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, *lnk = 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("# 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                 lnk = strjoin(arg_dest, "/" SPECIAL_SWAP_TARGET,
 153                               nofail ? ".wants/" : ".requires/", name, NULL);
 154                 if (!lnk)
 155                         return log_oom();
 156
 157                 mkdir_parents_label(lnk, 0755);
 158                 if (symlink(unit, lnk) < 0)
 159                         return log_error_errno(errno, "Failed to create symlink %s: %m", lnk);
 160         }
 161
 162         return 0;
 163 }
 164
 165 static bool mount_is_network(struct mntent *me) {
 166         assert(me);
 167
 168         return fstab_test_option(me->mnt_opts, "_netdev\0") ||
 169                fstype_is_network(me->mnt_type);
 170 }
 171
 172 static bool mount_in_initrd(struct mntent *me) {
 173         assert(me);
 174
 175         return fstab_test_option(me->mnt_opts, "x-initrd.mount\0") ||
 176                streq(me->mnt_dir, "/usr");
 177 }
 178
 179 static int write_timeout(FILE *f, const char *where, const char *opts,
 180                          const char *filter, const char *variable) {
 181         _cleanup_free_ char *timeout = NULL;
 182         char timespan[FORMAT_TIMESPAN_MAX];
 183         usec_t u;
 184         int r;
 185
 186         r = fstab_filter_options(opts, filter, NULL, &timeout, NULL);
 187         if (r < 0)
 188                 return log_warning_errno(r, "Failed to parse options: %m");
 189         if (r == 0)
 190                 return 0;
 191
 192         r = parse_sec_fix_0(timeout, &u);
 193         if (r < 0) {
 194                 log_warning("Failed to parse timeout for %s, ignoring: %s", where, timeout);
 195                 return 0;
 196         }
 197
 198         fprintf(f, "%s=%s\n", variable, format_timespan(timespan, sizeof(timespan), u, 0));
 199
 200         return 0;
 201 }
 202
 203 static int write_idle_timeout(FILE *f, const char *where, const char *opts) {
 204         return write_timeout(f, where, opts,
 205                              "x-systemd.idle-timeout\0", "TimeoutIdleSec");
 206 }
 207
 208 static int write_mount_timeout(FILE *f, const char *where, const char *opts) {
 209         return write_timeout(f, where, opts,
 210                              "x-systemd.mount-timeout\0", "TimeoutSec");
 211 }
 212
 213 static int write_dependency(FILE *f, const char *opts,
 214                 const char *filter, const char *format) {
 215         _cleanup_strv_free_ char **names = NULL, **units = NULL;
 216         _cleanup_free_ char *res = NULL;
 217         char **s;
 218         int r;
 219
 220         assert(f);
 221         assert(opts);
 222
 223         r = fstab_extract_values(opts, filter, &names);
 224         if (r < 0)
 225                 return log_warning_errno(r, "Failed to parse options: %m");
 226         if (r == 0)
 227                 return 0;
 228
 229         STRV_FOREACH(s, names) {
 230                 char *x;
 231
 232                 r = unit_name_mangle_with_suffix(*s, UNIT_NAME_NOGLOB, ".mount", &x);
 233                 if (r < 0)
 234                         return log_error_errno(r, "Failed to generate unit name: %m");
 235                 r = strv_consume(&units, x);
 236                 if (r < 0)
 237                         return log_oom();
 238         }
 239
 240         if (units) {
 241                 res = strv_join(units, " ");
 242                 if (!res)
 243                         return log_oom();
 244 #pragma GCC diagnostic push
 245 #pragma GCC diagnostic ignored "-Wformat-nonliteral"
 246                 fprintf(f, format, res);
 247 #pragma GCC diagnostic pop
 248         }
 249
 250         return 0;
 251 }
 252
 253 static int write_after(FILE *f, const char *opts) {
 254         return write_dependency(f, opts, "x-systemd.after", "After=%1$s\n");
 255 }
 256
 257 static int write_requires_after(FILE *f, const char *opts) {
 258         return write_dependency(f, opts,
 259                                 "x-systemd.requires", "After=%1$s\nRequires=%1$s\n");
 260 }
 261
 262 static int write_before(FILE *f, const char *opts) {
 263         return write_dependency(f, opts,
 264                                 "x-systemd.before", "Before=%1$s\n");
 265 }
 266
 267 static int write_requires_mounts_for(FILE *f, const char *opts) {
 268         _cleanup_strv_free_ char **paths = NULL;
 269         _cleanup_free_ char *res = NULL;
 270         int r;
 271
 272         assert(f);
 273         assert(opts);
 274
 275         r = fstab_extract_values(opts, "x-systemd.requires-mounts-for", &paths);
 276         if (r < 0)
 277                 return log_warning_errno(r, "Failed to parse options: %m");
 278         if (r == 0)
 279                 return 0;
 280
 281         res = strv_join(paths, " ");
 282         if (!res)
 283                 return log_oom();
 284
 285         fprintf(f, "RequiresMountsFor=%s\n", res);
 286
 287         return 0;
 288 }
 289
 290 static int add_mount(
 291                 const char *dest,
 292                 const char *what,
 293                 const char *where,
 294                 const char *original_where,
 295                 const char *fstype,
 296                 const char *opts,
 297                 int passno,
 298                 bool noauto,
 299                 bool nofail,
 300                 bool automount,
 301                 const char *post,
 302                 const char *source) {
 303
 304         _cleanup_free_ char
 305                 *name = NULL, *unit = NULL, *lnk = NULL,
 306                 *automount_name = NULL, *automount_unit = NULL,
 307                 *filtered = NULL;
 308         _cleanup_fclose_ FILE *f = NULL;
 309         int r;
 310
 311         assert(what);
 312         assert(where);
 313         assert(opts);
 314         assert(post);
 315         assert(source);
 316
 317         if (streq_ptr(fstype, "autofs"))
 318                 return 0;
 319
 320         if (!is_path(where)) {
 321                 log_warning("Mount point %s is not a valid path, ignoring.", where);
 322                 return 0;
 323         }
 324
 325         if (mount_point_is_api(where) ||
 326             mount_point_ignore(where))
 327                 return 0;
 328
 329         if (path_equal(where, "/")) {
 330                 if (noauto)
 331                         log_warning("Ignoring \"noauto\" for root device");
 332                 if (nofail)
 333                         log_warning("Ignoring \"nofail\" for root device");
 334                 if (automount)
 335                         log_warning("Ignoring automount option for root device");
 336
 337                 noauto = nofail = automount = false;
 338         }
 339
 340         r = unit_name_from_path(where, ".mount", &name);
 341         if (r < 0)
 342                 return log_error_errno(r, "Failed to generate unit name: %m");
 343
 344         unit = strjoin(dest, "/", name);
 345         if (!unit)
 346                 return log_oom();
 347
 348         f = fopen(unit, "wxe");
 349         if (!f)
 350                 return log_error_errno(errno,
 351                                        errno == EEXIST ?
 352                                        "Failed to create mount unit file %s, as it already exists. Duplicate entry in /etc/fstab?" :
 353                                        "Failed to create unit file %s: %m",
 354                                        unit);
 355
 356         fprintf(f,
 357                 "# Automatically generated by systemd-fstab-generator\n\n"
 358                 "[Unit]\n"
 359                 "SourcePath=%s\n"
 360                 "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n",
 361                 source);
 362
 363         if (STRPTR_IN_SET(fstype, "nfs", "nfs4") && !automount &&
 364             fstab_test_yes_no_option(opts, "bg\0" "fg\0")) {
 365                 /* The default retry timeout that mount.nfs uses for 'bg' mounts
 366                  * is 10000 minutes, where as it uses 2 minutes for 'fg' mounts.
 367                  * As we are making  'bg' mounts look like an 'fg' mount to
 368                  * mount.nfs (so systemd can manage the job-control aspects of 'bg'),
 369                  * we need to explicitly preserve that default, and also ensure
 370                  * the systemd mount-timeout doesn't interfere.
 371                  * By placing these options first, they can be over-ridden by
 372                  * settings in /etc/fstab. */
 373                 opts = strjoina("x-systemd.mount-timeout=infinity,retry=10000,", opts, ",fg");
 374                 nofail = true;
 375         }
 376
 377         if (!nofail && !automount)
 378                 fprintf(f, "Before=%s\n", post);
 379
 380         if (!automount && opts) {
 381                  r = write_after(f, opts);
 382                  if (r < 0)
 383                          return r;
 384                  r = write_requires_after(f, opts);
 385                  if (r < 0)
 386                          return r;
 387                  r = write_before(f, opts);
 388                  if (r < 0)
 389                          return r;
 390                  r = write_requires_mounts_for(f, opts);
 391                  if (r < 0)
 392                          return r;
 393         }
 394
 395         if (passno != 0) {
 396                 r = generator_write_fsck_deps(f, dest, what, where, fstype);
 397                 if (r < 0)
 398                         return r;
 399         }
 400
 401         fprintf(f, "\n[Mount]\n");
 402         if (original_where)
 403                 fprintf(f, "# Canonicalized from %s\n", original_where);
 404         fprintf(f, "Where=%s\n", where);
 405
 406         r = write_what(f, what);
 407         if (r < 0)
 408                 return r;
 409
 410         if (!isempty(fstype) && !streq(fstype, "auto"))
 411                 fprintf(f, "Type=%s\n", fstype);
 412
 413         r = generator_write_timeouts(dest, what, where, opts, &filtered);
 414         if (r < 0)
 415                 return r;
 416
 417         r = generator_write_device_deps(dest, what, where, opts);
 418         if (r < 0)
 419                 return r;
 420
 421         r = write_mount_timeout(f, where, opts);
 422         if (r < 0)
 423                 return r;
 424
 425         r = write_options(f, filtered);
 426         if (r < 0)
 427                 return r;
 428
 429         r = fflush_and_check(f);
 430         if (r < 0)
 431                 return log_error_errno(r, "Failed to write unit file %s: %m", unit);
 432
 433         if (!noauto && !automount) {
 434                 lnk = strjoin(dest, "/", post, nofail ? ".wants/" : ".requires/", name);
 435                 if (!lnk)
 436                         return log_oom();
 437
 438                 mkdir_parents_label(lnk, 0755);
 439                 if (symlink(unit, lnk) < 0)
 440                         return log_error_errno(errno, "Failed to create symlink %s: %m", lnk);
 441         }
 442
 443         if (automount) {
 444                 r = unit_name_from_path(where, ".automount", &automount_name);
 445                 if (r < 0)
 446                         return log_error_errno(r, "Failed to generate unit name: %m");
 447
 448                 automount_unit = strjoin(dest, "/", automount_name);
 449                 if (!automount_unit)
 450                         return log_oom();
 451
 452                 fclose(f);
 453                 f = fopen(automount_unit, "wxe");
 454                 if (!f)
 455                         return log_error_errno(errno, "Failed to create unit file %s: %m", automount_unit);
 456
 457                 fprintf(f,
 458                         "# Automatically generated by systemd-fstab-generator\n\n"
 459                         "[Unit]\n"
 460                         "SourcePath=%s\n"
 461                         "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n",
 462                         source);
 463
 464                 fprintf(f, "Before=%s\n", post);
 465
 466                 if (opts) {
 467                         r = write_after(f, opts);
 468                         if (r < 0)
 469                                 return r;
 470                         r = write_requires_after(f, opts);
 471                         if (r < 0)
 472                                 return r;
 473                         r = write_before(f, opts);
 474                         if (r < 0)
 475                                 return r;
 476                         r = write_requires_mounts_for(f, opts);
 477                         if (r < 0)
 478                                 return r;
 479                 }
 480
 481                 fprintf(f,
 482                         "\n"
 483                         "[Automount]\n"
 484                         "Where=%s\n",
 485                         where);
 486
 487                 r = write_idle_timeout(f, where, opts);
 488                 if (r < 0)
 489                         return r;
 490
 491                 r = fflush_and_check(f);
 492                 if (r < 0)
 493                         return log_error_errno(r, "Failed to write unit file %s: %m", automount_unit);
 494
 495                 free(lnk);
 496                 lnk = strjoin(dest, "/", post, nofail ? ".wants/" : ".requires/", automount_name);
 497                 if (!lnk)
 498                         return log_oom();
 499
 500                 mkdir_parents_label(lnk, 0755);
 501                 if (symlink(automount_unit, lnk) < 0)
 502                         return log_error_errno(errno, "Failed to create symlink %s: %m", lnk);
 503         }
 504
 505         return 0;
 506 }
 507
 508 static int parse_fstab(bool initrd) {
 509         _cleanup_endmntent_ FILE *f = NULL;
 510         const char *fstab_path;
 511         struct mntent *me;
 512         int r = 0;
 513
 514         fstab_path = initrd ? "/sysroot/etc/fstab" : "/etc/fstab";
 515         f = setmntent(fstab_path, "re");
 516         if (!f) {
 517                 if (errno == ENOENT)
 518                         return 0;
 519
 520                 return log_error_errno(errno, "Failed to open %s: %m", fstab_path);
 521         }
 522
 523         while ((me = getmntent(f))) {
 524                 _cleanup_free_ char *where = NULL, *what = NULL, *canonical_where = NULL;
 525                 bool noauto, nofail;
 526                 int k;
 527
 528                 if (initrd && !mount_in_initrd(me))
 529                         continue;
 530
 531                 what = fstab_node_to_udev_node(me->mnt_fsname);
 532                 if (!what)
 533                         return log_oom();
 534
 535                 if (is_device_path(what) && path_is_read_only_fs("sys") > 0) {
 536                         log_info("Running in a container, ignoring fstab device entry for %s.", what);
 537                         continue;
 538                 }
 539
 540                 where = initrd ? strappend("/sysroot/", me->mnt_dir) : strdup(me->mnt_dir);
 541                 if (!where)
 542                         return log_oom();
 543
 544                 if (is_path(where)) {
 545                         path_kill_slashes(where);
 546                         /* Follow symlinks here; see 5261ba901845c084de5a8fd06500ed09bfb0bd80 which makes sense for
 547                          * mount units, but causes problems since it historically worked to have symlinks in e.g.
 548                          * /etc/fstab. So we canonicalize here. Note that we use CHASE_NONEXISTENT to handle the case
 549                          * where a symlink refers to another mount target; this works assuming the sub-mountpoint
 550                          * target is the final directory.
 551                          */
 552                         r = chase_symlinks(where, initrd ? "/sysroot" : NULL,
 553                                            CHASE_PREFIX_ROOT | CHASE_NONEXISTENT,
 554                                            &canonical_where);
 555                         if (r < 0)
 556                                 /* In this case for now we continue on as if it wasn't a symlink */
 557                                 log_warning_errno(r, "Failed to read symlink target for %s: %m", where);
 558                         else {
 559                                 if (streq(canonical_where, where))
 560                                         canonical_where = mfree(canonical_where);
 561                                 else
 562                                         log_debug("Canonicalized what=%s where=%s to %s",
 563                                                   what, where, canonical_where);
 564                         }
 565                 }
 566
 567                 noauto = fstab_test_yes_no_option(me->mnt_opts, "noauto\0" "auto\0");
 568                 nofail = fstab_test_yes_no_option(me->mnt_opts, "nofail\0" "fail\0");
 569                 log_debug("Found entry what=%s where=%s type=%s nofail=%s noauto=%s",
 570                           what, where, me->mnt_type,
 571                           yes_no(noauto), yes_no(nofail));
 572
 573                 if (streq(me->mnt_type, "swap"))
 574                         k = add_swap(what, me, noauto, nofail);
 575                 else {
 576                         bool automount;
 577                         const char *post;
 578
 579                         automount = fstab_test_option(me->mnt_opts,
 580                                                       "comment=systemd.automount\0"
 581                                                       "x-systemd.automount\0");
 582                         if (initrd)
 583                                 post = SPECIAL_INITRD_FS_TARGET;
 584                         else if (mount_is_network(me))
 585                                 post = SPECIAL_REMOTE_FS_TARGET;
 586                         else
 587                                 post = SPECIAL_LOCAL_FS_TARGET;
 588
 589                         k = add_mount(arg_dest,
 590                                       what,
 591                                       canonical_where ?: where,
 592                                       canonical_where ? where: NULL,
 593                                       me->mnt_type,
 594                                       me->mnt_opts,
 595                                       me->mnt_passno,
 596                                       noauto,
 597                                       nofail,
 598                                       automount,
 599                                       post,
 600                                       fstab_path);
 601                 }
 602
 603                 if (k < 0)
 604                         r = k;
 605         }
 606
 607         return r;
 608 }
 609
 610 static int add_sysroot_mount(void) {
 611         _cleanup_free_ char *what = NULL;
 612         const char *opts;
 613         int r;
 614
 615         if (isempty(arg_root_what)) {
 616                 log_debug("Could not find a root= entry on the kernel command line.");
 617                 return 0;
 618         }
 619
 620         if (streq(arg_root_what, "gpt-auto")) {
 621                 /* This is handled by the gpt-auto generator */
 622                 log_debug("Skipping root directory handling, as gpt-auto was requested.");
 623                 return 0;
 624         }
 625
 626         if (path_equal(arg_root_what, "/dev/nfs")) {
 627                 /* This is handled by the kernel or the initrd */
 628                 log_debug("Skipping root directory handling, as /dev/nfs was requested.");
 629                 return 0;
 630         }
 631
 632         what = fstab_node_to_udev_node(arg_root_what);
 633         if (!what)
 634                 return log_oom();
 635
 636         if (!arg_root_options)
 637                 opts = arg_root_rw > 0 ? "rw" : "ro";
 638         else if (arg_root_rw >= 0 ||
 639                  !fstab_test_option(arg_root_options, "ro\0" "rw\0"))
 640                 opts = strjoina(arg_root_options, ",", arg_root_rw > 0 ? "rw" : "ro");
 641         else
 642                 opts = arg_root_options;
 643
 644         log_debug("Found entry what=%s where=/sysroot type=%s", what, strna(arg_root_fstype));
 645
 646         if (is_device_path(what)) {
 647                 r = generator_write_initrd_root_device_deps(arg_dest, what);
 648                 if (r < 0)
 649                         return r;
 650         }
 651
 652         return add_mount(arg_dest,
 653                          what,
 654                          "/sysroot",
 655                          NULL,
 656                          arg_root_fstype,
 657                          opts,
 658                          is_device_path(what) ? 1 : 0, /* passno */
 659                          false,                        /* noauto off */
 660                          false,                        /* nofail off */
 661                          false,                        /* automount off */
 662                          SPECIAL_INITRD_ROOT_FS_TARGET,
 663                          "/proc/cmdline");
 664 }
 665
 666 static int add_sysroot_usr_mount(void) {
 667         _cleanup_free_ char *what = NULL;
 668         const char *opts;
 669
 670         if (!arg_usr_what && !arg_usr_fstype && !arg_usr_options)
 671                 return 0;
 672
 673         if (arg_root_what && !arg_usr_what) {
 674                 /* Copy over the root device, in case the /usr mount just differs in a mount option (consider btrfs subvolumes) */
 675                 arg_usr_what = strdup(arg_root_what);
 676                 if (!arg_usr_what)
 677                         return log_oom();
 678         }
 679
 680         if (arg_root_fstype && !arg_usr_fstype) {
 681                 arg_usr_fstype = strdup(arg_root_fstype);
 682                 if (!arg_usr_fstype)
 683                         return log_oom();
 684         }
 685
 686         if (arg_root_options && !arg_usr_options) {
 687                 arg_usr_options = strdup(arg_root_options);
 688                 if (!arg_usr_options)
 689                         return log_oom();
 690         }
 691
 692         if (!arg_usr_what)
 693                 return 0;
 694
 695         what = fstab_node_to_udev_node(arg_usr_what);
 696         if (!what)
 697                 return log_oom();
 698
 699         if (!arg_usr_options)
 700                 opts = arg_root_rw > 0 ? "rw" : "ro";
 701         else if (!fstab_test_option(arg_usr_options, "ro\0" "rw\0"))
 702                 opts = strjoina(arg_usr_options, ",", arg_root_rw > 0 ? "rw" : "ro");
 703         else
 704                 opts = arg_usr_options;
 705
 706         log_debug("Found entry what=%s where=/sysroot/usr type=%s", what, strna(arg_usr_fstype));
 707         return add_mount(arg_dest,
 708                          what,
 709                          "/sysroot/usr",
 710                          NULL,
 711                          arg_usr_fstype,
 712                          opts,
 713                          is_device_path(what) ? 1 : 0, /* passno */
 714                          false,                        /* noauto off */
 715                          false,                        /* nofail off */
 716                          false,                        /* automount off */
 717                          SPECIAL_INITRD_FS_TARGET,
 718                          "/proc/cmdline");
 719 }
 720
 721 static int add_volatile_root(void) {
 722         const char *from, *to;
 723
 724         if (arg_volatile_mode != VOLATILE_YES)
 725                 return 0;
 726
 727         /* Let's add in systemd-remount-volatile.service which will remount the root device to tmpfs if this is
 728          * requested, leaving only /usr from the root mount inside. */
 729
 730         from = strjoina(SYSTEM_DATA_UNIT_PATH "/systemd-volatile-root.service");
 731         to = strjoina(arg_dest, "/" SPECIAL_INITRD_ROOT_FS_TARGET, ".requires/systemd-volatile-root.service");
 732
 733         (void) mkdir_parents(to, 0755);
 734
 735         if (symlink(from, to) < 0)
 736                 return log_error_errno(errno, "Failed to hook in volatile remount service: %m");
 737
 738         return 0;
 739 }
 740
 741 static int add_volatile_var(void) {
 742
 743         if (arg_volatile_mode != VOLATILE_STATE)
 744                 return 0;
 745
 746         /* If requested, mount /var as tmpfs, but do so only if there's nothing else defined for this. */
 747
 748         return add_mount(arg_dest_late,
 749                          "tmpfs",
 750                          "/var",
 751                          NULL,
 752                          "tmpfs",
 753                          "mode=0755",
 754                          0,
 755                          false,
 756                          false,
 757                          false,
 758                          SPECIAL_LOCAL_FS_TARGET,
 759                          "/proc/cmdline");
 760 }
 761
 762 static int parse_proc_cmdline_item(const char *key, const char *value, void *data) {
 763         int r;
 764
 765         /* root=, usr=, usrfstype= and roofstype= may occur more than once, the last
 766          * instance should take precedence.  In the case of multiple rootflags=
 767          * or usrflags= the arguments should be concatenated */
 768
 769         if (STR_IN_SET(key, "fstab", "rd.fstab")) {
 770
 771                 r = value ? parse_boolean(value) : 1;
 772                 if (r < 0)
 773                         log_warning("Failed to parse fstab switch %s. Ignoring.", value);
 774                 else
 775                         arg_fstab_enabled = r;
 776
 777         } else if (streq(key, "root")) {
 778
 779                 if (proc_cmdline_value_missing(key, value))
 780                         return 0;
 781
 782                 if (free_and_strdup(&arg_root_what, value) < 0)
 783                         return log_oom();
 784
 785         } else if (streq(key, "rootfstype")) {
 786
 787                 if (proc_cmdline_value_missing(key, value))
 788                         return 0;
 789
 790                 if (free_and_strdup(&arg_root_fstype, value) < 0)
 791                         return log_oom();
 792
 793         } else if (streq(key, "rootflags")) {
 794                 char *o;
 795
 796                 if (proc_cmdline_value_missing(key, value))
 797                         return 0;
 798
 799                 o = arg_root_options ?
 800                         strjoin(arg_root_options, ",", value) :
 801                         strdup(value);
 802                 if (!o)
 803                         return log_oom();
 804
 805                 free(arg_root_options);
 806                 arg_root_options = o;
 807         } else if (streq(key, "roothash")) {
 808
 809                 if (proc_cmdline_value_missing(key, value))
 810                         return 0;
 811
 812                 if (free_and_strdup(&arg_root_hash, value) < 0)
 813                         return log_oom();
 814
 815         } else if (streq(key, "mount.usr")) {
 816
 817                 if (proc_cmdline_value_missing(key, value))
 818                         return 0;
 819
 820                 if (free_and_strdup(&arg_usr_what, value) < 0)
 821                         return log_oom();
 822
 823         } else if (streq(key, "mount.usrfstype")) {
 824
 825                 if (proc_cmdline_value_missing(key, value))
 826                         return 0;
 827
 828                 if (free_and_strdup(&arg_usr_fstype, value) < 0)
 829                         return log_oom();
 830
 831         } else if (streq(key, "mount.usrflags")) {
 832                 char *o;
 833
 834                 if (proc_cmdline_value_missing(key, value))
 835                         return 0;
 836
 837                 o = arg_usr_options ?
 838                         strjoin(arg_usr_options, ",", value) :
 839                         strdup(value);
 840                 if (!o)
 841                         return log_oom();
 842
 843                 free(arg_usr_options);
 844                 arg_usr_options = o;
 845
 846         } else if (streq(key, "rw") && !value)
 847                 arg_root_rw = true;
 848         else if (streq(key, "ro") && !value)
 849                 arg_root_rw = false;
 850         else if (streq(key, "systemd.volatile")) {
 851                 VolatileMode m;
 852
 853                 if (value) {
 854                         m = volatile_mode_from_string(value);
 855                         if (m < 0)
 856                                 log_warning("Failed to parse systemd.volatile= argument: %s", value);
 857                         else
 858                                 arg_volatile_mode = m;
 859                 } else
 860                         arg_volatile_mode = VOLATILE_YES;
 861         }
 862
 863         return 0;
 864 }
 865
 866 static int determine_root(void) {
 867         /* If we have a root hash but no root device then Verity is used, and we use the "root" DM device as root. */
 868
 869         if (arg_root_what)
 870                 return 0;
 871
 872         if (!arg_root_hash)
 873                 return 0;
 874
 875         arg_root_what = strdup("/dev/mapper/root");
 876         if (!arg_root_what)
 877                 return log_oom();
 878
 879         log_info("Using verity root device %s.", arg_root_what);
 880
 881         return 1;
 882 }
 883
 884 int main(int argc, char *argv[]) {
 885         int r = 0;
 886
 887         if (argc > 1 && argc != 4) {
 888                 log_error("This program takes three or no arguments.");
 889                 return EXIT_FAILURE;
 890         }
 891
 892         if (argc > 1)
 893                 arg_dest = argv[1];
 894         if (argc > 3)
 895                 arg_dest_late = argv[3];
 896
 897         log_set_target(LOG_TARGET_SAFE);
 898         log_parse_environment();
 899         log_open();
 900
 901         umask(0022);
 902
 903         r = proc_cmdline_parse(parse_proc_cmdline_item, NULL, 0);
 904         if (r < 0)
 905                 log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m");
 906
 907         (void) determine_root();
 908
 909         /* Always honour root= and usr= in the kernel command line if we are in an initrd */
 910         if (in_initrd()) {
 911                 int k;
 912
 913                 r = add_sysroot_mount();
 914
 915                 k = add_sysroot_usr_mount();
 916                 if (k < 0)
 917                         r = k;
 918
 919                 k = add_volatile_root();
 920                 if (k < 0)
 921                         r = k;
 922         } else
 923                 r = add_volatile_var();
 924
 925         /* Honour /etc/fstab only when that's enabled */
 926         if (arg_fstab_enabled) {
 927                 int k;
 928
 929                 log_debug("Parsing /etc/fstab");
 930
 931                 /* Parse the local /etc/fstab, possibly from the initrd */
 932                 k = parse_fstab(false);
 933                 if (k < 0)
 934                         r = k;
 935
 936                 /* If running in the initrd also parse the /etc/fstab from the host */
 937                 if (in_initrd()) {
 938                         log_debug("Parsing /sysroot/etc/fstab");
 939
 940                         k = parse_fstab(true);
 941                         if (k < 0)
 942                                 r = k;
 943                 }
 944         }
 945
 946         free(arg_root_what);
 947         free(arg_root_fstype);
 948         free(arg_root_options);
 949         free(arg_root_hash);
 950
 951         free(arg_usr_what);
 952         free(arg_usr_fstype);
 953         free(arg_usr_options);
 954
 955         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 956 }