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lvm2/lib/device/dev-swap.c
Peter Rajnoha 03c941a4ca device: cleanup signature wiping functions
The wipe_known_signatures fn now wraps the _wipe_signature fn that is called
for each known signature (currently md, swap and luks). This patch makes the
code more readable, not repeating the same sequence when used anywhere in the
code. We're going to reuse this code later...
2013-11-27 12:56:58 +01:00

84 lines
1.7 KiB
C

/*
* Copyright (C) 2009 Red Hat, Inc. All rights reserved.
*
* This file is part of LVM2.
*
* This copyrighted material is made available to anyone wishing to use,
* modify, copy, or redistribute it subject to the terms and conditions
* of the GNU Lesser General Public License v.2.1.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "lib.h"
#include "dev-type.h"
#ifdef __linux__
#define MAX_PAGESIZE (64 * 1024)
#define SIGNATURE_SIZE 10
static int
_swap_detect_signature(const char *buf)
{
if (memcmp(buf, "SWAP-SPACE", 10) == 0 ||
memcmp(buf, "SWAPSPACE2", 10) == 0)
return 1;
if (memcmp(buf, "S1SUSPEND", 9) == 0 ||
memcmp(buf, "S2SUSPEND", 9) == 0 ||
memcmp(buf, "ULSUSPEND", 9) == 0 ||
memcmp(buf, "\xed\xc3\x02\xe9\x98\x56\xe5\x0c", 8) == 0)
return 1;
return 0;
}
int dev_is_swap(struct device *dev, uint64_t *offset_found)
{
char buf[10];
uint64_t size;
unsigned page;
int ret = 0;
if (!dev_get_size(dev, &size)) {
stack;
return -1;
}
if (!dev_open_readonly(dev)) {
stack;
return -1;
}
for (page = 0x1000; page <= MAX_PAGESIZE; page <<= 1) {
/*
* skip 32k pagesize since this does not seem to be supported
*/
if (page == 0x8000)
continue;
if (size < page)
break;
if (!dev_read(dev, page - SIGNATURE_SIZE,
SIGNATURE_SIZE, buf)) {
ret = -1;
break;
}
if (_swap_detect_signature(buf)) {
if (offset_found)
*offset_found = page - SIGNATURE_SIZE;
ret = 1;
break;
}
}
if (!dev_close(dev))
stack;
return ret;
}
#endif