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 "formats-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
 105          * around */
 106         if (a->where &&
 107             (UNIT(a)->manager->exit_code != MANAGER_RELOAD &&
 108              UNIT(a)->manager->exit_code != MANAGER_REEXECUTE)) {
 109                 automount_send_ready(a, a->tokens, -EHOSTDOWN);
 110                 automount_send_ready(a, a->expire_tokens, -EHOSTDOWN);
 111
 112                 r = repeat_unmount(a->where, MNT_DETACH);
 113                 if (r < 0)
 114                         log_error_errno(r, "Failed to unmount: %m");
 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_load(Unit *u) {
 190         Automount *a = AUTOMOUNT(u);
 191         int r;
 192
 193         assert(u);
 194         assert(u->load_state == UNIT_STUB);
 195
 196         /* Load a .automount file */
 197         r = unit_load_fragment_and_dropin_optional(u);
 198         if (r < 0)
 199                 return r;
 200
 201         if (u->load_state == UNIT_LOADED) {
 202                 Unit *x;
 203
 204                 if (!a->where) {
 205                         r = unit_name_to_path(u->id, &a->where);
 206                         if (r < 0)
 207                                 return r;
 208                 }
 209
 210                 path_kill_slashes(a->where);
 211
 212                 r = unit_load_related_unit(u, ".mount", &x);
 213                 if (r < 0)
 214                         return r;
 215
 216                 r = unit_add_two_dependencies(u, UNIT_BEFORE, UNIT_TRIGGERS, x, true);
 217                 if (r < 0)
 218                         return r;
 219
 220                 r = automount_add_mount_links(a);
 221                 if (r < 0)
 222                         return r;
 223
 224                 r = automount_add_default_dependencies(a);
 225                 if (r < 0)
 226                         return r;
 227         }
 228
 229         return automount_verify(a);
 230 }
 231
 232 static void automount_set_state(Automount *a, AutomountState state) {
 233         AutomountState old_state;
 234         assert(a);
 235
 236         old_state = a->state;
 237         a->state = state;
 238
 239         if (state != AUTOMOUNT_RUNNING)
 240                 automount_stop_expire(a);
 241
 242         if (state != AUTOMOUNT_WAITING &&
 243             state != AUTOMOUNT_RUNNING)
 244                 unmount_autofs(a);
 245
 246         if (state != old_state)
 247                 log_unit_debug(UNIT(a), "Changed %s -> %s", automount_state_to_string(old_state), automount_state_to_string(state));
 248
 249         unit_notify(UNIT(a), state_translation_table[old_state], state_translation_table[state], true);
 250 }
 251
 252 static int automount_coldplug(Unit *u) {
 253         Automount *a = AUTOMOUNT(u);
 254         int r;
 255
 256         assert(a);
 257         assert(a->state == AUTOMOUNT_DEAD);
 258
 259         if (a->deserialized_state != a->state) {
 260
 261                 r = open_dev_autofs(u->manager);
 262                 if (r < 0)
 263                         return r;
 264
 265                 if (a->deserialized_state == AUTOMOUNT_WAITING ||
 266                     a->deserialized_state == AUTOMOUNT_RUNNING) {
 267                         assert(a->pipe_fd >= 0);
 268
 269                         r = sd_event_add_io(u->manager->event, &a->pipe_event_source, a->pipe_fd, EPOLLIN, automount_dispatch_io, u);
 270                         if (r < 0)
 271                                 return r;
 272
 273                         (void) sd_event_source_set_description(a->pipe_event_source, "automount-io");
 274                 }
 275
 276                 automount_set_state(a, a->deserialized_state);
 277         }
 278
 279         return 0;
 280 }
 281
 282 static void automount_dump(Unit *u, FILE *f, const char *prefix) {
 283         char time_string[FORMAT_TIMESPAN_MAX];
 284         Automount *a = AUTOMOUNT(u);
 285
 286         assert(a);
 287
 288         fprintf(f,
 289                 "%sAutomount State: %s\n"
 290                 "%sResult: %s\n"
 291                 "%sWhere: %s\n"
 292                 "%sDirectoryMode: %04o\n"
 293                 "%sTimeoutIdleUSec: %s\n",
 294                 prefix, automount_state_to_string(a->state),
 295                 prefix, automount_result_to_string(a->result),
 296                 prefix, a->where,
 297                 prefix, a->directory_mode,
 298                 prefix, format_timespan(time_string, FORMAT_TIMESPAN_MAX, a->timeout_idle_usec, USEC_PER_SEC));
 299 }
 300
 301 static void automount_enter_dead(Automount *a, AutomountResult f) {
 302         assert(a);
 303
 304         if (f != AUTOMOUNT_SUCCESS)
 305                 a->result = f;
 306
 307         automount_set_state(a, a->result != AUTOMOUNT_SUCCESS ? AUTOMOUNT_FAILED : AUTOMOUNT_DEAD);
 308 }
 309
 310 static int open_dev_autofs(Manager *m) {
 311         struct autofs_dev_ioctl param;
 312
 313         assert(m);
 314
 315         if (m->dev_autofs_fd >= 0)
 316                 return m->dev_autofs_fd;
 317
 318         label_fix("/dev/autofs", false, false);
 319
 320         m->dev_autofs_fd = open("/dev/autofs", O_CLOEXEC|O_RDONLY);
 321         if (m->dev_autofs_fd < 0)
 322                 return log_error_errno(errno, "Failed to open /dev/autofs: %m");
 323
 324         init_autofs_dev_ioctl(&param);
 325         if (ioctl(m->dev_autofs_fd, AUTOFS_DEV_IOCTL_VERSION, &param) < 0) {
 326                 m->dev_autofs_fd = safe_close(m->dev_autofs_fd);
 327                 return -errno;
 328         }
 329
 330         log_debug("Autofs kernel version %i.%i", param.ver_major, param.ver_minor);
 331
 332         return m->dev_autofs_fd;
 333 }
 334
 335 static int open_ioctl_fd(int dev_autofs_fd, const char *where, dev_t devid) {
 336         struct autofs_dev_ioctl *param;
 337         size_t l;
 338
 339         assert(dev_autofs_fd >= 0);
 340         assert(where);
 341
 342         l = sizeof(struct autofs_dev_ioctl) + strlen(where) + 1;
 343         param = alloca(l);
 344
 345         init_autofs_dev_ioctl(param);
 346         param->size = l;
 347         param->ioctlfd = -1;
 348         param->openmount.devid = devid;
 349         strcpy(param->path, where);
 350
 351         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_OPENMOUNT, param) < 0)
 352                 return -errno;
 353
 354         if (param->ioctlfd < 0)
 355                 return -EIO;
 356
 357         (void) fd_cloexec(param->ioctlfd, true);
 358         return param->ioctlfd;
 359 }
 360
 361 static int autofs_protocol(int dev_autofs_fd, int ioctl_fd) {
 362         uint32_t major, minor;
 363         struct autofs_dev_ioctl param;
 364
 365         assert(dev_autofs_fd >= 0);
 366         assert(ioctl_fd >= 0);
 367
 368         init_autofs_dev_ioctl(&param);
 369         param.ioctlfd = ioctl_fd;
 370
 371         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_PROTOVER, &param) < 0)
 372                 return -errno;
 373
 374         major = param.protover.version;
 375
 376         init_autofs_dev_ioctl(&param);
 377         param.ioctlfd = ioctl_fd;
 378
 379         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_PROTOSUBVER, &param) < 0)
 380                 return -errno;
 381
 382         minor = param.protosubver.sub_version;
 383
 384         log_debug("Autofs protocol version %i.%i", major, minor);
 385         return 0;
 386 }
 387
 388 static int autofs_set_timeout(int dev_autofs_fd, int ioctl_fd, usec_t usec) {
 389         struct autofs_dev_ioctl param;
 390
 391         assert(dev_autofs_fd >= 0);
 392         assert(ioctl_fd >= 0);
 393
 394         init_autofs_dev_ioctl(&param);
 395         param.ioctlfd = ioctl_fd;
 396
 397         /* Convert to seconds, rounding up. */
 398         param.timeout.timeout = (usec + USEC_PER_SEC - 1) / USEC_PER_SEC;
 399
 400         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_TIMEOUT, &param) < 0)
 401                 return -errno;
 402
 403         return 0;
 404 }
 405
 406 static int autofs_send_ready(int dev_autofs_fd, int ioctl_fd, uint32_t token, int status) {
 407         struct autofs_dev_ioctl param;
 408
 409         assert(dev_autofs_fd >= 0);
 410         assert(ioctl_fd >= 0);
 411
 412         init_autofs_dev_ioctl(&param);
 413         param.ioctlfd = ioctl_fd;
 414
 415         if (status != 0) {
 416                 param.fail.token = token;
 417                 param.fail.status = status;
 418         } else
 419                 param.ready.token = token;
 420
 421         if (ioctl(dev_autofs_fd, status ? AUTOFS_DEV_IOCTL_FAIL : AUTOFS_DEV_IOCTL_READY, &param) < 0)
 422                 return -errno;
 423
 424         return 0;
 425 }
 426
 427 static int automount_send_ready(Automount *a, Set *tokens, int status) {
 428         _cleanup_close_ int ioctl_fd = -1;
 429         unsigned token;
 430         int r;
 431
 432         assert(a);
 433         assert(status <= 0);
 434
 435         if (set_isempty(tokens))
 436                 return 0;
 437
 438         ioctl_fd = open_ioctl_fd(UNIT(a)->manager->dev_autofs_fd, a->where, a->dev_id);
 439         if (ioctl_fd < 0)
 440                 return ioctl_fd;
 441
 442         if (status != 0)
 443                 log_unit_debug_errno(UNIT(a), status, "Sending failure: %m");
 444         else
 445                 log_unit_debug(UNIT(a), "Sending success.");
 446
 447         r = 0;
 448
 449         /* Autofs thankfully does not hand out 0 as a token */
 450         while ((token = PTR_TO_UINT(set_steal_first(tokens)))) {
 451                 int k;
 452
 453                 /* Autofs fun fact II:
 454                  *
 455                  * if you pass a positive status code here, the kernel will
 456                  * freeze! Yay! */
 457
 458                 k = autofs_send_ready(UNIT(a)->manager->dev_autofs_fd,
 459                                       ioctl_fd,
 460                                       token,
 461                                       status);
 462                 if (k < 0)
 463                         r = k;
 464         }
 465
 466         return r;
 467 }
 468
 469 static void automount_trigger_notify(Unit *u, Unit *other) {
 470         Automount *a = AUTOMOUNT(u);
 471         int r;
 472
 473         assert(a);
 474         assert(other);
 475
 476         /* Filter out invocations with bogus state */
 477         if (other->load_state != UNIT_LOADED || other->type != UNIT_MOUNT)
 478                 return;
 479
 480         /* Don't propagate state changes from the mount if we are already down */
 481         if (!IN_SET(a->state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING))
 482                 return;
 483
 484         /* Propagate start limit hit state */
 485         if (other->start_limit_hit) {
 486                 automount_enter_dead(a, AUTOMOUNT_FAILURE_MOUNT_START_LIMIT_HIT);
 487                 return;
 488         }
 489
 490         /* Don't propagate anything if there's still a job queued */
 491         if (other->job)
 492                 return;
 493
 494         /* The mount is successfully established */
 495         if (IN_SET(MOUNT(other)->state, MOUNT_MOUNTED, MOUNT_REMOUNTING)) {
 496                 (void) automount_send_ready(a, a->tokens, 0);
 497
 498                 r = automount_start_expire(a);
 499                 if (r < 0)
 500                         log_unit_warning_errno(UNIT(a), r, "Failed to start expiration timer, ignoring: %m");
 501
 502                 automount_set_state(a, AUTOMOUNT_RUNNING);
 503         }
 504
 505         if (IN_SET(MOUNT(other)->state,
 506                    MOUNT_MOUNTING, MOUNT_MOUNTING_DONE,
 507                    MOUNT_MOUNTED, MOUNT_REMOUNTING,
 508                    MOUNT_MOUNTING_SIGTERM, MOUNT_MOUNTING_SIGKILL,
 509                    MOUNT_REMOUNTING_SIGTERM, MOUNT_REMOUNTING_SIGKILL,
 510                    MOUNT_UNMOUNTING_SIGTERM, MOUNT_UNMOUNTING_SIGKILL,
 511                    MOUNT_FAILED)) {
 512
 513                 (void) automount_send_ready(a, a->expire_tokens, -ENODEV);
 514         }
 515
 516         if (MOUNT(other)->state == MOUNT_DEAD)
 517                 (void) automount_send_ready(a, a->expire_tokens, 0);
 518
 519         /* The mount is in some unhappy state now, let's unfreeze any waiting clients */
 520         if (IN_SET(MOUNT(other)->state,
 521                    MOUNT_DEAD, MOUNT_UNMOUNTING,
 522                    MOUNT_MOUNTING_SIGTERM, MOUNT_MOUNTING_SIGKILL,
 523                    MOUNT_REMOUNTING_SIGTERM, MOUNT_REMOUNTING_SIGKILL,
 524                    MOUNT_UNMOUNTING_SIGTERM, MOUNT_UNMOUNTING_SIGKILL,
 525                    MOUNT_FAILED)) {
 526
 527                 (void) automount_send_ready(a, a->tokens, -ENODEV);
 528
 529                 automount_set_state(a, AUTOMOUNT_WAITING);
 530         }
 531 }
 532
 533 static void automount_enter_waiting(Automount *a) {
 534         _cleanup_close_ int ioctl_fd = -1;
 535         int p[2] = { -1, -1 };
 536         char name[sizeof("systemd-")-1 + DECIMAL_STR_MAX(pid_t) + 1];
 537         char options[sizeof("fd=,pgrp=,minproto=5,maxproto=5,direct")-1
 538                      + DECIMAL_STR_MAX(int) + DECIMAL_STR_MAX(gid_t) + 1];
 539         bool mounted = false;
 540         int r, dev_autofs_fd;
 541         struct stat st;
 542
 543         assert(a);
 544         assert(a->pipe_fd < 0);
 545         assert(a->where);
 546
 547         set_clear(a->tokens);
 548
 549         r = unit_fail_if_symlink(UNIT(a), a->where);
 550         if (r < 0)
 551                 goto fail;
 552
 553         (void) mkdir_p_label(a->where, 0555);
 554
 555         unit_warn_if_dir_nonempty(UNIT(a), a->where);
 556
 557         dev_autofs_fd = open_dev_autofs(UNIT(a)->manager);
 558         if (dev_autofs_fd < 0) {
 559                 r = dev_autofs_fd;
 560                 goto fail;
 561         }
 562
 563         if (pipe2(p, O_NONBLOCK|O_CLOEXEC) < 0) {
 564                 r = -errno;
 565                 goto fail;
 566         }
 567
 568         xsprintf(options, "fd=%i,pgrp="PID_FMT",minproto=5,maxproto=5,direct", p[1], getpgrp());
 569         xsprintf(name, "systemd-"PID_FMT, getpid());
 570         if (mount(name, a->where, "autofs", 0, options) < 0) {
 571                 r = -errno;
 572                 goto fail;
 573         }
 574
 575         mounted = true;
 576
 577         p[1] = safe_close(p[1]);
 578
 579         if (stat(a->where, &st) < 0) {
 580                 r = -errno;
 581                 goto fail;
 582         }
 583
 584         ioctl_fd = open_ioctl_fd(dev_autofs_fd, a->where, st.st_dev);
 585         if (ioctl_fd < 0) {
 586                 r = ioctl_fd;
 587                 goto fail;
 588         }
 589
 590         r = autofs_protocol(dev_autofs_fd, ioctl_fd);
 591         if (r < 0)
 592                 goto fail;
 593
 594         r = autofs_set_timeout(dev_autofs_fd, ioctl_fd, a->timeout_idle_usec);
 595         if (r < 0)
 596                 goto fail;
 597
 598         /* Autofs fun fact:
 599          *
 600          * Unless we close the ioctl fd here, for some weird reason
 601          * the direct mount will not receive events from the
 602          * kernel. */
 603
 604         r = sd_event_add_io(UNIT(a)->manager->event, &a->pipe_event_source, p[0], EPOLLIN, automount_dispatch_io, a);
 605         if (r < 0)
 606                 goto fail;
 607
 608         (void) sd_event_source_set_description(a->pipe_event_source, "automount-io");
 609
 610         a->pipe_fd = p[0];
 611         a->dev_id = st.st_dev;
 612
 613         automount_set_state(a, AUTOMOUNT_WAITING);
 614
 615         return;
 616
 617 fail:
 618         log_unit_error_errno(UNIT(a), r, "Failed to initialize automounter: %m");
 619
 620         safe_close_pair(p);
 621
 622         if (mounted) {
 623                 r = repeat_unmount(a->where, MNT_DETACH);
 624                 if (r < 0)
 625                         log_error_errno(r, "Failed to unmount, ignoring: %m");
 626         }
 627
 628         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
 629 }
 630
 631 static void *expire_thread(void *p) {
 632         struct autofs_dev_ioctl param;
 633         _cleanup_(expire_data_freep) struct expire_data *data = (struct expire_data*)p;
 634         int r;
 635
 636         assert(data->dev_autofs_fd >= 0);
 637         assert(data->ioctl_fd >= 0);
 638
 639         init_autofs_dev_ioctl(&param);
 640         param.ioctlfd = data->ioctl_fd;
 641
 642         do {
 643                 r = ioctl(data->dev_autofs_fd, AUTOFS_DEV_IOCTL_EXPIRE, &param);
 644         } while (r >= 0);
 645
 646         if (errno != EAGAIN)
 647                 log_warning_errno(errno, "Failed to expire automount, ignoring: %m");
 648
 649         return NULL;
 650 }
 651
 652 static int automount_dispatch_expire(sd_event_source *source, usec_t usec, void *userdata) {
 653         Automount *a = AUTOMOUNT(userdata);
 654         _cleanup_(expire_data_freep) struct expire_data *data = NULL;
 655         int r;
 656
 657         assert(a);
 658         assert(source == a->expire_event_source);
 659
 660         data = new0(struct expire_data, 1);
 661         if (!data)
 662                 return log_oom();
 663
 664         data->ioctl_fd = -1;
 665
 666         data->dev_autofs_fd = fcntl(UNIT(a)->manager->dev_autofs_fd, F_DUPFD_CLOEXEC, 3);
 667         if (data->dev_autofs_fd < 0)
 668                 return log_unit_error_errno(UNIT(a), errno, "Failed to duplicate autofs fd: %m");
 669
 670         data->ioctl_fd = open_ioctl_fd(UNIT(a)->manager->dev_autofs_fd, a->where, a->dev_id);
 671         if (data->ioctl_fd < 0)
 672                 return log_unit_error_errno(UNIT(a), data->ioctl_fd, "Couldn't open autofs ioctl fd: %m");
 673
 674         r = asynchronous_job(expire_thread, data);
 675         if (r < 0)
 676                 return log_unit_error_errno(UNIT(a), r, "Failed to start expire job: %m");
 677
 678         data = NULL;
 679
 680         return automount_start_expire(a);
 681 }
 682
 683 static int automount_start_expire(Automount *a) {
 684         int r;
 685         usec_t timeout;
 686
 687         assert(a);
 688
 689         if (a->timeout_idle_usec == 0)
 690                 return 0;
 691
 692         timeout = now(CLOCK_MONOTONIC) + MAX(a->timeout_idle_usec/3, USEC_PER_SEC);
 693
 694         if (a->expire_event_source) {
 695                 r = sd_event_source_set_time(a->expire_event_source, timeout);
 696                 if (r < 0)
 697                         return r;
 698
 699                 return sd_event_source_set_enabled(a->expire_event_source, SD_EVENT_ONESHOT);
 700         }
 701
 702         r = sd_event_add_time(
 703                         UNIT(a)->manager->event,
 704                         &a->expire_event_source,
 705                         CLOCK_MONOTONIC, timeout, 0,
 706                         automount_dispatch_expire, a);
 707         if (r < 0)
 708                 return r;
 709
 710         (void) sd_event_source_set_description(a->expire_event_source, "automount-expire");
 711
 712         return 0;
 713 }
 714
 715 static void automount_stop_expire(Automount *a) {
 716         assert(a);
 717
 718         if (!a->expire_event_source)
 719                 return;
 720
 721         (void) sd_event_source_set_enabled(a->expire_event_source, SD_EVENT_OFF);
 722 }
 723
 724 static void automount_enter_runnning(Automount *a) {
 725         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 726         struct stat st;
 727         int r;
 728
 729         assert(a);
 730
 731         /* We don't take mount requests anymore if we are supposed to
 732          * shut down anyway */
 733         if (unit_stop_pending(UNIT(a))) {
 734                 log_unit_debug(UNIT(a), "Suppressing automount request since unit stop is scheduled.");
 735                 automount_send_ready(a, a->tokens, -EHOSTDOWN);
 736                 automount_send_ready(a, a->expire_tokens, -EHOSTDOWN);
 737                 return;
 738         }
 739
 740         mkdir_p_label(a->where, a->directory_mode);
 741
 742         /* Before we do anything, let's see if somebody is playing games with us? */
 743         if (lstat(a->where, &st) < 0) {
 744                 log_unit_warning_errno(UNIT(a), errno, "Failed to stat automount point: %m");
 745                 goto fail;
 746         }
 747
 748         if (!S_ISDIR(st.st_mode) || st.st_dev != a->dev_id)
 749                 log_unit_info(UNIT(a), "Automount point already active?");
 750         else {
 751                 Unit *trigger;
 752
 753                 trigger = UNIT_TRIGGER(UNIT(a));
 754                 if (!trigger) {
 755                         log_unit_error(UNIT(a), "Unit to trigger vanished.");
 756                         goto fail;
 757                 }
 758
 759                 r = manager_add_job(UNIT(a)->manager, JOB_START, trigger, JOB_REPLACE, &error, NULL);
 760                 if (r < 0) {
 761                         log_unit_warning(UNIT(a), "Failed to queue mount startup job: %s", bus_error_message(&error, r));
 762                         goto fail;
 763                 }
 764         }
 765
 766         automount_set_state(a, AUTOMOUNT_RUNNING);
 767         return;
 768
 769 fail:
 770         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
 771 }
 772
 773 static int automount_start(Unit *u) {
 774         Automount *a = AUTOMOUNT(u);
 775         Unit *trigger;
 776         int r;
 777
 778         assert(a);
 779         assert(a->state == AUTOMOUNT_DEAD || a->state == AUTOMOUNT_FAILED);
 780
 781         if (path_is_mount_point(a->where, 0) > 0) {
 782                 log_unit_error(u, "Path %s is already a mount point, refusing start.", a->where);
 783                 return -EEXIST;
 784         }
 785
 786         trigger = UNIT_TRIGGER(u);
 787         if (!trigger || trigger->load_state != UNIT_LOADED) {
 788                 log_unit_error(u, "Refusing to start, unit to trigger not loaded.");
 789                 return -ENOENT;
 790         }
 791
 792         r = unit_start_limit_test(u);
 793         if (r < 0) {
 794                 automount_enter_dead(a, AUTOMOUNT_FAILURE_START_LIMIT_HIT);
 795                 return r;
 796         }
 797
 798         a->result = AUTOMOUNT_SUCCESS;
 799         automount_enter_waiting(a);
 800         return 1;
 801 }
 802
 803 static int automount_stop(Unit *u) {
 804         Automount *a = AUTOMOUNT(u);
 805
 806         assert(a);
 807         assert(a->state == AUTOMOUNT_WAITING || a->state == AUTOMOUNT_RUNNING);
 808
 809         automount_enter_dead(a, AUTOMOUNT_SUCCESS);
 810         return 1;
 811 }
 812
 813 static int automount_serialize(Unit *u, FILE *f, FDSet *fds) {
 814         Automount *a = AUTOMOUNT(u);
 815         Iterator i;
 816         void *p;
 817         int r;
 818
 819         assert(a);
 820         assert(f);
 821         assert(fds);
 822
 823         unit_serialize_item(u, f, "state", automount_state_to_string(a->state));
 824         unit_serialize_item(u, f, "result", automount_result_to_string(a->result));
 825         unit_serialize_item_format(u, f, "dev-id", "%u", (unsigned) a->dev_id);
 826
 827         SET_FOREACH(p, a->tokens, i)
 828                 unit_serialize_item_format(u, f, "token", "%u", PTR_TO_UINT(p));
 829         SET_FOREACH(p, a->expire_tokens, i)
 830                 unit_serialize_item_format(u, f, "expire-token", "%u", PTR_TO_UINT(p));
 831
 832         r = unit_serialize_item_fd(u, f, fds, "pipe-fd", a->pipe_fd);
 833         if (r < 0)
 834                 return r;
 835
 836         return 0;
 837 }
 838
 839 static int automount_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 840         Automount *a = AUTOMOUNT(u);
 841         int r;
 842
 843         assert(a);
 844         assert(fds);
 845
 846         if (streq(key, "state")) {
 847                 AutomountState state;
 848
 849                 state = automount_state_from_string(value);
 850                 if (state < 0)
 851                         log_unit_debug(u, "Failed to parse state value: %s", value);
 852                 else
 853                         a->deserialized_state = state;
 854         } else if (streq(key, "result")) {
 855                 AutomountResult f;
 856
 857                 f = automount_result_from_string(value);
 858                 if (f < 0)
 859                         log_unit_debug(u, "Failed to parse result value: %s", value);
 860                 else if (f != AUTOMOUNT_SUCCESS)
 861                         a->result = f;
 862
 863         } else if (streq(key, "dev-id")) {
 864                 unsigned d;
 865
 866                 if (safe_atou(value, &d) < 0)
 867                         log_unit_debug(u, "Failed to parse dev-id value: %s", value);
 868                 else
 869                         a->dev_id = (unsigned) d;
 870         } else if (streq(key, "token")) {
 871                 unsigned token;
 872
 873                 if (safe_atou(value, &token) < 0)
 874                         log_unit_debug(u, "Failed to parse token value: %s", value);
 875                 else {
 876                         r = set_ensure_allocated(&a->tokens, NULL);
 877                         if (r < 0) {
 878                                 log_oom();
 879                                 return 0;
 880                         }
 881
 882                         r = set_put(a->tokens, UINT_TO_PTR(token));
 883                         if (r < 0)
 884                                 log_unit_error_errno(u, r, "Failed to add token to set: %m");
 885                 }
 886         } else if (streq(key, "expire-token")) {
 887                 unsigned token;
 888
 889                 if (safe_atou(value, &token) < 0)
 890                         log_unit_debug(u, "Failed to parse token value: %s", value);
 891                 else {
 892                         r = set_ensure_allocated(&a->expire_tokens, NULL);
 893                         if (r < 0) {
 894                                 log_oom();
 895                                 return 0;
 896                         }
 897
 898                         r = set_put(a->expire_tokens, UINT_TO_PTR(token));
 899                         if (r < 0)
 900                                 log_unit_error_errno(u, r, "Failed to add expire token to set: %m");
 901                 }
 902         } else if (streq(key, "pipe-fd")) {
 903                 int fd;
 904
 905                 if (safe_atoi(value, &fd) < 0 || fd < 0 || !fdset_contains(fds, fd))
 906                         log_unit_debug(u, "Failed to parse pipe-fd value: %s", value);
 907                 else {
 908                         safe_close(a->pipe_fd);
 909                         a->pipe_fd = fdset_remove(fds, fd);
 910                 }
 911         } else
 912                 log_unit_debug(u, "Unknown serialization key: %s", key);
 913
 914         return 0;
 915 }
 916
 917 static UnitActiveState automount_active_state(Unit *u) {
 918         assert(u);
 919
 920         return state_translation_table[AUTOMOUNT(u)->state];
 921 }
 922
 923 static const char *automount_sub_state_to_string(Unit *u) {
 924         assert(u);
 925
 926         return automount_state_to_string(AUTOMOUNT(u)->state);
 927 }
 928
 929 static bool automount_check_gc(Unit *u) {
 930         assert(u);
 931
 932         if (!UNIT_TRIGGER(u))
 933                 return false;
 934
 935         return UNIT_VTABLE(UNIT_TRIGGER(u))->check_gc(UNIT_TRIGGER(u));
 936 }
 937
 938 static int automount_dispatch_io(sd_event_source *s, int fd, uint32_t events, void *userdata) {
 939         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 940         union autofs_v5_packet_union packet;
 941         Automount *a = AUTOMOUNT(userdata);
 942         struct stat st;
 943         Unit *trigger;
 944         int r;
 945
 946         assert(a);
 947         assert(fd == a->pipe_fd);
 948
 949         if (events != EPOLLIN) {
 950                 log_unit_error(UNIT(a), "Got invalid poll event %"PRIu32" on pipe (fd=%d)", events, fd);
 951                 goto fail;
 952         }
 953
 954         r = loop_read_exact(a->pipe_fd, &packet, sizeof(packet), true);
 955         if (r < 0) {
 956                 log_unit_error_errno(UNIT(a), r, "Invalid read from pipe: %m");
 957                 goto fail;
 958         }
 959
 960         switch (packet.hdr.type) {
 961
 962         case autofs_ptype_missing_direct:
 963
 964                 if (packet.v5_packet.pid > 0) {
 965                         _cleanup_free_ char *p = NULL;
 966
 967                         get_process_comm(packet.v5_packet.pid, &p);
 968                         log_unit_info(UNIT(a), "Got automount request for %s, triggered by %"PRIu32" (%s)", a->where, packet.v5_packet.pid, strna(p));
 969                 } else
 970                         log_unit_debug(UNIT(a), "Got direct mount request on %s", a->where);
 971
 972                 r = set_ensure_allocated(&a->tokens, NULL);
 973                 if (r < 0) {
 974                         log_unit_error(UNIT(a), "Failed to allocate token set.");
 975                         goto fail;
 976                 }
 977
 978                 r = set_put(a->tokens, UINT_TO_PTR(packet.v5_packet.wait_queue_token));
 979                 if (r < 0) {
 980                         log_unit_error_errno(UNIT(a), r, "Failed to remember token: %m");
 981                         goto fail;
 982                 }
 983
 984                 automount_enter_runnning(a);
 985                 break;
 986
 987         case autofs_ptype_expire_direct:
 988                 log_unit_debug(UNIT(a), "Got direct umount request on %s", a->where);
 989
 990                 automount_stop_expire(a);
 991
 992                 r = set_ensure_allocated(&a->expire_tokens, NULL);
 993                 if (r < 0) {
 994                         log_unit_error(UNIT(a), "Failed to allocate token set.");
 995                         goto fail;
 996                 }
 997
 998                 r = set_put(a->expire_tokens, UINT_TO_PTR(packet.v5_packet.wait_queue_token));
 999                 if (r < 0) {
1000                         log_unit_error_errno(UNIT(a), r, "Failed to remember token: %m");
1001                         goto fail;
1002                 }
1003
1004                 /* Before we do anything, let's see if somebody is playing games with us? */
1005                 if (lstat(a->where, &st) < 0) {
1006                         log_unit_warning_errno(UNIT(a), errno, "Failed to stat automount point: %m");
1007                         goto fail;
1008                 }
1009
1010                 if (!S_ISDIR(st.st_mode) || st.st_dev == a->dev_id) {
1011                         log_unit_info(UNIT(a), "Automount point already unmounted?");
1012                         automount_send_ready(a, a->expire_tokens, 0);
1013                         break;
1014                 }
1015
1016                 trigger = UNIT_TRIGGER(UNIT(a));
1017                 if (!trigger) {
1018                         log_unit_error(UNIT(a), "Unit to trigger vanished.");
1019                         goto fail;
1020                 }
1021
1022                 r = manager_add_job(UNIT(a)->manager, JOB_STOP, trigger, JOB_REPLACE, &error, NULL);
1023                 if (r < 0) {
1024                         log_unit_warning(UNIT(a), "Failed to queue umount startup job: %s", bus_error_message(&error, r));
1025                         goto fail;
1026                 }
1027                 break;
1028
1029         default:
1030                 log_unit_error(UNIT(a), "Received unknown automount request %i", packet.hdr.type);
1031                 break;
1032         }
1033
1034         return 0;
1035
1036 fail:
1037         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
1038         return 0;
1039 }
1040
1041 static void automount_shutdown(Manager *m) {
1042         assert(m);
1043
1044         m->dev_autofs_fd = safe_close(m->dev_autofs_fd);
1045 }
1046
1047 static void automount_reset_failed(Unit *u) {
1048         Automount *a = AUTOMOUNT(u);
1049
1050         assert(a);
1051
1052         if (a->state == AUTOMOUNT_FAILED)
1053                 automount_set_state(a, AUTOMOUNT_DEAD);
1054
1055         a->result = AUTOMOUNT_SUCCESS;
1056 }
1057
1058 static bool automount_supported(void) {
1059         static int supported = -1;
1060
1061         if (supported < 0)
1062                 supported = access("/dev/autofs", F_OK) >= 0;
1063
1064         return supported;
1065 }
1066
1067 static const char* const automount_result_table[_AUTOMOUNT_RESULT_MAX] = {
1068         [AUTOMOUNT_SUCCESS] = "success",
1069         [AUTOMOUNT_FAILURE_RESOURCES] = "resources",
1070         [AUTOMOUNT_FAILURE_START_LIMIT_HIT] = "start-limit-hit",
1071         [AUTOMOUNT_FAILURE_MOUNT_START_LIMIT_HIT] = "mount-start-limit-hit",
1072 };
1073
1074 DEFINE_STRING_TABLE_LOOKUP(automount_result, AutomountResult);
1075
1076 const UnitVTable automount_vtable = {
1077         .object_size = sizeof(Automount),
1078
1079         .sections =
1080                 "Unit\0"
1081                 "Automount\0"
1082                 "Install\0",
1083
1084         .init = automount_init,
1085         .load = automount_load,
1086         .done = automount_done,
1087
1088         .coldplug = automount_coldplug,
1089
1090         .dump = automount_dump,
1091
1092         .start = automount_start,
1093         .stop = automount_stop,
1094
1095         .serialize = automount_serialize,
1096         .deserialize_item = automount_deserialize_item,
1097
1098         .active_state = automount_active_state,
1099         .sub_state_to_string = automount_sub_state_to_string,
1100
1101         .check_gc = automount_check_gc,
1102
1103         .trigger_notify = automount_trigger_notify,
1104
1105         .reset_failed = automount_reset_failed,
1106
1107         .bus_vtable = bus_automount_vtable,
1108         .bus_set_property = bus_automount_set_property,
1109
1110         .can_transient = true,
1111
1112         .shutdown = automount_shutdown,
1113         .supported = automount_supported,
1114
1115         .status_message_formats = {
1116                 .finished_start_job = {
1117                         [JOB_DONE]       = "Set up automount %s.",
1118                         [JOB_FAILED]     = "Failed to set up automount %s.",
1119                 },
1120                 .finished_stop_job = {
1121                         [JOB_DONE]       = "Unset automount %s.",
1122                         [JOB_FAILED]     = "Failed to unset automount %s.",
1123                 },
1124         },
1125 };