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                 /* Autofs fun fact:
 476                  *
 477                  * if you pass a positive status code here, kernels prior to 4.12 will freeze! Yay! */
 478                 RET_GATHER(r, autofs_send_ready(UNIT(a)->manager->dev_autofs_fd,
 479                                                 ioctl_fd,
 480                                                 token,
 481                                                 status));
 482
 483         return r;
 484 }
 485
 486 static void automount_trigger_notify(Unit *u, Unit *other) {
 487         Automount *a = ASSERT_PTR(AUTOMOUNT(u));
 488         int r;
 489
 490         assert(other);
 491
 492         /* Filter out invocations with bogus state */
 493         assert(UNIT_IS_LOAD_COMPLETE(other->load_state));
 494         assert(other->type == UNIT_MOUNT);
 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                 (void) automount_send_ready(a, a->expire_tokens, -ENODEV);
 528
 529         if (MOUNT(other)->state == MOUNT_DEAD)
 530                 (void) automount_send_ready(a, a->expire_tokens, 0);
 531
 532         /* The mount is in some unhappy state now, let's unfreeze any waiting clients */
 533         if (IN_SET(MOUNT(other)->state,
 534                    MOUNT_DEAD, MOUNT_UNMOUNTING,
 535                    MOUNT_REMOUNTING_SIGTERM, MOUNT_REMOUNTING_SIGKILL,
 536                    MOUNT_UNMOUNTING_SIGTERM, MOUNT_UNMOUNTING_SIGKILL,
 537                    MOUNT_FAILED)) {
 538
 539                 (void) automount_send_ready(a, a->tokens, -ENODEV);
 540
 541                 automount_set_state(a, AUTOMOUNT_WAITING);
 542         }
 543 }
 544
 545 static void automount_enter_waiting(Automount *a) {
 546         _cleanup_close_pair_ int pipe_fd[2] = EBADF_PAIR;
 547         _cleanup_close_ int ioctl_fd = -EBADF;
 548         char name[STRLEN("systemd-") + DECIMAL_STR_MAX(pid_t) + 1];
 549         _cleanup_free_ char *options = NULL;
 550         bool mounted = false;
 551         int r, dev_autofs_fd;
 552         struct stat st;
 553
 554         assert(a);
 555         assert(a->pipe_fd < 0);
 556         assert(a->where);
 557
 558         set_clear(a->tokens);
 559
 560         r = unit_fail_if_noncanonical(UNIT(a), a->where);
 561         if (r < 0)
 562                 goto fail;
 563
 564         (void) mkdir_p_label(a->where, a->directory_mode);
 565
 566         unit_warn_if_dir_nonempty(UNIT(a), a->where);
 567
 568         dev_autofs_fd = open_dev_autofs(UNIT(a)->manager);
 569         if (dev_autofs_fd < 0)
 570                 goto fail;
 571
 572         if (pipe2(pipe_fd, O_CLOEXEC) < 0) {
 573                 log_unit_warning_errno(UNIT(a), errno, "Failed to allocate autofs pipe: %m");
 574                 goto fail;
 575         }
 576         r = fd_nonblock(pipe_fd[0], true);
 577         if (r < 0) {
 578                 log_unit_warning_errno(UNIT(a), r, "Failed to make read side of pipe non-blocking: %m");
 579                 goto fail;
 580         }
 581
 582         if (asprintf(
 583                     &options,
 584                     "fd=%i,pgrp="PID_FMT",minproto=5,maxproto=5,direct%s%s",
 585                     pipe_fd[1],
 586                     getpgrp(),
 587                     isempty(a->extra_options) ? "" : ",",
 588                     strempty(a->extra_options)) < 0) {
 589                 log_oom();
 590                 goto fail;
 591         }
 592
 593         xsprintf(name, "systemd-"PID_FMT, getpid_cached());
 594         r = mount_nofollow_verbose(LOG_WARNING, name, a->where, "autofs", 0, options);
 595         if (r < 0)
 596                 goto fail;
 597
 598         mounted = true;
 599
 600         pipe_fd[1] = safe_close(pipe_fd[1]);
 601
 602         if (stat(a->where, &st) < 0) {
 603                 log_unit_warning_errno(UNIT(a), errno, "Failed to stat new automount point '%s': %m", a->where);
 604                 goto fail;
 605         }
 606
 607         ioctl_fd = open_ioctl_fd(dev_autofs_fd, a->where, st.st_dev);
 608         if (ioctl_fd < 0) {
 609                 log_unit_warning_errno(UNIT(a), ioctl_fd, "Failed to open automount ioctl fd for '%s': %m", a->where);
 610                 goto fail;
 611         }
 612
 613         r = autofs_protocol(dev_autofs_fd, ioctl_fd);
 614         if (r < 0) {
 615                 log_unit_warning_errno(UNIT(a), r, "Failed to validate autofs protocol for '%s': %m", a->where);
 616                 goto fail;
 617         }
 618
 619         r = autofs_set_timeout(dev_autofs_fd, ioctl_fd, a->timeout_idle_usec);
 620         if (r < 0) {
 621                 log_unit_warning_errno(UNIT(a), r, "Failed to set autofs timeout for '%s': %m", a->where);
 622                 goto fail;
 623         }
 624
 625         r = sd_event_add_io(UNIT(a)->manager->event, &a->pipe_event_source, pipe_fd[0], EPOLLIN, automount_dispatch_io, a);
 626         if (r < 0) {
 627                 log_unit_warning_errno(UNIT(a), r, "Failed to allocate IO event source for autofs mount '%s': %m", a->where);
 628                 goto fail;
 629         }
 630
 631         (void) sd_event_source_set_description(a->pipe_event_source, "automount-io");
 632
 633         a->pipe_fd = TAKE_FD(pipe_fd[0]);
 634         a->dev_id = st.st_dev;
 635
 636         automount_set_state(a, AUTOMOUNT_WAITING);
 637         return;
 638
 639 fail:
 640         if (mounted) {
 641                 r = repeat_unmount(a->where, MNT_DETACH|UMOUNT_NOFOLLOW);
 642                 if (r < 0)
 643                         log_unit_warning_errno(UNIT(a), r, "Failed to unmount, ignoring: %m");
 644         }
 645
 646         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
 647 }
 648
 649 static int asynchronous_expire(int dev_autofs_fd, int ioctl_fd) {
 650         int r;
 651
 652         assert(dev_autofs_fd >= 0);
 653         assert(ioctl_fd >= 0);
 654
 655         /* Issue AUTOFS_DEV_IOCTL_EXPIRE in subprocess, asynchronously. Note that we don't keep track of the
 656          * child's PID, we are PID1/autoreaper after all, hence when it dies we'll automatically clean it up
 657          * anyway. */
 658
 659         r = safe_fork_full("(sd-expire)",
 660                            /* stdio_fds= */ NULL,
 661                            (int[]) { dev_autofs_fd, ioctl_fd },
 662                            /* n_except_fds= */ 2,
 663                            FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS|FORK_REOPEN_LOG,
 664                            /* pid= */ NULL);
 665         if (r != 0)
 666                 return r;
 667
 668         /* Child */
 669         for (;;) {
 670                 struct autofs_dev_ioctl param;
 671                 init_autofs_dev_ioctl(&param);
 672                 param.ioctlfd = ioctl_fd;
 673
 674                 if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_EXPIRE, &param) < 0)
 675                         break;
 676         }
 677
 678         if (errno != EAGAIN)
 679                 log_warning_errno(errno, "Failed to expire automount, ignoring: %m");
 680
 681         _exit(EXIT_SUCCESS);
 682 }
 683
 684 static int automount_dispatch_expire(sd_event_source *source, usec_t usec, void *userdata) {
 685         Automount *a = ASSERT_PTR(AUTOMOUNT(userdata));
 686         _cleanup_close_ int ioctl_fd = -EBADF;
 687         int r;
 688
 689         assert(source == a->expire_event_source);
 690
 691         ioctl_fd = open_ioctl_fd(UNIT(a)->manager->dev_autofs_fd, a->where, a->dev_id);
 692         if (ioctl_fd < 0)
 693                 return log_unit_error_errno(UNIT(a), ioctl_fd, "Couldn't open autofs ioctl fd: %m");
 694
 695         r = asynchronous_expire(UNIT(a)->manager->dev_autofs_fd, ioctl_fd);
 696         if (r < 0)
 697                 return log_unit_error_errno(UNIT(a), r, "Failed to start expire job: %m");
 698
 699         return automount_start_expire(a);
 700 }
 701
 702 static int automount_start_expire(Automount *a) {
 703         usec_t timeout;
 704         int r;
 705
 706         assert(a);
 707
 708         if (a->timeout_idle_usec == 0)
 709                 return 0;
 710
 711         timeout = MAX(a->timeout_idle_usec/3, USEC_PER_SEC);
 712
 713         if (a->expire_event_source) {
 714                 r = sd_event_source_set_time_relative(a->expire_event_source, timeout);
 715                 if (r < 0)
 716                         return r;
 717
 718                 return sd_event_source_set_enabled(a->expire_event_source, SD_EVENT_ONESHOT);
 719         }
 720
 721         r = sd_event_add_time_relative(
 722                         UNIT(a)->manager->event,
 723                         &a->expire_event_source,
 724                         CLOCK_MONOTONIC, timeout, 0,
 725                         automount_dispatch_expire, a);
 726         if (r < 0)
 727                 return r;
 728
 729         (void) sd_event_source_set_description(a->expire_event_source, "automount-expire");
 730
 731         return 0;
 732 }
 733
 734 static void automount_stop_expire(Automount *a) {
 735         assert(a);
 736
 737         if (!a->expire_event_source)
 738                 return;
 739
 740         (void) sd_event_source_set_enabled(a->expire_event_source, SD_EVENT_OFF);
 741 }
 742
 743 static void automount_enter_running(Automount *a) {
 744         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 745         Unit *trigger;
 746         struct stat st;
 747         int r;
 748
 749         assert(a);
 750
 751         /* If the user masked our unit in the meantime, fail */
 752         if (UNIT(a)->load_state != UNIT_LOADED) {
 753                 log_unit_error(UNIT(a), "Suppressing automount event since unit is no longer loaded.");
 754                 goto fail;
 755         }
 756
 757         /* We don't take mount requests anymore if we are supposed to
 758          * shut down anyway */
 759         if (unit_stop_pending(UNIT(a))) {
 760                 log_unit_debug(UNIT(a), "Suppressing automount request since unit stop is scheduled.");
 761                 automount_send_ready(a, a->tokens, -EHOSTDOWN);
 762                 automount_send_ready(a, a->expire_tokens, -EHOSTDOWN);
 763                 return;
 764         }
 765
 766         (void) mkdir_p_label(a->where, a->directory_mode);
 767
 768         /* Before we do anything, let's see if somebody is playing games with us? */
 769         if (lstat(a->where, &st) < 0) {
 770                 log_unit_warning_errno(UNIT(a), errno, "Failed to stat automount point: %m");
 771                 goto fail;
 772         }
 773
 774         /* The mount unit may have been explicitly started before we got the
 775          * autofs request. Ack it to unblock anything waiting on the mount point. */
 776         if (!S_ISDIR(st.st_mode) || st.st_dev != a->dev_id) {
 777                 log_unit_info(UNIT(a), "Automount point already active?");
 778                 automount_send_ready(a, a->tokens, 0);
 779                 return;
 780         }
 781
 782         trigger = UNIT_TRIGGER(UNIT(a));
 783         if (!trigger) {
 784                 log_unit_error(UNIT(a), "Unit to trigger vanished.");
 785                 goto fail;
 786         }
 787
 788         r = manager_add_job(UNIT(a)->manager, JOB_START, trigger, JOB_REPLACE, NULL, &error, NULL);
 789         if (r < 0) {
 790                 log_unit_warning(UNIT(a), "Failed to queue mount startup job: %s", bus_error_message(&error, r));
 791                 goto fail;
 792         }
 793
 794         automount_set_state(a, AUTOMOUNT_RUNNING);
 795         return;
 796
 797 fail:
 798         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
 799 }
 800
 801 static int automount_start(Unit *u) {
 802         Automount *a = ASSERT_PTR(AUTOMOUNT(u));
 803         int r;
 804
 805         assert(IN_SET(a->state, AUTOMOUNT_DEAD, AUTOMOUNT_FAILED));
 806
 807         if (path_is_mount_point(a->where) > 0)
 808                 return log_unit_error_errno(u, SYNTHETIC_ERRNO(EEXIST), "Path %s is already a mount point, refusing start.", a->where);
 809
 810         r = unit_test_trigger_loaded(u);
 811         if (r < 0)
 812                 return r;
 813
 814         r = unit_acquire_invocation_id(u);
 815         if (r < 0)
 816                 return r;
 817
 818         a->result = AUTOMOUNT_SUCCESS;
 819         automount_enter_waiting(a);
 820         return 1;
 821 }
 822
 823 static int automount_stop(Unit *u) {
 824         Automount *a = ASSERT_PTR(AUTOMOUNT(u));
 825
 826         assert(IN_SET(a->state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING));
 827
 828         automount_enter_dead(a, AUTOMOUNT_SUCCESS);
 829         return 1;
 830 }
 831
 832 static int automount_serialize(Unit *u, FILE *f, FDSet *fds) {
 833         Automount *a = ASSERT_PTR(AUTOMOUNT(u));
 834         void *p;
 835         int r;
 836
 837         assert(f);
 838         assert(fds);
 839
 840         (void) serialize_item(f, "state", automount_state_to_string(a->state));
 841         (void) serialize_item(f, "result", automount_result_to_string(a->result));
 842         (void) serialize_item_format(f, "dev-id", "%lu", (unsigned long) a->dev_id);
 843
 844         SET_FOREACH(p, a->tokens)
 845                 (void) serialize_item_format(f, "token", "%u", PTR_TO_UINT(p));
 846         SET_FOREACH(p, a->expire_tokens)
 847                 (void) serialize_item_format(f, "expire-token", "%u", PTR_TO_UINT(p));
 848
 849         r = serialize_fd(f, fds, "pipe-fd", a->pipe_fd);
 850         if (r < 0)
 851                 return r;
 852
 853         return 0;
 854 }
 855
 856 static int automount_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 857         Automount *a = ASSERT_PTR(AUTOMOUNT(u));
 858         int r;
 859
 860         assert(fds);
 861
 862         if (streq(key, "state")) {
 863                 AutomountState state;
 864
 865                 state = automount_state_from_string(value);
 866                 if (state < 0)
 867                         log_unit_debug(u, "Failed to parse state value: %s", value);
 868                 else
 869                         a->deserialized_state = state;
 870         } else if (streq(key, "result")) {
 871                 AutomountResult f;
 872
 873                 f = automount_result_from_string(value);
 874                 if (f < 0)
 875                         log_unit_debug(u, "Failed to parse result value: %s", value);
 876                 else if (f != AUTOMOUNT_SUCCESS)
 877                         a->result = f;
 878
 879         } else if (streq(key, "dev-id")) {
 880                 unsigned long d;
 881
 882                 if (safe_atolu(value, &d) < 0)
 883                         log_unit_debug(u, "Failed to parse dev-id value: %s", value);
 884                 else
 885                         a->dev_id = (dev_t) d;
 886
 887         } else if (streq(key, "token")) {
 888                 unsigned token;
 889
 890                 if (safe_atou(value, &token) < 0)
 891                         log_unit_debug(u, "Failed to parse token value: %s", value);
 892                 else {
 893                         r = set_ensure_put(&a->tokens, NULL, UINT_TO_PTR(token));
 894                         if (r < 0)
 895                                 log_unit_error_errno(u, r, "Failed to add token to set: %m");
 896                 }
 897         } else if (streq(key, "expire-token")) {
 898                 unsigned token;
 899
 900                 if (safe_atou(value, &token) < 0)
 901                         log_unit_debug(u, "Failed to parse token value: %s", value);
 902                 else {
 903                         r = set_ensure_put(&a->expire_tokens, NULL, UINT_TO_PTR(token));
 904                         if (r < 0)
 905                                 log_unit_error_errno(u, r, "Failed to add expire token to set: %m");
 906                 }
 907         } else if (streq(key, "pipe-fd")) {
 908                 safe_close(a->pipe_fd);
 909                 a->pipe_fd = deserialize_fd(fds, value);
 910         } else
 911                 log_unit_debug(u, "Unknown serialization key: %s", key);
 912
 913         return 0;
 914 }
 915
 916 static UnitActiveState automount_active_state(Unit *u) {
 917         assert(u);
 918
 919         return state_translation_table[AUTOMOUNT(u)->state];
 920 }
 921
 922 static const char *automount_sub_state_to_string(Unit *u) {
 923         assert(u);
 924
 925         return automount_state_to_string(AUTOMOUNT(u)->state);
 926 }
 927
 928 static bool automount_may_gc(Unit *u) {
 929         Unit *t;
 930
 931         assert(u);
 932
 933         t = UNIT_TRIGGER(u);
 934         if (!t)
 935                 return true;
 936
 937         return UNIT_VTABLE(t)->may_gc(t);
 938 }
 939
 940 static int automount_dispatch_io(sd_event_source *s, int fd, uint32_t events, void *userdata) {
 941         Automount *a = ASSERT_PTR(AUTOMOUNT(userdata));
 942         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 943         union autofs_v5_packet_union packet;
 944         Unit *trigger;
 945         int r;
 946
 947         assert(fd == a->pipe_fd);
 948
 949         if (events & (EPOLLHUP|EPOLLERR)) {
 950                 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?");
 951                 automount_enter_dead(a, AUTOMOUNT_FAILURE_UNMOUNTED);
 952                 return 0;
 953         }
 954
 955         if (events != EPOLLIN) {
 956                 log_unit_error(UNIT(a), "Got invalid poll event %"PRIu32" on pipe (fd=%d)", events, fd);
 957                 goto fail;
 958         }
 959
 960         r = loop_read_exact(a->pipe_fd, &packet, sizeof(packet), true);
 961         if (r < 0) {
 962                 log_unit_error_errno(UNIT(a), r, "Invalid read from pipe: %m");
 963                 goto fail;
 964         }
 965
 966         switch (packet.hdr.type) {
 967
 968         case autofs_ptype_missing_direct:
 969
 970                 if (packet.v5_packet.pid > 0) {
 971                         _cleanup_free_ char *p = NULL;
 972
 973                         (void) pid_get_comm(packet.v5_packet.pid, &p);
 974                         log_unit_info(UNIT(a), "Got automount request for %s, triggered by %"PRIu32" (%s)", a->where, packet.v5_packet.pid, strna(p));
 975                 } else
 976                         log_unit_debug(UNIT(a), "Got direct mount request on %s", a->where);
 977
 978                 r = set_ensure_put(&a->tokens, NULL, UINT_TO_PTR(packet.v5_packet.wait_queue_token));
 979                 if (r < 0) {
 980                         log_unit_error_errno(UNIT(a), r, "Failed to remember token: %m");
 981                         goto fail;
 982                 }
 983
 984                 automount_enter_running(a);
 985                 break;
 986
 987         case autofs_ptype_expire_direct:
 988                 log_unit_debug(UNIT(a), "Got direct umount request on %s", a->where);
 989
 990                 automount_stop_expire(a);
 991
 992                 r = set_ensure_put(&a->expire_tokens, NULL, UINT_TO_PTR(packet.v5_packet.wait_queue_token));
 993                 if (r < 0) {
 994                         log_unit_error_errno(UNIT(a), r, "Failed to remember token: %m");
 995                         goto fail;
 996                 }
 997
 998                 trigger = UNIT_TRIGGER(UNIT(a));
 999                 if (!trigger) {
1000                         log_unit_error(UNIT(a), "Unit to trigger vanished.");
1001                         goto fail;
1002                 }
1003
1004                 r = manager_add_job(UNIT(a)->manager, JOB_STOP, trigger, JOB_REPLACE, NULL, &error, NULL);
1005                 if (r < 0) {
1006                         log_unit_warning(UNIT(a), "Failed to queue unmount job: %s", bus_error_message(&error, r));
1007                         goto fail;
1008                 }
1009                 break;
1010
1011         default:
1012                 log_unit_error(UNIT(a), "Received unknown automount request %i", packet.hdr.type);
1013                 break;
1014         }
1015
1016         return 0;
1017
1018 fail:
1019         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
1020         return 0;
1021 }
1022
1023 static void automount_shutdown(Manager *m) {
1024         assert(m);
1025
1026         m->dev_autofs_fd = safe_close(m->dev_autofs_fd);
1027 }
1028
1029 static void automount_reset_failed(Unit *u) {
1030         Automount *a = ASSERT_PTR(AUTOMOUNT(u));
1031
1032         if (a->state == AUTOMOUNT_FAILED)
1033                 automount_set_state(a, AUTOMOUNT_DEAD);
1034
1035         a->result = AUTOMOUNT_SUCCESS;
1036 }
1037
1038 static bool automount_supported(void) {
1039         static int supported = -1;
1040
1041         if (supported < 0)
1042                 supported = access("/dev/autofs", F_OK) >= 0;
1043
1044         return supported;
1045 }
1046
1047 static int automount_can_start(Unit *u) {
1048         Automount *a = ASSERT_PTR(AUTOMOUNT(u));
1049         int r;
1050
1051         r = unit_test_start_limit(u);
1052         if (r < 0) {
1053                 automount_enter_dead(a, AUTOMOUNT_FAILURE_START_LIMIT_HIT);
1054                 return r;
1055         }
1056
1057         return 1;
1058 }
1059
1060 static const char* const automount_result_table[_AUTOMOUNT_RESULT_MAX] = {
1061         [AUTOMOUNT_SUCCESS]                       = "success",
1062         [AUTOMOUNT_FAILURE_RESOURCES]             = "resources",
1063         [AUTOMOUNT_FAILURE_START_LIMIT_HIT]       = "start-limit-hit",
1064         [AUTOMOUNT_FAILURE_MOUNT_START_LIMIT_HIT] = "mount-start-limit-hit",
1065         [AUTOMOUNT_FAILURE_UNMOUNTED]             = "unmounted",
1066 };
1067
1068 DEFINE_STRING_TABLE_LOOKUP(automount_result, AutomountResult);
1069
1070 const UnitVTable automount_vtable = {
1071         .object_size = sizeof(Automount),
1072
1073         .sections =
1074                 "Unit\0"
1075                 "Automount\0"
1076                 "Install\0",
1077         .private_section = "Automount",
1078
1079         .can_transient = true,
1080         .can_fail = true,
1081         .can_trigger = true,
1082         .exclude_from_switch_root_serialization = true,
1083
1084         .init = automount_init,
1085         .load = automount_load,
1086         .done = automount_done,
1087
1088         .coldplug = automount_coldplug,
1089
1090         .dump = automount_dump,
1091
1092         .start = automount_start,
1093         .stop = automount_stop,
1094
1095         .serialize = automount_serialize,
1096         .deserialize_item = automount_deserialize_item,
1097
1098         .active_state = automount_active_state,
1099         .sub_state_to_string = automount_sub_state_to_string,
1100
1101         .may_gc = automount_may_gc,
1102
1103         .trigger_notify = automount_trigger_notify,
1104
1105         .reset_failed = automount_reset_failed,
1106
1107         .bus_set_property = bus_automount_set_property,
1108
1109         .shutdown = automount_shutdown,
1110         .supported = automount_supported,
1111
1112         .status_message_formats = {
1113                 .finished_start_job = {
1114                         [JOB_DONE]       = "Set up automount %s.",
1115                         [JOB_FAILED]     = "Failed to set up automount %s.",
1116                 },
1117                 .finished_stop_job = {
1118                         [JOB_DONE]       = "Unset automount %s.",
1119                         [JOB_FAILED]     = "Failed to unset automount %s.",
1120                 },
1121         },
1122
1123         .can_start = automount_can_start,
1124 };