minix/servers/mfs/const.h
Ben Gras bd3cde4571 Move primary cache code to libminixfs.
Add primary cache management feature to libminixfs as mfs and ext2
currently do separately, remove cache code from mfs and ext2, and make
them use the libminixfs interface. This makes all fields of the buf
struct private to libminixfs and FS clients aren't supposed to access
them at all. Only the opaque 'void *data' field (the FS block contents,
used to be called bp) is to be accessed by the FS client.

The main purpose is to implement the interface to the 2ndary vm cache
just once, get rid of some code duplication, and add a little
abstraction to reduce the code inertia of the whole caching business.

Some minor sanity checking and prohibition done by mfs in this code
as removed from the generic primary cache code as a result:
        - checking all inodes are not in use when allocating/resizing
          the cache
        - checking readonly filesystems aren't written to
        - checking the superblock isn't written to on mounted filesystems

The minixfslib code relies on fs_blockstats() in the client filesystem to
return some FS usage information.
2012-10-23 19:48:38 +02:00

99 lines
4 KiB
C

#ifndef __MFS_CONST_H__
#define __MFS_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_INODES 512 /* # slots in "in core" inode table,
* should be more or less the same as
* NR_VNODES in vfs
*/
#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)
/* Max. filename length */
#define MFS_NAME_MAX MFS_DIRSIZ
/* 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 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 /* in-block inode and memory copies identical */
#define IN_DIRTY 1 /* in-block inode 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 ((ino_t) 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 ((block_t) 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 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 */
#define NUL(str,l,m) mfs_nul_f(__FILE__,__LINE__,(str), (l), (m))
#endif