src/shared/machine-image.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2013 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 <dirent.h>
  21 #include <errno.h>
  22 #include <fcntl.h>
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <sys/file.h>
  27 #include <sys/stat.h>
  28 #include <unistd.h>
  29 #include <linux/fs.h>
  30 #include "alloc-util.h"
  31 #include "btrfs-util.h"
  32 #include "chattr-util.h"
  33 #include "copy.h"
  34 #include "dirent-util.h"
  35 #include "fd-util.h"
  36 #include "fs-util.h"
  37 #include "hashmap.h"
  38 #include "lockfile-util.h"
  39 #include "log.h"
  40 #include "macro.h"
  41 #include "machine-image.h"
  42 #include "mkdir.h"
  43 #include "path-util.h"
  44 #include "rm-rf.h"
  45 #include "string-table.h"
  46 #include "string-util.h"
  47 #include "strv.h"
  48 #include "time-util.h"
  49 #include "utf8.h"
  50 #include "util.h"
  51 #include "xattr-util.h"
  52
  53 static const char image_search_path[] =
  54         "/var/lib/machines\0"
  55         "/var/lib/container\0" /* legacy */
  56         "/usr/local/lib/machines\0"
  57         "/usr/lib/machines\0";
  58
  59 Image *image_unref(Image *i) {
  60         if (!i)
  61                 return NULL;
  62
  63         free(i->name);
  64         free(i->path);
  65         return mfree(i);
  66 }
  67
  68 static char **image_settings_path(Image *image) {
  69         _cleanup_strv_free_ char **l = NULL;
  70         char **ret;
  71         const char *fn, *s;
  72         unsigned i = 0;
  73
  74         assert(image);
  75
  76         l = new0(char*, 4);
  77         if (!l)
  78                 return NULL;
  79
  80         fn = strjoina(image->name, ".nspawn");
  81
  82         FOREACH_STRING(s, "/etc/systemd/nspawn/", "/run/systemd/nspawn/") {
  83                 l[i] = strappend(s, fn);
  84                 if (!l[i])
  85                         return NULL;
  86
  87                 i++;
  88         }
  89
  90         l[i] = file_in_same_dir(image->path, fn);
  91         if (!l[i])
  92                 return NULL;
  93
  94         ret = l;
  95         l = NULL;
  96
  97         return ret;
  98 }
  99
 100 static int image_new(
 101                 ImageType t,
 102                 const char *pretty,
 103                 const char *path,
 104                 const char *filename,
 105                 bool read_only,
 106                 usec_t crtime,
 107                 usec_t mtime,
 108                 Image **ret) {
 109
 110         _cleanup_(image_unrefp) Image *i = NULL;
 111
 112         assert(t >= 0);
 113         assert(t < _IMAGE_TYPE_MAX);
 114         assert(pretty);
 115         assert(filename);
 116         assert(ret);
 117
 118         i = new0(Image, 1);
 119         if (!i)
 120                 return -ENOMEM;
 121
 122         i->type = t;
 123         i->read_only = read_only;
 124         i->crtime = crtime;
 125         i->mtime = mtime;
 126         i->usage = i->usage_exclusive = (uint64_t) -1;
 127         i->limit = i->limit_exclusive = (uint64_t) -1;
 128
 129         i->name = strdup(pretty);
 130         if (!i->name)
 131                 return -ENOMEM;
 132
 133         if (path)
 134                 i->path = strjoin(path, "/", filename, NULL);
 135         else
 136                 i->path = strdup(filename);
 137
 138         if (!i->path)
 139                 return -ENOMEM;
 140
 141         path_kill_slashes(i->path);
 142
 143         *ret = i;
 144         i = NULL;
 145
 146         return 0;
 147 }
 148
 149 static int image_make(
 150                 const char *pretty,
 151                 int dfd,
 152                 const char *path,
 153                 const char *filename,
 154                 Image **ret) {
 155
 156         struct stat st;
 157         bool read_only;
 158         int r;
 159
 160         assert(filename);
 161
 162         /* We explicitly *do* follow symlinks here, since we want to
 163          * allow symlinking trees into /var/lib/machines/, and treat
 164          * them normally. */
 165
 166         if (fstatat(dfd, filename, &st, 0) < 0)
 167                 return -errno;
 168
 169         read_only =
 170                 (path && path_startswith(path, "/usr")) ||
 171                 (faccessat(dfd, filename, W_OK, AT_EACCESS) < 0 && errno == EROFS);
 172
 173         if (S_ISDIR(st.st_mode)) {
 174                 _cleanup_close_ int fd = -1;
 175                 unsigned file_attr = 0;
 176
 177                 if (!ret)
 178                         return 1;
 179
 180                 if (!pretty)
 181                         pretty = filename;
 182
 183                 fd = openat(dfd, filename, O_CLOEXEC|O_NOCTTY|O_DIRECTORY);
 184                 if (fd < 0)
 185                         return -errno;
 186
 187                 /* btrfs subvolumes have inode 256 */
 188                 if (st.st_ino == 256) {
 189
 190                         r = btrfs_is_filesystem(fd);
 191                         if (r < 0)
 192                                 return r;
 193                         if (r) {
 194                                 BtrfsSubvolInfo info;
 195
 196                                 /* It's a btrfs subvolume */
 197
 198                                 r = btrfs_subvol_get_info_fd(fd, 0, &info);
 199                                 if (r < 0)
 200                                         return r;
 201
 202                                 r = image_new(IMAGE_SUBVOLUME,
 203                                               pretty,
 204                                               path,
 205                                               filename,
 206                                               info.read_only || read_only,
 207                                               info.otime,
 208                                               0,
 209                                               ret);
 210                                 if (r < 0)
 211                                         return r;
 212
 213                                 if (btrfs_quota_scan_ongoing(fd) == 0) {
 214                                         BtrfsQuotaInfo quota;
 215
 216                                         r = btrfs_subvol_get_subtree_quota_fd(fd, 0, &quota);
 217                                         if (r >= 0) {
 218                                                 (*ret)->usage = quota.referenced;
 219                                                 (*ret)->usage_exclusive = quota.exclusive;
 220
 221                                                 (*ret)->limit = quota.referenced_max;
 222                                                 (*ret)->limit_exclusive = quota.exclusive_max;
 223                                         }
 224                                 }
 225
 226                                 return 1;
 227                         }
 228                 }
 229
 230                 /* If the IMMUTABLE bit is set, we consider the
 231                  * directory read-only. Since the ioctl is not
 232                  * supported everywhere we ignore failures. */
 233                 (void) read_attr_fd(fd, &file_attr);
 234
 235                 /* It's just a normal directory. */
 236                 r = image_new(IMAGE_DIRECTORY,
 237                               pretty,
 238                               path,
 239                               filename,
 240                               read_only || (file_attr & FS_IMMUTABLE_FL),
 241                               0,
 242                               0,
 243                               ret);
 244                 if (r < 0)
 245                         return r;
 246
 247                 return 1;
 248
 249         } else if (S_ISREG(st.st_mode) && endswith(filename, ".raw")) {
 250                 usec_t crtime = 0;
 251
 252                 /* It's a RAW disk image */
 253
 254                 if (!ret)
 255                         return 1;
 256
 257                 fd_getcrtime_at(dfd, filename, &crtime, 0);
 258
 259                 if (!pretty)
 260                         pretty = strndupa(filename, strlen(filename) - 4);
 261
 262                 r = image_new(IMAGE_RAW,
 263                               pretty,
 264                               path,
 265                               filename,
 266                               !(st.st_mode & 0222) || read_only,
 267                               crtime,
 268                               timespec_load(&st.st_mtim),
 269                               ret);
 270                 if (r < 0)
 271                         return r;
 272
 273                 (*ret)->usage = (*ret)->usage_exclusive = st.st_blocks * 512;
 274                 (*ret)->limit = (*ret)->limit_exclusive = st.st_size;
 275
 276                 return 1;
 277         }
 278
 279         return 0;
 280 }
 281
 282 int image_find(const char *name, Image **ret) {
 283         const char *path;
 284         int r;
 285
 286         assert(name);
 287
 288         /* There are no images with invalid names */
 289         if (!image_name_is_valid(name))
 290                 return 0;
 291
 292         NULSTR_FOREACH(path, image_search_path) {
 293                 _cleanup_closedir_ DIR *d = NULL;
 294
 295                 d = opendir(path);
 296                 if (!d) {
 297                         if (errno == ENOENT)
 298                                 continue;
 299
 300                         return -errno;
 301                 }
 302
 303                 r = image_make(NULL, dirfd(d), path, name, ret);
 304                 if (r == 0 || r == -ENOENT) {
 305                         _cleanup_free_ char *raw = NULL;
 306
 307                         raw = strappend(name, ".raw");
 308                         if (!raw)
 309                                 return -ENOMEM;
 310
 311                         r = image_make(NULL, dirfd(d), path, raw, ret);
 312                         if (r == 0 || r == -ENOENT)
 313                                 continue;
 314                 }
 315                 if (r < 0)
 316                         return r;
 317
 318                 return 1;
 319         }
 320
 321         if (streq(name, ".host"))
 322                 return image_make(".host", AT_FDCWD, NULL, "/", ret);
 323
 324         return 0;
 325 };
 326
 327 int image_discover(Hashmap *h) {
 328         const char *path;
 329         int r;
 330
 331         assert(h);
 332
 333         NULSTR_FOREACH(path, image_search_path) {
 334                 _cleanup_closedir_ DIR *d = NULL;
 335                 struct dirent *de;
 336
 337                 d = opendir(path);
 338                 if (!d) {
 339                         if (errno == ENOENT)
 340                                 continue;
 341
 342                         return -errno;
 343                 }
 344
 345                 FOREACH_DIRENT_ALL(de, d, return -errno) {
 346                         _cleanup_(image_unrefp) Image *image = NULL;
 347
 348                         if (!image_name_is_valid(de->d_name))
 349                                 continue;
 350
 351                         if (hashmap_contains(h, de->d_name))
 352                                 continue;
 353
 354                         r = image_make(NULL, dirfd(d), path, de->d_name, &image);
 355                         if (r == 0 || r == -ENOENT)
 356                                 continue;
 357                         if (r < 0)
 358                                 return r;
 359
 360                         r = hashmap_put(h, image->name, image);
 361                         if (r < 0)
 362                                 return r;
 363
 364                         image = NULL;
 365                 }
 366         }
 367
 368         if (!hashmap_contains(h, ".host")) {
 369                 _cleanup_(image_unrefp) Image *image = NULL;
 370
 371                 r = image_make(".host", AT_FDCWD, NULL, "/", &image);
 372                 if (r < 0)
 373                         return r;
 374
 375                 r = hashmap_put(h, image->name, image);
 376                 if (r < 0)
 377                         return r;
 378
 379                 image = NULL;
 380
 381         }
 382
 383         return 0;
 384 }
 385
 386 void image_hashmap_free(Hashmap *map) {
 387         Image *i;
 388
 389         while ((i = hashmap_steal_first(map)))
 390                 image_unref(i);
 391
 392         hashmap_free(map);
 393 }
 394
 395 int image_remove(Image *i) {
 396         _cleanup_release_lock_file_ LockFile global_lock = LOCK_FILE_INIT, local_lock = LOCK_FILE_INIT;
 397         _cleanup_strv_free_ char **settings = NULL;
 398         char **j;
 399         int r;
 400
 401         assert(i);
 402
 403         if (IMAGE_IS_VENDOR(i) || IMAGE_IS_HOST(i))
 404                 return -EROFS;
 405
 406         settings = image_settings_path(i);
 407         if (!settings)
 408                 return -ENOMEM;
 409
 410         /* Make sure we don't interfere with a running nspawn */
 411         r = image_path_lock(i->path, LOCK_EX|LOCK_NB, &global_lock, &local_lock);
 412         if (r < 0)
 413                 return r;
 414
 415         switch (i->type) {
 416
 417         case IMAGE_SUBVOLUME:
 418                 r = btrfs_subvol_remove(i->path, BTRFS_REMOVE_RECURSIVE|BTRFS_REMOVE_QUOTA);
 419                 if (r < 0)
 420                         return r;
 421                 break;
 422
 423         case IMAGE_DIRECTORY:
 424                 /* Allow deletion of read-only directories */
 425                 (void) chattr_path(i->path, 0, FS_IMMUTABLE_FL);
 426                 r = rm_rf(i->path, REMOVE_ROOT|REMOVE_PHYSICAL|REMOVE_SUBVOLUME);
 427                 if (r < 0)
 428                         return r;
 429
 430                 break;
 431
 432         case IMAGE_RAW:
 433                 if (unlink(i->path) < 0)
 434                         return -errno;
 435                 break;
 436
 437         default:
 438                 return -EOPNOTSUPP;
 439         }
 440
 441         STRV_FOREACH(j, settings) {
 442                 if (unlink(*j) < 0 && errno != ENOENT)
 443                         log_debug_errno(errno, "Failed to unlink %s, ignoring: %m", *j);
 444         }
 445
 446         return 0;
 447 }
 448
 449 static int rename_settings_file(const char *path, const char *new_name) {
 450         _cleanup_free_ char *rs = NULL;
 451         const char *fn;
 452
 453         fn = strjoina(new_name, ".nspawn");
 454
 455         rs = file_in_same_dir(path, fn);
 456         if (!rs)
 457                 return -ENOMEM;
 458
 459         return rename_noreplace(AT_FDCWD, path, AT_FDCWD, rs);
 460 }
 461
 462 int image_rename(Image *i, const char *new_name) {
 463         _cleanup_release_lock_file_ LockFile global_lock = LOCK_FILE_INIT, local_lock = LOCK_FILE_INIT, name_lock = LOCK_FILE_INIT;
 464         _cleanup_free_ char *new_path = NULL, *nn = NULL;
 465         _cleanup_strv_free_ char **settings = NULL;
 466         unsigned file_attr = 0;
 467         char **j;
 468         int r;
 469
 470         assert(i);
 471
 472         if (!image_name_is_valid(new_name))
 473                 return -EINVAL;
 474
 475         if (IMAGE_IS_VENDOR(i) || IMAGE_IS_HOST(i))
 476                 return -EROFS;
 477
 478         settings = image_settings_path(i);
 479         if (!settings)
 480                 return -ENOMEM;
 481
 482         /* Make sure we don't interfere with a running nspawn */
 483         r = image_path_lock(i->path, LOCK_EX|LOCK_NB, &global_lock, &local_lock);
 484         if (r < 0)
 485                 return r;
 486
 487         /* Make sure nobody takes the new name, between the time we
 488          * checked it is currently unused in all search paths, and the
 489          * time we take possession of it */
 490         r = image_name_lock(new_name, LOCK_EX|LOCK_NB, &name_lock);
 491         if (r < 0)
 492                 return r;
 493
 494         r = image_find(new_name, NULL);
 495         if (r < 0)
 496                 return r;
 497         if (r > 0)
 498                 return -EEXIST;
 499
 500         switch (i->type) {
 501
 502         case IMAGE_DIRECTORY:
 503                 /* Turn of the immutable bit while we rename the image, so that we can rename it */
 504                 (void) read_attr_path(i->path, &file_attr);
 505
 506                 if (file_attr & FS_IMMUTABLE_FL)
 507                         (void) chattr_path(i->path, 0, FS_IMMUTABLE_FL);
 508
 509                 /* fall through */
 510
 511         case IMAGE_SUBVOLUME:
 512                 new_path = file_in_same_dir(i->path, new_name);
 513                 break;
 514
 515         case IMAGE_RAW: {
 516                 const char *fn;
 517
 518                 fn = strjoina(new_name, ".raw");
 519                 new_path = file_in_same_dir(i->path, fn);
 520                 break;
 521         }
 522
 523         default:
 524                 return -EOPNOTSUPP;
 525         }
 526
 527         if (!new_path)
 528                 return -ENOMEM;
 529
 530         nn = strdup(new_name);
 531         if (!nn)
 532                 return -ENOMEM;
 533
 534         r = rename_noreplace(AT_FDCWD, i->path, AT_FDCWD, new_path);
 535         if (r < 0)
 536                 return r;
 537
 538         /* Restore the immutable bit, if it was set before */
 539         if (file_attr & FS_IMMUTABLE_FL)
 540                 (void) chattr_path(new_path, FS_IMMUTABLE_FL, FS_IMMUTABLE_FL);
 541
 542         free(i->path);
 543         i->path = new_path;
 544         new_path = NULL;
 545
 546         free(i->name);
 547         i->name = nn;
 548         nn = NULL;
 549
 550         STRV_FOREACH(j, settings) {
 551                 r = rename_settings_file(*j, new_name);
 552                 if (r < 0 && r != -ENOENT)
 553                         log_debug_errno(r, "Failed to rename settings file %s, ignoring: %m", *j);
 554         }
 555
 556         return 0;
 557 }
 558
 559 static int clone_settings_file(const char *path, const char *new_name) {
 560         _cleanup_free_ char *rs = NULL;
 561         const char *fn;
 562
 563         fn = strjoina(new_name, ".nspawn");
 564
 565         rs = file_in_same_dir(path, fn);
 566         if (!rs)
 567                 return -ENOMEM;
 568
 569         return copy_file_atomic(path, rs, 0664, false, 0);
 570 }
 571
 572 int image_clone(Image *i, const char *new_name, bool read_only) {
 573         _cleanup_release_lock_file_ LockFile name_lock = LOCK_FILE_INIT;
 574         _cleanup_strv_free_ char **settings = NULL;
 575         const char *new_path;
 576         char **j;
 577         int r;
 578
 579         assert(i);
 580
 581         if (!image_name_is_valid(new_name))
 582                 return -EINVAL;
 583
 584         settings = image_settings_path(i);
 585         if (!settings)
 586                 return -ENOMEM;
 587
 588         /* Make sure nobody takes the new name, between the time we
 589          * checked it is currently unused in all search paths, and the
 590          * time we take possession of it */
 591         r = image_name_lock(new_name, LOCK_EX|LOCK_NB, &name_lock);
 592         if (r < 0)
 593                 return r;
 594
 595         r = image_find(new_name, NULL);
 596         if (r < 0)
 597                 return r;
 598         if (r > 0)
 599                 return -EEXIST;
 600
 601         switch (i->type) {
 602
 603         case IMAGE_SUBVOLUME:
 604         case IMAGE_DIRECTORY:
 605                 /* If we can we'll always try to create a new btrfs subvolume here, even if the source is a plain
 606                  * directory.*/
 607
 608                 new_path = strjoina("/var/lib/machines/", new_name);
 609
 610                 r = btrfs_subvol_snapshot(i->path, new_path, (read_only ? BTRFS_SNAPSHOT_READ_ONLY : 0) | BTRFS_SNAPSHOT_FALLBACK_COPY | BTRFS_SNAPSHOT_RECURSIVE | BTRFS_SNAPSHOT_QUOTA);
 611                 if (r == -EOPNOTSUPP) {
 612                         /* No btrfs snapshots supported, create a normal directory then. */
 613
 614                         r = copy_directory(i->path, new_path, false);
 615                         if (r >= 0)
 616                                 (void) chattr_path(new_path, read_only ? FS_IMMUTABLE_FL : 0, FS_IMMUTABLE_FL);
 617                 } else if (r >= 0)
 618                         /* Enable "subtree" quotas for the copy, if we didn't copy any quota from the source. */
 619                         (void) btrfs_subvol_auto_qgroup(new_path, 0, true);
 620
 621                 break;
 622
 623         case IMAGE_RAW:
 624                 new_path = strjoina("/var/lib/machines/", new_name, ".raw");
 625
 626                 r = copy_file_atomic(i->path, new_path, read_only ? 0444 : 0644, false, FS_NOCOW_FL);
 627                 break;
 628
 629         default:
 630                 return -EOPNOTSUPP;
 631         }
 632
 633         if (r < 0)
 634                 return r;
 635
 636         STRV_FOREACH(j, settings) {
 637                 r = clone_settings_file(*j, new_name);
 638                 if (r < 0 && r != -ENOENT)
 639                         log_debug_errno(r, "Failed to clone settings %s, ignoring: %m", *j);
 640         }
 641
 642         return 0;
 643 }
 644
 645 int image_read_only(Image *i, bool b) {
 646         _cleanup_release_lock_file_ LockFile global_lock = LOCK_FILE_INIT, local_lock = LOCK_FILE_INIT;
 647         int r;
 648         assert(i);
 649
 650         if (IMAGE_IS_VENDOR(i) || IMAGE_IS_HOST(i))
 651                 return -EROFS;
 652
 653         /* Make sure we don't interfere with a running nspawn */
 654         r = image_path_lock(i->path, LOCK_EX|LOCK_NB, &global_lock, &local_lock);
 655         if (r < 0)
 656                 return r;
 657
 658         switch (i->type) {
 659
 660         case IMAGE_SUBVOLUME:
 661
 662                 /* Note that we set the flag only on the top-level
 663                  * subvolume of the image. */
 664
 665                 r = btrfs_subvol_set_read_only(i->path, b);
 666                 if (r < 0)
 667                         return r;
 668
 669                 break;
 670
 671         case IMAGE_DIRECTORY:
 672                 /* For simple directory trees we cannot use the access
 673                    mode of the top-level directory, since it has an
 674                    effect on the container itself.  However, we can
 675                    use the "immutable" flag, to at least make the
 676                    top-level directory read-only. It's not as good as
 677                    a read-only subvolume, but at least something, and
 678                    we can read the value back.*/
 679
 680                 r = chattr_path(i->path, b ? FS_IMMUTABLE_FL : 0, FS_IMMUTABLE_FL);
 681                 if (r < 0)
 682                         return r;
 683
 684                 break;
 685
 686         case IMAGE_RAW: {
 687                 struct stat st;
 688
 689                 if (stat(i->path, &st) < 0)
 690                         return -errno;
 691
 692                 if (chmod(i->path, (st.st_mode & 0444) | (b ? 0000 : 0200)) < 0)
 693                         return -errno;
 694
 695                 /* If the images is now read-only, it's a good time to
 696                  * defrag it, given that no write patterns will
 697                  * fragment it again. */
 698                 if (b)
 699                         (void) btrfs_defrag(i->path);
 700                 break;
 701         }
 702
 703         default:
 704                 return -EOPNOTSUPP;
 705         }
 706
 707         return 0;
 708 }
 709
 710 int image_path_lock(const char *path, int operation, LockFile *global, LockFile *local) {
 711         _cleanup_free_ char *p = NULL;
 712         LockFile t = LOCK_FILE_INIT;
 713         struct stat st;
 714         int r;
 715
 716         assert(path);
 717         assert(global);
 718         assert(local);
 719
 720         /* Locks an image path. This actually creates two locks: one
 721          * "local" one, next to the image path itself, which might be
 722          * shared via NFS. And another "global" one, in /run, that
 723          * uses the device/inode number. This has the benefit that we
 724          * can even lock a tree that is a mount point, correctly. */
 725
 726         if (path_equal(path, "/"))
 727                 return -EBUSY;
 728
 729         if (!path_is_absolute(path))
 730                 return -EINVAL;
 731
 732         if (stat(path, &st) >= 0) {
 733                 if (asprintf(&p, "/run/systemd/nspawn/locks/inode-%lu:%lu", (unsigned long) st.st_dev, (unsigned long) st.st_ino) < 0)
 734                         return -ENOMEM;
 735         }
 736
 737         r = make_lock_file_for(path, operation, &t);
 738         if (r < 0)
 739                 return r;
 740
 741         if (p) {
 742                 mkdir_p("/run/systemd/nspawn/locks", 0700);
 743
 744                 r = make_lock_file(p, operation, global);
 745                 if (r < 0) {
 746                         release_lock_file(&t);
 747                         return r;
 748                 }
 749         }
 750
 751         *local = t;
 752         return 0;
 753 }
 754
 755 int image_set_limit(Image *i, uint64_t referenced_max) {
 756         assert(i);
 757
 758         if (IMAGE_IS_VENDOR(i) || IMAGE_IS_HOST(i))
 759                 return -EROFS;
 760
 761         if (i->type != IMAGE_SUBVOLUME)
 762                 return -EOPNOTSUPP;
 763
 764         /* We set the quota both for the subvolume as well as for the
 765          * subtree. The latter is mostly for historical reasons, since
 766          * we didn't use to have a concept of subtree quota, and hence
 767          * only modified the subvolume quota. */
 768
 769         (void) btrfs_qgroup_set_limit(i->path, 0, referenced_max);
 770         (void) btrfs_subvol_auto_qgroup(i->path, 0, true);
 771         return btrfs_subvol_set_subtree_quota_limit(i->path, 0, referenced_max);
 772 }
 773
 774 int image_name_lock(const char *name, int operation, LockFile *ret) {
 775         const char *p;
 776
 777         assert(name);
 778         assert(ret);
 779
 780         /* Locks an image name, regardless of the precise path used. */
 781
 782         if (!image_name_is_valid(name))
 783                 return -EINVAL;
 784
 785         if (streq(name, ".host"))
 786                 return -EBUSY;
 787
 788         mkdir_p("/run/systemd/nspawn/locks", 0700);
 789         p = strjoina("/run/systemd/nspawn/locks/name-", name);
 790
 791         return make_lock_file(p, operation, ret);
 792 }
 793
 794 bool image_name_is_valid(const char *s) {
 795         if (!filename_is_valid(s))
 796                 return false;
 797
 798         if (string_has_cc(s, NULL))
 799                 return false;
 800
 801         if (!utf8_is_valid(s))
 802                 return false;
 803
 804         /* Temporary files for atomically creating new files */
 805         if (startswith(s, ".#"))
 806                 return false;
 807
 808         return true;
 809 }
 810
 811 static const char* const image_type_table[_IMAGE_TYPE_MAX] = {
 812         [IMAGE_DIRECTORY] = "directory",
 813         [IMAGE_SUBVOLUME] = "subvolume",
 814         [IMAGE_RAW] = "raw",
 815 };
 816
 817 DEFINE_STRING_TABLE_LOOKUP(image_type, ImageType);