src/core/automount.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include <errno.h>
   4 #include <fcntl.h>
   5 #include <limits.h>
   6 #include <linux/auto_dev-ioctl.h>
   7 #include <linux/auto_fs4.h>
   8 #include <sys/epoll.h>
   9 #include <sys/mount.h>
  10 #include <sys/stat.h>
  11 #include <unistd.h>
  12
  13 #include "alloc-util.h"
  14 #include "async.h"
  15 #include "automount.h"
  16 #include "bus-error.h"
  17 #include "bus-util.h"
  18 #include "dbus-automount.h"
  19 #include "fd-util.h"
  20 #include "format-util.h"
  21 #include "io-util.h"
  22 #include "label.h"
  23 #include "mkdir.h"
  24 #include "mount-util.h"
  25 #include "mount.h"
  26 #include "parse-util.h"
  27 #include "path-util.h"
  28 #include "process-util.h"
  29 #include "serialize.h"
  30 #include "special.h"
  31 #include "stdio-util.h"
  32 #include "string-table.h"
  33 #include "string-util.h"
  34 #include "unit-name.h"
  35 #include "unit.h"
  36
  37 static const UnitActiveState state_translation_table[_AUTOMOUNT_STATE_MAX] = {
  38         [AUTOMOUNT_DEAD] = UNIT_INACTIVE,
  39         [AUTOMOUNT_WAITING] = UNIT_ACTIVE,
  40         [AUTOMOUNT_RUNNING] = UNIT_ACTIVE,
  41         [AUTOMOUNT_FAILED] = UNIT_FAILED
  42 };
  43
  44 struct expire_data {
  45         int dev_autofs_fd;
  46         int ioctl_fd;
  47 };
  48
  49 static inline void expire_data_free(struct expire_data *data) {
  50         if (!data)
  51                 return;
  52
  53         safe_close(data->dev_autofs_fd);
  54         safe_close(data->ioctl_fd);
  55         free(data);
  56 }
  57
  58 DEFINE_TRIVIAL_CLEANUP_FUNC(struct expire_data*, expire_data_free);
  59
  60 static int open_dev_autofs(Manager *m);
  61 static int automount_dispatch_io(sd_event_source *s, int fd, uint32_t events, void *userdata);
  62 static int automount_start_expire(Automount *a);
  63 static void automount_stop_expire(Automount *a);
  64 static int automount_send_ready(Automount *a, Set *tokens, int status);
  65
  66 static void automount_init(Unit *u) {
  67         Automount *a = AUTOMOUNT(u);
  68
  69         assert(u);
  70         assert(u->load_state == UNIT_STUB);
  71
  72         a->pipe_fd = -1;
  73         a->directory_mode = 0755;
  74         UNIT(a)->ignore_on_isolate = true;
  75 }
  76
  77 static void unmount_autofs(Automount *a) {
  78         int r;
  79
  80         assert(a);
  81
  82         if (a->pipe_fd < 0)
  83                 return;
  84
  85         a->pipe_event_source = sd_event_source_unref(a->pipe_event_source);
  86         a->pipe_fd = safe_close(a->pipe_fd);
  87
  88         /* If we reload/reexecute things we keep the mount point around */
  89         if (!IN_SET(UNIT(a)->manager->objective, MANAGER_RELOAD, MANAGER_REEXECUTE)) {
  90
  91                 automount_send_ready(a, a->tokens, -EHOSTDOWN);
  92                 automount_send_ready(a, a->expire_tokens, -EHOSTDOWN);
  93
  94                 if (a->where) {
  95                         r = repeat_unmount(a->where, MNT_DETACH);
  96                         if (r < 0)
  97                                 log_error_errno(r, "Failed to unmount: %m");
  98                 }
  99         }
 100 }
 101
 102 static void automount_done(Unit *u) {
 103         Automount *a = AUTOMOUNT(u);
 104
 105         assert(a);
 106
 107         unmount_autofs(a);
 108
 109         a->where = mfree(a->where);
 110
 111         a->tokens = set_free(a->tokens);
 112         a->expire_tokens = set_free(a->expire_tokens);
 113
 114         a->expire_event_source = sd_event_source_unref(a->expire_event_source);
 115 }
 116
 117 static int automount_add_trigger_dependencies(Automount *a) {
 118         Unit *x;
 119         int r;
 120
 121         assert(a);
 122
 123         r = unit_load_related_unit(UNIT(a), ".mount", &x);
 124         if (r < 0)
 125                 return r;
 126
 127         return unit_add_two_dependencies(UNIT(a), UNIT_BEFORE, UNIT_TRIGGERS, x, true, UNIT_DEPENDENCY_IMPLICIT);
 128 }
 129
 130 static int automount_add_mount_dependencies(Automount *a) {
 131         _cleanup_free_ char *parent = NULL;
 132
 133         assert(a);
 134
 135         parent = dirname_malloc(a->where);
 136         if (!parent)
 137                 return -ENOMEM;
 138
 139         return unit_require_mounts_for(UNIT(a), parent, UNIT_DEPENDENCY_IMPLICIT);
 140 }
 141
 142 static int automount_add_default_dependencies(Automount *a) {
 143         int r;
 144
 145         assert(a);
 146
 147         if (!UNIT(a)->default_dependencies)
 148                 return 0;
 149
 150         if (!MANAGER_IS_SYSTEM(UNIT(a)->manager))
 151                 return 0;
 152
 153         r = unit_add_two_dependencies_by_name(UNIT(a), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_UMOUNT_TARGET, true, UNIT_DEPENDENCY_DEFAULT);
 154         if (r < 0)
 155                 return r;
 156
 157         return 0;
 158 }
 159
 160 static int automount_verify(Automount *a) {
 161         _cleanup_free_ char *e = NULL;
 162         int r;
 163
 164         assert(a);
 165
 166         if (UNIT(a)->load_state != UNIT_LOADED)
 167                 return 0;
 168
 169         if (path_equal(a->where, "/")) {
 170                 log_unit_error(UNIT(a), "Cannot have an automount unit for the root directory. Refusing.");
 171                 return -ENOEXEC;
 172         }
 173
 174         r = unit_name_from_path(a->where, ".automount", &e);
 175         if (r < 0)
 176                 return log_unit_error_errno(UNIT(a), r, "Failed to generate unit name from path: %m");
 177
 178         if (!unit_has_name(UNIT(a), e)) {
 179                 log_unit_error(UNIT(a), "Where= setting doesn't match unit name. Refusing.");
 180                 return -ENOEXEC;
 181         }
 182
 183         return 0;
 184 }
 185
 186 static int automount_set_where(Automount *a) {
 187         int r;
 188
 189         assert(a);
 190
 191         if (a->where)
 192                 return 0;
 193
 194         r = unit_name_to_path(UNIT(a)->id, &a->where);
 195         if (r < 0)
 196                 return r;
 197
 198         path_simplify(a->where, false);
 199         return 1;
 200 }
 201
 202 static int automount_load(Unit *u) {
 203         Automount *a = AUTOMOUNT(u);
 204         int r;
 205
 206         assert(u);
 207         assert(u->load_state == UNIT_STUB);
 208
 209         /* Load a .automount file */
 210         r = unit_load_fragment_and_dropin(u);
 211         if (r < 0)
 212                 return r;
 213
 214         if (u->load_state == UNIT_LOADED) {
 215                 r = automount_set_where(a);
 216                 if (r < 0)
 217                         return r;
 218
 219                 r = automount_add_trigger_dependencies(a);
 220                 if (r < 0)
 221                         return r;
 222
 223                 r = automount_add_mount_dependencies(a);
 224                 if (r < 0)
 225                         return r;
 226
 227                 r = automount_add_default_dependencies(a);
 228                 if (r < 0)
 229                         return r;
 230         }
 231
 232         return automount_verify(a);
 233 }
 234
 235 static void automount_set_state(Automount *a, AutomountState state) {
 236         AutomountState old_state;
 237         assert(a);
 238
 239         old_state = a->state;
 240         a->state = state;
 241
 242         if (state != AUTOMOUNT_RUNNING)
 243                 automount_stop_expire(a);
 244
 245         if (!IN_SET(state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING))
 246                 unmount_autofs(a);
 247
 248         if (state != old_state)
 249                 log_unit_debug(UNIT(a), "Changed %s -> %s", automount_state_to_string(old_state), automount_state_to_string(state));
 250
 251         unit_notify(UNIT(a), state_translation_table[old_state], state_translation_table[state], 0);
 252 }
 253
 254 static int automount_coldplug(Unit *u) {
 255         Automount *a = AUTOMOUNT(u);
 256         int r;
 257
 258         assert(a);
 259         assert(a->state == AUTOMOUNT_DEAD);
 260
 261         if (a->deserialized_state == a->state)
 262                 return 0;
 263
 264         if (IN_SET(a->deserialized_state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING)) {
 265
 266                 r = automount_set_where(a);
 267                 if (r < 0)
 268                         return r;
 269
 270                 r = open_dev_autofs(u->manager);
 271                 if (r < 0)
 272                         return r;
 273
 274                 assert(a->pipe_fd >= 0);
 275
 276                 r = sd_event_add_io(u->manager->event, &a->pipe_event_source, a->pipe_fd, EPOLLIN, automount_dispatch_io, u);
 277                 if (r < 0)
 278                         return r;
 279
 280                 (void) sd_event_source_set_description(a->pipe_event_source, "automount-io");
 281                 if (a->deserialized_state == AUTOMOUNT_RUNNING) {
 282                         r = automount_start_expire(a);
 283                         if (r < 0)
 284                                 log_unit_warning_errno(UNIT(a), r, "Failed to start expiration timer, ignoring: %m");
 285                 }
 286
 287                 automount_set_state(a, a->deserialized_state);
 288         }
 289
 290         return 0;
 291 }
 292
 293 static void automount_dump(Unit *u, FILE *f, const char *prefix) {
 294         char time_string[FORMAT_TIMESPAN_MAX];
 295         Automount *a = AUTOMOUNT(u);
 296
 297         assert(a);
 298
 299         fprintf(f,
 300                 "%sAutomount State: %s\n"
 301                 "%sResult: %s\n"
 302                 "%sWhere: %s\n"
 303                 "%sDirectoryMode: %04o\n"
 304                 "%sTimeoutIdleUSec: %s\n",
 305                 prefix, automount_state_to_string(a->state),
 306                 prefix, automount_result_to_string(a->result),
 307                 prefix, a->where,
 308                 prefix, a->directory_mode,
 309                 prefix, format_timespan(time_string, FORMAT_TIMESPAN_MAX, a->timeout_idle_usec, USEC_PER_SEC));
 310 }
 311
 312 static void automount_enter_dead(Automount *a, AutomountResult f) {
 313         assert(a);
 314
 315         if (a->result == AUTOMOUNT_SUCCESS)
 316                 a->result = f;
 317
 318         if (a->result != AUTOMOUNT_SUCCESS)
 319                 log_unit_warning(UNIT(a), "Failed with result '%s'.", automount_result_to_string(a->result));
 320
 321         automount_set_state(a, a->result != AUTOMOUNT_SUCCESS ? AUTOMOUNT_FAILED : AUTOMOUNT_DEAD);
 322 }
 323
 324 static int open_dev_autofs(Manager *m) {
 325         struct autofs_dev_ioctl param;
 326
 327         assert(m);
 328
 329         if (m->dev_autofs_fd >= 0)
 330                 return m->dev_autofs_fd;
 331
 332         (void) label_fix("/dev/autofs", 0);
 333
 334         m->dev_autofs_fd = open("/dev/autofs", O_CLOEXEC|O_RDONLY);
 335         if (m->dev_autofs_fd < 0)
 336                 return log_error_errno(errno, "Failed to open /dev/autofs: %m");
 337
 338         init_autofs_dev_ioctl(&param);
 339         if (ioctl(m->dev_autofs_fd, AUTOFS_DEV_IOCTL_VERSION, &param) < 0) {
 340                 m->dev_autofs_fd = safe_close(m->dev_autofs_fd);
 341                 return -errno;
 342         }
 343
 344         log_debug("Autofs kernel version %i.%i", param.ver_major, param.ver_minor);
 345
 346         return m->dev_autofs_fd;
 347 }
 348
 349 static int open_ioctl_fd(int dev_autofs_fd, const char *where, dev_t devid) {
 350         struct autofs_dev_ioctl *param;
 351         size_t l;
 352
 353         assert(dev_autofs_fd >= 0);
 354         assert(where);
 355
 356         l = sizeof(struct autofs_dev_ioctl) + strlen(where) + 1;
 357         param = alloca(l);
 358
 359         init_autofs_dev_ioctl(param);
 360         param->size = l;
 361         param->ioctlfd = -1;
 362         param->openmount.devid = devid;
 363         strcpy(param->path, where);
 364
 365         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_OPENMOUNT, param) < 0)
 366                 return -errno;
 367
 368         if (param->ioctlfd < 0)
 369                 return -EIO;
 370
 371         (void) fd_cloexec(param->ioctlfd, true);
 372         return param->ioctlfd;
 373 }
 374
 375 static int autofs_protocol(int dev_autofs_fd, int ioctl_fd) {
 376         uint32_t major, minor;
 377         struct autofs_dev_ioctl param;
 378
 379         assert(dev_autofs_fd >= 0);
 380         assert(ioctl_fd >= 0);
 381
 382         init_autofs_dev_ioctl(&param);
 383         param.ioctlfd = ioctl_fd;
 384
 385         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_PROTOVER, &param) < 0)
 386                 return -errno;
 387
 388         major = param.protover.version;
 389
 390         init_autofs_dev_ioctl(&param);
 391         param.ioctlfd = ioctl_fd;
 392
 393         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_PROTOSUBVER, &param) < 0)
 394                 return -errno;
 395
 396         minor = param.protosubver.sub_version;
 397
 398         log_debug("Autofs protocol version %i.%i", major, minor);
 399         return 0;
 400 }
 401
 402 static int autofs_set_timeout(int dev_autofs_fd, int ioctl_fd, usec_t usec) {
 403         struct autofs_dev_ioctl param;
 404
 405         assert(dev_autofs_fd >= 0);
 406         assert(ioctl_fd >= 0);
 407
 408         init_autofs_dev_ioctl(&param);
 409         param.ioctlfd = ioctl_fd;
 410
 411         if (usec == USEC_INFINITY)
 412                 param.timeout.timeout = 0;
 413         else
 414                 /* Convert to seconds, rounding up. */
 415                 param.timeout.timeout = DIV_ROUND_UP(usec, USEC_PER_SEC);
 416
 417         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_TIMEOUT, &param) < 0)
 418                 return -errno;
 419
 420         return 0;
 421 }
 422
 423 static int autofs_send_ready(int dev_autofs_fd, int ioctl_fd, uint32_t token, int status) {
 424         struct autofs_dev_ioctl param;
 425
 426         assert(dev_autofs_fd >= 0);
 427         assert(ioctl_fd >= 0);
 428
 429         init_autofs_dev_ioctl(&param);
 430         param.ioctlfd = ioctl_fd;
 431
 432         if (status != 0) {
 433                 param.fail.token = token;
 434                 param.fail.status = status;
 435         } else
 436                 param.ready.token = token;
 437
 438         if (ioctl(dev_autofs_fd, status ? AUTOFS_DEV_IOCTL_FAIL : AUTOFS_DEV_IOCTL_READY, &param) < 0)
 439                 return -errno;
 440
 441         return 0;
 442 }
 443
 444 static int automount_send_ready(Automount *a, Set *tokens, int status) {
 445         _cleanup_close_ int ioctl_fd = -1;
 446         unsigned token;
 447         int r;
 448
 449         assert(a);
 450         assert(status <= 0);
 451
 452         if (set_isempty(tokens))
 453                 return 0;
 454
 455         ioctl_fd = open_ioctl_fd(UNIT(a)->manager->dev_autofs_fd, a->where, a->dev_id);
 456         if (ioctl_fd < 0)
 457                 return ioctl_fd;
 458
 459         if (status != 0)
 460                 log_unit_debug_errno(UNIT(a), status, "Sending failure: %m");
 461         else
 462                 log_unit_debug(UNIT(a), "Sending success.");
 463
 464         r = 0;
 465
 466         /* Autofs thankfully does not hand out 0 as a token */
 467         while ((token = PTR_TO_UINT(set_steal_first(tokens)))) {
 468                 int k;
 469
 470                 /* Autofs fun fact:
 471                  *
 472                  * if you pass a positive status code here, kernels
 473                  * prior to 4.12 will freeze! Yay! */
 474
 475                 k = autofs_send_ready(UNIT(a)->manager->dev_autofs_fd,
 476                                       ioctl_fd,
 477                                       token,
 478                                       status);
 479                 if (k < 0)
 480                         r = k;
 481         }
 482
 483         return r;
 484 }
 485
 486 static void automount_trigger_notify(Unit *u, Unit *other) {
 487         Automount *a = AUTOMOUNT(u);
 488         int r;
 489
 490         assert(a);
 491         assert(other);
 492
 493         /* Filter out invocations with bogus state */
 494         if (other->load_state != UNIT_LOADED || other->type != UNIT_MOUNT)
 495                 return;
 496
 497         /* Don't propagate state changes from the mount if we are already down */
 498         if (!IN_SET(a->state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING))
 499                 return;
 500
 501         /* Propagate start limit hit state */
 502         if (other->start_limit_hit) {
 503                 automount_enter_dead(a, AUTOMOUNT_FAILURE_MOUNT_START_LIMIT_HIT);
 504                 return;
 505         }
 506
 507         /* Don't propagate anything if there's still a job queued */
 508         if (other->job)
 509                 return;
 510
 511         /* The mount is successfully established */
 512         if (IN_SET(MOUNT(other)->state, MOUNT_MOUNTED, MOUNT_REMOUNTING)) {
 513                 (void) automount_send_ready(a, a->tokens, 0);
 514
 515                 r = automount_start_expire(a);
 516                 if (r < 0)
 517                         log_unit_warning_errno(UNIT(a), r, "Failed to start expiration timer, ignoring: %m");
 518
 519                 automount_set_state(a, AUTOMOUNT_RUNNING);
 520         }
 521
 522         if (IN_SET(MOUNT(other)->state,
 523                    MOUNT_MOUNTING, MOUNT_MOUNTING_DONE,
 524                    MOUNT_MOUNTED, MOUNT_REMOUNTING,
 525                    MOUNT_REMOUNTING_SIGTERM, MOUNT_REMOUNTING_SIGKILL,
 526                    MOUNT_UNMOUNTING_SIGTERM, MOUNT_UNMOUNTING_SIGKILL,
 527                    MOUNT_FAILED)) {
 528
 529                 (void) automount_send_ready(a, a->expire_tokens, -ENODEV);
 530         }
 531
 532         if (MOUNT(other)->state == MOUNT_DEAD)
 533                 (void) automount_send_ready(a, a->expire_tokens, 0);
 534
 535         /* The mount is in some unhappy state now, let's unfreeze any waiting clients */
 536         if (IN_SET(MOUNT(other)->state,
 537                    MOUNT_DEAD, MOUNT_UNMOUNTING,
 538                    MOUNT_REMOUNTING_SIGTERM, MOUNT_REMOUNTING_SIGKILL,
 539                    MOUNT_UNMOUNTING_SIGTERM, MOUNT_UNMOUNTING_SIGKILL,
 540                    MOUNT_FAILED)) {
 541
 542                 (void) automount_send_ready(a, a->tokens, -ENODEV);
 543
 544                 automount_set_state(a, AUTOMOUNT_WAITING);
 545         }
 546 }
 547
 548 static void automount_enter_waiting(Automount *a) {
 549         _cleanup_close_ int ioctl_fd = -1;
 550         int p[2] = { -1, -1 };
 551         char name[STRLEN("systemd-") + DECIMAL_STR_MAX(pid_t) + 1];
 552         char options[STRLEN("fd=,pgrp=,minproto=5,maxproto=5,direct")
 553                      + DECIMAL_STR_MAX(int) + DECIMAL_STR_MAX(gid_t) + 1];
 554         bool mounted = false;
 555         int r, dev_autofs_fd;
 556         struct stat st;
 557
 558         assert(a);
 559         assert(a->pipe_fd < 0);
 560         assert(a->where);
 561
 562         set_clear(a->tokens);
 563
 564         r = unit_fail_if_noncanonical(UNIT(a), a->where);
 565         if (r < 0)
 566                 goto fail;
 567
 568         (void) mkdir_p_label(a->where, 0555);
 569
 570         unit_warn_if_dir_nonempty(UNIT(a), a->where);
 571
 572         dev_autofs_fd = open_dev_autofs(UNIT(a)->manager);
 573         if (dev_autofs_fd < 0) {
 574                 r = dev_autofs_fd;
 575                 goto fail;
 576         }
 577
 578         if (pipe2(p, O_NONBLOCK|O_CLOEXEC) < 0) {
 579                 r = -errno;
 580                 goto fail;
 581         }
 582
 583         xsprintf(options, "fd=%i,pgrp="PID_FMT",minproto=5,maxproto=5,direct", p[1], getpgrp());
 584         xsprintf(name, "systemd-"PID_FMT, getpid_cached());
 585         if (mount(name, a->where, "autofs", 0, options) < 0) {
 586                 r = -errno;
 587                 goto fail;
 588         }
 589
 590         mounted = true;
 591
 592         p[1] = safe_close(p[1]);
 593
 594         if (stat(a->where, &st) < 0) {
 595                 r = -errno;
 596                 goto fail;
 597         }
 598
 599         ioctl_fd = open_ioctl_fd(dev_autofs_fd, a->where, st.st_dev);
 600         if (ioctl_fd < 0) {
 601                 r = ioctl_fd;
 602                 goto fail;
 603         }
 604
 605         r = autofs_protocol(dev_autofs_fd, ioctl_fd);
 606         if (r < 0)
 607                 goto fail;
 608
 609         r = autofs_set_timeout(dev_autofs_fd, ioctl_fd, a->timeout_idle_usec);
 610         if (r < 0)
 611                 goto fail;
 612
 613         r = sd_event_add_io(UNIT(a)->manager->event, &a->pipe_event_source, p[0], EPOLLIN, automount_dispatch_io, a);
 614         if (r < 0)
 615                 goto fail;
 616
 617         (void) sd_event_source_set_description(a->pipe_event_source, "automount-io");
 618
 619         a->pipe_fd = p[0];
 620         a->dev_id = st.st_dev;
 621
 622         automount_set_state(a, AUTOMOUNT_WAITING);
 623
 624         return;
 625
 626 fail:
 627         log_unit_error_errno(UNIT(a), r, "Failed to initialize automounter: %m");
 628
 629         safe_close_pair(p);
 630
 631         if (mounted) {
 632                 r = repeat_unmount(a->where, MNT_DETACH);
 633                 if (r < 0)
 634                         log_error_errno(r, "Failed to unmount, ignoring: %m");
 635         }
 636
 637         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
 638 }
 639
 640 static void *expire_thread(void *p) {
 641         struct autofs_dev_ioctl param;
 642         _cleanup_(expire_data_freep) struct expire_data *data = (struct expire_data*)p;
 643         int r;
 644
 645         assert(data->dev_autofs_fd >= 0);
 646         assert(data->ioctl_fd >= 0);
 647
 648         init_autofs_dev_ioctl(&param);
 649         param.ioctlfd = data->ioctl_fd;
 650
 651         do {
 652                 r = ioctl(data->dev_autofs_fd, AUTOFS_DEV_IOCTL_EXPIRE, &param);
 653         } while (r >= 0);
 654
 655         if (errno != EAGAIN)
 656                 log_warning_errno(errno, "Failed to expire automount, ignoring: %m");
 657
 658         return NULL;
 659 }
 660
 661 static int automount_dispatch_expire(sd_event_source *source, usec_t usec, void *userdata) {
 662         Automount *a = AUTOMOUNT(userdata);
 663         _cleanup_(expire_data_freep) struct expire_data *data = NULL;
 664         int r;
 665
 666         assert(a);
 667         assert(source == a->expire_event_source);
 668
 669         data = new0(struct expire_data, 1);
 670         if (!data)
 671                 return log_oom();
 672
 673         data->ioctl_fd = -1;
 674
 675         data->dev_autofs_fd = fcntl(UNIT(a)->manager->dev_autofs_fd, F_DUPFD_CLOEXEC, 3);
 676         if (data->dev_autofs_fd < 0)
 677                 return log_unit_error_errno(UNIT(a), errno, "Failed to duplicate autofs fd: %m");
 678
 679         data->ioctl_fd = open_ioctl_fd(UNIT(a)->manager->dev_autofs_fd, a->where, a->dev_id);
 680         if (data->ioctl_fd < 0)
 681                 return log_unit_error_errno(UNIT(a), data->ioctl_fd, "Couldn't open autofs ioctl fd: %m");
 682
 683         r = asynchronous_job(expire_thread, data);
 684         if (r < 0)
 685                 return log_unit_error_errno(UNIT(a), r, "Failed to start expire job: %m");
 686
 687         data = NULL;
 688
 689         return automount_start_expire(a);
 690 }
 691
 692 static int automount_start_expire(Automount *a) {
 693         int r;
 694         usec_t timeout;
 695
 696         assert(a);
 697
 698         if (a->timeout_idle_usec == 0)
 699                 return 0;
 700
 701         timeout = now(CLOCK_MONOTONIC) + MAX(a->timeout_idle_usec/3, USEC_PER_SEC);
 702
 703         if (a->expire_event_source) {
 704                 r = sd_event_source_set_time(a->expire_event_source, timeout);
 705                 if (r < 0)
 706                         return r;
 707
 708                 return sd_event_source_set_enabled(a->expire_event_source, SD_EVENT_ONESHOT);
 709         }
 710
 711         r = sd_event_add_time(
 712                         UNIT(a)->manager->event,
 713                         &a->expire_event_source,
 714                         CLOCK_MONOTONIC, timeout, 0,
 715                         automount_dispatch_expire, a);
 716         if (r < 0)
 717                 return r;
 718
 719         (void) sd_event_source_set_description(a->expire_event_source, "automount-expire");
 720
 721         return 0;
 722 }
 723
 724 static void automount_stop_expire(Automount *a) {
 725         assert(a);
 726
 727         if (!a->expire_event_source)
 728                 return;
 729
 730         (void) sd_event_source_set_enabled(a->expire_event_source, SD_EVENT_OFF);
 731 }
 732
 733 static void automount_enter_running(Automount *a) {
 734         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 735         Unit *trigger;
 736         struct stat st;
 737         int r;
 738
 739         assert(a);
 740
 741         /* If the user masked our unit in the meantime, fail */
 742         if (UNIT(a)->load_state != UNIT_LOADED) {
 743                 log_unit_error(UNIT(a), "Suppressing automount event since unit is no longer loaded.");
 744                 goto fail;
 745         }
 746
 747         /* We don't take mount requests anymore if we are supposed to
 748          * shut down anyway */
 749         if (unit_stop_pending(UNIT(a))) {
 750                 log_unit_debug(UNIT(a), "Suppressing automount request since unit stop is scheduled.");
 751                 automount_send_ready(a, a->tokens, -EHOSTDOWN);
 752                 automount_send_ready(a, a->expire_tokens, -EHOSTDOWN);
 753                 return;
 754         }
 755
 756         mkdir_p_label(a->where, a->directory_mode);
 757
 758         /* Before we do anything, let's see if somebody is playing games with us? */
 759         if (lstat(a->where, &st) < 0) {
 760                 log_unit_warning_errno(UNIT(a), errno, "Failed to stat automount point: %m");
 761                 goto fail;
 762         }
 763
 764         /* The mount unit may have been explicitly started before we got the
 765          * autofs request. Ack it to unblock anything waiting on the mount point. */
 766         if (!S_ISDIR(st.st_mode) || st.st_dev != a->dev_id) {
 767                 log_unit_info(UNIT(a), "Automount point already active?");
 768                 automount_send_ready(a, a->tokens, 0);
 769                 return;
 770         }
 771
 772         trigger = UNIT_TRIGGER(UNIT(a));
 773         if (!trigger) {
 774                 log_unit_error(UNIT(a), "Unit to trigger vanished.");
 775                 goto fail;
 776         }
 777
 778         r = manager_add_job(UNIT(a)->manager, JOB_START, trigger, JOB_REPLACE, &error, NULL);
 779         if (r < 0) {
 780                 log_unit_warning(UNIT(a), "Failed to queue mount startup job: %s", bus_error_message(&error, r));
 781                 goto fail;
 782         }
 783
 784         automount_set_state(a, AUTOMOUNT_RUNNING);
 785         return;
 786
 787 fail:
 788         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
 789 }
 790
 791 static int automount_start(Unit *u) {
 792         Automount *a = AUTOMOUNT(u);
 793         Unit *trigger;
 794         int r;
 795
 796         assert(a);
 797         assert(IN_SET(a->state, AUTOMOUNT_DEAD, AUTOMOUNT_FAILED));
 798
 799         if (path_is_mount_point(a->where, NULL, 0) > 0) {
 800                 log_unit_error(u, "Path %s is already a mount point, refusing start.", a->where);
 801                 return -EEXIST;
 802         }
 803
 804         trigger = UNIT_TRIGGER(u);
 805         if (!trigger || trigger->load_state != UNIT_LOADED) {
 806                 log_unit_error(u, "Refusing to start, unit to trigger not loaded.");
 807                 return -ENOENT;
 808         }
 809
 810         r = unit_start_limit_test(u);
 811         if (r < 0) {
 812                 automount_enter_dead(a, AUTOMOUNT_FAILURE_START_LIMIT_HIT);
 813                 return r;
 814         }
 815
 816         r = unit_acquire_invocation_id(u);
 817         if (r < 0)
 818                 return r;
 819
 820         a->result = AUTOMOUNT_SUCCESS;
 821         automount_enter_waiting(a);
 822         return 1;
 823 }
 824
 825 static int automount_stop(Unit *u) {
 826         Automount *a = AUTOMOUNT(u);
 827
 828         assert(a);
 829         assert(IN_SET(a->state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING));
 830
 831         automount_enter_dead(a, AUTOMOUNT_SUCCESS);
 832         return 1;
 833 }
 834
 835 static int automount_serialize(Unit *u, FILE *f, FDSet *fds) {
 836         Automount *a = AUTOMOUNT(u);
 837         Iterator i;
 838         void *p;
 839         int r;
 840
 841         assert(a);
 842         assert(f);
 843         assert(fds);
 844
 845         (void) serialize_item(f, "state", automount_state_to_string(a->state));
 846         (void) serialize_item(f, "result", automount_result_to_string(a->result));
 847         (void) serialize_item_format(f, "dev-id", "%lu", (unsigned long) a->dev_id);
 848
 849         SET_FOREACH(p, a->tokens, i)
 850                 (void) serialize_item_format(f, "token", "%u", PTR_TO_UINT(p));
 851         SET_FOREACH(p, a->expire_tokens, i)
 852                 (void) serialize_item_format(f, "expire-token", "%u", PTR_TO_UINT(p));
 853
 854         r = serialize_fd(f, fds, "pipe-fd", a->pipe_fd);
 855         if (r < 0)
 856                 return r;
 857
 858         return 0;
 859 }
 860
 861 static int automount_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 862         Automount *a = AUTOMOUNT(u);
 863         int r;
 864
 865         assert(a);
 866         assert(fds);
 867
 868         if (streq(key, "state")) {
 869                 AutomountState state;
 870
 871                 state = automount_state_from_string(value);
 872                 if (state < 0)
 873                         log_unit_debug(u, "Failed to parse state value: %s", value);
 874                 else
 875                         a->deserialized_state = state;
 876         } else if (streq(key, "result")) {
 877                 AutomountResult f;
 878
 879                 f = automount_result_from_string(value);
 880                 if (f < 0)
 881                         log_unit_debug(u, "Failed to parse result value: %s", value);
 882                 else if (f != AUTOMOUNT_SUCCESS)
 883                         a->result = f;
 884
 885         } else if (streq(key, "dev-id")) {
 886                 unsigned long d;
 887
 888                 if (safe_atolu(value, &d) < 0)
 889                         log_unit_debug(u, "Failed to parse dev-id value: %s", value);
 890                 else
 891                         a->dev_id = (dev_t) d;
 892
 893         } else if (streq(key, "token")) {
 894                 unsigned token;
 895
 896                 if (safe_atou(value, &token) < 0)
 897                         log_unit_debug(u, "Failed to parse token value: %s", value);
 898                 else {
 899                         r = set_ensure_allocated(&a->tokens, NULL);
 900                         if (r < 0) {
 901                                 log_oom();
 902                                 return 0;
 903                         }
 904
 905                         r = set_put(a->tokens, UINT_TO_PTR(token));
 906                         if (r < 0)
 907                                 log_unit_error_errno(u, r, "Failed to add token to set: %m");
 908                 }
 909         } else if (streq(key, "expire-token")) {
 910                 unsigned token;
 911
 912                 if (safe_atou(value, &token) < 0)
 913                         log_unit_debug(u, "Failed to parse token value: %s", value);
 914                 else {
 915                         r = set_ensure_allocated(&a->expire_tokens, NULL);
 916                         if (r < 0) {
 917                                 log_oom();
 918                                 return 0;
 919                         }
 920
 921                         r = set_put(a->expire_tokens, 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_allocated(&a->tokens, NULL);
 998                 if (r < 0) {
 999                         log_unit_error(UNIT(a), "Failed to allocate token set.");
1000                         goto fail;
1001                 }
1002
1003                 r = set_put(a->tokens, UINT_TO_PTR(packet.v5_packet.wait_queue_token));
1004                 if (r < 0) {
1005                         log_unit_error_errno(UNIT(a), r, "Failed to remember token: %m");
1006                         goto fail;
1007                 }
1008
1009                 automount_enter_running(a);
1010                 break;
1011
1012         case autofs_ptype_expire_direct:
1013                 log_unit_debug(UNIT(a), "Got direct umount request on %s", a->where);
1014
1015                 automount_stop_expire(a);
1016
1017                 r = set_ensure_allocated(&a->expire_tokens, NULL);
1018                 if (r < 0) {
1019                         log_unit_error(UNIT(a), "Failed to allocate token set.");
1020                         goto fail;
1021                 }
1022
1023                 r = set_put(a->expire_tokens, UINT_TO_PTR(packet.v5_packet.wait_queue_token));
1024                 if (r < 0) {
1025                         log_unit_error_errno(UNIT(a), r, "Failed to remember token: %m");
1026                         goto fail;
1027                 }
1028
1029                 trigger = UNIT_TRIGGER(UNIT(a));
1030                 if (!trigger) {
1031                         log_unit_error(UNIT(a), "Unit to trigger vanished.");
1032                         goto fail;
1033                 }
1034
1035                 r = manager_add_job(UNIT(a)->manager, JOB_STOP, trigger, JOB_REPLACE, &error, NULL);
1036                 if (r < 0) {
1037                         log_unit_warning(UNIT(a), "Failed to queue umount startup job: %s", bus_error_message(&error, r));
1038                         goto fail;
1039                 }
1040                 break;
1041
1042         default:
1043                 log_unit_error(UNIT(a), "Received unknown automount request %i", packet.hdr.type);
1044                 break;
1045         }
1046
1047         return 0;
1048
1049 fail:
1050         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
1051         return 0;
1052 }
1053
1054 static void automount_shutdown(Manager *m) {
1055         assert(m);
1056
1057         m->dev_autofs_fd = safe_close(m->dev_autofs_fd);
1058 }
1059
1060 static void automount_reset_failed(Unit *u) {
1061         Automount *a = AUTOMOUNT(u);
1062
1063         assert(a);
1064
1065         if (a->state == AUTOMOUNT_FAILED)
1066                 automount_set_state(a, AUTOMOUNT_DEAD);
1067
1068         a->result = AUTOMOUNT_SUCCESS;
1069 }
1070
1071 static bool automount_supported(void) {
1072         static int supported = -1;
1073
1074         if (supported < 0)
1075                 supported = access("/dev/autofs", F_OK) >= 0;
1076
1077         return supported;
1078 }
1079
1080 static const char* const automount_result_table[_AUTOMOUNT_RESULT_MAX] = {
1081         [AUTOMOUNT_SUCCESS] = "success",
1082         [AUTOMOUNT_FAILURE_RESOURCES] = "resources",
1083         [AUTOMOUNT_FAILURE_START_LIMIT_HIT] = "start-limit-hit",
1084         [AUTOMOUNT_FAILURE_MOUNT_START_LIMIT_HIT] = "mount-start-limit-hit",
1085 };
1086
1087 DEFINE_STRING_TABLE_LOOKUP(automount_result, AutomountResult);
1088
1089 const UnitVTable automount_vtable = {
1090         .object_size = sizeof(Automount),
1091
1092         .sections =
1093                 "Unit\0"
1094                 "Automount\0"
1095                 "Install\0",
1096
1097         .init = automount_init,
1098         .load = automount_load,
1099         .done = automount_done,
1100
1101         .coldplug = automount_coldplug,
1102
1103         .dump = automount_dump,
1104
1105         .start = automount_start,
1106         .stop = automount_stop,
1107
1108         .serialize = automount_serialize,
1109         .deserialize_item = automount_deserialize_item,
1110
1111         .active_state = automount_active_state,
1112         .sub_state_to_string = automount_sub_state_to_string,
1113
1114         .may_gc = automount_may_gc,
1115
1116         .trigger_notify = automount_trigger_notify,
1117
1118         .reset_failed = automount_reset_failed,
1119
1120         .bus_vtable = bus_automount_vtable,
1121         .bus_set_property = bus_automount_set_property,
1122
1123         .can_transient = true,
1124
1125         .shutdown = automount_shutdown,
1126         .supported = automount_supported,
1127
1128         .status_message_formats = {
1129                 .finished_start_job = {
1130                         [JOB_DONE]       = "Set up automount %s.",
1131                         [JOB_FAILED]     = "Failed to set up automount %s.",
1132                 },
1133                 .finished_stop_job = {
1134                         [JOB_DONE]       = "Unset automount %s.",
1135                         [JOB_FAILED]     = "Failed to unset automount %s.",
1136                 },
1137         },
1138 };