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