src/core/automount.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   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 "fd-util.h"
  20 #include "format-util.h"
  21 #include "io-util.h"
  22 #include "label.h"
  23 #include "mkdir.h"
  24 #include "mount-util.h"
  25 #include "mount.h"
  26 #include "parse-util.h"
  27 #include "path-util.h"
  28 #include "process-util.h"
  29 #include "special.h"
  30 #include "stdio-util.h"
  31 #include "string-table.h"
  32 #include "string-util.h"
  33 #include "unit-name.h"
  34 #include "unit.h"
  35
  36 static const UnitActiveState state_translation_table[_AUTOMOUNT_STATE_MAX] = {
  37         [AUTOMOUNT_DEAD] = UNIT_INACTIVE,
  38         [AUTOMOUNT_WAITING] = UNIT_ACTIVE,
  39         [AUTOMOUNT_RUNNING] = UNIT_ACTIVE,
  40         [AUTOMOUNT_FAILED] = UNIT_FAILED
  41 };
  42
  43 struct expire_data {
  44         int dev_autofs_fd;
  45         int ioctl_fd;
  46 };
  47
  48 static inline void expire_data_free(struct expire_data *data) {
  49         if (!data)
  50                 return;
  51
  52         safe_close(data->dev_autofs_fd);
  53         safe_close(data->ioctl_fd);
  54         free(data);
  55 }
  56
  57 DEFINE_TRIVIAL_CLEANUP_FUNC(struct expire_data*, expire_data_free);
  58
  59 static int open_dev_autofs(Manager *m);
  60 static int automount_dispatch_io(sd_event_source *s, int fd, uint32_t events, void *userdata);
  61 static int automount_start_expire(Automount *a);
  62 static void automount_stop_expire(Automount *a);
  63 static int automount_send_ready(Automount *a, Set *tokens, int status);
  64
  65 static void automount_init(Unit *u) {
  66         Automount *a = AUTOMOUNT(u);
  67
  68         assert(u);
  69         assert(u->load_state == UNIT_STUB);
  70
  71         a->pipe_fd = -1;
  72         a->directory_mode = 0755;
  73         UNIT(a)->ignore_on_isolate = true;
  74 }
  75
  76 static void unmount_autofs(Automount *a) {
  77         int r;
  78
  79         assert(a);
  80
  81         if (a->pipe_fd < 0)
  82                 return;
  83
  84         a->pipe_event_source = sd_event_source_unref(a->pipe_event_source);
  85         a->pipe_fd = safe_close(a->pipe_fd);
  86
  87         /* If we reload/reexecute things we keep the mount point around */
  88         if (!IN_SET(UNIT(a)->manager->exit_code, MANAGER_RELOAD, MANAGER_REEXECUTE)) {
  89
  90                 automount_send_ready(a, a->tokens, -EHOSTDOWN);
  91                 automount_send_ready(a, a->expire_tokens, -EHOSTDOWN);
  92
  93                 if (a->where) {
  94                         r = repeat_unmount(a->where, MNT_DETACH);
  95                         if (r < 0)
  96                                 log_error_errno(r, "Failed to unmount: %m");
  97                 }
  98         }
  99 }
 100
 101 static void automount_done(Unit *u) {
 102         Automount *a = AUTOMOUNT(u);
 103
 104         assert(a);
 105
 106         unmount_autofs(a);
 107
 108         a->where = mfree(a->where);
 109
 110         a->tokens = set_free(a->tokens);
 111         a->expire_tokens = set_free(a->expire_tokens);
 112
 113         a->expire_event_source = sd_event_source_unref(a->expire_event_source);
 114 }
 115
 116 static int automount_add_trigger_dependencies(Automount *a) {
 117         Unit *x;
 118         int r;
 119
 120         assert(a);
 121
 122         r = unit_load_related_unit(UNIT(a), ".mount", &x);
 123         if (r < 0)
 124                 return r;
 125
 126         return unit_add_two_dependencies(UNIT(a), UNIT_BEFORE, UNIT_TRIGGERS, x, true, UNIT_DEPENDENCY_IMPLICIT);
 127 }
 128
 129 static int automount_add_mount_dependencies(Automount *a) {
 130         _cleanup_free_ char *parent = NULL;
 131
 132         assert(a);
 133
 134         parent = dirname_malloc(a->where);
 135         if (!parent)
 136                 return -ENOMEM;
 137
 138         return unit_require_mounts_for(UNIT(a), parent, UNIT_DEPENDENCY_IMPLICIT);
 139 }
 140
 141 static int automount_add_default_dependencies(Automount *a) {
 142         int r;
 143
 144         assert(a);
 145
 146         if (!UNIT(a)->default_dependencies)
 147                 return 0;
 148
 149         if (!MANAGER_IS_SYSTEM(UNIT(a)->manager))
 150                 return 0;
 151
 152         r = unit_add_two_dependencies_by_name(UNIT(a), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_UMOUNT_TARGET, true, UNIT_DEPENDENCY_DEFAULT);
 153         if (r < 0)
 154                 return r;
 155
 156         return 0;
 157 }
 158
 159 static int automount_verify(Automount *a) {
 160         _cleanup_free_ char *e = NULL;
 161         int r;
 162
 163         assert(a);
 164
 165         if (UNIT(a)->load_state != UNIT_LOADED)
 166                 return 0;
 167
 168         if (path_equal(a->where, "/")) {
 169                 log_unit_error(UNIT(a), "Cannot have an automount unit for the root directory. Refusing.");
 170                 return -ENOEXEC;
 171         }
 172
 173         r = unit_name_from_path(a->where, ".automount", &e);
 174         if (r < 0)
 175                 return log_unit_error_errno(UNIT(a), r, "Failed to generate unit name from path: %m");
 176
 177         if (!unit_has_name(UNIT(a), e)) {
 178                 log_unit_error(UNIT(a), "Where= setting doesn't match unit name. Refusing.");
 179                 return -ENOEXEC;
 180         }
 181
 182         return 0;
 183 }
 184
 185 static int automount_set_where(Automount *a) {
 186         int r;
 187
 188         assert(a);
 189
 190         if (a->where)
 191                 return 0;
 192
 193         r = unit_name_to_path(UNIT(a)->id, &a->where);
 194         if (r < 0)
 195                 return r;
 196
 197         path_simplify(a->where, false);
 198         return 1;
 199 }
 200
 201 static int automount_load(Unit *u) {
 202         Automount *a = AUTOMOUNT(u);
 203         int r;
 204
 205         assert(u);
 206         assert(u->load_state == UNIT_STUB);
 207
 208         /* Load a .automount file */
 209         r = unit_load_fragment_and_dropin(u);
 210         if (r < 0)
 211                 return r;
 212
 213         if (u->load_state == UNIT_LOADED) {
 214                 r = automount_set_where(a);
 215                 if (r < 0)
 216                         return r;
 217
 218                 r = automount_add_trigger_dependencies(a);
 219                 if (r < 0)
 220                         return r;
 221
 222                 r = automount_add_mount_dependencies(a);
 223                 if (r < 0)
 224                         return r;
 225
 226                 r = automount_add_default_dependencies(a);
 227                 if (r < 0)
 228                         return r;
 229         }
 230
 231         return automount_verify(a);
 232 }
 233
 234 static void automount_set_state(Automount *a, AutomountState state) {
 235         AutomountState old_state;
 236         assert(a);
 237
 238         old_state = a->state;
 239         a->state = state;
 240
 241         if (state != AUTOMOUNT_RUNNING)
 242                 automount_stop_expire(a);
 243
 244         if (!IN_SET(state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING))
 245                 unmount_autofs(a);
 246
 247         if (state != old_state)
 248                 log_unit_debug(UNIT(a), "Changed %s -> %s", automount_state_to_string(old_state), automount_state_to_string(state));
 249
 250         unit_notify(UNIT(a), state_translation_table[old_state], state_translation_table[state], 0);
 251 }
 252
 253 static int automount_coldplug(Unit *u) {
 254         Automount *a = AUTOMOUNT(u);
 255         int r;
 256
 257         assert(a);
 258         assert(a->state == AUTOMOUNT_DEAD);
 259
 260         if (a->deserialized_state == a->state)
 261                 return 0;
 262
 263         if (IN_SET(a->deserialized_state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING)) {
 264
 265                 r = automount_set_where(a);
 266                 if (r < 0)
 267                         return r;
 268
 269                 r = open_dev_autofs(u->manager);
 270                 if (r < 0)
 271                         return r;
 272
 273                 assert(a->pipe_fd >= 0);
 274
 275                 r = sd_event_add_io(u->manager->event, &a->pipe_event_source, a->pipe_fd, EPOLLIN, automount_dispatch_io, u);
 276                 if (r < 0)
 277                         return r;
 278
 279                 (void) sd_event_source_set_description(a->pipe_event_source, "automount-io");
 280                 if (a->deserialized_state == AUTOMOUNT_RUNNING) {
 281                         r = automount_start_expire(a);
 282                         if (r < 0)
 283                                 log_unit_warning_errno(UNIT(a), r, "Failed to start expiration timer, ignoring: %m");
 284                 }
 285
 286                 automount_set_state(a, a->deserialized_state);
 287         }
 288
 289         return 0;
 290 }
 291
 292 static void automount_dump(Unit *u, FILE *f, const char *prefix) {
 293         char time_string[FORMAT_TIMESPAN_MAX];
 294         Automount *a = AUTOMOUNT(u);
 295
 296         assert(a);
 297
 298         fprintf(f,
 299                 "%sAutomount State: %s\n"
 300                 "%sResult: %s\n"
 301                 "%sWhere: %s\n"
 302                 "%sDirectoryMode: %04o\n"
 303                 "%sTimeoutIdleUSec: %s\n",
 304                 prefix, automount_state_to_string(a->state),
 305                 prefix, automount_result_to_string(a->result),
 306                 prefix, a->where,
 307                 prefix, a->directory_mode,
 308                 prefix, format_timespan(time_string, FORMAT_TIMESPAN_MAX, a->timeout_idle_usec, USEC_PER_SEC));
 309 }
 310
 311 static void automount_enter_dead(Automount *a, AutomountResult f) {
 312         assert(a);
 313
 314         if (a->result == AUTOMOUNT_SUCCESS)
 315                 a->result = f;
 316
 317         if (a->result != AUTOMOUNT_SUCCESS)
 318                 log_unit_warning(UNIT(a), "Failed with result '%s'.", automount_result_to_string(a->result));
 319
 320         automount_set_state(a, a->result != AUTOMOUNT_SUCCESS ? AUTOMOUNT_FAILED : AUTOMOUNT_DEAD);
 321 }
 322
 323 static int open_dev_autofs(Manager *m) {
 324         struct autofs_dev_ioctl param;
 325
 326         assert(m);
 327
 328         if (m->dev_autofs_fd >= 0)
 329                 return m->dev_autofs_fd;
 330
 331         (void) label_fix("/dev/autofs", 0);
 332
 333         m->dev_autofs_fd = open("/dev/autofs", O_CLOEXEC|O_RDONLY);
 334         if (m->dev_autofs_fd < 0)
 335                 return log_error_errno(errno, "Failed to open /dev/autofs: %m");
 336
 337         init_autofs_dev_ioctl(&param);
 338         if (ioctl(m->dev_autofs_fd, AUTOFS_DEV_IOCTL_VERSION, &param) < 0) {
 339                 m->dev_autofs_fd = safe_close(m->dev_autofs_fd);
 340                 return -errno;
 341         }
 342
 343         log_debug("Autofs kernel version %i.%i", param.ver_major, param.ver_minor);
 344
 345         return m->dev_autofs_fd;
 346 }
 347
 348 static int open_ioctl_fd(int dev_autofs_fd, const char *where, dev_t devid) {
 349         struct autofs_dev_ioctl *param;
 350         size_t l;
 351
 352         assert(dev_autofs_fd >= 0);
 353         assert(where);
 354
 355         l = sizeof(struct autofs_dev_ioctl) + strlen(where) + 1;
 356         param = alloca(l);
 357
 358         init_autofs_dev_ioctl(param);
 359         param->size = l;
 360         param->ioctlfd = -1;
 361         param->openmount.devid = devid;
 362         strcpy(param->path, where);
 363
 364         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_OPENMOUNT, param) < 0)
 365                 return -errno;
 366
 367         if (param->ioctlfd < 0)
 368                 return -EIO;
 369
 370         (void) fd_cloexec(param->ioctlfd, true);
 371         return param->ioctlfd;
 372 }
 373
 374 static int autofs_protocol(int dev_autofs_fd, int ioctl_fd) {
 375         uint32_t major, minor;
 376         struct autofs_dev_ioctl param;
 377
 378         assert(dev_autofs_fd >= 0);
 379         assert(ioctl_fd >= 0);
 380
 381         init_autofs_dev_ioctl(&param);
 382         param.ioctlfd = ioctl_fd;
 383
 384         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_PROTOVER, &param) < 0)
 385                 return -errno;
 386
 387         major = param.protover.version;
 388
 389         init_autofs_dev_ioctl(&param);
 390         param.ioctlfd = ioctl_fd;
 391
 392         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_PROTOSUBVER, &param) < 0)
 393                 return -errno;
 394
 395         minor = param.protosubver.sub_version;
 396
 397         log_debug("Autofs protocol version %i.%i", major, minor);
 398         return 0;
 399 }
 400
 401 static int autofs_set_timeout(int dev_autofs_fd, int ioctl_fd, usec_t usec) {
 402         struct autofs_dev_ioctl param;
 403
 404         assert(dev_autofs_fd >= 0);
 405         assert(ioctl_fd >= 0);
 406
 407         init_autofs_dev_ioctl(&param);
 408         param.ioctlfd = ioctl_fd;
 409
 410         if (usec == USEC_INFINITY)
 411                 param.timeout.timeout = 0;
 412         else
 413                 /* Convert to seconds, rounding up. */
 414                 param.timeout.timeout = DIV_ROUND_UP(usec, USEC_PER_SEC);
 415
 416         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_TIMEOUT, &param) < 0)
 417                 return -errno;
 418
 419         return 0;
 420 }
 421
 422 static int autofs_send_ready(int dev_autofs_fd, int ioctl_fd, uint32_t token, int status) {
 423         struct autofs_dev_ioctl param;
 424
 425         assert(dev_autofs_fd >= 0);
 426         assert(ioctl_fd >= 0);
 427
 428         init_autofs_dev_ioctl(&param);
 429         param.ioctlfd = ioctl_fd;
 430
 431         if (status != 0) {
 432                 param.fail.token = token;
 433                 param.fail.status = status;
 434         } else
 435                 param.ready.token = token;
 436
 437         if (ioctl(dev_autofs_fd, status ? AUTOFS_DEV_IOCTL_FAIL : AUTOFS_DEV_IOCTL_READY, &param) < 0)
 438                 return -errno;
 439
 440         return 0;
 441 }
 442
 443 static int automount_send_ready(Automount *a, Set *tokens, int status) {
 444         _cleanup_close_ int ioctl_fd = -1;
 445         unsigned token;
 446         int r;
 447
 448         assert(a);
 449         assert(status <= 0);
 450
 451         if (set_isempty(tokens))
 452                 return 0;
 453
 454         ioctl_fd = open_ioctl_fd(UNIT(a)->manager->dev_autofs_fd, a->where, a->dev_id);
 455         if (ioctl_fd < 0)
 456                 return ioctl_fd;
 457
 458         if (status != 0)
 459                 log_unit_debug_errno(UNIT(a), status, "Sending failure: %m");
 460         else
 461                 log_unit_debug(UNIT(a), "Sending success.");
 462
 463         r = 0;
 464
 465         /* Autofs thankfully does not hand out 0 as a token */
 466         while ((token = PTR_TO_UINT(set_steal_first(tokens)))) {
 467                 int k;
 468
 469                 /* Autofs fun fact:
 470                  *
 471                  * if you pass a positive status code here, kernels
 472                  * prior to 4.12 will freeze! Yay! */
 473
 474                 k = autofs_send_ready(UNIT(a)->manager->dev_autofs_fd,
 475                                       ioctl_fd,
 476                                       token,
 477                                       status);
 478                 if (k < 0)
 479                         r = k;
 480         }
 481
 482         return r;
 483 }
 484
 485 static void automount_trigger_notify(Unit *u, Unit *other) {
 486         Automount *a = AUTOMOUNT(u);
 487         int r;
 488
 489         assert(a);
 490         assert(other);
 491
 492         /* Filter out invocations with bogus state */
 493         if (other->load_state != UNIT_LOADED || other->type != UNIT_MOUNT)
 494                 return;
 495
 496         /* Don't propagate state changes from the mount if we are already down */
 497         if (!IN_SET(a->state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING))
 498                 return;
 499
 500         /* Propagate start limit hit state */
 501         if (other->start_limit_hit) {
 502                 automount_enter_dead(a, AUTOMOUNT_FAILURE_MOUNT_START_LIMIT_HIT);
 503                 return;
 504         }
 505
 506         /* Don't propagate anything if there's still a job queued */
 507         if (other->job)
 508                 return;
 509
 510         /* The mount is successfully established */
 511         if (IN_SET(MOUNT(other)->state, MOUNT_MOUNTED, MOUNT_REMOUNTING)) {
 512                 (void) automount_send_ready(a, a->tokens, 0);
 513
 514                 r = automount_start_expire(a);
 515                 if (r < 0)
 516                         log_unit_warning_errno(UNIT(a), r, "Failed to start expiration timer, ignoring: %m");
 517
 518                 automount_set_state(a, AUTOMOUNT_RUNNING);
 519         }
 520
 521         if (IN_SET(MOUNT(other)->state,
 522                    MOUNT_MOUNTING, MOUNT_MOUNTING_DONE,
 523                    MOUNT_MOUNTED, MOUNT_REMOUNTING,
 524                    MOUNT_REMOUNTING_SIGTERM, MOUNT_REMOUNTING_SIGKILL,
 525                    MOUNT_UNMOUNTING_SIGTERM, MOUNT_UNMOUNTING_SIGKILL,
 526                    MOUNT_FAILED)) {
 527
 528                 (void) automount_send_ready(a, a->expire_tokens, -ENODEV);
 529         }
 530
 531         if (MOUNT(other)->state == MOUNT_DEAD)
 532                 (void) automount_send_ready(a, a->expire_tokens, 0);
 533
 534         /* The mount is in some unhappy state now, let's unfreeze any waiting clients */
 535         if (IN_SET(MOUNT(other)->state,
 536                    MOUNT_DEAD, MOUNT_UNMOUNTING,
 537                    MOUNT_REMOUNTING_SIGTERM, MOUNT_REMOUNTING_SIGKILL,
 538                    MOUNT_UNMOUNTING_SIGTERM, MOUNT_UNMOUNTING_SIGKILL,
 539                    MOUNT_FAILED)) {
 540
 541                 (void) automount_send_ready(a, a->tokens, -ENODEV);
 542
 543                 automount_set_state(a, AUTOMOUNT_WAITING);
 544         }
 545 }
 546
 547 static void automount_enter_waiting(Automount *a) {
 548         _cleanup_close_ int ioctl_fd = -1;
 549         int p[2] = { -1, -1 };
 550         char name[STRLEN("systemd-") + DECIMAL_STR_MAX(pid_t) + 1];
 551         char options[STRLEN("fd=,pgrp=,minproto=5,maxproto=5,direct")
 552                      + DECIMAL_STR_MAX(int) + DECIMAL_STR_MAX(gid_t) + 1];
 553         bool mounted = false;
 554         int r, dev_autofs_fd;
 555         struct stat st;
 556
 557         assert(a);
 558         assert(a->pipe_fd < 0);
 559         assert(a->where);
 560
 561         set_clear(a->tokens);
 562
 563         r = unit_fail_if_noncanonical(UNIT(a), a->where);
 564         if (r < 0)
 565                 goto fail;
 566
 567         (void) mkdir_p_label(a->where, 0555);
 568
 569         unit_warn_if_dir_nonempty(UNIT(a), a->where);
 570
 571         dev_autofs_fd = open_dev_autofs(UNIT(a)->manager);
 572         if (dev_autofs_fd < 0) {
 573                 r = dev_autofs_fd;
 574                 goto fail;
 575         }
 576
 577         if (pipe2(p, O_NONBLOCK|O_CLOEXEC) < 0) {
 578                 r = -errno;
 579                 goto fail;
 580         }
 581
 582         xsprintf(options, "fd=%i,pgrp="PID_FMT",minproto=5,maxproto=5,direct", p[1], getpgrp());
 583         xsprintf(name, "systemd-"PID_FMT, getpid_cached());
 584         if (mount(name, a->where, "autofs", 0, options) < 0) {
 585                 r = -errno;
 586                 goto fail;
 587         }
 588
 589         mounted = true;
 590
 591         p[1] = safe_close(p[1]);
 592
 593         if (stat(a->where, &st) < 0) {
 594                 r = -errno;
 595                 goto fail;
 596         }
 597
 598         ioctl_fd = open_ioctl_fd(dev_autofs_fd, a->where, st.st_dev);
 599         if (ioctl_fd < 0) {
 600                 r = ioctl_fd;
 601                 goto fail;
 602         }
 603
 604         r = autofs_protocol(dev_autofs_fd, ioctl_fd);
 605         if (r < 0)
 606                 goto fail;
 607
 608         r = autofs_set_timeout(dev_autofs_fd, ioctl_fd, a->timeout_idle_usec);
 609         if (r < 0)
 610                 goto fail;
 611
 612         r = sd_event_add_io(UNIT(a)->manager->event, &a->pipe_event_source, p[0], EPOLLIN, automount_dispatch_io, a);
 613         if (r < 0)
 614                 goto fail;
 615
 616         (void) sd_event_source_set_description(a->pipe_event_source, "automount-io");
 617
 618         a->pipe_fd = p[0];
 619         a->dev_id = st.st_dev;
 620
 621         automount_set_state(a, AUTOMOUNT_WAITING);
 622
 623         return;
 624
 625 fail:
 626         log_unit_error_errno(UNIT(a), r, "Failed to initialize automounter: %m");
 627
 628         safe_close_pair(p);
 629
 630         if (mounted) {
 631                 r = repeat_unmount(a->where, MNT_DETACH);
 632                 if (r < 0)
 633                         log_error_errno(r, "Failed to unmount, ignoring: %m");
 634         }
 635
 636         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
 637 }
 638
 639 static void *expire_thread(void *p) {
 640         struct autofs_dev_ioctl param;
 641         _cleanup_(expire_data_freep) struct expire_data *data = (struct expire_data*)p;
 642         int r;
 643
 644         assert(data->dev_autofs_fd >= 0);
 645         assert(data->ioctl_fd >= 0);
 646
 647         init_autofs_dev_ioctl(&param);
 648         param.ioctlfd = data->ioctl_fd;
 649
 650         do {
 651                 r = ioctl(data->dev_autofs_fd, AUTOFS_DEV_IOCTL_EXPIRE, &param);
 652         } while (r >= 0);
 653
 654         if (errno != EAGAIN)
 655                 log_warning_errno(errno, "Failed to expire automount, ignoring: %m");
 656
 657         return NULL;
 658 }
 659
 660 static int automount_dispatch_expire(sd_event_source *source, usec_t usec, void *userdata) {
 661         Automount *a = AUTOMOUNT(userdata);
 662         _cleanup_(expire_data_freep) struct expire_data *data = NULL;
 663         int r;
 664
 665         assert(a);
 666         assert(source == a->expire_event_source);
 667
 668         data = new0(struct expire_data, 1);
 669         if (!data)
 670                 return log_oom();
 671
 672         data->ioctl_fd = -1;
 673
 674         data->dev_autofs_fd = fcntl(UNIT(a)->manager->dev_autofs_fd, F_DUPFD_CLOEXEC, 3);
 675         if (data->dev_autofs_fd < 0)
 676                 return log_unit_error_errno(UNIT(a), errno, "Failed to duplicate autofs fd: %m");
 677
 678         data->ioctl_fd = open_ioctl_fd(UNIT(a)->manager->dev_autofs_fd, a->where, a->dev_id);
 679         if (data->ioctl_fd < 0)
 680                 return log_unit_error_errno(UNIT(a), data->ioctl_fd, "Couldn't open autofs ioctl fd: %m");
 681
 682         r = asynchronous_job(expire_thread, data);
 683         if (r < 0)
 684                 return log_unit_error_errno(UNIT(a), r, "Failed to start expire job: %m");
 685
 686         data = NULL;
 687
 688         return automount_start_expire(a);
 689 }
 690
 691 static int automount_start_expire(Automount *a) {
 692         int r;
 693         usec_t timeout;
 694
 695         assert(a);
 696
 697         if (a->timeout_idle_usec == 0)
 698                 return 0;
 699
 700         timeout = now(CLOCK_MONOTONIC) + MAX(a->timeout_idle_usec/3, USEC_PER_SEC);
 701
 702         if (a->expire_event_source) {
 703                 r = sd_event_source_set_time(a->expire_event_source, timeout);
 704                 if (r < 0)
 705                         return r;
 706
 707                 return sd_event_source_set_enabled(a->expire_event_source, SD_EVENT_ONESHOT);
 708         }
 709
 710         r = sd_event_add_time(
 711                         UNIT(a)->manager->event,
 712                         &a->expire_event_source,
 713                         CLOCK_MONOTONIC, timeout, 0,
 714                         automount_dispatch_expire, a);
 715         if (r < 0)
 716                 return r;
 717
 718         (void) sd_event_source_set_description(a->expire_event_source, "automount-expire");
 719
 720         return 0;
 721 }
 722
 723 static void automount_stop_expire(Automount *a) {
 724         assert(a);
 725
 726         if (!a->expire_event_source)
 727                 return;
 728
 729         (void) sd_event_source_set_enabled(a->expire_event_source, SD_EVENT_OFF);
 730 }
 731
 732 static void automount_enter_running(Automount *a) {
 733         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 734         Unit *trigger;
 735         struct stat st;
 736         int r;
 737
 738         assert(a);
 739
 740         /* If the user masked our unit in the meantime, fail */
 741         if (UNIT(a)->load_state != UNIT_LOADED) {
 742                 log_unit_error(UNIT(a), "Suppressing automount event since unit is no longer loaded.");
 743                 goto fail;
 744         }
 745
 746         /* We don't take mount requests anymore if we are supposed to
 747          * shut down anyway */
 748         if (unit_stop_pending(UNIT(a))) {
 749                 log_unit_debug(UNIT(a), "Suppressing automount request since unit stop is scheduled.");
 750                 automount_send_ready(a, a->tokens, -EHOSTDOWN);
 751                 automount_send_ready(a, a->expire_tokens, -EHOSTDOWN);
 752                 return;
 753         }
 754
 755         mkdir_p_label(a->where, a->directory_mode);
 756
 757         /* Before we do anything, let's see if somebody is playing games with us? */
 758         if (lstat(a->where, &st) < 0) {
 759                 log_unit_warning_errno(UNIT(a), errno, "Failed to stat automount point: %m");
 760                 goto fail;
 761         }
 762
 763         /* The mount unit may have been explicitly started before we got the
 764          * autofs request. Ack it to unblock anything waiting on the mount point. */
 765         if (!S_ISDIR(st.st_mode) || st.st_dev != a->dev_id) {
 766                 log_unit_info(UNIT(a), "Automount point already active?");
 767                 automount_send_ready(a, a->tokens, 0);
 768                 return;
 769         }
 770
 771         trigger = UNIT_TRIGGER(UNIT(a));
 772         if (!trigger) {
 773                 log_unit_error(UNIT(a), "Unit to trigger vanished.");
 774                 goto fail;
 775         }
 776
 777         r = manager_add_job(UNIT(a)->manager, JOB_START, trigger, JOB_REPLACE, &error, NULL);
 778         if (r < 0) {
 779                 log_unit_warning(UNIT(a), "Failed to queue mount startup job: %s", bus_error_message(&error, r));
 780                 goto fail;
 781         }
 782
 783         automount_set_state(a, AUTOMOUNT_RUNNING);
 784         return;
 785
 786 fail:
 787         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
 788 }
 789
 790 static int automount_start(Unit *u) {
 791         Automount *a = AUTOMOUNT(u);
 792         Unit *trigger;
 793         int r;
 794
 795         assert(a);
 796         assert(IN_SET(a->state, AUTOMOUNT_DEAD, AUTOMOUNT_FAILED));
 797
 798         if (path_is_mount_point(a->where, NULL, 0) > 0) {
 799                 log_unit_error(u, "Path %s is already a mount point, refusing start.", a->where);
 800                 return -EEXIST;
 801         }
 802
 803         trigger = UNIT_TRIGGER(u);
 804         if (!trigger || trigger->load_state != UNIT_LOADED) {
 805                 log_unit_error(u, "Refusing to start, unit to trigger not loaded.");
 806                 return -ENOENT;
 807         }
 808
 809         r = unit_start_limit_test(u);
 810         if (r < 0) {
 811                 automount_enter_dead(a, AUTOMOUNT_FAILURE_START_LIMIT_HIT);
 812                 return r;
 813         }
 814
 815         r = unit_acquire_invocation_id(u);
 816         if (r < 0)
 817                 return r;
 818
 819         a->result = AUTOMOUNT_SUCCESS;
 820         automount_enter_waiting(a);
 821         return 1;
 822 }
 823
 824 static int automount_stop(Unit *u) {
 825         Automount *a = AUTOMOUNT(u);
 826
 827         assert(a);
 828         assert(IN_SET(a->state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING));
 829
 830         automount_enter_dead(a, AUTOMOUNT_SUCCESS);
 831         return 1;
 832 }
 833
 834 static int automount_serialize(Unit *u, FILE *f, FDSet *fds) {
 835         Automount *a = AUTOMOUNT(u);
 836         Iterator i;
 837         void *p;
 838         int r;
 839
 840         assert(a);
 841         assert(f);
 842         assert(fds);
 843
 844         unit_serialize_item(u, f, "state", automount_state_to_string(a->state));
 845         unit_serialize_item(u, f, "result", automount_result_to_string(a->result));
 846         unit_serialize_item_format(u, f, "dev-id", "%u", (unsigned) a->dev_id);
 847
 848         SET_FOREACH(p, a->tokens, i)
 849                 unit_serialize_item_format(u, f, "token", "%u", PTR_TO_UINT(p));
 850         SET_FOREACH(p, a->expire_tokens, i)
 851                 unit_serialize_item_format(u, f, "expire-token", "%u", PTR_TO_UINT(p));
 852
 853         r = unit_serialize_item_fd(u, f, fds, "pipe-fd", a->pipe_fd);
 854         if (r < 0)
 855                 return r;
 856
 857         return 0;
 858 }
 859
 860 static int automount_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 861         Automount *a = AUTOMOUNT(u);
 862         int r;
 863
 864         assert(a);
 865         assert(fds);
 866
 867         if (streq(key, "state")) {
 868                 AutomountState state;
 869
 870                 state = automount_state_from_string(value);
 871                 if (state < 0)
 872                         log_unit_debug(u, "Failed to parse state value: %s", value);
 873                 else
 874                         a->deserialized_state = state;
 875         } else if (streq(key, "result")) {
 876                 AutomountResult f;
 877
 878                 f = automount_result_from_string(value);
 879                 if (f < 0)
 880                         log_unit_debug(u, "Failed to parse result value: %s", value);
 881                 else if (f != AUTOMOUNT_SUCCESS)
 882                         a->result = f;
 883
 884         } else if (streq(key, "dev-id")) {
 885                 unsigned d;
 886
 887                 if (safe_atou(value, &d) < 0)
 888                         log_unit_debug(u, "Failed to parse dev-id value: %s", value);
 889                 else
 890                         a->dev_id = (unsigned) d;
 891         } else if (streq(key, "token")) {
 892                 unsigned token;
 893
 894                 if (safe_atou(value, &token) < 0)
 895                         log_unit_debug(u, "Failed to parse token value: %s", value);
 896                 else {
 897                         r = set_ensure_allocated(&a->tokens, NULL);
 898                         if (r < 0) {
 899                                 log_oom();
 900                                 return 0;
 901                         }
 902
 903                         r = set_put(a->tokens, UINT_TO_PTR(token));
 904                         if (r < 0)
 905                                 log_unit_error_errno(u, r, "Failed to add token to set: %m");
 906                 }
 907         } else if (streq(key, "expire-token")) {
 908                 unsigned token;
 909
 910                 if (safe_atou(value, &token) < 0)
 911                         log_unit_debug(u, "Failed to parse token value: %s", value);
 912                 else {
 913                         r = set_ensure_allocated(&a->expire_tokens, NULL);
 914                         if (r < 0) {
 915                                 log_oom();
 916                                 return 0;
 917                         }
 918
 919                         r = set_put(a->expire_tokens, UINT_TO_PTR(token));
 920                         if (r < 0)
 921                                 log_unit_error_errno(u, r, "Failed to add expire token to set: %m");
 922                 }
 923         } else if (streq(key, "pipe-fd")) {
 924                 int fd;
 925
 926                 if (safe_atoi(value, &fd) < 0 || fd < 0 || !fdset_contains(fds, fd))
 927                         log_unit_debug(u, "Failed to parse pipe-fd value: %s", value);
 928                 else {
 929                         safe_close(a->pipe_fd);
 930                         a->pipe_fd = fdset_remove(fds, fd);
 931                 }
 932         } else
 933                 log_unit_debug(u, "Unknown serialization key: %s", key);
 934
 935         return 0;
 936 }
 937
 938 static UnitActiveState automount_active_state(Unit *u) {
 939         assert(u);
 940
 941         return state_translation_table[AUTOMOUNT(u)->state];
 942 }
 943
 944 static const char *automount_sub_state_to_string(Unit *u) {
 945         assert(u);
 946
 947         return automount_state_to_string(AUTOMOUNT(u)->state);
 948 }
 949
 950 static bool automount_may_gc(Unit *u) {
 951         Unit *t;
 952
 953         assert(u);
 954
 955         t = UNIT_TRIGGER(u);
 956         if (!t)
 957                 return true;
 958
 959         return UNIT_VTABLE(t)->may_gc(t);
 960 }
 961
 962 static int automount_dispatch_io(sd_event_source *s, int fd, uint32_t events, void *userdata) {
 963         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 964         union autofs_v5_packet_union packet;
 965         Automount *a = AUTOMOUNT(userdata);
 966         Unit *trigger;
 967         int r;
 968
 969         assert(a);
 970         assert(fd == a->pipe_fd);
 971
 972         if (events != EPOLLIN) {
 973                 log_unit_error(UNIT(a), "Got invalid poll event %"PRIu32" on pipe (fd=%d)", events, fd);
 974                 goto fail;
 975         }
 976
 977         r = loop_read_exact(a->pipe_fd, &packet, sizeof(packet), true);
 978         if (r < 0) {
 979                 log_unit_error_errno(UNIT(a), r, "Invalid read from pipe: %m");
 980                 goto fail;
 981         }
 982
 983         switch (packet.hdr.type) {
 984
 985         case autofs_ptype_missing_direct:
 986
 987                 if (packet.v5_packet.pid > 0) {
 988                         _cleanup_free_ char *p = NULL;
 989
 990                         get_process_comm(packet.v5_packet.pid, &p);
 991                         log_unit_info(UNIT(a), "Got automount request for %s, triggered by %"PRIu32" (%s)", a->where, packet.v5_packet.pid, strna(p));
 992                 } else
 993                         log_unit_debug(UNIT(a), "Got direct mount request on %s", a->where);
 994
 995                 r = set_ensure_allocated(&a->tokens, NULL);
 996                 if (r < 0) {
 997                         log_unit_error(UNIT(a), "Failed to allocate token set.");
 998                         goto fail;
 999                 }
1000
1001                 r = set_put(a->tokens, UINT_TO_PTR(packet.v5_packet.wait_queue_token));
1002                 if (r < 0) {
1003                         log_unit_error_errno(UNIT(a), r, "Failed to remember token: %m");
1004                         goto fail;
1005                 }
1006
1007                 automount_enter_running(a);
1008                 break;
1009
1010         case autofs_ptype_expire_direct:
1011                 log_unit_debug(UNIT(a), "Got direct umount request on %s", a->where);
1012
1013                 automount_stop_expire(a);
1014
1015                 r = set_ensure_allocated(&a->expire_tokens, NULL);
1016                 if (r < 0) {
1017                         log_unit_error(UNIT(a), "Failed to allocate token set.");
1018                         goto fail;
1019                 }
1020
1021                 r = set_put(a->expire_tokens, UINT_TO_PTR(packet.v5_packet.wait_queue_token));
1022                 if (r < 0) {
1023                         log_unit_error_errno(UNIT(a), r, "Failed to remember token: %m");
1024                         goto fail;
1025                 }
1026
1027                 trigger = UNIT_TRIGGER(UNIT(a));
1028                 if (!trigger) {
1029                         log_unit_error(UNIT(a), "Unit to trigger vanished.");
1030                         goto fail;
1031                 }
1032
1033                 r = manager_add_job(UNIT(a)->manager, JOB_STOP, trigger, JOB_REPLACE, &error, NULL);
1034                 if (r < 0) {
1035                         log_unit_warning(UNIT(a), "Failed to queue umount startup job: %s", bus_error_message(&error, r));
1036                         goto fail;
1037                 }
1038                 break;
1039
1040         default:
1041                 log_unit_error(UNIT(a), "Received unknown automount request %i", packet.hdr.type);
1042                 break;
1043         }
1044
1045         return 0;
1046
1047 fail:
1048         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
1049         return 0;
1050 }
1051
1052 static void automount_shutdown(Manager *m) {
1053         assert(m);
1054
1055         m->dev_autofs_fd = safe_close(m->dev_autofs_fd);
1056 }
1057
1058 static void automount_reset_failed(Unit *u) {
1059         Automount *a = AUTOMOUNT(u);
1060
1061         assert(a);
1062
1063         if (a->state == AUTOMOUNT_FAILED)
1064                 automount_set_state(a, AUTOMOUNT_DEAD);
1065
1066         a->result = AUTOMOUNT_SUCCESS;
1067 }
1068
1069 static bool automount_supported(void) {
1070         static int supported = -1;
1071
1072         if (supported < 0)
1073                 supported = access("/dev/autofs", F_OK) >= 0;
1074
1075         return supported;
1076 }
1077
1078 static const char* const automount_result_table[_AUTOMOUNT_RESULT_MAX] = {
1079         [AUTOMOUNT_SUCCESS] = "success",
1080         [AUTOMOUNT_FAILURE_RESOURCES] = "resources",
1081         [AUTOMOUNT_FAILURE_START_LIMIT_HIT] = "start-limit-hit",
1082         [AUTOMOUNT_FAILURE_MOUNT_START_LIMIT_HIT] = "mount-start-limit-hit",
1083 };
1084
1085 DEFINE_STRING_TABLE_LOOKUP(automount_result, AutomountResult);
1086
1087 const UnitVTable automount_vtable = {
1088         .object_size = sizeof(Automount),
1089
1090         .sections =
1091                 "Unit\0"
1092                 "Automount\0"
1093                 "Install\0",
1094
1095         .init = automount_init,
1096         .load = automount_load,
1097         .done = automount_done,
1098
1099         .coldplug = automount_coldplug,
1100
1101         .dump = automount_dump,
1102
1103         .start = automount_start,
1104         .stop = automount_stop,
1105
1106         .serialize = automount_serialize,
1107         .deserialize_item = automount_deserialize_item,
1108
1109         .active_state = automount_active_state,
1110         .sub_state_to_string = automount_sub_state_to_string,
1111
1112         .may_gc = automount_may_gc,
1113
1114         .trigger_notify = automount_trigger_notify,
1115
1116         .reset_failed = automount_reset_failed,
1117
1118         .bus_vtable = bus_automount_vtable,
1119         .bus_set_property = bus_automount_set_property,
1120
1121         .can_transient = true,
1122
1123         .shutdown = automount_shutdown,
1124         .supported = automount_supported,
1125
1126         .status_message_formats = {
1127                 .finished_start_job = {
1128                         [JOB_DONE]       = "Set up automount %s.",
1129                         [JOB_FAILED]     = "Failed to set up automount %s.",
1130                 },
1131                 .finished_stop_job = {
1132                         [JOB_DONE]       = "Unset automount %s.",
1133                         [JOB_FAILED]     = "Failed to unset automount %s.",
1134                 },
1135         },
1136 };