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      1 /*
      2  *  linux/include/linux/ext2_fs.h
      3  *
      4  * Copyright (C) 1992, 1993, 1994, 1995
      5  * Remy Card (card (at) masi.ibp.fr)
      6  * Laboratoire MASI - Institut Blaise Pascal
      7  * Universite Pierre et Marie Curie (Paris VI)
      8  *
      9  *  from
     10  *
     11  *  linux/include/linux/minix_fs.h
     12  *
     13  *  Copyright (C) 1991, 1992  Linus Torvalds
     14  */
     15 
     16 #ifndef _LINUX_EXT2_FS_H
     17 #define _LINUX_EXT2_FS_H
     18 
     19 #include <linux/types.h>
     20 #include <linux/magic.h>
     21 
     22 /*
     23  * The second extended filesystem constants/structures
     24  */
     25 
     26 /*
     27  * Define EXT2FS_DEBUG to produce debug messages
     28  */
     29 #undef EXT2FS_DEBUG
     30 
     31 /*
     32  * Define EXT2_RESERVATION to reserve data blocks for expanding files
     33  */
     34 #define EXT2_DEFAULT_RESERVE_BLOCKS     8
     35 /*max window size: 1024(direct blocks) + 3([t,d]indirect blocks) */
     36 #define EXT2_MAX_RESERVE_BLOCKS         1027
     37 #define EXT2_RESERVE_WINDOW_NOT_ALLOCATED 0
     38 /*
     39  * The second extended file system version
     40  */
     41 #define EXT2FS_DATE		"95/08/09"
     42 #define EXT2FS_VERSION		"0.5b"
     43 
     44 /*
     45  * Debug code
     46  */
     47 #ifdef EXT2FS_DEBUG
     48 #	define ext2_debug(f, a...)	{ \
     49 					printk ("EXT2-fs DEBUG (%s, %d): %s:", \
     50 						__FILE__, __LINE__, __FUNCTION__); \
     51 				  	printk (f, ## a); \
     52 					}
     53 #else
     54 #	define ext2_debug(f, a...)	/**/
     55 #endif
     56 
     57 /*
     58  * Special inode numbers
     59  */
     60 #define	EXT2_BAD_INO		 1	/* Bad blocks inode */
     61 #define EXT2_ROOT_INO		 2	/* Root inode */
     62 #define EXT2_BOOT_LOADER_INO	 5	/* Boot loader inode */
     63 #define EXT2_UNDEL_DIR_INO	 6	/* Undelete directory inode */
     64 
     65 /* First non-reserved inode for old ext2 filesystems */
     66 #define EXT2_GOOD_OLD_FIRST_INO	11
     67 
     68 /* Assume that user mode programs are passing in an ext2fs superblock, not
     69  * a kernel struct super_block.  This will allow us to call the feature-test
     70  * macros from user land. */
     71 #define EXT2_SB(sb)	(sb)
     72 
     73 /*
     74  * Maximal count of links to a file
     75  */
     76 #define EXT2_LINK_MAX		32000
     77 
     78 /*
     79  * Macro-instructions used to manage several block sizes
     80  */
     81 #define EXT2_MIN_BLOCK_SIZE		1024
     82 #define	EXT2_MAX_BLOCK_SIZE		4096
     83 #define EXT2_MIN_BLOCK_LOG_SIZE		  10
     84 # define EXT2_BLOCK_SIZE(s)		(EXT2_MIN_BLOCK_SIZE << (s)->s_log_block_size)
     85 #define	EXT2_ADDR_PER_BLOCK(s)		(EXT2_BLOCK_SIZE(s) / sizeof (__u32))
     86 # define EXT2_BLOCK_SIZE_BITS(s)	((s)->s_log_block_size + 10)
     87 #define EXT2_INODE_SIZE(s)	(((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
     88 				 EXT2_GOOD_OLD_INODE_SIZE : \
     89 				 (s)->s_inode_size)
     90 #define EXT2_FIRST_INO(s)	(((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
     91 				 EXT2_GOOD_OLD_FIRST_INO : \
     92 				 (s)->s_first_ino)
     93 
     94 /*
     95  * Macro-instructions used to manage fragments
     96  */
     97 #define EXT2_MIN_FRAG_SIZE		1024
     98 #define	EXT2_MAX_FRAG_SIZE		4096
     99 #define EXT2_MIN_FRAG_LOG_SIZE		  10
    100 # define EXT2_FRAG_SIZE(s)		(EXT2_MIN_FRAG_SIZE << (s)->s_log_frag_size)
    101 # define EXT2_FRAGS_PER_BLOCK(s)	(EXT2_BLOCK_SIZE(s) / EXT2_FRAG_SIZE(s))
    102 
    103 /*
    104  * Structure of a blocks group descriptor
    105  */
    106 struct ext2_group_desc
    107 {
    108 	__le32	bg_block_bitmap;		/* Blocks bitmap block */
    109 	__le32	bg_inode_bitmap;		/* Inodes bitmap block */
    110 	__le32	bg_inode_table;		/* Inodes table block */
    111 	__le16	bg_free_blocks_count;	/* Free blocks count */
    112 	__le16	bg_free_inodes_count;	/* Free inodes count */
    113 	__le16	bg_used_dirs_count;	/* Directories count */
    114 	__le16	bg_pad;
    115 	__le32	bg_reserved[3];
    116 };
    117 
    118 /*
    119  * Macro-instructions used to manage group descriptors
    120  */
    121 # define EXT2_BLOCKS_PER_GROUP(s)	((s)->s_blocks_per_group)
    122 # define EXT2_DESC_PER_BLOCK(s)		(EXT2_BLOCK_SIZE(s) / sizeof (struct ext2_group_desc))
    123 # define EXT2_INODES_PER_GROUP(s)	((s)->s_inodes_per_group)
    124 
    125 /*
    126  * Constants relative to the data blocks
    127  */
    128 #define	EXT2_NDIR_BLOCKS		12
    129 #define	EXT2_IND_BLOCK			EXT2_NDIR_BLOCKS
    130 #define	EXT2_DIND_BLOCK			(EXT2_IND_BLOCK + 1)
    131 #define	EXT2_TIND_BLOCK			(EXT2_DIND_BLOCK + 1)
    132 #define	EXT2_N_BLOCKS			(EXT2_TIND_BLOCK + 1)
    133 
    134 /*
    135  * Inode flags (GETFLAGS/SETFLAGS)
    136  */
    137 #define	EXT2_SECRM_FL			FS_SECRM_FL	/* Secure deletion */
    138 #define	EXT2_UNRM_FL			FS_UNRM_FL	/* Undelete */
    139 #define	EXT2_COMPR_FL			FS_COMPR_FL	/* Compress file */
    140 #define EXT2_SYNC_FL			FS_SYNC_FL	/* Synchronous updates */
    141 #define EXT2_IMMUTABLE_FL		FS_IMMUTABLE_FL	/* Immutable file */
    142 #define EXT2_APPEND_FL			FS_APPEND_FL	/* writes to file may only append */
    143 #define EXT2_NODUMP_FL			FS_NODUMP_FL	/* do not dump file */
    144 #define EXT2_NOATIME_FL			FS_NOATIME_FL	/* do not update atime */
    145 /* Reserved for compression usage... */
    146 #define EXT2_DIRTY_FL			FS_DIRTY_FL
    147 #define EXT2_COMPRBLK_FL		FS_COMPRBLK_FL	/* One or more compressed clusters */
    148 #define EXT2_NOCOMP_FL			FS_NOCOMP_FL	/* Don't compress */
    149 #define EXT2_ECOMPR_FL			FS_ECOMPR_FL	/* Compression error */
    150 /* End compression flags --- maybe not all used */
    151 #define EXT2_BTREE_FL			FS_BTREE_FL	/* btree format dir */
    152 #define EXT2_INDEX_FL			FS_INDEX_FL	/* hash-indexed directory */
    153 #define EXT2_IMAGIC_FL			FS_IMAGIC_FL	/* AFS directory */
    154 #define EXT2_JOURNAL_DATA_FL		FS_JOURNAL_DATA_FL /* Reserved for ext3 */
    155 #define EXT2_NOTAIL_FL			FS_NOTAIL_FL	/* file tail should not be merged */
    156 #define EXT2_DIRSYNC_FL			FS_DIRSYNC_FL	/* dirsync behaviour (directories only) */
    157 #define EXT2_TOPDIR_FL			FS_TOPDIR_FL	/* Top of directory hierarchies*/
    158 #define EXT2_RESERVED_FL		FS_RESERVED_FL	/* reserved for ext2 lib */
    159 
    160 #define EXT2_FL_USER_VISIBLE		FS_FL_USER_VISIBLE	/* User visible flags */
    161 #define EXT2_FL_USER_MODIFIABLE		FS_FL_USER_MODIFIABLE	/* User modifiable flags */
    162 
    163 /*
    164  * ioctl commands
    165  */
    166 #define	EXT2_IOC_GETFLAGS		FS_IOC_GETFLAGS
    167 #define	EXT2_IOC_SETFLAGS		FS_IOC_SETFLAGS
    168 #define	EXT2_IOC_GETVERSION		FS_IOC_GETVERSION
    169 #define	EXT2_IOC_SETVERSION		FS_IOC_SETVERSION
    170 #define	EXT2_IOC_GETRSVSZ		_IOR('f', 5, long)
    171 #define	EXT2_IOC_SETRSVSZ		_IOW('f', 6, long)
    172 
    173 /*
    174  * ioctl commands in 32 bit emulation
    175  */
    176 #define EXT2_IOC32_GETFLAGS		FS_IOC32_GETFLAGS
    177 #define EXT2_IOC32_SETFLAGS		FS_IOC32_SETFLAGS
    178 #define EXT2_IOC32_GETVERSION		FS_IOC32_GETVERSION
    179 #define EXT2_IOC32_SETVERSION		FS_IOC32_SETVERSION
    180 
    181 /*
    182  * Structure of an inode on the disk
    183  */
    184 struct ext2_inode {
    185 	__le16	i_mode;		/* File mode */
    186 	__le16	i_uid;		/* Low 16 bits of Owner Uid */
    187 	__le32	i_size;		/* Size in bytes */
    188 	__le32	i_atime;	/* Access time */
    189 	__le32	i_ctime;	/* Creation time */
    190 	__le32	i_mtime;	/* Modification time */
    191 	__le32	i_dtime;	/* Deletion Time */
    192 	__le16	i_gid;		/* Low 16 bits of Group Id */
    193 	__le16	i_links_count;	/* Links count */
    194 	__le32	i_blocks;	/* Blocks count */
    195 	__le32	i_flags;	/* File flags */
    196 	union {
    197 		struct {
    198 			__le32  l_i_reserved1;
    199 		} linux1;
    200 		struct {
    201 			__le32  h_i_translator;
    202 		} hurd1;
    203 		struct {
    204 			__le32  m_i_reserved1;
    205 		} masix1;
    206 	} osd1;				/* OS dependent 1 */
    207 	__le32	i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
    208 	__le32	i_generation;	/* File version (for NFS) */
    209 	__le32	i_file_acl;	/* File ACL */
    210 	__le32	i_dir_acl;	/* Directory ACL */
    211 	__le32	i_faddr;	/* Fragment address */
    212 	union {
    213 		struct {
    214 			__u8	l_i_frag;	/* Fragment number */
    215 			__u8	l_i_fsize;	/* Fragment size */
    216 			__u16	i_pad1;
    217 			__le16	l_i_uid_high;	/* these 2 fields    */
    218 			__le16	l_i_gid_high;	/* were reserved2[0] */
    219 			__u32	l_i_reserved2;
    220 		} linux2;
    221 		struct {
    222 			__u8	h_i_frag;	/* Fragment number */
    223 			__u8	h_i_fsize;	/* Fragment size */
    224 			__le16	h_i_mode_high;
    225 			__le16	h_i_uid_high;
    226 			__le16	h_i_gid_high;
    227 			__le32	h_i_author;
    228 		} hurd2;
    229 		struct {
    230 			__u8	m_i_frag;	/* Fragment number */
    231 			__u8	m_i_fsize;	/* Fragment size */
    232 			__u16	m_pad1;
    233 			__u32	m_i_reserved2[2];
    234 		} masix2;
    235 	} osd2;				/* OS dependent 2 */
    236 };
    237 
    238 #define i_size_high	i_dir_acl
    239 
    240 #if defined(__KERNEL__) || defined(__linux__)
    241 #define i_reserved1	osd1.linux1.l_i_reserved1
    242 #define i_frag		osd2.linux2.l_i_frag
    243 #define i_fsize		osd2.linux2.l_i_fsize
    244 #define i_uid_low	i_uid
    245 #define i_gid_low	i_gid
    246 #define i_uid_high	osd2.linux2.l_i_uid_high
    247 #define i_gid_high	osd2.linux2.l_i_gid_high
    248 #define i_reserved2	osd2.linux2.l_i_reserved2
    249 #endif
    250 
    251 #ifdef	__hurd__
    252 #define i_translator	osd1.hurd1.h_i_translator
    253 #define i_frag		osd2.hurd2.h_i_frag;
    254 #define i_fsize		osd2.hurd2.h_i_fsize;
    255 #define i_uid_high	osd2.hurd2.h_i_uid_high
    256 #define i_gid_high	osd2.hurd2.h_i_gid_high
    257 #define i_author	osd2.hurd2.h_i_author
    258 #endif
    259 
    260 #ifdef	__masix__
    261 #define i_reserved1	osd1.masix1.m_i_reserved1
    262 #define i_frag		osd2.masix2.m_i_frag
    263 #define i_fsize		osd2.masix2.m_i_fsize
    264 #define i_reserved2	osd2.masix2.m_i_reserved2
    265 #endif
    266 
    267 /*
    268  * File system states
    269  */
    270 #define	EXT2_VALID_FS			0x0001	/* Unmounted cleanly */
    271 #define	EXT2_ERROR_FS			0x0002	/* Errors detected */
    272 
    273 /*
    274  * Mount flags
    275  */
    276 #define EXT2_MOUNT_CHECK		0x000001  /* Do mount-time checks */
    277 #define EXT2_MOUNT_OLDALLOC		0x000002  /* Don't use the new Orlov allocator */
    278 #define EXT2_MOUNT_GRPID		0x000004  /* Create files with directory's group */
    279 #define EXT2_MOUNT_DEBUG		0x000008  /* Some debugging messages */
    280 #define EXT2_MOUNT_ERRORS_CONT		0x000010  /* Continue on errors */
    281 #define EXT2_MOUNT_ERRORS_RO		0x000020  /* Remount fs ro on errors */
    282 #define EXT2_MOUNT_ERRORS_PANIC		0x000040  /* Panic on errors */
    283 #define EXT2_MOUNT_MINIX_DF		0x000080  /* Mimics the Minix statfs */
    284 #define EXT2_MOUNT_NOBH			0x000100  /* No buffer_heads */
    285 #define EXT2_MOUNT_NO_UID32		0x000200  /* Disable 32-bit UIDs */
    286 #define EXT2_MOUNT_XATTR_USER		0x004000  /* Extended user attributes */
    287 #define EXT2_MOUNT_POSIX_ACL		0x008000  /* POSIX Access Control Lists */
    288 #define EXT2_MOUNT_XIP			0x010000  /* Execute in place */
    289 #define EXT2_MOUNT_USRQUOTA		0x020000  /* user quota */
    290 #define EXT2_MOUNT_GRPQUOTA		0x040000  /* group quota */
    291 #define EXT2_MOUNT_RESERVATION		0x080000  /* Preallocation */
    292 
    293 
    294 #define clear_opt(o, opt)		o &= ~EXT2_MOUNT_##opt
    295 #define set_opt(o, opt)			o |= EXT2_MOUNT_##opt
    296 #define test_opt(sb, opt)		(EXT2_SB(sb)->s_mount_opt & \
    297 					 EXT2_MOUNT_##opt)
    298 /*
    299  * Maximal mount counts between two filesystem checks
    300  */
    301 #define EXT2_DFL_MAX_MNT_COUNT		20	/* Allow 20 mounts */
    302 #define EXT2_DFL_CHECKINTERVAL		0	/* Don't use interval check */
    303 
    304 /*
    305  * Behaviour when detecting errors
    306  */
    307 #define EXT2_ERRORS_CONTINUE		1	/* Continue execution */
    308 #define EXT2_ERRORS_RO			2	/* Remount fs read-only */
    309 #define EXT2_ERRORS_PANIC		3	/* Panic */
    310 #define EXT2_ERRORS_DEFAULT		EXT2_ERRORS_CONTINUE
    311 
    312 /*
    313  * Structure of the super block
    314  */
    315 struct ext2_super_block {
    316 	__le32	s_inodes_count;		/* Inodes count */
    317 	__le32	s_blocks_count;		/* Blocks count */
    318 	__le32	s_r_blocks_count;	/* Reserved blocks count */
    319 	__le32	s_free_blocks_count;	/* Free blocks count */
    320 	__le32	s_free_inodes_count;	/* Free inodes count */
    321 	__le32	s_first_data_block;	/* First Data Block */
    322 	__le32	s_log_block_size;	/* Block size */
    323 	__le32	s_log_frag_size;	/* Fragment size */
    324 	__le32	s_blocks_per_group;	/* # Blocks per group */
    325 	__le32	s_frags_per_group;	/* # Fragments per group */
    326 	__le32	s_inodes_per_group;	/* # Inodes per group */
    327 	__le32	s_mtime;		/* Mount time */
    328 	__le32	s_wtime;		/* Write time */
    329 	__le16	s_mnt_count;		/* Mount count */
    330 	__le16	s_max_mnt_count;	/* Maximal mount count */
    331 	__le16	s_magic;		/* Magic signature */
    332 	__le16	s_state;		/* File system state */
    333 	__le16	s_errors;		/* Behaviour when detecting errors */
    334 	__le16	s_minor_rev_level; 	/* minor revision level */
    335 	__le32	s_lastcheck;		/* time of last check */
    336 	__le32	s_checkinterval;	/* max. time between checks */
    337 	__le32	s_creator_os;		/* OS */
    338 	__le32	s_rev_level;		/* Revision level */
    339 	__le16	s_def_resuid;		/* Default uid for reserved blocks */
    340 	__le16	s_def_resgid;		/* Default gid for reserved blocks */
    341 	/*
    342 	 * These fields are for EXT2_DYNAMIC_REV superblocks only.
    343 	 *
    344 	 * Note: the difference between the compatible feature set and
    345 	 * the incompatible feature set is that if there is a bit set
    346 	 * in the incompatible feature set that the kernel doesn't
    347 	 * know about, it should refuse to mount the filesystem.
    348 	 *
    349 	 * e2fsck's requirements are more strict; if it doesn't know
    350 	 * about a feature in either the compatible or incompatible
    351 	 * feature set, it must abort and not try to meddle with
    352 	 * things it doesn't understand...
    353 	 */
    354 	__le32	s_first_ino; 		/* First non-reserved inode */
    355 	__le16   s_inode_size; 		/* size of inode structure */
    356 	__le16	s_block_group_nr; 	/* block group # of this superblock */
    357 	__le32	s_feature_compat; 	/* compatible feature set */
    358 	__le32	s_feature_incompat; 	/* incompatible feature set */
    359 	__le32	s_feature_ro_compat; 	/* readonly-compatible feature set */
    360 	__u8	s_uuid[16];		/* 128-bit uuid for volume */
    361 	char	s_volume_name[16]; 	/* volume name */
    362 	char	s_last_mounted[64]; 	/* directory where last mounted */
    363 	__le32	s_algorithm_usage_bitmap; /* For compression */
    364 	/*
    365 	 * Performance hints.  Directory preallocation should only
    366 	 * happen if the EXT2_COMPAT_PREALLOC flag is on.
    367 	 */
    368 	__u8	s_prealloc_blocks;	/* Nr of blocks to try to preallocate*/
    369 	__u8	s_prealloc_dir_blocks;	/* Nr to preallocate for dirs */
    370 	__u16	s_padding1;
    371 	/*
    372 	 * Journaling support valid if EXT3_FEATURE_COMPAT_HAS_JOURNAL set.
    373 	 */
    374 	__u8	s_journal_uuid[16];	/* uuid of journal superblock */
    375 	__u32	s_journal_inum;		/* inode number of journal file */
    376 	__u32	s_journal_dev;		/* device number of journal file */
    377 	__u32	s_last_orphan;		/* start of list of inodes to delete */
    378 	__u32	s_hash_seed[4];		/* HTREE hash seed */
    379 	__u8	s_def_hash_version;	/* Default hash version to use */
    380 	__u8	s_reserved_char_pad;
    381 	__u16	s_reserved_word_pad;
    382 	__le32	s_default_mount_opts;
    383  	__le32	s_first_meta_bg; 	/* First metablock block group */
    384 	__u32	s_reserved[190];	/* Padding to the end of the block */
    385 };
    386 
    387 /*
    388  * Codes for operating systems
    389  */
    390 #define EXT2_OS_LINUX		0
    391 #define EXT2_OS_HURD		1
    392 #define EXT2_OS_MASIX		2
    393 #define EXT2_OS_FREEBSD		3
    394 #define EXT2_OS_LITES		4
    395 
    396 /*
    397  * Revision levels
    398  */
    399 #define EXT2_GOOD_OLD_REV	0	/* The good old (original) format */
    400 #define EXT2_DYNAMIC_REV	1 	/* V2 format w/ dynamic inode sizes */
    401 
    402 #define EXT2_CURRENT_REV	EXT2_GOOD_OLD_REV
    403 #define EXT2_MAX_SUPP_REV	EXT2_DYNAMIC_REV
    404 
    405 #define EXT2_GOOD_OLD_INODE_SIZE 128
    406 
    407 /*
    408  * Feature set definitions
    409  */
    410 
    411 #define EXT2_HAS_COMPAT_FEATURE(sb,mask)			\
    412 	( EXT2_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask) )
    413 #define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask)			\
    414 	( EXT2_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask) )
    415 #define EXT2_HAS_INCOMPAT_FEATURE(sb,mask)			\
    416 	( EXT2_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask) )
    417 #define EXT2_SET_COMPAT_FEATURE(sb,mask)			\
    418 	EXT2_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
    419 #define EXT2_SET_RO_COMPAT_FEATURE(sb,mask)			\
    420 	EXT2_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
    421 #define EXT2_SET_INCOMPAT_FEATURE(sb,mask)			\
    422 	EXT2_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
    423 #define EXT2_CLEAR_COMPAT_FEATURE(sb,mask)			\
    424 	EXT2_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
    425 #define EXT2_CLEAR_RO_COMPAT_FEATURE(sb,mask)			\
    426 	EXT2_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
    427 #define EXT2_CLEAR_INCOMPAT_FEATURE(sb,mask)			\
    428 	EXT2_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
    429 
    430 #define EXT2_FEATURE_COMPAT_DIR_PREALLOC	0x0001
    431 #define EXT2_FEATURE_COMPAT_IMAGIC_INODES	0x0002
    432 #define EXT3_FEATURE_COMPAT_HAS_JOURNAL		0x0004
    433 #define EXT2_FEATURE_COMPAT_EXT_ATTR		0x0008
    434 #define EXT2_FEATURE_COMPAT_RESIZE_INO		0x0010
    435 #define EXT2_FEATURE_COMPAT_DIR_INDEX		0x0020
    436 #define EXT2_FEATURE_COMPAT_ANY			0xffffffff
    437 
    438 #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
    439 #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
    440 #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR	0x0004
    441 #define EXT2_FEATURE_RO_COMPAT_ANY		0xffffffff
    442 
    443 #define EXT2_FEATURE_INCOMPAT_COMPRESSION	0x0001
    444 #define EXT2_FEATURE_INCOMPAT_FILETYPE		0x0002
    445 #define EXT3_FEATURE_INCOMPAT_RECOVER		0x0004
    446 #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008
    447 #define EXT2_FEATURE_INCOMPAT_META_BG		0x0010
    448 #define EXT2_FEATURE_INCOMPAT_ANY		0xffffffff
    449 
    450 #define EXT2_FEATURE_COMPAT_SUPP	EXT2_FEATURE_COMPAT_EXT_ATTR
    451 #define EXT2_FEATURE_INCOMPAT_SUPP	(EXT2_FEATURE_INCOMPAT_FILETYPE| \
    452 					 EXT2_FEATURE_INCOMPAT_META_BG)
    453 #define EXT2_FEATURE_RO_COMPAT_SUPP	(EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
    454 					 EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
    455 					 EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
    456 #define EXT2_FEATURE_RO_COMPAT_UNSUPPORTED	~EXT2_FEATURE_RO_COMPAT_SUPP
    457 #define EXT2_FEATURE_INCOMPAT_UNSUPPORTED	~EXT2_FEATURE_INCOMPAT_SUPP
    458 
    459 /*
    460  * Default values for user and/or group using reserved blocks
    461  */
    462 #define	EXT2_DEF_RESUID		0
    463 #define	EXT2_DEF_RESGID		0
    464 
    465 /*
    466  * Default mount options
    467  */
    468 #define EXT2_DEFM_DEBUG		0x0001
    469 #define EXT2_DEFM_BSDGROUPS	0x0002
    470 #define EXT2_DEFM_XATTR_USER	0x0004
    471 #define EXT2_DEFM_ACL		0x0008
    472 #define EXT2_DEFM_UID16		0x0010
    473     /* Not used by ext2, but reserved for use by ext3 */
    474 #define EXT3_DEFM_JMODE		0x0060
    475 #define EXT3_DEFM_JMODE_DATA	0x0020
    476 #define EXT3_DEFM_JMODE_ORDERED	0x0040
    477 #define EXT3_DEFM_JMODE_WBACK	0x0060
    478 
    479 /*
    480  * Structure of a directory entry
    481  */
    482 #define EXT2_NAME_LEN 255
    483 
    484 struct ext2_dir_entry {
    485 	__le32	inode;			/* Inode number */
    486 	__le16	rec_len;		/* Directory entry length */
    487 	__le16	name_len;		/* Name length */
    488 	char	name[EXT2_NAME_LEN];	/* File name */
    489 };
    490 
    491 /*
    492  * The new version of the directory entry.  Since EXT2 structures are
    493  * stored in intel byte order, and the name_len field could never be
    494  * bigger than 255 chars, it's safe to reclaim the extra byte for the
    495  * file_type field.
    496  */
    497 struct ext2_dir_entry_2 {
    498 	__le32	inode;			/* Inode number */
    499 	__le16	rec_len;		/* Directory entry length */
    500 	__u8	name_len;		/* Name length */
    501 	__u8	file_type;
    502 	char	name[EXT2_NAME_LEN];	/* File name */
    503 };
    504 
    505 /*
    506  * Ext2 directory file types.  Only the low 3 bits are used.  The
    507  * other bits are reserved for now.
    508  */
    509 enum {
    510 	EXT2_FT_UNKNOWN,
    511 	EXT2_FT_REG_FILE,
    512 	EXT2_FT_DIR,
    513 	EXT2_FT_CHRDEV,
    514 	EXT2_FT_BLKDEV,
    515 	EXT2_FT_FIFO,
    516 	EXT2_FT_SOCK,
    517 	EXT2_FT_SYMLINK,
    518 	EXT2_FT_MAX
    519 };
    520 
    521 /*
    522  * EXT2_DIR_PAD defines the directory entries boundaries
    523  *
    524  * NOTE: It must be a multiple of 4
    525  */
    526 #define EXT2_DIR_PAD		 	4
    527 #define EXT2_DIR_ROUND 			(EXT2_DIR_PAD - 1)
    528 #define EXT2_DIR_REC_LEN(name_len)	(((name_len) + 8 + EXT2_DIR_ROUND) & \
    529 					 ~EXT2_DIR_ROUND)
    530 #define EXT2_MAX_REC_LEN		((1<<16)-1)
    531 
    532 #endif	/* _LINUX_EXT2_FS_H */
    533