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64c4757e NB |
1 | /* |
2 | md_p.h : physical layout of Linux RAID devices | |
3 | Copyright (C) 1996-98 Ingo Molnar, Gadi Oxman | |
aba69144 | 4 | |
64c4757e NB |
5 | This program is free software; you can redistribute it and/or modify |
6 | it under the terms of the GNU General Public License as published by | |
7 | the Free Software Foundation; either version 2, or (at your option) | |
8 | any later version. | |
aba69144 | 9 | |
64c4757e NB |
10 | You should have received a copy of the GNU General Public License |
11 | (for example /usr/src/linux/COPYING); if not, write to the Free | |
aba69144 | 12 | Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
64c4757e NB |
13 | */ |
14 | ||
15 | #ifndef _MD_P_H | |
16 | #define _MD_P_H | |
17 | ||
18 | /* | |
19 | * RAID superblock. | |
20 | * | |
21 | * The RAID superblock maintains some statistics on each RAID configuration. | |
22 | * Each real device in the RAID set contains it near the end of the device. | |
23 | * Some of the ideas are copied from the ext2fs implementation. | |
24 | * | |
25 | * We currently use 4096 bytes as follows: | |
26 | * | |
27 | * word offset function | |
28 | * | |
29 | * 0 - 31 Constant generic RAID device information. | |
30 | * 32 - 63 Generic state information. | |
31 | * 64 - 127 Personality specific information. | |
32 | * 128 - 511 12 32-words descriptors of the disks in the raid set. | |
33 | * 512 - 911 Reserved. | |
34 | * 912 - 1023 Disk specific descriptor. | |
35 | */ | |
36 | ||
37 | /* | |
38 | * If x is the real device size in bytes, we return an apparent size of: | |
39 | * | |
40 | * y = (x & ~(MD_RESERVED_BYTES - 1)) - MD_RESERVED_BYTES | |
41 | * | |
42 | * and place the 4kB superblock at offset y. | |
43 | */ | |
44 | #define MD_RESERVED_BYTES (64 * 1024) | |
45 | #define MD_RESERVED_SECTORS (MD_RESERVED_BYTES / 512) | |
46 | #define MD_RESERVED_BLOCKS (MD_RESERVED_BYTES / BLOCK_SIZE) | |
47 | ||
48 | #define MD_NEW_SIZE_SECTORS(x) ((x & ~(MD_RESERVED_SECTORS - 1)) - MD_RESERVED_SECTORS) | |
49 | #define MD_NEW_SIZE_BLOCKS(x) ((x & ~(MD_RESERVED_BLOCKS - 1)) - MD_RESERVED_BLOCKS) | |
50 | ||
51 | #define MD_SB_BYTES 4096 | |
52 | #define MD_SB_WORDS (MD_SB_BYTES / 4) | |
53 | #define MD_SB_BLOCKS (MD_SB_BYTES / BLOCK_SIZE) | |
54 | #define MD_SB_SECTORS (MD_SB_BYTES / 512) | |
55 | ||
56 | /* | |
57 | * The following are counted in 32-bit words | |
58 | */ | |
59 | #define MD_SB_GENERIC_OFFSET 0 | |
60 | #define MD_SB_PERSONALITY_OFFSET 64 | |
61 | #define MD_SB_DISKS_OFFSET 128 | |
62 | #define MD_SB_DESCRIPTOR_OFFSET 992 | |
63 | ||
64 | #define MD_SB_GENERIC_CONSTANT_WORDS 32 | |
65 | #define MD_SB_GENERIC_STATE_WORDS 32 | |
66 | #define MD_SB_GENERIC_WORDS (MD_SB_GENERIC_CONSTANT_WORDS + MD_SB_GENERIC_STATE_WORDS) | |
67 | #define MD_SB_PERSONALITY_WORDS 64 | |
68 | #define MD_SB_DESCRIPTOR_WORDS 32 | |
69 | #define MD_SB_DISKS 27 | |
70 | #define MD_SB_DISKS_WORDS (MD_SB_DISKS*MD_SB_DESCRIPTOR_WORDS) | |
71 | #define MD_SB_RESERVED_WORDS (1024 - MD_SB_GENERIC_WORDS - MD_SB_PERSONALITY_WORDS - MD_SB_DISKS_WORDS - MD_SB_DESCRIPTOR_WORDS) | |
72 | #define MD_SB_EQUAL_WORDS (MD_SB_GENERIC_WORDS + MD_SB_PERSONALITY_WORDS + MD_SB_DISKS_WORDS) | |
73 | ||
74 | /* | |
75 | * Device "operational" state bits | |
76 | */ | |
77 | #define MD_DISK_FAULTY 0 /* disk is faulty / operational */ | |
f22385f9 | 78 | #define MD_DISK_ACTIVE 1 /* disk is running but may not be in sync */ |
64c4757e NB |
79 | #define MD_DISK_SYNC 2 /* disk is in sync with the raid set */ |
80 | #define MD_DISK_REMOVED 3 /* disk is in sync with the raid set */ | |
81 | ||
dfd4d8ee | 82 | #define MD_DISK_WRITEMOSTLY 9 /* disk is "write-mostly" is RAID1 config. |
aba69144 | 83 | * read requests will only be sent here in |
dfd4d8ee NB |
84 | * dire need |
85 | */ | |
86 | ||
64c4757e NB |
87 | typedef struct mdp_device_descriptor_s { |
88 | __u32 number; /* 0 Device number in the entire set */ | |
89 | __u32 major; /* 1 Device major number */ | |
90 | __u32 minor; /* 2 Device minor number */ | |
91 | __u32 raid_disk; /* 3 The role of the device in the raid set */ | |
92 | __u32 state; /* 4 Operational state */ | |
93 | __u32 reserved[MD_SB_DESCRIPTOR_WORDS - 5]; | |
94 | } mdp_disk_t; | |
95 | ||
96 | #define MD_SB_MAGIC 0xa92b4efc | |
97 | ||
98 | /* | |
99 | * Superblock state bits | |
100 | */ | |
101 | #define MD_SB_CLEAN 0 | |
102 | #define MD_SB_ERRORS 1 | |
a06d022d | 103 | #define MD_SB_BBM_ERRORS 2 |
64c4757e | 104 | |
55935d51 NB |
105 | #define MD_SB_BITMAP_PRESENT 8 /* bitmap may be present nearby */ |
106 | ||
64c4757e NB |
107 | typedef struct mdp_superblock_s { |
108 | /* | |
109 | * Constant generic information | |
110 | */ | |
111 | __u32 md_magic; /* 0 MD identifier */ | |
112 | __u32 major_version; /* 1 major version to which the set conforms */ | |
113 | __u32 minor_version; /* 2 minor version ... */ | |
114 | __u32 patch_version; /* 3 patchlevel version ... */ | |
115 | __u32 gvalid_words; /* 4 Number of used words in this section */ | |
116 | __u32 set_uuid0; /* 5 Raid set identifier */ | |
117 | __u32 ctime; /* 6 Creation time */ | |
118 | __u32 level; /* 7 Raid personality */ | |
119 | __u32 size; /* 8 Apparent size of each individual disk */ | |
120 | __u32 nr_disks; /* 9 total disks in the raid set */ | |
121 | __u32 raid_disks; /* 10 disks in a fully functional raid set */ | |
122 | __u32 md_minor; /* 11 preferred MD minor device number */ | |
123 | __u32 not_persistent; /* 12 does it have a persistent superblock */ | |
124 | __u32 set_uuid1; /* 13 Raid set identifier #2 */ | |
125 | __u32 set_uuid2; /* 14 Raid set identifier #3 */ | |
126 | __u32 set_uuid3; /* 15 Raid set identifier #4 */ | |
127 | __u32 gstate_creserved[MD_SB_GENERIC_CONSTANT_WORDS - 16]; | |
128 | ||
129 | /* | |
130 | * Generic state information | |
131 | */ | |
132 | __u32 utime; /* 0 Superblock update time */ | |
133 | __u32 state; /* 1 State bits (clean, ...) */ | |
134 | __u32 active_disks; /* 2 Number of currently active disks */ | |
135 | __u32 working_disks; /* 3 Number of working disks */ | |
136 | __u32 failed_disks; /* 4 Number of failed disks */ | |
137 | __u32 spare_disks; /* 5 Number of spare disks */ | |
138 | __u32 sb_csum; /* 6 checksum of the whole superblock */ | |
52826846 | 139 | #if __BYTE_ORDER == __BIG_ENDIAN |
64c4757e NB |
140 | __u32 events_hi; /* 7 high-order of superblock update count */ |
141 | __u32 events_lo; /* 8 low-order of superblock update count */ | |
e5329c37 NB |
142 | __u32 cp_events_hi; /* 9 high-order of checkpoint update count */ |
143 | __u32 cp_events_lo; /* 10 low-order of checkpoint update count */ | |
64c4757e NB |
144 | #else |
145 | __u32 events_lo; /* 7 low-order of superblock update count */ | |
146 | __u32 events_hi; /* 8 high-order of superblock update count */ | |
e5329c37 NB |
147 | __u32 cp_events_lo; /* 9 low-order of checkpoint update count */ |
148 | __u32 cp_events_hi; /* 10 high-order of checkpoint update count */ | |
64c4757e | 149 | #endif |
e5329c37 | 150 | __u32 recovery_cp; /* 11 recovery checkpoint sector count */ |
b674b5b8 NB |
151 | /* There are only valid for minor_version > 90 */ |
152 | __u64 reshape_position; /* 12,13 next address in array-space for reshape */ | |
153 | __u32 new_level; /* 14 new level we are reshaping to */ | |
154 | __u32 delta_disks; /* 15 change in number of raid_disks */ | |
155 | __u32 new_layout; /* 16 new layout */ | |
156 | __u32 new_chunk; /* 17 new chunk size (bytes) */ | |
157 | __u32 gstate_sreserved[MD_SB_GENERIC_STATE_WORDS - 18]; | |
64c4757e NB |
158 | |
159 | /* | |
160 | * Personality information | |
161 | */ | |
162 | __u32 layout; /* 0 the array's physical layout */ | |
163 | __u32 chunk_size; /* 1 chunk size in bytes */ | |
164 | __u32 root_pv; /* 2 LV root PV */ | |
165 | __u32 root_block; /* 3 LV root block */ | |
166 | __u32 pstate_reserved[MD_SB_PERSONALITY_WORDS - 4]; | |
167 | ||
168 | /* | |
169 | * Disks information | |
170 | */ | |
171 | mdp_disk_t disks[MD_SB_DISKS]; | |
172 | ||
173 | /* | |
174 | * Reserved | |
175 | */ | |
176 | __u32 reserved[MD_SB_RESERVED_WORDS]; | |
177 | ||
178 | /* | |
179 | * Active descriptor | |
180 | */ | |
181 | mdp_disk_t this_disk; | |
182 | ||
183 | } mdp_super_t; | |
184 | ||
5787fa49 NB |
185 | #ifdef __TINYC__ |
186 | typedef unsigned long long __u64; | |
187 | #endif | |
188 | ||
64c4757e NB |
189 | static inline __u64 md_event(mdp_super_t *sb) { |
190 | __u64 ev = sb->events_hi; | |
191 | return (ev<<32)| sb->events_lo; | |
192 | } | |
193 | ||
aba69144 | 194 | #endif |
64c4757e | 195 |