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1 /*
2  * Mach Operating System
3  * Copyright (c) 1991,1990 Carnegie Mellon University
4  * All Rights Reserved.
5  *
6  * Permission to use, copy, modify and distribute this software and its
7  * documentation is hereby granted, provided that both the copyright
8  * notice and this permission notice appear in all copies of the
9  * software, derivative works or modified versions, and any portions
10  * thereof, and that both notices appear in supporting documentation.
11  *
12  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
13  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
14  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
15  *
16  * Carnegie Mellon requests users of this software to return to
17  *
18  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
19  *  School of Computer Science
20  *  Carnegie Mellon University
21  *  Pittsburgh PA 15213-3890
22  *
23  * any improvements or extensions that they make and grant Carnegie Mellon
24  * the rights to redistribute these changes.
25  */
26 /*
27  * Common definitions for Berkeley Fast File System.
28  */
29 
30 /*
31  * Compatibility definitions for disk IO.
32  */
33 
34 /*
35  * Disk devices do all IO in 512-byte blocks.
36  */
37 #define	DEV_BSIZE	512
38 
39 /*
40  * Conversion between bytes and disk blocks.
41  */
42 #define	btodb(byte_offset)	((byte_offset) >> 9)
43 #define	dbtob(block_number)	((block_number) << 9)
44 
45 /*
46  * Compatibility definitions for old type names.
47  */
48 
49 typedef unsigned char u_char;	/* unsigned char */
50 typedef unsigned short u_short;	/* unsigned short */
51 typedef unsigned int u_int;	/* unsigned int */
52 
53 typedef struct _quad_
54   {
55     unsigned int val[2];	/* 2 int values make... */
56   }
57 quad;				/* an 8-byte item */
58 
59 typedef unsigned int mach_time_t;	/* an unsigned int */
60 typedef unsigned int mach_daddr_t;	/* an unsigned int */
61 typedef unsigned int mach_off_t;	/* another unsigned int */
62 
63 typedef unsigned short mach_uid_t;
64 typedef unsigned short mach_gid_t;
65 typedef unsigned int mach_ino_t;
66 
67 #define	NBBY	8
68 
69 /*
70  * The file system is made out of blocks of at most MAXBSIZE units,
71  * with smaller units (fragments) only in the last direct block.
72  * MAXBSIZE primarily determines the size of buffers in the buffer
73  * pool.  It may be made larger without any effect on existing
74  * file systems; however, making it smaller may make some file
75  * systems unmountable.
76  *
77  * Note that the disk devices are assumed to have DEV_BSIZE "sectors"
78  * and that fragments must be some multiple of this size.
79  */
80 #define	MAXBSIZE	8192
81 #define	MAXFRAG		8
82 
83 /*
84  * MAXPATHLEN defines the longest permissible path length
85  * after expanding symbolic links.
86  *
87  * MAXSYMLINKS defines the maximum number of symbolic links
88  * that may be expanded in a path name.  It should be set
89  * high enough to allow all legitimate uses, but halt infinite
90  * loops reasonably quickly.
91  */
92 
93 #define	MAXPATHLEN	1024
94 #define	MAXSYMLINKS	8
95