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-util.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 static int open_dev_autofs(Manager *m);
  48 static int automount_dispatch_io(sd_event_source *s, int fd, uint32_t events, void *userdata);
  49 static int automount_start_expire(Automount *a);
  50 static void automount_stop_expire(Automount *a);
  51 static int automount_send_ready(Automount *a, Set *tokens, int status);
  52
  53 static void automount_init(Unit *u) {
  54         Automount *a = ASSERT_PTR(AUTOMOUNT(u));
  55
  56         assert(u->load_state == UNIT_STUB);
  57
  58         a->pipe_fd = -EBADF;
  59         a->directory_mode = 0755;
  60         UNIT(a)->ignore_on_isolate = true;
  61 }
  62
  63 static void unmount_autofs(Automount *a) {
  64         int r;
  65
  66         assert(a);
  67
  68         if (a->pipe_fd < 0)
  69                 return;
  70
  71         a->pipe_event_source = sd_event_source_disable_unref(a->pipe_event_source);
  72         a->pipe_fd = safe_close(a->pipe_fd);
  73
  74         /* If we reload/reexecute things we keep the mount point around */
  75         if (!IN_SET(UNIT(a)->manager->objective, MANAGER_RELOAD, MANAGER_REEXECUTE)) {
  76
  77                 automount_send_ready(a, a->tokens, -EHOSTDOWN);
  78                 automount_send_ready(a, a->expire_tokens, -EHOSTDOWN);
  79
  80                 if (a->where) {
  81                         r = repeat_unmount(a->where, MNT_DETACH|UMOUNT_NOFOLLOW);
  82                         if (r < 0)
  83                                 log_unit_error_errno(UNIT(a), r, "Failed to unmount: %m");
  84                 }
  85         }
  86 }
  87
  88 static void automount_done(Unit *u) {
  89         Automount *a = ASSERT_PTR(AUTOMOUNT(u));
  90
  91         unmount_autofs(a);
  92
  93         a->where = mfree(a->where);
  94         a->extra_options = mfree(a->extra_options);
  95
  96         a->tokens = set_free(a->tokens);
  97         a->expire_tokens = set_free(a->expire_tokens);
  98
  99         a->expire_event_source = sd_event_source_disable_unref(a->expire_event_source);
 100 }
 101
 102 static int automount_add_trigger_dependencies(Automount *a) {
 103         Unit *x;
 104         int r;
 105
 106         assert(a);
 107
 108         r = unit_load_related_unit(UNIT(a), ".mount", &x);
 109         if (r < 0)
 110                 return r;
 111
 112         return unit_add_two_dependencies(UNIT(a), UNIT_BEFORE, UNIT_TRIGGERS, x, true, UNIT_DEPENDENCY_IMPLICIT);
 113 }
 114
 115 static int automount_add_mount_dependencies(Automount *a) {
 116         _cleanup_free_ char *parent = NULL;
 117         int r;
 118
 119         assert(a);
 120
 121         r = path_extract_directory(a->where, &parent);
 122         if (r < 0)
 123                 return r;
 124
 125         return unit_add_mounts_for(UNIT(a), parent, UNIT_DEPENDENCY_IMPLICIT, UNIT_MOUNT_REQUIRES);
 126 }
 127
 128 static int automount_add_default_dependencies(Automount *a) {
 129         int r;
 130
 131         assert(a);
 132
 133         if (!UNIT(a)->default_dependencies)
 134                 return 0;
 135
 136         if (!MANAGER_IS_SYSTEM(UNIT(a)->manager))
 137                 return 0;
 138
 139         r = unit_add_dependency_by_name(UNIT(a), UNIT_BEFORE, SPECIAL_LOCAL_FS_TARGET, true, UNIT_DEPENDENCY_DEFAULT);
 140         if (r < 0)
 141                 return r;
 142
 143         r = unit_add_dependency_by_name(UNIT(a), UNIT_AFTER, SPECIAL_LOCAL_FS_PRE_TARGET, true, UNIT_DEPENDENCY_DEFAULT);
 144         if (r < 0)
 145                 return r;
 146
 147         r = unit_add_two_dependencies_by_name(UNIT(a), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_UMOUNT_TARGET, true, UNIT_DEPENDENCY_DEFAULT);
 148         if (r < 0)
 149                 return r;
 150
 151         return 0;
 152 }
 153
 154 static int automount_verify(Automount *a) {
 155         static const char *const reserved_options[] = {
 156                 "fd\0",
 157                 "pgrp\0",
 158                 "minproto\0",
 159                 "maxproto\0",
 160                 "direct\0",
 161                 "indirect\0",
 162         };
 163
 164         _cleanup_free_ char *e = NULL;
 165         int r;
 166
 167         assert(a);
 168         assert(UNIT(a)->load_state == UNIT_LOADED);
 169
 170         if (path_equal(a->where, "/"))
 171                 return log_unit_error_errno(UNIT(a), SYNTHETIC_ERRNO(ENOEXEC), "Cannot have an automount unit for the root directory. Refusing.");
 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                 return log_unit_error_errno(UNIT(a), SYNTHETIC_ERRNO(ENOEXEC), "Where= setting doesn't match unit name. Refusing.");
 179
 180         for (size_t i = 0; i < ELEMENTSOF(reserved_options); i++)
 181                 if (fstab_test_option(a->extra_options, reserved_options[i]))
 182                         return log_unit_error_errno(
 183                                 UNIT(a),
 184                                 SYNTHETIC_ERRNO(ENOEXEC),
 185                                 "ExtraOptions= setting may not contain reserved option %s.",
 186                                 reserved_options[i]);
 187
 188         return 0;
 189 }
 190
 191 static int automount_set_where(Automount *a) {
 192         int r;
 193
 194         assert(a);
 195
 196         if (a->where)
 197                 return 0;
 198
 199         r = unit_name_to_path(UNIT(a)->id, &a->where);
 200         if (r < 0)
 201                 return r;
 202
 203         path_simplify(a->where);
 204         return 1;
 205 }
 206
 207 static int automount_add_extras(Automount *a) {
 208         int r;
 209
 210         r = automount_set_where(a);
 211         if (r < 0)
 212                 return r;
 213
 214         r = automount_add_trigger_dependencies(a);
 215         if (r < 0)
 216                 return r;
 217
 218         r = automount_add_mount_dependencies(a);
 219         if (r < 0)
 220                 return r;
 221
 222         return automount_add_default_dependencies(a);
 223 }
 224
 225 static int automount_load(Unit *u) {
 226         Automount *a = ASSERT_PTR(AUTOMOUNT(u));
 227         int r;
 228
 229         assert(u->load_state == UNIT_STUB);
 230
 231         /* Load a .automount file */
 232         r = unit_load_fragment_and_dropin(u, true);
 233         if (r < 0)
 234                 return r;
 235
 236         if (u->load_state != UNIT_LOADED)
 237                 return 0;
 238
 239         r = automount_add_extras(a);
 240         if (r < 0)
 241                 return r;
 242
 243         return automount_verify(a);
 244 }
 245
 246 static void automount_set_state(Automount *a, AutomountState state) {
 247         AutomountState old_state;
 248
 249         assert(a);
 250
 251         if (a->state != state)
 252                 bus_unit_send_pending_change_signal(UNIT(a), false);
 253
 254         old_state = a->state;
 255         a->state = state;
 256
 257         if (state != AUTOMOUNT_RUNNING)
 258                 automount_stop_expire(a);
 259
 260         if (!IN_SET(state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING))
 261                 unmount_autofs(a);
 262
 263         if (state != old_state)
 264                 log_unit_debug(UNIT(a), "Changed %s -> %s", automount_state_to_string(old_state), automount_state_to_string(state));
 265
 266         unit_notify(UNIT(a), state_translation_table[old_state], state_translation_table[state], /* reload_success = */ true);
 267 }
 268
 269 static int automount_coldplug(Unit *u) {
 270         Automount *a = ASSERT_PTR(AUTOMOUNT(u));
 271         int r;
 272
 273         assert(a->state == AUTOMOUNT_DEAD);
 274
 275         if (a->deserialized_state == a->state)
 276                 return 0;
 277
 278         if (IN_SET(a->deserialized_state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING)) {
 279
 280                 r = automount_set_where(a);
 281                 if (r < 0)
 282                         return r;
 283
 284                 r = open_dev_autofs(u->manager);
 285                 if (r < 0)
 286                         return r;
 287
 288                 assert(a->pipe_fd >= 0);
 289
 290                 r = sd_event_add_io(u->manager->event, &a->pipe_event_source, a->pipe_fd, EPOLLIN, automount_dispatch_io, u);
 291                 if (r < 0)
 292                         return r;
 293
 294                 (void) sd_event_source_set_description(a->pipe_event_source, "automount-io");
 295                 if (a->deserialized_state == AUTOMOUNT_RUNNING) {
 296                         r = automount_start_expire(a);
 297                         if (r < 0)
 298                                 log_unit_warning_errno(UNIT(a), r, "Failed to start expiration timer, ignoring: %m");
 299                 }
 300
 301                 automount_set_state(a, a->deserialized_state);
 302         }
 303
 304         return 0;
 305 }
 306
 307 static void automount_dump(Unit *u, FILE *f, const char *prefix) {
 308         Automount *a = ASSERT_PTR(AUTOMOUNT(u));
 309
 310         fprintf(f,
 311                 "%sAutomount State: %s\n"
 312                 "%sResult: %s\n"
 313                 "%sWhere: %s\n"
 314                 "%sExtraOptions: %s\n"
 315                 "%sDirectoryMode: %04o\n"
 316                 "%sTimeoutIdleUSec: %s\n",
 317                 prefix, automount_state_to_string(a->state),
 318                 prefix, automount_result_to_string(a->result),
 319                 prefix, a->where,
 320                 prefix, a->extra_options,
 321                 prefix, a->directory_mode,
 322                 prefix, FORMAT_TIMESPAN(a->timeout_idle_usec, USEC_PER_SEC));
 323 }
 324
 325 static void automount_enter_dead(Automount *a, AutomountResult f) {
 326         assert(a);
 327
 328         if (a->result == AUTOMOUNT_SUCCESS)
 329                 a->result = f;
 330
 331         unit_log_result(UNIT(a), a->result == AUTOMOUNT_SUCCESS, automount_result_to_string(a->result));
 332         automount_set_state(a, a->result != AUTOMOUNT_SUCCESS ? AUTOMOUNT_FAILED : AUTOMOUNT_DEAD);
 333 }
 334
 335 static int open_dev_autofs(Manager *m) {
 336         struct autofs_dev_ioctl param;
 337         int r;
 338
 339         assert(m);
 340
 341         if (m->dev_autofs_fd >= 0)
 342                 return m->dev_autofs_fd;
 343
 344         (void) label_fix("/dev/autofs", 0);
 345
 346         m->dev_autofs_fd = open("/dev/autofs", O_CLOEXEC|O_RDONLY);
 347         if (m->dev_autofs_fd < 0)
 348                 return log_error_errno(errno, "Failed to open /dev/autofs: %m");
 349
 350         init_autofs_dev_ioctl(&param);
 351         r = RET_NERRNO(ioctl(m->dev_autofs_fd, AUTOFS_DEV_IOCTL_VERSION, &param));
 352         if (r < 0) {
 353                 m->dev_autofs_fd = safe_close(m->dev_autofs_fd);
 354                 return log_error_errno(r, "Failed to issue AUTOFS_DEV_IOCTL_VERSION ioctl: %m");
 355         }
 356
 357         log_debug("Autofs kernel version %u.%u", param.ver_major, param.ver_minor);
 358
 359         return m->dev_autofs_fd;
 360 }
 361
 362 static int open_ioctl_fd(int dev_autofs_fd, const char *where, dev_t devid) {
 363         struct autofs_dev_ioctl *param;
 364         size_t l;
 365
 366         assert(dev_autofs_fd >= 0);
 367         assert(where);
 368
 369         l = sizeof(struct autofs_dev_ioctl) + strlen(where) + 1;
 370         param = alloca_safe(l);
 371
 372         init_autofs_dev_ioctl(param);
 373         param->size = l;
 374         param->ioctlfd = -EBADF;
 375         param->openmount.devid = devid;
 376         strcpy(param->path, where);
 377
 378         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_OPENMOUNT, param) < 0)
 379                 return -errno;
 380
 381         if (param->ioctlfd < 0)
 382                 return -EIO;
 383
 384         (void) fd_cloexec(param->ioctlfd, true);
 385         return param->ioctlfd;
 386 }
 387
 388 static int autofs_protocol(int dev_autofs_fd, int ioctl_fd) {
 389         uint32_t major, minor;
 390         struct autofs_dev_ioctl param;
 391
 392         assert(dev_autofs_fd >= 0);
 393         assert(ioctl_fd >= 0);
 394
 395         init_autofs_dev_ioctl(&param);
 396         param.ioctlfd = ioctl_fd;
 397
 398         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_PROTOVER, &param) < 0)
 399                 return -errno;
 400
 401         major = param.protover.version;
 402
 403         init_autofs_dev_ioctl(&param);
 404         param.ioctlfd = ioctl_fd;
 405
 406         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_PROTOSUBVER, &param) < 0)
 407                 return -errno;
 408
 409         minor = param.protosubver.sub_version;
 410
 411         log_debug("Autofs protocol version %u.%u", major, minor);
 412         return 0;
 413 }
 414
 415 static int autofs_set_timeout(int dev_autofs_fd, int ioctl_fd, usec_t usec) {
 416         struct autofs_dev_ioctl param;
 417
 418         assert(dev_autofs_fd >= 0);
 419         assert(ioctl_fd >= 0);
 420
 421         init_autofs_dev_ioctl(&param);
 422         param.ioctlfd = ioctl_fd;
 423
 424         if (usec == USEC_INFINITY)
 425                 param.timeout.timeout = 0;
 426         else
 427                 /* Convert to seconds, rounding up. */
 428                 param.timeout.timeout = DIV_ROUND_UP(usec, USEC_PER_SEC);
 429
 430         return RET_NERRNO(ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_TIMEOUT, &param));
 431 }
 432
 433 static int autofs_send_ready(int dev_autofs_fd, int ioctl_fd, uint32_t token, int status) {
 434         struct autofs_dev_ioctl param;
 435
 436         assert(dev_autofs_fd >= 0);
 437         assert(ioctl_fd >= 0);
 438
 439         init_autofs_dev_ioctl(&param);
 440         param.ioctlfd = ioctl_fd;
 441
 442         if (status != 0) {
 443                 param.fail.token = token;
 444                 param.fail.status = status;
 445         } else
 446                 param.ready.token = token;
 447
 448         return RET_NERRNO(ioctl(dev_autofs_fd, status ? AUTOFS_DEV_IOCTL_FAIL : AUTOFS_DEV_IOCTL_READY, &param));
 449 }
 450
 451 static int automount_send_ready(Automount *a, Set *tokens, int status) {
 452         _cleanup_close_ int ioctl_fd = -EBADF;
 453         unsigned token;
 454         int r;
 455
 456         assert(a);
 457         assert(status <= 0);
 458
 459         if (set_isempty(tokens))
 460                 return 0;
 461
 462         ioctl_fd = open_ioctl_fd(UNIT(a)->manager->dev_autofs_fd, a->where, a->dev_id);
 463         if (ioctl_fd < 0)
 464                 return ioctl_fd;
 465
 466         if (status != 0)
 467                 log_unit_debug_errno(UNIT(a), status, "Sending failure: %m");
 468         else
 469                 log_unit_debug(UNIT(a), "Sending success.");
 470
 471         r = 0;
 472
 473         /* Autofs thankfully does not hand out 0 as a token */
 474         while ((token = PTR_TO_UINT(set_steal_first(tokens)))) {
 475                 int k;
 476
 477                 /* Autofs fun fact:
 478                  *
 479                  * if you pass a positive status code here, kernels
 480                  * prior to 4.12 will freeze! Yay! */
 481
 482                 k = autofs_send_ready(UNIT(a)->manager->dev_autofs_fd,
 483                                       ioctl_fd,
 484                                       token,
 485                                       status);
 486                 if (k < 0)
 487                         r = k;
 488         }
 489
 490         return r;
 491 }
 492
 493 static void automount_trigger_notify(Unit *u, Unit *other) {
 494         Automount *a = ASSERT_PTR(AUTOMOUNT(u));
 495         int r;
 496
 497         assert(other);
 498
 499         /* Filter out invocations with bogus state */
 500         assert(UNIT_IS_LOAD_COMPLETE(other->load_state));
 501         assert(other->type == UNIT_MOUNT);
 502
 503         /* Don't propagate state changes from the mount if we are already down */
 504         if (!IN_SET(a->state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING))
 505                 return;
 506
 507         /* Propagate start limit hit state */
 508         if (other->start_limit_hit) {
 509                 automount_enter_dead(a, AUTOMOUNT_FAILURE_MOUNT_START_LIMIT_HIT);
 510                 return;
 511         }
 512
 513         /* Don't propagate anything if there's still a job queued */
 514         if (other->job)
 515                 return;
 516
 517         /* The mount is successfully established */
 518         if (IN_SET(MOUNT(other)->state, MOUNT_MOUNTED, MOUNT_REMOUNTING)) {
 519                 (void) automount_send_ready(a, a->tokens, 0);
 520
 521                 r = automount_start_expire(a);
 522                 if (r < 0)
 523                         log_unit_warning_errno(UNIT(a), r, "Failed to start expiration timer, ignoring: %m");
 524
 525                 automount_set_state(a, AUTOMOUNT_RUNNING);
 526         }
 527
 528         if (IN_SET(MOUNT(other)->state,
 529                    MOUNT_MOUNTING, MOUNT_MOUNTING_DONE,
 530                    MOUNT_MOUNTED, MOUNT_REMOUNTING,
 531                    MOUNT_REMOUNTING_SIGTERM, MOUNT_REMOUNTING_SIGKILL,
 532                    MOUNT_UNMOUNTING_SIGTERM, MOUNT_UNMOUNTING_SIGKILL,
 533                    MOUNT_FAILED))
 534                 (void) automount_send_ready(a, a->expire_tokens, -ENODEV);
 535
 536         if (MOUNT(other)->state == MOUNT_DEAD)
 537                 (void) automount_send_ready(a, a->expire_tokens, 0);
 538
 539         /* The mount is in some unhappy state now, let's unfreeze any waiting clients */
 540         if (IN_SET(MOUNT(other)->state,
 541                    MOUNT_DEAD, MOUNT_UNMOUNTING,
 542                    MOUNT_REMOUNTING_SIGTERM, MOUNT_REMOUNTING_SIGKILL,
 543                    MOUNT_UNMOUNTING_SIGTERM, MOUNT_UNMOUNTING_SIGKILL,
 544                    MOUNT_FAILED)) {
 545
 546                 (void) automount_send_ready(a, a->tokens, -ENODEV);
 547
 548                 automount_set_state(a, AUTOMOUNT_WAITING);
 549         }
 550 }
 551
 552 static void automount_enter_waiting(Automount *a) {
 553         _cleanup_close_pair_ int pipe_fd[2] = EBADF_PAIR;
 554         _cleanup_close_ int ioctl_fd = -EBADF;
 555         char name[STRLEN("systemd-") + DECIMAL_STR_MAX(pid_t) + 1];
 556         _cleanup_free_ char *options = NULL;
 557         bool mounted = false;
 558         int r, dev_autofs_fd;
 559         struct stat st;
 560
 561         assert(a);
 562         assert(a->pipe_fd < 0);
 563         assert(a->where);
 564
 565         set_clear(a->tokens);
 566
 567         r = unit_fail_if_noncanonical(UNIT(a), a->where);
 568         if (r < 0)
 569                 goto fail;
 570
 571         (void) mkdir_p_label(a->where, a->directory_mode);
 572
 573         unit_warn_if_dir_nonempty(UNIT(a), a->where);
 574
 575         dev_autofs_fd = open_dev_autofs(UNIT(a)->manager);
 576         if (dev_autofs_fd < 0)
 577                 goto fail;
 578
 579         if (pipe2(pipe_fd, O_CLOEXEC) < 0) {
 580                 log_unit_warning_errno(UNIT(a), errno, "Failed to allocate autofs pipe: %m");
 581                 goto fail;
 582         }
 583         r = fd_nonblock(pipe_fd[0], true);
 584         if (r < 0) {
 585                 log_unit_warning_errno(UNIT(a), r, "Failed to make read side of pipe non-blocking: %m");
 586                 goto fail;
 587         }
 588
 589         if (asprintf(
 590                     &options,
 591                     "fd=%i,pgrp="PID_FMT",minproto=5,maxproto=5,direct%s%s",
 592                     pipe_fd[1],
 593                     getpgrp(),
 594                     isempty(a->extra_options) ? "" : ",",
 595                     strempty(a->extra_options)) < 0) {
 596                 log_oom();
 597                 goto fail;
 598         }
 599
 600         xsprintf(name, "systemd-"PID_FMT, getpid_cached());
 601         r = mount_nofollow_verbose(LOG_WARNING, name, a->where, "autofs", 0, options);
 602         if (r < 0)
 603                 goto fail;
 604
 605         mounted = true;
 606
 607         pipe_fd[1] = safe_close(pipe_fd[1]);
 608
 609         if (stat(a->where, &st) < 0) {
 610                 log_unit_warning_errno(UNIT(a), errno, "Failed to stat new automount point '%s': %m", a->where);
 611                 goto fail;
 612         }
 613
 614         ioctl_fd = open_ioctl_fd(dev_autofs_fd, a->where, st.st_dev);
 615         if (ioctl_fd < 0) {
 616                 log_unit_warning_errno(UNIT(a), ioctl_fd, "Failed to open automount ioctl fd for '%s': %m", a->where);
 617                 goto fail;
 618         }
 619
 620         r = autofs_protocol(dev_autofs_fd, ioctl_fd);
 621         if (r < 0) {
 622                 log_unit_warning_errno(UNIT(a), r, "Failed to validate autofs protocol for '%s': %m", a->where);
 623                 goto fail;
 624         }
 625
 626         r = autofs_set_timeout(dev_autofs_fd, ioctl_fd, a->timeout_idle_usec);
 627         if (r < 0) {
 628                 log_unit_warning_errno(UNIT(a), r, "Failed to set autofs timeout for '%s': %m", a->where);
 629                 goto fail;
 630         }
 631
 632         r = sd_event_add_io(UNIT(a)->manager->event, &a->pipe_event_source, pipe_fd[0], EPOLLIN, automount_dispatch_io, a);
 633         if (r < 0) {
 634                 log_unit_warning_errno(UNIT(a), r, "Failed to allocate IO event source for autofs mount '%s': %m", a->where);
 635                 goto fail;
 636         }
 637
 638         (void) sd_event_source_set_description(a->pipe_event_source, "automount-io");
 639
 640         a->pipe_fd = TAKE_FD(pipe_fd[0]);
 641         a->dev_id = st.st_dev;
 642
 643         automount_set_state(a, AUTOMOUNT_WAITING);
 644         return;
 645
 646 fail:
 647         if (mounted) {
 648                 r = repeat_unmount(a->where, MNT_DETACH|UMOUNT_NOFOLLOW);
 649                 if (r < 0)
 650                         log_unit_warning_errno(UNIT(a), r, "Failed to unmount, ignoring: %m");
 651         }
 652
 653         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
 654 }
 655
 656 static int asynchronous_expire(int dev_autofs_fd, int ioctl_fd) {
 657         int r;
 658
 659         assert(dev_autofs_fd >= 0);
 660         assert(ioctl_fd >= 0);
 661
 662         /* Issue AUTOFS_DEV_IOCTL_EXPIRE in subprocess, asynchronously. Note that we don't keep track of the
 663          * child's PID, we are PID1/autoreaper after all, hence when it dies we'll automatically clean it up
 664          * anyway. */
 665
 666         r = safe_fork_full("(sd-expire)",
 667                            /* stdio_fds= */ NULL,
 668                            (int[]) { dev_autofs_fd, ioctl_fd },
 669                            /* n_except_fds= */ 2,
 670                            FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS|FORK_REOPEN_LOG,
 671                            /* pid= */ NULL);
 672         if (r != 0)
 673                 return r;
 674
 675         /* Child */
 676         for (;;) {
 677                 struct autofs_dev_ioctl param;
 678                 init_autofs_dev_ioctl(&param);
 679                 param.ioctlfd = ioctl_fd;
 680
 681                 if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_EXPIRE, &param) < 0)
 682                         break;
 683         }
 684
 685         if (errno != EAGAIN)
 686                 log_warning_errno(errno, "Failed to expire automount, ignoring: %m");
 687
 688         _exit(EXIT_SUCCESS);
 689 }
 690
 691 static int automount_dispatch_expire(sd_event_source *source, usec_t usec, void *userdata) {
 692         Automount *a = ASSERT_PTR(AUTOMOUNT(userdata));
 693         _cleanup_close_ int ioctl_fd = -EBADF;
 694         int r;
 695
 696         assert(source == a->expire_event_source);
 697
 698         ioctl_fd = open_ioctl_fd(UNIT(a)->manager->dev_autofs_fd, a->where, a->dev_id);
 699         if (ioctl_fd < 0)
 700                 return log_unit_error_errno(UNIT(a), ioctl_fd, "Couldn't open autofs ioctl fd: %m");
 701
 702         r = asynchronous_expire(UNIT(a)->manager->dev_autofs_fd, ioctl_fd);
 703         if (r < 0)
 704                 return log_unit_error_errno(UNIT(a), r, "Failed to start expire job: %m");
 705
 706         return automount_start_expire(a);
 707 }
 708
 709 static int automount_start_expire(Automount *a) {
 710         usec_t timeout;
 711         int r;
 712
 713         assert(a);
 714
 715         if (a->timeout_idle_usec == 0)
 716                 return 0;
 717
 718         timeout = MAX(a->timeout_idle_usec/3, USEC_PER_SEC);
 719
 720         if (a->expire_event_source) {
 721                 r = sd_event_source_set_time_relative(a->expire_event_source, timeout);
 722                 if (r < 0)
 723                         return r;
 724
 725                 return sd_event_source_set_enabled(a->expire_event_source, SD_EVENT_ONESHOT);
 726         }
 727
 728         r = sd_event_add_time_relative(
 729                         UNIT(a)->manager->event,
 730                         &a->expire_event_source,
 731                         CLOCK_MONOTONIC, timeout, 0,
 732                         automount_dispatch_expire, a);
 733         if (r < 0)
 734                 return r;
 735
 736         (void) sd_event_source_set_description(a->expire_event_source, "automount-expire");
 737
 738         return 0;
 739 }
 740
 741 static void automount_stop_expire(Automount *a) {
 742         assert(a);
 743
 744         if (!a->expire_event_source)
 745                 return;
 746
 747         (void) sd_event_source_set_enabled(a->expire_event_source, SD_EVENT_OFF);
 748 }
 749
 750 static void automount_enter_running(Automount *a) {
 751         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 752         Unit *trigger;
 753         struct stat st;
 754         int r;
 755
 756         assert(a);
 757
 758         /* If the user masked our unit in the meantime, fail */
 759         if (UNIT(a)->load_state != UNIT_LOADED) {
 760                 log_unit_error(UNIT(a), "Suppressing automount event since unit is no longer loaded.");
 761                 goto fail;
 762         }
 763
 764         /* We don't take mount requests anymore if we are supposed to
 765          * shut down anyway */
 766         if (unit_stop_pending(UNIT(a))) {
 767                 log_unit_debug(UNIT(a), "Suppressing automount request since unit stop is scheduled.");
 768                 automount_send_ready(a, a->tokens, -EHOSTDOWN);
 769                 automount_send_ready(a, a->expire_tokens, -EHOSTDOWN);
 770                 return;
 771         }
 772
 773         (void) mkdir_p_label(a->where, a->directory_mode);
 774
 775         /* Before we do anything, let's see if somebody is playing games with us? */
 776         if (lstat(a->where, &st) < 0) {
 777                 log_unit_warning_errno(UNIT(a), errno, "Failed to stat automount point: %m");
 778                 goto fail;
 779         }
 780
 781         /* The mount unit may have been explicitly started before we got the
 782          * autofs request. Ack it to unblock anything waiting on the mount point. */
 783         if (!S_ISDIR(st.st_mode) || st.st_dev != a->dev_id) {
 784                 log_unit_info(UNIT(a), "Automount point already active?");
 785                 automount_send_ready(a, a->tokens, 0);
 786                 return;
 787         }
 788
 789         trigger = UNIT_TRIGGER(UNIT(a));
 790         if (!trigger) {
 791                 log_unit_error(UNIT(a), "Unit to trigger vanished.");
 792                 goto fail;
 793         }
 794
 795         r = manager_add_job(UNIT(a)->manager, JOB_START, trigger, JOB_REPLACE, NULL, &error, NULL);
 796         if (r < 0) {
 797                 log_unit_warning(UNIT(a), "Failed to queue mount startup job: %s", bus_error_message(&error, r));
 798                 goto fail;
 799         }
 800
 801         automount_set_state(a, AUTOMOUNT_RUNNING);
 802         return;
 803
 804 fail:
 805         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
 806 }
 807
 808 static int automount_start(Unit *u) {
 809         Automount *a = ASSERT_PTR(AUTOMOUNT(u));
 810         int r;
 811
 812         assert(IN_SET(a->state, AUTOMOUNT_DEAD, AUTOMOUNT_FAILED));
 813
 814         if (path_is_mount_point(a->where) > 0)
 815                 return log_unit_error_errno(u, SYNTHETIC_ERRNO(EEXIST), "Path %s is already a mount point, refusing start.", a->where);
 816
 817         r = unit_test_trigger_loaded(u);
 818         if (r < 0)
 819                 return r;
 820
 821         r = unit_acquire_invocation_id(u);
 822         if (r < 0)
 823                 return r;
 824
 825         a->result = AUTOMOUNT_SUCCESS;
 826         automount_enter_waiting(a);
 827         return 1;
 828 }
 829
 830 static int automount_stop(Unit *u) {
 831         Automount *a = ASSERT_PTR(AUTOMOUNT(u));
 832
 833         assert(IN_SET(a->state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING));
 834
 835         automount_enter_dead(a, AUTOMOUNT_SUCCESS);
 836         return 1;
 837 }
 838
 839 static int automount_serialize(Unit *u, FILE *f, FDSet *fds) {
 840         Automount *a = ASSERT_PTR(AUTOMOUNT(u));
 841         void *p;
 842         int r;
 843
 844         assert(f);
 845         assert(fds);
 846
 847         (void) serialize_item(f, "state", automount_state_to_string(a->state));
 848         (void) serialize_item(f, "result", automount_result_to_string(a->result));
 849         (void) serialize_item_format(f, "dev-id", "%lu", (unsigned long) a->dev_id);
 850
 851         SET_FOREACH(p, a->tokens)
 852                 (void) serialize_item_format(f, "token", "%u", PTR_TO_UINT(p));
 853         SET_FOREACH(p, a->expire_tokens)
 854                 (void) serialize_item_format(f, "expire-token", "%u", PTR_TO_UINT(p));
 855
 856         r = serialize_fd(f, fds, "pipe-fd", a->pipe_fd);
 857         if (r < 0)
 858                 return r;
 859
 860         return 0;
 861 }
 862
 863 static int automount_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 864         Automount *a = ASSERT_PTR(AUTOMOUNT(u));
 865         int r;
 866
 867         assert(fds);
 868
 869         if (streq(key, "state")) {
 870                 AutomountState state;
 871
 872                 state = automount_state_from_string(value);
 873                 if (state < 0)
 874                         log_unit_debug(u, "Failed to parse state value: %s", value);
 875                 else
 876                         a->deserialized_state = state;
 877         } else if (streq(key, "result")) {
 878                 AutomountResult f;
 879
 880                 f = automount_result_from_string(value);
 881                 if (f < 0)
 882                         log_unit_debug(u, "Failed to parse result value: %s", value);
 883                 else if (f != AUTOMOUNT_SUCCESS)
 884                         a->result = f;
 885
 886         } else if (streq(key, "dev-id")) {
 887                 unsigned long d;
 888
 889                 if (safe_atolu(value, &d) < 0)
 890                         log_unit_debug(u, "Failed to parse dev-id value: %s", value);
 891                 else
 892                         a->dev_id = (dev_t) d;
 893
 894         } else if (streq(key, "token")) {
 895                 unsigned token;
 896
 897                 if (safe_atou(value, &token) < 0)
 898                         log_unit_debug(u, "Failed to parse token value: %s", value);
 899                 else {
 900                         r = set_ensure_put(&a->tokens, NULL, UINT_TO_PTR(token));
 901                         if (r < 0)
 902                                 log_unit_error_errno(u, r, "Failed to add token to set: %m");
 903                 }
 904         } else if (streq(key, "expire-token")) {
 905                 unsigned token;
 906
 907                 if (safe_atou(value, &token) < 0)
 908                         log_unit_debug(u, "Failed to parse token value: %s", value);
 909                 else {
 910                         r = set_ensure_put(&a->expire_tokens, NULL, UINT_TO_PTR(token));
 911                         if (r < 0)
 912                                 log_unit_error_errno(u, r, "Failed to add expire token to set: %m");
 913                 }
 914         } else if (streq(key, "pipe-fd")) {
 915                 safe_close(a->pipe_fd);
 916                 a->pipe_fd = deserialize_fd(fds, value);
 917         } else
 918                 log_unit_debug(u, "Unknown serialization key: %s", key);
 919
 920         return 0;
 921 }
 922
 923 static UnitActiveState automount_active_state(Unit *u) {
 924         assert(u);
 925
 926         return state_translation_table[AUTOMOUNT(u)->state];
 927 }
 928
 929 static const char *automount_sub_state_to_string(Unit *u) {
 930         assert(u);
 931
 932         return automount_state_to_string(AUTOMOUNT(u)->state);
 933 }
 934
 935 static bool automount_may_gc(Unit *u) {
 936         Unit *t;
 937
 938         assert(u);
 939
 940         t = UNIT_TRIGGER(u);
 941         if (!t)
 942                 return true;
 943
 944         return UNIT_VTABLE(t)->may_gc(t);
 945 }
 946
 947 static int automount_dispatch_io(sd_event_source *s, int fd, uint32_t events, void *userdata) {
 948         Automount *a = ASSERT_PTR(AUTOMOUNT(userdata));
 949         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 950         union autofs_v5_packet_union packet;
 951         Unit *trigger;
 952         int r;
 953
 954         assert(fd == a->pipe_fd);
 955
 956         if (events & (EPOLLHUP|EPOLLERR)) {
 957                 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?");
 958                 automount_enter_dead(a, AUTOMOUNT_FAILURE_UNMOUNTED);
 959                 return 0;
 960         }
 961
 962         if (events != EPOLLIN) {
 963                 log_unit_error(UNIT(a), "Got invalid poll event %"PRIu32" on pipe (fd=%d)", events, fd);
 964                 goto fail;
 965         }
 966
 967         r = loop_read_exact(a->pipe_fd, &packet, sizeof(packet), true);
 968         if (r < 0) {
 969                 log_unit_error_errno(UNIT(a), r, "Invalid read from pipe: %m");
 970                 goto fail;
 971         }
 972
 973         switch (packet.hdr.type) {
 974
 975         case autofs_ptype_missing_direct:
 976
 977                 if (packet.v5_packet.pid > 0) {
 978                         _cleanup_free_ char *p = NULL;
 979
 980                         (void) pid_get_comm(packet.v5_packet.pid, &p);
 981                         log_unit_info(UNIT(a), "Got automount request for %s, triggered by %"PRIu32" (%s)", a->where, packet.v5_packet.pid, strna(p));
 982                 } else
 983                         log_unit_debug(UNIT(a), "Got direct mount request on %s", a->where);
 984
 985                 r = set_ensure_put(&a->tokens, NULL, UINT_TO_PTR(packet.v5_packet.wait_queue_token));
 986                 if (r < 0) {
 987                         log_unit_error_errno(UNIT(a), r, "Failed to remember token: %m");
 988                         goto fail;
 989                 }
 990
 991                 automount_enter_running(a);
 992                 break;
 993
 994         case autofs_ptype_expire_direct:
 995                 log_unit_debug(UNIT(a), "Got direct umount request on %s", a->where);
 996
 997                 automount_stop_expire(a);
 998
 999                 r = set_ensure_put(&a->expire_tokens, NULL, UINT_TO_PTR(packet.v5_packet.wait_queue_token));
1000                 if (r < 0) {
1001                         log_unit_error_errno(UNIT(a), r, "Failed to remember token: %m");
1002                         goto fail;
1003                 }
1004
1005                 trigger = UNIT_TRIGGER(UNIT(a));
1006                 if (!trigger) {
1007                         log_unit_error(UNIT(a), "Unit to trigger vanished.");
1008                         goto fail;
1009                 }
1010
1011                 r = manager_add_job(UNIT(a)->manager, JOB_STOP, trigger, JOB_REPLACE, NULL, &error, NULL);
1012                 if (r < 0) {
1013                         log_unit_warning(UNIT(a), "Failed to queue unmount job: %s", bus_error_message(&error, r));
1014                         goto fail;
1015                 }
1016                 break;
1017
1018         default:
1019                 log_unit_error(UNIT(a), "Received unknown automount request %i", packet.hdr.type);
1020                 break;
1021         }
1022
1023         return 0;
1024
1025 fail:
1026         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
1027         return 0;
1028 }
1029
1030 static void automount_shutdown(Manager *m) {
1031         assert(m);
1032
1033         m->dev_autofs_fd = safe_close(m->dev_autofs_fd);
1034 }
1035
1036 static void automount_reset_failed(Unit *u) {
1037         Automount *a = ASSERT_PTR(AUTOMOUNT(u));
1038
1039         if (a->state == AUTOMOUNT_FAILED)
1040                 automount_set_state(a, AUTOMOUNT_DEAD);
1041
1042         a->result = AUTOMOUNT_SUCCESS;
1043 }
1044
1045 static bool automount_supported(void) {
1046         static int supported = -1;
1047
1048         if (supported < 0)
1049                 supported = access("/dev/autofs", F_OK) >= 0;
1050
1051         return supported;
1052 }
1053
1054 static int automount_can_start(Unit *u) {
1055         Automount *a = ASSERT_PTR(AUTOMOUNT(u));
1056         int r;
1057
1058         r = unit_test_start_limit(u);
1059         if (r < 0) {
1060                 automount_enter_dead(a, AUTOMOUNT_FAILURE_START_LIMIT_HIT);
1061                 return r;
1062         }
1063
1064         return 1;
1065 }
1066
1067 static const char* const automount_result_table[_AUTOMOUNT_RESULT_MAX] = {
1068         [AUTOMOUNT_SUCCESS]                       = "success",
1069         [AUTOMOUNT_FAILURE_RESOURCES]             = "resources",
1070         [AUTOMOUNT_FAILURE_START_LIMIT_HIT]       = "start-limit-hit",
1071         [AUTOMOUNT_FAILURE_MOUNT_START_LIMIT_HIT] = "mount-start-limit-hit",
1072         [AUTOMOUNT_FAILURE_UNMOUNTED]             = "unmounted",
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         .exclude_from_switch_root_serialization = true,
1090
1091         .init = automount_init,
1092         .load = automount_load,
1093         .done = automount_done,
1094
1095         .coldplug = automount_coldplug,
1096
1097         .dump = automount_dump,
1098
1099         .start = automount_start,
1100         .stop = automount_stop,
1101
1102         .serialize = automount_serialize,
1103         .deserialize_item = automount_deserialize_item,
1104
1105         .active_state = automount_active_state,
1106         .sub_state_to_string = automount_sub_state_to_string,
1107
1108         .may_gc = automount_may_gc,
1109
1110         .trigger_notify = automount_trigger_notify,
1111
1112         .reset_failed = automount_reset_failed,
1113
1114         .bus_set_property = bus_automount_set_property,
1115
1116         .shutdown = automount_shutdown,
1117         .supported = automount_supported,
1118
1119         .status_message_formats = {
1120                 .finished_start_job = {
1121                         [JOB_DONE]       = "Set up automount %s.",
1122                         [JOB_FAILED]     = "Failed to set up automount %s.",
1123                 },
1124                 .finished_stop_job = {
1125                         [JOB_DONE]       = "Unset automount %s.",
1126                         [JOB_FAILED]     = "Failed to unset automount %s.",
1127                 },
1128         },
1129
1130         .can_start = automount_can_start,
1131 };