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 "ext4_utils.h"
18 #include "uuid.h"
19 #include "allocate.h"
20 #include "indirect.h"
21 #include "extent.h"
22
23 #include <sparse/sparse.h>
24
25 #include <fcntl.h>
26 #include <sys/stat.h>
27 #include <sys/types.h>
28 #include <stddef.h>
29 #include <string.h>
30
31 #ifdef USE_MINGW
32 #include <winsock2.h>
33 #else
34 #include <arpa/inet.h>
35 #include <sys/ioctl.h>
36 #endif
37
38 #if defined(__linux__)
39 #include <linux/fs.h>
40 #elif defined(__APPLE__) && defined(__MACH__)
41 #include <sys/disk.h>
42 #endif
43
44 int force = 0;
45 struct fs_info info;
46 struct fs_aux_info aux_info;
47 struct sparse_file *ext4_sparse_file;
48
49 jmp_buf setjmp_env;
50
51 /* returns 1 if a is a power of b */
is_power_of(int a,int b)52 static int is_power_of(int a, int b)
53 {
54 while (a > b) {
55 if (a % b)
56 return 0;
57 a /= b;
58 }
59
60 return (a == b) ? 1 : 0;
61 }
62
63 /* Returns 1 if the bg contains a backup superblock. On filesystems with
64 the sparse_super feature, only block groups 0, 1, and powers of 3, 5,
65 and 7 have backup superblocks. Otherwise, all block groups have backup
66 superblocks */
ext4_bg_has_super_block(int bg)67 int ext4_bg_has_super_block(int bg)
68 {
69 /* Without sparse_super, every block group has a superblock */
70 if (!(info.feat_ro_compat & EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER))
71 return 1;
72
73 if (bg == 0 || bg == 1)
74 return 1;
75
76 if (is_power_of(bg, 3) || is_power_of(bg, 5) || is_power_of(bg, 7))
77 return 1;
78
79 return 0;
80 }
81
82 /* Write the filesystem image to a file */
write_ext4_image(int fd,int gz,int sparse,int crc)83 void write_ext4_image(int fd, int gz, int sparse, int crc)
84 {
85 sparse_file_write(ext4_sparse_file, fd, gz, sparse, crc);
86 }
87
88 /* Compute the rest of the parameters of the filesystem from the basic info */
ext4_create_fs_aux_info()89 void ext4_create_fs_aux_info()
90 {
91 aux_info.first_data_block = (info.block_size > 1024) ? 0 : 1;
92 aux_info.len_blocks = info.len / info.block_size;
93 aux_info.inode_table_blocks = DIV_ROUND_UP(info.inodes_per_group * info.inode_size,
94 info.block_size);
95 aux_info.groups = DIV_ROUND_UP(aux_info.len_blocks - aux_info.first_data_block,
96 info.blocks_per_group);
97 aux_info.blocks_per_ind = info.block_size / sizeof(u32);
98 aux_info.blocks_per_dind = aux_info.blocks_per_ind * aux_info.blocks_per_ind;
99 aux_info.blocks_per_tind = aux_info.blocks_per_dind * aux_info.blocks_per_dind;
100
101 aux_info.bg_desc_blocks =
102 DIV_ROUND_UP(aux_info.groups * sizeof(struct ext2_group_desc),
103 info.block_size);
104
105 aux_info.default_i_flags = EXT4_NOATIME_FL;
106
107 u32 last_group_size = aux_info.len_blocks % info.blocks_per_group;
108 u32 last_header_size = 2 + aux_info.inode_table_blocks;
109 if (ext4_bg_has_super_block(aux_info.groups - 1))
110 last_header_size += 1 + aux_info.bg_desc_blocks +
111 info.bg_desc_reserve_blocks;
112 if (last_group_size > 0 && last_group_size < last_header_size) {
113 aux_info.groups--;
114 aux_info.len_blocks -= last_group_size;
115 }
116
117 aux_info.sb = calloc(info.block_size, 1);
118 /* Alloc an array to hold the pointers to the backup superblocks */
119 aux_info.backup_sb = calloc(aux_info.groups, sizeof(char *));
120
121 if (!aux_info.sb)
122 critical_error_errno("calloc");
123
124 aux_info.bg_desc = calloc(info.block_size, aux_info.bg_desc_blocks);
125 if (!aux_info.bg_desc)
126 critical_error_errno("calloc");
127 aux_info.xattrs = NULL;
128 }
129
ext4_free_fs_aux_info()130 void ext4_free_fs_aux_info()
131 {
132 unsigned int i;
133
134 for (i=0; i<aux_info.groups; i++) {
135 if (aux_info.backup_sb[i])
136 free(aux_info.backup_sb[i]);
137 }
138 free(aux_info.sb);
139 free(aux_info.bg_desc);
140 }
141
142 /* Fill in the superblock memory buffer based on the filesystem parameters */
ext4_fill_in_sb()143 void ext4_fill_in_sb()
144 {
145 unsigned int i;
146 struct ext4_super_block *sb = aux_info.sb;
147
148 sb->s_inodes_count = info.inodes_per_group * aux_info.groups;
149 sb->s_blocks_count_lo = aux_info.len_blocks;
150 sb->s_r_blocks_count_lo = 0;
151 sb->s_free_blocks_count_lo = 0;
152 sb->s_free_inodes_count = 0;
153 sb->s_first_data_block = aux_info.first_data_block;
154 sb->s_log_block_size = log_2(info.block_size / 1024);
155 sb->s_obso_log_frag_size = log_2(info.block_size / 1024);
156 sb->s_blocks_per_group = info.blocks_per_group;
157 sb->s_obso_frags_per_group = info.blocks_per_group;
158 sb->s_inodes_per_group = info.inodes_per_group;
159 sb->s_mtime = 0;
160 sb->s_wtime = 0;
161 sb->s_mnt_count = 0;
162 sb->s_max_mnt_count = 0xFFFF;
163 sb->s_magic = EXT4_SUPER_MAGIC;
164 sb->s_state = EXT4_VALID_FS;
165 sb->s_errors = EXT4_ERRORS_RO;
166 sb->s_minor_rev_level = 0;
167 sb->s_lastcheck = 0;
168 sb->s_checkinterval = 0;
169 sb->s_creator_os = EXT4_OS_LINUX;
170 sb->s_rev_level = EXT4_DYNAMIC_REV;
171 sb->s_def_resuid = EXT4_DEF_RESUID;
172 sb->s_def_resgid = EXT4_DEF_RESGID;
173
174 sb->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
175 sb->s_inode_size = info.inode_size;
176 sb->s_block_group_nr = 0;
177 sb->s_feature_compat = info.feat_compat;
178 sb->s_feature_incompat = info.feat_incompat;
179 sb->s_feature_ro_compat = info.feat_ro_compat;
180 generate_uuid("extandroid/make_ext4fs", info.label, sb->s_uuid);
181 memset(sb->s_volume_name, 0, sizeof(sb->s_volume_name));
182 strncpy(sb->s_volume_name, info.label, sizeof(sb->s_volume_name));
183 memset(sb->s_last_mounted, 0, sizeof(sb->s_last_mounted));
184 sb->s_algorithm_usage_bitmap = 0;
185
186 sb->s_reserved_gdt_blocks = info.bg_desc_reserve_blocks;
187 sb->s_prealloc_blocks = 0;
188 sb->s_prealloc_dir_blocks = 0;
189
190 //memcpy(sb->s_journal_uuid, sb->s_uuid, sizeof(sb->s_journal_uuid));
191 if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL)
192 sb->s_journal_inum = EXT4_JOURNAL_INO;
193 sb->s_journal_dev = 0;
194 sb->s_last_orphan = 0;
195 sb->s_hash_seed[0] = 0; /* FIXME */
196 sb->s_def_hash_version = DX_HASH_TEA;
197 sb->s_reserved_char_pad = EXT4_JNL_BACKUP_BLOCKS;
198 sb->s_desc_size = sizeof(struct ext2_group_desc);
199 sb->s_default_mount_opts = 0; /* FIXME */
200 sb->s_first_meta_bg = 0;
201 sb->s_mkfs_time = 0;
202 //sb->s_jnl_blocks[17]; /* FIXME */
203
204 sb->s_blocks_count_hi = aux_info.len_blocks >> 32;
205 sb->s_r_blocks_count_hi = 0;
206 sb->s_free_blocks_count_hi = 0;
207 sb->s_min_extra_isize = sizeof(struct ext4_inode) -
208 EXT4_GOOD_OLD_INODE_SIZE;
209 sb->s_want_extra_isize = sizeof(struct ext4_inode) -
210 EXT4_GOOD_OLD_INODE_SIZE;
211 sb->s_flags = 2;
212 sb->s_raid_stride = 0;
213 sb->s_mmp_interval = 0;
214 sb->s_mmp_block = 0;
215 sb->s_raid_stripe_width = 0;
216 sb->s_log_groups_per_flex = 0;
217 sb->s_kbytes_written = 0;
218
219 for (i = 0; i < aux_info.groups; i++) {
220 u64 group_start_block = aux_info.first_data_block + i *
221 info.blocks_per_group;
222 u32 header_size = 0;
223 if (ext4_bg_has_super_block(i)) {
224 if (i != 0) {
225 aux_info.backup_sb[i] = calloc(info.block_size, 1);
226 memcpy(aux_info.backup_sb[i], sb, info.block_size);
227 /* Update the block group nr of this backup superblock */
228 aux_info.backup_sb[i]->s_block_group_nr = i;
229 sparse_file_add_data(ext4_sparse_file, aux_info.backup_sb[i],
230 info.block_size, group_start_block);
231 }
232 sparse_file_add_data(ext4_sparse_file, aux_info.bg_desc,
233 aux_info.bg_desc_blocks * info.block_size,
234 group_start_block + 1);
235 header_size = 1 + aux_info.bg_desc_blocks + info.bg_desc_reserve_blocks;
236 }
237
238 aux_info.bg_desc[i].bg_block_bitmap = group_start_block + header_size;
239 aux_info.bg_desc[i].bg_inode_bitmap = group_start_block + header_size + 1;
240 aux_info.bg_desc[i].bg_inode_table = group_start_block + header_size + 2;
241
242 aux_info.bg_desc[i].bg_free_blocks_count = sb->s_blocks_per_group;
243 aux_info.bg_desc[i].bg_free_inodes_count = sb->s_inodes_per_group;
244 aux_info.bg_desc[i].bg_used_dirs_count = 0;
245 }
246 }
247
ext4_queue_sb(void)248 void ext4_queue_sb(void)
249 {
250 /* The write_data* functions expect only block aligned calls.
251 * This is not an issue, except when we write out the super
252 * block on a system with a block size > 1K. So, we need to
253 * deal with that here.
254 */
255 if (info.block_size > 1024) {
256 u8 *buf = calloc(info.block_size, 1);
257 memcpy(buf + 1024, (u8*)aux_info.sb, 1024);
258 sparse_file_add_data(ext4_sparse_file, buf, info.block_size, 0);
259 } else {
260 sparse_file_add_data(ext4_sparse_file, aux_info.sb, 1024, 1);
261 }
262 }
263
ext4_parse_sb_info(struct ext4_super_block * sb)264 void ext4_parse_sb_info(struct ext4_super_block *sb)
265 {
266 if (sb->s_magic != EXT4_SUPER_MAGIC)
267 error("superblock magic incorrect");
268
269 if ((sb->s_state & EXT4_VALID_FS) != EXT4_VALID_FS)
270 error("filesystem state not valid");
271
272 ext4_parse_sb(sb, &info);
273
274 ext4_create_fs_aux_info();
275
276 memcpy(aux_info.sb, sb, sizeof(*sb));
277
278 if (aux_info.first_data_block != sb->s_first_data_block)
279 critical_error("first data block does not match");
280 }
281
ext4_create_resize_inode()282 void ext4_create_resize_inode()
283 {
284 struct block_allocation *reserve_inode_alloc = create_allocation();
285 u32 reserve_inode_len = 0;
286 unsigned int i;
287
288 struct ext4_inode *inode = get_inode(EXT4_RESIZE_INO);
289 if (inode == NULL) {
290 error("failed to get resize inode");
291 return;
292 }
293
294 for (i = 0; i < aux_info.groups; i++) {
295 if (ext4_bg_has_super_block(i)) {
296 u64 group_start_block = aux_info.first_data_block + i *
297 info.blocks_per_group;
298 u32 reserved_block_start = group_start_block + 1 +
299 aux_info.bg_desc_blocks;
300 u32 reserved_block_len = info.bg_desc_reserve_blocks;
301 append_region(reserve_inode_alloc, reserved_block_start,
302 reserved_block_len, i);
303 reserve_inode_len += reserved_block_len;
304 }
305 }
306
307 inode_attach_resize(inode, reserve_inode_alloc);
308
309 inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR;
310 inode->i_links_count = 1;
311
312 free_alloc(reserve_inode_alloc);
313 }
314
315 /* Allocate the blocks to hold a journal inode and connect them to the
316 reserved journal inode */
ext4_create_journal_inode()317 void ext4_create_journal_inode()
318 {
319 struct ext4_inode *inode = get_inode(EXT4_JOURNAL_INO);
320 if (inode == NULL) {
321 error("failed to get journal inode");
322 return;
323 }
324
325 u8 *journal_data = inode_allocate_data_extents(inode,
326 info.journal_blocks * info.block_size,
327 info.journal_blocks * info.block_size);
328 if (!journal_data) {
329 error("failed to allocate extents for journal data");
330 return;
331 }
332
333 inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR;
334 inode->i_links_count = 1;
335
336 journal_superblock_t *jsb = (journal_superblock_t *)journal_data;
337 jsb->s_header.h_magic = htonl(JBD2_MAGIC_NUMBER);
338 jsb->s_header.h_blocktype = htonl(JBD2_SUPERBLOCK_V2);
339 jsb->s_blocksize = htonl(info.block_size);
340 jsb->s_maxlen = htonl(info.journal_blocks);
341 jsb->s_nr_users = htonl(1);
342 jsb->s_first = htonl(1);
343 jsb->s_sequence = htonl(1);
344
345 memcpy(aux_info.sb->s_jnl_blocks, &inode->i_block, sizeof(inode->i_block));
346 }
347
348 /* Update the number of free blocks and inodes in the filesystem and in each
349 block group */
ext4_update_free()350 void ext4_update_free()
351 {
352 u32 i;
353
354 for (i = 0; i < aux_info.groups; i++) {
355 u32 bg_free_blocks = get_free_blocks(i);
356 u32 bg_free_inodes = get_free_inodes(i);
357 u16 crc;
358
359 aux_info.bg_desc[i].bg_free_blocks_count = bg_free_blocks;
360 aux_info.sb->s_free_blocks_count_lo += bg_free_blocks;
361
362 aux_info.bg_desc[i].bg_free_inodes_count = bg_free_inodes;
363 aux_info.sb->s_free_inodes_count += bg_free_inodes;
364
365 aux_info.bg_desc[i].bg_used_dirs_count += get_directories(i);
366
367 aux_info.bg_desc[i].bg_flags = get_bg_flags(i);
368
369 crc = ext4_crc16(~0, aux_info.sb->s_uuid, sizeof(aux_info.sb->s_uuid));
370 crc = ext4_crc16(crc, &i, sizeof(i));
371 crc = ext4_crc16(crc, &aux_info.bg_desc[i], offsetof(struct ext2_group_desc, bg_checksum));
372 aux_info.bg_desc[i].bg_checksum = crc;
373 }
374 }
375
get_block_device_size(int fd)376 u64 get_block_device_size(int fd)
377 {
378 u64 size = 0;
379 int ret;
380
381 #if defined(__linux__)
382 ret = ioctl(fd, BLKGETSIZE64, &size);
383 #elif defined(__APPLE__) && defined(__MACH__)
384 ret = ioctl(fd, DKIOCGETBLOCKCOUNT, &size);
385 #else
386 close(fd);
387 return 0;
388 #endif
389
390 if (ret)
391 return 0;
392
393 return size;
394 }
395
is_block_device_fd(int fd)396 int is_block_device_fd(int fd)
397 {
398 #ifdef USE_MINGW
399 return 0;
400 #else
401 struct stat st;
402 int ret = fstat(fd, &st);
403 if (ret < 0)
404 return 0;
405
406 return S_ISBLK(st.st_mode);
407 #endif
408 }
409
get_file_size(int fd)410 u64 get_file_size(int fd)
411 {
412 struct stat buf;
413 int ret;
414 u64 reserve_len = 0;
415 s64 computed_size;
416
417 ret = fstat(fd, &buf);
418 if (ret)
419 return 0;
420
421 if (info.len < 0)
422 reserve_len = -info.len;
423
424 if (S_ISREG(buf.st_mode))
425 computed_size = buf.st_size - reserve_len;
426 else if (S_ISBLK(buf.st_mode))
427 computed_size = get_block_device_size(fd) - reserve_len;
428 else
429 computed_size = 0;
430
431 if (computed_size < 0) {
432 warn("Computed filesystem size less than 0");
433 computed_size = 0;
434 }
435
436 return computed_size;
437 }
438
parse_num(const char * arg)439 u64 parse_num(const char *arg)
440 {
441 char *endptr;
442 u64 num = strtoull(arg, &endptr, 10);
443 if (*endptr == 'k' || *endptr == 'K')
444 num *= 1024LL;
445 else if (*endptr == 'm' || *endptr == 'M')
446 num *= 1024LL * 1024LL;
447 else if (*endptr == 'g' || *endptr == 'G')
448 num *= 1024LL * 1024LL * 1024LL;
449
450 return num;
451 }
452