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/*
md_p.h : physical layout of Linux RAID devices
Copyright (C) 1996-98 Ingo Molnar, Gadi Oxman
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
You should have received a copy of the GNU General Public License
(for example /usr/src/linux/COPYING); if not, write to the Free
Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#ifndef _MD_P_H
#define _MD_P_H
/*
* RAID superblock.
*
* The RAID superblock maintains some statistics on each RAID configuration.
* Each real device in the RAID set contains it near the end of the device.
* Some of the ideas are copied from the ext2fs implementation.
*
* We currently use 4096 bytes as follows:
*
* word offset function
*
* 0 - 31 Constant generic RAID device information.
* 32 - 63 Generic state information.
* 64 - 127 Personality specific information.
* 128 - 511 12 32-words descriptors of the disks in the raid set.
* 512 - 911 Reserved.
* 912 - 1023 Disk specific descriptor.
*/
/*
* If x is the real device size in bytes, we return an apparent size of:
*
* y = (x & ~(MD_RESERVED_BYTES - 1)) - MD_RESERVED_BYTES
*
* and place the 4kB superblock at offset y.
*/
#define MD_RESERVED_BYTES (64 * 1024)
#define MD_RESERVED_SECTORS (MD_RESERVED_BYTES / 512)
#define MD_RESERVED_BLOCKS (MD_RESERVED_BYTES / BLOCK_SIZE)
#define MD_NEW_SIZE_SECTORS(x) ((x & ~(MD_RESERVED_SECTORS - 1)) - MD_RESERVED_SECTORS)
#define MD_NEW_SIZE_BLOCKS(x) ((x & ~(MD_RESERVED_BLOCKS - 1)) - MD_RESERVED_BLOCKS)
#define MD_SB_BYTES 4096
#define MD_SB_WORDS (MD_SB_BYTES / 4)
#define MD_SB_BLOCKS (MD_SB_BYTES / BLOCK_SIZE)
#define MD_SB_SECTORS (MD_SB_BYTES / 512)
/*
* The following are counted in 32-bit words
*/
#define MD_SB_GENERIC_OFFSET 0
#define MD_SB_PERSONALITY_OFFSET 64
#define MD_SB_DISKS_OFFSET 128
#define MD_SB_DESCRIPTOR_OFFSET 992
#define MD_SB_GENERIC_CONSTANT_WORDS 32
#define MD_SB_GENERIC_STATE_WORDS 32
#define MD_SB_GENERIC_WORDS (MD_SB_GENERIC_CONSTANT_WORDS + MD_SB_GENERIC_STATE_WORDS)
#define MD_SB_PERSONALITY_WORDS 64
#define MD_SB_DESCRIPTOR_WORDS 32
#define MD_SB_DISKS 27
#define MD_SB_DISKS_WORDS (MD_SB_DISKS*MD_SB_DESCRIPTOR_WORDS)
#define MD_SB_RESERVED_WORDS (1024 - MD_SB_GENERIC_WORDS - MD_SB_PERSONALITY_WORDS - MD_SB_DISKS_WORDS - MD_SB_DESCRIPTOR_WORDS)
#define MD_SB_EQUAL_WORDS (MD_SB_GENERIC_WORDS + MD_SB_PERSONALITY_WORDS + MD_SB_DISKS_WORDS)
/*
* Device "operational" state bits
*/
#define MD_DISK_FAULTY 0 /* disk is faulty / operational */
#define MD_DISK_ACTIVE 1 /* disk is running or spare disk */
#define MD_DISK_SYNC 2 /* disk is in sync with the raid set */
#define MD_DISK_REMOVED 3 /* disk is in sync with the raid set */
typedef struct mdp_device_descriptor_s {
__u32 number; /* 0 Device number in the entire set */
__u32 major; /* 1 Device major number */
__u32 minor; /* 2 Device minor number */
__u32 raid_disk; /* 3 The role of the device in the raid set */
__u32 state; /* 4 Operational state */
__u32 reserved[MD_SB_DESCRIPTOR_WORDS - 5];
} mdp_disk_t;
#define MD_SB_MAGIC 0xa92b4efc
/*
* Superblock state bits
*/
#define MD_SB_CLEAN 0
#define MD_SB_ERRORS 1
typedef struct mdp_superblock_s {
/*
* Constant generic information
*/
__u32 md_magic; /* 0 MD identifier */
__u32 major_version; /* 1 major version to which the set conforms */
__u32 minor_version; /* 2 minor version ... */
__u32 patch_version; /* 3 patchlevel version ... */
__u32 gvalid_words; /* 4 Number of used words in this section */
__u32 set_uuid0; /* 5 Raid set identifier */
__u32 ctime; /* 6 Creation time */
__u32 level; /* 7 Raid personality */
__u32 size; /* 8 Apparent size of each individual disk */
__u32 nr_disks; /* 9 total disks in the raid set */
__u32 raid_disks; /* 10 disks in a fully functional raid set */
__u32 md_minor; /* 11 preferred MD minor device number */
__u32 not_persistent; /* 12 does it have a persistent superblock */
__u32 set_uuid1; /* 13 Raid set identifier #2 */
__u32 set_uuid2; /* 14 Raid set identifier #3 */
__u32 set_uuid3; /* 15 Raid set identifier #4 */
__u32 gstate_creserved[MD_SB_GENERIC_CONSTANT_WORDS - 16];
/*
* Generic state information
*/
__u32 utime; /* 0 Superblock update time */
__u32 state; /* 1 State bits (clean, ...) */
__u32 active_disks; /* 2 Number of currently active disks */
__u32 working_disks; /* 3 Number of working disks */
__u32 failed_disks; /* 4 Number of failed disks */
__u32 spare_disks; /* 5 Number of spare disks */
__u32 sb_csum; /* 6 checksum of the whole superblock */
#if __BYTE_ORDER == __BIG_ENDIAN
__u32 events_hi; /* 7 high-order of superblock update count */
__u32 events_lo; /* 8 low-order of superblock update count */
#else
__u32 events_lo; /* 7 low-order of superblock update count */
__u32 events_hi; /* 8 high-order of superblock update count */
#endif
__u32 gstate_sreserved[MD_SB_GENERIC_STATE_WORDS - 9];
/*
* Personality information
*/
__u32 layout; /* 0 the array's physical layout */
__u32 chunk_size; /* 1 chunk size in bytes */
__u32 root_pv; /* 2 LV root PV */
__u32 root_block; /* 3 LV root block */
__u32 pstate_reserved[MD_SB_PERSONALITY_WORDS - 4];
/*
* Disks information
*/
mdp_disk_t disks[MD_SB_DISKS];
/*
* Reserved
*/
__u32 reserved[MD_SB_RESERVED_WORDS];
/*
* Active descriptor
*/
mdp_disk_t this_disk;
} mdp_super_t;
static inline __u64 md_event(mdp_super_t *sb) {
__u64 ev = sb->events_hi;
return (ev<<32)| sb->events_lo;
}
#endif
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