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 * 3. 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 * $FreeBSD: src/sys/ufs/ffs/ffs_tables.c,v 1.7 1999/08/28 00:52:22 peter Exp $ 31 * $DragonFly: src/sys/vfs/ufs/ffs_tables.c,v 1.2 2003/06/17 04:28:59 dillon Exp $ 32 */ 33 34 #include <sys/param.h> 35 36 /* 37 * Bit patterns for identifying fragments in the block map 38 * used as ((map & around) == inside) 39 */ 40 int around[9] = { 41 0x3, 0x7, 0xf, 0x1f, 0x3f, 0x7f, 0xff, 0x1ff, 0x3ff 42 }; 43 int inside[9] = { 44 0x0, 0x2, 0x6, 0xe, 0x1e, 0x3e, 0x7e, 0xfe, 0x1fe 45 }; 46 47 /* 48 * Given a block map bit pattern, the frag tables tell whether a 49 * particular size fragment is available. 50 * 51 * used as: 52 * if ((1 << (size - 1)) & fragtbl[fs->fs_frag][map] { 53 * at least one fragment of the indicated size is available 54 * } 55 * 56 * These tables are used by the scanc instruction on the VAX to 57 * quickly find an appropriate fragment. 58 */ 59 static u_char fragtbl124[256] = { 60 0x00, 0x16, 0x16, 0x2a, 0x16, 0x16, 0x26, 0x4e, 61 0x16, 0x16, 0x16, 0x3e, 0x2a, 0x3e, 0x4e, 0x8a, 62 0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e, 63 0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e, 64 0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e, 65 0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e, 66 0x2a, 0x3e, 0x3e, 0x2a, 0x3e, 0x3e, 0x2e, 0x6e, 67 0x3e, 0x3e, 0x3e, 0x3e, 0x2a, 0x3e, 0x6e, 0xaa, 68 0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e, 69 0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e, 70 0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e, 71 0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e, 72 0x26, 0x36, 0x36, 0x2e, 0x36, 0x36, 0x26, 0x6e, 73 0x36, 0x36, 0x36, 0x3e, 0x2e, 0x3e, 0x6e, 0xae, 74 0x4e, 0x5e, 0x5e, 0x6e, 0x5e, 0x5e, 0x6e, 0x4e, 75 0x5e, 0x5e, 0x5e, 0x7e, 0x6e, 0x7e, 0x4e, 0xce, 76 0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e, 77 0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e, 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 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x7e, 83 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x7e, 0xbe, 84 0x2a, 0x3e, 0x3e, 0x2a, 0x3e, 0x3e, 0x2e, 0x6e, 85 0x3e, 0x3e, 0x3e, 0x3e, 0x2a, 0x3e, 0x6e, 0xaa, 86 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x7e, 87 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x7e, 0xbe, 88 0x4e, 0x5e, 0x5e, 0x6e, 0x5e, 0x5e, 0x6e, 0x4e, 89 0x5e, 0x5e, 0x5e, 0x7e, 0x6e, 0x7e, 0x4e, 0xce, 90 0x8a, 0x9e, 0x9e, 0xaa, 0x9e, 0x9e, 0xae, 0xce, 91 0x9e, 0x9e, 0x9e, 0xbe, 0xaa, 0xbe, 0xce, 0x8a, 92 }; 93 94 static u_char fragtbl8[256] = { 95 0x00, 0x01, 0x01, 0x02, 0x01, 0x01, 0x02, 0x04, 96 0x01, 0x01, 0x01, 0x03, 0x02, 0x03, 0x04, 0x08, 97 0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05, 98 0x02, 0x03, 0x03, 0x02, 0x04, 0x05, 0x08, 0x10, 99 0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05, 100 0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09, 101 0x02, 0x03, 0x03, 0x02, 0x03, 0x03, 0x02, 0x06, 102 0x04, 0x05, 0x05, 0x06, 0x08, 0x09, 0x10, 0x20, 103 0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05, 104 0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09, 105 0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05, 106 0x03, 0x03, 0x03, 0x03, 0x05, 0x05, 0x09, 0x11, 107 0x02, 0x03, 0x03, 0x02, 0x03, 0x03, 0x02, 0x06, 108 0x03, 0x03, 0x03, 0x03, 0x02, 0x03, 0x06, 0x0a, 109 0x04, 0x05, 0x05, 0x06, 0x05, 0x05, 0x06, 0x04, 110 0x08, 0x09, 0x09, 0x0a, 0x10, 0x11, 0x20, 0x40, 111 0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05, 112 0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09, 113 0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05, 114 0x03, 0x03, 0x03, 0x03, 0x05, 0x05, 0x09, 0x11, 115 0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05, 116 0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09, 117 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x07, 118 0x05, 0x05, 0x05, 0x07, 0x09, 0x09, 0x11, 0x21, 119 0x02, 0x03, 0x03, 0x02, 0x03, 0x03, 0x02, 0x06, 120 0x03, 0x03, 0x03, 0x03, 0x02, 0x03, 0x06, 0x0a, 121 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x07, 122 0x02, 0x03, 0x03, 0x02, 0x06, 0x07, 0x0a, 0x12, 123 0x04, 0x05, 0x05, 0x06, 0x05, 0x05, 0x06, 0x04, 124 0x05, 0x05, 0x05, 0x07, 0x06, 0x07, 0x04, 0x0c, 125 0x08, 0x09, 0x09, 0x0a, 0x09, 0x09, 0x0a, 0x0c, 126 0x10, 0x11, 0x11, 0x12, 0x20, 0x21, 0x40, 0x80, 127 }; 128 129 /* 130 * The actual fragtbl array. 131 */ 132 u_char *fragtbl[MAXFRAG + 1] = { 133 0, fragtbl124, fragtbl124, 0, fragtbl124, 0, 0, 0, fragtbl8, 134 }; 135