ffs_subr.c revision 186335 
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: head/usr.sbin/makefs/ffs/ffs_subr.c 186334 2008-12-19 18:45:43Z sam $");
36
37#include <sys/param.h>
38
39#include <ufs/ufs/dinode.h>
40#include <ufs/ffs/fs.h>
41/* XXX temporary */
42struct ufsmount;
43struct bufobj;
44struct mount;
45struct vnode;
46typedef 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"
50void    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 */
57void
58ffs_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 */
93int
94ffs_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 */
124int
125ffs_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 */
149void
150ffs_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 */
178void
179ffs_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