src/swap.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2010 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU General Public License as published by
  10   the Free Software Foundation; either version 2 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   General Public License for more details.
  17
  18   You should have received a copy of the GNU General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <errno.h>
  23 #include <limits.h>
  24 #include <unistd.h>
  25 #include <fcntl.h>
  26 #include <sys/epoll.h>
  27 #include <sys/stat.h>
  28 #include <sys/swap.h>
  29 #include <libudev.h>
  30
  31 #include "unit.h"
  32 #include "swap.h"
  33 #include "load-fragment.h"
  34 #include "load-dropin.h"
  35 #include "unit-name.h"
  36 #include "dbus-swap.h"
  37 #include "special.h"
  38 #include "bus-errors.h"
  39
  40 static const UnitActiveState state_translation_table[_SWAP_STATE_MAX] = {
  41         [SWAP_DEAD] = UNIT_INACTIVE,
  42         [SWAP_ACTIVATING] = UNIT_ACTIVATING,
  43         [SWAP_ACTIVE] = UNIT_ACTIVE,
  44         [SWAP_DEACTIVATING] = UNIT_DEACTIVATING,
  45         [SWAP_ACTIVATING_SIGTERM] = UNIT_DEACTIVATING,
  46         [SWAP_ACTIVATING_SIGKILL] = UNIT_DEACTIVATING,
  47         [SWAP_DEACTIVATING_SIGTERM] = UNIT_DEACTIVATING,
  48         [SWAP_DEACTIVATING_SIGKILL] = UNIT_DEACTIVATING,
  49         [SWAP_FAILED] = UNIT_FAILED
  50 };
  51
  52 static void swap_unset_proc_swaps(Swap *s) {
  53         Swap *first;
  54
  55         assert(s);
  56
  57         if (!s->parameters_proc_swaps.what)
  58                 return;
  59
  60         /* Remove this unit from the chain of swaps which share the
  61          * same kernel swap device. */
  62
  63         first = hashmap_get(s->meta.manager->swaps_by_proc_swaps, s->parameters_proc_swaps.what);
  64         LIST_REMOVE(Swap, same_proc_swaps, first, s);
  65
  66         if (first)
  67                 hashmap_remove_and_replace(s->meta.manager->swaps_by_proc_swaps, s->parameters_proc_swaps.what, first->parameters_proc_swaps.what, first);
  68         else
  69                 hashmap_remove(s->meta.manager->swaps_by_proc_swaps, s->parameters_proc_swaps.what);
  70
  71         free(s->parameters_proc_swaps.what);
  72         s->parameters_proc_swaps.what = NULL;
  73 }
  74
  75  static void swap_init(Unit *u) {
  76         Swap *s = SWAP(u);
  77
  78         assert(s);
  79         assert(s->meta.load_state == UNIT_STUB);
  80
  81         s->timeout_usec = DEFAULT_TIMEOUT_USEC;
  82
  83         exec_context_init(&s->exec_context);
  84
  85         s->parameters_etc_fstab.priority = s->parameters_proc_swaps.priority = s->parameters_fragment.priority = -1;
  86
  87         s->timer_watch.type = WATCH_INVALID;
  88
  89         s->control_command_id = _MOUNT_EXEC_COMMAND_INVALID;
  90 }
  91
  92 static void swap_unwatch_control_pid(Swap *s) {
  93         assert(s);
  94
  95         if (s->control_pid <= 0)
  96                 return;
  97
  98         unit_unwatch_pid(UNIT(s), s->control_pid);
  99         s->control_pid = 0;
 100 }
 101
 102 static void swap_done(Unit *u) {
 103         Swap *s = SWAP(u);
 104
 105         assert(s);
 106
 107         swap_unset_proc_swaps(s);
 108
 109         free(s->what);
 110         s->what = NULL;
 111
 112         free(s->parameters_etc_fstab.what);
 113         free(s->parameters_fragment.what);
 114         s->parameters_etc_fstab.what = s->parameters_fragment.what = NULL;
 115
 116         exec_context_done(&s->exec_context);
 117         exec_command_done_array(s->exec_command, _SWAP_EXEC_COMMAND_MAX);
 118         s->control_command = NULL;
 119
 120         swap_unwatch_control_pid(s);
 121
 122         unit_unwatch_timer(u, &s->timer_watch);
 123 }
 124
 125 int swap_add_one_mount_link(Swap *s, Mount *m) {
 126          int r;
 127
 128         assert(s);
 129         assert(m);
 130
 131         if (s->meta.load_state != UNIT_LOADED ||
 132             m->meta.load_state != UNIT_LOADED)
 133                 return 0;
 134
 135         if (is_device_path(s->what))
 136                 return 0;
 137
 138         if (!path_startswith(s->what, m->where))
 139                 return 0;
 140
 141         if ((r = unit_add_two_dependencies(UNIT(s), UNIT_AFTER, UNIT_REQUIRES, UNIT(m), true)) < 0)
 142                 return r;
 143
 144         return 0;
 145 }
 146
 147 static int swap_add_mount_links(Swap *s) {
 148         Meta *other;
 149         int r;
 150
 151         assert(s);
 152
 153         LIST_FOREACH(units_per_type, other, s->meta.manager->units_per_type[UNIT_MOUNT])
 154                 if ((r = swap_add_one_mount_link(s, (Mount*) other)) < 0)
 155                         return r;
 156
 157         return 0;
 158 }
 159
 160 static int swap_add_target_links(Swap *s) {
 161         Unit *tu;
 162         SwapParameters *p;
 163         int r;
 164
 165         assert(s);
 166
 167         if (s->from_fragment)
 168                 p = &s->parameters_fragment;
 169         else if (s->from_etc_fstab)
 170                 p = &s->parameters_etc_fstab;
 171         else
 172                 return 0;
 173
 174         if ((r = manager_load_unit(s->meta.manager, SPECIAL_SWAP_TARGET, NULL, NULL, &tu)) < 0)
 175                 return r;
 176
 177         if (!p->noauto &&
 178             (p->handle || s->meta.manager->swap_auto) &&
 179             s->from_etc_fstab &&
 180             s->meta.manager->running_as == MANAGER_SYSTEM)
 181                 if ((r = unit_add_dependency(tu, UNIT_WANTS, UNIT(s), true)) < 0)
 182                         return r;
 183
 184         return unit_add_dependency(UNIT(s), UNIT_BEFORE, tu, true);
 185 }
 186
 187 static int swap_add_device_links(Swap *s) {
 188         SwapParameters *p;
 189
 190         assert(s);
 191
 192         if (!s->what)
 193                 return 0;
 194
 195         if (s->from_fragment)
 196                 p = &s->parameters_fragment;
 197         else if (s->from_etc_fstab)
 198                 p = &s->parameters_etc_fstab;
 199         else
 200                 return 0;
 201
 202         if (is_device_path(s->what))
 203                 return unit_add_node_link(UNIT(s), s->what,
 204                                           !p->noauto && p->nofail &&
 205                                           s->meta.manager->running_as == MANAGER_SYSTEM);
 206         else
 207                 /* File based swap devices need to be ordered after
 208                  * remount-rootfs.service, since they might need a
 209                  * writable file system. */
 210                 return unit_add_dependency_by_name(UNIT(s), UNIT_AFTER, SPECIAL_REMOUNT_ROOTFS_SERVICE, NULL, true);
 211 }
 212
 213 static int swap_add_default_dependencies(Swap *s) {
 214         int r;
 215
 216         assert(s);
 217
 218         if (s->meta.manager->running_as == MANAGER_SYSTEM) {
 219
 220                 if ((r = unit_add_two_dependencies_by_name(UNIT(s), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_UMOUNT_TARGET, NULL, true)) < 0)
 221                         return r;
 222         }
 223
 224         return 0;
 225 }
 226
 227 static int swap_verify(Swap *s) {
 228         bool b;
 229         char *e;
 230
 231         if (s->meta.load_state != UNIT_LOADED)
 232                   return 0;
 233
 234         if (!(e = unit_name_from_path(s->what, ".swap")))
 235                   return -ENOMEM;
 236
 237         b = unit_has_name(UNIT(s), e);
 238         free(e);
 239
 240         if (!b) {
 241                 log_error("%s: Value of \"What\" and unit name do not match, not loading.\n", s->meta.id);
 242                 return -EINVAL;
 243         }
 244
 245         if (s->exec_context.pam_name && s->exec_context.kill_mode != KILL_CONTROL_GROUP) {
 246                 log_error("%s has PAM enabled. Kill mode must be set to 'control-group'. Refusing.", s->meta.id);
 247                 return -EINVAL;
 248         }
 249
 250         return 0;
 251 }
 252
 253 static int swap_load(Unit *u) {
 254         int r;
 255         Swap *s = SWAP(u);
 256
 257         assert(s);
 258         assert(u->meta.load_state == UNIT_STUB);
 259
 260         /* Load a .swap file */
 261         if ((r = unit_load_fragment_and_dropin_optional(u)) < 0)
 262                 return r;
 263
 264         if (u->meta.load_state == UNIT_LOADED) {
 265
 266                 if (s->meta.fragment_path)
 267                         s->from_fragment = true;
 268
 269                 if (!s->what) {
 270                         if (s->parameters_fragment.what)
 271                                 s->what = strdup(s->parameters_fragment.what);
 272                         else if (s->parameters_etc_fstab.what)
 273                                 s->what = strdup(s->parameters_etc_fstab.what);
 274                         else if (s->parameters_proc_swaps.what)
 275                                 s->what = strdup(s->parameters_proc_swaps.what);
 276                         else
 277                                 s->what = unit_name_to_path(u->meta.id);
 278
 279                         if (!s->what)
 280                                 return -ENOMEM;
 281                 }
 282
 283                 path_kill_slashes(s->what);
 284
 285                 if (!s->meta.description)
 286                         if ((r = unit_set_description(u, s->what)) < 0)
 287                                 return r;
 288
 289                 if ((r = swap_add_device_links(s)) < 0)
 290                         return r;
 291
 292                 if ((r = swap_add_mount_links(s)) < 0)
 293                         return r;
 294
 295                 if ((r = swap_add_target_links(s)) < 0)
 296                         return r;
 297
 298                 if ((r = unit_add_default_cgroups(u)) < 0)
 299                         return r;
 300
 301                 if (s->meta.default_dependencies)
 302                         if ((r = swap_add_default_dependencies(s)) < 0)
 303                                 return r;
 304         }
 305
 306         return swap_verify(s);
 307 }
 308
 309 int swap_add_one(
 310                 Manager *m,
 311                 const char *what,
 312                 const char *what_proc_swaps,
 313                 int priority,
 314                 bool noauto,
 315                 bool nofail,
 316                 bool handle,
 317                 bool set_flags) {
 318
 319         Unit *u = NULL;
 320         char *e = NULL, *wp = NULL;
 321         bool delete = false;
 322         int r;
 323         SwapParameters *p;
 324
 325         assert(m);
 326         assert(what);
 327
 328         if (!(e = unit_name_from_path(what, ".swap")))
 329                 return -ENOMEM;
 330
 331         u = manager_get_unit(m, e);
 332
 333         if (what_proc_swaps &&
 334             u &&
 335             SWAP(u)->from_proc_swaps &&
 336             !path_equal(SWAP(u)->parameters_proc_swaps.what, what_proc_swaps))
 337                 return -EEXIST;
 338
 339         if (!u) {
 340                 delete = true;
 341
 342                 if (!(u = unit_new(m))) {
 343                         free(e);
 344                         return -ENOMEM;
 345                 }
 346
 347                 if ((r = unit_add_name(u, e)) < 0)
 348                         goto fail;
 349
 350                 if (!(SWAP(u)->what = strdup(what))) {
 351                         r = -ENOMEM;
 352                         goto fail;
 353                 }
 354
 355                 unit_add_to_load_queue(u);
 356         } else
 357                 delete = false;
 358
 359         if (what_proc_swaps) {
 360                 Swap *first;
 361
 362                 p = &SWAP(u)->parameters_proc_swaps;
 363
 364                 if (!p->what) {
 365                         if (!(wp = strdup(what_proc_swaps))) {
 366                                 r = -ENOMEM;
 367                                 goto fail;
 368                         }
 369
 370                         if (!m->swaps_by_proc_swaps)
 371                                 if (!(m->swaps_by_proc_swaps = hashmap_new(string_hash_func, string_compare_func))) {
 372                                         r = -ENOMEM;
 373                                         goto fail;
 374                                 }
 375
 376                         free(p->what);
 377                         p->what = wp;
 378
 379                         first = hashmap_get(m->swaps_by_proc_swaps, wp);
 380                         LIST_PREPEND(Swap, same_proc_swaps, first, SWAP(u));
 381
 382                         if ((r = hashmap_replace(m->swaps_by_proc_swaps, wp, first)) < 0)
 383                                 goto fail;
 384                 }
 385
 386                 if (set_flags) {
 387                         SWAP(u)->is_active = true;
 388                         SWAP(u)->just_activated = !SWAP(u)->from_proc_swaps;
 389                 }
 390
 391                 SWAP(u)->from_proc_swaps = true;
 392
 393         } else {
 394                 p = &SWAP(u)->parameters_etc_fstab;
 395
 396                 if (!(wp = strdup(what))) {
 397                         r = -ENOMEM;
 398                         goto fail;
 399                 }
 400
 401                 free(p->what);
 402                 p->what = wp;
 403
 404                 SWAP(u)->from_etc_fstab = true;
 405         }
 406
 407         p->priority = priority;
 408         p->noauto = noauto;
 409         p->nofail = nofail;
 410         p->handle = handle;
 411
 412         unit_add_to_dbus_queue(u);
 413
 414         free(e);
 415
 416         return 0;
 417
 418 fail:
 419         log_warning("Failed to load swap unit: %s", strerror(-r));
 420
 421         free(wp);
 422         free(e);
 423
 424         if (delete && u)
 425                 unit_free(u);
 426
 427         return r;
 428 }
 429
 430 static int swap_process_new_swap(Manager *m, const char *device, int prio, bool set_flags) {
 431         struct stat st;
 432         int r = 0, k;
 433
 434         assert(m);
 435
 436         if (stat(device, &st) >= 0 && S_ISBLK(st.st_mode)) {
 437                 struct udev_device *d;
 438                 const char *dn;
 439                 struct udev_list_entry *item = NULL, *first = NULL;
 440
 441                 /* So this is a proper swap device. Create swap units
 442                  * for all names this swap device is known under */
 443
 444                 if (!(d = udev_device_new_from_devnum(m->udev, 'b', st.st_rdev)))
 445                         return -ENOMEM;
 446
 447                 if ((dn = udev_device_get_devnode(d)))
 448                         r = swap_add_one(m, dn, device, prio, false, false, false, set_flags);
 449
 450                 /* Add additional units for all symlinks */
 451                 first = udev_device_get_devlinks_list_entry(d);
 452                 udev_list_entry_foreach(item, first) {
 453                         const char *p;
 454
 455                         /* Don't bother with the /dev/block links */
 456                         p = udev_list_entry_get_name(item);
 457
 458                         if (path_startswith(p, "/dev/block/"))
 459                                 continue;
 460
 461                         if (stat(p, &st) >= 0)
 462                                 if ((!S_ISBLK(st.st_mode)) || st.st_rdev != udev_device_get_devnum(d))
 463                                         continue;
 464
 465                         if ((k = swap_add_one(m, p, device, prio, false, false, false, set_flags)) < 0)
 466                                 r = k;
 467                 }
 468
 469                 udev_device_unref(d);
 470         }
 471
 472         if ((k = swap_add_one(m, device, device, prio, false, false, false, set_flags)) < 0)
 473                 r = k;
 474
 475         return r;
 476 }
 477
 478 static void swap_set_state(Swap *s, SwapState state) {
 479         SwapState old_state;
 480
 481         assert(s);
 482
 483         old_state = s->state;
 484         s->state = state;
 485
 486         if (state != SWAP_ACTIVATING &&
 487             state != SWAP_ACTIVATING_SIGTERM &&
 488             state != SWAP_ACTIVATING_SIGKILL &&
 489             state != SWAP_DEACTIVATING &&
 490             state != SWAP_DEACTIVATING_SIGTERM &&
 491             state != SWAP_DEACTIVATING_SIGKILL) {
 492                 unit_unwatch_timer(UNIT(s), &s->timer_watch);
 493                 swap_unwatch_control_pid(s);
 494                 s->control_command = NULL;
 495                 s->control_command_id = _SWAP_EXEC_COMMAND_INVALID;
 496         }
 497
 498         if (state != old_state)
 499                 log_debug("%s changed %s -> %s",
 500                           s->meta.id,
 501                           swap_state_to_string(old_state),
 502                           swap_state_to_string(state));
 503
 504         unit_notify(UNIT(s), state_translation_table[old_state], state_translation_table[state], true);
 505 }
 506
 507 static int swap_coldplug(Unit *u) {
 508         Swap *s = SWAP(u);
 509         SwapState new_state = SWAP_DEAD;
 510         int r;
 511
 512         assert(s);
 513         assert(s->state == SWAP_DEAD);
 514
 515         if (s->deserialized_state != s->state)
 516                 new_state = s->deserialized_state;
 517         else if (s->from_proc_swaps)
 518                 new_state = SWAP_ACTIVE;
 519
 520         if (new_state != s->state) {
 521
 522                 if (new_state == SWAP_ACTIVATING ||
 523                     new_state == SWAP_ACTIVATING_SIGTERM ||
 524                     new_state == SWAP_ACTIVATING_SIGKILL ||
 525                     new_state == SWAP_DEACTIVATING ||
 526                     new_state == SWAP_DEACTIVATING_SIGTERM ||
 527                     new_state == SWAP_DEACTIVATING_SIGKILL) {
 528
 529                         if (s->control_pid <= 0)
 530                                 return -EBADMSG;
 531
 532                         if ((r = unit_watch_pid(UNIT(s), s->control_pid)) < 0)
 533                                 return r;
 534
 535                         if ((r = unit_watch_timer(UNIT(s), s->timeout_usec, &s->timer_watch)) < 0)
 536                                 return r;
 537                 }
 538
 539                 swap_set_state(s, new_state);
 540         }
 541
 542         return 0;
 543 }
 544
 545 static void swap_dump(Unit *u, FILE *f, const char *prefix) {
 546         Swap *s = SWAP(u);
 547         SwapParameters *p;
 548
 549         assert(s);
 550         assert(f);
 551
 552         if (s->from_proc_swaps)
 553                 p = &s->parameters_proc_swaps;
 554         else if (s->from_fragment)
 555                 p = &s->parameters_fragment;
 556         else
 557                 p = &s->parameters_etc_fstab;
 558
 559         fprintf(f,
 560                 "%sSwap State: %s\n"
 561                 "%sWhat: %s\n"
 562                 "%sPriority: %i\n"
 563                 "%sNoAuto: %s\n"
 564                 "%sNoFail: %s\n"
 565                 "%sHandle: %s\n"
 566                 "%sFrom /etc/fstab: %s\n"
 567                 "%sFrom /proc/swaps: %s\n"
 568                 "%sFrom fragment: %s\n",
 569                 prefix, swap_state_to_string(s->state),
 570                 prefix, s->what,
 571                 prefix, p->priority,
 572                 prefix, yes_no(p->noauto),
 573                 prefix, yes_no(p->nofail),
 574                 prefix, yes_no(p->handle),
 575                 prefix, yes_no(s->from_etc_fstab),
 576                 prefix, yes_no(s->from_proc_swaps),
 577                 prefix, yes_no(s->from_fragment));
 578
 579         if (s->control_pid > 0)
 580                 fprintf(f,
 581                         "%sControl PID: %lu\n",
 582                         prefix, (unsigned long) s->control_pid);
 583
 584         exec_context_dump(&s->exec_context, f, prefix);
 585 }
 586
 587 static int swap_spawn(Swap *s, ExecCommand *c, pid_t *_pid) {
 588         pid_t pid;
 589         int r;
 590
 591         assert(s);
 592         assert(c);
 593         assert(_pid);
 594
 595         if ((r = unit_watch_timer(UNIT(s), s->timeout_usec, &s->timer_watch)) < 0)
 596                 goto fail;
 597
 598         if ((r = exec_spawn(c,
 599                             NULL,
 600                             &s->exec_context,
 601                             NULL, 0,
 602                             s->meta.manager->environment,
 603                             true,
 604                             true,
 605                             true,
 606                             s->meta.manager->confirm_spawn,
 607                             s->meta.cgroup_bondings,
 608                             &pid)) < 0)
 609                 goto fail;
 610
 611         if ((r = unit_watch_pid(UNIT(s), pid)) < 0)
 612                 /* FIXME: we need to do something here */
 613                 goto fail;
 614
 615         *_pid = pid;
 616
 617         return 0;
 618
 619 fail:
 620         unit_unwatch_timer(UNIT(s), &s->timer_watch);
 621
 622         return r;
 623 }
 624
 625 static void swap_enter_dead(Swap *s, bool success) {
 626         assert(s);
 627
 628         if (!success)
 629                 s->failure = true;
 630
 631         swap_set_state(s, s->failure ? SWAP_FAILED : SWAP_DEAD);
 632 }
 633
 634 static void swap_enter_active(Swap *s, bool success) {
 635         assert(s);
 636
 637         if (!success)
 638                 s->failure = true;
 639
 640         swap_set_state(s, SWAP_ACTIVE);
 641 }
 642
 643 static void swap_enter_signal(Swap *s, SwapState state, bool success) {
 644         int r;
 645         Set *pid_set = NULL;
 646         bool wait_for_exit = false;
 647
 648         assert(s);
 649
 650         if (!success)
 651                 s->failure = true;
 652
 653         if (s->exec_context.kill_mode != KILL_NONE) {
 654                 int sig = (state == SWAP_ACTIVATING_SIGTERM ||
 655                            state == SWAP_DEACTIVATING_SIGTERM) ? s->exec_context.kill_signal : SIGKILL;
 656
 657                 if (s->control_pid > 0) {
 658                         if (kill(s->exec_context.kill_mode == KILL_PROCESS_GROUP ?
 659                                  -s->control_pid :
 660                                  s->control_pid, sig) < 0 && errno != ESRCH)
 661
 662                                 log_warning("Failed to kill control process %li: %m", (long) s->control_pid);
 663                         else
 664                                 wait_for_exit = true;
 665                 }
 666
 667                 if (s->exec_context.kill_mode == KILL_CONTROL_GROUP) {
 668
 669                         if (!(pid_set = set_new(trivial_hash_func, trivial_compare_func))) {
 670                                 r = -ENOMEM;
 671                                 goto fail;
 672                         }
 673
 674                         /* Exclude the control pid from being killed via the cgroup */
 675                         if (s->control_pid > 0)
 676                                 if ((r = set_put(pid_set, LONG_TO_PTR(s->control_pid))) < 0)
 677                                         goto fail;
 678
 679                         if ((r = cgroup_bonding_kill_list(s->meta.cgroup_bondings, sig, pid_set)) < 0) {
 680                                 if (r != -EAGAIN && r != -ESRCH && r != -ENOENT)
 681                                         log_warning("Failed to kill control group: %s", strerror(-r));
 682                         } else if (r > 0)
 683                                 wait_for_exit = true;
 684
 685                         set_free(pid_set);
 686                 }
 687         }
 688
 689         if (wait_for_exit) {
 690                 if ((r = unit_watch_timer(UNIT(s), s->timeout_usec, &s->timer_watch)) < 0)
 691                         goto fail;
 692
 693                 swap_set_state(s, state);
 694         } else
 695                 swap_enter_dead(s, true);
 696
 697         return;
 698
 699 fail:
 700         log_warning("%s failed to kill processes: %s", s->meta.id, strerror(-r));
 701
 702         swap_enter_dead(s, false);
 703
 704         if (pid_set)
 705                 set_free(pid_set);
 706 }
 707
 708 static void swap_enter_activating(Swap *s) {
 709         int r, priority;
 710
 711         assert(s);
 712
 713         s->control_command_id = SWAP_EXEC_ACTIVATE;
 714         s->control_command = s->exec_command + SWAP_EXEC_ACTIVATE;
 715
 716         if (s->from_fragment)
 717                 priority = s->parameters_fragment.priority;
 718         else if (s->from_etc_fstab)
 719                 priority = s->parameters_etc_fstab.priority;
 720         else
 721                 priority = -1;
 722
 723         if (priority >= 0) {
 724                 char p[LINE_MAX];
 725
 726                 snprintf(p, sizeof(p), "%i", priority);
 727                 char_array_0(p);
 728
 729                 r = exec_command_set(
 730                                 s->control_command,
 731                                 "/sbin/swapon",
 732                                 "-p",
 733                                 p,
 734                                 s->what,
 735                                 NULL);
 736         } else
 737                 r = exec_command_set(
 738                                 s->control_command,
 739                                 "/sbin/swapon",
 740                                 s->what,
 741                                 NULL);
 742
 743         if (r < 0)
 744                 goto fail;
 745
 746         swap_unwatch_control_pid(s);
 747
 748         if ((r = swap_spawn(s, s->control_command, &s->control_pid)) < 0)
 749                 goto fail;
 750
 751         swap_set_state(s, SWAP_ACTIVATING);
 752
 753         return;
 754
 755 fail:
 756         log_warning("%s failed to run 'swapon' task: %s", s->meta.id, strerror(-r));
 757         swap_enter_dead(s, false);
 758 }
 759
 760 static void swap_enter_deactivating(Swap *s, bool success) {
 761         int r;
 762
 763         assert(s);
 764
 765         if (!success)
 766                 s->failure = true;
 767
 768         s->control_command_id = SWAP_EXEC_DEACTIVATE;
 769         s->control_command = s->exec_command + SWAP_EXEC_DEACTIVATE;
 770
 771         if ((r = exec_command_set(
 772                              s->control_command,
 773                              "/sbin/swapoff",
 774                              s->what,
 775                              NULL)) < 0)
 776                 goto fail;
 777
 778         swap_unwatch_control_pid(s);
 779
 780         if ((r = swap_spawn(s, s->control_command, &s->control_pid)) < 0)
 781                 goto fail;
 782
 783         swap_set_state(s, SWAP_DEACTIVATING);
 784
 785         return;
 786
 787 fail:
 788         log_warning("%s failed to run 'swapoff' task: %s", s->meta.id, strerror(-r));
 789         swap_enter_active(s, false);
 790 }
 791
 792 static int swap_start(Unit *u) {
 793         Swap *s = SWAP(u);
 794
 795         assert(s);
 796
 797         /* We cannot fulfill this request right now, try again later
 798          * please! */
 799
 800         if (s->state == SWAP_DEACTIVATING ||
 801             s->state == SWAP_DEACTIVATING_SIGTERM ||
 802             s->state == SWAP_DEACTIVATING_SIGKILL ||
 803             s->state == SWAP_ACTIVATING_SIGTERM ||
 804             s->state == SWAP_ACTIVATING_SIGKILL)
 805                 return -EAGAIN;
 806
 807         if (s->state == SWAP_ACTIVATING)
 808                 return 0;
 809
 810         assert(s->state == SWAP_DEAD || s->state == SWAP_FAILED);
 811
 812         s->failure = false;
 813         swap_enter_activating(s);
 814         return 0;
 815 }
 816
 817 static int swap_stop(Unit *u) {
 818         Swap *s = SWAP(u);
 819
 820         assert(s);
 821
 822         if (s->state == SWAP_DEACTIVATING ||
 823             s->state == SWAP_DEACTIVATING_SIGTERM ||
 824             s->state == SWAP_DEACTIVATING_SIGKILL ||
 825             s->state == SWAP_ACTIVATING_SIGTERM ||
 826             s->state == SWAP_ACTIVATING_SIGKILL)
 827                 return 0;
 828
 829         assert(s->state == SWAP_ACTIVATING ||
 830                s->state == SWAP_ACTIVE);
 831
 832         swap_enter_deactivating(s, true);
 833         return 0;
 834 }
 835
 836 static int swap_serialize(Unit *u, FILE *f, FDSet *fds) {
 837         Swap *s = SWAP(u);
 838
 839         assert(s);
 840         assert(f);
 841         assert(fds);
 842
 843         unit_serialize_item(u, f, "state", swap_state_to_string(s->state));
 844         unit_serialize_item(u, f, "failure", yes_no(s->failure));
 845
 846         if (s->control_pid > 0)
 847                 unit_serialize_item_format(u, f, "control-pid", "%lu", (unsigned long) s->control_pid);
 848
 849         if (s->control_command_id >= 0)
 850                 unit_serialize_item(u, f, "control-command", swap_exec_command_to_string(s->control_command_id));
 851
 852         return 0;
 853 }
 854
 855 static int swap_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 856         Swap *s = SWAP(u);
 857
 858         assert(s);
 859         assert(fds);
 860
 861         if (streq(key, "state")) {
 862                 SwapState state;
 863
 864                 if ((state = swap_state_from_string(value)) < 0)
 865                         log_debug("Failed to parse state value %s", value);
 866                 else
 867                         s->deserialized_state = state;
 868         } else if (streq(key, "failure")) {
 869                 int b;
 870
 871                 if ((b = parse_boolean(value)) < 0)
 872                         log_debug("Failed to parse failure value %s", value);
 873                 else
 874                         s->failure = b || s->failure;
 875
 876         } else if (streq(key, "control-pid")) {
 877                 pid_t pid;
 878
 879                 if (parse_pid(value, &pid) < 0)
 880                         log_debug("Failed to parse control-pid value %s", value);
 881                 else
 882                         s->control_pid = pid;
 883
 884         } else if (streq(key, "control-command")) {
 885                 SwapExecCommand id;
 886
 887                 if ((id = swap_exec_command_from_string(value)) < 0)
 888                         log_debug("Failed to parse exec-command value %s", value);
 889                 else {
 890                         s->control_command_id = id;
 891                         s->control_command = s->exec_command + id;
 892                 }
 893
 894         } else
 895                 log_debug("Unknown serialization key '%s'", key);
 896
 897         return 0;
 898 }
 899
 900 static UnitActiveState swap_active_state(Unit *u) {
 901         assert(u);
 902
 903         return state_translation_table[SWAP(u)->state];
 904 }
 905
 906 static const char *swap_sub_state_to_string(Unit *u) {
 907         assert(u);
 908
 909         return swap_state_to_string(SWAP(u)->state);
 910 }
 911
 912 static bool swap_check_gc(Unit *u) {
 913         Swap *s = SWAP(u);
 914
 915         assert(s);
 916
 917         return s->from_etc_fstab || s->from_proc_swaps;
 918 }
 919
 920 static void swap_sigchld_event(Unit *u, pid_t pid, int code, int status) {
 921         Swap *s = SWAP(u);
 922         bool success;
 923
 924         assert(s);
 925         assert(pid >= 0);
 926
 927         if (pid != s->control_pid)
 928                 return;
 929
 930         s->control_pid = 0;
 931
 932         success = is_clean_exit(code, status);
 933         s->failure = s->failure || !success;
 934
 935         if (s->control_command) {
 936                 exec_status_exit(&s->control_command->exec_status, pid, code, status, s->exec_context.utmp_id);
 937                 s->control_command = NULL;
 938                 s->control_command_id = _SWAP_EXEC_COMMAND_INVALID;
 939         }
 940
 941         log_full(success ? LOG_DEBUG : LOG_NOTICE,
 942                  "%s swap process exited, code=%s status=%i", u->meta.id, sigchld_code_to_string(code), status);
 943
 944         switch (s->state) {
 945
 946         case SWAP_ACTIVATING:
 947         case SWAP_ACTIVATING_SIGTERM:
 948         case SWAP_ACTIVATING_SIGKILL:
 949
 950                 if (success)
 951                         swap_enter_active(s, true);
 952                 else
 953                         swap_enter_dead(s, false);
 954                 break;
 955
 956         case SWAP_DEACTIVATING:
 957         case SWAP_DEACTIVATING_SIGKILL:
 958         case SWAP_DEACTIVATING_SIGTERM:
 959
 960                 if (success)
 961                         swap_enter_dead(s, true);
 962                 else
 963                         swap_enter_dead(s, false);
 964                 break;
 965
 966         default:
 967                 assert_not_reached("Uh, control process died at wrong time.");
 968         }
 969
 970         /* Notify clients about changed exit status */
 971         unit_add_to_dbus_queue(u);
 972
 973         /* Request a reload of /proc/swaps, so that following units
 974          * can follow our state change */
 975         u->meta.manager->request_reload = true;
 976 }
 977
 978 static void swap_timer_event(Unit *u, uint64_t elapsed, Watch *w) {
 979         Swap *s = SWAP(u);
 980
 981         assert(s);
 982         assert(elapsed == 1);
 983         assert(w == &s->timer_watch);
 984
 985         switch (s->state) {
 986
 987         case SWAP_ACTIVATING:
 988                 log_warning("%s activation timed out. Stopping.", u->meta.id);
 989                 swap_enter_signal(s, SWAP_ACTIVATING_SIGTERM, false);
 990                 break;
 991
 992         case SWAP_DEACTIVATING:
 993                 log_warning("%s deactivation timed out. Stopping.", u->meta.id);
 994                 swap_enter_signal(s, SWAP_DEACTIVATING_SIGTERM, false);
 995                 break;
 996
 997         case SWAP_ACTIVATING_SIGTERM:
 998                 if (s->exec_context.send_sigkill) {
 999                         log_warning("%s activation timed out. Killing.", u->meta.id);
1000                         swap_enter_signal(s, SWAP_ACTIVATING_SIGKILL, false);
1001                 } else {
1002                         log_warning("%s activation timed out. Skipping SIGKILL. Ignoring.", u->meta.id);
1003                         swap_enter_dead(s, false);
1004                 }
1005                 break;
1006
1007         case SWAP_DEACTIVATING_SIGTERM:
1008                 if (s->exec_context.send_sigkill) {
1009                         log_warning("%s deactivation timed out. Killing.", u->meta.id);
1010                         swap_enter_signal(s, SWAP_DEACTIVATING_SIGKILL, false);
1011                 } else {
1012                         log_warning("%s deactivation timed out. Skipping SIGKILL. Ignoring.", u->meta.id);
1013                         swap_enter_dead(s, false);
1014                 }
1015                 break;
1016
1017         case SWAP_ACTIVATING_SIGKILL:
1018         case SWAP_DEACTIVATING_SIGKILL:
1019                 log_warning("%s swap process still around after SIGKILL. Ignoring.", u->meta.id);
1020                 swap_enter_dead(s, false);
1021                 break;
1022
1023         default:
1024                 assert_not_reached("Timeout at wrong time.");
1025         }
1026 }
1027
1028 static int swap_load_proc_swaps(Manager *m, bool set_flags) {
1029         unsigned i;
1030         int r = 0;
1031
1032         assert(m);
1033
1034         rewind(m->proc_swaps);
1035
1036         (void) fscanf(m->proc_swaps, "%*s %*s %*s %*s %*s\n");
1037
1038         for (i = 1;; i++) {
1039                 char *dev = NULL, *d;
1040                 int prio = 0, k;
1041
1042                 if ((k = fscanf(m->proc_swaps,
1043                                 "%ms "  /* device/file */
1044                                 "%*s "  /* type of swap */
1045                                 "%*s "  /* swap size */
1046                                 "%*s "  /* used */
1047                                 "%i\n", /* priority */
1048                                 &dev, &prio)) != 2) {
1049
1050                         if (k == EOF)
1051                                 break;
1052
1053                         log_warning("Failed to parse /proc/swaps:%u.", i);
1054                         free(dev);
1055                         continue;
1056                 }
1057
1058                 d = cunescape(dev);
1059                 free(dev);
1060
1061                 if (!d)
1062                         return -ENOMEM;
1063
1064                 k = swap_process_new_swap(m, d, prio, set_flags);
1065                 free(d);
1066
1067                 if (k < 0)
1068                         r = k;
1069         }
1070
1071         return r;
1072 }
1073
1074 int swap_dispatch_reload(Manager *m) {
1075         /* This function should go as soon as the kernel properly notifies us */
1076
1077         if (_likely_(!m->request_reload))
1078                 return 0;
1079
1080         m->request_reload = false;
1081
1082         return swap_fd_event(m, EPOLLPRI);
1083 }
1084
1085 int swap_fd_event(Manager *m, int events) {
1086         Meta *meta;
1087         int r;
1088
1089         assert(m);
1090         assert(events & EPOLLPRI);
1091
1092         if ((r == swap_load_proc_swaps(m, true)) < 0) {
1093                 log_error("Failed to reread /proc/swaps: %s", strerror(-r));
1094
1095                 /* Reset flags, just in case, for late calls */
1096                 LIST_FOREACH(units_per_type, meta, m->units_per_type[UNIT_SWAP]) {
1097                         Swap *swap = (Swap*) meta;
1098
1099                         swap->is_active = swap->just_activated = false;
1100                 }
1101
1102                 return 0;
1103         }
1104
1105         manager_dispatch_load_queue(m);
1106
1107         LIST_FOREACH(units_per_type, meta, m->units_per_type[UNIT_SWAP]) {
1108                 Swap *swap = (Swap*) meta;
1109
1110                 if (!swap->is_active) {
1111                         /* This has just been deactivated */
1112
1113                         swap->from_proc_swaps = false;
1114                         swap_unset_proc_swaps(swap);
1115
1116                         switch (swap->state) {
1117
1118                         case SWAP_ACTIVE:
1119                                 swap_enter_dead(swap, true);
1120                                 break;
1121
1122                         default:
1123                                 swap_set_state(swap, swap->state);
1124                                 break;
1125                         }
1126
1127                 } else if (swap->just_activated) {
1128
1129                         /* New swap entry */
1130
1131                         switch (swap->state) {
1132
1133                         case SWAP_DEAD:
1134                         case SWAP_FAILED:
1135                                 swap_enter_active(swap, true);
1136                                 break;
1137
1138                         default:
1139                                 /* Nothing really changed, but let's
1140                                  * issue an notification call
1141                                  * nonetheless, in case somebody is
1142                                  * waiting for this. */
1143                                 swap_set_state(swap, swap->state);
1144                                 break;
1145                         }
1146                 }
1147
1148                 /* Reset the flags for later calls */
1149                 swap->is_active = swap->just_activated = false;
1150         }
1151
1152         return 1;
1153 }
1154
1155 static Unit *swap_following(Unit *u) {
1156         Swap *s = SWAP(u);
1157         Swap *other, *first = NULL;
1158
1159         assert(s);
1160
1161         if (streq_ptr(s->what, s->parameters_proc_swaps.what))
1162                 return NULL;
1163
1164         /* Make everybody follow the unit that's named after the swap
1165          * device in the kernel */
1166
1167         LIST_FOREACH_AFTER(same_proc_swaps, other, s)
1168                 if (streq_ptr(other->what, other->parameters_proc_swaps.what))
1169                         return UNIT(other);
1170
1171         LIST_FOREACH_BEFORE(same_proc_swaps, other, s) {
1172                 if (streq_ptr(other->what, other->parameters_proc_swaps.what))
1173                         return UNIT(other);
1174
1175                 first = other;
1176         }
1177
1178         return UNIT(first);
1179 }
1180
1181 static int swap_following_set(Unit *u, Set **_set) {
1182         Swap *s = SWAP(u);
1183         Swap *other;
1184         Set *set;
1185         int r;
1186
1187         assert(s);
1188         assert(_set);
1189
1190         if (LIST_JUST_US(same_proc_swaps, s)) {
1191                 *_set = NULL;
1192                 return 0;
1193         }
1194
1195         if (!(set = set_new(NULL, NULL)))
1196                 return -ENOMEM;
1197
1198         LIST_FOREACH_AFTER(same_proc_swaps, other, s)
1199                 if ((r = set_put(set, other)) < 0)
1200                         goto fail;
1201
1202         LIST_FOREACH_BEFORE(same_proc_swaps, other, s)
1203                 if ((r = set_put(set, other)) < 0)
1204                         goto fail;
1205
1206         *_set = set;
1207         return 1;
1208
1209 fail:
1210         set_free(set);
1211         return r;
1212 }
1213
1214 static void swap_shutdown(Manager *m) {
1215         assert(m);
1216
1217         if (m->proc_swaps) {
1218                 fclose(m->proc_swaps);
1219                 m->proc_swaps = NULL;
1220         }
1221
1222         hashmap_free(m->swaps_by_proc_swaps);
1223         m->swaps_by_proc_swaps = NULL;
1224 }
1225
1226 static int swap_enumerate(Manager *m) {
1227         int r;
1228         struct epoll_event ev;
1229         assert(m);
1230
1231         if (!m->proc_swaps) {
1232                 if (!(m->proc_swaps = fopen("/proc/swaps", "re")))
1233                         return -errno;
1234
1235                 m->swap_watch.type = WATCH_SWAP;
1236                 m->swap_watch.fd = fileno(m->proc_swaps);
1237
1238                 zero(ev);
1239                 ev.events = EPOLLPRI;
1240                 ev.data.ptr = &m->swap_watch;
1241
1242                 if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->swap_watch.fd, &ev) < 0)
1243                         return -errno;
1244         }
1245
1246         /* We rely on mount.c to load /etc/fstab for us */
1247
1248         if ((r = swap_load_proc_swaps(m, false)) < 0)
1249                 swap_shutdown(m);
1250
1251         return r;
1252 }
1253
1254 static void swap_reset_failed(Unit *u) {
1255         Swap *s = SWAP(u);
1256
1257         assert(s);
1258
1259         if (s->state == SWAP_FAILED)
1260                 swap_set_state(s, SWAP_DEAD);
1261
1262         s->failure = false;
1263 }
1264
1265 static int swap_kill(Unit *u, KillWho who, KillMode mode, int signo, DBusError *error) {
1266         Swap *s = SWAP(u);
1267         int r = 0;
1268         Set *pid_set = NULL;
1269
1270         assert(s);
1271
1272         if (who == KILL_MAIN) {
1273                 dbus_set_error(error, BUS_ERROR_NO_SUCH_PROCESS, "Swap units have no main processes");
1274                 return -EINVAL;
1275         }
1276
1277         if (s->control_pid <= 0 && who == KILL_CONTROL) {
1278                 dbus_set_error(error, BUS_ERROR_NO_SUCH_PROCESS, "No control process to kill");
1279                 return -ENOENT;
1280         }
1281
1282         if (s->control_pid > 0)
1283                 if (kill(mode == KILL_PROCESS_GROUP ? -s->control_pid : s->control_pid, signo) < 0)
1284                         r = -errno;
1285
1286         if (mode == KILL_CONTROL_GROUP) {
1287                 int q;
1288
1289                 if (!(pid_set = set_new(trivial_hash_func, trivial_compare_func)))
1290                         return -ENOMEM;
1291
1292                 /* Exclude the control pid from being killed via the cgroup */
1293                 if (s->control_pid > 0)
1294                         if ((q = set_put(pid_set, LONG_TO_PTR(s->control_pid))) < 0) {
1295                                 r = q;
1296                                 goto finish;
1297                         }
1298
1299                 if ((q = cgroup_bonding_kill_list(s->meta.cgroup_bondings, signo, pid_set)) < 0)
1300                         if (r != -EAGAIN && r != -ESRCH && r != -ENOENT)
1301                                 r = q;
1302         }
1303
1304 finish:
1305         if (pid_set)
1306                 set_free(pid_set);
1307
1308         return r;
1309 }
1310
1311 static const char* const swap_state_table[_SWAP_STATE_MAX] = {
1312         [SWAP_DEAD] = "dead",
1313         [SWAP_ACTIVATING] = "activating",
1314         [SWAP_ACTIVE] = "active",
1315         [SWAP_DEACTIVATING] = "deactivating",
1316         [SWAP_ACTIVATING_SIGTERM] = "activating-sigterm",
1317         [SWAP_ACTIVATING_SIGKILL] = "activating-sigkill",
1318         [SWAP_DEACTIVATING_SIGTERM] = "deactivating-sigterm",
1319         [SWAP_DEACTIVATING_SIGKILL] = "deactivating-sigkill",
1320         [SWAP_FAILED] = "failed"
1321 };
1322
1323 DEFINE_STRING_TABLE_LOOKUP(swap_state, SwapState);
1324
1325 static const char* const swap_exec_command_table[_SWAP_EXEC_COMMAND_MAX] = {
1326         [SWAP_EXEC_ACTIVATE] = "ExecActivate",
1327         [SWAP_EXEC_DEACTIVATE] = "ExecDeactivate",
1328 };
1329
1330 DEFINE_STRING_TABLE_LOOKUP(swap_exec_command, SwapExecCommand);
1331
1332 const UnitVTable swap_vtable = {
1333         .suffix = ".swap",
1334
1335         .no_alias = true,
1336         .no_instances = true,
1337         .no_isolate = true,
1338         .show_status = true,
1339
1340         .init = swap_init,
1341         .load = swap_load,
1342         .done = swap_done,
1343
1344         .coldplug = swap_coldplug,
1345
1346         .dump = swap_dump,
1347
1348         .start = swap_start,
1349         .stop = swap_stop,
1350
1351         .kill = swap_kill,
1352
1353         .serialize = swap_serialize,
1354         .deserialize_item = swap_deserialize_item,
1355
1356         .active_state = swap_active_state,
1357         .sub_state_to_string = swap_sub_state_to_string,
1358
1359         .check_gc = swap_check_gc,
1360
1361         .sigchld_event = swap_sigchld_event,
1362         .timer_event = swap_timer_event,
1363
1364         .reset_failed = swap_reset_failed,
1365
1366         .bus_interface = "org.freedesktop.systemd1.Swap",
1367         .bus_message_handler = bus_swap_message_handler,
1368         .bus_invalidating_properties =  bus_swap_invalidating_properties,
1369
1370         .following = swap_following,
1371         .following_set = swap_following_set,
1372
1373         .enumerate = swap_enumerate,
1374         .shutdown = swap_shutdown
1375 };