ffs_subr.c revision 330897 
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: stable/11/usr.sbin/makefs/ffs/ffs_subr.c 330897 2018-03-14 03:19:51Z eadler $");
38
39#include <sys/param.h>
40
41#include <ufs/ufs/dinode.h>
42#include <ufs/ffs/fs.h>
43#include "ffs/ffs_extern.h"
44#include "ffs/ufs_bswap.h"
45
46/*
47 * Update the frsum fields to reflect addition or deletion
48 * of some frags.
49 */
50void
51ffs_fragacct_swap(struct fs *fs, int fragmap, int32_t fraglist[], int cnt, int needswap)
52{
53	int inblk;
54	int field, subfield;
55	int siz, pos;
56
57	inblk = (int)(fragtbl[fs->fs_frag][fragmap]) << 1;
58	fragmap <<= 1;
59	for (siz = 1; siz < fs->fs_frag; siz++) {
60		if ((inblk & (1 << (siz + (fs->fs_frag & (NBBY - 1))))) == 0)
61			continue;
62		field = around[siz];
63		subfield = inside[siz];
64		for (pos = siz; pos <= fs->fs_frag; pos++) {
65			if ((fragmap & field) == subfield) {
66				fraglist[siz] = ufs_rw32(
67				    ufs_rw32(fraglist[siz], needswap) + cnt,
68				    needswap);
69				pos += siz;
70				field <<= siz;
71				subfield <<= siz;
72			}
73			field <<= 1;
74			subfield <<= 1;
75		}
76	}
77}
78
79/*
80 * block operations
81 *
82 * check if a block is available
83 *  returns true if all the corresponding bits in the free map are 1
84 *  returns false if any corresponding bit in the free map is 0
85 */
86int
87ffs_isblock(fs, cp, h)
88	struct fs *fs;
89	u_char *cp;
90	int32_t h;
91{
92	u_char mask;
93
94	switch ((int)fs->fs_fragshift) {
95	case 3:
96		return (cp[h] == 0xff);
97	case 2:
98		mask = 0x0f << ((h & 0x1) << 2);
99		return ((cp[h >> 1] & mask) == mask);
100	case 1:
101		mask = 0x03 << ((h & 0x3) << 1);
102		return ((cp[h >> 2] & mask) == mask);
103	case 0:
104		mask = 0x01 << (h & 0x7);
105		return ((cp[h >> 3] & mask) == mask);
106	default:
107		panic("ffs_isblock: unknown fs_fragshift %d",
108		    (int)fs->fs_fragshift);
109	}
110}
111
112/*
113 * check if a block is completely allocated
114 *  returns true if all the corresponding bits in the free map are 0
115 *  returns false if any corresponding bit in the free map is 1
116 */
117int
118ffs_isfreeblock(fs, cp, h)
119	struct fs *fs;
120	u_char *cp;
121	int32_t h;
122{
123
124	switch ((int)fs->fs_fragshift) {
125	case 3:
126		return (cp[h] == 0);
127	case 2:
128		return ((cp[h >> 1] & (0x0f << ((h & 0x1) << 2))) == 0);
129	case 1:
130		return ((cp[h >> 2] & (0x03 << ((h & 0x3) << 1))) == 0);
131	case 0:
132		return ((cp[h >> 3] & (0x01 << (h & 0x7))) == 0);
133	default:
134		panic("ffs_isfreeblock: unknown fs_fragshift %d",
135		    (int)fs->fs_fragshift);
136	}
137}
138
139/*
140 * take a block out of the map
141 */
142void
143ffs_clrblock(fs, cp, h)
144	struct fs *fs;
145	u_char *cp;
146	int32_t h;
147{
148
149	switch ((int)fs->fs_fragshift) {
150	case 3:
151		cp[h] = 0;
152		return;
153	case 2:
154		cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2));
155		return;
156	case 1:
157		cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1));
158		return;
159	case 0:
160		cp[h >> 3] &= ~(0x01 << (h & 0x7));
161		return;
162	default:
163		panic("ffs_clrblock: unknown fs_fragshift %d",
164		    (int)fs->fs_fragshift);
165	}
166}
167
168/*
169 * put a block into the map
170 */
171void
172ffs_setblock(fs, cp, h)
173	struct fs *fs;
174	u_char *cp;
175	int32_t h;
176{
177
178	switch ((int)fs->fs_fragshift) {
179	case 3:
180		cp[h] = 0xff;
181		return;
182	case 2:
183		cp[h >> 1] |= (0x0f << ((h & 0x1) << 2));
184		return;
185	case 1:
186		cp[h >> 2] |= (0x03 << ((h & 0x3) << 1));
187		return;
188	case 0:
189		cp[h >> 3] |= (0x01 << (h & 0x7));
190		return;
191	default:
192		panic("ffs_setblock: unknown fs_fragshift %d",
193		    (int)fs->fs_fragshift);
194	}
195}
196