| /* |
| * 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.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 >> SECTOR_SHIFT)) |
| 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 |