ext4_utils/make_ext4fs.c

   1 /*
   2  * Copyright (C) 2010 The Android Open Source Project
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *      http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #include "make_ext4fs.h"
  18 #include "ext4_utils.h"
  19 #include "allocate.h"
  20 #include "contents.h"
  21 #include "uuid.h"
  22 #include "wipe.h"
  23
  24 #include <sparse/sparse.h>
  25
  26 #include <assert.h>
  27 #include <dirent.h>
  28 #include <fcntl.h>
  29 #include <libgen.h>
  30 #include <stdio.h>
  31 #include <stdlib.h>
  32 #include <string.h>
  33 #include <unistd.h>
  34 #include <sys/stat.h>
  35 #include <sys/types.h>
  36
  37 #ifdef USE_MINGW
  38
  39 #include <winsock2.h>
  40
  41 /* These match the Linux definitions of these flags.
  42    L_xx is defined to avoid conflicting with the win32 versions.
  43 */
  44 #define L_S_IRUSR 00400
  45 #define L_S_IWUSR 00200
  46 #define L_S_IXUSR 00100
  47 #define S_IRWXU (L_S_IRUSR | L_S_IWUSR | L_S_IXUSR)
  48 #define S_IRGRP 00040
  49 #define S_IWGRP 00020
  50 #define S_IXGRP 00010
  51 #define S_IRWXG (S_IRGRP | S_IWGRP | S_IXGRP)
  52 #define S_IROTH 00004
  53 #define S_IWOTH 00002
  54 #define S_IXOTH 00001
  55 #define S_IRWXO (S_IROTH | S_IWOTH | S_IXOTH)
  56 #define S_ISUID 0004000
  57 #define S_ISGID 0002000
  58 #define S_ISVTX 0001000
  59
  60 #else
  61
  62 #define O_BINARY 0
  63
  64 #endif
  65
  66 /* TODO: Not implemented:
  67    Allocating blocks in the same block group as the file inode
  68    Hash or binary tree directories
  69    Special files: sockets, devices, fifos
  70  */
  71
  72 static int filter_dot(const struct dirent *d)
  73 {
  74         return (strcmp(d->d_name, "..") && strcmp(d->d_name, "."));
  75 }
  76
  77 static u32 build_default_directory_structure()
  78 {
  79         u32 inode;
  80         u32 root_inode;
  81         struct dentry dentries = {
  82                         .filename = "lost+found",
  83                         .file_type = EXT4_FT_DIR,
  84                         .mode = S_IRWXU,
  85                         .uid = 0,
  86                         .gid = 0,
  87                         .mtime = 0,
  88         };
  89         root_inode = make_directory(0, 1, &dentries, 1);
  90         inode = make_directory(root_inode, 0, NULL, 0);
  91         *dentries.inode = inode;
  92         inode_set_permissions(inode, dentries.mode,
  93                 dentries.uid, dentries.gid, dentries.mtime);
  94
  95         return root_inode;
  96 }
  97
  98 #ifndef USE_MINGW
  99 /* Read a local directory and create the same tree in the generated filesystem.
 100    Calls itself recursively with each directory in the given directory */
 101 static u32 build_directory_structure(const char *full_path, const char *dir_path,
 102                 u32 dir_inode, fs_config_func_t fs_config_func,
 103                 struct selabel_handle *sehnd)
 104 {
 105         int entries = 0;
 106         struct dentry *dentries;
 107         struct dirent **namelist = NULL;
 108         struct stat stat;
 109         int ret;
 110         int i;
 111         u32 inode;
 112         u32 entry_inode;
 113         u32 dirs = 0;
 114         bool needs_lost_and_found = false;
 115
 116         if (full_path) {
 117                 entries = scandir(full_path, &namelist, filter_dot, (void*)alphasort);
 118                 if (entries < 0) {
 119                         error_errno("scandir");
 120                         return EXT4_ALLOCATE_FAILED;
 121                 }
 122         }
 123
 124         if (dir_inode == 0) {
 125                 /* root directory, check if lost+found already exists */
 126                 for (i = 0; i < entries; i++)
 127                         if (strcmp(namelist[i]->d_name, "lost+found") == 0)
 128                                 break;
 129                 if (i == entries)
 130                         needs_lost_and_found = true;
 131         }
 132
 133         dentries = calloc(entries, sizeof(struct dentry));
 134         if (dentries == NULL)
 135                 critical_error_errno("malloc");
 136
 137         for (i = 0; i < entries; i++) {
 138                 dentries[i].filename = strdup(namelist[i]->d_name);
 139                 if (dentries[i].filename == NULL)
 140                         critical_error_errno("strdup");
 141
 142                 asprintf(&dentries[i].path, "%s/%s", dir_path, namelist[i]->d_name);
 143                 asprintf(&dentries[i].full_path, "%s/%s", full_path, namelist[i]->d_name);
 144
 145                 free(namelist[i]);
 146
 147                 ret = lstat(dentries[i].full_path, &stat);
 148                 if (ret < 0) {
 149                         error_errno("lstat");
 150                         i--;
 151                         entries--;
 152                         continue;
 153                 }
 154
 155                 dentries[i].size = stat.st_size;
 156                 dentries[i].mode = stat.st_mode & (S_ISUID|S_ISGID|S_ISVTX|S_IRWXU|S_IRWXG|S_IRWXO);
 157                 dentries[i].mtime = stat.st_mtime;
 158                 if (fs_config_func != NULL) {
 159 #ifdef ANDROID
 160                         unsigned int mode = 0;
 161                         unsigned int uid = 0;
 162                         unsigned int gid = 0;
 163                         int dir = S_ISDIR(stat.st_mode);
 164                         fs_config_func(dentries[i].path, dir, &uid, &gid, &mode);
 165                         dentries[i].mode = mode;
 166                         dentries[i].uid = uid;
 167                         dentries[i].gid = gid;
 168 #else
 169                         error("can't set android permissions - built without android support");
 170 #endif
 171                 }
 172 #ifndef USE_MINGW
 173                 if (sehnd) {
 174                         char *sepath = NULL;
 175                         asprintf(&sepath, "/%s", dentries[i].path);
 176                         if (selabel_lookup(sehnd, &dentries[i].secon, sepath, stat.st_mode) < 0) {
 177                                 error("cannot lookup security context for %s", sepath);
 178                         }
 179 #if 0
 180                         // TODO make this a debug flag
 181                         if (dentries[i].secon)
 182                                 printf("Labeling %s as %s\n", sepath, dentries[i].secon);
 183 #endif
 184                         free(sepath);
 185                 }
 186 #endif
 187
 188                 if (S_ISREG(stat.st_mode)) {
 189                         dentries[i].file_type = EXT4_FT_REG_FILE;
 190                 } else if (S_ISDIR(stat.st_mode)) {
 191                         dentries[i].file_type = EXT4_FT_DIR;
 192                         dirs++;
 193                 } else if (S_ISCHR(stat.st_mode)) {
 194                         dentries[i].file_type = EXT4_FT_CHRDEV;
 195                 } else if (S_ISBLK(stat.st_mode)) {
 196                         dentries[i].file_type = EXT4_FT_BLKDEV;
 197                 } else if (S_ISFIFO(stat.st_mode)) {
 198                         dentries[i].file_type = EXT4_FT_FIFO;
 199                 } else if (S_ISSOCK(stat.st_mode)) {
 200                         dentries[i].file_type = EXT4_FT_SOCK;
 201                 } else if (S_ISLNK(stat.st_mode)) {
 202                         dentries[i].file_type = EXT4_FT_SYMLINK;
 203                         dentries[i].link = calloc(info.block_size, 1);
 204                         readlink(dentries[i].full_path, dentries[i].link, info.block_size - 1);
 205                 } else {
 206                         error("unknown file type on %s", dentries[i].path);
 207                         i--;
 208                         entries--;
 209                 }
 210         }
 211         free(namelist);
 212
 213         if (needs_lost_and_found) {
 214                 /* insert a lost+found directory at the beginning of the dentries */
 215                 struct dentry *tmp = calloc(entries + 1, sizeof(struct dentry));
 216                 memset(tmp, 0, sizeof(struct dentry));
 217                 memcpy(tmp + 1, dentries, entries * sizeof(struct dentry));
 218                 dentries = tmp;
 219
 220                 dentries[0].filename = strdup("lost+found");
 221                 asprintf(&dentries[0].path, "%s/lost+found", dir_path);
 222                 dentries[0].full_path = NULL;
 223                 dentries[0].size = 0;
 224                 dentries[0].mode = S_IRWXU;
 225                 dentries[0].file_type = EXT4_FT_DIR;
 226                 dentries[0].uid = 0;
 227                 dentries[0].gid = 0;
 228                 if (sehnd) {
 229                         char *sepath = NULL;
 230                         asprintf(&sepath, "/%s", dentries[0].path);
 231                         if (selabel_lookup(sehnd, &dentries[0].secon, sepath, dentries[0].mode) < 0)
 232                                 error("cannot lookup security context for %s", dentries[0].path);
 233                         free(sepath);
 234                 }
 235                 entries++;
 236                 dirs++;
 237         }
 238
 239         inode = make_directory(dir_inode, entries, dentries, dirs);
 240
 241         for (i = 0; i < entries; i++) {
 242                 if (dentries[i].file_type == EXT4_FT_REG_FILE) {
 243                         entry_inode = make_file(dentries[i].full_path, dentries[i].size);
 244                 } else if (dentries[i].file_type == EXT4_FT_DIR) {
 245                         entry_inode = build_directory_structure(dentries[i].full_path,
 246                                         dentries[i].path, inode, fs_config_func, sehnd);
 247                 } else if (dentries[i].file_type == EXT4_FT_SYMLINK) {
 248                         entry_inode = make_link(dentries[i].full_path, dentries[i].link);
 249                 } else {
 250                         error("unknown file type on %s", dentries[i].path);
 251                         entry_inode = 0;
 252                 }
 253                 *dentries[i].inode = entry_inode;
 254
 255                 ret = inode_set_permissions(entry_inode, dentries[i].mode,
 256                         dentries[i].uid, dentries[i].gid,
 257                         dentries[i].mtime);
 258                 if (ret)
 259                         error("failed to set permissions on %s\n", dentries[i].path);
 260                 ret = inode_set_selinux(entry_inode, dentries[i].secon);
 261                 if (ret)
 262                         error("failed to set SELinux context on %s\n", dentries[i].path);
 263
 264                 free(dentries[i].path);
 265                 free(dentries[i].full_path);
 266                 free(dentries[i].link);
 267                 free((void *)dentries[i].filename);
 268                 free(dentries[i].secon);
 269         }
 270
 271         free(dentries);
 272         return inode;
 273 }
 274 #endif
 275
 276 static u32 compute_block_size()
 277 {
 278         return 4096;
 279 }
 280
 281 static u32 compute_journal_blocks()
 282 {
 283         u32 journal_blocks = DIV_ROUND_UP(info.len, info.block_size) / 64;
 284         if (journal_blocks < 1024)
 285                 journal_blocks = 1024;
 286         if (journal_blocks > 32768)
 287                 journal_blocks = 32768;
 288         return journal_blocks;
 289 }
 290
 291 static u32 compute_blocks_per_group()
 292 {
 293         return info.block_size * 8;
 294 }
 295
 296 static u32 compute_inodes()
 297 {
 298         return DIV_ROUND_UP(info.len, info.block_size) / 4;
 299 }
 300
 301 static u32 compute_inodes_per_group()
 302 {
 303         u32 blocks = DIV_ROUND_UP(info.len, info.block_size);
 304         u32 block_groups = DIV_ROUND_UP(blocks, info.blocks_per_group);
 305         u32 inodes = DIV_ROUND_UP(info.inodes, block_groups);
 306         inodes = ALIGN(inodes, (info.block_size / info.inode_size));
 307
 308         /* After properly rounding up the number of inodes/group,
 309          * make sure to update the total inodes field in the info struct.
 310          */
 311         info.inodes = inodes * block_groups;
 312
 313         return inodes;
 314 }
 315
 316 static u32 compute_bg_desc_reserve_blocks()
 317 {
 318         u32 blocks = DIV_ROUND_UP(info.len, info.block_size);
 319         u32 block_groups = DIV_ROUND_UP(blocks, info.blocks_per_group);
 320         u32 bg_desc_blocks = DIV_ROUND_UP(block_groups * sizeof(struct ext2_group_desc),
 321                         info.block_size);
 322
 323         u32 bg_desc_reserve_blocks =
 324                         DIV_ROUND_UP(block_groups * 1024 * sizeof(struct ext2_group_desc),
 325                                         info.block_size) - bg_desc_blocks;
 326
 327         if (bg_desc_reserve_blocks > info.block_size / sizeof(u32))
 328                 bg_desc_reserve_blocks = info.block_size / sizeof(u32);
 329
 330         return bg_desc_reserve_blocks;
 331 }
 332
 333 void reset_ext4fs_info() {
 334     // Reset all the global data structures used by make_ext4fs so it
 335     // can be called again.
 336     memset(&info, 0, sizeof(info));
 337     memset(&aux_info, 0, sizeof(aux_info));
 338
 339     if (info.sparse_file) {
 340         sparse_file_destroy(info.sparse_file);
 341         info.sparse_file = NULL;
 342     }
 343 }
 344
 345 int make_ext4fs(const char *filename, s64 len,
 346                 const char *mountpoint, struct selabel_handle *sehnd)
 347 {
 348         int fd;
 349         int status;
 350
 351         reset_ext4fs_info();
 352         info.len = len;
 353
 354         fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
 355         if (fd < 0) {
 356                 error_errno("open");
 357                 return EXIT_FAILURE;
 358         }
 359
 360         status = make_ext4fs_internal(fd, NULL, mountpoint, NULL, 0, 0, 0, 1, 0, sehnd);
 361         close(fd);
 362
 363         return status;
 364 }
 365
 366 int make_ext4fs_internal(int fd, const char *directory,
 367                          const char *mountpoint, fs_config_func_t fs_config_func, int gzip,
 368                          int sparse, int crc, int wipe, int init_itabs,
 369                          struct selabel_handle *sehnd)
 370 {
 371         u32 root_inode_num;
 372         u16 root_mode;
 373
 374         if (setjmp(setjmp_env))
 375                 return EXIT_FAILURE; /* Handle a call to longjmp() */
 376
 377         if (info.len <= 0)
 378                 info.len = get_file_size(fd);
 379
 380         if (info.len <= 0) {
 381                 fprintf(stderr, "Need size of filesystem\n");
 382                 return EXIT_FAILURE;
 383         }
 384
 385         if (info.block_size <= 0)
 386                 info.block_size = compute_block_size();
 387
 388         /* Round down the filesystem length to be a multiple of the block size */
 389         info.len &= ~((u64)info.block_size - 1);
 390
 391         if (info.journal_blocks == 0)
 392                 info.journal_blocks = compute_journal_blocks();
 393
 394         if (info.no_journal == 0)
 395                 info.feat_compat = EXT4_FEATURE_COMPAT_HAS_JOURNAL;
 396         else
 397                 info.journal_blocks = 0;
 398
 399         if (info.blocks_per_group <= 0)
 400                 info.blocks_per_group = compute_blocks_per_group();
 401
 402         if (info.inodes <= 0)
 403                 info.inodes = compute_inodes();
 404
 405         if (info.inode_size <= 0)
 406                 info.inode_size = 256;
 407
 408         if (info.label == NULL)
 409                 info.label = "";
 410
 411         info.inodes_per_group = compute_inodes_per_group();
 412
 413         info.feat_compat |=
 414                         EXT4_FEATURE_COMPAT_RESIZE_INODE;
 415
 416         info.feat_ro_compat |=
 417                         EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER |
 418                         EXT4_FEATURE_RO_COMPAT_LARGE_FILE;
 419
 420         info.feat_incompat |=
 421                         EXT4_FEATURE_INCOMPAT_EXTENTS |
 422                         EXT4_FEATURE_INCOMPAT_FILETYPE;
 423
 424
 425         info.bg_desc_reserve_blocks = compute_bg_desc_reserve_blocks();
 426
 427         printf("Creating filesystem with parameters:\n");
 428         printf("    Size: %llu\n", info.len);
 429         printf("    Block size: %d\n", info.block_size);
 430         printf("    Blocks per group: %d\n", info.blocks_per_group);
 431         printf("    Inodes per group: %d\n", info.inodes_per_group);
 432         printf("    Inode size: %d\n", info.inode_size);
 433         printf("    Journal blocks: %d\n", info.journal_blocks);
 434         printf("    Label: %s\n", info.label);
 435
 436         ext4_create_fs_aux_info();
 437
 438         printf("    Blocks: %llu\n", aux_info.len_blocks);
 439         printf("    Block groups: %d\n", aux_info.groups);
 440         printf("    Reserved block group size: %d\n", info.bg_desc_reserve_blocks);
 441
 442         info.sparse_file = sparse_file_new(info.block_size, info.len);
 443
 444         block_allocator_init();
 445
 446         ext4_fill_in_sb();
 447
 448         if (reserve_inodes(0, 10) == EXT4_ALLOCATE_FAILED)
 449                 error("failed to reserve first 10 inodes");
 450
 451         if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL)
 452                 ext4_create_journal_inode();
 453
 454         if (info.feat_compat & EXT4_FEATURE_COMPAT_RESIZE_INODE)
 455                 ext4_create_resize_inode();
 456
 457 #ifdef USE_MINGW
 458         // Windows needs only 'create an empty fs image' functionality
 459         assert(!directory);
 460         root_inode_num = build_default_directory_structure();
 461 #else
 462         if (directory)
 463                 root_inode_num = build_directory_structure(directory, mountpoint, 0,
 464                         fs_config_func, sehnd);
 465         else
 466                 root_inode_num = build_default_directory_structure();
 467 #endif
 468
 469         root_mode = S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH;
 470         inode_set_permissions(root_inode_num, root_mode, 0, 0, 0);
 471
 472 #ifndef USE_MINGW
 473         if (sehnd) {
 474                 char *sepath = NULL;
 475                 char *secontext = NULL;
 476
 477                 if (mountpoint[0] == '/')
 478                         sepath = strdup(mountpoint);
 479                 else
 480                         asprintf(&sepath, "/%s", mountpoint);
 481                 if (!sepath)
 482                         critical_error_errno("malloc");
 483                 if (selabel_lookup(sehnd, &secontext, sepath, S_IFDIR) < 0) {
 484                         error("cannot lookup security context for %s", sepath);
 485                 }
 486                 if (secontext) {
 487                         printf("Labeling %s as %s\n", sepath, secontext);
 488                         inode_set_selinux(root_inode_num, secontext);
 489                 }
 490                 free(sepath);
 491                 freecon(secontext);
 492         }
 493 #endif
 494
 495         ext4_update_free();
 496
 497         if (init_itabs)
 498                 init_unused_inode_tables();
 499
 500         ext4_queue_sb();
 501
 502         printf("Created filesystem with %d/%d inodes and %d/%d blocks\n",
 503                         aux_info.sb->s_inodes_count - aux_info.sb->s_free_inodes_count,
 504                         aux_info.sb->s_inodes_count,
 505                         aux_info.sb->s_blocks_count_lo - aux_info.sb->s_free_blocks_count_lo,
 506                         aux_info.sb->s_blocks_count_lo);
 507
 508         if (wipe)
 509                 wipe_block_device(fd, info.len);
 510
 511         write_ext4_image(fd, gzip, sparse, crc);
 512
 513         sparse_file_destroy(info.sparse_file);
 514         info.sparse_file = NULL;
 515
 516         return 0;
 517 }