xref: /freebsd/usr.sbin/makefs/ffs/ffs_subr.c (revision 7d0d268b8a67f28ccefdd0b8ce6fb38acac78d80)
1 /*	$NetBSD: ffs_subr.c,v 1.32 2003/12/30 12:33:24 pk Exp $	*/
2 
3 /*
4  * Copyright (c) 1982, 1986, 1989, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	@(#)ffs_subr.c	8.5 (Berkeley) 3/21/95
32  */
33 
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36 
37 #include <sys/param.h>
38 
39 #include <ufs/ufs/dinode.h>
40 #include <ufs/ffs/fs.h>
41 /* XXX temporary */
42 struct ufsmount;
43 struct bufobj;
44 struct mount;
45 struct vnode;
46 typedef int vfs_vget_t(struct mount *mp, ino_t ino, int flags,
47                     struct vnode **vpp);
48 #include <ufs/ffs/ffs_extern.h>
49 #include "ffs/ufs_bswap.h"
50 void    panic __P((const char *, ...))
51     __attribute__((__noreturn__,__format__(__printf__,1,2)));
52 
53 /*
54  * Update the frsum fields to reflect addition or deletion
55  * of some frags.
56  */
57 void
58 ffs_fragacct_swap(struct fs *fs, int fragmap, int32_t fraglist[], int cnt, int needswap)
59 {
60 	int inblk;
61 	int field, subfield;
62 	int siz, pos;
63 
64 	inblk = (int)(fragtbl[fs->fs_frag][fragmap]) << 1;
65 	fragmap <<= 1;
66 	for (siz = 1; siz < fs->fs_frag; siz++) {
67 		if ((inblk & (1 << (siz + (fs->fs_frag & (NBBY - 1))))) == 0)
68 			continue;
69 		field = around[siz];
70 		subfield = inside[siz];
71 		for (pos = siz; pos <= fs->fs_frag; pos++) {
72 			if ((fragmap & field) == subfield) {
73 				fraglist[siz] = ufs_rw32(
74 				    ufs_rw32(fraglist[siz], needswap) + cnt,
75 				    needswap);
76 				pos += siz;
77 				field <<= siz;
78 				subfield <<= siz;
79 			}
80 			field <<= 1;
81 			subfield <<= 1;
82 		}
83 	}
84 }
85 
86 /*
87  * block operations
88  *
89  * check if a block is available
90  *  returns true if all the correponding bits in the free map are 1
91  *  returns false if any corresponding bit in the free map is 0
92  */
93 int
94 ffs_isblock(fs, cp, h)
95 	struct fs *fs;
96 	u_char *cp;
97 	int32_t h;
98 {
99 	u_char mask;
100 
101 	switch ((int)fs->fs_fragshift) {
102 	case 3:
103 		return (cp[h] == 0xff);
104 	case 2:
105 		mask = 0x0f << ((h & 0x1) << 2);
106 		return ((cp[h >> 1] & mask) == mask);
107 	case 1:
108 		mask = 0x03 << ((h & 0x3) << 1);
109 		return ((cp[h >> 2] & mask) == mask);
110 	case 0:
111 		mask = 0x01 << (h & 0x7);
112 		return ((cp[h >> 3] & mask) == mask);
113 	default:
114 		panic("ffs_isblock: unknown fs_fragshift %d",
115 		    (int)fs->fs_fragshift);
116 	}
117 }
118 
119 /*
120  * check if a block is completely allocated
121  *  returns true if all the corresponding bits in the free map are 0
122  *  returns false if any corresponding bit in the free map is 1
123  */
124 int
125 ffs_isfreeblock(fs, cp, h)
126 	struct fs *fs;
127 	u_char *cp;
128 	int32_t h;
129 {
130 
131 	switch ((int)fs->fs_fragshift) {
132 	case 3:
133 		return (cp[h] == 0);
134 	case 2:
135 		return ((cp[h >> 1] & (0x0f << ((h & 0x1) << 2))) == 0);
136 	case 1:
137 		return ((cp[h >> 2] & (0x03 << ((h & 0x3) << 1))) == 0);
138 	case 0:
139 		return ((cp[h >> 3] & (0x01 << (h & 0x7))) == 0);
140 	default:
141 		panic("ffs_isfreeblock: unknown fs_fragshift %d",
142 		    (int)fs->fs_fragshift);
143 	}
144 }
145 
146 /*
147  * take a block out of the map
148  */
149 void
150 ffs_clrblock(fs, cp, h)
151 	struct fs *fs;
152 	u_char *cp;
153 	int32_t h;
154 {
155 
156 	switch ((int)fs->fs_fragshift) {
157 	case 3:
158 		cp[h] = 0;
159 		return;
160 	case 2:
161 		cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2));
162 		return;
163 	case 1:
164 		cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1));
165 		return;
166 	case 0:
167 		cp[h >> 3] &= ~(0x01 << (h & 0x7));
168 		return;
169 	default:
170 		panic("ffs_clrblock: unknown fs_fragshift %d",
171 		    (int)fs->fs_fragshift);
172 	}
173 }
174 
175 /*
176  * put a block into the map
177  */
178 void
179 ffs_setblock(fs, cp, h)
180 	struct fs *fs;
181 	u_char *cp;
182 	int32_t h;
183 {
184 
185 	switch ((int)fs->fs_fragshift) {
186 	case 3:
187 		cp[h] = 0xff;
188 		return;
189 	case 2:
190 		cp[h >> 1] |= (0x0f << ((h & 0x1) << 2));
191 		return;
192 	case 1:
193 		cp[h >> 2] |= (0x03 << ((h & 0x3) << 1));
194 		return;
195 	case 0:
196 		cp[h >> 3] |= (0x01 << (h & 0x7));
197 		return;
198 	default:
199 		panic("ffs_setblock: unknown fs_fragshift %d",
200 		    (int)fs->fs_fragshift);
201 	}
202 }
203