src/swap.c

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