ext2_fs.h

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		struct {
			__u32  m_i_reserved1;
		} masix1;
	} osd1;				/* OS dependent 1 */
	__u32	i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
	__u32	i_generation;	/* File version (for NFS) */
	__u32	i_file_acl;	/* File ACL */
	__u32	i_dir_acl;	/* Directory ACL */
	__u32	i_faddr;	/* Fragment address */
	union {
		struct {
			__u8	l_i_frag;	/* Fragment number */
			__u8	l_i_fsize;	/* Fragment size */
			__u16	i_pad1;
			__u16	l_i_uid_high;	/* these 2 fields    */
			__u16	l_i_gid_high;	/* were reserved2[0] */
			__u32	l_i_reserved2;
		} linux2;
		struct {
			__u8	h_i_frag;	/* Fragment number */
			__u8	h_i_fsize;	/* Fragment size */
			__u16	h_i_mode_high;
			__u16	h_i_uid_high;
			__u16	h_i_gid_high;
			__u32	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 */
	__u16	i_extra_isize;
	__u16	i_pad1;
};

#define i_size_high	i_dir_acl

/*
 * File system states
 */
#define EXT2_VALID_FS			0x0001	/* Unmounted cleanly */
#define EXT2_ERROR_FS			0x0002	/* Errors detected */

/*
 * Mount flags
 */
#define EXT2_MOUNT_CHECK		0x0001	/* Do mount-time checks */
#define EXT2_MOUNT_GRPID		0x0004	/* Create files with directory's group */
#define EXT2_MOUNT_DEBUG		0x0008	/* Some debugging messages */
#define EXT2_MOUNT_ERRORS_CONT		0x0010	/* Continue on errors */
#define EXT2_MOUNT_ERRORS_RO		0x0020	/* Remount fs ro on errors */
#define EXT2_MOUNT_ERRORS_PANIC		0x0040	/* Panic on errors */
#define EXT2_MOUNT_MINIX_DF		0x0080	/* Mimics the Minix statfs */
#define EXT2_MOUNT_NO_UID32		0x0200  /* Disable 32-bit UIDs */

#define clear_opt(o, opt)		o &= ~EXT2_MOUNT_##opt
#define set_opt(o, opt)			o |= EXT2_MOUNT_##opt
#define test_opt(sb, opt)		(EXT2_SB(sb)->s_mount_opt & \
					 EXT2_MOUNT_##opt)
/*
 * Maximal mount counts between two filesystem checks
 */
#define EXT2_DFL_MAX_MNT_COUNT		20	/* Allow 20 mounts */
#define EXT2_DFL_CHECKINTERVAL		0	/* Don't use interval check */

/*
 * Behaviour when detecting errors
 */
#define EXT2_ERRORS_CONTINUE		1	/* Continue execution */
#define EXT2_ERRORS_RO			2	/* Remount fs read-only */
#define EXT2_ERRORS_PANIC		3	/* Panic */
#define EXT2_ERRORS_DEFAULT		EXT2_ERRORS_CONTINUE

/*
 * Structure of the super block
 */
struct ext2_super_block {
	__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_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 */
	__u16	s_reserved_gdt_blocks;	/* Per group table for online growth */
	/*
	 * Journaling support valid if EXT2_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_jnl_backup_type;	/* Default type of journal backup */
	__u16	s_reserved_word_pad;
	__u32	s_default_mount_opts;
	__u32	s_first_meta_bg;	/* First metablock group */
	__u32	s_mkfs_time;		/* When the filesystem was created */
	__u32	s_jnl_blocks[17];	/* Backup of the journal inode */
	__u32	s_reserved[172];	/* Padding to the end of the block */
};

/*
 * Codes for operating systems
 */
#define EXT2_OS_LINUX		0
#define EXT2_OS_HURD		1
#define EXT2_OS_MASIX		2
#define EXT2_OS_FREEBSD		3
#define EXT2_OS_LITES		4

/*
 * 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

/*
 * Journal inode backup types
 */
#define EXT3_JNL_BACKUP_BLOCKS	1

/*
 * Feature set definitions
 */

#define EXT2_HAS_COMPAT_FEATURE(sb,mask)			\
	( EXT2_SB(sb)->s_feature_compat & (mask) )
#define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask)			\
	( EXT2_SB(sb)->s_feature_ro_compat & (mask) )
#define EXT2_HAS_INCOMPAT_FEATURE(sb,mask)			\
	( EXT2_SB(sb)->s_feature_incompat & (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_INODE	0x0010
#define EXT2_FEATURE_COMPAT_DIR_INDEX		0x0020

#define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
#define EXT2_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
/* #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR	0x0004 not used */

#define EXT2_FEATURE_INCOMPAT_COMPRESSION	0x0001
#define EXT2_FEATURE_INCOMPAT_FILETYPE		0x0002
#define EXT3_FEATURE_INCOMPAT_RECOVER		0x0004 /* Needs recovery */
#define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008 /* Journal device */
#define EXT2_FEATURE_INCOMPAT_META_BG		0x0010
#define EXT3_FEATURE_INCOMPAT_EXTENTS		0x0040


#define EXT2_FEATURE_COMPAT_SUPP	0
#define EXT2_FEATURE_INCOMPAT_SUPP	(EXT2_FEATURE_INCOMPAT_FILETYPE)
#define EXT2_FEATURE_RO_COMPAT_SUPP	(EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
					 EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
					 EXT2_FEATURE_RO_COMPAT_BTREE_DIR)

/*
 * Default values for user and/or group using reserved blocks
 */
#define EXT2_DEF_RESUID		0
#define EXT2_DEF_RESGID		0

/*
 * Default mount options
 */
#define EXT2_DEFM_DEBUG		0x0001
#define EXT2_DEFM_BSDGROUPS	0x0002
#define EXT2_DEFM_XATTR_USER	0x0004
#define EXT2_DEFM_ACL		0x0008
#define EXT2_DEFM_UID16		0x0010
#define EXT3_DEFM_JMODE		0x0060
#define EXT3_DEFM_JMODE_DATA	0x0020
#define EXT3_DEFM_JMODE_ORDERED	0x0040
#define EXT3_DEFM_JMODE_WBACK	0x0060

/*
 * Structure of a directory entry
 */
#define EXT2_NAME_LEN 255

struct ext2_dir_entry {
	__u32	inode;			/* Inode number */
	__u16	rec_len;		/* Directory entry length */
	__u16	name_len;		/* Name length */
	char	name[EXT2_NAME_LEN];	/* File name */
};

/*
 * The new version of the directory entry.  Since EXT2 structures are
 * stored in intel byte order, and the name_len field could never be
 * bigger than 255 chars, it's safe to reclaim the extra byte for the
 * file_type field.
 */
struct ext2_dir_entry_2 {
	__u32	inode;			/* Inode number */
	__u16	rec_len;		/* Directory entry length */
	__u8	name_len;		/* Name length */
	__u8	file_type;
	char	name[EXT2_NAME_LEN];	/* File name */
};

/*
 * Ext2 directory file types.  Only the low 3 bits are used.  The
 * other bits are reserved for now.
 */
#define EXT2_FT_UNKNOWN		0
#define EXT2_FT_REG_FILE	1
#define EXT2_FT_DIR		2
#define EXT2_FT_CHRDEV		3
#define EXT2_FT_BLKDEV		4
#define EXT2_FT_FIFO		5
#define EXT2_FT_SOCK		6
#define EXT2_FT_SYMLINK		7

#define EXT2_FT_MAX		8

/*
 * EXT2_DIR_PAD defines the directory entries boundaries
 *
 * NOTE: It must be a multiple of 4
 */
#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)

#endif	/* _LINUX_EXT2_FS_H */