diff options
Diffstat (limited to 'ext4_utils/ext4_utils.c')
| -rw-r--r-- | ext4_utils/ext4_utils.c | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/ext4_utils/ext4_utils.c b/ext4_utils/ext4_utils.c index d4fbc7c8..1b70afee 100644 --- a/ext4_utils/ext4_utils.c +++ b/ext4_utils/ext4_utils.c @@ -62,6 +62,21 @@ static int is_power_of(int a, int 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 @@ -81,6 +96,38 @@ int ext4_bg_has_super_block(int bg) 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"); +} + /* Write the filesystem image to a file */ void write_ext4_image(int fd, int gz, int sparse, int crc) { @@ -450,3 +497,48 @@ u64 parse_num(const char *arg) return num; } + +int read_ext(int fd, int verbose) +{ + off64_t ret; + struct ext4_super_block sb; + + read_sb(fd, &sb); + + ext4_parse_sb(&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: %llu\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: %llu\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; +} + |