/* * Copyright (C) 2010 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include "ext4_utils/ext4_utils.h" #include #include #include #include #include #include #include #include "allocate.h" #include "extent.h" #include "indirect.h" #include "sha1.h" #ifdef REAL_UUID #include #endif #ifdef _WIN32 #include #else #include #include #endif #if defined(__linux__) #include #elif defined(__APPLE__) && defined(__MACH__) #include #endif int force = 0; struct fs_info info; struct fs_aux_info aux_info; struct sparse_file *ext4_sparse_file; struct block_allocation *base_fs_allocations = NULL; jmp_buf setjmp_env; /* Definition from RFC-4122 */ struct uuid { u32 time_low; u16 time_mid; u16 time_hi_and_version; u8 clk_seq_hi_res; u8 clk_seq_low; u16 node0_1; u32 node2_5; }; static void sha1_hash(const char *namespace, const char *name, unsigned char sha1[SHA1_DIGEST_LENGTH]) { SHA1_CTX ctx; SHA1Init(&ctx); SHA1Update(&ctx, (const u8*)namespace, strlen(namespace)); SHA1Update(&ctx, (const u8*)name, strlen(name)); SHA1Final(sha1, &ctx); } static void generate_sha1_uuid(const char *namespace, const char *name, u8 result[16]) { unsigned char sha1[SHA1_DIGEST_LENGTH]; struct uuid *uuid = (struct uuid *)result; sha1_hash(namespace, name, (unsigned char*)sha1); memcpy(uuid, sha1, sizeof(struct uuid)); uuid->time_low = ntohl(uuid->time_low); uuid->time_mid = ntohs(uuid->time_mid); uuid->time_hi_and_version = ntohs(uuid->time_hi_and_version); uuid->time_hi_and_version &= 0x0FFF; uuid->time_hi_and_version |= (5 << 12); uuid->clk_seq_hi_res &= ~(1 << 6); uuid->clk_seq_hi_res |= 1 << 7; } /* returns 1 if a is a power of b */ static int is_power_of(int a, int b) { while (a > b) { if (a % b) return 0; a /= b; } return (a == b) ? 1 : 0; } int bitmap_get_bit(u8 *bitmap, u32 bit) { if (bitmap[bit / 8] & (1 << (bit % 8))) return 1; return 0; } void bitmap_clear_bit(u8 *bitmap, u32 bit) { bitmap[bit / 8] &= ~(1 << (bit % 8)); return; } /* Returns 1 if the bg contains a backup superblock. On filesystems with the sparse_super feature, only block groups 0, 1, and powers of 3, 5, and 7 have backup superblocks. Otherwise, all block groups have backup superblocks */ int ext4_bg_has_super_block(int bg) { /* Without sparse_super, every block group has a superblock */ if (!(info.feat_ro_compat & EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER)) return 1; if (bg == 0 || bg == 1) return 1; if (is_power_of(bg, 3) || is_power_of(bg, 5) || is_power_of(bg, 7)) return 1; return 0; } /* Function to read the primary superblock */ void read_sb(int fd, struct ext4_super_block *sb) { off64_t ret; ret = lseek64(fd, 1024, SEEK_SET); if (ret < 0) critical_error_errno("failed to seek to superblock"); ret = read(fd, sb, sizeof(*sb)); if (ret < 0) critical_error_errno("failed to read superblock"); if (ret != sizeof(*sb)) critical_error("failed to read all of superblock"); } /* Function to write a primary or backup superblock at a given offset */ void write_sb(int fd, unsigned long long offset, struct ext4_super_block *sb) { off64_t ret; ret = lseek64(fd, offset, SEEK_SET); if (ret < 0) critical_error_errno("failed to seek to superblock"); ret = write(fd, sb, sizeof(*sb)); if (ret < 0) critical_error_errno("failed to write superblock"); if (ret != sizeof(*sb)) critical_error("failed to write all of superblock"); } static void block_device_write_sb(int fd) { unsigned long long offset; u32 i; /* write out the backup superblocks */ for (i = 1; i < aux_info.groups; i++) { if (ext4_bg_has_super_block(i)) { offset = (unsigned long long)info.block_size * (aux_info.first_data_block + i * info.blocks_per_group); write_sb(fd, offset, aux_info.backup_sb[i]); } } /* write out the primary superblock */ write_sb(fd, 1024, aux_info.sb); } /* Write the filesystem image to a file */ void write_ext4_image(int fd, int gz, int sparse, int crc) { sparse_file_write(ext4_sparse_file, fd, gz, sparse, crc); if (info.block_device) block_device_write_sb(fd); } /* Compute the rest of the parameters of the filesystem from the basic info */ void ext4_create_fs_aux_info() { aux_info.first_data_block = (info.block_size > 1024) ? 0 : 1; aux_info.len_blocks = info.len / info.block_size; aux_info.inode_table_blocks = DIV_ROUND_UP(info.inodes_per_group * info.inode_size, info.block_size); aux_info.groups = DIV_ROUND_UP(aux_info.len_blocks - aux_info.first_data_block, info.blocks_per_group); aux_info.blocks_per_ind = info.block_size / sizeof(u32); aux_info.blocks_per_dind = aux_info.blocks_per_ind * aux_info.blocks_per_ind; aux_info.blocks_per_tind = aux_info.blocks_per_dind * aux_info.blocks_per_dind; aux_info.bg_desc_blocks = DIV_ROUND_UP(aux_info.groups * sizeof(struct ext2_group_desc), info.block_size); aux_info.default_i_flags = EXT4_NOATIME_FL; u32 last_group_size = aux_info.len_blocks % info.blocks_per_group; u32 last_header_size = 2 + aux_info.inode_table_blocks; if (ext4_bg_has_super_block(aux_info.groups - 1)) last_header_size += 1 + aux_info.bg_desc_blocks + info.bg_desc_reserve_blocks; if (aux_info.groups <= 1 && last_group_size < last_header_size) { critical_error("filesystem size too small"); } if (last_group_size > 0 && last_group_size < last_header_size) { aux_info.groups--; aux_info.len_blocks -= last_group_size; } /* A zero-filled superblock to be written firstly to the block * device to mark the file-system as invalid */ aux_info.sb_zero = calloc(1, info.block_size); if (!aux_info.sb_zero) critical_error_errno("calloc"); /* The write_data* functions expect only block aligned calls. * This is not an issue, except when we write out the super * block on a system with a block size > 1K. So, we need to * deal with that here. */ aux_info.sb_block = calloc(1, info.block_size); if (!aux_info.sb_block) critical_error_errno("calloc"); if (info.block_size > 1024) aux_info.sb = (struct ext4_super_block *)((char *)aux_info.sb_block + 1024); else aux_info.sb = aux_info.sb_block; /* Alloc an array to hold the pointers to the backup superblocks */ aux_info.backup_sb = calloc(aux_info.groups, sizeof(char *)); if (!aux_info.sb) critical_error_errno("calloc"); aux_info.bg_desc = calloc(info.block_size, aux_info.bg_desc_blocks); if (!aux_info.bg_desc) critical_error_errno("calloc"); aux_info.xattrs = NULL; } void ext4_free_fs_aux_info() { unsigned int i; for (i=0; is_inodes_count = info.inodes_per_group * aux_info.groups; sb->s_blocks_count_lo = aux_info.len_blocks; sb->s_r_blocks_count_lo = 0; sb->s_free_blocks_count_lo = 0; sb->s_free_inodes_count = 0; sb->s_first_data_block = aux_info.first_data_block; sb->s_log_block_size = log_2(info.block_size / 1024); sb->s_obso_log_frag_size = log_2(info.block_size / 1024); sb->s_blocks_per_group = info.blocks_per_group; sb->s_obso_frags_per_group = info.blocks_per_group; sb->s_inodes_per_group = info.inodes_per_group; sb->s_mtime = 0; sb->s_wtime = 0; sb->s_mnt_count = 0; sb->s_max_mnt_count = 10; sb->s_magic = EXT4_SUPER_MAGIC; sb->s_state = EXT4_VALID_FS; sb->s_errors = EXT4_ERRORS_RO; sb->s_minor_rev_level = 0; sb->s_lastcheck = 0; sb->s_checkinterval = 0; sb->s_creator_os = EXT4_OS_LINUX; sb->s_rev_level = EXT4_DYNAMIC_REV; sb->s_def_resuid = EXT4_DEF_RESUID; sb->s_def_resgid = EXT4_DEF_RESGID; sb->s_first_ino = EXT4_GOOD_OLD_FIRST_INO; sb->s_inode_size = info.inode_size; sb->s_block_group_nr = 0; sb->s_feature_compat = info.feat_compat; sb->s_feature_incompat = info.feat_incompat; sb->s_feature_ro_compat = info.feat_ro_compat; if (real_uuid == 1) { #ifdef REAL_UUID uuid_generate(sb->s_uuid); #else fprintf(stderr, "Not compiled with real UUID support\n"); abort(); #endif } else { generate_sha1_uuid("extandroid/make_ext4fs", info.label, sb->s_uuid); } memset(sb->s_volume_name, 0, sizeof(sb->s_volume_name)); strncpy(sb->s_volume_name, info.label, sizeof(sb->s_volume_name)); memset(sb->s_last_mounted, 0, sizeof(sb->s_last_mounted)); sb->s_algorithm_usage_bitmap = 0; sb->s_reserved_gdt_blocks = info.bg_desc_reserve_blocks; sb->s_prealloc_blocks = 0; sb->s_prealloc_dir_blocks = 0; //memcpy(sb->s_journal_uuid, sb->s_uuid, sizeof(sb->s_journal_uuid)); if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL) sb->s_journal_inum = EXT4_JOURNAL_INO; sb->s_journal_dev = 0; sb->s_last_orphan = 0; sb->s_hash_seed[0] = 0; /* FIXME */ sb->s_def_hash_version = DX_HASH_TEA; sb->s_reserved_char_pad = EXT4_JNL_BACKUP_BLOCKS; sb->s_desc_size = sizeof(struct ext2_group_desc); sb->s_default_mount_opts = 0; /* FIXME */ sb->s_first_meta_bg = 0; sb->s_mkfs_time = 0; //sb->s_jnl_blocks[17]; /* FIXME */ sb->s_blocks_count_hi = aux_info.len_blocks >> 32; sb->s_r_blocks_count_hi = 0; sb->s_free_blocks_count_hi = 0; sb->s_min_extra_isize = sizeof(struct ext4_inode) - EXT4_GOOD_OLD_INODE_SIZE; sb->s_want_extra_isize = sizeof(struct ext4_inode) - EXT4_GOOD_OLD_INODE_SIZE; sb->s_flags = 2; sb->s_raid_stride = info.flash_logical_block_size / info.block_size; // stride should be the max of 8kb and logical block size if (info.flash_logical_block_size != 0 && info.flash_logical_block_size < 8192) { sb->s_raid_stride = 8192 / info.block_size; } sb->s_mmp_interval = 0; sb->s_mmp_block = 0; sb->s_raid_stripe_width = info.flash_erase_block_size / info.block_size; sb->s_log_groups_per_flex = 0; sb->s_kbytes_written = 0; for (i = 0; i < aux_info.groups; i++) { u64 group_start_block = aux_info.first_data_block + i * info.blocks_per_group; u32 header_size = 0; if (ext4_bg_has_super_block(i)) { if (i != 0) { aux_info.backup_sb[i] = calloc(info.block_size, 1); memcpy(aux_info.backup_sb[i], sb, sizeof(struct ext4_super_block)); /* Update the block group nr of this backup superblock */ aux_info.backup_sb[i]->s_block_group_nr = i; ext4_queue_sb(group_start_block, info.block_device ? aux_info.sb_zero : aux_info.backup_sb[i]); } sparse_file_add_data(ext4_sparse_file, aux_info.bg_desc, aux_info.bg_desc_blocks * info.block_size, group_start_block + 1); header_size = 1 + aux_info.bg_desc_blocks + info.bg_desc_reserve_blocks; } aux_info.bg_desc[i].bg_block_bitmap = group_start_block + header_size; aux_info.bg_desc[i].bg_inode_bitmap = group_start_block + header_size + 1; aux_info.bg_desc[i].bg_inode_table = group_start_block + header_size + 2; aux_info.bg_desc[i].bg_free_blocks_count = sb->s_blocks_per_group; aux_info.bg_desc[i].bg_free_inodes_count = sb->s_inodes_per_group; aux_info.bg_desc[i].bg_used_dirs_count = 0; } /* Queue the primary superblock to be written out - if it's a block device, * queue a zero-filled block first, the correct version of superblock will * be written to the block device after all other blocks are written. * * The file-system on the block device will not be valid until the correct * version of superblocks are written, this is to avoid the likelihood of a * partially created file-system. */ ext4_queue_sb(aux_info.first_data_block, info.block_device ? aux_info.sb_zero : aux_info.sb_block); } void ext4_queue_sb(u64 start_block, struct ext4_super_block *sb) { sparse_file_add_data(ext4_sparse_file, sb, info.block_size, start_block); } void ext4_parse_sb_info(struct ext4_super_block *sb) { if (sb->s_magic != EXT4_SUPER_MAGIC) error("superblock magic incorrect"); if ((sb->s_state & EXT4_VALID_FS) != EXT4_VALID_FS) error("filesystem state not valid"); ext4_parse_sb(sb, &info); ext4_create_fs_aux_info(); memcpy(aux_info.sb, sb, sizeof(*sb)); if (aux_info.first_data_block != sb->s_first_data_block) critical_error("first data block does not match"); } void ext4_create_resize_inode() { struct block_allocation *reserve_inode_alloc = create_allocation(); u32 reserve_inode_len = 0; unsigned int i; struct ext4_inode *inode = get_inode(EXT4_RESIZE_INO); if (inode == NULL) { error("failed to get resize inode"); return; } for (i = 0; i < aux_info.groups; i++) { if (ext4_bg_has_super_block(i)) { u64 group_start_block = aux_info.first_data_block + i * info.blocks_per_group; u32 reserved_block_start = group_start_block + 1 + aux_info.bg_desc_blocks; u32 reserved_block_len = info.bg_desc_reserve_blocks; append_region(reserve_inode_alloc, reserved_block_start, reserved_block_len, i); reserve_inode_len += reserved_block_len; } } inode_attach_resize(inode, reserve_inode_alloc); inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR; inode->i_links_count = 1; free_alloc(reserve_inode_alloc); } /* Allocate the blocks to hold a journal inode and connect them to the reserved journal inode */ void ext4_create_journal_inode() { struct ext4_inode *inode = get_inode(EXT4_JOURNAL_INO); if (inode == NULL) { error("failed to get journal inode"); return; } u8 *journal_data = inode_allocate_data_extents(inode, info.journal_blocks * info.block_size, info.journal_blocks * info.block_size); if (!journal_data) { error("failed to allocate extents for journal data"); return; } inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR; inode->i_links_count = 1; journal_superblock_t *jsb = (journal_superblock_t *)journal_data; jsb->s_header.h_magic = htonl(JBD2_MAGIC_NUMBER); jsb->s_header.h_blocktype = htonl(JBD2_SUPERBLOCK_V2); jsb->s_blocksize = htonl(info.block_size); jsb->s_maxlen = htonl(info.journal_blocks); jsb->s_nr_users = htonl(1); jsb->s_first = htonl(1); jsb->s_sequence = htonl(1); memcpy(aux_info.sb->s_jnl_blocks, &inode->i_block, sizeof(inode->i_block)); } /* Update the number of free blocks and inodes in the filesystem and in each block group */ void ext4_update_free() { u32 i; for (i = 0; i < aux_info.groups; i++) { u32 bg_free_blocks = get_free_blocks(i); u32 bg_free_inodes = get_free_inodes(i); u16 crc; aux_info.bg_desc[i].bg_free_blocks_count = bg_free_blocks; aux_info.sb->s_free_blocks_count_lo += bg_free_blocks; aux_info.bg_desc[i].bg_free_inodes_count = bg_free_inodes; aux_info.sb->s_free_inodes_count += bg_free_inodes; aux_info.bg_desc[i].bg_used_dirs_count += get_directories(i); aux_info.bg_desc[i].bg_flags = get_bg_flags(i); crc = ext4_crc16(~0, aux_info.sb->s_uuid, sizeof(aux_info.sb->s_uuid)); crc = ext4_crc16(crc, &i, sizeof(i)); crc = ext4_crc16(crc, &aux_info.bg_desc[i], offsetof(struct ext2_group_desc, bg_checksum)); aux_info.bg_desc[i].bg_checksum = crc; } } u64 get_block_device_size(int fd) { u64 size = 0; int ret; #if defined(__linux__) ret = ioctl(fd, BLKGETSIZE64, &size); #elif defined(__APPLE__) && defined(__MACH__) ret = ioctl(fd, DKIOCGETBLOCKCOUNT, &size); #else close(fd); return 0; #endif if (ret) return 0; return size; } int is_block_device_fd(int fd) { #ifdef _WIN32 return 0; #else struct stat st; int ret = fstat(fd, &st); if (ret < 0) return 0; return S_ISBLK(st.st_mode); #endif } u64 get_file_size(int fd) { struct stat buf; int ret; u64 reserve_len = 0; s64 computed_size; ret = fstat(fd, &buf); if (ret) return 0; if (info.len < 0) reserve_len = -info.len; if (S_ISREG(buf.st_mode)) computed_size = buf.st_size - reserve_len; else if (S_ISBLK(buf.st_mode)) computed_size = get_block_device_size(fd) - reserve_len; else computed_size = 0; if (computed_size < 0) { warn("Computed filesystem size less than 0"); computed_size = 0; } return computed_size; } u64 parse_num(const char *arg) { char *endptr; u64 num = strtoull(arg, &endptr, 10); if (*endptr == 'k' || *endptr == 'K') num *= 1024LL; else if (*endptr == 'm' || *endptr == 'M') num *= 1024LL * 1024LL; else if (*endptr == 'g' || *endptr == 'G') num *= 1024LL * 1024LL * 1024LL; return num; } int read_ext(int fd, int verbose) { off64_t ret; struct ext4_super_block sb; read_sb(fd, &sb); ext4_parse_sb_info(&sb); ret = lseek64(fd, info.len, SEEK_SET); if (ret < 0) critical_error_errno("failed to seek to end of input image"); ret = lseek64(fd, info.block_size * (aux_info.first_data_block + 1), SEEK_SET); if (ret < 0) critical_error_errno("failed to seek to block group descriptors"); ret = read(fd, aux_info.bg_desc, info.block_size * aux_info.bg_desc_blocks); if (ret < 0) critical_error_errno("failed to read block group descriptors"); if (ret != (int)info.block_size * (int)aux_info.bg_desc_blocks) critical_error("failed to read all of block group descriptors"); if (verbose) { printf("Found filesystem with parameters:\n"); printf(" Size: %"PRIu64"\n", info.len); printf(" Block size: %d\n", info.block_size); printf(" Blocks per group: %d\n", info.blocks_per_group); printf(" Inodes per group: %d\n", info.inodes_per_group); printf(" Inode size: %d\n", info.inode_size); printf(" Label: %s\n", info.label); printf(" Blocks: %"PRIu64"\n", aux_info.len_blocks); printf(" Block groups: %d\n", aux_info.groups); printf(" Reserved block group size: %d\n", info.bg_desc_reserve_blocks); printf(" Used %d/%d inodes and %d/%d blocks\n", aux_info.sb->s_inodes_count - aux_info.sb->s_free_inodes_count, aux_info.sb->s_inodes_count, aux_info.sb->s_blocks_count_lo - aux_info.sb->s_free_blocks_count_lo, aux_info.sb->s_blocks_count_lo); } return 0; }