make_ext4fs.c revision b4eca4b24af9c80ebb2a7fa2ba539a48096b7576
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 44static int filter_dot(const struct dirent *d) 45{ 46 return (strcmp(d->d_name, "..") && strcmp(d->d_name, ".")); 47} 48 49static 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 */ 72static u32 build_directory_structure(const char *full_path, const char *dir_path, 73 u32 dir_inode, int android, struct selabel_handle *sehnd) 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#ifdef HAVE_SELINUX 131 if (sehnd) { 132 char *sepath = NULL; 133 asprintf(&sepath, "/%s", dentries[i].path); 134 if (selabel_lookup(sehnd, &dentries[i].secon, sepath, stat.st_mode) < 0) { 135 error("cannot lookup security context for %s", sepath); 136 } 137 if (dentries[i].secon) 138 printf("Labeling %s as %s\n", sepath, dentries[i].secon); 139 free(sepath); 140 } 141#endif 142 143 if (S_ISREG(stat.st_mode)) { 144 dentries[i].file_type = EXT4_FT_REG_FILE; 145 } else if (S_ISDIR(stat.st_mode)) { 146 dentries[i].file_type = EXT4_FT_DIR; 147 dirs++; 148 } else if (S_ISCHR(stat.st_mode)) { 149 dentries[i].file_type = EXT4_FT_CHRDEV; 150 } else if (S_ISBLK(stat.st_mode)) { 151 dentries[i].file_type = EXT4_FT_BLKDEV; 152 } else if (S_ISFIFO(stat.st_mode)) { 153 dentries[i].file_type = EXT4_FT_FIFO; 154 } else if (S_ISSOCK(stat.st_mode)) { 155 dentries[i].file_type = EXT4_FT_SOCK; 156 } else if (S_ISLNK(stat.st_mode)) { 157 dentries[i].file_type = EXT4_FT_SYMLINK; 158 dentries[i].link = calloc(info.block_size, 1); 159 readlink(dentries[i].full_path, dentries[i].link, info.block_size - 1); 160 } else { 161 error("unknown file type on %s", dentries[i].path); 162 i--; 163 entries--; 164 } 165 } 166 free(namelist); 167 168 inode = make_directory(dir_inode, entries, dentries, dirs); 169 170 for (i = 0; i < entries; i++) { 171 if (dentries[i].file_type == EXT4_FT_REG_FILE) { 172 entry_inode = make_file(dentries[i].full_path, dentries[i].size); 173 } else if (dentries[i].file_type == EXT4_FT_DIR) { 174 entry_inode = build_directory_structure(dentries[i].full_path, 175 dentries[i].path, inode, android, sehnd); 176 } else if (dentries[i].file_type == EXT4_FT_SYMLINK) { 177 entry_inode = make_link(dentries[i].full_path, dentries[i].link); 178 } else { 179 error("unknown file type on %s", dentries[i].path); 180 entry_inode = 0; 181 } 182 *dentries[i].inode = entry_inode; 183 184 ret = inode_set_permissions(entry_inode, dentries[i].mode, 185 dentries[i].uid, dentries[i].gid, 186 dentries[i].mtime); 187 if (ret) 188 error("failed to set permissions on %s\n", dentries[i].path); 189 ret = inode_set_selinux(entry_inode, dentries[i].secon); 190 if (ret) 191 error("failed to set SELinux context on %s\n", dentries[i].path); 192 193 free(dentries[i].path); 194 free(dentries[i].full_path); 195 free(dentries[i].link); 196 free((void *)dentries[i].filename); 197 free(dentries[i].secon); 198 } 199 200 free(dentries); 201 return inode; 202} 203 204static u32 compute_block_size() 205{ 206 return 4096; 207} 208 209static u32 compute_journal_blocks() 210{ 211 u32 journal_blocks = DIV_ROUND_UP(info.len, info.block_size) / 64; 212 if (journal_blocks < 1024) 213 journal_blocks = 1024; 214 if (journal_blocks > 32768) 215 journal_blocks = 32768; 216 return journal_blocks; 217} 218 219static u32 compute_blocks_per_group() 220{ 221 return info.block_size * 8; 222} 223 224static u32 compute_inodes() 225{ 226 return DIV_ROUND_UP(info.len, info.block_size) / 4; 227} 228 229static u32 compute_inodes_per_group() 230{ 231 u32 blocks = DIV_ROUND_UP(info.len, info.block_size); 232 u32 block_groups = DIV_ROUND_UP(blocks, info.blocks_per_group); 233 u32 inodes = DIV_ROUND_UP(info.inodes, block_groups); 234 inodes = ALIGN(inodes, (info.block_size / info.inode_size)); 235 236 /* After properly rounding up the number of inodes/group, 237 * make sure to update the total inodes field in the info struct. 238 */ 239 info.inodes = inodes * block_groups; 240 241 return inodes; 242} 243 244static u32 compute_bg_desc_reserve_blocks() 245{ 246 u32 blocks = DIV_ROUND_UP(info.len, info.block_size); 247 u32 block_groups = DIV_ROUND_UP(blocks, info.blocks_per_group); 248 u32 bg_desc_blocks = DIV_ROUND_UP(block_groups * sizeof(struct ext2_group_desc), 249 info.block_size); 250 251 u32 bg_desc_reserve_blocks = 252 DIV_ROUND_UP(block_groups * 1024 * sizeof(struct ext2_group_desc), 253 info.block_size) - bg_desc_blocks; 254 255 if (bg_desc_reserve_blocks > info.block_size / sizeof(u32)) 256 bg_desc_reserve_blocks = info.block_size / sizeof(u32); 257 258 return bg_desc_reserve_blocks; 259} 260 261void reset_ext4fs_info() { 262 // Reset all the global data structures used by make_ext4fs so it 263 // can be called again. 264 memset(&info, 0, sizeof(info)); 265 memset(&aux_info, 0, sizeof(aux_info)); 266 free_data_blocks(); 267} 268 269int make_ext4fs(const char *filename, s64 len) 270{ 271 reset_ext4fs_info(); 272 info.len = len; 273 return make_ext4fs_internal(filename, NULL, NULL, 0, 0, 0, 0, 1, 0, 0); 274} 275 276int make_ext4fs_internal(const char *filename, const char *directory, 277 char *mountpoint, int android, int gzip, int sparse, 278 int crc, int wipe, int init_itabs, 279 struct selabel_handle *sehnd) 280{ 281 u32 root_inode_num; 282 u16 root_mode; 283 284 if (setjmp(setjmp_env)) 285 return EXIT_FAILURE; /* Handle a call to longjmp() */ 286 287 if (info.len <= 0) 288 info.len = get_file_size(filename); 289 290 if (info.len <= 0) { 291 fprintf(stderr, "Need size of filesystem\n"); 292 return EXIT_FAILURE; 293 } 294 295 if (info.block_size <= 0) 296 info.block_size = compute_block_size(); 297 298 /* Round down the filesystem length to be a multiple of the block size */ 299 info.len &= ~((u64)info.block_size - 1); 300 301 if (info.journal_blocks == 0) 302 info.journal_blocks = compute_journal_blocks(); 303 304 if (info.no_journal == 0) 305 info.feat_compat = EXT4_FEATURE_COMPAT_HAS_JOURNAL; 306 else 307 info.journal_blocks = 0; 308 309 if (info.blocks_per_group <= 0) 310 info.blocks_per_group = compute_blocks_per_group(); 311 312 if (info.inodes <= 0) 313 info.inodes = compute_inodes(); 314 315 if (info.inode_size <= 0) 316 info.inode_size = 256; 317 318 if (info.label == NULL) 319 info.label = ""; 320 321 info.inodes_per_group = compute_inodes_per_group(); 322 323 info.feat_compat |= 324 EXT4_FEATURE_COMPAT_RESIZE_INODE; 325 326 info.feat_ro_compat |= 327 EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER | 328 EXT4_FEATURE_RO_COMPAT_LARGE_FILE; 329 330 info.feat_incompat |= 331 EXT4_FEATURE_INCOMPAT_EXTENTS | 332 EXT4_FEATURE_INCOMPAT_FILETYPE; 333 334 335 info.bg_desc_reserve_blocks = compute_bg_desc_reserve_blocks(); 336 337 printf("Creating filesystem with parameters:\n"); 338 printf(" Size: %llu\n", info.len); 339 printf(" Block size: %d\n", info.block_size); 340 printf(" Blocks per group: %d\n", info.blocks_per_group); 341 printf(" Inodes per group: %d\n", info.inodes_per_group); 342 printf(" Inode size: %d\n", info.inode_size); 343 printf(" Journal blocks: %d\n", info.journal_blocks); 344 printf(" Label: %s\n", info.label); 345 346 ext4_create_fs_aux_info(); 347 348 printf(" Blocks: %llu\n", aux_info.len_blocks); 349 printf(" Block groups: %d\n", aux_info.groups); 350 printf(" Reserved block group size: %d\n", info.bg_desc_reserve_blocks); 351 352 block_allocator_init(); 353 354 ext4_fill_in_sb(); 355 356 if (reserve_inodes(0, 10) == EXT4_ALLOCATE_FAILED) 357 error("failed to reserve first 10 inodes"); 358 359 if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL) 360 ext4_create_journal_inode(); 361 362 if (info.feat_compat & EXT4_FEATURE_COMPAT_RESIZE_INODE) 363 ext4_create_resize_inode(); 364 365 if (directory) 366 root_inode_num = build_directory_structure(directory, mountpoint, 0, android, sehnd); 367 else 368 root_inode_num = build_default_directory_structure(); 369 370 root_mode = S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH; 371 inode_set_permissions(root_inode_num, root_mode, 0, 0, 0); 372 373#ifdef HAVE_SELINUX 374 if (sehnd) { 375 char *sepath = NULL; 376 char *secontext = NULL; 377 asprintf(&sepath, "/%s", mountpoint); 378 if (selabel_lookup(sehnd, &secontext, sepath, S_IFDIR) < 0) { 379 error("cannot lookup security context for %s", sepath); 380 } 381 if (secontext) { 382 printf("Labeling %s as %s\n", sepath, secontext); 383 inode_set_selinux(root_inode_num, secontext); 384 } 385 free(sepath); 386 freecon(secontext); 387 } 388#endif 389 390 ext4_update_free(); 391 392 if (init_itabs) 393 init_unused_inode_tables(); 394 395 ext4_queue_sb(); 396 397 printf("Created filesystem with %d/%d inodes and %d/%d blocks\n", 398 aux_info.sb->s_inodes_count - aux_info.sb->s_free_inodes_count, 399 aux_info.sb->s_inodes_count, 400 aux_info.sb->s_blocks_count_lo - aux_info.sb->s_free_blocks_count_lo, 401 aux_info.sb->s_blocks_count_lo); 402 403 write_ext4_image(filename, gzip, sparse, crc, wipe); 404 405 return 0; 406} 407