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/ext4_utils.h"
24 #include <sys/types.h>
26 #include <sparse/sparse.h>
40 #include <arpa/inet.h>
41 #include <sys/ioctl.h>
44 #if defined(__linux__)
46 #elif defined(__APPLE__) && defined(__MACH__)
52 struct fs_aux_info aux_info;
53 struct sparse_file *ext4_sparse_file;
54 struct block_allocation *base_fs_allocations = NULL;
58 /* Definition from RFC-4122 */
62 u16 time_hi_and_version;
69 static void sha1_hash(const char *namespace, const char *name,
70 unsigned char sha1[SHA1_DIGEST_LENGTH])
74 SHA1Update(&ctx, (const u8*)namespace, strlen(namespace));
75 SHA1Update(&ctx, (const u8*)name, strlen(name));
76 SHA1Final(sha1, &ctx);
79 static void generate_sha1_uuid(const char *namespace, const char *name, u8 result[16])
81 unsigned char sha1[SHA1_DIGEST_LENGTH];
82 struct uuid *uuid = (struct uuid *)result;
84 sha1_hash(namespace, name, (unsigned char*)sha1);
85 memcpy(uuid, sha1, sizeof(struct uuid));
87 uuid->time_low = ntohl(uuid->time_low);
88 uuid->time_mid = ntohs(uuid->time_mid);
89 uuid->time_hi_and_version = ntohs(uuid->time_hi_and_version);
90 uuid->time_hi_and_version &= 0x0FFF;
91 uuid->time_hi_and_version |= (5 << 12);
92 uuid->clk_seq_hi_res &= ~(1 << 6);
93 uuid->clk_seq_hi_res |= 1 << 7;
96 /* returns 1 if a is a power of b */
97 static int is_power_of(int a, int b)
105 return (a == b) ? 1 : 0;
108 int bitmap_get_bit(u8 *bitmap, u32 bit)
110 if (bitmap[bit / 8] & (1 << (bit % 8)))
116 void bitmap_clear_bit(u8 *bitmap, u32 bit)
118 bitmap[bit / 8] &= ~(1 << (bit % 8));
123 /* Returns 1 if the bg contains a backup superblock. On filesystems with
124 the sparse_super feature, only block groups 0, 1, and powers of 3, 5,
125 and 7 have backup superblocks. Otherwise, all block groups have backup
127 int ext4_bg_has_super_block(int bg)
129 /* Without sparse_super, every block group has a superblock */
130 if (!(info.feat_ro_compat & EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER))
133 if (bg == 0 || bg == 1)
136 if (is_power_of(bg, 3) || is_power_of(bg, 5) || is_power_of(bg, 7))
142 /* Function to read the primary superblock */
143 void read_sb(int fd, struct ext4_super_block *sb)
147 ret = lseek64(fd, 1024, SEEK_SET);
149 critical_error_errno("failed to seek to superblock");
151 ret = read(fd, sb, sizeof(*sb));
153 critical_error_errno("failed to read superblock");
154 if (ret != sizeof(*sb))
155 critical_error("failed to read all of superblock");
158 /* Function to write a primary or backup superblock at a given offset */
159 void write_sb(int fd, unsigned long long offset, struct ext4_super_block *sb)
163 ret = lseek64(fd, offset, SEEK_SET);
165 critical_error_errno("failed to seek to superblock");
167 ret = write(fd, sb, sizeof(*sb));
169 critical_error_errno("failed to write superblock");
170 if (ret != sizeof(*sb))
171 critical_error("failed to write all of superblock");
174 static void block_device_write_sb(int fd)
176 unsigned long long offset;
179 /* write out the backup superblocks */
180 for (i = 1; i < aux_info.groups; i++) {
181 if (ext4_bg_has_super_block(i)) {
182 offset = (unsigned long long)info.block_size * (aux_info.first_data_block
183 + i * info.blocks_per_group);
184 write_sb(fd, offset, aux_info.backup_sb[i]);
188 /* write out the primary superblock */
189 write_sb(fd, 1024, aux_info.sb);
192 /* Write the filesystem image to a file */
193 void write_ext4_image(int fd, int gz, int sparse, int crc)
195 sparse_file_write(ext4_sparse_file, fd, gz, sparse, crc);
197 if (info.block_device)
198 block_device_write_sb(fd);
201 /* Compute the rest of the parameters of the filesystem from the basic info */
202 void ext4_create_fs_aux_info()
204 aux_info.first_data_block = (info.block_size > 1024) ? 0 : 1;
205 aux_info.len_blocks = info.len / info.block_size;
206 aux_info.inode_table_blocks = DIV_ROUND_UP(info.inodes_per_group * info.inode_size,
208 aux_info.groups = DIV_ROUND_UP(aux_info.len_blocks - aux_info.first_data_block,
209 info.blocks_per_group);
210 aux_info.blocks_per_ind = info.block_size / sizeof(u32);
211 aux_info.blocks_per_dind = aux_info.blocks_per_ind * aux_info.blocks_per_ind;
212 aux_info.blocks_per_tind = aux_info.blocks_per_dind * aux_info.blocks_per_dind;
214 aux_info.bg_desc_blocks =
215 DIV_ROUND_UP(aux_info.groups * sizeof(struct ext2_group_desc),
218 aux_info.default_i_flags = EXT4_NOATIME_FL;
220 u32 last_group_size = aux_info.len_blocks % info.blocks_per_group;
221 u32 last_header_size = 2 + aux_info.inode_table_blocks;
222 if (ext4_bg_has_super_block(aux_info.groups - 1))
223 last_header_size += 1 + aux_info.bg_desc_blocks +
224 info.bg_desc_reserve_blocks;
225 if (aux_info.groups <= 1 && last_group_size < last_header_size) {
226 critical_error("filesystem size too small");
228 if (last_group_size > 0 && last_group_size < last_header_size) {
230 aux_info.len_blocks -= last_group_size;
233 /* A zero-filled superblock to be written firstly to the block
234 * device to mark the file-system as invalid
236 aux_info.sb_zero = calloc(1, info.block_size);
237 if (!aux_info.sb_zero)
238 critical_error_errno("calloc");
240 /* The write_data* functions expect only block aligned calls.
241 * This is not an issue, except when we write out the super
242 * block on a system with a block size > 1K. So, we need to
243 * deal with that here.
245 aux_info.sb_block = calloc(1, info.block_size);
246 if (!aux_info.sb_block)
247 critical_error_errno("calloc");
249 if (info.block_size > 1024)
250 aux_info.sb = (struct ext4_super_block *)((char *)aux_info.sb_block + 1024);
252 aux_info.sb = aux_info.sb_block;
254 /* Alloc an array to hold the pointers to the backup superblocks */
255 aux_info.backup_sb = calloc(aux_info.groups, sizeof(char *));
258 critical_error_errno("calloc");
260 aux_info.bg_desc = calloc(info.block_size, aux_info.bg_desc_blocks);
261 if (!aux_info.bg_desc)
262 critical_error_errno("calloc");
263 aux_info.xattrs = NULL;
266 void ext4_free_fs_aux_info()
270 for (i=0; i<aux_info.groups; i++) {
271 if (aux_info.backup_sb[i])
272 free(aux_info.backup_sb[i]);
274 free(aux_info.sb_block);
275 free(aux_info.sb_zero);
276 free(aux_info.bg_desc);
279 /* Fill in the superblock memory buffer based on the filesystem parameters */
280 void ext4_fill_in_sb(int real_uuid)
283 struct ext4_super_block *sb = aux_info.sb;
285 sb->s_inodes_count = info.inodes_per_group * aux_info.groups;
286 sb->s_blocks_count_lo = aux_info.len_blocks;
287 sb->s_r_blocks_count_lo = 0;
288 sb->s_free_blocks_count_lo = 0;
289 sb->s_free_inodes_count = 0;
290 sb->s_first_data_block = aux_info.first_data_block;
291 sb->s_log_block_size = log_2(info.block_size / 1024);
292 sb->s_obso_log_frag_size = log_2(info.block_size / 1024);
293 sb->s_blocks_per_group = info.blocks_per_group;
294 sb->s_obso_frags_per_group = info.blocks_per_group;
295 sb->s_inodes_per_group = info.inodes_per_group;
299 sb->s_max_mnt_count = 10;
300 sb->s_magic = EXT4_SUPER_MAGIC;
301 sb->s_state = EXT4_VALID_FS;
302 sb->s_errors = EXT4_ERRORS_RO;
303 sb->s_minor_rev_level = 0;
305 sb->s_checkinterval = 0;
306 sb->s_creator_os = EXT4_OS_LINUX;
307 sb->s_rev_level = EXT4_DYNAMIC_REV;
308 sb->s_def_resuid = EXT4_DEF_RESUID;
309 sb->s_def_resgid = EXT4_DEF_RESGID;
311 sb->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
312 sb->s_inode_size = info.inode_size;
313 sb->s_block_group_nr = 0;
314 sb->s_feature_compat = info.feat_compat;
315 sb->s_feature_incompat = info.feat_incompat;
316 sb->s_feature_ro_compat = info.feat_ro_compat;
317 if (real_uuid == 1) {
319 uuid_generate(sb->s_uuid);
321 fprintf(stderr, "Not compiled with real UUID support\n");
325 generate_sha1_uuid("extandroid/make_ext4fs", info.label, sb->s_uuid);
327 memset(sb->s_volume_name, 0, sizeof(sb->s_volume_name));
328 strncpy(sb->s_volume_name, info.label, sizeof(sb->s_volume_name));
329 memset(sb->s_last_mounted, 0, sizeof(sb->s_last_mounted));
330 sb->s_algorithm_usage_bitmap = 0;
332 sb->s_reserved_gdt_blocks = info.bg_desc_reserve_blocks;
333 sb->s_prealloc_blocks = 0;
334 sb->s_prealloc_dir_blocks = 0;
336 //memcpy(sb->s_journal_uuid, sb->s_uuid, sizeof(sb->s_journal_uuid));
337 if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL)
338 sb->s_journal_inum = EXT4_JOURNAL_INO;
339 sb->s_journal_dev = 0;
340 sb->s_last_orphan = 0;
341 sb->s_hash_seed[0] = 0; /* FIXME */
342 sb->s_def_hash_version = DX_HASH_TEA;
343 sb->s_reserved_char_pad = EXT4_JNL_BACKUP_BLOCKS;
344 sb->s_desc_size = sizeof(struct ext2_group_desc);
345 sb->s_default_mount_opts = 0; /* FIXME */
346 sb->s_first_meta_bg = 0;
348 //sb->s_jnl_blocks[17]; /* FIXME */
350 sb->s_blocks_count_hi = aux_info.len_blocks >> 32;
351 sb->s_r_blocks_count_hi = 0;
352 sb->s_free_blocks_count_hi = 0;
353 sb->s_min_extra_isize = sizeof(struct ext4_inode) -
354 EXT4_GOOD_OLD_INODE_SIZE;
355 sb->s_want_extra_isize = sizeof(struct ext4_inode) -
356 EXT4_GOOD_OLD_INODE_SIZE;
358 sb->s_raid_stride = info.flash_logical_block_size / info.block_size;
359 // stride should be the max of 8kb and logical block size
360 if (info.flash_logical_block_size != 0 && info.flash_logical_block_size < 8192) {
361 sb->s_raid_stride = 8192 / info.block_size;
363 sb->s_mmp_interval = 0;
365 sb->s_raid_stripe_width = info.flash_erase_block_size / info.block_size;
366 sb->s_log_groups_per_flex = 0;
367 sb->s_kbytes_written = 0;
369 for (i = 0; i < aux_info.groups; i++) {
370 u64 group_start_block = aux_info.first_data_block + i *
371 info.blocks_per_group;
373 if (ext4_bg_has_super_block(i)) {
375 aux_info.backup_sb[i] = calloc(info.block_size, 1);
376 memcpy(aux_info.backup_sb[i], sb, sizeof(struct ext4_super_block));
377 /* Update the block group nr of this backup superblock */
378 aux_info.backup_sb[i]->s_block_group_nr = i;
379 ext4_queue_sb(group_start_block, info.block_device ?
380 aux_info.sb_zero : aux_info.backup_sb[i]);
382 sparse_file_add_data(ext4_sparse_file, aux_info.bg_desc,
383 aux_info.bg_desc_blocks * info.block_size,
384 group_start_block + 1);
385 header_size = 1 + aux_info.bg_desc_blocks + info.bg_desc_reserve_blocks;
388 aux_info.bg_desc[i].bg_block_bitmap = group_start_block + header_size;
389 aux_info.bg_desc[i].bg_inode_bitmap = group_start_block + header_size + 1;
390 aux_info.bg_desc[i].bg_inode_table = group_start_block + header_size + 2;
392 aux_info.bg_desc[i].bg_free_blocks_count = sb->s_blocks_per_group;
393 aux_info.bg_desc[i].bg_free_inodes_count = sb->s_inodes_per_group;
394 aux_info.bg_desc[i].bg_used_dirs_count = 0;
397 /* Queue the primary superblock to be written out - if it's a block device,
398 * queue a zero-filled block first, the correct version of superblock will
399 * be written to the block device after all other blocks are written.
401 * The file-system on the block device will not be valid until the correct
402 * version of superblocks are written, this is to avoid the likelihood of a
403 * partially created file-system.
405 ext4_queue_sb(aux_info.first_data_block, info.block_device ?
406 aux_info.sb_zero : aux_info.sb_block);
410 void ext4_queue_sb(u64 start_block, struct ext4_super_block *sb)
412 sparse_file_add_data(ext4_sparse_file, sb, info.block_size, start_block);
415 void ext4_parse_sb_info(struct ext4_super_block *sb)
417 if (sb->s_magic != EXT4_SUPER_MAGIC)
418 error("superblock magic incorrect");
420 if ((sb->s_state & EXT4_VALID_FS) != EXT4_VALID_FS)
421 error("filesystem state not valid");
423 ext4_parse_sb(sb, &info);
425 ext4_create_fs_aux_info();
427 memcpy(aux_info.sb, sb, sizeof(*sb));
429 if (aux_info.first_data_block != sb->s_first_data_block)
430 critical_error("first data block does not match");
433 void ext4_create_resize_inode()
435 struct block_allocation *reserve_inode_alloc = create_allocation();
436 u32 reserve_inode_len = 0;
439 struct ext4_inode *inode = get_inode(EXT4_RESIZE_INO);
441 error("failed to get resize inode");
445 for (i = 0; i < aux_info.groups; i++) {
446 if (ext4_bg_has_super_block(i)) {
447 u64 group_start_block = aux_info.first_data_block + i *
448 info.blocks_per_group;
449 u32 reserved_block_start = group_start_block + 1 +
450 aux_info.bg_desc_blocks;
451 u32 reserved_block_len = info.bg_desc_reserve_blocks;
452 append_region(reserve_inode_alloc, reserved_block_start,
453 reserved_block_len, i);
454 reserve_inode_len += reserved_block_len;
458 inode_attach_resize(inode, reserve_inode_alloc);
460 inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR;
461 inode->i_links_count = 1;
463 free_alloc(reserve_inode_alloc);
466 /* Allocate the blocks to hold a journal inode and connect them to the
467 reserved journal inode */
468 void ext4_create_journal_inode()
470 struct ext4_inode *inode = get_inode(EXT4_JOURNAL_INO);
472 error("failed to get journal inode");
476 u8 *journal_data = inode_allocate_data_extents(inode,
477 info.journal_blocks * info.block_size,
478 info.journal_blocks * info.block_size);
480 error("failed to allocate extents for journal data");
484 inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR;
485 inode->i_links_count = 1;
487 journal_superblock_t *jsb = (journal_superblock_t *)journal_data;
488 jsb->s_header.h_magic = htonl(JBD2_MAGIC_NUMBER);
489 jsb->s_header.h_blocktype = htonl(JBD2_SUPERBLOCK_V2);
490 jsb->s_blocksize = htonl(info.block_size);
491 jsb->s_maxlen = htonl(info.journal_blocks);
492 jsb->s_nr_users = htonl(1);
493 jsb->s_first = htonl(1);
494 jsb->s_sequence = htonl(1);
496 memcpy(aux_info.sb->s_jnl_blocks, &inode->i_block, sizeof(inode->i_block));
499 /* Update the number of free blocks and inodes in the filesystem and in each
501 void ext4_update_free()
505 for (i = 0; i < aux_info.groups; i++) {
506 u32 bg_free_blocks = get_free_blocks(i);
507 u32 bg_free_inodes = get_free_inodes(i);
510 aux_info.bg_desc[i].bg_free_blocks_count = bg_free_blocks;
511 aux_info.sb->s_free_blocks_count_lo += bg_free_blocks;
513 aux_info.bg_desc[i].bg_free_inodes_count = bg_free_inodes;
514 aux_info.sb->s_free_inodes_count += bg_free_inodes;
516 aux_info.bg_desc[i].bg_used_dirs_count += get_directories(i);
518 aux_info.bg_desc[i].bg_flags = get_bg_flags(i);
520 crc = ext4_crc16(~0, aux_info.sb->s_uuid, sizeof(aux_info.sb->s_uuid));
521 crc = ext4_crc16(crc, &i, sizeof(i));
522 crc = ext4_crc16(crc, &aux_info.bg_desc[i], offsetof(struct ext2_group_desc, bg_checksum));
523 aux_info.bg_desc[i].bg_checksum = crc;
527 u64 get_block_device_size(int fd)
532 #if defined(__linux__)
533 ret = ioctl(fd, BLKGETSIZE64, &size);
534 #elif defined(__APPLE__) && defined(__MACH__)
535 ret = ioctl(fd, DKIOCGETBLOCKCOUNT, &size);
547 int is_block_device_fd(int fd)
553 int ret = fstat(fd, &st);
557 return S_ISBLK(st.st_mode);
561 u64 get_file_size(int fd)
568 ret = fstat(fd, &buf);
573 reserve_len = -info.len;
575 if (S_ISREG(buf.st_mode))
576 computed_size = buf.st_size - reserve_len;
577 else if (S_ISBLK(buf.st_mode))
578 computed_size = get_block_device_size(fd) - reserve_len;
582 if (computed_size < 0) {
583 warn("Computed filesystem size less than 0");
587 return computed_size;
590 u64 parse_num(const char *arg)
593 u64 num = strtoull(arg, &endptr, 10);
594 if (*endptr == 'k' || *endptr == 'K')
596 else if (*endptr == 'm' || *endptr == 'M')
597 num *= 1024LL * 1024LL;
598 else if (*endptr == 'g' || *endptr == 'G')
599 num *= 1024LL * 1024LL * 1024LL;
604 int read_ext(int fd, int verbose)
607 struct ext4_super_block sb;
611 ext4_parse_sb_info(&sb);
613 ret = lseek64(fd, info.len, SEEK_SET);
615 critical_error_errno("failed to seek to end of input image");
617 ret = lseek64(fd, info.block_size * (aux_info.first_data_block + 1), SEEK_SET);
619 critical_error_errno("failed to seek to block group descriptors");
621 ret = read(fd, aux_info.bg_desc, info.block_size * aux_info.bg_desc_blocks);
623 critical_error_errno("failed to read block group descriptors");
624 if (ret != (int)info.block_size * (int)aux_info.bg_desc_blocks)
625 critical_error("failed to read all of block group descriptors");
628 printf("Found filesystem with parameters:\n");
629 printf(" Size: %"PRIu64"\n", info.len);
630 printf(" Block size: %d\n", info.block_size);
631 printf(" Blocks per group: %d\n", info.blocks_per_group);
632 printf(" Inodes per group: %d\n", info.inodes_per_group);
633 printf(" Inode size: %d\n", info.inode_size);
634 printf(" Label: %s\n", info.label);
635 printf(" Blocks: %"PRIu64"\n", aux_info.len_blocks);
636 printf(" Block groups: %d\n", aux_info.groups);
637 printf(" Reserved block group size: %d\n", info.bg_desc_reserve_blocks);
638 printf(" Used %d/%d inodes and %d/%d blocks\n",
639 aux_info.sb->s_inodes_count - aux_info.sb->s_free_inodes_count,
640 aux_info.sb->s_inodes_count,
641 aux_info.sb->s_blocks_count_lo - aux_info.sb->s_free_blocks_count_lo,
642 aux_info.sb->s_blocks_count_lo);