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>
31 #include <sys/types.h>
38 #include <arpa/inet.h>
39 #include <sys/ioctl.h>
42 #if defined(__linux__)
44 #elif defined(__APPLE__) && defined(__MACH__)
50 struct fs_aux_info aux_info;
51 struct sparse_file *ext4_sparse_file;
52 struct block_allocation *base_fs_allocations = NULL;
56 /* Definition from RFC-4122 */
60 u16 time_hi_and_version;
67 static void sha1_hash(const char *namespace, const char *name,
68 unsigned char sha1[SHA1_DIGEST_LENGTH])
72 SHA1Update(&ctx, (const u8*)namespace, strlen(namespace));
73 SHA1Update(&ctx, (const u8*)name, strlen(name));
74 SHA1Final(sha1, &ctx);
77 static void generate_sha1_uuid(const char *namespace, const char *name, u8 result[16])
79 unsigned char sha1[SHA1_DIGEST_LENGTH];
80 struct uuid *uuid = (struct uuid *)result;
82 sha1_hash(namespace, name, (unsigned char*)sha1);
83 memcpy(uuid, sha1, sizeof(struct uuid));
85 uuid->time_low = ntohl(uuid->time_low);
86 uuid->time_mid = ntohs(uuid->time_mid);
87 uuid->time_hi_and_version = ntohs(uuid->time_hi_and_version);
88 uuid->time_hi_and_version &= 0x0FFF;
89 uuid->time_hi_and_version |= (5 << 12);
90 uuid->clk_seq_hi_res &= ~(1 << 6);
91 uuid->clk_seq_hi_res |= 1 << 7;
94 /* returns 1 if a is a power of b */
95 static int is_power_of(int a, int b)
103 return (a == b) ? 1 : 0;
106 int bitmap_get_bit(u8 *bitmap, u32 bit)
108 if (bitmap[bit / 8] & (1 << (bit % 8)))
114 void bitmap_clear_bit(u8 *bitmap, u32 bit)
116 bitmap[bit / 8] &= ~(1 << (bit % 8));
121 /* Returns 1 if the bg contains a backup superblock. On filesystems with
122 the sparse_super feature, only block groups 0, 1, and powers of 3, 5,
123 and 7 have backup superblocks. Otherwise, all block groups have backup
125 int ext4_bg_has_super_block(int bg)
127 /* Without sparse_super, every block group has a superblock */
128 if (!(info.feat_ro_compat & EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER))
131 if (bg == 0 || bg == 1)
134 if (is_power_of(bg, 3) || is_power_of(bg, 5) || is_power_of(bg, 7))
140 /* Function to read the primary superblock */
141 void read_sb(int fd, struct ext4_super_block *sb)
145 ret = lseek64(fd, 1024, SEEK_SET);
147 critical_error_errno("failed to seek to superblock");
149 ret = read(fd, sb, sizeof(*sb));
151 critical_error_errno("failed to read superblock");
152 if (ret != sizeof(*sb))
153 critical_error("failed to read all of superblock");
156 /* Function to write a primary or backup superblock at a given offset */
157 void write_sb(int fd, unsigned long long offset, struct ext4_super_block *sb)
161 ret = lseek64(fd, offset, SEEK_SET);
163 critical_error_errno("failed to seek to superblock");
165 ret = write(fd, sb, sizeof(*sb));
167 critical_error_errno("failed to write superblock");
168 if (ret != sizeof(*sb))
169 critical_error("failed to write all of superblock");
172 static void block_device_write_sb(int fd)
174 unsigned long long offset;
177 /* write out the backup superblocks */
178 for (i = 1; i < aux_info.groups; i++) {
179 if (ext4_bg_has_super_block(i)) {
180 offset = info.block_size * (aux_info.first_data_block
181 + i * info.blocks_per_group);
182 write_sb(fd, offset, aux_info.backup_sb[i]);
186 /* write out the primary superblock */
187 write_sb(fd, 1024, aux_info.sb);
190 /* Write the filesystem image to a file */
191 void write_ext4_image(int fd, int gz, int sparse, int crc)
193 sparse_file_write(ext4_sparse_file, fd, gz, sparse, crc);
195 if (info.block_device)
196 block_device_write_sb(fd);
199 /* Compute the rest of the parameters of the filesystem from the basic info */
200 void ext4_create_fs_aux_info()
202 aux_info.first_data_block = (info.block_size > 1024) ? 0 : 1;
203 aux_info.len_blocks = info.len / info.block_size;
204 aux_info.inode_table_blocks = DIV_ROUND_UP(info.inodes_per_group * info.inode_size,
206 aux_info.groups = DIV_ROUND_UP(aux_info.len_blocks - aux_info.first_data_block,
207 info.blocks_per_group);
208 aux_info.blocks_per_ind = info.block_size / sizeof(u32);
209 aux_info.blocks_per_dind = aux_info.blocks_per_ind * aux_info.blocks_per_ind;
210 aux_info.blocks_per_tind = aux_info.blocks_per_dind * aux_info.blocks_per_dind;
212 aux_info.bg_desc_blocks =
213 DIV_ROUND_UP(aux_info.groups * sizeof(struct ext2_group_desc),
216 aux_info.default_i_flags = EXT4_NOATIME_FL;
218 u32 last_group_size = aux_info.len_blocks % info.blocks_per_group;
219 u32 last_header_size = 2 + aux_info.inode_table_blocks;
220 if (ext4_bg_has_super_block(aux_info.groups - 1))
221 last_header_size += 1 + aux_info.bg_desc_blocks +
222 info.bg_desc_reserve_blocks;
223 if (last_group_size > 0 && last_group_size < last_header_size) {
225 aux_info.len_blocks -= last_group_size;
228 /* A zero-filled superblock to be written firstly to the block
229 * device to mark the file-system as invalid
231 aux_info.sb_zero = calloc(1, info.block_size);
232 if (!aux_info.sb_zero)
233 critical_error_errno("calloc");
235 /* The write_data* functions expect only block aligned calls.
236 * This is not an issue, except when we write out the super
237 * block on a system with a block size > 1K. So, we need to
238 * deal with that here.
240 aux_info.sb_block = calloc(1, info.block_size);
241 if (!aux_info.sb_block)
242 critical_error_errno("calloc");
244 if (info.block_size > 1024)
245 aux_info.sb = (struct ext4_super_block *)((char *)aux_info.sb_block + 1024);
247 aux_info.sb = aux_info.sb_block;
249 /* Alloc an array to hold the pointers to the backup superblocks */
250 aux_info.backup_sb = calloc(aux_info.groups, sizeof(char *));
253 critical_error_errno("calloc");
255 aux_info.bg_desc = calloc(info.block_size, aux_info.bg_desc_blocks);
256 if (!aux_info.bg_desc)
257 critical_error_errno("calloc");
258 aux_info.xattrs = NULL;
261 void ext4_free_fs_aux_info()
265 for (i=0; i<aux_info.groups; i++) {
266 if (aux_info.backup_sb[i])
267 free(aux_info.backup_sb[i]);
269 free(aux_info.sb_block);
270 free(aux_info.sb_zero);
271 free(aux_info.bg_desc);
274 /* Fill in the superblock memory buffer based on the filesystem parameters */
275 void ext4_fill_in_sb(int real_uuid)
278 struct ext4_super_block *sb = aux_info.sb;
280 sb->s_inodes_count = info.inodes_per_group * aux_info.groups;
281 sb->s_blocks_count_lo = aux_info.len_blocks;
282 sb->s_r_blocks_count_lo = 0;
283 sb->s_free_blocks_count_lo = 0;
284 sb->s_free_inodes_count = 0;
285 sb->s_first_data_block = aux_info.first_data_block;
286 sb->s_log_block_size = log_2(info.block_size / 1024);
287 sb->s_obso_log_frag_size = log_2(info.block_size / 1024);
288 sb->s_blocks_per_group = info.blocks_per_group;
289 sb->s_obso_frags_per_group = info.blocks_per_group;
290 sb->s_inodes_per_group = info.inodes_per_group;
294 sb->s_max_mnt_count = 10;
295 sb->s_magic = EXT4_SUPER_MAGIC;
296 sb->s_state = EXT4_VALID_FS;
297 sb->s_errors = EXT4_ERRORS_RO;
298 sb->s_minor_rev_level = 0;
300 sb->s_checkinterval = 0;
301 sb->s_creator_os = EXT4_OS_LINUX;
302 sb->s_rev_level = EXT4_DYNAMIC_REV;
303 sb->s_def_resuid = EXT4_DEF_RESUID;
304 sb->s_def_resgid = EXT4_DEF_RESGID;
306 sb->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
307 sb->s_inode_size = info.inode_size;
308 sb->s_block_group_nr = 0;
309 sb->s_feature_compat = info.feat_compat;
310 sb->s_feature_incompat = info.feat_incompat;
311 sb->s_feature_ro_compat = info.feat_ro_compat;
312 if (real_uuid == 1) {
314 uuid_generate(sb->s_uuid);
316 fprintf(stderr, "Not compiled with real UUID support\n");
320 generate_sha1_uuid("extandroid/make_ext4fs", info.label, sb->s_uuid);
322 memset(sb->s_volume_name, 0, sizeof(sb->s_volume_name));
323 strncpy(sb->s_volume_name, info.label, sizeof(sb->s_volume_name));
324 memset(sb->s_last_mounted, 0, sizeof(sb->s_last_mounted));
325 sb->s_algorithm_usage_bitmap = 0;
327 sb->s_reserved_gdt_blocks = info.bg_desc_reserve_blocks;
328 sb->s_prealloc_blocks = 0;
329 sb->s_prealloc_dir_blocks = 0;
331 //memcpy(sb->s_journal_uuid, sb->s_uuid, sizeof(sb->s_journal_uuid));
332 if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL)
333 sb->s_journal_inum = EXT4_JOURNAL_INO;
334 sb->s_journal_dev = 0;
335 sb->s_last_orphan = 0;
336 sb->s_hash_seed[0] = 0; /* FIXME */
337 sb->s_def_hash_version = DX_HASH_TEA;
338 sb->s_reserved_char_pad = EXT4_JNL_BACKUP_BLOCKS;
339 sb->s_desc_size = sizeof(struct ext2_group_desc);
340 sb->s_default_mount_opts = 0; /* FIXME */
341 sb->s_first_meta_bg = 0;
343 //sb->s_jnl_blocks[17]; /* FIXME */
345 sb->s_blocks_count_hi = aux_info.len_blocks >> 32;
346 sb->s_r_blocks_count_hi = 0;
347 sb->s_free_blocks_count_hi = 0;
348 sb->s_min_extra_isize = sizeof(struct ext4_inode) -
349 EXT4_GOOD_OLD_INODE_SIZE;
350 sb->s_want_extra_isize = sizeof(struct ext4_inode) -
351 EXT4_GOOD_OLD_INODE_SIZE;
353 sb->s_raid_stride = 0;
354 sb->s_mmp_interval = 0;
356 sb->s_raid_stripe_width = 0;
357 sb->s_log_groups_per_flex = 0;
358 sb->s_kbytes_written = 0;
360 for (i = 0; i < aux_info.groups; i++) {
361 u64 group_start_block = aux_info.first_data_block + i *
362 info.blocks_per_group;
364 if (ext4_bg_has_super_block(i)) {
366 aux_info.backup_sb[i] = calloc(info.block_size, 1);
367 memcpy(aux_info.backup_sb[i], sb, sizeof(struct ext4_super_block));
368 /* Update the block group nr of this backup superblock */
369 aux_info.backup_sb[i]->s_block_group_nr = i;
370 ext4_queue_sb(group_start_block, info.block_device ?
371 aux_info.sb_zero : aux_info.backup_sb[i]);
373 sparse_file_add_data(ext4_sparse_file, aux_info.bg_desc,
374 aux_info.bg_desc_blocks * info.block_size,
375 group_start_block + 1);
376 header_size = 1 + aux_info.bg_desc_blocks + info.bg_desc_reserve_blocks;
379 aux_info.bg_desc[i].bg_block_bitmap = group_start_block + header_size;
380 aux_info.bg_desc[i].bg_inode_bitmap = group_start_block + header_size + 1;
381 aux_info.bg_desc[i].bg_inode_table = group_start_block + header_size + 2;
383 aux_info.bg_desc[i].bg_free_blocks_count = sb->s_blocks_per_group;
384 aux_info.bg_desc[i].bg_free_inodes_count = sb->s_inodes_per_group;
385 aux_info.bg_desc[i].bg_used_dirs_count = 0;
388 /* Queue the primary superblock to be written out - if it's a block device,
389 * queue a zero-filled block first, the correct version of superblock will
390 * be written to the block device after all other blocks are written.
392 * The file-system on the block device will not be valid until the correct
393 * version of superblocks are written, this is to avoid the likelihood of a
394 * partially created file-system.
396 ext4_queue_sb(aux_info.first_data_block, info.block_device ?
397 aux_info.sb_zero : aux_info.sb_block);
401 void ext4_queue_sb(u64 start_block, struct ext4_super_block *sb)
403 sparse_file_add_data(ext4_sparse_file, sb, info.block_size, start_block);
406 void ext4_parse_sb_info(struct ext4_super_block *sb)
408 if (sb->s_magic != EXT4_SUPER_MAGIC)
409 error("superblock magic incorrect");
411 if ((sb->s_state & EXT4_VALID_FS) != EXT4_VALID_FS)
412 error("filesystem state not valid");
414 ext4_parse_sb(sb, &info);
416 ext4_create_fs_aux_info();
418 memcpy(aux_info.sb, sb, sizeof(*sb));
420 if (aux_info.first_data_block != sb->s_first_data_block)
421 critical_error("first data block does not match");
424 void ext4_create_resize_inode()
426 struct block_allocation *reserve_inode_alloc = create_allocation();
427 u32 reserve_inode_len = 0;
430 struct ext4_inode *inode = get_inode(EXT4_RESIZE_INO);
432 error("failed to get resize inode");
436 for (i = 0; i < aux_info.groups; i++) {
437 if (ext4_bg_has_super_block(i)) {
438 u64 group_start_block = aux_info.first_data_block + i *
439 info.blocks_per_group;
440 u32 reserved_block_start = group_start_block + 1 +
441 aux_info.bg_desc_blocks;
442 u32 reserved_block_len = info.bg_desc_reserve_blocks;
443 append_region(reserve_inode_alloc, reserved_block_start,
444 reserved_block_len, i);
445 reserve_inode_len += reserved_block_len;
449 inode_attach_resize(inode, reserve_inode_alloc);
451 inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR;
452 inode->i_links_count = 1;
454 free_alloc(reserve_inode_alloc);
457 /* Allocate the blocks to hold a journal inode and connect them to the
458 reserved journal inode */
459 void ext4_create_journal_inode()
461 struct ext4_inode *inode = get_inode(EXT4_JOURNAL_INO);
463 error("failed to get journal inode");
467 u8 *journal_data = inode_allocate_data_extents(inode,
468 info.journal_blocks * info.block_size,
469 info.journal_blocks * info.block_size);
471 error("failed to allocate extents for journal data");
475 inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR;
476 inode->i_links_count = 1;
478 journal_superblock_t *jsb = (journal_superblock_t *)journal_data;
479 jsb->s_header.h_magic = htonl(JBD2_MAGIC_NUMBER);
480 jsb->s_header.h_blocktype = htonl(JBD2_SUPERBLOCK_V2);
481 jsb->s_blocksize = htonl(info.block_size);
482 jsb->s_maxlen = htonl(info.journal_blocks);
483 jsb->s_nr_users = htonl(1);
484 jsb->s_first = htonl(1);
485 jsb->s_sequence = htonl(1);
487 memcpy(aux_info.sb->s_jnl_blocks, &inode->i_block, sizeof(inode->i_block));
490 /* Update the number of free blocks and inodes in the filesystem and in each
492 void ext4_update_free()
496 for (i = 0; i < aux_info.groups; i++) {
497 u32 bg_free_blocks = get_free_blocks(i);
498 u32 bg_free_inodes = get_free_inodes(i);
501 aux_info.bg_desc[i].bg_free_blocks_count = bg_free_blocks;
502 aux_info.sb->s_free_blocks_count_lo += bg_free_blocks;
504 aux_info.bg_desc[i].bg_free_inodes_count = bg_free_inodes;
505 aux_info.sb->s_free_inodes_count += bg_free_inodes;
507 aux_info.bg_desc[i].bg_used_dirs_count += get_directories(i);
509 aux_info.bg_desc[i].bg_flags = get_bg_flags(i);
511 crc = ext4_crc16(~0, aux_info.sb->s_uuid, sizeof(aux_info.sb->s_uuid));
512 crc = ext4_crc16(crc, &i, sizeof(i));
513 crc = ext4_crc16(crc, &aux_info.bg_desc[i], offsetof(struct ext2_group_desc, bg_checksum));
514 aux_info.bg_desc[i].bg_checksum = crc;
518 u64 get_block_device_size(int fd)
523 #if defined(__linux__)
524 ret = ioctl(fd, BLKGETSIZE64, &size);
525 #elif defined(__APPLE__) && defined(__MACH__)
526 ret = ioctl(fd, DKIOCGETBLOCKCOUNT, &size);
538 int is_block_device_fd(int fd)
544 int ret = fstat(fd, &st);
548 return S_ISBLK(st.st_mode);
552 u64 get_file_size(int fd)
559 ret = fstat(fd, &buf);
564 reserve_len = -info.len;
566 if (S_ISREG(buf.st_mode))
567 computed_size = buf.st_size - reserve_len;
568 else if (S_ISBLK(buf.st_mode))
569 computed_size = get_block_device_size(fd) - reserve_len;
573 if (computed_size < 0) {
574 warn("Computed filesystem size less than 0");
578 return computed_size;
581 u64 parse_num(const char *arg)
584 u64 num = strtoull(arg, &endptr, 10);
585 if (*endptr == 'k' || *endptr == 'K')
587 else if (*endptr == 'm' || *endptr == 'M')
588 num *= 1024LL * 1024LL;
589 else if (*endptr == 'g' || *endptr == 'G')
590 num *= 1024LL * 1024LL * 1024LL;
595 int read_ext(int fd, int verbose)
598 struct ext4_super_block sb;
602 ext4_parse_sb_info(&sb);
604 ret = lseek64(fd, info.len, SEEK_SET);
606 critical_error_errno("failed to seek to end of input image");
608 ret = lseek64(fd, info.block_size * (aux_info.first_data_block + 1), SEEK_SET);
610 critical_error_errno("failed to seek to block group descriptors");
612 ret = read(fd, aux_info.bg_desc, info.block_size * aux_info.bg_desc_blocks);
614 critical_error_errno("failed to read block group descriptors");
615 if (ret != (int)info.block_size * (int)aux_info.bg_desc_blocks)
616 critical_error("failed to read all of block group descriptors");
619 printf("Found filesystem with parameters:\n");
620 printf(" Size: %"PRIu64"\n", info.len);
621 printf(" Block size: %d\n", info.block_size);
622 printf(" Blocks per group: %d\n", info.blocks_per_group);
623 printf(" Inodes per group: %d\n", info.inodes_per_group);
624 printf(" Inode size: %d\n", info.inode_size);
625 printf(" Label: %s\n", info.label);
626 printf(" Blocks: %"PRIu64"\n", aux_info.len_blocks);
627 printf(" Block groups: %d\n", aux_info.groups);
628 printf(" Reserved block group size: %d\n", info.bg_desc_reserve_blocks);
629 printf(" Used %d/%d inodes and %d/%d blocks\n",
630 aux_info.sb->s_inodes_count - aux_info.sb->s_free_inodes_count,
631 aux_info.sb->s_inodes_count,
632 aux_info.sb->s_blocks_count_lo - aux_info.sb->s_free_blocks_count_lo,
633 aux_info.sb->s_blocks_count_lo);