1 #ifndef EXT2_CONST_H 2 #define EXT2_CONST_H 3 4 /* Tables sizes */ 5 6 #define NR_INODES 512 /* # slots in "in core" inode table; 7 * should be more or less the same as 8 * NR_VNODES in vfs 9 */ 10 #define GETDENTS_BUFSIZ 257 11 12 #define INODE_HASH_LOG2 7 /* 2 based logarithm of the inode hash size */ 13 #define INODE_HASH_SIZE ((unsigned long)1<<INODE_HASH_LOG2) 14 #define INODE_HASH_MASK (((unsigned long)1<<INODE_HASH_LOG2)-1) 15 16 17 /* The type of sizeof may be (unsigned) long. Use the following macro for 18 * taking the sizes of small objects so that there are no surprises like 19 * (small) long constants being passed to routines expecting an int. 20 */ 21 #define usizeof(t) ((unsigned) sizeof(t)) 22 23 #define SUPER_MAGIC 0xEF53 /* magic number contained in super-block */ 24 25 #define EXT2_NAME_MAX 255 26 27 /* Miscellaneous constants */ 28 #define SU_UID ((uid_t) 0) /* super_user's uid_t */ 29 #define NORMAL 0 /* forces get_block to do disk read */ 30 #define NO_READ 1 /* prevents get_block from doing disk read */ 31 #define PREFETCH 2 /* tells get_block not to read or mark dev */ 32 33 #define NO_BIT ((bit_t) 0) /* returned by alloc_bit() to signal failure */ 34 35 #define LOOK_UP 0 /* tells search_dir to lookup string */ 36 #define ENTER 1 /* tells search_dir to make dir entry */ 37 #define DELETE 2 /* tells search_dir to delete entry */ 38 #define IS_EMPTY 3 /* tells search_dir to ret. OK or ENOTEMPTY */ 39 40 /* write_map() args */ 41 #define WMAP_FREE (1 << 0) 42 43 #define IGN_PERM 0 44 #define CHK_PERM 1 45 46 #define IN_CLEAN 0 /* inode disk and memory copies identical */ 47 #define IN_DIRTY 1 /* inode disk and memory copies differ */ 48 #define ATIME 002 /* set if atime field needs updating */ 49 #define CTIME 004 /* set if ctime field needs updating */ 50 #define MTIME 010 /* set if mtime field needs updating */ 51 52 #define BYTE_SWAP 0 /* tells conv2/conv4 to swap bytes */ 53 54 #define END_OF_FILE (-104) /* eof detected */ 55 56 #define SUPER_BLOCK_BYTES (1024) /* bytes offset */ 57 58 #define ROOT_INODE ((ino_t) 2) /* inode number for root directory */ 59 #define BOOT_BLOCK ((block_t) 0) /* block number of boot block */ 60 #define START_BLOCK ((block_t) 2) /* first block of FS (not counting SB) */ 61 #define BLOCK_ADDRESS_BYTES 4 /* bytes per address */ 62 63 #define SUPER_SIZE usizeof (struct super_block) /* sb size in RAM */ 64 #define SUPER_SIZE_D (1024) /* max size of superblock stored on disk */ 65 66 /* Directories related macroses */ 67 68 #define DIR_ENTRY_ALIGN 4 69 70 /* ino + rec_len + name_len + file_type, doesn't include name and padding */ 71 #define MIN_DIR_ENTRY_SIZE 8 72 73 #define DIR_ENTRY_CONTENTS_SIZE(d) (MIN_DIR_ENTRY_SIZE + (d)->d_name_len) 74 75 /* size with padding */ 76 #define DIR_ENTRY_ACTUAL_SIZE(d) (DIR_ENTRY_CONTENTS_SIZE(d) + \ 77 ((DIR_ENTRY_CONTENTS_SIZE(d) & 0x03) == 0 ? 0 : \ 78 DIR_ENTRY_ALIGN - (DIR_ENTRY_CONTENTS_SIZE(d) & 0x03) )) 79 80 /* How many bytes can be taken from the end of dentry */ 81 #define DIR_ENTRY_SHRINK(d) (conv2(le_CPU, (d)->d_rec_len) \ 82 - DIR_ENTRY_ACTUAL_SIZE(d)) 83 84 /* Dentry can have padding, which can be used to enlarge namelen */ 85 #define DIR_ENTRY_MAX_NAME_LEN(d) (conv2(le_CPU, (d)->d_rec_len) \ 86 - MIN_DIR_ENTRY_SIZE) 87 88 /* Constants relative to the data blocks */ 89 /* When change EXT2_NDIR_BLOCKS, modify ext2_max_size()!!!*/ 90 #define EXT2_NDIR_BLOCKS 12 91 #define EXT2_IND_BLOCK EXT2_NDIR_BLOCKS 92 #define EXT2_DIND_BLOCK (EXT2_IND_BLOCK + 1) 93 #define EXT2_TIND_BLOCK (EXT2_DIND_BLOCK + 1) 94 #define EXT2_N_BLOCKS (EXT2_TIND_BLOCK + 1) 95 96 #define FS_BITMAP_CHUNKS(b) ((b)/usizeof (bitchunk_t))/* # map chunks/blk */ 97 #define FS_BITCHUNK_BITS (usizeof(bitchunk_t) * CHAR_BIT) 98 #define FS_BITS_PER_BLOCK(b) (FS_BITMAP_CHUNKS(b) * FS_BITCHUNK_BITS) 99 100 /* Inodes */ 101 102 /* Next 4 following macroses were taken from linux' ext2_fs.h */ 103 #define EXT2_GOOD_OLD_INODE_SIZE 128 104 #define EXT2_GOOD_OLD_FIRST_INO 11 105 106 #define EXT2_INODE_SIZE(s) (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \ 107 EXT2_GOOD_OLD_INODE_SIZE : \ 108 (s)->s_inode_size) 109 #define EXT2_FIRST_INO(s) (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \ 110 EXT2_GOOD_OLD_FIRST_INO : \ 111 (s)->s_first_ino) 112 113 /* Maximum size of a fast symlink including trailing '\0' */ 114 #define MAX_FAST_SYMLINK_LENGTH \ 115 ( sizeof(((d_inode *)0)->i_block[0]) * EXT2_N_BLOCKS ) 116 117 #define NUL(str,l,m) mfs_nul_f(__FILE__,__LINE__,(str), (l), (m)) 118 119 /* FS states */ 120 #define EXT2_VALID_FS 0x0001 /* Cleanly unmounted */ 121 #define EXT2_ERROR_FS 0x0002 /* Errors detected */ 122 123 #define EXT2_GOOD_OLD_REV 0 /* The good old (original) format */ 124 #define EXT2_DYNAMIC_REV 1 /* V2 format w/ dynamic inode sizes */ 125 126 /* ext2 features, names shorted (cut EXT2_ prefix) */ 127 #define COMPAT_DIR_PREALLOC 0x0001 128 #define COMPAT_IMAGIC_INODES 0x0002 129 #define COMPAT_HAS_JOURNAL 0x0004 130 #define COMPAT_EXT_ATTR 0x0008 131 #define COMPAT_RESIZE_INO 0x0010 132 #define COMPAT_DIR_INDEX 0x0020 133 #define COMPAT_ANY 0xffffffff 134 135 #define RO_COMPAT_SPARSE_SUPER 0x0001 136 #define RO_COMPAT_LARGE_FILE 0x0002 137 #define RO_COMPAT_BTREE_DIR 0x0004 138 #define RO_COMPAT_ANY 0xffffffff 139 140 #define INCOMPAT_COMPRESSION 0x0001 141 #define INCOMPAT_FILETYPE 0x0002 142 #define INCOMPAT_RECOVER 0x0004 143 #define INCOMPAT_JOURNAL_DEV 0x0008 144 #define INCOMPAT_META_BG 0x0010 145 #define INCOMPAT_ANY 0xffffffff 146 147 /* What do we support? */ 148 #define SUPPORTED_INCOMPAT_FEATURES (INCOMPAT_FILETYPE) 149 #define SUPPORTED_RO_COMPAT_FEATURES (RO_COMPAT_SPARSE_SUPER | \ 150 RO_COMPAT_LARGE_FILE) 151 152 /* Ext2 directory file types. Only the low 3 bits are used. 153 * The other bits are reserved for now. 154 */ 155 #define EXT2_FT_UNKNOWN 0 156 #define EXT2_FT_REG_FILE 1 157 #define EXT2_FT_DIR 2 158 #define EXT2_FT_CHRDEV 3 159 #define EXT2_FT_BLKDEV 4 160 #define EXT2_FT_FIFO 5 161 #define EXT2_FT_SOCK 6 162 #define EXT2_FT_SYMLINK 7 163 164 #define EXT2_FT_MAX 8 165 166 #define HAS_COMPAT_FEATURE(sp, mask) \ 167 ( (sp)->s_feature_compat & (mask) ) 168 #define HAS_RO_COMPAT_FEATURE(sp, mask) \ 169 ( (sp)->s_feature_ro_compat & (mask) ) 170 #define HAS_INCOMPAT_FEATURE(sp, mask) \ 171 ( (sp)->s_feature_incompat & (mask) ) 172 173 174 /* hash-indexed directory */ 175 #define EXT2_INDEX_FL 0x00001000 176 /* Top of directory hierarchies*/ 177 #define EXT2_TOPDIR_FL 0x00020000 178 179 #define EXT2_PREALLOC_BLOCKS 8 180 181 182 #endif /* EXT2_CONST_H */ 183