minix/servers/fs/const.h

/* Tables sizes */
#define V1_NR_DZONES       7	/* # direct zone numbers in a V1 inode */
#define V1_NR_TZONES       9	/* total # zone numbers in a V1 inode */
#define V2_NR_DZONES       7	/* # direct zone numbers in a V2 inode */
#define V2_NR_TZONES      10	/* total # zone numbers in a V2 inode */

#define NR_FILPS         256	/* # slots in filp table */
#define NR_INODES        256	/* # slots in "in core" inode table */
#define NR_SUPERS         12	/* # slots in super block table */
#define NR_LOCKS           8	/* # slots in the file locking table */

/* 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))

/* File system types. */
#define SUPER_MAGIC   0x137F	/* magic number contained in super-block */
#define SUPER_REV     0x7F13	/* magic # when 68000 disk read on PC or vv */
#define SUPER_V2      0x2468	/* magic # for V2 file systems */
#define SUPER_V2_REV  0x6824	/* V2 magic written on PC, read on 68K or vv */
#define SUPER_V3      0x4d5a	/* magic # for V3 file systems */

#define V1		   1	/* version number of V1 file systems */ 
#define V2		   2	/* version number of V2 file systems */ 
#define V3		   3	/* version number of V3 file systems */ 

/* Miscellaneous constants */
#define SU_UID 	 ((uid_t) 0)	/* super_user's uid_t */
#define SERVERS_UID ((uid_t) 11) /* who may do FSSIGNON */
#define SYS_UID  ((uid_t) 0)	/* uid_t for processes MM and INIT */
#define SYS_GID  ((gid_t) 0)	/* gid_t for processes MM and INIT */
#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 XPIPE   (-NR_TASKS-1)	/* used in fp_task when susp'd on pipe */
#define XLOCK   (-NR_TASKS-2)	/* used in fp_task when susp'd on lock */
#define XPOPEN  (-NR_TASKS-3)	/* used in fp_task when susp'd on pipe open */
#define XSELECT (-NR_TASKS-4)	/* used in fp_task when susp'd on select */

#define NO_BIT   ((bit_t) 0)	/* returned by alloc_bit() to signal failure */

#define DUP_MASK        0100	/* mask to distinguish dup2 from dup */

#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 PATH_TRANSPARENT 000   /* parse_path stops at final object */
#define PATH_PENULTIMATE 001   /* parse_path stops at last but one name */
#define PATH_OPAQUE      002   /* parse_path stops at final name */
#define PATH_NONSYMBOLIC 004   /* parse_path scans final name if symbolic */
#define PATH_STRIPDOT    010   /* parse_path strips /. from path */
#define EAT_PATH         PATH_TRANSPARENT
#define EAT_PATH_OPAQUE  PATH_OPAQUE 
#define LAST_DIR         PATH_PENULTIMATE
#define LAST_DIR_NOTDOT  PATH_PENULTIMATE | PATH_STRIPDOT
#define LAST_DIR_EATSYM  PATH_NONSYMBOLIC
#define SYMLOOP		16

#define CLEAN              0	/* disk and memory copies identical */
#define DIRTY              1	/* 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 ROOT_INODE         1		/* inode number for root directory */
#define BOOT_BLOCK  ((block_t) 0)	/* block number of boot block */
#define SUPER_BLOCK_BYTES (1024)	/* bytes offset */
#define START_BLOCK 	2		/* first block of FS (not counting SB) */

#define DIR_ENTRY_SIZE       usizeof (struct direct)  /* # bytes/dir entry   */
#define NR_DIR_ENTRIES(b)   ((b)/DIR_ENTRY_SIZE)  /* # dir entries/blk   */
#define SUPER_SIZE      usizeof (struct super_block)  /* super_block size    */
#define PIPE_SIZE(b)          (V1_NR_DZONES*(b))  /* pipe size in bytes  */

#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)

/* Derived sizes pertaining to the V1 file system. */
#define V1_ZONE_NUM_SIZE           usizeof (zone1_t)  /* # bytes in V1 zone  */
#define V1_INODE_SIZE             usizeof (d1_inode)  /* bytes in V1 dsk ino */

/* # zones/indir block */
#define V1_INDIRECTS (_STATIC_BLOCK_SIZE/V1_ZONE_NUM_SIZE)  

/* # V1 dsk inodes/blk */
#define V1_INODES_PER_BLOCK (_STATIC_BLOCK_SIZE/V1_INODE_SIZE)

/* Derived sizes pertaining to the V2 file system. */
#define V2_ZONE_NUM_SIZE            usizeof (zone_t)  /* # bytes in V2 zone  */
#define V2_INODE_SIZE             usizeof (d2_inode)  /* bytes in V2 dsk ino */
#define V2_INDIRECTS(b)   ((b)/V2_ZONE_NUM_SIZE)  /* # zones/indir block */
#define V2_INODES_PER_BLOCK(b) ((b)/V2_INODE_SIZE)/* # V2 dsk inodes/blk */