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         if (a->result != AUTOMOUNT_SUCCESS)
 329                 log_unit_warning(UNIT(a), "Failed with result '%s'.", automount_result_to_string(a->result));
 330
 331         automount_set_state(a, a->result != AUTOMOUNT_SUCCESS ? AUTOMOUNT_FAILED : AUTOMOUNT_DEAD);
 332 }
 333
 334 static int open_dev_autofs(Manager *m) {
 335         struct autofs_dev_ioctl param;
 336
 337         assert(m);
 338
 339         if (m->dev_autofs_fd >= 0)
 340                 return m->dev_autofs_fd;
 341
 342         label_fix("/dev/autofs", false, false);
 343
 344         m->dev_autofs_fd = open("/dev/autofs", O_CLOEXEC|O_RDONLY);
 345         if (m->dev_autofs_fd < 0)
 346                 return log_error_errno(errno, "Failed to open /dev/autofs: %m");
 347
 348         init_autofs_dev_ioctl(&param);
 349         if (ioctl(m->dev_autofs_fd, AUTOFS_DEV_IOCTL_VERSION, &param) < 0) {
 350                 m->dev_autofs_fd = safe_close(m->dev_autofs_fd);
 351                 return -errno;
 352         }
 353
 354         log_debug("Autofs kernel version %i.%i", param.ver_major, param.ver_minor);
 355
 356         return m->dev_autofs_fd;
 357 }
 358
 359 static int open_ioctl_fd(int dev_autofs_fd, const char *where, dev_t devid) {
 360         struct autofs_dev_ioctl *param;
 361         size_t l;
 362
 363         assert(dev_autofs_fd >= 0);
 364         assert(where);
 365
 366         l = sizeof(struct autofs_dev_ioctl) + strlen(where) + 1;
 367         param = alloca(l);
 368
 369         init_autofs_dev_ioctl(param);
 370         param->size = l;
 371         param->ioctlfd = -1;
 372         param->openmount.devid = devid;
 373         strcpy(param->path, where);
 374
 375         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_OPENMOUNT, param) < 0)
 376                 return -errno;
 377
 378         if (param->ioctlfd < 0)
 379                 return -EIO;
 380
 381         (void) fd_cloexec(param->ioctlfd, true);
 382         return param->ioctlfd;
 383 }
 384
 385 static int autofs_protocol(int dev_autofs_fd, int ioctl_fd) {
 386         uint32_t major, minor;
 387         struct autofs_dev_ioctl param;
 388
 389         assert(dev_autofs_fd >= 0);
 390         assert(ioctl_fd >= 0);
 391
 392         init_autofs_dev_ioctl(&param);
 393         param.ioctlfd = ioctl_fd;
 394
 395         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_PROTOVER, &param) < 0)
 396                 return -errno;
 397
 398         major = param.protover.version;
 399
 400         init_autofs_dev_ioctl(&param);
 401         param.ioctlfd = ioctl_fd;
 402
 403         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_PROTOSUBVER, &param) < 0)
 404                 return -errno;
 405
 406         minor = param.protosubver.sub_version;
 407
 408         log_debug("Autofs protocol version %i.%i", major, minor);
 409         return 0;
 410 }
 411
 412 static int autofs_set_timeout(int dev_autofs_fd, int ioctl_fd, usec_t usec) {
 413         struct autofs_dev_ioctl param;
 414
 415         assert(dev_autofs_fd >= 0);
 416         assert(ioctl_fd >= 0);
 417
 418         init_autofs_dev_ioctl(&param);
 419         param.ioctlfd = ioctl_fd;
 420
 421         if (usec == USEC_INFINITY)
 422                 param.timeout.timeout = 0;
 423         else
 424                 /* Convert to seconds, rounding up. */
 425                 param.timeout.timeout = (usec + USEC_PER_SEC - 1) / USEC_PER_SEC;
 426
 427         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_TIMEOUT, &param) < 0)
 428                 return -errno;
 429
 430         return 0;
 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         if (ioctl(dev_autofs_fd, status ? AUTOFS_DEV_IOCTL_FAIL : AUTOFS_DEV_IOCTL_READY, &param) < 0)
 449                 return -errno;
 450
 451         return 0;
 452 }
 453
 454 static int automount_send_ready(Automount *a, Set *tokens, int status) {
 455         _cleanup_close_ int ioctl_fd = -1;
 456         unsigned token;
 457         int r;
 458
 459         assert(a);
 460         assert(status <= 0);
 461
 462         if (set_isempty(tokens))
 463                 return 0;
 464
 465         ioctl_fd = open_ioctl_fd(UNIT(a)->manager->dev_autofs_fd, a->where, a->dev_id);
 466         if (ioctl_fd < 0)
 467                 return ioctl_fd;
 468
 469         if (status != 0)
 470                 log_unit_debug_errno(UNIT(a), status, "Sending failure: %m");
 471         else
 472                 log_unit_debug(UNIT(a), "Sending success.");
 473
 474         r = 0;
 475
 476         /* Autofs thankfully does not hand out 0 as a token */
 477         while ((token = PTR_TO_UINT(set_steal_first(tokens)))) {
 478                 int k;
 479
 480                 /* Autofs fun fact:
 481                  *
 482                  * if you pass a positive status code here, kernels
 483                  * prior to 4.12 will freeze! Yay! */
 484
 485                 k = autofs_send_ready(UNIT(a)->manager->dev_autofs_fd,
 486                                       ioctl_fd,
 487                                       token,
 488                                       status);
 489                 if (k < 0)
 490                         r = k;
 491         }
 492
 493         return r;
 494 }
 495
 496 static void automount_trigger_notify(Unit *u, Unit *other) {
 497         Automount *a = AUTOMOUNT(u);
 498         int r;
 499
 500         assert(a);
 501         assert(other);
 502
 503         /* Filter out invocations with bogus state */
 504         if (other->load_state != UNIT_LOADED || other->type != UNIT_MOUNT)
 505                 return;
 506
 507         /* Don't propagate state changes from the mount if we are already down */
 508         if (!IN_SET(a->state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING))
 509                 return;
 510
 511         /* Propagate start limit hit state */
 512         if (other->start_limit_hit) {
 513                 automount_enter_dead(a, AUTOMOUNT_FAILURE_MOUNT_START_LIMIT_HIT);
 514                 return;
 515         }
 516
 517         /* Don't propagate anything if there's still a job queued */
 518         if (other->job)
 519                 return;
 520
 521         /* The mount is successfully established */
 522         if (IN_SET(MOUNT(other)->state, MOUNT_MOUNTED, MOUNT_REMOUNTING)) {
 523                 (void) automount_send_ready(a, a->tokens, 0);
 524
 525                 r = automount_start_expire(a);
 526                 if (r < 0)
 527                         log_unit_warning_errno(UNIT(a), r, "Failed to start expiration timer, ignoring: %m");
 528
 529                 automount_set_state(a, AUTOMOUNT_RUNNING);
 530         }
 531
 532         if (IN_SET(MOUNT(other)->state,
 533                    MOUNT_MOUNTING, MOUNT_MOUNTING_DONE,
 534                    MOUNT_MOUNTED, MOUNT_REMOUNTING,
 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->expire_tokens, -ENODEV);
 540         }
 541
 542         if (MOUNT(other)->state == MOUNT_DEAD)
 543                 (void) automount_send_ready(a, a->expire_tokens, 0);
 544
 545         /* The mount is in some unhappy state now, let's unfreeze any waiting clients */
 546         if (IN_SET(MOUNT(other)->state,
 547                    MOUNT_DEAD, MOUNT_UNMOUNTING,
 548                    MOUNT_REMOUNTING_SIGTERM, MOUNT_REMOUNTING_SIGKILL,
 549                    MOUNT_UNMOUNTING_SIGTERM, MOUNT_UNMOUNTING_SIGKILL,
 550                    MOUNT_FAILED)) {
 551
 552                 (void) automount_send_ready(a, a->tokens, -ENODEV);
 553
 554                 automount_set_state(a, AUTOMOUNT_WAITING);
 555         }
 556 }
 557
 558 static void automount_enter_waiting(Automount *a) {
 559         _cleanup_close_ int ioctl_fd = -1;
 560         int p[2] = { -1, -1 };
 561         char name[sizeof("systemd-")-1 + DECIMAL_STR_MAX(pid_t) + 1];
 562         char options[sizeof("fd=,pgrp=,minproto=5,maxproto=5,direct")-1
 563                      + DECIMAL_STR_MAX(int) + DECIMAL_STR_MAX(gid_t) + 1];
 564         bool mounted = false;
 565         int r, dev_autofs_fd;
 566         struct stat st;
 567
 568         assert(a);
 569         assert(a->pipe_fd < 0);
 570         assert(a->where);
 571
 572         set_clear(a->tokens);
 573
 574         r = unit_fail_if_symlink(UNIT(a), a->where);
 575         if (r < 0)
 576                 goto fail;
 577
 578         (void) mkdir_p_label(a->where, 0555);
 579
 580         unit_warn_if_dir_nonempty(UNIT(a), a->where);
 581
 582         dev_autofs_fd = open_dev_autofs(UNIT(a)->manager);
 583         if (dev_autofs_fd < 0) {
 584                 r = dev_autofs_fd;
 585                 goto fail;
 586         }
 587
 588         if (pipe2(p, O_NONBLOCK|O_CLOEXEC) < 0) {
 589                 r = -errno;
 590                 goto fail;
 591         }
 592
 593         xsprintf(options, "fd=%i,pgrp="PID_FMT",minproto=5,maxproto=5,direct", p[1], getpgrp());
 594         xsprintf(name, "systemd-"PID_FMT, getpid_cached());
 595         if (mount(name, a->where, "autofs", 0, options) < 0) {
 596                 r = -errno;
 597                 goto fail;
 598         }
 599
 600         mounted = true;
 601
 602         p[1] = safe_close(p[1]);
 603
 604         if (stat(a->where, &st) < 0) {
 605                 r = -errno;
 606                 goto fail;
 607         }
 608
 609         ioctl_fd = open_ioctl_fd(dev_autofs_fd, a->where, st.st_dev);
 610         if (ioctl_fd < 0) {
 611                 r = ioctl_fd;
 612                 goto fail;
 613         }
 614
 615         r = autofs_protocol(dev_autofs_fd, ioctl_fd);
 616         if (r < 0)
 617                 goto fail;
 618
 619         r = autofs_set_timeout(dev_autofs_fd, ioctl_fd, a->timeout_idle_usec);
 620         if (r < 0)
 621                 goto fail;
 622
 623         r = sd_event_add_io(UNIT(a)->manager->event, &a->pipe_event_source, p[0], EPOLLIN, automount_dispatch_io, a);
 624         if (r < 0)
 625                 goto fail;
 626
 627         (void) sd_event_source_set_description(a->pipe_event_source, "automount-io");
 628
 629         a->pipe_fd = p[0];
 630         a->dev_id = st.st_dev;
 631
 632         automount_set_state(a, AUTOMOUNT_WAITING);
 633
 634         return;
 635
 636 fail:
 637         log_unit_error_errno(UNIT(a), r, "Failed to initialize automounter: %m");
 638
 639         safe_close_pair(p);
 640
 641         if (mounted) {
 642                 r = repeat_unmount(a->where, MNT_DETACH);
 643                 if (r < 0)
 644                         log_error_errno(r, "Failed to unmount, ignoring: %m");
 645         }
 646
 647         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
 648 }
 649
 650 static void *expire_thread(void *p) {
 651         struct autofs_dev_ioctl param;
 652         _cleanup_(expire_data_freep) struct expire_data *data = (struct expire_data*)p;
 653         int r;
 654
 655         assert(data->dev_autofs_fd >= 0);
 656         assert(data->ioctl_fd >= 0);
 657
 658         init_autofs_dev_ioctl(&param);
 659         param.ioctlfd = data->ioctl_fd;
 660
 661         do {
 662                 r = ioctl(data->dev_autofs_fd, AUTOFS_DEV_IOCTL_EXPIRE, &param);
 663         } while (r >= 0);
 664
 665         if (errno != EAGAIN)
 666                 log_warning_errno(errno, "Failed to expire automount, ignoring: %m");
 667
 668         return NULL;
 669 }
 670
 671 static int automount_dispatch_expire(sd_event_source *source, usec_t usec, void *userdata) {
 672         Automount *a = AUTOMOUNT(userdata);
 673         _cleanup_(expire_data_freep) struct expire_data *data = NULL;
 674         int r;
 675
 676         assert(a);
 677         assert(source == a->expire_event_source);
 678
 679         data = new0(struct expire_data, 1);
 680         if (!data)
 681                 return log_oom();
 682
 683         data->ioctl_fd = -1;
 684
 685         data->dev_autofs_fd = fcntl(UNIT(a)->manager->dev_autofs_fd, F_DUPFD_CLOEXEC, 3);
 686         if (data->dev_autofs_fd < 0)
 687                 return log_unit_error_errno(UNIT(a), errno, "Failed to duplicate autofs fd: %m");
 688
 689         data->ioctl_fd = open_ioctl_fd(UNIT(a)->manager->dev_autofs_fd, a->where, a->dev_id);
 690         if (data->ioctl_fd < 0)
 691                 return log_unit_error_errno(UNIT(a), data->ioctl_fd, "Couldn't open autofs ioctl fd: %m");
 692
 693         r = asynchronous_job(expire_thread, data);
 694         if (r < 0)
 695                 return log_unit_error_errno(UNIT(a), r, "Failed to start expire job: %m");
 696
 697         data = NULL;
 698
 699         return automount_start_expire(a);
 700 }
 701
 702 static int automount_start_expire(Automount *a) {
 703         int r;
 704         usec_t timeout;
 705
 706         assert(a);
 707
 708         if (a->timeout_idle_usec == 0)
 709                 return 0;
 710
 711         timeout = now(CLOCK_MONOTONIC) + MAX(a->timeout_idle_usec/3, USEC_PER_SEC);
 712
 713         if (a->expire_event_source) {
 714                 r = sd_event_source_set_time(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(
 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         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, &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 = AUTOMOUNT(u);
 803         Unit *trigger;
 804         int r;
 805
 806         assert(a);
 807         assert(a->state == AUTOMOUNT_DEAD || a->state == AUTOMOUNT_FAILED);
 808
 809         if (path_is_mount_point(a->where, NULL, 0) > 0) {
 810                 log_unit_error(u, "Path %s is already a mount point, refusing start.", a->where);
 811                 return -EEXIST;
 812         }
 813
 814         trigger = UNIT_TRIGGER(u);
 815         if (!trigger || trigger->load_state != UNIT_LOADED) {
 816                 log_unit_error(u, "Refusing to start, unit to trigger not loaded.");
 817                 return -ENOENT;
 818         }
 819
 820         r = unit_start_limit_test(u);
 821         if (r < 0) {
 822                 automount_enter_dead(a, AUTOMOUNT_FAILURE_START_LIMIT_HIT);
 823                 return r;
 824         }
 825
 826         r = unit_acquire_invocation_id(u);
 827         if (r < 0)
 828                 return r;
 829
 830         a->result = AUTOMOUNT_SUCCESS;
 831         automount_enter_waiting(a);
 832         return 1;
 833 }
 834
 835 static int automount_stop(Unit *u) {
 836         Automount *a = AUTOMOUNT(u);
 837
 838         assert(a);
 839         assert(a->state == AUTOMOUNT_WAITING || a->state == AUTOMOUNT_RUNNING);
 840
 841         automount_enter_dead(a, AUTOMOUNT_SUCCESS);
 842         return 1;
 843 }
 844
 845 static int automount_serialize(Unit *u, FILE *f, FDSet *fds) {
 846         Automount *a = AUTOMOUNT(u);
 847         Iterator i;
 848         void *p;
 849         int r;
 850
 851         assert(a);
 852         assert(f);
 853         assert(fds);
 854
 855         unit_serialize_item(u, f, "state", automount_state_to_string(a->state));
 856         unit_serialize_item(u, f, "result", automount_result_to_string(a->result));
 857         unit_serialize_item_format(u, f, "dev-id", "%u", (unsigned) a->dev_id);
 858
 859         SET_FOREACH(p, a->tokens, i)
 860                 unit_serialize_item_format(u, f, "token", "%u", PTR_TO_UINT(p));
 861         SET_FOREACH(p, a->expire_tokens, i)
 862                 unit_serialize_item_format(u, f, "expire-token", "%u", PTR_TO_UINT(p));
 863
 864         r = unit_serialize_item_fd(u, f, fds, "pipe-fd", a->pipe_fd);
 865         if (r < 0)
 866                 return r;
 867
 868         return 0;
 869 }
 870
 871 static int automount_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 872         Automount *a = AUTOMOUNT(u);
 873         int r;
 874
 875         assert(a);
 876         assert(fds);
 877
 878         if (streq(key, "state")) {
 879                 AutomountState state;
 880
 881                 state = automount_state_from_string(value);
 882                 if (state < 0)
 883                         log_unit_debug(u, "Failed to parse state value: %s", value);
 884                 else
 885                         a->deserialized_state = state;
 886         } else if (streq(key, "result")) {
 887                 AutomountResult f;
 888
 889                 f = automount_result_from_string(value);
 890                 if (f < 0)
 891                         log_unit_debug(u, "Failed to parse result value: %s", value);
 892                 else if (f != AUTOMOUNT_SUCCESS)
 893                         a->result = f;
 894
 895         } else if (streq(key, "dev-id")) {
 896                 unsigned d;
 897
 898                 if (safe_atou(value, &d) < 0)
 899                         log_unit_debug(u, "Failed to parse dev-id value: %s", value);
 900                 else
 901                         a->dev_id = (unsigned) d;
 902         } else if (streq(key, "token")) {
 903                 unsigned token;
 904
 905                 if (safe_atou(value, &token) < 0)
 906                         log_unit_debug(u, "Failed to parse token value: %s", value);
 907                 else {
 908                         r = set_ensure_allocated(&a->tokens, NULL);
 909                         if (r < 0) {
 910                                 log_oom();
 911                                 return 0;
 912                         }
 913
 914                         r = set_put(a->tokens, UINT_TO_PTR(token));
 915                         if (r < 0)
 916                                 log_unit_error_errno(u, r, "Failed to add token to set: %m");
 917                 }
 918         } else if (streq(key, "expire-token")) {
 919                 unsigned token;
 920
 921                 if (safe_atou(value, &token) < 0)
 922                         log_unit_debug(u, "Failed to parse token value: %s", value);
 923                 else {
 924                         r = set_ensure_allocated(&a->expire_tokens, NULL);
 925                         if (r < 0) {
 926                                 log_oom();
 927                                 return 0;
 928                         }
 929
 930                         r = set_put(a->expire_tokens, UINT_TO_PTR(token));
 931                         if (r < 0)
 932                                 log_unit_error_errno(u, r, "Failed to add expire token to set: %m");
 933                 }
 934         } else if (streq(key, "pipe-fd")) {
 935                 int fd;
 936
 937                 if (safe_atoi(value, &fd) < 0 || fd < 0 || !fdset_contains(fds, fd))
 938                         log_unit_debug(u, "Failed to parse pipe-fd value: %s", value);
 939                 else {
 940                         safe_close(a->pipe_fd);
 941                         a->pipe_fd = fdset_remove(fds, fd);
 942                 }
 943         } else
 944                 log_unit_debug(u, "Unknown serialization key: %s", key);
 945
 946         return 0;
 947 }
 948
 949 static UnitActiveState automount_active_state(Unit *u) {
 950         assert(u);
 951
 952         return state_translation_table[AUTOMOUNT(u)->state];
 953 }
 954
 955 static const char *automount_sub_state_to_string(Unit *u) {
 956         assert(u);
 957
 958         return automount_state_to_string(AUTOMOUNT(u)->state);
 959 }
 960
 961 static bool automount_check_gc(Unit *u) {
 962         assert(u);
 963
 964         if (!UNIT_TRIGGER(u))
 965                 return false;
 966
 967         return UNIT_VTABLE(UNIT_TRIGGER(u))->check_gc(UNIT_TRIGGER(u));
 968 }
 969
 970 static int automount_dispatch_io(sd_event_source *s, int fd, uint32_t events, void *userdata) {
 971         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 972         union autofs_v5_packet_union packet;
 973         Automount *a = AUTOMOUNT(userdata);
 974         Unit *trigger;
 975         int r;
 976
 977         assert(a);
 978         assert(fd == a->pipe_fd);
 979
 980         if (events != EPOLLIN) {
 981                 log_unit_error(UNIT(a), "Got invalid poll event %"PRIu32" on pipe (fd=%d)", events, fd);
 982                 goto fail;
 983         }
 984
 985         r = loop_read_exact(a->pipe_fd, &packet, sizeof(packet), true);
 986         if (r < 0) {
 987                 log_unit_error_errno(UNIT(a), r, "Invalid read from pipe: %m");
 988                 goto fail;
 989         }
 990
 991         switch (packet.hdr.type) {
 992
 993         case autofs_ptype_missing_direct:
 994
 995                 if (packet.v5_packet.pid > 0) {
 996                         _cleanup_free_ char *p = NULL;
 997
 998                         get_process_comm(packet.v5_packet.pid, &p);
 999                         log_unit_info(UNIT(a), "Got automount request for %s, triggered by %"PRIu32" (%s)", a->where, packet.v5_packet.pid, strna(p));
1000                 } else
1001                         log_unit_debug(UNIT(a), "Got direct mount request on %s", a->where);
1002
1003                 r = set_ensure_allocated(&a->tokens, NULL);
1004                 if (r < 0) {
1005                         log_unit_error(UNIT(a), "Failed to allocate token set.");
1006                         goto fail;
1007                 }
1008
1009                 r = set_put(a->tokens, UINT_TO_PTR(packet.v5_packet.wait_queue_token));
1010                 if (r < 0) {
1011                         log_unit_error_errno(UNIT(a), r, "Failed to remember token: %m");
1012                         goto fail;
1013                 }
1014
1015                 automount_enter_running(a);
1016                 break;
1017
1018         case autofs_ptype_expire_direct:
1019                 log_unit_debug(UNIT(a), "Got direct umount request on %s", a->where);
1020
1021                 automount_stop_expire(a);
1022
1023                 r = set_ensure_allocated(&a->expire_tokens, NULL);
1024                 if (r < 0) {
1025                         log_unit_error(UNIT(a), "Failed to allocate token set.");
1026                         goto fail;
1027                 }
1028
1029                 r = set_put(a->expire_tokens, UINT_TO_PTR(packet.v5_packet.wait_queue_token));
1030                 if (r < 0) {
1031                         log_unit_error_errno(UNIT(a), r, "Failed to remember token: %m");
1032                         goto fail;
1033                 }
1034
1035                 trigger = UNIT_TRIGGER(UNIT(a));
1036                 if (!trigger) {
1037                         log_unit_error(UNIT(a), "Unit to trigger vanished.");
1038                         goto fail;
1039                 }
1040
1041                 r = manager_add_job(UNIT(a)->manager, JOB_STOP, trigger, JOB_REPLACE, &error, NULL);
1042                 if (r < 0) {
1043                         log_unit_warning(UNIT(a), "Failed to queue umount startup job: %s", bus_error_message(&error, r));
1044                         goto fail;
1045                 }
1046                 break;
1047
1048         default:
1049                 log_unit_error(UNIT(a), "Received unknown automount request %i", packet.hdr.type);
1050                 break;
1051         }
1052
1053         return 0;
1054
1055 fail:
1056         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
1057         return 0;
1058 }
1059
1060 static void automount_shutdown(Manager *m) {
1061         assert(m);
1062
1063         m->dev_autofs_fd = safe_close(m->dev_autofs_fd);
1064 }
1065
1066 static void automount_reset_failed(Unit *u) {
1067         Automount *a = AUTOMOUNT(u);
1068
1069         assert(a);
1070
1071         if (a->state == AUTOMOUNT_FAILED)
1072                 automount_set_state(a, AUTOMOUNT_DEAD);
1073
1074         a->result = AUTOMOUNT_SUCCESS;
1075 }
1076
1077 static bool automount_supported(void) {
1078         static int supported = -1;
1079
1080         if (supported < 0)
1081                 supported = access("/dev/autofs", F_OK) >= 0;
1082
1083         return supported;
1084 }
1085
1086 static const char* const automount_result_table[_AUTOMOUNT_RESULT_MAX] = {
1087         [AUTOMOUNT_SUCCESS] = "success",
1088         [AUTOMOUNT_FAILURE_RESOURCES] = "resources",
1089         [AUTOMOUNT_FAILURE_START_LIMIT_HIT] = "start-limit-hit",
1090         [AUTOMOUNT_FAILURE_MOUNT_START_LIMIT_HIT] = "mount-start-limit-hit",
1091 };
1092
1093 DEFINE_STRING_TABLE_LOOKUP(automount_result, AutomountResult);
1094
1095 const UnitVTable automount_vtable = {
1096         .object_size = sizeof(Automount),
1097
1098         .sections =
1099                 "Unit\0"
1100                 "Automount\0"
1101                 "Install\0",
1102
1103         .init = automount_init,
1104         .load = automount_load,
1105         .done = automount_done,
1106
1107         .coldplug = automount_coldplug,
1108
1109         .dump = automount_dump,
1110
1111         .start = automount_start,
1112         .stop = automount_stop,
1113
1114         .serialize = automount_serialize,
1115         .deserialize_item = automount_deserialize_item,
1116
1117         .active_state = automount_active_state,
1118         .sub_state_to_string = automount_sub_state_to_string,
1119
1120         .check_gc = automount_check_gc,
1121
1122         .trigger_notify = automount_trigger_notify,
1123
1124         .reset_failed = automount_reset_failed,
1125
1126         .bus_vtable = bus_automount_vtable,
1127         .bus_set_property = bus_automount_set_property,
1128
1129         .can_transient = true,
1130
1131         .shutdown = automount_shutdown,
1132         .supported = automount_supported,
1133
1134         .status_message_formats = {
1135                 .finished_start_job = {
1136                         [JOB_DONE]       = "Set up automount %s.",
1137                         [JOB_FAILED]     = "Failed to set up automount %s.",
1138                 },
1139                 .finished_stop_job = {
1140                         [JOB_DONE]       = "Unset automount %s.",
1141                         [JOB_FAILED]     = "Failed to unset automount %s.",
1142                 },
1143         },
1144 };