src/fstab-generator/fstab-generator.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   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 } MountpointFlags;
  39
  40 static const char *arg_dest = NULL;
  41 static const char *arg_dest_late = NULL;
  42 static bool arg_fstab_enabled = true;
  43 static bool arg_swap_enabled = true;
  44 static char *arg_root_what = NULL;
  45 static char *arg_root_fstype = NULL;
  46 static char *arg_root_options = NULL;
  47 static char *arg_root_hash = NULL;
  48 static int arg_root_rw = -1;
  49 static char *arg_usr_what = NULL;
  50 static char *arg_usr_fstype = NULL;
  51 static char *arg_usr_options = NULL;
  52 static VolatileMode arg_volatile_mode = _VOLATILE_MODE_INVALID;
  53
  54 STATIC_DESTRUCTOR_REGISTER(arg_root_what, freep);
  55 STATIC_DESTRUCTOR_REGISTER(arg_root_fstype, freep);
  56 STATIC_DESTRUCTOR_REGISTER(arg_root_options, freep);
  57 STATIC_DESTRUCTOR_REGISTER(arg_root_hash, freep);
  58 STATIC_DESTRUCTOR_REGISTER(arg_usr_what, freep);
  59 STATIC_DESTRUCTOR_REGISTER(arg_usr_fstype, freep);
  60 STATIC_DESTRUCTOR_REGISTER(arg_usr_options, freep);
  61
  62 static int write_options(FILE *f, const char *options) {
  63         _cleanup_free_ char *o = NULL;
  64
  65         if (isempty(options))
  66                 return 0;
  67
  68         if (streq(options, "defaults"))
  69                 return 0;
  70
  71         o = specifier_escape(options);
  72         if (!o)
  73                 return log_oom();
  74
  75         fprintf(f, "Options=%s\n", o);
  76         return 1;
  77 }
  78
  79 static int write_what(FILE *f, const char *what) {
  80         _cleanup_free_ char *w = NULL;
  81
  82         w = specifier_escape(what);
  83         if (!w)
  84                 return log_oom();
  85
  86         fprintf(f, "What=%s\n", w);
  87         return 1;
  88 }
  89
  90 static int add_swap(
  91                 const char *what,
  92                 struct mntent *me,
  93                 MountpointFlags flags) {
  94
  95         _cleanup_free_ char *name = NULL;
  96         _cleanup_fclose_ FILE *f = NULL;
  97         int r;
  98
  99         assert(what);
 100         assert(me);
 101
 102         if (!arg_swap_enabled) {
 103                 log_info("Swap unit generation disabled on kernel command line, ignoring fstab swap entry for %s.", what);
 104                 return 0;
 105         }
 106
 107         if (access("/proc/swaps", F_OK) < 0) {
 108                 log_info("Swap not supported, ignoring fstab swap entry for %s.", what);
 109                 return 0;
 110         }
 111
 112         if (detect_container() > 0) {
 113                 log_info("Running in a container, ignoring fstab swap entry for %s.", what);
 114                 return 0;
 115         }
 116
 117         r = unit_name_from_path(what, ".swap", &name);
 118         if (r < 0)
 119                 return log_error_errno(r, "Failed to generate unit name: %m");
 120
 121         r = generator_open_unit_file(arg_dest, fstab_path(), name, &f);
 122         if (r < 0)
 123                 return r;
 124
 125         fprintf(f,
 126                 "[Unit]\n"
 127                 "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n"
 128                 "SourcePath=%s\n",
 129                 fstab_path());
 130
 131         r = generator_write_blockdev_dependency(f, what);
 132         if (r < 0)
 133                 return r;
 134
 135         fprintf(f,
 136                 "\n"
 137                 "[Swap]\n");
 138
 139         r = write_what(f, what);
 140         if (r < 0)
 141                 return r;
 142
 143         r = write_options(f, me->mnt_opts);
 144         if (r < 0)
 145                 return r;
 146
 147         r = fflush_and_check(f);
 148         if (r < 0)
 149                 return log_error_errno(r, "Failed to write unit file %s: %m", name);
 150
 151         /* use what as where, to have a nicer error message */
 152         r = generator_write_timeouts(arg_dest, what, what, me->mnt_opts, NULL);
 153         if (r < 0)
 154                 return r;
 155
 156         if (flags & MAKEFS) {
 157                 r = generator_hook_up_mkswap(arg_dest, what);
 158                 if (r < 0)
 159                         return r;
 160         }
 161
 162         if (flags & GROWFS)
 163                 /* TODO: swap devices must be wiped and recreated */
 164                 log_warning("%s: growing swap devices is currently unsupported.", what);
 165
 166         if (!(flags & NOAUTO)) {
 167                 r = generator_add_symlink(arg_dest, SPECIAL_SWAP_TARGET,
 168                                           (flags & NOFAIL) ? "wants" : "requires", name);
 169                 if (r < 0)
 170                         return r;
 171         }
 172
 173         return 0;
 174 }
 175
 176 static bool mount_is_network(struct mntent *me) {
 177         assert(me);
 178
 179         return fstab_test_option(me->mnt_opts, "_netdev\0") ||
 180                fstype_is_network(me->mnt_type);
 181 }
 182
 183 static bool mount_in_initrd(struct mntent *me) {
 184         assert(me);
 185
 186         return fstab_test_option(me->mnt_opts, "x-initrd.mount\0") ||
 187                streq(me->mnt_dir, "/usr");
 188 }
 189
 190 static int write_timeout(
 191                 FILE *f,
 192                 const char *where,
 193                 const char *opts,
 194                 const char *filter,
 195                 const char *variable) {
 196
 197         _cleanup_free_ char *timeout = NULL;
 198         char timespan[FORMAT_TIMESPAN_MAX];
 199         usec_t u;
 200         int r;
 201
 202         r = fstab_filter_options(opts, filter, NULL, &timeout, NULL);
 203         if (r < 0)
 204                 return log_warning_errno(r, "Failed to parse options: %m");
 205         if (r == 0)
 206                 return 0;
 207
 208         r = parse_sec_fix_0(timeout, &u);
 209         if (r < 0) {
 210                 log_warning("Failed to parse timeout for %s, ignoring: %s", where, timeout);
 211                 return 0;
 212         }
 213
 214         fprintf(f, "%s=%s\n", variable, format_timespan(timespan, sizeof(timespan), u, 0));
 215
 216         return 0;
 217 }
 218
 219 static int write_idle_timeout(FILE *f, const char *where, const char *opts) {
 220         return write_timeout(f, where, opts,
 221                              "x-systemd.idle-timeout\0", "TimeoutIdleSec");
 222 }
 223
 224 static int write_mount_timeout(FILE *f, const char *where, const char *opts) {
 225         return write_timeout(f, where, opts,
 226                              "x-systemd.mount-timeout\0", "TimeoutSec");
 227 }
 228
 229 static int write_dependency(
 230                 FILE *f,
 231                 const char *opts,
 232                 const char *filter,
 233                 const char *format) {
 234
 235         _cleanup_strv_free_ char **names = NULL, **units = NULL;
 236         _cleanup_free_ char *res = NULL;
 237         char **s;
 238         int r;
 239
 240         assert(f);
 241         assert(opts);
 242
 243         r = fstab_extract_values(opts, filter, &names);
 244         if (r < 0)
 245                 return log_warning_errno(r, "Failed to parse options: %m");
 246         if (r == 0)
 247                 return 0;
 248
 249         STRV_FOREACH(s, names) {
 250                 char *x;
 251
 252                 r = unit_name_mangle_with_suffix(*s, "as dependency", 0, ".mount", &x);
 253                 if (r < 0)
 254                         return log_error_errno(r, "Failed to generate unit name: %m");
 255
 256                 r = strv_consume(&units, x);
 257                 if (r < 0)
 258                         return log_oom();
 259         }
 260
 261         if (units) {
 262                 res = strv_join(units, " ");
 263                 if (!res)
 264                         return log_oom();
 265 #pragma GCC diagnostic push
 266 #pragma GCC diagnostic ignored "-Wformat-nonliteral"
 267                 fprintf(f, format, res);
 268 #pragma GCC diagnostic pop
 269         }
 270
 271         return 0;
 272 }
 273
 274 static int write_after(FILE *f, const char *opts) {
 275         return write_dependency(f, opts,
 276                                 "x-systemd.after", "After=%1$s\n");
 277 }
 278
 279 static int write_requires_after(FILE *f, const char *opts) {
 280         return write_dependency(f, opts,
 281                                 "x-systemd.requires", "After=%1$s\nRequires=%1$s\n");
 282 }
 283
 284 static int write_before(FILE *f, const char *opts) {
 285         return write_dependency(f, opts,
 286                                 "x-systemd.before", "Before=%1$s\n");
 287 }
 288
 289 static int write_requires_mounts_for(FILE *f, const char *opts) {
 290         _cleanup_strv_free_ char **paths = NULL, **paths_escaped = NULL;
 291         _cleanup_free_ char *res = NULL;
 292         int r;
 293
 294         assert(f);
 295         assert(opts);
 296
 297         r = fstab_extract_values(opts, "x-systemd.requires-mounts-for", &paths);
 298         if (r < 0)
 299                 return log_warning_errno(r, "Failed to parse options: %m");
 300         if (r == 0)
 301                 return 0;
 302
 303         r = specifier_escape_strv(paths, &paths_escaped);
 304         if (r < 0)
 305                 return log_error_errno(r, "Failed to escape paths: %m");
 306
 307         res = strv_join(paths_escaped, " ");
 308         if (!res)
 309                 return log_oom();
 310
 311         fprintf(f, "RequiresMountsFor=%s\n", res);
 312
 313         return 0;
 314 }
 315
 316 static int add_mount(
 317                 const char *dest,
 318                 const char *what,
 319                 const char *where,
 320                 const char *original_where,
 321                 const char *fstype,
 322                 const char *opts,
 323                 int passno,
 324                 MountpointFlags flags,
 325                 const char *post,
 326                 const char *source) {
 327
 328         _cleanup_free_ char
 329                 *name = NULL,
 330                 *automount_name = NULL,
 331                 *filtered = NULL,
 332                 *where_escaped = NULL;
 333         _cleanup_strv_free_ char **wanted_by = NULL, **required_by = NULL;
 334         _cleanup_fclose_ FILE *f = NULL;
 335         int r;
 336
 337         assert(what);
 338         assert(where);
 339         assert(opts);
 340         assert(post);
 341         assert(source);
 342
 343         if (streq_ptr(fstype, "autofs"))
 344                 return 0;
 345
 346         if (!is_path(where)) {
 347                 log_warning("Mount point %s is not a valid path, ignoring.", where);
 348                 return 0;
 349         }
 350
 351         if (mount_point_is_api(where) ||
 352             mount_point_ignore(where))
 353                 return 0;
 354
 355         r = fstab_extract_values(opts, "x-systemd.wanted-by", &wanted_by);
 356         if (r < 0)
 357                 return r;
 358
 359         r = fstab_extract_values(opts, "x-systemd.required-by", &required_by);
 360         if (r < 0)
 361                 return r;
 362
 363         if (path_equal(where, "/")) {
 364                 if (flags & NOAUTO)
 365                         log_warning("Ignoring \"noauto\" for root device");
 366                 if (flags & NOFAIL)
 367                         log_warning("Ignoring \"nofail\" for root device");
 368                 if (flags & AUTOMOUNT)
 369                         log_warning("Ignoring automount option for root device");
 370                 if (!strv_isempty(wanted_by))
 371                         log_warning("Ignoring \"x-systemd.wanted-by=\" for root device");
 372                 if (!strv_isempty(required_by))
 373                         log_warning("Ignoring \"x-systemd.required-by=\" for root device");
 374
 375                 required_by = strv_free(required_by);
 376                 wanted_by = strv_free(wanted_by);
 377                 SET_FLAG(flags, NOAUTO | NOFAIL | AUTOMOUNT, false);
 378         }
 379
 380         r = unit_name_from_path(where, ".mount", &name);
 381         if (r < 0)
 382                 return log_error_errno(r, "Failed to generate unit name: %m");
 383
 384         r = generator_open_unit_file(dest, fstab_path(), name, &f);
 385         if (r < 0)
 386                 return r;
 387
 388         fprintf(f,
 389                 "[Unit]\n"
 390                 "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n"
 391                 "SourcePath=%s\n",
 392                 source);
 393
 394         /* All mounts under /sysroot need to happen later, at initrd-fs.target time. IOW, it's not
 395          * technically part of the basic initrd filesystem itself, and so shouldn't inherit the default
 396          * Before=local-fs.target dependency. */
 397         if (in_initrd() && path_startswith(where, "/sysroot"))
 398                 fprintf(f, "DefaultDependencies=no\n");
 399
 400         if (STRPTR_IN_SET(fstype, "nfs", "nfs4") && !(flags & AUTOMOUNT) &&
 401             fstab_test_yes_no_option(opts, "bg\0" "fg\0")) {
 402                 /* The default retry timeout that mount.nfs uses for 'bg' mounts
 403                  * is 10000 minutes, where as it uses 2 minutes for 'fg' mounts.
 404                  * As we are making  'bg' mounts look like an 'fg' mount to
 405                  * mount.nfs (so systemd can manage the job-control aspects of 'bg'),
 406                  * we need to explicitly preserve that default, and also ensure
 407                  * the systemd mount-timeout doesn't interfere.
 408                  * By placing these options first, they can be over-ridden by
 409                  * settings in /etc/fstab. */
 410                 opts = strjoina("x-systemd.mount-timeout=infinity,retry=10000,", opts, ",fg");
 411                 SET_FLAG(flags, NOFAIL, true);
 412         }
 413
 414         if (!(flags & NOFAIL) && !(flags & AUTOMOUNT))
 415                 fprintf(f, "Before=%s\n", post);
 416
 417         if (!(flags & AUTOMOUNT) && opts) {
 418                  r = write_after(f, opts);
 419                  if (r < 0)
 420                          return r;
 421                  r = write_requires_after(f, opts);
 422                  if (r < 0)
 423                          return r;
 424                  r = write_before(f, opts);
 425                  if (r < 0)
 426                          return r;
 427                  r = write_requires_mounts_for(f, opts);
 428                  if (r < 0)
 429                          return r;
 430         }
 431
 432         if (passno != 0) {
 433                 r = generator_write_fsck_deps(f, dest, what, where, fstype);
 434                 if (r < 0)
 435                         return r;
 436         }
 437
 438         r = generator_write_blockdev_dependency(f, what);
 439         if (r < 0)
 440                 return r;
 441
 442         fprintf(f,
 443                 "\n"
 444                 "[Mount]\n");
 445
 446         if (original_where)
 447                 fprintf(f, "# Canonicalized from %s\n", original_where);
 448
 449         where_escaped = specifier_escape(where);
 450         if (!where_escaped)
 451                 return log_oom();
 452         fprintf(f, "Where=%s\n", where_escaped);
 453
 454         r = write_what(f, what);
 455         if (r < 0)
 456                 return r;
 457
 458         if (!isempty(fstype) && !streq(fstype, "auto")) {
 459                 _cleanup_free_ char *t;
 460
 461                 t = specifier_escape(fstype);
 462                 if (!t)
 463                         return -ENOMEM;
 464
 465                 fprintf(f, "Type=%s\n", t);
 466         }
 467
 468         r = generator_write_timeouts(dest, what, where, opts, &filtered);
 469         if (r < 0)
 470                 return r;
 471
 472         r = generator_write_device_deps(dest, what, where, opts);
 473         if (r < 0)
 474                 return r;
 475
 476         r = write_mount_timeout(f, where, opts);
 477         if (r < 0)
 478                 return r;
 479
 480         r = write_options(f, filtered);
 481         if (r < 0)
 482                 return r;
 483
 484         r = fflush_and_check(f);
 485         if (r < 0)
 486                 return log_error_errno(r, "Failed to write unit file %s: %m", name);
 487
 488         if (flags & MAKEFS) {
 489                 r = generator_hook_up_mkfs(dest, what, where, fstype);
 490                 if (r < 0)
 491                         return r;
 492         }
 493
 494         if (flags & GROWFS) {
 495                 r = generator_hook_up_growfs(dest, where, post);
 496                 if (r < 0)
 497                         return r;
 498         }
 499
 500         if (!FLAGS_SET(flags, AUTOMOUNT)) {
 501                 if (!FLAGS_SET(flags, NOAUTO) && strv_isempty(wanted_by) && strv_isempty(required_by)) {
 502                         r = generator_add_symlink(dest, post,
 503                                                   (flags & NOFAIL) ? "wants" : "requires", name);
 504                         if (r < 0)
 505                                 return r;
 506                 } else {
 507                         char **s;
 508
 509                         STRV_FOREACH(s, wanted_by) {
 510                                 r = generator_add_symlink(dest, *s, "wants", name);
 511                                 if (r < 0)
 512                                         return r;
 513                         }
 514
 515                         STRV_FOREACH(s, required_by) {
 516                                 r = generator_add_symlink(dest, *s, "requires", name);
 517                                 if (r < 0)
 518                                         return r;
 519                         }
 520                 }
 521         } else {
 522                 r = unit_name_from_path(where, ".automount", &automount_name);
 523                 if (r < 0)
 524                         return log_error_errno(r, "Failed to generate unit name: %m");
 525
 526                 f = safe_fclose(f);
 527
 528                 r = generator_open_unit_file(dest, fstab_path(), automount_name, &f);
 529                 if (r < 0)
 530                         return r;
 531
 532                 fprintf(f,
 533                         "[Unit]\n"
 534                         "SourcePath=%s\n"
 535                         "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n",
 536                         source);
 537
 538                 fprintf(f, "Before=%s\n", post);
 539
 540                 if (opts) {
 541                         r = write_after(f, opts);
 542                         if (r < 0)
 543                                 return r;
 544                         r = write_requires_after(f, opts);
 545                         if (r < 0)
 546                                 return r;
 547                         r = write_before(f, opts);
 548                         if (r < 0)
 549                                 return r;
 550                         r = write_requires_mounts_for(f, opts);
 551                         if (r < 0)
 552                                 return r;
 553                 }
 554
 555                 fprintf(f,
 556                         "\n"
 557                         "[Automount]\n"
 558                         "Where=%s\n",
 559                         where_escaped);
 560
 561                 r = write_idle_timeout(f, where, opts);
 562                 if (r < 0)
 563                         return r;
 564
 565                 r = fflush_and_check(f);
 566                 if (r < 0)
 567                         return log_error_errno(r, "Failed to write unit file %s: %m", automount_name);
 568
 569                 r = generator_add_symlink(dest, post,
 570                                           (flags & NOFAIL) ? "wants" : "requires", automount_name);
 571                 if (r < 0)
 572                         return r;
 573         }
 574
 575         return 0;
 576 }
 577
 578 static int parse_fstab(bool initrd) {
 579         _cleanup_endmntent_ FILE *f = NULL;
 580         const char *fstab;
 581         struct mntent *me;
 582         int r = 0;
 583
 584         fstab = initrd ? "/sysroot/etc/fstab" : fstab_path();
 585         log_debug("Parsing %s...", fstab);
 586
 587         f = setmntent(fstab, "re");
 588         if (!f) {
 589                 if (errno == ENOENT)
 590                         return 0;
 591
 592                 return log_error_errno(errno, "Failed to open %s: %m", fstab);
 593         }
 594
 595         while ((me = getmntent(f))) {
 596                 _cleanup_free_ char *where = NULL, *what = NULL, *canonical_where = NULL;
 597                 bool makefs, growfs, noauto, nofail;
 598                 int k;
 599
 600                 if (initrd && !mount_in_initrd(me))
 601                         continue;
 602
 603                 what = fstab_node_to_udev_node(me->mnt_fsname);
 604                 if (!what)
 605                         return log_oom();
 606
 607                 if (is_device_path(what) && path_is_read_only_fs("/sys") > 0) {
 608                         log_info("Running in a container, ignoring fstab device entry for %s.", what);
 609                         continue;
 610                 }
 611
 612                 where = strdup(me->mnt_dir);
 613                 if (!where)
 614                         return log_oom();
 615
 616                 if (is_path(where)) {
 617                         path_simplify(where, false);
 618
 619                         /* Follow symlinks here; see 5261ba901845c084de5a8fd06500ed09bfb0bd80 which makes sense for
 620                          * mount units, but causes problems since it historically worked to have symlinks in e.g.
 621                          * /etc/fstab. So we canonicalize here. Note that we use CHASE_NONEXISTENT to handle the case
 622                          * where a symlink refers to another mount target; this works assuming the sub-mountpoint
 623                          * target is the final directory. */
 624                         r = chase_symlinks(where, initrd ? "/sysroot" : NULL,
 625                                            CHASE_PREFIX_ROOT | CHASE_NONEXISTENT,
 626                                            &canonical_where, NULL);
 627                         if (r < 0) /* If we can't canonicalize we continue on as if it wasn't a symlink */
 628                                 log_debug_errno(r, "Failed to read symlink target for %s, ignoring: %m", where);
 629                         else if (streq(canonical_where, where)) /* If it was fully canonicalized, suppress the change */
 630                                 canonical_where = mfree(canonical_where);
 631                         else
 632                                 log_debug("Canonicalized what=%s where=%s to %s", what, where, canonical_where);
 633                 }
 634
 635                 makefs = fstab_test_option(me->mnt_opts, "x-systemd.makefs\0");
 636                 growfs = fstab_test_option(me->mnt_opts, "x-systemd.growfs\0");
 637                 noauto = fstab_test_yes_no_option(me->mnt_opts, "noauto\0" "auto\0");
 638                 nofail = fstab_test_yes_no_option(me->mnt_opts, "nofail\0" "fail\0");
 639
 640                 log_debug("Found entry what=%s where=%s type=%s makefs=%s growfs=%s noauto=%s nofail=%s",
 641                           what, where, me->mnt_type,
 642                           yes_no(makefs), yes_no(growfs),
 643                           yes_no(noauto), yes_no(nofail));
 644
 645                 if (streq(me->mnt_type, "swap"))
 646                         k = add_swap(what, me,
 647                                      makefs*MAKEFS | growfs*GROWFS | noauto*NOAUTO | nofail*NOFAIL);
 648                 else {
 649                         bool automount;
 650                         const char *post;
 651
 652                         automount = fstab_test_option(me->mnt_opts,
 653                                                       "comment=systemd.automount\0"
 654                                                       "x-systemd.automount\0");
 655                         if (initrd)
 656                                 post = SPECIAL_INITRD_FS_TARGET;
 657                         else if (mount_is_network(me))
 658                                 post = SPECIAL_REMOTE_FS_TARGET;
 659                         else
 660                                 post = SPECIAL_LOCAL_FS_TARGET;
 661
 662                         k = add_mount(arg_dest,
 663                                       what,
 664                                       canonical_where ?: where,
 665                                       canonical_where ? where: NULL,
 666                                       me->mnt_type,
 667                                       me->mnt_opts,
 668                                       me->mnt_passno,
 669                                       makefs*MAKEFS | growfs*GROWFS | noauto*NOAUTO | nofail*NOFAIL | automount*AUTOMOUNT,
 670                                       post,
 671                                       fstab);
 672                 }
 673
 674                 if (r >= 0 && k < 0)
 675                         r = k;
 676         }
 677
 678         return r;
 679 }
 680
 681 static int add_sysroot_mount(void) {
 682         _cleanup_free_ char *what = NULL;
 683         const char *opts;
 684         int r;
 685
 686         if (isempty(arg_root_what)) {
 687                 log_debug("Could not find a root= entry on the kernel command line.");
 688                 return 0;
 689         }
 690
 691         if (streq(arg_root_what, "gpt-auto")) {
 692                 /* This is handled by the gpt-auto generator */
 693                 log_debug("Skipping root directory handling, as gpt-auto was requested.");
 694                 return 0;
 695         }
 696
 697         if (path_equal(arg_root_what, "/dev/nfs")) {
 698                 /* This is handled by the kernel or the initrd */
 699                 log_debug("Skipping root directory handling, as /dev/nfs was requested.");
 700                 return 0;
 701         }
 702
 703         what = fstab_node_to_udev_node(arg_root_what);
 704         if (!what)
 705                 return log_oom();
 706
 707         if (!arg_root_options)
 708                 opts = arg_root_rw > 0 ? "rw" : "ro";
 709         else if (arg_root_rw >= 0 ||
 710                  !fstab_test_option(arg_root_options, "ro\0" "rw\0"))
 711                 opts = strjoina(arg_root_options, ",", arg_root_rw > 0 ? "rw" : "ro");
 712         else
 713                 opts = arg_root_options;
 714
 715         log_debug("Found entry what=%s where=/sysroot type=%s", what, strna(arg_root_fstype));
 716
 717         if (is_device_path(what)) {
 718                 r = generator_write_initrd_root_device_deps(arg_dest, what);
 719                 if (r < 0)
 720                         return r;
 721         }
 722
 723         return add_mount(arg_dest,
 724                          what,
 725                          "/sysroot",
 726                          NULL,
 727                          arg_root_fstype,
 728                          opts,
 729                          is_device_path(what) ? 1 : 0, /* passno */
 730                          0,                            /* makefs off, growfs off, noauto off, nofail off, automount off */
 731                          SPECIAL_INITRD_ROOT_FS_TARGET,
 732                          "/proc/cmdline");
 733 }
 734
 735 static int add_sysroot_usr_mount(void) {
 736         _cleanup_free_ char *what = NULL;
 737         const char *opts;
 738
 739         if (!arg_usr_what && !arg_usr_fstype && !arg_usr_options)
 740                 return 0;
 741
 742         if (arg_root_what && !arg_usr_what) {
 743                 /* Copy over the root device, in case the /usr mount just differs in a mount option (consider btrfs subvolumes) */
 744                 arg_usr_what = strdup(arg_root_what);
 745                 if (!arg_usr_what)
 746                         return log_oom();
 747         }
 748
 749         if (arg_root_fstype && !arg_usr_fstype) {
 750                 arg_usr_fstype = strdup(arg_root_fstype);
 751                 if (!arg_usr_fstype)
 752                         return log_oom();
 753         }
 754
 755         if (arg_root_options && !arg_usr_options) {
 756                 arg_usr_options = strdup(arg_root_options);
 757                 if (!arg_usr_options)
 758                         return log_oom();
 759         }
 760
 761         if (!arg_usr_what)
 762                 return 0;
 763
 764         what = fstab_node_to_udev_node(arg_usr_what);
 765         if (!what)
 766                 return log_oom();
 767
 768         if (!arg_usr_options)
 769                 opts = arg_root_rw > 0 ? "rw" : "ro";
 770         else if (!fstab_test_option(arg_usr_options, "ro\0" "rw\0"))
 771                 opts = strjoina(arg_usr_options, ",", arg_root_rw > 0 ? "rw" : "ro");
 772         else
 773                 opts = arg_usr_options;
 774
 775         log_debug("Found entry what=%s where=/sysroot/usr type=%s", what, strna(arg_usr_fstype));
 776         return add_mount(arg_dest,
 777                          what,
 778                          "/sysroot/usr",
 779                          NULL,
 780                          arg_usr_fstype,
 781                          opts,
 782                          is_device_path(what) ? 1 : 0, /* passno */
 783                          0,
 784                          SPECIAL_INITRD_FS_TARGET,
 785                          "/proc/cmdline");
 786 }
 787
 788 static int add_volatile_root(void) {
 789
 790         /* Let's add in systemd-remount-volatile.service which will remount the root device to tmpfs if this is
 791          * requested (or as an overlayfs), leaving only /usr from the root mount inside. */
 792
 793         if (!IN_SET(arg_volatile_mode, VOLATILE_YES, VOLATILE_OVERLAY))
 794                 return 0;
 795
 796         return generator_add_symlink(arg_dest, SPECIAL_INITRD_ROOT_FS_TARGET, "requires",
 797                                      SYSTEM_DATA_UNIT_PATH "/" SPECIAL_VOLATILE_ROOT_SERVICE);
 798 }
 799
 800 static int add_volatile_var(void) {
 801
 802         if (arg_volatile_mode != VOLATILE_STATE)
 803                 return 0;
 804
 805         /* If requested, mount /var as tmpfs, but do so only if there's nothing else defined for this. */
 806
 807         return add_mount(arg_dest_late,
 808                          "tmpfs",
 809                          "/var",
 810                          NULL,
 811                          "tmpfs",
 812                          "mode=0755",
 813                          0,
 814                          0,
 815                          SPECIAL_LOCAL_FS_TARGET,
 816                          "/proc/cmdline");
 817 }
 818
 819 static int parse_proc_cmdline_item(const char *key, const char *value, void *data) {
 820         int r;
 821
 822         /* root=, usr=, usrfstype= and roofstype= may occur more than once, the last
 823          * instance should take precedence.  In the case of multiple rootflags=
 824          * or usrflags= the arguments should be concatenated */
 825
 826         if (STR_IN_SET(key, "fstab", "rd.fstab")) {
 827
 828                 r = value ? parse_boolean(value) : 1;
 829                 if (r < 0)
 830                         log_warning("Failed to parse fstab switch %s. Ignoring.", value);
 831                 else
 832                         arg_fstab_enabled = r;
 833
 834         } else if (streq(key, "root")) {
 835
 836                 if (proc_cmdline_value_missing(key, value))
 837                         return 0;
 838
 839                 if (free_and_strdup(&arg_root_what, value) < 0)
 840                         return log_oom();
 841
 842         } else if (streq(key, "rootfstype")) {
 843
 844                 if (proc_cmdline_value_missing(key, value))
 845                         return 0;
 846
 847                 if (free_and_strdup(&arg_root_fstype, value) < 0)
 848                         return log_oom();
 849
 850         } else if (streq(key, "rootflags")) {
 851
 852                 if (proc_cmdline_value_missing(key, value))
 853                         return 0;
 854
 855                 if (!strextend_with_separator(&arg_root_options, ",", value, NULL))
 856                         return log_oom();
 857
 858         } else if (streq(key, "roothash")) {
 859
 860                 if (proc_cmdline_value_missing(key, value))
 861                         return 0;
 862
 863                 if (free_and_strdup(&arg_root_hash, value) < 0)
 864                         return log_oom();
 865
 866         } else if (streq(key, "mount.usr")) {
 867
 868                 if (proc_cmdline_value_missing(key, value))
 869                         return 0;
 870
 871                 if (free_and_strdup(&arg_usr_what, value) < 0)
 872                         return log_oom();
 873
 874         } else if (streq(key, "mount.usrfstype")) {
 875
 876                 if (proc_cmdline_value_missing(key, value))
 877                         return 0;
 878
 879                 if (free_and_strdup(&arg_usr_fstype, value) < 0)
 880                         return log_oom();
 881
 882         } else if (streq(key, "mount.usrflags")) {
 883
 884                 if (proc_cmdline_value_missing(key, value))
 885                         return 0;
 886
 887                 if (!strextend_with_separator(&arg_usr_options, ",", value, NULL))
 888                         return log_oom();
 889
 890         } else if (streq(key, "rw") && !value)
 891                 arg_root_rw = true;
 892         else if (streq(key, "ro") && !value)
 893                 arg_root_rw = false;
 894         else if (streq(key, "systemd.volatile")) {
 895                 VolatileMode m;
 896
 897                 if (value) {
 898                         m = volatile_mode_from_string(value);
 899                         if (m < 0)
 900                                 log_warning("Failed to parse systemd.volatile= argument: %s", value);
 901                         else
 902                                 arg_volatile_mode = m;
 903                 } else
 904                         arg_volatile_mode = VOLATILE_YES;
 905
 906         } else if (streq(key, "systemd.swap")) {
 907
 908                 r = value ? parse_boolean(value) : 1;
 909                 if (r < 0)
 910                         log_warning("Failed to parse systemd.swap switch %s. Ignoring.", value);
 911                 else
 912                         arg_swap_enabled = r;
 913         }
 914
 915         return 0;
 916 }
 917
 918 static int determine_root(void) {
 919         /* If we have a root hash but no root device then Verity is used, and we use the "root" DM device as root. */
 920
 921         if (arg_root_what)
 922                 return 0;
 923
 924         if (!arg_root_hash)
 925                 return 0;
 926
 927         arg_root_what = strdup("/dev/mapper/root");
 928         if (!arg_root_what)
 929                 return log_oom();
 930
 931         log_info("Using verity root device %s.", arg_root_what);
 932
 933         return 1;
 934 }
 935
 936 static int run(const char *dest, const char *dest_early, const char *dest_late) {
 937         int r, r2 = 0, r3 = 0;
 938
 939         assert_se(arg_dest = dest);
 940         assert_se(arg_dest_late = dest_late);
 941
 942         r = proc_cmdline_parse(parse_proc_cmdline_item, NULL, 0);
 943         if (r < 0)
 944                 log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m");
 945
 946         (void) determine_root();
 947
 948         /* Always honour root= and usr= in the kernel command line if we are in an initrd */
 949         if (in_initrd()) {
 950                 r = add_sysroot_mount();
 951
 952                 r2 = add_sysroot_usr_mount();
 953
 954                 r3 = add_volatile_root();
 955         } else
 956                 r = add_volatile_var();
 957
 958         /* Honour /etc/fstab only when that's enabled */
 959         if (arg_fstab_enabled) {
 960                 /* Parse the local /etc/fstab, possibly from the initrd */
 961                 r2 = parse_fstab(false);
 962
 963                 /* If running in the initrd also parse the /etc/fstab from the host */
 964                 if (in_initrd())
 965                         r3 = parse_fstab(true);
 966                 else
 967                         r3 = generator_enable_remount_fs_service(arg_dest);
 968         }
 969
 970         return r < 0 ? r : r2 < 0 ? r2 : r3;
 971 }
 972
 973 DEFINE_MAIN_GENERATOR_FUNCTION(run);