2 * Copyright (C) 2010 The Android Open Source Project
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
8 * http://www.apache.org/licenses/LICENSE-2.0
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.
17 #include "make_ext4fs.h"
18 #include "ext4_utils.h"
24 #include <sparse/sparse.h>
36 #include <sys/types.h>
44 /* TODO: Not implemented:
45 Allocating blocks in the same block group as the file inode
46 Hash or binary tree directories
47 Special files: sockets, devices, fifos
50 static int filter_dot(const struct dirent *d)
52 return (strcmp(d->d_name, "..") && strcmp(d->d_name, "."));
55 static u32 build_default_directory_structure(const char *dir_path)
59 struct dentry dentries = {
60 .filename = "lost+found",
61 .file_type = EXT4_FT_DIR,
67 root_inode = make_directory(0, 1, &dentries, 1);
68 inode = make_directory(root_inode, 0, NULL, 0);
69 *dentries.inode = inode;
70 inode_set_permissions(inode, dentries.mode,
71 dentries.uid, dentries.gid, dentries.mtime);
77 /* Read a local directory and create the same tree in the generated filesystem.
78 Calls itself recursively with each directory in the given directory.
79 full_path is an absolute or relative path, with a trailing slash, to the
80 directory on disk that should be copied, or NULL if this is a directory
81 that does not exist on disk (e.g. lost+found).
82 dir_path is an absolute path, with trailing slash, to the same directory
83 if the image were mounted at the specified mount point */
84 static u32 build_directory_structure(const char *full_path, const char *dir_path,
85 u32 dir_inode, fs_config_func_t fs_config_func,
86 int verbose, time_t fixed_time)
89 struct dentry *dentries;
90 struct dirent **namelist = NULL;
97 bool needs_lost_and_found = false;
100 entries = scandir(full_path, &namelist, filter_dot, (void*)alphasort);
103 /* The scandir function implemented in glibc has a bug that makes it
104 erroneously fail with ENOMEM under certain circumstances.
105 As a workaround we can retry the scandir call with the same arguments.
106 GLIBC BZ: https://sourceware.org/bugzilla/show_bug.cgi?id=17804 */
108 entries = scandir(full_path, &namelist, filter_dot, (void*)alphasort);
111 error_errno("scandir");
112 return EXT4_ALLOCATE_FAILED;
117 if (dir_inode == 0) {
118 /* root directory, check if lost+found already exists */
119 for (i = 0; i < entries; i++)
120 if (strcmp(namelist[i]->d_name, "lost+found") == 0)
123 needs_lost_and_found = true;
126 dentries = calloc(entries, sizeof(struct dentry));
127 if (dentries == NULL)
128 critical_error_errno("malloc");
130 for (i = 0; i < entries; i++) {
131 dentries[i].filename = strdup(namelist[i]->d_name);
132 if (dentries[i].filename == NULL)
133 critical_error_errno("strdup");
135 asprintf(&dentries[i].path, "%s%s", dir_path, namelist[i]->d_name);
136 asprintf(&dentries[i].full_path, "%s%s", full_path, namelist[i]->d_name);
140 ret = lstat(dentries[i].full_path, &stat);
142 error_errno("lstat");
148 dentries[i].size = stat.st_size;
149 dentries[i].mode = stat.st_mode & (S_ISUID|S_ISGID|S_ISVTX|S_IRWXU|S_IRWXG|S_IRWXO);
150 if (fixed_time == -1) {
151 dentries[i].mtime = stat.st_mtime;
153 dentries[i].mtime = fixed_time;
155 uint64_t capabilities;
156 if (fs_config_func != NULL) {
158 unsigned int mode = 0;
159 unsigned int uid = 0;
160 unsigned int gid = 0;
161 int dir = S_ISDIR(stat.st_mode);
162 fs_config_func(dentries[i].path, dir, &uid, &gid, &mode, &capabilities);
163 dentries[i].mode = mode;
164 dentries[i].uid = uid;
165 dentries[i].gid = gid;
166 dentries[i].capabilities = capabilities;
168 error("can't set android permissions - built without android support");
172 if (S_ISREG(stat.st_mode)) {
173 dentries[i].file_type = EXT4_FT_REG_FILE;
174 } else if (S_ISDIR(stat.st_mode)) {
175 dentries[i].file_type = EXT4_FT_DIR;
177 } else if (S_ISCHR(stat.st_mode)) {
178 dentries[i].file_type = EXT4_FT_CHRDEV;
179 } else if (S_ISBLK(stat.st_mode)) {
180 dentries[i].file_type = EXT4_FT_BLKDEV;
181 } else if (S_ISFIFO(stat.st_mode)) {
182 dentries[i].file_type = EXT4_FT_FIFO;
183 } else if (S_ISSOCK(stat.st_mode)) {
184 dentries[i].file_type = EXT4_FT_SOCK;
185 } else if (S_ISLNK(stat.st_mode)) {
186 dentries[i].file_type = EXT4_FT_SYMLINK;
187 dentries[i].link = calloc(info.block_size, 1);
188 readlink(dentries[i].full_path, dentries[i].link, info.block_size - 1);
190 error("unknown file type on %s", dentries[i].path);
197 if (needs_lost_and_found) {
198 /* insert a lost+found directory at the beginning of the dentries */
199 struct dentry *tmp = calloc(entries + 1, sizeof(struct dentry));
200 memset(tmp, 0, sizeof(struct dentry));
201 memcpy(tmp + 1, dentries, entries * sizeof(struct dentry));
204 dentries[0].filename = strdup("lost+found");
205 asprintf(&dentries[0].path, "%slost+found", dir_path);
206 dentries[0].full_path = NULL;
207 dentries[0].size = 0;
208 dentries[0].mode = S_IRWXU;
209 dentries[0].file_type = EXT4_FT_DIR;
216 inode = make_directory(dir_inode, entries, dentries, dirs);
218 for (i = 0; i < entries; i++) {
219 if (dentries[i].file_type == EXT4_FT_REG_FILE) {
220 entry_inode = make_file(dentries[i].full_path, dentries[i].size);
221 } else if (dentries[i].file_type == EXT4_FT_DIR) {
222 char *subdir_full_path = NULL;
223 char *subdir_dir_path;
224 if (dentries[i].full_path) {
225 ret = asprintf(&subdir_full_path, "%s/", dentries[i].full_path);
227 critical_error_errno("asprintf");
229 ret = asprintf(&subdir_dir_path, "%s/", dentries[i].path);
231 critical_error_errno("asprintf");
232 entry_inode = build_directory_structure(subdir_full_path,
233 subdir_dir_path, inode, fs_config_func, verbose, fixed_time);
234 free(subdir_full_path);
235 free(subdir_dir_path);
236 } else if (dentries[i].file_type == EXT4_FT_SYMLINK) {
237 entry_inode = make_link(dentries[i].link);
239 error("unknown file type on %s", dentries[i].path);
242 *dentries[i].inode = entry_inode;
244 ret = inode_set_permissions(entry_inode, dentries[i].mode,
245 dentries[i].uid, dentries[i].gid,
248 error("failed to set permissions on %s\n", dentries[i].path);
251 * It's important to call inode_set_selinux() before
252 * inode_set_capabilities(). Extended attributes need to
253 * be stored sorted order, and we guarantee this by making
254 * the calls in the proper order.
255 * Please see xattr_assert_sane() in contents.c
257 ret = inode_set_selinux(entry_inode, dentries[i].secon);
259 error("failed to set SELinux context on %s\n", dentries[i].path);
260 ret = inode_set_capabilities(entry_inode, dentries[i].capabilities);
262 error("failed to set capability on %s\n", dentries[i].path);
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);
276 static u32 compute_block_size()
281 static u32 compute_journal_blocks()
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;
291 static u32 compute_blocks_per_group()
293 return info.block_size * 8;
296 static u32 compute_inodes()
298 return DIV_ROUND_UP(info.len, info.block_size) / 4;
301 static u32 compute_inodes_per_group()
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 = EXT4_ALIGN(inodes, (info.block_size / info.inode_size));
308 /* After properly rounding up the number of inodes/group,
309 * make sure to update the total inodes field in the info struct.
311 info.inodes = inodes * block_groups;
316 static u32 compute_bg_desc_reserve_blocks()
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),
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;
327 if (bg_desc_reserve_blocks > info.block_size / sizeof(u32))
328 bg_desc_reserve_blocks = info.block_size / sizeof(u32);
330 return bg_desc_reserve_blocks;
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));
339 if (ext4_sparse_file) {
340 sparse_file_destroy(ext4_sparse_file);
341 ext4_sparse_file = NULL;
345 int make_ext4fs_sparse_fd(int fd, long long len,
346 const char *mountpoint)
351 return make_ext4fs_internal(fd, NULL, mountpoint, NULL, 0, 1, 0, 0, 0, -1, NULL);
354 int make_ext4fs(const char *filename, long long len,
355 const char *mountpoint)
363 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
369 status = make_ext4fs_internal(fd, NULL, mountpoint, NULL, 0, 0, 0, 1, 0, -1, NULL);
375 /* return a newly-malloc'd string that is a copy of str. The new string
376 is guaranteed to have a trailing slash. If absolute is true, the new string
377 is also guaranteed to have a leading slash.
379 static char *canonicalize_slashes(const char *str, bool absolute)
382 int len = strlen(str);
393 if (str[0] != '/' && absolute) {
396 if (str[len - 1] != '/') {
399 ret = malloc(newlen + 1);
401 critical_error("malloc");
405 if (str[0] != '/' && absolute) {
412 if (str[len - 1] != '/') {
416 if (ptr != ret + newlen) {
417 critical_error("assertion failed\n");
425 static char *canonicalize_abs_slashes(const char *str)
427 return canonicalize_slashes(str, true);
430 static char *canonicalize_rel_slashes(const char *str)
432 return canonicalize_slashes(str, false);
435 int make_ext4fs_internal(int fd, const char *_directory,
436 const char *_mountpoint, fs_config_func_t fs_config_func, int gzip,
437 int sparse, int crc, int wipe,
438 int verbose, time_t fixed_time,
439 FILE* block_list_file)
444 char *directory = NULL;
446 if (setjmp(setjmp_env))
447 return EXIT_FAILURE; /* Handle a call to longjmp() */
449 if (_mountpoint == NULL) {
450 mountpoint = strdup("");
452 mountpoint = canonicalize_abs_slashes(_mountpoint);
456 directory = canonicalize_rel_slashes(_directory);
460 info.len = get_file_size(fd);
463 fprintf(stderr, "Need size of filesystem\n");
467 if (info.block_size <= 0)
468 info.block_size = compute_block_size();
470 /* Round down the filesystem length to be a multiple of the block size */
471 info.len &= ~((u64)info.block_size - 1);
473 if (info.journal_blocks == 0)
474 info.journal_blocks = compute_journal_blocks();
476 if (info.no_journal == 0)
477 info.feat_compat = EXT4_FEATURE_COMPAT_HAS_JOURNAL;
479 info.journal_blocks = 0;
481 if (info.blocks_per_group <= 0)
482 info.blocks_per_group = compute_blocks_per_group();
484 if (info.inodes <= 0)
485 info.inodes = compute_inodes();
487 if (info.inode_size <= 0)
488 info.inode_size = 256;
490 if (info.label == NULL)
493 info.inodes_per_group = compute_inodes_per_group();
496 EXT4_FEATURE_COMPAT_RESIZE_INODE |
497 EXT4_FEATURE_COMPAT_EXT_ATTR;
499 info.feat_ro_compat |=
500 EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER |
501 EXT4_FEATURE_RO_COMPAT_LARGE_FILE |
502 EXT4_FEATURE_RO_COMPAT_GDT_CSUM;
504 info.feat_incompat |=
505 EXT4_FEATURE_INCOMPAT_EXTENTS |
506 EXT4_FEATURE_INCOMPAT_FILETYPE;
509 info.bg_desc_reserve_blocks = compute_bg_desc_reserve_blocks();
511 printf("Creating filesystem with parameters:\n");
512 printf(" Size: %"PRIu64"\n", info.len);
513 printf(" Block size: %d\n", info.block_size);
514 printf(" Blocks per group: %d\n", info.blocks_per_group);
515 printf(" Inodes per group: %d\n", info.inodes_per_group);
516 printf(" Inode size: %d\n", info.inode_size);
517 printf(" Journal blocks: %d\n", info.journal_blocks);
518 printf(" Label: %s\n", info.label);
520 ext4_create_fs_aux_info();
522 printf(" Blocks: %"PRIu64"\n", aux_info.len_blocks);
523 printf(" Block groups: %d\n", aux_info.groups);
524 printf(" Reserved block group size: %d\n", info.bg_desc_reserve_blocks);
526 ext4_sparse_file = sparse_file_new(info.block_size, info.len);
528 block_allocator_init();
532 if (reserve_inodes(0, 10) == EXT4_ALLOCATE_FAILED)
533 error("failed to reserve first 10 inodes");
535 if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL)
536 ext4_create_journal_inode();
538 if (info.feat_compat & EXT4_FEATURE_COMPAT_RESIZE_INODE)
539 ext4_create_resize_inode();
542 // Windows needs only 'create an empty fs image' functionality
544 root_inode_num = build_default_directory_structure(mountpoint);
547 root_inode_num = build_directory_structure(directory, mountpoint, 0,
548 fs_config_func, verbose, fixed_time);
550 root_inode_num = build_default_directory_structure(mountpoint);
553 root_mode = S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH;
554 inode_set_permissions(root_inode_num, root_mode, 0, 0, 0);
560 if (block_list_file) {
561 size_t dirlen = directory ? strlen(directory) : 0;
562 struct block_allocation* p = get_saved_allocation_chain();
564 if (directory && strncmp(p->filename, directory, dirlen) == 0) {
565 // substitute mountpoint for the leading directory in the filename, in the output file
566 fprintf(block_list_file, "%s%s", mountpoint, p->filename + dirlen);
568 fprintf(block_list_file, "%s", p->filename);
570 print_blocks(block_list_file, p);
571 struct block_allocation* pn = p->next;
577 printf("Created filesystem with %d/%d inodes and %d/%d blocks\n",
578 aux_info.sb->s_inodes_count - aux_info.sb->s_free_inodes_count,
579 aux_info.sb->s_inodes_count,
580 aux_info.sb->s_blocks_count_lo - aux_info.sb->s_free_blocks_count_lo,
581 aux_info.sb->s_blocks_count_lo);
583 if (wipe && WIPE_IS_SUPPORTED) {
584 wipe_block_device(fd, info.len);
587 write_ext4_image(fd, gzip, sparse, crc);
589 sparse_file_destroy(ext4_sparse_file);
590 ext4_sparse_file = NULL;