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;
55 /* Definition from RFC-4122 */
59 u16 time_hi_and_version;
66 static void sha1_hash(const char *namespace, const char *name,
67 unsigned char sha1[SHA1_DIGEST_LENGTH])
71 SHA1Update(&ctx, (const u8*)namespace, strlen(namespace));
72 SHA1Update(&ctx, (const u8*)name, strlen(name));
73 SHA1Final(sha1, &ctx);
76 static void generate_sha1_uuid(const char *namespace, const char *name, u8 result[16])
78 unsigned char sha1[SHA1_DIGEST_LENGTH];
79 struct uuid *uuid = (struct uuid *)result;
81 sha1_hash(namespace, name, (unsigned char*)sha1);
82 memcpy(uuid, sha1, sizeof(struct uuid));
84 uuid->time_low = ntohl(uuid->time_low);
85 uuid->time_mid = ntohs(uuid->time_mid);
86 uuid->time_hi_and_version = ntohs(uuid->time_hi_and_version);
87 uuid->time_hi_and_version &= 0x0FFF;
88 uuid->time_hi_and_version |= (5 << 12);
89 uuid->clk_seq_hi_res &= ~(1 << 6);
90 uuid->clk_seq_hi_res |= 1 << 7;
93 /* returns 1 if a is a power of b */
94 static int is_power_of(int a, int b)
102 return (a == b) ? 1 : 0;
105 int bitmap_get_bit(u8 *bitmap, u32 bit)
107 if (bitmap[bit / 8] & (1 << (bit % 8)))
113 void bitmap_clear_bit(u8 *bitmap, u32 bit)
115 bitmap[bit / 8] &= ~(1 << (bit % 8));
120 /* Returns 1 if the bg contains a backup superblock. On filesystems with
121 the sparse_super feature, only block groups 0, 1, and powers of 3, 5,
122 and 7 have backup superblocks. Otherwise, all block groups have backup
124 int ext4_bg_has_super_block(int bg)
126 /* Without sparse_super, every block group has a superblock */
127 if (!(info.feat_ro_compat & EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER))
130 if (bg == 0 || bg == 1)
133 if (is_power_of(bg, 3) || is_power_of(bg, 5) || is_power_of(bg, 7))
139 /* Function to read the primary superblock */
140 void read_sb(int fd, struct ext4_super_block *sb)
144 ret = lseek64(fd, 1024, SEEK_SET);
146 critical_error_errno("failed to seek to superblock");
148 ret = read(fd, sb, sizeof(*sb));
150 critical_error_errno("failed to read superblock");
151 if (ret != sizeof(*sb))
152 critical_error("failed to read all of superblock");
155 /* Function to write a primary or backup superblock at a given offset */
156 void write_sb(int fd, unsigned long long offset, struct ext4_super_block *sb)
160 ret = lseek64(fd, offset, SEEK_SET);
162 critical_error_errno("failed to seek to superblock");
164 ret = write(fd, sb, sizeof(*sb));
166 critical_error_errno("failed to write superblock");
167 if (ret != sizeof(*sb))
168 critical_error("failed to write all of superblock");
171 static void block_device_write_sb(int fd)
173 unsigned long long offset;
176 /* write out the backup superblocks */
177 for (i = 1; i < aux_info.groups; i++) {
178 if (ext4_bg_has_super_block(i)) {
179 offset = info.block_size * (aux_info.first_data_block
180 + i * info.blocks_per_group);
181 write_sb(fd, offset, aux_info.backup_sb[i]);
185 /* write out the primary superblock */
186 write_sb(fd, 1024, aux_info.sb);
189 /* Write the filesystem image to a file */
190 void write_ext4_image(int fd, int gz, int sparse, int crc)
192 sparse_file_write(ext4_sparse_file, fd, gz, sparse, crc);
194 if (info.block_device)
195 block_device_write_sb(fd);
198 /* Compute the rest of the parameters of the filesystem from the basic info */
199 void ext4_create_fs_aux_info()
201 aux_info.first_data_block = (info.block_size > 1024) ? 0 : 1;
202 aux_info.len_blocks = info.len / info.block_size;
203 aux_info.inode_table_blocks = DIV_ROUND_UP(info.inodes_per_group * info.inode_size,
205 aux_info.groups = DIV_ROUND_UP(aux_info.len_blocks - aux_info.first_data_block,
206 info.blocks_per_group);
207 aux_info.blocks_per_ind = info.block_size / sizeof(u32);
208 aux_info.blocks_per_dind = aux_info.blocks_per_ind * aux_info.blocks_per_ind;
209 aux_info.blocks_per_tind = aux_info.blocks_per_dind * aux_info.blocks_per_dind;
211 aux_info.bg_desc_blocks =
212 DIV_ROUND_UP(aux_info.groups * sizeof(struct ext2_group_desc),
215 aux_info.default_i_flags = EXT4_NOATIME_FL;
217 u32 last_group_size = aux_info.len_blocks % info.blocks_per_group;
218 u32 last_header_size = 2 + aux_info.inode_table_blocks;
219 if (ext4_bg_has_super_block(aux_info.groups - 1))
220 last_header_size += 1 + aux_info.bg_desc_blocks +
221 info.bg_desc_reserve_blocks;
222 if (last_group_size > 0 && last_group_size < last_header_size) {
224 aux_info.len_blocks -= last_group_size;
227 /* A zero-filled superblock to be written firstly to the block
228 * device to mark the file-system as invalid
230 aux_info.sb_zero = calloc(1, info.block_size);
231 if (!aux_info.sb_zero)
232 critical_error_errno("calloc");
234 /* The write_data* functions expect only block aligned calls.
235 * This is not an issue, except when we write out the super
236 * block on a system with a block size > 1K. So, we need to
237 * deal with that here.
239 aux_info.sb_block = calloc(1, info.block_size);
240 if (!aux_info.sb_block)
241 critical_error_errno("calloc");
243 if (info.block_size > 1024)
244 aux_info.sb = (struct ext4_super_block *)((char *)aux_info.sb_block + 1024);
246 aux_info.sb = aux_info.sb_block;
248 /* Alloc an array to hold the pointers to the backup superblocks */
249 aux_info.backup_sb = calloc(aux_info.groups, sizeof(char *));
252 critical_error_errno("calloc");
254 aux_info.bg_desc = calloc(info.block_size, aux_info.bg_desc_blocks);
255 if (!aux_info.bg_desc)
256 critical_error_errno("calloc");
257 aux_info.xattrs = NULL;
260 void ext4_free_fs_aux_info()
264 for (i=0; i<aux_info.groups; i++) {
265 if (aux_info.backup_sb[i])
266 free(aux_info.backup_sb[i]);
268 free(aux_info.sb_block);
269 free(aux_info.sb_zero);
270 free(aux_info.bg_desc);
273 /* Fill in the superblock memory buffer based on the filesystem parameters */
274 void ext4_fill_in_sb(int real_uuid)
277 struct ext4_super_block *sb = aux_info.sb;
279 sb->s_inodes_count = info.inodes_per_group * aux_info.groups;
280 sb->s_blocks_count_lo = aux_info.len_blocks;
281 sb->s_r_blocks_count_lo = 0;
282 sb->s_free_blocks_count_lo = 0;
283 sb->s_free_inodes_count = 0;
284 sb->s_first_data_block = aux_info.first_data_block;
285 sb->s_log_block_size = log_2(info.block_size / 1024);
286 sb->s_obso_log_frag_size = log_2(info.block_size / 1024);
287 sb->s_blocks_per_group = info.blocks_per_group;
288 sb->s_obso_frags_per_group = info.blocks_per_group;
289 sb->s_inodes_per_group = info.inodes_per_group;
293 sb->s_max_mnt_count = 10;
294 sb->s_magic = EXT4_SUPER_MAGIC;
295 sb->s_state = EXT4_VALID_FS;
296 sb->s_errors = EXT4_ERRORS_RO;
297 sb->s_minor_rev_level = 0;
299 sb->s_checkinterval = 0;
300 sb->s_creator_os = EXT4_OS_LINUX;
301 sb->s_rev_level = EXT4_DYNAMIC_REV;
302 sb->s_def_resuid = EXT4_DEF_RESUID;
303 sb->s_def_resgid = EXT4_DEF_RESGID;
305 sb->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
306 sb->s_inode_size = info.inode_size;
307 sb->s_block_group_nr = 0;
308 sb->s_feature_compat = info.feat_compat;
309 sb->s_feature_incompat = info.feat_incompat;
310 sb->s_feature_ro_compat = info.feat_ro_compat;
311 if (real_uuid == 1) {
313 uuid_generate(sb->s_uuid);
315 fprintf(stderr, "Not compiled with real UUID support\n");
319 generate_sha1_uuid("extandroid/make_ext4fs", info.label, sb->s_uuid);
321 memset(sb->s_volume_name, 0, sizeof(sb->s_volume_name));
322 strncpy(sb->s_volume_name, info.label, sizeof(sb->s_volume_name));
323 memset(sb->s_last_mounted, 0, sizeof(sb->s_last_mounted));
324 sb->s_algorithm_usage_bitmap = 0;
326 sb->s_reserved_gdt_blocks = info.bg_desc_reserve_blocks;
327 sb->s_prealloc_blocks = 0;
328 sb->s_prealloc_dir_blocks = 0;
330 //memcpy(sb->s_journal_uuid, sb->s_uuid, sizeof(sb->s_journal_uuid));
331 if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL)
332 sb->s_journal_inum = EXT4_JOURNAL_INO;
333 sb->s_journal_dev = 0;
334 sb->s_last_orphan = 0;
335 sb->s_hash_seed[0] = 0; /* FIXME */
336 sb->s_def_hash_version = DX_HASH_TEA;
337 sb->s_reserved_char_pad = EXT4_JNL_BACKUP_BLOCKS;
338 sb->s_desc_size = sizeof(struct ext2_group_desc);
339 sb->s_default_mount_opts = 0; /* FIXME */
340 sb->s_first_meta_bg = 0;
342 //sb->s_jnl_blocks[17]; /* FIXME */
344 sb->s_blocks_count_hi = aux_info.len_blocks >> 32;
345 sb->s_r_blocks_count_hi = 0;
346 sb->s_free_blocks_count_hi = 0;
347 sb->s_min_extra_isize = sizeof(struct ext4_inode) -
348 EXT4_GOOD_OLD_INODE_SIZE;
349 sb->s_want_extra_isize = sizeof(struct ext4_inode) -
350 EXT4_GOOD_OLD_INODE_SIZE;
352 sb->s_raid_stride = 0;
353 sb->s_mmp_interval = 0;
355 sb->s_raid_stripe_width = 0;
356 sb->s_log_groups_per_flex = 0;
357 sb->s_kbytes_written = 0;
359 for (i = 0; i < aux_info.groups; i++) {
360 u64 group_start_block = aux_info.first_data_block + i *
361 info.blocks_per_group;
363 if (ext4_bg_has_super_block(i)) {
365 aux_info.backup_sb[i] = calloc(info.block_size, 1);
366 memcpy(aux_info.backup_sb[i], sb, sizeof(struct ext4_super_block));
367 /* Update the block group nr of this backup superblock */
368 aux_info.backup_sb[i]->s_block_group_nr = i;
369 ext4_queue_sb(group_start_block, info.block_device ?
370 aux_info.sb_zero : aux_info.backup_sb[i]);
372 sparse_file_add_data(ext4_sparse_file, aux_info.bg_desc,
373 aux_info.bg_desc_blocks * info.block_size,
374 group_start_block + 1);
375 header_size = 1 + aux_info.bg_desc_blocks + info.bg_desc_reserve_blocks;
378 aux_info.bg_desc[i].bg_block_bitmap = group_start_block + header_size;
379 aux_info.bg_desc[i].bg_inode_bitmap = group_start_block + header_size + 1;
380 aux_info.bg_desc[i].bg_inode_table = group_start_block + header_size + 2;
382 aux_info.bg_desc[i].bg_free_blocks_count = sb->s_blocks_per_group;
383 aux_info.bg_desc[i].bg_free_inodes_count = sb->s_inodes_per_group;
384 aux_info.bg_desc[i].bg_used_dirs_count = 0;
387 /* Queue the primary superblock to be written out - if it's a block device,
388 * queue a zero-filled block first, the correct version of superblock will
389 * be written to the block device after all other blocks are written.
391 * The file-system on the block device will not be valid until the correct
392 * version of superblocks are written, this is to avoid the likelihood of a
393 * partially created file-system.
395 ext4_queue_sb(aux_info.first_data_block, info.block_device ?
396 aux_info.sb_zero : aux_info.sb_block);
400 void ext4_queue_sb(u64 start_block, struct ext4_super_block *sb)
402 sparse_file_add_data(ext4_sparse_file, sb, info.block_size, start_block);
405 void ext4_parse_sb_info(struct ext4_super_block *sb)
407 if (sb->s_magic != EXT4_SUPER_MAGIC)
408 error("superblock magic incorrect");
410 if ((sb->s_state & EXT4_VALID_FS) != EXT4_VALID_FS)
411 error("filesystem state not valid");
413 ext4_parse_sb(sb, &info);
415 ext4_create_fs_aux_info();
417 memcpy(aux_info.sb, sb, sizeof(*sb));
419 if (aux_info.first_data_block != sb->s_first_data_block)
420 critical_error("first data block does not match");
423 void ext4_create_resize_inode()
425 struct block_allocation *reserve_inode_alloc = create_allocation();
426 u32 reserve_inode_len = 0;
429 struct ext4_inode *inode = get_inode(EXT4_RESIZE_INO);
431 error("failed to get resize inode");
435 for (i = 0; i < aux_info.groups; i++) {
436 if (ext4_bg_has_super_block(i)) {
437 u64 group_start_block = aux_info.first_data_block + i *
438 info.blocks_per_group;
439 u32 reserved_block_start = group_start_block + 1 +
440 aux_info.bg_desc_blocks;
441 u32 reserved_block_len = info.bg_desc_reserve_blocks;
442 append_region(reserve_inode_alloc, reserved_block_start,
443 reserved_block_len, i);
444 reserve_inode_len += reserved_block_len;
448 inode_attach_resize(inode, reserve_inode_alloc);
450 inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR;
451 inode->i_links_count = 1;
453 free_alloc(reserve_inode_alloc);
456 /* Allocate the blocks to hold a journal inode and connect them to the
457 reserved journal inode */
458 void ext4_create_journal_inode()
460 struct ext4_inode *inode = get_inode(EXT4_JOURNAL_INO);
462 error("failed to get journal inode");
466 u8 *journal_data = inode_allocate_data_extents(inode,
467 info.journal_blocks * info.block_size,
468 info.journal_blocks * info.block_size);
470 error("failed to allocate extents for journal data");
474 inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR;
475 inode->i_links_count = 1;
477 journal_superblock_t *jsb = (journal_superblock_t *)journal_data;
478 jsb->s_header.h_magic = htonl(JBD2_MAGIC_NUMBER);
479 jsb->s_header.h_blocktype = htonl(JBD2_SUPERBLOCK_V2);
480 jsb->s_blocksize = htonl(info.block_size);
481 jsb->s_maxlen = htonl(info.journal_blocks);
482 jsb->s_nr_users = htonl(1);
483 jsb->s_first = htonl(1);
484 jsb->s_sequence = htonl(1);
486 memcpy(aux_info.sb->s_jnl_blocks, &inode->i_block, sizeof(inode->i_block));
489 /* Update the number of free blocks and inodes in the filesystem and in each
491 void ext4_update_free()
495 for (i = 0; i < aux_info.groups; i++) {
496 u32 bg_free_blocks = get_free_blocks(i);
497 u32 bg_free_inodes = get_free_inodes(i);
500 aux_info.bg_desc[i].bg_free_blocks_count = bg_free_blocks;
501 aux_info.sb->s_free_blocks_count_lo += bg_free_blocks;
503 aux_info.bg_desc[i].bg_free_inodes_count = bg_free_inodes;
504 aux_info.sb->s_free_inodes_count += bg_free_inodes;
506 aux_info.bg_desc[i].bg_used_dirs_count += get_directories(i);
508 aux_info.bg_desc[i].bg_flags = get_bg_flags(i);
510 crc = ext4_crc16(~0, aux_info.sb->s_uuid, sizeof(aux_info.sb->s_uuid));
511 crc = ext4_crc16(crc, &i, sizeof(i));
512 crc = ext4_crc16(crc, &aux_info.bg_desc[i], offsetof(struct ext2_group_desc, bg_checksum));
513 aux_info.bg_desc[i].bg_checksum = crc;
517 u64 get_block_device_size(int fd)
522 #if defined(__linux__)
523 ret = ioctl(fd, BLKGETSIZE64, &size);
524 #elif defined(__APPLE__) && defined(__MACH__)
525 ret = ioctl(fd, DKIOCGETBLOCKCOUNT, &size);
537 int is_block_device_fd(int fd)
543 int ret = fstat(fd, &st);
547 return S_ISBLK(st.st_mode);
551 u64 get_file_size(int fd)
558 ret = fstat(fd, &buf);
563 reserve_len = -info.len;
565 if (S_ISREG(buf.st_mode))
566 computed_size = buf.st_size - reserve_len;
567 else if (S_ISBLK(buf.st_mode))
568 computed_size = get_block_device_size(fd) - reserve_len;
572 if (computed_size < 0) {
573 warn("Computed filesystem size less than 0");
577 return computed_size;
580 u64 parse_num(const char *arg)
583 u64 num = strtoull(arg, &endptr, 10);
584 if (*endptr == 'k' || *endptr == 'K')
586 else if (*endptr == 'm' || *endptr == 'M')
587 num *= 1024LL * 1024LL;
588 else if (*endptr == 'g' || *endptr == 'G')
589 num *= 1024LL * 1024LL * 1024LL;
594 int read_ext(int fd, int verbose)
597 struct ext4_super_block sb;
601 ext4_parse_sb_info(&sb);
603 ret = lseek64(fd, info.len, SEEK_SET);
605 critical_error_errno("failed to seek to end of input image");
607 ret = lseek64(fd, info.block_size * (aux_info.first_data_block + 1), SEEK_SET);
609 critical_error_errno("failed to seek to block group descriptors");
611 ret = read(fd, aux_info.bg_desc, info.block_size * aux_info.bg_desc_blocks);
613 critical_error_errno("failed to read block group descriptors");
614 if (ret != (int)info.block_size * (int)aux_info.bg_desc_blocks)
615 critical_error("failed to read all of block group descriptors");
618 printf("Found filesystem with parameters:\n");
619 printf(" Size: %"PRIu64"\n", info.len);
620 printf(" Block size: %d\n", info.block_size);
621 printf(" Blocks per group: %d\n", info.blocks_per_group);
622 printf(" Inodes per group: %d\n", info.inodes_per_group);
623 printf(" Inode size: %d\n", info.inode_size);
624 printf(" Label: %s\n", info.label);
625 printf(" Blocks: %"PRIu64"\n", aux_info.len_blocks);
626 printf(" Block groups: %d\n", aux_info.groups);
627 printf(" Reserved block group size: %d\n", info.bg_desc_reserve_blocks);
628 printf(" Used %d/%d inodes and %d/%d blocks\n",
629 aux_info.sb->s_inodes_count - aux_info.sb->s_free_inodes_count,
630 aux_info.sb->s_inodes_count,
631 aux_info.sb->s_blocks_count_lo - aux_info.sb->s_free_blocks_count_lo,
632 aux_info.sb->s_blocks_count_lo);