xref: /minix/minix/usr.sbin/mkfs.mfs/v1/const.h (revision 7f5f010b)
1 #ifndef _MKFS_MFS_CONST_H__
2 #define _MKFS_MFS_CONST_H__
3 
4 /* Tables sizes */
5 #define NR_DZONES       7	/* # direct zone numbers in a V1 inode */
6 #define NR_TZONES       9	/* total # zone numbers in a V1 inode */
7 
8 /* V1 file systems are special in that zone numbers are only 16-bit */
9 #define zone_t		uint16_t
10 
11 /* Blocks are of a fixed size */
12 #define MFS_STATIC_BLOCK_SIZE	1024
13 
14 #define SUPER_BLOCK_BYTES  MFS_STATIC_BLOCK_SIZE	/* 1 block */
15 
16 /* The type of sizeof may be (unsigned) long.  Use the following macro for
17  * taking the sizes of small objects so that there are no surprises like
18  * (small) long constants being passed to routines expecting an int.
19  */
20 #define usizeof(t) ((unsigned) sizeof(t))
21 
22 /* File system types: magic number contained in super-block. */
23 #define SUPER_V1	0x137F	/* magic # for V1 file systems */
24 #define SUPER_MAGIC	SUPER_V1
25 
26 /* Miscellaneous constants */
27 #define SU_UID		((uid_t) 0)	/* super_user's uid_t */
28 #define SECTOR_SIZE	512
29 
30 #define BOOT_BLOCK	((block_t) 0)	/* block number of boot block */
31 #define SUPER_BLOCK	((block_t) 1)	/* block number of super block */
32 #define START_BLOCK	((block_t) 2)	/* first block of FS (not counting SB) */
33 
34 #define ROOT_INODE	((ino_t) 1)	/* inode number for root directory */
35 
36 /* Derived sizes pertaining to the file system. */
37 #define FS_BITMAP_CHUNKS(b)	((b)/usizeof(bitchunk_t)) /*# map chunks/blk*/
38 #define FS_BITCHUNK_BITS	(usizeof(bitchunk_t) * CHAR_BIT)
39 #define FS_BITS_PER_BLOCK(b)	(FS_BITMAP_CHUNKS(b) * FS_BITCHUNK_BITS)
40 
41 #define ZONE_NUM_SIZE		usizeof (zone_t)  /* # bytes in zone */
42 #define INODE_SIZE		usizeof (struct inode)  /* bytes in dsk ino */
43 #define INODES_PER_BLOCK(b)	((b)/INODE_SIZE)  /* # V2 dsk inodes/blk */
44 #define INDIRECTS(b)		((b)/ZONE_NUM_SIZE)  /* # zones/indir block */
45 
46 #define DIR_ENTRY_SIZE		usizeof(struct direct) /* # bytes/dir entry */
47 #define NR_DIR_ENTRIES(b)	((b)/DIR_ENTRY_SIZE)  /* # dir entries/blk  */
48 
49 #endif
50