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;
 108         struct stat stat;
 109         int ret;
 110         int i;
 111         u32 inode;
 112         u32 entry_inode;
 113         u32 dirs = 0;
 114
 115         entries = scandir(full_path, &namelist, filter_dot, (void*)alphasort);
 116         if (entries < 0) {
 117                 error_errno("scandir");
 118                 return EXT4_ALLOCATE_FAILED;
 119         }
 120
 121         dentries = calloc(entries, sizeof(struct dentry));
 122         if (dentries == NULL)
 123                 critical_error_errno("malloc");
 124
 125         for (i = 0; i < entries; i++) {
 126                 dentries[i].filename = strdup(namelist[i]->d_name);
 127                 if (dentries[i].filename == NULL)
 128                         critical_error_errno("strdup");
 129
 130                 asprintf(&dentries[i].path, "%s/%s", dir_path, namelist[i]->d_name);
 131                 asprintf(&dentries[i].full_path, "%s/%s", full_path, namelist[i]->d_name);
 132
 133                 free(namelist[i]);
 134
 135                 ret = lstat(dentries[i].full_path, &stat);
 136                 if (ret < 0) {
 137                         error_errno("lstat");
 138                         i--;
 139                         entries--;
 140                         continue;
 141                 }
 142
 143                 dentries[i].size = stat.st_size;
 144                 dentries[i].mode = stat.st_mode & (S_ISUID|S_ISGID|S_ISVTX|S_IRWXU|S_IRWXG|S_IRWXO);
 145                 dentries[i].mtime = stat.st_mtime;
 146                 if (fs_config_func != NULL) {
 147 #ifdef ANDROID
 148                         unsigned int mode = 0;
 149                         unsigned int uid = 0;
 150                         unsigned int gid = 0;
 151                         int dir = S_ISDIR(stat.st_mode);
 152                         fs_config_func(dentries[i].path, dir, &uid, &gid, &mode);
 153                         dentries[i].mode = mode;
 154                         dentries[i].uid = uid;
 155                         dentries[i].gid = gid;
 156 #else
 157                         error("can't set android permissions - built without android support");
 158 #endif
 159                 }
 160 #ifndef USE_MINGW
 161                 if (sehnd) {
 162                         char *sepath = NULL;
 163                         asprintf(&sepath, "/%s", dentries[i].path);
 164                         if (selabel_lookup(sehnd, &dentries[i].secon, sepath, stat.st_mode) < 0) {
 165                                 error("cannot lookup security context for %s", sepath);
 166                         }
 167 #if 0
 168                         // TODO make this a debug flag
 169                         if (dentries[i].secon)
 170                                 printf("Labeling %s as %s\n", sepath, dentries[i].secon);
 171 #endif
 172                         free(sepath);
 173                 }
 174 #endif
 175
 176                 if (S_ISREG(stat.st_mode)) {
 177                         dentries[i].file_type = EXT4_FT_REG_FILE;
 178                 } else if (S_ISDIR(stat.st_mode)) {
 179                         dentries[i].file_type = EXT4_FT_DIR;
 180                         dirs++;
 181                 } else if (S_ISCHR(stat.st_mode)) {
 182                         dentries[i].file_type = EXT4_FT_CHRDEV;
 183                 } else if (S_ISBLK(stat.st_mode)) {
 184                         dentries[i].file_type = EXT4_FT_BLKDEV;
 185                 } else if (S_ISFIFO(stat.st_mode)) {
 186                         dentries[i].file_type = EXT4_FT_FIFO;
 187                 } else if (S_ISSOCK(stat.st_mode)) {
 188                         dentries[i].file_type = EXT4_FT_SOCK;
 189                 } else if (S_ISLNK(stat.st_mode)) {
 190                         dentries[i].file_type = EXT4_FT_SYMLINK;
 191                         dentries[i].link = calloc(info.block_size, 1);
 192                         readlink(dentries[i].full_path, dentries[i].link, info.block_size - 1);
 193                 } else {
 194                         error("unknown file type on %s", dentries[i].path);
 195                         i--;
 196                         entries--;
 197                 }
 198         }
 199         free(namelist);
 200
 201         inode = make_directory(dir_inode, entries, dentries, dirs);
 202
 203         for (i = 0; i < entries; i++) {
 204                 if (dentries[i].file_type == EXT4_FT_REG_FILE) {
 205                         entry_inode = make_file(dentries[i].full_path, dentries[i].size);
 206                 } else if (dentries[i].file_type == EXT4_FT_DIR) {
 207                         entry_inode = build_directory_structure(dentries[i].full_path,
 208                                         dentries[i].path, inode, fs_config_func, sehnd);
 209                 } else if (dentries[i].file_type == EXT4_FT_SYMLINK) {
 210                         entry_inode = make_link(dentries[i].full_path, dentries[i].link);
 211                 } else {
 212                         error("unknown file type on %s", dentries[i].path);
 213                         entry_inode = 0;
 214                 }
 215                 *dentries[i].inode = entry_inode;
 216
 217                 ret = inode_set_permissions(entry_inode, dentries[i].mode,
 218                         dentries[i].uid, dentries[i].gid,
 219                         dentries[i].mtime);
 220                 if (ret)
 221                         error("failed to set permissions on %s\n", dentries[i].path);
 222                 ret = inode_set_selinux(entry_inode, dentries[i].secon);
 223                 if (ret)
 224                         error("failed to set SELinux context on %s\n", dentries[i].path);
 225
 226                 free(dentries[i].path);
 227                 free(dentries[i].full_path);
 228                 free(dentries[i].link);
 229                 free((void *)dentries[i].filename);
 230                 free(dentries[i].secon);
 231         }
 232
 233         free(dentries);
 234         return inode;
 235 }
 236 #endif
 237
 238 static u32 compute_block_size()
 239 {
 240         return 4096;
 241 }
 242
 243 static u32 compute_journal_blocks()
 244 {
 245         u32 journal_blocks = DIV_ROUND_UP(info.len, info.block_size) / 64;
 246         if (journal_blocks < 1024)
 247                 journal_blocks = 1024;
 248         if (journal_blocks > 32768)
 249                 journal_blocks = 32768;
 250         return journal_blocks;
 251 }
 252
 253 static u32 compute_blocks_per_group()
 254 {
 255         return info.block_size * 8;
 256 }
 257
 258 static u32 compute_inodes()
 259 {
 260         return DIV_ROUND_UP(info.len, info.block_size) / 4;
 261 }
 262
 263 static u32 compute_inodes_per_group()
 264 {
 265         u32 blocks = DIV_ROUND_UP(info.len, info.block_size);
 266         u32 block_groups = DIV_ROUND_UP(blocks, info.blocks_per_group);
 267         u32 inodes = DIV_ROUND_UP(info.inodes, block_groups);
 268         inodes = ALIGN(inodes, (info.block_size / info.inode_size));
 269
 270         /* After properly rounding up the number of inodes/group,
 271          * make sure to update the total inodes field in the info struct.
 272          */
 273         info.inodes = inodes * block_groups;
 274
 275         return inodes;
 276 }
 277
 278 static u32 compute_bg_desc_reserve_blocks()
 279 {
 280         u32 blocks = DIV_ROUND_UP(info.len, info.block_size);
 281         u32 block_groups = DIV_ROUND_UP(blocks, info.blocks_per_group);
 282         u32 bg_desc_blocks = DIV_ROUND_UP(block_groups * sizeof(struct ext2_group_desc),
 283                         info.block_size);
 284
 285         u32 bg_desc_reserve_blocks =
 286                         DIV_ROUND_UP(block_groups * 1024 * sizeof(struct ext2_group_desc),
 287                                         info.block_size) - bg_desc_blocks;
 288
 289         if (bg_desc_reserve_blocks > info.block_size / sizeof(u32))
 290                 bg_desc_reserve_blocks = info.block_size / sizeof(u32);
 291
 292         return bg_desc_reserve_blocks;
 293 }
 294
 295 void reset_ext4fs_info() {
 296     // Reset all the global data structures used by make_ext4fs so it
 297     // can be called again.
 298     memset(&info, 0, sizeof(info));
 299     memset(&aux_info, 0, sizeof(aux_info));
 300
 301     if (info.sparse_file) {
 302         sparse_file_destroy(info.sparse_file);
 303         info.sparse_file = NULL;
 304     }
 305 }
 306
 307 int make_ext4fs(const char *filename, s64 len,
 308                 const char *mountpoint, struct selabel_handle *sehnd)
 309 {
 310         int fd;
 311         int status;
 312
 313         reset_ext4fs_info();
 314         info.len = len;
 315
 316         fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
 317         if (fd < 0) {
 318                 error_errno("open");
 319                 return EXIT_FAILURE;
 320         }
 321
 322         status = make_ext4fs_internal(fd, NULL, mountpoint, NULL, 0, 0, 0, 1, 0, sehnd);
 323         close(fd);
 324
 325         return status;
 326 }
 327
 328 int make_ext4fs_internal(int fd, const char *directory,
 329                          const char *mountpoint, fs_config_func_t fs_config_func, int gzip,
 330                          int sparse, int crc, int wipe, int init_itabs,
 331                          struct selabel_handle *sehnd)
 332 {
 333         u32 root_inode_num;
 334         u16 root_mode;
 335
 336         if (setjmp(setjmp_env))
 337                 return EXIT_FAILURE; /* Handle a call to longjmp() */
 338
 339         if (info.len <= 0)
 340                 info.len = get_file_size(fd);
 341
 342         if (info.len <= 0) {
 343                 fprintf(stderr, "Need size of filesystem\n");
 344                 return EXIT_FAILURE;
 345         }
 346
 347         if (info.block_size <= 0)
 348                 info.block_size = compute_block_size();
 349
 350         /* Round down the filesystem length to be a multiple of the block size */
 351         info.len &= ~((u64)info.block_size - 1);
 352
 353         if (info.journal_blocks == 0)
 354                 info.journal_blocks = compute_journal_blocks();
 355
 356         if (info.no_journal == 0)
 357                 info.feat_compat = EXT4_FEATURE_COMPAT_HAS_JOURNAL;
 358         else
 359                 info.journal_blocks = 0;
 360
 361         if (info.blocks_per_group <= 0)
 362                 info.blocks_per_group = compute_blocks_per_group();
 363
 364         if (info.inodes <= 0)
 365                 info.inodes = compute_inodes();
 366
 367         if (info.inode_size <= 0)
 368                 info.inode_size = 256;
 369
 370         if (info.label == NULL)
 371                 info.label = "";
 372
 373         info.inodes_per_group = compute_inodes_per_group();
 374
 375         info.feat_compat |=
 376                         EXT4_FEATURE_COMPAT_RESIZE_INODE;
 377
 378         info.feat_ro_compat |=
 379                         EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER |
 380                         EXT4_FEATURE_RO_COMPAT_LARGE_FILE;
 381
 382         info.feat_incompat |=
 383                         EXT4_FEATURE_INCOMPAT_EXTENTS |
 384                         EXT4_FEATURE_INCOMPAT_FILETYPE;
 385
 386
 387         info.bg_desc_reserve_blocks = compute_bg_desc_reserve_blocks();
 388
 389         printf("Creating filesystem with parameters:\n");
 390         printf("    Size: %llu\n", info.len);
 391         printf("    Block size: %d\n", info.block_size);
 392         printf("    Blocks per group: %d\n", info.blocks_per_group);
 393         printf("    Inodes per group: %d\n", info.inodes_per_group);
 394         printf("    Inode size: %d\n", info.inode_size);
 395         printf("    Journal blocks: %d\n", info.journal_blocks);
 396         printf("    Label: %s\n", info.label);
 397
 398         ext4_create_fs_aux_info();
 399
 400         printf("    Blocks: %llu\n", aux_info.len_blocks);
 401         printf("    Block groups: %d\n", aux_info.groups);
 402         printf("    Reserved block group size: %d\n", info.bg_desc_reserve_blocks);
 403
 404         info.sparse_file = sparse_file_new(info.block_size, info.len);
 405
 406         block_allocator_init();
 407
 408         ext4_fill_in_sb();
 409
 410         if (reserve_inodes(0, 10) == EXT4_ALLOCATE_FAILED)
 411                 error("failed to reserve first 10 inodes");
 412
 413         if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL)
 414                 ext4_create_journal_inode();
 415
 416         if (info.feat_compat & EXT4_FEATURE_COMPAT_RESIZE_INODE)
 417                 ext4_create_resize_inode();
 418
 419 #ifdef USE_MINGW
 420         // Windows needs only 'create an empty fs image' functionality
 421         assert(!directory);
 422         root_inode_num = build_default_directory_structure();
 423 #else
 424         if (directory)
 425                 root_inode_num = build_directory_structure(directory, mountpoint, 0,
 426                         fs_config_func, sehnd);
 427         else
 428                 root_inode_num = build_default_directory_structure();
 429 #endif
 430
 431         root_mode = S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH;
 432         inode_set_permissions(root_inode_num, root_mode, 0, 0, 0);
 433
 434 #ifndef USE_MINGW
 435         if (sehnd) {
 436                 char *sepath = NULL;
 437                 char *secontext = NULL;
 438
 439                 if (mountpoint[0] == '/')
 440                         sepath = strdup(mountpoint);
 441                 else
 442                         asprintf(&sepath, "/%s", mountpoint);
 443                 if (!sepath)
 444                         critical_error_errno("malloc");
 445                 if (selabel_lookup(sehnd, &secontext, sepath, S_IFDIR) < 0) {
 446                         error("cannot lookup security context for %s", sepath);
 447                 }
 448                 if (secontext) {
 449                         printf("Labeling %s as %s\n", sepath, secontext);
 450                         inode_set_selinux(root_inode_num, secontext);
 451                 }
 452                 free(sepath);
 453                 freecon(secontext);
 454         }
 455 #endif
 456
 457         ext4_update_free();
 458
 459         if (init_itabs)
 460                 init_unused_inode_tables();
 461
 462         ext4_queue_sb();
 463
 464         printf("Created filesystem with %d/%d inodes and %d/%d blocks\n",
 465                         aux_info.sb->s_inodes_count - aux_info.sb->s_free_inodes_count,
 466                         aux_info.sb->s_inodes_count,
 467                         aux_info.sb->s_blocks_count_lo - aux_info.sb->s_free_blocks_count_lo,
 468                         aux_info.sb->s_blocks_count_lo);
 469
 470         if (wipe)
 471                 wipe_block_device(fd, info.len);
 472
 473         write_ext4_image(fd, gzip, sparse, crc);
 474
 475         sparse_file_destroy(info.sparse_file);
 476         info.sparse_file = NULL;
 477
 478         return 0;
 479 }