src/core/automount.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2010 Lennart Poettering
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <errno.h>
  21 #include <fcntl.h>
  22 #include <limits.h>
  23 #include <linux/auto_dev-ioctl.h>
  24 #include <linux/auto_fs4.h>
  25 #include <sys/epoll.h>
  26 #include <sys/mount.h>
  27 #include <sys/stat.h>
  28 #include <unistd.h>
  29
  30 #include "alloc-util.h"
  31 #include "async.h"
  32 #include "automount.h"
  33 #include "bus-error.h"
  34 #include "bus-util.h"
  35 #include "dbus-automount.h"
  36 #include "fd-util.h"
  37 #include "format-util.h"
  38 #include "io-util.h"
  39 #include "label.h"
  40 #include "mkdir.h"
  41 #include "mount-util.h"
  42 #include "mount.h"
  43 #include "parse-util.h"
  44 #include "path-util.h"
  45 #include "process-util.h"
  46 #include "special.h"
  47 #include "stdio-util.h"
  48 #include "string-table.h"
  49 #include "string-util.h"
  50 #include "unit-name.h"
  51 #include "unit.h"
  52
  53 static const UnitActiveState state_translation_table[_AUTOMOUNT_STATE_MAX] = {
  54         [AUTOMOUNT_DEAD] = UNIT_INACTIVE,
  55         [AUTOMOUNT_WAITING] = UNIT_ACTIVE,
  56         [AUTOMOUNT_RUNNING] = UNIT_ACTIVE,
  57         [AUTOMOUNT_FAILED] = UNIT_FAILED
  58 };
  59
  60 struct expire_data {
  61         int dev_autofs_fd;
  62         int ioctl_fd;
  63 };
  64
  65 static inline void expire_data_free(struct expire_data *data) {
  66         if (!data)
  67                 return;
  68
  69         safe_close(data->dev_autofs_fd);
  70         safe_close(data->ioctl_fd);
  71         free(data);
  72 }
  73
  74 DEFINE_TRIVIAL_CLEANUP_FUNC(struct expire_data*, expire_data_free);
  75
  76 static int open_dev_autofs(Manager *m);
  77 static int automount_dispatch_io(sd_event_source *s, int fd, uint32_t events, void *userdata);
  78 static int automount_start_expire(Automount *a);
  79 static void automount_stop_expire(Automount *a);
  80 static int automount_send_ready(Automount *a, Set *tokens, int status);
  81
  82 static void automount_init(Unit *u) {
  83         Automount *a = AUTOMOUNT(u);
  84
  85         assert(u);
  86         assert(u->load_state == UNIT_STUB);
  87
  88         a->pipe_fd = -1;
  89         a->directory_mode = 0755;
  90         UNIT(a)->ignore_on_isolate = true;
  91 }
  92
  93 static void unmount_autofs(Automount *a) {
  94         int r;
  95
  96         assert(a);
  97
  98         if (a->pipe_fd < 0)
  99                 return;
 100
 101         a->pipe_event_source = sd_event_source_unref(a->pipe_event_source);
 102         a->pipe_fd = safe_close(a->pipe_fd);
 103
 104         /* If we reload/reexecute things we keep the mount point around */
 105         if (!IN_SET(UNIT(a)->manager->exit_code, MANAGER_RELOAD, MANAGER_REEXECUTE)) {
 106
 107                 automount_send_ready(a, a->tokens, -EHOSTDOWN);
 108                 automount_send_ready(a, a->expire_tokens, -EHOSTDOWN);
 109
 110                 if (a->where) {
 111                         r = repeat_unmount(a->where, MNT_DETACH);
 112                         if (r < 0)
 113                                 log_error_errno(r, "Failed to unmount: %m");
 114                 }
 115         }
 116 }
 117
 118 static void automount_done(Unit *u) {
 119         Automount *a = AUTOMOUNT(u);
 120
 121         assert(a);
 122
 123         unmount_autofs(a);
 124
 125         a->where = mfree(a->where);
 126
 127         a->tokens = set_free(a->tokens);
 128         a->expire_tokens = set_free(a->expire_tokens);
 129
 130         a->expire_event_source = sd_event_source_unref(a->expire_event_source);
 131 }
 132
 133 static int automount_add_mount_links(Automount *a) {
 134         _cleanup_free_ char *parent = NULL;
 135
 136         assert(a);
 137
 138         parent = dirname_malloc(a->where);
 139         if (!parent)
 140                 return -ENOMEM;
 141
 142         return unit_require_mounts_for(UNIT(a), parent);
 143 }
 144
 145 static int automount_add_default_dependencies(Automount *a) {
 146         int r;
 147
 148         assert(a);
 149
 150         if (!UNIT(a)->default_dependencies)
 151                 return 0;
 152
 153         if (!MANAGER_IS_SYSTEM(UNIT(a)->manager))
 154                 return 0;
 155
 156         r = unit_add_two_dependencies_by_name(UNIT(a), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_UMOUNT_TARGET, NULL, true);
 157         if (r < 0)
 158                 return r;
 159
 160         return 0;
 161 }
 162
 163 static int automount_verify(Automount *a) {
 164         _cleanup_free_ char *e = NULL;
 165         int r;
 166
 167         assert(a);
 168
 169         if (UNIT(a)->load_state != UNIT_LOADED)
 170                 return 0;
 171
 172         if (path_equal(a->where, "/")) {
 173                 log_unit_error(UNIT(a), "Cannot have an automount unit for the root directory. Refusing.");
 174                 return -EINVAL;
 175         }
 176
 177         r = unit_name_from_path(a->where, ".automount", &e);
 178         if (r < 0)
 179                 return log_unit_error(UNIT(a), "Failed to generate unit name from path: %m");
 180
 181         if (!unit_has_name(UNIT(a), e)) {
 182                 log_unit_error(UNIT(a), "Where= setting doesn't match unit name. Refusing.");
 183                 return -EINVAL;
 184         }
 185
 186         return 0;
 187 }
 188
 189 static int automount_set_where(Automount *a) {
 190         int r;
 191
 192         assert(a);
 193
 194         if (a->where)
 195                 return 0;
 196
 197         r = unit_name_to_path(UNIT(a)->id, &a->where);
 198         if (r < 0)
 199                 return r;
 200
 201         path_kill_slashes(a->where);
 202         return 1;
 203 }
 204
 205 static int automount_load(Unit *u) {
 206         Automount *a = AUTOMOUNT(u);
 207         int r;
 208
 209         assert(u);
 210         assert(u->load_state == UNIT_STUB);
 211
 212         /* Load a .automount file */
 213         r = unit_load_fragment_and_dropin_optional(u);
 214         if (r < 0)
 215                 return r;
 216
 217         if (u->load_state == UNIT_LOADED) {
 218                 Unit *x;
 219
 220                 r = automount_set_where(a);
 221                 if (r < 0)
 222                         return r;
 223
 224                 r = unit_load_related_unit(u, ".mount", &x);
 225                 if (r < 0)
 226                         return r;
 227
 228                 r = unit_add_two_dependencies(u, UNIT_BEFORE, UNIT_TRIGGERS, x, true);
 229                 if (r < 0)
 230                         return r;
 231
 232                 r = automount_add_mount_links(a);
 233                 if (r < 0)
 234                         return r;
 235
 236                 r = automount_add_default_dependencies(a);
 237                 if (r < 0)
 238                         return r;
 239         }
 240
 241         return automount_verify(a);
 242 }
 243
 244 static void automount_set_state(Automount *a, AutomountState state) {
 245         AutomountState old_state;
 246         assert(a);
 247
 248         old_state = a->state;
 249         a->state = state;
 250
 251         if (state != AUTOMOUNT_RUNNING)
 252                 automount_stop_expire(a);
 253
 254         if (state != AUTOMOUNT_WAITING &&
 255             state != AUTOMOUNT_RUNNING)
 256                 unmount_autofs(a);
 257
 258         if (state != old_state)
 259                 log_unit_debug(UNIT(a), "Changed %s -> %s", automount_state_to_string(old_state), automount_state_to_string(state));
 260
 261         unit_notify(UNIT(a), state_translation_table[old_state], state_translation_table[state], true);
 262 }
 263
 264 static int automount_coldplug(Unit *u) {
 265         Automount *a = AUTOMOUNT(u);
 266         int r;
 267
 268         assert(a);
 269         assert(a->state == AUTOMOUNT_DEAD);
 270
 271         if (a->deserialized_state == a->state)
 272                 return 0;
 273
 274         if (IN_SET(a->deserialized_state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING)) {
 275
 276                 r = automount_set_where(a);
 277                 if (r < 0)
 278                         return r;
 279
 280                 r = open_dev_autofs(u->manager);
 281                 if (r < 0)
 282                         return r;
 283
 284                 assert(a->pipe_fd >= 0);
 285
 286                 r = sd_event_add_io(u->manager->event, &a->pipe_event_source, a->pipe_fd, EPOLLIN, automount_dispatch_io, u);
 287                 if (r < 0)
 288                         return r;
 289
 290                 (void) sd_event_source_set_description(a->pipe_event_source, "automount-io");
 291                 if (a->deserialized_state == AUTOMOUNT_RUNNING) {
 292                         r = automount_start_expire(a);
 293                         if (r < 0)
 294                                 log_unit_warning_errno(UNIT(a), r, "Failed to start expiration timer, ignoring: %m");
 295                 }
 296
 297                 automount_set_state(a, a->deserialized_state);
 298         }
 299
 300         return 0;
 301 }
 302
 303 static void automount_dump(Unit *u, FILE *f, const char *prefix) {
 304         char time_string[FORMAT_TIMESPAN_MAX];
 305         Automount *a = AUTOMOUNT(u);
 306
 307         assert(a);
 308
 309         fprintf(f,
 310                 "%sAutomount State: %s\n"
 311                 "%sResult: %s\n"
 312                 "%sWhere: %s\n"
 313                 "%sDirectoryMode: %04o\n"
 314                 "%sTimeoutIdleUSec: %s\n",
 315                 prefix, automount_state_to_string(a->state),
 316                 prefix, automount_result_to_string(a->result),
 317                 prefix, a->where,
 318                 prefix, a->directory_mode,
 319                 prefix, format_timespan(time_string, FORMAT_TIMESPAN_MAX, a->timeout_idle_usec, USEC_PER_SEC));
 320 }
 321
 322 static void automount_enter_dead(Automount *a, AutomountResult f) {
 323         assert(a);
 324
 325         if (a->result == AUTOMOUNT_SUCCESS)
 326                 a->result = f;
 327
 328         automount_set_state(a, a->result != AUTOMOUNT_SUCCESS ? AUTOMOUNT_FAILED : AUTOMOUNT_DEAD);
 329 }
 330
 331 static int open_dev_autofs(Manager *m) {
 332         struct autofs_dev_ioctl param;
 333
 334         assert(m);
 335
 336         if (m->dev_autofs_fd >= 0)
 337                 return m->dev_autofs_fd;
 338
 339         label_fix("/dev/autofs", false, false);
 340
 341         m->dev_autofs_fd = open("/dev/autofs", O_CLOEXEC|O_RDONLY);
 342         if (m->dev_autofs_fd < 0)
 343                 return log_error_errno(errno, "Failed to open /dev/autofs: %m");
 344
 345         init_autofs_dev_ioctl(&param);
 346         if (ioctl(m->dev_autofs_fd, AUTOFS_DEV_IOCTL_VERSION, &param) < 0) {
 347                 m->dev_autofs_fd = safe_close(m->dev_autofs_fd);
 348                 return -errno;
 349         }
 350
 351         log_debug("Autofs kernel version %i.%i", param.ver_major, param.ver_minor);
 352
 353         return m->dev_autofs_fd;
 354 }
 355
 356 static int open_ioctl_fd(int dev_autofs_fd, const char *where, dev_t devid) {
 357         struct autofs_dev_ioctl *param;
 358         size_t l;
 359
 360         assert(dev_autofs_fd >= 0);
 361         assert(where);
 362
 363         l = sizeof(struct autofs_dev_ioctl) + strlen(where) + 1;
 364         param = alloca(l);
 365
 366         init_autofs_dev_ioctl(param);
 367         param->size = l;
 368         param->ioctlfd = -1;
 369         param->openmount.devid = devid;
 370         strcpy(param->path, where);
 371
 372         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_OPENMOUNT, param) < 0)
 373                 return -errno;
 374
 375         if (param->ioctlfd < 0)
 376                 return -EIO;
 377
 378         (void) fd_cloexec(param->ioctlfd, true);
 379         return param->ioctlfd;
 380 }
 381
 382 static int autofs_protocol(int dev_autofs_fd, int ioctl_fd) {
 383         uint32_t major, minor;
 384         struct autofs_dev_ioctl param;
 385
 386         assert(dev_autofs_fd >= 0);
 387         assert(ioctl_fd >= 0);
 388
 389         init_autofs_dev_ioctl(&param);
 390         param.ioctlfd = ioctl_fd;
 391
 392         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_PROTOVER, &param) < 0)
 393                 return -errno;
 394
 395         major = param.protover.version;
 396
 397         init_autofs_dev_ioctl(&param);
 398         param.ioctlfd = ioctl_fd;
 399
 400         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_PROTOSUBVER, &param) < 0)
 401                 return -errno;
 402
 403         minor = param.protosubver.sub_version;
 404
 405         log_debug("Autofs protocol version %i.%i", major, minor);
 406         return 0;
 407 }
 408
 409 static int autofs_set_timeout(int dev_autofs_fd, int ioctl_fd, usec_t usec) {
 410         struct autofs_dev_ioctl param;
 411
 412         assert(dev_autofs_fd >= 0);
 413         assert(ioctl_fd >= 0);
 414
 415         init_autofs_dev_ioctl(&param);
 416         param.ioctlfd = ioctl_fd;
 417
 418         if (usec == USEC_INFINITY)
 419                 param.timeout.timeout = 0;
 420         else
 421                 /* Convert to seconds, rounding up. */
 422                 param.timeout.timeout = (usec + USEC_PER_SEC - 1) / USEC_PER_SEC;
 423
 424         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_TIMEOUT, &param) < 0)
 425                 return -errno;
 426
 427         return 0;
 428 }
 429
 430 static int autofs_send_ready(int dev_autofs_fd, int ioctl_fd, uint32_t token, int status) {
 431         struct autofs_dev_ioctl param;
 432
 433         assert(dev_autofs_fd >= 0);
 434         assert(ioctl_fd >= 0);
 435
 436         init_autofs_dev_ioctl(&param);
 437         param.ioctlfd = ioctl_fd;
 438
 439         if (status != 0) {
 440                 param.fail.token = token;
 441                 param.fail.status = status;
 442         } else
 443                 param.ready.token = token;
 444
 445         if (ioctl(dev_autofs_fd, status ? AUTOFS_DEV_IOCTL_FAIL : AUTOFS_DEV_IOCTL_READY, &param) < 0)
 446                 return -errno;
 447
 448         return 0;
 449 }
 450
 451 static int automount_send_ready(Automount *a, Set *tokens, int status) {
 452         _cleanup_close_ int ioctl_fd = -1;
 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 = AUTOMOUNT(u);
 495         int r;
 496
 497         assert(a);
 498         assert(other);
 499
 500         /* Filter out invocations with bogus state */
 501         if (other->load_state != UNIT_LOADED || other->type != UNIT_MOUNT)
 502                 return;
 503
 504         /* Don't propagate state changes from the mount if we are already down */
 505         if (!IN_SET(a->state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING))
 506                 return;
 507
 508         /* Propagate start limit hit state */
 509         if (other->start_limit_hit) {
 510                 automount_enter_dead(a, AUTOMOUNT_FAILURE_MOUNT_START_LIMIT_HIT);
 511                 return;
 512         }
 513
 514         /* Don't propagate anything if there's still a job queued */
 515         if (other->job)
 516                 return;
 517
 518         /* The mount is successfully established */
 519         if (IN_SET(MOUNT(other)->state, MOUNT_MOUNTED, MOUNT_REMOUNTING)) {
 520                 (void) automount_send_ready(a, a->tokens, 0);
 521
 522                 r = automount_start_expire(a);
 523                 if (r < 0)
 524                         log_unit_warning_errno(UNIT(a), r, "Failed to start expiration timer, ignoring: %m");
 525
 526                 automount_set_state(a, AUTOMOUNT_RUNNING);
 527         }
 528
 529         if (IN_SET(MOUNT(other)->state,
 530                    MOUNT_MOUNTING, MOUNT_MOUNTING_DONE,
 531                    MOUNT_MOUNTED, MOUNT_REMOUNTING,
 532                    MOUNT_MOUNTING_SIGTERM, MOUNT_MOUNTING_SIGKILL,
 533                    MOUNT_REMOUNTING_SIGTERM, MOUNT_REMOUNTING_SIGKILL,
 534                    MOUNT_UNMOUNTING_SIGTERM, MOUNT_UNMOUNTING_SIGKILL,
 535                    MOUNT_FAILED)) {
 536
 537                 (void) automount_send_ready(a, a->expire_tokens, -ENODEV);
 538         }
 539
 540         if (MOUNT(other)->state == MOUNT_DEAD)
 541                 (void) automount_send_ready(a, a->expire_tokens, 0);
 542
 543         /* The mount is in some unhappy state now, let's unfreeze any waiting clients */
 544         if (IN_SET(MOUNT(other)->state,
 545                    MOUNT_DEAD, MOUNT_UNMOUNTING,
 546                    MOUNT_MOUNTING_SIGTERM, MOUNT_MOUNTING_SIGKILL,
 547                    MOUNT_REMOUNTING_SIGTERM, MOUNT_REMOUNTING_SIGKILL,
 548                    MOUNT_UNMOUNTING_SIGTERM, MOUNT_UNMOUNTING_SIGKILL,
 549                    MOUNT_FAILED)) {
 550
 551                 (void) automount_send_ready(a, a->tokens, -ENODEV);
 552
 553                 automount_set_state(a, AUTOMOUNT_WAITING);
 554         }
 555 }
 556
 557 static void automount_enter_waiting(Automount *a) {
 558         _cleanup_close_ int ioctl_fd = -1;
 559         int p[2] = { -1, -1 };
 560         char name[sizeof("systemd-")-1 + DECIMAL_STR_MAX(pid_t) + 1];
 561         char options[sizeof("fd=,pgrp=,minproto=5,maxproto=5,direct")-1
 562                      + DECIMAL_STR_MAX(int) + DECIMAL_STR_MAX(gid_t) + 1];
 563         bool mounted = false;
 564         int r, dev_autofs_fd;
 565         struct stat st;
 566
 567         assert(a);
 568         assert(a->pipe_fd < 0);
 569         assert(a->where);
 570
 571         set_clear(a->tokens);
 572
 573         r = unit_fail_if_symlink(UNIT(a), a->where);
 574         if (r < 0)
 575                 goto fail;
 576
 577         (void) mkdir_p_label(a->where, 0555);
 578
 579         unit_warn_if_dir_nonempty(UNIT(a), a->where);
 580
 581         dev_autofs_fd = open_dev_autofs(UNIT(a)->manager);
 582         if (dev_autofs_fd < 0) {
 583                 r = dev_autofs_fd;
 584                 goto fail;
 585         }
 586
 587         if (pipe2(p, O_NONBLOCK|O_CLOEXEC) < 0) {
 588                 r = -errno;
 589                 goto fail;
 590         }
 591
 592         xsprintf(options, "fd=%i,pgrp="PID_FMT",minproto=5,maxproto=5,direct", p[1], getpgrp());
 593         xsprintf(name, "systemd-"PID_FMT, getpid_cached());
 594         if (mount(name, a->where, "autofs", 0, options) < 0) {
 595                 r = -errno;
 596                 goto fail;
 597         }
 598
 599         mounted = true;
 600
 601         p[1] = safe_close(p[1]);
 602
 603         if (stat(a->where, &st) < 0) {
 604                 r = -errno;
 605                 goto fail;
 606         }
 607
 608         ioctl_fd = open_ioctl_fd(dev_autofs_fd, a->where, st.st_dev);
 609         if (ioctl_fd < 0) {
 610                 r = ioctl_fd;
 611                 goto fail;
 612         }
 613
 614         r = autofs_protocol(dev_autofs_fd, ioctl_fd);
 615         if (r < 0)
 616                 goto fail;
 617
 618         r = autofs_set_timeout(dev_autofs_fd, ioctl_fd, a->timeout_idle_usec);
 619         if (r < 0)
 620                 goto fail;
 621
 622         r = sd_event_add_io(UNIT(a)->manager->event, &a->pipe_event_source, p[0], EPOLLIN, automount_dispatch_io, a);
 623         if (r < 0)
 624                 goto fail;
 625
 626         (void) sd_event_source_set_description(a->pipe_event_source, "automount-io");
 627
 628         a->pipe_fd = p[0];
 629         a->dev_id = st.st_dev;
 630
 631         automount_set_state(a, AUTOMOUNT_WAITING);
 632
 633         return;
 634
 635 fail:
 636         log_unit_error_errno(UNIT(a), r, "Failed to initialize automounter: %m");
 637
 638         safe_close_pair(p);
 639
 640         if (mounted) {
 641                 r = repeat_unmount(a->where, MNT_DETACH);
 642                 if (r < 0)
 643                         log_error_errno(r, "Failed to unmount, ignoring: %m");
 644         }
 645
 646         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
 647 }
 648
 649 static void *expire_thread(void *p) {
 650         struct autofs_dev_ioctl param;
 651         _cleanup_(expire_data_freep) struct expire_data *data = (struct expire_data*)p;
 652         int r;
 653
 654         assert(data->dev_autofs_fd >= 0);
 655         assert(data->ioctl_fd >= 0);
 656
 657         init_autofs_dev_ioctl(&param);
 658         param.ioctlfd = data->ioctl_fd;
 659
 660         do {
 661                 r = ioctl(data->dev_autofs_fd, AUTOFS_DEV_IOCTL_EXPIRE, &param);
 662         } while (r >= 0);
 663
 664         if (errno != EAGAIN)
 665                 log_warning_errno(errno, "Failed to expire automount, ignoring: %m");
 666
 667         return NULL;
 668 }
 669
 670 static int automount_dispatch_expire(sd_event_source *source, usec_t usec, void *userdata) {
 671         Automount *a = AUTOMOUNT(userdata);
 672         _cleanup_(expire_data_freep) struct expire_data *data = NULL;
 673         int r;
 674
 675         assert(a);
 676         assert(source == a->expire_event_source);
 677
 678         data = new0(struct expire_data, 1);
 679         if (!data)
 680                 return log_oom();
 681
 682         data->ioctl_fd = -1;
 683
 684         data->dev_autofs_fd = fcntl(UNIT(a)->manager->dev_autofs_fd, F_DUPFD_CLOEXEC, 3);
 685         if (data->dev_autofs_fd < 0)
 686                 return log_unit_error_errno(UNIT(a), errno, "Failed to duplicate autofs fd: %m");
 687
 688         data->ioctl_fd = open_ioctl_fd(UNIT(a)->manager->dev_autofs_fd, a->where, a->dev_id);
 689         if (data->ioctl_fd < 0)
 690                 return log_unit_error_errno(UNIT(a), data->ioctl_fd, "Couldn't open autofs ioctl fd: %m");
 691
 692         r = asynchronous_job(expire_thread, data);
 693         if (r < 0)
 694                 return log_unit_error_errno(UNIT(a), r, "Failed to start expire job: %m");
 695
 696         data = NULL;
 697
 698         return automount_start_expire(a);
 699 }
 700
 701 static int automount_start_expire(Automount *a) {
 702         int r;
 703         usec_t timeout;
 704
 705         assert(a);
 706
 707         if (a->timeout_idle_usec == 0)
 708                 return 0;
 709
 710         timeout = now(CLOCK_MONOTONIC) + MAX(a->timeout_idle_usec/3, USEC_PER_SEC);
 711
 712         if (a->expire_event_source) {
 713                 r = sd_event_source_set_time(a->expire_event_source, timeout);
 714                 if (r < 0)
 715                         return r;
 716
 717                 return sd_event_source_set_enabled(a->expire_event_source, SD_EVENT_ONESHOT);
 718         }
 719
 720         r = sd_event_add_time(
 721                         UNIT(a)->manager->event,
 722                         &a->expire_event_source,
 723                         CLOCK_MONOTONIC, timeout, 0,
 724                         automount_dispatch_expire, a);
 725         if (r < 0)
 726                 return r;
 727
 728         (void) sd_event_source_set_description(a->expire_event_source, "automount-expire");
 729
 730         return 0;
 731 }
 732
 733 static void automount_stop_expire(Automount *a) {
 734         assert(a);
 735
 736         if (!a->expire_event_source)
 737                 return;
 738
 739         (void) sd_event_source_set_enabled(a->expire_event_source, SD_EVENT_OFF);
 740 }
 741
 742 static void automount_enter_running(Automount *a) {
 743         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 744         Unit *trigger;
 745         struct stat st;
 746         int r;
 747
 748         assert(a);
 749
 750         /* If the user masked our unit in the meantime, fail */
 751         if (UNIT(a)->load_state != UNIT_LOADED) {
 752                 log_unit_error(UNIT(a), "Suppressing automount event since unit is no longer loaded.");
 753                 goto fail;
 754         }
 755
 756         /* We don't take mount requests anymore if we are supposed to
 757          * shut down anyway */
 758         if (unit_stop_pending(UNIT(a))) {
 759                 log_unit_debug(UNIT(a), "Suppressing automount request since unit stop is scheduled.");
 760                 automount_send_ready(a, a->tokens, -EHOSTDOWN);
 761                 automount_send_ready(a, a->expire_tokens, -EHOSTDOWN);
 762                 return;
 763         }
 764
 765         mkdir_p_label(a->where, a->directory_mode);
 766
 767         /* Before we do anything, let's see if somebody is playing games with us? */
 768         if (lstat(a->where, &st) < 0) {
 769                 log_unit_warning_errno(UNIT(a), errno, "Failed to stat automount point: %m");
 770                 goto fail;
 771         }
 772
 773         /* The mount unit may have been explicitly started before we got the
 774          * autofs request. Ack it to unblock anything waiting on the mount point. */
 775         if (!S_ISDIR(st.st_mode) || st.st_dev != a->dev_id) {
 776                 log_unit_info(UNIT(a), "Automount point already active?");
 777                 automount_send_ready(a, a->tokens, 0);
 778                 return;
 779         }
 780
 781         trigger = UNIT_TRIGGER(UNIT(a));
 782         if (!trigger) {
 783                 log_unit_error(UNIT(a), "Unit to trigger vanished.");
 784                 goto fail;
 785         }
 786
 787         r = manager_add_job(UNIT(a)->manager, JOB_START, trigger, JOB_REPLACE, &error, NULL);
 788         if (r < 0) {
 789                 log_unit_warning(UNIT(a), "Failed to queue mount startup job: %s", bus_error_message(&error, r));
 790                 goto fail;
 791         }
 792
 793         automount_set_state(a, AUTOMOUNT_RUNNING);
 794         return;
 795
 796 fail:
 797         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
 798 }
 799
 800 static int automount_start(Unit *u) {
 801         Automount *a = AUTOMOUNT(u);
 802         Unit *trigger;
 803         int r;
 804
 805         assert(a);
 806         assert(a->state == AUTOMOUNT_DEAD || a->state == AUTOMOUNT_FAILED);
 807
 808         if (path_is_mount_point(a->where, NULL, 0) > 0) {
 809                 log_unit_error(u, "Path %s is already a mount point, refusing start.", a->where);
 810                 return -EEXIST;
 811         }
 812
 813         trigger = UNIT_TRIGGER(u);
 814         if (!trigger || trigger->load_state != UNIT_LOADED) {
 815                 log_unit_error(u, "Refusing to start, unit to trigger not loaded.");
 816                 return -ENOENT;
 817         }
 818
 819         r = unit_start_limit_test(u);
 820         if (r < 0) {
 821                 automount_enter_dead(a, AUTOMOUNT_FAILURE_START_LIMIT_HIT);
 822                 return r;
 823         }
 824
 825         r = unit_acquire_invocation_id(u);
 826         if (r < 0)
 827                 return r;
 828
 829         a->result = AUTOMOUNT_SUCCESS;
 830         automount_enter_waiting(a);
 831         return 1;
 832 }
 833
 834 static int automount_stop(Unit *u) {
 835         Automount *a = AUTOMOUNT(u);
 836
 837         assert(a);
 838         assert(a->state == AUTOMOUNT_WAITING || a->state == AUTOMOUNT_RUNNING);
 839
 840         automount_enter_dead(a, AUTOMOUNT_SUCCESS);
 841         return 1;
 842 }
 843
 844 static int automount_serialize(Unit *u, FILE *f, FDSet *fds) {
 845         Automount *a = AUTOMOUNT(u);
 846         Iterator i;
 847         void *p;
 848         int r;
 849
 850         assert(a);
 851         assert(f);
 852         assert(fds);
 853
 854         unit_serialize_item(u, f, "state", automount_state_to_string(a->state));
 855         unit_serialize_item(u, f, "result", automount_result_to_string(a->result));
 856         unit_serialize_item_format(u, f, "dev-id", "%u", (unsigned) a->dev_id);
 857
 858         SET_FOREACH(p, a->tokens, i)
 859                 unit_serialize_item_format(u, f, "token", "%u", PTR_TO_UINT(p));
 860         SET_FOREACH(p, a->expire_tokens, i)
 861                 unit_serialize_item_format(u, f, "expire-token", "%u", PTR_TO_UINT(p));
 862
 863         r = unit_serialize_item_fd(u, f, fds, "pipe-fd", a->pipe_fd);
 864         if (r < 0)
 865                 return r;
 866
 867         return 0;
 868 }
 869
 870 static int automount_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 871         Automount *a = AUTOMOUNT(u);
 872         int r;
 873
 874         assert(a);
 875         assert(fds);
 876
 877         if (streq(key, "state")) {
 878                 AutomountState state;
 879
 880                 state = automount_state_from_string(value);
 881                 if (state < 0)
 882                         log_unit_debug(u, "Failed to parse state value: %s", value);
 883                 else
 884                         a->deserialized_state = state;
 885         } else if (streq(key, "result")) {
 886                 AutomountResult f;
 887
 888                 f = automount_result_from_string(value);
 889                 if (f < 0)
 890                         log_unit_debug(u, "Failed to parse result value: %s", value);
 891                 else if (f != AUTOMOUNT_SUCCESS)
 892                         a->result = f;
 893
 894         } else if (streq(key, "dev-id")) {
 895                 unsigned d;
 896
 897                 if (safe_atou(value, &d) < 0)
 898                         log_unit_debug(u, "Failed to parse dev-id value: %s", value);
 899                 else
 900                         a->dev_id = (unsigned) d;
 901         } else if (streq(key, "token")) {
 902                 unsigned token;
 903
 904                 if (safe_atou(value, &token) < 0)
 905                         log_unit_debug(u, "Failed to parse token value: %s", value);
 906                 else {
 907                         r = set_ensure_allocated(&a->tokens, NULL);
 908                         if (r < 0) {
 909                                 log_oom();
 910                                 return 0;
 911                         }
 912
 913                         r = set_put(a->tokens, UINT_TO_PTR(token));
 914                         if (r < 0)
 915                                 log_unit_error_errno(u, r, "Failed to add token to set: %m");
 916                 }
 917         } else if (streq(key, "expire-token")) {
 918                 unsigned token;
 919
 920                 if (safe_atou(value, &token) < 0)
 921                         log_unit_debug(u, "Failed to parse token value: %s", value);
 922                 else {
 923                         r = set_ensure_allocated(&a->expire_tokens, NULL);
 924                         if (r < 0) {
 925                                 log_oom();
 926                                 return 0;
 927                         }
 928
 929                         r = set_put(a->expire_tokens, UINT_TO_PTR(token));
 930                         if (r < 0)
 931                                 log_unit_error_errno(u, r, "Failed to add expire token to set: %m");
 932                 }
 933         } else if (streq(key, "pipe-fd")) {
 934                 int fd;
 935
 936                 if (safe_atoi(value, &fd) < 0 || fd < 0 || !fdset_contains(fds, fd))
 937                         log_unit_debug(u, "Failed to parse pipe-fd value: %s", value);
 938                 else {
 939                         safe_close(a->pipe_fd);
 940                         a->pipe_fd = fdset_remove(fds, fd);
 941                 }
 942         } else
 943                 log_unit_debug(u, "Unknown serialization key: %s", key);
 944
 945         return 0;
 946 }
 947
 948 static UnitActiveState automount_active_state(Unit *u) {
 949         assert(u);
 950
 951         return state_translation_table[AUTOMOUNT(u)->state];
 952 }
 953
 954 static const char *automount_sub_state_to_string(Unit *u) {
 955         assert(u);
 956
 957         return automount_state_to_string(AUTOMOUNT(u)->state);
 958 }
 959
 960 static bool automount_check_gc(Unit *u) {
 961         assert(u);
 962
 963         if (!UNIT_TRIGGER(u))
 964                 return false;
 965
 966         return UNIT_VTABLE(UNIT_TRIGGER(u))->check_gc(UNIT_TRIGGER(u));
 967 }
 968
 969 static int automount_dispatch_io(sd_event_source *s, int fd, uint32_t events, void *userdata) {
 970         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 971         union autofs_v5_packet_union packet;
 972         Automount *a = AUTOMOUNT(userdata);
 973         Unit *trigger;
 974         int r;
 975
 976         assert(a);
 977         assert(fd == a->pipe_fd);
 978
 979         if (events != EPOLLIN) {
 980                 log_unit_error(UNIT(a), "Got invalid poll event %"PRIu32" on pipe (fd=%d)", events, fd);
 981                 goto fail;
 982         }
 983
 984         r = loop_read_exact(a->pipe_fd, &packet, sizeof(packet), true);
 985         if (r < 0) {
 986                 log_unit_error_errno(UNIT(a), r, "Invalid read from pipe: %m");
 987                 goto fail;
 988         }
 989
 990         switch (packet.hdr.type) {
 991
 992         case autofs_ptype_missing_direct:
 993
 994                 if (packet.v5_packet.pid > 0) {
 995                         _cleanup_free_ char *p = NULL;
 996
 997                         get_process_comm(packet.v5_packet.pid, &p);
 998                         log_unit_info(UNIT(a), "Got automount request for %s, triggered by %"PRIu32" (%s)", a->where, packet.v5_packet.pid, strna(p));
 999                 } else
1000                         log_unit_debug(UNIT(a), "Got direct mount request on %s", a->where);
1001
1002                 r = set_ensure_allocated(&a->tokens, NULL);
1003                 if (r < 0) {
1004                         log_unit_error(UNIT(a), "Failed to allocate token set.");
1005                         goto fail;
1006                 }
1007
1008                 r = set_put(a->tokens, UINT_TO_PTR(packet.v5_packet.wait_queue_token));
1009                 if (r < 0) {
1010                         log_unit_error_errno(UNIT(a), r, "Failed to remember token: %m");
1011                         goto fail;
1012                 }
1013
1014                 automount_enter_running(a);
1015                 break;
1016
1017         case autofs_ptype_expire_direct:
1018                 log_unit_debug(UNIT(a), "Got direct umount request on %s", a->where);
1019
1020                 automount_stop_expire(a);
1021
1022                 r = set_ensure_allocated(&a->expire_tokens, NULL);
1023                 if (r < 0) {
1024                         log_unit_error(UNIT(a), "Failed to allocate token set.");
1025                         goto fail;
1026                 }
1027
1028                 r = set_put(a->expire_tokens, UINT_TO_PTR(packet.v5_packet.wait_queue_token));
1029                 if (r < 0) {
1030                         log_unit_error_errno(UNIT(a), r, "Failed to remember token: %m");
1031                         goto fail;
1032                 }
1033
1034                 trigger = UNIT_TRIGGER(UNIT(a));
1035                 if (!trigger) {
1036                         log_unit_error(UNIT(a), "Unit to trigger vanished.");
1037                         goto fail;
1038                 }
1039
1040                 r = manager_add_job(UNIT(a)->manager, JOB_STOP, trigger, JOB_REPLACE, &error, NULL);
1041                 if (r < 0) {
1042                         log_unit_warning(UNIT(a), "Failed to queue umount startup job: %s", bus_error_message(&error, r));
1043                         goto fail;
1044                 }
1045                 break;
1046
1047         default:
1048                 log_unit_error(UNIT(a), "Received unknown automount request %i", packet.hdr.type);
1049                 break;
1050         }
1051
1052         return 0;
1053
1054 fail:
1055         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
1056         return 0;
1057 }
1058
1059 static void automount_shutdown(Manager *m) {
1060         assert(m);
1061
1062         m->dev_autofs_fd = safe_close(m->dev_autofs_fd);
1063 }
1064
1065 static void automount_reset_failed(Unit *u) {
1066         Automount *a = AUTOMOUNT(u);
1067
1068         assert(a);
1069
1070         if (a->state == AUTOMOUNT_FAILED)
1071                 automount_set_state(a, AUTOMOUNT_DEAD);
1072
1073         a->result = AUTOMOUNT_SUCCESS;
1074 }
1075
1076 static bool automount_supported(void) {
1077         static int supported = -1;
1078
1079         if (supported < 0)
1080                 supported = access("/dev/autofs", F_OK) >= 0;
1081
1082         return supported;
1083 }
1084
1085 static const char* const automount_result_table[_AUTOMOUNT_RESULT_MAX] = {
1086         [AUTOMOUNT_SUCCESS] = "success",
1087         [AUTOMOUNT_FAILURE_RESOURCES] = "resources",
1088         [AUTOMOUNT_FAILURE_START_LIMIT_HIT] = "start-limit-hit",
1089         [AUTOMOUNT_FAILURE_MOUNT_START_LIMIT_HIT] = "mount-start-limit-hit",
1090 };
1091
1092 DEFINE_STRING_TABLE_LOOKUP(automount_result, AutomountResult);
1093
1094 const UnitVTable automount_vtable = {
1095         .object_size = sizeof(Automount),
1096
1097         .sections =
1098                 "Unit\0"
1099                 "Automount\0"
1100                 "Install\0",
1101
1102         .init = automount_init,
1103         .load = automount_load,
1104         .done = automount_done,
1105
1106         .coldplug = automount_coldplug,
1107
1108         .dump = automount_dump,
1109
1110         .start = automount_start,
1111         .stop = automount_stop,
1112
1113         .serialize = automount_serialize,
1114         .deserialize_item = automount_deserialize_item,
1115
1116         .active_state = automount_active_state,
1117         .sub_state_to_string = automount_sub_state_to_string,
1118
1119         .check_gc = automount_check_gc,
1120
1121         .trigger_notify = automount_trigger_notify,
1122
1123         .reset_failed = automount_reset_failed,
1124
1125         .bus_vtable = bus_automount_vtable,
1126         .bus_set_property = bus_automount_set_property,
1127
1128         .can_transient = true,
1129
1130         .shutdown = automount_shutdown,
1131         .supported = automount_supported,
1132
1133         .status_message_formats = {
1134                 .finished_start_job = {
1135                         [JOB_DONE]       = "Set up automount %s.",
1136                         [JOB_FAILED]     = "Failed to set up automount %s.",
1137                 },
1138                 .finished_stop_job = {
1139                         [JOB_DONE]       = "Unset automount %s.",
1140                         [JOB_FAILED]     = "Failed to unset automount %s.",
1141                 },
1142         },
1143 };