1 | /*
|
---|
2 | * volume_id - reads filesystem label and uuid
|
---|
3 | *
|
---|
4 | * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
|
---|
5 | * Copyright (C) 2009 Vladimir Dronnikov <dronnikov@gmail.com>
|
---|
6 | *
|
---|
7 | * This library is free software; you can redistribute it and/or
|
---|
8 | * modify it under the terms of the GNU Lesser General Public
|
---|
9 | * License as published by the Free Software Foundation; either
|
---|
10 | * version 2.1 of the License, or (at your option) any later version.
|
---|
11 | *
|
---|
12 | * This library is distributed in the hope that it will be useful,
|
---|
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
|
---|
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
---|
15 | * Lesser General Public License for more details.
|
---|
16 | *
|
---|
17 | * You should have received a copy of the GNU Lesser General Public
|
---|
18 | * License along with this library; if not, write to the Free Software
|
---|
19 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
---|
20 | */
|
---|
21 |
|
---|
22 | //kbuild:lib-$(CONFIG_FEATURE_VOLUMEID_BTRFS) += btrfs.o
|
---|
23 |
|
---|
24 | //config:
|
---|
25 | //config:config FEATURE_VOLUMEID_BTRFS
|
---|
26 | //config: bool "btrfs filesystem"
|
---|
27 | //config: default y
|
---|
28 | //config: depends on VOLUMEID
|
---|
29 | //config: help
|
---|
30 | //config: TODO
|
---|
31 | //config:
|
---|
32 |
|
---|
33 | #include "volume_id_internal.h"
|
---|
34 |
|
---|
35 | #define BTRFS_UUID_SIZE 16
|
---|
36 | #define BTRFS_LABEL_SIZE 256
|
---|
37 | #define BTRFS_CSUM_SIZE 32
|
---|
38 | #define BTRFS_FSID_SIZE 16
|
---|
39 |
|
---|
40 | #define BTRFS_MAGIC "_BHRfS_M"
|
---|
41 |
|
---|
42 | struct btrfs_dev_item {
|
---|
43 | uint64_t devid;
|
---|
44 | uint64_t total_bytes;
|
---|
45 | uint64_t bytes_used;
|
---|
46 | uint32_t io_align;
|
---|
47 | uint32_t io_width;
|
---|
48 | uint32_t sector_size;
|
---|
49 | uint64_t type;
|
---|
50 | uint64_t generation;
|
---|
51 | uint64_t start_offset;
|
---|
52 | uint32_t dev_group;
|
---|
53 | uint8_t seek_speed;
|
---|
54 | uint8_t bandwidth;
|
---|
55 | uint8_t uuid[BTRFS_UUID_SIZE];
|
---|
56 | uint8_t fsid[BTRFS_UUID_SIZE];
|
---|
57 | } PACKED;
|
---|
58 |
|
---|
59 | struct btrfs_super_block {
|
---|
60 | uint8_t csum[BTRFS_CSUM_SIZE];
|
---|
61 | uint8_t fsid[BTRFS_FSID_SIZE]; // UUID
|
---|
62 | uint64_t bytenr;
|
---|
63 | uint64_t flags;
|
---|
64 | uint8_t magic[8];
|
---|
65 | uint64_t generation;
|
---|
66 | uint64_t root;
|
---|
67 | uint64_t chunk_root;
|
---|
68 | uint64_t log_root;
|
---|
69 | uint64_t log_root_transid;
|
---|
70 | uint64_t total_bytes;
|
---|
71 | uint64_t bytes_used;
|
---|
72 | uint64_t root_dir_objectid;
|
---|
73 | uint64_t num_devices;
|
---|
74 | uint32_t sectorsize;
|
---|
75 | uint32_t nodesize;
|
---|
76 | uint32_t leafsize;
|
---|
77 | uint32_t stripesize;
|
---|
78 | uint32_t sys_chunk_array_size;
|
---|
79 | uint64_t chunk_root_generation;
|
---|
80 | uint64_t compat_flags;
|
---|
81 | uint64_t compat_ro_flags;
|
---|
82 | uint64_t incompat_flags;
|
---|
83 | uint16_t csum_type;
|
---|
84 | uint8_t root_level;
|
---|
85 | uint8_t chunk_root_level;
|
---|
86 | uint8_t log_root_level;
|
---|
87 | struct btrfs_dev_item dev_item;
|
---|
88 | uint8_t label[BTRFS_LABEL_SIZE]; // LABEL
|
---|
89 | // ...
|
---|
90 | } PACKED;
|
---|
91 |
|
---|
92 | int FAST_FUNC volume_id_probe_btrfs(struct volume_id *id /*,uint64_t off*/)
|
---|
93 | {
|
---|
94 | // btrfs has superblocks at 64K, 64M and 256G
|
---|
95 | // minimum btrfs size is 256M
|
---|
96 | // so we never step out the device if we analyze
|
---|
97 | // the first and the second superblocks
|
---|
98 | struct btrfs_super_block *sb;
|
---|
99 | unsigned off = 64;
|
---|
100 |
|
---|
101 | while (off < 64*1024*1024) {
|
---|
102 | off *= 1024;
|
---|
103 | dbg("btrfs: probing at offset 0x%x", off);
|
---|
104 |
|
---|
105 | sb = volume_id_get_buffer(id, off, sizeof(*sb));
|
---|
106 | if (sb == NULL)
|
---|
107 | return -1;
|
---|
108 |
|
---|
109 | if (memcmp(sb->magic, BTRFS_MAGIC, 8) != 0)
|
---|
110 | return -1;
|
---|
111 | }
|
---|
112 |
|
---|
113 | // N.B.: btrfs natively supports 256 (>VOLUME_ID_LABEL_SIZE) size labels
|
---|
114 | volume_id_set_label_string(id, sb->label, VOLUME_ID_LABEL_SIZE);
|
---|
115 | volume_id_set_uuid(id, sb->fsid, UUID_DCE);
|
---|
116 | IF_FEATURE_BLKID_TYPE(id->type = "btrfs";)
|
---|
117 |
|
---|
118 | return 0;
|
---|
119 | }
|
---|