1 /* $OpenBSD: ffs_tables.c,v 1.6 2011/07/03 18:23:10 tedu Exp $ */ 2 /* $NetBSD: ffs_tables.c,v 1.2 1994/06/29 06:46:35 cgd Exp $ */ 3 4 /* 5 * Copyright (c) 1982, 1986, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)ffs_tables.c 8.1 (Berkeley) 6/11/93 33 */ 34 35 #include <sys/param.h> 36 #include <ufs/ffs/fs.h> 37 38 /* 39 * Bit patterns for identifying fragments in the block map 40 * used as ((map & around) == inside) 41 */ 42 const int around[9] = { 43 0x3, 0x7, 0xf, 0x1f, 0x3f, 0x7f, 0xff, 0x1ff, 0x3ff 44 }; 45 const int inside[9] = { 46 0x0, 0x2, 0x6, 0xe, 0x1e, 0x3e, 0x7e, 0xfe, 0x1fe 47 }; 48 49 /* 50 * Given a block map bit pattern, the frag tables tell whether a 51 * particular size fragment is available. 52 * 53 * used as: 54 * if ((1 << (size - 1)) & fragtbl[fs->fs_frag][map] { 55 * at least one fragment of the indicated size is available 56 * } 57 * 58 * These tables are used by the scanc instruction on the VAX to 59 * quickly find an appropriate fragment. 60 */ 61 const u_char fragtbl124[256] = { 62 0x00, 0x16, 0x16, 0x2a, 0x16, 0x16, 0x26, 0x4e, 63 0x16, 0x16, 0x16, 0x3e, 0x2a, 0x3e, 0x4e, 0x8a, 64 0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e, 65 0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e, 66 0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e, 67 0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e, 68 0x2a, 0x3e, 0x3e, 0x2a, 0x3e, 0x3e, 0x2e, 0x6e, 69 0x3e, 0x3e, 0x3e, 0x3e, 0x2a, 0x3e, 0x6e, 0xaa, 70 0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e, 71 0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e, 72 0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e, 73 0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e, 74 0x26, 0x36, 0x36, 0x2e, 0x36, 0x36, 0x26, 0x6e, 75 0x36, 0x36, 0x36, 0x3e, 0x2e, 0x3e, 0x6e, 0xae, 76 0x4e, 0x5e, 0x5e, 0x6e, 0x5e, 0x5e, 0x6e, 0x4e, 77 0x5e, 0x5e, 0x5e, 0x7e, 0x6e, 0x7e, 0x4e, 0xce, 78 0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e, 79 0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e, 80 0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e, 81 0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e, 82 0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e, 83 0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e, 84 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x7e, 85 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x7e, 0xbe, 86 0x2a, 0x3e, 0x3e, 0x2a, 0x3e, 0x3e, 0x2e, 0x6e, 87 0x3e, 0x3e, 0x3e, 0x3e, 0x2a, 0x3e, 0x6e, 0xaa, 88 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x7e, 89 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x7e, 0xbe, 90 0x4e, 0x5e, 0x5e, 0x6e, 0x5e, 0x5e, 0x6e, 0x4e, 91 0x5e, 0x5e, 0x5e, 0x7e, 0x6e, 0x7e, 0x4e, 0xce, 92 0x8a, 0x9e, 0x9e, 0xaa, 0x9e, 0x9e, 0xae, 0xce, 93 0x9e, 0x9e, 0x9e, 0xbe, 0xaa, 0xbe, 0xce, 0x8a, 94 }; 95 96 const u_char fragtbl8[256] = { 97 0x00, 0x01, 0x01, 0x02, 0x01, 0x01, 0x02, 0x04, 98 0x01, 0x01, 0x01, 0x03, 0x02, 0x03, 0x04, 0x08, 99 0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05, 100 0x02, 0x03, 0x03, 0x02, 0x04, 0x05, 0x08, 0x10, 101 0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05, 102 0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09, 103 0x02, 0x03, 0x03, 0x02, 0x03, 0x03, 0x02, 0x06, 104 0x04, 0x05, 0x05, 0x06, 0x08, 0x09, 0x10, 0x20, 105 0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05, 106 0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09, 107 0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05, 108 0x03, 0x03, 0x03, 0x03, 0x05, 0x05, 0x09, 0x11, 109 0x02, 0x03, 0x03, 0x02, 0x03, 0x03, 0x02, 0x06, 110 0x03, 0x03, 0x03, 0x03, 0x02, 0x03, 0x06, 0x0a, 111 0x04, 0x05, 0x05, 0x06, 0x05, 0x05, 0x06, 0x04, 112 0x08, 0x09, 0x09, 0x0a, 0x10, 0x11, 0x20, 0x40, 113 0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05, 114 0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09, 115 0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05, 116 0x03, 0x03, 0x03, 0x03, 0x05, 0x05, 0x09, 0x11, 117 0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05, 118 0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09, 119 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x07, 120 0x05, 0x05, 0x05, 0x07, 0x09, 0x09, 0x11, 0x21, 121 0x02, 0x03, 0x03, 0x02, 0x03, 0x03, 0x02, 0x06, 122 0x03, 0x03, 0x03, 0x03, 0x02, 0x03, 0x06, 0x0a, 123 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x07, 124 0x02, 0x03, 0x03, 0x02, 0x06, 0x07, 0x0a, 0x12, 125 0x04, 0x05, 0x05, 0x06, 0x05, 0x05, 0x06, 0x04, 126 0x05, 0x05, 0x05, 0x07, 0x06, 0x07, 0x04, 0x0c, 127 0x08, 0x09, 0x09, 0x0a, 0x09, 0x09, 0x0a, 0x0c, 128 0x10, 0x11, 0x11, 0x12, 0x20, 0x21, 0x40, 0x80, 129 }; 130 131 /* 132 * The actual fragtbl array. 133 */ 134 const u_char *fragtbl[MAXFRAG + 1] = { 135 NULL, fragtbl124, fragtbl124, NULL, fragtbl124, NULL, NULL, NULL, 136 fragtbl8, 137 }; 138