src/swap.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2010 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU General Public License as published by
  10   the Free Software Foundation; either version 2 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   General Public License for more details.
  17
  18   You should have received a copy of the GNU General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <errno.h>
  23 #include <limits.h>
  24 #include <unistd.h>
  25 #include <fcntl.h>
  26 #include <sys/epoll.h>
  27 #include <sys/stat.h>
  28 #include <sys/swap.h>
  29 #include <libudev.h>
  30
  31 #include "unit.h"
  32 #include "swap.h"
  33 #include "load-fragment.h"
  34 #include "load-dropin.h"
  35 #include "unit-name.h"
  36 #include "dbus-swap.h"
  37 #include "special.h"
  38 #include "bus-errors.h"
  39 #include "exit-status.h"
  40
  41 static const UnitActiveState state_translation_table[_SWAP_STATE_MAX] = {
  42         [SWAP_DEAD] = UNIT_INACTIVE,
  43         [SWAP_ACTIVATING] = UNIT_ACTIVATING,
  44         [SWAP_ACTIVE] = UNIT_ACTIVE,
  45         [SWAP_DEACTIVATING] = UNIT_DEACTIVATING,
  46         [SWAP_ACTIVATING_SIGTERM] = UNIT_DEACTIVATING,
  47         [SWAP_ACTIVATING_SIGKILL] = UNIT_DEACTIVATING,
  48         [SWAP_DEACTIVATING_SIGTERM] = UNIT_DEACTIVATING,
  49         [SWAP_DEACTIVATING_SIGKILL] = UNIT_DEACTIVATING,
  50         [SWAP_FAILED] = UNIT_FAILED
  51 };
  52
  53 static void swap_unset_proc_swaps(Swap *s) {
  54         Swap *first;
  55
  56         assert(s);
  57
  58         if (!s->parameters_proc_swaps.what)
  59                 return;
  60
  61         /* Remove this unit from the chain of swaps which share the
  62          * same kernel swap device. */
  63
  64         first = hashmap_get(s->meta.manager->swaps_by_proc_swaps, s->parameters_proc_swaps.what);
  65         LIST_REMOVE(Swap, same_proc_swaps, first, s);
  66
  67         if (first)
  68                 hashmap_remove_and_replace(s->meta.manager->swaps_by_proc_swaps, s->parameters_proc_swaps.what, first->parameters_proc_swaps.what, first);
  69         else
  70                 hashmap_remove(s->meta.manager->swaps_by_proc_swaps, s->parameters_proc_swaps.what);
  71
  72         free(s->parameters_proc_swaps.what);
  73         s->parameters_proc_swaps.what = NULL;
  74 }
  75
  76  static void swap_init(Unit *u) {
  77         Swap *s = SWAP(u);
  78
  79         assert(s);
  80         assert(s->meta.load_state == UNIT_STUB);
  81
  82         s->timeout_usec = DEFAULT_TIMEOUT_USEC;
  83
  84         exec_context_init(&s->exec_context);
  85         s->exec_context.std_output = EXEC_OUTPUT_KMSG;
  86
  87         s->parameters_etc_fstab.priority = s->parameters_proc_swaps.priority = s->parameters_fragment.priority = -1;
  88
  89         s->timer_watch.type = WATCH_INVALID;
  90
  91         s->control_command_id = _MOUNT_EXEC_COMMAND_INVALID;
  92 }
  93
  94 static void swap_unwatch_control_pid(Swap *s) {
  95         assert(s);
  96
  97         if (s->control_pid <= 0)
  98                 return;
  99
 100         unit_unwatch_pid(UNIT(s), s->control_pid);
 101         s->control_pid = 0;
 102 }
 103
 104 static void swap_done(Unit *u) {
 105         Swap *s = SWAP(u);
 106
 107         assert(s);
 108
 109         swap_unset_proc_swaps(s);
 110
 111         free(s->what);
 112         s->what = NULL;
 113
 114         free(s->parameters_etc_fstab.what);
 115         free(s->parameters_fragment.what);
 116         s->parameters_etc_fstab.what = s->parameters_fragment.what = NULL;
 117
 118         exec_context_done(&s->exec_context);
 119         exec_command_done_array(s->exec_command, _SWAP_EXEC_COMMAND_MAX);
 120         s->control_command = NULL;
 121
 122         swap_unwatch_control_pid(s);
 123
 124         unit_unwatch_timer(u, &s->timer_watch);
 125 }
 126
 127 int swap_add_one_mount_link(Swap *s, Mount *m) {
 128          int r;
 129
 130         assert(s);
 131         assert(m);
 132
 133         if (s->meta.load_state != UNIT_LOADED ||
 134             m->meta.load_state != UNIT_LOADED)
 135                 return 0;
 136
 137         if (is_device_path(s->what))
 138                 return 0;
 139
 140         if (!path_startswith(s->what, m->where))
 141                 return 0;
 142
 143         if ((r = unit_add_two_dependencies(UNIT(s), UNIT_AFTER, UNIT_REQUIRES, UNIT(m), true)) < 0)
 144                 return r;
 145
 146         return 0;
 147 }
 148
 149 static int swap_add_mount_links(Swap *s) {
 150         Meta *other;
 151         int r;
 152
 153         assert(s);
 154
 155         LIST_FOREACH(units_per_type, other, s->meta.manager->units_per_type[UNIT_MOUNT])
 156                 if ((r = swap_add_one_mount_link(s, (Mount*) other)) < 0)
 157                         return r;
 158
 159         return 0;
 160 }
 161
 162 static int swap_add_target_links(Swap *s) {
 163         Unit *tu;
 164         SwapParameters *p;
 165         int r;
 166
 167         assert(s);
 168
 169         if (s->from_fragment)
 170                 p = &s->parameters_fragment;
 171         else if (s->from_etc_fstab)
 172                 p = &s->parameters_etc_fstab;
 173         else
 174                 return 0;
 175
 176         if ((r = manager_load_unit(s->meta.manager, SPECIAL_SWAP_TARGET, NULL, NULL, &tu)) < 0)
 177                 return r;
 178
 179         if (!p->noauto &&
 180             (p->handle || s->meta.manager->swap_auto) &&
 181             s->from_etc_fstab &&
 182             s->meta.manager->running_as == MANAGER_SYSTEM)
 183                 if ((r = unit_add_dependency(tu, UNIT_WANTS, UNIT(s), true)) < 0)
 184                         return r;
 185
 186         return unit_add_dependency(UNIT(s), UNIT_BEFORE, tu, true);
 187 }
 188
 189 static int swap_add_device_links(Swap *s) {
 190         SwapParameters *p;
 191
 192         assert(s);
 193
 194         if (!s->what)
 195                 return 0;
 196
 197         if (s->from_fragment)
 198                 p = &s->parameters_fragment;
 199         else if (s->from_etc_fstab)
 200                 p = &s->parameters_etc_fstab;
 201         else
 202                 return 0;
 203
 204         if (is_device_path(s->what))
 205                 return unit_add_node_link(UNIT(s), s->what,
 206                                           !p->noauto && p->nofail &&
 207                                           s->meta.manager->running_as == MANAGER_SYSTEM);
 208         else
 209                 /* File based swap devices need to be ordered after
 210                  * remount-rootfs.service, since they might need a
 211                  * writable file system. */
 212                 return unit_add_dependency_by_name(UNIT(s), UNIT_AFTER, SPECIAL_REMOUNT_ROOTFS_SERVICE, NULL, true);
 213 }
 214
 215 static int swap_add_default_dependencies(Swap *s) {
 216         int r;
 217
 218         assert(s);
 219
 220         if (s->meta.manager->running_as == MANAGER_SYSTEM) {
 221
 222                 if ((r = unit_add_two_dependencies_by_name(UNIT(s), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_UMOUNT_TARGET, NULL, true)) < 0)
 223                         return r;
 224         }
 225
 226         return 0;
 227 }
 228
 229 static int swap_verify(Swap *s) {
 230         bool b;
 231         char *e;
 232
 233         if (s->meta.load_state != UNIT_LOADED)
 234                   return 0;
 235
 236         if (!(e = unit_name_from_path(s->what, ".swap")))
 237                   return -ENOMEM;
 238
 239         b = unit_has_name(UNIT(s), e);
 240         free(e);
 241
 242         if (!b) {
 243                 log_error("%s: Value of \"What\" and unit name do not match, not loading.\n", s->meta.id);
 244                 return -EINVAL;
 245         }
 246
 247         if (s->exec_context.pam_name && s->exec_context.kill_mode != KILL_CONTROL_GROUP) {
 248                 log_error("%s has PAM enabled. Kill mode must be set to 'control-group'. Refusing.", s->meta.id);
 249                 return -EINVAL;
 250         }
 251
 252         return 0;
 253 }
 254
 255 static int swap_load(Unit *u) {
 256         int r;
 257         Swap *s = SWAP(u);
 258
 259         assert(s);
 260         assert(u->meta.load_state == UNIT_STUB);
 261
 262         /* Load a .swap file */
 263         if ((r = unit_load_fragment_and_dropin_optional(u)) < 0)
 264                 return r;
 265
 266         if (u->meta.load_state == UNIT_LOADED) {
 267
 268                 if (s->meta.fragment_path)
 269                         s->from_fragment = true;
 270
 271                 if (!s->what) {
 272                         if (s->parameters_fragment.what)
 273                                 s->what = strdup(s->parameters_fragment.what);
 274                         else if (s->parameters_etc_fstab.what)
 275                                 s->what = strdup(s->parameters_etc_fstab.what);
 276                         else if (s->parameters_proc_swaps.what)
 277                                 s->what = strdup(s->parameters_proc_swaps.what);
 278                         else
 279                                 s->what = unit_name_to_path(u->meta.id);
 280
 281                         if (!s->what)
 282                                 return -ENOMEM;
 283                 }
 284
 285                 path_kill_slashes(s->what);
 286
 287                 if (!s->meta.description)
 288                         if ((r = unit_set_description(u, s->what)) < 0)
 289                                 return r;
 290
 291                 if ((r = swap_add_device_links(s)) < 0)
 292                         return r;
 293
 294                 if ((r = swap_add_mount_links(s)) < 0)
 295                         return r;
 296
 297                 if ((r = swap_add_target_links(s)) < 0)
 298                         return r;
 299
 300                 if ((r = unit_add_default_cgroups(u)) < 0)
 301                         return r;
 302
 303                 if (s->meta.default_dependencies)
 304                         if ((r = swap_add_default_dependencies(s)) < 0)
 305                                 return r;
 306         }
 307
 308         return swap_verify(s);
 309 }
 310
 311 int swap_add_one(
 312                 Manager *m,
 313                 const char *what,
 314                 const char *what_proc_swaps,
 315                 int priority,
 316                 bool noauto,
 317                 bool nofail,
 318                 bool handle,
 319                 bool set_flags) {
 320
 321         Unit *u = NULL;
 322         char *e = NULL, *wp = NULL;
 323         bool delete = false;
 324         int r;
 325         SwapParameters *p;
 326
 327         assert(m);
 328         assert(what);
 329
 330         if (!(e = unit_name_from_path(what, ".swap")))
 331                 return -ENOMEM;
 332
 333         u = manager_get_unit(m, e);
 334
 335         if (what_proc_swaps &&
 336             u &&
 337             SWAP(u)->from_proc_swaps &&
 338             !path_equal(SWAP(u)->parameters_proc_swaps.what, what_proc_swaps))
 339                 return -EEXIST;
 340
 341         if (!u) {
 342                 delete = true;
 343
 344                 if (!(u = unit_new(m))) {
 345                         free(e);
 346                         return -ENOMEM;
 347                 }
 348
 349                 if ((r = unit_add_name(u, e)) < 0)
 350                         goto fail;
 351
 352                 if (!(SWAP(u)->what = strdup(what))) {
 353                         r = -ENOMEM;
 354                         goto fail;
 355                 }
 356
 357                 unit_add_to_load_queue(u);
 358         } else
 359                 delete = false;
 360
 361         if (what_proc_swaps) {
 362                 Swap *first;
 363
 364                 p = &SWAP(u)->parameters_proc_swaps;
 365
 366                 if (!p->what) {
 367                         if (!(wp = strdup(what_proc_swaps))) {
 368                                 r = -ENOMEM;
 369                                 goto fail;
 370                         }
 371
 372                         if (!m->swaps_by_proc_swaps)
 373                                 if (!(m->swaps_by_proc_swaps = hashmap_new(string_hash_func, string_compare_func))) {
 374                                         r = -ENOMEM;
 375                                         goto fail;
 376                                 }
 377
 378                         free(p->what);
 379                         p->what = wp;
 380
 381                         first = hashmap_get(m->swaps_by_proc_swaps, wp);
 382                         LIST_PREPEND(Swap, same_proc_swaps, first, SWAP(u));
 383
 384                         if ((r = hashmap_replace(m->swaps_by_proc_swaps, wp, first)) < 0)
 385                                 goto fail;
 386                 }
 387
 388                 if (set_flags) {
 389                         SWAP(u)->is_active = true;
 390                         SWAP(u)->just_activated = !SWAP(u)->from_proc_swaps;
 391                 }
 392
 393                 SWAP(u)->from_proc_swaps = true;
 394
 395         } else {
 396                 p = &SWAP(u)->parameters_etc_fstab;
 397
 398                 if (!(wp = strdup(what))) {
 399                         r = -ENOMEM;
 400                         goto fail;
 401                 }
 402
 403                 free(p->what);
 404                 p->what = wp;
 405
 406                 SWAP(u)->from_etc_fstab = true;
 407         }
 408
 409         p->priority = priority;
 410         p->noauto = noauto;
 411         p->nofail = nofail;
 412         p->handle = handle;
 413
 414         unit_add_to_dbus_queue(u);
 415
 416         free(e);
 417
 418         return 0;
 419
 420 fail:
 421         log_warning("Failed to load swap unit: %s", strerror(-r));
 422
 423         free(wp);
 424         free(e);
 425
 426         if (delete && u)
 427                 unit_free(u);
 428
 429         return r;
 430 }
 431
 432 static int swap_process_new_swap(Manager *m, const char *device, int prio, bool set_flags) {
 433         struct stat st;
 434         int r = 0, k;
 435
 436         assert(m);
 437
 438         if (stat(device, &st) >= 0 && S_ISBLK(st.st_mode)) {
 439                 struct udev_device *d;
 440                 const char *dn;
 441                 struct udev_list_entry *item = NULL, *first = NULL;
 442
 443                 /* So this is a proper swap device. Create swap units
 444                  * for all names this swap device is known under */
 445
 446                 if (!(d = udev_device_new_from_devnum(m->udev, 'b', st.st_rdev)))
 447                         return -ENOMEM;
 448
 449                 if ((dn = udev_device_get_devnode(d)))
 450                         r = swap_add_one(m, dn, device, prio, false, false, false, set_flags);
 451
 452                 /* Add additional units for all symlinks */
 453                 first = udev_device_get_devlinks_list_entry(d);
 454                 udev_list_entry_foreach(item, first) {
 455                         const char *p;
 456
 457                         /* Don't bother with the /dev/block links */
 458                         p = udev_list_entry_get_name(item);
 459
 460                         if (path_startswith(p, "/dev/block/"))
 461                                 continue;
 462
 463                         if (stat(p, &st) >= 0)
 464                                 if ((!S_ISBLK(st.st_mode)) || st.st_rdev != udev_device_get_devnum(d))
 465                                         continue;
 466
 467                         if ((k = swap_add_one(m, p, device, prio, false, false, false, set_flags)) < 0)
 468                                 r = k;
 469                 }
 470
 471                 udev_device_unref(d);
 472         }
 473
 474         if ((k = swap_add_one(m, device, device, prio, false, false, false, set_flags)) < 0)
 475                 r = k;
 476
 477         return r;
 478 }
 479
 480 static void swap_set_state(Swap *s, SwapState state) {
 481         SwapState old_state;
 482
 483         assert(s);
 484
 485         old_state = s->state;
 486         s->state = state;
 487
 488         if (state != SWAP_ACTIVATING &&
 489             state != SWAP_ACTIVATING_SIGTERM &&
 490             state != SWAP_ACTIVATING_SIGKILL &&
 491             state != SWAP_DEACTIVATING &&
 492             state != SWAP_DEACTIVATING_SIGTERM &&
 493             state != SWAP_DEACTIVATING_SIGKILL) {
 494                 unit_unwatch_timer(UNIT(s), &s->timer_watch);
 495                 swap_unwatch_control_pid(s);
 496                 s->control_command = NULL;
 497                 s->control_command_id = _SWAP_EXEC_COMMAND_INVALID;
 498         }
 499
 500         if (state != old_state)
 501                 log_debug("%s changed %s -> %s",
 502                           s->meta.id,
 503                           swap_state_to_string(old_state),
 504                           swap_state_to_string(state));
 505
 506         unit_notify(UNIT(s), state_translation_table[old_state], state_translation_table[state], true);
 507 }
 508
 509 static int swap_coldplug(Unit *u) {
 510         Swap *s = SWAP(u);
 511         SwapState new_state = SWAP_DEAD;
 512         int r;
 513
 514         assert(s);
 515         assert(s->state == SWAP_DEAD);
 516
 517         if (s->deserialized_state != s->state)
 518                 new_state = s->deserialized_state;
 519         else if (s->from_proc_swaps)
 520                 new_state = SWAP_ACTIVE;
 521
 522         if (new_state != s->state) {
 523
 524                 if (new_state == SWAP_ACTIVATING ||
 525                     new_state == SWAP_ACTIVATING_SIGTERM ||
 526                     new_state == SWAP_ACTIVATING_SIGKILL ||
 527                     new_state == SWAP_DEACTIVATING ||
 528                     new_state == SWAP_DEACTIVATING_SIGTERM ||
 529                     new_state == SWAP_DEACTIVATING_SIGKILL) {
 530
 531                         if (s->control_pid <= 0)
 532                                 return -EBADMSG;
 533
 534                         if ((r = unit_watch_pid(UNIT(s), s->control_pid)) < 0)
 535                                 return r;
 536
 537                         if ((r = unit_watch_timer(UNIT(s), s->timeout_usec, &s->timer_watch)) < 0)
 538                                 return r;
 539                 }
 540
 541                 swap_set_state(s, new_state);
 542         }
 543
 544         return 0;
 545 }
 546
 547 static void swap_dump(Unit *u, FILE *f, const char *prefix) {
 548         Swap *s = SWAP(u);
 549         SwapParameters *p;
 550
 551         assert(s);
 552         assert(f);
 553
 554         if (s->from_proc_swaps)
 555                 p = &s->parameters_proc_swaps;
 556         else if (s->from_fragment)
 557                 p = &s->parameters_fragment;
 558         else
 559                 p = &s->parameters_etc_fstab;
 560
 561         fprintf(f,
 562                 "%sSwap State: %s\n"
 563                 "%sWhat: %s\n"
 564                 "%sPriority: %i\n"
 565                 "%sNoAuto: %s\n"
 566                 "%sNoFail: %s\n"
 567                 "%sHandle: %s\n"
 568                 "%sFrom /etc/fstab: %s\n"
 569                 "%sFrom /proc/swaps: %s\n"
 570                 "%sFrom fragment: %s\n",
 571                 prefix, swap_state_to_string(s->state),
 572                 prefix, s->what,
 573                 prefix, p->priority,
 574                 prefix, yes_no(p->noauto),
 575                 prefix, yes_no(p->nofail),
 576                 prefix, yes_no(p->handle),
 577                 prefix, yes_no(s->from_etc_fstab),
 578                 prefix, yes_no(s->from_proc_swaps),
 579                 prefix, yes_no(s->from_fragment));
 580
 581         if (s->control_pid > 0)
 582                 fprintf(f,
 583                         "%sControl PID: %lu\n",
 584                         prefix, (unsigned long) s->control_pid);
 585
 586         exec_context_dump(&s->exec_context, f, prefix);
 587 }
 588
 589 static int swap_spawn(Swap *s, ExecCommand *c, pid_t *_pid) {
 590         pid_t pid;
 591         int r;
 592
 593         assert(s);
 594         assert(c);
 595         assert(_pid);
 596
 597         if ((r = unit_watch_timer(UNIT(s), s->timeout_usec, &s->timer_watch)) < 0)
 598                 goto fail;
 599
 600         if ((r = exec_spawn(c,
 601                             NULL,
 602                             &s->exec_context,
 603                             NULL, 0,
 604                             s->meta.manager->environment,
 605                             true,
 606                             true,
 607                             true,
 608                             s->meta.manager->confirm_spawn,
 609                             s->meta.cgroup_bondings,
 610                             &pid)) < 0)
 611                 goto fail;
 612
 613         if ((r = unit_watch_pid(UNIT(s), pid)) < 0)
 614                 /* FIXME: we need to do something here */
 615                 goto fail;
 616
 617         *_pid = pid;
 618
 619         return 0;
 620
 621 fail:
 622         unit_unwatch_timer(UNIT(s), &s->timer_watch);
 623
 624         return r;
 625 }
 626
 627 static void swap_enter_dead(Swap *s, bool success) {
 628         assert(s);
 629
 630         if (!success)
 631                 s->failure = true;
 632
 633         swap_set_state(s, s->failure ? SWAP_FAILED : SWAP_DEAD);
 634 }
 635
 636 static void swap_enter_active(Swap *s, bool success) {
 637         assert(s);
 638
 639         if (!success)
 640                 s->failure = true;
 641
 642         swap_set_state(s, SWAP_ACTIVE);
 643 }
 644
 645 static void swap_enter_signal(Swap *s, SwapState state, bool success) {
 646         int r;
 647         Set *pid_set = NULL;
 648         bool wait_for_exit = false;
 649
 650         assert(s);
 651
 652         if (!success)
 653                 s->failure = true;
 654
 655         if (s->exec_context.kill_mode != KILL_NONE) {
 656                 int sig = (state == SWAP_ACTIVATING_SIGTERM ||
 657                            state == SWAP_DEACTIVATING_SIGTERM) ? s->exec_context.kill_signal : SIGKILL;
 658
 659                 if (s->control_pid > 0) {
 660                         if (kill(s->exec_context.kill_mode == KILL_PROCESS_GROUP ?
 661                                  -s->control_pid :
 662                                  s->control_pid, sig) < 0 && errno != ESRCH)
 663
 664                                 log_warning("Failed to kill control process %li: %m", (long) s->control_pid);
 665                         else
 666                                 wait_for_exit = true;
 667                 }
 668
 669                 if (s->exec_context.kill_mode == KILL_CONTROL_GROUP) {
 670
 671                         if (!(pid_set = set_new(trivial_hash_func, trivial_compare_func))) {
 672                                 r = -ENOMEM;
 673                                 goto fail;
 674                         }
 675
 676                         /* Exclude the control pid from being killed via the cgroup */
 677                         if (s->control_pid > 0)
 678                                 if ((r = set_put(pid_set, LONG_TO_PTR(s->control_pid))) < 0)
 679                                         goto fail;
 680
 681                         if ((r = cgroup_bonding_kill_list(s->meta.cgroup_bondings, sig, pid_set)) < 0) {
 682                                 if (r != -EAGAIN && r != -ESRCH && r != -ENOENT)
 683                                         log_warning("Failed to kill control group: %s", strerror(-r));
 684                         } else if (r > 0)
 685                                 wait_for_exit = true;
 686
 687                         set_free(pid_set);
 688                 }
 689         }
 690
 691         if (wait_for_exit) {
 692                 if ((r = unit_watch_timer(UNIT(s), s->timeout_usec, &s->timer_watch)) < 0)
 693                         goto fail;
 694
 695                 swap_set_state(s, state);
 696         } else
 697                 swap_enter_dead(s, true);
 698
 699         return;
 700
 701 fail:
 702         log_warning("%s failed to kill processes: %s", s->meta.id, strerror(-r));
 703
 704         swap_enter_dead(s, false);
 705
 706         if (pid_set)
 707                 set_free(pid_set);
 708 }
 709
 710 static void swap_enter_activating(Swap *s) {
 711         int r, priority;
 712
 713         assert(s);
 714
 715         s->control_command_id = SWAP_EXEC_ACTIVATE;
 716         s->control_command = s->exec_command + SWAP_EXEC_ACTIVATE;
 717
 718         if (s->from_fragment)
 719                 priority = s->parameters_fragment.priority;
 720         else if (s->from_etc_fstab)
 721                 priority = s->parameters_etc_fstab.priority;
 722         else
 723                 priority = -1;
 724
 725         if (priority >= 0) {
 726                 char p[LINE_MAX];
 727
 728                 snprintf(p, sizeof(p), "%i", priority);
 729                 char_array_0(p);
 730
 731                 r = exec_command_set(
 732                                 s->control_command,
 733                                 "/sbin/swapon",
 734                                 "-p",
 735                                 p,
 736                                 s->what,
 737                                 NULL);
 738         } else
 739                 r = exec_command_set(
 740                                 s->control_command,
 741                                 "/sbin/swapon",
 742                                 s->what,
 743                                 NULL);
 744
 745         if (r < 0)
 746                 goto fail;
 747
 748         swap_unwatch_control_pid(s);
 749
 750         if ((r = swap_spawn(s, s->control_command, &s->control_pid)) < 0)
 751                 goto fail;
 752
 753         swap_set_state(s, SWAP_ACTIVATING);
 754
 755         return;
 756
 757 fail:
 758         log_warning("%s failed to run 'swapon' task: %s", s->meta.id, strerror(-r));
 759         swap_enter_dead(s, false);
 760 }
 761
 762 static void swap_enter_deactivating(Swap *s, bool success) {
 763         int r;
 764
 765         assert(s);
 766
 767         if (!success)
 768                 s->failure = true;
 769
 770         s->control_command_id = SWAP_EXEC_DEACTIVATE;
 771         s->control_command = s->exec_command + SWAP_EXEC_DEACTIVATE;
 772
 773         if ((r = exec_command_set(
 774                              s->control_command,
 775                              "/sbin/swapoff",
 776                              s->what,
 777                              NULL)) < 0)
 778                 goto fail;
 779
 780         swap_unwatch_control_pid(s);
 781
 782         if ((r = swap_spawn(s, s->control_command, &s->control_pid)) < 0)
 783                 goto fail;
 784
 785         swap_set_state(s, SWAP_DEACTIVATING);
 786
 787         return;
 788
 789 fail:
 790         log_warning("%s failed to run 'swapoff' task: %s", s->meta.id, strerror(-r));
 791         swap_enter_active(s, false);
 792 }
 793
 794 static int swap_start(Unit *u) {
 795         Swap *s = SWAP(u);
 796
 797         assert(s);
 798
 799         /* We cannot fulfill this request right now, try again later
 800          * please! */
 801
 802         if (s->state == SWAP_DEACTIVATING ||
 803             s->state == SWAP_DEACTIVATING_SIGTERM ||
 804             s->state == SWAP_DEACTIVATING_SIGKILL ||
 805             s->state == SWAP_ACTIVATING_SIGTERM ||
 806             s->state == SWAP_ACTIVATING_SIGKILL)
 807                 return -EAGAIN;
 808
 809         if (s->state == SWAP_ACTIVATING)
 810                 return 0;
 811
 812         assert(s->state == SWAP_DEAD || s->state == SWAP_FAILED);
 813
 814         s->failure = false;
 815         swap_enter_activating(s);
 816         return 0;
 817 }
 818
 819 static int swap_stop(Unit *u) {
 820         Swap *s = SWAP(u);
 821
 822         assert(s);
 823
 824         if (s->state == SWAP_DEACTIVATING ||
 825             s->state == SWAP_DEACTIVATING_SIGTERM ||
 826             s->state == SWAP_DEACTIVATING_SIGKILL ||
 827             s->state == SWAP_ACTIVATING_SIGTERM ||
 828             s->state == SWAP_ACTIVATING_SIGKILL)
 829                 return 0;
 830
 831         assert(s->state == SWAP_ACTIVATING ||
 832                s->state == SWAP_ACTIVE);
 833
 834         swap_enter_deactivating(s, true);
 835         return 0;
 836 }
 837
 838 static int swap_serialize(Unit *u, FILE *f, FDSet *fds) {
 839         Swap *s = SWAP(u);
 840
 841         assert(s);
 842         assert(f);
 843         assert(fds);
 844
 845         unit_serialize_item(u, f, "state", swap_state_to_string(s->state));
 846         unit_serialize_item(u, f, "failure", yes_no(s->failure));
 847
 848         if (s->control_pid > 0)
 849                 unit_serialize_item_format(u, f, "control-pid", "%lu", (unsigned long) s->control_pid);
 850
 851         if (s->control_command_id >= 0)
 852                 unit_serialize_item(u, f, "control-command", swap_exec_command_to_string(s->control_command_id));
 853
 854         return 0;
 855 }
 856
 857 static int swap_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 858         Swap *s = SWAP(u);
 859
 860         assert(s);
 861         assert(fds);
 862
 863         if (streq(key, "state")) {
 864                 SwapState state;
 865
 866                 if ((state = swap_state_from_string(value)) < 0)
 867                         log_debug("Failed to parse state value %s", value);
 868                 else
 869                         s->deserialized_state = state;
 870         } else if (streq(key, "failure")) {
 871                 int b;
 872
 873                 if ((b = parse_boolean(value)) < 0)
 874                         log_debug("Failed to parse failure value %s", value);
 875                 else
 876                         s->failure = b || s->failure;
 877
 878         } else if (streq(key, "control-pid")) {
 879                 pid_t pid;
 880
 881                 if (parse_pid(value, &pid) < 0)
 882                         log_debug("Failed to parse control-pid value %s", value);
 883                 else
 884                         s->control_pid = pid;
 885
 886         } else if (streq(key, "control-command")) {
 887                 SwapExecCommand id;
 888
 889                 if ((id = swap_exec_command_from_string(value)) < 0)
 890                         log_debug("Failed to parse exec-command value %s", value);
 891                 else {
 892                         s->control_command_id = id;
 893                         s->control_command = s->exec_command + id;
 894                 }
 895
 896         } else
 897                 log_debug("Unknown serialization key '%s'", key);
 898
 899         return 0;
 900 }
 901
 902 static UnitActiveState swap_active_state(Unit *u) {
 903         assert(u);
 904
 905         return state_translation_table[SWAP(u)->state];
 906 }
 907
 908 static const char *swap_sub_state_to_string(Unit *u) {
 909         assert(u);
 910
 911         return swap_state_to_string(SWAP(u)->state);
 912 }
 913
 914 static bool swap_check_gc(Unit *u) {
 915         Swap *s = SWAP(u);
 916
 917         assert(s);
 918
 919         return s->from_etc_fstab || s->from_proc_swaps;
 920 }
 921
 922 static void swap_sigchld_event(Unit *u, pid_t pid, int code, int status) {
 923         Swap *s = SWAP(u);
 924         bool success;
 925
 926         assert(s);
 927         assert(pid >= 0);
 928
 929         if (pid != s->control_pid)
 930                 return;
 931
 932         s->control_pid = 0;
 933
 934         success = is_clean_exit(code, status);
 935         s->failure = s->failure || !success;
 936
 937         if (s->control_command) {
 938                 exec_status_exit(&s->control_command->exec_status, pid, code, status, s->exec_context.utmp_id);
 939                 s->control_command = NULL;
 940                 s->control_command_id = _SWAP_EXEC_COMMAND_INVALID;
 941         }
 942
 943         log_full(success ? LOG_DEBUG : LOG_NOTICE,
 944                  "%s swap process exited, code=%s status=%i", u->meta.id, sigchld_code_to_string(code), status);
 945
 946         switch (s->state) {
 947
 948         case SWAP_ACTIVATING:
 949         case SWAP_ACTIVATING_SIGTERM:
 950         case SWAP_ACTIVATING_SIGKILL:
 951
 952                 if (success)
 953                         swap_enter_active(s, true);
 954                 else
 955                         swap_enter_dead(s, false);
 956                 break;
 957
 958         case SWAP_DEACTIVATING:
 959         case SWAP_DEACTIVATING_SIGKILL:
 960         case SWAP_DEACTIVATING_SIGTERM:
 961
 962                 if (success)
 963                         swap_enter_dead(s, true);
 964                 else
 965                         swap_enter_dead(s, false);
 966                 break;
 967
 968         default:
 969                 assert_not_reached("Uh, control process died at wrong time.");
 970         }
 971
 972         /* Notify clients about changed exit status */
 973         unit_add_to_dbus_queue(u);
 974
 975         /* Request a reload of /proc/swaps, so that following units
 976          * can follow our state change */
 977         u->meta.manager->request_reload = true;
 978 }
 979
 980 static void swap_timer_event(Unit *u, uint64_t elapsed, Watch *w) {
 981         Swap *s = SWAP(u);
 982
 983         assert(s);
 984         assert(elapsed == 1);
 985         assert(w == &s->timer_watch);
 986
 987         switch (s->state) {
 988
 989         case SWAP_ACTIVATING:
 990                 log_warning("%s activation timed out. Stopping.", u->meta.id);
 991                 swap_enter_signal(s, SWAP_ACTIVATING_SIGTERM, false);
 992                 break;
 993
 994         case SWAP_DEACTIVATING:
 995                 log_warning("%s deactivation timed out. Stopping.", u->meta.id);
 996                 swap_enter_signal(s, SWAP_DEACTIVATING_SIGTERM, false);
 997                 break;
 998
 999         case SWAP_ACTIVATING_SIGTERM:
1000                 if (s->exec_context.send_sigkill) {
1001                         log_warning("%s activation timed out. Killing.", u->meta.id);
1002                         swap_enter_signal(s, SWAP_ACTIVATING_SIGKILL, false);
1003                 } else {
1004                         log_warning("%s activation timed out. Skipping SIGKILL. Ignoring.", u->meta.id);
1005                         swap_enter_dead(s, false);
1006                 }
1007                 break;
1008
1009         case SWAP_DEACTIVATING_SIGTERM:
1010                 if (s->exec_context.send_sigkill) {
1011                         log_warning("%s deactivation timed out. Killing.", u->meta.id);
1012                         swap_enter_signal(s, SWAP_DEACTIVATING_SIGKILL, false);
1013                 } else {
1014                         log_warning("%s deactivation timed out. Skipping SIGKILL. Ignoring.", u->meta.id);
1015                         swap_enter_dead(s, false);
1016                 }
1017                 break;
1018
1019         case SWAP_ACTIVATING_SIGKILL:
1020         case SWAP_DEACTIVATING_SIGKILL:
1021                 log_warning("%s swap process still around after SIGKILL. Ignoring.", u->meta.id);
1022                 swap_enter_dead(s, false);
1023                 break;
1024
1025         default:
1026                 assert_not_reached("Timeout at wrong time.");
1027         }
1028 }
1029
1030 static int swap_load_proc_swaps(Manager *m, bool set_flags) {
1031         unsigned i;
1032         int r = 0;
1033
1034         assert(m);
1035
1036         rewind(m->proc_swaps);
1037
1038         (void) fscanf(m->proc_swaps, "%*s %*s %*s %*s %*s\n");
1039
1040         for (i = 1;; i++) {
1041                 char *dev = NULL, *d;
1042                 int prio = 0, k;
1043
1044                 if ((k = fscanf(m->proc_swaps,
1045                                 "%ms "  /* device/file */
1046                                 "%*s "  /* type of swap */
1047                                 "%*s "  /* swap size */
1048                                 "%*s "  /* used */
1049                                 "%i\n", /* priority */
1050                                 &dev, &prio)) != 2) {
1051
1052                         if (k == EOF)
1053                                 break;
1054
1055                         log_warning("Failed to parse /proc/swaps:%u.", i);
1056                         free(dev);
1057                         continue;
1058                 }
1059
1060                 d = cunescape(dev);
1061                 free(dev);
1062
1063                 if (!d)
1064                         return -ENOMEM;
1065
1066                 k = swap_process_new_swap(m, d, prio, set_flags);
1067                 free(d);
1068
1069                 if (k < 0)
1070                         r = k;
1071         }
1072
1073         return r;
1074 }
1075
1076 int swap_dispatch_reload(Manager *m) {
1077         /* This function should go as soon as the kernel properly notifies us */
1078
1079         if (_likely_(!m->request_reload))
1080                 return 0;
1081
1082         m->request_reload = false;
1083
1084         return swap_fd_event(m, EPOLLPRI);
1085 }
1086
1087 int swap_fd_event(Manager *m, int events) {
1088         Meta *meta;
1089         int r;
1090
1091         assert(m);
1092         assert(events & EPOLLPRI);
1093
1094         if ((r = swap_load_proc_swaps(m, true)) < 0) {
1095                 log_error("Failed to reread /proc/swaps: %s", strerror(-r));
1096
1097                 /* Reset flags, just in case, for late calls */
1098                 LIST_FOREACH(units_per_type, meta, m->units_per_type[UNIT_SWAP]) {
1099                         Swap *swap = (Swap*) meta;
1100
1101                         swap->is_active = swap->just_activated = false;
1102                 }
1103
1104                 return 0;
1105         }
1106
1107         manager_dispatch_load_queue(m);
1108
1109         LIST_FOREACH(units_per_type, meta, m->units_per_type[UNIT_SWAP]) {
1110                 Swap *swap = (Swap*) meta;
1111
1112                 if (!swap->is_active) {
1113                         /* This has just been deactivated */
1114
1115                         swap->from_proc_swaps = false;
1116                         swap_unset_proc_swaps(swap);
1117
1118                         switch (swap->state) {
1119
1120                         case SWAP_ACTIVE:
1121                                 swap_enter_dead(swap, true);
1122                                 break;
1123
1124                         default:
1125                                 swap_set_state(swap, swap->state);
1126                                 break;
1127                         }
1128
1129                 } else if (swap->just_activated) {
1130
1131                         /* New swap entry */
1132
1133                         switch (swap->state) {
1134
1135                         case SWAP_DEAD:
1136                         case SWAP_FAILED:
1137                                 swap_enter_active(swap, true);
1138                                 break;
1139
1140                         default:
1141                                 /* Nothing really changed, but let's
1142                                  * issue an notification call
1143                                  * nonetheless, in case somebody is
1144                                  * waiting for this. */
1145                                 swap_set_state(swap, swap->state);
1146                                 break;
1147                         }
1148                 }
1149
1150                 /* Reset the flags for later calls */
1151                 swap->is_active = swap->just_activated = false;
1152         }
1153
1154         return 1;
1155 }
1156
1157 static Unit *swap_following(Unit *u) {
1158         Swap *s = SWAP(u);
1159         Swap *other, *first = NULL;
1160
1161         assert(s);
1162
1163         if (streq_ptr(s->what, s->parameters_proc_swaps.what))
1164                 return NULL;
1165
1166         /* Make everybody follow the unit that's named after the swap
1167          * device in the kernel */
1168
1169         LIST_FOREACH_AFTER(same_proc_swaps, other, s)
1170                 if (streq_ptr(other->what, other->parameters_proc_swaps.what))
1171                         return UNIT(other);
1172
1173         LIST_FOREACH_BEFORE(same_proc_swaps, other, s) {
1174                 if (streq_ptr(other->what, other->parameters_proc_swaps.what))
1175                         return UNIT(other);
1176
1177                 first = other;
1178         }
1179
1180         return UNIT(first);
1181 }
1182
1183 static int swap_following_set(Unit *u, Set **_set) {
1184         Swap *s = SWAP(u);
1185         Swap *other;
1186         Set *set;
1187         int r;
1188
1189         assert(s);
1190         assert(_set);
1191
1192         if (LIST_JUST_US(same_proc_swaps, s)) {
1193                 *_set = NULL;
1194                 return 0;
1195         }
1196
1197         if (!(set = set_new(NULL, NULL)))
1198                 return -ENOMEM;
1199
1200         LIST_FOREACH_AFTER(same_proc_swaps, other, s)
1201                 if ((r = set_put(set, other)) < 0)
1202                         goto fail;
1203
1204         LIST_FOREACH_BEFORE(same_proc_swaps, other, s)
1205                 if ((r = set_put(set, other)) < 0)
1206                         goto fail;
1207
1208         *_set = set;
1209         return 1;
1210
1211 fail:
1212         set_free(set);
1213         return r;
1214 }
1215
1216 static void swap_shutdown(Manager *m) {
1217         assert(m);
1218
1219         if (m->proc_swaps) {
1220                 fclose(m->proc_swaps);
1221                 m->proc_swaps = NULL;
1222         }
1223
1224         hashmap_free(m->swaps_by_proc_swaps);
1225         m->swaps_by_proc_swaps = NULL;
1226 }
1227
1228 static int swap_enumerate(Manager *m) {
1229         int r;
1230         struct epoll_event ev;
1231         assert(m);
1232
1233         if (!m->proc_swaps) {
1234                 if (!(m->proc_swaps = fopen("/proc/swaps", "re")))
1235                         return -errno;
1236
1237                 m->swap_watch.type = WATCH_SWAP;
1238                 m->swap_watch.fd = fileno(m->proc_swaps);
1239
1240                 zero(ev);
1241                 ev.events = EPOLLPRI;
1242                 ev.data.ptr = &m->swap_watch;
1243
1244                 if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->swap_watch.fd, &ev) < 0)
1245                         return -errno;
1246         }
1247
1248         /* We rely on mount.c to load /etc/fstab for us */
1249
1250         if ((r = swap_load_proc_swaps(m, false)) < 0)
1251                 swap_shutdown(m);
1252
1253         return r;
1254 }
1255
1256 static void swap_reset_failed(Unit *u) {
1257         Swap *s = SWAP(u);
1258
1259         assert(s);
1260
1261         if (s->state == SWAP_FAILED)
1262                 swap_set_state(s, SWAP_DEAD);
1263
1264         s->failure = false;
1265 }
1266
1267 static int swap_kill(Unit *u, KillWho who, KillMode mode, int signo, DBusError *error) {
1268         Swap *s = SWAP(u);
1269         int r = 0;
1270         Set *pid_set = NULL;
1271
1272         assert(s);
1273
1274         if (who == KILL_MAIN) {
1275                 dbus_set_error(error, BUS_ERROR_NO_SUCH_PROCESS, "Swap units have no main processes");
1276                 return -EINVAL;
1277         }
1278
1279         if (s->control_pid <= 0 && who == KILL_CONTROL) {
1280                 dbus_set_error(error, BUS_ERROR_NO_SUCH_PROCESS, "No control process to kill");
1281                 return -ENOENT;
1282         }
1283
1284         if (s->control_pid > 0)
1285                 if (kill(mode == KILL_PROCESS_GROUP ? -s->control_pid : s->control_pid, signo) < 0)
1286                         r = -errno;
1287
1288         if (mode == KILL_CONTROL_GROUP) {
1289                 int q;
1290
1291                 if (!(pid_set = set_new(trivial_hash_func, trivial_compare_func)))
1292                         return -ENOMEM;
1293
1294                 /* Exclude the control pid from being killed via the cgroup */
1295                 if (s->control_pid > 0)
1296                         if ((q = set_put(pid_set, LONG_TO_PTR(s->control_pid))) < 0) {
1297                                 r = q;
1298                                 goto finish;
1299                         }
1300
1301                 if ((q = cgroup_bonding_kill_list(s->meta.cgroup_bondings, signo, pid_set)) < 0)
1302                         if (r != -EAGAIN && r != -ESRCH && r != -ENOENT)
1303                                 r = q;
1304         }
1305
1306 finish:
1307         if (pid_set)
1308                 set_free(pid_set);
1309
1310         return r;
1311 }
1312
1313 static const char* const swap_state_table[_SWAP_STATE_MAX] = {
1314         [SWAP_DEAD] = "dead",
1315         [SWAP_ACTIVATING] = "activating",
1316         [SWAP_ACTIVE] = "active",
1317         [SWAP_DEACTIVATING] = "deactivating",
1318         [SWAP_ACTIVATING_SIGTERM] = "activating-sigterm",
1319         [SWAP_ACTIVATING_SIGKILL] = "activating-sigkill",
1320         [SWAP_DEACTIVATING_SIGTERM] = "deactivating-sigterm",
1321         [SWAP_DEACTIVATING_SIGKILL] = "deactivating-sigkill",
1322         [SWAP_FAILED] = "failed"
1323 };
1324
1325 DEFINE_STRING_TABLE_LOOKUP(swap_state, SwapState);
1326
1327 static const char* const swap_exec_command_table[_SWAP_EXEC_COMMAND_MAX] = {
1328         [SWAP_EXEC_ACTIVATE] = "ExecActivate",
1329         [SWAP_EXEC_DEACTIVATE] = "ExecDeactivate",
1330 };
1331
1332 DEFINE_STRING_TABLE_LOOKUP(swap_exec_command, SwapExecCommand);
1333
1334 const UnitVTable swap_vtable = {
1335         .suffix = ".swap",
1336
1337         .no_alias = true,
1338         .no_instances = true,
1339         .no_isolate = true,
1340         .show_status = true,
1341
1342         .init = swap_init,
1343         .load = swap_load,
1344         .done = swap_done,
1345
1346         .coldplug = swap_coldplug,
1347
1348         .dump = swap_dump,
1349
1350         .start = swap_start,
1351         .stop = swap_stop,
1352
1353         .kill = swap_kill,
1354
1355         .serialize = swap_serialize,
1356         .deserialize_item = swap_deserialize_item,
1357
1358         .active_state = swap_active_state,
1359         .sub_state_to_string = swap_sub_state_to_string,
1360
1361         .check_gc = swap_check_gc,
1362
1363         .sigchld_event = swap_sigchld_event,
1364         .timer_event = swap_timer_event,
1365
1366         .reset_failed = swap_reset_failed,
1367
1368         .bus_interface = "org.freedesktop.systemd1.Swap",
1369         .bus_message_handler = bus_swap_message_handler,
1370         .bus_invalidating_properties =  bus_swap_invalidating_properties,
1371
1372         .following = swap_following,
1373         .following_set = swap_following_set,
1374
1375         .enumerate = swap_enumerate,
1376         .shutdown = swap_shutdown
1377 };