xref: /freebsd/sys/ufs/ffs/ffs_tables.c (revision f0a75d274af375d15b97b830966b99a02b7db911)
1 /*-
2  * Copyright (c) 1982, 1986, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	@(#)ffs_tables.c	8.1 (Berkeley) 6/11/93
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include <sys/param.h>
36 #include <ufs/ufs/dinode.h>
37 #include <ufs/ffs/fs.h>
38 
39 /*
40  * Bit patterns for identifying fragments in the block map
41  * used as ((map & around) == inside)
42  */
43 int around[9] = {
44 	0x3, 0x7, 0xf, 0x1f, 0x3f, 0x7f, 0xff, 0x1ff, 0x3ff
45 };
46 int inside[9] = {
47 	0x0, 0x2, 0x6, 0xe, 0x1e, 0x3e, 0x7e, 0xfe, 0x1fe
48 };
49 
50 /*
51  * Given a block map bit pattern, the frag tables tell whether a
52  * particular size fragment is available.
53  *
54  * used as:
55  * if ((1 << (size - 1)) & fragtbl[fs->fs_frag][map] {
56  *	at least one fragment of the indicated size is available
57  * }
58  *
59  * These tables are used by the scanc instruction on the VAX to
60  * quickly find an appropriate fragment.
61  */
62 static u_char fragtbl124[256] = {
63 	0x00, 0x16, 0x16, 0x2a, 0x16, 0x16, 0x26, 0x4e,
64 	0x16, 0x16, 0x16, 0x3e, 0x2a, 0x3e, 0x4e, 0x8a,
65 	0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
66 	0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
67 	0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
68 	0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
69 	0x2a, 0x3e, 0x3e, 0x2a, 0x3e, 0x3e, 0x2e, 0x6e,
70 	0x3e, 0x3e, 0x3e, 0x3e, 0x2a, 0x3e, 0x6e, 0xaa,
71 	0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
72 	0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
73 	0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
74 	0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
75 	0x26, 0x36, 0x36, 0x2e, 0x36, 0x36, 0x26, 0x6e,
76 	0x36, 0x36, 0x36, 0x3e, 0x2e, 0x3e, 0x6e, 0xae,
77 	0x4e, 0x5e, 0x5e, 0x6e, 0x5e, 0x5e, 0x6e, 0x4e,
78 	0x5e, 0x5e, 0x5e, 0x7e, 0x6e, 0x7e, 0x4e, 0xce,
79 	0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
80 	0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
81 	0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
82 	0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
83 	0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
84 	0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
85 	0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x7e,
86 	0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x7e, 0xbe,
87 	0x2a, 0x3e, 0x3e, 0x2a, 0x3e, 0x3e, 0x2e, 0x6e,
88 	0x3e, 0x3e, 0x3e, 0x3e, 0x2a, 0x3e, 0x6e, 0xaa,
89 	0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x7e,
90 	0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x7e, 0xbe,
91 	0x4e, 0x5e, 0x5e, 0x6e, 0x5e, 0x5e, 0x6e, 0x4e,
92 	0x5e, 0x5e, 0x5e, 0x7e, 0x6e, 0x7e, 0x4e, 0xce,
93 	0x8a, 0x9e, 0x9e, 0xaa, 0x9e, 0x9e, 0xae, 0xce,
94 	0x9e, 0x9e, 0x9e, 0xbe, 0xaa, 0xbe, 0xce, 0x8a,
95 };
96 
97 static u_char fragtbl8[256] = {
98 	0x00, 0x01, 0x01, 0x02, 0x01, 0x01, 0x02, 0x04,
99 	0x01, 0x01, 0x01, 0x03, 0x02, 0x03, 0x04, 0x08,
100 	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
101 	0x02, 0x03, 0x03, 0x02, 0x04, 0x05, 0x08, 0x10,
102 	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
103 	0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09,
104 	0x02, 0x03, 0x03, 0x02, 0x03, 0x03, 0x02, 0x06,
105 	0x04, 0x05, 0x05, 0x06, 0x08, 0x09, 0x10, 0x20,
106 	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
107 	0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09,
108 	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
109 	0x03, 0x03, 0x03, 0x03, 0x05, 0x05, 0x09, 0x11,
110 	0x02, 0x03, 0x03, 0x02, 0x03, 0x03, 0x02, 0x06,
111 	0x03, 0x03, 0x03, 0x03, 0x02, 0x03, 0x06, 0x0a,
112 	0x04, 0x05, 0x05, 0x06, 0x05, 0x05, 0x06, 0x04,
113 	0x08, 0x09, 0x09, 0x0a, 0x10, 0x11, 0x20, 0x40,
114 	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
115 	0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09,
116 	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
117 	0x03, 0x03, 0x03, 0x03, 0x05, 0x05, 0x09, 0x11,
118 	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
119 	0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09,
120 	0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x07,
121 	0x05, 0x05, 0x05, 0x07, 0x09, 0x09, 0x11, 0x21,
122 	0x02, 0x03, 0x03, 0x02, 0x03, 0x03, 0x02, 0x06,
123 	0x03, 0x03, 0x03, 0x03, 0x02, 0x03, 0x06, 0x0a,
124 	0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x07,
125 	0x02, 0x03, 0x03, 0x02, 0x06, 0x07, 0x0a, 0x12,
126 	0x04, 0x05, 0x05, 0x06, 0x05, 0x05, 0x06, 0x04,
127 	0x05, 0x05, 0x05, 0x07, 0x06, 0x07, 0x04, 0x0c,
128 	0x08, 0x09, 0x09, 0x0a, 0x09, 0x09, 0x0a, 0x0c,
129 	0x10, 0x11, 0x11, 0x12, 0x20, 0x21, 0x40, 0x80,
130 };
131 
132 /*
133  * The actual fragtbl array.
134  */
135 u_char *fragtbl[MAXFRAG + 1] = {
136 	0, fragtbl124, fragtbl124, 0, fragtbl124, 0, 0, 0, fragtbl8,
137 };
138