2 * volume_id - reads filesystem label and uuid
4 * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
35 #include <asm/types.h>
37 #include "volume_id.h"
42 struct msdos_partition_entry {
53 } __attribute__((packed));
55 #define MSDOS_MAGIC "\x55\xaa"
56 #define MSDOS_PARTTABLE_OFFSET 0x1be
57 #define MSDOS_SIG_OFF 0x1fe
59 #define DOS_EXTENDED_PARTITION 0x05
60 #define LINUX_EXTENDED_PARTITION 0x85
61 #define WIN98_EXTENDED_PARTITION 0x0f
62 #define LINUX_RAID_PARTITION 0xfd
63 #define is_extended(type) \
64 (type == DOS_EXTENDED_PARTITION || \
65 type == WIN98_EXTENDED_PARTITION || \
66 type == LINUX_EXTENDED_PARTITION)
67 #define is_raid(type) \
68 (type == LINUX_RAID_PARTITION)
70 int volume_id_probe_msdos_part_table(struct volume_id *id, __u64 off)
81 struct msdos_partition_entry *part;
82 struct volume_id_partition *p;
84 dbg("probing at offset 0x%llx", (unsigned long long) off);
86 buf = volume_id_get_buffer(id, off, 0x200);
90 if (memcmp(&buf[MSDOS_SIG_OFF], MSDOS_MAGIC, 2) != 0)
93 /* check flags on all entries for a valid partition table */
94 part = (struct msdos_partition_entry*) &buf[MSDOS_PARTTABLE_OFFSET];
95 for (i = 0; i < 4; i++) {
96 if (part[i].boot_ind != 0 &&
97 part[i].boot_ind != 0x80)
100 if (le32_to_cpu(part[i].nr_sects) != 0)
106 if (id->partitions != NULL)
107 free(id->partitions);
108 id->partitions = malloc(VOLUME_ID_PARTITIONS_MAX *
109 sizeof(struct volume_id_partition));
110 if (id->partitions == NULL)
112 memset(id->partitions, 0x00,
113 VOLUME_ID_PARTITIONS_MAX * sizeof(struct volume_id_partition));
115 for (i = 0; i < 4; i++) {
116 poff = (__u64) le32_to_cpu(part[i].start_sect) * BSIZE;
117 plen = (__u64) le32_to_cpu(part[i].nr_sects) * BSIZE;
122 p = &id->partitions[i];
124 p->partition_type_raw = part[i].sys_ind;
126 if (is_extended(part[i].sys_ind)) {
127 dbg("found extended partition at 0x%llx", (unsigned long long) poff);
128 volume_id_set_usage_part(p, VOLUME_ID_PARTITIONTABLE);
129 p->type = "msdos_extended_partition";
131 extended = off + poff;
133 dbg("found 0x%x data partition at 0x%llx, len 0x%llx",
134 part[i].sys_ind, (unsigned long long) poff, (unsigned long long) plen);
136 if (is_raid(part[i].sys_ind))
137 volume_id_set_usage_part(p, VOLUME_ID_RAID);
139 volume_id_set_usage_part(p, VOLUME_ID_UNPROBED);
144 id->partition_count = i+1;
151 /* follow extended partition chain and add data partitions */
154 dbg("extended chain limit reached");
158 buf = volume_id_get_buffer(id, current, 0x200);
162 part = (struct msdos_partition_entry*) &buf[MSDOS_PARTTABLE_OFFSET];
164 if (memcmp(&buf[MSDOS_SIG_OFF], MSDOS_MAGIC, 2) != 0)
169 for (i = 0; i < 4; i++) {
170 poff = (__u64) le32_to_cpu(part[i].start_sect) * BSIZE;
171 plen = (__u64) le32_to_cpu(part[i].nr_sects) * BSIZE;
176 if (is_extended(part[i].sys_ind)) {
177 dbg("found extended partition at 0x%llx", (unsigned long long) poff);
179 next = extended + poff;
181 dbg("found 0x%x data partition at 0x%llx, len 0x%llx",
182 part[i].sys_ind, (unsigned long long) poff, (unsigned long long) plen);
184 /* we always start at the 5th entry */
185 while (id->partition_count < 4)
186 volume_id_set_usage_part(&id->partitions[id->partition_count++], VOLUME_ID_UNUSED);
188 p = &id->partitions[id->partition_count];
190 if (is_raid(part[i].sys_ind))
191 volume_id_set_usage_part(p, VOLUME_ID_RAID);
193 volume_id_set_usage_part(p, VOLUME_ID_UNPROBED);
195 p->off = current + poff;
197 id->partition_count++;
199 p->partition_type_raw = part[i].sys_ind;
201 if (id->partition_count >= VOLUME_ID_PARTITIONS_MAX) {
202 dbg("too many partitions");
211 volume_id_set_usage(id, VOLUME_ID_PARTITIONTABLE);
212 id->type = "msdos_partition_table";