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
49 static int filter_dot(const struct dirent *d)
51 return (strcmp(d->d_name, "..") && strcmp(d->d_name, "."));
54 static u32 build_default_directory_structure(const char *dir_path)
58 struct dentry dentries = {
59 .filename = "lost+found",
60 .file_type = EXT4_FT_DIR,
66 root_inode = make_directory(0, 1, &dentries, 1);
67 inode = make_directory(root_inode, 0, NULL, 0);
68 *dentries.inode = inode;
69 inode_set_permissions(inode, dentries.mode,
70 dentries.uid, dentries.gid, dentries.mtime);
76 /* Read a local directory and create the same tree in the generated filesystem.
77 Calls itself recursively with each directory in the given directory.
78 full_path is an absolute or relative path, with a trailing slash, to the
79 directory on disk that should be copied, or NULL if this is a directory
80 that does not exist on disk (e.g. lost+found).
81 dir_path is an absolute path, with trailing slash, to the same directory
82 if the image were mounted at the specified mount point */
83 static u32 build_directory_structure(const char *full_path, const char *dir_path,
84 u32 dir_inode, fs_config_func_t fs_config_func,
85 int verbose, time_t fixed_time)
88 struct dentry *dentries;
89 struct dirent **namelist = NULL;
96 bool needs_lost_and_found = false;
99 entries = scandir(full_path, &namelist, filter_dot, (void*)alphasort);
102 /* The scandir function implemented in glibc has a bug that makes it
103 erroneously fail with ENOMEM under certain circumstances.
104 As a workaround we can retry the scandir call with the same arguments.
105 GLIBC BZ: https://sourceware.org/bugzilla/show_bug.cgi?id=17804 */
107 entries = scandir(full_path, &namelist, filter_dot, (void*)alphasort);
110 error_errno("scandir");
111 return EXT4_ALLOCATE_FAILED;
116 if (dir_inode == 0) {
117 /* root directory, check if lost+found already exists */
118 for (i = 0; i < entries; i++)
119 if (strcmp(namelist[i]->d_name, "lost+found") == 0)
122 needs_lost_and_found = true;
125 dentries = calloc(entries, sizeof(struct dentry));
126 if (dentries == NULL)
127 critical_error_errno("malloc");
129 for (i = 0; i < entries; i++) {
130 dentries[i].filename = strdup(namelist[i]->d_name);
131 if (dentries[i].filename == NULL)
132 critical_error_errno("strdup");
134 asprintf(&dentries[i].path, "%s%s", dir_path, namelist[i]->d_name);
135 asprintf(&dentries[i].full_path, "%s%s", full_path, namelist[i]->d_name);
139 ret = lstat(dentries[i].full_path, &stat);
141 error_errno("lstat");
147 dentries[i].size = stat.st_size;
148 dentries[i].mode = stat.st_mode & (S_ISUID|S_ISGID|S_ISVTX|S_IRWXU|S_IRWXG|S_IRWXO);
149 if (fixed_time == -1) {
150 dentries[i].mtime = stat.st_mtime;
152 dentries[i].mtime = fixed_time;
154 uint64_t capabilities;
155 if (fs_config_func != NULL) {
157 unsigned int mode = 0;
158 unsigned int uid = 0;
159 unsigned int gid = 0;
160 int dir = S_ISDIR(stat.st_mode);
161 fs_config_func(dentries[i].path, dir, &uid, &gid, &mode, &capabilities);
162 dentries[i].mode = mode;
163 dentries[i].uid = uid;
164 dentries[i].gid = gid;
165 dentries[i].capabilities = capabilities;
167 error("can't set android permissions - built without android support");
171 if (S_ISREG(stat.st_mode)) {
172 dentries[i].file_type = EXT4_FT_REG_FILE;
173 } else if (S_ISDIR(stat.st_mode)) {
174 dentries[i].file_type = EXT4_FT_DIR;
176 } else if (S_ISCHR(stat.st_mode)) {
177 dentries[i].file_type = EXT4_FT_CHRDEV;
178 } else if (S_ISBLK(stat.st_mode)) {
179 dentries[i].file_type = EXT4_FT_BLKDEV;
180 } else if (S_ISFIFO(stat.st_mode)) {
181 dentries[i].file_type = EXT4_FT_FIFO;
182 } else if (S_ISSOCK(stat.st_mode)) {
183 dentries[i].file_type = EXT4_FT_SOCK;
184 } else if (S_ISLNK(stat.st_mode)) {
185 dentries[i].file_type = EXT4_FT_SYMLINK;
186 dentries[i].link = calloc(info.block_size, 1);
187 readlink(dentries[i].full_path, dentries[i].link, info.block_size - 1);
189 error("unknown file type on %s", dentries[i].path);
196 if (needs_lost_and_found) {
197 /* insert a lost+found directory at the beginning of the dentries */
198 struct dentry *tmp = calloc(entries + 1, sizeof(struct dentry));
199 memset(tmp, 0, sizeof(struct dentry));
200 memcpy(tmp + 1, dentries, entries * sizeof(struct dentry));
203 dentries[0].filename = strdup("lost+found");
204 asprintf(&dentries[0].path, "%slost+found", dir_path);
205 dentries[0].full_path = NULL;
206 dentries[0].size = 0;
207 dentries[0].mode = S_IRWXU;
208 dentries[0].file_type = EXT4_FT_DIR;
215 inode = make_directory(dir_inode, entries, dentries, dirs);
217 for (i = 0; i < entries; i++) {
218 if (dentries[i].file_type == EXT4_FT_REG_FILE) {
219 entry_inode = make_file(dentries[i].full_path, dentries[i].size);
220 } else if (dentries[i].file_type == EXT4_FT_DIR) {
221 char *subdir_full_path = NULL;
222 char *subdir_dir_path;
223 if (dentries[i].full_path) {
224 ret = asprintf(&subdir_full_path, "%s/", dentries[i].full_path);
226 critical_error_errno("asprintf");
228 ret = asprintf(&subdir_dir_path, "%s/", dentries[i].path);
230 critical_error_errno("asprintf");
231 entry_inode = build_directory_structure(subdir_full_path,
232 subdir_dir_path, inode, fs_config_func, verbose, fixed_time);
233 free(subdir_full_path);
234 free(subdir_dir_path);
235 } else if (dentries[i].file_type == EXT4_FT_SYMLINK) {
236 entry_inode = make_link(dentries[i].link);
237 } else if (dentries[i].file_type == EXT4_FT_CHRDEV ||
238 dentries[i].file_type == EXT4_FT_BLKDEV ||
239 dentries[i].file_type == EXT4_FT_SOCK ||
240 dentries[i].file_type == EXT4_FT_FIFO) {
241 entry_inode = make_special(dentries[i].full_path);
243 error("unknown file type on %s", dentries[i].path);
246 *dentries[i].inode = entry_inode;
248 ret = inode_set_permissions(entry_inode, dentries[i].mode,
249 dentries[i].uid, dentries[i].gid,
252 error("failed to set permissions on %s\n", dentries[i].path);
255 * It's important to call inode_set_selinux() before
256 * inode_set_capabilities(). Extended attributes need to
257 * be stored sorted order, and we guarantee this by making
258 * the calls in the proper order.
259 * Please see xattr_assert_sane() in contents.c
261 ret = inode_set_selinux(entry_inode, dentries[i].secon);
263 error("failed to set SELinux context on %s\n", dentries[i].path);
264 ret = inode_set_capabilities(entry_inode, dentries[i].capabilities);
266 error("failed to set capability on %s\n", dentries[i].path);
268 free(dentries[i].path);
269 free(dentries[i].full_path);
270 free(dentries[i].link);
271 free((void *)dentries[i].filename);
272 free(dentries[i].secon);
280 static u32 compute_block_size()
285 static u32 compute_journal_blocks()
287 u32 journal_blocks = DIV_ROUND_UP(info.len, info.block_size) / 64;
288 if (journal_blocks < 1024)
289 journal_blocks = 1024;
290 if (journal_blocks > 32768)
291 journal_blocks = 32768;
292 return journal_blocks;
295 static u32 compute_blocks_per_group()
297 return info.block_size * 8;
300 static u32 compute_inodes()
302 return DIV_ROUND_UP(info.len, info.block_size) / 4;
305 static u32 compute_inodes_per_group()
307 u32 blocks = DIV_ROUND_UP(info.len, info.block_size);
308 u32 block_groups = DIV_ROUND_UP(blocks, info.blocks_per_group);
309 u32 inodes = DIV_ROUND_UP(info.inodes, block_groups);
310 inodes = EXT4_ALIGN(inodes, (info.block_size / info.inode_size));
312 /* After properly rounding up the number of inodes/group,
313 * make sure to update the total inodes field in the info struct.
315 info.inodes = inodes * block_groups;
320 static u32 compute_bg_desc_reserve_blocks()
322 u32 blocks = DIV_ROUND_UP(info.len, info.block_size);
323 u32 block_groups = DIV_ROUND_UP(blocks, info.blocks_per_group);
324 u32 bg_desc_blocks = DIV_ROUND_UP(block_groups * sizeof(struct ext2_group_desc),
327 u32 bg_desc_reserve_blocks =
328 DIV_ROUND_UP(block_groups * 1024 * sizeof(struct ext2_group_desc),
329 info.block_size) - bg_desc_blocks;
331 if (bg_desc_reserve_blocks > info.block_size / sizeof(u32))
332 bg_desc_reserve_blocks = info.block_size / sizeof(u32);
334 return bg_desc_reserve_blocks;
337 void reset_ext4fs_info() {
338 // Reset all the global data structures used by make_ext4fs so it
339 // can be called again.
340 memset(&info, 0, sizeof(info));
341 memset(&aux_info, 0, sizeof(aux_info));
343 if (ext4_sparse_file) {
344 sparse_file_destroy(ext4_sparse_file);
345 ext4_sparse_file = NULL;
349 int make_ext4fs_sparse_fd(int fd, long long len,
350 const char *mountpoint)
355 return make_ext4fs_internal(fd, NULL, mountpoint, NULL, 0, 1, 0, 0, 0, -1, NULL);
358 int make_ext4fs(const char *filename, long long len,
359 const char *mountpoint)
367 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
373 status = make_ext4fs_internal(fd, NULL, mountpoint, NULL, 0, 0, 0, 1, 0, -1, NULL);
379 /* return a newly-malloc'd string that is a copy of str. The new string
380 is guaranteed to have a trailing slash. If absolute is true, the new string
381 is also guaranteed to have a leading slash.
383 static char *canonicalize_slashes(const char *str, bool absolute)
386 int len = strlen(str);
397 if (str[0] != '/' && absolute) {
400 if (str[len - 1] != '/') {
403 ret = malloc(newlen + 1);
405 critical_error("malloc");
409 if (str[0] != '/' && absolute) {
416 if (str[len - 1] != '/') {
420 if (ptr != ret + newlen) {
421 critical_error("assertion failed\n");
429 static char *canonicalize_abs_slashes(const char *str)
431 return canonicalize_slashes(str, true);
434 static char *canonicalize_rel_slashes(const char *str)
436 return canonicalize_slashes(str, false);
439 int make_ext4fs_internal(int fd, const char *_directory,
440 const char *_mountpoint, fs_config_func_t fs_config_func, int gzip,
441 int sparse, int crc, int wipe,
442 int verbose, time_t fixed_time,
443 FILE* block_list_file)
448 char *directory = NULL;
450 if (setjmp(setjmp_env))
451 return EXIT_FAILURE; /* Handle a call to longjmp() */
453 if (_mountpoint == NULL) {
454 mountpoint = strdup("");
456 mountpoint = canonicalize_abs_slashes(_mountpoint);
460 directory = canonicalize_rel_slashes(_directory);
464 info.len = get_file_size(fd);
467 fprintf(stderr, "Need size of filesystem\n");
471 if (info.block_size <= 0)
472 info.block_size = compute_block_size();
474 /* Round down the filesystem length to be a multiple of the block size */
475 info.len &= ~((u64)info.block_size - 1);
477 if (info.journal_blocks == 0)
478 info.journal_blocks = compute_journal_blocks();
480 if (info.no_journal == 0)
481 info.feat_compat = EXT4_FEATURE_COMPAT_HAS_JOURNAL;
483 info.journal_blocks = 0;
485 if (info.blocks_per_group <= 0)
486 info.blocks_per_group = compute_blocks_per_group();
488 if (info.inodes <= 0)
489 info.inodes = compute_inodes();
491 if (info.inode_size <= 0)
492 info.inode_size = 256;
494 if (info.label == NULL)
497 info.inodes_per_group = compute_inodes_per_group();
500 EXT4_FEATURE_COMPAT_RESIZE_INODE |
501 EXT4_FEATURE_COMPAT_EXT_ATTR;
503 info.feat_ro_compat |=
504 EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER |
505 EXT4_FEATURE_RO_COMPAT_LARGE_FILE |
506 EXT4_FEATURE_RO_COMPAT_GDT_CSUM;
508 info.feat_incompat |=
509 EXT4_FEATURE_INCOMPAT_EXTENTS |
510 EXT4_FEATURE_INCOMPAT_FILETYPE;
513 info.bg_desc_reserve_blocks = compute_bg_desc_reserve_blocks();
515 printf("Creating filesystem with parameters:\n");
516 printf(" Size: %"PRIu64"\n", info.len);
517 printf(" Block size: %d\n", info.block_size);
518 printf(" Blocks per group: %d\n", info.blocks_per_group);
519 printf(" Inodes per group: %d\n", info.inodes_per_group);
520 printf(" Inode size: %d\n", info.inode_size);
521 printf(" Journal blocks: %d\n", info.journal_blocks);
522 printf(" Label: %s\n", info.label);
524 ext4_create_fs_aux_info();
526 printf(" Blocks: %"PRIu64"\n", aux_info.len_blocks);
527 printf(" Block groups: %d\n", aux_info.groups);
528 printf(" Reserved block group size: %d\n", info.bg_desc_reserve_blocks);
530 ext4_sparse_file = sparse_file_new(info.block_size, info.len);
532 block_allocator_init();
536 if (reserve_inodes(0, 10) == EXT4_ALLOCATE_FAILED)
537 error("failed to reserve first 10 inodes");
539 if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL)
540 ext4_create_journal_inode();
542 if (info.feat_compat & EXT4_FEATURE_COMPAT_RESIZE_INODE)
543 ext4_create_resize_inode();
546 // Windows needs only 'create an empty fs image' functionality
548 root_inode_num = build_default_directory_structure(mountpoint);
551 root_inode_num = build_directory_structure(directory, mountpoint, 0,
552 fs_config_func, verbose, fixed_time);
554 root_inode_num = build_default_directory_structure(mountpoint);
557 root_mode = S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH;
558 inode_set_permissions(root_inode_num, root_mode, 0, 0, 0);
564 if (block_list_file) {
565 size_t dirlen = directory ? strlen(directory) : 0;
566 struct block_allocation* p = get_saved_allocation_chain();
568 if (directory && strncmp(p->filename, directory, dirlen) == 0) {
569 // substitute mountpoint for the leading directory in the filename, in the output file
570 fprintf(block_list_file, "%s%s", mountpoint, p->filename + dirlen);
572 fprintf(block_list_file, "%s", p->filename);
574 print_blocks(block_list_file, p);
575 struct block_allocation* pn = p->next;
581 printf("Created filesystem with %d/%d inodes and %d/%d blocks\n",
582 aux_info.sb->s_inodes_count - aux_info.sb->s_free_inodes_count,
583 aux_info.sb->s_inodes_count,
584 aux_info.sb->s_blocks_count_lo - aux_info.sb->s_free_blocks_count_lo,
585 aux_info.sb->s_blocks_count_lo);
587 if (wipe && WIPE_IS_SUPPORTED) {
588 wipe_block_device(fd, info.len);
591 write_ext4_image(fd, gzip, sparse, crc);
593 sparse_file_destroy(ext4_sparse_file);
594 ext4_sparse_file = NULL;