1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
28 /* All Rights Reserved */
29
30
31 #include <sys/types.h>
32 #include <sys/param.h>
33 #include <sys/sysmacros.h>
34
35 /*
36 * This should not be a constant, but for ufs it is 12, not 10 like for s5.
37 */
38 #define DIRECT 12 /* Number of logical blocks before indirection */
39
40 fsblkcnt_t
nblk(fsblkcnt_t size,ulong_t bsize,ulong_t frsize)41 nblk(fsblkcnt_t size, ulong_t bsize, ulong_t frsize)
42 {
43 fsblkcnt_t tot, count, count1, d_indirect, t_indirect, ind;
44 fsblkcnt_t frags = 0;
45
46 if (size == 0 || bsize == 0)
47 return (1);
48
49 /*
50 * Need to keep track of indirect blocks.
51 */
52
53 ind = howmany(bsize, sizeof (daddr_t));
54 d_indirect = ind + DIRECT; /* double indirection */
55 t_indirect = ind * (ind + 1) + DIRECT; /* triple indirection */
56
57 tot = howmany(size, bsize);
58
59 if (tot > t_indirect) {
60 count1 = (tot - ind * ind - (DIRECT + 1)) / ind;
61 count = count1 + count1 / ind + ind + 3;
62 } else if (tot > d_indirect) {
63 count = (tot - (DIRECT + 1)) / ind + 2;
64 } else if (tot > DIRECT) {
65 count = 1;
66 } else {
67 count = 0;
68 frags = (frsize > 0) ?
69 roundup(size, frsize) :
70 roundup(size, bsize);
71 }
72
73 /* Accounting for the indirect blocks, the total becomes */
74 tot += count;
75
76 /*
77 * calculate number of 512 byte blocks, for frag or full block cases.
78 */
79 if (!frags)
80 tot *= howmany(bsize, DEV_BSIZE);
81 else
82 tot = howmany(frags, DEV_BSIZE);
83 return (tot);
84 }
85