busybox/util-linux/volume_id/ext.c
Denis Vlasenko de7684a309 support for mount by label (not yet tested)
Also adds findfs applet. Closes bug 1143.
2008-02-18 21:08:49 +00:00

72 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 ext2_super_block {
uint32_t inodes_count;
uint32_t blocks_count;
uint32_t r_blocks_count;
uint32_t free_blocks_count;
uint32_t free_inodes_count;
uint32_t first_data_block;
uint32_t log_block_size;
uint32_t dummy3[7];
uint8_t magic[2];
uint16_t state;
uint32_t dummy5[8];
uint32_t feature_compat;
uint32_t feature_incompat;
uint32_t feature_ro_compat;
uint8_t uuid[16];
uint8_t volume_name[16];
} __attribute__((__packed__));
#define EXT3_FEATURE_COMPAT_HAS_JOURNAL 0x00000004
#define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV 0x00000008
#define EXT_SUPERBLOCK_OFFSET 0x400
int volume_id_probe_ext(struct volume_id *id, uint64_t off)
{
struct ext2_super_block *es;
dbg("probing at offset 0x%llx", (unsigned long long) off);
es = volume_id_get_buffer(id, off + EXT_SUPERBLOCK_OFFSET, 0x200);
if (es == NULL)
return -1;
if (es->magic[0] != 0123 ||
es->magic[1] != 0357)
return -1;
volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
volume_id_set_label_raw(id, es->volume_name, 16);
volume_id_set_label_string(id, es->volume_name, 16);
volume_id_set_uuid(id, es->uuid, UUID_DCE);
if ((le32_to_cpu(es->feature_compat) & EXT3_FEATURE_COMPAT_HAS_JOURNAL) != 0)
id->type = "ext3";
else
id->type = "ext2";
return 0;
}