src/core/automount.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <errno.h>
   4 #include <fcntl.h>
   5 #include <limits.h>
   6 #include <linux/auto_dev-ioctl.h>
   7 #include <linux/auto_fs4.h>
   8 #include <sys/epoll.h>
   9 #include <sys/mount.h>
  10 #include <sys/stat.h>
  11 #include <unistd.h>
  12
  13 #include "alloc-util.h"
  14 #include "async.h"
  15 #include "automount.h"
  16 #include "bus-error.h"
  17 #include "bus-util.h"
  18 #include "dbus-automount.h"
  19 #include "dbus-unit.h"
  20 #include "fd-util.h"
  21 #include "format-util.h"
  22 #include "fstab-util.h"
  23 #include "io-util.h"
  24 #include "label.h"
  25 #include "mkdir-label.h"
  26 #include "mount-util.h"
  27 #include "mount.h"
  28 #include "mountpoint-util.h"
  29 #include "parse-util.h"
  30 #include "path-util.h"
  31 #include "process-util.h"
  32 #include "serialize.h"
  33 #include "special.h"
  34 #include "stdio-util.h"
  35 #include "string-table.h"
  36 #include "string-util.h"
  37 #include "unit-name.h"
  38 #include "unit.h"
  39
  40 static const UnitActiveState state_translation_table[_AUTOMOUNT_STATE_MAX] = {
  41         [AUTOMOUNT_DEAD] = UNIT_INACTIVE,
  42         [AUTOMOUNT_WAITING] = UNIT_ACTIVE,
  43         [AUTOMOUNT_RUNNING] = UNIT_ACTIVE,
  44         [AUTOMOUNT_FAILED] = UNIT_FAILED
  45 };
  46
  47 struct expire_data {
  48         int dev_autofs_fd;
  49         int ioctl_fd;
  50 };
  51
  52 static struct expire_data* expire_data_free(struct expire_data *data) {
  53         if (!data)
  54                 return NULL;
  55
  56         safe_close(data->dev_autofs_fd);
  57         safe_close(data->ioctl_fd);
  58         return mfree(data);
  59 }
  60
  61 DEFINE_TRIVIAL_CLEANUP_FUNC(struct expire_data*, expire_data_free);
  62
  63 static int open_dev_autofs(Manager *m);
  64 static int automount_dispatch_io(sd_event_source *s, int fd, uint32_t events, void *userdata);
  65 static int automount_start_expire(Automount *a);
  66 static void automount_stop_expire(Automount *a);
  67 static int automount_send_ready(Automount *a, Set *tokens, int status);
  68
  69 static void automount_init(Unit *u) {
  70         Automount *a = AUTOMOUNT(u);
  71
  72         assert(a);
  73         assert(u);
  74         assert(u->load_state == UNIT_STUB);
  75
  76         a->pipe_fd = -EBADF;
  77         a->directory_mode = 0755;
  78         UNIT(a)->ignore_on_isolate = true;
  79 }
  80
  81 static void unmount_autofs(Automount *a) {
  82         int r;
  83
  84         assert(a);
  85
  86         if (a->pipe_fd < 0)
  87                 return;
  88
  89         a->pipe_event_source = sd_event_source_disable_unref(a->pipe_event_source);
  90         a->pipe_fd = safe_close(a->pipe_fd);
  91
  92         /* If we reload/reexecute things we keep the mount point around */
  93         if (!IN_SET(UNIT(a)->manager->objective, MANAGER_RELOAD, MANAGER_REEXECUTE)) {
  94
  95                 automount_send_ready(a, a->tokens, -EHOSTDOWN);
  96                 automount_send_ready(a, a->expire_tokens, -EHOSTDOWN);
  97
  98                 if (a->where) {
  99                         r = repeat_unmount(a->where, MNT_DETACH|UMOUNT_NOFOLLOW);
 100                         if (r < 0)
 101                                 log_error_errno(r, "Failed to unmount: %m");
 102                 }
 103         }
 104 }
 105
 106 static void automount_done(Unit *u) {
 107         Automount *a = AUTOMOUNT(u);
 108
 109         assert(a);
 110
 111         unmount_autofs(a);
 112
 113         a->where = mfree(a->where);
 114         a->extra_options = mfree(a->extra_options);
 115
 116         a->tokens = set_free(a->tokens);
 117         a->expire_tokens = set_free(a->expire_tokens);
 118
 119         a->expire_event_source = sd_event_source_disable_unref(a->expire_event_source);
 120 }
 121
 122 static int automount_add_trigger_dependencies(Automount *a) {
 123         Unit *x;
 124         int r;
 125
 126         assert(a);
 127
 128         r = unit_load_related_unit(UNIT(a), ".mount", &x);
 129         if (r < 0)
 130                 return r;
 131
 132         return unit_add_two_dependencies(UNIT(a), UNIT_BEFORE, UNIT_TRIGGERS, x, true, UNIT_DEPENDENCY_IMPLICIT);
 133 }
 134
 135 static int automount_add_mount_dependencies(Automount *a) {
 136         _cleanup_free_ char *parent = NULL;
 137         int r;
 138
 139         assert(a);
 140
 141         r = path_extract_directory(a->where, &parent);
 142         if (r < 0)
 143                 return r;
 144
 145         return unit_require_mounts_for(UNIT(a), parent, UNIT_DEPENDENCY_IMPLICIT);
 146 }
 147
 148 static int automount_add_default_dependencies(Automount *a) {
 149         int r;
 150
 151         assert(a);
 152
 153         if (!UNIT(a)->default_dependencies)
 154                 return 0;
 155
 156         if (!MANAGER_IS_SYSTEM(UNIT(a)->manager))
 157                 return 0;
 158
 159         r = unit_add_dependency_by_name(UNIT(a), UNIT_BEFORE, SPECIAL_LOCAL_FS_TARGET, true, UNIT_DEPENDENCY_DEFAULT);
 160         if (r < 0)
 161                 return r;
 162
 163         r = unit_add_dependency_by_name(UNIT(a), UNIT_AFTER, SPECIAL_LOCAL_FS_PRE_TARGET, true, UNIT_DEPENDENCY_DEFAULT);
 164         if (r < 0)
 165                 return r;
 166
 167         r = unit_add_two_dependencies_by_name(UNIT(a), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_UMOUNT_TARGET, true, UNIT_DEPENDENCY_DEFAULT);
 168         if (r < 0)
 169                 return r;
 170
 171         return 0;
 172 }
 173
 174 static int automount_verify(Automount *a) {
 175         static const char *const reserved_options[] = {
 176                 "fd\0",
 177                 "pgrp\0",
 178                 "minproto\0",
 179                 "maxproto\0",
 180                 "direct\0",
 181                 "indirect\0",
 182         };
 183
 184         _cleanup_free_ char *e = NULL;
 185         int r;
 186
 187         assert(a);
 188         assert(UNIT(a)->load_state == UNIT_LOADED);
 189
 190         if (path_equal(a->where, "/"))
 191                 return log_unit_error_errno(UNIT(a), SYNTHETIC_ERRNO(ENOEXEC), "Cannot have an automount unit for the root directory. Refusing.");
 192
 193         r = unit_name_from_path(a->where, ".automount", &e);
 194         if (r < 0)
 195                 return log_unit_error_errno(UNIT(a), r, "Failed to generate unit name from path: %m");
 196
 197         if (!unit_has_name(UNIT(a), e))
 198                 return log_unit_error_errno(UNIT(a), SYNTHETIC_ERRNO(ENOEXEC), "Where= setting doesn't match unit name. Refusing.");
 199
 200         for (size_t i = 0; i < ELEMENTSOF(reserved_options); i++)
 201                 if (fstab_test_option(a->extra_options, reserved_options[i]))
 202                         return log_unit_error_errno(
 203                                 UNIT(a),
 204                                 SYNTHETIC_ERRNO(ENOEXEC),
 205                                 "ExtraOptions= setting may not contain reserved option %s.",
 206                                 reserved_options[i]);
 207
 208         return 0;
 209 }
 210
 211 static int automount_set_where(Automount *a) {
 212         int r;
 213
 214         assert(a);
 215
 216         if (a->where)
 217                 return 0;
 218
 219         r = unit_name_to_path(UNIT(a)->id, &a->where);
 220         if (r < 0)
 221                 return r;
 222
 223         path_simplify(a->where);
 224         return 1;
 225 }
 226
 227 static int automount_add_extras(Automount *a) {
 228         int r;
 229
 230         r = automount_set_where(a);
 231         if (r < 0)
 232                 return r;
 233
 234         r = automount_add_trigger_dependencies(a);
 235         if (r < 0)
 236                 return r;
 237
 238         r = automount_add_mount_dependencies(a);
 239         if (r < 0)
 240                 return r;
 241
 242         return automount_add_default_dependencies(a);
 243 }
 244
 245 static int automount_load(Unit *u) {
 246         Automount *a = AUTOMOUNT(u);
 247         int r;
 248
 249         assert(u);
 250         assert(u->load_state == UNIT_STUB);
 251
 252         /* Load a .automount file */
 253         r = unit_load_fragment_and_dropin(u, true);
 254         if (r < 0)
 255                 return r;
 256
 257         if (u->load_state != UNIT_LOADED)
 258                 return 0;
 259
 260         r = automount_add_extras(a);
 261         if (r < 0)
 262                 return r;
 263
 264         return automount_verify(a);
 265 }
 266
 267 static void automount_set_state(Automount *a, AutomountState state) {
 268         AutomountState old_state;
 269         assert(a);
 270
 271         if (a->state != state)
 272                 bus_unit_send_pending_change_signal(UNIT(a), false);
 273
 274         old_state = a->state;
 275         a->state = state;
 276
 277         if (state != AUTOMOUNT_RUNNING)
 278                 automount_stop_expire(a);
 279
 280         if (!IN_SET(state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING))
 281                 unmount_autofs(a);
 282
 283         if (state != old_state)
 284                 log_unit_debug(UNIT(a), "Changed %s -> %s", automount_state_to_string(old_state), automount_state_to_string(state));
 285
 286         unit_notify(UNIT(a), state_translation_table[old_state], state_translation_table[state], /* reload_success = */ true);
 287 }
 288
 289 static int automount_coldplug(Unit *u) {
 290         Automount *a = AUTOMOUNT(u);
 291         int r;
 292
 293         assert(a);
 294         assert(a->state == AUTOMOUNT_DEAD);
 295
 296         if (a->deserialized_state == a->state)
 297                 return 0;
 298
 299         if (IN_SET(a->deserialized_state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING)) {
 300
 301                 r = automount_set_where(a);
 302                 if (r < 0)
 303                         return r;
 304
 305                 r = open_dev_autofs(u->manager);
 306                 if (r < 0)
 307                         return r;
 308
 309                 assert(a->pipe_fd >= 0);
 310
 311                 r = sd_event_add_io(u->manager->event, &a->pipe_event_source, a->pipe_fd, EPOLLIN, automount_dispatch_io, u);
 312                 if (r < 0)
 313                         return r;
 314
 315                 (void) sd_event_source_set_description(a->pipe_event_source, "automount-io");
 316                 if (a->deserialized_state == AUTOMOUNT_RUNNING) {
 317                         r = automount_start_expire(a);
 318                         if (r < 0)
 319                                 log_unit_warning_errno(UNIT(a), r, "Failed to start expiration timer, ignoring: %m");
 320                 }
 321
 322                 automount_set_state(a, a->deserialized_state);
 323         }
 324
 325         return 0;
 326 }
 327
 328 static void automount_dump(Unit *u, FILE *f, const char *prefix) {
 329         Automount *a = AUTOMOUNT(u);
 330
 331         assert(a);
 332
 333         fprintf(f,
 334                 "%sAutomount State: %s\n"
 335                 "%sResult: %s\n"
 336                 "%sWhere: %s\n"
 337                 "%sExtraOptions: %s\n"
 338                 "%sDirectoryMode: %04o\n"
 339                 "%sTimeoutIdleUSec: %s\n",
 340                 prefix, automount_state_to_string(a->state),
 341                 prefix, automount_result_to_string(a->result),
 342                 prefix, a->where,
 343                 prefix, a->extra_options,
 344                 prefix, a->directory_mode,
 345                 prefix, FORMAT_TIMESPAN(a->timeout_idle_usec, USEC_PER_SEC));
 346 }
 347
 348 static void automount_enter_dead(Automount *a, AutomountResult f) {
 349         assert(a);
 350
 351         if (a->result == AUTOMOUNT_SUCCESS)
 352                 a->result = f;
 353
 354         unit_log_result(UNIT(a), a->result == AUTOMOUNT_SUCCESS, automount_result_to_string(a->result));
 355         automount_set_state(a, a->result != AUTOMOUNT_SUCCESS ? AUTOMOUNT_FAILED : AUTOMOUNT_DEAD);
 356 }
 357
 358 static int open_dev_autofs(Manager *m) {
 359         struct autofs_dev_ioctl param;
 360
 361         assert(m);
 362
 363         if (m->dev_autofs_fd >= 0)
 364                 return m->dev_autofs_fd;
 365
 366         (void) label_fix("/dev/autofs", 0);
 367
 368         m->dev_autofs_fd = open("/dev/autofs", O_CLOEXEC|O_RDONLY);
 369         if (m->dev_autofs_fd < 0)
 370                 return log_error_errno(errno, "Failed to open /dev/autofs: %m");
 371
 372         init_autofs_dev_ioctl(&param);
 373         if (ioctl(m->dev_autofs_fd, AUTOFS_DEV_IOCTL_VERSION, &param) < 0) {
 374                 m->dev_autofs_fd = safe_close(m->dev_autofs_fd);
 375                 return -errno;
 376         }
 377
 378         log_debug("Autofs kernel version %u.%u", param.ver_major, param.ver_minor);
 379
 380         return m->dev_autofs_fd;
 381 }
 382
 383 static int open_ioctl_fd(int dev_autofs_fd, const char *where, dev_t devid) {
 384         struct autofs_dev_ioctl *param;
 385         size_t l;
 386
 387         assert(dev_autofs_fd >= 0);
 388         assert(where);
 389
 390         l = sizeof(struct autofs_dev_ioctl) + strlen(where) + 1;
 391         param = alloca_safe(l);
 392
 393         init_autofs_dev_ioctl(param);
 394         param->size = l;
 395         param->ioctlfd = -EBADF;
 396         param->openmount.devid = devid;
 397         strcpy(param->path, where);
 398
 399         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_OPENMOUNT, param) < 0)
 400                 return -errno;
 401
 402         if (param->ioctlfd < 0)
 403                 return -EIO;
 404
 405         (void) fd_cloexec(param->ioctlfd, true);
 406         return param->ioctlfd;
 407 }
 408
 409 static int autofs_protocol(int dev_autofs_fd, int ioctl_fd) {
 410         uint32_t major, minor;
 411         struct autofs_dev_ioctl param;
 412
 413         assert(dev_autofs_fd >= 0);
 414         assert(ioctl_fd >= 0);
 415
 416         init_autofs_dev_ioctl(&param);
 417         param.ioctlfd = ioctl_fd;
 418
 419         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_PROTOVER, &param) < 0)
 420                 return -errno;
 421
 422         major = param.protover.version;
 423
 424         init_autofs_dev_ioctl(&param);
 425         param.ioctlfd = ioctl_fd;
 426
 427         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_PROTOSUBVER, &param) < 0)
 428                 return -errno;
 429
 430         minor = param.protosubver.sub_version;
 431
 432         log_debug("Autofs protocol version %u.%u", major, minor);
 433         return 0;
 434 }
 435
 436 static int autofs_set_timeout(int dev_autofs_fd, int ioctl_fd, usec_t usec) {
 437         struct autofs_dev_ioctl param;
 438
 439         assert(dev_autofs_fd >= 0);
 440         assert(ioctl_fd >= 0);
 441
 442         init_autofs_dev_ioctl(&param);
 443         param.ioctlfd = ioctl_fd;
 444
 445         if (usec == USEC_INFINITY)
 446                 param.timeout.timeout = 0;
 447         else
 448                 /* Convert to seconds, rounding up. */
 449                 param.timeout.timeout = DIV_ROUND_UP(usec, USEC_PER_SEC);
 450
 451         return RET_NERRNO(ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_TIMEOUT, &param));
 452 }
 453
 454 static int autofs_send_ready(int dev_autofs_fd, int ioctl_fd, uint32_t token, int status) {
 455         struct autofs_dev_ioctl param;
 456
 457         assert(dev_autofs_fd >= 0);
 458         assert(ioctl_fd >= 0);
 459
 460         init_autofs_dev_ioctl(&param);
 461         param.ioctlfd = ioctl_fd;
 462
 463         if (status != 0) {
 464                 param.fail.token = token;
 465                 param.fail.status = status;
 466         } else
 467                 param.ready.token = token;
 468
 469         return RET_NERRNO(ioctl(dev_autofs_fd, status ? AUTOFS_DEV_IOCTL_FAIL : AUTOFS_DEV_IOCTL_READY, &param));
 470 }
 471
 472 static int automount_send_ready(Automount *a, Set *tokens, int status) {
 473         _cleanup_close_ int ioctl_fd = -EBADF;
 474         unsigned token;
 475         int r;
 476
 477         assert(a);
 478         assert(status <= 0);
 479
 480         if (set_isempty(tokens))
 481                 return 0;
 482
 483         ioctl_fd = open_ioctl_fd(UNIT(a)->manager->dev_autofs_fd, a->where, a->dev_id);
 484         if (ioctl_fd < 0)
 485                 return ioctl_fd;
 486
 487         if (status != 0)
 488                 log_unit_debug_errno(UNIT(a), status, "Sending failure: %m");
 489         else
 490                 log_unit_debug(UNIT(a), "Sending success.");
 491
 492         r = 0;
 493
 494         /* Autofs thankfully does not hand out 0 as a token */
 495         while ((token = PTR_TO_UINT(set_steal_first(tokens)))) {
 496                 int k;
 497
 498                 /* Autofs fun fact:
 499                  *
 500                  * if you pass a positive status code here, kernels
 501                  * prior to 4.12 will freeze! Yay! */
 502
 503                 k = autofs_send_ready(UNIT(a)->manager->dev_autofs_fd,
 504                                       ioctl_fd,
 505                                       token,
 506                                       status);
 507                 if (k < 0)
 508                         r = k;
 509         }
 510
 511         return r;
 512 }
 513
 514 static void automount_trigger_notify(Unit *u, Unit *other) {
 515         Automount *a = AUTOMOUNT(u);
 516         int r;
 517
 518         assert(a);
 519         assert(other);
 520
 521         /* Filter out invocations with bogus state */
 522         assert(UNIT_IS_LOAD_COMPLETE(other->load_state));
 523         assert(other->type == UNIT_MOUNT);
 524
 525         /* Don't propagate state changes from the mount if we are already down */
 526         if (!IN_SET(a->state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING))
 527                 return;
 528
 529         /* Propagate start limit hit state */
 530         if (other->start_limit_hit) {
 531                 automount_enter_dead(a, AUTOMOUNT_FAILURE_MOUNT_START_LIMIT_HIT);
 532                 return;
 533         }
 534
 535         /* Don't propagate anything if there's still a job queued */
 536         if (other->job)
 537                 return;
 538
 539         /* The mount is successfully established */
 540         if (IN_SET(MOUNT(other)->state, MOUNT_MOUNTED, MOUNT_REMOUNTING)) {
 541                 (void) automount_send_ready(a, a->tokens, 0);
 542
 543                 r = automount_start_expire(a);
 544                 if (r < 0)
 545                         log_unit_warning_errno(UNIT(a), r, "Failed to start expiration timer, ignoring: %m");
 546
 547                 automount_set_state(a, AUTOMOUNT_RUNNING);
 548         }
 549
 550         if (IN_SET(MOUNT(other)->state,
 551                    MOUNT_MOUNTING, MOUNT_MOUNTING_DONE,
 552                    MOUNT_MOUNTED, MOUNT_REMOUNTING,
 553                    MOUNT_REMOUNTING_SIGTERM, MOUNT_REMOUNTING_SIGKILL,
 554                    MOUNT_UNMOUNTING_SIGTERM, MOUNT_UNMOUNTING_SIGKILL,
 555                    MOUNT_FAILED))
 556                 (void) automount_send_ready(a, a->expire_tokens, -ENODEV);
 557
 558         if (MOUNT(other)->state == MOUNT_DEAD)
 559                 (void) automount_send_ready(a, a->expire_tokens, 0);
 560
 561         /* The mount is in some unhappy state now, let's unfreeze any waiting clients */
 562         if (IN_SET(MOUNT(other)->state,
 563                    MOUNT_DEAD, MOUNT_UNMOUNTING,
 564                    MOUNT_REMOUNTING_SIGTERM, MOUNT_REMOUNTING_SIGKILL,
 565                    MOUNT_UNMOUNTING_SIGTERM, MOUNT_UNMOUNTING_SIGKILL,
 566                    MOUNT_FAILED)) {
 567
 568                 (void) automount_send_ready(a, a->tokens, -ENODEV);
 569
 570                 automount_set_state(a, AUTOMOUNT_WAITING);
 571         }
 572 }
 573
 574 static void automount_enter_waiting(Automount *a) {
 575         _cleanup_close_ int ioctl_fd = -EBADF;
 576         int pipe_fd[2] = PIPE_EBADF;
 577         char name[STRLEN("systemd-") + DECIMAL_STR_MAX(pid_t) + 1];
 578         _cleanup_free_ char *options = NULL;
 579         bool mounted = false;
 580         int r, dev_autofs_fd;
 581         struct stat st;
 582
 583         assert(a);
 584         assert(a->pipe_fd < 0);
 585         assert(a->where);
 586
 587         set_clear(a->tokens);
 588
 589         r = unit_fail_if_noncanonical(UNIT(a), a->where);
 590         if (r < 0)
 591                 goto fail;
 592
 593         (void) mkdir_p_label(a->where, a->directory_mode);
 594
 595         unit_warn_if_dir_nonempty(UNIT(a), a->where);
 596
 597         dev_autofs_fd = open_dev_autofs(UNIT(a)->manager);
 598         if (dev_autofs_fd < 0) {
 599                 r = dev_autofs_fd;
 600                 goto fail;
 601         }
 602
 603         if (pipe2(pipe_fd, O_CLOEXEC) < 0) {
 604                 r = -errno;
 605                 goto fail;
 606         }
 607         r = fd_nonblock(pipe_fd[0], true);
 608         if (r < 0)
 609                 goto fail;
 610
 611         if (asprintf(
 612                     &options,
 613                     "fd=%i,pgrp="PID_FMT",minproto=5,maxproto=5,direct%s%s",
 614                     pipe_fd[1],
 615                     getpgrp(),
 616                     isempty(a->extra_options) ? "" : ",",
 617                     strempty(a->extra_options)) < 0) {
 618                 r = -ENOMEM;
 619                 goto fail;
 620         }
 621
 622         xsprintf(name, "systemd-"PID_FMT, getpid_cached());
 623         r = mount_nofollow(name, a->where, "autofs", 0, options);
 624         if (r < 0)
 625                 goto fail;
 626
 627         mounted = true;
 628
 629         pipe_fd[1] = safe_close(pipe_fd[1]);
 630
 631         if (stat(a->where, &st) < 0) {
 632                 r = -errno;
 633                 goto fail;
 634         }
 635
 636         ioctl_fd = open_ioctl_fd(dev_autofs_fd, a->where, st.st_dev);
 637         if (ioctl_fd < 0) {
 638                 r = ioctl_fd;
 639                 goto fail;
 640         }
 641
 642         r = autofs_protocol(dev_autofs_fd, ioctl_fd);
 643         if (r < 0)
 644                 goto fail;
 645
 646         r = autofs_set_timeout(dev_autofs_fd, ioctl_fd, a->timeout_idle_usec);
 647         if (r < 0)
 648                 goto fail;
 649
 650         r = sd_event_add_io(UNIT(a)->manager->event, &a->pipe_event_source, pipe_fd[0], EPOLLIN, automount_dispatch_io, a);
 651         if (r < 0)
 652                 goto fail;
 653
 654         (void) sd_event_source_set_description(a->pipe_event_source, "automount-io");
 655
 656         a->pipe_fd = pipe_fd[0];
 657         a->dev_id = st.st_dev;
 658
 659         automount_set_state(a, AUTOMOUNT_WAITING);
 660
 661         return;
 662
 663 fail:
 664         log_unit_error_errno(UNIT(a), r, "Failed to initialize automounter: %m");
 665
 666         safe_close_pair(pipe_fd);
 667
 668         if (mounted) {
 669                 r = repeat_unmount(a->where, MNT_DETACH|UMOUNT_NOFOLLOW);
 670                 if (r < 0)
 671                         log_error_errno(r, "Failed to unmount, ignoring: %m");
 672         }
 673
 674         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
 675 }
 676
 677 static void *expire_thread(void *p) {
 678         struct autofs_dev_ioctl param;
 679         _cleanup_(expire_data_freep) struct expire_data *data = p;
 680         int r;
 681
 682         assert(data->dev_autofs_fd >= 0);
 683         assert(data->ioctl_fd >= 0);
 684
 685         init_autofs_dev_ioctl(&param);
 686         param.ioctlfd = data->ioctl_fd;
 687
 688         do {
 689                 r = ioctl(data->dev_autofs_fd, AUTOFS_DEV_IOCTL_EXPIRE, &param);
 690         } while (r >= 0);
 691
 692         if (errno != EAGAIN)
 693                 log_warning_errno(errno, "Failed to expire automount, ignoring: %m");
 694
 695         return NULL;
 696 }
 697
 698 static int automount_dispatch_expire(sd_event_source *source, usec_t usec, void *userdata) {
 699         Automount *a = AUTOMOUNT(userdata);
 700         _cleanup_(expire_data_freep) struct expire_data *data = NULL;
 701         int r;
 702
 703         assert(a);
 704         assert(source == a->expire_event_source);
 705
 706         data = new0(struct expire_data, 1);
 707         if (!data)
 708                 return log_oom();
 709
 710         data->ioctl_fd = -EBADF;
 711
 712         data->dev_autofs_fd = fcntl(UNIT(a)->manager->dev_autofs_fd, F_DUPFD_CLOEXEC, 3);
 713         if (data->dev_autofs_fd < 0)
 714                 return log_unit_error_errno(UNIT(a), errno, "Failed to duplicate autofs fd: %m");
 715
 716         data->ioctl_fd = open_ioctl_fd(UNIT(a)->manager->dev_autofs_fd, a->where, a->dev_id);
 717         if (data->ioctl_fd < 0)
 718                 return log_unit_error_errno(UNIT(a), data->ioctl_fd, "Couldn't open autofs ioctl fd: %m");
 719
 720         r = asynchronous_job(expire_thread, data);
 721         if (r < 0)
 722                 return log_unit_error_errno(UNIT(a), r, "Failed to start expire job: %m");
 723
 724         data = NULL;
 725
 726         return automount_start_expire(a);
 727 }
 728
 729 static int automount_start_expire(Automount *a) {
 730         usec_t timeout;
 731         int r;
 732
 733         assert(a);
 734
 735         if (a->timeout_idle_usec == 0)
 736                 return 0;
 737
 738         timeout = MAX(a->timeout_idle_usec/3, USEC_PER_SEC);
 739
 740         if (a->expire_event_source) {
 741                 r = sd_event_source_set_time_relative(a->expire_event_source, timeout);
 742                 if (r < 0)
 743                         return r;
 744
 745                 return sd_event_source_set_enabled(a->expire_event_source, SD_EVENT_ONESHOT);
 746         }
 747
 748         r = sd_event_add_time_relative(
 749                         UNIT(a)->manager->event,
 750                         &a->expire_event_source,
 751                         CLOCK_MONOTONIC, timeout, 0,
 752                         automount_dispatch_expire, a);
 753         if (r < 0)
 754                 return r;
 755
 756         (void) sd_event_source_set_description(a->expire_event_source, "automount-expire");
 757
 758         return 0;
 759 }
 760
 761 static void automount_stop_expire(Automount *a) {
 762         assert(a);
 763
 764         if (!a->expire_event_source)
 765                 return;
 766
 767         (void) sd_event_source_set_enabled(a->expire_event_source, SD_EVENT_OFF);
 768 }
 769
 770 static void automount_enter_running(Automount *a) {
 771         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 772         Unit *trigger;
 773         struct stat st;
 774         int r;
 775
 776         assert(a);
 777
 778         /* If the user masked our unit in the meantime, fail */
 779         if (UNIT(a)->load_state != UNIT_LOADED) {
 780                 log_unit_error(UNIT(a), "Suppressing automount event since unit is no longer loaded.");
 781                 goto fail;
 782         }
 783
 784         /* We don't take mount requests anymore if we are supposed to
 785          * shut down anyway */
 786         if (unit_stop_pending(UNIT(a))) {
 787                 log_unit_debug(UNIT(a), "Suppressing automount request since unit stop is scheduled.");
 788                 automount_send_ready(a, a->tokens, -EHOSTDOWN);
 789                 automount_send_ready(a, a->expire_tokens, -EHOSTDOWN);
 790                 return;
 791         }
 792
 793         (void) mkdir_p_label(a->where, a->directory_mode);
 794
 795         /* Before we do anything, let's see if somebody is playing games with us? */
 796         if (lstat(a->where, &st) < 0) {
 797                 log_unit_warning_errno(UNIT(a), errno, "Failed to stat automount point: %m");
 798                 goto fail;
 799         }
 800
 801         /* The mount unit may have been explicitly started before we got the
 802          * autofs request. Ack it to unblock anything waiting on the mount point. */
 803         if (!S_ISDIR(st.st_mode) || st.st_dev != a->dev_id) {
 804                 log_unit_info(UNIT(a), "Automount point already active?");
 805                 automount_send_ready(a, a->tokens, 0);
 806                 return;
 807         }
 808
 809         trigger = UNIT_TRIGGER(UNIT(a));
 810         if (!trigger) {
 811                 log_unit_error(UNIT(a), "Unit to trigger vanished.");
 812                 goto fail;
 813         }
 814
 815         r = manager_add_job(UNIT(a)->manager, JOB_START, trigger, JOB_REPLACE, NULL, &error, NULL);
 816         if (r < 0) {
 817                 log_unit_warning(UNIT(a), "Failed to queue mount startup job: %s", bus_error_message(&error, r));
 818                 goto fail;
 819         }
 820
 821         automount_set_state(a, AUTOMOUNT_RUNNING);
 822         return;
 823
 824 fail:
 825         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
 826 }
 827
 828 static int automount_start(Unit *u) {
 829         Automount *a = AUTOMOUNT(u);
 830         int r;
 831
 832         assert(a);
 833         assert(IN_SET(a->state, AUTOMOUNT_DEAD, AUTOMOUNT_FAILED));
 834
 835         if (path_is_mount_point(a->where, NULL, 0) > 0)
 836                 return log_unit_error_errno(u, SYNTHETIC_ERRNO(EEXIST), "Path %s is already a mount point, refusing start.", a->where);
 837
 838         r = unit_test_trigger_loaded(u);
 839         if (r < 0)
 840                 return r;
 841
 842         r = unit_acquire_invocation_id(u);
 843         if (r < 0)
 844                 return r;
 845
 846         a->result = AUTOMOUNT_SUCCESS;
 847         automount_enter_waiting(a);
 848         return 1;
 849 }
 850
 851 static int automount_stop(Unit *u) {
 852         Automount *a = AUTOMOUNT(u);
 853
 854         assert(a);
 855         assert(IN_SET(a->state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING));
 856
 857         automount_enter_dead(a, AUTOMOUNT_SUCCESS);
 858         return 1;
 859 }
 860
 861 static int automount_serialize(Unit *u, FILE *f, FDSet *fds) {
 862         Automount *a = AUTOMOUNT(u);
 863         void *p;
 864         int r;
 865
 866         assert(a);
 867         assert(f);
 868         assert(fds);
 869
 870         (void) serialize_item(f, "state", automount_state_to_string(a->state));
 871         (void) serialize_item(f, "result", automount_result_to_string(a->result));
 872         (void) serialize_item_format(f, "dev-id", "%lu", (unsigned long) a->dev_id);
 873
 874         SET_FOREACH(p, a->tokens)
 875                 (void) serialize_item_format(f, "token", "%u", PTR_TO_UINT(p));
 876         SET_FOREACH(p, a->expire_tokens)
 877                 (void) serialize_item_format(f, "expire-token", "%u", PTR_TO_UINT(p));
 878
 879         r = serialize_fd(f, fds, "pipe-fd", a->pipe_fd);
 880         if (r < 0)
 881                 return r;
 882
 883         return 0;
 884 }
 885
 886 static int automount_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 887         Automount *a = AUTOMOUNT(u);
 888         int r;
 889
 890         assert(a);
 891         assert(fds);
 892
 893         if (streq(key, "state")) {
 894                 AutomountState state;
 895
 896                 state = automount_state_from_string(value);
 897                 if (state < 0)
 898                         log_unit_debug(u, "Failed to parse state value: %s", value);
 899                 else
 900                         a->deserialized_state = state;
 901         } else if (streq(key, "result")) {
 902                 AutomountResult f;
 903
 904                 f = automount_result_from_string(value);
 905                 if (f < 0)
 906                         log_unit_debug(u, "Failed to parse result value: %s", value);
 907                 else if (f != AUTOMOUNT_SUCCESS)
 908                         a->result = f;
 909
 910         } else if (streq(key, "dev-id")) {
 911                 unsigned long d;
 912
 913                 if (safe_atolu(value, &d) < 0)
 914                         log_unit_debug(u, "Failed to parse dev-id value: %s", value);
 915                 else
 916                         a->dev_id = (dev_t) d;
 917
 918         } else if (streq(key, "token")) {
 919                 unsigned token;
 920
 921                 if (safe_atou(value, &token) < 0)
 922                         log_unit_debug(u, "Failed to parse token value: %s", value);
 923                 else {
 924                         r = set_ensure_put(&a->tokens, NULL, UINT_TO_PTR(token));
 925                         if (r < 0)
 926                                 log_unit_error_errno(u, r, "Failed to add token to set: %m");
 927                 }
 928         } else if (streq(key, "expire-token")) {
 929                 unsigned token;
 930
 931                 if (safe_atou(value, &token) < 0)
 932                         log_unit_debug(u, "Failed to parse token value: %s", value);
 933                 else {
 934                         r = set_ensure_put(&a->expire_tokens, NULL, UINT_TO_PTR(token));
 935                         if (r < 0)
 936                                 log_unit_error_errno(u, r, "Failed to add expire token to set: %m");
 937                 }
 938         } else if (streq(key, "pipe-fd")) {
 939                 int fd;
 940
 941                 if ((fd = parse_fd(value)) < 0 || !fdset_contains(fds, fd))
 942                         log_unit_debug(u, "Failed to parse pipe-fd value: %s", value);
 943                 else {
 944                         safe_close(a->pipe_fd);
 945                         a->pipe_fd = fdset_remove(fds, fd);
 946                 }
 947         } else
 948                 log_unit_debug(u, "Unknown serialization key: %s", key);
 949
 950         return 0;
 951 }
 952
 953 static UnitActiveState automount_active_state(Unit *u) {
 954         assert(u);
 955
 956         return state_translation_table[AUTOMOUNT(u)->state];
 957 }
 958
 959 static const char *automount_sub_state_to_string(Unit *u) {
 960         assert(u);
 961
 962         return automount_state_to_string(AUTOMOUNT(u)->state);
 963 }
 964
 965 static bool automount_may_gc(Unit *u) {
 966         Unit *t;
 967
 968         assert(u);
 969
 970         t = UNIT_TRIGGER(u);
 971         if (!t)
 972                 return true;
 973
 974         return UNIT_VTABLE(t)->may_gc(t);
 975 }
 976
 977 static int automount_dispatch_io(sd_event_source *s, int fd, uint32_t events, void *userdata) {
 978         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 979         union autofs_v5_packet_union packet;
 980         Automount *a = AUTOMOUNT(userdata);
 981         Unit *trigger;
 982         int r;
 983
 984         assert(a);
 985         assert(fd == a->pipe_fd);
 986
 987         if (events & (EPOLLHUP|EPOLLERR)) {
 988                 log_unit_error(UNIT(a), "Got hangup/error on autofs pipe from kernel. Likely our automount point has been unmounted by someone or something else?");
 989                 automount_enter_dead(a, AUTOMOUNT_FAILURE_UNMOUNTED);
 990                 return 0;
 991         }
 992
 993         if (events != EPOLLIN) {
 994                 log_unit_error(UNIT(a), "Got invalid poll event %"PRIu32" on pipe (fd=%d)", events, fd);
 995                 goto fail;
 996         }
 997
 998         r = loop_read_exact(a->pipe_fd, &packet, sizeof(packet), true);
 999         if (r < 0) {
1000                 log_unit_error_errno(UNIT(a), r, "Invalid read from pipe: %m");
1001                 goto fail;
1002         }
1003
1004         switch (packet.hdr.type) {
1005
1006         case autofs_ptype_missing_direct:
1007
1008                 if (packet.v5_packet.pid > 0) {
1009                         _cleanup_free_ char *p = NULL;
1010
1011                         (void) get_process_comm(packet.v5_packet.pid, &p);
1012                         log_unit_info(UNIT(a), "Got automount request for %s, triggered by %"PRIu32" (%s)", a->where, packet.v5_packet.pid, strna(p));
1013                 } else
1014                         log_unit_debug(UNIT(a), "Got direct mount request on %s", a->where);
1015
1016                 r = set_ensure_put(&a->tokens, NULL, UINT_TO_PTR(packet.v5_packet.wait_queue_token));
1017                 if (r < 0) {
1018                         log_unit_error_errno(UNIT(a), r, "Failed to remember token: %m");
1019                         goto fail;
1020                 }
1021
1022                 automount_enter_running(a);
1023                 break;
1024
1025         case autofs_ptype_expire_direct:
1026                 log_unit_debug(UNIT(a), "Got direct umount request on %s", a->where);
1027
1028                 automount_stop_expire(a);
1029
1030                 r = set_ensure_put(&a->expire_tokens, NULL, UINT_TO_PTR(packet.v5_packet.wait_queue_token));
1031                 if (r < 0) {
1032                         log_unit_error_errno(UNIT(a), r, "Failed to remember token: %m");
1033                         goto fail;
1034                 }
1035
1036                 trigger = UNIT_TRIGGER(UNIT(a));
1037                 if (!trigger) {
1038                         log_unit_error(UNIT(a), "Unit to trigger vanished.");
1039                         goto fail;
1040                 }
1041
1042                 r = manager_add_job(UNIT(a)->manager, JOB_STOP, trigger, JOB_REPLACE, NULL, &error, NULL);
1043                 if (r < 0) {
1044                         log_unit_warning(UNIT(a), "Failed to queue unmount job: %s", bus_error_message(&error, r));
1045                         goto fail;
1046                 }
1047                 break;
1048
1049         default:
1050                 log_unit_error(UNIT(a), "Received unknown automount request %i", packet.hdr.type);
1051                 break;
1052         }
1053
1054         return 0;
1055
1056 fail:
1057         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
1058         return 0;
1059 }
1060
1061 static void automount_shutdown(Manager *m) {
1062         assert(m);
1063
1064         m->dev_autofs_fd = safe_close(m->dev_autofs_fd);
1065 }
1066
1067 static void automount_reset_failed(Unit *u) {
1068         Automount *a = AUTOMOUNT(u);
1069
1070         assert(a);
1071
1072         if (a->state == AUTOMOUNT_FAILED)
1073                 automount_set_state(a, AUTOMOUNT_DEAD);
1074
1075         a->result = AUTOMOUNT_SUCCESS;
1076 }
1077
1078 static bool automount_supported(void) {
1079         static int supported = -1;
1080
1081         if (supported < 0)
1082                 supported = access("/dev/autofs", F_OK) >= 0;
1083
1084         return supported;
1085 }
1086
1087 static int automount_can_start(Unit *u) {
1088         Automount *a = AUTOMOUNT(u);
1089         int r;
1090
1091         assert(a);
1092
1093         r = unit_test_start_limit(u);
1094         if (r < 0) {
1095                 automount_enter_dead(a, AUTOMOUNT_FAILURE_START_LIMIT_HIT);
1096                 return r;
1097         }
1098
1099         return 1;
1100 }
1101
1102 static const char* const automount_result_table[_AUTOMOUNT_RESULT_MAX] = {
1103         [AUTOMOUNT_SUCCESS]                       = "success",
1104         [AUTOMOUNT_FAILURE_RESOURCES]             = "resources",
1105         [AUTOMOUNT_FAILURE_START_LIMIT_HIT]       = "start-limit-hit",
1106         [AUTOMOUNT_FAILURE_MOUNT_START_LIMIT_HIT] = "mount-start-limit-hit",
1107         [AUTOMOUNT_FAILURE_UNMOUNTED]             = "unmounted",
1108 };
1109
1110 DEFINE_STRING_TABLE_LOOKUP(automount_result, AutomountResult);
1111
1112 const UnitVTable automount_vtable = {
1113         .object_size = sizeof(Automount),
1114
1115         .sections =
1116                 "Unit\0"
1117                 "Automount\0"
1118                 "Install\0",
1119         .private_section = "Automount",
1120
1121         .can_transient = true,
1122         .can_fail = true,
1123         .can_trigger = true,
1124         .exclude_from_switch_root_serialization = true,
1125
1126         .init = automount_init,
1127         .load = automount_load,
1128         .done = automount_done,
1129
1130         .coldplug = automount_coldplug,
1131
1132         .dump = automount_dump,
1133
1134         .start = automount_start,
1135         .stop = automount_stop,
1136
1137         .serialize = automount_serialize,
1138         .deserialize_item = automount_deserialize_item,
1139
1140         .active_state = automount_active_state,
1141         .sub_state_to_string = automount_sub_state_to_string,
1142
1143         .may_gc = automount_may_gc,
1144
1145         .trigger_notify = automount_trigger_notify,
1146
1147         .reset_failed = automount_reset_failed,
1148
1149         .bus_set_property = bus_automount_set_property,
1150
1151         .shutdown = automount_shutdown,
1152         .supported = automount_supported,
1153
1154         .status_message_formats = {
1155                 .finished_start_job = {
1156                         [JOB_DONE]       = "Set up automount %s.",
1157                         [JOB_FAILED]     = "Failed to set up automount %s.",
1158                 },
1159                 .finished_stop_job = {
1160                         [JOB_DONE]       = "Unset automount %s.",
1161                         [JOB_FAILED]     = "Failed to unset automount %s.",
1162                 },
1163         },
1164
1165         .can_start = automount_can_start,
1166 };