ref: 9dc5fd9ed3705ab5ff9244ae77cb57598074aee5
dir: /include/ext4_types.h/
/*
* Copyright (c) 2013 Grzegorz Kostka (kostka.grzegorz@gmail.com)
*
*
* HelenOS:
* Copyright (c) 2012 Martin Sucha
* Copyright (c) 2012 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 lwext4
* @{
*/
/**
* @file ext4_types.h
* @brief Ext4 data structure definitions.
*/
#ifndef EXT4_TYPES_H_
#define EXT4_TYPES_H_
#ifdef __cplusplus
extern "C" {
#endif
#include "ext4_config.h"
#include "ext4_blockdev.h"
#include "misc/tree.h"
#include <stddef.h>
#include <stdint.h>
/*
* Types of blocks.
*/
typedef uint32_t ext4_lblk_t;
typedef uint64_t ext4_fsblk_t;
#define EXT4_CHECKSUM_CRC32C 1
#define UUID_SIZE 16
#pragma pack(push, 1)
/*
* Structure of the super block
*/
struct ext4_sblock {
uint32_t inodes_count; /* I-nodes count */
uint32_t blocks_count_lo; /* Blocks count */
uint32_t reserved_blocks_count_lo; /* Reserved blocks count */
uint32_t free_blocks_count_lo; /* Free blocks count */
uint32_t free_inodes_count; /* Free inodes count */
uint32_t first_data_block; /* First Data Block */
uint32_t log_block_size; /* Block size */
uint32_t log_cluster_size; /* Obsoleted fragment size */
uint32_t blocks_per_group; /* Number of blocks per group */
uint32_t frags_per_group; /* Obsoleted fragments per group */
uint32_t inodes_per_group; /* Number of inodes per group */
uint32_t mount_time; /* Mount time */
uint32_t write_time; /* Write time */
uint16_t mount_count; /* Mount count */
uint16_t max_mount_count; /* Maximal mount count */
uint16_t magic; /* Magic signature */
uint16_t state; /* File system state */
uint16_t errors; /* Behavior when detecting errors */
uint16_t minor_rev_level; /* Minor revision level */
uint32_t last_check_time; /* Time of last check */
uint32_t check_interval; /* Maximum time between checks */
uint32_t creator_os; /* Creator OS */
uint32_t rev_level; /* Revision level */
uint16_t def_resuid; /* Default uid for reserved blocks */
uint16_t def_resgid; /* Default gid for reserved blocks */
/* Fields for EXT4_DYNAMIC_REV superblocks only. */
uint32_t first_inode; /* First non-reserved inode */
uint16_t inode_size; /* Size of inode structure */
uint16_t block_group_index; /* Block group index of this superblock */
uint32_t features_compatible; /* Compatible feature set */
uint32_t features_incompatible; /* Incompatible feature set */
uint32_t features_read_only; /* Readonly-compatible feature set */
uint8_t uuid[UUID_SIZE]; /* 128-bit uuid for volume */
char volume_name[16]; /* Volume name */
char last_mounted[64]; /* Directory where last mounted */
uint32_t 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 journal_uuid[UUID_SIZE]; /* UUID of journal superblock */
uint32_t journal_inode_number; /* Inode number of journal file */
uint32_t journal_dev; /* Device number of journal file */
uint32_t last_orphan; /* Head of list of inodes to delete */
uint32_t hash_seed[4]; /* HTREE hash seed */
uint8_t default_hash_version; /* Default hash version to use */
uint8_t journal_backup_type;
uint16_t desc_size; /* Size of group descriptor */
uint32_t default_mount_opts; /* Default mount options */
uint32_t first_meta_bg; /* First metablock block group */
uint32_t mkfs_time; /* When the filesystem was created */
uint32_t journal_blocks[17]; /* Backup of the journal inode */
/* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
uint32_t blocks_count_hi; /* Blocks count */
uint32_t reserved_blocks_count_hi; /* Reserved blocks count */
uint32_t free_blocks_count_hi; /* Free blocks count */
uint16_t min_extra_isize; /* All inodes have at least # bytes */
uint16_t want_extra_isize; /* New inodes should reserve # bytes */
uint32_t flags; /* Miscellaneous flags */
uint16_t raid_stride; /* RAID stride */
uint16_t mmp_interval; /* # seconds to wait in MMP checking */
uint64_t mmp_block; /* Block for multi-mount protection */
uint32_t raid_stripe_width; /* Blocks on all data disks (N * stride) */
uint8_t log_groups_per_flex; /* FLEX_BG group size */
uint8_t checksum_type;
uint16_t reserved_pad;
uint64_t kbytes_written; /* Number of lifetime kilobytes written */
uint32_t snapshot_inum; /* I-node number of active snapshot */
uint32_t snapshot_id; /* Sequential ID of active snapshot */
uint64_t
snapshot_r_blocks_count; /* Reserved blocks for active snapshot's
future use */
uint32_t
snapshot_list; /* I-node number of the head of the on-disk snapshot
list */
uint32_t error_count; /* Number of file system errors */
uint32_t first_error_time; /* First time an error happened */
uint32_t first_error_ino; /* I-node involved in first error */
uint64_t first_error_block; /* Block involved of first error */
uint8_t first_error_func[32]; /* Function where the error happened */
uint32_t first_error_line; /* Line number where error happened */
uint32_t last_error_time; /* Most recent time of an error */
uint32_t last_error_ino; /* I-node involved in last error */
uint32_t last_error_line; /* Line number where error happened */
uint64_t last_error_block; /* Block involved of last error */
uint8_t last_error_func[32]; /* Function where the error happened */
uint8_t mount_opts[64];
uint32_t usr_quota_inum; /* inode for tracking user quota */
uint32_t grp_quota_inum; /* inode for tracking group quota */
uint32_t overhead_clusters; /* overhead blocks/clusters in fs */
uint32_t backup_bgs[2]; /* groups with sparse_super2 SBs */
uint8_t encrypt_algos[4]; /* Encryption algorithms in use */
uint8_t encrypt_pw_salt[16]; /* Salt used for string2key algorithm */
uint32_t lpf_ino; /* Location of the lost+found inode */
uint32_t padding[100]; /* Padding to the end of the block */
uint32_t checksum; /* crc32c(superblock) */
};
#pragma pack(pop)
#define EXT4_SUPERBLOCK_MAGIC 0xEF53
#define EXT4_SUPERBLOCK_SIZE 1024
#define EXT4_SUPERBLOCK_OFFSET 1024
#define EXT4_SUPERBLOCK_OS_LINUX 0
#define EXT4_SUPERBLOCK_OS_HURD 1
/*
* Misc. filesystem flags
*/
#define EXT4_SUPERBLOCK_FLAGS_SIGNED_HASH 0x0001
#define EXT4_SUPERBLOCK_FLAGS_UNSIGNED_HASH 0x0002
#define EXT4_SUPERBLOCK_FLAGS_TEST_FILESYS 0x0004
/*
* Filesystem states
*/
#define EXT4_SUPERBLOCK_STATE_VALID_FS 0x0001 /* Unmounted cleanly */
#define EXT4_SUPERBLOCK_STATE_ERROR_FS 0x0002 /* Errors detected */
#define EXT4_SUPERBLOCK_STATE_ORPHAN_FS 0x0004 /* Orphans being recovered */
/*
* Behaviour when errors detected
*/
#define EXT4_SUPERBLOCK_ERRORS_CONTINUE 1 /* Continue execution */
#define EXT4_SUPERBLOCK_ERRORS_RO 2 /* Remount fs read-only */
#define EXT4_SUPERBLOCK_ERRORS_PANIC 3 /* Panic */
#define EXT4_SUPERBLOCK_ERRORS_DEFAULT EXT4_ERRORS_CONTINUE
/*
* Compatible features
*/
#define EXT4_FCOM_DIR_PREALLOC 0x0001
#define EXT4_FCOM_IMAGIC_INODES 0x0002
#define EXT4_FCOM_HAS_JOURNAL 0x0004
#define EXT4_FCOM_EXT_ATTR 0x0008
#define EXT4_FCOM_RESIZE_INODE 0x0010
#define EXT4_FCOM_DIR_INDEX 0x0020
/*
* Read-only compatible features
*/
#define EXT4_FRO_COM_SPARSE_SUPER 0x0001
#define EXT4_FRO_COM_LARGE_FILE 0x0002
#define EXT4_FRO_COM_BTREE_DIR 0x0004
#define EXT4_FRO_COM_HUGE_FILE 0x0008
#define EXT4_FRO_COM_GDT_CSUM 0x0010
#define EXT4_FRO_COM_DIR_NLINK 0x0020
#define EXT4_FRO_COM_EXTRA_ISIZE 0x0040
#define EXT4_FRO_COM_QUOTA 0x0100
#define EXT4_FRO_COM_BIGALLOC 0x0200
#define EXT4_FRO_COM_METADATA_CSUM 0x0400
/*
* Incompatible features
*/
#define EXT4_FINCOM_COMPRESSION 0x0001
#define EXT4_FINCOM_FILETYPE 0x0002
#define EXT4_FINCOM_RECOVER 0x0004 /* Needs recovery */
#define EXT4_FINCOM_JOURNAL_DEV 0x0008 /* Journal device */
#define EXT4_FINCOM_META_BG 0x0010
#define EXT4_FINCOM_EXTENTS 0x0040 /* extents support */
#define EXT4_FINCOM_64BIT 0x0080
#define EXT4_FINCOM_MMP 0x0100
#define EXT4_FINCOM_FLEX_BG 0x0200
#define EXT4_FINCOM_EA_INODE 0x0400 /* EA in inode */
#define EXT4_FINCOM_DIRDATA 0x1000 /* data in dirent */
#define EXT4_FINCOM_BG_USE_META_CSUM 0x2000 /* use crc32c for bg */
#define EXT4_FINCOM_LARGEDIR 0x4000 /* >2GB or 3-lvl htree */
#define EXT4_FINCOM_INLINE_DATA 0x8000 /* data in inode */
/*
* EXT2 supported feature set
*/
#define EXT2_SUPPORTED_FCOM 0x0000
#define EXT2_SUPPORTED_FINCOM \
(EXT4_FINCOM_FILETYPE | EXT4_FINCOM_META_BG)
#define EXT2_SUPPORTED_FRO_COM \
(EXT4_FRO_COM_SPARSE_SUPER | \
EXT4_FRO_COM_LARGE_FILE)
/*
* EXT3 supported feature set
*/
#define EXT3_SUPPORTED_FCOM (EXT4_FCOM_DIR_INDEX)
#define EXT3_SUPPORTED_FINCOM \
(EXT4_FINCOM_FILETYPE | EXT4_FINCOM_META_BG)
#define EXT3_SUPPORTED_FRO_COM \
(EXT4_FRO_COM_SPARSE_SUPER | EXT4_FRO_COM_LARGE_FILE)
/*
* EXT4 supported feature set
*/
#define EXT4_SUPPORTED_FCOM (EXT4_FCOM_DIR_INDEX)
#define EXT4_SUPPORTED_FINCOM \
(EXT4_FINCOM_FILETYPE | EXT4_FINCOM_META_BG | \
EXT4_FINCOM_EXTENTS | EXT4_FINCOM_FLEX_BG | \
EXT4_FINCOM_64BIT)
#define EXT4_SUPPORTED_FRO_COM \
(EXT4_FRO_COM_SPARSE_SUPER | \
EXT4_FRO_COM_METADATA_CSUM | \
EXT4_FRO_COM_LARGE_FILE | EXT4_FRO_COM_GDT_CSUM | \
EXT4_FRO_COM_DIR_NLINK | \
EXT4_FRO_COM_EXTRA_ISIZE | EXT4_FRO_COM_HUGE_FILE)
/*Ignored features:
* RECOVER - journaling in lwext4 is not supported
* (probably won't be ever...)
* MMP - multi-mout protection (impossible scenario)
* */
#define EXT_FINCOM_IGNORED \
EXT4_FINCOM_RECOVER | EXT4_FINCOM_MMP
#if 0
/*TODO: Features incompatible to implement*/
#define EXT4_SUPPORTED_FINCOM
(EXT4_FINCOM_INLINE_DATA)
/*TODO: Features read only to implement*/
#define EXT4_SUPPORTED_FRO_COM
EXT4_FRO_COM_BIGALLOC |\
EXT4_FRO_COM_QUOTA)
#endif
/* Inode table/bitmap not in use */
#define EXT4_BLOCK_GROUP_INODE_UNINIT 0x0001
/* Block bitmap not in use */
#define EXT4_BLOCK_GROUP_BLOCK_UNINIT 0x0002
/* On-disk itable initialized to zero */
#define EXT4_BLOCK_GROUP_ITABLE_ZEROED 0x0004
/*
* Structure of a blocks group descriptor
*/
struct ext4_bgroup {
uint32_t block_bitmap_lo; /* Blocks bitmap block */
uint32_t inode_bitmap_lo; /* Inodes bitmap block */
uint32_t inode_table_first_block_lo; /* Inodes table block */
uint16_t free_blocks_count_lo; /* Free blocks count */
uint16_t free_inodes_count_lo; /* Free inodes count */
uint16_t used_dirs_count_lo; /* Directories count */
uint16_t flags; /* EXT4_BG_flags (INODE_UNINIT, etc) */
uint32_t exclude_bitmap_lo; /* Exclude bitmap for snapshots */
uint16_t block_bitmap_csum_lo; /* crc32c(s_uuid+grp_num+bbitmap) LE */
uint16_t inode_bitmap_csum_lo; /* crc32c(s_uuid+grp_num+ibitmap) LE */
uint16_t itable_unused_lo; /* Unused inodes count */
uint16_t checksum; /* crc16(sb_uuid+group+desc) */
uint32_t block_bitmap_hi; /* Blocks bitmap block MSB */
uint32_t inode_bitmap_hi; /* I-nodes bitmap block MSB */
uint32_t inode_table_first_block_hi; /* I-nodes table block MSB */
uint16_t free_blocks_count_hi; /* Free blocks count MSB */
uint16_t free_inodes_count_hi; /* Free i-nodes count MSB */
uint16_t used_dirs_count_hi; /* Directories count MSB */
uint16_t itable_unused_hi; /* Unused inodes count MSB */
uint32_t exclude_bitmap_hi; /* Exclude bitmap block MSB */
uint16_t block_bitmap_csum_hi; /* crc32c(s_uuid+grp_num+bbitmap) BE */
uint16_t inode_bitmap_csum_hi; /* crc32c(s_uuid+grp_num+ibitmap) BE */
uint32_t reserved; /* Padding */
};
#define EXT4_MIN_BLOCK_GROUP_DESCRIPTOR_SIZE 32
#define EXT4_MAX_BLOCK_GROUP_DESCRIPTOR_SIZE 64
#define EXT4_MIN_BLOCK_SIZE 1024 /* 1 KiB */
#define EXT4_MAX_BLOCK_SIZE 65536 /* 64 KiB */
#define EXT4_REV0_INODE_SIZE 128
#define EXT4_INODE_BLOCK_SIZE 512
#define EXT4_INODE_DIRECT_BLOCK_COUNT 12
#define EXT4_INODE_INDIRECT_BLOCK EXT4_INODE_DIRECT_BLOCK_COUNT
#define EXT4_INODE_DOUBLE_INDIRECT_BLOCK (EXT4_INODE_INDIRECT_BLOCK + 1)
#define EXT4_INODE_TRIPPLE_INDIRECT_BLOCK (EXT4_INODE_DOUBLE_INDIRECT_BLOCK + 1)
#define EXT4_INODE_BLOCKS (EXT4_INODE_TRIPPLE_INDIRECT_BLOCK + 1)
#define EXT4_INODE_INDIRECT_BLOCK_COUNT \
(EXT4_INODE_BLOCKS - EXT4_INODE_DIRECT_BLOCK_COUNT)
#pragma pack(push, 1)
/*
* Structure of an inode on the disk
*/
struct ext4_inode {
uint16_t mode; /* File mode */
uint16_t uid; /* Low 16 bits of owner uid */
uint32_t size_lo; /* Size in bytes */
uint32_t access_time; /* Access time */
uint32_t change_inode_time; /* I-node change time */
uint32_t modification_time; /* Modification time */
uint32_t deletion_time; /* Deletion time */
uint16_t gid; /* Low 16 bits of group id */
uint16_t links_count; /* Links count */
uint32_t blocks_count_lo; /* Blocks count */
uint32_t flags; /* File flags */
uint32_t unused_osd1; /* OS dependent - not used in HelenOS */
uint32_t blocks[EXT4_INODE_BLOCKS]; /* Pointers to blocks */
uint32_t generation; /* File version (for NFS) */
uint32_t file_acl_lo; /* File ACL */
uint32_t size_hi;
uint32_t obso_faddr; /* Obsoleted fragment address */
union {
struct {
uint16_t blocks_high;
uint16_t file_acl_high;
uint16_t uid_high;
uint16_t gid_high;
uint16_t checksum_lo; /* crc32c(uuid+inum+inode) LE */
uint16_t reserved2;
} linux2;
struct {
uint16_t reserved1;
uint16_t mode_high;
uint16_t uid_high;
uint16_t gid_high;
uint32_t author;
} hurd2;
} osd2;
uint16_t extra_isize;
uint16_t checksum_hi; /* crc32c(uuid+inum+inode) BE */
uint32_t ctime_extra; /* Extra change time (nsec << 2 | epoch) */
uint32_t mtime_extra; /* Extra Modification time (nsec << 2 | epoch) */
uint32_t atime_extra; /* Extra Access time (nsec << 2 | epoch) */
uint32_t crtime; /* File creation time */
uint32_t
crtime_extra; /* Extra file creation time (nsec << 2 | epoch) */
uint32_t version_hi; /* High 32 bits for 64-bit version */
};
#pragma pack(pop)
#define EXT4_INODE_MODE_FIFO 0x1000
#define EXT4_INODE_MODE_CHARDEV 0x2000
#define EXT4_INODE_MODE_DIRECTORY 0x4000
#define EXT4_INODE_MODE_BLOCKDEV 0x6000
#define EXT4_INODE_MODE_FILE 0x8000
#define EXT4_INODE_MODE_SOFTLINK 0xA000
#define EXT4_INODE_MODE_SOCKET 0xC000
#define EXT4_INODE_MODE_TYPE_MASK 0xF000
/*
* Inode flags
*/
#define EXT4_INODE_FLAG_SECRM 0x00000001 /* Secure deletion */
#define EXT4_INODE_FLAG_UNRM 0x00000002 /* Undelete */
#define EXT4_INODE_FLAG_COMPR 0x00000004 /* Compress file */
#define EXT4_INODE_FLAG_SYNC 0x00000008 /* Synchronous updates */
#define EXT4_INODE_FLAG_IMMUTABLE 0x00000010 /* Immutable file */
#define EXT4_INODE_FLAG_APPEND 0x00000020 /* writes to file may only append */
#define EXT4_INODE_FLAG_NODUMP 0x00000040 /* do not dump file */
#define EXT4_INODE_FLAG_NOATIME 0x00000080 /* do not update atime */
/* Compression flags */
#define EXT4_INODE_FLAG_DIRTY 0x00000100
#define EXT4_INODE_FLAG_COMPRBLK \
0x00000200 /* One or more compressed clusters */
#define EXT4_INODE_FLAG_NOCOMPR 0x00000400 /* Don't compress */
#define EXT4_INODE_FLAG_ECOMPR 0x00000800 /* Compression error */
#define EXT4_INODE_FLAG_INDEX 0x00001000 /* hash-indexed directory */
#define EXT4_INODE_FLAG_IMAGIC 0x00002000 /* AFS directory */
#define EXT4_INODE_FLAG_JOURNAL_DATA \
0x00004000 /* File data should be journaled */
#define EXT4_INODE_FLAG_NOTAIL 0x00008000 /* File tail should not be merged */
#define EXT4_INODE_FLAG_DIRSYNC \
0x00010000 /* Dirsync behaviour (directories only) */
#define EXT4_INODE_FLAG_TOPDIR 0x00020000 /* Top of directory hierarchies */
#define EXT4_INODE_FLAG_HUGE_FILE 0x00040000 /* Set to each huge file */
#define EXT4_INODE_FLAG_EXTENTS 0x00080000 /* Inode uses extents */
#define EXT4_INODE_FLAG_EA_INODE 0x00200000 /* Inode used for large EA */
#define EXT4_INODE_FLAG_EOFBLOCKS 0x00400000 /* Blocks allocated beyond EOF */
#define EXT4_INODE_FLAG_RESERVED 0x80000000 /* reserved for ext4 lib */
#define EXT4_INODE_ROOT_INDEX 2
#define EXT4_DIRECTORY_FILENAME_LEN 255
/**@brief Directory entry types. */
enum { EXT4_DE_UNKNOWN = 0,
EXT4_DE_REG_FILE,
EXT4_DE_DIR,
EXT4_DE_CHRDEV,
EXT4_DE_BLKDEV,
EXT4_DE_FIFO,
EXT4_DE_SOCK,
EXT4_DE_SYMLINK };
#define EXT4_DIRENTRY_DIR_CSUM 0xDE
#pragma pack(push, 1)
union ext4_dir_en_internal {
uint8_t name_length_high; /* Higher 8 bits of name length */
uint8_t inode_type; /* Type of referenced inode (in rev >= 0.5) */
};
/**
* Linked list directory entry structure
*/
struct ext4_dir_en {
uint32_t inode; /* I-node for the entry */
uint16_t entry_len; /* Distance to the next directory entry */
uint8_t name_len; /* Lower 8 bits of name length */
union ext4_dir_en_internal in;
uint8_t name[EXT4_DIRECTORY_FILENAME_LEN]; /* Entry name */
};
/* Structures for indexed directory */
struct ext4_dir_idx_climit {
uint16_t limit;
uint16_t count;
};
struct ext4_dir_idx_dot_en {
uint32_t inode;
uint16_t entry_length;
uint8_t name_length;
uint8_t inode_type;
uint8_t name[4];
};
struct ext4_dir_idx_rinfo {
uint32_t reserved_zero;
uint8_t hash_version;
uint8_t info_length;
uint8_t indirect_levels;
uint8_t unused_flags;
};
struct ext4_dir_idx_entry {
uint32_t hash;
uint32_t block;
};
struct ext4_dir_idx_root {
struct ext4_dir_idx_dot_en dots[2];
struct ext4_dir_idx_rinfo info;
struct ext4_dir_idx_entry en[];
};
struct ext4_fake_dir_entry {
uint32_t inode;
uint16_t entry_length;
uint8_t name_length;
uint8_t inode_type;
};
struct ext4_dir_idx_node {
struct ext4_fake_dir_entry fake;
struct ext4_dir_idx_entry entries[];
};
/*
* This goes at the end of each htree block.
*/
struct ext4_dir_idx_tail {
uint32_t reserved;
uint32_t checksum; /* crc32c(uuid+inum+dirblock) */
};
/*
* This is a bogus directory entry at the end of each leaf block that
* records checksums.
*/
struct ext4_dir_entry_tail {
uint32_t reserved_zero1; /* Pretend to be unused */
uint16_t rec_len; /* 12 */
uint8_t reserved_zero2; /* Zero name length */
uint8_t reserved_ft; /* 0xDE, fake file type */
uint32_t checksum; /* crc32c(uuid+inum+dirblock) */
};
#pragma pack(pop)
#define EXT4_DIRENT_TAIL(block, blocksize) \
((struct ext4_dir_entry_tail *)(((char *)(block)) + ((blocksize) - \
sizeof(struct ext4_dir_entry_tail))))
#define EXT4_ERR_BAD_DX_DIR (-25000)
#define EXT4_LINK_MAX 65000
#define EXT4_BAD_INO 1
#define EXT4_ROOT_INO 2
#define EXT4_BOOT_LOADER_INO 5
#define EXT4_UNDEL_DIR_INO 6
#define EXT4_RESIZE_INO 7
#define EXT4_JOURNAL_INO 8
#define EXT4_GOOD_OLD_FIRST_INO 11
#define EXT4_EXT_UNWRITTEN_MASK (1L << 15)
#define EXT4_EXT_MAX_LEN_WRITTEN (1L << 15)
#define EXT4_EXT_MAX_LEN_UNWRITTEN \
(EXT4_EXT_MAX_LEN_WRITTEN - 1)
#define EXT4_EXT_GET_LEN(ex) to_le16((ex)->block_count)
#define EXT4_EXT_GET_LEN_UNWRITTEN(ex) \
(EXT4_EXT_GET_LEN(ex) &= ~(EXT4_EXT_UNWRITTEN_MASK))
#define EXT4_EXT_SET_LEN(ex, count) \
((ex)->block_count = to_le16(count))
#define EXT4_EXT_IS_UNWRITTEN(ex) \
(EXT4_EXT_GET_LEN(ex) > EXT4_EXT_MAX_LEN_WRITTEN)
#define EXT4_EXT_SET_UNWRITTEN(ex) \
((ex)->block_count |= to_le16(EXT4_EXT_UNWRITTEN_MASK))
#define EXT4_EXT_SET_WRITTEN(ex) \
((ex)->block_count &= ~(to_le16(EXT4_EXT_UNWRITTEN_MASK)))
#pragma pack(push, 1)
/*
* This is the extent tail on-disk structure.
* All other extent structures are 12 bytes long. It turns out that
* block_size % 12 >= 4 for at least all powers of 2 greater than 512, which
* covers all valid ext4 block sizes. Therefore, this tail structure can be
* crammed into the end of the block without having to rebalance the tree.
*/
struct ext4_extent_tail
{
uint32_t et_checksum; /* crc32c(uuid+inum+extent_block) */
};
/*
* This is the extent on-disk structure.
* It's used at the bottom of the tree.
*/
struct ext4_extent {
uint32_t first_block; /* First logical block extent covers */
uint16_t block_count; /* Number of blocks covered by extent */
uint16_t start_hi; /* High 16 bits of physical block */
uint32_t 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_index {
uint32_t first_block; /* Index covers logical blocks from 'block' */
/**
* Pointer to the physical block of the next
* level. leaf or next index could be there
* high 16 bits of physical block
*/
uint32_t leaf_lo;
uint16_t leaf_hi;
uint16_t padding;
};
/*
* Each block (leaves and indexes), even inode-stored has header.
*/
struct ext4_extent_header {
uint16_t magic;
uint16_t entries_count; /* Number of valid entries */
uint16_t max_entries_count; /* Capacity of store in entries */
uint16_t depth; /* Has tree real underlying blocks? */
uint32_t generation; /* generation of the tree */
};
#pragma pack(pop)
#define EXT4_EXTENT_MAGIC 0xF30A
#define EXT4_EXTENT_FIRST(header) \
((struct ext4_extent *)(((char *)(header)) + \
sizeof(struct ext4_extent_header)))
#define EXT4_EXTENT_FIRST_INDEX(header) \
((struct ext4_extent_index *)(((char *)(header)) + \
sizeof(struct ext4_extent_header)))
/*
* EXT_INIT_MAX_LEN is the maximum number of blocks we can have in an
* initialized extent. This is 2^15 and not (2^16 - 1), since we use the
* MSB of ee_len field in the extent datastructure to signify if this
* particular extent is an initialized extent or an uninitialized (i.e.
* preallocated).
* EXT_UNINIT_MAX_LEN is the maximum number of blocks we can have in an
* uninitialized extent.
* If ee_len is <= 0x8000, it is an initialized extent. Otherwise, it is an
* uninitialized one. In other words, if MSB of ee_len is set, it is an
* uninitialized extent with only one special scenario when ee_len = 0x8000.
* In this case we can not have an uninitialized extent of zero length and
* thus we make it as a special case of initialized extent with 0x8000 length.
* This way we get better extent-to-group alignment for initialized extents.
* Hence, the maximum number of blocks we can have in an *initialized*
* extent is 2^15 (32768) and in an *uninitialized* extent is 2^15-1 (32767).
*/
#define EXT_INIT_MAX_LEN (1L << 15)
#define EXT_UNWRITTEN_MAX_LEN (EXT_INIT_MAX_LEN - 1)
#define EXT_EXTENT_SIZE sizeof(struct ext4_extent)
#define EXT_INDEX_SIZE sizeof(struct ext4_extent_idx)
#define EXT_FIRST_EXTENT(__hdr__) \
((struct ext4_extent *)(((char *)(__hdr__)) + \
sizeof(struct ext4_extent_header)))
#define EXT_FIRST_INDEX(__hdr__) \
((struct ext4_extent_index *)(((char *)(__hdr__)) + \
sizeof(struct ext4_extent_header)))
#define EXT_HAS_FREE_INDEX(__path__) \
((__path__)->header->entries_count < (__path__)->header->max_entries_count)
#define EXT_LAST_EXTENT(__hdr__) \
(EXT_FIRST_EXTENT((__hdr__)) + (__hdr__)->entries_count - 1)
#define EXT_LAST_INDEX(__hdr__) \
(EXT_FIRST_INDEX((__hdr__)) + (__hdr__)->entries_count - 1)
#define EXT_MAX_EXTENT(__hdr__) \
(EXT_FIRST_EXTENT((__hdr__)) + (__hdr__)->max_entries_count - 1)
#define EXT_MAX_INDEX(__hdr__) \
(EXT_FIRST_INDEX((__hdr__)) + (__hdr__)->max_entries_count - 1)
#define EXT4_EXTENT_TAIL_OFFSET(hdr) \
(sizeof(struct ext4_extent_header) + \
(sizeof(struct ext4_extent) * (hdr)->max_entries_count))
/*
* ext4_ext_next_allocated_block:
* returns allocated block in subsequent extent or EXT_MAX_BLOCKS.
* NOTE: it considers block number from index entry as
* allocated block. Thus, index entries have to be consistent
* with leaves.
*/
#define EXT_MAX_BLOCKS (ext4_lblk_t) (-1)
#define IN_RANGE(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1)
/******************************************************************************/
/* EXT3 HTree directory indexing */
#define EXT2_HTREE_LEGACY 0
#define EXT2_HTREE_HALF_MD4 1
#define EXT2_HTREE_TEA 2
#define EXT2_HTREE_LEGACY_UNSIGNED 3
#define EXT2_HTREE_HALF_MD4_UNSIGNED 4
#define EXT2_HTREE_TEA_UNSIGNED 5
#define EXT2_HTREE_EOF 0x7FFFFFFFUL
/* Extended Attribute(EA) */
/* Magic value in attribute blocks */
#define EXT4_XATTR_MAGIC 0xEA020000
/* Maximum number of references to one attribute block */
#define EXT4_XATTR_REFCOUNT_MAX 1024
/* Name indexes */
#define EXT4_XATTR_INDEX_USER 1
#define EXT4_XATTR_INDEX_POSIX_ACL_ACCESS 2
#define EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT 3
#define EXT4_XATTR_INDEX_TRUSTED 4
#define EXT4_XATTR_INDEX_LUSTRE 5
#define EXT4_XATTR_INDEX_SECURITY 6
#define EXT4_XATTR_INDEX_SYSTEM 7
#define EXT4_XATTR_INDEX_RICHACL 8
#define EXT4_XATTR_INDEX_ENCRYPTION 9
#pragma pack(push, 1)
struct ext4_xattr_header {
uint32_t h_magic; /* magic number for identification */
uint32_t h_refcount; /* reference count */
uint32_t h_blocks; /* number of disk blocks used */
uint32_t h_hash; /* hash value of all attributes */
uint32_t h_checksum; /* crc32c(uuid+id+xattrblock) */
/* id = inum if refcount=1, blknum otherwise */
uint32_t h_reserved[3]; /* zero right now */
};
struct ext4_xattr_ibody_header {
uint32_t h_magic; /* magic number for identification */
};
struct ext4_xattr_entry {
uint8_t e_name_len; /* length of name */
uint8_t e_name_index; /* attribute name index */
uint16_t e_value_offs; /* offset in disk block of value */
uint32_t e_value_block; /* disk block attribute is stored on (n/i) */
uint32_t e_value_size; /* size of attribute value */
uint32_t e_hash; /* hash value of name and value */
};
#pragma pack(pop)
#define EXT4_GOOD_OLD_INODE_SIZE 128
#define EXT4_XATTR_PAD_BITS 2
#define EXT4_XATTR_PAD (1<<EXT4_XATTR_PAD_BITS)
#define EXT4_XATTR_ROUND (EXT4_XATTR_PAD-1)
#define EXT4_XATTR_LEN(name_len) \
(((name_len) + EXT4_XATTR_ROUND + \
sizeof(struct ext4_xattr_entry)) & ~EXT4_XATTR_ROUND)
#define EXT4_XATTR_NEXT(entry) \
((struct ext4_xattr_entry *)( \
(char *)(entry) + EXT4_XATTR_LEN((entry)->e_name_len)))
#define EXT4_XATTR_SIZE(size) \
(((size) + EXT4_XATTR_ROUND) & ~EXT4_XATTR_ROUND)
#define EXT4_XATTR_NAME(entry) \
((char *)((entry) + 1))
#define EXT4_XATTR_IHDR(raw_inode) \
((struct ext4_xattr_ibody_header *) \
((char *)raw_inode + \
EXT4_GOOD_OLD_INODE_SIZE + \
(raw_inode)->extra_isize))
#define EXT4_XATTR_IFIRST(hdr) \
((struct ext4_xattr_entry *)((hdr)+1))
#define EXT4_XATTR_BHDR(block) \
((struct ext4_xattr_header *)((block)->data))
#define EXT4_XATTR_ENTRY(ptr) \
((struct ext4_xattr_entry *)(ptr))
#define EXT4_XATTR_BFIRST(block) \
EXT4_XATTR_ENTRY(EXT4_XATTR_BHDR(block)+1)
#define EXT4_XATTR_IS_LAST_ENTRY(entry) \
(*(uint32_t *)(entry) == 0)
#define EXT4_ZERO_XATTR_VALUE ((void *)-1)
/*****************************************************************************/
/*
* JBD stores integers in big endian.
*/
#define JBD_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */
/*
* Descriptor block types:
*/
#define JBD_DESCRIPTOR_BLOCK 1
#define JBD_COMMIT_BLOCK 2
#define JBD_SUPERBLOCK 3
#define JBD_SUPERBLOCK_V2 4
#define JBD_REVOKE_BLOCK 5
#pragma pack(push, 1)
/*
* Standard header for all descriptor blocks:
*/
struct jbd_bhdr {
uint32_t magic;
uint32_t blocktype;
uint32_t sequence;
};
#pragma pack(pop)
/*
* Checksum types.
*/
#define JBD_CRC32_CHKSUM 1
#define JBD_MD5_CHKSUM 2
#define JBD_SHA1_CHKSUM 3
#define JBD_CRC32C_CHKSUM 4
#define JBD_CRC32_CHKSUM_SIZE 4
#define JBD_CHECKSUM_BYTES (32 / sizeof(uint32_t))
#pragma pack(push, 1)
/*
* Commit block header for storing transactional checksums:
*
* NOTE: If FEATURE_COMPAT_CHECKSUM (checksum v1) is set, the h_chksum*
* fields are used to store a checksum of the descriptor and data blocks.
*
* If FEATURE_INCOMPAT_CSUM_V2 (checksum v2) is set, then the h_chksum
* field is used to store crc32c(uuid+commit_block). Each journal metadata
* block gets its own checksum, and data block checksums are stored in
* journal_block_tag (in the descriptor). The other h_chksum* fields are
* not used.
*
* If FEATURE_INCOMPAT_CSUM_V3 is set, the descriptor block uses
* journal_block_tag3_t to store a full 32-bit checksum. Everything else
* is the same as v2.
*
* Checksum v1, v2, and v3 are mutually exclusive features.
*/
struct jbd_commit_header {
struct jbd_bhdr header;
uint8_t chksum_type;
uint8_t chksum_size;
uint8_t padding[2];
uint32_t chksum[JBD_CHECKSUM_BYTES];
uint64_t commit_sec;
uint32_t commit_nsec;
};
/*
* The block tag: used to describe a single buffer in the journal
*/
struct jbd_block_tag3 {
uint32_t blocknr; /* The on-disk block number */
uint32_t flags; /* See below */
uint32_t blocknr_high; /* most-significant high 32bits. */
uint32_t checksum; /* crc32c(uuid+seq+block) */
};
struct jbd_block_tag {
uint32_t blocknr; /* The on-disk block number */
uint16_t checksum; /* truncated crc32c(uuid+seq+block) */
uint16_t flags; /* See below */
uint32_t blocknr_high; /* most-significant high 32bits. */
};
#pragma pack(pop)
/* Definitions for the journal tag flags word: */
#define JBD_FLAG_ESCAPE 1 /* on-disk block is escaped */
#define JBD_FLAG_SAME_UUID 2 /* block has same uuid as previous */
#define JBD_FLAG_DELETED 4 /* block deleted by this transaction */
#define JBD_FLAG_LAST_TAG 8 /* last tag in this descriptor block */
#pragma pack(push, 1)
/* Tail of descriptor block, for checksumming */
struct jbd_block_tail {
uint32_t checksum;
};
/*
* The revoke descriptor: used on disk to describe a series of blocks to
* be revoked from the log
*/
struct jbd_revoke_header {
struct jbd_bhdr header;
uint32_t count; /* Count of bytes used in the block */
};
/* Tail of revoke block, for checksumming */
struct jbd_revoke_tail {
uint32_t checksum;
};
#pragma pack(pop)
#define JBD_USERS_MAX 48
#define JBD_USERS_SIZE (UUID_SIZE * JBD_USERS_MAX)
#pragma pack(push, 1)
/*
* The journal superblock. All fields are in big-endian byte order.
*/
struct jbd_sb {
/* 0x0000 */
struct jbd_bhdr header;
/* 0x000C */
/* Static information describing the journal */
uint32_t blocksize; /* journal device blocksize */
uint32_t maxlen; /* total blocks in journal file */
uint32_t first; /* first block of log information */
/* 0x0018 */
/* Dynamic information describing the current state of the log */
uint32_t sequence; /* first commit ID expected in log */
uint32_t start; /* blocknr of start of log */
/* 0x0020 */
/* Error value, as set by journal_abort(). */
int32_t error_val;
/* 0x0024 */
/* Remaining fields are only valid in a version-2 superblock */
uint32_t feature_compat; /* compatible feature set */
uint32_t feature_incompat; /* incompatible feature set */
uint32_t feature_ro_compat; /* readonly-compatible feature set */
/* 0x0030 */
uint8_t uuid[UUID_SIZE]; /* 128-bit uuid for journal */
/* 0x0040 */
uint32_t nr_users; /* Nr of filesystems sharing log */
uint32_t dynsuper; /* Blocknr of dynamic superblock copy*/
/* 0x0048 */
uint32_t max_transaction; /* Limit of journal blocks per trans.*/
uint32_t max_trandata; /* Limit of data blocks per trans. */
/* 0x0050 */
uint8_t checksum_type; /* checksum type */
uint8_t padding2[3];
uint32_t padding[42];
uint32_t checksum; /* crc32c(superblock) */
/* 0x0100 */
uint8_t users[JBD_USERS_SIZE]; /* ids of all fs'es sharing the log */
/* 0x0400 */
};
#pragma pack(pop)
#define JBD_SUPERBLOCK_SIZE sizeof(struct jbd_sb)
#define JBD_HAS_COMPAT_FEATURE(jsb,mask) \
((jsb)->header.blocktype >= to_be32(2) && \
((jsb)->feature_compat & to_be32((mask))))
#define JBD_HAS_RO_COMPAT_FEATURE(jsb,mask) \
((jsb)->header.blocktype >= to_be32(2) && \
((jsb)->feature_ro_compat & to_be32((mask))))
#define JBD_HAS_INCOMPAT_FEATURE(jsb,mask) \
((jsb)->header.blocktype >= to_be32(2) && \
((jsb)->feature_incompat & to_be32((mask))))
#define JBD_FEATURE_COMPAT_CHECKSUM 0x00000001
#define JBD_FEATURE_INCOMPAT_REVOKE 0x00000001
#define JBD_FEATURE_INCOMPAT_64BIT 0x00000002
#define JBD_FEATURE_INCOMPAT_ASYNC_COMMIT 0x00000004
#define JBD_FEATURE_INCOMPAT_CSUM_V2 0x00000008
#define JBD_FEATURE_INCOMPAT_CSUM_V3 0x00000010
/* Features known to this kernel version: */
#define JBD_KNOWN_COMPAT_FEATURES 0
#define JBD_KNOWN_ROCOMPAT_FEATURES 0
#define JBD_KNOWN_INCOMPAT_FEATURES (JBD_FEATURE_INCOMPAT_REVOKE|\
JBD_FEATURE_INCOMPAT_ASYNC_COMMIT|\
JBD_FEATURE_INCOMPAT_64BIT|\
JBD_FEATURE_INCOMPAT_CSUM_V2|\
JBD_FEATURE_INCOMPAT_CSUM_V3)
/*****************************************************************************/
#define EXT4_CRC32_INIT (0xFFFFFFFFUL)
/*****************************************************************************/
#ifdef __cplusplus
}
#endif
#endif /* EXT4_TYPES_H_ */
/**
* @}
*/