src/fstab-generator/fstab-generator.c

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