- * The ext2fs library private definition of the ext2 superblock, so we
- * don't have to depend on the kernel's definition of the superblock,
- * which might not have the latest features.
- */
-struct ext2fs_sb {
- __u32 s_inodes_count; /* Inodes count */
- __u32 s_blocks_count; /* Blocks count */
- __u32 s_r_blocks_count; /* Reserved blocks count */
- __u32 s_free_blocks_count; /* Free blocks count */
- __u32 s_free_inodes_count; /* Free inodes count */
- __u32 s_first_data_block; /* First Data Block */
- __u32 s_log_block_size; /* Block size */
- __s32 s_log_frag_size; /* Fragment size */
- __u32 s_blocks_per_group; /* # Blocks per group */
- __u32 s_frags_per_group; /* # Fragments per group */
- __u32 s_inodes_per_group; /* # Inodes per group */
- __u32 s_mtime; /* Mount time */
- __u32 s_wtime; /* Write time */
- __u16 s_mnt_count; /* Mount count */
- __s16 s_max_mnt_count; /* Maximal mount count */
- __u16 s_magic; /* Magic signature */
- __u16 s_state; /* File system state */
- __u16 s_errors; /* Behaviour when detecting errors */
- __u16 s_minor_rev_level; /* minor revision level */
- __u32 s_lastcheck; /* time of last check */
- __u32 s_checkinterval; /* max. time between checks */
- __u32 s_creator_os; /* OS */
- __u32 s_rev_level; /* Revision level */
- __u16 s_def_resuid; /* Default uid for reserved blocks */
- __u16 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...
- */
- __u32 s_first_ino; /* First non-reserved inode */
- __u16 s_inode_size; /* size of inode structure */
- __u16 s_block_group_nr; /* block group # of this superblock */
- __u32 s_feature_compat; /* compatible feature set */
- __u32 s_feature_incompat; /* incompatible feature set */
- __u32 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 */
- __u32 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.
- */
- __u8 s_journal_uuid[16]; /* uuid of journal superblock */
- __u32 s_journal_inum; /* inode number of journal file */
-
- __u32 s_reserved[199]; /* Padding to the end of the block */
-};