/* * Copyright (c) 2011 Frantisek Princ * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * - Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * - Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * - The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /** @addtogroup libext4 * @{ */ #ifndef LIBEXT4_LIBEXT4_SUPERBLOCK_H_ #define LIBEXT4_LIBEXT4_SUPERBLOCK_H_ #include /* * Structure of the super block */ typedef struct ext4_superblock { uint32_t s_inodes_count; // Inodes count uint32_t s_blocks_count_lo; // Blocks count uint32_t s_r_blocks_count_lo; // Reserved blocks count uint32_t s_free_blocks_count_lo; // Free blocks count uint32_t s_free_inodes_count; // Free inodes count uint32_t s_first_data_block; // First Data Block uint32_t s_log_block_size; // Block size uint32_t s_obso_log_frag_size; // Obsoleted fragment size uint32_t s_blocks_per_group; // Number of blocks per group uint32_t s_obso_frags_per_group; // Obsoleted fragments per group uint32_t s_inodes_per_group; // Number of inodes per group uint32_t s_mtime; // Mount time uint32_t s_wtime; // Write time uint16_t s_mnt_count; // Mount count uint16_t s_max_mnt_count; // Maximal mount count uint16_t s_magic; // Magic signature uint16_t s_state; // File system state uint16_t s_errors; // Behaviour when detecting errors uint16_t s_minor_rev_level; // Minor revision level uint32_t s_lastcheck; // Time of last check uint32_t s_checkinterval; // Maximum time between checks uint32_t s_creator_os; // Creator OS uint32_t s_rev_level; // Revision level uint16_t s_def_resuid; // Default uid for reserved blocks uint16_t s_def_resgid; // Default gid for reserved blocks // Fields for EXT4_DYNAMIC_REV superblocks only. uint32_t s_first_ino; // First non-reserved inode uint16_t s_inode_size; // Size of inode structure uint16_t s_block_group_nr; // Block group number of this superblock uint32_t s_feature_compat; // Compatible feature set uint32_t s_feature_incompat; // Incompatible feature set uint32_t s_feature_ro_compat; // Readonly-compatible feature set uint8_t s_uuid[16]; // 128-bit uuid for volume char s_volume_name[16]; // Volume name char s_last_mounted[64]; // Directory where last mounted uint32_t s_algorithm_usage_bitmap; // For compression /* * Performance hints. Directory preallocation should only * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on. */ uint8_t s_prealloc_blocks; // Number of blocks to try to preallocate uint8_t s_prealloc_dir_blocks; // Number to preallocate for dirs uint16_t s_reserved_gdt_blocks; // Per group desc for online growth /* * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set. */ uint8_t s_journal_uuid[16]; // UUID of journal superblock uint32_t s_journal_inum; // Inode number of journal file uint32_t s_journal_dev; // Device number of journal file uint32_t s_last_orphan; // Head of list of inodes to delete uint32_t s_hash_seed[4]; // HTREE hash seed uint8_t s_def_hash_version; // Default hash version to use uint8_t s_jnl_backup_type; uint16_t s_desc_size; // Size of group descriptor uint32_t s_default_mount_opts; // Default mount options uint32_t s_first_meta_bg; // First metablock block group uint32_t s_mkfs_time; // When the filesystem was created uint32_t s_jnl_blocks[17]; // Backup of the journal inode /* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */ uint32_t s_blocks_count_hi; // Blocks count uint32_t s_r_blocks_count_hi; // Reserved blocks count uint32_t s_free_blocks_count_hi; // Free blocks count uint16_t s_min_extra_isize; // All inodes have at least # bytes uint16_t s_want_extra_isize; // New inodes should reserve # bytes uint32_t s_flags; // Miscellaneous flags uint16_t s_raid_stride; // RAID stride uint16_t s_mmp_interval; // # seconds to wait in MMP checking uint64_t s_mmp_block; // Block for multi-mount protection uint32_t s_raid_stripe_width; // blocks on all data disks (N*stride) uint8_t s_log_groups_per_flex; // FLEX_BG group size uint8_t s_reserved_char_pad; uint16_t s_reserved_pad; uint64_t s_kbytes_written; // Number of lifetime kilobytes written uint32_t s_snapshot_inum; // Inode number of active snapshot uint32_t s_snapshot_id; // Sequential ID of active snapshot uint64_t s_snapshot_r_blocks_count; /* reserved blocks for active snapshot's future use */ uint32_t s_snapshot_list; // inode number of the head of the on-disk snapshot list //#define EXT4_S_ERR_START offsetof(struct ext4_super_block, s_error_count) uint32_t s_error_count; // number of fs errors uint32_t s_first_error_time; // First time an error happened uint32_t s_first_error_ino; // Inode involved in first error uint64_t s_first_error_block; // block involved of first error uint8_t s_first_error_func[32]; // Function where the error happened uint32_t s_first_error_line; // Line number where error happened uint32_t s_last_error_time; // Most recent time of an error uint32_t s_last_error_ino; // Inode involved in last error uint32_t s_last_error_line; // Line number where error happened uint64_t s_last_error_block; /* block involved of last error */ uint8_t s_last_error_func[32]; /* function where the error happened */ //#define EXT4_S_ERR_END offsetof(struct ext4_super_block, s_mount_opts) uint8_t s_mount_opts[64]; uint32_t s_reserved[112]; // Padding to the end of the block } __attribute__((packed)) ext4_superblock_t; #endif /** * @} */