hush/util-linux/volume_id/ext.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
2.2 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*/)
{
#define off ((uint64_t)0)
struct ext2_super_block *es;
dbg("ext: 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) {
dbg("ext: no magic found");
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);
dbg("ext: label '%s' uuid '%s'", id->label, id->uuid);
// if ((le32_to_cpu(es->feature_compat) & EXT3_FEATURE_COMPAT_HAS_JOURNAL) != 0)
// id->type = "ext3";
// else
// id->type = "ext2";
return 0;
}