src/gpt-auto-generator/gpt-auto-generator.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include <blkid.h>
   4 #include <stdlib.h>
   5 #include <sys/statfs.h>
   6 #include <unistd.h>
   7
   8 #include "sd-device.h"
   9 #include "sd-id128.h"
  10
  11 #include "alloc-util.h"
  12 #include "blkid-util.h"
  13 #include "blockdev-util.h"
  14 #include "btrfs-util.h"
  15 #include "device-util.h"
  16 #include "dirent-util.h"
  17 #include "dissect-image.h"
  18 #include "efivars.h"
  19 #include "fd-util.h"
  20 #include "fileio.h"
  21 #include "fs-util.h"
  22 #include "fstab-util.h"
  23 #include "generator.h"
  24 #include "gpt.h"
  25 #include "missing.h"
  26 #include "mkdir.h"
  27 #include "mountpoint-util.h"
  28 #include "parse-util.h"
  29 #include "path-util.h"
  30 #include "proc-cmdline.h"
  31 #include "special.h"
  32 #include "specifier.h"
  33 #include "stat-util.h"
  34 #include "string-util.h"
  35 #include "strv.h"
  36 #include "unit-name.h"
  37 #include "util.h"
  38 #include "virt.h"
  39
  40 static const char *arg_dest = NULL;
  41 static bool arg_enabled = true;
  42 static bool arg_root_enabled = true;
  43 static int arg_root_rw = -1;
  44
  45 static int add_cryptsetup(const char *id, const char *what, bool rw, bool require, char **device) {
  46         _cleanup_free_ char *e = NULL, *n = NULL, *d = NULL, *id_escaped = NULL, *what_escaped = NULL;
  47         _cleanup_fclose_ FILE *f = NULL;
  48         const char *p;
  49         int r;
  50
  51         assert(id);
  52         assert(what);
  53
  54         r = unit_name_from_path(what, ".device", &d);
  55         if (r < 0)
  56                 return log_error_errno(r, "Failed to generate unit name: %m");
  57
  58         e = unit_name_escape(id);
  59         if (!e)
  60                 return log_oom();
  61
  62         r = unit_name_build("systemd-cryptsetup", e, ".service", &n);
  63         if (r < 0)
  64                 return log_error_errno(r, "Failed to generate unit name: %m");
  65
  66         id_escaped = specifier_escape(id);
  67         if (!id_escaped)
  68                 return log_oom();
  69
  70         what_escaped = specifier_escape(what);
  71         if (!what_escaped)
  72                 return log_oom();
  73
  74         p = strjoina(arg_dest, "/", n);
  75         f = fopen(p, "wxe");
  76         if (!f)
  77                 return log_error_errno(errno, "Failed to create unit file %s: %m", p);
  78
  79         fprintf(f,
  80                 "# Automatically generated by systemd-gpt-auto-generator\n\n"
  81                 "[Unit]\n"
  82                 "Description=Cryptography Setup for %%I\n"
  83                 "Documentation=man:systemd-gpt-auto-generator(8) man:systemd-cryptsetup@.service(8)\n"
  84                 "DefaultDependencies=no\n"
  85                 "Conflicts=umount.target\n"
  86                 "BindsTo=dev-mapper-%%i.device %s\n"
  87                 "Before=umount.target cryptsetup.target\n"
  88                 "After=%s\n"
  89                 "IgnoreOnIsolate=true\n"
  90                 "[Service]\n"
  91                 "Type=oneshot\n"
  92                 "RemainAfterExit=yes\n"
  93                 "TimeoutSec=0\n" /* the binary handles timeouts anyway */
  94                 "KeyringMode=shared\n" /* make sure we can share cached keys among instances */
  95                 "ExecStart=" SYSTEMD_CRYPTSETUP_PATH " attach '%s' '%s' '' '%s'\n"
  96                 "ExecStop=" SYSTEMD_CRYPTSETUP_PATH " detach '%s'\n",
  97                 d, d,
  98                 id_escaped, what_escaped, rw ? "" : "read-only",
  99                 id_escaped);
 100
 101         r = fflush_and_check(f);
 102         if (r < 0)
 103                 return log_error_errno(r, "Failed to write file %s: %m", p);
 104
 105         r = generator_add_symlink(arg_dest, d, "wants", n);
 106         if (r < 0)
 107                 return r;
 108
 109         if (require) {
 110                 const char *dmname;
 111
 112                 r = generator_add_symlink(arg_dest, "cryptsetup.target", "requires", n);
 113                 if (r < 0)
 114                         return r;
 115
 116                 dmname = strjoina("dev-mapper-", e, ".device");
 117                 r = generator_add_symlink(arg_dest, dmname, "requires", n);
 118                 if (r < 0)
 119                         return r;
 120         }
 121
 122         p = strjoina(arg_dest, "/dev-mapper-", e, ".device.d/50-job-timeout-sec-0.conf");
 123         mkdir_parents_label(p, 0755);
 124         r = write_string_file(p,
 125                         "# Automatically generated by systemd-gpt-auto-generator\n\n"
 126                         "[Unit]\n"
 127                         "JobTimeoutSec=0\n",
 128                         WRITE_STRING_FILE_CREATE); /* the binary handles timeouts anyway */
 129         if (r < 0)
 130                 return log_error_errno(r, "Failed to write device drop-in: %m");
 131
 132         if (device) {
 133                 char *ret;
 134
 135                 ret = strappend("/dev/mapper/", id);
 136                 if (!ret)
 137                         return log_oom();
 138
 139                 *device = ret;
 140         }
 141
 142         return 0;
 143 }
 144
 145 static int add_mount(
 146                 const char *id,
 147                 const char *what,
 148                 const char *where,
 149                 const char *fstype,
 150                 bool rw,
 151                 const char *options,
 152                 const char *description,
 153                 const char *post) {
 154
 155         _cleanup_free_ char *unit = NULL, *crypto_what = NULL, *p = NULL;
 156         _cleanup_fclose_ FILE *f = NULL;
 157         int r;
 158
 159         /* Note that we don't apply specifier escaping on the input strings here, since we know they are not configured
 160          * externally, but all originate from our own sources here, and hence we know they contain no % characters that
 161          * could potentially be understood as specifiers. */
 162
 163         assert(id);
 164         assert(what);
 165         assert(where);
 166         assert(description);
 167
 168         log_debug("Adding %s: %s %s", where, what, strna(fstype));
 169
 170         if (streq_ptr(fstype, "crypto_LUKS")) {
 171
 172                 r = add_cryptsetup(id, what, rw, true, &crypto_what);
 173                 if (r < 0)
 174                         return r;
 175
 176                 what = crypto_what;
 177                 fstype = NULL;
 178         }
 179
 180         r = unit_name_from_path(where, ".mount", &unit);
 181         if (r < 0)
 182                 return log_error_errno(r, "Failed to generate unit name: %m");
 183
 184         p = path_join(empty_to_root(arg_dest), unit);
 185         if (!p)
 186                 return log_oom();
 187
 188         f = fopen(p, "wxe");
 189         if (!f)
 190                 return log_error_errno(errno, "Failed to create unit file %s: %m", unit);
 191
 192         fprintf(f,
 193                 "# Automatically generated by systemd-gpt-auto-generator\n\n"
 194                 "[Unit]\n"
 195                 "Description=%s\n"
 196                 "Documentation=man:systemd-gpt-auto-generator(8)\n",
 197                 description);
 198
 199         if (post)
 200                 fprintf(f, "Before=%s\n", post);
 201
 202         r = generator_write_fsck_deps(f, arg_dest, what, where, fstype);
 203         if (r < 0)
 204                 return r;
 205
 206         fprintf(f,
 207                 "\n"
 208                 "[Mount]\n"
 209                 "What=%s\n"
 210                 "Where=%s\n",
 211                 what, where);
 212
 213         if (fstype)
 214                 fprintf(f, "Type=%s\n", fstype);
 215
 216         if (options)
 217                 fprintf(f, "Options=%s,%s\n", options, rw ? "rw" : "ro");
 218         else
 219                 fprintf(f, "Options=%s\n", rw ? "rw" : "ro");
 220
 221         r = fflush_and_check(f);
 222         if (r < 0)
 223                 return log_error_errno(r, "Failed to write unit file %s: %m", p);
 224
 225         if (post)
 226                 return generator_add_symlink(arg_dest, post, "requires", unit);
 227         return 0;
 228 }
 229
 230 static int path_is_busy(const char *where) {
 231         int r;
 232
 233         /* already a mountpoint; generators run during reload */
 234         r = path_is_mount_point(where, NULL, AT_SYMLINK_FOLLOW);
 235         if (r > 0)
 236                 return false;
 237
 238         /* the directory might not exist on a stateless system */
 239         if (r == -ENOENT)
 240                 return false;
 241
 242         if (r < 0)
 243                 return log_warning_errno(r, "Cannot check if \"%s\" is a mount point: %m", where);
 244
 245         /* not a mountpoint but it contains files */
 246         r = dir_is_empty(where);
 247         if (r < 0)
 248                 return log_warning_errno(r, "Cannot check if \"%s\" is empty: %m", where);
 249         if (r > 0)
 250                 return false;
 251
 252         log_debug("\"%s\" already populated, ignoring.", where);
 253         return true;
 254 }
 255
 256 static int add_partition_mount(
 257                 DissectedPartition *p,
 258                 const char *id,
 259                 const char *where,
 260                 const char *description) {
 261
 262         int r;
 263         assert(p);
 264
 265         r = path_is_busy(where);
 266         if (r != 0)
 267                 return r < 0 ? r : 0;
 268
 269         return add_mount(
 270                         id,
 271                         p->node,
 272                         where,
 273                         p->fstype,
 274                         p->rw,
 275                         NULL,
 276                         description,
 277                         SPECIAL_LOCAL_FS_TARGET);
 278 }
 279
 280 static int add_swap(const char *path) {
 281         _cleanup_free_ char *name = NULL, *unit = NULL;
 282         _cleanup_fclose_ FILE *f = NULL;
 283         int r;
 284
 285         assert(path);
 286
 287         /* Disable the swap auto logic if at least one swap is defined in /etc/fstab, see #6192. */
 288         r = fstab_has_fstype("swap");
 289         if (r < 0)
 290                 return log_error_errno(r, "Failed to parse fstab: %m");
 291         if (r > 0) {
 292                 log_debug("swap specified in fstab, ignoring.");
 293                 return 0;
 294         }
 295
 296         log_debug("Adding swap: %s", path);
 297
 298         r = unit_name_from_path(path, ".swap", &name);
 299         if (r < 0)
 300                 return log_error_errno(r, "Failed to generate unit name: %m");
 301
 302         unit = path_join(empty_to_root(arg_dest), name);
 303         if (!unit)
 304                 return log_oom();
 305
 306         f = fopen(unit, "wxe");
 307         if (!f)
 308                 return log_error_errno(errno, "Failed to create unit file %s: %m", unit);
 309
 310         fprintf(f,
 311                 "# Automatically generated by systemd-gpt-auto-generator\n\n"
 312                 "[Unit]\n"
 313                 "Description=Swap Partition\n"
 314                 "Documentation=man:systemd-gpt-auto-generator(8)\n\n"
 315                 "[Swap]\n"
 316                 "What=%s\n",
 317                 path);
 318
 319         r = fflush_and_check(f);
 320         if (r < 0)
 321                 return log_error_errno(r, "Failed to write unit file %s: %m", unit);
 322
 323         return generator_add_symlink(arg_dest, SPECIAL_SWAP_TARGET, "wants", name);
 324 }
 325
 326 static int add_automount(
 327                 const char *id,
 328                 const char *what,
 329                 const char *where,
 330                 const char *fstype,
 331                 bool rw,
 332                 const char *options,
 333                 const char *description,
 334                 usec_t timeout) {
 335
 336         _cleanup_free_ char *unit = NULL;
 337         _cleanup_fclose_ FILE *f = NULL;
 338         const char *opt = "noauto", *p;
 339         int r;
 340
 341         assert(id);
 342         assert(where);
 343         assert(description);
 344
 345         if (options)
 346                 opt = strjoina(options, ",", opt);
 347
 348         r = add_mount(id,
 349                       what,
 350                       where,
 351                       fstype,
 352                       rw,
 353                       opt,
 354                       description,
 355                       NULL);
 356         if (r < 0)
 357                 return r;
 358
 359         r = unit_name_from_path(where, ".automount", &unit);
 360         if (r < 0)
 361                 return log_error_errno(r, "Failed to generate unit name: %m");
 362
 363         p = strjoina(arg_dest, "/", unit);
 364         f = fopen(p, "wxe");
 365         if (!f)
 366                 return log_error_errno(errno, "Failed to create unit file %s: %m", unit);
 367
 368         fprintf(f,
 369                 "# Automatically generated by systemd-gpt-auto-generator\n\n"
 370                 "[Unit]\n"
 371                 "Description=%s\n"
 372                 "Documentation=man:systemd-gpt-auto-generator(8)\n"
 373                 "[Automount]\n"
 374                 "Where=%s\n"
 375                 "TimeoutIdleSec="USEC_FMT"\n",
 376                 description,
 377                 where,
 378                 timeout / USEC_PER_SEC);
 379
 380         r = fflush_and_check(f);
 381         if (r < 0)
 382                 return log_error_errno(r, "Failed to write unit file %s: %m", p);
 383
 384         return generator_add_symlink(arg_dest, SPECIAL_LOCAL_FS_TARGET, "wants", unit);
 385 }
 386
 387 static int add_xbootldr(DissectedPartition *p) {
 388         int r;
 389
 390         assert(p);
 391
 392         if (in_initrd()) {
 393                 log_debug("In initrd, ignoring the XBOOTLDR partition.");
 394                 return 0;
 395         }
 396
 397         r = fstab_is_mount_point("/boot");
 398         if (r < 0)
 399                 return log_error_errno(r, "Failed to parse fstab: %m");
 400         if (r > 0) {
 401                 log_debug("/boot specified in fstab, ignoring XBOOTLDR partition.");
 402                 return 0;
 403         }
 404
 405         r = path_is_busy("/boot");
 406         if (r < 0)
 407                 return r;
 408         if (r > 0)
 409                 return 0;
 410
 411         return add_automount("boot",
 412                              p->node,
 413                              "/boot",
 414                              p->fstype,
 415                              true,
 416                              "umask=0077",
 417                              "Boot Loader Partition",
 418                              120 * USEC_PER_SEC);
 419 }
 420
 421 #if ENABLE_EFI
 422 static int add_esp(DissectedPartition *p, bool has_xbootldr) {
 423         const char *esp_path = NULL, *id = NULL;
 424         int r;
 425
 426         assert(p);
 427
 428         if (in_initrd()) {
 429                 log_debug("In initrd, ignoring the ESP.");
 430                 return 0;
 431         }
 432
 433         /* If /efi exists we'll use that. Otherwise we'll use /boot, as that's usually the better choice, but
 434          * only if there's no explicit XBOOTLDR partition around. */
 435         if (access("/efi", F_OK) < 0) {
 436                 if (errno != ENOENT)
 437                         return log_error_errno(errno, "Failed to determine whether /efi exists: %m");
 438
 439                 /* Use /boot as fallback, but only if there's no XBOOTLDR partition */
 440                 if (!has_xbootldr) {
 441                         esp_path = "/boot";
 442                         id = "boot";
 443                 }
 444         }
 445         if (!esp_path)
 446                 esp_path = "/efi";
 447         if (!id)
 448                 id = "efi";
 449
 450         /* We create an .automount which is not overridden by the .mount from the fstab generator. */
 451         r = fstab_is_mount_point(esp_path);
 452         if (r < 0)
 453                 return log_error_errno(r, "Failed to parse fstab: %m");
 454         if (r > 0) {
 455                 log_debug("%s specified in fstab, ignoring.", esp_path);
 456                 return 0;
 457         }
 458
 459         r = path_is_busy(esp_path);
 460         if (r < 0)
 461                 return r;
 462         if (r > 0)
 463                 return 0;
 464
 465         if (is_efi_boot()) {
 466                 sd_id128_t loader_uuid;
 467
 468                 /* If this is an EFI boot, be extra careful, and only mount the ESP if it was the ESP used for booting. */
 469
 470                 r = efi_loader_get_device_part_uuid(&loader_uuid);
 471                 if (r == -ENOENT) {
 472                         log_debug("EFI loader partition unknown.");
 473                         return 0;
 474                 }
 475                 if (r < 0)
 476                         return log_error_errno(r, "Failed to read ESP partition UUID: %m");
 477
 478                 if (!sd_id128_equal(p->uuid, loader_uuid)) {
 479                         log_debug("Partition for %s does not appear to be the partition we are booted from.", p->node);
 480                         return 0;
 481                 }
 482         } else
 483                 log_debug("Not an EFI boot, skipping ESP check.");
 484
 485         return add_automount(id,
 486                              p->node,
 487                              esp_path,
 488                              p->fstype,
 489                              true,
 490                              "umask=0077",
 491                              "EFI System Partition Automount",
 492                              120 * USEC_PER_SEC);
 493 }
 494 #else
 495 static int add_esp(DissectedPartition *p, bool has_xbootldr) {
 496         return 0;
 497 }
 498 #endif
 499
 500 static int add_root_rw(DissectedPartition *p) {
 501         const char *path;
 502         int r;
 503
 504         assert(p);
 505
 506         if (in_initrd()) {
 507                 log_debug("In initrd, not generating drop-in for systemd-remount-fs.service.");
 508                 return 0;
 509         }
 510
 511         if (arg_root_rw >= 0) {
 512                 log_debug("Parameter ro/rw specified on kernel command line, not generating drop-in for systemd-remount-fs.service.");
 513                 return 0;
 514         }
 515
 516         if (!p->rw) {
 517                 log_debug("Root partition marked read-only in GPT partition table, not generating drop-in for systemd-remount-fs.service.");
 518                 return 0;
 519         }
 520
 521         (void) generator_enable_remount_fs_service(arg_dest);
 522
 523         path = strjoina(arg_dest, "/systemd-remount-fs.service.d/50-remount-rw.conf");
 524
 525         r = write_string_file(path,
 526                               "# Automatically generated by systemd-gpt-generator\n\n"
 527                               "[Service]\n"
 528                               "Environment=SYSTEMD_REMOUNT_ROOT_RW=1\n",
 529                               WRITE_STRING_FILE_CREATE|WRITE_STRING_FILE_NOFOLLOW|WRITE_STRING_FILE_MKDIR_0755);
 530         if (r < 0)
 531                 return log_error_errno(r, "Failed to write drop-in file %s: %m", path);
 532
 533         return 0;
 534 }
 535
 536 static int open_parent_devno(dev_t devnum, int *ret) {
 537         _cleanup_(sd_device_unrefp) sd_device *d = NULL;
 538         const char *name, *devtype, *node;
 539         sd_device *parent;
 540         dev_t pn;
 541         int fd, r;
 542
 543         assert(ret);
 544
 545         r = sd_device_new_from_devnum(&d, 'b', devnum);
 546         if (r < 0)
 547                 return log_debug_errno(r, "Failed to open device: %m");
 548
 549         if (sd_device_get_devname(d, &name) < 0) {
 550                 r = sd_device_get_syspath(d, &name);
 551                 if (r < 0) {
 552                         log_device_debug_errno(d, r, "Device %u:%u does not have a name, ignoring: %m", major(devnum), minor(devnum));
 553                         return 0;
 554                 }
 555         }
 556
 557         r = sd_device_get_parent(d, &parent);
 558         if (r < 0) {
 559                 log_device_debug_errno(d, r, "Not a partitioned device, ignoring: %m");
 560                 return 0;
 561         }
 562
 563         /* Does it have a devtype? */
 564         r = sd_device_get_devtype(parent, &devtype);
 565         if (r < 0) {
 566                 log_device_debug_errno(parent, r, "Parent doesn't have a device type, ignoring: %m");
 567                 return 0;
 568         }
 569
 570         /* Is this a disk or a partition? We only care for disks... */
 571         if (!streq(devtype, "disk")) {
 572                 log_device_debug(parent, "Parent isn't a raw disk, ignoring.");
 573                 return 0;
 574         }
 575
 576         /* Does it have a device node? */
 577         r = sd_device_get_devname(parent, &node);
 578         if (r < 0) {
 579                 log_device_debug_errno(parent, r, "Parent device does not have device node, ignoring: %m");
 580                 return 0;
 581         }
 582
 583         log_device_debug(d, "Root device %s.", node);
 584
 585         r = sd_device_get_devnum(parent, &pn);
 586         if (r < 0) {
 587                 log_device_debug_errno(parent, r, "Parent device is not a proper block device, ignoring: %m");
 588                 return 0;
 589         }
 590
 591         fd = open(node, O_RDONLY|O_CLOEXEC|O_NOCTTY);
 592         if (fd < 0)
 593                 return log_error_errno(errno, "Failed to open %s: %m", node);
 594
 595         *ret = fd;
 596         return 1;
 597 }
 598
 599 static int enumerate_partitions(dev_t devnum) {
 600         _cleanup_close_ int fd = -1;
 601         _cleanup_(dissected_image_unrefp) DissectedImage *m = NULL;
 602         int r, k;
 603
 604         r = open_parent_devno(devnum, &fd);
 605         if (r <= 0)
 606                 return r;
 607
 608         r = dissect_image(fd, NULL, 0, DISSECT_IMAGE_GPT_ONLY|DISSECT_IMAGE_NO_UDEV, &m);
 609         if (r == -ENOPKG) {
 610                 log_debug_errno(r, "No suitable partition table found, ignoring.");
 611                 return 0;
 612         }
 613         if (r < 0)
 614                 return log_error_errno(r, "Failed to dissect: %m");
 615
 616         if (m->partitions[PARTITION_SWAP].found) {
 617                 k = add_swap(m->partitions[PARTITION_SWAP].node);
 618                 if (k < 0)
 619                         r = k;
 620         }
 621
 622         if (m->partitions[PARTITION_XBOOTLDR].found) {
 623                 k = add_xbootldr(m->partitions + PARTITION_XBOOTLDR);
 624                 if (k < 0)
 625                         r = k;
 626         }
 627
 628         if (m->partitions[PARTITION_ESP].found) {
 629                 k = add_esp(m->partitions + PARTITION_ESP, m->partitions[PARTITION_XBOOTLDR].found);
 630                 if (k < 0)
 631                         r = k;
 632         }
 633
 634         if (m->partitions[PARTITION_HOME].found) {
 635                 k = add_partition_mount(m->partitions + PARTITION_HOME, "home", "/home", "Home Partition");
 636                 if (k < 0)
 637                         r = k;
 638         }
 639
 640         if (m->partitions[PARTITION_SRV].found) {
 641                 k = add_partition_mount(m->partitions + PARTITION_SRV, "srv", "/srv", "Server Data Partition");
 642                 if (k < 0)
 643                         r = k;
 644         }
 645
 646         if (m->partitions[PARTITION_ROOT].found) {
 647                 k = add_root_rw(m->partitions + PARTITION_ROOT);
 648                 if (k < 0)
 649                         r = k;
 650         }
 651
 652         return r;
 653 }
 654
 655 static int parse_proc_cmdline_item(const char *key, const char *value, void *data) {
 656         int r;
 657
 658         assert(key);
 659
 660         if (proc_cmdline_key_streq(key, "systemd.gpt_auto") ||
 661             proc_cmdline_key_streq(key, "rd.systemd.gpt_auto")) {
 662
 663                 r = value ? parse_boolean(value) : 1;
 664                 if (r < 0)
 665                         log_warning_errno(r, "Failed to parse gpt-auto switch \"%s\", ignoring: %m", value);
 666                 else
 667                         arg_enabled = r;
 668
 669         } else if (proc_cmdline_key_streq(key, "root")) {
 670
 671                 if (proc_cmdline_value_missing(key, value))
 672                         return 0;
 673
 674                 /* Disable root disk logic if there's a root= value
 675                  * specified (unless it happens to be "gpt-auto") */
 676
 677                 arg_root_enabled = streq(value, "gpt-auto");
 678
 679         } else if (proc_cmdline_key_streq(key, "roothash")) {
 680
 681                 if (proc_cmdline_value_missing(key, value))
 682                         return 0;
 683
 684                 /* Disable root disk logic if there's roothash= defined (i.e. verity enabled) */
 685
 686                 arg_root_enabled = false;
 687
 688         } else if (proc_cmdline_key_streq(key, "rw") && !value)
 689                 arg_root_rw = true;
 690         else if (proc_cmdline_key_streq(key, "ro") && !value)
 691                 arg_root_rw = false;
 692
 693         return 0;
 694 }
 695
 696 #if ENABLE_EFI
 697 static int add_root_cryptsetup(void) {
 698
 699         /* If a device /dev/gpt-auto-root-luks appears, then make it pull in systemd-cryptsetup-root.service, which
 700          * sets it up, and causes /dev/gpt-auto-root to appear which is all we are looking for. */
 701
 702         return add_cryptsetup("root", "/dev/gpt-auto-root-luks", true, false, NULL);
 703 }
 704 #endif
 705
 706 static int add_root_mount(void) {
 707
 708 #if ENABLE_EFI
 709         int r;
 710
 711         if (!is_efi_boot()) {
 712                 log_debug("Not a EFI boot, not creating root mount.");
 713                 return 0;
 714         }
 715
 716         r = efi_loader_get_device_part_uuid(NULL);
 717         if (r == -ENOENT) {
 718                 log_debug("EFI loader partition unknown, exiting.");
 719                 return 0;
 720         } else if (r < 0)
 721                 return log_error_errno(r, "Failed to read ESP partition UUID: %m");
 722
 723         /* OK, we have an ESP partition, this is fantastic, so let's
 724          * wait for a root device to show up. A udev rule will create
 725          * the link for us under the right name. */
 726
 727         if (in_initrd()) {
 728                 r = generator_write_initrd_root_device_deps(arg_dest, "/dev/gpt-auto-root");
 729                 if (r < 0)
 730                         return 0;
 731
 732                 r = add_root_cryptsetup();
 733                 if (r < 0)
 734                         return r;
 735         }
 736
 737         /* Note that we do not need to enable systemd-remount-fs.service here. If
 738          * /etc/fstab exists, systemd-fstab-generator will pull it in for us. */
 739
 740         return add_mount(
 741                         "root",
 742                         "/dev/gpt-auto-root",
 743                         in_initrd() ? "/sysroot" : "/",
 744                         NULL,
 745                         arg_root_rw > 0,
 746                         NULL,
 747                         "Root Partition",
 748                         in_initrd() ? SPECIAL_INITRD_ROOT_FS_TARGET : SPECIAL_LOCAL_FS_TARGET);
 749 #else
 750         return 0;
 751 #endif
 752 }
 753
 754 static int add_mounts(void) {
 755         dev_t devno;
 756         int r;
 757
 758         r = get_block_device_harder("/", &devno);
 759         if (r < 0)
 760                 return log_error_errno(r, "Failed to determine block device of root file system: %m");
 761         if (r == 0) {
 762                 r = get_block_device_harder("/usr", &devno);
 763                 if (r < 0)
 764                         return log_error_errno(r, "Failed to determine block device of /usr file system: %m");
 765                 if (r == 0) {
 766                         _cleanup_free_ char *p = NULL;
 767                         mode_t m;
 768
 769                         /* If the root mount has been replaced by some form of volatile file system (overlayfs), the
 770                          * original root block device node is symlinked in /run/systemd/volatile-root. Let's read that
 771                          * here. */
 772                         r = readlink_malloc("/run/systemd/volatile-root", &p);
 773                         if (r == -ENOENT) {
 774                                 log_debug("Neither root nor /usr file system are on a (single) block device.");
 775                                 return 0;
 776                         }
 777                         if (r < 0)
 778                                 return log_error_errno(r, "Failed to read symlink /run/systemd/volatile-root: %m");
 779
 780                         r = device_path_parse_major_minor(p, &m, &devno);
 781                         if (r < 0)
 782                                 return log_error_errno(r, "Failed to parse major/minor device node: %m");
 783                         if (!S_ISBLK(m))
 784                                 return log_error_errno(SYNTHETIC_ERRNO(ENOTBLK), "Volatile root device is of wrong type.");
 785                 }
 786         }
 787
 788         return enumerate_partitions(devno);
 789 }
 790
 791 static int run(const char *dest, const char *dest_early, const char *dest_late) {
 792         int r, k;
 793
 794         assert_se(arg_dest = dest_late);
 795
 796         if (detect_container() > 0) {
 797                 log_debug("In a container, exiting.");
 798                 return 0;
 799         }
 800
 801         r = proc_cmdline_parse(parse_proc_cmdline_item, NULL, 0);
 802         if (r < 0)
 803                 log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m");
 804
 805         if (!arg_enabled) {
 806                 log_debug("Disabled, exiting.");
 807                 return 0;
 808         }
 809
 810         if (arg_root_enabled)
 811                 r = add_root_mount();
 812
 813         if (!in_initrd()) {
 814                 k = add_mounts();
 815                 if (r >= 0)
 816                         r = k;
 817         }
 818
 819         return r;
 820 }
 821
 822 DEFINE_MAIN_GENERATOR_FUNCTION(run);