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