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 "fs-util.h"
  29 #include "fileio.h"
  30 #include "fstab-util.h"
  31 #include "generator.h"
  32 #include "log.h"
  33 #include "mkdir.h"
  34 #include "mount-setup.h"
  35 #include "mount-util.h"
  36 #include "parse-util.h"
  37 #include "path-util.h"
  38 #include "proc-cmdline.h"
  39 #include "special.h"
  40 #include "stat-util.h"
  41 #include "string-util.h"
  42 #include "strv.h"
  43 #include "unit-name.h"
  44 #include "util.h"
  45 #include "virt.h"
  46 #include "volatile-util.h"
  47
  48 static const char *arg_dest = "/tmp";
  49 static const char *arg_dest_late = "/tmp";
  50 static bool arg_fstab_enabled = true;
  51 static char *arg_root_what = NULL;
  52 static char *arg_root_fstype = NULL;
  53 static char *arg_root_options = NULL;
  54 static char *arg_root_hash = NULL;
  55 static int arg_root_rw = -1;
  56 static char *arg_usr_what = NULL;
  57 static char *arg_usr_fstype = NULL;
  58 static char *arg_usr_options = NULL;
  59 static VolatileMode arg_volatile_mode = _VOLATILE_MODE_INVALID;
  60
  61 static int write_options(FILE *f, const char *options) {
  62         _cleanup_free_ char *o = NULL;
  63
  64         if (isempty(options))
  65                 return 0;
  66
  67         if (streq(options, "defaults"))
  68                 return 0;
  69
  70         o = strreplace(options, "%", "%%");
  71         if (!o)
  72                 return log_oom();
  73
  74         fprintf(f, "Options=%s\n", o);
  75         return 1;
  76 }
  77
  78 static int write_what(FILE *f, const char *what) {
  79         _cleanup_free_ char *w = NULL;
  80
  81         w = strreplace(what, "%", "%%");
  82         if (!w)
  83                 return log_oom();
  84
  85         fprintf(f, "What=%s\n", w);
  86         return 1;
  87 }
  88
  89 static int add_swap(
  90                 const char *what,
  91                 struct mntent *me,
  92                 bool noauto,
  93                 bool nofail) {
  94
  95         _cleanup_free_ char *name = NULL, *unit = NULL;
  96         _cleanup_fclose_ FILE *f = NULL;
  97         int r;
  98
  99         assert(what);
 100         assert(me);
 101
 102         if (access("/proc/swaps", F_OK) < 0) {
 103                 log_info("Swap not supported, ignoring fstab swap entry for %s.", what);
 104                 return 0;
 105         }
 106
 107         if (detect_container() > 0) {
 108                 log_info("Running in a container, ignoring fstab swap entry for %s.", what);
 109                 return 0;
 110         }
 111
 112         r = unit_name_from_path(what, ".swap", &name);
 113         if (r < 0)
 114                 return log_error_errno(r, "Failed to generate unit name: %m");
 115
 116         unit = strjoin(arg_dest, "/", name);
 117         if (!unit)
 118                 return log_oom();
 119
 120         f = fopen(unit, "wxe");
 121         if (!f)
 122                 return log_error_errno(errno,
 123                                        errno == EEXIST ?
 124                                        "Failed to create swap unit file %s, as it already exists. Duplicate entry in /etc/fstab?" :
 125                                        "Failed to create unit file %s: %m",
 126                                        unit);
 127
 128         fputs_unlocked("# Automatically generated by systemd-fstab-generator\n\n"
 129                        "[Unit]\n"
 130                        "SourcePath=/etc/fstab\n"
 131                        "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n\n"
 132                        "[Swap]\n", f);
 133
 134         r = write_what(f, what);
 135         if (r < 0)
 136                 return r;
 137
 138         r = write_options(f, me->mnt_opts);
 139         if (r < 0)
 140                 return r;
 141
 142         r = fflush_and_check(f);
 143         if (r < 0)
 144                 return log_error_errno(r, "Failed to write unit file %s: %m", unit);
 145
 146         /* use what as where, to have a nicer error message */
 147         r = generator_write_timeouts(arg_dest, what, what, me->mnt_opts, NULL);
 148         if (r < 0)
 149                 return r;
 150
 151         if (!noauto) {
 152                 r = generator_add_symlink(arg_dest, SPECIAL_SWAP_TARGET,
 153                                           nofail ? "wants" : "requires", name);
 154                 if (r < 0)
 155                         return r;
 156         }
 157
 158         return 0;
 159 }
 160
 161 static bool mount_is_network(struct mntent *me) {
 162         assert(me);
 163
 164         return fstab_test_option(me->mnt_opts, "_netdev\0") ||
 165                fstype_is_network(me->mnt_type);
 166 }
 167
 168 static bool mount_in_initrd(struct mntent *me) {
 169         assert(me);
 170
 171         return fstab_test_option(me->mnt_opts, "x-initrd.mount\0") ||
 172                streq(me->mnt_dir, "/usr");
 173 }
 174
 175 static int write_timeout(FILE *f, const char *where, const char *opts,
 176                          const char *filter, const char *variable) {
 177         _cleanup_free_ char *timeout = NULL;
 178         char timespan[FORMAT_TIMESPAN_MAX];
 179         usec_t u;
 180         int r;
 181
 182         r = fstab_filter_options(opts, filter, NULL, &timeout, NULL);
 183         if (r < 0)
 184                 return log_warning_errno(r, "Failed to parse options: %m");
 185         if (r == 0)
 186                 return 0;
 187
 188         r = parse_sec_fix_0(timeout, &u);
 189         if (r < 0) {
 190                 log_warning("Failed to parse timeout for %s, ignoring: %s", where, timeout);
 191                 return 0;
 192         }
 193
 194         fprintf(f, "%s=%s\n", variable, format_timespan(timespan, sizeof(timespan), u, 0));
 195
 196         return 0;
 197 }
 198
 199 static int write_idle_timeout(FILE *f, const char *where, const char *opts) {
 200         return write_timeout(f, where, opts,
 201                              "x-systemd.idle-timeout\0", "TimeoutIdleSec");
 202 }
 203
 204 static int write_mount_timeout(FILE *f, const char *where, const char *opts) {
 205         return write_timeout(f, where, opts,
 206                              "x-systemd.mount-timeout\0", "TimeoutSec");
 207 }
 208
 209 static int write_dependency(FILE *f, const char *opts,
 210                 const char *filter, const char *format) {
 211         _cleanup_strv_free_ char **names = NULL, **units = NULL;
 212         _cleanup_free_ char *res = NULL;
 213         char **s;
 214         int r;
 215
 216         assert(f);
 217         assert(opts);
 218
 219         r = fstab_extract_values(opts, filter, &names);
 220         if (r < 0)
 221                 return log_warning_errno(r, "Failed to parse options: %m");
 222         if (r == 0)
 223                 return 0;
 224
 225         STRV_FOREACH(s, names) {
 226                 char *x;
 227
 228                 r = unit_name_mangle_with_suffix(*s, UNIT_NAME_NOGLOB, ".mount", &x);
 229                 if (r < 0)
 230                         return log_error_errno(r, "Failed to generate unit name: %m");
 231                 r = strv_consume(&units, x);
 232                 if (r < 0)
 233                         return log_oom();
 234         }
 235
 236         if (units) {
 237                 res = strv_join(units, " ");
 238                 if (!res)
 239                         return log_oom();
 240 #pragma GCC diagnostic push
 241 #pragma GCC diagnostic ignored "-Wformat-nonliteral"
 242                 fprintf(f, format, res);
 243 #pragma GCC diagnostic pop
 244         }
 245
 246         return 0;
 247 }
 248
 249 static int write_after(FILE *f, const char *opts) {
 250         return write_dependency(f, opts, "x-systemd.after", "After=%1$s\n");
 251 }
 252
 253 static int write_requires_after(FILE *f, const char *opts) {
 254         return write_dependency(f, opts,
 255                                 "x-systemd.requires", "After=%1$s\nRequires=%1$s\n");
 256 }
 257
 258 static int write_before(FILE *f, const char *opts) {
 259         return write_dependency(f, opts,
 260                                 "x-systemd.before", "Before=%1$s\n");
 261 }
 262
 263 static int write_requires_mounts_for(FILE *f, const char *opts) {
 264         _cleanup_strv_free_ char **paths = NULL;
 265         _cleanup_free_ char *res = NULL;
 266         int r;
 267
 268         assert(f);
 269         assert(opts);
 270
 271         r = fstab_extract_values(opts, "x-systemd.requires-mounts-for", &paths);
 272         if (r < 0)
 273                 return log_warning_errno(r, "Failed to parse options: %m");
 274         if (r == 0)
 275                 return 0;
 276
 277         res = strv_join(paths, " ");
 278         if (!res)
 279                 return log_oom();
 280
 281         fprintf(f, "RequiresMountsFor=%s\n", res);
 282
 283         return 0;
 284 }
 285
 286 static int add_mount(
 287                 const char *dest,
 288                 const char *what,
 289                 const char *where,
 290                 const char *original_where,
 291                 const char *fstype,
 292                 const char *opts,
 293                 int passno,
 294                 bool noauto,
 295                 bool nofail,
 296                 bool automount,
 297                 const char *post,
 298                 const char *source) {
 299
 300         _cleanup_free_ char
 301                 *name = NULL, *unit = NULL,
 302                 *automount_name = NULL, *automount_unit = NULL,
 303                 *filtered = NULL;
 304         _cleanup_fclose_ FILE *f = NULL;
 305         int r;
 306
 307         assert(what);
 308         assert(where);
 309         assert(opts);
 310         assert(post);
 311         assert(source);
 312
 313         if (streq_ptr(fstype, "autofs"))
 314                 return 0;
 315
 316         if (!is_path(where)) {
 317                 log_warning("Mount point %s is not a valid path, ignoring.", where);
 318                 return 0;
 319         }
 320
 321         if (mount_point_is_api(where) ||
 322             mount_point_ignore(where))
 323                 return 0;
 324
 325         if (path_equal(where, "/")) {
 326                 if (noauto)
 327                         log_warning("Ignoring \"noauto\" for root device");
 328                 if (nofail)
 329                         log_warning("Ignoring \"nofail\" for root device");
 330                 if (automount)
 331                         log_warning("Ignoring automount option for root device");
 332
 333                 noauto = nofail = automount = false;
 334         }
 335
 336         r = unit_name_from_path(where, ".mount", &name);
 337         if (r < 0)
 338                 return log_error_errno(r, "Failed to generate unit name: %m");
 339
 340         unit = strjoin(dest, "/", name);
 341         if (!unit)
 342                 return log_oom();
 343
 344         f = fopen(unit, "wxe");
 345         if (!f)
 346                 return log_error_errno(errno,
 347                                        errno == EEXIST ?
 348                                        "Failed to create mount unit file %s, as it already exists. Duplicate entry in /etc/fstab?" :
 349                                        "Failed to create unit file %s: %m",
 350                                        unit);
 351
 352         fprintf(f,
 353                 "# Automatically generated by systemd-fstab-generator\n\n"
 354                 "[Unit]\n"
 355                 "SourcePath=%s\n"
 356                 "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n",
 357                 source);
 358
 359         if (STRPTR_IN_SET(fstype, "nfs", "nfs4") && !automount &&
 360             fstab_test_yes_no_option(opts, "bg\0" "fg\0")) {
 361                 /* The default retry timeout that mount.nfs uses for 'bg' mounts
 362                  * is 10000 minutes, where as it uses 2 minutes for 'fg' mounts.
 363                  * As we are making  'bg' mounts look like an 'fg' mount to
 364                  * mount.nfs (so systemd can manage the job-control aspects of 'bg'),
 365                  * we need to explicitly preserve that default, and also ensure
 366                  * the systemd mount-timeout doesn't interfere.
 367                  * By placing these options first, they can be over-ridden by
 368                  * settings in /etc/fstab. */
 369                 opts = strjoina("x-systemd.mount-timeout=infinity,retry=10000,", opts, ",fg");
 370                 nofail = true;
 371         }
 372
 373         if (!nofail && !automount)
 374                 fprintf(f, "Before=%s\n", post);
 375
 376         if (!automount && opts) {
 377                  r = write_after(f, opts);
 378                  if (r < 0)
 379                          return r;
 380                  r = write_requires_after(f, opts);
 381                  if (r < 0)
 382                          return r;
 383                  r = write_before(f, opts);
 384                  if (r < 0)
 385                          return r;
 386                  r = write_requires_mounts_for(f, opts);
 387                  if (r < 0)
 388                          return r;
 389         }
 390
 391         if (passno != 0) {
 392                 r = generator_write_fsck_deps(f, dest, what, where, fstype);
 393                 if (r < 0)
 394                         return r;
 395         }
 396
 397         fprintf(f, "\n[Mount]\n");
 398         if (original_where)
 399                 fprintf(f, "# Canonicalized from %s\n", original_where);
 400         fprintf(f, "Where=%s\n", where);
 401
 402         r = write_what(f, what);
 403         if (r < 0)
 404                 return r;
 405
 406         if (!isempty(fstype) && !streq(fstype, "auto"))
 407                 fprintf(f, "Type=%s\n", fstype);
 408
 409         r = generator_write_timeouts(dest, what, where, opts, &filtered);
 410         if (r < 0)
 411                 return r;
 412
 413         r = generator_write_device_deps(dest, what, where, opts);
 414         if (r < 0)
 415                 return r;
 416
 417         r = write_mount_timeout(f, where, opts);
 418         if (r < 0)
 419                 return r;
 420
 421         r = write_options(f, filtered);
 422         if (r < 0)
 423                 return r;
 424
 425         r = fflush_and_check(f);
 426         if (r < 0)
 427                 return log_error_errno(r, "Failed to write unit file %s: %m", unit);
 428
 429         if (!noauto && !automount) {
 430                 r = generator_add_symlink(dest, post,
 431                                           nofail ? "wants" : "requires", name);
 432                 if (r < 0)
 433                         return r;
 434         }
 435
 436         if (automount) {
 437                 r = unit_name_from_path(where, ".automount", &automount_name);
 438                 if (r < 0)
 439                         return log_error_errno(r, "Failed to generate unit name: %m");
 440
 441                 automount_unit = strjoin(dest, "/", automount_name);
 442                 if (!automount_unit)
 443                         return log_oom();
 444
 445                 fclose(f);
 446                 f = fopen(automount_unit, "wxe");
 447                 if (!f)
 448                         return log_error_errno(errno, "Failed to create unit file %s: %m", automount_unit);
 449
 450                 fprintf(f,
 451                         "# Automatically generated by systemd-fstab-generator\n\n"
 452                         "[Unit]\n"
 453                         "SourcePath=%s\n"
 454                         "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n",
 455                         source);
 456
 457                 fprintf(f, "Before=%s\n", post);
 458
 459                 if (opts) {
 460                         r = write_after(f, opts);
 461                         if (r < 0)
 462                                 return r;
 463                         r = write_requires_after(f, opts);
 464                         if (r < 0)
 465                                 return r;
 466                         r = write_before(f, opts);
 467                         if (r < 0)
 468                                 return r;
 469                         r = write_requires_mounts_for(f, opts);
 470                         if (r < 0)
 471                                 return r;
 472                 }
 473
 474                 fprintf(f,
 475                         "\n"
 476                         "[Automount]\n"
 477                         "Where=%s\n",
 478                         where);
 479
 480                 r = write_idle_timeout(f, where, opts);
 481                 if (r < 0)
 482                         return r;
 483
 484                 r = fflush_and_check(f);
 485                 if (r < 0)
 486                         return log_error_errno(r, "Failed to write unit file %s: %m", automount_unit);
 487
 488                 r = generator_add_symlink(dest, post,
 489                                           nofail ? "wants" : "requires", automount_name);
 490                 if (r < 0)
 491                         return r;
 492         }
 493
 494         return 0;
 495 }
 496
 497 static int parse_fstab(bool initrd) {
 498         _cleanup_endmntent_ FILE *f = NULL;
 499         const char *fstab_path;
 500         struct mntent *me;
 501         int r = 0;
 502
 503         fstab_path = initrd ? "/sysroot/etc/fstab" : "/etc/fstab";
 504         f = setmntent(fstab_path, "re");
 505         if (!f) {
 506                 if (errno == ENOENT)
 507                         return 0;
 508
 509                 return log_error_errno(errno, "Failed to open %s: %m", fstab_path);
 510         }
 511
 512         while ((me = getmntent(f))) {
 513                 _cleanup_free_ char *where = NULL, *what = NULL, *canonical_where = NULL;
 514                 bool noauto, nofail;
 515                 int k;
 516
 517                 if (initrd && !mount_in_initrd(me))
 518                         continue;
 519
 520                 what = fstab_node_to_udev_node(me->mnt_fsname);
 521                 if (!what)
 522                         return log_oom();
 523
 524                 if (is_device_path(what) && path_is_read_only_fs("sys") > 0) {
 525                         log_info("Running in a container, ignoring fstab device entry for %s.", what);
 526                         continue;
 527                 }
 528
 529                 where = strdup(me->mnt_dir);
 530                 if (!where)
 531                         return log_oom();
 532
 533                 if (is_path(where)) {
 534                         path_kill_slashes(where);
 535                         /* Follow symlinks here; see 5261ba901845c084de5a8fd06500ed09bfb0bd80 which makes sense for
 536                          * mount units, but causes problems since it historically worked to have symlinks in e.g.
 537                          * /etc/fstab. So we canonicalize here. Note that we use CHASE_NONEXISTENT to handle the case
 538                          * where a symlink refers to another mount target; this works assuming the sub-mountpoint
 539                          * target is the final directory.
 540                          */
 541                         r = chase_symlinks(where, initrd ? "/sysroot" : NULL,
 542                                            CHASE_PREFIX_ROOT | CHASE_NONEXISTENT,
 543                                            &canonical_where);
 544                         if (r < 0)
 545                                 /* In this case for now we continue on as if it wasn't a symlink */
 546                                 log_warning_errno(r, "Failed to read symlink target for %s: %m", where);
 547                         else {
 548                                 if (streq(canonical_where, where))
 549                                         canonical_where = mfree(canonical_where);
 550                                 else
 551                                         log_debug("Canonicalized what=%s where=%s to %s",
 552                                                   what, where, canonical_where);
 553                         }
 554                 }
 555
 556                 noauto = fstab_test_yes_no_option(me->mnt_opts, "noauto\0" "auto\0");
 557                 nofail = fstab_test_yes_no_option(me->mnt_opts, "nofail\0" "fail\0");
 558                 log_debug("Found entry what=%s where=%s type=%s nofail=%s noauto=%s",
 559                           what, where, me->mnt_type,
 560                           yes_no(noauto), yes_no(nofail));
 561
 562                 if (streq(me->mnt_type, "swap"))
 563                         k = add_swap(what, me, noauto, nofail);
 564                 else {
 565                         bool automount;
 566                         const char *post;
 567
 568                         automount = fstab_test_option(me->mnt_opts,
 569                                                       "comment=systemd.automount\0"
 570                                                       "x-systemd.automount\0");
 571                         if (initrd)
 572                                 post = SPECIAL_INITRD_FS_TARGET;
 573                         else if (mount_is_network(me))
 574                                 post = SPECIAL_REMOTE_FS_TARGET;
 575                         else
 576                                 post = SPECIAL_LOCAL_FS_TARGET;
 577
 578                         k = add_mount(arg_dest,
 579                                       what,
 580                                       canonical_where ?: where,
 581                                       canonical_where ? where: NULL,
 582                                       me->mnt_type,
 583                                       me->mnt_opts,
 584                                       me->mnt_passno,
 585                                       noauto,
 586                                       nofail,
 587                                       automount,
 588                                       post,
 589                                       fstab_path);
 590                 }
 591
 592                 if (k < 0)
 593                         r = k;
 594         }
 595
 596         return r;
 597 }
 598
 599 static int add_sysroot_mount(void) {
 600         _cleanup_free_ char *what = NULL;
 601         const char *opts;
 602         int r;
 603
 604         if (isempty(arg_root_what)) {
 605                 log_debug("Could not find a root= entry on the kernel command line.");
 606                 return 0;
 607         }
 608
 609         if (streq(arg_root_what, "gpt-auto")) {
 610                 /* This is handled by the gpt-auto generator */
 611                 log_debug("Skipping root directory handling, as gpt-auto was requested.");
 612                 return 0;
 613         }
 614
 615         if (path_equal(arg_root_what, "/dev/nfs")) {
 616                 /* This is handled by the kernel or the initrd */
 617                 log_debug("Skipping root directory handling, as /dev/nfs was requested.");
 618                 return 0;
 619         }
 620
 621         what = fstab_node_to_udev_node(arg_root_what);
 622         if (!what)
 623                 return log_oom();
 624
 625         if (!arg_root_options)
 626                 opts = arg_root_rw > 0 ? "rw" : "ro";
 627         else if (arg_root_rw >= 0 ||
 628                  !fstab_test_option(arg_root_options, "ro\0" "rw\0"))
 629                 opts = strjoina(arg_root_options, ",", arg_root_rw > 0 ? "rw" : "ro");
 630         else
 631                 opts = arg_root_options;
 632
 633         log_debug("Found entry what=%s where=/sysroot type=%s", what, strna(arg_root_fstype));
 634
 635         if (is_device_path(what)) {
 636                 r = generator_write_initrd_root_device_deps(arg_dest, what);
 637                 if (r < 0)
 638                         return r;
 639         }
 640
 641         return add_mount(arg_dest,
 642                          what,
 643                          "/sysroot",
 644                          NULL,
 645                          arg_root_fstype,
 646                          opts,
 647                          is_device_path(what) ? 1 : 0, /* passno */
 648                          false,                        /* noauto off */
 649                          false,                        /* nofail off */
 650                          false,                        /* automount off */
 651                          SPECIAL_INITRD_ROOT_FS_TARGET,
 652                          "/proc/cmdline");
 653 }
 654
 655 static int add_sysroot_usr_mount(void) {
 656         _cleanup_free_ char *what = NULL;
 657         const char *opts;
 658
 659         if (!arg_usr_what && !arg_usr_fstype && !arg_usr_options)
 660                 return 0;
 661
 662         if (arg_root_what && !arg_usr_what) {
 663                 /* Copy over the root device, in case the /usr mount just differs in a mount option (consider btrfs subvolumes) */
 664                 arg_usr_what = strdup(arg_root_what);
 665                 if (!arg_usr_what)
 666                         return log_oom();
 667         }
 668
 669         if (arg_root_fstype && !arg_usr_fstype) {
 670                 arg_usr_fstype = strdup(arg_root_fstype);
 671                 if (!arg_usr_fstype)
 672                         return log_oom();
 673         }
 674
 675         if (arg_root_options && !arg_usr_options) {
 676                 arg_usr_options = strdup(arg_root_options);
 677                 if (!arg_usr_options)
 678                         return log_oom();
 679         }
 680
 681         if (!arg_usr_what)
 682                 return 0;
 683
 684         what = fstab_node_to_udev_node(arg_usr_what);
 685         if (!what)
 686                 return log_oom();
 687
 688         if (!arg_usr_options)
 689                 opts = arg_root_rw > 0 ? "rw" : "ro";
 690         else if (!fstab_test_option(arg_usr_options, "ro\0" "rw\0"))
 691                 opts = strjoina(arg_usr_options, ",", arg_root_rw > 0 ? "rw" : "ro");
 692         else
 693                 opts = arg_usr_options;
 694
 695         log_debug("Found entry what=%s where=/sysroot/usr type=%s", what, strna(arg_usr_fstype));
 696         return add_mount(arg_dest,
 697                          what,
 698                          "/sysroot/usr",
 699                          NULL,
 700                          arg_usr_fstype,
 701                          opts,
 702                          is_device_path(what) ? 1 : 0, /* passno */
 703                          false,                        /* noauto off */
 704                          false,                        /* nofail off */
 705                          false,                        /* automount off */
 706                          SPECIAL_INITRD_FS_TARGET,
 707                          "/proc/cmdline");
 708 }
 709
 710 static int add_volatile_root(void) {
 711         const char *from, *to;
 712
 713         if (arg_volatile_mode != VOLATILE_YES)
 714                 return 0;
 715
 716         /* Let's add in systemd-remount-volatile.service which will remount the root device to tmpfs if this is
 717          * requested, leaving only /usr from the root mount inside. */
 718
 719         from = strjoina(SYSTEM_DATA_UNIT_PATH "/systemd-volatile-root.service");
 720         to = strjoina(arg_dest, "/" SPECIAL_INITRD_ROOT_FS_TARGET, ".requires/systemd-volatile-root.service");
 721
 722         (void) mkdir_parents(to, 0755);
 723
 724         if (symlink(from, to) < 0)
 725                 return log_error_errno(errno, "Failed to hook in volatile remount service: %m");
 726
 727         return 0;
 728 }
 729
 730 static int add_volatile_var(void) {
 731
 732         if (arg_volatile_mode != VOLATILE_STATE)
 733                 return 0;
 734
 735         /* If requested, mount /var as tmpfs, but do so only if there's nothing else defined for this. */
 736
 737         return add_mount(arg_dest_late,
 738                          "tmpfs",
 739                          "/var",
 740                          NULL,
 741                          "tmpfs",
 742                          "mode=0755",
 743                          0,
 744                          false,
 745                          false,
 746                          false,
 747                          SPECIAL_LOCAL_FS_TARGET,
 748                          "/proc/cmdline");
 749 }
 750
 751 static int parse_proc_cmdline_item(const char *key, const char *value, void *data) {
 752         int r;
 753
 754         /* root=, usr=, usrfstype= and roofstype= may occur more than once, the last
 755          * instance should take precedence.  In the case of multiple rootflags=
 756          * or usrflags= the arguments should be concatenated */
 757
 758         if (STR_IN_SET(key, "fstab", "rd.fstab")) {
 759
 760                 r = value ? parse_boolean(value) : 1;
 761                 if (r < 0)
 762                         log_warning("Failed to parse fstab switch %s. Ignoring.", value);
 763                 else
 764                         arg_fstab_enabled = r;
 765
 766         } else if (streq(key, "root")) {
 767
 768                 if (proc_cmdline_value_missing(key, value))
 769                         return 0;
 770
 771                 if (free_and_strdup(&arg_root_what, value) < 0)
 772                         return log_oom();
 773
 774         } else if (streq(key, "rootfstype")) {
 775
 776                 if (proc_cmdline_value_missing(key, value))
 777                         return 0;
 778
 779                 if (free_and_strdup(&arg_root_fstype, value) < 0)
 780                         return log_oom();
 781
 782         } else if (streq(key, "rootflags")) {
 783                 char *o;
 784
 785                 if (proc_cmdline_value_missing(key, value))
 786                         return 0;
 787
 788                 o = arg_root_options ?
 789                         strjoin(arg_root_options, ",", value) :
 790                         strdup(value);
 791                 if (!o)
 792                         return log_oom();
 793
 794                 free(arg_root_options);
 795                 arg_root_options = o;
 796         } else if (streq(key, "roothash")) {
 797
 798                 if (proc_cmdline_value_missing(key, value))
 799                         return 0;
 800
 801                 if (free_and_strdup(&arg_root_hash, value) < 0)
 802                         return log_oom();
 803
 804         } else if (streq(key, "mount.usr")) {
 805
 806                 if (proc_cmdline_value_missing(key, value))
 807                         return 0;
 808
 809                 if (free_and_strdup(&arg_usr_what, value) < 0)
 810                         return log_oom();
 811
 812         } else if (streq(key, "mount.usrfstype")) {
 813
 814                 if (proc_cmdline_value_missing(key, value))
 815                         return 0;
 816
 817                 if (free_and_strdup(&arg_usr_fstype, value) < 0)
 818                         return log_oom();
 819
 820         } else if (streq(key, "mount.usrflags")) {
 821                 char *o;
 822
 823                 if (proc_cmdline_value_missing(key, value))
 824                         return 0;
 825
 826                 o = arg_usr_options ?
 827                         strjoin(arg_usr_options, ",", value) :
 828                         strdup(value);
 829                 if (!o)
 830                         return log_oom();
 831
 832                 free(arg_usr_options);
 833                 arg_usr_options = o;
 834
 835         } else if (streq(key, "rw") && !value)
 836                 arg_root_rw = true;
 837         else if (streq(key, "ro") && !value)
 838                 arg_root_rw = false;
 839         else if (streq(key, "systemd.volatile")) {
 840                 VolatileMode m;
 841
 842                 if (value) {
 843                         m = volatile_mode_from_string(value);
 844                         if (m < 0)
 845                                 log_warning("Failed to parse systemd.volatile= argument: %s", value);
 846                         else
 847                                 arg_volatile_mode = m;
 848                 } else
 849                         arg_volatile_mode = VOLATILE_YES;
 850         }
 851
 852         return 0;
 853 }
 854
 855 static int determine_root(void) {
 856         /* If we have a root hash but no root device then Verity is used, and we use the "root" DM device as root. */
 857
 858         if (arg_root_what)
 859                 return 0;
 860
 861         if (!arg_root_hash)
 862                 return 0;
 863
 864         arg_root_what = strdup("/dev/mapper/root");
 865         if (!arg_root_what)
 866                 return log_oom();
 867
 868         log_info("Using verity root device %s.", arg_root_what);
 869
 870         return 1;
 871 }
 872
 873 int main(int argc, char *argv[]) {
 874         int r = 0;
 875
 876         if (argc > 1 && argc != 4) {
 877                 log_error("This program takes three or no arguments.");
 878                 return EXIT_FAILURE;
 879         }
 880
 881         if (argc > 1)
 882                 arg_dest = argv[1];
 883         if (argc > 3)
 884                 arg_dest_late = argv[3];
 885
 886         log_set_target(LOG_TARGET_SAFE);
 887         log_parse_environment();
 888         log_open();
 889
 890         umask(0022);
 891
 892         r = proc_cmdline_parse(parse_proc_cmdline_item, NULL, 0);
 893         if (r < 0)
 894                 log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m");
 895
 896         (void) determine_root();
 897
 898         /* Always honour root= and usr= in the kernel command line if we are in an initrd */
 899         if (in_initrd()) {
 900                 int k;
 901
 902                 r = add_sysroot_mount();
 903
 904                 k = add_sysroot_usr_mount();
 905                 if (k < 0)
 906                         r = k;
 907
 908                 k = add_volatile_root();
 909                 if (k < 0)
 910                         r = k;
 911         } else
 912                 r = add_volatile_var();
 913
 914         /* Honour /etc/fstab only when that's enabled */
 915         if (arg_fstab_enabled) {
 916                 int k;
 917
 918                 log_debug("Parsing /etc/fstab");
 919
 920                 /* Parse the local /etc/fstab, possibly from the initrd */
 921                 k = parse_fstab(false);
 922                 if (k < 0)
 923                         r = k;
 924
 925                 /* If running in the initrd also parse the /etc/fstab from the host */
 926                 if (in_initrd()) {
 927                         log_debug("Parsing /sysroot/etc/fstab");
 928
 929                         k = parse_fstab(true);
 930                         if (k < 0)
 931                                 r = k;
 932                 }
 933         }
 934
 935         free(arg_root_what);
 936         free(arg_root_fstype);
 937         free(arg_root_options);
 938         free(arg_root_hash);
 939
 940         free(arg_usr_what);
 941         free(arg_usr_fstype);
 942         free(arg_usr_options);
 943
 944         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 945 }