2 * volume_id - reads filesystem label and uuid
4 * Copyright (C) 2004-2008 Kay Sievers <kay.sievers@vrfy.org>
5 * Copyright (C) 2008 Theodore Ts'o <tytso@mit.edu>
7 * This program is free software: you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation, either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program. If not, see <http://www.gnu.org/licenses/>.
32 #include "libvolume_id.h"
33 #include "libvolume_id-private.h"
35 struct ext2_super_block {
36 uint32_t s_inodes_count;
37 uint32_t s_blocks_count;
38 uint32_t s_r_blocks_count;
39 uint32_t s_free_blocks_count;
40 uint32_t s_free_inodes_count;
41 uint32_t s_first_data_block;
42 uint32_t s_log_block_size;
43 uint32_t s_log_frag_size;
44 uint32_t s_blocks_per_group;
45 uint32_t s_frags_per_group;
46 uint32_t s_inodes_per_group;
50 uint16_t s_max_mnt_count;
54 uint16_t s_minor_rev_level;
56 uint32_t s_checkinterval;
57 uint32_t s_creator_os;
59 uint16_t s_def_resuid;
60 uint16_t s_def_resgid;
62 uint16_t s_inode_size;
63 uint16_t s_block_group_nr;
64 uint32_t s_feature_compat;
65 uint32_t s_feature_incompat;
66 uint32_t s_feature_ro_compat;
68 uint8_t s_volume_name[16];
69 uint8_t s_last_mounted[64];
70 uint32_t s_algorithm_usage_bitmap;
71 uint8_t s_prealloc_blocks;
72 uint8_t s_prealloc_dir_blocks;
73 uint16_t s_reserved_gdt_blocks;
74 uint8_t s_journal_uuid[16];
75 uint32_t s_journal_inum;
76 uint32_t s_journal_dev;
77 uint32_t s_last_orphan;
78 uint32_t s_hash_seed[4];
79 uint8_t s_def_hash_version;
80 uint8_t s_jnl_backup_type;
81 uint16_t s_reserved_word_pad;
82 uint32_t s_default_mount_opts;
83 uint32_t s_first_meta_bg;
85 uint32_t s_jnl_blocks[17];
86 uint32_t s_blocks_count_hi;
87 uint32_t s_r_blocks_count_hi;
88 uint32_t s_free_blocks_hi;
89 uint16_t s_min_extra_isize;
90 uint16_t s_want_extra_isize;
94 #define EXT_SUPER_MAGIC 0xEF53
95 #define EXT2_FLAGS_TEST_FILESYS 0x0004
96 #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER 0x0001
97 #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE 0x0002
98 #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR 0x0004
99 #define EXT2_FEATURE_INCOMPAT_FILETYPE 0x0002
100 #define EXT2_FEATURE_INCOMPAT_META_BG 0x0010
101 #define EXT3_FEATURE_COMPAT_HAS_JOURNAL 0x0004
102 #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV 0x0008
103 #define EXT3_FEATURE_INCOMPAT_RECOVER 0x0004
106 #define EXT2_FEATURE_RO_COMPAT_SUPP (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
107 EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
108 EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
109 #define EXT2_FEATURE_RO_COMPAT_UNSUPPORTED ~EXT2_FEATURE_RO_COMPAT_SUPP
111 #define EXT2_FEATURE_INCOMPAT_SUPP (EXT2_FEATURE_INCOMPAT_FILETYPE| \
112 EXT2_FEATURE_INCOMPAT_META_BG)
113 #define EXT2_FEATURE_INCOMPAT_UNSUPPORTED ~EXT2_FEATURE_INCOMPAT_SUPP
115 #define EXT3_FEATURE_RO_COMPAT_SUPP (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
116 EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
117 EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
118 #define EXT3_FEATURE_RO_COMPAT_UNSUPPORTED ~EXT3_FEATURE_RO_COMPAT_SUPP
120 #define EXT3_FEATURE_INCOMPAT_SUPP (EXT2_FEATURE_INCOMPAT_FILETYPE| \
121 EXT3_FEATURE_INCOMPAT_RECOVER| \
122 EXT2_FEATURE_INCOMPAT_META_BG)
123 #define EXT3_FEATURE_INCOMPAT_UNSUPPORTED ~EXT3_FEATURE_INCOMPAT_SUPP
125 #define EXT_SUPERBLOCK_OFFSET 0x400
126 #define EXT3_MIN_BLOCK_SIZE 0x400
127 #define EXT3_MAX_BLOCK_SIZE 0x1000
129 int volume_id_probe_ext(struct volume_id *id, uint64_t off, uint64_t size)
131 struct ext2_super_block *es;
133 uint32_t feature_compat;
134 uint32_t feature_ro_compat;
135 uint32_t feature_incompat;
138 info("probing at offset 0x%" PRIx64 "\n", off);
140 es = (struct ext2_super_block *) volume_id_get_buffer(id, off + EXT_SUPERBLOCK_OFFSET, 0x200);
144 if (es->s_magic != cpu_to_le16(EXT_SUPER_MAGIC))
147 bsize = 0x400 << le32_to_cpu(es->s_log_block_size);
148 dbg("ext blocksize 0x%zx\n", bsize);
149 if (bsize < EXT3_MIN_BLOCK_SIZE || bsize > EXT3_MAX_BLOCK_SIZE) {
150 dbg("invalid ext blocksize\n");
154 feature_compat = le32_to_cpu(es->s_feature_compat);
155 feature_ro_compat = le32_to_cpu(es->s_feature_ro_compat);
156 feature_incompat = le32_to_cpu(es->s_feature_incompat);
157 flags = le32_to_cpu(es->s_flags);
159 /* external journal device is jbd */
160 if ((feature_incompat & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) != 0) {
161 volume_id_set_usage(id, VOLUME_ID_OTHER);
167 if ((feature_compat & EXT3_FEATURE_COMPAT_HAS_JOURNAL) != 0) {
168 /* "use on development code" is ext4dev */
169 if ((flags & EXT2_FLAGS_TEST_FILESYS) != 0) {
170 id->type = "ext4dev";
174 /* incompatible ext3 features is ext4 */
175 if ((feature_ro_compat & EXT3_FEATURE_RO_COMPAT_UNSUPPORTED) != 0 ||
176 (feature_incompat & EXT3_FEATURE_INCOMPAT_UNSUPPORTED) != 0) {
184 /* no incompatible ext2 feature is ext2 */
185 if ((feature_ro_compat & EXT2_FEATURE_RO_COMPAT_UNSUPPORTED) == 0 &&
186 (feature_incompat & EXT2_FEATURE_INCOMPAT_UNSUPPORTED) == 0) {
195 volume_id_set_label_raw(id, es->s_volume_name, 16);
196 volume_id_set_label_string(id, es->s_volume_name, 16);
197 volume_id_set_uuid(id, es->s_uuid, 0, UUID_DCE);
198 snprintf(id->type_version, sizeof(id->type_version)-1, "%u.%u",
199 le32_to_cpu(es->s_rev_level), le16_to_cpu(es->s_minor_rev_level));
201 volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);