1 /*
2 * volume_id - reads filesystem label and uuid
3 *
4 * Copyright (C) Andre Masella <andre@masella.no-ip.org>
5 *
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.
10 *
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.
15 *
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
19 */
20 //config:config FEATURE_VOLUMEID_OCFS2
21 //config: bool "ocfs2 filesystem"
22 //config: default y
23 //config: depends on VOLUMEID
24
25 //kbuild:lib-$(CONFIG_FEATURE_VOLUMEID_OCFS2) += ocfs2.o
26
27 #include "volume_id_internal.h"
28
29 /* All these values are taken from ocfs2-tools's ocfs2_fs.h */
30 #define OCFS2_VOL_UUID_LEN 16
31 #define OCFS2_MAX_VOL_LABEL_LEN 64
32 #define OCFS2_SUPERBLOCK_OFFSET 0x2000
33
34
35 /* This is the superblock. The OCFS2 header files have structs in structs.
36 This is one has been simplified since we only care about the superblock.
37 */
38
39 struct ocfs2_super_block {
40 uint8_t i_signature[8]; /* Signature for validation */
41 uint32_t i_generation; /* Generation number */
42 int16_t i_suballoc_slot; /* Slot suballocator this inode belongs to */
43 uint16_t i_suballoc_bit; /* Bit offset in suballocator block group */
44 uint32_t i_reserved0;
45 uint32_t i_clusters; /* Cluster count */
46 uint32_t i_uid; /* Owner UID */
47 uint32_t i_gid; /* Owning GID */
48 uint64_t i_size; /* Size in bytes */
49 uint16_t i_mode; /* File mode */
50 uint16_t i_links_count; /* Links count */
51 uint32_t i_flags; /* File flags */
52 uint64_t i_atime; /* Access time */
53 uint64_t i_ctime; /* Creation time */
54 uint64_t i_mtime; /* Modification time */
55 uint64_t i_dtime; /* Deletion time */
56 uint64_t i_blkno; /* Offset on disk, in blocks */
57 uint64_t i_last_eb_blk; /* Pointer to last extent block */
58 uint32_t i_fs_generation; /* Generation per fs-instance */
59 uint32_t i_atime_nsec;
60 uint32_t i_ctime_nsec;
61 uint32_t i_mtime_nsec;
62 uint64_t i_reserved1[9];
63 uint64_t i_pad1; /* Generic way to refer to this 64bit union */
64 /* Normally there is a union of the different block types, but we only care about the superblock. */
65 uint16_t s_major_rev_level;
66 uint16_t s_minor_rev_level;
67 uint16_t s_mnt_count;
68 int16_t s_max_mnt_count;
69 uint16_t s_state; /* File system state */
70 uint16_t s_errors; /* Behaviour when detecting errors */
71 uint32_t s_checkinterval; /* Max time between checks */
72 uint64_t s_lastcheck; /* Time of last check */
73 uint32_t s_creator_os; /* OS */
74 uint32_t s_feature_compat; /* Compatible feature set */
75 uint32_t s_feature_incompat; /* Incompatible feature set */
76 uint32_t s_feature_ro_compat; /* Readonly-compatible feature set */
77 uint64_t s_root_blkno; /* Offset, in blocks, of root directory dinode */
78 uint64_t s_system_dir_blkno; /* Offset, in blocks, of system directory dinode */
79 uint32_t s_blocksize_bits; /* Blocksize for this fs */
80 uint32_t s_clustersize_bits; /* Clustersize for this fs */
81 uint16_t s_max_slots; /* Max number of simultaneous mounts before tunefs required */
82 uint16_t s_reserved1;
83 uint32_t s_reserved2;
84 uint64_t s_first_cluster_group; /* Block offset of 1st cluster group header */
85 uint8_t s_label[OCFS2_MAX_VOL_LABEL_LEN]; /* Label for mounting, etc. */
86 uint8_t s_uuid[OCFS2_VOL_UUID_LEN]; /* 128-bit uuid */
87 } PACKED;
88
volume_id_probe_ocfs2(struct volume_id * id)89 int FAST_FUNC volume_id_probe_ocfs2(struct volume_id *id /*,uint64_t off*/)
90 {
91 #define off ((uint64_t)0)
92 struct ocfs2_super_block *os;
93
94 dbg("probing at offset 0x%llx", (unsigned long long) off);
95
96 os = volume_id_get_buffer(id, off + OCFS2_SUPERBLOCK_OFFSET, 0x200);
97 if (os == NULL)
98 return -1;
99
100 if (memcmp(os->i_signature, "OCFSV2", 6) != 0) {
101 return -1;
102 }
103
104 // volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
105 // volume_id_set_label_raw(id, os->s_label, OCFS2_MAX_VOL_LABEL_LEN < VOLUME_ID_LABEL_SIZE ?
106 // OCFS2_MAX_VOL_LABEL_LEN : VOLUME_ID_LABEL_SIZE);
107 volume_id_set_label_string(id, os->s_label, OCFS2_MAX_VOL_LABEL_LEN < VOLUME_ID_LABEL_SIZE ?
108 OCFS2_MAX_VOL_LABEL_LEN : VOLUME_ID_LABEL_SIZE);
109 volume_id_set_uuid(id, os->s_uuid, UUID_DCE);
110 IF_FEATURE_BLKID_TYPE(id->type = "ocfs2";)
111 return 0;
112 }
113