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 "output_file.h"
  19 #include "ext4_utils.h"
  20 #include "allocate.h"
  21 #include "contents.h"
  22 #include "uuid.h"
  23 #include "backed_block.h"
  24
  25 #include <dirent.h>
  26 #include <libgen.h>
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <string.h>
  30 #include <unistd.h>
  31 #include <sys/stat.h>
  32 #include <sys/types.h>
  33
  34 #ifdef ANDROID
  35 #include <private/android_filesystem_config.h>
  36 #endif
  37
  38 /* TODO: Not implemented:
  39    Allocating blocks in the same block group as the file inode
  40    Hash or binary tree directories
  41    Special files: sockets, devices, fifos
  42  */
  43
  44 static int filter_dot(const struct dirent *d)
  45 {
  46         return (strcmp(d->d_name, "..") && strcmp(d->d_name, "."));
  47 }
  48
  49 static u32 build_default_directory_structure()
  50 {
  51         u32 inode;
  52         u32 root_inode;
  53         struct dentry dentries = {
  54                         .filename = "lost+found",
  55                         .file_type = EXT4_FT_DIR,
  56                         .mode = S_IRWXU,
  57                         .uid = 0,
  58                         .gid = 0,
  59                         .mtime = 0,
  60         };
  61         root_inode = make_directory(0, 1, &dentries, 1);
  62         inode = make_directory(root_inode, 0, NULL, 0);
  63         *dentries.inode = inode;
  64         inode_set_permissions(inode, dentries.mode,
  65                 dentries.uid, dentries.gid, dentries.mtime);
  66
  67         return root_inode;
  68 }
  69
  70 /* Read a local directory and create the same tree in the generated filesystem.
  71    Calls itself recursively with each directory in the given directory */
  72 static u32 build_directory_structure(const char *full_path, const char *dir_path,
  73                 u32 dir_inode, int android)
  74 {
  75         int entries = 0;
  76         struct dentry *dentries;
  77         struct dirent **namelist;
  78         struct stat stat;
  79         int ret;
  80         int i;
  81         u32 inode;
  82         u32 entry_inode;
  83         u32 dirs = 0;
  84
  85         entries = scandir(full_path, &namelist, filter_dot, (void*)alphasort);
  86         if (entries < 0) {
  87                 error_errno("scandir");
  88                 return EXT4_ALLOCATE_FAILED;
  89         }
  90
  91         dentries = calloc(entries, sizeof(struct dentry));
  92         if (dentries == NULL)
  93                 critical_error_errno("malloc");
  94
  95         for (i = 0; i < entries; i++) {
  96                 dentries[i].filename = strdup(namelist[i]->d_name);
  97                 if (dentries[i].filename == NULL)
  98                         critical_error_errno("strdup");
  99
 100                 asprintf(&dentries[i].path, "%s/%s", dir_path, namelist[i]->d_name);
 101                 asprintf(&dentries[i].full_path, "%s/%s", full_path, namelist[i]->d_name);
 102
 103                 free(namelist[i]);
 104
 105                 ret = lstat(dentries[i].full_path, &stat);
 106                 if (ret < 0) {
 107                         error_errno("lstat");
 108                         i--;
 109                         entries--;
 110                         continue;
 111                 }
 112
 113                 dentries[i].size = stat.st_size;
 114                 dentries[i].mode = stat.st_mode & (S_ISUID|S_ISGID|S_ISVTX|S_IRWXU|S_IRWXG|S_IRWXO);
 115                 dentries[i].mtime = stat.st_mtime;
 116                 if (android) {
 117 #ifdef ANDROID
 118                         unsigned int mode = 0;
 119                         unsigned int uid = 0;
 120                         unsigned int gid = 0;
 121                         int dir = S_ISDIR(stat.st_mode);
 122                         fs_config(dentries[i].path, dir, &uid, &gid, &mode);
 123                         dentries[i].mode = mode;
 124                         dentries[i].uid = uid;
 125                         dentries[i].gid = gid;
 126 #else
 127                         error("can't set android permissions - built without android support");
 128 #endif
 129                 }
 130
 131                 if (S_ISREG(stat.st_mode)) {
 132                         dentries[i].file_type = EXT4_FT_REG_FILE;
 133                 } else if (S_ISDIR(stat.st_mode)) {
 134                         dentries[i].file_type = EXT4_FT_DIR;
 135                         dirs++;
 136                 } else if (S_ISCHR(stat.st_mode)) {
 137                         dentries[i].file_type = EXT4_FT_CHRDEV;
 138                 } else if (S_ISBLK(stat.st_mode)) {
 139                         dentries[i].file_type = EXT4_FT_BLKDEV;
 140                 } else if (S_ISFIFO(stat.st_mode)) {
 141                         dentries[i].file_type = EXT4_FT_FIFO;
 142                 } else if (S_ISSOCK(stat.st_mode)) {
 143                         dentries[i].file_type = EXT4_FT_SOCK;
 144                 } else if (S_ISLNK(stat.st_mode)) {
 145                         dentries[i].file_type = EXT4_FT_SYMLINK;
 146                         dentries[i].link = calloc(info.block_size, 1);
 147                         readlink(dentries[i].full_path, dentries[i].link, info.block_size - 1);
 148                 } else {
 149                         error("unknown file type on %s", dentries[i].path);
 150                         i--;
 151                         entries--;
 152                 }
 153         }
 154         free(namelist);
 155
 156         inode = make_directory(dir_inode, entries, dentries, dirs);
 157
 158         for (i = 0; i < entries; i++) {
 159                 if (dentries[i].file_type == EXT4_FT_REG_FILE) {
 160                         entry_inode = make_file(dentries[i].full_path, dentries[i].size);
 161                 } else if (dentries[i].file_type == EXT4_FT_DIR) {
 162                         entry_inode = build_directory_structure(dentries[i].full_path,
 163                                         dentries[i].path, inode, android);
 164                 } else if (dentries[i].file_type == EXT4_FT_SYMLINK) {
 165                         entry_inode = make_link(dentries[i].full_path, dentries[i].link);
 166                 } else {
 167                         error("unknown file type on %s", dentries[i].path);
 168                         entry_inode = 0;
 169                 }
 170                 *dentries[i].inode = entry_inode;
 171
 172                 ret = inode_set_permissions(entry_inode, dentries[i].mode,
 173                         dentries[i].uid, dentries[i].gid,
 174                         dentries[i].mtime);
 175                 if (ret)
 176                         error("failed to set permissions on %s\n", dentries[i].path);
 177
 178                 free(dentries[i].path);
 179                 free(dentries[i].full_path);
 180                 free(dentries[i].link);
 181                 free((void *)dentries[i].filename);
 182         }
 183
 184         free(dentries);
 185         return inode;
 186 }
 187
 188 static u32 compute_block_size()
 189 {
 190         return 4096;
 191 }
 192
 193 static u32 compute_journal_blocks()
 194 {
 195         u32 journal_blocks = DIV_ROUND_UP(info.len, info.block_size) / 64;
 196         if (journal_blocks < 1024)
 197                 journal_blocks = 1024;
 198         if (journal_blocks > 32768)
 199                 journal_blocks = 32768;
 200         return journal_blocks;
 201 }
 202
 203 static u32 compute_blocks_per_group()
 204 {
 205         return info.block_size * 8;
 206 }
 207
 208 static u32 compute_inodes()
 209 {
 210         return DIV_ROUND_UP(info.len, info.block_size) / 4;
 211 }
 212
 213 static u32 compute_inodes_per_group()
 214 {
 215         u32 blocks = DIV_ROUND_UP(info.len, info.block_size);
 216         u32 block_groups = DIV_ROUND_UP(blocks, info.blocks_per_group);
 217         return DIV_ROUND_UP(info.inodes, block_groups);
 218 }
 219
 220 static u32 compute_bg_desc_reserve_blocks()
 221 {
 222         u32 blocks = DIV_ROUND_UP(info.len, info.block_size);
 223         u32 block_groups = DIV_ROUND_UP(blocks, info.blocks_per_group);
 224         u32 bg_desc_blocks = DIV_ROUND_UP(block_groups * sizeof(struct ext2_group_desc),
 225                         info.block_size);
 226
 227         u32 bg_desc_reserve_blocks =
 228                         DIV_ROUND_UP(block_groups * 1024 * sizeof(struct ext2_group_desc),
 229                                         info.block_size) - bg_desc_blocks;
 230
 231         if (bg_desc_reserve_blocks > info.block_size / sizeof(u32))
 232                 bg_desc_reserve_blocks = info.block_size / sizeof(u32);
 233
 234         return bg_desc_reserve_blocks;
 235 }
 236
 237 void reset_ext4fs_info() {
 238     // Reset all the global data structures used by make_ext4fs so it
 239     // can be called again.
 240     memset(&info, 0, sizeof(info));
 241     memset(&aux_info, 0, sizeof(aux_info));
 242     free_data_blocks();
 243 }
 244
 245 int make_ext4fs(const char *filename, s64 len)
 246 {
 247     reset_ext4fs_info();
 248     info.len = len;
 249     return make_ext4fs_internal(filename, NULL, NULL, 0, 0, 0, 0, 1);
 250 }
 251
 252 int make_ext4fs_internal(const char *filename, const char *directory,
 253                          char *mountpoint, int android, int gzip, int sparse,
 254                          int crc, int wipe)
 255 {
 256         u32 root_inode_num;
 257         u16 root_mode;
 258
 259         if (info.len <= 0)
 260                 info.len = get_file_size(filename);
 261
 262         if (info.len <= 0) {
 263                 fprintf(stderr, "Need size of filesystem\n");
 264                 return EXIT_FAILURE;
 265         }
 266
 267         if (info.block_size <= 0)
 268                 info.block_size = compute_block_size();
 269
 270         if (info.journal_blocks == 0)
 271                 info.journal_blocks = compute_journal_blocks();
 272
 273         if (info.no_journal == 0)
 274                 info.feat_compat = EXT4_FEATURE_COMPAT_HAS_JOURNAL;
 275         else
 276                 info.journal_blocks = 0;
 277
 278         if (info.blocks_per_group <= 0)
 279                 info.blocks_per_group = compute_blocks_per_group();
 280
 281         if (info.inodes <= 0)
 282                 info.inodes = compute_inodes();
 283
 284         if (info.inode_size <= 0)
 285                 info.inode_size = 256;
 286
 287         if (info.label == NULL)
 288                 info.label = "";
 289
 290         info.inodes_per_group = compute_inodes_per_group();
 291
 292         info.feat_compat |=
 293                         EXT4_FEATURE_COMPAT_RESIZE_INODE;
 294
 295         info.feat_ro_compat |=
 296                         EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER |
 297                         EXT4_FEATURE_RO_COMPAT_LARGE_FILE;
 298
 299         info.feat_incompat |=
 300                         EXT4_FEATURE_INCOMPAT_EXTENTS |
 301                         EXT4_FEATURE_INCOMPAT_FILETYPE;
 302
 303
 304         info.bg_desc_reserve_blocks = compute_bg_desc_reserve_blocks();
 305
 306         printf("Creating filesystem with parameters:\n");
 307         printf("    Size: %llu\n", info.len);
 308         printf("    Block size: %d\n", info.block_size);
 309         printf("    Blocks per group: %d\n", info.blocks_per_group);
 310         printf("    Inodes per group: %d\n", info.inodes_per_group);
 311         printf("    Inode size: %d\n", info.inode_size);
 312         printf("    Journal blocks: %d\n", info.journal_blocks);
 313         printf("    Label: %s\n", info.label);
 314
 315         ext4_create_fs_aux_info();
 316
 317         printf("    Blocks: %llu\n", aux_info.len_blocks);
 318         printf("    Block groups: %d\n", aux_info.groups);
 319         printf("    Reserved block group size: %d\n", info.bg_desc_reserve_blocks);
 320
 321         block_allocator_init();
 322
 323         ext4_fill_in_sb();
 324
 325         if (reserve_inodes(0, 10) == EXT4_ALLOCATE_FAILED)
 326                 error("failed to reserve first 10 inodes");
 327
 328         if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL)
 329                 ext4_create_journal_inode();
 330
 331         if (info.feat_compat & EXT4_FEATURE_COMPAT_RESIZE_INODE)
 332                 ext4_create_resize_inode();
 333
 334         if (directory)
 335                 root_inode_num = build_directory_structure(directory, mountpoint, 0, android);
 336         else
 337                 root_inode_num = build_default_directory_structure();
 338
 339         root_mode = S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH;
 340         inode_set_permissions(root_inode_num, root_mode, 0, 0, 0);
 341
 342         ext4_update_free();
 343
 344         ext4_queue_sb();
 345
 346         printf("Created filesystem with %d/%d inodes and %d/%d blocks\n",
 347                         aux_info.sb->s_inodes_count - aux_info.sb->s_free_inodes_count,
 348                         aux_info.sb->s_inodes_count,
 349                         aux_info.sb->s_blocks_count_lo - aux_info.sb->s_free_blocks_count_lo,
 350                         aux_info.sb->s_blocks_count_lo);
 351
 352         write_ext4_image(filename, gzip, sparse, crc, wipe);
 353
 354         return 0;
 355 }