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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 <ext2fs/ext2_types.h>		/* Changed from linux/types.h */
     20 
     21 /*
     22  * The second extended filesystem constants/structures
     23  */
     24 
     25 /*
     26  * Define EXT2FS_DEBUG to produce debug messages
     27  */
     28 #undef EXT2FS_DEBUG
     29 
     30 /*
     31  * Define EXT2_PREALLOCATE to preallocate data blocks for expanding files
     32  */
     33 #define EXT2_PREALLOCATE
     34 #define EXT2_DEFAULT_PREALLOC_BLOCKS	8
     35 
     36 /*
     37  * The second extended file system version
     38  */
     39 #define EXT2FS_DATE		"95/08/09"
     40 #define EXT2FS_VERSION		"0.5b"
     41 
     42 /*
     43  * Special inode numbers
     44  */
     45 #define EXT2_BAD_INO		 1	/* Bad blocks inode */
     46 #define EXT2_ROOT_INO		 2	/* Root inode */
     47 #define EXT2_ACL_IDX_INO	 3	/* ACL inode */
     48 #define EXT2_ACL_DATA_INO	 4	/* ACL inode */
     49 #define EXT2_BOOT_LOADER_INO	 5	/* Boot loader inode */
     50 #define EXT2_UNDEL_DIR_INO	 6	/* Undelete directory inode */
     51 #define EXT2_RESIZE_INO		 7	/* Reserved group descriptors inode */
     52 #define EXT2_JOURNAL_INO	 8	/* Journal inode */
     53 
     54 /* First non-reserved inode for old ext2 filesystems */
     55 #define EXT2_GOOD_OLD_FIRST_INO	11
     56 
     57 /*
     58  * The second extended file system magic number
     59  */
     60 #define EXT2_SUPER_MAGIC	0xEF53
     61 
     62 #ifdef __KERNEL__
     63 #define EXT2_SB(sb)	(&((sb)->u.ext2_sb))
     64 #else
     65 /* Assume that user mode programs are passing in an ext2fs superblock, not
     66  * a kernel struct super_block.  This will allow us to call the feature-test
     67  * macros from user land. */
     68 #define EXT2_SB(sb)	(sb)
     69 #endif
     70 
     71 /*
     72  * Maximal count of links to a file
     73  */
     74 #define EXT2_LINK_MAX		65000
     75 
     76 /*
     77  * Macro-instructions used to manage several block sizes
     78  */
     79 #define EXT2_MIN_BLOCK_LOG_SIZE		10	/* 1024 */
     80 #define EXT2_MAX_BLOCK_LOG_SIZE		16	/* 65536 */
     81 #define EXT2_MIN_BLOCK_SIZE	(1 << EXT2_MIN_BLOCK_LOG_SIZE)
     82 #define EXT2_MAX_BLOCK_SIZE	(1 << EXT2_MAX_BLOCK_LOG_SIZE)
     83 #ifdef __KERNEL__
     84 #define EXT2_BLOCK_SIZE(s)	((s)->s_blocksize)
     85 #define EXT2_BLOCK_SIZE_BITS(s)	((s)->s_blocksize_bits)
     86 #define EXT2_ADDR_PER_BLOCK_BITS(s)	(EXT2_SB(s)->addr_per_block_bits)
     87 #define EXT2_INODE_SIZE(s)	(EXT2_SB(s)->s_inode_size)
     88 #define EXT2_FIRST_INO(s)	(EXT2_SB(s)->s_first_ino)
     89 #else
     90 #define EXT2_BLOCK_SIZE(s)	(EXT2_MIN_BLOCK_SIZE << (s)->s_log_block_size)
     91 #define EXT2_BLOCK_SIZE_BITS(s)	((s)->s_log_block_size + 10)
     92 #define EXT2_INODE_SIZE(s)	(((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
     93 				 EXT2_GOOD_OLD_INODE_SIZE : (s)->s_inode_size)
     94 #define EXT2_FIRST_INO(s)	(((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
     95 				 EXT2_GOOD_OLD_FIRST_INO : (s)->s_first_ino)
     96 #endif
     97 #define EXT2_ADDR_PER_BLOCK(s)	(EXT2_BLOCK_SIZE(s) / sizeof(__u32))
     98 
     99 /*
    100  * Macro-instructions used to manage fragments
    101  */
    102 #define EXT2_MIN_FRAG_SIZE		EXT2_MIN_BLOCK_SIZE
    103 #define EXT2_MAX_FRAG_SIZE		EXT2_MAX_BLOCK_SIZE
    104 #define EXT2_MIN_FRAG_LOG_SIZE		EXT2_MIN_BLOCK_LOG_SIZE
    105 #ifdef __KERNEL__
    106 # define EXT2_FRAG_SIZE(s)		(EXT2_SB(s)->s_frag_size)
    107 # define EXT2_FRAGS_PER_BLOCK(s)	(EXT2_SB(s)->s_frags_per_block)
    108 #else
    109 # define EXT2_FRAG_SIZE(s)		(EXT2_MIN_FRAG_SIZE << (s)->s_log_frag_size)
    110 # define EXT2_FRAGS_PER_BLOCK(s)	(EXT2_BLOCK_SIZE(s) / EXT2_FRAG_SIZE(s))
    111 #endif
    112 
    113 /*
    114  * ACL structures
    115  */
    116 struct ext2_acl_header	/* Header of Access Control Lists */
    117 {
    118 	__u32	aclh_size;
    119 	__u32	aclh_file_count;
    120 	__u32	aclh_acle_count;
    121 	__u32	aclh_first_acle;
    122 };
    123 
    124 struct ext2_acl_entry	/* Access Control List Entry */
    125 {
    126 	__u32	acle_size;
    127 	__u16	acle_perms;	/* Access permissions */
    128 	__u16	acle_type;	/* Type of entry */
    129 	__u16	acle_tag;	/* User or group identity */
    130 	__u16	acle_pad1;
    131 	__u32	acle_next;	/* Pointer on next entry for the */
    132 					/* same inode or on next free entry */
    133 };
    134 
    135 /*
    136  * Structure of a blocks group descriptor
    137  */
    138 struct ext2_group_desc
    139 {
    140 	__u32	bg_block_bitmap;	/* Blocks bitmap block */
    141 	__u32	bg_inode_bitmap;	/* Inodes bitmap block */
    142 	__u32	bg_inode_table;		/* Inodes table block */
    143 	__u16	bg_free_blocks_count;	/* Free blocks count */
    144 	__u16	bg_free_inodes_count;	/* Free inodes count */
    145 	__u16	bg_used_dirs_count;	/* Directories count */
    146 	__u16	bg_flags;
    147 	__u32	bg_reserved[2];
    148 	__u16	bg_itable_unused;	/* Unused inodes count */
    149 	__u16	bg_checksum;		/* crc16(s_uuid+grouo_num+group_desc)*/
    150 };
    151 
    152 struct ext4_group_desc
    153 {
    154 	__u32	bg_block_bitmap;	/* Blocks bitmap block */
    155 	__u32	bg_inode_bitmap;	/* Inodes bitmap block */
    156 	__u32	bg_inode_table;		/* Inodes table block */
    157 	__u16	bg_free_blocks_count;	/* Free blocks count */
    158 	__u16	bg_free_inodes_count;	/* Free inodes count */
    159 	__u16	bg_used_dirs_count;	/* Directories count */
    160 	__u16	bg_flags;
    161 	__u32	bg_reserved[2];
    162 	__u16	bg_itable_unused;	/* Unused inodes count */
    163 	__u16	bg_checksum;		/* crc16(s_uuid+grouo_num+group_desc)*/
    164 	__u32	bg_block_bitmap_hi;	/* Blocks bitmap block MSB */
    165 	__u32	bg_inode_bitmap_hi;	/* Inodes bitmap block MSB */
    166 	__u32	bg_inode_table_hi;	/* Inodes table block MSB */
    167 	__u16	bg_free_blocks_count_hi;/* Free blocks count MSB */
    168 	__u16	bg_free_inodes_count_hi;/* Free inodes count MSB */
    169 	__u16	bg_used_dirs_count_hi;	/* Directories count MSB */
    170 	__u16   bg_pad;
    171 	__u32	bg_reserved2[3];
    172 };
    173 
    174 #define EXT2_BG_INODE_UNINIT	0x0001 /* Inode table/bitmap not initialized */
    175 #define EXT2_BG_BLOCK_UNINIT	0x0002 /* Block bitmap not initialized */
    176 
    177 /*
    178  * Data structures used by the directory indexing feature
    179  *
    180  * Note: all of the multibyte integer fields are little endian.
    181  */
    182 
    183 /*
    184  * Note: dx_root_info is laid out so that if it should somehow get
    185  * overlaid by a dirent the two low bits of the hash version will be
    186  * zero.  Therefore, the hash version mod 4 should never be 0.
    187  * Sincerely, the paranoia department.
    188  */
    189 struct ext2_dx_root_info {
    190 	__u32 reserved_zero;
    191 	__u8 hash_version; /* 0 now, 1 at release */
    192 	__u8 info_length; /* 8 */
    193 	__u8 indirect_levels;
    194 	__u8 unused_flags;
    195 };
    196 
    197 #define EXT2_HASH_LEGACY		0
    198 #define EXT2_HASH_HALF_MD4		1
    199 #define EXT2_HASH_TEA			2
    200 #define EXT2_HASH_LEGACY_UNSIGNED	3 /* reserved for userspace lib */
    201 #define EXT2_HASH_HALF_MD4_UNSIGNED	4 /* reserved for userspace lib */
    202 #define EXT2_HASH_TEA_UNSIGNED		5 /* reserved for userspace lib */
    203 
    204 #define EXT2_HASH_FLAG_INCOMPAT	0x1
    205 
    206 struct ext2_dx_entry {
    207 	__u32 hash;
    208 	__u32 block;
    209 };
    210 
    211 struct ext2_dx_countlimit {
    212 	__u16 limit;
    213 	__u16 count;
    214 };
    215 
    216 
    217 /*
    218  * Macro-instructions used to manage group descriptors
    219  */
    220 #define EXT2_BLOCKS_PER_GROUP(s)	(EXT2_SB(s)->s_blocks_per_group)
    221 #define EXT2_INODES_PER_GROUP(s)	(EXT2_SB(s)->s_inodes_per_group)
    222 #define EXT2_INODES_PER_BLOCK(s)	(EXT2_BLOCK_SIZE(s)/EXT2_INODE_SIZE(s))
    223 /* limits imposed by 16-bit value gd_free_{blocks,inode}_count */
    224 #define EXT2_MAX_BLOCKS_PER_GROUP(s)	((1 << 16) - 8)
    225 #define EXT2_MAX_INODES_PER_GROUP(s)	((1 << 16) - EXT2_INODES_PER_BLOCK(s))
    226 #ifdef __KERNEL__
    227 #define EXT2_DESC_PER_BLOCK(s)		(EXT2_SB(s)->s_desc_per_block)
    228 #define EXT2_DESC_PER_BLOCK_BITS(s)	(EXT2_SB(s)->s_desc_per_block_bits)
    229 #else
    230 #define EXT2_DESC_PER_BLOCK(s)		(EXT2_BLOCK_SIZE(s) / sizeof (struct ext2_group_desc))
    231 #endif
    232 
    233 /*
    234  * Constants relative to the data blocks
    235  */
    236 #define EXT2_NDIR_BLOCKS		12
    237 #define EXT2_IND_BLOCK			EXT2_NDIR_BLOCKS
    238 #define EXT2_DIND_BLOCK			(EXT2_IND_BLOCK + 1)
    239 #define EXT2_TIND_BLOCK			(EXT2_DIND_BLOCK + 1)
    240 #define EXT2_N_BLOCKS			(EXT2_TIND_BLOCK + 1)
    241 
    242 /*
    243  * Inode flags
    244  */
    245 #define EXT2_SECRM_FL			0x00000001 /* Secure deletion */
    246 #define EXT2_UNRM_FL			0x00000002 /* Undelete */
    247 #define EXT2_COMPR_FL			0x00000004 /* Compress file */
    248 #define EXT2_SYNC_FL			0x00000008 /* Synchronous updates */
    249 #define EXT2_IMMUTABLE_FL		0x00000010 /* Immutable file */
    250 #define EXT2_APPEND_FL			0x00000020 /* writes to file may only append */
    251 #define EXT2_NODUMP_FL			0x00000040 /* do not dump file */
    252 #define EXT2_NOATIME_FL			0x00000080 /* do not update atime */
    253 /* Reserved for compression usage... */
    254 #define EXT2_DIRTY_FL			0x00000100
    255 #define EXT2_COMPRBLK_FL		0x00000200 /* One or more compressed clusters */
    256 #define EXT2_NOCOMPR_FL			0x00000400 /* Access raw compressed data */
    257 #define EXT2_ECOMPR_FL			0x00000800 /* Compression error */
    258 /* End compression flags --- maybe not all used */
    259 #define EXT2_BTREE_FL			0x00001000 /* btree format dir */
    260 #define EXT2_INDEX_FL			0x00001000 /* hash-indexed directory */
    261 #define EXT2_IMAGIC_FL			0x00002000
    262 #define EXT3_JOURNAL_DATA_FL		0x00004000 /* file data should be journaled */
    263 #define EXT2_NOTAIL_FL			0x00008000 /* file tail should not be merged */
    264 #define EXT2_DIRSYNC_FL 		0x00010000 /* Synchronous directory modifications */
    265 #define EXT2_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/
    266 #define EXT4_EXTENTS_FL 		0x00080000 /* Inode uses extents */
    267 #define EXT2_RESERVED_FL		0x80000000 /* reserved for ext2 lib */
    268 
    269 #define EXT2_FL_USER_VISIBLE		0x000BDFFF /* User visible flags */
    270 #define EXT2_FL_USER_MODIFIABLE		0x000080FF /* User modifiable flags */
    271 
    272 /*
    273  * ioctl commands
    274  */
    275 
    276 /* Used for online resize */
    277 struct ext2_new_group_input {
    278 	__u32 group;		/* Group number for this data */
    279 	__u32 block_bitmap;	/* Absolute block number of block bitmap */
    280 	__u32 inode_bitmap;	/* Absolute block number of inode bitmap */
    281 	__u32 inode_table;	/* Absolute block number of inode table start */
    282 	__u32 blocks_count;	/* Total number of blocks in this group */
    283 	__u16 reserved_blocks;	/* Number of reserved blocks in this group */
    284 	__u16 unused;		/* Number of reserved GDT blocks in group */
    285 };
    286 
    287 #ifdef __GNU__			/* Needed for the Hurd */
    288 #define _IOT_ext2_new_group_input _IOT (_IOTS(__u32), 5, _IOTS(__u16), 2, 0, 0)
    289 #endif
    290 
    291 #define EXT2_IOC_GETFLAGS		_IOR('f', 1, long)
    292 #define EXT2_IOC_SETFLAGS		_IOW('f', 2, long)
    293 #define EXT2_IOC_GETVERSION		_IOR('v', 1, long)
    294 #define EXT2_IOC_SETVERSION		_IOW('v', 2, long)
    295 #define EXT2_IOC_GETVERSION_NEW		_IOR('f', 3, long)
    296 #define EXT2_IOC_SETVERSION_NEW		_IOW('f', 4, long)
    297 #define EXT2_IOC_GROUP_EXTEND		_IOW('f', 7, unsigned long)
    298 #define EXT2_IOC_GROUP_ADD		_IOW('f', 8,struct ext2_new_group_input)
    299 
    300 /*
    301  * Structure of an inode on the disk
    302  */
    303 struct ext2_inode {
    304 	__u16	i_mode;		/* File mode */
    305 	__u16	i_uid;		/* Low 16 bits of Owner Uid */
    306 	__u32	i_size;		/* Size in bytes */
    307 	__u32	i_atime;	/* Access time */
    308 	__u32	i_ctime;	/* Inode change time */
    309 	__u32	i_mtime;	/* Modification time */
    310 	__u32	i_dtime;	/* Deletion Time */
    311 	__u16	i_gid;		/* Low 16 bits of Group Id */
    312 	__u16	i_links_count;	/* Links count */
    313 	__u32	i_blocks;	/* Blocks count */
    314 	__u32	i_flags;	/* File flags */
    315 	union {
    316 		struct {
    317 			__u32	l_i_version; /* was l_i_reserved1 */
    318 		} linux1;
    319 		struct {
    320 			__u32  h_i_translator;
    321 		} hurd1;
    322 		struct {
    323 			__u32  m_i_reserved1;
    324 		} masix1;
    325 	} osd1;				/* OS dependent 1 */
    326 	__u32	i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
    327 	__u32	i_generation;	/* File version (for NFS) */
    328 	__u32	i_file_acl;	/* File ACL */
    329 	__u32	i_dir_acl;	/* Directory ACL */
    330 	__u32	i_faddr;	/* Fragment address */
    331 	union {
    332 		struct {
    333 			__u16	l_i_blocks_hi;
    334 			__u16	i_pad1;
    335 			__u16	l_i_uid_high;	/* these 2 fields    */
    336 			__u16	l_i_gid_high;	/* were reserved2[0] */
    337 			__u32	l_i_reserved2;
    338 		} linux2;
    339 		struct {
    340 			__u8	h_i_frag;	/* Fragment number */
    341 			__u8	h_i_fsize;	/* Fragment size */
    342 			__u16	h_i_mode_high;
    343 			__u16	h_i_uid_high;
    344 			__u16	h_i_gid_high;
    345 			__u32	h_i_author;
    346 		} hurd2;
    347 		struct {
    348 			__u8	m_i_frag;	/* Fragment number */
    349 			__u8	m_i_fsize;	/* Fragment size */
    350 			__u16	m_pad1;
    351 			__u32	m_i_reserved2[2];
    352 		} masix2;
    353 	} osd2;				/* OS dependent 2 */
    354 };
    355 
    356 /*
    357  * Permanent part of an large inode on the disk
    358  */
    359 struct ext2_inode_large {
    360 	__u16	i_mode;		/* File mode */
    361 	__u16	i_uid;		/* Low 16 bits of Owner Uid */
    362 	__u32	i_size;		/* Size in bytes */
    363 	__u32	i_atime;	/* Access time */
    364 	__u32	i_ctime;	/* Inode Change time */
    365 	__u32	i_mtime;	/* Modification time */
    366 	__u32	i_dtime;	/* Deletion Time */
    367 	__u16	i_gid;		/* Low 16 bits of Group Id */
    368 	__u16	i_links_count;	/* Links count */
    369 	__u32	i_blocks;	/* Blocks count */
    370 	__u32	i_flags;	/* File flags */
    371 	union {
    372 		struct {
    373 			__u32	l_i_version; /* was l_i_reserved1 */
    374 		} linux1;
    375 		struct {
    376 			__u32  h_i_translator;
    377 		} hurd1;
    378 		struct {
    379 			__u32  m_i_reserved1;
    380 		} masix1;
    381 	} osd1;				/* OS dependent 1 */
    382 	__u32	i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
    383 	__u32	i_generation;	/* File version (for NFS) */
    384 	__u32	i_file_acl;	/* File ACL */
    385 	__u32	i_dir_acl;	/* Directory ACL */
    386 	__u32	i_faddr;	/* Fragment address */
    387 	union {
    388 		struct {
    389 			__u16	l_i_blocks_hi;
    390 			__u16	i_pad1;
    391 			__u16	l_i_uid_high;	/* these 2 fields    */
    392 			__u16	l_i_gid_high;	/* were reserved2[0] */
    393 			__u32	l_i_reserved2;
    394 		} linux2;
    395 		struct {
    396 			__u8	h_i_frag;	/* Fragment number */
    397 			__u8	h_i_fsize;	/* Fragment size */
    398 			__u16	h_i_mode_high;
    399 			__u16	h_i_uid_high;
    400 			__u16	h_i_gid_high;
    401 			__u32	h_i_author;
    402 		} hurd2;
    403 		struct {
    404 			__u8	m_i_frag;	/* Fragment number */
    405 			__u8	m_i_fsize;	/* Fragment size */
    406 			__u16	m_pad1;
    407 			__u32	m_i_reserved2[2];
    408 		} masix2;
    409 	} osd2;				/* OS dependent 2 */
    410 	__u16	i_extra_isize;
    411 	__u16	i_pad1;
    412 	__u32	i_ctime_extra;	/* extra Change time (nsec << 2 | epoch) */
    413 	__u32	i_mtime_extra;	/* extra Modification time (nsec << 2 | epoch) */
    414 	__u32	i_atime_extra;	/* extra Access time (nsec << 2 | epoch) */
    415 	__u32	i_crtime;	/* File creation time */
    416 	__u32	i_crtime_extra;	/* extra File creation time (nsec << 2 | epoch)*/
    417 };
    418 
    419 #define i_size_high	i_dir_acl
    420 
    421 #if defined(__KERNEL__) || defined(__linux__)
    422 #define i_reserved1	osd1.linux1.l_i_reserved1
    423 #define i_frag		osd2.linux2.l_i_frag
    424 #define i_fsize		osd2.linux2.l_i_fsize
    425 #define i_uid_low	i_uid
    426 #define i_gid_low	i_gid
    427 #define i_uid_high	osd2.linux2.l_i_uid_high
    428 #define i_gid_high	osd2.linux2.l_i_gid_high
    429 #define i_reserved2	osd2.linux2.l_i_reserved2
    430 #else
    431 #if defined(__GNU__)
    432 
    433 #define i_translator	osd1.hurd1.h_i_translator
    434 #define i_frag		osd2.hurd2.h_i_frag;
    435 #define i_fsize		osd2.hurd2.h_i_fsize;
    436 #define i_uid_high	osd2.hurd2.h_i_uid_high
    437 #define i_gid_high	osd2.hurd2.h_i_gid_high
    438 #define i_author	osd2.hurd2.h_i_author
    439 
    440 #else
    441 #if defined(__masix__)
    442 
    443 #define i_reserved1	osd1.masix1.m_i_reserved1
    444 #define i_frag		osd2.masix2.m_i_frag
    445 #define i_fsize		osd2.masix2.m_i_fsize
    446 #define i_reserved2	osd2.masix2.m_i_reserved2
    447 
    448 #endif  /* __masix__ */
    449 #endif  /* __GNU__ */
    450 #endif	/* defined(__KERNEL__) || defined(__linux__) */
    451 
    452 #if defined(__masix__)
    453 #define inode_uid(inode)	((inode).i_uid)
    454 #define inode_gid(inode)	((inode).i_gid)
    455 #define ext2fs_set_i_uid_high(inode,x) (x)
    456 #define ext2fs_set_i_gid_high(inode,x) (x)
    457 
    458 #else
    459 #define inode_uid(inode)	((inode).i_uid | (inode).osd2.linux2.l_i_uid_high << 16)
    460 #define inode_gid(inode)	((inode).i_gid | (inode).osd2.linux2.l_i_gid_high << 16)
    461 #define ext2fs_set_i_uid_high(inode,x) ((inode).osd2.linux2.l_i_uid_high = (x))
    462 #define ext2fs_set_i_gid_high(inode,x) ((inode).osd2.linux2.l_i_gid_high = (x))
    463 #endif
    464 
    465 /*
    466  * File system states
    467  */
    468 #define EXT2_VALID_FS			0x0001	/* Unmounted cleanly */
    469 #define EXT2_ERROR_FS			0x0002	/* Errors detected */
    470 #define EXT4_ORPHAN_FS			0x0004	/* Orphans being recovered */
    471 
    472 /*
    473  * Misc. filesystem flags
    474  */
    475 #define EXT2_FLAGS_SIGNED_HASH		0x0001  /* Signed dirhash in use */
    476 #define EXT2_FLAGS_UNSIGNED_HASH	0x0002  /* Unsigned dirhash in use */
    477 #define EXT2_FLAGS_TEST_FILESYS		0x0004	/* OK for use on development code */
    478 
    479 /*
    480  * Mount flags
    481  */
    482 #define EXT2_MOUNT_CHECK		0x0001	/* Do mount-time checks */
    483 #define EXT2_MOUNT_GRPID		0x0004	/* Create files with directory's group */
    484 #define EXT2_MOUNT_DEBUG		0x0008	/* Some debugging messages */
    485 #define EXT2_MOUNT_ERRORS_CONT		0x0010	/* Continue on errors */
    486 #define EXT2_MOUNT_ERRORS_RO		0x0020	/* Remount fs ro on errors */
    487 #define EXT2_MOUNT_ERRORS_PANIC		0x0040	/* Panic on errors */
    488 #define EXT2_MOUNT_MINIX_DF		0x0080	/* Mimics the Minix statfs */
    489 #define EXT2_MOUNT_NO_UID32		0x0200  /* Disable 32-bit UIDs */
    490 
    491 #define clear_opt(o, opt)		o &= ~EXT2_MOUNT_##opt
    492 #define set_opt(o, opt)			o |= EXT2_MOUNT_##opt
    493 #define test_opt(sb, opt)		(EXT2_SB(sb)->s_mount_opt & \
    494 					 EXT2_MOUNT_##opt)
    495 /*
    496  * Maximal mount counts between two filesystem checks
    497  */
    498 #define EXT2_DFL_MAX_MNT_COUNT		20	/* Allow 20 mounts */
    499 #define EXT2_DFL_CHECKINTERVAL		0	/* Don't use interval check */
    500 
    501 /*
    502  * Behaviour when detecting errors
    503  */
    504 #define EXT2_ERRORS_CONTINUE		1	/* Continue execution */
    505 #define EXT2_ERRORS_RO			2	/* Remount fs read-only */
    506 #define EXT2_ERRORS_PANIC		3	/* Panic */
    507 #define EXT2_ERRORS_DEFAULT		EXT2_ERRORS_CONTINUE
    508 
    509 /*
    510  * Structure of the super block
    511  */
    512 struct ext2_super_block {
    513 	__u32	s_inodes_count;		/* Inodes count */
    514 	__u32	s_blocks_count;		/* Blocks count */
    515 	__u32	s_r_blocks_count;	/* Reserved blocks count */
    516 	__u32	s_free_blocks_count;	/* Free blocks count */
    517 	__u32	s_free_inodes_count;	/* Free inodes count */
    518 	__u32	s_first_data_block;	/* First Data Block */
    519 	__u32	s_log_block_size;	/* Block size */
    520 	__s32	s_log_frag_size;	/* Fragment size */
    521 	__u32	s_blocks_per_group;	/* # Blocks per group */
    522 	__u32	s_frags_per_group;	/* # Fragments per group */
    523 	__u32	s_inodes_per_group;	/* # Inodes per group */
    524 	__u32	s_mtime;		/* Mount time */
    525 	__u32	s_wtime;		/* Write time */
    526 	__u16	s_mnt_count;		/* Mount count */
    527 	__s16	s_max_mnt_count;	/* Maximal mount count */
    528 	__u16	s_magic;		/* Magic signature */
    529 	__u16	s_state;		/* File system state */
    530 	__u16	s_errors;		/* Behaviour when detecting errors */
    531 	__u16	s_minor_rev_level;	/* minor revision level */
    532 	__u32	s_lastcheck;		/* time of last check */
    533 	__u32	s_checkinterval;	/* max. time between checks */
    534 	__u32	s_creator_os;		/* OS */
    535 	__u32	s_rev_level;		/* Revision level */
    536 	__u16	s_def_resuid;		/* Default uid for reserved blocks */
    537 	__u16	s_def_resgid;		/* Default gid for reserved blocks */
    538 	/*
    539 	 * These fields are for EXT2_DYNAMIC_REV superblocks only.
    540 	 *
    541 	 * Note: the difference between the compatible feature set and
    542 	 * the incompatible feature set is that if there is a bit set
    543 	 * in the incompatible feature set that the kernel doesn't
    544 	 * know about, it should refuse to mount the filesystem.
    545 	 *
    546 	 * e2fsck's requirements are more strict; if it doesn't know
    547 	 * about a feature in either the compatible or incompatible
    548 	 * feature set, it must abort and not try to meddle with
    549 	 * things it doesn't understand...
    550 	 */
    551 	__u32	s_first_ino;		/* First non-reserved inode */
    552 	__u16   s_inode_size;		/* size of inode structure */
    553 	__u16	s_block_group_nr;	/* block group # of this superblock */
    554 	__u32	s_feature_compat;	/* compatible feature set */
    555 	__u32	s_feature_incompat;	/* incompatible feature set */
    556 	__u32	s_feature_ro_compat;	/* readonly-compatible feature set */
    557 	__u8	s_uuid[16];		/* 128-bit uuid for volume */
    558 	char	s_volume_name[16];	/* volume name */
    559 	char	s_last_mounted[64];	/* directory where last mounted */
    560 	__u32	s_algorithm_usage_bitmap; /* For compression */
    561 	/*
    562 	 * Performance hints.  Directory preallocation should only
    563 	 * happen if the EXT2_FEATURE_COMPAT_DIR_PREALLOC flag is on.
    564 	 */
    565 	__u8	s_prealloc_blocks;	/* Nr of blocks to try to preallocate*/
    566 	__u8	s_prealloc_dir_blocks;	/* Nr to preallocate for dirs */
    567 	__u16	s_reserved_gdt_blocks;	/* Per group table for online growth */
    568 	/*
    569 	 * Journaling support valid if EXT2_FEATURE_COMPAT_HAS_JOURNAL set.
    570 	 */
    571 	__u8	s_journal_uuid[16];	/* uuid of journal superblock */
    572 	__u32	s_journal_inum;		/* inode number of journal file */
    573 	__u32	s_journal_dev;		/* device number of journal file */
    574 	__u32	s_last_orphan;		/* start of list of inodes to delete */
    575 	__u32	s_hash_seed[4];		/* HTREE hash seed */
    576 	__u8	s_def_hash_version;	/* Default hash version to use */
    577 	__u8	s_jnl_backup_type; 	/* Default type of journal backup */
    578 	__u16	s_desc_size;		/* Group desc. size: INCOMPAT_64BIT */
    579 	__u32	s_default_mount_opts;
    580 	__u32	s_first_meta_bg;	/* First metablock group */
    581 	__u32	s_mkfs_time;		/* When the filesystem was created */
    582 	__u32	s_jnl_blocks[17]; 	/* Backup of the journal inode */
    583 	__u32	s_blocks_count_hi;	/* Blocks count high 32bits */
    584 	__u32	s_r_blocks_count_hi;	/* Reserved blocks count high 32 bits*/
    585 	__u32	s_free_blocks_hi; 	/* Free blocks count */
    586 	__u16	s_min_extra_isize;	/* All inodes have at least # bytes */
    587 	__u16	s_want_extra_isize; 	/* New inodes should reserve # bytes */
    588 	__u32	s_flags;		/* Miscellaneous flags */
    589 	__u16   s_raid_stride;		/* RAID stride */
    590 	__u16   s_mmp_interval;         /* # seconds to wait in MMP checking */
    591 	__u64   s_mmp_block;            /* Block for multi-mount protection */
    592 	__u32   s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
    593 	__u32   s_reserved[163];        /* Padding to the end of the block */
    594 };
    595 
    596 /*
    597  * Codes for operating systems
    598  */
    599 #define EXT2_OS_LINUX		0
    600 #define EXT2_OS_HURD		1
    601 #define EXT2_OS_MASIX		2
    602 #define EXT2_OS_FREEBSD		3
    603 #define EXT2_OS_LITES		4
    604 
    605 /*
    606  * Revision levels
    607  */
    608 #define EXT2_GOOD_OLD_REV	0	/* The good old (original) format */
    609 #define EXT2_DYNAMIC_REV	1	/* V2 format w/ dynamic inode sizes */
    610 
    611 #define EXT2_CURRENT_REV	EXT2_GOOD_OLD_REV
    612 #define EXT2_MAX_SUPP_REV	EXT2_DYNAMIC_REV
    613 
    614 #define EXT2_GOOD_OLD_INODE_SIZE 128
    615 
    616 /*
    617  * Journal inode backup types
    618  */
    619 #define EXT3_JNL_BACKUP_BLOCKS	1
    620 
    621 /*
    622  * Feature set definitions
    623  */
    624 
    625 #define EXT2_HAS_COMPAT_FEATURE(sb,mask)			\
    626 	( EXT2_SB(sb)->s_feature_compat & (mask) )
    627 #define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask)			\
    628 	( EXT2_SB(sb)->s_feature_ro_compat & (mask) )
    629 #define EXT2_HAS_INCOMPAT_FEATURE(sb,mask)			\
    630 	( EXT2_SB(sb)->s_feature_incompat & (mask) )
    631 
    632 #define EXT2_FEATURE_COMPAT_DIR_PREALLOC	0x0001
    633 #define EXT2_FEATURE_COMPAT_IMAGIC_INODES	0x0002
    634 #define EXT3_FEATURE_COMPAT_HAS_JOURNAL		0x0004
    635 #define EXT2_FEATURE_COMPAT_EXT_ATTR		0x0008
    636 #define EXT2_FEATURE_COMPAT_RESIZE_INODE	0x0010
    637 #define EXT2_FEATURE_COMPAT_DIR_INDEX		0x0020
    638 #define EXT2_FEATURE_COMPAT_LAZY_BG		0x0040
    639 
    640 #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
    641 #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
    642 /* #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR	0x0004 not used */
    643 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE	0x0008
    644 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM		0x0010
    645 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK	0x0020
    646 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE	0x0040
    647 
    648 #define EXT2_FEATURE_INCOMPAT_COMPRESSION	0x0001
    649 #define EXT2_FEATURE_INCOMPAT_FILETYPE		0x0002
    650 #define EXT3_FEATURE_INCOMPAT_RECOVER		0x0004 /* Needs recovery */
    651 #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008 /* Journal device */
    652 #define EXT2_FEATURE_INCOMPAT_META_BG		0x0010
    653 #define EXT3_FEATURE_INCOMPAT_EXTENTS		0x0040
    654 #define EXT4_FEATURE_INCOMPAT_64BIT		0x0080
    655 #define EXT4_FEATURE_INCOMPAT_MMP		0x0100
    656 
    657 
    658 #define EXT2_FEATURE_COMPAT_SUPP	0
    659 #define EXT2_FEATURE_INCOMPAT_SUPP	(EXT2_FEATURE_INCOMPAT_FILETYPE)
    660 #define EXT2_FEATURE_RO_COMPAT_SUPP	(EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
    661 					 EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
    662 					 EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
    663 
    664 /*
    665  * Default values for user and/or group using reserved blocks
    666  */
    667 #define EXT2_DEF_RESUID		0
    668 #define EXT2_DEF_RESGID		0
    669 
    670 /*
    671  * Default mount options
    672  */
    673 #define EXT2_DEFM_DEBUG		0x0001
    674 #define EXT2_DEFM_BSDGROUPS	0x0002
    675 #define EXT2_DEFM_XATTR_USER	0x0004
    676 #define EXT2_DEFM_ACL		0x0008
    677 #define EXT2_DEFM_UID16		0x0010
    678 #define EXT3_DEFM_JMODE		0x0060
    679 #define EXT3_DEFM_JMODE_DATA	0x0020
    680 #define EXT3_DEFM_JMODE_ORDERED	0x0040
    681 #define EXT3_DEFM_JMODE_WBACK	0x0060
    682 
    683 /*
    684  * Structure of a directory entry
    685  */
    686 #define EXT2_NAME_LEN 255
    687 
    688 struct ext2_dir_entry {
    689 	__u32	inode;			/* Inode number */
    690 	__u16	rec_len;		/* Directory entry length */
    691 	__u16	name_len;		/* Name length */
    692 	char	name[EXT2_NAME_LEN];	/* File name */
    693 };
    694 
    695 /*
    696  * The new version of the directory entry.  Since EXT2 structures are
    697  * stored in intel byte order, and the name_len field could never be
    698  * bigger than 255 chars, it's safe to reclaim the extra byte for the
    699  * file_type field.
    700  */
    701 struct ext2_dir_entry_2 {
    702 	__u32	inode;			/* Inode number */
    703 	__u16	rec_len;		/* Directory entry length */
    704 	__u8	name_len;		/* Name length */
    705 	__u8	file_type;
    706 	char	name[EXT2_NAME_LEN];	/* File name */
    707 };
    708 
    709 /*
    710  * Ext2 directory file types.  Only the low 3 bits are used.  The
    711  * other bits are reserved for now.
    712  */
    713 #define EXT2_FT_UNKNOWN		0
    714 #define EXT2_FT_REG_FILE	1
    715 #define EXT2_FT_DIR		2
    716 #define EXT2_FT_CHRDEV		3
    717 #define EXT2_FT_BLKDEV		4
    718 #define EXT2_FT_FIFO		5
    719 #define EXT2_FT_SOCK		6
    720 #define EXT2_FT_SYMLINK		7
    721 
    722 #define EXT2_FT_MAX		8
    723 
    724 /*
    725  * EXT2_DIR_PAD defines the directory entries boundaries
    726  *
    727  * NOTE: It must be a multiple of 4
    728  */
    729 #define EXT2_DIR_PAD			4
    730 #define EXT2_DIR_ROUND			(EXT2_DIR_PAD - 1)
    731 #define EXT2_DIR_REC_LEN(name_len)	(((name_len) + 8 + EXT2_DIR_ROUND) & \
    732 					 ~EXT2_DIR_ROUND)
    733 
    734 /*
    735  * This structure will be used for multiple mount protection. It will be
    736  * written into the block number saved in the s_mmp_block field in the
    737  * superblock.
    738  */
    739 #define	EXT2_MMP_MAGIC    0x004D4D50 /* ASCII for MMP */
    740 #define	EXT2_MMP_CLEAN    0xFF4D4D50 /* Value of mmp_seq for clean unmount */
    741 #define	EXT2_MMP_FSCK_ON  0xE24D4D50 /* Value of mmp_seq when being fscked */
    742 
    743 struct mmp_struct {
    744 	__u32	mmp_magic;
    745 	__u32	mmp_seq;
    746 	__u64	mmp_time;
    747 	char	mmp_nodename[64];
    748 	char	mmp_bdevname[32];
    749 	__u16	mmp_interval;
    750 	__u16	mmp_pad1;
    751 	__u32	mmp_pad2;
    752 };
    753 
    754 /*
    755  * Interval in number of seconds to update the MMP sequence number.
    756  */
    757 #define EXT2_MMP_DEF_INTERVAL	5
    758 
    759 #endif	/* _LINUX_EXT2_FS_H */
    760