busybox/util-linux/volume_id/linux_raid.c

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/*
* 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 mdp_super_block {
uint32_t md_magic;
uint32_t major_version;
uint32_t minor_version;
uint32_t patch_version;
uint32_t gvalid_words;
uint32_t set_uuid0;
uint32_t ctime;
uint32_t level;
uint32_t size;
uint32_t nr_disks;
uint32_t raid_disks;
uint32_t md_minor;
uint32_t not_persistent;
uint32_t set_uuid1;
uint32_t set_uuid2;
uint32_t set_uuid3;
} __attribute__((packed));
#define MD_RESERVED_BYTES 0x10000
#define MD_MAGIC 0xa92b4efc
int volume_id_probe_linux_raid(struct volume_id *id, uint64_t off, uint64_t size)
{
uint64_t sboff;
uint8_t uuid[16];
struct mdp_super_block *mdp;
dbg("probing at offset 0x%llx, size 0x%llx",
(unsigned long long) off, (unsigned long long) size);
if (size < 0x10000)
return -1;
sboff = (size & ~(MD_RESERVED_BYTES - 1)) - MD_RESERVED_BYTES;
mdp = volume_id_get_buffer(id, off + sboff, 0x800);
if (mdp == NULL)
return -1;
if (mdp->md_magic != cpu_to_le32(MD_MAGIC))
return -1;
memcpy(uuid, &mdp->set_uuid0, 4);
memcpy(&uuid[4], &mdp->set_uuid1, 12);
volume_id_set_uuid(id, uuid, UUID_DCE);
snprintf(id->type_version, sizeof(id->type_version)-1, "%u.%u.%u",
le32_to_cpu(mdp->major_version),
le32_to_cpu(mdp->minor_version),
le32_to_cpu(mdp->patch_version));
dbg("found raid signature");
volume_id_set_usage(id, VOLUME_ID_RAID);
id->type = "linux_raid_member";
return 0;
}