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 * $FreeBSD: head/usr.sbin/makefs/ffs/ffs_subr.c 333664 2018-05-16 02:58:05Z emaste $
35 */
36
37 #include <sys/param.h>
38 #include <sys/types.h>
39
40 #include <vfs/ufs/dinode.h>
41 #include <vfs/ufs/fs.h>
42 #include "ffs/ffs_extern.h"
43 #include "ffs/ufs_bswap.h"
44
45 /*
46 * Update the frsum fields to reflect addition or deletion
47 * of some frags.
48 */
49 void
ffs_fragacct_swap(struct fs * fs,int fragmap,uint32_t fraglist[],int cnt,int needswap)50 ffs_fragacct_swap(struct fs *fs, int fragmap, uint32_t fraglist[], int cnt, int needswap)
51 {
52 int inblk;
53 int field, subfield;
54 int siz, pos;
55
56 inblk = (int)(fragtbl[fs->fs_frag][fragmap]) << 1;
57 fragmap <<= 1;
58 for (siz = 1; siz < fs->fs_frag; siz++) {
59 if ((inblk & (1 << (siz + (fs->fs_frag & (NBBY - 1))))) == 0)
60 continue;
61 field = around[siz];
62 subfield = inside[siz];
63 for (pos = siz; pos <= fs->fs_frag; pos++) {
64 if ((fragmap & field) == subfield) {
65 fraglist[siz] = ufs_rw32(
66 ufs_rw32(fraglist[siz], needswap) + cnt,
67 needswap);
68 pos += siz;
69 field <<= siz;
70 subfield <<= siz;
71 }
72 field <<= 1;
73 subfield <<= 1;
74 }
75 }
76 }
77
78 /*
79 * block operations
80 *
81 * check if a block is available
82 * returns true if all the corresponding bits in the free map are 1
83 * returns false if any corresponding bit in the free map is 0
84 */
85 int
ffs_isblock(struct fs * fs,u_char * cp,int32_t h)86 ffs_isblock(struct fs *fs, u_char *cp, int32_t h)
87 {
88 u_char mask;
89
90 switch ((int)fs->fs_fragshift) {
91 case 3:
92 return (cp[h] == 0xff);
93 case 2:
94 mask = 0x0f << ((h & 0x1) << 2);
95 return ((cp[h >> 1] & mask) == mask);
96 case 1:
97 mask = 0x03 << ((h & 0x3) << 1);
98 return ((cp[h >> 2] & mask) == mask);
99 case 0:
100 mask = 0x01 << (h & 0x7);
101 return ((cp[h >> 3] & mask) == mask);
102 default:
103 panic("ffs_isblock: unknown fs_fragshift %d",
104 (int)fs->fs_fragshift);
105 }
106 }
107
108 /*
109 * check if a block is completely allocated
110 * returns true if all the corresponding bits in the free map are 0
111 * returns false if any corresponding bit in the free map is 1
112 */
113 int
ffs_isfreeblock(struct fs * fs,u_char * cp,int32_t h)114 ffs_isfreeblock(struct fs *fs, u_char *cp, int32_t h)
115 {
116
117 switch ((int)fs->fs_fragshift) {
118 case 3:
119 return (cp[h] == 0);
120 case 2:
121 return ((cp[h >> 1] & (0x0f << ((h & 0x1) << 2))) == 0);
122 case 1:
123 return ((cp[h >> 2] & (0x03 << ((h & 0x3) << 1))) == 0);
124 case 0:
125 return ((cp[h >> 3] & (0x01 << (h & 0x7))) == 0);
126 default:
127 panic("ffs_isfreeblock: unknown fs_fragshift %d",
128 (int)fs->fs_fragshift);
129 }
130 }
131
132 /*
133 * take a block out of the map
134 */
135 void
ffs_clrblock(struct fs * fs,u_char * cp,int32_t h)136 ffs_clrblock(struct fs *fs, u_char *cp, int32_t h)
137 {
138
139 switch ((int)fs->fs_fragshift) {
140 case 3:
141 cp[h] = 0;
142 return;
143 case 2:
144 cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2));
145 return;
146 case 1:
147 cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1));
148 return;
149 case 0:
150 cp[h >> 3] &= ~(0x01 << (h & 0x7));
151 return;
152 default:
153 panic("ffs_clrblock: unknown fs_fragshift %d",
154 (int)fs->fs_fragshift);
155 }
156 }
157
158 /*
159 * put a block into the map
160 */
161 void
ffs_setblock(struct fs * fs,u_char * cp,int32_t h)162 ffs_setblock(struct fs *fs, u_char *cp, int32_t h)
163 {
164
165 switch ((int)fs->fs_fragshift) {
166 case 3:
167 cp[h] = 0xff;
168 return;
169 case 2:
170 cp[h >> 1] |= (0x0f << ((h & 0x1) << 2));
171 return;
172 case 1:
173 cp[h >> 2] |= (0x03 << ((h & 0x3) << 1));
174 return;
175 case 0:
176 cp[h >> 3] |= (0x01 << (h & 0x7));
177 return;
178 default:
179 panic("ffs_setblock: unknown fs_fragshift %d",
180 (int)fs->fs_fragshift);
181 }
182 }
183