From b18b33e0f256138220934e44d6bf9b01ab7c2213 Mon Sep 17 00:00:00 2001 From: Liu Aleaxander Date: Wed, 3 Jun 2009 15:29:25 +0800 Subject: [PATCH] add ext2 fs header file --- core/ext2_fs.h | 252 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 252 insertions(+) create mode 100644 core/ext2_fs.h diff --git a/core/ext2_fs.h b/core/ext2_fs.h new file mode 100644 index 0000000..d579ead --- /dev/null +++ b/core/ext2_fs.h @@ -0,0 +1,252 @@ +#ifndef __EXT2_FS_H +#define __EXT2_FS_H + +#include + +#define EXT2_SUPER_MAGIC 0xEF53 + +#define EXT2_GOOD_OLD_REV 0 // The good old (original) format +#define EXT2_DYNAMIC_REV 1 // V2 format w/ dynamic inode sizes +#define EXT2_GOOD_OLD_INODE_SIZE 128 + +// Special inode numbers +#define EXT2_BAD_INO 1 // Bad blocks inode +#define EXT2_ROOT_INO 2 // Root inode +#define EXT2_BOOT_LOADER_INO 5 // Boot loader inode +#define EXT2_UNDEL_DIR_INO 6 // Undelete directory inode +#define EXT3_RESIZE_INO 7 // Reserved group descriptors inode +#define EXT3_JOURNAL_INO 8 // Journal inode + +// We're readonly, so we only care about incompat features. +#define EXT2_FEATURE_INCOMPAT_COMPRESSION 0x0001 +#define EXT2_FEATURE_INCOMPAT_FILETYPE 0x0002 +#define EXT3_FEATURE_INCOMPAT_RECOVER 0x0004 +#define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV 0x0008 +#define EXT2_FEATURE_INCOMPAT_META_BG 0x0010 +#define EXT2_FEATURE_INCOMPAT_ANY 0xffffffff + +#define EXT2_NDIR_BLOCKS 12 +#define EXT2_IND_BLOCK EXT2_NDIR_BLOCKS +#define EXT2_DIND_BLOCK (EXT2_IND_BLOCK+1) +#define EXT2_TIND_BLOCK (EXT2_DIND_BLOCK+1) +#define EXT2_N_BLOCKS (EXT2_TIND_BLOCK+1) + + +/* for EXT4 extent */ +#define EXT4_EXT_MAGIC 0xf30a +#define EXT4_EXTENTS_FLAG 0x00080000 + +/* + * File types and file modes + */ +#define S_IFDIR 0040000 // Directory +#define S_IFCHR 0020000 // Character device +#define S_IFBLK 0060000 // Block device +#define S_IFREG 0100000 // Regular file +#define S_IFIFO 0010000 // FIFO +#define S_IFLNK 0120000 // Symbolic link +#define S_IFSOCK 0140000 // Socket + +#define S_IFSHIFT 12 + +#define T_IFDIR (S_IFDIR >> S_IFSHIFT) +#define T_IFCHR (S_IFCHR >> S_IFSHIFT) +#define T_IFBLK (S_IFBLK >> S_IFSHIFT) +#define T_IFREG (S_IFREG >> S_IFSHIFT) +#define T_IFIFO (S_IFIFO >> S_IFSHIFT) +#define T_IFLNK (S_IFLNK >> S_IFSHIFT) +#define T_IFSOCK (S_IFSOCK >> S_IFSHIFT) + + +#define ext2_group_desc_lg2size 5 + + + +/* + * super block structure: + * include/linux/ext2_fs.h + */ +struct ext2_super_block { + uint32_t s_inodes_count; /* Inodes count */ + uint32_t s_blocks_count; /* Blocks count */ + uint32_t s_r_blocks_count; /* Reserved blocks count */ + uint32_t s_free_blocks_count; /* 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_log_frag_size; /* Fragment size */ + uint32_t s_blocks_per_group; /* # Blocks per group */ + uint32_t s_frags_per_group; /* # Fragments per group */ + uint32_t s_inodes_per_group; /* # Inodes per group */ + uint32_t s_mtime; /* Mount time */ + uint32_t s_wtime; /* Write time */ + uint16_t s_mnt_count; /* Mount count */ + int16_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; + uint32_t s_lastcheck; /* time of last check */ + uint32_t s_checkinterval; /* max. time between checks */ + uint32_t s_creator_os; /* 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 */ + + 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 # 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 */ + uint8_t s_prealloc_blocks; /* Nr of blocks to try to preallocate*/ + uint8_t s_prealloc_dir_blocks; + uint16_t s_padding1; + uint32_t s_reserved[204]; /* Padding to the end of the block */ +}; + +/******************************************************************************* +#ifndef DEPEND +#if ext2_super_block_size != 1024 +#error ext2_super_block definition bogus +#endif +#endif +*******************************************************************************/ + +/* + * ext2 group desc structure: + */ +struct ext2_group_desc { + uint32_t bg_block_bitmap; /* Blocks bitmap block */ + uint32_t bg_inode_bitmap; /* Inodes bitmap block */ + uint32_t bg_inode_table; /* Inodes table block */ + uint16_t bg_free_blocks_count; /* Free blocks count */ + uint16_t bg_free_inodes_count; /* Free inodes count */ + uint16_t bg_used_dirs_count; /* Directories count */ + uint16_t bg_pad; + uint32_t bg_reserved[3]; +}; + +/******************************************************************************* +#ifndef DEPEND +#if ext2_group_desc_size != 32 +#error ext2_group_desc definition bogus +#endif +#endif +*******************************************************************************/ + + +/* + * ext2 inode structure: + */ +struct ext2_inode { + uint16_t i_mode; /* File mode */ + uint16_t i_uid; /* Owner Uid */ + uint32_t i_size; /* 4: Size in bytes */ + uint32_t i_atime; /* Access time */ + uint32_t i_ctime; /* 12: Creation time */ + uint32_t i_mtime; /* Modification time */ + uint32_t i_dtime; /* 20: Deletion Time */ + uint16_t i_gid; /* Group Id */ + uint16_t i_links_count; /* 24: Links count */ + uint32_t i_blocks; /* Blocks count */ + uint32_t i_flags; /* 32: File flags */ + uint32_t l_i_reserved1; + uint32_t i_block[EXT2_N_BLOCKS]; /* 40: Pointers to blocks */ + uint32_t i_version; /* File version (for NFS) */ + uint32_t i_file_acl; /* File ACL */ + uint32_t i_dir_acl; /* Directory ACL */ + uint32_t i_faddr; /* Fragment address */ + uint8_t l_i_frag; /* Fragment number */ + uint8_t l_i_fsize; /* Fragment size */ + uint16_t i_pad1; + uint32_t l_i_reserved2[2]; +}; + +/******************************************************************************* +#ifndef DEPEND +#if ext2_inode_size != 128 +#error ext2_inode definition bogus +#endif +#endif +*******************************************************************************/ + + +#define EXT2_NAME_LEN 255 +struct ext2_dir_entry { + unsigned int d_inode; /* Inode number */ + unsigned short d_rec_len; /* Directory entry length */ + unsigned char d_name_len; /* Name length */ + unsigned char d_file_type; + char d_name[EXT2_NAME_LEN]; /* File name */ +}; + +/******************************************************************************* +#define EXT2_DIR_PAD 4 +#define EXT2_DIR_ROUND (EXT2_DIR_PAD - 1) +#define EXT2_DIR_REC_LEN(name_len) (((name_len) + 8 + EXT2_DIR_ROUND) & \ + ~EXT2_DIR_ROUND) +*******************************************************************************/ + + + + + + +/* + * This is the extent on-disk structure. + * It's used at the bottom of the tree. + */ +struct ext4_extent { + uint32_t ee_block; /* first logical block extent covers */ + uint16_t ee_len; /* number of blocks covered by extent */ + uint16_t ee_start_hi; /* high 16 bits of physical block */ + uint32_t ee_start_lo; /* low 32 bits of physical block */ +}; + +/* + * This is index on-disk structure. + * It's used at all the levels except the bottom. + */ +struct ext4_extent_idx { + uint32_t ei_block; /* index covers logical blocks from 'block' */ + uint32_t ei_leaf_lo; /* pointer to the physical block of the next * + * level. leaf or next index could be there */ + uint16_t ei_leaf_hi; /* high 16 bits of physical block */ + uint16_t ei_unused; +}; + +/* + * Each block (leaves and indexes), even inode-stored has header. + */ +struct ext4_extent_header { + uint16_t eh_magic; /* probably will support different formats */ + uint16_t eh_entries; /* number of valid entries */ + uint16_t eh_max; /* capacity of store in entries */ + uint16_t eh_depth; /* has tree real underlying blocks? */ + uint32_t eh_generation; /* generation of the tree */ +}; + + + +#define EXT4_FIRST_EXTENT(header) ( (struct ext4_extent *)(header + 1) ) +#define EXT4_FIRST_INDEX(header) ( (struct ext4_extent_idx *) (header + 1) ) + + + + + + + +/* function declartion */ +/******************************************************************************* +extern struct open_file_t * ext2_read(char *); +extern int ext2_read(struct open_file_t *, char *, int); +*******************************************************************************/ + + +#endif /* ext2_fs.h */ -- 2.7.4