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>
32 #include <arpa/inet.h>
33 #include <sys/ioctl.h>
35 #if defined(__linux__)
37 #elif defined(__APPLE__) && defined(__MACH__)
43 struct fs_aux_info aux_info
;
44 struct sparse_file
*ext4_sparse_file
;
48 /* returns 1 if a is a power of b */
49 static int is_power_of(int a
, int b
)
57 return (a
== b
) ? 1 : 0;
60 int bitmap_get_bit(u8
*bitmap
, u32 bit
)
62 if (bitmap
[bit
/ 8] & (1 << (bit
% 8)))
68 void bitmap_clear_bit(u8
*bitmap
, u32 bit
)
70 bitmap
[bit
/ 8] &= ~(1 << (bit
% 8));
75 /* Returns 1 if the bg contains a backup superblock. On filesystems with
76 the sparse_super feature, only block groups 0, 1, and powers of 3, 5,
77 and 7 have backup superblocks. Otherwise, all block groups have backup
79 int ext4_bg_has_super_block(int bg
)
81 /* Without sparse_super, every block group has a superblock */
82 if (!(info
.feat_ro_compat
& EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER
))
85 if (bg
== 0 || bg
== 1)
88 if (is_power_of(bg
, 3) || is_power_of(bg
, 5) || is_power_of(bg
, 7))
94 /* Function to read the primary superblock */
95 void read_sb(int fd
, struct ext4_super_block
*sb
)
99 ret
= lseek64(fd
, 1024, SEEK_SET
);
101 critical_error_errno("failed to seek to superblock");
103 ret
= read(fd
, sb
, sizeof(*sb
));
105 critical_error_errno("failed to read superblock");
106 if (ret
!= sizeof(*sb
))
107 critical_error("failed to read all of superblock");
110 /* Function to write a primary or backup superblock at a given offset */
111 void write_sb(int fd
, unsigned long long offset
, struct ext4_super_block
*sb
)
115 ret
= lseek64(fd
, offset
, SEEK_SET
);
117 critical_error_errno("failed to seek to superblock");
119 ret
= write(fd
, sb
, sizeof(*sb
));
121 critical_error_errno("failed to write superblock");
122 if (ret
!= sizeof(*sb
))
123 critical_error("failed to write all of superblock");
126 /* Write the filesystem image to a file */
127 void write_ext4_image(int fd
, int gz
, int sparse
, int crc
)
129 sparse_file_write(ext4_sparse_file
, fd
, gz
, sparse
, crc
);
132 /* Compute the rest of the parameters of the filesystem from the basic info */
133 void ext4_create_fs_aux_info()
135 aux_info
.first_data_block
= (info
.block_size
> 1024) ? 0 : 1;
136 aux_info
.len_blocks
= info
.len
/ info
.block_size
;
137 aux_info
.inode_table_blocks
= DIV_ROUND_UP(info
.inodes_per_group
* info
.inode_size
,
139 aux_info
.groups
= DIV_ROUND_UP(aux_info
.len_blocks
- aux_info
.first_data_block
,
140 info
.blocks_per_group
);
141 aux_info
.blocks_per_ind
= info
.block_size
/ sizeof(u32
);
142 aux_info
.blocks_per_dind
= aux_info
.blocks_per_ind
* aux_info
.blocks_per_ind
;
143 aux_info
.blocks_per_tind
= aux_info
.blocks_per_dind
* aux_info
.blocks_per_dind
;
145 aux_info
.bg_desc_blocks
=
146 DIV_ROUND_UP(aux_info
.groups
* sizeof(struct ext2_group_desc
),
149 aux_info
.default_i_flags
= EXT4_NOATIME_FL
;
151 u32 last_group_size
= aux_info
.len_blocks
% info
.blocks_per_group
;
152 u32 last_header_size
= 2 + aux_info
.inode_table_blocks
;
153 if (ext4_bg_has_super_block(aux_info
.groups
- 1))
154 last_header_size
+= 1 + aux_info
.bg_desc_blocks
+
155 info
.bg_desc_reserve_blocks
;
156 if (last_group_size
> 0 && last_group_size
< last_header_size
) {
158 aux_info
.len_blocks
-= last_group_size
;
161 aux_info
.sb
= calloc(info
.block_size
, 1);
162 /* Alloc an array to hold the pointers to the backup superblocks */
163 aux_info
.backup_sb
= calloc(aux_info
.groups
, sizeof(char *));
166 critical_error_errno("calloc");
168 aux_info
.bg_desc
= calloc(info
.block_size
, aux_info
.bg_desc_blocks
);
169 if (!aux_info
.bg_desc
)
170 critical_error_errno("calloc");
171 aux_info
.xattrs
= NULL
;
174 void ext4_free_fs_aux_info()
178 for (i
=0; i
<aux_info
.groups
; i
++) {
179 if (aux_info
.backup_sb
[i
])
180 free(aux_info
.backup_sb
[i
]);
183 free(aux_info
.bg_desc
);
186 /* Fill in the superblock memory buffer based on the filesystem parameters */
187 void ext4_fill_in_sb()
190 struct ext4_super_block
*sb
= aux_info
.sb
;
192 sb
->s_inodes_count
= info
.inodes_per_group
* aux_info
.groups
;
193 sb
->s_blocks_count_lo
= aux_info
.len_blocks
;
194 sb
->s_r_blocks_count_lo
= 0;
195 sb
->s_free_blocks_count_lo
= 0;
196 sb
->s_free_inodes_count
= 0;
197 sb
->s_first_data_block
= aux_info
.first_data_block
;
198 sb
->s_log_block_size
= log_2(info
.block_size
/ 1024);
199 sb
->s_obso_log_frag_size
= log_2(info
.block_size
/ 1024);
200 sb
->s_blocks_per_group
= info
.blocks_per_group
;
201 sb
->s_obso_frags_per_group
= info
.blocks_per_group
;
202 sb
->s_inodes_per_group
= info
.inodes_per_group
;
206 sb
->s_max_mnt_count
= 0xFFFF;
207 sb
->s_magic
= EXT4_SUPER_MAGIC
;
208 sb
->s_state
= EXT4_VALID_FS
;
209 sb
->s_errors
= EXT4_ERRORS_RO
;
210 sb
->s_minor_rev_level
= 0;
212 sb
->s_checkinterval
= 0;
213 sb
->s_creator_os
= EXT4_OS_LINUX
;
214 sb
->s_rev_level
= EXT4_DYNAMIC_REV
;
215 sb
->s_def_resuid
= EXT4_DEF_RESUID
;
216 sb
->s_def_resgid
= EXT4_DEF_RESGID
;
218 sb
->s_first_ino
= EXT4_GOOD_OLD_FIRST_INO
;
219 sb
->s_inode_size
= info
.inode_size
;
220 sb
->s_block_group_nr
= 0;
221 sb
->s_feature_compat
= info
.feat_compat
;
222 sb
->s_feature_incompat
= info
.feat_incompat
;
223 sb
->s_feature_ro_compat
= info
.feat_ro_compat
;
224 generate_uuid("extandroid/make_ext4fs", info
.label
, sb
->s_uuid
);
225 memset(sb
->s_volume_name
, 0, sizeof(sb
->s_volume_name
));
226 strncpy(sb
->s_volume_name
, info
.label
, sizeof(sb
->s_volume_name
));
227 memset(sb
->s_last_mounted
, 0, sizeof(sb
->s_last_mounted
));
228 sb
->s_algorithm_usage_bitmap
= 0;
230 sb
->s_reserved_gdt_blocks
= info
.bg_desc_reserve_blocks
;
231 sb
->s_prealloc_blocks
= 0;
232 sb
->s_prealloc_dir_blocks
= 0;
234 //memcpy(sb->s_journal_uuid, sb->s_uuid, sizeof(sb->s_journal_uuid));
235 if (info
.feat_compat
& EXT4_FEATURE_COMPAT_HAS_JOURNAL
)
236 sb
->s_journal_inum
= EXT4_JOURNAL_INO
;
237 sb
->s_journal_dev
= 0;
238 sb
->s_last_orphan
= 0;
239 sb
->s_hash_seed
[0] = 0; /* FIXME */
240 sb
->s_def_hash_version
= DX_HASH_TEA
;
241 sb
->s_reserved_char_pad
= EXT4_JNL_BACKUP_BLOCKS
;
242 sb
->s_desc_size
= sizeof(struct ext2_group_desc
);
243 sb
->s_default_mount_opts
= 0; /* FIXME */
244 sb
->s_first_meta_bg
= 0;
246 //sb->s_jnl_blocks[17]; /* FIXME */
248 sb
->s_blocks_count_hi
= aux_info
.len_blocks
>> 32;
249 sb
->s_r_blocks_count_hi
= 0;
250 sb
->s_free_blocks_count_hi
= 0;
251 sb
->s_min_extra_isize
= sizeof(struct ext4_inode
) -
252 EXT4_GOOD_OLD_INODE_SIZE
;
253 sb
->s_want_extra_isize
= sizeof(struct ext4_inode
) -
254 EXT4_GOOD_OLD_INODE_SIZE
;
256 sb
->s_raid_stride
= 0;
257 sb
->s_mmp_interval
= 0;
259 sb
->s_raid_stripe_width
= 0;
260 sb
->s_log_groups_per_flex
= 0;
261 sb
->s_kbytes_written
= 0;
263 for (i
= 0; i
< aux_info
.groups
; i
++) {
264 u64 group_start_block
= aux_info
.first_data_block
+ i
*
265 info
.blocks_per_group
;
267 if (ext4_bg_has_super_block(i
)) {
269 aux_info
.backup_sb
[i
] = calloc(info
.block_size
, 1);
270 memcpy(aux_info
.backup_sb
[i
], sb
, info
.block_size
);
271 /* Update the block group nr of this backup superblock */
272 aux_info
.backup_sb
[i
]->s_block_group_nr
= i
;
273 sparse_file_add_data(ext4_sparse_file
, aux_info
.backup_sb
[i
],
274 info
.block_size
, group_start_block
);
276 sparse_file_add_data(ext4_sparse_file
, aux_info
.bg_desc
,
277 aux_info
.bg_desc_blocks
* info
.block_size
,
278 group_start_block
+ 1);
279 header_size
= 1 + aux_info
.bg_desc_blocks
+ info
.bg_desc_reserve_blocks
;
282 aux_info
.bg_desc
[i
].bg_block_bitmap
= group_start_block
+ header_size
;
283 aux_info
.bg_desc
[i
].bg_inode_bitmap
= group_start_block
+ header_size
+ 1;
284 aux_info
.bg_desc
[i
].bg_inode_table
= group_start_block
+ header_size
+ 2;
286 aux_info
.bg_desc
[i
].bg_free_blocks_count
= sb
->s_blocks_per_group
;
287 aux_info
.bg_desc
[i
].bg_free_inodes_count
= sb
->s_inodes_per_group
;
288 aux_info
.bg_desc
[i
].bg_used_dirs_count
= 0;
292 void ext4_queue_sb(void)
294 /* The write_data* functions expect only block aligned calls.
295 * This is not an issue, except when we write out the super
296 * block on a system with a block size > 1K. So, we need to
297 * deal with that here.
299 if (info
.block_size
> 1024) {
300 u8
*buf
= calloc(info
.block_size
, 1);
301 memcpy(buf
+ 1024, (u8
*)aux_info
.sb
, 1024);
302 sparse_file_add_data(ext4_sparse_file
, buf
, info
.block_size
, 0);
304 sparse_file_add_data(ext4_sparse_file
, aux_info
.sb
, 1024, 1);
308 void ext4_parse_sb_info(struct ext4_super_block
*sb
)
310 if (sb
->s_magic
!= EXT4_SUPER_MAGIC
)
311 error("superblock magic incorrect");
313 if ((sb
->s_state
& EXT4_VALID_FS
) != EXT4_VALID_FS
)
314 error("filesystem state not valid");
316 ext4_parse_sb(sb
, &info
);
318 ext4_create_fs_aux_info();
320 memcpy(aux_info
.sb
, sb
, sizeof(*sb
));
322 if (aux_info
.first_data_block
!= sb
->s_first_data_block
)
323 critical_error("first data block does not match");
326 void ext4_create_resize_inode()
328 struct block_allocation
*reserve_inode_alloc
= create_allocation();
329 u32 reserve_inode_len
= 0;
332 struct ext4_inode
*inode
= get_inode(EXT4_RESIZE_INO
);
334 error("failed to get resize inode");
338 for (i
= 0; i
< aux_info
.groups
; i
++) {
339 if (ext4_bg_has_super_block(i
)) {
340 u64 group_start_block
= aux_info
.first_data_block
+ i
*
341 info
.blocks_per_group
;
342 u32 reserved_block_start
= group_start_block
+ 1 +
343 aux_info
.bg_desc_blocks
;
344 u32 reserved_block_len
= info
.bg_desc_reserve_blocks
;
345 append_region(reserve_inode_alloc
, reserved_block_start
,
346 reserved_block_len
, i
);
347 reserve_inode_len
+= reserved_block_len
;
351 inode_attach_resize(inode
, reserve_inode_alloc
);
353 inode
->i_mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
354 inode
->i_links_count
= 1;
356 free_alloc(reserve_inode_alloc
);
359 /* Allocate the blocks to hold a journal inode and connect them to the
360 reserved journal inode */
361 void ext4_create_journal_inode()
363 struct ext4_inode
*inode
= get_inode(EXT4_JOURNAL_INO
);
365 error("failed to get journal inode");
369 u8
*journal_data
= inode_allocate_data_extents(inode
,
370 info
.journal_blocks
* info
.block_size
,
371 info
.journal_blocks
* info
.block_size
);
373 error("failed to allocate extents for journal data");
377 inode
->i_mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
378 inode
->i_links_count
= 1;
380 journal_superblock_t
*jsb
= (journal_superblock_t
*)journal_data
;
381 jsb
->s_header
.h_magic
= htonl(JBD2_MAGIC_NUMBER
);
382 jsb
->s_header
.h_blocktype
= htonl(JBD2_SUPERBLOCK_V2
);
383 jsb
->s_blocksize
= htonl(info
.block_size
);
384 jsb
->s_maxlen
= htonl(info
.journal_blocks
);
385 jsb
->s_nr_users
= htonl(1);
386 jsb
->s_first
= htonl(1);
387 jsb
->s_sequence
= htonl(1);
389 memcpy(aux_info
.sb
->s_jnl_blocks
, &inode
->i_block
, sizeof(inode
->i_block
));
392 /* Update the number of free blocks and inodes in the filesystem and in each
394 void ext4_update_free()
398 for (i
= 0; i
< aux_info
.groups
; i
++) {
399 u32 bg_free_blocks
= get_free_blocks(i
);
400 u32 bg_free_inodes
= get_free_inodes(i
);
403 aux_info
.bg_desc
[i
].bg_free_blocks_count
= bg_free_blocks
;
404 aux_info
.sb
->s_free_blocks_count_lo
+= bg_free_blocks
;
406 aux_info
.bg_desc
[i
].bg_free_inodes_count
= bg_free_inodes
;
407 aux_info
.sb
->s_free_inodes_count
+= bg_free_inodes
;
409 aux_info
.bg_desc
[i
].bg_used_dirs_count
+= get_directories(i
);
411 aux_info
.bg_desc
[i
].bg_flags
= get_bg_flags(i
);
413 crc
= ext4_crc16(~0, aux_info
.sb
->s_uuid
, sizeof(aux_info
.sb
->s_uuid
));
414 crc
= ext4_crc16(crc
, &i
, sizeof(i
));
415 crc
= ext4_crc16(crc
, &aux_info
.bg_desc
[i
], offsetof(struct ext2_group_desc
, bg_checksum
));
416 aux_info
.bg_desc
[i
].bg_checksum
= crc
;
420 u64
get_block_device_size(int fd
)
425 #if defined(__linux__)
426 ret
= ioctl(fd
, BLKGETSIZE64
, &size
);
427 #elif defined(__APPLE__) && defined(__MACH__)
428 ret
= ioctl(fd
, DKIOCGETBLOCKCOUNT
, &size
);
440 int is_block_device_fd(int fd
)
443 int ret
= fstat(fd
, &st
);
447 return S_ISBLK(st
.st_mode
);
450 u64
get_file_size(int fd
)
457 ret
= fstat(fd
, &buf
);
462 reserve_len
= -info
.len
;
464 if (S_ISREG(buf
.st_mode
))
465 computed_size
= buf
.st_size
- reserve_len
;
466 else if (S_ISBLK(buf
.st_mode
))
467 computed_size
= get_block_device_size(fd
) - reserve_len
;
471 if (computed_size
< 0) {
472 warn("Computed filesystem size less than 0");
476 return computed_size
;
479 u64
parse_num(const char *arg
)
482 u64 num
= strtoull(arg
, &endptr
, 10);
483 if (*endptr
== 'k' || *endptr
== 'K')
485 else if (*endptr
== 'm' || *endptr
== 'M')
486 num
*= 1024LL * 1024LL;
487 else if (*endptr
== 'g' || *endptr
== 'G')
488 num
*= 1024LL * 1024LL * 1024LL;
493 int read_ext(int fd
, int verbose
)
496 struct ext4_super_block sb
;
500 ext4_parse_sb_info(&sb
);
502 ret
= lseek64(fd
, info
.len
, SEEK_SET
);
504 critical_error_errno("failed to seek to end of input image");
506 ret
= lseek64(fd
, info
.block_size
* (aux_info
.first_data_block
+ 1), SEEK_SET
);
508 critical_error_errno("failed to seek to block group descriptors");
510 ret
= read(fd
, aux_info
.bg_desc
, info
.block_size
* aux_info
.bg_desc_blocks
);
512 critical_error_errno("failed to read block group descriptors");
513 if (ret
!= (int)info
.block_size
* (int)aux_info
.bg_desc_blocks
)
514 critical_error("failed to read all of block group descriptors");
517 printf("Found filesystem with parameters:\n");
518 printf(" Size: %"PRIu64
"\n", info
.len
);
519 printf(" Block size: %d\n", info
.block_size
);
520 printf(" Blocks per group: %d\n", info
.blocks_per_group
);
521 printf(" Inodes per group: %d\n", info
.inodes_per_group
);
522 printf(" Inode size: %d\n", info
.inode_size
);
523 printf(" Label: %s\n", info
.label
);
524 printf(" Blocks: %"PRIu64
"\n", aux_info
.len_blocks
);
525 printf(" Block groups: %d\n", aux_info
.groups
);
526 printf(" Reserved block group size: %d\n", info
.bg_desc_reserve_blocks
);
527 printf(" Used %d/%d inodes and %d/%d blocks\n",
528 aux_info
.sb
->s_inodes_count
- aux_info
.sb
->s_free_inodes_count
,
529 aux_info
.sb
->s_inodes_count
,
530 aux_info
.sb
->s_blocks_count_lo
- aux_info
.sb
->s_free_blocks_count_lo
,
531 aux_info
.sb
->s_blocks_count_lo
);