src/swap.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2010 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU General Public License as published by
  10   the Free Software Foundation; either version 2 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   General Public License for more details.
  17
  18   You should have received a copy of the GNU General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <errno.h>
  23 #include <limits.h>
  24 #include <unistd.h>
  25 #include <fcntl.h>
  26 #include <sys/epoll.h>
  27 #include <sys/stat.h>
  28 #include <sys/swap.h>
  29 #include <libudev.h>
  30
  31 #include "unit.h"
  32 #include "swap.h"
  33 #include "load-fragment.h"
  34 #include "load-dropin.h"
  35 #include "unit-name.h"
  36 #include "dbus-swap.h"
  37 #include "special.h"
  38 #include "bus-errors.h"
  39 #include "exit-status.h"
  40 #include "def.h"
  41
  42 static const UnitActiveState state_translation_table[_SWAP_STATE_MAX] = {
  43         [SWAP_DEAD] = UNIT_INACTIVE,
  44         [SWAP_ACTIVATING] = UNIT_ACTIVATING,
  45         [SWAP_ACTIVE] = UNIT_ACTIVE,
  46         [SWAP_DEACTIVATING] = UNIT_DEACTIVATING,
  47         [SWAP_ACTIVATING_SIGTERM] = UNIT_DEACTIVATING,
  48         [SWAP_ACTIVATING_SIGKILL] = UNIT_DEACTIVATING,
  49         [SWAP_DEACTIVATING_SIGTERM] = UNIT_DEACTIVATING,
  50         [SWAP_DEACTIVATING_SIGKILL] = UNIT_DEACTIVATING,
  51         [SWAP_FAILED] = UNIT_FAILED
  52 };
  53
  54 static void swap_unset_proc_swaps(Swap *s) {
  55         Swap *first;
  56
  57         assert(s);
  58
  59         if (!s->parameters_proc_swaps.what)
  60                 return;
  61
  62         /* Remove this unit from the chain of swaps which share the
  63          * same kernel swap device. */
  64
  65         first = hashmap_get(s->meta.manager->swaps_by_proc_swaps, s->parameters_proc_swaps.what);
  66         LIST_REMOVE(Swap, same_proc_swaps, first, s);
  67
  68         if (first)
  69                 hashmap_remove_and_replace(s->meta.manager->swaps_by_proc_swaps, s->parameters_proc_swaps.what, first->parameters_proc_swaps.what, first);
  70         else
  71                 hashmap_remove(s->meta.manager->swaps_by_proc_swaps, s->parameters_proc_swaps.what);
  72
  73         free(s->parameters_proc_swaps.what);
  74         s->parameters_proc_swaps.what = NULL;
  75 }
  76
  77 static void swap_init(Unit *u) {
  78         Swap *s = SWAP(u);
  79
  80         assert(s);
  81         assert(s->meta.load_state == UNIT_STUB);
  82
  83         s->timeout_usec = DEFAULT_TIMEOUT_USEC;
  84
  85         exec_context_init(&s->exec_context);
  86         s->exec_context.std_output = u->meta.manager->default_std_output;
  87         s->exec_context.std_error = u->meta.manager->default_std_error;
  88
  89         s->parameters_etc_fstab.priority = s->parameters_proc_swaps.priority = s->parameters_fragment.priority = -1;
  90
  91         s->timer_watch.type = WATCH_INVALID;
  92
  93         s->control_command_id = _MOUNT_EXEC_COMMAND_INVALID;
  94
  95         s->meta.ignore_on_isolate = true;
  96 }
  97
  98 static void swap_unwatch_control_pid(Swap *s) {
  99         assert(s);
 100
 101         if (s->control_pid <= 0)
 102                 return;
 103
 104         unit_unwatch_pid(UNIT(s), s->control_pid);
 105         s->control_pid = 0;
 106 }
 107
 108 static void swap_done(Unit *u) {
 109         Swap *s = SWAP(u);
 110
 111         assert(s);
 112
 113         swap_unset_proc_swaps(s);
 114
 115         free(s->what);
 116         s->what = NULL;
 117
 118         free(s->parameters_etc_fstab.what);
 119         free(s->parameters_fragment.what);
 120         s->parameters_etc_fstab.what = s->parameters_fragment.what = NULL;
 121
 122         exec_context_done(&s->exec_context);
 123         exec_command_done_array(s->exec_command, _SWAP_EXEC_COMMAND_MAX);
 124         s->control_command = NULL;
 125
 126         swap_unwatch_control_pid(s);
 127
 128         unit_unwatch_timer(u, &s->timer_watch);
 129 }
 130
 131 int swap_add_one_mount_link(Swap *s, Mount *m) {
 132          int r;
 133
 134         assert(s);
 135         assert(m);
 136
 137         if (s->meta.load_state != UNIT_LOADED ||
 138             m->meta.load_state != UNIT_LOADED)
 139                 return 0;
 140
 141         if (is_device_path(s->what))
 142                 return 0;
 143
 144         if (!path_startswith(s->what, m->where))
 145                 return 0;
 146
 147         if ((r = unit_add_two_dependencies(UNIT(s), UNIT_AFTER, UNIT_REQUIRES, UNIT(m), true)) < 0)
 148                 return r;
 149
 150         return 0;
 151 }
 152
 153 static int swap_add_mount_links(Swap *s) {
 154         Meta *other;
 155         int r;
 156
 157         assert(s);
 158
 159         LIST_FOREACH(units_by_type, other, s->meta.manager->units_by_type[UNIT_MOUNT])
 160                 if ((r = swap_add_one_mount_link(s, (Mount*) other)) < 0)
 161                         return r;
 162
 163         return 0;
 164 }
 165
 166 static int swap_add_target_links(Swap *s) {
 167         Unit *tu;
 168         SwapParameters *p;
 169         int r;
 170
 171         assert(s);
 172
 173         if (s->from_fragment)
 174                 p = &s->parameters_fragment;
 175         else if (s->from_etc_fstab)
 176                 p = &s->parameters_etc_fstab;
 177         else
 178                 return 0;
 179
 180         if ((r = manager_load_unit(s->meta.manager, SPECIAL_SWAP_TARGET, NULL, NULL, &tu)) < 0)
 181                 return r;
 182
 183         if (!p->noauto &&
 184             !p->nofail &&
 185             (p->handle || s->meta.manager->swap_auto) &&
 186             s->from_etc_fstab &&
 187             s->meta.manager->running_as == MANAGER_SYSTEM)
 188                 if ((r = unit_add_dependency(tu, UNIT_WANTS, UNIT(s), true)) < 0)
 189                         return r;
 190
 191         return unit_add_dependency(UNIT(s), UNIT_BEFORE, tu, true);
 192 }
 193
 194 static int swap_add_device_links(Swap *s) {
 195         SwapParameters *p;
 196
 197         assert(s);
 198
 199         if (!s->what)
 200                 return 0;
 201
 202         if (s->from_fragment)
 203                 p = &s->parameters_fragment;
 204         else if (s->from_etc_fstab)
 205                 p = &s->parameters_etc_fstab;
 206         else
 207                 return 0;
 208
 209         if (is_device_path(s->what))
 210                 return unit_add_node_link(UNIT(s), s->what,
 211                                           !p->noauto && p->nofail &&
 212                                           s->meta.manager->running_as == MANAGER_SYSTEM);
 213         else
 214                 /* File based swap devices need to be ordered after
 215                  * remount-rootfs.service, since they might need a
 216                  * writable file system. */
 217                 return unit_add_dependency_by_name(UNIT(s), UNIT_AFTER, SPECIAL_REMOUNT_ROOTFS_SERVICE, NULL, true);
 218 }
 219
 220 static int swap_add_default_dependencies(Swap *s) {
 221         int r;
 222
 223         assert(s);
 224
 225         if (s->meta.manager->running_as == MANAGER_SYSTEM) {
 226
 227                 if ((r = unit_add_two_dependencies_by_name(UNIT(s), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_UMOUNT_TARGET, NULL, true)) < 0)
 228                         return r;
 229         }
 230
 231         return 0;
 232 }
 233
 234 static int swap_verify(Swap *s) {
 235         bool b;
 236         char *e;
 237
 238         if (s->meta.load_state != UNIT_LOADED)
 239                   return 0;
 240
 241         if (!(e = unit_name_from_path(s->what, ".swap")))
 242                   return -ENOMEM;
 243
 244         b = unit_has_name(UNIT(s), e);
 245         free(e);
 246
 247         if (!b) {
 248                 log_error("%s: Value of \"What\" and unit name do not match, not loading.\n", s->meta.id);
 249                 return -EINVAL;
 250         }
 251
 252         if (s->exec_context.pam_name && s->exec_context.kill_mode != KILL_CONTROL_GROUP) {
 253                 log_error("%s has PAM enabled. Kill mode must be set to 'control-group'. Refusing.", s->meta.id);
 254                 return -EINVAL;
 255         }
 256
 257         return 0;
 258 }
 259
 260 static int swap_load(Unit *u) {
 261         int r;
 262         Swap *s = SWAP(u);
 263
 264         assert(s);
 265         assert(u->meta.load_state == UNIT_STUB);
 266
 267         /* Load a .swap file */
 268         if ((r = unit_load_fragment_and_dropin_optional(u)) < 0)
 269                 return r;
 270
 271         if (u->meta.load_state == UNIT_LOADED) {
 272                 if ((r = unit_add_exec_dependencies(u, &s->exec_context)) < 0)
 273                         return r;
 274
 275                 if (s->meta.fragment_path)
 276                         s->from_fragment = true;
 277
 278                 if (!s->what) {
 279                         if (s->parameters_fragment.what)
 280                                 s->what = strdup(s->parameters_fragment.what);
 281                         else if (s->parameters_etc_fstab.what)
 282                                 s->what = strdup(s->parameters_etc_fstab.what);
 283                         else if (s->parameters_proc_swaps.what)
 284                                 s->what = strdup(s->parameters_proc_swaps.what);
 285                         else
 286                                 s->what = unit_name_to_path(u->meta.id);
 287
 288                         if (!s->what)
 289                                 return -ENOMEM;
 290                 }
 291
 292                 path_kill_slashes(s->what);
 293
 294                 if (!s->meta.description)
 295                         if ((r = unit_set_description(u, s->what)) < 0)
 296                                 return r;
 297
 298                 if ((r = swap_add_device_links(s)) < 0)
 299                         return r;
 300
 301                 if ((r = swap_add_mount_links(s)) < 0)
 302                         return r;
 303
 304                 if ((r = swap_add_target_links(s)) < 0)
 305                         return r;
 306
 307                 if ((r = unit_add_default_cgroups(u)) < 0)
 308                         return r;
 309
 310                 if (s->meta.default_dependencies)
 311                         if ((r = swap_add_default_dependencies(s)) < 0)
 312                                 return r;
 313         }
 314
 315         return swap_verify(s);
 316 }
 317
 318 int swap_add_one(
 319                 Manager *m,
 320                 const char *what,
 321                 const char *what_proc_swaps,
 322                 int priority,
 323                 bool noauto,
 324                 bool nofail,
 325                 bool handle,
 326                 bool set_flags) {
 327
 328         Unit *u = NULL;
 329         char *e = NULL, *wp = NULL;
 330         bool delete = false;
 331         int r;
 332         SwapParameters *p;
 333
 334         assert(m);
 335         assert(what);
 336
 337         if (!(e = unit_name_from_path(what, ".swap")))
 338                 return -ENOMEM;
 339
 340         u = manager_get_unit(m, e);
 341
 342         if (what_proc_swaps &&
 343             u &&
 344             SWAP(u)->from_proc_swaps &&
 345             !path_equal(SWAP(u)->parameters_proc_swaps.what, what_proc_swaps))
 346                 return -EEXIST;
 347
 348         if (!u) {
 349                 delete = true;
 350
 351                 if (!(u = unit_new(m))) {
 352                         free(e);
 353                         return -ENOMEM;
 354                 }
 355
 356                 if ((r = unit_add_name(u, e)) < 0)
 357                         goto fail;
 358
 359                 if (!(SWAP(u)->what = strdup(what))) {
 360                         r = -ENOMEM;
 361                         goto fail;
 362                 }
 363
 364                 unit_add_to_load_queue(u);
 365         } else
 366                 delete = false;
 367
 368         if (what_proc_swaps) {
 369                 Swap *first;
 370
 371                 p = &SWAP(u)->parameters_proc_swaps;
 372
 373                 if (!p->what) {
 374                         if (!(wp = strdup(what_proc_swaps))) {
 375                                 r = -ENOMEM;
 376                                 goto fail;
 377                         }
 378
 379                         if (!m->swaps_by_proc_swaps)
 380                                 if (!(m->swaps_by_proc_swaps = hashmap_new(string_hash_func, string_compare_func))) {
 381                                         r = -ENOMEM;
 382                                         goto fail;
 383                                 }
 384
 385                         free(p->what);
 386                         p->what = wp;
 387
 388                         first = hashmap_get(m->swaps_by_proc_swaps, wp);
 389                         LIST_PREPEND(Swap, same_proc_swaps, first, SWAP(u));
 390
 391                         if ((r = hashmap_replace(m->swaps_by_proc_swaps, wp, first)) < 0)
 392                                 goto fail;
 393                 }
 394
 395                 if (set_flags) {
 396                         SWAP(u)->is_active = true;
 397                         SWAP(u)->just_activated = !SWAP(u)->from_proc_swaps;
 398                 }
 399
 400                 SWAP(u)->from_proc_swaps = true;
 401
 402         } else {
 403                 p = &SWAP(u)->parameters_etc_fstab;
 404
 405                 if (!(wp = strdup(what))) {
 406                         r = -ENOMEM;
 407                         goto fail;
 408                 }
 409
 410                 free(p->what);
 411                 p->what = wp;
 412
 413                 SWAP(u)->from_etc_fstab = true;
 414         }
 415
 416         p->priority = priority;
 417         p->noauto = noauto;
 418         p->nofail = nofail;
 419         p->handle = handle;
 420
 421         unit_add_to_dbus_queue(u);
 422
 423         free(e);
 424
 425         return 0;
 426
 427 fail:
 428         log_warning("Failed to load swap unit: %s", strerror(-r));
 429
 430         free(wp);
 431         free(e);
 432
 433         if (delete && u)
 434                 unit_free(u);
 435
 436         return r;
 437 }
 438
 439 static int swap_process_new_swap(Manager *m, const char *device, int prio, bool set_flags) {
 440         struct stat st;
 441         int r = 0, k;
 442
 443         assert(m);
 444
 445         if (stat(device, &st) >= 0 && S_ISBLK(st.st_mode)) {
 446                 struct udev_device *d;
 447                 const char *dn;
 448                 struct udev_list_entry *item = NULL, *first = NULL;
 449
 450                 /* So this is a proper swap device. Create swap units
 451                  * for all names this swap device is known under */
 452
 453                 if (!(d = udev_device_new_from_devnum(m->udev, 'b', st.st_rdev)))
 454                         return -ENOMEM;
 455
 456                 if ((dn = udev_device_get_devnode(d)))
 457                         r = swap_add_one(m, dn, device, prio, false, false, false, set_flags);
 458
 459                 /* Add additional units for all symlinks */
 460                 first = udev_device_get_devlinks_list_entry(d);
 461                 udev_list_entry_foreach(item, first) {
 462                         const char *p;
 463
 464                         /* Don't bother with the /dev/block links */
 465                         p = udev_list_entry_get_name(item);
 466
 467                         if (path_startswith(p, "/dev/block/"))
 468                                 continue;
 469
 470                         if (stat(p, &st) >= 0)
 471                                 if ((!S_ISBLK(st.st_mode)) || st.st_rdev != udev_device_get_devnum(d))
 472                                         continue;
 473
 474                         if ((k = swap_add_one(m, p, device, prio, false, false, false, set_flags)) < 0)
 475                                 r = k;
 476                 }
 477
 478                 udev_device_unref(d);
 479         }
 480
 481         if ((k = swap_add_one(m, device, device, prio, false, false, false, set_flags)) < 0)
 482                 r = k;
 483
 484         return r;
 485 }
 486
 487 static void swap_set_state(Swap *s, SwapState state) {
 488         SwapState old_state;
 489
 490         assert(s);
 491
 492         old_state = s->state;
 493         s->state = state;
 494
 495         if (state != SWAP_ACTIVATING &&
 496             state != SWAP_ACTIVATING_SIGTERM &&
 497             state != SWAP_ACTIVATING_SIGKILL &&
 498             state != SWAP_DEACTIVATING &&
 499             state != SWAP_DEACTIVATING_SIGTERM &&
 500             state != SWAP_DEACTIVATING_SIGKILL) {
 501                 unit_unwatch_timer(UNIT(s), &s->timer_watch);
 502                 swap_unwatch_control_pid(s);
 503                 s->control_command = NULL;
 504                 s->control_command_id = _SWAP_EXEC_COMMAND_INVALID;
 505         }
 506
 507         if (state != old_state)
 508                 log_debug("%s changed %s -> %s",
 509                           s->meta.id,
 510                           swap_state_to_string(old_state),
 511                           swap_state_to_string(state));
 512
 513         unit_notify(UNIT(s), state_translation_table[old_state], state_translation_table[state], true);
 514 }
 515
 516 static int swap_coldplug(Unit *u) {
 517         Swap *s = SWAP(u);
 518         SwapState new_state = SWAP_DEAD;
 519         int r;
 520
 521         assert(s);
 522         assert(s->state == SWAP_DEAD);
 523
 524         if (s->deserialized_state != s->state)
 525                 new_state = s->deserialized_state;
 526         else if (s->from_proc_swaps)
 527                 new_state = SWAP_ACTIVE;
 528
 529         if (new_state != s->state) {
 530
 531                 if (new_state == SWAP_ACTIVATING ||
 532                     new_state == SWAP_ACTIVATING_SIGTERM ||
 533                     new_state == SWAP_ACTIVATING_SIGKILL ||
 534                     new_state == SWAP_DEACTIVATING ||
 535                     new_state == SWAP_DEACTIVATING_SIGTERM ||
 536                     new_state == SWAP_DEACTIVATING_SIGKILL) {
 537
 538                         if (s->control_pid <= 0)
 539                                 return -EBADMSG;
 540
 541                         if ((r = unit_watch_pid(UNIT(s), s->control_pid)) < 0)
 542                                 return r;
 543
 544                         if ((r = unit_watch_timer(UNIT(s), s->timeout_usec, &s->timer_watch)) < 0)
 545                                 return r;
 546                 }
 547
 548                 swap_set_state(s, new_state);
 549         }
 550
 551         return 0;
 552 }
 553
 554 static void swap_dump(Unit *u, FILE *f, const char *prefix) {
 555         Swap *s = SWAP(u);
 556         SwapParameters *p;
 557
 558         assert(s);
 559         assert(f);
 560
 561         if (s->from_proc_swaps)
 562                 p = &s->parameters_proc_swaps;
 563         else if (s->from_fragment)
 564                 p = &s->parameters_fragment;
 565         else
 566                 p = &s->parameters_etc_fstab;
 567
 568         fprintf(f,
 569                 "%sSwap State: %s\n"
 570                 "%sWhat: %s\n"
 571                 "%sPriority: %i\n"
 572                 "%sNoAuto: %s\n"
 573                 "%sNoFail: %s\n"
 574                 "%sHandle: %s\n"
 575                 "%sFrom /etc/fstab: %s\n"
 576                 "%sFrom /proc/swaps: %s\n"
 577                 "%sFrom fragment: %s\n",
 578                 prefix, swap_state_to_string(s->state),
 579                 prefix, s->what,
 580                 prefix, p->priority,
 581                 prefix, yes_no(p->noauto),
 582                 prefix, yes_no(p->nofail),
 583                 prefix, yes_no(p->handle),
 584                 prefix, yes_no(s->from_etc_fstab),
 585                 prefix, yes_no(s->from_proc_swaps),
 586                 prefix, yes_no(s->from_fragment));
 587
 588         if (s->control_pid > 0)
 589                 fprintf(f,
 590                         "%sControl PID: %lu\n",
 591                         prefix, (unsigned long) s->control_pid);
 592
 593         exec_context_dump(&s->exec_context, f, prefix);
 594 }
 595
 596 static int swap_spawn(Swap *s, ExecCommand *c, pid_t *_pid) {
 597         pid_t pid;
 598         int r;
 599
 600         assert(s);
 601         assert(c);
 602         assert(_pid);
 603
 604         if ((r = unit_watch_timer(UNIT(s), s->timeout_usec, &s->timer_watch)) < 0)
 605                 goto fail;
 606
 607         if ((r = exec_spawn(c,
 608                             NULL,
 609                             &s->exec_context,
 610                             NULL, 0,
 611                             s->meta.manager->environment,
 612                             true,
 613                             true,
 614                             true,
 615                             s->meta.manager->confirm_spawn,
 616                             s->meta.cgroup_bondings,
 617                             s->meta.cgroup_attributes,
 618                             &pid)) < 0)
 619                 goto fail;
 620
 621         if ((r = unit_watch_pid(UNIT(s), pid)) < 0)
 622                 /* FIXME: we need to do something here */
 623                 goto fail;
 624
 625         *_pid = pid;
 626
 627         return 0;
 628
 629 fail:
 630         unit_unwatch_timer(UNIT(s), &s->timer_watch);
 631
 632         return r;
 633 }
 634
 635 static void swap_enter_dead(Swap *s, bool success) {
 636         assert(s);
 637
 638         if (!success)
 639                 s->failure = true;
 640
 641         swap_set_state(s, s->failure ? SWAP_FAILED : SWAP_DEAD);
 642 }
 643
 644 static void swap_enter_active(Swap *s, bool success) {
 645         assert(s);
 646
 647         if (!success)
 648                 s->failure = true;
 649
 650         swap_set_state(s, SWAP_ACTIVE);
 651 }
 652
 653 static void swap_enter_signal(Swap *s, SwapState state, bool success) {
 654         int r;
 655         Set *pid_set = NULL;
 656         bool wait_for_exit = false;
 657
 658         assert(s);
 659
 660         if (!success)
 661                 s->failure = true;
 662
 663         if (s->exec_context.kill_mode != KILL_NONE) {
 664                 int sig = (state == SWAP_ACTIVATING_SIGTERM ||
 665                            state == SWAP_DEACTIVATING_SIGTERM) ? s->exec_context.kill_signal : SIGKILL;
 666
 667                 if (s->control_pid > 0) {
 668                         if (kill_and_sigcont(s->control_pid, sig) < 0 && errno != ESRCH)
 669
 670                                 log_warning("Failed to kill control process %li: %m", (long) s->control_pid);
 671                         else
 672                                 wait_for_exit = true;
 673                 }
 674
 675                 if (s->exec_context.kill_mode == KILL_CONTROL_GROUP) {
 676
 677                         if (!(pid_set = set_new(trivial_hash_func, trivial_compare_func))) {
 678                                 r = -ENOMEM;
 679                                 goto fail;
 680                         }
 681
 682                         /* Exclude the control pid from being killed via the cgroup */
 683                         if (s->control_pid > 0)
 684                                 if ((r = set_put(pid_set, LONG_TO_PTR(s->control_pid))) < 0)
 685                                         goto fail;
 686
 687                         if ((r = cgroup_bonding_kill_list(s->meta.cgroup_bondings, sig, true, pid_set)) < 0) {
 688                                 if (r != -EAGAIN && r != -ESRCH && r != -ENOENT)
 689                                         log_warning("Failed to kill control group: %s", strerror(-r));
 690                         } else if (r > 0)
 691                                 wait_for_exit = true;
 692
 693                         set_free(pid_set);
 694                         pid_set = NULL;
 695                 }
 696         }
 697
 698         if (wait_for_exit) {
 699                 if ((r = unit_watch_timer(UNIT(s), s->timeout_usec, &s->timer_watch)) < 0)
 700                         goto fail;
 701
 702                 swap_set_state(s, state);
 703         } else
 704                 swap_enter_dead(s, true);
 705
 706         return;
 707
 708 fail:
 709         log_warning("%s failed to kill processes: %s", s->meta.id, strerror(-r));
 710
 711         swap_enter_dead(s, false);
 712
 713         if (pid_set)
 714                 set_free(pid_set);
 715 }
 716
 717 static void swap_enter_activating(Swap *s) {
 718         int r, priority;
 719
 720         assert(s);
 721
 722         s->control_command_id = SWAP_EXEC_ACTIVATE;
 723         s->control_command = s->exec_command + SWAP_EXEC_ACTIVATE;
 724
 725         if (s->from_fragment)
 726                 priority = s->parameters_fragment.priority;
 727         else if (s->from_etc_fstab)
 728                 priority = s->parameters_etc_fstab.priority;
 729         else
 730                 priority = -1;
 731
 732         if (priority >= 0) {
 733                 char p[LINE_MAX];
 734
 735                 snprintf(p, sizeof(p), "%i", priority);
 736                 char_array_0(p);
 737
 738                 r = exec_command_set(
 739                                 s->control_command,
 740                                 "/sbin/swapon",
 741                                 "-p",
 742                                 p,
 743                                 s->what,
 744                                 NULL);
 745         } else
 746                 r = exec_command_set(
 747                                 s->control_command,
 748                                 "/sbin/swapon",
 749                                 s->what,
 750                                 NULL);
 751
 752         if (r < 0)
 753                 goto fail;
 754
 755         swap_unwatch_control_pid(s);
 756
 757         if ((r = swap_spawn(s, s->control_command, &s->control_pid)) < 0)
 758                 goto fail;
 759
 760         swap_set_state(s, SWAP_ACTIVATING);
 761
 762         return;
 763
 764 fail:
 765         log_warning("%s failed to run 'swapon' task: %s", s->meta.id, strerror(-r));
 766         swap_enter_dead(s, false);
 767 }
 768
 769 static void swap_enter_deactivating(Swap *s, bool success) {
 770         int r;
 771
 772         assert(s);
 773
 774         if (!success)
 775                 s->failure = true;
 776
 777         s->control_command_id = SWAP_EXEC_DEACTIVATE;
 778         s->control_command = s->exec_command + SWAP_EXEC_DEACTIVATE;
 779
 780         if ((r = exec_command_set(
 781                              s->control_command,
 782                              "/sbin/swapoff",
 783                              s->what,
 784                              NULL)) < 0)
 785                 goto fail;
 786
 787         swap_unwatch_control_pid(s);
 788
 789         if ((r = swap_spawn(s, s->control_command, &s->control_pid)) < 0)
 790                 goto fail;
 791
 792         swap_set_state(s, SWAP_DEACTIVATING);
 793
 794         return;
 795
 796 fail:
 797         log_warning("%s failed to run 'swapoff' task: %s", s->meta.id, strerror(-r));
 798         swap_enter_active(s, false);
 799 }
 800
 801 static int swap_start(Unit *u) {
 802         Swap *s = SWAP(u);
 803
 804         assert(s);
 805
 806         /* We cannot fulfill this request right now, try again later
 807          * please! */
 808
 809         if (s->state == SWAP_DEACTIVATING ||
 810             s->state == SWAP_DEACTIVATING_SIGTERM ||
 811             s->state == SWAP_DEACTIVATING_SIGKILL ||
 812             s->state == SWAP_ACTIVATING_SIGTERM ||
 813             s->state == SWAP_ACTIVATING_SIGKILL)
 814                 return -EAGAIN;
 815
 816         if (s->state == SWAP_ACTIVATING)
 817                 return 0;
 818
 819         assert(s->state == SWAP_DEAD || s->state == SWAP_FAILED);
 820
 821         s->failure = false;
 822         swap_enter_activating(s);
 823         return 0;
 824 }
 825
 826 static int swap_stop(Unit *u) {
 827         Swap *s = SWAP(u);
 828
 829         assert(s);
 830
 831         if (s->state == SWAP_DEACTIVATING ||
 832             s->state == SWAP_DEACTIVATING_SIGTERM ||
 833             s->state == SWAP_DEACTIVATING_SIGKILL ||
 834             s->state == SWAP_ACTIVATING_SIGTERM ||
 835             s->state == SWAP_ACTIVATING_SIGKILL)
 836                 return 0;
 837
 838         assert(s->state == SWAP_ACTIVATING ||
 839                s->state == SWAP_ACTIVE);
 840
 841         swap_enter_deactivating(s, true);
 842         return 0;
 843 }
 844
 845 static int swap_serialize(Unit *u, FILE *f, FDSet *fds) {
 846         Swap *s = SWAP(u);
 847
 848         assert(s);
 849         assert(f);
 850         assert(fds);
 851
 852         unit_serialize_item(u, f, "state", swap_state_to_string(s->state));
 853         unit_serialize_item(u, f, "failure", yes_no(s->failure));
 854
 855         if (s->control_pid > 0)
 856                 unit_serialize_item_format(u, f, "control-pid", "%lu", (unsigned long) s->control_pid);
 857
 858         if (s->control_command_id >= 0)
 859                 unit_serialize_item(u, f, "control-command", swap_exec_command_to_string(s->control_command_id));
 860
 861         return 0;
 862 }
 863
 864 static int swap_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 865         Swap *s = SWAP(u);
 866
 867         assert(s);
 868         assert(fds);
 869
 870         if (streq(key, "state")) {
 871                 SwapState state;
 872
 873                 if ((state = swap_state_from_string(value)) < 0)
 874                         log_debug("Failed to parse state value %s", value);
 875                 else
 876                         s->deserialized_state = state;
 877         } else if (streq(key, "failure")) {
 878                 int b;
 879
 880                 if ((b = parse_boolean(value)) < 0)
 881                         log_debug("Failed to parse failure value %s", value);
 882                 else
 883                         s->failure = b || s->failure;
 884
 885         } else if (streq(key, "control-pid")) {
 886                 pid_t pid;
 887
 888                 if (parse_pid(value, &pid) < 0)
 889                         log_debug("Failed to parse control-pid value %s", value);
 890                 else
 891                         s->control_pid = pid;
 892
 893         } else if (streq(key, "control-command")) {
 894                 SwapExecCommand id;
 895
 896                 if ((id = swap_exec_command_from_string(value)) < 0)
 897                         log_debug("Failed to parse exec-command value %s", value);
 898                 else {
 899                         s->control_command_id = id;
 900                         s->control_command = s->exec_command + id;
 901                 }
 902
 903         } else
 904                 log_debug("Unknown serialization key '%s'", key);
 905
 906         return 0;
 907 }
 908
 909 static UnitActiveState swap_active_state(Unit *u) {
 910         assert(u);
 911
 912         return state_translation_table[SWAP(u)->state];
 913 }
 914
 915 static const char *swap_sub_state_to_string(Unit *u) {
 916         assert(u);
 917
 918         return swap_state_to_string(SWAP(u)->state);
 919 }
 920
 921 static bool swap_check_gc(Unit *u) {
 922         Swap *s = SWAP(u);
 923
 924         assert(s);
 925
 926         return s->from_etc_fstab || s->from_proc_swaps;
 927 }
 928
 929 static void swap_sigchld_event(Unit *u, pid_t pid, int code, int status) {
 930         Swap *s = SWAP(u);
 931         bool success;
 932
 933         assert(s);
 934         assert(pid >= 0);
 935
 936         if (pid != s->control_pid)
 937                 return;
 938
 939         s->control_pid = 0;
 940
 941         success = is_clean_exit(code, status);
 942         s->failure = s->failure || !success;
 943
 944         if (s->control_command) {
 945                 exec_status_exit(&s->control_command->exec_status, &s->exec_context, pid, code, status);
 946                 s->control_command = NULL;
 947                 s->control_command_id = _SWAP_EXEC_COMMAND_INVALID;
 948         }
 949
 950         log_full(success ? LOG_DEBUG : LOG_NOTICE,
 951                  "%s swap process exited, code=%s status=%i", u->meta.id, sigchld_code_to_string(code), status);
 952
 953         switch (s->state) {
 954
 955         case SWAP_ACTIVATING:
 956         case SWAP_ACTIVATING_SIGTERM:
 957         case SWAP_ACTIVATING_SIGKILL:
 958
 959                 if (success)
 960                         swap_enter_active(s, true);
 961                 else
 962                         swap_enter_dead(s, false);
 963                 break;
 964
 965         case SWAP_DEACTIVATING:
 966         case SWAP_DEACTIVATING_SIGKILL:
 967         case SWAP_DEACTIVATING_SIGTERM:
 968
 969                 if (success)
 970                         swap_enter_dead(s, true);
 971                 else
 972                         swap_enter_dead(s, false);
 973                 break;
 974
 975         default:
 976                 assert_not_reached("Uh, control process died at wrong time.");
 977         }
 978
 979         /* Notify clients about changed exit status */
 980         unit_add_to_dbus_queue(u);
 981
 982         /* Request a reload of /proc/swaps, so that following units
 983          * can follow our state change */
 984         u->meta.manager->request_reload = true;
 985 }
 986
 987 static void swap_timer_event(Unit *u, uint64_t elapsed, Watch *w) {
 988         Swap *s = SWAP(u);
 989
 990         assert(s);
 991         assert(elapsed == 1);
 992         assert(w == &s->timer_watch);
 993
 994         switch (s->state) {
 995
 996         case SWAP_ACTIVATING:
 997                 log_warning("%s activation timed out. Stopping.", u->meta.id);
 998                 swap_enter_signal(s, SWAP_ACTIVATING_SIGTERM, false);
 999                 break;
1000
1001         case SWAP_DEACTIVATING:
1002                 log_warning("%s deactivation timed out. Stopping.", u->meta.id);
1003                 swap_enter_signal(s, SWAP_DEACTIVATING_SIGTERM, false);
1004                 break;
1005
1006         case SWAP_ACTIVATING_SIGTERM:
1007                 if (s->exec_context.send_sigkill) {
1008                         log_warning("%s activation timed out. Killing.", u->meta.id);
1009                         swap_enter_signal(s, SWAP_ACTIVATING_SIGKILL, false);
1010                 } else {
1011                         log_warning("%s activation timed out. Skipping SIGKILL. Ignoring.", u->meta.id);
1012                         swap_enter_dead(s, false);
1013                 }
1014                 break;
1015
1016         case SWAP_DEACTIVATING_SIGTERM:
1017                 if (s->exec_context.send_sigkill) {
1018                         log_warning("%s deactivation timed out. Killing.", u->meta.id);
1019                         swap_enter_signal(s, SWAP_DEACTIVATING_SIGKILL, false);
1020                 } else {
1021                         log_warning("%s deactivation timed out. Skipping SIGKILL. Ignoring.", u->meta.id);
1022                         swap_enter_dead(s, false);
1023                 }
1024                 break;
1025
1026         case SWAP_ACTIVATING_SIGKILL:
1027         case SWAP_DEACTIVATING_SIGKILL:
1028                 log_warning("%s swap process still around after SIGKILL. Ignoring.", u->meta.id);
1029                 swap_enter_dead(s, false);
1030                 break;
1031
1032         default:
1033                 assert_not_reached("Timeout at wrong time.");
1034         }
1035 }
1036
1037 static int swap_load_proc_swaps(Manager *m, bool set_flags) {
1038         unsigned i;
1039         int r = 0;
1040
1041         assert(m);
1042
1043         rewind(m->proc_swaps);
1044
1045         (void) fscanf(m->proc_swaps, "%*s %*s %*s %*s %*s\n");
1046
1047         for (i = 1;; i++) {
1048                 char *dev = NULL, *d;
1049                 int prio = 0, k;
1050
1051                 if ((k = fscanf(m->proc_swaps,
1052                                 "%ms "  /* device/file */
1053                                 "%*s "  /* type of swap */
1054                                 "%*s "  /* swap size */
1055                                 "%*s "  /* used */
1056                                 "%i\n", /* priority */
1057                                 &dev, &prio)) != 2) {
1058
1059                         if (k == EOF)
1060                                 break;
1061
1062                         log_warning("Failed to parse /proc/swaps:%u.", i);
1063                         free(dev);
1064                         continue;
1065                 }
1066
1067                 d = cunescape(dev);
1068                 free(dev);
1069
1070                 if (!d)
1071                         return -ENOMEM;
1072
1073                 k = swap_process_new_swap(m, d, prio, set_flags);
1074                 free(d);
1075
1076                 if (k < 0)
1077                         r = k;
1078         }
1079
1080         return r;
1081 }
1082
1083 int swap_dispatch_reload(Manager *m) {
1084         /* This function should go as soon as the kernel properly notifies us */
1085
1086         if (_likely_(!m->request_reload))
1087                 return 0;
1088
1089         m->request_reload = false;
1090
1091         return swap_fd_event(m, EPOLLPRI);
1092 }
1093
1094 int swap_fd_event(Manager *m, int events) {
1095         Meta *meta;
1096         int r;
1097
1098         assert(m);
1099         assert(events & EPOLLPRI);
1100
1101         if ((r = swap_load_proc_swaps(m, true)) < 0) {
1102                 log_error("Failed to reread /proc/swaps: %s", strerror(-r));
1103
1104                 /* Reset flags, just in case, for late calls */
1105                 LIST_FOREACH(units_by_type, meta, m->units_by_type[UNIT_SWAP]) {
1106                         Swap *swap = (Swap*) meta;
1107
1108                         swap->is_active = swap->just_activated = false;
1109                 }
1110
1111                 return 0;
1112         }
1113
1114         manager_dispatch_load_queue(m);
1115
1116         LIST_FOREACH(units_by_type, meta, m->units_by_type[UNIT_SWAP]) {
1117                 Swap *swap = (Swap*) meta;
1118
1119                 if (!swap->is_active) {
1120                         /* This has just been deactivated */
1121
1122                         swap->from_proc_swaps = false;
1123                         swap_unset_proc_swaps(swap);
1124
1125                         switch (swap->state) {
1126
1127                         case SWAP_ACTIVE:
1128                                 swap_enter_dead(swap, true);
1129                                 break;
1130
1131                         default:
1132                                 swap_set_state(swap, swap->state);
1133                                 break;
1134                         }
1135
1136                 } else if (swap->just_activated) {
1137
1138                         /* New swap entry */
1139
1140                         switch (swap->state) {
1141
1142                         case SWAP_DEAD:
1143                         case SWAP_FAILED:
1144                                 swap_enter_active(swap, true);
1145                                 break;
1146
1147                         default:
1148                                 /* Nothing really changed, but let's
1149                                  * issue an notification call
1150                                  * nonetheless, in case somebody is
1151                                  * waiting for this. */
1152                                 swap_set_state(swap, swap->state);
1153                                 break;
1154                         }
1155                 }
1156
1157                 /* Reset the flags for later calls */
1158                 swap->is_active = swap->just_activated = false;
1159         }
1160
1161         return 1;
1162 }
1163
1164 static Unit *swap_following(Unit *u) {
1165         Swap *s = SWAP(u);
1166         Swap *other, *first = NULL;
1167
1168         assert(s);
1169
1170         if (streq_ptr(s->what, s->parameters_proc_swaps.what))
1171                 return NULL;
1172
1173         /* Make everybody follow the unit that's named after the swap
1174          * device in the kernel */
1175
1176         LIST_FOREACH_AFTER(same_proc_swaps, other, s)
1177                 if (streq_ptr(other->what, other->parameters_proc_swaps.what))
1178                         return UNIT(other);
1179
1180         LIST_FOREACH_BEFORE(same_proc_swaps, other, s) {
1181                 if (streq_ptr(other->what, other->parameters_proc_swaps.what))
1182                         return UNIT(other);
1183
1184                 first = other;
1185         }
1186
1187         return UNIT(first);
1188 }
1189
1190 static int swap_following_set(Unit *u, Set **_set) {
1191         Swap *s = SWAP(u);
1192         Swap *other;
1193         Set *set;
1194         int r;
1195
1196         assert(s);
1197         assert(_set);
1198
1199         if (LIST_JUST_US(same_proc_swaps, s)) {
1200                 *_set = NULL;
1201                 return 0;
1202         }
1203
1204         if (!(set = set_new(NULL, NULL)))
1205                 return -ENOMEM;
1206
1207         LIST_FOREACH_AFTER(same_proc_swaps, other, s)
1208                 if ((r = set_put(set, other)) < 0)
1209                         goto fail;
1210
1211         LIST_FOREACH_BEFORE(same_proc_swaps, other, s)
1212                 if ((r = set_put(set, other)) < 0)
1213                         goto fail;
1214
1215         *_set = set;
1216         return 1;
1217
1218 fail:
1219         set_free(set);
1220         return r;
1221 }
1222
1223 static void swap_shutdown(Manager *m) {
1224         assert(m);
1225
1226         if (m->proc_swaps) {
1227                 fclose(m->proc_swaps);
1228                 m->proc_swaps = NULL;
1229         }
1230
1231         hashmap_free(m->swaps_by_proc_swaps);
1232         m->swaps_by_proc_swaps = NULL;
1233 }
1234
1235 static int swap_enumerate(Manager *m) {
1236         int r;
1237         struct epoll_event ev;
1238         assert(m);
1239
1240         if (!m->proc_swaps) {
1241                 if (!(m->proc_swaps = fopen("/proc/swaps", "re")))
1242                         return (errno == ENOENT) ? 0 : -errno;
1243
1244                 m->swap_watch.type = WATCH_SWAP;
1245                 m->swap_watch.fd = fileno(m->proc_swaps);
1246
1247                 zero(ev);
1248                 ev.events = EPOLLPRI;
1249                 ev.data.ptr = &m->swap_watch;
1250
1251                 if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->swap_watch.fd, &ev) < 0)
1252                         return -errno;
1253         }
1254
1255         /* We rely on mount.c to load /etc/fstab for us */
1256
1257         if ((r = swap_load_proc_swaps(m, false)) < 0)
1258                 swap_shutdown(m);
1259
1260         return r;
1261 }
1262
1263 static void swap_reset_failed(Unit *u) {
1264         Swap *s = SWAP(u);
1265
1266         assert(s);
1267
1268         if (s->state == SWAP_FAILED)
1269                 swap_set_state(s, SWAP_DEAD);
1270
1271         s->failure = false;
1272 }
1273
1274 static int swap_kill(Unit *u, KillWho who, KillMode mode, int signo, DBusError *error) {
1275         Swap *s = SWAP(u);
1276         int r = 0;
1277         Set *pid_set = NULL;
1278
1279         assert(s);
1280
1281         if (who == KILL_MAIN) {
1282                 dbus_set_error(error, BUS_ERROR_NO_SUCH_PROCESS, "Swap units have no main processes");
1283                 return -ESRCH;
1284         }
1285
1286         if (s->control_pid <= 0 && who == KILL_CONTROL) {
1287                 dbus_set_error(error, BUS_ERROR_NO_SUCH_PROCESS, "No control process to kill");
1288                 return -ESRCH;
1289         }
1290
1291         if (who == KILL_CONTROL || who == KILL_ALL)
1292                 if (s->control_pid > 0)
1293                         if (kill(s->control_pid, signo) < 0)
1294                                 r = -errno;
1295
1296         if (who == KILL_ALL && mode == KILL_CONTROL_GROUP) {
1297                 int q;
1298
1299                 if (!(pid_set = set_new(trivial_hash_func, trivial_compare_func)))
1300                         return -ENOMEM;
1301
1302                 /* Exclude the control pid from being killed via the cgroup */
1303                 if (s->control_pid > 0)
1304                         if ((q = set_put(pid_set, LONG_TO_PTR(s->control_pid))) < 0) {
1305                                 r = q;
1306                                 goto finish;
1307                         }
1308
1309                 if ((q = cgroup_bonding_kill_list(s->meta.cgroup_bondings, signo, false, pid_set)) < 0)
1310                         if (q != -EAGAIN && q != -ESRCH && q != -ENOENT)
1311                                 r = q;
1312         }
1313
1314 finish:
1315         if (pid_set)
1316                 set_free(pid_set);
1317
1318         return r;
1319 }
1320
1321 static const char* const swap_state_table[_SWAP_STATE_MAX] = {
1322         [SWAP_DEAD] = "dead",
1323         [SWAP_ACTIVATING] = "activating",
1324         [SWAP_ACTIVE] = "active",
1325         [SWAP_DEACTIVATING] = "deactivating",
1326         [SWAP_ACTIVATING_SIGTERM] = "activating-sigterm",
1327         [SWAP_ACTIVATING_SIGKILL] = "activating-sigkill",
1328         [SWAP_DEACTIVATING_SIGTERM] = "deactivating-sigterm",
1329         [SWAP_DEACTIVATING_SIGKILL] = "deactivating-sigkill",
1330         [SWAP_FAILED] = "failed"
1331 };
1332
1333 DEFINE_STRING_TABLE_LOOKUP(swap_state, SwapState);
1334
1335 static const char* const swap_exec_command_table[_SWAP_EXEC_COMMAND_MAX] = {
1336         [SWAP_EXEC_ACTIVATE] = "ExecActivate",
1337         [SWAP_EXEC_DEACTIVATE] = "ExecDeactivate",
1338 };
1339
1340 DEFINE_STRING_TABLE_LOOKUP(swap_exec_command, SwapExecCommand);
1341
1342 const UnitVTable swap_vtable = {
1343         .suffix = ".swap",
1344         .sections =
1345                 "Unit\0"
1346                 "Swap\0"
1347                 "Install\0",
1348
1349         .no_alias = true,
1350         .no_instances = true,
1351         .show_status = true,
1352
1353         .init = swap_init,
1354         .load = swap_load,
1355         .done = swap_done,
1356
1357         .coldplug = swap_coldplug,
1358
1359         .dump = swap_dump,
1360
1361         .start = swap_start,
1362         .stop = swap_stop,
1363
1364         .kill = swap_kill,
1365
1366         .serialize = swap_serialize,
1367         .deserialize_item = swap_deserialize_item,
1368
1369         .active_state = swap_active_state,
1370         .sub_state_to_string = swap_sub_state_to_string,
1371
1372         .check_gc = swap_check_gc,
1373
1374         .sigchld_event = swap_sigchld_event,
1375         .timer_event = swap_timer_event,
1376
1377         .reset_failed = swap_reset_failed,
1378
1379         .bus_interface = "org.freedesktop.systemd1.Swap",
1380         .bus_message_handler = bus_swap_message_handler,
1381         .bus_invalidating_properties =  bus_swap_invalidating_properties,
1382
1383         .following = swap_following,
1384         .following_set = swap_following_set,
1385
1386         .enumerate = swap_enumerate,
1387         .shutdown = swap_shutdown
1388 };