Linux_Ext分区超级块结构

//ext4 /* * Behaviour when detecting errors */ #define EXT4_ERRORS_CONTINUE 1 /* Continue execution */ #define EXT4_ERRORS_RO 2 /* Remount fs read-only */ #define EXT4_ERRORS_PANIC 3 /* Panic */ #define EXT4_ERRORS_DEFAULT EXT4_ERRORS_CONTINUE /* Metadata checksum algorithm codes */ #define EXT4_CRC32C_CHKSUM 1 /* * Structure of the super block */ struct ext4_super_block { /*00*/ __le32 s_inodes_count; /* Inodes count */ __le32 s_blocks_count_lo; /* Blocks count */ __le32 s_r_blocks_count_lo; /* Reserved blocks count */ __le32 s_free_blocks_count_lo; /* Free blocks count */ /*10*/ __le32 s_free_inodes_count; /* Free inodes count */ __le32 s_first_data_block; /* First Data Block */ __le32 s_log_block_size; /* Block size */ __le32 s_log_cluster_size; /* Allocation cluster size */ /*20*/ __le32 s_blocks_per_group; /* # Blocks per group */ __le32 s_clusters_per_group; /* # Clusters per group */ __le32 s_inodes_per_group; /* # Inodes per group */ __le32 s_mtime; /* Mount time */ /*30*/ __le32 s_wtime; /* Write time */ __le16 s_mnt_count; /* Mount count */ __le16 s_max_mnt_count; /* Maximal mount count */ __le16 s_magic; /* Magic signature */ __le16 s_state; /* File system state */ __le16 s_errors; /* Behaviour when detecting errors */ __le16 s_minor_rev_level; /* minor revision level */ /*40*/ __le32 s_lastcheck; /* time of last check */ __le32 s_checkinterval; /* max. time between checks */ __le32 s_creator_os; /* OS */ __le32 s_rev_level; /* Revision level */ /*50*/ __le16 s_def_resuid; /* Default uid for reserved blocks */ __le16 s_def_resgid; /* Default gid for reserved blocks */ /* * These fields are for EXT4_DYNAMIC_REV superblocks only. * * Note: the difference between the compatible feature set and * the incompatible feature set is that if there is a bit set * in the incompatible feature set that the kernel doesn't * know about, it should refuse to mount the filesystem. * * e2fsck's requirements are more strict; if it doesn't know * about a feature in either the compatible or incompatible * feature set, it must abort and not try to meddle with * things it doesn't understand... */ __le32 s_first_ino; /* First non-reserved inode */ __le16 s_inode_size; /* size of inode structure */ __le16 s_block_group_nr; /* block group # of this superblock */ __le32 s_feature_compat; /* compatible feature set */ /*60*/ __le32 s_feature_incompat; /* incompatible feature set */ __le32 s_feature_ro_compat; /* readonly-compatible feature set */ /*68*/ __u8 s_uuid[16]; /* 128-bit uuid for volume */ /*78*/ char s_volume_name[16]; /* volume name */ /*88*/ char s_last_mounted[64]; /* directory where last mounted */ /*C8*/ __le32 s_algorithm_usage_bitmap; /* For compression */ /* * Performance hints. Directory preallocation should only * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on. */ __u8 s_prealloc_blocks; /* Nr of blocks to try to preallocate*/ __u8 s_prealloc_dir_blocks; /* Nr to preallocate for dirs */ __le16 s_reserved_gdt_blocks; /* Per group desc for online growth */ /* * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set. */ /*D0*/ __u8 s_journal_uuid[16]; /* uuid of journal superblock */ /*E0*/ __le32 s_journal_inum; /* inode number of journal file */ __le32 s_journal_dev; /* device number of journal file */ __le32 s_last_orphan; /* start of list of inodes to delete */ __le32 s_hash_seed[4]; /* HTREE hash seed */ __u8 s_def_hash_version; /* Default hash version to use */ __u8 s_jnl_backup_type; __le16 s_desc_size; /* size of group descriptor */ /*100*/ __le32 s_default_mount_opts; __le32 s_first_meta_bg; /* First metablock block group */ __le32 s_mkfs_time; /* When the filesystem was created */ __le32 s_jnl_blocks[17]; /* Backup of the journal inode */ /* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */ /*150*/ __le32 s_blocks_count_hi; /* Blocks count */ __le32 s_r_blocks_count_hi; /* Reserved blocks count */ __le32 s_free_blocks_count_hi; /* Free blocks count */ __le16 s_min_extra_isize; /* All inodes have at least # bytes */ __le16 s_want_extra_isize; /* New inodes should reserve # bytes */ __le32 s_flags; /* Miscellaneous flags */ __le16 s_raid_stride; /* RAID stride */ __le16 s_mmp_update_interval; /* # seconds to wait in MMP checking */ __le64 s_mmp_block; /* Block for multi-mount protection */ __le32 s_raid_stripe_width; /* blocks on all data disks (N*stride)*/ __u8 s_log_groups_per_flex; /* FLEX_BG group size */ __u8 s_checksum_type; /* metadata checksum algorithm used */ __le16 s_reserved_pad; __le64 s_kbytes_written; /* nr of lifetime kilobytes written */ __le32 s_snapshot_inum; /* Inode number of active snapshot */ __le32 s_snapshot_id; /* sequential ID of active snapshot */ __le64 s_snapshot_r_blocks_count; /* reserved blocks for active snapshot's future use */ __le32 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) __le32 s_error_count; /* number of fs errors */ __le32 s_first_error_time; /* first time an error happened */ __le32 s_first_error_ino; /* inode involved in first error */ __le64 s_first_error_block; /* block involved of first error */ __u8 s_first_error_func[32]; /* function where the error happened */ __le32 s_first_error_line; /* line number where error happened */ __le32 s_last_error_time; /* most recent time of an error */ __le32 s_last_error_ino; /* inode involved in last error */ __le32 s_last_error_line; /* line number where error happened */ __le64 s_last_error_block; /* block involved of last error */ __u8 s_last_error_func[32]; /* function where the error happened */ #define EXT4_S_ERR_END offsetof(struct ext4_super_block, s_mount_opts) __u8 s_mount_opts[64]; __le32 s_usr_quota_inum; /* inode for tracking user quota */ __le32 s_grp_quota_inum; /* inode for tracking group quota */ __le32 s_overhead_clusters; /* overhead blocks/clusters in fs */ __le32 s_reserved[108]; /* Padding to the end of the block */ __le32 s_checksum; /* crc32c(superblock) */ }; //ext3 /* * Structure of the super block */ struct ext3_super_block { /*00*/ __le32 s_inodes_count; /* Inodes count */ __le32 s_blocks_count; /* Blocks count */ __le32 s_r_blocks_count; /* Reserved blocks count */ __le32 s_free_blocks_count; /* Free blocks count */ /*10*/ __le32 s_free_inodes_count; /* Free inodes count */ __le32 s_first_data_block; /* First Data Block */ __le32 s_log_block_size; /* Block size */ __le32 s_log_frag_size; /* Fragment size */ /*20*/ __le32 s_blocks_per_group; /* # Blocks per group */ __le32 s_frags_per_group; /* # Fragments per group */ __le32 s_inodes_per_group; /* # Inodes per group */ __le32 s_mtime; /* Mount time */ /*30*/ __le32 s_wtime; /* Write time */ __le16 s_mnt_count; /* Mount count */ __le16 s_max_mnt_count; /* Maximal mount count */ __le16 s_magic; /* Magic signature */ __le16 s_state; /* File system state */ __le16 s_errors; /* Behaviour when detecting errors */ __le16 s_minor_rev_level; /* minor revision level */ /*40*/ __le32 s_lastcheck; /* time of last check */ __le32 s_checkinterval; /* max. time between checks */ __le32 s_creator_os; /* OS */ __le32 s_rev_level; /* Revision level */ /*50*/ __le16 s_def_resuid; /* Default uid for reserved blocks */ __le16 s_def_resgid; /* Default gid for reserved blocks */ /* * These fields are for EXT3_DYNAMIC_REV superblocks only. * * Note: the difference between the compatible feature set and * the incompatible feature set is that if there is a bit set * in the incompatible feature set that the kernel doesn't * know about, it should refuse to mount the filesystem. * * e2fsck's requirements are more strict; if it doesn't know * about a feature in either the compatible or incompatible * feature set, it must abort and not try to meddle with * things it doesn't understand... */ __le32 s_first_ino; /* First non-reserved inode */ __le16 s_inode_size; /* size of inode structure */ __le16 s_block_group_nr; /* block group # of this superblock */ __le32 s_feature_compat; /* compatible feature set */ /*60*/ __le32 s_feature_incompat; /* incompatible feature set */ __le32 s_feature_ro_compat; /* readonly-compatible feature set */ /*68*/ __u8 s_uuid[16]; /* 128-bit uuid for volume */ /*78*/ char s_volume_name[16]; /* volume name */ /*88*/ char s_last_mounted[64]; /* directory where last mounted */ /*C8*/ __le32 s_algorithm_usage_bitmap; /* For compression */ /* * Performance hints. Directory preallocation should only * happen if the EXT3_FEATURE_COMPAT_DIR_PREALLOC flag is on. */ __u8 s_prealloc_blocks; /* Nr of blocks to try to preallocate*/ __u8 s_prealloc_dir_blocks; /* Nr to preallocate for dirs */ __le16 s_reserved_gdt_blocks; /* Per group desc for online growth */ /* * Journaling support valid if EXT3_FEATURE_COMPAT_HAS_JOURNAL set. */ /*D0*/ __u8 s_journal_uuid[16]; /* uuid of journal superblock */ /*E0*/ __le32 s_journal_inum; /* inode number of journal file */ __le32 s_journal_dev; /* device number of journal file */ __le32 s_last_orphan; /* start of list of inodes to delete */ __le32 s_hash_seed[4]; /* HTREE hash seed */ __u8 s_def_hash_version; /* Default hash version to use */ __u8 s_reserved_char_pad; __u16 s_reserved_word_pad; __le32 s_default_mount_opts; __le32 s_first_meta_bg; /* First metablock block group */ __le32 s_mkfs_time; /* When the filesystem was created */ __le32 s_jnl_blocks[17]; /* Backup of the journal inode */ /* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */ /*150*/ __le32 s_blocks_count_hi; /* Blocks count */ __le32 s_r_blocks_count_hi; /* Reserved blocks count */ __le32 s_free_blocks_count_hi; /* Free blocks count */ __le16 s_min_extra_isize; /* All inodes have at least # bytes */ __le16 s_want_extra_isize; /* New inodes should reserve # bytes */ __le32 s_flags; /* Miscellaneous flags */ __le16 s_raid_stride; /* RAID stride */ __le16 s_mmp_interval; /* # seconds to wait in MMP checking */ __le64 s_mmp_block; /* Block for multi-mount protection */ __le32 s_raid_stripe_width; /* blocks on all data disks (N*stride)*/ __u8 s_log_groups_per_flex; /* FLEX_BG group size */ __u8 s_reserved_char_pad2; __le16 s_reserved_pad; __u32 s_reserved[162]; /* Padding to the end of the block */ }; //ext2 /* * Structure of the super block */ struct ext2_super_block { __le32 s_inodes_count; /* Inodes count */ __le32 s_blocks_count; /* Blocks count */ __le32 s_r_blocks_count; /* Reserved blocks count */ __le32 s_free_blocks_count; /* Free blocks count */ __le32 s_free_inodes_count; /* Free inodes count */ __le32 s_first_data_block; /* First Data Block */ __le32 s_log_block_size; /* Block size */ __le32 s_log_frag_size; /* Fragment size */ __le32 s_blocks_per_group; /* # Blocks per group */ __le32 s_frags_per_group; /* # Fragments per group */ __le32 s_inodes_per_group; /* # Inodes per group */ __le32 s_mtime; /* Mount time */ __le32 s_wtime; /* Write time */ __le16 s_mnt_count; /* Mount count */ __le16 s_max_mnt_count; /* Maximal mount count */ __le16 s_magic; /* Magic signature */ __le16 s_state; /* File system state */ __le16 s_errors; /* Behaviour when detecting errors */ __le16 s_minor_rev_level; /* minor revision level */ __le32 s_lastcheck; /* time of last check */ __le32 s_checkinterval; /* max. time between checks */ __le32 s_creator_os; /* OS */ __le32 s_rev_level; /* Revision level */ __le16 s_def_resuid; /* Default uid for reserved blocks */ __le16 s_def_resgid; /* Default gid for reserved blocks */ /* * These fields are for EXT2_DYNAMIC_REV superblocks only. * * Note: the difference between the compatible feature set and * the incompatible feature set is that if there is a bit set * in the incompatible feature set that the kernel doesn't * know about, it should refuse to mount the filesystem. * * e2fsck's requirements are more strict; if it doesn't know * about a feature in either the compatible or incompatible * feature set, it must abort and not try to meddle with * things it doesn't understand... */ __le32 s_first_ino; /* First non-reserved inode */ __le16 s_inode_size; /* size of inode structure */ __le16 s_block_group_nr; /* block group # of this superblock */ __le32 s_feature_compat; /* compatible feature set */ __le32 s_feature_incompat; /* incompatible feature set */ __le32 s_feature_ro_compat; /* readonly-compatible feature set */ __u8 s_uuid[16]; /* 128-bit uuid for volume */ char s_volume_name[16]; /* volume name */ char s_last_mounted[64]; /* directory where last mounted */ __le32 s_algorithm_usage_bitmap; /* For compression */ /* * Performance hints. Directory preallocation should only * happen if the EXT2_COMPAT_PREALLOC flag is on. */ __u8 s_prealloc_blocks; /* Nr of blocks to try to preallocate*/ __u8 s_prealloc_dir_blocks; /* Nr to preallocate for dirs */ __u16 s_padding1; /* * Journaling support valid if EXT3_FEATURE_COMPAT_HAS_JOURNAL set. */ __u8 s_journal_uuid[16]; /* uuid of journal superblock */ __u32 s_journal_inum; /* inode number of journal file */ __u32 s_journal_dev; /* device number of journal file */ __u32 s_last_orphan; /* start of list of inodes to delete */ __u32 s_hash_seed[4]; /* HTREE hash seed */ __u8 s_def_hash_version; /* Default hash version to use */ __u8 s_reserved_char_pad; __u16 s_reserved_word_pad; __le32 s_default_mount_opts; __le32 s_first_meta_bg; /* First metablock block group */ __u32 s_reserved[190]; /* Padding to the end of the block */ };

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//ext4 /* * Behaviour when detecting errors */ #define EXT4_ERRORS_CONTINUE 1 /* Continue execution */ #define EXT4_ERRORS_RO 2 /* Remount fs read-only */ #define EXT4_ERRORS_PANIC 3 /* Panic */ #define EXT4_ERRORS_DEFAULT EXT4_ERRORS_CONTINUE   /* Metadata checksum algorithm codes */ #define EXT4_CRC32C_CHKSUM 1   /* * Structure of the super block */ struct ext4_super_block { /*00*/ __le32 s_inodes_count; /* Inodes count */ __le32 s_blocks_count_lo; /* Blocks count */ __le32 s_r_blocks_count_lo; /* Reserved blocks count */ __le32 s_free_blocks_count_lo; /* Free blocks count */ /*10*/ __le32 s_free_inodes_count; /* Free inodes count */ __le32 s_first_data_block; /* First Data Block */ __le32 s_log_block_size; /* Block size */ __le32 s_log_cluster_size; /* Allocation cluster size */ /*20*/ __le32 s_blocks_per_group; /* # Blocks per group */ __le32 s_clusters_per_group; /* # Clusters per group */ __le32 s_inodes_per_group; /* # Inodes per group */ __le32 s_mtime; /* Mount time */ /*30*/ __le32 s_wtime; /* Write time */ __le16 s_mnt_count; /* Mount count */ __le16 s_max_mnt_count; /* Maximal mount count */ __le16 s_magic; /* Magic signature */ __le16 s_state; /* File system state */ __le16 s_errors; /* Behaviour when detecting errors */ __le16 s_minor_rev_level; /* minor revision level */ /*40*/ __le32 s_lastcheck; /* time of last check */ __le32 s_checkinterval; /* max. time between checks */ __le32 s_creator_os; /* OS */ __le32 s_rev_level; /* Revision level */ /*50*/ __le16 s_def_resuid; /* Default uid for reserved blocks */ __le16 s_def_resgid; /* Default gid for reserved blocks */ /* * These fields are for EXT4_DYNAMIC_REV superblocks only. * * Note: the difference between the compatible feature set and * the incompatible feature set is that if there is a bit set * in the incompatible feature set that the kernel doesn't * know about, it should refuse to mount the filesystem. * * e2fsck's requirements are more strict; if it doesn't know * about a feature in either the compatible or incompatible * feature set, it must abort and not try to meddle with * things it doesn't understand... */ __le32 s_first_ino; /* First non-reserved inode */ __le16  s_inode_size; /* size of inode structure */ __le16 s_block_group_nr; /* block group # of this superblock */ __le32 s_feature_compat; /* compatible feature set */ /*60*/ __le32 s_feature_incompat; /* incompatible feature set */ __le32 s_feature_ro_compat; /* readonly-compatible feature set */ /*68*/ __u8 s_uuid[16]; /* 128-bit uuid for volume */ /*78*/ char s_volume_name[16]; /* volume name */ /*88*/ char s_last_mounted[64]; /* directory where last mounted */ /*C8*/ __le32 s_algorithm_usage_bitmap; /* For compression */ /* * Performance hints.  Directory preallocation should only * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on. */ __u8 s_prealloc_blocks; /* Nr of blocks to try to preallocate*/ __u8 s_prealloc_dir_blocks; /* Nr to preallocate for dirs */ __le16 s_reserved_gdt_blocks; /* Per group desc for online growth */ /* * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set. */ /*D0*/ __u8 s_journal_uuid[16]; /* uuid of journal superblock */ /*E0*/ __le32 s_journal_inum; /* inode number of journal file */ __le32 s_journal_dev; /* device number of journal file */ __le32 s_last_orphan; /* start of list of inodes to delete */ __le32 s_hash_seed[4]; /* HTREE hash seed */ __u8 s_def_hash_version; /* Default hash version to use */ __u8 s_jnl_backup_type; __le16  s_desc_size; /* size of group descriptor */ /*100*/ __le32 s_default_mount_opts; __le32 s_first_meta_bg; /* First metablock block group */ __le32 s_mkfs_time; /* When the filesystem was created */ __le32 s_jnl_blocks[17]; /* Backup of the journal inode */ /* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */ /*150*/ __le32 s_blocks_count_hi; /* Blocks count */ __le32 s_r_blocks_count_hi; /* Reserved blocks count */ __le32 s_free_blocks_count_hi; /* Free blocks count */ __le16 s_min_extra_isize; /* All inodes have at least # bytes */ __le16 s_want_extra_isize; /* New inodes should reserve # bytes */ __le32 s_flags; /* Miscellaneous flags */ __le16  s_raid_stride; /* RAID stride */ __le16  s_mmp_update_interval;  /* # seconds to wait in MMP checking */ __le64  s_mmp_block;            /* Block for multi-mount protection */ __le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/ __u8 s_log_groups_per_flex;  /* FLEX_BG group size */ __u8 s_checksum_type; /* metadata checksum algorithm used */ __le16  s_reserved_pad; __le64 s_kbytes_written; /* nr of lifetime kilobytes written */ __le32 s_snapshot_inum; /* Inode number of active snapshot */ __le32 s_snapshot_id; /* sequential ID of active snapshot */ __le64 s_snapshot_r_blocks_count; /* reserved blocks for active       snapshot's future use */ __le32 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) __le32 s_error_count; /* number of fs errors */ __le32 s_first_error_time; /* first time an error happened */ __le32 s_first_error_ino; /* inode involved in first error */ __le64 s_first_error_block; /* block involved of first error */ __u8 s_first_error_func[32]; /* function where the error happened */ __le32 s_first_error_line; /* line number where error happened */ __le32 s_last_error_time; /* most recent time of an error */ __le32 s_last_error_ino; /* inode involved in last error */ __le32 s_last_error_line; /* line number where error happened */ __le64 s_last_error_block; /* block involved of last error */ __u8 s_last_error_func[32]; /* function where the error happened */ #define EXT4_S_ERR_END offsetof(struct ext4_super_block, s_mount_opts) __u8 s_mount_opts[64]; __le32 s_usr_quota_inum; /* inode for tracking user quota */ __le32 s_grp_quota_inum; /* inode for tracking group quota */ __le32 s_overhead_clusters; /* overhead blocks/clusters in fs */ __le32 s_reserved[108]; /* Padding to the end of the block */ __le32 s_checksum; /* crc32c(superblock) */ };   //ext3 /* * Structure of the super block */ struct ext3_super_block { /*00*/ __le32 s_inodes_count; /* Inodes count */ __le32 s_blocks_count; /* Blocks count */ __le32 s_r_blocks_count; /* Reserved blocks count */ __le32 s_free_blocks_count; /* Free blocks count */ /*10*/ __le32 s_free_inodes_count; /* Free inodes count */ __le32 s_first_data_block; /* First Data Block */ __le32 s_log_block_size; /* Block size */ __le32 s_log_frag_size; /* Fragment size */ /*20*/ __le32 s_blocks_per_group; /* # Blocks per group */ __le32 s_frags_per_group; /* # Fragments per group */ __le32 s_inodes_per_group; /* # Inodes per group */ __le32 s_mtime; /* Mount time */ /*30*/ __le32 s_wtime; /* Write time */ __le16 s_mnt_count; /* Mount count */ __le16 s_max_mnt_count; /* Maximal mount count */ __le16 s_magic; /* Magic signature */ __le16 s_state; /* File system state */ __le16 s_errors; /* Behaviour when detecting errors */ __le16 s_minor_rev_level; /* minor revision level */ /*40*/ __le32 s_lastcheck; /* time of last check */ __le32 s_checkinterval; /* max. time between checks */ __le32 s_creator_os; /* OS */ __le32 s_rev_level; /* Revision level */ /*50*/ __le16 s_def_resuid; /* Default uid for reserved blocks */ __le16 s_def_resgid; /* Default gid for reserved blocks */ /* * These fields are for EXT3_DYNAMIC_REV superblocks only. * * Note: the difference between the compatible feature set and * the incompatible feature set is that if there is a bit set * in the incompatible feature set that the kernel doesn't * know about, it should refuse to mount the filesystem. * * e2fsck's requirements are more strict; if it doesn't know * about a feature in either the compatible or incompatible * feature set, it must abort and not try to meddle with * things it doesn't understand... */ __le32 s_first_ino; /* First non-reserved inode */ __le16   s_inode_size; /* size of inode structure */ __le16 s_block_group_nr; /* block group # of this superblock */ __le32 s_feature_compat; /* compatible feature set */ /*60*/ __le32 s_feature_incompat; /* incompatible feature set */ __le32 s_feature_ro_compat; /* readonly-compatible feature set */ /*68*/ __u8 s_uuid[16]; /* 128-bit uuid for volume */ /*78*/ char s_volume_name[16]; /* volume name */ /*88*/ char s_last_mounted[64]; /* directory where last mounted */ /*C8*/ __le32 s_algorithm_usage_bitmap; /* For compression */ /* * Performance hints.  Directory preallocation should only * happen if the EXT3_FEATURE_COMPAT_DIR_PREALLOC flag is on. */ __u8 s_prealloc_blocks; /* Nr of blocks to try to preallocate*/ __u8 s_prealloc_dir_blocks; /* Nr to preallocate for dirs */ __le16 s_reserved_gdt_blocks; /* Per group desc for online growth */ /* * Journaling support valid if EXT3_FEATURE_COMPAT_HAS_JOURNAL set. */ /*D0*/ __u8 s_journal_uuid[16]; /* uuid of journal superblock */ /*E0*/ __le32 s_journal_inum; /* inode number of journal file */ __le32 s_journal_dev; /* device number of journal file */ __le32 s_last_orphan; /* start of list of inodes to delete */ __le32 s_hash_seed[4]; /* HTREE hash seed */ __u8 s_def_hash_version; /* Default hash version to use */ __u8 s_reserved_char_pad; __u16 s_reserved_word_pad; __le32 s_default_mount_opts; __le32 s_first_meta_bg; /* First metablock block group */ __le32 s_mkfs_time; /* When the filesystem was created */ __le32 s_jnl_blocks[17]; /* Backup of the journal inode */ /* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */ /*150*/ __le32 s_blocks_count_hi; /* Blocks count */ __le32 s_r_blocks_count_hi; /* Reserved blocks count */ __le32 s_free_blocks_count_hi; /* Free blocks count */ __le16 s_min_extra_isize; /* All inodes have at least # bytes */ __le16 s_want_extra_isize; /* New inodes should reserve # bytes */ __le32 s_flags; /* Miscellaneous flags */ __le16  s_raid_stride; /* RAID stride */ __le16  s_mmp_interval;         /* # seconds to wait in MMP checking */ __le64  s_mmp_block;            /* Block for multi-mount protection */ __le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/ __u8 s_log_groups_per_flex;  /* FLEX_BG group size */ __u8 s_reserved_char_pad2; __le16  s_reserved_pad; __u32   s_reserved[162];        /* Padding to the end of the block */ };   //ext2 /* * Structure of the super block */ struct ext2_super_block { __le32 s_inodes_count; /* Inodes count */ __le32 s_blocks_count; /* Blocks count */ __le32 s_r_blocks_count; /* Reserved blocks count */ __le32 s_free_blocks_count; /* Free blocks count */ __le32 s_free_inodes_count; /* Free inodes count */ __le32 s_first_data_block; /* First Data Block */ __le32 s_log_block_size; /* Block size */ __le32 s_log_frag_size; /* Fragment size */ __le32 s_blocks_per_group; /* # Blocks per group */ __le32 s_frags_per_group; /* # Fragments per group */ __le32 s_inodes_per_group; /* # Inodes per group */ __le32 s_mtime; /* Mount time */ __le32 s_wtime; /* Write time */ __le16 s_mnt_count; /* Mount count */ __le16 s_max_mnt_count; /* Maximal mount count */ __le16 s_magic; /* Magic signature */ __le16 s_state; /* File system state */ __le16 s_errors; /* Behaviour when detecting errors */ __le16 s_minor_rev_level; /* minor revision level */ __le32 s_lastcheck; /* time of last check */ __le32 s_checkinterval; /* max. time between checks */ __le32 s_creator_os; /* OS */ __le32 s_rev_level; /* Revision level */ __le16 s_def_resuid; /* Default uid for reserved blocks */ __le16 s_def_resgid; /* Default gid for reserved blocks */ /* * These fields are for EXT2_DYNAMIC_REV superblocks only. * * Note: the difference between the compatible feature set and * the incompatible feature set is that if there is a bit set * in the incompatible feature set that the kernel doesn't * know about, it should refuse to mount the filesystem. * * e2fsck's requirements are more strict; if it doesn't know * about a feature in either the compatible or incompatible * feature set, it must abort and not try to meddle with * things it doesn't understand... */ __le32 s_first_ino; /* First non-reserved inode */ __le16   s_inode_size; /* size of inode structure */ __le16 s_block_group_nr; /* block group # of this superblock */ __le32 s_feature_compat; /* compatible feature set */ __le32 s_feature_incompat; /* incompatible feature set */ __le32 s_feature_ro_compat; /* readonly-compatible feature set */ __u8 s_uuid[16]; /* 128-bit uuid for volume */ char s_volume_name[16]; /* volume name */ char s_last_mounted[64]; /* directory where last mounted */ __le32 s_algorithm_usage_bitmap; /* For compression */ /* * Performance hints.  Directory preallocation should only * happen if the EXT2_COMPAT_PREALLOC flag is on. */ __u8 s_prealloc_blocks; /* Nr of blocks to try to preallocate*/ __u8 s_prealloc_dir_blocks; /* Nr to preallocate for dirs */ __u16 s_padding1; /* * Journaling support valid if EXT3_FEATURE_COMPAT_HAS_JOURNAL set. */ __u8 s_journal_uuid[16]; /* uuid of journal superblock */ __u32 s_journal_inum; /* inode number of journal file */ __u32 s_journal_dev; /* device number of journal file */ __u32 s_last_orphan; /* start of list of inodes to delete */ __u32 s_hash_seed[4]; /* HTREE hash seed */ __u8 s_def_hash_version; /* Default hash version to use */ __u8 s_reserved_char_pad; __u16 s_reserved_word_pad; __le32 s_default_mount_opts; __le32 s_first_meta_bg; /* First metablock block group */ __u32 s_reserved[190]; /* Padding to the end of the block */ };