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mirror of git://sourceware.org/git/lvm2.git synced 2024-10-12 13:52:28 +03:00
lvm2/lib/device/dev-swap.c
David Teigland 6cb0b44cd2 filter: remove unused EAGAIN case and flag
The case of filters returning EAGAIN and using the
FILTER_AFTER_SCAN flag is no longer used.
2022-04-06 12:51:34 -05:00

74 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "lib/misc/lib.h"
#include "lib/device/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 cmd_context *cmd, struct device *dev, uint64_t *offset_found, int full)
{
char buf[10];
uint64_t size;
unsigned page;
int ret = 0;
if (!dev_get_size(dev, &size)) {
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 >> SECTOR_SHIFT))
break;
if (!dev_read_bytes(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;
}
}
return ret;
}
#endif