src/fstab-generator/fstab-generator.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /***
   3   This file is part of systemd.
   4
   5   Copyright 2012 Lennart Poettering
   6 ***/
   7
   8 #include <errno.h>
   9 #include <mntent.h>
  10 #include <stdio.h>
  11 #include <string.h>
  12 #include <unistd.h>
  13 #include <stdio_ext.h>
  14
  15 #include "alloc-util.h"
  16 #include "fd-util.h"
  17 #include "fileio.h"
  18 #include "fs-util.h"
  19 #include "fstab-util.h"
  20 #include "generator.h"
  21 #include "log.h"
  22 #include "mkdir.h"
  23 #include "mount-setup.h"
  24 #include "mount-util.h"
  25 #include "parse-util.h"
  26 #include "path-util.h"
  27 #include "proc-cmdline.h"
  28 #include "special.h"
  29 #include "specifier.h"
  30 #include "stat-util.h"
  31 #include "string-util.h"
  32 #include "strv.h"
  33 #include "unit-name.h"
  34 #include "util.h"
  35 #include "virt.h"
  36 #include "volatile-util.h"
  37
  38 typedef enum MountpointFlags {
  39         NOAUTO    = 1 << 0,
  40         NOFAIL    = 1 << 1,
  41         AUTOMOUNT = 1 << 2,
  42         MAKEFS    = 1 << 3,
  43         GROWFS    = 1 << 4,
  44 } MountpointFlags;
  45
  46 static const char *arg_dest = "/tmp";
  47 static const char *arg_dest_late = "/tmp";
  48 static bool arg_fstab_enabled = true;
  49 static char *arg_root_what = NULL;
  50 static char *arg_root_fstype = NULL;
  51 static char *arg_root_options = NULL;
  52 static char *arg_root_hash = NULL;
  53 static int arg_root_rw = -1;
  54 static char *arg_usr_what = NULL;
  55 static char *arg_usr_fstype = NULL;
  56 static char *arg_usr_options = NULL;
  57 static VolatileMode arg_volatile_mode = _VOLATILE_MODE_INVALID;
  58
  59 static int write_options(FILE *f, const char *options) {
  60         _cleanup_free_ char *o = NULL;
  61
  62         if (isempty(options))
  63                 return 0;
  64
  65         if (streq(options, "defaults"))
  66                 return 0;
  67
  68         o = specifier_escape(options);
  69         if (!o)
  70                 return log_oom();
  71
  72         fprintf(f, "Options=%s\n", o);
  73         return 1;
  74 }
  75
  76 static int write_what(FILE *f, const char *what) {
  77         _cleanup_free_ char *w = NULL;
  78
  79         w = specifier_escape(what);
  80         if (!w)
  81                 return log_oom();
  82
  83         fprintf(f, "What=%s\n", w);
  84         return 1;
  85 }
  86
  87 static int add_swap(
  88                 const char *what,
  89                 struct mntent *me,
  90                 MountpointFlags flags) {
  91
  92         _cleanup_free_ char *name = NULL;
  93         _cleanup_fclose_ FILE *f = NULL;
  94         int r;
  95
  96         assert(what);
  97         assert(me);
  98
  99         if (access("/proc/swaps", F_OK) < 0) {
 100                 log_info("Swap not supported, ignoring fstab swap entry for %s.", what);
 101                 return 0;
 102         }
 103
 104         if (detect_container() > 0) {
 105                 log_info("Running in a container, ignoring fstab swap entry for %s.", what);
 106                 return 0;
 107         }
 108
 109         r = unit_name_from_path(what, ".swap", &name);
 110         if (r < 0)
 111                 return log_error_errno(r, "Failed to generate unit name: %m");
 112
 113         r = generator_open_unit_file(arg_dest, "/etc/fstab", name, &f);
 114         if (r < 0)
 115                 return r;
 116
 117         fputs("# Automatically generated by systemd-fstab-generator\n\n"
 118               "[Unit]\n"
 119               "SourcePath=/etc/fstab\n"
 120               "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n\n"
 121               "[Swap]\n", f);
 122
 123         r = write_what(f, what);
 124         if (r < 0)
 125                 return r;
 126
 127         r = write_options(f, me->mnt_opts);
 128         if (r < 0)
 129                 return r;
 130
 131         r = fflush_and_check(f);
 132         if (r < 0)
 133                 return log_error_errno(r, "Failed to write unit file %s: %m", name);
 134
 135         /* use what as where, to have a nicer error message */
 136         r = generator_write_timeouts(arg_dest, what, what, me->mnt_opts, NULL);
 137         if (r < 0)
 138                 return r;
 139
 140         if (flags & MAKEFS) {
 141                 r = generator_hook_up_mkswap(arg_dest, what);
 142                 if (r < 0)
 143                         return r;
 144         }
 145
 146         if (flags & GROWFS)
 147                 /* TODO: swap devices must be wiped and recreated */
 148                 log_warning("%s: growing swap devices is currently unsupported.", what);
 149
 150         if (!(flags & NOAUTO)) {
 151                 r = generator_add_symlink(arg_dest, SPECIAL_SWAP_TARGET,
 152                                           (flags & NOFAIL) ? "wants" : "requires", name);
 153                 if (r < 0)
 154                         return r;
 155         }
 156
 157         return 0;
 158 }
 159
 160 static bool mount_is_network(struct mntent *me) {
 161         assert(me);
 162
 163         return fstab_test_option(me->mnt_opts, "_netdev\0") ||
 164                fstype_is_network(me->mnt_type);
 165 }
 166
 167 static bool mount_in_initrd(struct mntent *me) {
 168         assert(me);
 169
 170         return fstab_test_option(me->mnt_opts, "x-initrd.mount\0") ||
 171                streq(me->mnt_dir, "/usr");
 172 }
 173
 174 static int write_timeout(FILE *f, const char *where, const char *opts,
 175                          const char *filter, const char *variable) {
 176         _cleanup_free_ char *timeout = NULL;
 177         char timespan[FORMAT_TIMESPAN_MAX];
 178         usec_t u;
 179         int r;
 180
 181         r = fstab_filter_options(opts, filter, NULL, &timeout, NULL);
 182         if (r < 0)
 183                 return log_warning_errno(r, "Failed to parse options: %m");
 184         if (r == 0)
 185                 return 0;
 186
 187         r = parse_sec_fix_0(timeout, &u);
 188         if (r < 0) {
 189                 log_warning("Failed to parse timeout for %s, ignoring: %s", where, timeout);
 190                 return 0;
 191         }
 192
 193         fprintf(f, "%s=%s\n", variable, format_timespan(timespan, sizeof(timespan), u, 0));
 194
 195         return 0;
 196 }
 197
 198 static int write_idle_timeout(FILE *f, const char *where, const char *opts) {
 199         return write_timeout(f, where, opts,
 200                              "x-systemd.idle-timeout\0", "TimeoutIdleSec");
 201 }
 202
 203 static int write_mount_timeout(FILE *f, const char *where, const char *opts) {
 204         return write_timeout(f, where, opts,
 205                              "x-systemd.mount-timeout\0", "TimeoutSec");
 206 }
 207
 208 static int write_dependency(FILE *f, const char *opts,
 209                 const char *filter, const char *format) {
 210         _cleanup_strv_free_ char **names = NULL, **units = NULL;
 211         _cleanup_free_ char *res = NULL;
 212         char **s;
 213         int r;
 214
 215         assert(f);
 216         assert(opts);
 217
 218         r = fstab_extract_values(opts, filter, &names);
 219         if (r < 0)
 220                 return log_warning_errno(r, "Failed to parse options: %m");
 221         if (r == 0)
 222                 return 0;
 223
 224         STRV_FOREACH(s, names) {
 225                 char *x;
 226
 227                 r = unit_name_mangle_with_suffix(*s, 0, ".mount", &x);
 228                 if (r < 0)
 229                         return log_error_errno(r, "Failed to generate unit name: %m");
 230                 r = strv_consume(&units, x);
 231                 if (r < 0)
 232                         return log_oom();
 233         }
 234
 235         if (units) {
 236                 res = strv_join(units, " ");
 237                 if (!res)
 238                         return log_oom();
 239 #pragma GCC diagnostic push
 240 #pragma GCC diagnostic ignored "-Wformat-nonliteral"
 241                 fprintf(f, format, res);
 242 #pragma GCC diagnostic pop
 243         }
 244
 245         return 0;
 246 }
 247
 248 static int write_after(FILE *f, const char *opts) {
 249         return write_dependency(f, opts, "x-systemd.after", "After=%1$s\n");
 250 }
 251
 252 static int write_requires_after(FILE *f, const char *opts) {
 253         return write_dependency(f, opts,
 254                                 "x-systemd.requires", "After=%1$s\nRequires=%1$s\n");
 255 }
 256
 257 static int write_before(FILE *f, const char *opts) {
 258         return write_dependency(f, opts,
 259                                 "x-systemd.before", "Before=%1$s\n");
 260 }
 261
 262 static int write_requires_mounts_for(FILE *f, const char *opts) {
 263         _cleanup_strv_free_ char **paths = NULL, **paths_escaped = NULL;
 264         _cleanup_free_ char *res = NULL;
 265         int r;
 266
 267         assert(f);
 268         assert(opts);
 269
 270         r = fstab_extract_values(opts, "x-systemd.requires-mounts-for", &paths);
 271         if (r < 0)
 272                 return log_warning_errno(r, "Failed to parse options: %m");
 273         if (r == 0)
 274                 return 0;
 275
 276         r = specifier_escape_strv(paths, &paths_escaped);
 277         if (r < 0)
 278                 return log_error_errno(r, "Failed to escape paths: %m");
 279
 280         res = strv_join(paths_escaped, " ");
 281         if (!res)
 282                 return log_oom();
 283
 284         fprintf(f, "RequiresMountsFor=%s\n", res);
 285
 286         return 0;
 287 }
 288
 289 static int add_mount(
 290                 const char *dest,
 291                 const char *what,
 292                 const char *where,
 293                 const char *original_where,
 294                 const char *fstype,
 295                 const char *opts,
 296                 int passno,
 297                 MountpointFlags flags,
 298                 const char *post,
 299                 const char *source) {
 300
 301         _cleanup_free_ char
 302                 *name = NULL,
 303                 *automount_name = NULL,
 304                 *filtered = NULL,
 305                 *where_escaped = NULL;
 306         _cleanup_fclose_ FILE *f = NULL;
 307         int r;
 308
 309         assert(what);
 310         assert(where);
 311         assert(opts);
 312         assert(post);
 313         assert(source);
 314
 315         if (streq_ptr(fstype, "autofs"))
 316                 return 0;
 317
 318         if (!is_path(where)) {
 319                 log_warning("Mount point %s is not a valid path, ignoring.", where);
 320                 return 0;
 321         }
 322
 323         if (mount_point_is_api(where) ||
 324             mount_point_ignore(where))
 325                 return 0;
 326
 327         if (path_equal(where, "/")) {
 328                 if (flags & NOAUTO)
 329                         log_warning("Ignoring \"noauto\" for root device");
 330                 if (flags & NOFAIL)
 331                         log_warning("Ignoring \"nofail\" for root device");
 332                 if (flags & AUTOMOUNT)
 333                         log_warning("Ignoring automount option for root device");
 334
 335                 SET_FLAG(flags, NOAUTO | NOFAIL | AUTOMOUNT, false);
 336         }
 337
 338         r = unit_name_from_path(where, ".mount", &name);
 339         if (r < 0)
 340                 return log_error_errno(r, "Failed to generate unit name: %m");
 341
 342         r = generator_open_unit_file(dest, "/etc/fstab", name, &f);
 343         if (r < 0)
 344                 return r;
 345
 346         fprintf(f,
 347                 "[Unit]\n"
 348                 "SourcePath=%s\n"
 349                 "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n",
 350                 source);
 351
 352         if (STRPTR_IN_SET(fstype, "nfs", "nfs4") && !(flags & AUTOMOUNT) &&
 353             fstab_test_yes_no_option(opts, "bg\0" "fg\0")) {
 354                 /* The default retry timeout that mount.nfs uses for 'bg' mounts
 355                  * is 10000 minutes, where as it uses 2 minutes for 'fg' mounts.
 356                  * As we are making  'bg' mounts look like an 'fg' mount to
 357                  * mount.nfs (so systemd can manage the job-control aspects of 'bg'),
 358                  * we need to explicitly preserve that default, and also ensure
 359                  * the systemd mount-timeout doesn't interfere.
 360                  * By placing these options first, they can be over-ridden by
 361                  * settings in /etc/fstab. */
 362                 opts = strjoina("x-systemd.mount-timeout=infinity,retry=10000,", opts, ",fg");
 363                 SET_FLAG(flags, NOFAIL, true);
 364         }
 365
 366         if (!(flags & NOFAIL) && !(flags & AUTOMOUNT))
 367                 fprintf(f, "Before=%s\n", post);
 368
 369         if (!(flags & AUTOMOUNT) && opts) {
 370                  r = write_after(f, opts);
 371                  if (r < 0)
 372                          return r;
 373                  r = write_requires_after(f, opts);
 374                  if (r < 0)
 375                          return r;
 376                  r = write_before(f, opts);
 377                  if (r < 0)
 378                          return r;
 379                  r = write_requires_mounts_for(f, opts);
 380                  if (r < 0)
 381                          return r;
 382         }
 383
 384         if (passno != 0) {
 385                 r = generator_write_fsck_deps(f, dest, what, where, fstype);
 386                 if (r < 0)
 387                         return r;
 388         }
 389
 390         fprintf(f, "\n[Mount]\n");
 391         if (original_where)
 392                 fprintf(f, "# Canonicalized from %s\n", original_where);
 393
 394         where_escaped = specifier_escape(where);
 395         if (!where_escaped)
 396                 return log_oom();
 397         fprintf(f, "Where=%s\n", where_escaped);
 398
 399         r = write_what(f, what);
 400         if (r < 0)
 401                 return r;
 402
 403         if (!isempty(fstype) && !streq(fstype, "auto")) {
 404                 _cleanup_free_ char *t;
 405
 406                 t = specifier_escape(fstype);
 407                 if (!t)
 408                         return -ENOMEM;
 409
 410                 fprintf(f, "Type=%s\n", t);
 411         }
 412
 413         r = generator_write_timeouts(dest, what, where, opts, &filtered);
 414         if (r < 0)
 415                 return r;
 416
 417         r = generator_write_device_deps(dest, what, where, opts);
 418         if (r < 0)
 419                 return r;
 420
 421         r = write_mount_timeout(f, where, opts);
 422         if (r < 0)
 423                 return r;
 424
 425         r = write_options(f, filtered);
 426         if (r < 0)
 427                 return r;
 428
 429         r = fflush_and_check(f);
 430         if (r < 0)
 431                 return log_error_errno(r, "Failed to write unit file %s: %m", name);
 432
 433         if (flags & MAKEFS) {
 434                 r = generator_hook_up_mkfs(dest, what, where, fstype);
 435                 if (r < 0)
 436                         return r;
 437         }
 438
 439         if (flags & GROWFS) {
 440                 r = generator_hook_up_growfs(dest, where, post);
 441                 if (r < 0)
 442                         return r;
 443         }
 444
 445         if (!(flags & NOAUTO) && !(flags & AUTOMOUNT)) {
 446                 r = generator_add_symlink(dest, post,
 447                                           (flags & NOFAIL) ? "wants" : "requires", name);
 448                 if (r < 0)
 449                         return r;
 450         }
 451
 452         if (flags & AUTOMOUNT) {
 453                 r = unit_name_from_path(where, ".automount", &automount_name);
 454                 if (r < 0)
 455                         return log_error_errno(r, "Failed to generate unit name: %m");
 456
 457                 fclose(f);
 458
 459                 r = generator_open_unit_file(dest, "/etc/fstab", automount_name, &f);
 460                 if (r < 0)
 461                         return r;
 462
 463                 fprintf(f,
 464                         "[Unit]\n"
 465                         "SourcePath=%s\n"
 466                         "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n",
 467                         source);
 468
 469                 fprintf(f, "Before=%s\n", post);
 470
 471                 if (opts) {
 472                         r = write_after(f, opts);
 473                         if (r < 0)
 474                                 return r;
 475                         r = write_requires_after(f, opts);
 476                         if (r < 0)
 477                                 return r;
 478                         r = write_before(f, opts);
 479                         if (r < 0)
 480                                 return r;
 481                         r = write_requires_mounts_for(f, opts);
 482                         if (r < 0)
 483                                 return r;
 484                 }
 485
 486                 fprintf(f,
 487                         "\n"
 488                         "[Automount]\n"
 489                         "Where=%s\n",
 490                         where_escaped);
 491
 492                 r = write_idle_timeout(f, where, opts);
 493                 if (r < 0)
 494                         return r;
 495
 496                 r = fflush_and_check(f);
 497                 if (r < 0)
 498                         return log_error_errno(r, "Failed to write unit file %s: %m", automount_name);
 499
 500                 r = generator_add_symlink(dest, post,
 501                                           (flags & NOFAIL) ? "wants" : "requires", automount_name);
 502                 if (r < 0)
 503                         return r;
 504         }
 505
 506         return 0;
 507 }
 508
 509 static int parse_fstab(bool initrd) {
 510         _cleanup_endmntent_ FILE *f = NULL;
 511         const char *fstab_path;
 512         struct mntent *me;
 513         int r = 0;
 514
 515         fstab_path = initrd ? "/sysroot/etc/fstab" : "/etc/fstab";
 516         f = setmntent(fstab_path, "re");
 517         if (!f) {
 518                 if (errno == ENOENT)
 519                         return 0;
 520
 521                 return log_error_errno(errno, "Failed to open %s: %m", fstab_path);
 522         }
 523
 524         while ((me = getmntent(f))) {
 525                 _cleanup_free_ char *where = NULL, *what = NULL, *canonical_where = NULL;
 526                 bool makefs, growfs, noauto, nofail;
 527                 int k;
 528
 529                 if (initrd && !mount_in_initrd(me))
 530                         continue;
 531
 532                 what = fstab_node_to_udev_node(me->mnt_fsname);
 533                 if (!what)
 534                         return log_oom();
 535
 536                 if (is_device_path(what) && path_is_read_only_fs("sys") > 0) {
 537                         log_info("Running in a container, ignoring fstab device entry for %s.", what);
 538                         continue;
 539                 }
 540
 541                 where = strdup(me->mnt_dir);
 542                 if (!where)
 543                         return log_oom();
 544
 545                 if (is_path(where)) {
 546                         path_simplify(where, false);
 547
 548                         /* Follow symlinks here; see 5261ba901845c084de5a8fd06500ed09bfb0bd80 which makes sense for
 549                          * mount units, but causes problems since it historically worked to have symlinks in e.g.
 550                          * /etc/fstab. So we canonicalize here. Note that we use CHASE_NONEXISTENT to handle the case
 551                          * where a symlink refers to another mount target; this works assuming the sub-mountpoint
 552                          * target is the final directory. */
 553                         r = chase_symlinks(where, initrd ? "/sysroot" : NULL,
 554                                            CHASE_PREFIX_ROOT | CHASE_NONEXISTENT,
 555                                            &canonical_where);
 556                         if (r < 0) /* If we can't canonicalize we continue on as if it wasn't a symlink */
 557                                 log_debug_errno(r, "Failed to read symlink target for %s, ignoring: %m", where);
 558                         else if (streq(canonical_where, where)) /* If it was fully canonicalized, suppress the change */
 559                                 canonical_where = mfree(canonical_where);
 560                         else
 561                                 log_debug("Canonicalized what=%s where=%s to %s", what, where, canonical_where);
 562                 }
 563
 564                 makefs = fstab_test_option(me->mnt_opts, "x-systemd.makefs\0");
 565                 growfs = fstab_test_option(me->mnt_opts, "x-systemd.growfs\0");
 566                 noauto = fstab_test_yes_no_option(me->mnt_opts, "noauto\0" "auto\0");
 567                 nofail = fstab_test_yes_no_option(me->mnt_opts, "nofail\0" "fail\0");
 568
 569                 log_debug("Found entry what=%s where=%s type=%s makefs=%s nofail=%s noauto=%s",
 570                           what, where, me->mnt_type,
 571                           yes_no(makefs),
 572                           yes_no(noauto), yes_no(nofail));
 573
 574                 if (streq(me->mnt_type, "swap"))
 575                         k = add_swap(what, me,
 576                                      makefs*MAKEFS | growfs*GROWFS | noauto*NOAUTO | nofail*NOFAIL);
 577                 else {
 578                         bool automount;
 579                         const char *post;
 580
 581                         automount = fstab_test_option(me->mnt_opts,
 582                                                       "comment=systemd.automount\0"
 583                                                       "x-systemd.automount\0");
 584                         if (initrd)
 585                                 post = SPECIAL_INITRD_FS_TARGET;
 586                         else if (mount_is_network(me))
 587                                 post = SPECIAL_REMOTE_FS_TARGET;
 588                         else
 589                                 post = SPECIAL_LOCAL_FS_TARGET;
 590
 591                         k = add_mount(arg_dest,
 592                                       what,
 593                                       canonical_where ?: where,
 594                                       canonical_where ? where: NULL,
 595                                       me->mnt_type,
 596                                       me->mnt_opts,
 597                                       me->mnt_passno,
 598                                       makefs*MAKEFS | growfs*GROWFS | noauto*NOAUTO | nofail*NOFAIL | automount*AUTOMOUNT,
 599                                       post,
 600                                       fstab_path);
 601                 }
 602
 603                 if (r >= 0 && k < 0)
 604                         r = k;
 605         }
 606
 607         return r;
 608 }
 609
 610 static int add_sysroot_mount(void) {
 611         _cleanup_free_ char *what = NULL;
 612         const char *opts;
 613         int r;
 614
 615         if (isempty(arg_root_what)) {
 616                 log_debug("Could not find a root= entry on the kernel command line.");
 617                 return 0;
 618         }
 619
 620         if (streq(arg_root_what, "gpt-auto")) {
 621                 /* This is handled by the gpt-auto generator */
 622                 log_debug("Skipping root directory handling, as gpt-auto was requested.");
 623                 return 0;
 624         }
 625
 626         if (path_equal(arg_root_what, "/dev/nfs")) {
 627                 /* This is handled by the kernel or the initrd */
 628                 log_debug("Skipping root directory handling, as /dev/nfs was requested.");
 629                 return 0;
 630         }
 631
 632         what = fstab_node_to_udev_node(arg_root_what);
 633         if (!what)
 634                 return log_oom();
 635
 636         if (!arg_root_options)
 637                 opts = arg_root_rw > 0 ? "rw" : "ro";
 638         else if (arg_root_rw >= 0 ||
 639                  !fstab_test_option(arg_root_options, "ro\0" "rw\0"))
 640                 opts = strjoina(arg_root_options, ",", arg_root_rw > 0 ? "rw" : "ro");
 641         else
 642                 opts = arg_root_options;
 643
 644         log_debug("Found entry what=%s where=/sysroot type=%s", what, strna(arg_root_fstype));
 645
 646         if (is_device_path(what)) {
 647                 r = generator_write_initrd_root_device_deps(arg_dest, what);
 648                 if (r < 0)
 649                         return r;
 650         }
 651
 652         return add_mount(arg_dest,
 653                          what,
 654                          "/sysroot",
 655                          NULL,
 656                          arg_root_fstype,
 657                          opts,
 658                          is_device_path(what) ? 1 : 0, /* passno */
 659                          0,                            /* makefs off, growfs off, noauto off, nofail off, automount off */
 660                          SPECIAL_INITRD_ROOT_FS_TARGET,
 661                          "/proc/cmdline");
 662 }
 663
 664 static int add_sysroot_usr_mount(void) {
 665         _cleanup_free_ char *what = NULL;
 666         const char *opts;
 667
 668         if (!arg_usr_what && !arg_usr_fstype && !arg_usr_options)
 669                 return 0;
 670
 671         if (arg_root_what && !arg_usr_what) {
 672                 /* Copy over the root device, in case the /usr mount just differs in a mount option (consider btrfs subvolumes) */
 673                 arg_usr_what = strdup(arg_root_what);
 674                 if (!arg_usr_what)
 675                         return log_oom();
 676         }
 677
 678         if (arg_root_fstype && !arg_usr_fstype) {
 679                 arg_usr_fstype = strdup(arg_root_fstype);
 680                 if (!arg_usr_fstype)
 681                         return log_oom();
 682         }
 683
 684         if (arg_root_options && !arg_usr_options) {
 685                 arg_usr_options = strdup(arg_root_options);
 686                 if (!arg_usr_options)
 687                         return log_oom();
 688         }
 689
 690         if (!arg_usr_what)
 691                 return 0;
 692
 693         what = fstab_node_to_udev_node(arg_usr_what);
 694         if (!what)
 695                 return log_oom();
 696
 697         if (!arg_usr_options)
 698                 opts = arg_root_rw > 0 ? "rw" : "ro";
 699         else if (!fstab_test_option(arg_usr_options, "ro\0" "rw\0"))
 700                 opts = strjoina(arg_usr_options, ",", arg_root_rw > 0 ? "rw" : "ro");
 701         else
 702                 opts = arg_usr_options;
 703
 704         log_debug("Found entry what=%s where=/sysroot/usr type=%s", what, strna(arg_usr_fstype));
 705         return add_mount(arg_dest,
 706                          what,
 707                          "/sysroot/usr",
 708                          NULL,
 709                          arg_usr_fstype,
 710                          opts,
 711                          is_device_path(what) ? 1 : 0, /* passno */
 712                          0,
 713                          SPECIAL_INITRD_FS_TARGET,
 714                          "/proc/cmdline");
 715 }
 716
 717 static int add_volatile_root(void) {
 718         const char *from, *to;
 719
 720         if (arg_volatile_mode != VOLATILE_YES)
 721                 return 0;
 722
 723         /* Let's add in systemd-remount-volatile.service which will remount the root device to tmpfs if this is
 724          * requested, leaving only /usr from the root mount inside. */
 725
 726         from = strjoina(SYSTEM_DATA_UNIT_PATH "/systemd-volatile-root.service");
 727         to = strjoina(arg_dest, "/" SPECIAL_INITRD_ROOT_FS_TARGET, ".requires/systemd-volatile-root.service");
 728
 729         (void) mkdir_parents(to, 0755);
 730
 731         if (symlink(from, to) < 0)
 732                 return log_error_errno(errno, "Failed to hook in volatile remount service: %m");
 733
 734         return 0;
 735 }
 736
 737 static int add_volatile_var(void) {
 738
 739         if (arg_volatile_mode != VOLATILE_STATE)
 740                 return 0;
 741
 742         /* If requested, mount /var as tmpfs, but do so only if there's nothing else defined for this. */
 743
 744         return add_mount(arg_dest_late,
 745                          "tmpfs",
 746                          "/var",
 747                          NULL,
 748                          "tmpfs",
 749                          "mode=0755",
 750                          0,
 751                          0,
 752                          SPECIAL_LOCAL_FS_TARGET,
 753                          "/proc/cmdline");
 754 }
 755
 756 static int parse_proc_cmdline_item(const char *key, const char *value, void *data) {
 757         int r;
 758
 759         /* root=, usr=, usrfstype= and roofstype= may occur more than once, the last
 760          * instance should take precedence.  In the case of multiple rootflags=
 761          * or usrflags= the arguments should be concatenated */
 762
 763         if (STR_IN_SET(key, "fstab", "rd.fstab")) {
 764
 765                 r = value ? parse_boolean(value) : 1;
 766                 if (r < 0)
 767                         log_warning("Failed to parse fstab switch %s. Ignoring.", value);
 768                 else
 769                         arg_fstab_enabled = r;
 770
 771         } else if (streq(key, "root")) {
 772
 773                 if (proc_cmdline_value_missing(key, value))
 774                         return 0;
 775
 776                 if (free_and_strdup(&arg_root_what, value) < 0)
 777                         return log_oom();
 778
 779         } else if (streq(key, "rootfstype")) {
 780
 781                 if (proc_cmdline_value_missing(key, value))
 782                         return 0;
 783
 784                 if (free_and_strdup(&arg_root_fstype, value) < 0)
 785                         return log_oom();
 786
 787         } else if (streq(key, "rootflags")) {
 788
 789                 if (proc_cmdline_value_missing(key, value))
 790                         return 0;
 791
 792                 if (!strextend_with_separator(&arg_root_options, ",", value, NULL))
 793                         return log_oom();
 794
 795         } else if (streq(key, "roothash")) {
 796
 797                 if (proc_cmdline_value_missing(key, value))
 798                         return 0;
 799
 800                 if (free_and_strdup(&arg_root_hash, value) < 0)
 801                         return log_oom();
 802
 803         } else if (streq(key, "mount.usr")) {
 804
 805                 if (proc_cmdline_value_missing(key, value))
 806                         return 0;
 807
 808                 if (free_and_strdup(&arg_usr_what, value) < 0)
 809                         return log_oom();
 810
 811         } else if (streq(key, "mount.usrfstype")) {
 812
 813                 if (proc_cmdline_value_missing(key, value))
 814                         return 0;
 815
 816                 if (free_and_strdup(&arg_usr_fstype, value) < 0)
 817                         return log_oom();
 818
 819         } else if (streq(key, "mount.usrflags")) {
 820
 821                 if (proc_cmdline_value_missing(key, value))
 822                         return 0;
 823
 824                 if (!strextend_with_separator(&arg_usr_options, ",", value, NULL))
 825                         return log_oom();
 826
 827         } else if (streq(key, "rw") && !value)
 828                 arg_root_rw = true;
 829         else if (streq(key, "ro") && !value)
 830                 arg_root_rw = false;
 831         else if (streq(key, "systemd.volatile")) {
 832                 VolatileMode m;
 833
 834                 if (value) {
 835                         m = volatile_mode_from_string(value);
 836                         if (m < 0)
 837                                 log_warning("Failed to parse systemd.volatile= argument: %s", value);
 838                         else
 839                                 arg_volatile_mode = m;
 840                 } else
 841                         arg_volatile_mode = VOLATILE_YES;
 842         }
 843
 844         return 0;
 845 }
 846
 847 static int determine_root(void) {
 848         /* If we have a root hash but no root device then Verity is used, and we use the "root" DM device as root. */
 849
 850         if (arg_root_what)
 851                 return 0;
 852
 853         if (!arg_root_hash)
 854                 return 0;
 855
 856         arg_root_what = strdup("/dev/mapper/root");
 857         if (!arg_root_what)
 858                 return log_oom();
 859
 860         log_info("Using verity root device %s.", arg_root_what);
 861
 862         return 1;
 863 }
 864
 865 int main(int argc, char *argv[]) {
 866         int r = 0;
 867
 868         if (argc > 1 && argc != 4) {
 869                 log_error("This program takes three or no arguments.");
 870                 return EXIT_FAILURE;
 871         }
 872
 873         if (argc > 1)
 874                 arg_dest = argv[1];
 875         if (argc > 3)
 876                 arg_dest_late = argv[3];
 877
 878         log_set_prohibit_ipc(true);
 879         log_set_target(LOG_TARGET_AUTO);
 880         log_parse_environment();
 881         log_open();
 882
 883         umask(0022);
 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         free(arg_root_what);
 929         free(arg_root_fstype);
 930         free(arg_root_options);
 931         free(arg_root_hash);
 932
 933         free(arg_usr_what);
 934         free(arg_usr_fstype);
 935         free(arg_usr_options);
 936
 937         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 938 }