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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 EXT4_USR_QUOTA_INO	 3	/* User quota inode */
     48 #define EXT4_GRP_QUOTA_INO	 4	/* Group quota 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 #define EXT2_EXCLUDE_INO	 9	/* The "exclude" inode, for snapshots */
     54 #define EXT4_REPLICA_INO	10	/* Used by non-upstream feature */
     55 
     56 /* First non-reserved inode for old ext2 filesystems */
     57 #define EXT2_GOOD_OLD_FIRST_INO	11
     58 
     59 /*
     60  * The second extended file system magic number
     61  */
     62 #define EXT2_SUPER_MAGIC	0xEF53
     63 
     64 #ifdef __KERNEL__
     65 #define EXT2_SB(sb)	(&((sb)->u.ext2_sb))
     66 #else
     67 /* Assume that user mode programs are passing in an ext2fs superblock, not
     68  * a kernel struct super_block.  This will allow us to call the feature-test
     69  * macros from user land. */
     70 #define EXT2_SB(sb)	(sb)
     71 #endif
     72 
     73 /*
     74  * Maximal count of links to a file
     75  */
     76 #define EXT2_LINK_MAX		65000
     77 
     78 /*
     79  * Macro-instructions used to manage several block sizes
     80  */
     81 #define EXT2_MIN_BLOCK_LOG_SIZE		10	/* 1024 */
     82 #define EXT2_MAX_BLOCK_LOG_SIZE		16	/* 65536 */
     83 #define EXT2_MIN_BLOCK_SIZE	(1 << EXT2_MIN_BLOCK_LOG_SIZE)
     84 #define EXT2_MAX_BLOCK_SIZE	(1 << EXT2_MAX_BLOCK_LOG_SIZE)
     85 #ifdef __KERNEL__
     86 #define EXT2_BLOCK_SIZE(s)	((s)->s_blocksize)
     87 #define EXT2_BLOCK_SIZE_BITS(s)	((s)->s_blocksize_bits)
     88 #define EXT2_ADDR_PER_BLOCK_BITS(s)	(EXT2_SB(s)->addr_per_block_bits)
     89 #define EXT2_INODE_SIZE(s)	(EXT2_SB(s)->s_inode_size)
     90 #define EXT2_FIRST_INO(s)	(EXT2_SB(s)->s_first_ino)
     91 #else
     92 #define EXT2_BLOCK_SIZE(s)	(EXT2_MIN_BLOCK_SIZE << (s)->s_log_block_size)
     93 #define EXT2_BLOCK_SIZE_BITS(s)	((s)->s_log_block_size + 10)
     94 #define EXT2_INODE_SIZE(s)	(((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
     95 				 EXT2_GOOD_OLD_INODE_SIZE : (s)->s_inode_size)
     96 #define EXT2_FIRST_INO(s)	(((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
     97 				 EXT2_GOOD_OLD_FIRST_INO : (s)->s_first_ino)
     98 #endif
     99 #define EXT2_ADDR_PER_BLOCK(s)	(EXT2_BLOCK_SIZE(s) / sizeof(__u32))
    100 
    101 /*
    102  * Macro-instructions used to manage allocation clusters
    103  */
    104 #define EXT2_MIN_CLUSTER_LOG_SIZE	EXT2_MIN_BLOCK_LOG_SIZE
    105 #define EXT2_MAX_CLUSTER_LOG_SIZE	29	/* 512MB  */
    106 #define EXT2_MIN_CLUSTER_SIZE		EXT2_MIN_BLOCK_SIZE
    107 #define EXT2_MAX_CLUSTER_SIZE		(1 << EXT2_MAX_CLUSTER_LOG_SIZE)
    108 #define EXT2_CLUSTER_SIZE(s)		(EXT2_MIN_BLOCK_SIZE << \
    109 						(s)->s_log_cluster_size)
    110 #define EXT2_CLUSTER_SIZE_BITS(s)	((s)->s_log_cluster_size + 10)
    111 
    112 /*
    113  * Macro-instructions used to manage fragments
    114  *
    115  * Note: for backwards compatibility only, for the dump program.
    116  * Ext2/3/4 will never support fragments....
    117  */
    118 #define EXT2_MIN_FRAG_SIZE              EXT2_MIN_BLOCK_SIZE
    119 #define EXT2_MAX_FRAG_SIZE              EXT2_MAX_BLOCK_SIZE
    120 #define EXT2_MIN_FRAG_LOG_SIZE          EXT2_MIN_BLOCK_LOG_SIZE
    121 #define EXT2_FRAG_SIZE(s)		EXT2_BLOCK_SIZE(s)
    122 #define EXT2_FRAGS_PER_BLOCK(s)		1
    123 
    124 /*
    125  * ACL structures
    126  */
    127 struct ext2_acl_header	/* Header of Access Control Lists */
    128 {
    129 	__u32	aclh_size;
    130 	__u32	aclh_file_count;
    131 	__u32	aclh_acle_count;
    132 	__u32	aclh_first_acle;
    133 };
    134 
    135 struct ext2_acl_entry	/* Access Control List Entry */
    136 {
    137 	__u32	acle_size;
    138 	__u16	acle_perms;	/* Access permissions */
    139 	__u16	acle_type;	/* Type of entry */
    140 	__u16	acle_tag;	/* User or group identity */
    141 	__u16	acle_pad1;
    142 	__u32	acle_next;	/* Pointer on next entry for the */
    143 					/* same inode or on next free entry */
    144 };
    145 
    146 /*
    147  * Structure of a blocks group descriptor
    148  */
    149 struct ext2_group_desc
    150 {
    151 	__u32	bg_block_bitmap;	/* Blocks bitmap block */
    152 	__u32	bg_inode_bitmap;	/* Inodes bitmap block */
    153 	__u32	bg_inode_table;		/* Inodes table block */
    154 	__u16	bg_free_blocks_count;	/* Free blocks count */
    155 	__u16	bg_free_inodes_count;	/* Free inodes count */
    156 	__u16	bg_used_dirs_count;	/* Directories count */
    157 	__u16	bg_flags;
    158 	__u32	bg_exclude_bitmap_lo;	/* Exclude bitmap for snapshots */
    159 	__u16	bg_block_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+bitmap) LSB */
    160 	__u16	bg_inode_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+bitmap) LSB */
    161 	__u16	bg_itable_unused;	/* Unused inodes count */
    162 	__u16	bg_checksum;		/* crc16(s_uuid+group_num+group_desc)*/
    163 };
    164 
    165 /*
    166  * Structure of a blocks group descriptor
    167  */
    168 struct ext4_group_desc
    169 {
    170 	__u32	bg_block_bitmap;	/* Blocks bitmap block */
    171 	__u32	bg_inode_bitmap;	/* Inodes bitmap block */
    172 	__u32	bg_inode_table;		/* Inodes table block */
    173 	__u16	bg_free_blocks_count;	/* Free blocks count */
    174 	__u16	bg_free_inodes_count;	/* Free inodes count */
    175 	__u16	bg_used_dirs_count;	/* Directories count */
    176 	__u16	bg_flags;		/* EXT4_BG_flags (INODE_UNINIT, etc) */
    177 	__u32	bg_exclude_bitmap_lo;	/* Exclude bitmap for snapshots */
    178 	__u16	bg_block_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+bitmap) LSB */
    179 	__u16	bg_inode_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+bitmap) LSB */
    180 	__u16	bg_itable_unused;	/* Unused inodes count */
    181 	__u16	bg_checksum;		/* crc16(sb_uuid+group+desc) */
    182 	__u32	bg_block_bitmap_hi;	/* Blocks bitmap block MSB */
    183 	__u32	bg_inode_bitmap_hi;	/* Inodes bitmap block MSB */
    184 	__u32	bg_inode_table_hi;	/* Inodes table block MSB */
    185 	__u16	bg_free_blocks_count_hi;/* Free blocks count MSB */
    186 	__u16	bg_free_inodes_count_hi;/* Free inodes count MSB */
    187 	__u16	bg_used_dirs_count_hi;	/* Directories count MSB */
    188 	__u16	bg_itable_unused_hi;	/* Unused inodes count MSB */
    189 	__u32	bg_exclude_bitmap_hi;	/* Exclude bitmap block MSB */
    190 	__u16	bg_block_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+bitmap) MSB */
    191 	__u16	bg_inode_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+bitmap) MSB */
    192 	__u32	bg_reserved;
    193 };
    194 
    195 #define EXT4_BG_INODE_BITMAP_CSUM_HI_END	\
    196 	(offsetof(struct ext4_group_desc, bg_inode_bitmap_csum_hi) + \
    197 	 sizeof(__u16))
    198 #define EXT4_BG_BLOCK_BITMAP_CSUM_HI_LOCATION	\
    199 	(offsetof(struct ext4_group_desc, bg_block_bitmap_csum_hi) + \
    200 	 sizeof(__u16))
    201 
    202 #define EXT2_BG_INODE_UNINIT	0x0001 /* Inode table/bitmap not initialized */
    203 #define EXT2_BG_BLOCK_UNINIT	0x0002 /* Block bitmap not initialized */
    204 #define EXT2_BG_INODE_ZEROED	0x0004 /* On-disk itable initialized to zero */
    205 
    206 /*
    207  * Data structures used by the directory indexing feature
    208  *
    209  * Note: all of the multibyte integer fields are little endian.
    210  */
    211 
    212 /*
    213  * Note: dx_root_info is laid out so that if it should somehow get
    214  * overlaid by a dirent the two low bits of the hash version will be
    215  * zero.  Therefore, the hash version mod 4 should never be 0.
    216  * Sincerely, the paranoia department.
    217  */
    218 struct ext2_dx_root_info {
    219 	__u32 reserved_zero;
    220 	__u8 hash_version; /* 0 now, 1 at release */
    221 	__u8 info_length; /* 8 */
    222 	__u8 indirect_levels;
    223 	__u8 unused_flags;
    224 };
    225 
    226 #define EXT2_HASH_LEGACY		0
    227 #define EXT2_HASH_HALF_MD4		1
    228 #define EXT2_HASH_TEA			2
    229 #define EXT2_HASH_LEGACY_UNSIGNED	3 /* reserved for userspace lib */
    230 #define EXT2_HASH_HALF_MD4_UNSIGNED	4 /* reserved for userspace lib */
    231 #define EXT2_HASH_TEA_UNSIGNED		5 /* reserved for userspace lib */
    232 
    233 #define EXT2_HASH_FLAG_INCOMPAT	0x1
    234 
    235 struct ext2_dx_entry {
    236 	__le32 hash;
    237 	__le32 block;
    238 };
    239 
    240 struct ext2_dx_countlimit {
    241 	__le16 limit;
    242 	__le16 count;
    243 };
    244 
    245 /*
    246  * This goes at the end of each htree block.
    247  */
    248 struct ext2_dx_tail {
    249 	__le32 dt_reserved;
    250 	__le32 dt_checksum;	/* crc32c(uuid+inum+dxblock) */
    251 };
    252 
    253 /*
    254  * Macro-instructions used to manage group descriptors
    255  */
    256 #define EXT2_MIN_DESC_SIZE             32
    257 #define EXT2_MIN_DESC_SIZE_64BIT       64
    258 #define EXT2_MAX_DESC_SIZE             EXT2_MIN_BLOCK_SIZE
    259 #define EXT2_DESC_SIZE(s)                                                \
    260        ((EXT2_SB(s)->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT) ? \
    261 	(s)->s_desc_size : EXT2_MIN_DESC_SIZE)
    262 
    263 #define EXT2_BLOCKS_PER_GROUP(s)	(EXT2_SB(s)->s_blocks_per_group)
    264 #define EXT2_INODES_PER_GROUP(s)	(EXT2_SB(s)->s_inodes_per_group)
    265 #define EXT2_CLUSTERS_PER_GROUP(s)	(EXT2_SB(s)->s_clusters_per_group)
    266 #define EXT2_INODES_PER_BLOCK(s)	(EXT2_BLOCK_SIZE(s)/EXT2_INODE_SIZE(s))
    267 /* limits imposed by 16-bit value gd_free_{blocks,inode}_count */
    268 #define EXT2_MAX_BLOCKS_PER_GROUP(s)	((((unsigned) 1 << 16) - 8) *	\
    269 					 (EXT2_CLUSTER_SIZE(s) / \
    270 					  EXT2_BLOCK_SIZE(s)))
    271 #define EXT2_MAX_CLUSTERS_PER_GROUP(s)	(((unsigned) 1 << 16) - 8)
    272 #define EXT2_MAX_INODES_PER_GROUP(s)	(((unsigned) 1 << 16) - \
    273 					 EXT2_INODES_PER_BLOCK(s))
    274 #ifdef __KERNEL__
    275 #define EXT2_DESC_PER_BLOCK(s)		(EXT2_SB(s)->s_desc_per_block)
    276 #define EXT2_DESC_PER_BLOCK_BITS(s)	(EXT2_SB(s)->s_desc_per_block_bits)
    277 #else
    278 #define EXT2_DESC_PER_BLOCK(s)		(EXT2_BLOCK_SIZE(s) / EXT2_DESC_SIZE(s))
    279 #endif
    280 
    281 #define EXT2_GROUPS_TO_BLOCKS(s, g)   ((blk64_t) EXT2_BLOCKS_PER_GROUP(s) * \
    282 				       (g))
    283 #define EXT2_GROUPS_TO_CLUSTERS(s, g) ((blk64_t) EXT2_CLUSTERS_PER_GROUP(s) * \
    284 				       (g))
    285 
    286 /*
    287  * Constants relative to the data blocks
    288  */
    289 #define EXT2_NDIR_BLOCKS		12
    290 #define EXT2_IND_BLOCK			EXT2_NDIR_BLOCKS
    291 #define EXT2_DIND_BLOCK			(EXT2_IND_BLOCK + 1)
    292 #define EXT2_TIND_BLOCK			(EXT2_DIND_BLOCK + 1)
    293 #define EXT2_N_BLOCKS			(EXT2_TIND_BLOCK + 1)
    294 
    295 /*
    296  * Inode flags
    297  */
    298 #define EXT2_SECRM_FL			0x00000001 /* Secure deletion */
    299 #define EXT2_UNRM_FL			0x00000002 /* Undelete */
    300 #define EXT2_COMPR_FL			0x00000004 /* Compress file */
    301 #define EXT2_SYNC_FL			0x00000008 /* Synchronous updates */
    302 #define EXT2_IMMUTABLE_FL		0x00000010 /* Immutable file */
    303 #define EXT2_APPEND_FL			0x00000020 /* writes to file may only append */
    304 #define EXT2_NODUMP_FL			0x00000040 /* do not dump file */
    305 #define EXT2_NOATIME_FL			0x00000080 /* do not update atime */
    306 /* Reserved for compression usage... */
    307 #define EXT2_DIRTY_FL			0x00000100
    308 #define EXT2_COMPRBLK_FL		0x00000200 /* One or more compressed clusters */
    309 #define EXT2_NOCOMPR_FL			0x00000400 /* Access raw compressed data */
    310 	/* nb: was previously EXT2_ECOMPR_FL */
    311 #define EXT4_ENCRYPT_FL			0x00000800 /* encrypted inode */
    312 /* End compression flags --- maybe not all used */
    313 #define EXT2_BTREE_FL			0x00001000 /* btree format dir */
    314 #define EXT2_INDEX_FL			0x00001000 /* hash-indexed directory */
    315 #define EXT2_IMAGIC_FL			0x00002000
    316 #define EXT3_JOURNAL_DATA_FL		0x00004000 /* file data should be journaled */
    317 #define EXT2_NOTAIL_FL			0x00008000 /* file tail should not be merged */
    318 #define EXT2_DIRSYNC_FL 		0x00010000 /* Synchronous directory modifications */
    319 #define EXT2_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/
    320 #define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
    321 #define EXT4_EXTENTS_FL 		0x00080000 /* Inode uses extents */
    322 #define EXT4_EA_INODE_FL	        0x00200000 /* Inode used for large EA */
    323 /* EXT4_EOFBLOCKS_FL 0x00400000 was here */
    324 #define FS_NOCOW_FL			0x00800000 /* Do not cow file */
    325 #define EXT4_SNAPFILE_FL		0x01000000  /* Inode is a snapshot */
    326 #define EXT4_SNAPFILE_DELETED_FL	0x04000000  /* Snapshot is being deleted */
    327 #define EXT4_SNAPFILE_SHRUNK_FL		0x08000000  /* Snapshot shrink has completed */
    328 #define EXT4_INLINE_DATA_FL		0x10000000 /* Inode has inline data */
    329 #define EXT4_PROJINHERIT_FL		0x20000000 /* Create with parents projid */
    330 #define EXT2_RESERVED_FL		0x80000000 /* reserved for ext2 lib */
    331 
    332 #define EXT2_FL_USER_VISIBLE		0x204BDFFF /* User visible flags */
    333 #define EXT2_FL_USER_MODIFIABLE		0x204B80FF /* User modifiable flags */
    334 
    335 /*
    336  * ioctl commands
    337  */
    338 
    339 /* Used for online resize */
    340 struct ext2_new_group_input {
    341 	__u32 group;		/* Group number for this data */
    342 	__u32 block_bitmap;	/* Absolute block number of block bitmap */
    343 	__u32 inode_bitmap;	/* Absolute block number of inode bitmap */
    344 	__u32 inode_table;	/* Absolute block number of inode table start */
    345 	__u32 blocks_count;	/* Total number of blocks in this group */
    346 	__u16 reserved_blocks;	/* Number of reserved blocks in this group */
    347 	__u16 unused;		/* Number of reserved GDT blocks in group */
    348 };
    349 
    350 struct ext4_new_group_input {
    351 	__u32 group;		/* Group number for this data */
    352 	__u64 block_bitmap;	/* Absolute block number of block bitmap */
    353 	__u64 inode_bitmap;	/* Absolute block number of inode bitmap */
    354 	__u64 inode_table;	/* Absolute block number of inode table start */
    355 	__u32 blocks_count;	/* Total number of blocks in this group */
    356 	__u16 reserved_blocks;	/* Number of reserved blocks in this group */
    357 	__u16 unused;
    358 };
    359 
    360 #ifdef __GNU__			/* Needed for the Hurd */
    361 #define _IOT_ext2_new_group_input _IOT (_IOTS(__u32), 5, _IOTS(__u16), 2, 0, 0)
    362 #endif
    363 
    364 #define EXT2_IOC_GETFLAGS		_IOR('f', 1, long)
    365 #define EXT2_IOC_SETFLAGS		_IOW('f', 2, long)
    366 #define EXT2_IOC_GETVERSION		_IOR('v', 1, long)
    367 #define EXT2_IOC_SETVERSION		_IOW('v', 2, long)
    368 #define EXT2_IOC_GETVERSION_NEW		_IOR('f', 3, long)
    369 #define EXT2_IOC_SETVERSION_NEW		_IOW('f', 4, long)
    370 #define EXT2_IOC_GROUP_EXTEND		_IOW('f', 7, unsigned long)
    371 #define EXT2_IOC_GROUP_ADD		_IOW('f', 8,struct ext2_new_group_input)
    372 #define EXT4_IOC_GROUP_ADD		_IOW('f', 8,struct ext4_new_group_input)
    373 #define EXT4_IOC_RESIZE_FS		_IOW('f', 16, __u64)
    374 
    375 /*
    376  * Structure of an inode on the disk
    377  */
    378 struct ext2_inode {
    379 	__u16	i_mode;		/* File mode */
    380 	__u16	i_uid;		/* Low 16 bits of Owner Uid */
    381 	__u32	i_size;		/* Size in bytes */
    382 	__u32	i_atime;	/* Access time */
    383 	__u32	i_ctime;	/* Inode change time */
    384 	__u32	i_mtime;	/* Modification time */
    385 	__u32	i_dtime;	/* Deletion Time */
    386 	__u16	i_gid;		/* Low 16 bits of Group Id */
    387 	__u16	i_links_count;	/* Links count */
    388 	__u32	i_blocks;	/* Blocks count */
    389 	__u32	i_flags;	/* File flags */
    390 	union {
    391 		struct {
    392 			__u32	l_i_version; /* was l_i_reserved1 */
    393 		} linux1;
    394 		struct {
    395 			__u32  h_i_translator;
    396 		} hurd1;
    397 	} osd1;				/* OS dependent 1 */
    398 	__u32	i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
    399 	__u32	i_generation;	/* File version (for NFS) */
    400 	__u32	i_file_acl;	/* File ACL */
    401 	__u32	i_size_high;	/* Formerly i_dir_acl, directory ACL */
    402 	__u32	i_faddr;	/* Fragment address */
    403 	union {
    404 		struct {
    405 			__u16	l_i_blocks_hi;
    406 			__u16	l_i_file_acl_high;
    407 			__u16	l_i_uid_high;	/* these 2 fields    */
    408 			__u16	l_i_gid_high;	/* were reserved2[0] */
    409 			__u16	l_i_checksum_lo; /* crc32c(uuid+inum+inode) */
    410 			__u16	l_i_reserved;
    411 		} linux2;
    412 		struct {
    413 			__u8	h_i_frag;	/* Fragment number */
    414 			__u8	h_i_fsize;	/* Fragment size */
    415 			__u16	h_i_mode_high;
    416 			__u16	h_i_uid_high;
    417 			__u16	h_i_gid_high;
    418 			__u32	h_i_author;
    419 		} hurd2;
    420 	} osd2;				/* OS dependent 2 */
    421 };
    422 
    423 /*
    424  * Permanent part of an large inode on the disk
    425  */
    426 struct ext2_inode_large {
    427 	__u16	i_mode;		/* File mode */
    428 	__u16	i_uid;		/* Low 16 bits of Owner Uid */
    429 	__u32	i_size;		/* Size in bytes */
    430 	__u32	i_atime;	/* Access time */
    431 	__u32	i_ctime;	/* Inode Change time */
    432 	__u32	i_mtime;	/* Modification time */
    433 	__u32	i_dtime;	/* Deletion Time */
    434 	__u16	i_gid;		/* Low 16 bits of Group Id */
    435 	__u16	i_links_count;	/* Links count */
    436 	__u32	i_blocks;	/* Blocks count */
    437 	__u32	i_flags;	/* File flags */
    438 	union {
    439 		struct {
    440 			__u32	l_i_version; /* was l_i_reserved1 */
    441 		} linux1;
    442 		struct {
    443 			__u32  h_i_translator;
    444 		} hurd1;
    445 	} osd1;				/* OS dependent 1 */
    446 	__u32	i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
    447 	__u32	i_generation;	/* File version (for NFS) */
    448 	__u32	i_file_acl;	/* File ACL */
    449 	__u32	i_size_high;	/* Formerly i_dir_acl, directory ACL */
    450 	__u32	i_faddr;	/* Fragment address */
    451 	union {
    452 		struct {
    453 			__u16	l_i_blocks_hi;
    454 			__u16	l_i_file_acl_high;
    455 			__u16	l_i_uid_high;	/* these 2 fields    */
    456 			__u16	l_i_gid_high;	/* were reserved2[0] */
    457 			__u16	l_i_checksum_lo; /* crc32c(uuid+inum+inode) */
    458 			__u16	l_i_reserved;
    459 		} linux2;
    460 		struct {
    461 			__u8	h_i_frag;	/* Fragment number */
    462 			__u8	h_i_fsize;	/* Fragment size */
    463 			__u16	h_i_mode_high;
    464 			__u16	h_i_uid_high;
    465 			__u16	h_i_gid_high;
    466 			__u32	h_i_author;
    467 		} hurd2;
    468 	} osd2;				/* OS dependent 2 */
    469 	__u16	i_extra_isize;
    470 	__u16	i_checksum_hi;	/* crc32c(uuid+inum+inode) */
    471 	__u32	i_ctime_extra;	/* extra Change time (nsec << 2 | epoch) */
    472 	__u32	i_mtime_extra;	/* extra Modification time (nsec << 2 | epoch) */
    473 	__u32	i_atime_extra;	/* extra Access time (nsec << 2 | epoch) */
    474 	__u32	i_crtime;	/* File creation time */
    475 	__u32	i_crtime_extra;	/* extra File creation time (nsec << 2 | epoch)*/
    476 	__u32	i_version_hi;	/* high 32 bits for 64-bit version */
    477 	__u32   i_projid;       /* Project ID */
    478 };
    479 
    480 #define EXT4_INODE_CSUM_HI_EXTRA_END	\
    481 	(offsetof(struct ext2_inode_large, i_checksum_hi) + sizeof(__u16) - \
    482 	 EXT2_GOOD_OLD_INODE_SIZE)
    483 
    484 #define EXT4_EPOCH_BITS 2
    485 #define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
    486 
    487 #define i_dir_acl	i_size_high
    488 
    489 #define i_checksum_lo	osd2.linux2.l_i_checksum_lo
    490 
    491 #define inode_includes(size, field)			\
    492        (size >= (sizeof(((struct ext2_inode_large *)0)->field) + \
    493                  offsetof(struct ext2_inode_large, field)))
    494 
    495 #if defined(__KERNEL__) || defined(__linux__)
    496 #define i_reserved1	osd1.linux1.l_i_reserved1
    497 #define i_frag		osd2.linux2.l_i_frag
    498 #define i_fsize		osd2.linux2.l_i_fsize
    499 #define i_uid_low	i_uid
    500 #define i_gid_low	i_gid
    501 #define i_uid_high	osd2.linux2.l_i_uid_high
    502 #define i_gid_high	osd2.linux2.l_i_gid_high
    503 #else
    504 #if defined(__GNU__)
    505 
    506 #define i_translator	osd1.hurd1.h_i_translator
    507 #define i_frag		osd2.hurd2.h_i_frag;
    508 #define i_fsize		osd2.hurd2.h_i_fsize;
    509 #define i_uid_high	osd2.hurd2.h_i_uid_high
    510 #define i_gid_high	osd2.hurd2.h_i_gid_high
    511 #define i_author	osd2.hurd2.h_i_author
    512 
    513 #endif  /* __GNU__ */
    514 #endif	/* defined(__KERNEL__) || defined(__linux__) */
    515 
    516 #define inode_uid(inode)	((inode).i_uid | (inode).osd2.linux2.l_i_uid_high << 16)
    517 #define inode_gid(inode)	((inode).i_gid | (inode).osd2.linux2.l_i_gid_high << 16)
    518 #define inode_projid(inode)	((inode).i_projid)
    519 #define ext2fs_set_i_uid_high(inode,x) ((inode).osd2.linux2.l_i_uid_high = (x))
    520 #define ext2fs_set_i_gid_high(inode,x) ((inode).osd2.linux2.l_i_gid_high = (x))
    521 
    522 static inline
    523 struct ext2_inode *EXT2_INODE(struct ext2_inode_large *large_inode)
    524 {
    525 	return (struct ext2_inode *) large_inode;
    526 }
    527 
    528 /*
    529  * File system states
    530  */
    531 #define EXT2_VALID_FS			0x0001	/* Unmounted cleanly */
    532 #define EXT2_ERROR_FS			0x0002	/* Errors detected */
    533 #define EXT3_ORPHAN_FS			0x0004	/* Orphans being recovered */
    534 
    535 /*
    536  * Misc. filesystem flags
    537  */
    538 #define EXT2_FLAGS_SIGNED_HASH		0x0001  /* Signed dirhash in use */
    539 #define EXT2_FLAGS_UNSIGNED_HASH	0x0002  /* Unsigned dirhash in use */
    540 #define EXT2_FLAGS_TEST_FILESYS		0x0004	/* OK for use on development code */
    541 #define EXT2_FLAGS_IS_SNAPSHOT		0x0010	/* This is a snapshot image */
    542 #define EXT2_FLAGS_FIX_SNAPSHOT		0x0020	/* Snapshot inodes corrupted */
    543 #define EXT2_FLAGS_FIX_EXCLUDE		0x0040	/* Exclude bitmaps corrupted */
    544 
    545 /*
    546  * Mount flags
    547  */
    548 #define EXT2_MOUNT_CHECK		0x0001	/* Do mount-time checks */
    549 #define EXT2_MOUNT_GRPID		0x0004	/* Create files with directory's group */
    550 #define EXT2_MOUNT_DEBUG		0x0008	/* Some debugging messages */
    551 #define EXT2_MOUNT_ERRORS_CONT		0x0010	/* Continue on errors */
    552 #define EXT2_MOUNT_ERRORS_RO		0x0020	/* Remount fs ro on errors */
    553 #define EXT2_MOUNT_ERRORS_PANIC		0x0040	/* Panic on errors */
    554 #define EXT2_MOUNT_MINIX_DF		0x0080	/* Mimics the Minix statfs */
    555 #define EXT2_MOUNT_NO_UID32		0x0200  /* Disable 32-bit UIDs */
    556 
    557 #define clear_opt(o, opt)		o &= ~EXT2_MOUNT_##opt
    558 #define set_opt(o, opt)			o |= EXT2_MOUNT_##opt
    559 #define test_opt(sb, opt)		(EXT2_SB(sb)->s_mount_opt & \
    560 					 EXT2_MOUNT_##opt)
    561 /*
    562  * Maximal mount counts between two filesystem checks
    563  */
    564 #define EXT2_DFL_MAX_MNT_COUNT		20	/* Allow 20 mounts */
    565 #define EXT2_DFL_CHECKINTERVAL		0	/* Don't use interval check */
    566 
    567 /*
    568  * Behaviour when detecting errors
    569  */
    570 #define EXT2_ERRORS_CONTINUE		1	/* Continue execution */
    571 #define EXT2_ERRORS_RO			2	/* Remount fs read-only */
    572 #define EXT2_ERRORS_PANIC		3	/* Panic */
    573 #define EXT2_ERRORS_DEFAULT		EXT2_ERRORS_CONTINUE
    574 
    575 #if (__GNUC__ >= 4)
    576 #define ext4_offsetof(TYPE,MEMBER) __builtin_offsetof(TYPE,MEMBER)
    577 #else
    578 #define ext4_offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
    579 #endif
    580 
    581 /* Metadata checksum algorithms */
    582 #define EXT2_CRC32C_CHKSUM		1
    583 
    584 /* Encryption algorithms, key size and key reference len */
    585 #define EXT4_ENCRYPTION_MODE_INVALID		0
    586 #define EXT4_ENCRYPTION_MODE_AES_256_XTS	1
    587 #define EXT4_ENCRYPTION_MODE_AES_256_GCM	2
    588 #define EXT4_ENCRYPTION_MODE_AES_256_CBC	3
    589 #define EXT4_ENCRYPTION_MODE_AES_256_CTS	4
    590 
    591 #define EXT4_AES_256_XTS_KEY_SIZE		64
    592 #define EXT4_AES_256_GCM_KEY_SIZE		32
    593 #define EXT4_AES_256_CBC_KEY_SIZE		32
    594 #define EXT4_AES_256_CTS_KEY_SIZE		32
    595 #define EXT4_MAX_KEY_SIZE			64
    596 
    597 #define EXT4_KEY_DESCRIPTOR_SIZE		8
    598 #define EXT4_CRYPTO_BLOCK_SIZE			16
    599 
    600 /* Password derivation constants */
    601 #define EXT4_MAX_PASSPHRASE_SIZE		1024
    602 #define EXT4_MAX_SALT_SIZE			256
    603 #define EXT4_PBKDF2_ITERATIONS			0xFFFF
    604 
    605 #define EXT2_LABEL_LEN				16
    606 
    607 /*
    608  * Policy provided via an ioctl on the topmost directory. This
    609  * structure is also in the kernel.
    610  */
    611 struct ext4_encryption_policy {
    612   char version;
    613   char contents_encryption_mode;
    614   char filenames_encryption_mode;
    615   char flags;
    616   char master_key_descriptor[EXT4_KEY_DESCRIPTOR_SIZE];
    617 } __attribute__((__packed__));
    618 
    619 struct ext4_encryption_key {
    620         __u32 mode;
    621         char raw[EXT4_MAX_KEY_SIZE];
    622         __u32 size;
    623 } __attribute__((__packed__));
    624 
    625 /*
    626  * Structure of the super block
    627  */
    628 struct ext2_super_block {
    629 	__u32	s_inodes_count;		/* Inodes count */
    630 	__u32	s_blocks_count;		/* Blocks count */
    631 	__u32	s_r_blocks_count;	/* Reserved blocks count */
    632 	__u32	s_free_blocks_count;	/* Free blocks count */
    633 	__u32	s_free_inodes_count;	/* Free inodes count */
    634 	__u32	s_first_data_block;	/* First Data Block */
    635 	__u32	s_log_block_size;	/* Block size */
    636 	__u32	s_log_cluster_size;	/* Allocation cluster size */
    637 	__u32	s_blocks_per_group;	/* # Blocks per group */
    638 	__u32	s_clusters_per_group;	/* # Fragments per group */
    639 	__u32	s_inodes_per_group;	/* # Inodes per group */
    640 	__u32	s_mtime;		/* Mount time */
    641 	__u32	s_wtime;		/* Write time */
    642 	__u16	s_mnt_count;		/* Mount count */
    643 	__s16	s_max_mnt_count;	/* Maximal mount count */
    644 	__u16	s_magic;		/* Magic signature */
    645 	__u16	s_state;		/* File system state */
    646 	__u16	s_errors;		/* Behaviour when detecting errors */
    647 	__u16	s_minor_rev_level;	/* minor revision level */
    648 	__u32	s_lastcheck;		/* time of last check */
    649 	__u32	s_checkinterval;	/* max. time between checks */
    650 	__u32	s_creator_os;		/* OS */
    651 	__u32	s_rev_level;		/* Revision level */
    652 	__u16	s_def_resuid;		/* Default uid for reserved blocks */
    653 	__u16	s_def_resgid;		/* Default gid for reserved blocks */
    654 	/*
    655 	 * These fields are for EXT2_DYNAMIC_REV superblocks only.
    656 	 *
    657 	 * Note: the difference between the compatible feature set and
    658 	 * the incompatible feature set is that if there is a bit set
    659 	 * in the incompatible feature set that the kernel doesn't
    660 	 * know about, it should refuse to mount the filesystem.
    661 	 *
    662 	 * e2fsck's requirements are more strict; if it doesn't know
    663 	 * about a feature in either the compatible or incompatible
    664 	 * feature set, it must abort and not try to meddle with
    665 	 * things it doesn't understand...
    666 	 */
    667 	__u32	s_first_ino;		/* First non-reserved inode */
    668 	__u16   s_inode_size;		/* size of inode structure */
    669 	__u16	s_block_group_nr;	/* block group # of this superblock */
    670 	__u32	s_feature_compat;	/* compatible feature set */
    671 	__u32	s_feature_incompat;	/* incompatible feature set */
    672 	__u32	s_feature_ro_compat;	/* readonly-compatible feature set */
    673 	__u8	s_uuid[16];		/* 128-bit uuid for volume */
    674 	char	s_volume_name[EXT2_LABEL_LEN];	/* volume name */
    675 	char	s_last_mounted[64];	/* directory where last mounted */
    676 	__u32	s_algorithm_usage_bitmap; /* For compression */
    677 	/*
    678 	 * Performance hints.  Directory preallocation should only
    679 	 * happen if the EXT2_FEATURE_COMPAT_DIR_PREALLOC flag is on.
    680 	 */
    681 	__u8	s_prealloc_blocks;	/* Nr of blocks to try to preallocate*/
    682 	__u8	s_prealloc_dir_blocks;	/* Nr to preallocate for dirs */
    683 	__u16	s_reserved_gdt_blocks;	/* Per group table for online growth */
    684 	/*
    685 	 * Journaling support valid if EXT2_FEATURE_COMPAT_HAS_JOURNAL set.
    686 	 */
    687 	__u8	s_journal_uuid[16];	/* uuid of journal superblock */
    688 	__u32	s_journal_inum;		/* inode number of journal file */
    689 	__u32	s_journal_dev;		/* device number of journal file */
    690 	__u32	s_last_orphan;		/* start of list of inodes to delete */
    691 	__u32	s_hash_seed[4];		/* HTREE hash seed */
    692 	__u8	s_def_hash_version;	/* Default hash version to use */
    693 	__u8	s_jnl_backup_type; 	/* Default type of journal backup */
    694 	__u16	s_desc_size;		/* Group desc. size: INCOMPAT_64BIT */
    695 	__u32	s_default_mount_opts;
    696 	__u32	s_first_meta_bg;	/* First metablock group */
    697 	__u32	s_mkfs_time;		/* When the filesystem was created */
    698 	__u32	s_jnl_blocks[17]; 	/* Backup of the journal inode */
    699 	__u32	s_blocks_count_hi;	/* Blocks count high 32bits */
    700 	__u32	s_r_blocks_count_hi;	/* Reserved blocks count high 32 bits*/
    701 	__u32	s_free_blocks_hi; 	/* Free blocks count */
    702 	__u16	s_min_extra_isize;	/* All inodes have at least # bytes */
    703 	__u16	s_want_extra_isize; 	/* New inodes should reserve # bytes */
    704 	__u32	s_flags;		/* Miscellaneous flags */
    705 	__u16   s_raid_stride;		/* RAID stride */
    706 	__u16   s_mmp_update_interval;  /* # seconds to wait in MMP checking */
    707 	__u64   s_mmp_block;            /* Block for multi-mount protection */
    708 	__u32   s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
    709 	__u8	s_log_groups_per_flex;	/* FLEX_BG group size */
    710 	__u8    s_checksum_type;	/* metadata checksum algorithm */
    711 	__u8	s_encryption_level;	/* versioning level for encryption */
    712 	__u8	s_reserved_pad;		/* Padding to next 32bits */
    713 	__u64	s_kbytes_written;	/* nr of lifetime kilobytes written */
    714 	__u32	s_snapshot_inum;	/* Inode number of active snapshot */
    715 	__u32	s_snapshot_id;		/* sequential ID of active snapshot */
    716 	__u64	s_snapshot_r_blocks_count; /* reserved blocks for active
    717 					      snapshot's future use */
    718 	__u32	s_snapshot_list;	/* inode number of the head of the on-disk snapshot list */
    719 #define EXT4_S_ERR_START ext4_offsetof(struct ext2_super_block, s_error_count)
    720 	__u32	s_error_count;		/* number of fs errors */
    721 	__u32	s_first_error_time;	/* first time an error happened */
    722 	__u32	s_first_error_ino;	/* inode involved in first error */
    723 	__u64	s_first_error_block;	/* block involved of first error */
    724 	__u8	s_first_error_func[32];	/* function where the error happened */
    725 	__u32	s_first_error_line;	/* line number where error happened */
    726 	__u32	s_last_error_time;	/* most recent time of an error */
    727 	__u32	s_last_error_ino;	/* inode involved in last error */
    728 	__u32	s_last_error_line;	/* line number where error happened */
    729 	__u64	s_last_error_block;	/* block involved of last error */
    730 	__u8	s_last_error_func[32];	/* function where the error happened */
    731 #define EXT4_S_ERR_END ext4_offsetof(struct ext2_super_block, s_mount_opts)
    732 	__u8	s_mount_opts[64];
    733 	__u32	s_usr_quota_inum;	/* inode number of user quota file */
    734 	__u32	s_grp_quota_inum;	/* inode number of group quota file */
    735 	__u32	s_overhead_blocks;	/* overhead blocks/clusters in fs */
    736 	__u32	s_backup_bgs[2];	/* If sparse_super2 enabled */
    737 	__u8	s_encrypt_algos[4];	/* Encryption algorithms in use  */
    738 	__u8	s_encrypt_pw_salt[16];	/* Salt used for string2key algorithm */
    739 	__le32	s_lpf_ino;		/* Location of the lost+found inode */
    740 	__le32  s_prj_quota_inum;	/* inode for tracking project quota */
    741 	__le32	s_checksum_seed;	/* crc32c(orig_uuid) if csum_seed set */
    742 	__le32	s_reserved[98];		/* Padding to the end of the block */
    743 	__u32	s_checksum;		/* crc32c(superblock) */
    744 };
    745 
    746 #define EXT4_S_ERR_LEN (EXT4_S_ERR_END - EXT4_S_ERR_START)
    747 
    748 /*
    749  * Codes for operating systems
    750  */
    751 #define EXT2_OS_LINUX		0
    752 #define EXT2_OS_HURD		1
    753 #define EXT2_OBSO_OS_MASIX	2
    754 #define EXT2_OS_FREEBSD		3
    755 #define EXT2_OS_LITES		4
    756 
    757 /*
    758  * Revision levels
    759  */
    760 #define EXT2_GOOD_OLD_REV	0	/* The good old (original) format */
    761 #define EXT2_DYNAMIC_REV	1	/* V2 format w/ dynamic inode sizes */
    762 
    763 #define EXT2_CURRENT_REV	EXT2_GOOD_OLD_REV
    764 #define EXT2_MAX_SUPP_REV	EXT2_DYNAMIC_REV
    765 
    766 #define EXT2_GOOD_OLD_INODE_SIZE 128
    767 
    768 /*
    769  * Journal inode backup types
    770  */
    771 #define EXT3_JNL_BACKUP_BLOCKS	1
    772 
    773 /*
    774  * Feature set definitions
    775  */
    776 
    777 #define EXT2_HAS_COMPAT_FEATURE(sb,mask)			\
    778 	( EXT2_SB(sb)->s_feature_compat & (mask) )
    779 #define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask)			\
    780 	( EXT2_SB(sb)->s_feature_ro_compat & (mask) )
    781 #define EXT2_HAS_INCOMPAT_FEATURE(sb,mask)			\
    782 	( EXT2_SB(sb)->s_feature_incompat & (mask) )
    783 
    784 #define EXT2_FEATURE_COMPAT_DIR_PREALLOC	0x0001
    785 #define EXT2_FEATURE_COMPAT_IMAGIC_INODES	0x0002
    786 #define EXT3_FEATURE_COMPAT_HAS_JOURNAL		0x0004
    787 #define EXT2_FEATURE_COMPAT_EXT_ATTR		0x0008
    788 #define EXT2_FEATURE_COMPAT_RESIZE_INODE	0x0010
    789 #define EXT2_FEATURE_COMPAT_DIR_INDEX		0x0020
    790 #define EXT2_FEATURE_COMPAT_LAZY_BG		0x0040
    791 /* #define EXT2_FEATURE_COMPAT_EXCLUDE_INODE	0x0080 not used, legacy */
    792 #define EXT2_FEATURE_COMPAT_EXCLUDE_BITMAP	0x0100
    793 #define EXT4_FEATURE_COMPAT_SPARSE_SUPER2	0x0200
    794 
    795 
    796 #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
    797 #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
    798 /* #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR	0x0004 not used */
    799 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE	0x0008
    800 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM		0x0010
    801 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK	0x0020
    802 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE	0x0040
    803 #define EXT4_FEATURE_RO_COMPAT_HAS_SNAPSHOT	0x0080
    804 #define EXT4_FEATURE_RO_COMPAT_QUOTA		0x0100
    805 #define EXT4_FEATURE_RO_COMPAT_BIGALLOC		0x0200
    806 /*
    807  * METADATA_CSUM implies GDT_CSUM.  When METADATA_CSUM is set, group
    808  * descriptor checksums use the same algorithm as all other data
    809  * structures' checksums.
    810  */
    811 #define EXT4_FEATURE_RO_COMPAT_METADATA_CSUM	0x0400
    812 #define EXT4_FEATURE_RO_COMPAT_REPLICA		0x0800
    813 #define EXT4_FEATURE_RO_COMPAT_READONLY		0x1000
    814 #define EXT4_FEATURE_RO_COMPAT_PROJECT		0x2000 /* Project quota */
    815 
    816 
    817 #define EXT2_FEATURE_INCOMPAT_COMPRESSION	0x0001
    818 #define EXT2_FEATURE_INCOMPAT_FILETYPE		0x0002
    819 #define EXT3_FEATURE_INCOMPAT_RECOVER		0x0004 /* Needs recovery */
    820 #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008 /* Journal device */
    821 #define EXT2_FEATURE_INCOMPAT_META_BG		0x0010
    822 #define EXT3_FEATURE_INCOMPAT_EXTENTS		0x0040
    823 #define EXT4_FEATURE_INCOMPAT_64BIT		0x0080
    824 #define EXT4_FEATURE_INCOMPAT_MMP		0x0100
    825 #define EXT4_FEATURE_INCOMPAT_FLEX_BG		0x0200
    826 #define EXT4_FEATURE_INCOMPAT_EA_INODE		0x0400
    827 #define EXT4_FEATURE_INCOMPAT_DIRDATA		0x1000
    828 #define EXT4_FEATURE_INCOMPAT_CSUM_SEED		0x2000
    829 #define EXT4_FEATURE_INCOMPAT_LARGEDIR		0x4000 /* >2GB or 3-lvl htree */
    830 #define EXT4_FEATURE_INCOMPAT_INLINE_DATA	0x8000 /* data in inode */
    831 #define EXT4_FEATURE_INCOMPAT_ENCRYPT		0x10000
    832 
    833 #define EXT4_FEATURE_COMPAT_FUNCS(name, ver, flagname) \
    834 static inline int ext2fs_has_feature_##name(struct ext2_super_block *sb) \
    835 { \
    836 	return ((EXT2_SB(sb)->s_feature_compat & \
    837 		 EXT##ver##_FEATURE_COMPAT_##flagname) != 0); \
    838 } \
    839 static inline void ext2fs_set_feature_##name(struct ext2_super_block *sb) \
    840 { \
    841 	EXT2_SB(sb)->s_feature_compat |= \
    842 		EXT##ver##_FEATURE_COMPAT_##flagname; \
    843 } \
    844 static inline void ext2fs_clear_feature_##name(struct ext2_super_block *sb) \
    845 { \
    846 	EXT2_SB(sb)->s_feature_compat &= \
    847 		~EXT##ver##_FEATURE_COMPAT_##flagname; \
    848 }
    849 
    850 #define EXT4_FEATURE_RO_COMPAT_FUNCS(name, ver, flagname) \
    851 static inline int ext2fs_has_feature_##name(struct ext2_super_block *sb) \
    852 { \
    853 	return ((EXT2_SB(sb)->s_feature_ro_compat & \
    854 		 EXT##ver##_FEATURE_RO_COMPAT_##flagname) != 0); \
    855 } \
    856 static inline void ext2fs_set_feature_##name(struct ext2_super_block *sb) \
    857 { \
    858 	EXT2_SB(sb)->s_feature_ro_compat |= \
    859 		EXT##ver##_FEATURE_RO_COMPAT_##flagname; \
    860 } \
    861 static inline void ext2fs_clear_feature_##name(struct ext2_super_block *sb) \
    862 { \
    863 	EXT2_SB(sb)->s_feature_ro_compat &= \
    864 		~EXT##ver##_FEATURE_RO_COMPAT_##flagname; \
    865 }
    866 
    867 #define EXT4_FEATURE_INCOMPAT_FUNCS(name, ver, flagname) \
    868 static inline int ext2fs_has_feature_##name(struct ext2_super_block *sb) \
    869 { \
    870 	return ((EXT2_SB(sb)->s_feature_incompat & \
    871 		 EXT##ver##_FEATURE_INCOMPAT_##flagname) != 0); \
    872 } \
    873 static inline void ext2fs_set_feature_##name(struct ext2_super_block *sb) \
    874 { \
    875 	EXT2_SB(sb)->s_feature_incompat |= \
    876 		EXT##ver##_FEATURE_INCOMPAT_##flagname; \
    877 } \
    878 static inline void ext2fs_clear_feature_##name(struct ext2_super_block *sb) \
    879 { \
    880 	EXT2_SB(sb)->s_feature_incompat &= \
    881 		~EXT##ver##_FEATURE_INCOMPAT_##flagname; \
    882 }
    883 
    884 EXT4_FEATURE_COMPAT_FUNCS(dir_prealloc,		2, DIR_PREALLOC)
    885 EXT4_FEATURE_COMPAT_FUNCS(imagic_inodes,	2, IMAGIC_INODES)
    886 EXT4_FEATURE_COMPAT_FUNCS(journal,		3, HAS_JOURNAL)
    887 EXT4_FEATURE_COMPAT_FUNCS(xattr,		2, EXT_ATTR)
    888 EXT4_FEATURE_COMPAT_FUNCS(resize_inode,		2, RESIZE_INODE)
    889 EXT4_FEATURE_COMPAT_FUNCS(dir_index,		2, DIR_INDEX)
    890 EXT4_FEATURE_COMPAT_FUNCS(lazy_bg,		2, LAZY_BG)
    891 EXT4_FEATURE_COMPAT_FUNCS(exclude_bitmap,	2, EXCLUDE_BITMAP)
    892 EXT4_FEATURE_COMPAT_FUNCS(sparse_super2,	4, SPARSE_SUPER2)
    893 
    894 EXT4_FEATURE_RO_COMPAT_FUNCS(sparse_super,	2, SPARSE_SUPER)
    895 EXT4_FEATURE_RO_COMPAT_FUNCS(large_file,	2, LARGE_FILE)
    896 EXT4_FEATURE_RO_COMPAT_FUNCS(huge_file,		4, HUGE_FILE)
    897 EXT4_FEATURE_RO_COMPAT_FUNCS(gdt_csum,		4, GDT_CSUM)
    898 EXT4_FEATURE_RO_COMPAT_FUNCS(dir_nlink,		4, DIR_NLINK)
    899 EXT4_FEATURE_RO_COMPAT_FUNCS(extra_isize,	4, EXTRA_ISIZE)
    900 EXT4_FEATURE_RO_COMPAT_FUNCS(has_snapshot,	4, HAS_SNAPSHOT)
    901 EXT4_FEATURE_RO_COMPAT_FUNCS(quota,		4, QUOTA)
    902 EXT4_FEATURE_RO_COMPAT_FUNCS(bigalloc,		4, BIGALLOC)
    903 EXT4_FEATURE_RO_COMPAT_FUNCS(metadata_csum,	4, METADATA_CSUM)
    904 EXT4_FEATURE_RO_COMPAT_FUNCS(replica,		4, REPLICA)
    905 EXT4_FEATURE_RO_COMPAT_FUNCS(readonly,		4, READONLY)
    906 EXT4_FEATURE_RO_COMPAT_FUNCS(project,		4, PROJECT)
    907 
    908 EXT4_FEATURE_INCOMPAT_FUNCS(compression,	2, COMPRESSION)
    909 EXT4_FEATURE_INCOMPAT_FUNCS(filetype,		2, FILETYPE)
    910 EXT4_FEATURE_INCOMPAT_FUNCS(journal_needs_recovery,	3, RECOVER)
    911 EXT4_FEATURE_INCOMPAT_FUNCS(journal_dev,	3, JOURNAL_DEV)
    912 EXT4_FEATURE_INCOMPAT_FUNCS(meta_bg,		2, META_BG)
    913 EXT4_FEATURE_INCOMPAT_FUNCS(extents,		3, EXTENTS)
    914 EXT4_FEATURE_INCOMPAT_FUNCS(64bit,		4, 64BIT)
    915 EXT4_FEATURE_INCOMPAT_FUNCS(mmp,		4, MMP)
    916 EXT4_FEATURE_INCOMPAT_FUNCS(flex_bg,		4, FLEX_BG)
    917 EXT4_FEATURE_INCOMPAT_FUNCS(ea_inode,		4, EA_INODE)
    918 EXT4_FEATURE_INCOMPAT_FUNCS(dirdata,		4, DIRDATA)
    919 EXT4_FEATURE_INCOMPAT_FUNCS(csum_seed,		4, CSUM_SEED)
    920 EXT4_FEATURE_INCOMPAT_FUNCS(largedir,		4, LARGEDIR)
    921 EXT4_FEATURE_INCOMPAT_FUNCS(inline_data,	4, INLINE_DATA)
    922 EXT4_FEATURE_INCOMPAT_FUNCS(encrypt,		4, ENCRYPT)
    923 
    924 #define EXT2_FEATURE_COMPAT_SUPP	0
    925 #define EXT2_FEATURE_INCOMPAT_SUPP    (EXT2_FEATURE_INCOMPAT_FILETYPE| \
    926 				       EXT4_FEATURE_INCOMPAT_MMP)
    927 #define EXT2_FEATURE_RO_COMPAT_SUPP	(EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
    928 					 EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
    929 					 EXT4_FEATURE_RO_COMPAT_DIR_NLINK| \
    930 					 EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
    931 
    932 /*
    933  * Default values for user and/or group using reserved blocks
    934  */
    935 #define EXT2_DEF_RESUID		0
    936 #define EXT2_DEF_RESGID		0
    937 
    938 /*
    939  * Default mount options
    940  */
    941 #define EXT2_DEFM_DEBUG		0x0001
    942 #define EXT2_DEFM_BSDGROUPS	0x0002
    943 #define EXT2_DEFM_XATTR_USER	0x0004
    944 #define EXT2_DEFM_ACL		0x0008
    945 #define EXT2_DEFM_UID16		0x0010
    946 #define EXT3_DEFM_JMODE		0x0060
    947 #define EXT3_DEFM_JMODE_DATA	0x0020
    948 #define EXT3_DEFM_JMODE_ORDERED	0x0040
    949 #define EXT3_DEFM_JMODE_WBACK	0x0060
    950 #define EXT4_DEFM_NOBARRIER	0x0100
    951 #define EXT4_DEFM_BLOCK_VALIDITY 0x0200
    952 #define EXT4_DEFM_DISCARD	0x0400
    953 #define EXT4_DEFM_NODELALLOC	0x0800
    954 
    955 /*
    956  * Structure of a directory entry
    957  */
    958 #define EXT2_NAME_LEN 255
    959 
    960 struct ext2_dir_entry {
    961 	__u32	inode;			/* Inode number */
    962 	__u16	rec_len;		/* Directory entry length */
    963 	__u16	name_len;		/* Name length */
    964 	char	name[EXT2_NAME_LEN];	/* File name */
    965 };
    966 
    967 /*
    968  * The new version of the directory entry.  Since EXT2 structures are
    969  * stored in intel byte order, and the name_len field could never be
    970  * bigger than 255 chars, it's safe to reclaim the extra byte for the
    971  * file_type field.
    972  *
    973  * This structure is deprecated due to endianity issues. Please use struct
    974  * ext2_dir_entry and accessor functions
    975  *   ext2fs_dirent_name_len
    976  *   ext2fs_dirent_set_name_len
    977  *   ext2fs_dirent_file_type
    978  *   ext2fs_dirent_set_file_type
    979  * to get and set name_len and file_type fields.
    980  */
    981 struct ext2_dir_entry_2 {
    982 	__u32	inode;			/* Inode number */
    983 	__u16	rec_len;		/* Directory entry length */
    984 	__u8	name_len;		/* Name length */
    985 	__u8	file_type;
    986 	char	name[EXT2_NAME_LEN];	/* File name */
    987 };
    988 
    989 /*
    990  * This is a bogus directory entry at the end of each leaf block that
    991  * records checksums.
    992  */
    993 struct ext2_dir_entry_tail {
    994 	__u32	det_reserved_zero1;	/* Pretend to be unused */
    995 	__u16	det_rec_len;		/* 12 */
    996 	__u16	det_reserved_name_len;	/* 0xDE00, fake namelen/filetype */
    997 	__u32	det_checksum;		/* crc32c(uuid+inode+dirent) */
    998 };
    999 
   1000 /*
   1001  * Ext2 directory file types.  Only the low 3 bits are used.  The
   1002  * other bits are reserved for now.
   1003  */
   1004 #define EXT2_FT_UNKNOWN		0
   1005 #define EXT2_FT_REG_FILE	1
   1006 #define EXT2_FT_DIR		2
   1007 #define EXT2_FT_CHRDEV		3
   1008 #define EXT2_FT_BLKDEV		4
   1009 #define EXT2_FT_FIFO		5
   1010 #define EXT2_FT_SOCK		6
   1011 #define EXT2_FT_SYMLINK		7
   1012 
   1013 #define EXT2_FT_MAX		8
   1014 
   1015 /*
   1016  * Annoyingly, e2fsprogs always swab16s ext2_dir_entry.name_len, so we
   1017  * have to build ext2_dir_entry_tail with that assumption too.  This
   1018  * constant helps to build the dir_entry_tail to look like it has an
   1019  * "invalid" file type.
   1020  */
   1021 #define EXT2_DIR_NAME_LEN_CSUM	0xDE00
   1022 
   1023 /*
   1024  * EXT2_DIR_PAD defines the directory entries boundaries
   1025  *
   1026  * NOTE: It must be a multiple of 4
   1027  */
   1028 #define EXT2_DIR_ENTRY_HEADER_LEN	8
   1029 #define EXT2_DIR_PAD			4
   1030 #define EXT2_DIR_ROUND			(EXT2_DIR_PAD - 1)
   1031 #define EXT2_DIR_REC_LEN(name_len)	(((name_len) + \
   1032 					  EXT2_DIR_ENTRY_HEADER_LEN + \
   1033 					  EXT2_DIR_ROUND) & \
   1034 					 ~EXT2_DIR_ROUND)
   1035 
   1036 /*
   1037  * Constants for ext4's extended time encoding
   1038  */
   1039 #define EXT4_EPOCH_BITS 2
   1040 #define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
   1041 #define EXT4_NSEC_MASK  (~0UL << EXT4_EPOCH_BITS)
   1042 
   1043 /*
   1044  * This structure is used for multiple mount protection. It is written
   1045  * into the block number saved in the s_mmp_block field in the superblock.
   1046  * Programs that check MMP should assume that if SEQ_FSCK (or any unknown
   1047  * code above SEQ_MAX) is present then it is NOT safe to use the filesystem,
   1048  * regardless of how old the timestamp is.
   1049  *
   1050  * The timestamp in the MMP structure will be updated by e2fsck at some
   1051  * arbitary intervals (start of passes, after every few groups of inodes
   1052  * in pass1 and pass1b).  There is no guarantee that e2fsck is updating
   1053  * the MMP block in a timely manner, and the updates it does are purely
   1054  * for the convenience of the sysadmin and not for automatic validation.
   1055  *
   1056  * Note: Only the mmp_seq value is used to determine whether the MMP block
   1057  *	is being updated.  The mmp_time, mmp_nodename, and mmp_bdevname
   1058  *	fields are only for informational purposes for the administrator,
   1059  *	due to clock skew between nodes and hostname HA service takeover.
   1060  */
   1061 #define EXT4_MMP_MAGIC     0x004D4D50U /* ASCII for MMP */
   1062 #define EXT4_MMP_SEQ_CLEAN 0xFF4D4D50U /* mmp_seq value for clean unmount */
   1063 #define EXT4_MMP_SEQ_FSCK  0xE24D4D50U /* mmp_seq value when being fscked */
   1064 #define EXT4_MMP_SEQ_MAX   0xE24D4D4FU /* maximum valid mmp_seq value */
   1065 
   1066 /* Not endian-annotated; it's swapped at read/write time */
   1067 struct mmp_struct {
   1068 	__u32	mmp_magic;		/* Magic number for MMP */
   1069 	__u32	mmp_seq;		/* Sequence no. updated periodically */
   1070 	__u64	mmp_time;		/* Time last updated */
   1071 	char	mmp_nodename[64];	/* Node which last updated MMP block */
   1072 	char	mmp_bdevname[32];	/* Bdev which last updated MMP block */
   1073 	__u16	mmp_check_interval;	/* Changed mmp_check_interval */
   1074 	__u16	mmp_pad1;
   1075 	__u32	mmp_pad2[226];
   1076 	__u32	mmp_checksum;		/* crc32c(uuid+mmp_block) */
   1077 };
   1078 
   1079 /*
   1080  * Default interval for MMP update in seconds.
   1081  */
   1082 #define EXT4_MMP_UPDATE_INTERVAL	5
   1083 
   1084 /*
   1085  * Maximum interval for MMP update in seconds.
   1086  */
   1087 #define EXT4_MMP_MAX_UPDATE_INTERVAL	300
   1088 
   1089 /*
   1090  * Minimum interval for MMP checking in seconds.
   1091  */
   1092 #define EXT4_MMP_MIN_CHECK_INTERVAL     5
   1093 
   1094 /*
   1095  * Minimum size of inline data.
   1096  */
   1097 #define EXT4_MIN_INLINE_DATA_SIZE	((sizeof(__u32) * EXT2_N_BLOCKS))
   1098 
   1099 /*
   1100  * Size of a parent inode in inline data directory.
   1101  */
   1102 #define EXT4_INLINE_DATA_DOTDOT_SIZE	(4)
   1103 
   1104 #endif	/* _LINUX_EXT2_FS_H */
   1105