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 * The probe logic is based on libblkid from e2fsutils.
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the
11 * Free Software Foundation version 2 of the License.
29 #include "libvolume_id.h"
30 #include "libvolume_id-private.h"
33 struct ext2_super_block {
34 uint32_t s_inodes_count;
35 uint32_t s_blocks_count;
36 uint32_t s_r_blocks_count;
37 uint32_t s_free_blocks_count;
38 uint32_t s_free_inodes_count;
39 uint32_t s_first_data_block;
40 uint32_t s_log_block_size;
41 uint32_t s_log_frag_size;
42 uint32_t s_blocks_per_group;
43 uint32_t s_frags_per_group;
44 uint32_t s_inodes_per_group;
48 uint16_t s_max_mnt_count;
52 uint16_t s_minor_rev_level;
54 uint32_t s_checkinterval;
55 uint32_t s_creator_os;
57 uint16_t s_def_resuid;
58 uint16_t s_def_resgid;
60 uint16_t s_inode_size;
61 uint16_t s_block_group_nr;
62 uint32_t s_feature_compat;
63 uint32_t s_feature_incompat;
64 uint32_t s_feature_ro_compat;
66 uint8_t s_volume_name[16];
67 uint8_t s_last_mounted[64];
68 uint32_t s_algorithm_usage_bitmap;
69 uint8_t s_prealloc_blocks;
70 uint8_t s_prealloc_dir_blocks;
71 uint16_t s_reserved_gdt_blocks;
72 uint8_t s_journal_uuid[16];
73 uint32_t s_journal_inum;
74 uint32_t s_journal_dev;
75 uint32_t s_last_orphan;
76 uint32_t s_hash_seed[4];
77 uint8_t s_def_hash_version;
78 uint8_t s_jnl_backup_type;
79 uint16_t s_reserved_word_pad;
80 uint32_t s_default_mount_opts;
81 uint32_t s_first_meta_bg;
83 uint32_t s_jnl_blocks[17];
84 uint32_t s_blocks_count_hi;
85 uint32_t s_r_blocks_count_hi;
86 uint32_t s_free_blocks_hi;
87 uint16_t s_min_extra_isize;
88 uint16_t s_want_extra_isize;
92 #define EXT_SUPER_MAGIC 0xEF53
93 #define EXT2_FLAGS_TEST_FILESYS 0x0004
94 #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER 0x0001
95 #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE 0x0002
96 #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR 0x0004
97 #define EXT2_FEATURE_INCOMPAT_FILETYPE 0x0002
98 #define EXT2_FEATURE_INCOMPAT_META_BG 0x0010
99 #define EXT3_FEATURE_COMPAT_HAS_JOURNAL 0x0004
100 #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV 0x0008
101 #define EXT3_FEATURE_INCOMPAT_RECOVER 0x0004
104 #define EXT2_FEATURE_RO_COMPAT_SUPP (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
105 EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
106 EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
107 #define EXT2_FEATURE_RO_COMPAT_UNSUPPORTED ~EXT2_FEATURE_RO_COMPAT_SUPP
109 #define EXT2_FEATURE_INCOMPAT_SUPP (EXT2_FEATURE_INCOMPAT_FILETYPE| \
110 EXT2_FEATURE_INCOMPAT_META_BG)
111 #define EXT2_FEATURE_INCOMPAT_UNSUPPORTED ~EXT2_FEATURE_INCOMPAT_SUPP
113 #define EXT3_FEATURE_RO_COMPAT_SUPP (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
114 EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
115 EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
116 #define EXT3_FEATURE_RO_COMPAT_UNSUPPORTED ~EXT3_FEATURE_RO_COMPAT_SUPP
118 #define EXT3_FEATURE_INCOMPAT_SUPP (EXT2_FEATURE_INCOMPAT_FILETYPE| \
119 EXT3_FEATURE_INCOMPAT_RECOVER| \
120 EXT2_FEATURE_INCOMPAT_META_BG)
121 #define EXT3_FEATURE_INCOMPAT_UNSUPPORTED ~EXT3_FEATURE_INCOMPAT_SUPP
123 #define EXT_SUPERBLOCK_OFFSET 0x400
124 #define EXT3_MIN_BLOCK_SIZE 0x400
125 #define EXT3_MAX_BLOCK_SIZE 0x1000
127 int volume_id_probe_ext(struct volume_id *id, uint64_t off, uint64_t size)
129 struct ext2_super_block *es;
131 uint32_t feature_compat;
132 uint32_t feature_ro_compat;
133 uint32_t feature_incompat;
136 info("probing at offset 0x%llx\n", (unsigned long long) off);
138 es = (struct ext2_super_block *) volume_id_get_buffer(id, off + EXT_SUPERBLOCK_OFFSET, 0x200);
142 if (es->s_magic != cpu_to_le16(EXT_SUPER_MAGIC))
145 bsize = 0x400 << le32_to_cpu(es->s_log_block_size);
146 dbg("ext blocksize 0x%zx\n", bsize);
147 if (bsize < EXT3_MIN_BLOCK_SIZE || bsize > EXT3_MAX_BLOCK_SIZE) {
148 dbg("invalid ext blocksize\n");
152 feature_compat = le32_to_cpu(es->s_feature_compat);
153 feature_ro_compat = le32_to_cpu(es->s_feature_ro_compat);
154 feature_incompat = le32_to_cpu(es->s_feature_incompat);
155 flags = le32_to_cpu(es->s_flags);
157 /* external journal device is jbd */
158 if ((feature_incompat & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) != 0) {
159 volume_id_set_usage(id, VOLUME_ID_OTHER);
165 if ((feature_compat & EXT3_FEATURE_COMPAT_HAS_JOURNAL) != 0) {
166 /* "use on development code" is ext4dev */
167 if ((flags & EXT2_FLAGS_TEST_FILESYS) != 0) {
168 id->type = "ext4dev";
172 /* incompatible ext3 features is ext4 */
173 if ((feature_ro_compat & EXT3_FEATURE_RO_COMPAT_UNSUPPORTED) != 0 ||
174 (feature_incompat & EXT3_FEATURE_INCOMPAT_UNSUPPORTED) != 0) {
182 /* no incompatible ext2 feature is ext2 */
183 if ((feature_ro_compat & EXT2_FEATURE_RO_COMPAT_UNSUPPORTED) == 0 &&
184 (feature_incompat & EXT2_FEATURE_INCOMPAT_UNSUPPORTED) == 0) {
193 volume_id_set_label_raw(id, es->s_volume_name, 16);
194 volume_id_set_label_string(id, es->s_volume_name, 16);
195 volume_id_set_uuid(id, es->s_uuid, 0, UUID_DCE);
196 snprintf(id->type_version, sizeof(id->type_version)-1, "%u.%u",
197 le32_to_cpu(es->s_rev_level), le16_to_cpu(es->s_minor_rev_level));
199 volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);