/** * \file fsw_ext2_disk.h * ext2 file system on-disk structures. */ /*- * Copyright (c) 2006 Christoph Pfisterer * Portions Copyright (c) 1991-2006 by various Linux kernel contributors * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #ifndef _FSW_EXT2_DISK_H_ #define _FSW_EXT2_DISK_H_ // types typedef fsw_s8 __s8; typedef fsw_u8 __u8; typedef fsw_s16 __s16; typedef fsw_u16 __u16; typedef fsw_s32 __s32; typedef fsw_u32 __u32; typedef fsw_s64 __s64; typedef fsw_u64 __u64; typedef __u16 __le16; typedef __u32 __le32; typedef __u64 __le64; // // from Linux kernel, include/linux/ext2_fs.h // /* * 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 */ /* * The second extended file system magic number */ #define EXT2_SUPER_MAGIC 0xEF53 /* * Macro-instructions used to manage several block sizes */ #define EXT2_MIN_BLOCK_SIZE 1024 #define EXT2_MAX_BLOCK_SIZE 4096 #define EXT2_MIN_BLOCK_LOG_SIZE 10 #define EXT2_BLOCK_SIZE(s) (EXT2_MIN_BLOCK_SIZE << (s)->s_log_block_size) #define EXT2_ADDR_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / sizeof (__u32)) #define EXT2_BLOCK_SIZE_BITS(s) ((s)->s_log_block_size + 10) #define EXT2_INODE_SIZE(s) (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \ EXT2_GOOD_OLD_INODE_SIZE : \ (s)->s_inode_size) #define EXT2_FIRST_INO(s) (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \ EXT2_GOOD_OLD_FIRST_INO : \ (s)->s_first_ino) /* * Structure of a blocks group descriptor */ struct ext2_group_desc { __le32 bg_block_bitmap; /* Blocks bitmap block */ __le32 bg_inode_bitmap; /* Inodes bitmap block */ __le32 bg_inode_table; /* Inodes table block */ __le16 bg_free_blocks_count; /* Free blocks count */ __le16 bg_free_inodes_count; /* Free inodes count */ __le16 bg_used_dirs_count; /* Directories count */ __le16 bg_pad; __le32 bg_reserved[3]; }; /* * Macro-instructions used to manage group descriptors */ #define EXT2_BLOCKS_PER_GROUP(s) ((s)->s_blocks_per_group) #define EXT2_DESC_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / sizeof (struct ext2_group_desc)) #define EXT2_INODES_PER_GROUP(s) ((s)->s_inodes_per_group) /* * Constants relative to the data blocks */ #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) /* * Inode flags */ #define EXT2_SECRM_FL 0x00000001 /* Secure deletion */ #define EXT2_UNRM_FL 0x00000002 /* Undelete */ #define EXT2_COMPR_FL 0x00000004 /* Compress file */ #define EXT2_SYNC_FL 0x00000008 /* Synchronous updates */ #define EXT2_IMMUTABLE_FL 0x00000010 /* Immutable file */ #define EXT2_APPEND_FL 0x00000020 /* writes to file may only append */ #define EXT2_NODUMP_FL 0x00000040 /* do not dump file */ #define EXT2_NOATIME_FL 0x00000080 /* do not update atime */ /* Reserved for compression usage... */ #define EXT2_DIRTY_FL 0x00000100 #define EXT2_COMPRBLK_FL 0x00000200 /* One or more compressed clusters */ #define EXT2_NOCOMP_FL 0x00000400 /* Don't compress */ #define EXT2_ECOMPR_FL 0x00000800 /* Compression error */ /* End compression flags --- maybe not all used */ #define EXT2_BTREE_FL 0x00001000 /* btree format dir */ #define EXT2_INDEX_FL 0x00001000 /* hash-indexed directory */ #define EXT2_IMAGIC_FL 0x00002000 /* AFS directory */ #define EXT2_JOURNAL_DATA_FL 0x00004000 /* Reserved for ext3 */ #define EXT2_NOTAIL_FL 0x00008000 /* file tail should not be merged */ #define EXT2_DIRSYNC_FL 0x00010000 /* dirsync behaviour (directories only) */ #define EXT2_TOPDIR_FL 0x00020000 /* Top of directory hierarchies*/ #define EXT2_RESERVED_FL 0x80000000 /* reserved for ext2 lib */ #define EXT2_FL_USER_VISIBLE 0x0003DFFF /* User visible flags */ #define EXT2_FL_USER_MODIFIABLE 0x000380FF /* User modifiable flags */ /* * Structure of an inode on the disk */ struct ext2_inode { __le16 i_mode; /* 0: File mode */ __le16 i_uid; /* 2: Low 16 bits of Owner Uid */ __le32 i_size; /* 4: Size in bytes */ __le32 i_atime; /* 8: Access time */ __le32 i_ctime; /* 12: Creation time */ __le32 i_mtime; /* 16: Modification time */ __le32 i_dtime; /* 20: Deletion Time */ __le16 i_gid; /* 24: Low 16 bits of Group Id */ __le16 i_links_count; /* 26: Links count */ __le32 i_blocks; /* 28: Blocks count */ __le32 i_flags; /* 32: File flags */ union { struct { __le32 l_i_reserved1; } linux1; struct { __le32 h_i_translator; } hurd1; struct { __le32 m_i_reserved1; } masix1; } osd1; /* 36: OS dependent 1 */ __le32 i_block[EXT2_N_BLOCKS];/* 40: Pointers to blocks */ __le32 i_generation; /* 100: File version (for NFS) */ __le32 i_file_acl; /* 104: File ACL */ __le32 i_dir_acl; /* 108: Directory ACL */ __le32 i_faddr; /* 112: Fragment address */ union { struct { __u8 l_i_frag; /* 116: Fragment number */ __u8 l_i_fsize; /* 117: Fragment size */ __u16 i_pad1; __le16 l_i_uid_high; /* 120: these 2 fields */ __le16 l_i_gid_high; /* 122: were reserved2[0] */ __u32 l_i_reserved2; } linux2; struct { __u8 h_i_frag; /* Fragment number */ __u8 h_i_fsize; /* Fragment size */ __le16 h_i_mode_high; __le16 h_i_uid_high; __le16 h_i_gid_high; __le32 h_i_author; } hurd2; struct { __u8 m_i_frag; /* Fragment number */ __u8 m_i_fsize; /* Fragment size */ __u16 m_pad1; __u32 m_i_reserved2[2]; } masix2; } osd2; /* OS dependent 2 */ }; #define i_size_high i_dir_acl /* * 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 */ }; /* * Revision levels */ #define EXT2_GOOD_OLD_REV 0 /* The good old (original) format */ #define EXT2_DYNAMIC_REV 1 /* V2 format w/ dynamic inode sizes */ #define EXT2_CURRENT_REV EXT2_GOOD_OLD_REV #define EXT2_MAX_SUPP_REV EXT2_DYNAMIC_REV #define EXT2_GOOD_OLD_INODE_SIZE 128 /* * Feature set definitions */ #define EXT2_HAS_COMPAT_FEATURE(sb,mask) \ ( EXT2_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask) ) #define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask) \ ( EXT2_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask) ) #define EXT2_HAS_INCOMPAT_FEATURE(sb,mask) \ ( EXT2_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask) ) #define EXT2_SET_COMPAT_FEATURE(sb,mask) \ EXT2_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask) #define EXT2_SET_RO_COMPAT_FEATURE(sb,mask) \ EXT2_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask) #define EXT2_SET_INCOMPAT_FEATURE(sb,mask) \ EXT2_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask) #define EXT2_CLEAR_COMPAT_FEATURE(sb,mask) \ EXT2_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask) #define EXT2_CLEAR_RO_COMPAT_FEATURE(sb,mask) \ EXT2_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask) #define EXT2_CLEAR_INCOMPAT_FEATURE(sb,mask) \ EXT2_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask) #define EXT2_FEATURE_COMPAT_DIR_PREALLOC 0x0001 #define EXT2_FEATURE_COMPAT_IMAGIC_INODES 0x0002 #define EXT3_FEATURE_COMPAT_HAS_JOURNAL 0x0004 #define EXT2_FEATURE_COMPAT_EXT_ATTR 0x0008 #define EXT2_FEATURE_COMPAT_RESIZE_INO 0x0010 #define EXT2_FEATURE_COMPAT_DIR_INDEX 0x0020 #define EXT2_FEATURE_COMPAT_ANY 0xffffffff #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER 0x0001 #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE 0x0002 #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR 0x0004 #define EXT2_FEATURE_RO_COMPAT_ANY 0xffffffff #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_FEATURE_COMPAT_SUPP EXT2_FEATURE_COMPAT_EXT_ATTR #define EXT2_FEATURE_INCOMPAT_SUPP (EXT2_FEATURE_INCOMPAT_FILETYPE| \ EXT2_FEATURE_INCOMPAT_META_BG) #define EXT2_FEATURE_RO_COMPAT_SUPP (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \ EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \ EXT2_FEATURE_RO_COMPAT_BTREE_DIR) #define EXT2_FEATURE_RO_COMPAT_UNSUPPORTED ~EXT2_FEATURE_RO_COMPAT_SUPP #define EXT2_FEATURE_INCOMPAT_UNSUPPORTED ~EXT2_FEATURE_INCOMPAT_SUPP */ /* * Structure of a directory entry */ #define EXT2_NAME_LEN 255 struct ext2_dir_entry { __le32 inode; /* Inode number */ __le16 rec_len; /* Directory entry length */ __u8 name_len; /* Name length */ __u8 file_type; char name[EXT2_NAME_LEN]; /* File name */ }; // NOTE: The original Linux kernel header defines ext2_dir_entry with the original // layout and ext2_dir_entry_2 with the revised layout. We simply use the revised one. /* * Ext2 directory file types. Only the low 3 bits are used. The * other bits are reserved for now. */ enum { EXT2_FT_UNKNOWN, EXT2_FT_REG_FILE, EXT2_FT_DIR, EXT2_FT_CHRDEV, EXT2_FT_BLKDEV, EXT2_FT_FIFO, EXT2_FT_SOCK, EXT2_FT_SYMLINK, EXT2_FT_MAX }; #endif