1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
|
/* $NetBSD: bmap.c,v 1.3 1994/10/27 04:21:48 cgd Exp $ */
/*
* Copyright (c) 1982, 1986, 1989 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)ufs_bmap.c 7.13 (Berkeley) 5/8/91
*/
#include "param.h"
#include "dinode.h"
#include "fs.h"
#include "errno.h"
/*
* Bmap converts a the logical block number of a file
* to its physical block number on the disk. The conversion
* is done by using the logical block number to index into
* the array of block pointers described by the dinode.
*/
extern struct fs *fs;
extern int bdev;
static daddr_t bap[2*1024];
static daddr_t bnobap;
bmap(dip, bn, bnp)
register struct dinode *dip;
register daddr_t bn;
daddr_t *bnp;
{
register daddr_t nb;
int i, j, sh;
int error;
/*fprintf(stderr, "bmap %d ", bn);*/
if (bn < 0)
return (EFBIG);
/*
* The first NDADDR blocks are direct blocks
*/
if (bn < NDADDR) {
nb = dip->di_db[bn];
if (nb == 0) {
*bnp = (daddr_t)-1;
/*fprintf(stderr, "%d\n", *bnp);*/
return (0);
}
*bnp = fsbtodb(fs, nb);
/*fprintf(stderr, "%d\n", *bnp);*/
return (0);
}
/*
* Determine the number of levels of indirection.
*/
sh = 1;
bn -= NDADDR;
for (j = NIADDR; j > 0; j--) {
sh *= NINDIR(fs);
if (bn < sh)
break;
bn -= sh;
}
if (j == 0)
return (EFBIG);
/*
* Fetch through the indirect blocks.
*/
nb = dip->di_ib[NIADDR - j];
if (nb == 0) {
*bnp = (daddr_t)-1;
/*fprintf(stderr, "%d\n", *bnp);*/
return (0);
}
for (; j <= NIADDR; j++) {
daddr_t bno = fsbtodb(fs, nb);
if (bnobap != bno &&
(error = bread(bdev, bno, &bap,
(int)fs->fs_bsize))) {
return (error);
}
bnobap = bno;
sh /= NINDIR(fs);
i = (bn / sh) % NINDIR(fs);
nb = bap[i];
if (nb == 0) {
*bnp = (daddr_t)-1;
/*fprintf(stderr, "%d\n", *bnp);*/
return (0);
}
}
*bnp = fsbtodb(fs, nb);
/*fprintf(stderr, "%d\n", *bnp);*/
return (0);
}
|
