const.h

一个简单的操作系统minix的核心代码

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				src/fs/const.h	 	 
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19500	/* Tables sizes */
19501	#define V1_NR_DZONES       7    /* # direct zone numbers in a V1 inode */
19502	#define V1_NR_TZONES       9    /* total # zone numbers in a V1 inode */
19503	#define V2_NR_DZONES       7    /* # direct zone numbers in a V2 inode */
19504	#define V2_NR_TZONES      10    /* total # zone numbers in a V2 inode */
19505	
19506	#define NR_FILPS         128    /* # slots in filp table */
19507	#define NR_INODES         64    /* # slots in "in core" inode table */
19508	#define NR_SUPERS          8    /* # slots in super block table */
19509	#define NR_LOCKS           8    /* # slots in the file locking table */
19510	
19511	/* The type of sizeof may be (unsigned) long.  Use the following macro for
19512	 * taking the sizes of small objects so that there are no surprises like
19513	 * (small) long constants being passed to routines expecting an int.
19514	 */
19515	#define usizeof(t) ((unsigned) sizeof(t))
19516	
19517	/* File system types. */
19518	#define SUPER_MAGIC   0x137F    /* magic number contained in super-block */
19519	#define SUPER_REV     0x7F13    /* magic # when 68000 disk read on PC or vv */
19520	#define SUPER_V2      0x2468    /* magic # for V2 file systems */
19521	#define SUPER_V2_REV  0x6824    /* V2 magic written on PC, read on 68K or vv */
19522	
19523	#define V1                 1    /* version number of V1 file systems */ 
19524	#define V2                 2    /* version number of V2 file systems */ 
19525	
19526	/* Miscellaneous constants */
19527	#define SU_UID   ((uid_t) 0)    /* super_user's uid_t */
19528	#define SYS_UID  ((uid_t) 0)    /* uid_t for processes MM and INIT */
19529	#define SYS_GID  ((gid_t) 0)    /* gid_t for processes MM and INIT */
19530	#define NORMAL             0    /* forces get_block to do disk read */
19531	#define NO_READ            1    /* prevents get_block from doing disk read */
19532	#define PREFETCH           2    /* tells get_block not to read or mark dev */
19533	
19534	#define XPIPE  (-NR_TASKS-1)    /* used in fp_task when susp'd on pipe */
19535	#define XOPEN  (-NR_TASKS-2)    /* used in fp_task when susp'd on open */
19536	#define XLOCK  (-NR_TASKS-3)    /* used in fp_task when susp'd on lock */
19537	#define XPOPEN (-NR_TASKS-4)    /* used in fp_task when susp'd on pipe open */
19538	
19539	#define NO_BIT   ((bit_t) 0)    /* returned by alloc_bit() to signal failure */
19540	
19541	#define DUP_MASK        0100    /* mask to distinguish dup2 from dup */
19542	
19543	#define LOOK_UP            0    /* tells search_dir to lookup string */
19544	#define ENTER              1    /* tells search_dir to make dir entry */
19545	#define DELETE             2    /* tells search_dir to delete entry */
19546	#define IS_EMPTY           3    /* tells search_dir to ret. OK or ENOTEMPTY */  
19547	
19548	#define CLEAN              0    /* disk and memory copies identical */
19549	#define DIRTY              1    /* disk and memory copies differ */
19550	#define ATIME            002    /* set if atime field needs updating */
19551	#define CTIME            004    /* set if ctime field needs updating */
19552	#define MTIME            010    /* set if mtime field needs updating */
19553	
19554	#define BYTE_SWAP          0    /* tells conv2/conv4 to swap bytes */
19555	#define DONT_SWAP          1    /* tells conv2/conv4 not to swap bytes */
19556	
19557	#define END_OF_FILE   (-104)    /* eof detected */
19558	
19559	#define ROOT_INODE         1    /* inode number for root directory */
19560	#define BOOT_BLOCK  ((block_t) 0)       /* block number of boot block */
19561	#define SUPER_BLOCK ((block_t) 1)       /* block number of super block */
19562	
19563	#define DIR_ENTRY_SIZE       usizeof (struct direct)  /* # bytes/dir entry   */
19564	#define NR_DIR_ENTRIES   (BLOCK_SIZE/DIR_ENTRY_SIZE)  /* # dir entries/blk   */
19565	#define SUPER_SIZE      usizeof (struct super_block)  /* super_block size    */
19566	#define PIPE_SIZE          (V1_NR_DZONES*BLOCK_SIZE)  /* pipe size in bytes  */
19567	#define BITMAP_CHUNKS (BLOCK_SIZE/usizeof (bitchunk_t))/* # map chunks/blk   */
19568	
19569	/* Derived sizes pertaining to the V1 file system. */
19570	#define V1_ZONE_NUM_SIZE           usizeof (zone1_t)  /* # bytes in V1 zone  */
19571	#define V1_INODE_SIZE             usizeof (d1_inode)  /* bytes in V1 dsk ino */
19572	#define V1_INDIRECTS   (BLOCK_SIZE/V1_ZONE_NUM_SIZE)  /* # zones/indir block */
19573	#define V1_INODES_PER_BLOCK (BLOCK_SIZE/V1_INODE_SIZE)/* # V1 dsk inodes/blk */
19574	
19575	/* Derived sizes pertaining to the V2 file system. */
19576	#define V2_ZONE_NUM_SIZE            usizeof (zone_t)  /* # bytes in V2 zone  */
19577	#define V2_INODE_SIZE             usizeof (d2_inode)  /* bytes in V2 dsk ino */
19578	#define V2_INDIRECTS   (BLOCK_SIZE/V2_ZONE_NUM_SIZE)  /* # zones/indir block */
19579	#define V2_INODES_PER_BLOCK (BLOCK_SIZE/V2_INODE_SIZE)/* # V2 dsk inodes/blk */
19580	
19581	#define printf printk