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>
35 #include <sys/types.h>
41 /* These match the Linux definitions of these flags.
42 L_xx is defined to avoid conflicting with the win32 versions.
44 #define L_S_IRUSR 00400
45 #define L_S_IWUSR 00200
46 #define L_S_IXUSR 00100
47 #define S_IRWXU (L_S_IRUSR | L_S_IWUSR | L_S_IXUSR)
51 #define S_IRWXG (S_IRGRP | S_IWGRP | S_IXGRP)
55 #define S_IRWXO (S_IROTH | S_IWOTH | S_IXOTH)
56 #define S_ISUID 0004000
57 #define S_ISGID 0002000
58 #define S_ISVTX 0001000
66 /* TODO: Not implemented:
67 Allocating blocks in the same block group as the file inode
68 Hash or binary tree directories
69 Special files: sockets, devices, fifos
72 static int filter_dot(const struct dirent *d)
74 return (strcmp(d->d_name, "..") && strcmp(d->d_name, "."));
77 static u32 build_default_directory_structure()
81 struct dentry dentries = {
82 .filename = "lost+found",
83 .file_type = EXT4_FT_DIR,
89 root_inode = make_directory(0, 1, &dentries, 1);
90 inode = make_directory(root_inode, 0, NULL, 0);
91 *dentries.inode = inode;
92 inode_set_permissions(inode, dentries.mode,
93 dentries.uid, dentries.gid, dentries.mtime);
99 /* Read a local directory and create the same tree in the generated filesystem.
100 Calls itself recursively with each directory in the given directory */
101 static u32 build_directory_structure(const char *full_path, const char *dir_path,
102 u32 dir_inode, fs_config_func_t fs_config_func,
103 struct selabel_handle *sehnd)
106 struct dentry *dentries;
107 struct dirent **namelist;
115 entries = scandir(full_path, &namelist, filter_dot, (void*)alphasort);
117 error_errno("scandir");
118 return EXT4_ALLOCATE_FAILED;
121 dentries = calloc(entries, sizeof(struct dentry));
122 if (dentries == NULL)
123 critical_error_errno("malloc");
125 for (i = 0; i < entries; i++) {
126 dentries[i].filename = strdup(namelist[i]->d_name);
127 if (dentries[i].filename == NULL)
128 critical_error_errno("strdup");
130 asprintf(&dentries[i].path, "%s/%s", dir_path, namelist[i]->d_name);
131 asprintf(&dentries[i].full_path, "%s/%s", full_path, namelist[i]->d_name);
135 ret = lstat(dentries[i].full_path, &stat);
137 error_errno("lstat");
143 dentries[i].size = stat.st_size;
144 dentries[i].mode = stat.st_mode & (S_ISUID|S_ISGID|S_ISVTX|S_IRWXU|S_IRWXG|S_IRWXO);
145 dentries[i].mtime = stat.st_mtime;
146 if (fs_config_func != NULL) {
148 unsigned int mode = 0;
149 unsigned int uid = 0;
150 unsigned int gid = 0;
151 int dir = S_ISDIR(stat.st_mode);
152 fs_config_func(dentries[i].path, dir, &uid, &gid, &mode);
153 dentries[i].mode = mode;
154 dentries[i].uid = uid;
155 dentries[i].gid = gid;
157 error("can't set android permissions - built without android support");
163 asprintf(&sepath, "/%s", dentries[i].path);
164 if (selabel_lookup(sehnd, &dentries[i].secon, sepath, stat.st_mode) < 0) {
165 error("cannot lookup security context for %s", sepath);
167 if (dentries[i].secon)
168 printf("Labeling %s as %s\n", sepath, dentries[i].secon);
173 if (S_ISREG(stat.st_mode)) {
174 dentries[i].file_type = EXT4_FT_REG_FILE;
175 } else if (S_ISDIR(stat.st_mode)) {
176 dentries[i].file_type = EXT4_FT_DIR;
178 } else if (S_ISCHR(stat.st_mode)) {
179 dentries[i].file_type = EXT4_FT_CHRDEV;
180 } else if (S_ISBLK(stat.st_mode)) {
181 dentries[i].file_type = EXT4_FT_BLKDEV;
182 } else if (S_ISFIFO(stat.st_mode)) {
183 dentries[i].file_type = EXT4_FT_FIFO;
184 } else if (S_ISSOCK(stat.st_mode)) {
185 dentries[i].file_type = EXT4_FT_SOCK;
186 } else if (S_ISLNK(stat.st_mode)) {
187 dentries[i].file_type = EXT4_FT_SYMLINK;
188 dentries[i].link = calloc(info.block_size, 1);
189 readlink(dentries[i].full_path, dentries[i].link, info.block_size - 1);
191 error("unknown file type on %s", dentries[i].path);
198 inode = make_directory(dir_inode, entries, dentries, dirs);
200 for (i = 0; i < entries; i++) {
201 if (dentries[i].file_type == EXT4_FT_REG_FILE) {
202 entry_inode = make_file(dentries[i].full_path, dentries[i].size);
203 } else if (dentries[i].file_type == EXT4_FT_DIR) {
204 entry_inode = build_directory_structure(dentries[i].full_path,
205 dentries[i].path, inode, fs_config_func, sehnd);
206 } else if (dentries[i].file_type == EXT4_FT_SYMLINK) {
207 entry_inode = make_link(dentries[i].full_path, dentries[i].link);
209 error("unknown file type on %s", dentries[i].path);
212 *dentries[i].inode = entry_inode;
214 ret = inode_set_permissions(entry_inode, dentries[i].mode,
215 dentries[i].uid, dentries[i].gid,
218 error("failed to set permissions on %s\n", dentries[i].path);
219 ret = inode_set_selinux(entry_inode, dentries[i].secon);
221 error("failed to set SELinux context on %s\n", dentries[i].path);
223 free(dentries[i].path);
224 free(dentries[i].full_path);
225 free(dentries[i].link);
226 free((void *)dentries[i].filename);
227 free(dentries[i].secon);
235 static u32 compute_block_size()
240 static u32 compute_journal_blocks()
242 u32 journal_blocks = DIV_ROUND_UP(info.len, info.block_size) / 64;
243 if (journal_blocks < 1024)
244 journal_blocks = 1024;
245 if (journal_blocks > 32768)
246 journal_blocks = 32768;
247 return journal_blocks;
250 static u32 compute_blocks_per_group()
252 return info.block_size * 8;
255 static u32 compute_inodes()
257 return DIV_ROUND_UP(info.len, info.block_size) / 4;
260 static u32 compute_inodes_per_group()
262 u32 blocks = DIV_ROUND_UP(info.len, info.block_size);
263 u32 block_groups = DIV_ROUND_UP(blocks, info.blocks_per_group);
264 u32 inodes = DIV_ROUND_UP(info.inodes, block_groups);
265 inodes = ALIGN(inodes, (info.block_size / info.inode_size));
267 /* After properly rounding up the number of inodes/group,
268 * make sure to update the total inodes field in the info struct.
270 info.inodes = inodes * block_groups;
275 static u32 compute_bg_desc_reserve_blocks()
277 u32 blocks = DIV_ROUND_UP(info.len, info.block_size);
278 u32 block_groups = DIV_ROUND_UP(blocks, info.blocks_per_group);
279 u32 bg_desc_blocks = DIV_ROUND_UP(block_groups * sizeof(struct ext2_group_desc),
282 u32 bg_desc_reserve_blocks =
283 DIV_ROUND_UP(block_groups * 1024 * sizeof(struct ext2_group_desc),
284 info.block_size) - bg_desc_blocks;
286 if (bg_desc_reserve_blocks > info.block_size / sizeof(u32))
287 bg_desc_reserve_blocks = info.block_size / sizeof(u32);
289 return bg_desc_reserve_blocks;
292 void reset_ext4fs_info() {
293 // Reset all the global data structures used by make_ext4fs so it
294 // can be called again.
295 memset(&info, 0, sizeof(info));
296 memset(&aux_info, 0, sizeof(aux_info));
298 if (info.sparse_file) {
299 sparse_file_destroy(info.sparse_file);
300 info.sparse_file = NULL;
304 int make_ext4fs(const char *filename, s64 len,
305 const char *mountpoint, struct selabel_handle *sehnd)
313 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
319 status = make_ext4fs_internal(fd, NULL, mountpoint, NULL, 0, 0, 0, 1, 0, sehnd);
325 int make_ext4fs_internal(int fd, const char *directory,
326 const char *mountpoint, fs_config_func_t fs_config_func, int gzip,
327 int sparse, int crc, int wipe, int init_itabs,
328 struct selabel_handle *sehnd)
333 if (setjmp(setjmp_env))
334 return EXIT_FAILURE; /* Handle a call to longjmp() */
337 info.len = get_file_size(fd);
340 fprintf(stderr, "Need size of filesystem\n");
344 if (info.block_size <= 0)
345 info.block_size = compute_block_size();
347 /* Round down the filesystem length to be a multiple of the block size */
348 info.len &= ~((u64)info.block_size - 1);
350 if (info.journal_blocks == 0)
351 info.journal_blocks = compute_journal_blocks();
353 if (info.no_journal == 0)
354 info.feat_compat = EXT4_FEATURE_COMPAT_HAS_JOURNAL;
356 info.journal_blocks = 0;
358 if (info.blocks_per_group <= 0)
359 info.blocks_per_group = compute_blocks_per_group();
361 if (info.inodes <= 0)
362 info.inodes = compute_inodes();
364 if (info.inode_size <= 0)
365 info.inode_size = 256;
367 if (info.label == NULL)
370 info.inodes_per_group = compute_inodes_per_group();
373 EXT4_FEATURE_COMPAT_RESIZE_INODE;
375 info.feat_ro_compat |=
376 EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER |
377 EXT4_FEATURE_RO_COMPAT_LARGE_FILE;
379 info.feat_incompat |=
380 EXT4_FEATURE_INCOMPAT_EXTENTS |
381 EXT4_FEATURE_INCOMPAT_FILETYPE;
384 info.bg_desc_reserve_blocks = compute_bg_desc_reserve_blocks();
386 printf("Creating filesystem with parameters:\n");
387 printf(" Size: %llu\n", info.len);
388 printf(" Block size: %d\n", info.block_size);
389 printf(" Blocks per group: %d\n", info.blocks_per_group);
390 printf(" Inodes per group: %d\n", info.inodes_per_group);
391 printf(" Inode size: %d\n", info.inode_size);
392 printf(" Journal blocks: %d\n", info.journal_blocks);
393 printf(" Label: %s\n", info.label);
395 ext4_create_fs_aux_info();
397 printf(" Blocks: %llu\n", aux_info.len_blocks);
398 printf(" Block groups: %d\n", aux_info.groups);
399 printf(" Reserved block group size: %d\n", info.bg_desc_reserve_blocks);
401 info.sparse_file = sparse_file_new(info.block_size, info.len);
403 block_allocator_init();
407 if (reserve_inodes(0, 10) == EXT4_ALLOCATE_FAILED)
408 error("failed to reserve first 10 inodes");
410 if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL)
411 ext4_create_journal_inode();
413 if (info.feat_compat & EXT4_FEATURE_COMPAT_RESIZE_INODE)
414 ext4_create_resize_inode();
417 // Windows needs only 'create an empty fs image' functionality
419 root_inode_num = build_default_directory_structure();
422 root_inode_num = build_directory_structure(directory, mountpoint, 0,
423 fs_config_func, sehnd);
425 root_inode_num = build_default_directory_structure();
428 root_mode = S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH;
429 inode_set_permissions(root_inode_num, root_mode, 0, 0, 0);
434 char *secontext = NULL;
436 if (mountpoint[0] == '/')
437 sepath = strdup(mountpoint);
439 asprintf(&sepath, "/%s", mountpoint);
441 critical_error_errno("malloc");
442 if (selabel_lookup(sehnd, &secontext, sepath, S_IFDIR) < 0) {
443 error("cannot lookup security context for %s", sepath);
446 printf("Labeling %s as %s\n", sepath, secontext);
447 inode_set_selinux(root_inode_num, secontext);
457 init_unused_inode_tables();
461 printf("Created filesystem with %d/%d inodes and %d/%d blocks\n",
462 aux_info.sb->s_inodes_count - aux_info.sb->s_free_inodes_count,
463 aux_info.sb->s_inodes_count,
464 aux_info.sb->s_blocks_count_lo - aux_info.sb->s_free_blocks_count_lo,
465 aux_info.sb->s_blocks_count_lo);
468 wipe_block_device(fd, info.len);
470 write_ext4_image(fd, gzip, sparse, crc);
472 sparse_file_destroy(info.sparse_file);
473 info.sparse_file = NULL;