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;
  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                 r = generator_add_symlink(arg_dest, SPECIAL_SWAP_TARGET,
 152                                           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, UNIT_NAME_NOGLOB, ".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;
 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         res = strv_join(paths, " ");
 277         if (!res)
 278                 return log_oom();
 279
 280         fprintf(f, "RequiresMountsFor=%s\n", res);
 281
 282         return 0;
 283 }
 284
 285 static int add_mount(
 286                 const char *dest,
 287                 const char *what,
 288                 const char *where,
 289                 const char *fstype,
 290                 const char *opts,
 291                 int passno,
 292                 bool noauto,
 293                 bool nofail,
 294                 bool automount,
 295                 const char *post,
 296                 const char *source) {
 297
 298         _cleanup_free_ char
 299                 *name = NULL, *unit = NULL,
 300                 *automount_name = NULL, *automount_unit = NULL,
 301                 *filtered = NULL;
 302         _cleanup_fclose_ FILE *f = NULL;
 303         int r;
 304
 305         assert(what);
 306         assert(where);
 307         assert(opts);
 308         assert(post);
 309         assert(source);
 310
 311         if (streq_ptr(fstype, "autofs"))
 312                 return 0;
 313
 314         if (!is_path(where)) {
 315                 log_warning("Mount point %s is not a valid path, ignoring.", where);
 316                 return 0;
 317         }
 318
 319         if (mount_point_is_api(where) ||
 320             mount_point_ignore(where))
 321                 return 0;
 322
 323         if (path_equal(where, "/")) {
 324                 if (noauto)
 325                         log_warning("Ignoring \"noauto\" for root device");
 326                 if (nofail)
 327                         log_warning("Ignoring \"nofail\" for root device");
 328                 if (automount)
 329                         log_warning("Ignoring automount option for root device");
 330
 331                 noauto = nofail = automount = false;
 332         }
 333
 334         r = unit_name_from_path(where, ".mount", &name);
 335         if (r < 0)
 336                 return log_error_errno(r, "Failed to generate unit name: %m");
 337
 338         unit = strjoin(dest, "/", name);
 339         if (!unit)
 340                 return log_oom();
 341
 342         f = fopen(unit, "wxe");
 343         if (!f)
 344                 return log_error_errno(errno,
 345                                        errno == EEXIST ?
 346                                        "Failed to create mount unit file %s, as it already exists. Duplicate entry in /etc/fstab?" :
 347                                        "Failed to create unit file %s: %m",
 348                                        unit);
 349
 350         fprintf(f,
 351                 "# Automatically generated by systemd-fstab-generator\n\n"
 352                 "[Unit]\n"
 353                 "SourcePath=%s\n"
 354                 "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n",
 355                 source);
 356
 357         if (STRPTR_IN_SET(fstype, "nfs", "nfs4") && !automount &&
 358             fstab_test_yes_no_option(opts, "bg\0" "fg\0")) {
 359                 /* The default retry timeout that mount.nfs uses for 'bg' mounts
 360                  * is 10000 minutes, where as it uses 2 minutes for 'fg' mounts.
 361                  * As we are making  'bg' mounts look like an 'fg' mount to
 362                  * mount.nfs (so systemd can manage the job-control aspects of 'bg'),
 363                  * we need to explicitly preserve that default, and also ensure
 364                  * the systemd mount-timeout doesn't interfere.
 365                  * By placing these options first, they can be over-ridden by
 366                  * settings in /etc/fstab. */
 367                 opts = strjoina("x-systemd.mount-timeout=infinity,retry=10000,", opts, ",fg");
 368                 nofail = true;
 369         }
 370
 371         if (!nofail && !automount)
 372                 fprintf(f, "Before=%s\n", post);
 373
 374         if (!automount && opts) {
 375                  r = write_after(f, opts);
 376                  if (r < 0)
 377                          return r;
 378                  r = write_requires_after(f, opts);
 379                  if (r < 0)
 380                          return r;
 381                  r = write_before(f, opts);
 382                  if (r < 0)
 383                          return r;
 384                  r = write_requires_mounts_for(f, opts);
 385                  if (r < 0)
 386                          return r;
 387         }
 388
 389         if (passno != 0) {
 390                 r = generator_write_fsck_deps(f, dest, what, where, fstype);
 391                 if (r < 0)
 392                         return r;
 393         }
 394
 395         fprintf(f,
 396                 "\n"
 397                 "[Mount]\n"
 398                 "Where=%s\n",
 399                 where);
 400
 401         r = write_what(f, what);
 402         if (r < 0)
 403                 return r;
 404
 405         if (!isempty(fstype) && !streq(fstype, "auto"))
 406                 fprintf(f, "Type=%s\n", fstype);
 407
 408         r = generator_write_timeouts(dest, what, where, opts, &filtered);
 409         if (r < 0)
 410                 return r;
 411
 412         r = generator_write_device_deps(dest, what, where, opts);
 413         if (r < 0)
 414                 return r;
 415
 416         r = write_mount_timeout(f, where, opts);
 417         if (r < 0)
 418                 return r;
 419
 420         r = write_options(f, filtered);
 421         if (r < 0)
 422                 return r;
 423
 424         r = fflush_and_check(f);
 425         if (r < 0)
 426                 return log_error_errno(r, "Failed to write unit file %s: %m", unit);
 427
 428         if (!noauto && !automount) {
 429                 r = generator_add_symlink(dest, post,
 430                                           nofail ? "wants" : "requires", name);
 431                 if (r < 0)
 432                         return r;
 433         }
 434
 435         if (automount) {
 436                 r = unit_name_from_path(where, ".automount", &automount_name);
 437                 if (r < 0)
 438                         return log_error_errno(r, "Failed to generate unit name: %m");
 439
 440                 automount_unit = strjoin(dest, "/", automount_name);
 441                 if (!automount_unit)
 442                         return log_oom();
 443
 444                 fclose(f);
 445                 f = fopen(automount_unit, "wxe");
 446                 if (!f)
 447                         return log_error_errno(errno, "Failed to create unit file %s: %m", automount_unit);
 448
 449                 fprintf(f,
 450                         "# Automatically generated by systemd-fstab-generator\n\n"
 451                         "[Unit]\n"
 452                         "SourcePath=%s\n"
 453                         "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n",
 454                         source);
 455
 456                 fprintf(f, "Before=%s\n", post);
 457
 458                 if (opts) {
 459                         r = write_after(f, opts);
 460                         if (r < 0)
 461                                 return r;
 462                         r = write_requires_after(f, opts);
 463                         if (r < 0)
 464                                 return r;
 465                         r = write_before(f, opts);
 466                         if (r < 0)
 467                                 return r;
 468                         r = write_requires_mounts_for(f, opts);
 469                         if (r < 0)
 470                                 return r;
 471                 }
 472
 473                 fprintf(f,
 474                         "\n"
 475                         "[Automount]\n"
 476                         "Where=%s\n",
 477                         where);
 478
 479                 r = write_idle_timeout(f, where, opts);
 480                 if (r < 0)
 481                         return r;
 482
 483                 r = fflush_and_check(f);
 484                 if (r < 0)
 485                         return log_error_errno(r, "Failed to write unit file %s: %m", automount_unit);
 486
 487                 r = generator_add_symlink(dest, post,
 488                                           nofail ? "wants" : "requires", automount_name);
 489                 if (r < 0)
 490                         return r;
 491         }
 492
 493         return 0;
 494 }
 495
 496 static int parse_fstab(bool initrd) {
 497         _cleanup_endmntent_ FILE *f = NULL;
 498         const char *fstab_path;
 499         struct mntent *me;
 500         int r = 0;
 501
 502         fstab_path = initrd ? "/sysroot/etc/fstab" : "/etc/fstab";
 503         f = setmntent(fstab_path, "re");
 504         if (!f) {
 505                 if (errno == ENOENT)
 506                         return 0;
 507
 508                 return log_error_errno(errno, "Failed to open %s: %m", fstab_path);
 509         }
 510
 511         while ((me = getmntent(f))) {
 512                 _cleanup_free_ char *where = NULL, *what = NULL;
 513                 bool noauto, nofail;
 514                 int k;
 515
 516                 if (initrd && !mount_in_initrd(me))
 517                         continue;
 518
 519                 what = fstab_node_to_udev_node(me->mnt_fsname);
 520                 if (!what)
 521                         return log_oom();
 522
 523                 if (is_device_path(what) && path_is_read_only_fs("sys") > 0) {
 524                         log_info("Running in a container, ignoring fstab device entry for %s.", what);
 525                         continue;
 526                 }
 527
 528                 where = initrd ? strappend("/sysroot/", me->mnt_dir) : strdup(me->mnt_dir);
 529                 if (!where)
 530                         return log_oom();
 531
 532                 if (is_path(where))
 533                         path_kill_slashes(where);
 534
 535                 noauto = fstab_test_yes_no_option(me->mnt_opts, "noauto\0" "auto\0");
 536                 nofail = fstab_test_yes_no_option(me->mnt_opts, "nofail\0" "fail\0");
 537                 log_debug("Found entry what=%s where=%s type=%s nofail=%s noauto=%s",
 538                           what, where, me->mnt_type,
 539                           yes_no(noauto), yes_no(nofail));
 540
 541                 if (streq(me->mnt_type, "swap"))
 542                         k = add_swap(what, me, noauto, nofail);
 543                 else {
 544                         bool automount;
 545                         const char *post;
 546
 547                         automount = fstab_test_option(me->mnt_opts,
 548                                                       "comment=systemd.automount\0"
 549                                                       "x-systemd.automount\0");
 550                         if (initrd)
 551                                 post = SPECIAL_INITRD_FS_TARGET;
 552                         else if (mount_is_network(me))
 553                                 post = SPECIAL_REMOTE_FS_TARGET;
 554                         else
 555                                 post = SPECIAL_LOCAL_FS_TARGET;
 556
 557                         k = add_mount(arg_dest,
 558                                       what,
 559                                       where,
 560                                       me->mnt_type,
 561                                       me->mnt_opts,
 562                                       me->mnt_passno,
 563                                       noauto,
 564                                       nofail,
 565                                       automount,
 566                                       post,
 567                                       fstab_path);
 568                 }
 569
 570                 if (k < 0)
 571                         r = k;
 572         }
 573
 574         return r;
 575 }
 576
 577 static int add_sysroot_mount(void) {
 578         _cleanup_free_ char *what = NULL;
 579         const char *opts;
 580         int r;
 581
 582         if (isempty(arg_root_what)) {
 583                 log_debug("Could not find a root= entry on the kernel command line.");
 584                 return 0;
 585         }
 586
 587         if (streq(arg_root_what, "gpt-auto")) {
 588                 /* This is handled by the gpt-auto generator */
 589                 log_debug("Skipping root directory handling, as gpt-auto was requested.");
 590                 return 0;
 591         }
 592
 593         if (path_equal(arg_root_what, "/dev/nfs")) {
 594                 /* This is handled by the kernel or the initrd */
 595                 log_debug("Skipping root directory handling, as /dev/nfs was requested.");
 596                 return 0;
 597         }
 598
 599         what = fstab_node_to_udev_node(arg_root_what);
 600         if (!what)
 601                 return log_oom();
 602
 603         if (!arg_root_options)
 604                 opts = arg_root_rw > 0 ? "rw" : "ro";
 605         else if (arg_root_rw >= 0 ||
 606                  !fstab_test_option(arg_root_options, "ro\0" "rw\0"))
 607                 opts = strjoina(arg_root_options, ",", arg_root_rw > 0 ? "rw" : "ro");
 608         else
 609                 opts = arg_root_options;
 610
 611         log_debug("Found entry what=%s where=/sysroot type=%s", what, strna(arg_root_fstype));
 612
 613         if (is_device_path(what)) {
 614                 r = generator_write_initrd_root_device_deps(arg_dest, what);
 615                 if (r < 0)
 616                         return r;
 617         }
 618
 619         return add_mount(arg_dest,
 620                          what,
 621                          "/sysroot",
 622                          arg_root_fstype,
 623                          opts,
 624                          is_device_path(what) ? 1 : 0, /* passno */
 625                          false,                        /* noauto off */
 626                          false,                        /* nofail off */
 627                          false,                        /* automount off */
 628                          SPECIAL_INITRD_ROOT_FS_TARGET,
 629                          "/proc/cmdline");
 630 }
 631
 632 static int add_sysroot_usr_mount(void) {
 633         _cleanup_free_ char *what = NULL;
 634         const char *opts;
 635
 636         if (!arg_usr_what && !arg_usr_fstype && !arg_usr_options)
 637                 return 0;
 638
 639         if (arg_root_what && !arg_usr_what) {
 640                 /* Copy over the root device, in case the /usr mount just differs in a mount option (consider btrfs subvolumes) */
 641                 arg_usr_what = strdup(arg_root_what);
 642                 if (!arg_usr_what)
 643                         return log_oom();
 644         }
 645
 646         if (arg_root_fstype && !arg_usr_fstype) {
 647                 arg_usr_fstype = strdup(arg_root_fstype);
 648                 if (!arg_usr_fstype)
 649                         return log_oom();
 650         }
 651
 652         if (arg_root_options && !arg_usr_options) {
 653                 arg_usr_options = strdup(arg_root_options);
 654                 if (!arg_usr_options)
 655                         return log_oom();
 656         }
 657
 658         if (!arg_usr_what)
 659                 return 0;
 660
 661         what = fstab_node_to_udev_node(arg_usr_what);
 662         if (!what)
 663                 return log_oom();
 664
 665         if (!arg_usr_options)
 666                 opts = arg_root_rw > 0 ? "rw" : "ro";
 667         else if (!fstab_test_option(arg_usr_options, "ro\0" "rw\0"))
 668                 opts = strjoina(arg_usr_options, ",", arg_root_rw > 0 ? "rw" : "ro");
 669         else
 670                 opts = arg_usr_options;
 671
 672         log_debug("Found entry what=%s where=/sysroot/usr type=%s", what, strna(arg_usr_fstype));
 673         return add_mount(arg_dest,
 674                          what,
 675                          "/sysroot/usr",
 676                          arg_usr_fstype,
 677                          opts,
 678                          is_device_path(what) ? 1 : 0, /* passno */
 679                          false,                        /* noauto off */
 680                          false,                        /* nofail off */
 681                          false,                        /* automount off */
 682                          SPECIAL_INITRD_FS_TARGET,
 683                          "/proc/cmdline");
 684 }
 685
 686 static int add_volatile_root(void) {
 687         const char *from, *to;
 688
 689         if (arg_volatile_mode != VOLATILE_YES)
 690                 return 0;
 691
 692         /* Let's add in systemd-remount-volatile.service which will remount the root device to tmpfs if this is
 693          * requested, leaving only /usr from the root mount inside. */
 694
 695         from = strjoina(SYSTEM_DATA_UNIT_PATH "/systemd-volatile-root.service");
 696         to = strjoina(arg_dest, "/" SPECIAL_INITRD_ROOT_FS_TARGET, ".requires/systemd-volatile-root.service");
 697
 698         (void) mkdir_parents(to, 0755);
 699
 700         if (symlink(from, to) < 0)
 701                 return log_error_errno(errno, "Failed to hook in volatile remount service: %m");
 702
 703         return 0;
 704 }
 705
 706 static int add_volatile_var(void) {
 707
 708         if (arg_volatile_mode != VOLATILE_STATE)
 709                 return 0;
 710
 711         /* If requested, mount /var as tmpfs, but do so only if there's nothing else defined for this. */
 712
 713         return add_mount(arg_dest_late,
 714                          "tmpfs",
 715                          "/var",
 716                          "tmpfs",
 717                          "mode=0755",
 718                          0,
 719                          false,
 720                          false,
 721                          false,
 722                          SPECIAL_LOCAL_FS_TARGET,
 723                          "/proc/cmdline");
 724 }
 725
 726 static int parse_proc_cmdline_item(const char *key, const char *value, void *data) {
 727         int r;
 728
 729         /* root=, usr=, usrfstype= and roofstype= may occur more than once, the last
 730          * instance should take precedence.  In the case of multiple rootflags=
 731          * or usrflags= the arguments should be concatenated */
 732
 733         if (STR_IN_SET(key, "fstab", "rd.fstab")) {
 734
 735                 r = value ? parse_boolean(value) : 1;
 736                 if (r < 0)
 737                         log_warning("Failed to parse fstab switch %s. Ignoring.", value);
 738                 else
 739                         arg_fstab_enabled = r;
 740
 741         } else if (streq(key, "root")) {
 742
 743                 if (proc_cmdline_value_missing(key, value))
 744                         return 0;
 745
 746                 if (free_and_strdup(&arg_root_what, value) < 0)
 747                         return log_oom();
 748
 749         } else if (streq(key, "rootfstype")) {
 750
 751                 if (proc_cmdline_value_missing(key, value))
 752                         return 0;
 753
 754                 if (free_and_strdup(&arg_root_fstype, value) < 0)
 755                         return log_oom();
 756
 757         } else if (streq(key, "rootflags")) {
 758                 char *o;
 759
 760                 if (proc_cmdline_value_missing(key, value))
 761                         return 0;
 762
 763                 o = arg_root_options ?
 764                         strjoin(arg_root_options, ",", value) :
 765                         strdup(value);
 766                 if (!o)
 767                         return log_oom();
 768
 769                 free(arg_root_options);
 770                 arg_root_options = o;
 771         } else if (streq(key, "roothash")) {
 772
 773                 if (proc_cmdline_value_missing(key, value))
 774                         return 0;
 775
 776                 if (free_and_strdup(&arg_root_hash, value) < 0)
 777                         return log_oom();
 778
 779         } else if (streq(key, "mount.usr")) {
 780
 781                 if (proc_cmdline_value_missing(key, value))
 782                         return 0;
 783
 784                 if (free_and_strdup(&arg_usr_what, value) < 0)
 785                         return log_oom();
 786
 787         } else if (streq(key, "mount.usrfstype")) {
 788
 789                 if (proc_cmdline_value_missing(key, value))
 790                         return 0;
 791
 792                 if (free_and_strdup(&arg_usr_fstype, value) < 0)
 793                         return log_oom();
 794
 795         } else if (streq(key, "mount.usrflags")) {
 796                 char *o;
 797
 798                 if (proc_cmdline_value_missing(key, value))
 799                         return 0;
 800
 801                 o = arg_usr_options ?
 802                         strjoin(arg_usr_options, ",", value) :
 803                         strdup(value);
 804                 if (!o)
 805                         return log_oom();
 806
 807                 free(arg_usr_options);
 808                 arg_usr_options = o;
 809
 810         } else if (streq(key, "rw") && !value)
 811                 arg_root_rw = true;
 812         else if (streq(key, "ro") && !value)
 813                 arg_root_rw = false;
 814         else if (streq(key, "systemd.volatile")) {
 815                 VolatileMode m;
 816
 817                 if (value) {
 818                         m = volatile_mode_from_string(value);
 819                         if (m < 0)
 820                                 log_warning("Failed to parse systemd.volatile= argument: %s", value);
 821                         else
 822                                 arg_volatile_mode = m;
 823                 } else
 824                         arg_volatile_mode = VOLATILE_YES;
 825         }
 826
 827         return 0;
 828 }
 829
 830 static int determine_root(void) {
 831         /* If we have a root hash but no root device then Verity is used, and we use the "root" DM device as root. */
 832
 833         if (arg_root_what)
 834                 return 0;
 835
 836         if (!arg_root_hash)
 837                 return 0;
 838
 839         arg_root_what = strdup("/dev/mapper/root");
 840         if (!arg_root_what)
 841                 return log_oom();
 842
 843         log_info("Using verity root device %s.", arg_root_what);
 844
 845         return 1;
 846 }
 847
 848 int main(int argc, char *argv[]) {
 849         int r = 0;
 850
 851         if (argc > 1 && argc != 4) {
 852                 log_error("This program takes three or no arguments.");
 853                 return EXIT_FAILURE;
 854         }
 855
 856         if (argc > 1)
 857                 arg_dest = argv[1];
 858         if (argc > 3)
 859                 arg_dest_late = argv[3];
 860
 861         log_set_target(LOG_TARGET_SAFE);
 862         log_parse_environment();
 863         log_open();
 864
 865         umask(0022);
 866
 867         r = proc_cmdline_parse(parse_proc_cmdline_item, NULL, 0);
 868         if (r < 0)
 869                 log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m");
 870
 871         (void) determine_root();
 872
 873         /* Always honour root= and usr= in the kernel command line if we are in an initrd */
 874         if (in_initrd()) {
 875                 int k;
 876
 877                 r = add_sysroot_mount();
 878
 879                 k = add_sysroot_usr_mount();
 880                 if (k < 0)
 881                         r = k;
 882
 883                 k = add_volatile_root();
 884                 if (k < 0)
 885                         r = k;
 886         } else
 887                 r = add_volatile_var();
 888
 889         /* Honour /etc/fstab only when that's enabled */
 890         if (arg_fstab_enabled) {
 891                 int k;
 892
 893                 log_debug("Parsing /etc/fstab");
 894
 895                 /* Parse the local /etc/fstab, possibly from the initrd */
 896                 k = parse_fstab(false);
 897                 if (k < 0)
 898                         r = k;
 899
 900                 /* If running in the initrd also parse the /etc/fstab from the host */
 901                 if (in_initrd()) {
 902                         log_debug("Parsing /sysroot/etc/fstab");
 903
 904                         k = parse_fstab(true);
 905                         if (k < 0)
 906                                 r = k;
 907                 }
 908         }
 909
 910         free(arg_root_what);
 911         free(arg_root_fstype);
 912         free(arg_root_options);
 913         free(arg_root_hash);
 914
 915         free(arg_usr_what);
 916         free(arg_usr_fstype);
 917         free(arg_usr_options);
 918
 919         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 920 }