src/core/umount.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /***
   3   Copyright © 2010 ProFUSION embedded systems
   4 ***/
   5
   6 #include <errno.h>
   7 #include <fcntl.h>
   8 #include <linux/loop.h>
   9 #include <string.h>
  10 #include <sys/mount.h>
  11 #include <sys/swap.h>
  12
  13 /* This needs to be after sys/mount.h :( */
  14 #include <libmount.h>
  15
  16 #include "sd-device.h"
  17
  18 #include "alloc-util.h"
  19 #include "blockdev-util.h"
  20 #include "def.h"
  21 #include "device-util.h"
  22 #include "escape.h"
  23 #include "fd-util.h"
  24 #include "fstab-util.h"
  25 #include "linux-3.13/dm-ioctl.h"
  26 #include "mount-setup.h"
  27 #include "mount-util.h"
  28 #include "mountpoint-util.h"
  29 #include "path-util.h"
  30 #include "process-util.h"
  31 #include "signal-util.h"
  32 #include "string-util.h"
  33 #include "strv.h"
  34 #include "umount.h"
  35 #include "util.h"
  36 #include "virt.h"
  37
  38 DEFINE_TRIVIAL_CLEANUP_FUNC(struct libmnt_table*, mnt_free_table);
  39 DEFINE_TRIVIAL_CLEANUP_FUNC(struct libmnt_iter*, mnt_free_iter);
  40
  41 static void mount_point_free(MountPoint **head, MountPoint *m) {
  42         assert(head);
  43         assert(m);
  44
  45         LIST_REMOVE(mount_point, *head, m);
  46
  47         free(m->path);
  48         free(m->remount_options);
  49         free(m);
  50 }
  51
  52 void mount_points_list_free(MountPoint **head) {
  53         assert(head);
  54
  55         while (*head)
  56                 mount_point_free(head, *head);
  57 }
  58
  59 int mount_points_list_get(const char *mountinfo, MountPoint **head) {
  60         _cleanup_(mnt_free_tablep) struct libmnt_table *t = NULL;
  61         _cleanup_(mnt_free_iterp) struct libmnt_iter *i = NULL;
  62         int r;
  63
  64         assert(head);
  65
  66         t = mnt_new_table();
  67         i = mnt_new_iter(MNT_ITER_FORWARD);
  68         if (!t || !i)
  69                 return log_oom();
  70
  71         r = mnt_table_parse_mtab(t, mountinfo);
  72         if (r < 0)
  73                 return log_error_errno(r, "Failed to parse %s: %m", mountinfo);
  74
  75         for (;;) {
  76                 struct libmnt_fs *fs;
  77                 const char *path, *fstype;
  78                 _cleanup_free_ char *options = NULL;
  79                 _cleanup_free_ char *p = NULL;
  80                 unsigned long remount_flags = 0u;
  81                 _cleanup_free_ char *remount_options = NULL;
  82                 bool try_remount_ro;
  83                 MountPoint *m;
  84
  85                 r = mnt_table_next_fs(t, i, &fs);
  86                 if (r == 1)
  87                         break;
  88                 if (r < 0)
  89                         return log_error_errno(r, "Failed to get next entry from %s: %m", mountinfo);
  90
  91                 path = mnt_fs_get_target(fs);
  92                 if (!path)
  93                         continue;
  94
  95                 if (cunescape(path, UNESCAPE_RELAX, &p) < 0)
  96                         return log_oom();
  97
  98                 fstype = mnt_fs_get_fstype(fs);
  99
 100                 /* Combine the generic VFS options with the FS-specific
 101                  * options. Duplicates are not a problem here, because the only
 102                  * options that should come up twice are typically ro/rw, which
 103                  * are turned into MS_RDONLY or the invertion of it.
 104                  *
 105                  * Even if there are duplicates later in mount_option_mangle()
 106                  * it shouldn't hurt anyways as they override each other.
 107                  */
 108                 if (!strextend_with_separator(&options, ",",
 109                                               mnt_fs_get_vfs_options(fs),
 110                                               NULL))
 111                         return log_oom();
 112                 if (!strextend_with_separator(&options, ",",
 113                                               mnt_fs_get_fs_options(fs),
 114                                               NULL))
 115                         return log_oom();
 116
 117                 /* Ignore mount points we can't unmount because they
 118                  * are API or because we are keeping them open (like
 119                  * /dev/console). Also, ignore all mounts below API
 120                  * file systems, since they are likely virtual too,
 121                  * and hence not worth spending time on. Also, in
 122                  * unprivileged containers we might lack the rights to
 123                  * unmount these things, hence don't bother. */
 124                 if (mount_point_is_api(p) ||
 125                     mount_point_ignore(p) ||
 126                     PATH_STARTSWITH_SET(p, "/dev", "/sys", "/proc"))
 127                         continue;
 128
 129                 /* If we are in a container, don't attempt to
 130                  * read-only mount anything as that brings no real
 131                  * benefits, but might confuse the host, as we remount
 132                  * the superblock here, not the bind mount.
 133                  *
 134                  * If the filesystem is a network fs, also skip the
 135                  * remount. It brings no value (we cannot leave
 136                  * a "dirty fs") and could hang if the network is down.
 137                  * Note that umount2() is more careful and will not
 138                  * hang because of the network being down. */
 139                 try_remount_ro = detect_container() <= 0 &&
 140                                  !fstype_is_network(fstype) &&
 141                                  !fstype_is_api_vfs(fstype) &&
 142                                  !fstype_is_ro(fstype) &&
 143                                  !fstab_test_yes_no_option(options, "ro\0rw\0");
 144
 145                 if (try_remount_ro) {
 146                         /* mount(2) states that mount flags and options need to be exactly the same
 147                          * as they were when the filesystem was mounted, except for the desired
 148                          * changes. So we reconstruct both here and adjust them for the later
 149                          * remount call too. */
 150
 151                         r = mnt_fs_get_propagation(fs, &remount_flags);
 152                         if (r < 0) {
 153                                 log_warning_errno(r, "mnt_fs_get_propagation() failed for %s, ignoring: %m", path);
 154                                 continue;
 155                         }
 156
 157                         r = mount_option_mangle(options, remount_flags, &remount_flags, &remount_options);
 158                         if (r < 0) {
 159                                 log_warning_errno(r, "mount_option_mangle failed for %s, ignoring: %m", path);
 160                                 continue;
 161                         }
 162
 163                         /* MS_BIND is special. If it is provided it will only make the mount-point
 164                          * read-only. If left out, the super block itself is remounted, which we want. */
 165                         remount_flags = (remount_flags|MS_REMOUNT|MS_RDONLY) & ~MS_BIND;
 166                 }
 167
 168                 m = new0(MountPoint, 1);
 169                 if (!m)
 170                         return log_oom();
 171
 172                 free_and_replace(m->path, p);
 173                 free_and_replace(m->remount_options, remount_options);
 174                 m->remount_flags = remount_flags;
 175                 m->try_remount_ro = try_remount_ro;
 176
 177                 LIST_PREPEND(mount_point, *head, m);
 178         }
 179
 180         return 0;
 181 }
 182
 183 int swap_list_get(const char *swaps, MountPoint **head) {
 184         _cleanup_(mnt_free_tablep) struct libmnt_table *t = NULL;
 185         _cleanup_(mnt_free_iterp) struct libmnt_iter *i = NULL;
 186         int r;
 187
 188         assert(head);
 189
 190         t = mnt_new_table();
 191         i = mnt_new_iter(MNT_ITER_FORWARD);
 192         if (!t || !i)
 193                 return log_oom();
 194
 195         r = mnt_table_parse_swaps(t, swaps);
 196         if (r < 0)
 197                 return log_error_errno(r, "Failed to parse %s: %m", swaps);
 198
 199         for (;;) {
 200                 struct libmnt_fs *fs;
 201
 202                 MountPoint *swap;
 203                 const char *source;
 204                 _cleanup_free_ char *d = NULL;
 205
 206                 r = mnt_table_next_fs(t, i, &fs);
 207                 if (r == 1)
 208                         break;
 209                 if (r < 0)
 210                         return log_error_errno(r, "Failed to get next entry from %s: %m", swaps);
 211
 212                 source = mnt_fs_get_source(fs);
 213                 if (!source)
 214                         continue;
 215
 216                 r = cunescape(source, UNESCAPE_RELAX, &d);
 217                 if (r < 0)
 218                         return r;
 219
 220                 swap = new0(MountPoint, 1);
 221                 if (!swap)
 222                         return -ENOMEM;
 223
 224                 free_and_replace(swap->path, d);
 225                 LIST_PREPEND(mount_point, *head, swap);
 226         }
 227
 228         return 0;
 229 }
 230
 231 static int loopback_list_get(MountPoint **head) {
 232         _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL;
 233         sd_device *d;
 234         int r;
 235
 236         assert(head);
 237
 238         r = sd_device_enumerator_new(&e);
 239         if (r < 0)
 240                 return r;
 241
 242         r = sd_device_enumerator_allow_uninitialized(e);
 243         if (r < 0)
 244                 return r;
 245
 246         r = sd_device_enumerator_add_match_subsystem(e, "block", true);
 247         if (r < 0)
 248                 return r;
 249
 250         r = sd_device_enumerator_add_match_sysname(e, "loop*");
 251         if (r < 0)
 252                 return r;
 253
 254         r = sd_device_enumerator_add_match_sysattr(e, "loop/backing_file", NULL, true);
 255         if (r < 0)
 256                 return r;
 257
 258         FOREACH_DEVICE(e, d) {
 259                 _cleanup_free_ char *p = NULL;
 260                 const char *dn;
 261                 MountPoint *lb;
 262
 263                 if (sd_device_get_devname(d, &dn) < 0)
 264                         continue;
 265
 266                 p = strdup(dn);
 267                 if (!p)
 268                         return -ENOMEM;
 269
 270                 lb = new(MountPoint, 1);
 271                 if (!lb)
 272                         return -ENOMEM;
 273
 274                 *lb = (MountPoint) {
 275                         .path = TAKE_PTR(p),
 276                 };
 277
 278                 LIST_PREPEND(mount_point, *head, lb);
 279         }
 280
 281         return 0;
 282 }
 283
 284 static int dm_list_get(MountPoint **head) {
 285         _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL;
 286         sd_device *d;
 287         int r;
 288
 289         assert(head);
 290
 291         r = sd_device_enumerator_new(&e);
 292         if (r < 0)
 293                 return r;
 294
 295         r = sd_device_enumerator_allow_uninitialized(e);
 296         if (r < 0)
 297                 return r;
 298
 299         r = sd_device_enumerator_add_match_subsystem(e, "block", true);
 300         if (r < 0)
 301                 return r;
 302
 303         r = sd_device_enumerator_add_match_sysname(e, "dm-*");
 304         if (r < 0)
 305                 return r;
 306
 307         FOREACH_DEVICE(e, d) {
 308                 _cleanup_free_ char *p = NULL;
 309                 const char *dn;
 310                 MountPoint *m;
 311                 dev_t devnum;
 312
 313                 if (sd_device_get_devnum(d, &devnum) < 0 ||
 314                     sd_device_get_devname(d, &dn) < 0)
 315                         continue;
 316
 317                 p = strdup(dn);
 318                 if (!p)
 319                         return -ENOMEM;
 320
 321                 m = new(MountPoint, 1);
 322                 if (!m)
 323                         return -ENOMEM;
 324
 325                 *m = (MountPoint) {
 326                         .path = TAKE_PTR(p),
 327                         .devnum = devnum,
 328                 };
 329
 330                 LIST_PREPEND(mount_point, *head, m);
 331         }
 332
 333         return 0;
 334 }
 335
 336 static int delete_loopback(const char *device) {
 337         _cleanup_close_ int fd = -1;
 338         int r;
 339
 340         assert(device);
 341
 342         fd = open(device, O_RDONLY|O_CLOEXEC);
 343         if (fd < 0)
 344                 return errno == ENOENT ? 0 : -errno;
 345
 346         r = ioctl(fd, LOOP_CLR_FD, 0);
 347         if (r >= 0)
 348                 return 1;
 349
 350         /* ENXIO: not bound, so no error */
 351         if (errno == ENXIO)
 352                 return 0;
 353
 354         return -errno;
 355 }
 356
 357 static int delete_dm(dev_t devnum) {
 358
 359         struct dm_ioctl dm = {
 360                 .version = {
 361                         DM_VERSION_MAJOR,
 362                         DM_VERSION_MINOR,
 363                         DM_VERSION_PATCHLEVEL
 364                 },
 365                 .data_size = sizeof(dm),
 366                 .dev = devnum,
 367         };
 368
 369         _cleanup_close_ int fd = -1;
 370
 371         assert(major(devnum) != 0);
 372
 373         fd = open("/dev/mapper/control", O_RDWR|O_CLOEXEC);
 374         if (fd < 0)
 375                 return -errno;
 376
 377         if (ioctl(fd, DM_DEV_REMOVE, &dm) < 0)
 378                 return -errno;
 379
 380         return 0;
 381 }
 382
 383 static bool nonunmountable_path(const char *path) {
 384         return path_equal(path, "/")
 385 #if ! HAVE_SPLIT_USR
 386                 || path_equal(path, "/usr")
 387 #endif
 388                 || path_startswith(path, "/run/initramfs");
 389 }
 390
 391 static int remount_with_timeout(MountPoint *m, int umount_log_level) {
 392         pid_t pid;
 393         int r;
 394
 395         BLOCK_SIGNALS(SIGCHLD);
 396
 397         assert(m);
 398
 399         /* Due to the possiblity of a remount operation hanging, we
 400          * fork a child process and set a timeout. If the timeout
 401          * lapses, the assumption is that that particular remount
 402          * failed. */
 403         r = safe_fork("(sd-remount)", FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS|FORK_LOG|FORK_REOPEN_LOG, &pid);
 404         if (r < 0)
 405                 return r;
 406         if (r == 0) {
 407                 log_info("Remounting '%s' read-only in with options '%s'.", m->path, m->remount_options);
 408
 409                 /* Start the mount operation here in the child */
 410                 r = mount(NULL, m->path, NULL, m->remount_flags, m->remount_options);
 411                 if (r < 0)
 412                         log_full_errno(umount_log_level, errno, "Failed to remount '%s' read-only: %m", m->path);
 413
 414                 _exit(r < 0 ? EXIT_FAILURE : EXIT_SUCCESS);
 415         }
 416
 417         r = wait_for_terminate_with_timeout(pid, DEFAULT_TIMEOUT_USEC);
 418         if (r == -ETIMEDOUT) {
 419                 log_error_errno(r, "Remounting '%s' timed out, issuing SIGKILL to PID " PID_FMT ".", m->path, pid);
 420                 (void) kill(pid, SIGKILL);
 421         } else if (r == -EPROTO)
 422                 log_debug_errno(r, "Remounting '%s' failed abnormally, child process " PID_FMT " aborted or exited non-zero.", m->path, pid);
 423         else if (r < 0)
 424                 log_error_errno(r, "Remounting '%s' failed unexpectedly, couldn't wait for child process " PID_FMT ": %m", m->path, pid);
 425
 426         return r;
 427 }
 428
 429 static int umount_with_timeout(MountPoint *m, int umount_log_level) {
 430         pid_t pid;
 431         int r;
 432
 433         BLOCK_SIGNALS(SIGCHLD);
 434
 435         assert(m);
 436
 437         /* Due to the possiblity of a umount operation hanging, we
 438          * fork a child process and set a timeout. If the timeout
 439          * lapses, the assumption is that that particular umount
 440          * failed. */
 441         r = safe_fork("(sd-umount)", FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS|FORK_LOG|FORK_REOPEN_LOG, &pid);
 442         if (r < 0)
 443                 return r;
 444         if (r == 0) {
 445                 log_info("Unmounting '%s'.", m->path);
 446
 447                 /* Start the mount operation here in the child Using MNT_FORCE
 448                  * causes some filesystems (e.g. FUSE and NFS and other network
 449                  * filesystems) to abort any pending requests and return -EIO
 450                  * rather than blocking indefinitely. If the filesysten is
 451                  * "busy", this may allow processes to die, thus making the
 452                  * filesystem less busy so the unmount might succeed (rather
 453                  * then return EBUSY).*/
 454                 r = umount2(m->path, MNT_FORCE);
 455                 if (r < 0)
 456                         log_full_errno(umount_log_level, errno, "Failed to unmount %s: %m", m->path);
 457
 458                 _exit(r < 0 ? EXIT_FAILURE : EXIT_SUCCESS);
 459         }
 460
 461         r = wait_for_terminate_with_timeout(pid, DEFAULT_TIMEOUT_USEC);
 462         if (r == -ETIMEDOUT) {
 463                 log_error_errno(r, "Unmounting '%s' timed out, issuing SIGKILL to PID " PID_FMT ".", m->path, pid);
 464                 (void) kill(pid, SIGKILL);
 465         } else if (r == -EPROTO)
 466                 log_debug_errno(r, "Unmounting '%s' failed abnormally, child process " PID_FMT " aborted or exited non-zero.", m->path, pid);
 467         else if (r < 0)
 468                 log_error_errno(r, "Unmounting '%s' failed unexpectedly, couldn't wait for child process " PID_FMT ": %m", m->path, pid);
 469
 470         return r;
 471 }
 472
 473 /* This includes remounting readonly, which changes the kernel mount options.
 474  * Therefore the list passed to this function is invalidated, and should not be reused. */
 475 static int mount_points_list_umount(MountPoint **head, bool *changed, int umount_log_level) {
 476         MountPoint *m;
 477         int n_failed = 0;
 478
 479         assert(head);
 480         assert(changed);
 481
 482         LIST_FOREACH(mount_point, m, *head) {
 483                 if (m->try_remount_ro) {
 484                         /* We always try to remount directories
 485                          * read-only first, before we go on and umount
 486                          * them.
 487                          *
 488                          * Mount points can be stacked. If a mount
 489                          * point is stacked below / or /usr, we
 490                          * cannot umount or remount it directly,
 491                          * since there is no way to refer to the
 492                          * underlying mount. There's nothing we can do
 493                          * about it for the general case, but we can
 494                          * do something about it if it is aliased
 495                          * somehwere else via a bind mount. If we
 496                          * explicitly remount the super block of that
 497                          * alias read-only we hence should be
 498                          * relatively safe regarding keeping a dirty fs
 499                          * we cannot otherwise see.
 500                          *
 501                          * Since the remount can hang in the instance of
 502                          * remote filesystems, we remount asynchronously
 503                          * and skip the subsequent umount if it fails. */
 504                         if (remount_with_timeout(m, umount_log_level) < 0) {
 505                                 /* Remount failed, but try unmounting anyway,
 506                                  * unless this is a mount point we want to skip. */
 507                                 if (nonunmountable_path(m->path)) {
 508                                         n_failed++;
 509                                         continue;
 510                                 }
 511                         }
 512                 }
 513
 514                 /* Skip / and /usr since we cannot unmount that
 515                  * anyway, since we are running from it. They have
 516                  * already been remounted ro. */
 517                 if (nonunmountable_path(m->path))
 518                         continue;
 519
 520                 /* Trying to umount */
 521                 if (umount_with_timeout(m, umount_log_level) < 0)
 522                         n_failed++;
 523                 else
 524                         *changed = true;
 525         }
 526
 527         return n_failed;
 528 }
 529
 530 static int swap_points_list_off(MountPoint **head, bool *changed) {
 531         MountPoint *m, *n;
 532         int n_failed = 0;
 533
 534         assert(head);
 535         assert(changed);
 536
 537         LIST_FOREACH_SAFE(mount_point, m, n, *head) {
 538                 log_info("Deactivating swap %s.", m->path);
 539                 if (swapoff(m->path) == 0) {
 540                         *changed = true;
 541                         mount_point_free(head, m);
 542                 } else {
 543                         log_warning_errno(errno, "Could not deactivate swap %s: %m", m->path);
 544                         n_failed++;
 545                 }
 546         }
 547
 548         return n_failed;
 549 }
 550
 551 static int loopback_points_list_detach(MountPoint **head, bool *changed, int umount_log_level) {
 552         MountPoint *m, *n;
 553         int n_failed = 0, k;
 554         struct stat root_st;
 555
 556         assert(head);
 557         assert(changed);
 558
 559         k = lstat("/", &root_st);
 560
 561         LIST_FOREACH_SAFE(mount_point, m, n, *head) {
 562                 int r;
 563                 struct stat loopback_st;
 564
 565                 if (k >= 0 &&
 566                     major(root_st.st_dev) != 0 &&
 567                     lstat(m->path, &loopback_st) >= 0 &&
 568                     root_st.st_dev == loopback_st.st_rdev) {
 569                         n_failed++;
 570                         continue;
 571                 }
 572
 573                 log_info("Detaching loopback %s.", m->path);
 574                 r = delete_loopback(m->path);
 575                 if (r >= 0) {
 576                         if (r > 0)
 577                                 *changed = true;
 578
 579                         mount_point_free(head, m);
 580                 } else {
 581                         log_full_errno(umount_log_level, errno, "Could not detach loopback %s: %m", m->path);
 582                         n_failed++;
 583                 }
 584         }
 585
 586         return n_failed;
 587 }
 588
 589 static int dm_points_list_detach(MountPoint **head, bool *changed, int umount_log_level) {
 590         MountPoint *m, *n;
 591         int n_failed = 0, r;
 592         dev_t rootdev;
 593
 594         assert(head);
 595         assert(changed);
 596
 597         r = get_block_device("/", &rootdev);
 598         if (r <= 0)
 599                 rootdev = 0;
 600
 601         LIST_FOREACH_SAFE(mount_point, m, n, *head) {
 602
 603                 if (major(rootdev) != 0 && rootdev == m->devnum) {
 604                         n_failed ++;
 605                         continue;
 606                 }
 607
 608                 log_info("Detaching DM %u:%u.", major(m->devnum), minor(m->devnum));
 609                 r = delete_dm(m->devnum);
 610                 if (r >= 0) {
 611                         *changed = true;
 612                         mount_point_free(head, m);
 613                 } else {
 614                         log_full_errno(umount_log_level, errno, "Could not detach DM %s: %m", m->path);
 615                         n_failed++;
 616                 }
 617         }
 618
 619         return n_failed;
 620 }
 621
 622 static int umount_all_once(bool *changed, int umount_log_level) {
 623         int r;
 624         _cleanup_(mount_points_list_free) LIST_HEAD(MountPoint, mp_list_head);
 625
 626         assert(changed);
 627
 628         LIST_HEAD_INIT(mp_list_head);
 629         r = mount_points_list_get(NULL, &mp_list_head);
 630         if (r < 0)
 631                 return r;
 632
 633         return mount_points_list_umount(&mp_list_head, changed, umount_log_level);
 634 }
 635
 636 int umount_all(bool *changed, int umount_log_level) {
 637         bool umount_changed;
 638         int r;
 639
 640         assert(changed);
 641
 642         /* Retry umount, until nothing can be umounted anymore. Mounts are
 643          * processed in order, newest first. The retries are needed when
 644          * an old mount has been moved, to a path inside a newer mount. */
 645         do {
 646                 umount_changed = false;
 647
 648                 r = umount_all_once(&umount_changed, umount_log_level);
 649                 if (umount_changed)
 650                         *changed = true;
 651         } while (umount_changed);
 652
 653         return r;
 654 }
 655
 656 int swapoff_all(bool *changed) {
 657         _cleanup_(mount_points_list_free) LIST_HEAD(MountPoint, swap_list_head);
 658         int r;
 659
 660         assert(changed);
 661
 662         LIST_HEAD_INIT(swap_list_head);
 663
 664         r = swap_list_get(NULL, &swap_list_head);
 665         if (r < 0)
 666                 return r;
 667
 668         return swap_points_list_off(&swap_list_head, changed);
 669 }
 670
 671 int loopback_detach_all(bool *changed, int umount_log_level) {
 672         _cleanup_(mount_points_list_free) LIST_HEAD(MountPoint, loopback_list_head);
 673         int r;
 674
 675         assert(changed);
 676
 677         LIST_HEAD_INIT(loopback_list_head);
 678
 679         r = loopback_list_get(&loopback_list_head);
 680         if (r < 0)
 681                 return r;
 682
 683         return loopback_points_list_detach(&loopback_list_head, changed, umount_log_level);
 684 }
 685
 686 int dm_detach_all(bool *changed, int umount_log_level) {
 687         _cleanup_(mount_points_list_free) LIST_HEAD(MountPoint, dm_list_head);
 688         int r;
 689
 690         assert(changed);
 691
 692         LIST_HEAD_INIT(dm_list_head);
 693
 694         r = dm_list_get(&dm_list_head);
 695         if (r < 0)
 696                 return r;
 697
 698         return dm_points_list_detach(&dm_list_head, changed, umount_log_level);
 699 }