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