2 * volume_id - reads filesystem label and uuid
4 * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation version 2 of the License.
26 #include "libvolume_id.h"
29 struct ext2_super_block {
30 uint32_t s_inodes_count;
31 uint32_t s_blocks_count;
32 uint32_t s_r_blocks_count;
33 uint32_t s_free_blocks_count;
34 uint32_t s_free_inodes_count;
35 uint32_t s_first_data_block;
36 uint32_t s_log_block_size;
37 uint32_t s_log_frag_size;
38 uint32_t s_blocks_per_group;
39 uint32_t s_frags_per_group;
40 uint32_t s_inodes_per_group;
44 uint16_t s_max_mnt_count;
48 uint16_t s_minor_rev_level;
50 uint32_t s_checkinterval;
51 uint32_t s_creator_os;
53 uint16_t s_def_resuid;
54 uint16_t s_def_resgid;
56 uint16_t s_inode_size;
57 uint16_t s_block_group_nr;
58 uint32_t s_feature_compat;
59 uint32_t s_feature_incompat;
60 uint32_t s_feature_ro_compat;
62 uint8_t s_volume_name[16];
65 #define EXT_SUPER_MAGIC 0xEF53
66 #define EXT3_FEATURE_COMPAT_HAS_JOURNAL 0x0004
67 #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV 0x0008
68 #define EXT3_FEATURE_INCOMPAT_EXTENTS 0x0040
69 #define EXT4_FEATURE_INCOMPAT_64BIT 0x0080
70 #define EXT4_FEATURE_INCOMPAT_MMP 0x0100
72 #define EXT_SUPERBLOCK_OFFSET 0x400
74 #define EXT3_MIN_BLOCK_SIZE 0x400
75 #define EXT3_MAX_BLOCK_SIZE 0x1000
77 int volume_id_probe_ext(struct volume_id *id, uint64_t off, uint64_t size)
79 struct ext2_super_block *es;
81 uint32_t feature_compat;
82 uint32_t feature_incompat;
84 info("probing at offset 0x%llx", (unsigned long long) off);
86 es = (struct ext2_super_block *) volume_id_get_buffer(id, off + EXT_SUPERBLOCK_OFFSET, 0x200);
90 if (es->s_magic != cpu_to_le16(EXT_SUPER_MAGIC))
93 bsize = 0x400 << le32_to_cpu(es->s_log_block_size);
94 dbg("ext blocksize 0x%zx", bsize);
95 if (bsize < EXT3_MIN_BLOCK_SIZE || bsize > EXT3_MAX_BLOCK_SIZE) {
96 dbg("invalid ext blocksize");
100 volume_id_set_label_raw(id, es->s_volume_name, 16);
101 volume_id_set_label_string(id, es->s_volume_name, 16);
102 volume_id_set_uuid(id, es->s_uuid, 0, UUID_DCE);
103 snprintf(id->type_version, sizeof(id->type_version)-1, "%u.%u",
104 le32_to_cpu(es->s_rev_level), le16_to_cpu(es->s_minor_rev_level));
106 feature_compat = le32_to_cpu(es->s_feature_compat);
107 feature_incompat = le32_to_cpu(es->s_feature_incompat);
109 /* check for external journal device */
110 if ((feature_incompat & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) != 0) {
111 volume_id_set_usage(id, VOLUME_ID_OTHER);
116 volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
118 if ((feature_incompat & EXT3_FEATURE_INCOMPAT_EXTENTS) != 0 ||
119 (feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT) != 0 ||
120 (feature_incompat & EXT4_FEATURE_INCOMPAT_MMP) != 0) {
125 if ((feature_compat & EXT3_FEATURE_COMPAT_HAS_JOURNAL) != 0) {