71c0805cb4
As this is used to flag an internal bitmap. Also, introduce symbolic names for feature bits. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
248 lines
9.0 KiB
C
248 lines
9.0 KiB
C
/*
|
|
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 */
|
|
|
|
#define MD_DISK_WRITEMOSTLY 9 /* disk is "write-mostly" is RAID1 config.
|
|
* read requests will only be sent here in
|
|
* dire need
|
|
*/
|
|
|
|
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
|
|
|
|
#define MD_SB_BITMAP_PRESENT 8 /* bitmap may be present nearby */
|
|
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 */
|
|
#ifdef __BIG_ENDIAN
|
|
__u32 events_hi; /* 7 high-order of superblock update count */
|
|
__u32 events_lo; /* 8 low-order of superblock update count */
|
|
__u32 cp_events_hi; /* 9 high-order of checkpoint update count */
|
|
__u32 cp_events_lo; /* 10 low-order of checkpoint update count */
|
|
#else
|
|
__u32 events_lo; /* 7 low-order of superblock update count */
|
|
__u32 events_hi; /* 8 high-order of superblock update count */
|
|
__u32 cp_events_lo; /* 9 low-order of checkpoint update count */
|
|
__u32 cp_events_hi; /* 10 high-order of checkpoint update count */
|
|
#endif
|
|
__u32 recovery_cp; /* 11 recovery checkpoint sector count */
|
|
__u32 gstate_sreserved[MD_SB_GENERIC_STATE_WORDS - 12];
|
|
|
|
/*
|
|
* 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;
|
|
}
|
|
|
|
/*
|
|
* The version-1 superblock :
|
|
* All numeric fields are little-endian.
|
|
*
|
|
* total size: 256 bytes plus 2 per device.
|
|
* 1K allows 384 devices.
|
|
*/
|
|
struct mdp_superblock_1 {
|
|
/* constant array information - 128 bytes */
|
|
__u32 magic; /* MD_SB_MAGIC: 0xa92b4efc - little endian */
|
|
__u32 major_version; /* 1 */
|
|
__u32 feature_map; /* bit 0 set if 'bitmap_offset' is meaningful */
|
|
__u32 pad0; /* always set to 0 when writing */
|
|
|
|
__u8 set_uuid[16]; /* user-space generated. */
|
|
char set_name[32]; /* set and interpreted by user-space */
|
|
|
|
__u64 ctime; /* lo 40 bits are seconds, top 24 are microseconds or 0*/
|
|
__u32 level; /* -4 (multipath), -1 (linear), 0,1,4,5 */
|
|
__u32 layout; /* only for raid5 and raid10 currently */
|
|
__u64 size; /* used size of component devices, in 512byte sectors */
|
|
|
|
__u32 chunksize; /* in 512byte sectors */
|
|
__u32 raid_disks;
|
|
__u32 bitmap_offset; /* sectors after start of superblock that bitmap starts
|
|
* NOTE: signed, so bitmap can be before superblock
|
|
* only meaningful of feature_map[0] is set.
|
|
*/
|
|
__u8 pad1[128-100]; /* set to 0 when written */
|
|
|
|
/* constant this-device information - 64 bytes */
|
|
__u64 data_offset; /* sector start of data, often 0 */
|
|
__u64 data_size; /* sectors in this device that can be used for data */
|
|
__u64 super_offset; /* sector start of this superblock */
|
|
__u64 recovery_offset;/* sectors before this offset (from data_offset) have been recovered */
|
|
__u32 dev_number; /* permanent identifier of this device - not role in raid */
|
|
__u32 cnt_corrected_read; /* number of read errors that were corrected by re-writing */
|
|
__u8 device_uuid[16]; /* user-space setable, ignored by kernel */
|
|
__u8 devflags; /* per-device flags. Only one defined...*/
|
|
#define WriteMostly1 1 /* mask for writemostly flag in above */
|
|
__u8 pad2[64-57]; /* set to 0 when writing */
|
|
|
|
/* array state information - 64 bytes */
|
|
__u64 utime; /* 40 bits second, 24 btes microseconds */
|
|
__u64 events; /* incremented when superblock updated */
|
|
__u64 resync_offset; /* data before this offset (from data_offset) known to be in sync */
|
|
__u32 sb_csum; /* checksum upto devs[max_dev] */
|
|
__u32 max_dev; /* size of devs[] array to consider */
|
|
__u8 pad3[64-32]; /* set to 0 when writing */
|
|
|
|
/* device state information. Indexed by dev_number.
|
|
* 2 bytes per device
|
|
* Note there are no per-device state flags. State information is rolled
|
|
* into the 'roles' value. If a device is spare or faulty, then it doesn't
|
|
* have a meaningful role.
|
|
*/
|
|
__u16 dev_roles[0]; /* role in array, or 0xffff for a spare, or 0xfffe for faulty */
|
|
};
|
|
|
|
/* feature_map bits */
|
|
#define MD_FEATURE_BITMAP_OFFSET 1
|
|
|
|
#define MD_FEATURE_ALL 1
|
|
|
|
#endif
|
|
|