1 /* $NetBSD: ffs_subr.c,v 1.32 2003/12/30 12:33:24 pk Exp $ */ 2 3 /*- 4 * SPDX-License-Identifier: BSD-3-Clause 5 * 6 * Copyright (c) 1982, 1986, 1989, 1993 7 * The Regents of the University of California. All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)ffs_subr.c 8.5 (Berkeley) 3/21/95 34 */ 35 36 #include <sys/cdefs.h> 37 __FBSDID("$FreeBSD$"); 38 39 #include <sys/param.h> 40 #include <sys/types.h> 41 42 #include <ufs/ufs/dinode.h> 43 #include <ufs/ffs/fs.h> 44 #include "ffs/ffs_extern.h" 45 #include "ffs/ufs_bswap.h" 46 47 /* 48 * Update the frsum fields to reflect addition or deletion 49 * of some frags. 50 */ 51 void 52 ffs_fragacct_swap(struct fs *fs, int fragmap, int32_t fraglist[], int cnt, int needswap) 53 { 54 int inblk; 55 int field, subfield; 56 int siz, pos; 57 58 inblk = (int)(fragtbl[fs->fs_frag][fragmap]) << 1; 59 fragmap <<= 1; 60 for (siz = 1; siz < fs->fs_frag; siz++) { 61 if ((inblk & (1 << (siz + (fs->fs_frag & (NBBY - 1))))) == 0) 62 continue; 63 field = around[siz]; 64 subfield = inside[siz]; 65 for (pos = siz; pos <= fs->fs_frag; pos++) { 66 if ((fragmap & field) == subfield) { 67 fraglist[siz] = ufs_rw32( 68 ufs_rw32(fraglist[siz], needswap) + cnt, 69 needswap); 70 pos += siz; 71 field <<= siz; 72 subfield <<= siz; 73 } 74 field <<= 1; 75 subfield <<= 1; 76 } 77 } 78 } 79 80 /* 81 * block operations 82 * 83 * check if a block is available 84 * returns true if all the corresponding bits in the free map are 1 85 * returns false if any corresponding bit in the free map is 0 86 */ 87 int 88 ffs_isblock(struct fs *fs, u_char *cp, int32_t h) 89 { 90 u_char mask; 91 92 switch ((int)fs->fs_fragshift) { 93 case 3: 94 return (cp[h] == 0xff); 95 case 2: 96 mask = 0x0f << ((h & 0x1) << 2); 97 return ((cp[h >> 1] & mask) == mask); 98 case 1: 99 mask = 0x03 << ((h & 0x3) << 1); 100 return ((cp[h >> 2] & mask) == mask); 101 case 0: 102 mask = 0x01 << (h & 0x7); 103 return ((cp[h >> 3] & mask) == mask); 104 default: 105 panic("ffs_isblock: unknown fs_fragshift %d", 106 (int)fs->fs_fragshift); 107 } 108 } 109 110 /* 111 * check if a block is completely allocated 112 * returns true if all the corresponding bits in the free map are 0 113 * returns false if any corresponding bit in the free map is 1 114 */ 115 int 116 ffs_isfreeblock(struct fs *fs, u_char *cp, int32_t h) 117 { 118 119 switch ((int)fs->fs_fragshift) { 120 case 3: 121 return (cp[h] == 0); 122 case 2: 123 return ((cp[h >> 1] & (0x0f << ((h & 0x1) << 2))) == 0); 124 case 1: 125 return ((cp[h >> 2] & (0x03 << ((h & 0x3) << 1))) == 0); 126 case 0: 127 return ((cp[h >> 3] & (0x01 << (h & 0x7))) == 0); 128 default: 129 panic("ffs_isfreeblock: unknown fs_fragshift %d", 130 (int)fs->fs_fragshift); 131 } 132 } 133 134 /* 135 * take a block out of the map 136 */ 137 void 138 ffs_clrblock(struct fs *fs, u_char *cp, int32_t h) 139 { 140 141 switch ((int)fs->fs_fragshift) { 142 case 3: 143 cp[h] = 0; 144 return; 145 case 2: 146 cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2)); 147 return; 148 case 1: 149 cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1)); 150 return; 151 case 0: 152 cp[h >> 3] &= ~(0x01 << (h & 0x7)); 153 return; 154 default: 155 panic("ffs_clrblock: unknown fs_fragshift %d", 156 (int)fs->fs_fragshift); 157 } 158 } 159 160 /* 161 * put a block into the map 162 */ 163 void 164 ffs_setblock(struct fs *fs, u_char *cp, int32_t h) 165 { 166 167 switch ((int)fs->fs_fragshift) { 168 case 3: 169 cp[h] = 0xff; 170 return; 171 case 2: 172 cp[h >> 1] |= (0x0f << ((h & 0x1) << 2)); 173 return; 174 case 1: 175 cp[h >> 2] |= (0x03 << ((h & 0x3) << 1)); 176 return; 177 case 0: 178 cp[h >> 3] |= (0x01 << (h & 0x7)); 179 return; 180 default: 181 panic("ffs_setblock: unknown fs_fragshift %d", 182 (int)fs->fs_fragshift); 183 } 184 } 185