashmap_get(m->swaps_by_proc_swaps, wp);
 393                         LIST_PREPEND(Swap, same_proc_swaps, first, SWAP(u));
 394
 395                         if ((r = hashmap_replace(m->swaps_by_proc_swaps, wp, first)) < 0)
 396                                 goto fail;
 397                 }
 398
 399                 if (set_flags) {
 400                         SWAP(u)->is_active = true;
 401                         SWAP(u)->just_activated = !SWAP(u)->from_proc_swaps;
 402                 }
 403
 404                 SWAP(u)->from_proc_swaps = true;
 405
 406         } else {
 407                 p = &SWAP(u)->parameters_etc_fstab;
 408
 409                 if (!(wp = strdup(what))) {
 410                         r = -ENOMEM;
 411                         goto fail;
 412                 }
 413
 414                 free(p->what);
 415                 p->what = wp;
 416
 417                 SWAP(u)->from_etc_fstab = true;
 418         }
 419
 420         p->priority = priority;
 421         p->noauto = noauto;
 422         p->nofail = nofail;
 423         p->handle = handle;
 424
 425         unit_add_to_dbus_queue(u);
 426
 427         free(e);
 428
 429         return 0;
 430
 431 fail:
 432         log_warning("Failed to load swap unit: %s", strerror(-r));
 433
 434         free(wp);
 435         free(e);
 436
 437         if (delete && u)
 438                 unit_free(u);
 439
 440         return r;
 441 }
 442
 443 static int swap_process_new_swap(Manager *m, const char *device, int prio, bool set_flags) {
 444         struct stat st;
 445         int r = 0, k;
 446
 447         assert(m);
 448
 449         if (stat(device, &st) >= 0 && S_ISBLK(st.st_mode)) {
 450                 struct udev_device *d;
 451                 const char *dn;
 452                 struct udev_list_entry *item = NULL, *first = NULL;
 453
 454                 /* So this is a proper swap device. Create swap units
 455                  * for all names this swap device is known under */
 456
 457                 if (!(d = udev_device_new_from_devnum(m->udev, 'b', st.st_rdev)))
 458                         return -ENOMEM;
 459
 460                 if ((dn = udev_device_get_devnode(d)))
 461                         r = swap_add_one(m, dn, device, prio, false, false, false, set_flags);
 462
 463                 /* Add additional units for all symlinks */
 464                 first = udev_device_get_devlinks_list_entry(d);
 465                 udev_list_entry_foreach(item, first) {
 466                         const char *p;
 467
 468                         /* Don't bother with the /dev/block links */
 469                         p = udev_list_entry_get_name(item);
 470
 471                         if (path_startswith(p, "/dev/block/"))
 472                                 continue;
 473
 474                         if (stat(p, &st) >= 0)
 475                                 if ((!S_ISBLK(st.st_mode)) || st.st_rdev != udev_device_get_devnum(d))
 476                                         continue;
 477
 478                         if ((k = swap_add_one(m, p, device, prio, false, false, false, set_flags)) < 0)
 479                                 r = k;
 480                 }
 481
 482                 udev_device_unref(d);
 483         }
 484
 485         if ((k = swap_add_one(m, device, device, prio, false, false, false, set_flags)) < 0)
 486                 r = k;
 487
 488         return r;
 489 }
 490
 491 static void swap_set_state(Swap *s, SwapState state) {
 492         SwapState old_state;
 493
 494         assert(s);
 495
 496         old_state = s->state;
 497         s->state = state;
 498
 499         if (state != SWAP_ACTIVATING &&
 500             state != SWAP_ACTIVATING_SIGTERM &&
 501             state != SWAP_ACTIVATING_SIGKILL &&
 502             state != SWAP_DEACTIVATING &&
 503             state != SWAP_DEACTIVATING_SIGTERM &&
 504             state != SWAP_DEACTIVATING_SIGKILL) {
 505                 unit_unwatch_timer(UNIT(s), &s->timer_watch);
 506                 swap_unwatch_control_pid(s);
 507                 s->control_command = NULL;
 508                 s->control_command_id = _SWAP_EXEC_COMMAND_INVALID;
 509         }
 510
 511         if (state != old_state)
 512                 log_debug("%s changed %s -> %s",
 513                           UNIT(s)->id,
 514                           swap_state_to_string(old_state),
 515                           swap_state_to_string(state));
 516
 517         unit_notify(UNIT(s), state_translation_table[old_state], state_translation_table[state], true);
 518 }
 519
 520 static int swap_coldplug(Unit *u) {
 521         Swap *s = SWAP(u);
 522         SwapState new_state = SWAP_DEAD;
 523         int r;
 524
 525         assert(s);
 526         assert(s->state == SWAP_DEAD);
 527
 528         if (s->deserialized_state != s->state)
 529                 new_state = s->deserialized_state;
 530         else if (s->from_proc_swaps)
 531                 new_state = SWAP_ACTIVE;
 532
 533         if (new_state != s->state) {
 534
 535                 if (new_state == SWAP_ACTIVATING ||
 536                     new_state == SWAP_ACTIVATING_SIGTERM ||
 537                     new_state == SWAP_ACTIVATING_SIGKILL ||
 538                     new_state == SWAP_DEACTIVATING ||
 539                     new_state == SWAP_DEACTIVATING_SIGTERM ||
 540                     new_state == SWAP_DEACTIVATING_SIGKILL) {
 541
 542                         if (s->control_pid <= 0)
 543                                 return -EBADMSG;
 544
 545                         if ((r = unit_watch_pid(UNIT(s), s->control_pid)) < 0)
 546                                 return r;
 547
 548                         if ((r = unit_watch_timer(UNIT(s), s->timeout_usec, &s->timer_watch)) < 0)
 549                                 return r;
 550                 }
 551
 552                 swap_set_state(s, new_state);
 553         }
 554
 555         return 0;
 556 }
 557
 558 static void swap_dump(Unit *u, FILE *f, const char *prefix) {
 559         Swap *s = SWAP(u);
 560         SwapParameters *p;
 561
 562         assert(s);
 563         assert(f);
 564
 565         if (s->from_proc_swaps)
 566                 p = &s->parameters_proc_swaps;
 567         else if (s->from_fragment)
 568                 p = &s->parameters_fragment;
 569         else
 570                 p = &s->parameters_etc_fstab;
 571
 572         fprintf(f,
 573                 "%sSwap State: %s\n"
 574                 "%sWhat: %s\n"
 575                 "%sPriority: %i\n"
 576                 "%sNoAuto: %s\n"
 577                 "%sNoFail: %s\n"
 578                 "%sHandle: %s\n"
 579                 "%sFrom /etc/fstab: %s\n"
 580                 "%sFrom /proc/swaps: %s\n"
 581                 "%sFrom fragment: %s\n",
 582                 prefix, swap_state_to_string(s->state),
 583                 prefix, s->what,
 584                 prefix, p->priority,
 585                 prefix, yes_no(p->noauto),
 586                 prefix, yes_no(p->nofail),
 587                 prefix, yes_no(p->handle),
 588                 prefix, yes_no(s->from_etc_fstab),
 589                 prefix, yes_no(s->from_proc_swaps),
 590                 prefix, yes_no(s->from_fragment));
 591
 592         if (s->control_pid > 0)
 593                 fprintf(f,
 594                         "%sControl PID: %lu\n",
 595                         prefix, (unsigned long) s->control_pid);
 596
 597         exec_context_dump(&s->exec_context, f, prefix);
 598 }
 599
 600 static int swap_spawn(Swap *s, ExecCommand *c, pid_t *_pid) {
 601         pid_t pid;
 602         int r;
 603
 604         assert(s);
 605         assert(c);
 606         assert(_pid);
 607
 608         if ((r = unit_watch_timer(UNIT(s), s->timeout_usec, &s->timer_watch)) < 0)
 609                 goto fail;
 610
 611         if ((r = exec_spawn(c,
 612                             NULL,
 613                             &s->exec_context,
 614                             NULL, 0,
 615                             UNIT(s)->manager->environment,
 616                             true,
 617                             true,
 618                             true,
 619                             UNIT(s)->manager->confirm_spawn,
 620                             UNIT(s)->cgroup_bondings,
 621                             UNIT(s)->cgroup_attributes,
 622                             &pid)) < 0)
 623                 goto fail;
 624
 625         if ((r = unit_watch_pid(UNIT(s), pid)) < 0)
 626                 /* FIXME: we need to do something here */
 627                 goto fail;
 628
 629         *_pid = pid;
 630
 631         return 0;
 632
 633 fail:
 634         unit_unwatch_timer(UNIT(s), &s->timer_watch);
 635
 636         return r;
 637 }
 638
 639 static void swap_enter_dead(Swap *s, bool success) {
 640         assert(s);
 641
 642         if (!success)
 643                 s->failure = true;
 644
 645         swap_set_state(s, s->failure ? SWAP_FAILED : SWAP_DEAD);
 646 }
 647
 648 static void swap_enter_active(Swap *s, bool success) {
 649         assert(s);
 650
 651         if (!success)
 652                 s->failure = true;
 653
 654         swap_set_state(s, SWAP_ACTIVE);
 655 }
 656
 657 static void swap_enter_signal(Swap *s, SwapState state, bool success) {
 658         int r;
 659         Set *pid_set = NULL;
 660         bool wait_for_exit = false;
 661
 662         assert(s);
 663
 664         if (!success)
 665                 s->failure = true;
 666
 667         if (s->exec_context.kill_mode != KILL_NONE) {
 668                 int sig = (state == SWAP_ACTIVATING_SIGTERM ||
 669                            state == SWAP_DEACTIVATING_SIGTERM) ? s->exec_context.kill_signal : SIGKILL;
 670
 671                 if (s->control_pid > 0) {
 672                         if (kill_and_sigcont(s->control_pid, sig) < 0 && errno != ESRCH)
 673
 674                                 log_warning("Failed to kill control process %li: %m", (long) s->control_pid);
 675                         else
 676                                 wait_for_exit = true;
 677                 }
 678
 679                 if (s->exec_context.kill_mode == KILL_CONTROL_GROUP) {
 680
 681                         if (!(pid_set = set_new(trivial_hash_func, trivial_compare_func))) {
 682                                 r = -ENOMEM;
 683                                 goto fail;
 684                         }
 685
 686                         /* Exclude the control pid from being killed via the cgroup */
 687                         if (s->control_pid > 0)
 688                                 if ((r = set_put(pid_set, LONG_TO_PTR(s->control_pid))) < 0)
 689                                         goto fail;
 690
 691                         if ((r = cgroup_bonding_kill_list(UNIT(s)->cgroup_bondings, sig, true, pid_set)) < 0) {
 692                                 if (r != -EAGAIN && r != -ESRCH && r != -ENOENT)
 693                                         log_warning("Failed to kill control group: %s", strerror(-r));
 694                         } else if (r > 0)
 695                                 wait_for_exit = true;
 696
 697                         set_free(pid_set);
 698                         pid_set = NULL;
 699                 }
 700         }
 701
 702         if (wait_for_exit) {
 703                 if ((r = unit_watch_timer(UNIT(s), s->timeout_usec, &s->timer_watch)) < 0)
 704                         goto fail;
 705
 706                 swap_set_state(s, state);
 707         } else
 708                 swap_enter_dead(s, true);
 709
 710         return;
 711
 712 fail:
 713         log_warning("%s failed to kill processes: %s", UNIT(s)->id, strerror(-r));
 714
 715         swap_enter_dead(s, false);
 716
 717         if (pid_set)
 718                 set_free(pid_set);
 719 }
 720
 721 static void swap_enter_activating(Swap *s) {
 722         int r, priority;
 723
 724         assert(s);
 725
 726         s->control_command_id = SWAP_EXEC_ACTIVATE;
 727         s->control_command = s->exec_command + SWAP_EXEC_ACTIVATE;
 728
 729         if (s->from_fragment)
 730                 priority = s->parameters_fragment.priority;
 731         else if (s->from_etc_fstab)
 732                 priority = s->parameters_etc_fstab.priority;
 733         else
 734                 priority = -1;
 735
 736         if (priority >= 0) {
 737                 char p[LINE_MAX];
 738
 739                 snprintf(p, sizeof(p), "%i", priority);
 740                 char_array_0(p);
 741
 742                 r = exec_command_set(
 743                                 s->control_command,
 744                                 "/sbin/swapon",
 745                                 "-p",
 746                                 p,
 747                                 s->what,
 748                                 NULL);
 749         } else
 750                 r = exec_command_set(
 751                                 s->control_command,
 752                                 "/sbin/swapon",
 753                                 s->what,
 754                                 NULL);
 755
 756         if (r < 0)
 757                 goto fail;
 758
 759         swap_unwatch_control_pid(s);
 760
 761         if ((r = swap_spawn(s, s->control_command, &s->control_pid)) < 0)
 762                 goto fail;
 763
 764         swap_set_state(s, SWAP_ACTIVATING);
 765
 766         return;
 767
 768 fail:
 769         log_warning("%s failed to run 'swapon' task: %s", UNIT(s)->id, strerror(-r));
 770         swap_enter_dead(s, false);
 771 }
 772
 773 static void swap_enter_deactivating(Swap *s, bool success) {
 774         int r;
 775
 776         assert(s);
 777
 778         if (!success)
 779                 s->failure = true;
 780
 781         s->control_command_id = SWAP_EXEC_DEACTIVATE;
 782         s->control_command = s->exec_command + SWAP_EXEC_DEACTIVATE;
 783
 784         if ((r = exec_command_set(
 785                              s->control_command,
 786                              "/sbin/swapoff",
 787                              s->what,
 788                              NULL)) < 0)
 789                 goto fail;
 790
 791         swap_unwatch_control_pid(s);
 792
 793         if ((r = swap_spawn(s, s->control_command, &s->control_pid)) < 0)
 794                 goto fail;
 795
 796         swap_set_state(s, SWAP_DEACTIVATING);
 797
 798         return;
 799
 800 fail:
 801         log_warning("%s failed to run 'swapoff' task: %s", UNIT(s)->id, strerror(-r));
 802         swap_enter_active(s, false);
 803 }
 804
 805 static int swap_start(Unit *u) {
 806         Swap *s = SWAP(u);
 807
 808         assert(s);
 809
 810         /* We cannot fulfill this request right now, try again later
 811          * please! */
 812
 813         if (s->state == SWAP_DEACTIVATING ||
 814             s->state == SWAP_DEACTIVATING_SIGTERM ||
 815             s->state == SWAP_DEACTIVATING_SIGKILL ||
 816             s->state == SWAP_ACTIVATING_SIGTERM ||
 817             s->state == SWAP_ACTIVATING_SIGKILL)
 818                 return -EAGAIN;
 819
 820         if (s->state == SWAP_ACTIVATING)
 821                 return 0;
 822
 823         assert(s->state == SWAP_DEAD || s->state == SWAP_FAILED);
 824
 825         s->failure = false;
 826         swap_enter_activating(s);
 827         return 0;
 828 }
 829
 830 static int swap_stop(Unit *u) {
 831         Swap *s = SWAP(u);
 832
 833         assert(s);
 834
 835         if (s->state == SWAP_DEACTIVATING ||
 836             s->state == SWAP_DEACTIVATING_SIGTERM ||
 837             s->state == SWAP_DEACTIVATING_SIGKILL ||
 838             s->state == SWAP_ACTIVATING_SIGTERM ||
 839             s->state == SWAP_ACTIVATING_SIGKILL)
 840                 return 0;
 841
 842         assert(s->state == SWAP_ACTIVATING ||
 843                s->state == SWAP_ACTIVE);
 844
 845         swap_enter_deactivating(s, true);
 846         return 0;
 847 }
 848
 849 static int swap_serialize(Unit *u, FILE *f, FDSet *fds) {
 850         Swap *s = SWAP(u);
 851
 852         assert(s);
 853         assert(f);
 854         assert(fds);
 855
 856         unit_serialize_item(u, f, "state", swap_state_to_string(s->state));
 857         unit_serialize_item(u, f, "failure", yes_no(s->failure));
 858
 859         if (s->control_pid > 0)
 860                 unit_serialize_item_format(u, f, "control-pid", "%lu", (unsigned long) s->control_pid);
 861
 862         if (s->control_command_id >= 0)
 863                 unit_serialize_item(u, f, "control-command", swap_exec_command_to_string(s->control_command_id));
 864
 865         return 0;
 866 }
 867
 868 static int swap_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 869         Swap *s = SWAP(u);
 870
 871         assert(s);
 872         assert(fds);
 873
 874         if (streq(key, "state")) {
 875                 SwapState state;
 876
 877                 if ((state = swap_state_from_string(value)) < 0)
 878                         log_debug("Failed to parse state value %s", value);
 879                 else
 880                         s->deserialized_state = state;
 881         } else if (streq(key, "failure")) {
 882                 int b;
 883
 884                 if ((b = parse_boolean(value)) < 0)
 885                         log_debug("Failed to parse failure value %s", value);
 886                 else
 887                         s->failure = b || s->failure;
 888
 889         } else if (streq(key, "control-pid")) {
 890                 pid_t pid;
 891
 892                 if (parse_pid(value, &pid) < 0)
 893                         log_debug("Failed to parse control-pid value %s", value);
 894                 else
 895                         s->control_pid = pid;
 896
 897         } else if (streq(key, "control-command")) {
 898                 SwapExecCommand id;
 899
 900                 if ((id = swap_exec_command_from_string(value)) < 0)
 901                         log_debug("Failed to parse exec-command value %s", value);
 902                 else {
 903                         s->control_command_id = id;
 904                         s->control_command = s->exec_command + id;
 905                 }
 906
 907         } else
 908                 log_debug("Unknown serialization key '%s'", key);
 909
 910         return 0;
 911 }
 912
 913 static UnitActiveState swap_active_state(Unit *u) {
 914         assert(u);
 915
 916         return state_translation_table[SWAP(u)->state];
 917 }
 918
 919 static const char *swap_sub_state_to_string(Unit *u) {
 920         assert(u);
 921
 922         return swap_state_to_string(SWAP(u)->state);
 923 }
 924
 925 static bool swap_check_gc(Unit *u) {
 926         Swap *s = SWAP(u);
 927
 928         assert(s);
 929
 930         return s->from_etc_fstab || s->from_proc_swaps;
 931 }
 932
 933 static void swap_sigchld_event(Unit *u, pid_t pid, int code, int status) {
 934         Swap *s = SWAP(u);
 935         bool success;
 936
 937         assert(s);
 938         assert(pid >= 0);
 939
 940         if (pid != s->control_pid)
 941                 return;
 942
 943         s->control_pid = 0;
 944
 945         success = is_clean_exit(code, status);
 946         s->failure = s->failure || !success;
 947
 948         if (s->control_command) {
 949                 exec_status_exit(&s->control_command->exec_status, &s->exec_context, pid, code, status);
 950                 s->control_command = NULL;
 951                 s->control_command_id = _SWAP_EXEC_COMMAND_INVALID;
 952         }
 953
 954         log_full(success ? LOG_DEBUG : LOG_NOTICE,
 955                  "%s swap process exited, code=%s status=%i", u->id, sigchld_code_to_string(code), status);
 956
 957         switch (s->state) {
 958
 959         case SWAP_ACTIVATING:
 960         case SWAP_ACTIVATING_SIGTERM:
 961         case SWAP_ACTIVATING_SIGKILL:
 962
 963                 if (success)
 964                         swap_enter_active(s, true);
 965                 else
 966                         swap_enter_dead(s, false);
 967                 break;
 968
 969         case SWAP_DEACTIVATING:
 970         case SWAP_DEACTIVATING_SIGKILL:
 971         case SWAP_DEACTIVATING_SIGTERM:
 972
 973                 if (success)
 974                         swap_enter_dead(s, true);
 975                 else
 976                         swap_enter_dead(s, false);
 977                 break;
 978
 979         default:
 980                 assert_not_reached("Uh, control process died at wrong time.");
 981         }
 982
 983         /* Notify clients about changed exit status */
 984         unit_add_to_dbus_queue(u);
 985
 986         /* Request a reload of /proc/swaps, so that following units
 987          * can follow our state change */
 988         u->manager->request_reload = true;
 989 }
 990
 991 static void swap_timer_event(Unit *u, uint64_t elapsed, Watch *w) {
 992         Swap *s = SWAP(u);
 993
 994         assert(s);
 995         assert(elapsed == 1);
 996         assert(w == &s->timer_watch);
 997
 998         switch (s->state) {
 999
1000         case SWAP_ACTIVATING:
1001                 log_warning("%s activation timed out. Stopping.", u->id);
1002                 swap_enter_signal(s, SWAP_ACTIVATING_SIGTERM, false);
1003                 break;
1004
1005         case SWAP_DEACTIVATING:
1006                 log_warning("%s deactivation timed out. Stopping.", u->id);
1007                 swap_enter_signal(s, SWAP_DEACTIVATING_SIGTERM, false);
1008                 break;
1009
1010         case SWAP_ACTIVATING_SIGTERM:
1011                 if (s->exec_context.send_sigkill) {
1012                         log_warning("%s activation timed out. Killing.", u->id);
1013                         swap_enter_signal(s, SWAP_ACTIVATING_SIGKILL, false);
1014                 } else {
1015                         log_warning("%s activation timed out. Skipping SIGKILL. Ignoring.", u->id);
1016                         swap_enter_dead(s, false);
1017                 }
1018                 break;
1019
1020         case SWAP_DEACTIVATING_SIGTERM:
1021                 if (s->exec_context.send_sigkill) {
1022                         log_warning("%s deactivation timed out. Killing.", u->id);
1023                         swap_enter_signal(s, SWAP_DEACTIVATING_SIGKILL, false);
1024                 } else {
1025                         log_warning("%s deactivation timed out. Skipping SIGKILL. Ignoring.", u->id);
1026                         swap_enter_dead(s, false);
1027                 }
1028                 break;
1029
1030         case SWAP_ACTIVATING_SIGKILL:
1031         case SWAP_DEACTIVATING_SIGKILL:
1032                 log_warning("%s swap process still around after SIGKILL. Ignoring.", u->id);
1033                 swap_enter_dead(s, false);
1034                 break;
1035
1036         default:
1037                 assert_not_reached("Timeout at wrong time.");
1038         }
1039 }
1040
1041 static int swap_load_proc_swaps(Manager *m, bool set_flags) {
1042         unsigned i;
1043         int r = 0;
1044
1045         assert(m);
1046
1047         rewind(m->proc_swaps);
1048
1049         (void) fscanf(m->proc_swaps, "%*s %*s %*s %*s %*s\n");
1050
1051         for (i = 1;; i++) {
1052                 char *dev = NULL, *d;
1053                 int prio = 0, k;
1054
1055                 if ((k = fscanf(m->proc_swaps,
1056                                 "%ms "  /* device/file */
1057                                 "%*s "  /* type of swap */
1058                                 "%*s "  /* swap size */
1059                                 "%*s "  /* used */
1060                                 "%i\n", /* priority */
1061                                 &dev, &prio)) != 2) {
1062
1063                         if (k == EOF)
1064                                 break;
1065
1066                         log_warning("Failed to parse /proc/swaps:%u.", i);
1067                         free(dev);
1068                         continue;
1069                 }
1070
1071                 d = cunescape(dev);
1072                 free(dev);
1073
1074                 if (!d)
1075                         return -ENOMEM;
1076
1077                 k = swap_process_new_swap(m, d, prio, set_flags);
1078                 free(d);
1079
1080                 if (k < 0)
1081                         r = k;
1082         }
1083
1084         return r;
1085 }
1086
1087 int swap_dispatch_reload(Manager *m) {
1088         /* This function should go as soon as the kernel properly notifies us */
1089
1090         if (_likely_(!m->request_reload))
1091                 return 0;
1092
1093         m->request_reload = false;
1094
1095         return swap_fd_event(m, EPOLLPRI);
1096 }
1097
1098 int swap_fd_event(Manager *m, int events) {
1099         Unit *meta;
1100         int r;
1101
1102         assert(m);
1103         assert(events & EPOLLPRI);
1104
1105         if ((r = swap_load_proc_swaps(m, true)) < 0) {
1106                 log_error("Failed to reread /proc/swaps: %s", strerror(-r));
1107
1108                 /* Reset flags, just in case, for late calls */
1109                 LIST_FOREACH(units_by_type, meta, m->units_by_type[UNIT_SWAP]) {
1110                         Swap *swap = (Swap*) meta;
1111
1112                         swap->is_active = swap->just_activated = false;
1113                 }
1114
1115                 return 0;
1116         }
1117
1118         manager_dispatch_load_queue(m);
1119
1120         LIST_FOREACH(units_by_type, meta, m->units_by_type[UNIT_SWAP]) {
1121                 Swap *swap = (Swap*) meta;
1122
1123                 if (!swap->is_active) {
1124                         /* This has just been deactivated */
1125
1126                         swap->from_proc_swaps = false;
1127                         swap_unset_proc_swaps(swap);
1128
1129                         switch (swap->state) {
1130
1131                         case SWAP_ACTIVE:
1132                                 swap_enter_dead(swap, true);
1133                                 break;
1134
1135                         default:
1136                                 swap_set_state(swap, swap->state);
1137                                 break;
1138                         }
1139
1140                 } else if (swap->just_activated) {
1141
1142                         /* New swap entry */
1143
1144                         switch (swap->state) {
1145
1146                         case SWAP_DEAD:
1147                         case SWAP_FAILED:
1148                                 swap_enter_active(swap, true);
1149                                 break;
1150
1151                         default:
1152                                 /* Nothing really changed, but let's
1153                                  * issue an notification call
1154                                  * nonetheless, in case somebody is
1155                                  * waiting for this. */
1156                                 swap_set_state(swap, swap->state);
1157                                 break;
1158                         }
1159                 }
1160
1161                 /* Reset the flags for later calls */
1162                 swap->is_active = swap->just_activated = false;
1163         }
1164
1165         return 1;
1166 }
1167
1168 static Unit *swap_following(Unit *u) {
1169         Swap *s = SWAP(u);
1170         Swap *other, *first = NULL;
1171
1172         assert(s);
1173
1174         if (streq_ptr(s->what, s->parameters_proc_swaps.what))
1175                 return NULL;
1176
1177         /* Make everybody follow the unit that's named after the swap
1178          * device in the kernel */
1179
1180         LIST_FOREACH_AFTER(same_proc_swaps, other, s)
1181                 if (streq_ptr(other->what, other->parameters_proc_swaps.what))
1182                         return UNIT(other);
1183
1184         LIST_FOREACH_BEFORE(same_proc_swaps, other, s) {
1185                 if (streq_ptr(other->what, other->parameters_proc_swaps.what))
1186                         return UNIT(other);
1187
1188                 first = other;
1189         }
1190
1191         return UNIT(first);
1192 }
1193
1194 static int swap_following_set(Unit *u, Set **_set) {
1195         Swap *s = SWAP(u);
1196         Swap *other;
1197         Set *set;
1198         int r;
1199
1200         assert(s);
1201         assert(_set);
1202
1203         if (LIST_JUST_US(same_proc_swaps, s)) {
1204                 *_set = NULL;
1205                 return 0;
1206         }
1207
1208         if (!(set = set_new(NULL, NULL)))
1209                 return -ENOMEM;
1210
1211         LIST_FOREACH_AFTER(same_proc_swaps, other, s)
1212                 if ((r = set_put(set, other)) < 0)
1213                         goto fail;
1214
1215         LIST_FOREACH_BEFORE(same_proc_swaps, other, s)
1216                 if ((r = set_put(set, other)) < 0)
1217                         goto fail;
1218
1219         *_set = set;
1220         return 1;
1221
1222 fail:
1223         set_free(set);
1224         return r;
1225 }
1226
1227 static void swap_shutdown(Manager *m) {
1228         assert(m);
1229
1230         if (m->proc_swaps) {
1231                 fclose(m->proc_swaps);
1232                 m->proc_swaps = NULL;
1233         }
1234
1235         hashmap_free(m->swaps_by_proc_swaps);
1236         m->swaps_by_proc_swaps = NULL;
1237 }
1238
1239 static int swap_enumerate(Manager *m) {
1240         int r;
1241         struct epoll_event ev;
1242         assert(m);
1243
1244         if (!m->proc_swaps) {
1245                 if (!(m->proc_swaps = fopen("/proc/swaps", "re")))
1246                         return (errno == ENOENT) ? 0 : -errno;
1247
1248                 m->swap_watch.type = WATCH_SWAP;
1249                 m->swap_watch.fd = fileno(m->proc_swaps);
1250
1251                 zero(ev);
1252                 ev.events = EPOLLPRI;
1253                 ev.data.ptr = &m->swap_watch;
1254
1255                 if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->swap_watch.fd, &ev) < 0)
1256                         return -errno;
1257         }
1258
1259         /* We rely on mount.c to load /etc/fstab for us */
1260
1261         if ((r = swap_load_proc_swaps(m, false)) < 0)
1262                 swap_shutdown(m);
1263
1264         return r;
1265 }
1266
1267 static void swap_reset_failed(Unit *u) {
1268         Swap *s = SWAP(u);
1269
1270         assert(s);
1271
1272         if (s->state == SWAP_FAILED)
1273                 swap_set_state(s, SWAP_DEAD);
1274
1275         s->failure = false;
1276 }
1277
1278 static int swap_kill(Unit *u, KillWho who, KillMode mode, int signo, DBusError *error) {
1279         Swap *s = SWAP(u);
1280         int r = 0;
1281         Set *pid_set = NULL;
1282
1283         assert(s);
1284
1285         if (who == KILL_MAIN) {
1286                 dbus_set_error(error, BUS_ERROR_NO_SUCH_PROCESS, "Swap units have no main processes");
1287                 return -ESRCH;
1288         }
1289
1290         if (s->control_pid <= 0 && who == KILL_CONTROL) {
1291                 dbus_set_error(error, BUS_ERROR_NO_SUCH_PROCESS, "No control process to kill");
1292                 return -ESRCH;
1293         }
1294
1295         if (who == KILL_CONTROL || who == KILL_ALL)
1296                 if (s->control_pid > 0)
1297                         if (kill(s->control_pid, signo) < 0)
1298                                 r = -errno;
1299
1300         if (who == KILL_ALL && mode == KILL_CONTROL_GROUP) {
1301                 int q;
1302
1303                 if (!(pid_set = set_new(trivial_hash_func, trivial_compare_func)))
1304                         return -ENOMEM;
1305
1306                 /* Exclude the control pid from being killed via the cgroup */
1307                 if (s->control_pid > 0)
1308                         if ((q = set_put(pid_set, LONG_TO_PTR(s->control_pid))) < 0) {
1309                                 r = q;
1310                                 goto finish;
1311                         }
1312
1313                 if ((q = cgroup_bonding_kill_list(UNIT(s)->cgroup_bondings, signo, false, pid_set)) < 0)
1314                         if (q != -EAGAIN && q != -ESRCH && q != -ENOENT)
1315                                 r = q;
1316         }
1317
1318 finish:
1319         if (pid_set)
1320                 set_free(pid_set);
1321
1322         return r;
1323 }
1324
1325 static const char* const swap_state_table[_SWAP_STATE_MAX] = {
1326         [SWAP_DEAD] = "dead",
1327         [SWAP_ACTIVATING] = "activating",
1328         [SWAP_ACTIVE] = "active",
1329         [SWAP_DEACTIVATING] = "deactivating",
1330         [SWAP_ACTIVATING_SIGTERM] = "activating-sigterm",
1331         [SWAP_ACTIVATING_SIGKILL] = "activating-sigkill",
1332         [SWAP_DEACTIVATING_SIGTERM] = "deactivating-sigterm",
1333         [SWAP_DEACTIVATING_SIGKILL] = "deactivating-sigkill",
1334         [SWAP_FAILED] = "failed"
1335 };
1336
1337 DEFINE_STRING_TABLE_LOOKUP(swap_state, SwapState);
1338
1339 static const char* const swap_exec_command_table[_SWAP_EXEC_COMMAND_MAX] = {
1340         [SWAP_EXEC_ACTIVATE] = "ExecActivate",
1341         [SWAP_EXEC_DEACTIVATE] = "ExecDeactivate",
1342 };
1343
1344 DEFINE_STRING_TABLE_LOOKUP(swap_exec_command, SwapExecCommand);
1345
1346 const UnitVTable swap_vtable = {
1347         .suffix = ".swap",
1348         .object_size = sizeof(Swap),
1349         .sections =
1350                 "Unit\0"
1351                 "Swap\0"
1352                 "Install\0",
1353
1354         .no_alias = true,
1355         .no_instances = true,
1356         .show_status = true,
1357
1358         .init = swap_init,
1359         .load = swap_load,
1360         .done = swap_done,
1361
1362         .coldplug = swap_coldplug,
1363
1364         .dump = swap_dump,
1365
1366         .start = swap_start,
1367         .stop = swap_stop,
1368
1369         .kill = swap_kill,
1370
1371         .serialize = swap_serialize,
1372         .deserialize_item = swap_deserialize_item,
1373
1374         .active_state = swap_active_state,
1375         .sub_state_to_string = swap_sub_state_to_string,
1376
1377         .check_gc = swap_check_gc,
1378
1379         .sigchld_event = swap_sigchld_event,
1380         .timer_event = swap_timer_event,
1381
1382         .reset_failed = swap_reset_failed,
1383
1384         .bus_interface = "org.freedesktop.systemd1.Swap",
1385         .bus_message_handler = bus_swap_message_handler,
1386         .bus_invalidating_properties =  bus_swap_invalidating_properties,
1387
1388         .following = swap_following,
1389         .following_set = swap_following_set,
1390
1391         .enumerate = swap_enumerate,
1392         .shutdown = swap_shutdown
1393 };