blob: ffe919f36db148cc9613f59e8a19ec311a3c469b [file] [log] [blame]
Sven-Göran Berghc5a9fa22012-09-02 15:34:39 +02001/*
2 * volume_id - reads filesystem label and uuid
3 *
4 * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
5 * Copyright (C) 2012 S-G Bergh <sgb@systemasis.org>
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
Sven-Göran Bergh3b458012013-07-31 15:45:20 +020022//kbuild:lib-$(CONFIG_FEATURE_VOLUMEID_NILFS) += nilfs.o
23
Sven-Göran Bergh15d0a862013-07-31 15:57:59 +020024//config:config FEATURE_VOLUMEID_NILFS
25//config: bool "nilfs filesystem"
26//config: default y
27//config: depends on VOLUMEID
28//config: help
Sven-Göran Berghe418b2e2013-07-31 18:30:34 +020029//config: NILFS is a New Implementation of a Log-Structured File System (LFS)
30//config: that supports continuous snapshots. This provides features like
31//config: versioning of the entire filesystem, restoration of files that
32//config: were deleted a few minutes ago. NILFS keeps consistency like
33//config: conventional LFS, so it provides quick recovery after system crashes.
34//config:
35//config: The possible use of NILFS includes versioning, tamper detection,
36//config: SOX compliance logging, and so forth. It can serve as an alternative
37//config: filesystem for Linux desktop environment, or as a basis of advanced
38//config: storage appliances.
Sven-Göran Bergh15d0a862013-07-31 15:57:59 +020039
Sven-Göran Berghc5a9fa22012-09-02 15:34:39 +020040#include "volume_id_internal.h"
41
42#define NILFS_UUID_SIZE 16
43#define NILFS_LABEL_SIZE 80
44#define NILFS_SB1_OFFSET 0x400
45#define NILFS_SB2_OFFSET 0x1000
46#define NILFS_MAGIC 0x3434
47
48struct nilfs2_super_block {
49/* 0x00 */ uint32_t s_rev_level; // Major revision level.
50/* 0x04 */ uint16_t s_minor_rev_level; // Minor revision level.
51/* 0x06 */ uint16_t s_magic; // Magic signature.
52/* 0x08 */ uint16_t s_bytes;
53/* 0x0A */ uint16_t s_flags;
54/* 0x0C */ uint32_t s_crc_seed;
55/* 0x10 */ uint32_t s_sum;
56/* 0x14 */ uint32_t s_log_block_size;
57/* 0x18 */ uint64_t s_nsegments;
58/* 0x20 */ uint64_t s_dev_size; // Block device size in bytes.
59/* 0x28 */ uint64_t s_first_data_block;
60/* 0x30 */ uint32_t s_blocks_per_segment;
61/* 0x34 */ uint32_t s_r_segments_percentage;
62/* 0x38 */ uint64_t s_last_cno;
63/* 0x40 */ uint64_t s_last_pseg;
64/* 0x48 */ uint64_t s_last_seq;
65/* 0x50 */ uint64_t s_free_blocks_count;
66/* 0x58 */ uint64_t s_ctime;
67/* 0x60 */ uint64_t s_mtime;
68/* 0x68 */ uint64_t s_wtime;
69/* 0x70 */ uint16_t s_mnt_count;
70/* 0x72 */ uint16_t s_max_mnt_count;
71/* 0x74 */ uint16_t s_state;
72/* 0x76 */ uint16_t s_errors;
73/* 0x78 */ uint64_t s_lastcheck;
74/* 0x80 */ uint32_t s_checkinterval;
75/* 0x84 */ uint32_t s_creator_os;
76/* 0x88 */ uint16_t s_def_resuid;
77/* 0x8A */ uint16_t s_def_resgid;
78/* 0x8C */ uint32_t s_first_ino;
79/* 0x90 */ uint16_t s_inode_size;
80/* 0x92 */ uint16_t s_dat_entry_size;
81/* 0x94 */ uint16_t s_checkpoint_size;
82/* 0x96 */ uint16_t s_segment_usage_size;
83/* 0x98 */ uint8_t s_uuid[NILFS_UUID_SIZE]; // 128-bit UUID for volume.
84/* 0xA8 */ uint8_t s_volume_name[NILFS_LABEL_SIZE]; // Volume label.
85/* 0xF8 */ // ...
86} PACKED;
87
88int FAST_FUNC volume_id_probe_nilfs(struct volume_id *id /*,uint64_t off*/)
89{
90 struct nilfs2_super_block *sb;
91
92 // Primary super block
93 dbg("nilfs: probing at offset 0x%x", NILFS_SB1_OFFSET);
94
95 sb = volume_id_get_buffer(id, NILFS_SB1_OFFSET, sizeof(*sb));
96
97 if (sb == NULL)
98 return -1;
99
100 if (sb->s_magic != NILFS_MAGIC)
101 return -1;
102
103 // The secondary superblock is not always used, so ignore it for now.
104 // When used it is at 4K from the end of the partition (sb->s_dev_size - NILFS_SB2_OFFSET).
105
106 volume_id_set_label_string(id, sb->s_volume_name, NILFS_LABEL_SIZE < VOLUME_ID_LABEL_SIZE ?
Denys Vlasenko60cb48c2013-01-14 15:57:44 +0100107 NILFS_LABEL_SIZE : VOLUME_ID_LABEL_SIZE);
Sven-Göran Berghc5a9fa22012-09-02 15:34:39 +0200108 volume_id_set_uuid(id, sb->s_uuid, UUID_DCE);
109
110 if (sb->s_rev_level == 2)
111 IF_FEATURE_BLKID_TYPE(id->type = "nilfs2");
112
113 return 0;
114}