git.ozlabs.org Git - petitboot/blob - discover/device-handler.c

   1 #include <assert.h>
   2 #include <stdlib.h>
   3 #include <stdbool.h>
   4 #include <unistd.h>
   5 #include <string.h>
   6 #include <errno.h>
   7 #include <mntent.h>
   8 #include <sys/stat.h>
   9 #include <sys/wait.h>
  10
  11 #include <pb-config/pb-config.h>
  12 #include <talloc/talloc.h>
  13 #include <list/list.h>
  14 #include <log/log.h>
  15 #include <types/types.h>
  16 #include <system/system.h>
  17 #include <process/process.h>
  18 #include <url/url.h>
  19
  20 #include "device-handler.h"
  21 #include "discover-server.h"
  22 #include "event.h"
  23 #include "parser.h"
  24 #include "resource.h"
  25 #include "paths.h"
  26 #include "sysinfo.h"
  27 #include "boot.h"
  28
  29 struct device_handler {
  30         struct discover_server  *server;
  31         int                     dry_run;
  32
  33         struct discover_device  **devices;
  34         unsigned int            n_devices;
  35
  36         struct waitset          *waitset;
  37         struct waiter           *timeout_waiter;
  38         bool                    autoboot_enabled;
  39         unsigned int            sec_to_boot;
  40
  41         struct discover_boot_option *default_boot_option;
  42         struct list             unresolved_boot_options;
  43
  44         struct boot_task        *pending_boot;
  45         bool                    pending_boot_is_default;
  46 };
  47
  48 static int mount_device(struct discover_device *dev);
  49 static int umount_device(struct discover_device *dev);
  50
  51 void discover_context_add_boot_option(struct discover_context *ctx,
  52                 struct discover_boot_option *boot_option)
  53 {
  54         boot_option->source = ctx->parser;
  55         list_add_tail(&ctx->boot_options, &boot_option->list);
  56         talloc_steal(ctx, boot_option);
  57 }
  58
  59 /**
  60  * device_handler_get_device_count - Get the count of current handler devices.
  61  */
  62
  63 int device_handler_get_device_count(const struct device_handler *handler)
  64 {
  65         return handler->n_devices;
  66 }
  67
  68 /**
  69  * device_handler_get_device - Get a handler device by index.
  70  */
  71
  72 const struct discover_device *device_handler_get_device(
  73         const struct device_handler *handler, unsigned int index)
  74 {
  75         if (index >= handler->n_devices) {
  76                 assert(0 && "bad index");
  77                 return NULL;
  78         }
  79
  80         return handler->devices[index];
  81 }
  82
  83 struct discover_boot_option *discover_boot_option_create(
  84                 struct discover_context *ctx,
  85                 struct discover_device *device)
  86 {
  87         struct discover_boot_option *opt;
  88
  89         opt = talloc_zero(ctx, struct discover_boot_option);
  90         opt->option = talloc_zero(opt, struct boot_option);
  91         opt->device = device;
  92
  93         return opt;
  94 }
  95
  96 static int device_match_uuid(struct discover_device *dev, const char *uuid)
  97 {
  98         return dev->uuid && !strcmp(dev->uuid, uuid);
  99 }
 100
 101 static int device_match_label(struct discover_device *dev, const char *label)
 102 {
 103         return dev->label && !strcmp(dev->label, label);
 104 }
 105
 106 static int device_match_id(struct discover_device *dev, const char *id)
 107 {
 108         return !strcmp(dev->device->id, id);
 109 }
 110
 111 static int device_match_serial(struct discover_device *dev, const char *serial)
 112 {
 113         const char *val = discover_device_get_param(dev, "ID_SERIAL");
 114         return val && !strcmp(val, serial);
 115 }
 116
 117 static struct discover_device *device_lookup(
 118                 struct device_handler *device_handler,
 119                 int (match_fn)(struct discover_device *, const char *),
 120                 const char *str)
 121 {
 122         struct discover_device *dev;
 123         unsigned int i;
 124
 125         if (!str)
 126                 return NULL;
 127
 128         for (i = 0; i < device_handler->n_devices; i++) {
 129                 dev = device_handler->devices[i];
 130
 131                 if (match_fn(dev, str))
 132                         return dev;
 133         }
 134
 135         return NULL;
 136 }
 137
 138 struct discover_device *device_lookup_by_name(struct device_handler *handler,
 139                 const char *name)
 140 {
 141         if (!strncmp(name, "/dev/", strlen("/dev/")))
 142                 name += strlen("/dev/");
 143
 144         return device_lookup_by_id(handler, name);
 145 }
 146
 147 struct discover_device *device_lookup_by_uuid(
 148                 struct device_handler *device_handler,
 149                 const char *uuid)
 150 {
 151         return device_lookup(device_handler, device_match_uuid, uuid);
 152 }
 153
 154 struct discover_device *device_lookup_by_label(
 155                 struct device_handler *device_handler,
 156                 const char *label)
 157 {
 158         return device_lookup(device_handler, device_match_label, label);
 159 }
 160
 161 struct discover_device *device_lookup_by_id(
 162                 struct device_handler *device_handler,
 163                 const char *id)
 164 {
 165         return device_lookup(device_handler, device_match_id, id);
 166 }
 167
 168 struct discover_device *device_lookup_by_serial(
 169                 struct device_handler *device_handler,
 170                 const char *serial)
 171 {
 172         return device_lookup(device_handler, device_match_serial, serial);
 173 }
 174
 175 void device_handler_destroy(struct device_handler *handler)
 176 {
 177         talloc_free(handler);
 178 }
 179
 180 static int destroy_device(void *arg)
 181 {
 182         struct discover_device *dev = arg;
 183
 184         umount_device(dev);
 185
 186         return 0;
 187 }
 188
 189 struct discover_device *discover_device_create(struct device_handler *handler,
 190                 const char *id)
 191 {
 192         struct discover_device *dev;
 193
 194         dev = device_lookup_by_id(handler, id);
 195         if (dev)
 196                 return dev;
 197
 198         dev = talloc_zero(handler, struct discover_device);
 199         dev->device = talloc_zero(dev, struct device);
 200         dev->device->id = talloc_strdup(dev->device, id);
 201         list_init(&dev->params);
 202         list_init(&dev->boot_options);
 203
 204         talloc_set_destructor(dev, destroy_device);
 205
 206         return dev;
 207 }
 208
 209 struct discover_device_param {
 210         char                    *name;
 211         char                    *value;
 212         struct list_item        list;
 213 };
 214
 215 void discover_device_set_param(struct discover_device *device,
 216                 const char *name, const char *value)
 217 {
 218         struct discover_device_param *param;
 219         bool found = false;
 220
 221         list_for_each_entry(&device->params, param, list) {
 222                 if (!strcmp(param->name, name)) {
 223                         found = true;
 224                         break;
 225                 }
 226         }
 227
 228         if (!found) {
 229                 if (!value)
 230                         return;
 231                 param = talloc(device, struct discover_device_param);
 232                 param->name = talloc_strdup(param, name);
 233                 list_add(&device->params, &param->list);
 234         } else {
 235                 if (!value) {
 236                         list_remove(&param->list);
 237                         talloc_free(param);
 238                         return;
 239                 }
 240                 talloc_free(param->value);
 241         }
 242
 243         param->value = talloc_strdup(param, value);
 244 }
 245
 246 const char *discover_device_get_param(struct discover_device *device,
 247                 const char *name)
 248 {
 249         struct discover_device_param *param;
 250
 251         list_for_each_entry(&device->params, param, list) {
 252                 if (!strcmp(param->name, name))
 253                         return param->name;
 254         }
 255         return NULL;
 256 }
 257
 258 struct device_handler *device_handler_init(struct discover_server *server,
 259                 struct waitset *waitset, int dry_run)
 260 {
 261         struct device_handler *handler;
 262
 263         handler = talloc_zero(NULL, struct device_handler);
 264         handler->server = server;
 265         handler->waitset = waitset;
 266         handler->dry_run = dry_run;
 267         handler->autoboot_enabled = config_get()->autoboot_enabled;
 268
 269         list_init(&handler->unresolved_boot_options);
 270
 271         /* set up our mount point base */
 272         pb_mkdir_recursive(mount_base());
 273
 274         parser_init();
 275
 276         return handler;
 277 }
 278
 279 void device_handler_remove(struct device_handler *handler,
 280                 struct discover_device *device)
 281 {
 282         unsigned int i;
 283
 284         for (i = 0; i < handler->n_devices; i++)
 285                 if (handler->devices[i] == device)
 286                         break;
 287
 288         if (i == handler->n_devices) {
 289                 talloc_free(device);
 290                 return;
 291         }
 292
 293         handler->n_devices--;
 294         memmove(&handler->devices[i], &handler->devices[i + 1],
 295                 (handler->n_devices - i) * sizeof(handler->devices[0]));
 296         handler->devices = talloc_realloc(handler, handler->devices,
 297                 struct discover_device *, handler->n_devices);
 298
 299         if (device->notified)
 300                 discover_server_notify_device_remove(handler->server,
 301                                                         device->device);
 302
 303         talloc_free(device);
 304 }
 305
 306 static void boot_status(void *arg, struct boot_status *status)
 307 {
 308         struct device_handler *handler = arg;
 309
 310         discover_server_notify_boot_status(handler->server, status);
 311 }
 312
 313 static void countdown_status(struct device_handler *handler,
 314                 struct discover_boot_option *opt, unsigned int sec)
 315 {
 316         struct boot_status status;
 317
 318         status.type = BOOT_STATUS_INFO;
 319         status.progress = -1;
 320         status.detail = NULL;
 321         status.message = talloc_asprintf(handler,
 322                         "Booting %s in %u sec", opt->option->name, sec);
 323
 324         discover_server_notify_boot_status(handler->server, &status);
 325
 326         talloc_free(status.message);
 327 }
 328
 329 static int default_timeout(void *arg)
 330 {
 331         struct device_handler *handler = arg;
 332         struct discover_boot_option *opt;
 333
 334         if (!handler->default_boot_option)
 335                 return 0;
 336
 337         if (handler->pending_boot)
 338                 return 0;
 339
 340         opt = handler->default_boot_option;
 341
 342         if (handler->sec_to_boot) {
 343                 countdown_status(handler, opt, handler->sec_to_boot);
 344                 handler->sec_to_boot--;
 345                 handler->timeout_waiter = waiter_register_timeout(
 346                                                 handler->waitset, 1000,
 347                                                 default_timeout, handler);
 348                 return 0;
 349         }
 350
 351         handler->timeout_waiter = NULL;
 352
 353         pb_log("Timeout expired, booting default option %s\n", opt->option->id);
 354
 355         handler->pending_boot = boot(handler, handler->default_boot_option,
 356                         NULL, handler->dry_run, boot_status, handler);
 357         handler->pending_boot_is_default = true;
 358         return 0;
 359 }
 360
 361 static bool priority_match(struct boot_priority *prio,
 362                 struct discover_boot_option *opt)
 363 {
 364         return prio->type == opt->device->device->type;
 365 }
 366
 367 static int default_option_priority(struct discover_boot_option *opt)
 368 {
 369         const struct config *config;
 370         struct boot_priority *prio;
 371         unsigned int i;
 372
 373         config = config_get();
 374
 375         for (i = 0; i < config->n_boot_priorities; i++) {
 376                 prio = &config->boot_priorities[i];
 377                 if (priority_match(prio, opt))
 378                         break;
 379         }
 380
 381         return i;
 382 }
 383
 384 static void set_default(struct device_handler *handler,
 385                 struct discover_boot_option *opt)
 386 {
 387         if (!handler->autoboot_enabled)
 388                 return;
 389
 390         /* Resolve any conflicts: if we have a new default option, it only
 391          * replaces the current if it has a higher priority. */
 392         if (handler->default_boot_option) {
 393                 int new_prio, cur_prio;
 394
 395                 new_prio = default_option_priority(opt);
 396                 cur_prio = default_option_priority(
 397                                         handler->default_boot_option);
 398
 399                 if (new_prio < cur_prio) {
 400                         handler->default_boot_option = opt;
 401                         /* extend the timeout a little, so the user sees some
 402                          * indication of the change */
 403                         handler->sec_to_boot += 2;
 404                 }
 405
 406                 return;
 407         }
 408
 409         handler->sec_to_boot = config_get()->autoboot_timeout_sec;
 410         handler->default_boot_option = opt;
 411
 412         pb_log("Boot option %s set as default, timeout %u sec.\n",
 413                opt->option->id, handler->sec_to_boot);
 414
 415         default_timeout(handler);
 416 }
 417
 418 static bool resource_is_resolved(struct resource *res)
 419 {
 420         return !res || res->resolved;
 421 }
 422
 423 /* We only use this in an assert, which will disappear if we're compiling
 424  * with NDEBUG, so we need the 'used' attribute for these builds */
 425 static bool __attribute__((used)) boot_option_is_resolved(
 426                 struct discover_boot_option *opt)
 427 {
 428         return resource_is_resolved(opt->boot_image) &&
 429                 resource_is_resolved(opt->initrd) &&
 430                 resource_is_resolved(opt->dtb) &&
 431                 resource_is_resolved(opt->icon);
 432 }
 433
 434 static bool resource_resolve(struct resource *res, const char *name,
 435                 struct discover_boot_option *opt,
 436                 struct device_handler *handler)
 437 {
 438         struct parser *parser = opt->source;
 439
 440         if (resource_is_resolved(res))
 441                 return true;
 442
 443         pb_debug("Attempting to resolve resource %s->%s with parser %s\n",
 444                         opt->option->id, name, parser->name);
 445         parser->resolve_resource(handler, res);
 446
 447         return res->resolved;
 448 }
 449
 450 static bool boot_option_resolve(struct discover_boot_option *opt,
 451                 struct device_handler *handler)
 452 {
 453         return resource_resolve(opt->boot_image, "boot_image", opt, handler) &&
 454                 resource_resolve(opt->initrd, "initrd", opt, handler) &&
 455                 resource_resolve(opt->dtb, "dtb", opt, handler) &&
 456                 resource_resolve(opt->icon, "icon", opt, handler);
 457 }
 458
 459 static void boot_option_finalise(struct device_handler *handler,
 460                 struct discover_boot_option *opt)
 461 {
 462         assert(boot_option_is_resolved(opt));
 463
 464         /* check that the parsers haven't set any of the final data */
 465         assert(!opt->option->boot_image_file);
 466         assert(!opt->option->initrd_file);
 467         assert(!opt->option->dtb_file);
 468         assert(!opt->option->icon_file);
 469         assert(!opt->option->device_id);
 470
 471         if (opt->boot_image)
 472                 opt->option->boot_image_file = opt->boot_image->url->full;
 473         if (opt->initrd)
 474                 opt->option->initrd_file = opt->initrd->url->full;
 475         if (opt->dtb)
 476                 opt->option->dtb_file = opt->dtb->url->full;
 477         if (opt->icon)
 478                 opt->option->icon_file = opt->icon->url->full;
 479
 480         opt->option->device_id = opt->device->device->id;
 481
 482         if (opt->option->is_default)
 483                 set_default(handler, opt);
 484 }
 485
 486 static void notify_boot_option(struct device_handler *handler,
 487                 struct discover_boot_option *opt)
 488 {
 489         struct discover_device *dev = opt->device;
 490
 491         if (!dev->notified)
 492                 discover_server_notify_device_add(handler->server,
 493                                                   opt->device->device);
 494         dev->notified = true;
 495         discover_server_notify_boot_option_add(handler->server, opt->option);
 496 }
 497
 498 static void process_boot_option_queue(struct device_handler *handler)
 499 {
 500         struct discover_boot_option *opt, *tmp;
 501
 502         list_for_each_entry_safe(&handler->unresolved_boot_options,
 503                         opt, tmp, list) {
 504
 505                 pb_debug("queue: attempting resolution for %s\n",
 506                                 opt->option->id);
 507
 508                 if (!boot_option_resolve(opt, handler))
 509                         continue;
 510
 511                 pb_debug("\tresolved!\n");
 512
 513                 list_remove(&opt->list);
 514                 list_add_tail(&opt->device->boot_options, &opt->list);
 515                 talloc_steal(opt->device, opt);
 516                 boot_option_finalise(handler, opt);
 517                 notify_boot_option(handler, opt);
 518         }
 519 }
 520
 521 struct discover_context *device_handler_discover_context_create(
 522                 struct device_handler *handler,
 523                 struct discover_device *device)
 524 {
 525         struct discover_context *ctx;
 526
 527         ctx = talloc_zero(handler, struct discover_context);
 528         ctx->device = device;
 529         list_init(&ctx->boot_options);
 530
 531         return ctx;
 532 }
 533
 534 /**
 535  * context_commit - Commit a temporary discovery context to the handler,
 536  * and notify the clients about any new options / devices
 537  */
 538 void device_handler_discover_context_commit(struct device_handler *handler,
 539                 struct discover_context *ctx)
 540 {
 541         struct discover_device *dev = ctx->device;
 542         struct discover_boot_option *opt, *tmp;
 543
 544         if (!device_lookup_by_id(handler, dev->device->id))
 545                 device_handler_add_device(handler, dev);
 546
 547         /* move boot options from the context to the device */
 548         list_for_each_entry_safe(&ctx->boot_options, opt, tmp, list) {
 549                 list_remove(&opt->list);
 550
 551                 if (boot_option_resolve(opt, handler)) {
 552                         pb_log("boot option %s is resolved, "
 553                                         "sending to clients\n",
 554                                         opt->option->id);
 555                         list_add_tail(&dev->boot_options, &opt->list);
 556                         talloc_steal(dev, opt);
 557                         boot_option_finalise(handler, opt);
 558                         notify_boot_option(handler, opt);
 559                 } else {
 560                         if (!opt->source->resolve_resource) {
 561                                 pb_log("parser %s gave us an unresolved "
 562                                         "resource (%s), but no way to "
 563                                         "resolve it\n",
 564                                         opt->source->name, opt->option->id);
 565                                 talloc_free(opt);
 566                         } else {
 567                                 pb_log("boot option %s is unresolved, "
 568                                                 "adding to queue\n",
 569                                                 opt->option->id);
 570                                 list_add(&handler->unresolved_boot_options,
 571                                                 &opt->list);
 572                                 talloc_steal(handler, opt);
 573                         }
 574                 }
 575         }
 576 }
 577
 578 void device_handler_add_device(struct device_handler *handler,
 579                 struct discover_device *device)
 580 {
 581         handler->n_devices++;
 582         handler->devices = talloc_realloc(handler, handler->devices,
 583                                 struct discover_device *, handler->n_devices);
 584         handler->devices[handler->n_devices - 1] = device;
 585
 586 }
 587
 588 /* Start discovery on a hotplugged device. The device will be in our devices
 589  * array, but has only just been initialised by the hotplug source.
 590  */
 591 int device_handler_discover(struct device_handler *handler,
 592                 struct discover_device *dev)
 593 {
 594         struct discover_context *ctx;
 595         int rc;
 596
 597         process_boot_option_queue(handler);
 598
 599         /* create our context */
 600         ctx = device_handler_discover_context_create(handler, dev);
 601
 602         rc = mount_device(dev);
 603         if (rc)
 604                 goto out;
 605
 606         /* add this device to our system info */
 607         system_info_register_blockdev(dev->device->id, dev->uuid,
 608                         dev->mount_path);
 609
 610         /* run the parsers. This will populate the ctx's boot_option list. */
 611         iterate_parsers(ctx);
 612
 613         /* add discovered stuff to the handler */
 614         device_handler_discover_context_commit(handler, ctx);
 615
 616 out:
 617         talloc_free(ctx);
 618
 619         return 0;
 620 }
 621
 622 /* Incoming dhcp event */
 623 int device_handler_dhcp(struct device_handler *handler,
 624                 struct discover_device *dev, struct event *event)
 625 {
 626         struct discover_context *ctx;
 627
 628         /* create our context */
 629         ctx = device_handler_discover_context_create(handler, dev);
 630         ctx->event = event;
 631
 632         iterate_parsers(ctx);
 633
 634         device_handler_discover_context_commit(handler, ctx);
 635
 636         talloc_free(ctx);
 637
 638         return 0;
 639 }
 640
 641 /* incoming conf event */
 642 int device_handler_conf(struct device_handler *handler,
 643                 struct discover_device *dev, struct pb_url *url)
 644 {
 645         struct discover_context *ctx;
 646
 647         /* create our context */
 648         ctx = device_handler_discover_context_create(handler, dev);
 649         ctx->conf_url = url;
 650
 651         iterate_parsers(ctx);
 652
 653         device_handler_discover_context_commit(handler, ctx);
 654
 655         talloc_free(ctx);
 656
 657         return 0;
 658 }
 659
 660 static struct discover_boot_option *find_boot_option_by_id(
 661                 struct device_handler *handler, const char *id)
 662 {
 663         unsigned int i;
 664
 665         for (i = 0; i < handler->n_devices; i++) {
 666                 struct discover_device *dev = handler->devices[i];
 667                 struct discover_boot_option *opt;
 668
 669                 list_for_each_entry(&dev->boot_options, opt, list)
 670                         if (!strcmp(opt->option->id, id))
 671                                 return opt;
 672         }
 673
 674         return NULL;
 675 }
 676
 677 void device_handler_boot(struct device_handler *handler,
 678                 struct boot_command *cmd)
 679 {
 680         struct discover_boot_option *opt = NULL;
 681
 682         if (cmd->option_id && strlen(cmd->option_id))
 683                 opt = find_boot_option_by_id(handler, cmd->option_id);
 684
 685         if (handler->pending_boot)
 686                 boot_cancel(handler->pending_boot);
 687         handler->pending_boot = boot(handler, opt, cmd, handler->dry_run,
 688                         boot_status, handler);
 689         handler->pending_boot_is_default = false;
 690 }
 691
 692 void device_handler_cancel_default(struct device_handler *handler)
 693 {
 694         struct boot_status status;
 695
 696         if (handler->timeout_waiter)
 697                 waiter_remove(handler->timeout_waiter);
 698
 699         handler->timeout_waiter = NULL;
 700         handler->autoboot_enabled = false;
 701
 702         /* we only send status if we had a default boot option queued */
 703         if (!handler->default_boot_option)
 704                 return;
 705
 706         pb_log("Cancelling default boot option\n");
 707
 708         if (handler->pending_boot && handler->pending_boot_is_default) {
 709                 boot_cancel(handler->pending_boot);
 710                 handler->pending_boot = NULL;
 711                 handler->pending_boot_is_default = false;
 712         }
 713
 714         handler->default_boot_option = NULL;
 715
 716         status.type = BOOT_STATUS_INFO;
 717         status.progress = -1;
 718         status.detail = NULL;
 719         status.message = "Default boot cancelled";
 720
 721         discover_server_notify_boot_status(handler->server, &status);
 722 }
 723
 724 void device_handler_update_config(struct device_handler *handler,
 725                 struct config *config)
 726 {
 727         config_set(config);
 728         discover_server_notify_config(handler->server, config);
 729 }
 730
 731 #ifndef PETITBOOT_TEST
 732 static bool check_existing_mount(struct discover_device *dev)
 733 {
 734         struct stat devstat, mntstat;
 735         struct mntent *mnt;
 736         FILE *fp;
 737         int rc;
 738
 739         rc = stat(dev->device_path, &devstat);
 740         if (rc) {
 741                 pb_debug("%s: stat failed: %s\n", __func__, strerror(errno));
 742                 return false;
 743         }
 744
 745         if (!S_ISBLK(devstat.st_mode)) {
 746                 pb_debug("%s: %s isn't a block device?\n", __func__,
 747                                 dev->device_path);
 748                 return false;
 749         }
 750
 751         fp = fopen("/proc/self/mounts", "r");
 752
 753         for (;;) {
 754                 mnt = getmntent(fp);
 755                 if (!mnt)
 756                         break;
 757
 758                 if (!mnt->mnt_fsname || mnt->mnt_fsname[0] != '/')
 759                         continue;
 760
 761                 rc = stat(mnt->mnt_fsname, &mntstat);
 762                 if (rc)
 763                         continue;
 764
 765                 if (!S_ISBLK(mntstat.st_mode))
 766                         continue;
 767
 768                 if (mntstat.st_rdev == devstat.st_rdev) {
 769                         dev->mount_path = talloc_strdup(dev, mnt->mnt_dir);
 770                         dev->mounted_rw = !!hasmntopt(mnt, "rw");
 771                         dev->mounted = true;
 772                         dev->unmount = false;
 773
 774                         pb_debug("%s: %s is already mounted (r%c) at %s\n",
 775                                         __func__, dev->device_path,
 776                                         dev->mounted_rw ? 'w' : 'o',
 777                                         mnt->mnt_dir);
 778                         break;
 779                 }
 780         }
 781
 782         fclose(fp);
 783
 784         return mnt != NULL;
 785 }
 786
 787 static int mount_device(struct discover_device *dev)
 788 {
 789         int rc;
 790
 791         if (!dev->device_path)
 792                 return -1;
 793
 794         if (dev->mounted)
 795                 return 0;
 796
 797         if (check_existing_mount(dev))
 798                 return 0;
 799
 800         dev->mount_path = join_paths(dev, mount_base(),
 801                                         dev->device_path);
 802
 803         if (pb_mkdir_recursive(dev->mount_path)) {
 804                 pb_log("couldn't create mount directory %s: %s\n",
 805                                 dev->mount_path, strerror(errno));
 806                 goto err_free;
 807         }
 808
 809         rc = process_run_simple(dev, pb_system_apps.mount,
 810                         dev->device_path, dev->mount_path,
 811                         "-o", "ro", NULL);
 812         if (!rc) {
 813                 dev->mounted = true;
 814                 dev->mounted_rw = false;
 815                 dev->unmount = true;
 816                 return 0;
 817         }
 818
 819         /* Retry mount without ro option. */
 820         rc = process_run_simple(dev, pb_system_apps.mount,
 821                         dev->device_path, dev->mount_path, NULL);
 822
 823         if (!rc) {
 824                 dev->mounted = true;
 825                 dev->mounted_rw = true;
 826                 dev->unmount = true;
 827                 return 0;
 828         }
 829
 830         pb_rmdir_recursive(mount_base(), dev->mount_path);
 831 err_free:
 832         talloc_free(dev->mount_path);
 833         dev->mount_path = NULL;
 834         return -1;
 835 }
 836
 837 static int umount_device(struct discover_device *dev)
 838 {
 839         int status;
 840
 841         if (!dev->mounted || !dev->unmount)
 842                 return 0;
 843
 844         status = process_run_simple(dev, pb_system_apps.umount,
 845                         dev->mount_path, NULL);
 846
 847         if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
 848                 return -1;
 849
 850         dev->mounted = false;
 851
 852         pb_rmdir_recursive(mount_base(), dev->mount_path);
 853
 854         talloc_free(dev->mount_path);
 855         dev->mount_path = NULL;
 856
 857         return 0;
 858 }
 859
 860 int device_request_write(struct discover_device *dev, bool *release)
 861 {
 862         int rc;
 863
 864         *release = false;
 865
 866         if (!dev->mounted)
 867                 return -1;
 868
 869         if (dev->mounted_rw)
 870                 return 0;
 871
 872         rc = process_run_simple(dev, pb_system_apps.mount, dev->mount_path,
 873                         "-o", "remount,rw", NULL);
 874         if (rc)
 875                 return -1;
 876
 877         dev->mounted_rw = true;
 878         *release = true;
 879         return 0;
 880 }
 881
 882 void device_release_write(struct discover_device *dev, bool release)
 883 {
 884         if (!release)
 885                 return;
 886
 887         process_run_simple(dev, pb_system_apps.mount, dev->mount_path,
 888                         "-o", "remount,ro", NULL);
 889         dev->mounted_rw = false;
 890 }
 891
 892 #else
 893
 894 static int umount_device(struct discover_device *dev __attribute__((unused)))
 895 {
 896         return 0;
 897 }
 898
 899 static int __attribute__((unused)) mount_device(
 900                 struct discover_device *dev __attribute__((unused)))
 901 {
 902         return 0;
 903 }
 904
 905 int device_request_write(struct discover_device *dev __attribute__((unused)),
 906                 bool *release)
 907 {
 908         *release = true;
 909         return 0;
 910 }
 911
 912 void device_release_write(struct discover_device *dev __attribute__((unused)),
 913         bool release __attribute__((unused)))
 914 {
 915 }
 916
 917 #endif
 918