ext2_fs.h

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/* vi: set sw=4 ts=4: */
/*
 *  linux/include/linux/ext2_fs.h
 *
 * Copyright (C) 1992, 1993, 1994, 1995
 * Remy Card ([e-mail])
 * Laboratoire MASI - Institut Blaise Pascal
 * Universite Pierre et Marie Curie (Paris VI)
 *
 *  from
 *
 *  linux/include/linux/minix_fs.h
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 */

#ifndef _LINUX_EXT2_FS_H
#define _LINUX_EXT2_FS_H

#include "ext2_types.h"		/* Changed from linux/types.h */

/*
 * Special inode numbers
 */
#define EXT2_BAD_INO		 1	/* Bad blocks inode */
#define EXT2_ROOT_INO		 2	/* Root inode */
#define EXT2_ACL_IDX_INO	 3	/* ACL inode */
#define EXT2_ACL_DATA_INO	 4	/* ACL inode */
#define EXT2_BOOT_LOADER_INO	 5	/* Boot loader inode */
#define EXT2_UNDEL_DIR_INO	 6	/* Undelete directory inode */
#define EXT2_RESIZE_INO		 7	/* Reserved group descriptors inode */
#define EXT2_JOURNAL_INO	 8	/* Journal inode */

/* First non-reserved inode for old ext2 filesystems */
#define EXT2_GOOD_OLD_FIRST_INO	11

/*
 * The second extended file system magic number
 */
#define EXT2_SUPER_MAGIC	0xEF53

/* Assume that user mode programs are passing in an ext2fs superblock, not
 * a kernel struct super_block.  This will allow us to call the feature-test
 * macros from user land. */
#define EXT2_SB(sb)	(sb)

/*
 * Maximal count of links to a file
 */
#define EXT2_LINK_MAX		32000

/*
 * Macro-instructions used to manage several block sizes
 */
#define EXT2_MIN_BLOCK_LOG_SIZE		10	/* 1024 */
#define EXT2_MAX_BLOCK_LOG_SIZE		16	/* 65536 */
#define EXT2_MIN_BLOCK_SIZE	(1 << EXT2_MIN_BLOCK_LOG_SIZE)
#define EXT2_MAX_BLOCK_SIZE	(1 << EXT2_MAX_BLOCK_LOG_SIZE)
#define EXT2_BLOCK_SIZE(s)	(EXT2_MIN_BLOCK_SIZE << (s)->s_log_block_size)
#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)
#define EXT2_ADDR_PER_BLOCK(s)	(EXT2_BLOCK_SIZE(s) / sizeof(__u32))

/*
 * Macro-instructions used to manage fragments
 */
#define EXT2_MIN_FRAG_SIZE		EXT2_MIN_BLOCK_SIZE
#define EXT2_MAX_FRAG_SIZE		EXT2_MAX_BLOCK_SIZE
#define EXT2_MIN_FRAG_LOG_SIZE		EXT2_MIN_BLOCK_LOG_SIZE
# define EXT2_FRAG_SIZE(s)		(EXT2_MIN_FRAG_SIZE << (s)->s_log_frag_size)
# define EXT2_FRAGS_PER_BLOCK(s)	(EXT2_BLOCK_SIZE(s) / EXT2_FRAG_SIZE(s))

/*
 * ACL structures
 */
struct ext2_acl_header	/* Header of Access Control Lists */
{
	__u32	aclh_size;
	__u32	aclh_file_count;
	__u32	aclh_acle_count;
	__u32	aclh_first_acle;
};

struct ext2_acl_entry	/* Access Control List Entry */
{
	__u32	acle_size;
	__u16	acle_perms;	/* Access permissions */
	__u16	acle_type;	/* Type of entry */
	__u16	acle_tag;	/* User or group identity */
	__u16	acle_pad1;
	__u32	acle_next;	/* Pointer on next entry for the */
					/* same inode or on next free entry */
};

/*
 * Structure of a blocks group descriptor
 */
struct ext2_group_desc
{
	__u32	bg_block_bitmap;		/* Blocks bitmap block */
	__u32	bg_inode_bitmap;		/* Inodes bitmap block */
	__u32	bg_inode_table;		/* Inodes table block */
	__u16	bg_free_blocks_count;	/* Free blocks count */
	__u16	bg_free_inodes_count;	/* Free inodes count */
	__u16	bg_used_dirs_count;	/* Directories count */
	__u16	bg_pad;
	__u32	bg_reserved[3];
};

/*
 * Data structures used by the directory indexing feature
 *
 * Note: all of the multibyte integer fields are little endian.
 */

/*
 * Note: dx_root_info is laid out so that if it should somehow get
 * overlaid by a dirent the two low bits of the hash version will be
 * zero.  Therefore, the hash version mod 4 should never be 0.
 * Sincerely, the paranoia department.
 */
struct ext2_dx_root_info {
	__u32 reserved_zero;
	__u8 hash_version; /* 0 now, 1 at release */
	__u8 info_length; /* 8 */
	__u8 indirect_levels;
	__u8 unused_flags;
};

#define EXT2_HASH_LEGACY	0
#define EXT2_HASH_HALF_MD4	1
#define EXT2_HASH_TEA		2

#define EXT2_HASH_FLAG_INCOMPAT	0x1

struct ext2_dx_entry {
	__u32 hash;
	__u32 block;
};

struct ext2_dx_countlimit {
	__u16 limit;
	__u16 count;
};


/*
 * Macro-instructions used to manage group descriptors
 */
#define EXT2_BLOCKS_PER_GROUP(s)	(EXT2_SB(s)->s_blocks_per_group)
#define EXT2_INODES_PER_GROUP(s)	(EXT2_SB(s)->s_inodes_per_group)
#define EXT2_INODES_PER_BLOCK(s)	(EXT2_BLOCK_SIZE(s)/EXT2_INODE_SIZE(s))
/* limits imposed by 16-bit value gd_free_{blocks,inode}_count */
#define EXT2_MAX_BLOCKS_PER_GROUP(s)	((1 << 16) - 8)
#define EXT2_MAX_INODES_PER_GROUP(s)	((1 << 16) - EXT2_INODES_PER_BLOCK(s))
#define EXT2_DESC_PER_BLOCK(s)		(EXT2_BLOCK_SIZE(s) / sizeof (struct ext2_group_desc))

/*
 * 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_NOCOMPR_FL			0x00000400 /* Access raw compressed data */
#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
#define EXT3_JOURNAL_DATA_FL		0x00004000 /* file data should be journaled */
#define EXT2_NOTAIL_FL			0x00008000 /* file tail should not be merged */
#define EXT2_DIRSYNC_FL			0x00010000 /* Synchronous directory modifications */
#define EXT2_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/
#define EXT3_EXTENTS_FL			0x00080000 /* Inode uses extents */
#define EXT2_RESERVED_FL		0x80000000 /* reserved for ext2 lib */

#define EXT2_FL_USER_VISIBLE		0x0003DFFF /* User visible flags */
#define EXT2_FL_USER_MODIFIABLE		0x000080FF /* User modifiable flags */

/*
 * ioctl commands
 */
#define EXT2_IOC_GETFLAGS		_IOR('f', 1, long)
#define EXT2_IOC_SETFLAGS		_IOW('f', 2, long)
#define EXT2_IOC_GETVERSION		_IOR('v', 1, long)
#define EXT2_IOC_SETVERSION		_IOW('v', 2, long)

/*
 * Structure of an inode on the disk
 */
struct ext2_inode {
	__u16	i_mode;		/* File mode */
	__u16	i_uid;		/* Low 16 bits of Owner Uid */
	__u32	i_size;		/* Size in bytes */
	__u32	i_atime;	/* Access time */
	__u32	i_ctime;	/* Creation time */
	__u32	i_mtime;	/* Modification time */
	__u32	i_dtime;	/* Deletion Time */
	__u16	i_gid;		/* Low 16 bits of Group Id */
	__u16	i_links_count;	/* Links count */
	__u32	i_blocks;	/* Blocks count */
	__u32	i_flags;	/* File flags */
	union {
		struct {
			__u32  l_i_reserved1;
		} linux1;
		struct {
			__u32  h_i_translator;
		} hurd1;
		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 */
};

/*
 * Permanent part of an large inode on the disk
 */
struct ext2_inode_large {
	__u16	i_mode;		/* File mode */
	__u16	i_uid;		/* Low 16 bits of Owner Uid */
	__u32	i_size;		/* Size in bytes */
	__u32	i_atime;	/* Access time */
	__u32	i_ctime;	/* Creation time */
	__u32	i_mtime;	/* Modification time */
	__u32	i_dtime;	/* Deletion Time */
	__u16	i_gid;		/* Low 16 bits of Group Id */
	__u16	i_links_count;	/* Links count */
	__u32	i_blocks;	/* Blocks count */
	__u32	i_flags;	/* File flags */
	union {
		struct {
			__u32  l_i_reserved1;
		} linux1;
		struct {
			__u32  h_i_translator;
		} hurd1;