src/fstab-generator/fstab-generator.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <errno.h>
   4 #include <stdio.h>
   5 #include <unistd.h>
   6
   7 #include "alloc-util.h"
   8 #include "fd-util.h"
   9 #include "fileio.h"
  10 #include "fs-util.h"
  11 #include "fstab-util.h"
  12 #include "generator.h"
  13 #include "log.h"
  14 #include "main-func.h"
  15 #include "mkdir.h"
  16 #include "mount-setup.h"
  17 #include "mount-util.h"
  18 #include "mountpoint-util.h"
  19 #include "parse-util.h"
  20 #include "path-util.h"
  21 #include "proc-cmdline.h"
  22 #include "special.h"
  23 #include "specifier.h"
  24 #include "stat-util.h"
  25 #include "string-util.h"
  26 #include "strv.h"
  27 #include "unit-name.h"
  28 #include "util.h"
  29 #include "virt.h"
  30 #include "volatile-util.h"
  31
  32 typedef enum MountpointFlags {
  33         NOAUTO    = 1 << 0,
  34         NOFAIL    = 1 << 1,
  35         AUTOMOUNT = 1 << 2,
  36         MAKEFS    = 1 << 3,
  37         GROWFS    = 1 << 4,
  38         RWONLY    = 1 << 5,
  39 } MountpointFlags;
  40
  41 static const char *arg_dest = NULL;
  42 static const char *arg_dest_late = NULL;
  43 static bool arg_fstab_enabled = true;
  44 static bool arg_swap_enabled = true;
  45 static char *arg_root_what = NULL;
  46 static char *arg_root_fstype = NULL;
  47 static char *arg_root_options = NULL;
  48 static char *arg_root_hash = NULL;
  49 static int arg_root_rw = -1;
  50 static char *arg_usr_what = NULL;
  51 static char *arg_usr_fstype = NULL;
  52 static char *arg_usr_options = NULL;
  53 static VolatileMode arg_volatile_mode = _VOLATILE_MODE_INVALID;
  54
  55 STATIC_DESTRUCTOR_REGISTER(arg_root_what, freep);
  56 STATIC_DESTRUCTOR_REGISTER(arg_root_fstype, freep);
  57 STATIC_DESTRUCTOR_REGISTER(arg_root_options, freep);
  58 STATIC_DESTRUCTOR_REGISTER(arg_root_hash, freep);
  59 STATIC_DESTRUCTOR_REGISTER(arg_usr_what, freep);
  60 STATIC_DESTRUCTOR_REGISTER(arg_usr_fstype, freep);
  61 STATIC_DESTRUCTOR_REGISTER(arg_usr_options, freep);
  62
  63 static int write_options(FILE *f, const char *options) {
  64         _cleanup_free_ char *o = NULL;
  65
  66         if (isempty(options))
  67                 return 0;
  68
  69         if (streq(options, "defaults"))
  70                 return 0;
  71
  72         o = specifier_escape(options);
  73         if (!o)
  74                 return log_oom();
  75
  76         fprintf(f, "Options=%s\n", o);
  77         return 1;
  78 }
  79
  80 static int write_what(FILE *f, const char *what) {
  81         _cleanup_free_ char *w = NULL;
  82
  83         w = specifier_escape(what);
  84         if (!w)
  85                 return log_oom();
  86
  87         fprintf(f, "What=%s\n", w);
  88         return 1;
  89 }
  90
  91 static int add_swap(
  92                 const char *what,
  93                 struct mntent *me,
  94                 MountpointFlags flags) {
  95
  96         _cleanup_free_ char *name = NULL;
  97         _cleanup_fclose_ FILE *f = NULL;
  98         int r;
  99
 100         assert(what);
 101         assert(me);
 102
 103         if (!arg_swap_enabled) {
 104                 log_info("Swap unit generation disabled on kernel command line, ignoring fstab swap entry for %s.", what);
 105                 return 0;
 106         }
 107
 108         if (access("/proc/swaps", F_OK) < 0) {
 109                 log_info("Swap not supported, ignoring fstab swap entry for %s.", what);
 110                 return 0;
 111         }
 112
 113         if (detect_container() > 0) {
 114                 log_info("Running in a container, ignoring fstab swap entry for %s.", what);
 115                 return 0;
 116         }
 117
 118         r = unit_name_from_path(what, ".swap", &name);
 119         if (r < 0)
 120                 return log_error_errno(r, "Failed to generate unit name: %m");
 121
 122         r = generator_open_unit_file(arg_dest, fstab_path(), name, &f);
 123         if (r < 0)
 124                 return r;
 125
 126         fprintf(f,
 127                 "[Unit]\n"
 128                 "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n"
 129                 "SourcePath=%s\n",
 130                 fstab_path());
 131
 132         r = generator_write_blockdev_dependency(f, what);
 133         if (r < 0)
 134                 return r;
 135
 136         fprintf(f,
 137                 "\n"
 138                 "[Swap]\n");
 139
 140         r = write_what(f, what);
 141         if (r < 0)
 142                 return r;
 143
 144         r = write_options(f, me->mnt_opts);
 145         if (r < 0)
 146                 return r;
 147
 148         r = fflush_and_check(f);
 149         if (r < 0)
 150                 return log_error_errno(r, "Failed to write unit file %s: %m", name);
 151
 152         /* use what as where, to have a nicer error message */
 153         r = generator_write_timeouts(arg_dest, what, what, me->mnt_opts, NULL);
 154         if (r < 0)
 155                 return r;
 156
 157         if (flags & MAKEFS) {
 158                 r = generator_hook_up_mkswap(arg_dest, what);
 159                 if (r < 0)
 160                         return r;
 161         }
 162
 163         if (flags & GROWFS)
 164                 /* TODO: swap devices must be wiped and recreated */
 165                 log_warning("%s: growing swap devices is currently unsupported.", what);
 166
 167         if (!(flags & NOAUTO)) {
 168                 r = generator_add_symlink(arg_dest, SPECIAL_SWAP_TARGET,
 169                                           (flags & NOFAIL) ? "wants" : "requires", name);
 170                 if (r < 0)
 171                         return r;
 172         }
 173
 174         return 0;
 175 }
 176
 177 static bool mount_is_network(struct mntent *me) {
 178         assert(me);
 179
 180         return fstab_test_option(me->mnt_opts, "_netdev\0") ||
 181                fstype_is_network(me->mnt_type);
 182 }
 183
 184 static bool mount_in_initrd(struct mntent *me) {
 185         assert(me);
 186
 187         return fstab_test_option(me->mnt_opts, "x-initrd.mount\0") ||
 188                streq(me->mnt_dir, "/usr");
 189 }
 190
 191 static int write_timeout(
 192                 FILE *f,
 193                 const char *where,
 194                 const char *opts,
 195                 const char *filter,
 196                 const char *variable) {
 197
 198         _cleanup_free_ char *timeout = NULL;
 199         char timespan[FORMAT_TIMESPAN_MAX];
 200         usec_t u;
 201         int r;
 202
 203         r = fstab_filter_options(opts, filter, NULL, &timeout, NULL);
 204         if (r < 0)
 205                 return log_warning_errno(r, "Failed to parse options: %m");
 206         if (r == 0)
 207                 return 0;
 208
 209         r = parse_sec_fix_0(timeout, &u);
 210         if (r < 0) {
 211                 log_warning("Failed to parse timeout for %s, ignoring: %s", where, timeout);
 212                 return 0;
 213         }
 214
 215         fprintf(f, "%s=%s\n", variable, format_timespan(timespan, sizeof(timespan), u, 0));
 216
 217         return 0;
 218 }
 219
 220 static int write_idle_timeout(FILE *f, const char *where, const char *opts) {
 221         return write_timeout(f, where, opts,
 222                              "x-systemd.idle-timeout\0", "TimeoutIdleSec");
 223 }
 224
 225 static int write_mount_timeout(FILE *f, const char *where, const char *opts) {
 226         return write_timeout(f, where, opts,
 227                              "x-systemd.mount-timeout\0", "TimeoutSec");
 228 }
 229
 230 static int write_dependency(
 231                 FILE *f,
 232                 const char *opts,
 233                 const char *filter,
 234                 const char *format) {
 235
 236         _cleanup_strv_free_ char **names = NULL, **units = NULL;
 237         _cleanup_free_ char *res = NULL;
 238         char **s;
 239         int r;
 240
 241         assert(f);
 242         assert(opts);
 243
 244         r = fstab_extract_values(opts, filter, &names);
 245         if (r < 0)
 246                 return log_warning_errno(r, "Failed to parse options: %m");
 247         if (r == 0)
 248                 return 0;
 249
 250         STRV_FOREACH(s, names) {
 251                 char *x;
 252
 253                 r = unit_name_mangle_with_suffix(*s, "as dependency", 0, ".mount", &x);
 254                 if (r < 0)
 255                         return log_error_errno(r, "Failed to generate unit name: %m");
 256
 257                 r = strv_consume(&units, x);
 258                 if (r < 0)
 259                         return log_oom();
 260         }
 261
 262         if (units) {
 263                 res = strv_join(units, " ");
 264                 if (!res)
 265                         return log_oom();
 266
 267                 DISABLE_WARNING_FORMAT_NONLITERAL;
 268                 fprintf(f, format, res);
 269                 REENABLE_WARNING;
 270         }
 271
 272         return 0;
 273 }
 274
 275 static int write_after(FILE *f, const char *opts) {
 276         return write_dependency(f, opts,
 277                                 "x-systemd.after", "After=%1$s\n");
 278 }
 279
 280 static int write_requires_after(FILE *f, const char *opts) {
 281         return write_dependency(f, opts,
 282                                 "x-systemd.requires", "After=%1$s\nRequires=%1$s\n");
 283 }
 284
 285 static int write_before(FILE *f, const char *opts) {
 286         return write_dependency(f, opts,
 287                                 "x-systemd.before", "Before=%1$s\n");
 288 }
 289
 290 static int write_requires_mounts_for(FILE *f, const char *opts) {
 291         _cleanup_strv_free_ char **paths = NULL, **paths_escaped = NULL;
 292         _cleanup_free_ char *res = NULL;
 293         int r;
 294
 295         assert(f);
 296         assert(opts);
 297
 298         r = fstab_extract_values(opts, "x-systemd.requires-mounts-for", &paths);
 299         if (r < 0)
 300                 return log_warning_errno(r, "Failed to parse options: %m");
 301         if (r == 0)
 302                 return 0;
 303
 304         r = specifier_escape_strv(paths, &paths_escaped);
 305         if (r < 0)
 306                 return log_error_errno(r, "Failed to escape paths: %m");
 307
 308         res = strv_join(paths_escaped, " ");
 309         if (!res)
 310                 return log_oom();
 311
 312         fprintf(f, "RequiresMountsFor=%s\n", res);
 313
 314         return 0;
 315 }
 316
 317 static int write_extra_dependencies(FILE *f, const char *opts) {
 318         int r;
 319
 320         assert(f);
 321
 322         if (opts) {
 323                 r = write_after(f, opts);
 324                 if (r < 0)
 325                         return r;
 326                 r = write_requires_after(f, opts);
 327                 if (r < 0)
 328                         return r;
 329                 r = write_before(f, opts);
 330                 if (r < 0)
 331                         return r;
 332                 r = write_requires_mounts_for(f, opts);
 333                 if (r < 0)
 334                         return r;
 335         }
 336
 337         return 0;
 338 }
 339
 340 static int add_mount(
 341                 const char *dest,
 342                 const char *what,
 343                 const char *where,
 344                 const char *original_where,
 345                 const char *fstype,
 346                 const char *opts,
 347                 int passno,
 348                 MountpointFlags flags,
 349                 const char *post,
 350                 const char *source) {
 351
 352         _cleanup_free_ char
 353                 *name = NULL,
 354                 *automount_name = NULL,
 355                 *filtered = NULL,
 356                 *where_escaped = NULL;
 357         _cleanup_strv_free_ char **wanted_by = NULL, **required_by = NULL;
 358         _cleanup_fclose_ FILE *f = NULL;
 359         int r;
 360
 361         assert(what);
 362         assert(where);
 363         assert(opts);
 364         assert(post);
 365         assert(source);
 366
 367         if (streq_ptr(fstype, "autofs"))
 368                 return 0;
 369
 370         if (!is_path(where)) {
 371                 log_warning("Mount point %s is not a valid path, ignoring.", where);
 372                 return 0;
 373         }
 374
 375         if (mount_point_is_api(where) ||
 376             mount_point_ignore(where))
 377                 return 0;
 378
 379         r = fstab_extract_values(opts, "x-systemd.wanted-by", &wanted_by);
 380         if (r < 0)
 381                 return r;
 382
 383         r = fstab_extract_values(opts, "x-systemd.required-by", &required_by);
 384         if (r < 0)
 385                 return r;
 386
 387         if (path_equal(where, "/")) {
 388                 if (flags & NOAUTO)
 389                         log_warning("Ignoring \"noauto\" for root device");
 390                 if (flags & NOFAIL)
 391                         log_warning("Ignoring \"nofail\" for root device");
 392                 if (flags & AUTOMOUNT)
 393                         log_warning("Ignoring automount option for root device");
 394                 if (!strv_isempty(wanted_by))
 395                         log_warning("Ignoring \"x-systemd.wanted-by=\" for root device");
 396                 if (!strv_isempty(required_by))
 397                         log_warning("Ignoring \"x-systemd.required-by=\" for root device");
 398
 399                 required_by = strv_free(required_by);
 400                 wanted_by = strv_free(wanted_by);
 401                 SET_FLAG(flags, NOAUTO | NOFAIL | AUTOMOUNT, false);
 402         }
 403
 404         r = unit_name_from_path(where, ".mount", &name);
 405         if (r < 0)
 406                 return log_error_errno(r, "Failed to generate unit name: %m");
 407
 408         r = generator_open_unit_file(dest, fstab_path(), name, &f);
 409         if (r < 0)
 410                 return r;
 411
 412         fprintf(f,
 413                 "[Unit]\n"
 414                 "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n"
 415                 "SourcePath=%s\n",
 416                 source);
 417
 418         if (STRPTR_IN_SET(fstype, "nfs", "nfs4") && !(flags & AUTOMOUNT) &&
 419             fstab_test_yes_no_option(opts, "bg\0" "fg\0")) {
 420                 /* The default retry timeout that mount.nfs uses for 'bg' mounts
 421                  * is 10000 minutes, where as it uses 2 minutes for 'fg' mounts.
 422                  * As we are making  'bg' mounts look like an 'fg' mount to
 423                  * mount.nfs (so systemd can manage the job-control aspects of 'bg'),
 424                  * we need to explicitly preserve that default, and also ensure
 425                  * the systemd mount-timeout doesn't interfere.
 426                  * By placing these options first, they can be over-ridden by
 427                  * settings in /etc/fstab. */
 428                 opts = strjoina("x-systemd.mount-timeout=infinity,retry=10000,nofail,", opts, ",fg");
 429                 SET_FLAG(flags, NOFAIL, true);
 430         }
 431
 432         r = write_extra_dependencies(f, opts);
 433         if (r < 0)
 434                 return r;
 435
 436         if (passno != 0) {
 437                 r = generator_write_fsck_deps(f, dest, what, where, fstype);
 438                 if (r < 0)
 439                         return r;
 440         }
 441
 442         r = generator_write_blockdev_dependency(f, what);
 443         if (r < 0)
 444                 return r;
 445
 446         fprintf(f,
 447                 "\n"
 448                 "[Mount]\n");
 449
 450         if (original_where)
 451                 fprintf(f, "# Canonicalized from %s\n", original_where);
 452
 453         where_escaped = specifier_escape(where);
 454         if (!where_escaped)
 455                 return log_oom();
 456         fprintf(f, "Where=%s\n", where_escaped);
 457
 458         r = write_what(f, what);
 459         if (r < 0)
 460                 return r;
 461
 462         if (!isempty(fstype) && !streq(fstype, "auto")) {
 463                 _cleanup_free_ char *t;
 464
 465                 t = specifier_escape(fstype);
 466                 if (!t)
 467                         return -ENOMEM;
 468
 469                 fprintf(f, "Type=%s\n", t);
 470         }
 471
 472         r = generator_write_timeouts(dest, what, where, opts, &filtered);
 473         if (r < 0)
 474                 return r;
 475
 476         r = generator_write_device_deps(dest, what, where, opts);
 477         if (r < 0)
 478                 return r;
 479
 480         r = write_mount_timeout(f, where, opts);
 481         if (r < 0)
 482                 return r;
 483
 484         r = write_options(f, filtered);
 485         if (r < 0)
 486                 return r;
 487
 488         if (flags & RWONLY)
 489                 fprintf(f, "ReadWriteOnly=yes\n");
 490
 491         r = fflush_and_check(f);
 492         if (r < 0)
 493                 return log_error_errno(r, "Failed to write unit file %s: %m", name);
 494
 495         if (flags & MAKEFS) {
 496                 r = generator_hook_up_mkfs(dest, what, where, fstype);
 497                 if (r < 0)
 498                         return r;
 499         }
 500
 501         if (flags & GROWFS) {
 502                 r = generator_hook_up_growfs(dest, where, post);
 503                 if (r < 0)
 504                         return r;
 505         }
 506
 507         if (!FLAGS_SET(flags, AUTOMOUNT)) {
 508                 if (!FLAGS_SET(flags, NOAUTO) && strv_isempty(wanted_by) && strv_isempty(required_by)) {
 509                         r = generator_add_symlink(dest, post,
 510                                                   (flags & NOFAIL) ? "wants" : "requires", name);
 511                         if (r < 0)
 512                                 return r;
 513                 } else {
 514                         char **s;
 515
 516                         STRV_FOREACH(s, wanted_by) {
 517                                 r = generator_add_symlink(dest, *s, "wants", name);
 518                                 if (r < 0)
 519                                         return r;
 520                         }
 521
 522                         STRV_FOREACH(s, required_by) {
 523                                 r = generator_add_symlink(dest, *s, "requires", name);
 524                                 if (r < 0)
 525                                         return r;
 526                         }
 527                 }
 528         } else {
 529                 r = unit_name_from_path(where, ".automount", &automount_name);
 530                 if (r < 0)
 531                         return log_error_errno(r, "Failed to generate unit name: %m");
 532
 533                 f = safe_fclose(f);
 534
 535                 r = generator_open_unit_file(dest, fstab_path(), automount_name, &f);
 536                 if (r < 0)
 537                         return r;
 538
 539                 fprintf(f,
 540                         "[Unit]\n"
 541                         "SourcePath=%s\n"
 542                         "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n",
 543                         source);
 544
 545                 fprintf(f,
 546                         "\n"
 547                         "[Automount]\n"
 548                         "Where=%s\n",
 549                         where_escaped);
 550
 551                 r = write_idle_timeout(f, where, opts);
 552                 if (r < 0)
 553                         return r;
 554
 555                 r = fflush_and_check(f);
 556                 if (r < 0)
 557                         return log_error_errno(r, "Failed to write unit file %s: %m", automount_name);
 558
 559                 r = generator_add_symlink(dest, post,
 560                                           (flags & NOFAIL) ? "wants" : "requires", automount_name);
 561                 if (r < 0)
 562                         return r;
 563         }
 564
 565         return 0;
 566 }
 567
 568 static int parse_fstab(bool initrd) {
 569         _cleanup_endmntent_ FILE *f = NULL;
 570         const char *fstab;
 571         struct mntent *me;
 572         int r = 0;
 573
 574         fstab = initrd ? "/sysroot/etc/fstab" : fstab_path();
 575         log_debug("Parsing %s...", fstab);
 576
 577         f = setmntent(fstab, "re");
 578         if (!f) {
 579                 if (errno == ENOENT)
 580                         return 0;
 581
 582                 return log_error_errno(errno, "Failed to open %s: %m", fstab);
 583         }
 584
 585         while ((me = getmntent(f))) {
 586                 _cleanup_free_ char *where = NULL, *what = NULL, *canonical_where = NULL;
 587                 bool makefs, growfs, noauto, nofail, rwonly;
 588                 int k;
 589
 590                 if (initrd && !mount_in_initrd(me))
 591                         continue;
 592
 593                 what = fstab_node_to_udev_node(me->mnt_fsname);
 594                 if (!what)
 595                         return log_oom();
 596
 597                 if (is_device_path(what) && path_is_read_only_fs("/sys") > 0) {
 598                         log_info("Running in a container, ignoring fstab device entry for %s.", what);
 599                         continue;
 600                 }
 601
 602                 where = strdup(me->mnt_dir);
 603                 if (!where)
 604                         return log_oom();
 605
 606                 if (is_path(where)) {
 607                         path_simplify(where, false);
 608
 609                         /* Follow symlinks here; see 5261ba901845c084de5a8fd06500ed09bfb0bd80 which makes sense for
 610                          * mount units, but causes problems since it historically worked to have symlinks in e.g.
 611                          * /etc/fstab. So we canonicalize here. Note that we use CHASE_NONEXISTENT to handle the case
 612                          * where a symlink refers to another mount target; this works assuming the sub-mountpoint
 613                          * target is the final directory. */
 614                         r = chase_symlinks(where, initrd ? "/sysroot" : NULL,
 615                                            CHASE_PREFIX_ROOT | CHASE_NONEXISTENT,
 616                                            &canonical_where, NULL);
 617                         if (r < 0) /* If we can't canonicalize we continue on as if it wasn't a symlink */
 618                                 log_debug_errno(r, "Failed to read symlink target for %s, ignoring: %m", where);
 619                         else if (streq(canonical_where, where)) /* If it was fully canonicalized, suppress the change */
 620                                 canonical_where = mfree(canonical_where);
 621                         else
 622                                 log_debug("Canonicalized what=%s where=%s to %s", what, where, canonical_where);
 623                 }
 624
 625                 makefs = fstab_test_option(me->mnt_opts, "x-systemd.makefs\0");
 626                 growfs = fstab_test_option(me->mnt_opts, "x-systemd.growfs\0");
 627                 rwonly = fstab_test_option(me->mnt_opts, "x-systemd.rw-only\0");
 628                 noauto = fstab_test_yes_no_option(me->mnt_opts, "noauto\0" "auto\0");
 629                 nofail = fstab_test_yes_no_option(me->mnt_opts, "nofail\0" "fail\0");
 630
 631                 log_debug("Found entry what=%s where=%s type=%s makefs=%s growfs=%s noauto=%s nofail=%s",
 632                           what, where, me->mnt_type,
 633                           yes_no(makefs), yes_no(growfs),
 634                           yes_no(noauto), yes_no(nofail));
 635
 636                 if (streq(me->mnt_type, "swap"))
 637                         k = add_swap(what, me,
 638                                      makefs*MAKEFS | growfs*GROWFS | noauto*NOAUTO | nofail*NOFAIL);
 639                 else {
 640                         bool automount;
 641                         const char *post;
 642
 643                         automount = fstab_test_option(me->mnt_opts,
 644                                                       "comment=systemd.automount\0"
 645                                                       "x-systemd.automount\0");
 646                         if (initrd)
 647                                 post = SPECIAL_INITRD_FS_TARGET;
 648                         else if (mount_is_network(me))
 649                                 post = SPECIAL_REMOTE_FS_TARGET;
 650                         else
 651                                 post = SPECIAL_LOCAL_FS_TARGET;
 652
 653                         k = add_mount(arg_dest,
 654                                       what,
 655                                       canonical_where ?: where,
 656                                       canonical_where ? where: NULL,
 657                                       me->mnt_type,
 658                                       me->mnt_opts,
 659                                       me->mnt_passno,
 660                                       makefs*MAKEFS | growfs*GROWFS | noauto*NOAUTO | nofail*NOFAIL | automount*AUTOMOUNT | rwonly*RWONLY,
 661                                       post,
 662                                       fstab);
 663                 }
 664
 665                 if (r >= 0 && k < 0)
 666                         r = k;
 667         }
 668
 669         return r;
 670 }
 671
 672 static int add_sysroot_mount(void) {
 673         _cleanup_free_ char *what = NULL;
 674         const char *opts;
 675         int r;
 676
 677         if (isempty(arg_root_what)) {
 678                 log_debug("Could not find a root= entry on the kernel command line.");
 679                 return 0;
 680         }
 681
 682         if (streq(arg_root_what, "gpt-auto")) {
 683                 /* This is handled by the gpt-auto generator */
 684                 log_debug("Skipping root directory handling, as gpt-auto was requested.");
 685                 return 0;
 686         }
 687
 688         if (path_equal(arg_root_what, "/dev/nfs")) {
 689                 /* This is handled by the kernel or the initrd */
 690                 log_debug("Skipping root directory handling, as /dev/nfs was requested.");
 691                 return 0;
 692         }
 693
 694         what = fstab_node_to_udev_node(arg_root_what);
 695         if (!what)
 696                 return log_oom();
 697
 698         if (!arg_root_options)
 699                 opts = arg_root_rw > 0 ? "rw" : "ro";
 700         else if (arg_root_rw >= 0 ||
 701                  !fstab_test_option(arg_root_options, "ro\0" "rw\0"))
 702                 opts = strjoina(arg_root_options, ",", arg_root_rw > 0 ? "rw" : "ro");
 703         else
 704                 opts = arg_root_options;
 705
 706         log_debug("Found entry what=%s where=/sysroot type=%s", what, strna(arg_root_fstype));
 707
 708         if (is_device_path(what)) {
 709                 r = generator_write_initrd_root_device_deps(arg_dest, what);
 710                 if (r < 0)
 711                         return r;
 712         }
 713
 714         return add_mount(arg_dest,
 715                          what,
 716                          "/sysroot",
 717                          NULL,
 718                          arg_root_fstype,
 719                          opts,
 720                          is_device_path(what) ? 1 : 0, /* passno */
 721                          0,                            /* makefs off, growfs off, noauto off, nofail off, automount off */
 722                          SPECIAL_INITRD_ROOT_FS_TARGET,
 723                          "/proc/cmdline");
 724 }
 725
 726 static int add_sysroot_usr_mount(void) {
 727         _cleanup_free_ char *what = NULL;
 728         const char *opts;
 729
 730         if (!arg_usr_what && !arg_usr_fstype && !arg_usr_options)
 731                 return 0;
 732
 733         if (arg_root_what && !arg_usr_what) {
 734                 /* Copy over the root device, in case the /usr mount just differs in a mount option (consider btrfs subvolumes) */
 735                 arg_usr_what = strdup(arg_root_what);
 736                 if (!arg_usr_what)
 737                         return log_oom();
 738         }
 739
 740         if (arg_root_fstype && !arg_usr_fstype) {
 741                 arg_usr_fstype = strdup(arg_root_fstype);
 742                 if (!arg_usr_fstype)
 743                         return log_oom();
 744         }
 745
 746         if (arg_root_options && !arg_usr_options) {
 747                 arg_usr_options = strdup(arg_root_options);
 748                 if (!arg_usr_options)
 749                         return log_oom();
 750         }
 751
 752         if (!arg_usr_what)
 753                 return 0;
 754
 755         what = fstab_node_to_udev_node(arg_usr_what);
 756         if (!what)
 757                 return log_oom();
 758
 759         if (!arg_usr_options)
 760                 opts = arg_root_rw > 0 ? "rw" : "ro";
 761         else if (!fstab_test_option(arg_usr_options, "ro\0" "rw\0"))
 762                 opts = strjoina(arg_usr_options, ",", arg_root_rw > 0 ? "rw" : "ro");
 763         else
 764                 opts = arg_usr_options;
 765
 766         log_debug("Found entry what=%s where=/sysroot/usr type=%s", what, strna(arg_usr_fstype));
 767         return add_mount(arg_dest,
 768                          what,
 769                          "/sysroot/usr",
 770                          NULL,
 771                          arg_usr_fstype,
 772                          opts,
 773                          is_device_path(what) ? 1 : 0, /* passno */
 774                          0,
 775                          SPECIAL_INITRD_FS_TARGET,
 776                          "/proc/cmdline");
 777 }
 778
 779 static int add_volatile_root(void) {
 780
 781         /* Let's add in systemd-remount-volatile.service which will remount the root device to tmpfs if this is
 782          * requested (or as an overlayfs), leaving only /usr from the root mount inside. */
 783
 784         if (!IN_SET(arg_volatile_mode, VOLATILE_YES, VOLATILE_OVERLAY))
 785                 return 0;
 786
 787         return generator_add_symlink(arg_dest, SPECIAL_INITRD_ROOT_FS_TARGET, "requires",
 788                                      SYSTEM_DATA_UNIT_PATH "/" SPECIAL_VOLATILE_ROOT_SERVICE);
 789 }
 790
 791 static int add_volatile_var(void) {
 792
 793         if (arg_volatile_mode != VOLATILE_STATE)
 794                 return 0;
 795
 796         /* If requested, mount /var as tmpfs, but do so only if there's nothing else defined for this. */
 797
 798         return add_mount(arg_dest_late,
 799                          "tmpfs",
 800                          "/var",
 801                          NULL,
 802                          "tmpfs",
 803                          "mode=0755" TMPFS_LIMITS_VAR,
 804                          0,
 805                          0,
 806                          SPECIAL_LOCAL_FS_TARGET,
 807                          "/proc/cmdline");
 808 }
 809
 810 static int parse_proc_cmdline_item(const char *key, const char *value, void *data) {
 811         int r;
 812
 813         /* root=, usr=, usrfstype= and roofstype= may occur more than once, the last
 814          * instance should take precedence.  In the case of multiple rootflags=
 815          * or usrflags= the arguments should be concatenated */
 816
 817         if (STR_IN_SET(key, "fstab", "rd.fstab")) {
 818
 819                 r = value ? parse_boolean(value) : 1;
 820                 if (r < 0)
 821                         log_warning("Failed to parse fstab switch %s. Ignoring.", value);
 822                 else
 823                         arg_fstab_enabled = r;
 824
 825         } else if (streq(key, "root")) {
 826
 827                 if (proc_cmdline_value_missing(key, value))
 828                         return 0;
 829
 830                 if (free_and_strdup(&arg_root_what, value) < 0)
 831                         return log_oom();
 832
 833         } else if (streq(key, "rootfstype")) {
 834
 835                 if (proc_cmdline_value_missing(key, value))
 836                         return 0;
 837
 838                 if (free_and_strdup(&arg_root_fstype, value) < 0)
 839                         return log_oom();
 840
 841         } else if (streq(key, "rootflags")) {
 842
 843                 if (proc_cmdline_value_missing(key, value))
 844                         return 0;
 845
 846                 if (!strextend_with_separator(&arg_root_options, ",", value))
 847                         return log_oom();
 848
 849         } else if (streq(key, "roothash")) {
 850
 851                 if (proc_cmdline_value_missing(key, value))
 852                         return 0;
 853
 854                 if (free_and_strdup(&arg_root_hash, value) < 0)
 855                         return log_oom();
 856
 857         } else if (streq(key, "mount.usr")) {
 858
 859                 if (proc_cmdline_value_missing(key, value))
 860                         return 0;
 861
 862                 if (free_and_strdup(&arg_usr_what, value) < 0)
 863                         return log_oom();
 864
 865         } else if (streq(key, "mount.usrfstype")) {
 866
 867                 if (proc_cmdline_value_missing(key, value))
 868                         return 0;
 869
 870                 if (free_and_strdup(&arg_usr_fstype, value) < 0)
 871                         return log_oom();
 872
 873         } else if (streq(key, "mount.usrflags")) {
 874
 875                 if (proc_cmdline_value_missing(key, value))
 876                         return 0;
 877
 878                 if (!strextend_with_separator(&arg_usr_options, ",", value))
 879                         return log_oom();
 880
 881         } else if (streq(key, "rw") && !value)
 882                 arg_root_rw = true;
 883         else if (streq(key, "ro") && !value)
 884                 arg_root_rw = false;
 885         else if (streq(key, "systemd.volatile")) {
 886                 VolatileMode m;
 887
 888                 if (value) {
 889                         m = volatile_mode_from_string(value);
 890                         if (m < 0)
 891                                 log_warning("Failed to parse systemd.volatile= argument: %s", value);
 892                         else
 893                                 arg_volatile_mode = m;
 894                 } else
 895                         arg_volatile_mode = VOLATILE_YES;
 896
 897         } else if (streq(key, "systemd.swap")) {
 898
 899                 r = value ? parse_boolean(value) : 1;
 900                 if (r < 0)
 901                         log_warning("Failed to parse systemd.swap switch %s. Ignoring.", value);
 902                 else
 903                         arg_swap_enabled = r;
 904         }
 905
 906         return 0;
 907 }
 908
 909 static int determine_root(void) {
 910         /* If we have a root hash but no root device then Verity is used, and we use the "root" DM device as root. */
 911
 912         if (arg_root_what)
 913                 return 0;
 914
 915         if (!arg_root_hash)
 916                 return 0;
 917
 918         arg_root_what = strdup("/dev/mapper/root");
 919         if (!arg_root_what)
 920                 return log_oom();
 921
 922         log_info("Using verity root device %s.", arg_root_what);
 923
 924         return 1;
 925 }
 926
 927 static int run(const char *dest, const char *dest_early, const char *dest_late) {
 928         int r, r2 = 0, r3 = 0;
 929
 930         assert_se(arg_dest = dest);
 931         assert_se(arg_dest_late = dest_late);
 932
 933         r = proc_cmdline_parse(parse_proc_cmdline_item, NULL, 0);
 934         if (r < 0)
 935                 log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m");
 936
 937         (void) determine_root();
 938
 939         /* Always honour root= and usr= in the kernel command line if we are in an initrd */
 940         if (in_initrd()) {
 941                 r = add_sysroot_mount();
 942
 943                 r2 = add_sysroot_usr_mount();
 944
 945                 r3 = add_volatile_root();
 946         } else
 947                 r = add_volatile_var();
 948
 949         /* Honour /etc/fstab only when that's enabled */
 950         if (arg_fstab_enabled) {
 951                 /* Parse the local /etc/fstab, possibly from the initrd */
 952                 r2 = parse_fstab(false);
 953
 954                 /* If running in the initrd also parse the /etc/fstab from the host */
 955                 if (in_initrd())
 956                         r3 = parse_fstab(true);
 957                 else
 958                         r3 = generator_enable_remount_fs_service(arg_dest);
 959         }
 960
 961         return r < 0 ? r : r2 < 0 ? r2 : r3;
 962 }
 963
 964 DEFINE_MAIN_GENERATOR_FUNCTION(run);