1 /* $NetBSD: dev-swap.c,v 1.2 2009/12/02 01:53:25 haad Exp $ */
2
3 /*
4 * Copyright (C) 2009 Red Hat, Inc. All rights reserved.
5 *
6 * This file is part of LVM2.
7 *
8 * This copyrighted material is made available to anyone wishing to use,
9 * modify, copy, or redistribute it subject to the terms and conditions
10 * of the GNU Lesser General Public License v.2.1.
11 *
12 * You should have received a copy of the GNU Lesser General Public License
13 * along with this program; if not, write to the Free Software Foundation,
14 * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
15 */
16
17 #include "lib.h"
18 #include "metadata.h"
19 #include "xlate.h"
20 #include "filter.h"
21
22 #ifdef linux
23
24 #define MAX_PAGESIZE (64 * 1024)
25 #define SIGNATURE_SIZE 10
26
27 static int
_swap_detect_signature(const char * buf)28 _swap_detect_signature(const char *buf)
29 {
30 if (memcmp(buf, "SWAP-SPACE", 10) == 0 ||
31 memcmp(buf, "SWAPSPACE2", 10) == 0)
32 return 1;
33
34 if (memcmp(buf, "S1SUSPEND", 9) == 0 ||
35 memcmp(buf, "S2SUSPEND", 9) == 0 ||
36 memcmp(buf, "ULSUSPEND", 9) == 0 ||
37 memcmp(buf, "\xed\xc3\x02\xe9\x98\x56\xe5\x0c", 8) == 0)
38 return 1;
39
40 return 0;
41 }
42
dev_is_swap(struct device * dev,uint64_t * signature)43 int dev_is_swap(struct device *dev, uint64_t *signature)
44 {
45 char buf[10];
46 uint64_t size;
47 int page;
48
49 if (!dev_get_size(dev, &size)) {
50 stack;
51 return -1;
52 }
53
54 if (!dev_open(dev)) {
55 stack;
56 return -1;
57 }
58
59 *signature = 0;
60
61 for (page = 0x1000; page <= MAX_PAGESIZE; page <<= 1) {
62 /*
63 * skip 32k pagesize since this does not seem to be supported
64 */
65 if (page == 0x8000)
66 continue;
67 if (size < page)
68 break;
69 if (!dev_read(dev, page - SIGNATURE_SIZE,
70 SIGNATURE_SIZE, buf)) {
71 stack;
72 return -1;
73 }
74 if (_swap_detect_signature(buf)) {
75 *signature = page - SIGNATURE_SIZE;
76 break;
77 }
78 }
79
80 if (!dev_close(dev))
81 stack;
82
83 if (*signature)
84 return 1;
85
86 return 0;
87 }
88
89 #else
90
91 #ifdef __NetBSD__
dev_is_swap(struct device * dev,uint64_t * signature)92 int dev_is_swap(struct device *dev, uint64_t *signature)
93 {
94 return 0;
95 }
96 #endif
97
98 #endif
99