hush/util-linux/volume_id/linux_swap.c
Denis Vlasenko 28ea4298e3 volume_id: abort early on read failures.
should help with probing missing fdd's
2009-02-15 05:51:19 +00:00

75 lines
2.1 KiB
C

/*
* volume_id - reads filesystem label and uuid
*
* Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "volume_id_internal.h"
struct swap_header_v1_2 {
uint8_t bootbits[1024];
uint32_t version;
uint32_t last_page;
uint32_t nr_badpages;
uint8_t uuid[16];
uint8_t volume_name[16];
} __attribute__((__packed__));
#define LARGEST_PAGESIZE 0x4000
int volume_id_probe_linux_swap(struct volume_id *id /*,uint64_t off*/)
{
#define off ((uint64_t)0)
struct swap_header_v1_2 *sw;
const uint8_t *buf;
unsigned page;
dbg("probing at offset 0x%llx", (unsigned long long) off);
/* the swap signature is at the end of the PAGE_SIZE */
for (page = 0x1000; page <= LARGEST_PAGESIZE; page <<= 1) {
buf = volume_id_get_buffer(id, off + page-10, 10);
if (buf == NULL)
return -1;
if (memcmp(buf, "SWAP-SPACE", 10) == 0) {
// id->type_version[0] = '1';
// id->type_version[1] = '\0';
goto found;
}
if (memcmp(buf, "SWAPSPACE2", 10) == 0) {
sw = volume_id_get_buffer(id, off, sizeof(struct swap_header_v1_2));
if (sw == NULL)
return -1;
// id->type_version[0] = '2';
// id->type_version[1] = '\0';
// volume_id_set_label_raw(id, sw->volume_name, 16);
volume_id_set_label_string(id, sw->volume_name, 16);
volume_id_set_uuid(id, sw->uuid, UUID_DCE);
goto found;
}
}
return -1;
found:
// volume_id_set_usage(id, VOLUME_ID_OTHER);
// id->type = "swap";
return 0;
}