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 */
51void
52ffs_fragacct_swap(struct fs *fs, int fragmap, uint32_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 */
87int
88ffs_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 */
115int
116ffs_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 */
137void
138ffs_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 */
163void
164ffs_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