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433 lines
16 KiB
433 lines
16 KiB
/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */ |
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/* |
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md_p.h : physical layout of Linux RAID devices |
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Copyright (C) 1996-98 Ingo Molnar, Gadi Oxman |
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This program is free software; you can redistribute it and/or modify |
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it under the terms of the GNU General Public License as published by |
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the Free Software Foundation; either version 2, or (at your option) |
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any later version. |
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You should have received a copy of the GNU General Public License |
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(for example /usr/src/linux/COPYING); if not, write to the Free |
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Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
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*/ |
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#ifndef _MD_P_H |
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#define _MD_P_H |
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#include <linux/types.h> |
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#include <asm/byteorder.h> |
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/* |
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* RAID superblock. |
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* |
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* The RAID superblock maintains some statistics on each RAID configuration. |
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* Each real device in the RAID set contains it near the end of the device. |
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* Some of the ideas are copied from the ext2fs implementation. |
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* |
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* We currently use 4096 bytes as follows: |
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* |
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* word offset function |
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* |
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* 0 - 31 Constant generic RAID device information. |
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* 32 - 63 Generic state information. |
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* 64 - 127 Personality specific information. |
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* 128 - 511 12 32-words descriptors of the disks in the raid set. |
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* 512 - 911 Reserved. |
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* 912 - 1023 Disk specific descriptor. |
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*/ |
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/* |
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* If x is the real device size in bytes, we return an apparent size of: |
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* |
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* y = (x & ~(MD_RESERVED_BYTES - 1)) - MD_RESERVED_BYTES |
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* |
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* and place the 4kB superblock at offset y. |
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*/ |
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#define MD_RESERVED_BYTES (64 * 1024) |
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#define MD_RESERVED_SECTORS (MD_RESERVED_BYTES / 512) |
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#define MD_NEW_SIZE_SECTORS(x) ((x & ~(MD_RESERVED_SECTORS - 1)) - MD_RESERVED_SECTORS) |
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#define MD_SB_BYTES 4096 |
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#define MD_SB_WORDS (MD_SB_BYTES / 4) |
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#define MD_SB_SECTORS (MD_SB_BYTES / 512) |
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/* |
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* The following are counted in 32-bit words |
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*/ |
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#define MD_SB_GENERIC_OFFSET 0 |
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#define MD_SB_PERSONALITY_OFFSET 64 |
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#define MD_SB_DISKS_OFFSET 128 |
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#define MD_SB_DESCRIPTOR_OFFSET 992 |
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#define MD_SB_GENERIC_CONSTANT_WORDS 32 |
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#define MD_SB_GENERIC_STATE_WORDS 32 |
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#define MD_SB_GENERIC_WORDS (MD_SB_GENERIC_CONSTANT_WORDS + MD_SB_GENERIC_STATE_WORDS) |
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#define MD_SB_PERSONALITY_WORDS 64 |
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#define MD_SB_DESCRIPTOR_WORDS 32 |
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#define MD_SB_DISKS 27 |
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#define MD_SB_DISKS_WORDS (MD_SB_DISKS*MD_SB_DESCRIPTOR_WORDS) |
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#define MD_SB_RESERVED_WORDS (1024 - MD_SB_GENERIC_WORDS - MD_SB_PERSONALITY_WORDS - MD_SB_DISKS_WORDS - MD_SB_DESCRIPTOR_WORDS) |
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#define MD_SB_EQUAL_WORDS (MD_SB_GENERIC_WORDS + MD_SB_PERSONALITY_WORDS + MD_SB_DISKS_WORDS) |
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/* |
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* Device "operational" state bits |
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*/ |
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#define MD_DISK_FAULTY 0 /* disk is faulty / operational */ |
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#define MD_DISK_ACTIVE 1 /* disk is running or spare disk */ |
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#define MD_DISK_SYNC 2 /* disk is in sync with the raid set */ |
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#define MD_DISK_REMOVED 3 /* disk is in sync with the raid set */ |
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#define MD_DISK_CLUSTER_ADD 4 /* Initiate a disk add across the cluster |
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* For clustered enviroments only. |
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*/ |
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#define MD_DISK_CANDIDATE 5 /* disk is added as spare (local) until confirmed |
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* For clustered enviroments only. |
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*/ |
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#define MD_DISK_FAILFAST 10 /* Send REQ_FAILFAST if there are multiple |
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* devices available - and don't try to |
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* correct read errors. |
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*/ |
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#define MD_DISK_WRITEMOSTLY 9 /* disk is "write-mostly" is RAID1 config. |
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* read requests will only be sent here in |
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* dire need |
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*/ |
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#define MD_DISK_JOURNAL 18 /* disk is used as the write journal in RAID-5/6 */ |
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#define MD_DISK_ROLE_SPARE 0xffff |
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#define MD_DISK_ROLE_FAULTY 0xfffe |
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#define MD_DISK_ROLE_JOURNAL 0xfffd |
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#define MD_DISK_ROLE_MAX 0xff00 /* max value of regular disk role */ |
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typedef struct mdp_device_descriptor_s { |
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__u32 number; /* 0 Device number in the entire set */ |
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__u32 major; /* 1 Device major number */ |
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__u32 minor; /* 2 Device minor number */ |
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__u32 raid_disk; /* 3 The role of the device in the raid set */ |
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__u32 state; /* 4 Operational state */ |
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__u32 reserved[MD_SB_DESCRIPTOR_WORDS - 5]; |
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} mdp_disk_t; |
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#define MD_SB_MAGIC 0xa92b4efc |
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/* |
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* Superblock state bits |
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*/ |
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#define MD_SB_CLEAN 0 |
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#define MD_SB_ERRORS 1 |
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#define MD_SB_CLUSTERED 5 /* MD is clustered */ |
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#define MD_SB_BITMAP_PRESENT 8 /* bitmap may be present nearby */ |
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/* |
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* Notes: |
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* - if an array is being reshaped (restriped) in order to change |
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* the number of active devices in the array, 'raid_disks' will be |
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* the larger of the old and new numbers. 'delta_disks' will |
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* be the "new - old". So if +ve, raid_disks is the new value, and |
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* "raid_disks-delta_disks" is the old. If -ve, raid_disks is the |
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* old value and "raid_disks+delta_disks" is the new (smaller) value. |
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*/ |
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typedef struct mdp_superblock_s { |
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/* |
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* Constant generic information |
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*/ |
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__u32 md_magic; /* 0 MD identifier */ |
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__u32 major_version; /* 1 major version to which the set conforms */ |
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__u32 minor_version; /* 2 minor version ... */ |
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__u32 patch_version; /* 3 patchlevel version ... */ |
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__u32 gvalid_words; /* 4 Number of used words in this section */ |
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__u32 set_uuid0; /* 5 Raid set identifier */ |
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__u32 ctime; /* 6 Creation time */ |
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__u32 level; /* 7 Raid personality */ |
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__u32 size; /* 8 Apparent size of each individual disk */ |
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__u32 nr_disks; /* 9 total disks in the raid set */ |
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__u32 raid_disks; /* 10 disks in a fully functional raid set */ |
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__u32 md_minor; /* 11 preferred MD minor device number */ |
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__u32 not_persistent; /* 12 does it have a persistent superblock */ |
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__u32 set_uuid1; /* 13 Raid set identifier #2 */ |
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__u32 set_uuid2; /* 14 Raid set identifier #3 */ |
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__u32 set_uuid3; /* 15 Raid set identifier #4 */ |
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__u32 gstate_creserved[MD_SB_GENERIC_CONSTANT_WORDS - 16]; |
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/* |
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* Generic state information |
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*/ |
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__u32 utime; /* 0 Superblock update time */ |
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__u32 state; /* 1 State bits (clean, ...) */ |
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__u32 active_disks; /* 2 Number of currently active disks */ |
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__u32 working_disks; /* 3 Number of working disks */ |
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__u32 failed_disks; /* 4 Number of failed disks */ |
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__u32 spare_disks; /* 5 Number of spare disks */ |
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__u32 sb_csum; /* 6 checksum of the whole superblock */ |
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#if defined(__BYTE_ORDER) ? __BYTE_ORDER == __BIG_ENDIAN : defined(__BIG_ENDIAN) |
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__u32 events_hi; /* 7 high-order of superblock update count */ |
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__u32 events_lo; /* 8 low-order of superblock update count */ |
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__u32 cp_events_hi; /* 9 high-order of checkpoint update count */ |
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__u32 cp_events_lo; /* 10 low-order of checkpoint update count */ |
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#elif defined(__BYTE_ORDER) ? __BYTE_ORDER == __LITTLE_ENDIAN : defined(__LITTLE_ENDIAN) |
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__u32 events_lo; /* 7 low-order of superblock update count */ |
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__u32 events_hi; /* 8 high-order of superblock update count */ |
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__u32 cp_events_lo; /* 9 low-order of checkpoint update count */ |
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__u32 cp_events_hi; /* 10 high-order of checkpoint update count */ |
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#else |
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#error unspecified endianness |
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#endif |
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__u32 recovery_cp; /* 11 recovery checkpoint sector count */ |
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/* There are only valid for minor_version > 90 */ |
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__u64 reshape_position; /* 12,13 next address in array-space for reshape */ |
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__u32 new_level; /* 14 new level we are reshaping to */ |
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__u32 delta_disks; /* 15 change in number of raid_disks */ |
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__u32 new_layout; /* 16 new layout */ |
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__u32 new_chunk; /* 17 new chunk size (bytes) */ |
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__u32 gstate_sreserved[MD_SB_GENERIC_STATE_WORDS - 18]; |
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/* |
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* Personality information |
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*/ |
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__u32 layout; /* 0 the array's physical layout */ |
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__u32 chunk_size; /* 1 chunk size in bytes */ |
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__u32 root_pv; /* 2 LV root PV */ |
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__u32 root_block; /* 3 LV root block */ |
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__u32 pstate_reserved[MD_SB_PERSONALITY_WORDS - 4]; |
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/* |
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* Disks information |
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*/ |
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mdp_disk_t disks[MD_SB_DISKS]; |
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/* |
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* Reserved |
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*/ |
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__u32 reserved[MD_SB_RESERVED_WORDS]; |
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/* |
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* Active descriptor |
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*/ |
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mdp_disk_t this_disk; |
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} mdp_super_t; |
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static inline __u64 md_event(mdp_super_t *sb) { |
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__u64 ev = sb->events_hi; |
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return (ev<<32)| sb->events_lo; |
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} |
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#define MD_SUPERBLOCK_1_TIME_SEC_MASK ((1ULL<<40) - 1) |
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/* |
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* The version-1 superblock : |
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* All numeric fields are little-endian. |
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* |
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* total size: 256 bytes plus 2 per device. |
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* 1K allows 384 devices. |
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*/ |
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struct mdp_superblock_1 { |
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/* constant array information - 128 bytes */ |
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__le32 magic; /* MD_SB_MAGIC: 0xa92b4efc - little endian */ |
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__le32 major_version; /* 1 */ |
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__le32 feature_map; /* bit 0 set if 'bitmap_offset' is meaningful */ |
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__le32 pad0; /* always set to 0 when writing */ |
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__u8 set_uuid[16]; /* user-space generated. */ |
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char set_name[32]; /* set and interpreted by user-space */ |
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__le64 ctime; /* lo 40 bits are seconds, top 24 are microseconds or 0*/ |
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__le32 level; /* -4 (multipath), -1 (linear), 0,1,4,5 */ |
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__le32 layout; /* only for raid5 and raid10 currently */ |
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__le64 size; /* used size of component devices, in 512byte sectors */ |
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__le32 chunksize; /* in 512byte sectors */ |
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__le32 raid_disks; |
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union { |
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__le32 bitmap_offset; /* sectors after start of superblock that bitmap starts |
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* NOTE: signed, so bitmap can be before superblock |
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* only meaningful of feature_map[0] is set. |
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*/ |
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/* only meaningful when feature_map[MD_FEATURE_PPL] is set */ |
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struct { |
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__le16 offset; /* sectors from start of superblock that ppl starts (signed) */ |
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__le16 size; /* ppl size in sectors */ |
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} ppl; |
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}; |
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/* These are only valid with feature bit '4' */ |
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__le32 new_level; /* new level we are reshaping to */ |
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__le64 reshape_position; /* next address in array-space for reshape */ |
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__le32 delta_disks; /* change in number of raid_disks */ |
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__le32 new_layout; /* new layout */ |
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__le32 new_chunk; /* new chunk size (512byte sectors) */ |
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__le32 new_offset; /* signed number to add to data_offset in new |
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* layout. 0 == no-change. This can be |
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* different on each device in the array. |
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*/ |
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/* constant this-device information - 64 bytes */ |
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__le64 data_offset; /* sector start of data, often 0 */ |
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__le64 data_size; /* sectors in this device that can be used for data */ |
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__le64 super_offset; /* sector start of this superblock */ |
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union { |
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__le64 recovery_offset;/* sectors before this offset (from data_offset) have been recovered */ |
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__le64 journal_tail;/* journal tail of journal device (from data_offset) */ |
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}; |
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__le32 dev_number; /* permanent identifier of this device - not role in raid */ |
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__le32 cnt_corrected_read; /* number of read errors that were corrected by re-writing */ |
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__u8 device_uuid[16]; /* user-space setable, ignored by kernel */ |
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__u8 devflags; /* per-device flags. Only two defined...*/ |
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#define WriteMostly1 1 /* mask for writemostly flag in above */ |
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#define FailFast1 2 /* Should avoid retries and fixups and just fail */ |
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/* Bad block log. If there are any bad blocks the feature flag is set. |
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* If offset and size are non-zero, that space is reserved and available |
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*/ |
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__u8 bblog_shift; /* shift from sectors to block size */ |
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__le16 bblog_size; /* number of sectors reserved for list */ |
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__le32 bblog_offset; /* sector offset from superblock to bblog, |
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* signed - not unsigned */ |
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/* array state information - 64 bytes */ |
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__le64 utime; /* 40 bits second, 24 bits microseconds */ |
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__le64 events; /* incremented when superblock updated */ |
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__le64 resync_offset; /* data before this offset (from data_offset) known to be in sync */ |
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__le32 sb_csum; /* checksum up to devs[max_dev] */ |
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__le32 max_dev; /* size of devs[] array to consider */ |
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__u8 pad3[64-32]; /* set to 0 when writing */ |
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/* device state information. Indexed by dev_number. |
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* 2 bytes per device |
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* Note there are no per-device state flags. State information is rolled |
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* into the 'roles' value. If a device is spare or faulty, then it doesn't |
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* have a meaningful role. |
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*/ |
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__le16 dev_roles[0]; /* role in array, or 0xffff for a spare, or 0xfffe for faulty */ |
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}; |
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/* feature_map bits */ |
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#define MD_FEATURE_BITMAP_OFFSET 1 |
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#define MD_FEATURE_RECOVERY_OFFSET 2 /* recovery_offset is present and |
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* must be honoured |
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*/ |
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#define MD_FEATURE_RESHAPE_ACTIVE 4 |
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#define MD_FEATURE_BAD_BLOCKS 8 /* badblock list is not empty */ |
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#define MD_FEATURE_REPLACEMENT 16 /* This device is replacing an |
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* active device with same 'role'. |
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* 'recovery_offset' is also set. |
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*/ |
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#define MD_FEATURE_RESHAPE_BACKWARDS 32 /* Reshape doesn't change number |
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* of devices, but is going |
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* backwards anyway. |
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*/ |
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#define MD_FEATURE_NEW_OFFSET 64 /* new_offset must be honoured */ |
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#define MD_FEATURE_RECOVERY_BITMAP 128 /* recovery that is happening |
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* is guided by bitmap. |
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*/ |
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#define MD_FEATURE_CLUSTERED 256 /* clustered MD */ |
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#define MD_FEATURE_JOURNAL 512 /* support write cache */ |
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#define MD_FEATURE_PPL 1024 /* support PPL */ |
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#define MD_FEATURE_MULTIPLE_PPLS 2048 /* support for multiple PPLs */ |
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#define MD_FEATURE_RAID0_LAYOUT 4096 /* layout is meaningful for RAID0 */ |
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#define MD_FEATURE_ALL (MD_FEATURE_BITMAP_OFFSET \ |
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|MD_FEATURE_RECOVERY_OFFSET \ |
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|MD_FEATURE_RESHAPE_ACTIVE \ |
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|MD_FEATURE_BAD_BLOCKS \ |
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|MD_FEATURE_REPLACEMENT \ |
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|MD_FEATURE_RESHAPE_BACKWARDS \ |
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|MD_FEATURE_NEW_OFFSET \ |
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|MD_FEATURE_RECOVERY_BITMAP \ |
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|MD_FEATURE_CLUSTERED \ |
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|MD_FEATURE_JOURNAL \ |
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|MD_FEATURE_PPL \ |
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|MD_FEATURE_MULTIPLE_PPLS \ |
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|MD_FEATURE_RAID0_LAYOUT \ |
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) |
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struct r5l_payload_header { |
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__le16 type; |
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__le16 flags; |
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} __attribute__ ((__packed__)); |
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enum r5l_payload_type { |
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R5LOG_PAYLOAD_DATA = 0, |
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R5LOG_PAYLOAD_PARITY = 1, |
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R5LOG_PAYLOAD_FLUSH = 2, |
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}; |
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struct r5l_payload_data_parity { |
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struct r5l_payload_header header; |
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__le32 size; /* sector. data/parity size. each 4k |
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* has a checksum */ |
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__le64 location; /* sector. For data, it's raid sector. For |
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* parity, it's stripe sector */ |
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__le32 checksum[]; |
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} __attribute__ ((__packed__)); |
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enum r5l_payload_data_parity_flag { |
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R5LOG_PAYLOAD_FLAG_DISCARD = 1, /* payload is discard */ |
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/* |
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* RESHAPED/RESHAPING is only set when there is reshape activity. Note, |
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* both data/parity of a stripe should have the same flag set |
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* |
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* RESHAPED: reshape is running, and this stripe finished reshape |
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* RESHAPING: reshape is running, and this stripe isn't reshaped |
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*/ |
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R5LOG_PAYLOAD_FLAG_RESHAPED = 2, |
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R5LOG_PAYLOAD_FLAG_RESHAPING = 3, |
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}; |
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struct r5l_payload_flush { |
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struct r5l_payload_header header; |
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__le32 size; /* flush_stripes size, bytes */ |
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__le64 flush_stripes[]; |
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} __attribute__ ((__packed__)); |
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enum r5l_payload_flush_flag { |
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R5LOG_PAYLOAD_FLAG_FLUSH_STRIPE = 1, /* data represents whole stripe */ |
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}; |
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struct r5l_meta_block { |
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__le32 magic; |
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__le32 checksum; |
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__u8 version; |
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__u8 __zero_pading_1; |
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__le16 __zero_pading_2; |
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__le32 meta_size; /* whole size of the block */ |
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__le64 seq; |
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__le64 position; /* sector, start from rdev->data_offset, current position */ |
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struct r5l_payload_header payloads[]; |
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} __attribute__ ((__packed__)); |
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#define R5LOG_VERSION 0x1 |
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#define R5LOG_MAGIC 0x6433c509 |
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struct ppl_header_entry { |
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__le64 data_sector; /* raid sector of the new data */ |
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__le32 pp_size; /* length of partial parity */ |
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__le32 data_size; /* length of data */ |
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__le32 parity_disk; /* member disk containing parity */ |
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__le32 checksum; /* checksum of partial parity data for this |
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* entry (~crc32c) */ |
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} __attribute__ ((__packed__)); |
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#define PPL_HEADER_SIZE 4096 |
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#define PPL_HDR_RESERVED 512 |
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#define PPL_HDR_ENTRY_SPACE \ |
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(PPL_HEADER_SIZE - PPL_HDR_RESERVED - 4 * sizeof(__le32) - sizeof(__le64)) |
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#define PPL_HDR_MAX_ENTRIES \ |
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(PPL_HDR_ENTRY_SPACE / sizeof(struct ppl_header_entry)) |
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struct ppl_header { |
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__u8 reserved[PPL_HDR_RESERVED];/* reserved space, fill with 0xff */ |
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__le32 signature; /* signature (family number of volume) */ |
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__le32 padding; /* zero pad */ |
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__le64 generation; /* generation number of the header */ |
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__le32 entries_count; /* number of entries in entry array */ |
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__le32 checksum; /* checksum of the header (~crc32c) */ |
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struct ppl_header_entry entries[PPL_HDR_MAX_ENTRIES]; |
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} __attribute__ ((__packed__)); |
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#endif
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