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 #define _GNU_SOURCE
  18
  19 #include <dirent.h>
  20 #include <libgen.h>
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <unistd.h>
  25 #include <sys/stat.h>
  26 #include <sys/types.h>
  27
  28 #include "make_ext4fs.h"
  29 #include "output_file.h"
  30 #include "ext4_utils.h"
  31 #include "allocate.h"
  32 #include "contents.h"
  33 #include "uuid.h"
  34
  35 #ifdef ANDROID
  36 #include <private/android_filesystem_config.h>
  37 #endif
  38
  39 /* TODO: Not implemented:
  40    Allocating blocks in the same block group as the file inode
  41    Hash or binary tree directories
  42    Special files: sockets, devices, fifos
  43  */
  44
  45 static int filter_dot(const struct dirent *d)
  46 {
  47         return (strcmp(d->d_name, "..") && strcmp(d->d_name, "."));
  48 }
  49
  50 static u32 build_default_directory_structure()
  51 {
  52         u32 inode;
  53         u32 root_inode;
  54         struct dentry dentries = {
  55                         .filename = "lost+found",
  56                         .file_type = EXT4_FT_DIR,
  57                         .mode = S_IRWXU,
  58                         .uid = 0,
  59                         .gid = 0,
  60                         .mtime = 0,
  61         };
  62         root_inode = make_directory(0, 1, &dentries, 1);
  63         inode = make_directory(root_inode, 0, NULL, 0);
  64         *dentries.inode = inode;
  65
  66         return root_inode;
  67 }
  68
  69 /* Read a local directory and create the same tree in the generated filesystem.
  70    Calls itself recursively with each directory in the given directory */
  71 static u32 build_directory_structure(const char *full_path, const char *dir_path,
  72                 u32 dir_inode, int android)
  73 {
  74         int entries = 0;
  75         struct dentry *dentries;
  76         struct dirent **namelist;
  77         struct stat stat;
  78         int ret;
  79         int i;
  80         u32 inode;
  81         u32 entry_inode;
  82         u32 dirs = 0;
  83
  84         entries = scandir(full_path, &namelist, filter_dot, (void*)alphasort);
  85         if (entries < 0) {
  86                 error_errno("scandir");
  87                 return EXT4_ALLOCATE_FAILED;
  88         }
  89
  90         dentries = calloc(entries, sizeof(struct dentry));
  91         if (dentries == NULL)
  92                 critical_error_errno("malloc");
  93
  94         for (i = 0; i < entries; i++) {
  95                 dentries[i].filename = strdup(namelist[i]->d_name);
  96                 if (dentries[i].filename == NULL)
  97                         critical_error_errno("strdup");
  98
  99                 asprintf(&dentries[i].path, "%s/%s", dir_path, namelist[i]->d_name);
 100                 asprintf(&dentries[i].full_path, "%s/%s", full_path, namelist[i]->d_name);
 101
 102                 free(namelist[i]);
 103
 104                 ret = lstat(dentries[i].full_path, &stat);
 105                 if (ret < 0) {
 106                         error_errno("lstat");
 107                         i--;
 108                         entries--;
 109                         continue;
 110                 }
 111
 112                 dentries[i].size = stat.st_size;
 113                 dentries[i].mode = stat.st_mode & (S_ISUID|S_ISGID|S_ISVTX|S_IRWXU|S_IRWXG|S_IRWXO);
 114                 dentries[i].mtime = stat.st_mtime;
 115                 if (android) {
 116 #ifdef ANDROID
 117                         unsigned int mode = 0;
 118                         unsigned int uid = 0;
 119                         unsigned int gid = 0;
 120                         int dir = S_ISDIR(stat.st_mode);
 121                         fs_config(dentries[i].path, dir, &uid, &gid, &mode);
 122                         dentries[i].mode = mode;
 123                         dentries[i].uid = uid;
 124                         dentries[i].gid = gid;
 125 #else
 126                         error("can't set android permissions - built without android support");
 127 #endif
 128                 }
 129
 130                 if (S_ISREG(stat.st_mode)) {
 131                         dentries[i].file_type = EXT4_FT_REG_FILE;
 132                 } else if (S_ISDIR(stat.st_mode)) {
 133                         dentries[i].file_type = EXT4_FT_DIR;
 134                         dirs++;
 135                 } else if (S_ISCHR(stat.st_mode)) {
 136                         dentries[i].file_type = EXT4_FT_CHRDEV;
 137                 } else if (S_ISBLK(stat.st_mode)) {
 138                         dentries[i].file_type = EXT4_FT_BLKDEV;
 139                 } else if (S_ISFIFO(stat.st_mode)) {
 140                         dentries[i].file_type = EXT4_FT_FIFO;
 141                 } else if (S_ISSOCK(stat.st_mode)) {
 142                         dentries[i].file_type = EXT4_FT_SOCK;
 143                 } else if (S_ISLNK(stat.st_mode)) {
 144                         dentries[i].file_type = EXT4_FT_SYMLINK;
 145                         dentries[i].link = calloc(info.block_size, 1);
 146                         readlink(dentries[i].full_path, dentries[i].link, info.block_size - 1);
 147                 } else {
 148                         error("unknown file type on %s", dentries[i].path);
 149                         i--;
 150                         entries--;
 151                 }
 152         }
 153         free(namelist);
 154
 155         inode = make_directory(dir_inode, entries, dentries, dirs);
 156
 157         for (i = 0; i < entries; i++) {
 158                 if (dentries[i].file_type == EXT4_FT_REG_FILE) {
 159                         entry_inode = make_file(dentries[i].full_path, dentries[i].size);
 160                 } else if (dentries[i].file_type == EXT4_FT_DIR) {
 161                         entry_inode = build_directory_structure(dentries[i].full_path,
 162                                         dentries[i].path, inode, android);
 163                 } else if (dentries[i].file_type == EXT4_FT_SYMLINK) {
 164                         entry_inode = make_link(dentries[i].full_path, dentries[i].link);
 165                 } else {
 166                         error("unknown file type on %s", dentries[i].path);
 167                         entry_inode = 0;
 168                 }
 169                 *dentries[i].inode = entry_inode;
 170
 171                 ret = inode_set_permissions(entry_inode, dentries[i].mode,
 172                         dentries[i].uid, dentries[i].gid,
 173                         dentries[i].mtime);
 174                 if (ret)
 175                         error("failed to set permissions on %s\n", dentries[i].path);
 176
 177                 free(dentries[i].path);
 178                 free(dentries[i].full_path);
 179                 free(dentries[i].link);
 180                 free((void *)dentries[i].filename);
 181         }
 182
 183         free(dentries);
 184         return inode;
 185 }
 186
 187 static u32 compute_block_size()
 188 {
 189         return 4096;
 190 }
 191
 192 static u32 compute_journal_blocks()
 193 {
 194         u32 journal_blocks = DIV_ROUND_UP(info.len, info.block_size) / 64;
 195         if (journal_blocks < 1024)
 196                 journal_blocks = 1024;
 197         if (journal_blocks > 32768)
 198                 journal_blocks = 32768;
 199         return journal_blocks;
 200 }
 201
 202 static u32 compute_blocks_per_group()
 203 {
 204         return info.block_size * 8;
 205 }
 206
 207 static u32 compute_inodes()
 208 {
 209         return DIV_ROUND_UP(info.len, info.block_size) / 4;
 210 }
 211
 212 static u32 compute_inodes_per_group()
 213 {
 214         u32 blocks = DIV_ROUND_UP(info.len, info.block_size);
 215         u32 block_groups = DIV_ROUND_UP(blocks, info.blocks_per_group);
 216         return DIV_ROUND_UP(info.inodes, block_groups);
 217 }
 218
 219 void reset_ext4fs_info() {
 220     // Reset all the global data structures used by make_ext4fs so it
 221     // can be called again.
 222     memset(&info, 0, sizeof(info));
 223     memset(&aux_info, 0, sizeof(aux_info));
 224     free_data_blocks();
 225 }
 226
 227 int make_ext4fs(const char *filename, const char *directory,
 228                 char *mountpoint, int android, int gzip)
 229 {
 230         u32 root_inode_num;
 231         u16 root_mode;
 232
 233         if (info.len == 0)
 234                 info.len = get_file_size(filename);
 235
 236         if (info.len <= 0) {
 237                 fprintf(stderr, "Need size of filesystem\n");
 238                 return EXIT_FAILURE;
 239         }
 240
 241         if (info.block_size <= 0)
 242                 info.block_size = compute_block_size();
 243
 244         if (info.journal_blocks == 0)
 245                 info.journal_blocks = compute_journal_blocks();
 246
 247         if (info.no_journal == 0)
 248                 info.feat_compat = EXT4_FEATURE_COMPAT_HAS_JOURNAL;
 249         else
 250                 info.journal_blocks = 0;
 251
 252         if (info.blocks_per_group <= 0)
 253                 info.blocks_per_group = compute_blocks_per_group();
 254
 255         if (info.inodes <= 0)
 256                 info.inodes = compute_inodes();
 257
 258         if (info.inode_size <= 0)
 259                 info.inode_size = 256;
 260
 261         if (info.label == NULL)
 262                 info.label = "";
 263
 264         info.inodes_per_group = compute_inodes_per_group();
 265
 266         info.feat_compat |=
 267                         EXT4_FEATURE_COMPAT_RESIZE_INODE;
 268
 269         info.feat_ro_compat |=
 270                         EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER |
 271                         EXT4_FEATURE_RO_COMPAT_LARGE_FILE;
 272
 273         info.feat_incompat |=
 274                         EXT4_FEATURE_INCOMPAT_EXTENTS |
 275                         EXT4_FEATURE_INCOMPAT_FILETYPE;
 276
 277
 278         printf("Creating filesystem with parameters:\n");
 279         printf("    Size: %llu\n", info.len);
 280         printf("    Block size: %d\n", info.block_size);
 281         printf("    Blocks per group: %d\n", info.blocks_per_group);
 282         printf("    Inodes per group: %d\n", info.inodes_per_group);
 283         printf("    Inode size: %d\n", info.inode_size);
 284         printf("    Journal blocks: %d\n", info.journal_blocks);
 285         printf("    Label: %s\n", info.label);
 286
 287         ext4_create_fs_aux_info();
 288
 289         printf("    Blocks: %llu\n", aux_info.len_blocks);
 290         printf("    Block groups: %d\n", aux_info.groups);
 291         printf("    Reserved block group size: %d\n", aux_info.bg_desc_reserve_blocks);
 292
 293         block_allocator_init();
 294
 295         ext4_fill_in_sb();
 296
 297         if (reserve_inodes(0, 10) == EXT4_ALLOCATE_FAILED)
 298                 error("failed to reserve first 10 inodes");
 299
 300         if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL)
 301                 ext4_create_journal_inode();
 302
 303         if (info.feat_compat & EXT4_FEATURE_COMPAT_RESIZE_INODE)
 304                 ext4_create_resize_inode();
 305
 306         if (directory)
 307                 root_inode_num = build_directory_structure(directory, mountpoint, 0, android);
 308         else
 309                 root_inode_num = build_default_directory_structure();
 310
 311         root_mode = S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH;
 312         inode_set_permissions(root_inode_num, root_mode, 0, 0, 0);
 313
 314         ext4_update_free();
 315
 316         printf("Created filesystem with %d/%d inodes and %d/%d blocks\n",
 317                         aux_info.sb->s_inodes_count - aux_info.sb->s_free_inodes_count,
 318                         aux_info.sb->s_inodes_count,
 319                         aux_info.sb->s_blocks_count_lo - aux_info.sb->s_free_blocks_count_lo,
 320                         aux_info.sb->s_blocks_count_lo);
 321
 322         write_ext4_image(filename, gzip);
 323
 324         return 0;
 325 }