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