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"
32 struct ext2_super_block {
33 uint32_t s_inodes_count;
34 uint32_t s_blocks_count;
35 uint32_t s_r_blocks_count;
36 uint32_t s_free_blocks_count;
37 uint32_t s_free_inodes_count;
38 uint32_t s_first_data_block;
39 uint32_t s_log_block_size;
40 uint32_t s_log_frag_size;
41 uint32_t s_blocks_per_group;
42 uint32_t s_frags_per_group;
43 uint32_t s_inodes_per_group;
47 uint16_t s_max_mnt_count;
51 uint16_t s_minor_rev_level;
53 uint32_t s_checkinterval;
54 uint32_t s_creator_os;
56 uint16_t s_def_resuid;
57 uint16_t s_def_resgid;
59 uint16_t s_inode_size;
60 uint16_t s_block_group_nr;
61 uint32_t s_feature_compat;
62 uint32_t s_feature_incompat;
63 uint32_t s_feature_ro_compat;
65 uint8_t s_volume_name[16];
66 uint8_t s_last_mounted[64];
67 uint32_t s_algorithm_usage_bitmap;
68 uint8_t s_prealloc_blocks;
69 uint8_t s_prealloc_dir_blocks;
70 uint16_t s_reserved_gdt_blocks;
71 uint8_t s_journal_uuid[16];
72 uint32_t s_journal_inum;
73 uint32_t s_journal_dev;
74 uint32_t s_last_orphan;
75 uint32_t s_hash_seed[4];
76 uint8_t s_def_hash_version;
77 uint8_t s_jnl_backup_type;
78 uint16_t s_reserved_word_pad;
79 uint32_t s_default_mount_opts;
80 uint32_t s_first_meta_bg;
82 uint32_t s_jnl_blocks[17];
83 uint32_t s_blocks_count_hi;
84 uint32_t s_r_blocks_count_hi;
85 uint32_t s_free_blocks_hi;
86 uint16_t s_min_extra_isize;
87 uint16_t s_want_extra_isize;
91 #define EXT_SUPER_MAGIC 0xEF53
92 #define EXT2_FLAGS_TEST_FILESYS 0x0004
93 #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER 0x0001
94 #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE 0x0002
95 #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR 0x0004
96 #define EXT2_FEATURE_INCOMPAT_FILETYPE 0x0002
97 #define EXT2_FEATURE_INCOMPAT_META_BG 0x0010
98 #define EXT3_FEATURE_COMPAT_HAS_JOURNAL 0x0004
99 #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV 0x0008
100 #define EXT3_FEATURE_INCOMPAT_RECOVER 0x0004
103 #define EXT2_FEATURE_RO_COMPAT_SUPP (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
104 EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
105 EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
106 #define EXT2_FEATURE_RO_COMPAT_UNSUPPORTED ~EXT2_FEATURE_RO_COMPAT_SUPP
108 #define EXT2_FEATURE_INCOMPAT_SUPP (EXT2_FEATURE_INCOMPAT_FILETYPE| \
109 EXT2_FEATURE_INCOMPAT_META_BG)
110 #define EXT2_FEATURE_INCOMPAT_UNSUPPORTED ~EXT2_FEATURE_INCOMPAT_SUPP
112 #define EXT3_FEATURE_RO_COMPAT_SUPP (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
113 EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
114 EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
115 #define EXT3_FEATURE_RO_COMPAT_UNSUPPORTED ~EXT3_FEATURE_RO_COMPAT_SUPP
117 #define EXT3_FEATURE_INCOMPAT_SUPP (EXT2_FEATURE_INCOMPAT_FILETYPE| \
118 EXT3_FEATURE_INCOMPAT_RECOVER| \
119 EXT2_FEATURE_INCOMPAT_META_BG)
120 #define EXT3_FEATURE_INCOMPAT_UNSUPPORTED ~EXT3_FEATURE_INCOMPAT_SUPP
122 #define EXT_SUPERBLOCK_OFFSET 0x400
123 #define EXT3_MIN_BLOCK_SIZE 0x400
124 #define EXT3_MAX_BLOCK_SIZE 0x1000
126 int volume_id_probe_ext(struct volume_id *id, uint64_t off, uint64_t size)
128 struct ext2_super_block *es;
130 uint32_t feature_compat;
131 uint32_t feature_ro_compat;
132 uint32_t feature_incompat;
135 info("probing at offset 0x%llx\n", (unsigned long long) off);
137 es = (struct ext2_super_block *) volume_id_get_buffer(id, off + EXT_SUPERBLOCK_OFFSET, 0x200);
141 if (es->s_magic != cpu_to_le16(EXT_SUPER_MAGIC))
144 bsize = 0x400 << le32_to_cpu(es->s_log_block_size);
145 dbg("ext blocksize 0x%zx\n", bsize);
146 if (bsize < EXT3_MIN_BLOCK_SIZE || bsize > EXT3_MAX_BLOCK_SIZE) {
147 dbg("invalid ext blocksize\n");
151 feature_compat = le32_to_cpu(es->s_feature_compat);
152 feature_ro_compat = le32_to_cpu(es->s_feature_ro_compat);
153 feature_incompat = le32_to_cpu(es->s_feature_incompat);
154 flags = le32_to_cpu(es->s_flags);
156 /* external journal device is jbd */
157 if ((feature_incompat & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) != 0) {
158 volume_id_set_usage(id, VOLUME_ID_OTHER);
164 if ((feature_compat & EXT3_FEATURE_COMPAT_HAS_JOURNAL) != 0) {
165 /* "use on development code" is ext4dev */
166 if ((flags & EXT2_FLAGS_TEST_FILESYS) != 0) {
167 id->type = "ext4dev";
171 /* incompatible ext3 features is ext4 */
172 if ((feature_ro_compat & EXT3_FEATURE_RO_COMPAT_UNSUPPORTED) != 0 ||
173 (feature_incompat & EXT3_FEATURE_INCOMPAT_UNSUPPORTED) != 0) {
181 /* no incompatible ext2 feature is ext2 */
182 if ((feature_ro_compat & EXT2_FEATURE_RO_COMPAT_UNSUPPORTED) == 0 &&
183 (feature_incompat & EXT2_FEATURE_INCOMPAT_UNSUPPORTED) == 0) {
192 volume_id_set_label_raw(id, es->s_volume_name, 16);
193 volume_id_set_label_string(id, es->s_volume_name, 16);
194 volume_id_set_uuid(id, es->s_uuid, 0, UUID_DCE);
195 snprintf(id->type_version, sizeof(id->type_version)-1, "%u.%u",
196 le32_to_cpu(es->s_rev_level), le16_to_cpu(es->s_minor_rev_level));
198 volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);