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
filter_dot(const struct dirent * d)44 static int filter_dot(const struct dirent *d)
45 {
46 return (strcmp(d->d_name, "..") && strcmp(d->d_name, "."));
47 }
48
build_default_directory_structure()49 static 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 */
build_directory_structure(const char * full_path,const char * dir_path,u32 dir_inode,int android)72 static u32 build_directory_structure(const char *full_path, const char *dir_path,
73 u32 dir_inode, int android)
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
131 if (S_ISREG(stat.st_mode)) {
132 dentries[i].file_type = EXT4_FT_REG_FILE;
133 } else if (S_ISDIR(stat.st_mode)) {
134 dentries[i].file_type = EXT4_FT_DIR;
135 dirs++;
136 } else if (S_ISCHR(stat.st_mode)) {
137 dentries[i].file_type = EXT4_FT_CHRDEV;
138 } else if (S_ISBLK(stat.st_mode)) {
139 dentries[i].file_type = EXT4_FT_BLKDEV;
140 } else if (S_ISFIFO(stat.st_mode)) {
141 dentries[i].file_type = EXT4_FT_FIFO;
142 } else if (S_ISSOCK(stat.st_mode)) {
143 dentries[i].file_type = EXT4_FT_SOCK;
144 } else if (S_ISLNK(stat.st_mode)) {
145 dentries[i].file_type = EXT4_FT_SYMLINK;
146 dentries[i].link = calloc(info.block_size, 1);
147 readlink(dentries[i].full_path, dentries[i].link, info.block_size - 1);
148 } else {
149 error("unknown file type on %s", dentries[i].path);
150 i--;
151 entries--;
152 }
153 }
154 free(namelist);
155
156 inode = make_directory(dir_inode, entries, dentries, dirs);
157
158 for (i = 0; i < entries; i++) {
159 if (dentries[i].file_type == EXT4_FT_REG_FILE) {
160 entry_inode = make_file(dentries[i].full_path, dentries[i].size);
161 } else if (dentries[i].file_type == EXT4_FT_DIR) {
162 entry_inode = build_directory_structure(dentries[i].full_path,
163 dentries[i].path, inode, android);
164 } else if (dentries[i].file_type == EXT4_FT_SYMLINK) {
165 entry_inode = make_link(dentries[i].full_path, dentries[i].link);
166 } else {
167 error("unknown file type on %s", dentries[i].path);
168 entry_inode = 0;
169 }
170 *dentries[i].inode = entry_inode;
171
172 ret = inode_set_permissions(entry_inode, dentries[i].mode,
173 dentries[i].uid, dentries[i].gid,
174 dentries[i].mtime);
175 if (ret)
176 error("failed to set permissions on %s\n", dentries[i].path);
177
178 free(dentries[i].path);
179 free(dentries[i].full_path);
180 free(dentries[i].link);
181 free((void *)dentries[i].filename);
182 }
183
184 free(dentries);
185 return inode;
186 }
187
compute_block_size()188 static u32 compute_block_size()
189 {
190 return 4096;
191 }
192
compute_journal_blocks()193 static u32 compute_journal_blocks()
194 {
195 u32 journal_blocks = DIV_ROUND_UP(info.len, info.block_size) / 64;
196 if (journal_blocks < 1024)
197 journal_blocks = 1024;
198 if (journal_blocks > 32768)
199 journal_blocks = 32768;
200 return journal_blocks;
201 }
202
compute_blocks_per_group()203 static u32 compute_blocks_per_group()
204 {
205 return info.block_size * 8;
206 }
207
compute_inodes()208 static u32 compute_inodes()
209 {
210 return DIV_ROUND_UP(info.len, info.block_size) / 4;
211 }
212
compute_inodes_per_group()213 static u32 compute_inodes_per_group()
214 {
215 u32 blocks = DIV_ROUND_UP(info.len, info.block_size);
216 u32 block_groups = DIV_ROUND_UP(blocks, info.blocks_per_group);
217 u32 inodes = DIV_ROUND_UP(info.inodes, block_groups);
218 inodes = ALIGN(inodes, (info.block_size / info.inode_size));
219
220 /* After properly rounding up the number of inodes/group,
221 * make sure to update the total inodes field in the info struct.
222 */
223 info.inodes = inodes * block_groups;
224
225 return inodes;
226 }
227
compute_bg_desc_reserve_blocks()228 static u32 compute_bg_desc_reserve_blocks()
229 {
230 u32 blocks = DIV_ROUND_UP(info.len, info.block_size);
231 u32 block_groups = DIV_ROUND_UP(blocks, info.blocks_per_group);
232 u32 bg_desc_blocks = DIV_ROUND_UP(block_groups * sizeof(struct ext2_group_desc),
233 info.block_size);
234
235 u32 bg_desc_reserve_blocks =
236 DIV_ROUND_UP(block_groups * 1024 * sizeof(struct ext2_group_desc),
237 info.block_size) - bg_desc_blocks;
238
239 if (bg_desc_reserve_blocks > info.block_size / sizeof(u32))
240 bg_desc_reserve_blocks = info.block_size / sizeof(u32);
241
242 return bg_desc_reserve_blocks;
243 }
244
reset_ext4fs_info()245 void reset_ext4fs_info() {
246 // Reset all the global data structures used by make_ext4fs so it
247 // can be called again.
248 memset(&info, 0, sizeof(info));
249 memset(&aux_info, 0, sizeof(aux_info));
250 free_data_blocks();
251 }
252
make_ext4fs(const char * filename,s64 len)253 int make_ext4fs(const char *filename, s64 len)
254 {
255 reset_ext4fs_info();
256 info.len = len;
257 return make_ext4fs_internal(filename, NULL, NULL, 0, 0, 0, 0, 1, 0);
258 }
259
make_ext4fs_internal(const char * filename,const char * directory,char * mountpoint,int android,int gzip,int sparse,int crc,int wipe,int init_itabs)260 int make_ext4fs_internal(const char *filename, const char *directory,
261 char *mountpoint, int android, int gzip, int sparse,
262 int crc, int wipe, int init_itabs)
263 {
264 u32 root_inode_num;
265 u16 root_mode;
266
267 if (setjmp(setjmp_env))
268 return EXIT_FAILURE; /* Handle a call to longjmp() */
269
270 if (info.len <= 0)
271 info.len = get_file_size(filename);
272
273 if (info.len <= 0) {
274 fprintf(stderr, "Need size of filesystem\n");
275 return EXIT_FAILURE;
276 }
277
278 if (info.block_size <= 0)
279 info.block_size = compute_block_size();
280
281 /* Round down the filesystem length to be a multiple of the block size */
282 info.len &= ~((u64)info.block_size - 1);
283
284 if (info.journal_blocks == 0)
285 info.journal_blocks = compute_journal_blocks();
286
287 if (info.no_journal == 0)
288 info.feat_compat = EXT4_FEATURE_COMPAT_HAS_JOURNAL;
289 else
290 info.journal_blocks = 0;
291
292 if (info.blocks_per_group <= 0)
293 info.blocks_per_group = compute_blocks_per_group();
294
295 if (info.inodes <= 0)
296 info.inodes = compute_inodes();
297
298 if (info.inode_size <= 0)
299 info.inode_size = 256;
300
301 if (info.label == NULL)
302 info.label = "";
303
304 info.inodes_per_group = compute_inodes_per_group();
305
306 info.feat_compat |=
307 EXT4_FEATURE_COMPAT_RESIZE_INODE;
308
309 info.feat_ro_compat |=
310 EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER |
311 EXT4_FEATURE_RO_COMPAT_LARGE_FILE;
312
313 info.feat_incompat |=
314 EXT4_FEATURE_INCOMPAT_EXTENTS |
315 EXT4_FEATURE_INCOMPAT_FILETYPE;
316
317
318 info.bg_desc_reserve_blocks = compute_bg_desc_reserve_blocks();
319
320 printf("Creating filesystem with parameters:\n");
321 printf(" Size: %llu\n", info.len);
322 printf(" Block size: %d\n", info.block_size);
323 printf(" Blocks per group: %d\n", info.blocks_per_group);
324 printf(" Inodes per group: %d\n", info.inodes_per_group);
325 printf(" Inode size: %d\n", info.inode_size);
326 printf(" Journal blocks: %d\n", info.journal_blocks);
327 printf(" Label: %s\n", info.label);
328
329 ext4_create_fs_aux_info();
330
331 printf(" Blocks: %llu\n", aux_info.len_blocks);
332 printf(" Block groups: %d\n", aux_info.groups);
333 printf(" Reserved block group size: %d\n", info.bg_desc_reserve_blocks);
334
335 block_allocator_init();
336
337 ext4_fill_in_sb();
338
339 if (reserve_inodes(0, 10) == EXT4_ALLOCATE_FAILED)
340 error("failed to reserve first 10 inodes");
341
342 if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL)
343 ext4_create_journal_inode();
344
345 if (info.feat_compat & EXT4_FEATURE_COMPAT_RESIZE_INODE)
346 ext4_create_resize_inode();
347
348 if (directory)
349 root_inode_num = build_directory_structure(directory, mountpoint, 0, android);
350 else
351 root_inode_num = build_default_directory_structure();
352
353 root_mode = S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH;
354 inode_set_permissions(root_inode_num, root_mode, 0, 0, 0);
355
356 ext4_update_free();
357
358 if (init_itabs)
359 init_unused_inode_tables();
360
361 ext4_queue_sb();
362
363 printf("Created filesystem with %d/%d inodes and %d/%d blocks\n",
364 aux_info.sb->s_inodes_count - aux_info.sb->s_free_inodes_count,
365 aux_info.sb->s_inodes_count,
366 aux_info.sb->s_blocks_count_lo - aux_info.sb->s_free_blocks_count_lo,
367 aux_info.sb->s_blocks_count_lo);
368
369 write_ext4_image(filename, gzip, sparse, crc, wipe);
370
371 return 0;
372 }
373