src/fstab-generator/fstab-generator.c

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