src/fstab-generator/fstab-generator.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /***
   3   Copyright 2012 Lennart Poettering
   4 ***/
   5
   6 #include <errno.h>
   7 #include <mntent.h>
   8 #include <stdio.h>
   9 #include <string.h>
  10 #include <unistd.h>
  11 #include <stdio_ext.h>
  12
  13 #include "alloc-util.h"
  14 #include "fd-util.h"
  15 #include "fileio.h"
  16 #include "fs-util.h"
  17 #include "fstab-util.h"
  18 #include "generator.h"
  19 #include "log.h"
  20 #include "mkdir.h"
  21 #include "mount-setup.h"
  22 #include "mount-util.h"
  23 #include "parse-util.h"
  24 #include "path-util.h"
  25 #include "proc-cmdline.h"
  26 #include "special.h"
  27 #include "specifier.h"
  28 #include "stat-util.h"
  29 #include "string-util.h"
  30 #include "strv.h"
  31 #include "unit-name.h"
  32 #include "util.h"
  33 #include "virt.h"
  34 #include "volatile-util.h"
  35
  36 typedef enum MountpointFlags {
  37         NOAUTO    = 1 << 0,
  38         NOFAIL    = 1 << 1,
  39         AUTOMOUNT = 1 << 2,
  40         MAKEFS    = 1 << 3,
  41         GROWFS    = 1 << 4,
  42 } MountpointFlags;
  43
  44 static const char *arg_dest = "/tmp";
  45 static const char *arg_dest_late = "/tmp";
  46 static bool arg_fstab_enabled = true;
  47 static char *arg_root_what = NULL;
  48 static char *arg_root_fstype = NULL;
  49 static char *arg_root_options = NULL;
  50 static char *arg_root_hash = NULL;
  51 static int arg_root_rw = -1;
  52 static char *arg_usr_what = NULL;
  53 static char *arg_usr_fstype = NULL;
  54 static char *arg_usr_options = NULL;
  55 static VolatileMode arg_volatile_mode = _VOLATILE_MODE_INVALID;
  56
  57 static int write_options(FILE *f, const char *options) {
  58         _cleanup_free_ char *o = NULL;
  59
  60         if (isempty(options))
  61                 return 0;
  62
  63         if (streq(options, "defaults"))
  64                 return 0;
  65
  66         o = specifier_escape(options);
  67         if (!o)
  68                 return log_oom();
  69
  70         fprintf(f, "Options=%s\n", o);
  71         return 1;
  72 }
  73
  74 static int write_what(FILE *f, const char *what) {
  75         _cleanup_free_ char *w = NULL;
  76
  77         w = specifier_escape(what);
  78         if (!w)
  79                 return log_oom();
  80
  81         fprintf(f, "What=%s\n", w);
  82         return 1;
  83 }
  84
  85 static int add_swap(
  86                 const char *what,
  87                 struct mntent *me,
  88                 MountpointFlags flags) {
  89
  90         _cleanup_free_ char *name = NULL;
  91         _cleanup_fclose_ FILE *f = NULL;
  92         int r;
  93
  94         assert(what);
  95         assert(me);
  96
  97         if (access("/proc/swaps", F_OK) < 0) {
  98                 log_info("Swap not supported, ignoring fstab swap entry for %s.", what);
  99                 return 0;
 100         }
 101
 102         if (detect_container() > 0) {
 103                 log_info("Running in a container, ignoring fstab swap entry for %s.", what);
 104                 return 0;
 105         }
 106
 107         r = unit_name_from_path(what, ".swap", &name);
 108         if (r < 0)
 109                 return log_error_errno(r, "Failed to generate unit name: %m");
 110
 111         r = generator_open_unit_file(arg_dest, "/etc/fstab", name, &f);
 112         if (r < 0)
 113                 return r;
 114
 115         fputs("# Automatically generated by systemd-fstab-generator\n\n"
 116               "[Unit]\n"
 117               "SourcePath=/etc/fstab\n"
 118               "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n\n"
 119               "[Swap]\n", f);
 120
 121         r = write_what(f, what);
 122         if (r < 0)
 123                 return r;
 124
 125         r = write_options(f, me->mnt_opts);
 126         if (r < 0)
 127                 return r;
 128
 129         r = fflush_and_check(f);
 130         if (r < 0)
 131                 return log_error_errno(r, "Failed to write unit file %s: %m", name);
 132
 133         /* use what as where, to have a nicer error message */
 134         r = generator_write_timeouts(arg_dest, what, what, me->mnt_opts, NULL);
 135         if (r < 0)
 136                 return r;
 137
 138         if (flags & MAKEFS) {
 139                 r = generator_hook_up_mkswap(arg_dest, what);
 140                 if (r < 0)
 141                         return r;
 142         }
 143
 144         if (flags & GROWFS)
 145                 /* TODO: swap devices must be wiped and recreated */
 146                 log_warning("%s: growing swap devices is currently unsupported.", what);
 147
 148         if (!(flags & NOAUTO)) {
 149                 r = generator_add_symlink(arg_dest, SPECIAL_SWAP_TARGET,
 150                                           (flags & NOFAIL) ? "wants" : "requires", name);
 151                 if (r < 0)
 152                         return r;
 153         }
 154
 155         return 0;
 156 }
 157
 158 static bool mount_is_network(struct mntent *me) {
 159         assert(me);
 160
 161         return fstab_test_option(me->mnt_opts, "_netdev\0") ||
 162                fstype_is_network(me->mnt_type);
 163 }
 164
 165 static bool mount_in_initrd(struct mntent *me) {
 166         assert(me);
 167
 168         return fstab_test_option(me->mnt_opts, "x-initrd.mount\0") ||
 169                streq(me->mnt_dir, "/usr");
 170 }
 171
 172 static int write_timeout(FILE *f, const char *where, const char *opts,
 173                          const char *filter, const char *variable) {
 174         _cleanup_free_ char *timeout = NULL;
 175         char timespan[FORMAT_TIMESPAN_MAX];
 176         usec_t u;
 177         int r;
 178
 179         r = fstab_filter_options(opts, filter, NULL, &timeout, NULL);
 180         if (r < 0)
 181                 return log_warning_errno(r, "Failed to parse options: %m");
 182         if (r == 0)
 183                 return 0;
 184
 185         r = parse_sec_fix_0(timeout, &u);
 186         if (r < 0) {
 187                 log_warning("Failed to parse timeout for %s, ignoring: %s", where, timeout);
 188                 return 0;
 189         }
 190
 191         fprintf(f, "%s=%s\n", variable, format_timespan(timespan, sizeof(timespan), u, 0));
 192
 193         return 0;
 194 }
 195
 196 static int write_idle_timeout(FILE *f, const char *where, const char *opts) {
 197         return write_timeout(f, where, opts,
 198                              "x-systemd.idle-timeout\0", "TimeoutIdleSec");
 199 }
 200
 201 static int write_mount_timeout(FILE *f, const char *where, const char *opts) {
 202         return write_timeout(f, where, opts,
 203                              "x-systemd.mount-timeout\0", "TimeoutSec");
 204 }
 205
 206 static int write_dependency(FILE *f, const char *opts,
 207                 const char *filter, const char *format) {
 208         _cleanup_strv_free_ char **names = NULL, **units = NULL;
 209         _cleanup_free_ char *res = NULL;
 210         char **s;
 211         int r;
 212
 213         assert(f);
 214         assert(opts);
 215
 216         r = fstab_extract_values(opts, filter, &names);
 217         if (r < 0)
 218                 return log_warning_errno(r, "Failed to parse options: %m");
 219         if (r == 0)
 220                 return 0;
 221
 222         STRV_FOREACH(s, names) {
 223                 char *x;
 224
 225                 r = unit_name_mangle_with_suffix(*s, 0, ".mount", &x);
 226                 if (r < 0)
 227                         return log_error_errno(r, "Failed to generate unit name: %m");
 228                 r = strv_consume(&units, x);
 229                 if (r < 0)
 230                         return log_oom();
 231         }
 232
 233         if (units) {
 234                 res = strv_join(units, " ");
 235                 if (!res)
 236                         return log_oom();
 237 #pragma GCC diagnostic push
 238 #pragma GCC diagnostic ignored "-Wformat-nonliteral"
 239                 fprintf(f, format, res);
 240 #pragma GCC diagnostic pop
 241         }
 242
 243         return 0;
 244 }
 245
 246 static int write_after(FILE *f, const char *opts) {
 247         return write_dependency(f, opts, "x-systemd.after", "After=%1$s\n");
 248 }
 249
 250 static int write_requires_after(FILE *f, const char *opts) {
 251         return write_dependency(f, opts,
 252                                 "x-systemd.requires", "After=%1$s\nRequires=%1$s\n");
 253 }
 254
 255 static int write_before(FILE *f, const char *opts) {
 256         return write_dependency(f, opts,
 257                                 "x-systemd.before", "Before=%1$s\n");
 258 }
 259
 260 static int write_requires_mounts_for(FILE *f, const char *opts) {
 261         _cleanup_strv_free_ char **paths = NULL, **paths_escaped = NULL;
 262         _cleanup_free_ char *res = NULL;
 263         int r;
 264
 265         assert(f);
 266         assert(opts);
 267
 268         r = fstab_extract_values(opts, "x-systemd.requires-mounts-for", &paths);
 269         if (r < 0)
 270                 return log_warning_errno(r, "Failed to parse options: %m");
 271         if (r == 0)
 272                 return 0;
 273
 274         r = specifier_escape_strv(paths, &paths_escaped);
 275         if (r < 0)
 276                 return log_error_errno(r, "Failed to escape paths: %m");
 277
 278         res = strv_join(paths_escaped, " ");
 279         if (!res)
 280                 return log_oom();
 281
 282         fprintf(f, "RequiresMountsFor=%s\n", res);
 283
 284         return 0;
 285 }
 286
 287 static int add_mount(
 288                 const char *dest,
 289                 const char *what,
 290                 const char *where,
 291                 const char *original_where,
 292                 const char *fstype,
 293                 const char *opts,
 294                 int passno,
 295                 MountpointFlags flags,
 296                 const char *post,
 297                 const char *source) {
 298
 299         _cleanup_free_ char
 300                 *name = NULL,
 301                 *automount_name = NULL,
 302                 *filtered = NULL,
 303                 *where_escaped = NULL;
 304         _cleanup_fclose_ FILE *f = NULL;
 305         int r;
 306
 307         assert(what);
 308         assert(where);
 309         assert(opts);
 310         assert(post);
 311         assert(source);
 312
 313         if (streq_ptr(fstype, "autofs"))
 314                 return 0;
 315
 316         if (!is_path(where)) {
 317                 log_warning("Mount point %s is not a valid path, ignoring.", where);
 318                 return 0;
 319         }
 320
 321         if (mount_point_is_api(where) ||
 322             mount_point_ignore(where))
 323                 return 0;
 324
 325         if (path_equal(where, "/")) {
 326                 if (flags & NOAUTO)
 327                         log_warning("Ignoring \"noauto\" for root device");
 328                 if (flags & NOFAIL)
 329                         log_warning("Ignoring \"nofail\" for root device");
 330                 if (flags & AUTOMOUNT)
 331                         log_warning("Ignoring automount option for root device");
 332
 333                 SET_FLAG(flags, NOAUTO | NOFAIL | AUTOMOUNT, false);
 334         }
 335
 336         r = unit_name_from_path(where, ".mount", &name);
 337         if (r < 0)
 338                 return log_error_errno(r, "Failed to generate unit name: %m");
 339
 340         r = generator_open_unit_file(dest, "/etc/fstab", name, &f);
 341         if (r < 0)
 342                 return r;
 343
 344         fprintf(f,
 345                 "[Unit]\n"
 346                 "SourcePath=%s\n"
 347                 "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n",
 348                 source);
 349
 350         if (STRPTR_IN_SET(fstype, "nfs", "nfs4") && !(flags & AUTOMOUNT) &&
 351             fstab_test_yes_no_option(opts, "bg\0" "fg\0")) {
 352                 /* The default retry timeout that mount.nfs uses for 'bg' mounts
 353                  * is 10000 minutes, where as it uses 2 minutes for 'fg' mounts.
 354                  * As we are making  'bg' mounts look like an 'fg' mount to
 355                  * mount.nfs (so systemd can manage the job-control aspects of 'bg'),
 356                  * we need to explicitly preserve that default, and also ensure
 357                  * the systemd mount-timeout doesn't interfere.
 358                  * By placing these options first, they can be over-ridden by
 359                  * settings in /etc/fstab. */
 360                 opts = strjoina("x-systemd.mount-timeout=infinity,retry=10000,", opts, ",fg");
 361                 SET_FLAG(flags, NOFAIL, true);
 362         }
 363
 364         if (!(flags & NOFAIL) && !(flags & AUTOMOUNT))
 365                 fprintf(f, "Before=%s\n", post);
 366
 367         if (!(flags & AUTOMOUNT) && opts) {
 368                  r = write_after(f, opts);
 369                  if (r < 0)
 370                          return r;
 371                  r = write_requires_after(f, opts);
 372                  if (r < 0)
 373                          return r;
 374                  r = write_before(f, opts);
 375                  if (r < 0)
 376                          return r;
 377                  r = write_requires_mounts_for(f, opts);
 378                  if (r < 0)
 379                          return r;
 380         }
 381
 382         if (passno != 0) {
 383                 r = generator_write_fsck_deps(f, dest, what, where, fstype);
 384                 if (r < 0)
 385                         return r;
 386         }
 387
 388         fprintf(f, "\n[Mount]\n");
 389         if (original_where)
 390                 fprintf(f, "# Canonicalized from %s\n", original_where);
 391
 392         where_escaped = specifier_escape(where);
 393         if (!where_escaped)
 394                 return log_oom();
 395         fprintf(f, "Where=%s\n", where_escaped);
 396
 397         r = write_what(f, what);
 398         if (r < 0)
 399                 return r;
 400
 401         if (!isempty(fstype) && !streq(fstype, "auto")) {
 402                 _cleanup_free_ char *t;
 403
 404                 t = specifier_escape(fstype);
 405                 if (!t)
 406                         return -ENOMEM;
 407
 408                 fprintf(f, "Type=%s\n", t);
 409         }
 410
 411         r = generator_write_timeouts(dest, what, where, opts, &filtered);
 412         if (r < 0)
 413                 return r;
 414
 415         r = generator_write_device_deps(dest, what, where, opts);
 416         if (r < 0)
 417                 return r;
 418
 419         r = write_mount_timeout(f, where, opts);
 420         if (r < 0)
 421                 return r;
 422
 423         r = write_options(f, filtered);
 424         if (r < 0)
 425                 return r;
 426
 427         r = fflush_and_check(f);
 428         if (r < 0)
 429                 return log_error_errno(r, "Failed to write unit file %s: %m", name);
 430
 431         if (flags & MAKEFS) {
 432                 r = generator_hook_up_mkfs(dest, what, where, fstype);
 433                 if (r < 0)
 434                         return r;
 435         }
 436
 437         if (flags & GROWFS) {
 438                 r = generator_hook_up_growfs(dest, where, post);
 439                 if (r < 0)
 440                         return r;
 441         }
 442
 443         if (!(flags & NOAUTO) && !(flags & AUTOMOUNT)) {
 444                 r = generator_add_symlink(dest, post,
 445                                           (flags & NOFAIL) ? "wants" : "requires", name);
 446                 if (r < 0)
 447                         return r;
 448         }
 449
 450         if (flags & AUTOMOUNT) {
 451                 r = unit_name_from_path(where, ".automount", &automount_name);
 452                 if (r < 0)
 453                         return log_error_errno(r, "Failed to generate unit name: %m");
 454
 455                 fclose(f);
 456
 457                 r = generator_open_unit_file(dest, "/etc/fstab", automount_name, &f);
 458                 if (r < 0)
 459                         return r;
 460
 461                 fprintf(f,
 462                         "[Unit]\n"
 463                         "SourcePath=%s\n"
 464                         "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n",
 465                         source);
 466
 467                 fprintf(f, "Before=%s\n", post);
 468
 469                 if (opts) {
 470                         r = write_after(f, opts);
 471                         if (r < 0)
 472                                 return r;
 473                         r = write_requires_after(f, opts);
 474                         if (r < 0)
 475                                 return r;
 476                         r = write_before(f, opts);
 477                         if (r < 0)
 478                                 return r;
 479                         r = write_requires_mounts_for(f, opts);
 480                         if (r < 0)
 481                                 return r;
 482                 }
 483
 484                 fprintf(f,
 485                         "\n"
 486                         "[Automount]\n"
 487                         "Where=%s\n",
 488                         where_escaped);
 489
 490                 r = write_idle_timeout(f, where, opts);
 491                 if (r < 0)
 492                         return r;
 493
 494                 r = fflush_and_check(f);
 495                 if (r < 0)
 496                         return log_error_errno(r, "Failed to write unit file %s: %m", automount_name);
 497
 498                 r = generator_add_symlink(dest, post,
 499                                           (flags & NOFAIL) ? "wants" : "requires", automount_name);
 500                 if (r < 0)
 501                         return r;
 502         }
 503
 504         return 0;
 505 }
 506
 507 static int parse_fstab(bool initrd) {
 508         _cleanup_endmntent_ FILE *f = NULL;
 509         const char *fstab_path;
 510         struct mntent *me;
 511         int r = 0;
 512
 513         fstab_path = initrd ? "/sysroot/etc/fstab" : "/etc/fstab";
 514         f = setmntent(fstab_path, "re");
 515         if (!f) {
 516                 if (errno == ENOENT)
 517                         return 0;
 518
 519                 return log_error_errno(errno, "Failed to open %s: %m", fstab_path);
 520         }
 521
 522         while ((me = getmntent(f))) {
 523                 _cleanup_free_ char *where = NULL, *what = NULL, *canonical_where = NULL;
 524                 bool makefs, growfs, noauto, nofail;
 525                 int k;
 526
 527                 if (initrd && !mount_in_initrd(me))
 528                         continue;
 529
 530                 what = fstab_node_to_udev_node(me->mnt_fsname);
 531                 if (!what)
 532                         return log_oom();
 533
 534                 if (is_device_path(what) && path_is_read_only_fs("sys") > 0) {
 535                         log_info("Running in a container, ignoring fstab device entry for %s.", what);
 536                         continue;
 537                 }
 538
 539                 where = strdup(me->mnt_dir);
 540                 if (!where)
 541                         return log_oom();
 542
 543                 if (is_path(where)) {
 544                         path_simplify(where, false);
 545
 546                         /* Follow symlinks here; see 5261ba901845c084de5a8fd06500ed09bfb0bd80 which makes sense for
 547                          * mount units, but causes problems since it historically worked to have symlinks in e.g.
 548                          * /etc/fstab. So we canonicalize here. Note that we use CHASE_NONEXISTENT to handle the case
 549                          * where a symlink refers to another mount target; this works assuming the sub-mountpoint
 550                          * target is the final directory. */
 551                         r = chase_symlinks(where, initrd ? "/sysroot" : NULL,
 552                                            CHASE_PREFIX_ROOT | CHASE_NONEXISTENT,
 553                                            &canonical_where);
 554                         if (r < 0) /* If we can't canonicalize we continue on as if it wasn't a symlink */
 555                                 log_debug_errno(r, "Failed to read symlink target for %s, ignoring: %m", where);
 556                         else if (streq(canonical_where, where)) /* If it was fully canonicalized, suppress the change */
 557                                 canonical_where = mfree(canonical_where);
 558                         else
 559                                 log_debug("Canonicalized what=%s where=%s to %s", what, where, canonical_where);
 560                 }
 561
 562                 makefs = fstab_test_option(me->mnt_opts, "x-systemd.makefs\0");
 563                 growfs = fstab_test_option(me->mnt_opts, "x-systemd.growfs\0");
 564                 noauto = fstab_test_yes_no_option(me->mnt_opts, "noauto\0" "auto\0");
 565                 nofail = fstab_test_yes_no_option(me->mnt_opts, "nofail\0" "fail\0");
 566
 567                 log_debug("Found entry what=%s where=%s type=%s makefs=%s nofail=%s noauto=%s",
 568                           what, where, me->mnt_type,
 569                           yes_no(makefs),
 570                           yes_no(noauto), yes_no(nofail));
 571
 572                 if (streq(me->mnt_type, "swap"))
 573                         k = add_swap(what, me,
 574                                      makefs*MAKEFS | growfs*GROWFS | noauto*NOAUTO | nofail*NOFAIL);
 575                 else {
 576                         bool automount;
 577                         const char *post;
 578
 579                         automount = fstab_test_option(me->mnt_opts,
 580                                                       "comment=systemd.automount\0"
 581                                                       "x-systemd.automount\0");
 582                         if (initrd)
 583                                 post = SPECIAL_INITRD_FS_TARGET;
 584                         else if (mount_is_network(me))
 585                                 post = SPECIAL_REMOTE_FS_TARGET;
 586                         else
 587                                 post = SPECIAL_LOCAL_FS_TARGET;
 588
 589                         k = add_mount(arg_dest,
 590                                       what,
 591                                       canonical_where ?: where,
 592                                       canonical_where ? where: NULL,
 593                                       me->mnt_type,
 594                                       me->mnt_opts,
 595                                       me->mnt_passno,
 596                                       makefs*MAKEFS | growfs*GROWFS | noauto*NOAUTO | nofail*NOFAIL | automount*AUTOMOUNT,
 597                                       post,
 598                                       fstab_path);
 599                 }
 600
 601                 if (r >= 0 && k < 0)
 602                         r = k;
 603         }
 604
 605         return r;
 606 }
 607
 608 static int add_sysroot_mount(void) {
 609         _cleanup_free_ char *what = NULL;
 610         const char *opts;
 611         int r;
 612
 613         if (isempty(arg_root_what)) {
 614                 log_debug("Could not find a root= entry on the kernel command line.");
 615                 return 0;
 616         }
 617
 618         if (streq(arg_root_what, "gpt-auto")) {
 619                 /* This is handled by the gpt-auto generator */
 620                 log_debug("Skipping root directory handling, as gpt-auto was requested.");
 621                 return 0;
 622         }
 623
 624         if (path_equal(arg_root_what, "/dev/nfs")) {
 625                 /* This is handled by the kernel or the initrd */
 626                 log_debug("Skipping root directory handling, as /dev/nfs was requested.");
 627                 return 0;
 628         }
 629
 630         what = fstab_node_to_udev_node(arg_root_what);
 631         if (!what)
 632                 return log_oom();
 633
 634         if (!arg_root_options)
 635                 opts = arg_root_rw > 0 ? "rw" : "ro";
 636         else if (arg_root_rw >= 0 ||
 637                  !fstab_test_option(arg_root_options, "ro\0" "rw\0"))
 638                 opts = strjoina(arg_root_options, ",", arg_root_rw > 0 ? "rw" : "ro");
 639         else
 640                 opts = arg_root_options;
 641
 642         log_debug("Found entry what=%s where=/sysroot type=%s", what, strna(arg_root_fstype));
 643
 644         if (is_device_path(what)) {
 645                 r = generator_write_initrd_root_device_deps(arg_dest, what);
 646                 if (r < 0)
 647                         return r;
 648         }
 649
 650         return add_mount(arg_dest,
 651                          what,
 652                          "/sysroot",
 653                          NULL,
 654                          arg_root_fstype,
 655                          opts,
 656                          is_device_path(what) ? 1 : 0, /* passno */
 657                          0,                            /* makefs off, growfs off, noauto off, nofail off, automount off */
 658                          SPECIAL_INITRD_ROOT_FS_TARGET,
 659                          "/proc/cmdline");
 660 }
 661
 662 static int add_sysroot_usr_mount(void) {
 663         _cleanup_free_ char *what = NULL;
 664         const char *opts;
 665
 666         if (!arg_usr_what && !arg_usr_fstype && !arg_usr_options)
 667                 return 0;
 668
 669         if (arg_root_what && !arg_usr_what) {
 670                 /* Copy over the root device, in case the /usr mount just differs in a mount option (consider btrfs subvolumes) */
 671                 arg_usr_what = strdup(arg_root_what);
 672                 if (!arg_usr_what)
 673                         return log_oom();
 674         }
 675
 676         if (arg_root_fstype && !arg_usr_fstype) {
 677                 arg_usr_fstype = strdup(arg_root_fstype);
 678                 if (!arg_usr_fstype)
 679                         return log_oom();
 680         }
 681
 682         if (arg_root_options && !arg_usr_options) {
 683                 arg_usr_options = strdup(arg_root_options);
 684                 if (!arg_usr_options)
 685                         return log_oom();
 686         }
 687
 688         if (!arg_usr_what)
 689                 return 0;
 690
 691         what = fstab_node_to_udev_node(arg_usr_what);
 692         if (!what)
 693                 return log_oom();
 694
 695         if (!arg_usr_options)
 696                 opts = arg_root_rw > 0 ? "rw" : "ro";
 697         else if (!fstab_test_option(arg_usr_options, "ro\0" "rw\0"))
 698                 opts = strjoina(arg_usr_options, ",", arg_root_rw > 0 ? "rw" : "ro");
 699         else
 700                 opts = arg_usr_options;
 701
 702         log_debug("Found entry what=%s where=/sysroot/usr type=%s", what, strna(arg_usr_fstype));
 703         return add_mount(arg_dest,
 704                          what,
 705                          "/sysroot/usr",
 706                          NULL,
 707                          arg_usr_fstype,
 708                          opts,
 709                          is_device_path(what) ? 1 : 0, /* passno */
 710                          0,
 711                          SPECIAL_INITRD_FS_TARGET,
 712                          "/proc/cmdline");
 713 }
 714
 715 static int add_volatile_root(void) {
 716         const char *from, *to;
 717
 718         if (arg_volatile_mode != VOLATILE_YES)
 719                 return 0;
 720
 721         /* Let's add in systemd-remount-volatile.service which will remount the root device to tmpfs if this is
 722          * requested, leaving only /usr from the root mount inside. */
 723
 724         from = strjoina(SYSTEM_DATA_UNIT_PATH "/systemd-volatile-root.service");
 725         to = strjoina(arg_dest, "/" SPECIAL_INITRD_ROOT_FS_TARGET, ".requires/systemd-volatile-root.service");
 726
 727         (void) mkdir_parents(to, 0755);
 728
 729         if (symlink(from, to) < 0)
 730                 return log_error_errno(errno, "Failed to hook in volatile remount service: %m");
 731
 732         return 0;
 733 }
 734
 735 static int add_volatile_var(void) {
 736
 737         if (arg_volatile_mode != VOLATILE_STATE)
 738                 return 0;
 739
 740         /* If requested, mount /var as tmpfs, but do so only if there's nothing else defined for this. */
 741
 742         return add_mount(arg_dest_late,
 743                          "tmpfs",
 744                          "/var",
 745                          NULL,
 746                          "tmpfs",
 747                          "mode=0755",
 748                          0,
 749                          0,
 750                          SPECIAL_LOCAL_FS_TARGET,
 751                          "/proc/cmdline");
 752 }
 753
 754 static int parse_proc_cmdline_item(const char *key, const char *value, void *data) {
 755         int r;
 756
 757         /* root=, usr=, usrfstype= and roofstype= may occur more than once, the last
 758          * instance should take precedence.  In the case of multiple rootflags=
 759          * or usrflags= the arguments should be concatenated */
 760
 761         if (STR_IN_SET(key, "fstab", "rd.fstab")) {
 762
 763                 r = value ? parse_boolean(value) : 1;
 764                 if (r < 0)
 765                         log_warning("Failed to parse fstab switch %s. Ignoring.", value);
 766                 else
 767                         arg_fstab_enabled = r;
 768
 769         } else if (streq(key, "root")) {
 770
 771                 if (proc_cmdline_value_missing(key, value))
 772                         return 0;
 773
 774                 if (free_and_strdup(&arg_root_what, value) < 0)
 775                         return log_oom();
 776
 777         } else if (streq(key, "rootfstype")) {
 778
 779                 if (proc_cmdline_value_missing(key, value))
 780                         return 0;
 781
 782                 if (free_and_strdup(&arg_root_fstype, value) < 0)
 783                         return log_oom();
 784
 785         } else if (streq(key, "rootflags")) {
 786
 787                 if (proc_cmdline_value_missing(key, value))
 788                         return 0;
 789
 790                 if (!strextend_with_separator(&arg_root_options, ",", value, NULL))
 791                         return log_oom();
 792
 793         } else if (streq(key, "roothash")) {
 794
 795                 if (proc_cmdline_value_missing(key, value))
 796                         return 0;
 797
 798                 if (free_and_strdup(&arg_root_hash, value) < 0)
 799                         return log_oom();
 800
 801         } else if (streq(key, "mount.usr")) {
 802
 803                 if (proc_cmdline_value_missing(key, value))
 804                         return 0;
 805
 806                 if (free_and_strdup(&arg_usr_what, value) < 0)
 807                         return log_oom();
 808
 809         } else if (streq(key, "mount.usrfstype")) {
 810
 811                 if (proc_cmdline_value_missing(key, value))
 812                         return 0;
 813
 814                 if (free_and_strdup(&arg_usr_fstype, value) < 0)
 815                         return log_oom();
 816
 817         } else if (streq(key, "mount.usrflags")) {
 818
 819                 if (proc_cmdline_value_missing(key, value))
 820                         return 0;
 821
 822                 if (!strextend_with_separator(&arg_usr_options, ",", value, NULL))
 823                         return log_oom();
 824
 825         } else if (streq(key, "rw") && !value)
 826                 arg_root_rw = true;
 827         else if (streq(key, "ro") && !value)
 828                 arg_root_rw = false;
 829         else if (streq(key, "systemd.volatile")) {
 830                 VolatileMode m;
 831
 832                 if (value) {
 833                         m = volatile_mode_from_string(value);
 834                         if (m < 0)
 835                                 log_warning("Failed to parse systemd.volatile= argument: %s", value);
 836                         else
 837                                 arg_volatile_mode = m;
 838                 } else
 839                         arg_volatile_mode = VOLATILE_YES;
 840         }
 841
 842         return 0;
 843 }
 844
 845 static int determine_root(void) {
 846         /* If we have a root hash but no root device then Verity is used, and we use the "root" DM device as root. */
 847
 848         if (arg_root_what)
 849                 return 0;
 850
 851         if (!arg_root_hash)
 852                 return 0;
 853
 854         arg_root_what = strdup("/dev/mapper/root");
 855         if (!arg_root_what)
 856                 return log_oom();
 857
 858         log_info("Using verity root device %s.", arg_root_what);
 859
 860         return 1;
 861 }
 862
 863 int main(int argc, char *argv[]) {
 864         int r = 0;
 865
 866         if (argc > 1 && argc != 4) {
 867                 log_error("This program takes three or no arguments.");
 868                 return EXIT_FAILURE;
 869         }
 870
 871         if (argc > 1)
 872                 arg_dest = argv[1];
 873         if (argc > 3)
 874                 arg_dest_late = argv[3];
 875
 876         log_set_prohibit_ipc(true);
 877         log_set_target(LOG_TARGET_AUTO);
 878         log_parse_environment();
 879         log_open();
 880
 881         umask(0022);
 882
 883         r = proc_cmdline_parse(parse_proc_cmdline_item, NULL, 0);
 884         if (r < 0)
 885                 log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m");
 886
 887         (void) determine_root();
 888
 889         /* Always honour root= and usr= in the kernel command line if we are in an initrd */
 890         if (in_initrd()) {
 891                 int k;
 892
 893                 r = add_sysroot_mount();
 894
 895                 k = add_sysroot_usr_mount();
 896                 if (k < 0)
 897                         r = k;
 898
 899                 k = add_volatile_root();
 900                 if (k < 0)
 901                         r = k;
 902         } else
 903                 r = add_volatile_var();
 904
 905         /* Honour /etc/fstab only when that's enabled */
 906         if (arg_fstab_enabled) {
 907                 int k;
 908
 909                 log_debug("Parsing /etc/fstab");
 910
 911                 /* Parse the local /etc/fstab, possibly from the initrd */
 912                 k = parse_fstab(false);
 913                 if (k < 0)
 914                         r = k;
 915
 916                 /* If running in the initrd also parse the /etc/fstab from the host */
 917                 if (in_initrd()) {
 918                         log_debug("Parsing /sysroot/etc/fstab");
 919
 920                         k = parse_fstab(true);
 921                         if (k < 0)
 922                                 r = k;
 923                 }
 924         }
 925
 926         free(arg_root_what);
 927         free(arg_root_fstype);
 928         free(arg_root_options);
 929         free(arg_root_hash);
 930
 931         free(arg_usr_what);
 932         free(arg_usr_fstype);
 933         free(arg_usr_options);
 934
 935         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 936 }