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 "ext4_utils.h"
23 #include <sparse/sparse.h>
28 #include <sys/types.h>
35 #include <arpa/inet.h>
36 #include <sys/ioctl.h>
39 #if defined(__linux__)
41 #elif defined(__APPLE__) && defined(__MACH__)
47 struct fs_aux_info aux_info
;
48 struct sparse_file
*ext4_sparse_file
;
52 /* returns 1 if a is a power of b */
53 static int is_power_of(int a
, int b
)
61 return (a
== b
) ? 1 : 0;
64 int bitmap_get_bit(u8
*bitmap
, u32 bit
)
66 if (bitmap
[bit
/ 8] & (1 << (bit
% 8)))
72 void bitmap_clear_bit(u8
*bitmap
, u32 bit
)
74 bitmap
[bit
/ 8] &= ~(1 << (bit
% 8));
79 /* Returns 1 if the bg contains a backup superblock. On filesystems with
80 the sparse_super feature, only block groups 0, 1, and powers of 3, 5,
81 and 7 have backup superblocks. Otherwise, all block groups have backup
83 int ext4_bg_has_super_block(int bg
)
85 /* Without sparse_super, every block group has a superblock */
86 if (!(info
.feat_ro_compat
& EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER
))
89 if (bg
== 0 || bg
== 1)
92 if (is_power_of(bg
, 3) || is_power_of(bg
, 5) || is_power_of(bg
, 7))
98 /* Function to read the primary superblock */
99 void read_sb(int fd
, struct ext4_super_block
*sb
)
103 ret
= lseek64(fd
, 1024, SEEK_SET
);
105 critical_error_errno("failed to seek to superblock");
107 ret
= read(fd
, sb
, sizeof(*sb
));
109 critical_error_errno("failed to read superblock");
110 if (ret
!= sizeof(*sb
))
111 critical_error("failed to read all of superblock");
114 /* Function to write a primary or backup superblock at a given offset */
115 void write_sb(int fd
, unsigned long long offset
, struct ext4_super_block
*sb
)
119 ret
= lseek64(fd
, offset
, SEEK_SET
);
121 critical_error_errno("failed to seek to superblock");
123 ret
= write(fd
, sb
, sizeof(*sb
));
125 critical_error_errno("failed to write superblock");
126 if (ret
!= sizeof(*sb
))
127 critical_error("failed to write all of superblock");
130 /* Write the filesystem image to a file */
131 void write_ext4_image(int fd
, int gz
, int sparse
, int crc
)
133 sparse_file_write(ext4_sparse_file
, fd
, gz
, sparse
, crc
);
136 /* Compute the rest of the parameters of the filesystem from the basic info */
137 void ext4_create_fs_aux_info()
139 aux_info
.first_data_block
= (info
.block_size
> 1024) ? 0 : 1;
140 aux_info
.len_blocks
= info
.len
/ info
.block_size
;
141 aux_info
.inode_table_blocks
= DIV_ROUND_UP(info
.inodes_per_group
* info
.inode_size
,
143 aux_info
.groups
= DIV_ROUND_UP(aux_info
.len_blocks
- aux_info
.first_data_block
,
144 info
.blocks_per_group
);
145 aux_info
.blocks_per_ind
= info
.block_size
/ sizeof(u32
);
146 aux_info
.blocks_per_dind
= aux_info
.blocks_per_ind
* aux_info
.blocks_per_ind
;
147 aux_info
.blocks_per_tind
= aux_info
.blocks_per_dind
* aux_info
.blocks_per_dind
;
149 aux_info
.bg_desc_blocks
=
150 DIV_ROUND_UP(aux_info
.groups
* sizeof(struct ext2_group_desc
),
153 aux_info
.default_i_flags
= EXT4_NOATIME_FL
;
155 u32 last_group_size
= aux_info
.len_blocks
% info
.blocks_per_group
;
156 u32 last_header_size
= 2 + aux_info
.inode_table_blocks
;
157 if (ext4_bg_has_super_block(aux_info
.groups
- 1))
158 last_header_size
+= 1 + aux_info
.bg_desc_blocks
+
159 info
.bg_desc_reserve_blocks
;
160 if (last_group_size
> 0 && last_group_size
< last_header_size
) {
162 aux_info
.len_blocks
-= last_group_size
;
165 aux_info
.sb
= calloc(info
.block_size
, 1);
166 /* Alloc an array to hold the pointers to the backup superblocks */
167 aux_info
.backup_sb
= calloc(aux_info
.groups
, sizeof(char *));
170 critical_error_errno("calloc");
172 aux_info
.bg_desc
= calloc(info
.block_size
, aux_info
.bg_desc_blocks
);
173 if (!aux_info
.bg_desc
)
174 critical_error_errno("calloc");
175 aux_info
.xattrs
= NULL
;
178 void ext4_free_fs_aux_info()
182 for (i
=0; i
<aux_info
.groups
; i
++) {
183 if (aux_info
.backup_sb
[i
])
184 free(aux_info
.backup_sb
[i
]);
187 free(aux_info
.bg_desc
);
190 /* Fill in the superblock memory buffer based on the filesystem parameters */
191 void ext4_fill_in_sb()
194 struct ext4_super_block
*sb
= aux_info
.sb
;
196 sb
->s_inodes_count
= info
.inodes_per_group
* aux_info
.groups
;
197 sb
->s_blocks_count_lo
= aux_info
.len_blocks
;
198 sb
->s_r_blocks_count_lo
= 0;
199 sb
->s_free_blocks_count_lo
= 0;
200 sb
->s_free_inodes_count
= 0;
201 sb
->s_first_data_block
= aux_info
.first_data_block
;
202 sb
->s_log_block_size
= log_2(info
.block_size
/ 1024);
203 sb
->s_obso_log_frag_size
= log_2(info
.block_size
/ 1024);
204 sb
->s_blocks_per_group
= info
.blocks_per_group
;
205 sb
->s_obso_frags_per_group
= info
.blocks_per_group
;
206 sb
->s_inodes_per_group
= info
.inodes_per_group
;
210 sb
->s_max_mnt_count
= 0xFFFF;
211 sb
->s_magic
= EXT4_SUPER_MAGIC
;
212 sb
->s_state
= EXT4_VALID_FS
;
213 sb
->s_errors
= EXT4_ERRORS_RO
;
214 sb
->s_minor_rev_level
= 0;
216 sb
->s_checkinterval
= 0;
217 sb
->s_creator_os
= EXT4_OS_LINUX
;
218 sb
->s_rev_level
= EXT4_DYNAMIC_REV
;
219 sb
->s_def_resuid
= EXT4_DEF_RESUID
;
220 sb
->s_def_resgid
= EXT4_DEF_RESGID
;
222 sb
->s_first_ino
= EXT4_GOOD_OLD_FIRST_INO
;
223 sb
->s_inode_size
= info
.inode_size
;
224 sb
->s_block_group_nr
= 0;
225 sb
->s_feature_compat
= info
.feat_compat
;
226 sb
->s_feature_incompat
= info
.feat_incompat
;
227 sb
->s_feature_ro_compat
= info
.feat_ro_compat
;
228 generate_uuid("extandroid/make_ext4fs", info
.label
, sb
->s_uuid
);
229 memset(sb
->s_volume_name
, 0, sizeof(sb
->s_volume_name
));
230 strncpy(sb
->s_volume_name
, info
.label
, sizeof(sb
->s_volume_name
));
231 memset(sb
->s_last_mounted
, 0, sizeof(sb
->s_last_mounted
));
232 sb
->s_algorithm_usage_bitmap
= 0;
234 sb
->s_reserved_gdt_blocks
= info
.bg_desc_reserve_blocks
;
235 sb
->s_prealloc_blocks
= 0;
236 sb
->s_prealloc_dir_blocks
= 0;
238 //memcpy(sb->s_journal_uuid, sb->s_uuid, sizeof(sb->s_journal_uuid));
239 if (info
.feat_compat
& EXT4_FEATURE_COMPAT_HAS_JOURNAL
)
240 sb
->s_journal_inum
= EXT4_JOURNAL_INO
;
241 sb
->s_journal_dev
= 0;
242 sb
->s_last_orphan
= 0;
243 sb
->s_hash_seed
[0] = 0; /* FIXME */
244 sb
->s_def_hash_version
= DX_HASH_TEA
;
245 sb
->s_reserved_char_pad
= EXT4_JNL_BACKUP_BLOCKS
;
246 sb
->s_desc_size
= sizeof(struct ext2_group_desc
);
247 sb
->s_default_mount_opts
= 0; /* FIXME */
248 sb
->s_first_meta_bg
= 0;
250 //sb->s_jnl_blocks[17]; /* FIXME */
252 sb
->s_blocks_count_hi
= aux_info
.len_blocks
>> 32;
253 sb
->s_r_blocks_count_hi
= 0;
254 sb
->s_free_blocks_count_hi
= 0;
255 sb
->s_min_extra_isize
= sizeof(struct ext4_inode
) -
256 EXT4_GOOD_OLD_INODE_SIZE
;
257 sb
->s_want_extra_isize
= sizeof(struct ext4_inode
) -
258 EXT4_GOOD_OLD_INODE_SIZE
;
260 sb
->s_raid_stride
= 0;
261 sb
->s_mmp_interval
= 0;
263 sb
->s_raid_stripe_width
= 0;
264 sb
->s_log_groups_per_flex
= 0;
265 sb
->s_kbytes_written
= 0;
267 for (i
= 0; i
< aux_info
.groups
; i
++) {
268 u64 group_start_block
= aux_info
.first_data_block
+ i
*
269 info
.blocks_per_group
;
271 if (ext4_bg_has_super_block(i
)) {
273 aux_info
.backup_sb
[i
] = calloc(info
.block_size
, 1);
274 memcpy(aux_info
.backup_sb
[i
], sb
, info
.block_size
);
275 /* Update the block group nr of this backup superblock */
276 aux_info
.backup_sb
[i
]->s_block_group_nr
= i
;
277 sparse_file_add_data(ext4_sparse_file
, aux_info
.backup_sb
[i
],
278 info
.block_size
, group_start_block
);
280 sparse_file_add_data(ext4_sparse_file
, aux_info
.bg_desc
,
281 aux_info
.bg_desc_blocks
* info
.block_size
,
282 group_start_block
+ 1);
283 header_size
= 1 + aux_info
.bg_desc_blocks
+ info
.bg_desc_reserve_blocks
;
286 aux_info
.bg_desc
[i
].bg_block_bitmap
= group_start_block
+ header_size
;
287 aux_info
.bg_desc
[i
].bg_inode_bitmap
= group_start_block
+ header_size
+ 1;
288 aux_info
.bg_desc
[i
].bg_inode_table
= group_start_block
+ header_size
+ 2;
290 aux_info
.bg_desc
[i
].bg_free_blocks_count
= sb
->s_blocks_per_group
;
291 aux_info
.bg_desc
[i
].bg_free_inodes_count
= sb
->s_inodes_per_group
;
292 aux_info
.bg_desc
[i
].bg_used_dirs_count
= 0;
296 void ext4_queue_sb(void)
298 /* The write_data* functions expect only block aligned calls.
299 * This is not an issue, except when we write out the super
300 * block on a system with a block size > 1K. So, we need to
301 * deal with that here.
303 if (info
.block_size
> 1024) {
304 u8
*buf
= calloc(info
.block_size
, 1);
305 memcpy(buf
+ 1024, (u8
*)aux_info
.sb
, 1024);
306 sparse_file_add_data(ext4_sparse_file
, buf
, info
.block_size
, 0);
308 sparse_file_add_data(ext4_sparse_file
, aux_info
.sb
, 1024, 1);
312 void ext4_parse_sb_info(struct ext4_super_block
*sb
)
314 if (sb
->s_magic
!= EXT4_SUPER_MAGIC
)
315 error("superblock magic incorrect");
317 if ((sb
->s_state
& EXT4_VALID_FS
) != EXT4_VALID_FS
)
318 error("filesystem state not valid");
320 ext4_parse_sb(sb
, &info
);
322 ext4_create_fs_aux_info();
324 memcpy(aux_info
.sb
, sb
, sizeof(*sb
));
326 if (aux_info
.first_data_block
!= sb
->s_first_data_block
)
327 critical_error("first data block does not match");
330 void ext4_create_resize_inode()
332 struct block_allocation
*reserve_inode_alloc
= create_allocation();
333 u32 reserve_inode_len
= 0;
336 struct ext4_inode
*inode
= get_inode(EXT4_RESIZE_INO
);
338 error("failed to get resize inode");
342 for (i
= 0; i
< aux_info
.groups
; i
++) {
343 if (ext4_bg_has_super_block(i
)) {
344 u64 group_start_block
= aux_info
.first_data_block
+ i
*
345 info
.blocks_per_group
;
346 u32 reserved_block_start
= group_start_block
+ 1 +
347 aux_info
.bg_desc_blocks
;
348 u32 reserved_block_len
= info
.bg_desc_reserve_blocks
;
349 append_region(reserve_inode_alloc
, reserved_block_start
,
350 reserved_block_len
, i
);
351 reserve_inode_len
+= reserved_block_len
;
355 inode_attach_resize(inode
, reserve_inode_alloc
);
357 inode
->i_mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
358 inode
->i_links_count
= 1;
360 free_alloc(reserve_inode_alloc
);
363 /* Allocate the blocks to hold a journal inode and connect them to the
364 reserved journal inode */
365 void ext4_create_journal_inode()
367 struct ext4_inode
*inode
= get_inode(EXT4_JOURNAL_INO
);
369 error("failed to get journal inode");
373 u8
*journal_data
= inode_allocate_data_extents(inode
,
374 info
.journal_blocks
* info
.block_size
,
375 info
.journal_blocks
* info
.block_size
);
377 error("failed to allocate extents for journal data");
381 inode
->i_mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
382 inode
->i_links_count
= 1;
384 journal_superblock_t
*jsb
= (journal_superblock_t
*)journal_data
;
385 jsb
->s_header
.h_magic
= htonl(JBD2_MAGIC_NUMBER
);
386 jsb
->s_header
.h_blocktype
= htonl(JBD2_SUPERBLOCK_V2
);
387 jsb
->s_blocksize
= htonl(info
.block_size
);
388 jsb
->s_maxlen
= htonl(info
.journal_blocks
);
389 jsb
->s_nr_users
= htonl(1);
390 jsb
->s_first
= htonl(1);
391 jsb
->s_sequence
= htonl(1);
393 memcpy(aux_info
.sb
->s_jnl_blocks
, &inode
->i_block
, sizeof(inode
->i_block
));
396 /* Update the number of free blocks and inodes in the filesystem and in each
398 void ext4_update_free()
402 for (i
= 0; i
< aux_info
.groups
; i
++) {
403 u32 bg_free_blocks
= get_free_blocks(i
);
404 u32 bg_free_inodes
= get_free_inodes(i
);
407 aux_info
.bg_desc
[i
].bg_free_blocks_count
= bg_free_blocks
;
408 aux_info
.sb
->s_free_blocks_count_lo
+= bg_free_blocks
;
410 aux_info
.bg_desc
[i
].bg_free_inodes_count
= bg_free_inodes
;
411 aux_info
.sb
->s_free_inodes_count
+= bg_free_inodes
;
413 aux_info
.bg_desc
[i
].bg_used_dirs_count
+= get_directories(i
);
415 aux_info
.bg_desc
[i
].bg_flags
= get_bg_flags(i
);
417 crc
= ext4_crc16(~0, aux_info
.sb
->s_uuid
, sizeof(aux_info
.sb
->s_uuid
));
418 crc
= ext4_crc16(crc
, &i
, sizeof(i
));
419 crc
= ext4_crc16(crc
, &aux_info
.bg_desc
[i
], offsetof(struct ext2_group_desc
, bg_checksum
));
420 aux_info
.bg_desc
[i
].bg_checksum
= crc
;
424 u64
get_block_device_size(int fd
)
429 #if defined(__linux__)
430 ret
= ioctl(fd
, BLKGETSIZE64
, &size
);
431 #elif defined(__APPLE__) && defined(__MACH__)
432 ret
= ioctl(fd
, DKIOCGETBLOCKCOUNT
, &size
);
444 int is_block_device_fd(int fd
)
450 int ret
= fstat(fd
, &st
);
454 return S_ISBLK(st
.st_mode
);
458 u64
get_file_size(int fd
)
465 ret
= fstat(fd
, &buf
);
470 reserve_len
= -info
.len
;
472 if (S_ISREG(buf
.st_mode
))
473 computed_size
= buf
.st_size
- reserve_len
;
474 else if (S_ISBLK(buf
.st_mode
))
475 computed_size
= get_block_device_size(fd
) - reserve_len
;
479 if (computed_size
< 0) {
480 warn("Computed filesystem size less than 0");
484 return computed_size
;
487 u64
parse_num(const char *arg
)
490 u64 num
= strtoull(arg
, &endptr
, 10);
491 if (*endptr
== 'k' || *endptr
== 'K')
493 else if (*endptr
== 'm' || *endptr
== 'M')
494 num
*= 1024LL * 1024LL;
495 else if (*endptr
== 'g' || *endptr
== 'G')
496 num
*= 1024LL * 1024LL * 1024LL;
501 int read_ext(int fd
, int verbose
)
504 struct ext4_super_block sb
;
508 ext4_parse_sb_info(&sb
);
510 ret
= lseek64(fd
, info
.len
, SEEK_SET
);
512 critical_error_errno("failed to seek to end of input image");
514 ret
= lseek64(fd
, info
.block_size
* (aux_info
.first_data_block
+ 1), SEEK_SET
);
516 critical_error_errno("failed to seek to block group descriptors");
518 ret
= read(fd
, aux_info
.bg_desc
, info
.block_size
* aux_info
.bg_desc_blocks
);
520 critical_error_errno("failed to read block group descriptors");
521 if (ret
!= (int)info
.block_size
* (int)aux_info
.bg_desc_blocks
)
522 critical_error("failed to read all of block group descriptors");
525 printf("Found filesystem with parameters:\n");
526 printf(" Size: %"PRIu64
"\n", info
.len
);
527 printf(" Block size: %d\n", info
.block_size
);
528 printf(" Blocks per group: %d\n", info
.blocks_per_group
);
529 printf(" Inodes per group: %d\n", info
.inodes_per_group
);
530 printf(" Inode size: %d\n", info
.inode_size
);
531 printf(" Label: %s\n", info
.label
);
532 printf(" Blocks: %"PRIu64
"\n", aux_info
.len_blocks
);
533 printf(" Block groups: %d\n", aux_info
.groups
);
534 printf(" Reserved block group size: %d\n", info
.bg_desc_reserve_blocks
);
535 printf(" Used %d/%d inodes and %d/%d blocks\n",
536 aux_info
.sb
->s_inodes_count
- aux_info
.sb
->s_free_inodes_count
,
537 aux_info
.sb
->s_inodes_count
,
538 aux_info
.sb
->s_blocks_count_lo
- aux_info
.sb
->s_free_blocks_count_lo
,
539 aux_info
.sb
->s_blocks_count_lo
);