2 * volume_id - reads filesystem label and uuid
4 * Copyright (C) Andre Masella <andre@masella.no-ip.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
36 #include "volume_id.h"
42 /* All these values are taken from ocfs2-tools's ocfs2_fs.h */
43 #define OCFS2_VOL_UUID_LEN 16
44 #define OCFS2_MAX_VOL_LABEL_LEN 64
45 #define OCFS2_SUPERBLOCK_OFFSET 0x2000
48 /* This is the superblock. The OCFS2 header files have structs in structs.
49 This is one has been simplified since we only care about the superblock.
52 struct ocfs2_super_block {
53 uint8_t i_signature[8]; /* Signature for validation */
54 uint32_t i_generation; /* Generation number */
55 int16_t i_suballoc_slot; /* Slot suballocator this inode belongs to */
56 uint16_t i_suballoc_bit; /* Bit offset in suballocator block group */
58 uint32_t i_clusters; /* Cluster count */
59 uint32_t i_uid; /* Owner UID */
60 uint32_t i_gid; /* Owning GID */
61 uint64_t i_size; /* Size in bytes */
62 uint16_t i_mode; /* File mode */
63 uint16_t i_links_count; /* Links count */
64 uint32_t i_flags; /* File flags */
65 uint64_t i_atime; /* Access time */
66 uint64_t i_ctime; /* Creation time */
67 uint64_t i_mtime; /* Modification time */
68 uint64_t i_dtime; /* Deletion time */
69 uint64_t i_blkno; /* Offset on disk, in blocks */
70 uint64_t i_last_eb_blk; /* Pointer to last extent block */
71 uint32_t i_fs_generation; /* Generation per fs-instance */
72 uint32_t i_atime_nsec;
73 uint32_t i_ctime_nsec;
74 uint32_t i_mtime_nsec;
75 uint64_t i_reserved1[9];
76 uint64_t i_pad1; /* Generic way to refer to this 64bit union */
77 /* Normally there is a union of the different block types, but we only care about the superblock. */
78 uint16_t s_major_rev_level;
79 uint16_t s_minor_rev_level;
81 int16_t s_max_mnt_count;
82 uint16_t s_state; /* File system state */
83 uint16_t s_errors; /* Behaviour when detecting errors */
84 uint32_t s_checkinterval; /* Max time between checks */
85 uint64_t s_lastcheck; /* Time of last check */
86 uint32_t s_creator_os; /* OS */
87 uint32_t s_feature_compat; /* Compatible feature set */
88 uint32_t s_feature_incompat; /* Incompatible feature set */
89 uint32_t s_feature_ro_compat; /* Readonly-compatible feature set */
90 uint64_t s_root_blkno; /* Offset, in blocks, of root directory dinode */
91 uint64_t s_system_dir_blkno; /* Offset, in blocks, of system directory dinode */
92 uint32_t s_blocksize_bits; /* Blocksize for this fs */
93 uint32_t s_clustersize_bits; /* Clustersize for this fs */
94 uint16_t s_max_slots; /* Max number of simultaneous mounts before tunefs required */
97 uint64_t s_first_cluster_group; /* Block offset of 1st cluster group header */
98 uint8_t s_label[OCFS2_MAX_VOL_LABEL_LEN]; /* Label for mounting, etc. */
99 uint8_t s_uuid[OCFS2_VOL_UUID_LEN]; /* 128-bit uuid */
100 } __attribute__((__packed__));
102 int volume_id_probe_ocfs2(struct volume_id *id, uint64_t off)
104 struct ocfs2_super_block *os;
106 dbg("probing at offset 0x%llx", (unsigned long long) off);
108 os = (struct ocfs2_super_block *) volume_id_get_buffer(id, off + OCFS2_SUPERBLOCK_OFFSET, 0x200);
112 if (memcmp(os->i_signature, "OCFSV2", 6) != 0) {
116 volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
117 volume_id_set_label_raw(id, os->s_label, OCFS2_MAX_VOL_LABEL_LEN < VOLUME_ID_LABEL_SIZE ?
118 OCFS2_MAX_VOL_LABEL_LEN : VOLUME_ID_LABEL_SIZE);
119 volume_id_set_label_string(id, os->s_label, OCFS2_MAX_VOL_LABEL_LEN < VOLUME_ID_LABEL_SIZE ?
120 OCFS2_MAX_VOL_LABEL_LEN : VOLUME_ID_LABEL_SIZE);
121 volume_id_set_uuid(id, os->s_uuid, UUID_DCE);