minix3/fs/ext2/const.h

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2020-02-21 00:59:27 +05:30
#ifndef EXT2_CONST_H
#define EXT2_CONST_H
/* Tables sizes */
#define NR_INODES 512 /* # slots in "in core" inode table;
* should be more or less the same as
* NR_VNODES in vfs
*/
#define GETDENTS_BUFSIZ 257
#define INODE_HASH_LOG2 7 /* 2 based logarithm of the inode hash size */
#define INODE_HASH_SIZE ((unsigned long)1<<INODE_HASH_LOG2)
#define INODE_HASH_MASK (((unsigned long)1<<INODE_HASH_LOG2)-1)
/* The type of sizeof may be (unsigned) long. Use the following macro for
* taking the sizes of small objects so that there are no surprises like
* (small) long constants being passed to routines expecting an int.
*/
#define usizeof(t) ((unsigned) sizeof(t))
#define SUPER_MAGIC 0xEF53 /* magic number contained in super-block */
#define EXT2_NAME_MAX 255
/* Miscellaneous constants */
#define SU_UID ((uid_t) 0) /* super_user's uid_t */
#define NORMAL 0 /* forces get_block to do disk read */
#define NO_READ 1 /* prevents get_block from doing disk read */
#define PREFETCH 2 /* tells get_block not to read or mark dev */
#define NO_BIT ((bit_t) 0) /* returned by alloc_bit() to signal failure */
#define LOOK_UP 0 /* tells search_dir to lookup string */
#define ENTER 1 /* tells search_dir to make dir entry */
#define DELETE 2 /* tells search_dir to delete entry */
#define IS_EMPTY 3 /* tells search_dir to ret. OK or ENOTEMPTY */
/* write_map() args */
#define WMAP_FREE (1 << 0)
#define IGN_PERM 0
#define CHK_PERM 1
#define IN_CLEAN 0 /* inode disk and memory copies identical */
#define IN_DIRTY 1 /* inode disk and memory copies differ */
#define ATIME 002 /* set if atime field needs updating */
#define CTIME 004 /* set if ctime field needs updating */
#define MTIME 010 /* set if mtime field needs updating */
#define BYTE_SWAP 0 /* tells conv2/conv4 to swap bytes */
#define END_OF_FILE (-104) /* eof detected */
#define SUPER_BLOCK_BYTES (1024) /* bytes offset */
#define ROOT_INODE ((ino_t) 2) /* inode number for root directory */
#define BOOT_BLOCK ((block_t) 0) /* block number of boot block */
#define START_BLOCK ((block_t) 2) /* first block of FS (not counting SB) */
#define BLOCK_ADDRESS_BYTES 4 /* bytes per address */
#define SUPER_SIZE usizeof (struct super_block) /* sb size in RAM */
#define SUPER_SIZE_D (1024) /* max size of superblock stored on disk */
/* Directories related macroses */
#define DIR_ENTRY_ALIGN 4
/* ino + rec_len + name_len + file_type, doesn't include name and padding */
#define MIN_DIR_ENTRY_SIZE 8
#define DIR_ENTRY_CONTENTS_SIZE(d) (MIN_DIR_ENTRY_SIZE + (d)->d_name_len)
/* size with padding */
#define DIR_ENTRY_ACTUAL_SIZE(d) (DIR_ENTRY_CONTENTS_SIZE(d) + \
((DIR_ENTRY_CONTENTS_SIZE(d) & 0x03) == 0 ? 0 : \
DIR_ENTRY_ALIGN - (DIR_ENTRY_CONTENTS_SIZE(d) & 0x03) ))
/* How many bytes can be taken from the end of dentry */
#define DIR_ENTRY_SHRINK(d) (conv2(le_CPU, (d)->d_rec_len) \
- DIR_ENTRY_ACTUAL_SIZE(d))
/* Dentry can have padding, which can be used to enlarge namelen */
#define DIR_ENTRY_MAX_NAME_LEN(d) (conv2(le_CPU, (d)->d_rec_len) \
- MIN_DIR_ENTRY_SIZE)
/* Constants relative to the data blocks */
/* When change EXT2_NDIR_BLOCKS, modify ext2_max_size()!!!*/
#define EXT2_NDIR_BLOCKS 12
#define EXT2_IND_BLOCK EXT2_NDIR_BLOCKS
#define EXT2_DIND_BLOCK (EXT2_IND_BLOCK + 1)
#define EXT2_TIND_BLOCK (EXT2_DIND_BLOCK + 1)
#define EXT2_N_BLOCKS (EXT2_TIND_BLOCK + 1)
#define FS_BITMAP_CHUNKS(b) ((b)/usizeof (bitchunk_t))/* # map chunks/blk */
#define FS_BITCHUNK_BITS (usizeof(bitchunk_t) * CHAR_BIT)
#define FS_BITS_PER_BLOCK(b) (FS_BITMAP_CHUNKS(b) * FS_BITCHUNK_BITS)
/* Inodes */
/* Next 4 following macroses were taken from linux' ext2_fs.h */
#define EXT2_GOOD_OLD_INODE_SIZE 128
#define EXT2_GOOD_OLD_FIRST_INO 11
#define EXT2_INODE_SIZE(s) (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
EXT2_GOOD_OLD_INODE_SIZE : \
(s)->s_inode_size)
#define EXT2_FIRST_INO(s) (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
EXT2_GOOD_OLD_FIRST_INO : \
(s)->s_first_ino)
/* Maximum size of a fast symlink including trailing '\0' */
#define MAX_FAST_SYMLINK_LENGTH \
( sizeof(((d_inode *)0)->i_block[0]) * EXT2_N_BLOCKS )
#define NUL(str,l,m) mfs_nul_f(__FILE__,__LINE__,(str), (l), (m))
/* FS states */
#define EXT2_VALID_FS 0x0001 /* Cleanly unmounted */
#define EXT2_ERROR_FS 0x0002 /* Errors detected */
#define EXT2_GOOD_OLD_REV 0 /* The good old (original) format */
#define EXT2_DYNAMIC_REV 1 /* V2 format w/ dynamic inode sizes */
/* ext2 features, names shorted (cut EXT2_ prefix) */
#define COMPAT_DIR_PREALLOC 0x0001
#define COMPAT_IMAGIC_INODES 0x0002
#define COMPAT_HAS_JOURNAL 0x0004
#define COMPAT_EXT_ATTR 0x0008
#define COMPAT_RESIZE_INO 0x0010
#define COMPAT_DIR_INDEX 0x0020
#define COMPAT_ANY 0xffffffff
#define RO_COMPAT_SPARSE_SUPER 0x0001
#define RO_COMPAT_LARGE_FILE 0x0002
#define RO_COMPAT_BTREE_DIR 0x0004
#define RO_COMPAT_ANY 0xffffffff
#define INCOMPAT_COMPRESSION 0x0001
#define INCOMPAT_FILETYPE 0x0002
#define INCOMPAT_RECOVER 0x0004
#define INCOMPAT_JOURNAL_DEV 0x0008
#define INCOMPAT_META_BG 0x0010
#define INCOMPAT_ANY 0xffffffff
/* What do we support? */
#define SUPPORTED_INCOMPAT_FEATURES (INCOMPAT_FILETYPE)
#define SUPPORTED_RO_COMPAT_FEATURES (RO_COMPAT_SPARSE_SUPER | \
RO_COMPAT_LARGE_FILE)
/* Ext2 directory file types. Only the low 3 bits are used.
* The other bits are reserved for now.
*/
#define EXT2_FT_UNKNOWN 0
#define EXT2_FT_REG_FILE 1
#define EXT2_FT_DIR 2
#define EXT2_FT_CHRDEV 3
#define EXT2_FT_BLKDEV 4
#define EXT2_FT_FIFO 5
#define EXT2_FT_SOCK 6
#define EXT2_FT_SYMLINK 7
#define EXT2_FT_MAX 8
#define HAS_COMPAT_FEATURE(sp, mask) \
( (sp)->s_feature_compat & (mask) )
#define HAS_RO_COMPAT_FEATURE(sp, mask) \
( (sp)->s_feature_ro_compat & (mask) )
#define HAS_INCOMPAT_FEATURE(sp, mask) \
( (sp)->s_feature_incompat & (mask) )
/* hash-indexed directory */
#define EXT2_INDEX_FL 0x00001000
/* Top of directory hierarchies*/
#define EXT2_TOPDIR_FL 0x00020000
#define EXT2_PREALLOC_BLOCKS 8
#endif /* EXT2_CONST_H */