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 #include "ext4.h"
45 #include "jbd2.h"
46
47 int force = 0;
48 struct fs_info info;
49 struct fs_aux_info aux_info;
50
51 jmp_buf setjmp_env;
52
53 /* returns 1 if a is a power of b */
is_power_of(int a,int b)54 static int is_power_of(int a, int b)
55 {
56 while (a > b) {
57 if (a % b)
58 return 0;
59 a /= b;
60 }
61
62 return (a == b) ? 1 : 0;
63 }
64
65 /* Returns 1 if the bg contains a backup superblock. On filesystems with
66 the sparse_super feature, only block groups 0, 1, and powers of 3, 5,
67 and 7 have backup superblocks. Otherwise, all block groups have backup
68 superblocks */
ext4_bg_has_super_block(int bg)69 int ext4_bg_has_super_block(int bg)
70 {
71 /* Without sparse_super, every block group has a superblock */
72 if (!(info.feat_ro_compat & EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER))
73 return 1;
74
75 if (bg == 0 || bg == 1)
76 return 1;
77
78 if (is_power_of(bg, 3) || is_power_of(bg, 5) || is_power_of(bg, 7))
79 return 1;
80
81 return 0;
82 }
83
84 /* Write the filesystem image to a file */
write_ext4_image(int fd,int gz,int sparse,int crc)85 void write_ext4_image(int fd, int gz, int sparse, int crc)
86 {
87 sparse_file_write(info.sparse_file, fd, gz, sparse, crc);
88 }
89
90 /* Compute the rest of the parameters of the filesystem from the basic info */
ext4_create_fs_aux_info()91 void ext4_create_fs_aux_info()
92 {
93 aux_info.first_data_block = (info.block_size > 1024) ? 0 : 1;
94 aux_info.len_blocks = info.len / info.block_size;
95 aux_info.inode_table_blocks = DIV_ROUND_UP(info.inodes_per_group * info.inode_size,
96 info.block_size);
97 aux_info.groups = DIV_ROUND_UP(aux_info.len_blocks - aux_info.first_data_block,
98 info.blocks_per_group);
99 aux_info.blocks_per_ind = info.block_size / sizeof(u32);
100 aux_info.blocks_per_dind = aux_info.blocks_per_ind * aux_info.blocks_per_ind;
101 aux_info.blocks_per_tind = aux_info.blocks_per_dind * aux_info.blocks_per_dind;
102
103 aux_info.bg_desc_blocks =
104 DIV_ROUND_UP(aux_info.groups * sizeof(struct ext2_group_desc),
105 info.block_size);
106
107 aux_info.default_i_flags = EXT4_NOATIME_FL;
108
109 u32 last_group_size = aux_info.len_blocks % info.blocks_per_group;
110 u32 last_header_size = 2 + aux_info.inode_table_blocks;
111 if (ext4_bg_has_super_block(aux_info.groups - 1))
112 last_header_size += 1 + aux_info.bg_desc_blocks +
113 info.bg_desc_reserve_blocks;
114 if (last_group_size > 0 && last_group_size < last_header_size) {
115 aux_info.groups--;
116 aux_info.len_blocks -= last_group_size;
117 }
118
119 aux_info.sb = calloc(info.block_size, 1);
120 /* Alloc an array to hold the pointers to the backup superblocks */
121 aux_info.backup_sb = calloc(aux_info.groups, sizeof(char *));
122
123 if (!aux_info.sb)
124 critical_error_errno("calloc");
125
126 aux_info.bg_desc = calloc(info.block_size, aux_info.bg_desc_blocks);
127 if (!aux_info.bg_desc)
128 critical_error_errno("calloc");
129 aux_info.xattrs = NULL;
130 }
131
ext4_free_fs_aux_info()132 void ext4_free_fs_aux_info()
133 {
134 unsigned int i;
135
136 for (i=0; i<aux_info.groups; i++) {
137 if (aux_info.backup_sb[i])
138 free(aux_info.backup_sb[i]);
139 }
140 free(aux_info.sb);
141 free(aux_info.bg_desc);
142 }
143
144 /* Fill in the superblock memory buffer based on the filesystem parameters */
ext4_fill_in_sb()145 void ext4_fill_in_sb()
146 {
147 unsigned int i;
148 struct ext4_super_block *sb = aux_info.sb;
149
150 sb->s_inodes_count = info.inodes_per_group * aux_info.groups;
151 sb->s_blocks_count_lo = aux_info.len_blocks;
152 sb->s_r_blocks_count_lo = 0;
153 sb->s_free_blocks_count_lo = 0;
154 sb->s_free_inodes_count = 0;
155 sb->s_first_data_block = aux_info.first_data_block;
156 sb->s_log_block_size = log_2(info.block_size / 1024);
157 sb->s_obso_log_frag_size = log_2(info.block_size / 1024);
158 sb->s_blocks_per_group = info.blocks_per_group;
159 sb->s_obso_frags_per_group = info.blocks_per_group;
160 sb->s_inodes_per_group = info.inodes_per_group;
161 sb->s_mtime = 0;
162 sb->s_wtime = 0;
163 sb->s_mnt_count = 0;
164 sb->s_max_mnt_count = 0xFFFF;
165 sb->s_magic = EXT4_SUPER_MAGIC;
166 sb->s_state = EXT4_VALID_FS;
167 sb->s_errors = EXT4_ERRORS_RO;
168 sb->s_minor_rev_level = 0;
169 sb->s_lastcheck = 0;
170 sb->s_checkinterval = 0;
171 sb->s_creator_os = EXT4_OS_LINUX;
172 sb->s_rev_level = EXT4_DYNAMIC_REV;
173 sb->s_def_resuid = EXT4_DEF_RESUID;
174 sb->s_def_resgid = EXT4_DEF_RESGID;
175
176 sb->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
177 sb->s_inode_size = info.inode_size;
178 sb->s_block_group_nr = 0;
179 sb->s_feature_compat = info.feat_compat;
180 sb->s_feature_incompat = info.feat_incompat;
181 sb->s_feature_ro_compat = info.feat_ro_compat;
182 generate_uuid("extandroid/make_ext4fs", info.label, sb->s_uuid);
183 memset(sb->s_volume_name, 0, sizeof(sb->s_volume_name));
184 strncpy(sb->s_volume_name, info.label, sizeof(sb->s_volume_name));
185 memset(sb->s_last_mounted, 0, sizeof(sb->s_last_mounted));
186 sb->s_algorithm_usage_bitmap = 0;
187
188 sb->s_reserved_gdt_blocks = info.bg_desc_reserve_blocks;
189 sb->s_prealloc_blocks = 0;
190 sb->s_prealloc_dir_blocks = 0;
191
192 //memcpy(sb->s_journal_uuid, sb->s_uuid, sizeof(sb->s_journal_uuid));
193 if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL)
194 sb->s_journal_inum = EXT4_JOURNAL_INO;
195 sb->s_journal_dev = 0;
196 sb->s_last_orphan = 0;
197 sb->s_hash_seed[0] = 0; /* FIXME */
198 sb->s_def_hash_version = DX_HASH_TEA;
199 sb->s_reserved_char_pad = EXT4_JNL_BACKUP_BLOCKS;
200 sb->s_desc_size = sizeof(struct ext2_group_desc);
201 sb->s_default_mount_opts = 0; /* FIXME */
202 sb->s_first_meta_bg = 0;
203 sb->s_mkfs_time = 0;
204 //sb->s_jnl_blocks[17]; /* FIXME */
205
206 sb->s_blocks_count_hi = aux_info.len_blocks >> 32;
207 sb->s_r_blocks_count_hi = 0;
208 sb->s_free_blocks_count_hi = 0;
209 sb->s_min_extra_isize = sizeof(struct ext4_inode) -
210 EXT4_GOOD_OLD_INODE_SIZE;
211 sb->s_want_extra_isize = sizeof(struct ext4_inode) -
212 EXT4_GOOD_OLD_INODE_SIZE;
213 sb->s_flags = 0;
214 sb->s_raid_stride = 0;
215 sb->s_mmp_interval = 0;
216 sb->s_mmp_block = 0;
217 sb->s_raid_stripe_width = 0;
218 sb->s_log_groups_per_flex = 0;
219 sb->s_kbytes_written = 0;
220
221 for (i = 0; i < aux_info.groups; i++) {
222 u64 group_start_block = aux_info.first_data_block + i *
223 info.blocks_per_group;
224 u32 header_size = 0;
225 if (ext4_bg_has_super_block(i)) {
226 if (i != 0) {
227 aux_info.backup_sb[i] = calloc(info.block_size, 1);
228 memcpy(aux_info.backup_sb[i], sb, info.block_size);
229 /* Update the block group nr of this backup superblock */
230 aux_info.backup_sb[i]->s_block_group_nr = i;
231 sparse_file_add_data(info.sparse_file, aux_info.backup_sb[i],
232 info.block_size, group_start_block);
233 }
234 sparse_file_add_data(info.sparse_file, aux_info.bg_desc,
235 aux_info.bg_desc_blocks * info.block_size,
236 group_start_block + 1);
237 header_size = 1 + aux_info.bg_desc_blocks + info.bg_desc_reserve_blocks;
238 }
239
240 aux_info.bg_desc[i].bg_block_bitmap = group_start_block + header_size;
241 aux_info.bg_desc[i].bg_inode_bitmap = group_start_block + header_size + 1;
242 aux_info.bg_desc[i].bg_inode_table = group_start_block + header_size + 2;
243
244 aux_info.bg_desc[i].bg_free_blocks_count = sb->s_blocks_per_group;
245 aux_info.bg_desc[i].bg_free_inodes_count = sb->s_inodes_per_group;
246 aux_info.bg_desc[i].bg_used_dirs_count = 0;
247 }
248 }
249
ext4_queue_sb(void)250 void ext4_queue_sb(void)
251 {
252 /* The write_data* functions expect only block aligned calls.
253 * This is not an issue, except when we write out the super
254 * block on a system with a block size > 1K. So, we need to
255 * deal with that here.
256 */
257 if (info.block_size > 1024) {
258 u8 *buf = calloc(info.block_size, 1);
259 memcpy(buf + 1024, (u8*)aux_info.sb, 1024);
260 sparse_file_add_data(info.sparse_file, buf, info.block_size, 0);
261 } else {
262 sparse_file_add_data(info.sparse_file, aux_info.sb, 1024, 1);
263 }
264 }
265
ext4_parse_sb(struct ext4_super_block * sb)266 void ext4_parse_sb(struct ext4_super_block *sb)
267 {
268 if (sb->s_magic != EXT4_SUPER_MAGIC)
269 error("superblock magic incorrect");
270
271 if ((sb->s_state & EXT4_VALID_FS) != EXT4_VALID_FS)
272 error("filesystem state not valid");
273
274 info.block_size = 1024 << sb->s_log_block_size;
275 info.blocks_per_group = sb->s_blocks_per_group;
276 info.inodes_per_group = sb->s_inodes_per_group;
277 info.inode_size = sb->s_inode_size;
278 info.inodes = sb->s_inodes_count;
279 info.feat_ro_compat = sb->s_feature_ro_compat;
280 info.feat_compat = sb->s_feature_compat;
281 info.feat_incompat = sb->s_feature_incompat;
282 info.bg_desc_reserve_blocks = sb->s_reserved_gdt_blocks;
283 info.label = sb->s_volume_name;
284
285 aux_info.len_blocks = ((u64)sb->s_blocks_count_hi << 32) +
286 sb->s_blocks_count_lo;
287 info.len = (u64)info.block_size * aux_info.len_blocks;
288
289 ext4_create_fs_aux_info();
290
291 memcpy(aux_info.sb, sb, sizeof(*sb));
292
293 if (aux_info.first_data_block != sb->s_first_data_block)
294 critical_error("first data block does not match");
295 }
296
ext4_create_resize_inode()297 void ext4_create_resize_inode()
298 {
299 struct block_allocation *reserve_inode_alloc = create_allocation();
300 u32 reserve_inode_len = 0;
301 unsigned int i;
302
303 struct ext4_inode *inode = get_inode(EXT4_RESIZE_INO);
304 if (inode == NULL) {
305 error("failed to get resize inode");
306 return;
307 }
308
309 for (i = 0; i < aux_info.groups; i++) {
310 if (ext4_bg_has_super_block(i)) {
311 u64 group_start_block = aux_info.first_data_block + i *
312 info.blocks_per_group;
313 u32 reserved_block_start = group_start_block + 1 +
314 aux_info.bg_desc_blocks;
315 u32 reserved_block_len = info.bg_desc_reserve_blocks;
316 append_region(reserve_inode_alloc, reserved_block_start,
317 reserved_block_len, i);
318 reserve_inode_len += reserved_block_len;
319 }
320 }
321
322 inode_attach_resize(inode, reserve_inode_alloc);
323
324 inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR;
325 inode->i_links_count = 1;
326
327 free_alloc(reserve_inode_alloc);
328 }
329
330 /* Allocate the blocks to hold a journal inode and connect them to the
331 reserved journal inode */
ext4_create_journal_inode()332 void ext4_create_journal_inode()
333 {
334 struct ext4_inode *inode = get_inode(EXT4_JOURNAL_INO);
335 if (inode == NULL) {
336 error("failed to get journal inode");
337 return;
338 }
339
340 u8 *journal_data = inode_allocate_data_extents(inode,
341 info.journal_blocks * info.block_size,
342 info.journal_blocks * info.block_size);
343 if (!journal_data) {
344 error("failed to allocate extents for journal data");
345 return;
346 }
347
348 inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR;
349 inode->i_links_count = 1;
350
351 journal_superblock_t *jsb = (journal_superblock_t *)journal_data;
352 jsb->s_header.h_magic = htonl(JBD2_MAGIC_NUMBER);
353 jsb->s_header.h_blocktype = htonl(JBD2_SUPERBLOCK_V2);
354 jsb->s_blocksize = htonl(info.block_size);
355 jsb->s_maxlen = htonl(info.journal_blocks);
356 jsb->s_nr_users = htonl(1);
357 jsb->s_first = htonl(1);
358 jsb->s_sequence = htonl(1);
359
360 memcpy(aux_info.sb->s_jnl_blocks, &inode->i_block, sizeof(inode->i_block));
361 }
362
363 /* Update the number of free blocks and inodes in the filesystem and in each
364 block group */
ext4_update_free()365 void ext4_update_free()
366 {
367 u32 i;
368
369 for (i = 0; i < aux_info.groups; i++) {
370 u32 bg_free_blocks = get_free_blocks(i);
371 u32 bg_free_inodes = get_free_inodes(i);
372 u16 crc;
373
374 aux_info.bg_desc[i].bg_free_blocks_count = bg_free_blocks;
375 aux_info.sb->s_free_blocks_count_lo += bg_free_blocks;
376
377 aux_info.bg_desc[i].bg_free_inodes_count = bg_free_inodes;
378 aux_info.sb->s_free_inodes_count += bg_free_inodes;
379
380 aux_info.bg_desc[i].bg_used_dirs_count += get_directories(i);
381
382 aux_info.bg_desc[i].bg_flags = get_bg_flags(i);
383
384 crc = ext4_crc16(~0, aux_info.sb->s_uuid, sizeof(aux_info.sb->s_uuid));
385 crc = ext4_crc16(crc, &i, sizeof(i));
386 crc = ext4_crc16(crc, &aux_info.bg_desc[i], offsetof(struct ext2_group_desc, bg_checksum));
387 aux_info.bg_desc[i].bg_checksum = crc;
388 }
389 }
390
get_block_device_size(int fd)391 u64 get_block_device_size(int fd)
392 {
393 u64 size = 0;
394 int ret;
395
396 #if defined(__linux__)
397 ret = ioctl(fd, BLKGETSIZE64, &size);
398 #elif defined(__APPLE__) && defined(__MACH__)
399 ret = ioctl(fd, DKIOCGETBLOCKCOUNT, &size);
400 #else
401 close(fd);
402 return 0;
403 #endif
404
405 if (ret)
406 return 0;
407
408 return size;
409 }
410
get_file_size(int fd)411 u64 get_file_size(int fd)
412 {
413 struct stat buf;
414 int ret;
415 u64 reserve_len = 0;
416 s64 computed_size;
417
418 ret = fstat(fd, &buf);
419 if (ret)
420 return 0;
421
422 if (info.len < 0)
423 reserve_len = -info.len;
424
425 if (S_ISREG(buf.st_mode))
426 computed_size = buf.st_size - reserve_len;
427 else if (S_ISBLK(buf.st_mode))
428 computed_size = get_block_device_size(fd) - reserve_len;
429 else
430 computed_size = 0;
431
432 if (computed_size < 0) {
433 warn("Computed filesystem size less than 0");
434 computed_size = 0;
435 }
436
437 return computed_size;
438 }
439
parse_num(const char * arg)440 u64 parse_num(const char *arg)
441 {
442 char *endptr;
443 u64 num = strtoull(arg, &endptr, 10);
444 if (*endptr == 'k' || *endptr == 'K')
445 num *= 1024LL;
446 else if (*endptr == 'm' || *endptr == 'M')
447 num *= 1024LL * 1024LL;
448 else if (*endptr == 'g' || *endptr == 'G')
449 num *= 1024LL * 1024LL * 1024LL;
450
451 return num;
452 }
453