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Creation of Cybook 2416 (actually Gen4) repository

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mlt
2009-12-18 17:10:00 +00:00
committed by godzil
commit 76f20f4d40
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2
include/linux/raid/Kbuild Normal file
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header-y += md_p.h
header-y += md_u.h

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include/linux/raid/bitmap.h Normal file
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/*
* bitmap.h: Copyright (C) Peter T. Breuer (ptb@ot.uc3m.es) 2003
*
* additions: Copyright (C) 2003-2004, Paul Clements, SteelEye Technology, Inc.
*/
#ifndef BITMAP_H
#define BITMAP_H 1
#define BITMAP_MAJOR_LO 3
/* version 4 insists the bitmap is in little-endian order
* with version 3, it is host-endian which is non-portable
*/
#define BITMAP_MAJOR_HI 4
#define BITMAP_MAJOR_HOSTENDIAN 3
#define BITMAP_MINOR 39
/*
* in-memory bitmap:
*
* Use 16 bit block counters to track pending writes to each "chunk".
* The 2 high order bits are special-purpose, the first is a flag indicating
* whether a resync is needed. The second is a flag indicating whether a
* resync is active.
* This means that the counter is actually 14 bits:
*
* +--------+--------+------------------------------------------------+
* | resync | resync | counter |
* | needed | active | |
* | (0-1) | (0-1) | (0-16383) |
* +--------+--------+------------------------------------------------+
*
* The "resync needed" bit is set when:
* a '1' bit is read from storage at startup.
* a write request fails on some drives
* a resync is aborted on a chunk with 'resync active' set
* It is cleared (and resync-active set) when a resync starts across all drives
* of the chunk.
*
*
* The "resync active" bit is set when:
* a resync is started on all drives, and resync_needed is set.
* resync_needed will be cleared (as long as resync_active wasn't already set).
* It is cleared when a resync completes.
*
* The counter counts pending write requests, plus the on-disk bit.
* When the counter is '1' and the resync bits are clear, the on-disk
* bit can be cleared aswell, thus setting the counter to 0.
* When we set a bit, or in the counter (to start a write), if the fields is
* 0, we first set the disk bit and set the counter to 1.
*
* If the counter is 0, the on-disk bit is clear and the stipe is clean
* Anything that dirties the stipe pushes the counter to 2 (at least)
* and sets the on-disk bit (lazily).
* If a periodic sweep find the counter at 2, it is decremented to 1.
* If the sweep find the counter at 1, the on-disk bit is cleared and the
* counter goes to zero.
*
* Also, we'll hijack the "map" pointer itself and use it as two 16 bit block
* counters as a fallback when "page" memory cannot be allocated:
*
* Normal case (page memory allocated):
*
* page pointer (32-bit)
*
* [ ] ------+
* |
* +-------> [ ][ ]..[ ] (4096 byte page == 2048 counters)
* c1 c2 c2048
*
* Hijacked case (page memory allocation failed):
*
* hijacked page pointer (32-bit)
*
* [ ][ ] (no page memory allocated)
* counter #1 (16-bit) counter #2 (16-bit)
*
*/
#ifdef __KERNEL__
#define PAGE_BITS (PAGE_SIZE << 3)
#define PAGE_BIT_SHIFT (PAGE_SHIFT + 3)
typedef __u16 bitmap_counter_t;
#define COUNTER_BITS 16
#define COUNTER_BIT_SHIFT 4
#define COUNTER_BYTE_RATIO (COUNTER_BITS / 8)
#define COUNTER_BYTE_SHIFT (COUNTER_BIT_SHIFT - 3)
#define NEEDED_MASK ((bitmap_counter_t) (1 << (COUNTER_BITS - 1)))
#define RESYNC_MASK ((bitmap_counter_t) (1 << (COUNTER_BITS - 2)))
#define COUNTER_MAX ((bitmap_counter_t) RESYNC_MASK - 1)
#define NEEDED(x) (((bitmap_counter_t) x) & NEEDED_MASK)
#define RESYNC(x) (((bitmap_counter_t) x) & RESYNC_MASK)
#define COUNTER(x) (((bitmap_counter_t) x) & COUNTER_MAX)
/* how many counters per page? */
#define PAGE_COUNTER_RATIO (PAGE_BITS / COUNTER_BITS)
/* same, except a shift value for more efficient bitops */
#define PAGE_COUNTER_SHIFT (PAGE_BIT_SHIFT - COUNTER_BIT_SHIFT)
/* same, except a mask value for more efficient bitops */
#define PAGE_COUNTER_MASK (PAGE_COUNTER_RATIO - 1)
#define BITMAP_BLOCK_SIZE 512
#define BITMAP_BLOCK_SHIFT 9
/* how many blocks per chunk? (this is variable) */
#define CHUNK_BLOCK_RATIO(bitmap) ((bitmap)->chunksize >> BITMAP_BLOCK_SHIFT)
#define CHUNK_BLOCK_SHIFT(bitmap) ((bitmap)->chunkshift - BITMAP_BLOCK_SHIFT)
#define CHUNK_BLOCK_MASK(bitmap) (CHUNK_BLOCK_RATIO(bitmap) - 1)
/* when hijacked, the counters and bits represent even larger "chunks" */
/* there will be 1024 chunks represented by each counter in the page pointers */
#define PAGEPTR_BLOCK_RATIO(bitmap) \
(CHUNK_BLOCK_RATIO(bitmap) << PAGE_COUNTER_SHIFT >> 1)
#define PAGEPTR_BLOCK_SHIFT(bitmap) \
(CHUNK_BLOCK_SHIFT(bitmap) + PAGE_COUNTER_SHIFT - 1)
#define PAGEPTR_BLOCK_MASK(bitmap) (PAGEPTR_BLOCK_RATIO(bitmap) - 1)
/*
* on-disk bitmap:
*
* Use one bit per "chunk" (block set). We do the disk I/O on the bitmap
* file a page at a time. There's a superblock at the start of the file.
*/
/* map chunks (bits) to file pages - offset by the size of the superblock */
#define CHUNK_BIT_OFFSET(chunk) ((chunk) + (sizeof(bitmap_super_t) << 3))
#endif
/*
* bitmap structures:
*/
#define BITMAP_MAGIC 0x6d746962
/* use these for bitmap->flags and bitmap->sb->state bit-fields */
enum bitmap_state {
BITMAP_ACTIVE = 0x001, /* the bitmap is in use */
BITMAP_STALE = 0x002, /* the bitmap file is out of date or had -EIO */
BITMAP_WRITE_ERROR = 0x004, /* A write error has occurred */
BITMAP_HOSTENDIAN = 0x8000,
};
/* the superblock at the front of the bitmap file -- little endian */
typedef struct bitmap_super_s {
__le32 magic; /* 0 BITMAP_MAGIC */
__le32 version; /* 4 the bitmap major for now, could change... */
__u8 uuid[16]; /* 8 128 bit uuid - must match md device uuid */
__le64 events; /* 24 event counter for the bitmap (1)*/
__le64 events_cleared;/*32 event counter when last bit cleared (2) */
__le64 sync_size; /* 40 the size of the md device's sync range(3) */
__le32 state; /* 48 bitmap state information */
__le32 chunksize; /* 52 the bitmap chunk size in bytes */
__le32 daemon_sleep; /* 56 seconds between disk flushes */
__le32 write_behind; /* 60 number of outstanding write-behind writes */
__u8 pad[256 - 64]; /* set to zero */
} bitmap_super_t;
/* notes:
* (1) This event counter is updated before the eventcounter in the md superblock
* When a bitmap is loaded, it is only accepted if this event counter is equal
* to, or one greater than, the event counter in the superblock.
* (2) This event counter is updated when the other one is *if*and*only*if* the
* array is not degraded. As bits are not cleared when the array is degraded,
* this represents the last time that any bits were cleared.
* If a device is being added that has an event count with this value or
* higher, it is accepted as conforming to the bitmap.
* (3)This is the number of sectors represented by the bitmap, and is the range that
* resync happens across. For raid1 and raid5/6 it is the size of individual
* devices. For raid10 it is the size of the array.
*/
#ifdef __KERNEL__
/* the in-memory bitmap is represented by bitmap_pages */
struct bitmap_page {
/*
* map points to the actual memory page
*/
char *map;
/*
* in emergencies (when map cannot be alloced), hijack the map
* pointer and use it as two counters itself
*/
unsigned int hijacked:1;
/*
* count of dirty bits on the page
*/
unsigned int count:31;
};
/* keep track of bitmap file pages that have pending writes on them */
struct page_list {
struct list_head list;
struct page *page;
};
/* the main bitmap structure - one per mddev */
struct bitmap {
struct bitmap_page *bp;
unsigned long pages; /* total number of pages in the bitmap */
unsigned long missing_pages; /* number of pages not yet allocated */
mddev_t *mddev; /* the md device that the bitmap is for */
int counter_bits; /* how many bits per block counter */
/* bitmap chunksize -- how much data does each bit represent? */
unsigned long chunksize;
unsigned long chunkshift; /* chunksize = 2^chunkshift (for bitops) */
unsigned long chunks; /* total number of data chunks for the array */
/* We hold a count on the chunk currently being synced, and drop
* it when the last block is started. If the resync is aborted
* midway, we need to be able to drop that count, so we remember
* the counted chunk..
*/
unsigned long syncchunk;
__u64 events_cleared;
/* bitmap spinlock */
spinlock_t lock;
long offset; /* offset from superblock if file is NULL */
struct file *file; /* backing disk file */
struct page *sb_page; /* cached copy of the bitmap file superblock */
struct page **filemap; /* list of cache pages for the file */
unsigned long *filemap_attr; /* attributes associated w/ filemap pages */
unsigned long file_pages; /* number of pages in the file */
int last_page_size; /* bytes in the last page */
unsigned long flags;
unsigned long max_write_behind; /* write-behind mode */
atomic_t behind_writes;
/*
* the bitmap daemon - periodically wakes up and sweeps the bitmap
* file, cleaning up bits and flushing out pages to disk as necessary
*/
unsigned long daemon_lastrun; /* jiffies of last run */
unsigned long daemon_sleep; /* how many seconds between updates? */
atomic_t pending_writes; /* pending writes to the bitmap file */
wait_queue_head_t write_wait;
wait_queue_head_t overflow_wait;
};
/* the bitmap API */
/* these are used only by md/bitmap */
int bitmap_create(mddev_t *mddev);
void bitmap_flush(mddev_t *mddev);
void bitmap_destroy(mddev_t *mddev);
int bitmap_active(struct bitmap *bitmap);
char *file_path(struct file *file, char *buf, int count);
void bitmap_print_sb(struct bitmap *bitmap);
int bitmap_update_sb(struct bitmap *bitmap);
int bitmap_setallbits(struct bitmap *bitmap);
void bitmap_write_all(struct bitmap *bitmap);
void bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e);
/* these are exported */
int bitmap_startwrite(struct bitmap *bitmap, sector_t offset,
unsigned long sectors, int behind);
void bitmap_endwrite(struct bitmap *bitmap, sector_t offset,
unsigned long sectors, int success, int behind);
int bitmap_start_sync(struct bitmap *bitmap, sector_t offset, int *blocks, int degraded);
void bitmap_end_sync(struct bitmap *bitmap, sector_t offset, int *blocks, int aborted);
void bitmap_close_sync(struct bitmap *bitmap);
int bitmap_unplug(struct bitmap *bitmap);
int bitmap_daemon_work(struct bitmap *bitmap);
#endif
#endif

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#ifndef _LINEAR_H
#define _LINEAR_H
#include <linux/raid/md.h>
struct dev_info {
mdk_rdev_t *rdev;
sector_t size;
sector_t offset;
};
typedef struct dev_info dev_info_t;
struct linear_private_data
{
struct linear_private_data *prev; /* earlier version */
dev_info_t **hash_table;
sector_t hash_spacing;
sector_t array_size;
int preshift; /* shift before dividing by hash_spacing */
dev_info_t disks[0];
};
typedef struct linear_private_data linear_conf_t;
#define mddev_to_conf(mddev) ((linear_conf_t *) mddev->private)
#endif

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include/linux/raid/md.h Normal file
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/*
md.h : Multiple Devices driver for Linux
Copyright (C) 1996-98 Ingo Molnar, Gadi Oxman
Copyright (C) 1994-96 Marc ZYNGIER
<zyngier@ufr-info-p7.ibp.fr> or
<maz@gloups.fdn.fr>
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_H
#define _MD_H
#include <linux/blkdev.h>
#include <asm/semaphore.h>
#include <linux/major.h>
#include <linux/ioctl.h>
#include <linux/types.h>
#include <linux/bitops.h>
#include <linux/module.h>
#include <linux/hdreg.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/smp_lock.h>
#include <linux/delay.h>
#include <net/checksum.h>
#include <linux/random.h>
#include <linux/kernel_stat.h>
#include <asm/io.h>
#include <linux/completion.h>
#include <linux/mempool.h>
#include <linux/list.h>
#include <linux/reboot.h>
#include <linux/vmalloc.h>
#include <linux/blkpg.h>
#include <linux/bio.h>
/*
* 'md_p.h' holds the 'physical' layout of RAID devices
* 'md_u.h' holds the user <=> kernel API
*
* 'md_k.h' holds kernel internal definitions
*/
#include <linux/raid/md_p.h>
#include <linux/raid/md_u.h>
#include <linux/raid/md_k.h>
#ifdef CONFIG_MD
/*
* Different major versions are not compatible.
* Different minor versions are only downward compatible.
* Different patchlevel versions are downward and upward compatible.
*/
#define MD_MAJOR_VERSION 0
#define MD_MINOR_VERSION 90
/*
* MD_PATCHLEVEL_VERSION indicates kernel functionality.
* >=1 means different superblock formats are selectable using SET_ARRAY_INFO
* and major_version/minor_version accordingly
* >=2 means that Internal bitmaps are supported by setting MD_SB_BITMAP_PRESENT
* in the super status byte
* >=3 means that bitmap superblock version 4 is supported, which uses
* little-ending representation rather than host-endian
*/
#define MD_PATCHLEVEL_VERSION 3
extern int register_md_personality (struct mdk_personality *p);
extern int unregister_md_personality (struct mdk_personality *p);
extern mdk_thread_t * md_register_thread (void (*run) (mddev_t *mddev),
mddev_t *mddev, const char *name);
extern void md_unregister_thread (mdk_thread_t *thread);
extern void md_wakeup_thread(mdk_thread_t *thread);
extern void md_check_recovery(mddev_t *mddev);
extern void md_write_start(mddev_t *mddev, struct bio *bi);
extern void md_write_end(mddev_t *mddev);
extern void md_handle_safemode(mddev_t *mddev);
extern void md_done_sync(mddev_t *mddev, int blocks, int ok);
extern void md_error (mddev_t *mddev, mdk_rdev_t *rdev);
extern void md_unplug_mddev(mddev_t *mddev);
extern void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
sector_t sector, int size, struct page *page);
extern void md_super_wait(mddev_t *mddev);
extern int sync_page_io(struct block_device *bdev, sector_t sector, int size,
struct page *page, int rw);
extern void md_do_sync(mddev_t *mddev);
extern void md_new_event(mddev_t *mddev);
extern void md_allow_write(mddev_t *mddev);
#endif /* CONFIG_MD */
#endif

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/*
md_k.h : kernel internal structure of the Linux MD driver
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_K_H
#define _MD_K_H
/* and dm-bio-list.h is not under include/linux because.... ??? */
#include "../../../drivers/md/dm-bio-list.h"
#ifdef CONFIG_BLOCK
#define LEVEL_MULTIPATH (-4)
#define LEVEL_LINEAR (-1)
#define LEVEL_FAULTY (-5)
/* we need a value for 'no level specified' and 0
* means 'raid0', so we need something else. This is
* for internal use only
*/
#define LEVEL_NONE (-1000000)
#define MaxSector (~(sector_t)0)
typedef struct mddev_s mddev_t;
typedef struct mdk_rdev_s mdk_rdev_t;
/*
* options passed in raidrun:
*/
/* Currently this must fit in an 'int' */
#define MAX_CHUNK_SIZE (1<<30)
/*
* MD's 'extended' device
*/
struct mdk_rdev_s
{
struct list_head same_set; /* RAID devices within the same set */
sector_t size; /* Device size (in blocks) */
mddev_t *mddev; /* RAID array if running */
unsigned long last_events; /* IO event timestamp */
struct block_device *bdev; /* block device handle */
struct page *sb_page;
int sb_loaded;
__u64 sb_events;
sector_t data_offset; /* start of data in array */
sector_t sb_offset;
int sb_size; /* bytes in the superblock */
int preferred_minor; /* autorun support */
struct kobject kobj;
/* A device can be in one of three states based on two flags:
* Not working: faulty==1 in_sync==0
* Fully working: faulty==0 in_sync==1
* Working, but not
* in sync with array
* faulty==0 in_sync==0
*
* It can never have faulty==1, in_sync==1
* This reduces the burden of testing multiple flags in many cases
*/
unsigned long flags;
#define Faulty 1 /* device is known to have a fault */
#define In_sync 2 /* device is in_sync with rest of array */
#define WriteMostly 4 /* Avoid reading if at all possible */
#define BarriersNotsupp 5 /* BIO_RW_BARRIER is not supported */
int desc_nr; /* descriptor index in the superblock */
int raid_disk; /* role of device in array */
int saved_raid_disk; /* role that device used to have in the
* array and could again if we did a partial
* resync from the bitmap
*/
sector_t recovery_offset;/* If this device has been partially
* recovered, this is where we were
* up to.
*/
atomic_t nr_pending; /* number of pending requests.
* only maintained for arrays that
* support hot removal
*/
atomic_t read_errors; /* number of consecutive read errors that
* we have tried to ignore.
*/
atomic_t corrected_errors; /* number of corrected read errors,
* for reporting to userspace and storing
* in superblock.
*/
struct work_struct del_work; /* used for delayed sysfs removal */
};
struct mddev_s
{
void *private;
struct mdk_personality *pers;
dev_t unit;
int md_minor;
struct list_head disks;
unsigned long flags;
#define MD_CHANGE_DEVS 0 /* Some device status has changed */
#define MD_CHANGE_CLEAN 1 /* transition to or from 'clean' */
#define MD_CHANGE_PENDING 2 /* superblock update in progress */
int ro;
struct gendisk *gendisk;
struct kobject kobj;
/* Superblock information */
int major_version,
minor_version,
patch_version;
int persistent;
int chunk_size;
time_t ctime, utime;
int level, layout;
char clevel[16];
int raid_disks;
int max_disks;
sector_t size; /* used size of component devices */
sector_t array_size; /* exported array size */
__u64 events;
char uuid[16];
/* If the array is being reshaped, we need to record the
* new shape and an indication of where we are up to.
* This is written to the superblock.
* If reshape_position is MaxSector, then no reshape is happening (yet).
*/
sector_t reshape_position;
int delta_disks, new_level, new_layout, new_chunk;
struct mdk_thread_s *thread; /* management thread */
struct mdk_thread_s *sync_thread; /* doing resync or reconstruct */
sector_t curr_resync; /* last block scheduled */
unsigned long resync_mark; /* a recent timestamp */
sector_t resync_mark_cnt;/* blocks written at resync_mark */
sector_t curr_mark_cnt; /* blocks scheduled now */
sector_t resync_max_sectors; /* may be set by personality */
sector_t resync_mismatches; /* count of sectors where
* parity/replica mismatch found
*/
/* allow user-space to request suspension of IO to regions of the array */
sector_t suspend_lo;
sector_t suspend_hi;
/* if zero, use the system-wide default */
int sync_speed_min;
int sync_speed_max;
int ok_start_degraded;
/* recovery/resync flags
* NEEDED: we might need to start a resync/recover
* RUNNING: a thread is running, or about to be started
* SYNC: actually doing a resync, not a recovery
* ERR: and IO error was detected - abort the resync/recovery
* INTR: someone requested a (clean) early abort.
* DONE: thread is done and is waiting to be reaped
* REQUEST: user-space has requested a sync (used with SYNC)
* CHECK: user-space request for for check-only, no repair
* RESHAPE: A reshape is happening
*
* If neither SYNC or RESHAPE are set, then it is a recovery.
*/
#define MD_RECOVERY_RUNNING 0
#define MD_RECOVERY_SYNC 1
#define MD_RECOVERY_ERR 2
#define MD_RECOVERY_INTR 3
#define MD_RECOVERY_DONE 4
#define MD_RECOVERY_NEEDED 5
#define MD_RECOVERY_REQUESTED 6
#define MD_RECOVERY_CHECK 7
#define MD_RECOVERY_RESHAPE 8
#define MD_RECOVERY_FROZEN 9
unsigned long recovery;
int in_sync; /* know to not need resync */
struct mutex reconfig_mutex;
atomic_t active;
int changed; /* true if we might need to reread partition info */
int degraded; /* whether md should consider
* adding a spare
*/
int barriers_work; /* initialised to true, cleared as soon
* as a barrier request to slave
* fails. Only supported
*/
struct bio *biolist; /* bios that need to be retried
* because BIO_RW_BARRIER is not supported
*/
atomic_t recovery_active; /* blocks scheduled, but not written */
wait_queue_head_t recovery_wait;
sector_t recovery_cp;
spinlock_t write_lock;
wait_queue_head_t sb_wait; /* for waiting on superblock updates */
atomic_t pending_writes; /* number of active superblock writes */
unsigned int safemode; /* if set, update "clean" superblock
* when no writes pending.
*/
unsigned int safemode_delay;
struct timer_list safemode_timer;
atomic_t writes_pending;
request_queue_t *queue; /* for plugging ... */
atomic_t write_behind; /* outstanding async IO */
unsigned int max_write_behind; /* 0 = sync */
struct bitmap *bitmap; /* the bitmap for the device */
struct file *bitmap_file; /* the bitmap file */
long bitmap_offset; /* offset from superblock of
* start of bitmap. May be
* negative, but not '0'
*/
long default_bitmap_offset; /* this is the offset to use when
* hot-adding a bitmap. It should
* eventually be settable by sysfs.
*/
struct list_head all_mddevs;
};
static inline void rdev_dec_pending(mdk_rdev_t *rdev, mddev_t *mddev)
{
int faulty = test_bit(Faulty, &rdev->flags);
if (atomic_dec_and_test(&rdev->nr_pending) && faulty)
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
}
static inline void md_sync_acct(struct block_device *bdev, unsigned long nr_sectors)
{
atomic_add(nr_sectors, &bdev->bd_contains->bd_disk->sync_io);
}
struct mdk_personality
{
char *name;
int level;
struct list_head list;
struct module *owner;
int (*make_request)(request_queue_t *q, struct bio *bio);
int (*run)(mddev_t *mddev);
int (*stop)(mddev_t *mddev);
void (*status)(struct seq_file *seq, mddev_t *mddev);
/* error_handler must set ->faulty and clear ->in_sync
* if appropriate, and should abort recovery if needed
*/
void (*error_handler)(mddev_t *mddev, mdk_rdev_t *rdev);
int (*hot_add_disk) (mddev_t *mddev, mdk_rdev_t *rdev);
int (*hot_remove_disk) (mddev_t *mddev, int number);
int (*spare_active) (mddev_t *mddev);
sector_t (*sync_request)(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster);
int (*resize) (mddev_t *mddev, sector_t sectors);
int (*check_reshape) (mddev_t *mddev);
int (*start_reshape) (mddev_t *mddev);
int (*reconfig) (mddev_t *mddev, int layout, int chunk_size);
/* quiesce moves between quiescence states
* 0 - fully active
* 1 - no new requests allowed
* others - reserved
*/
void (*quiesce) (mddev_t *mddev, int state);
};
struct md_sysfs_entry {
struct attribute attr;
ssize_t (*show)(mddev_t *, char *);
ssize_t (*store)(mddev_t *, const char *, size_t);
};
static inline char * mdname (mddev_t * mddev)
{
return mddev->gendisk ? mddev->gendisk->disk_name : "mdX";
}
/*
* iterates through some rdev ringlist. It's safe to remove the
* current 'rdev'. Dont touch 'tmp' though.
*/
#define ITERATE_RDEV_GENERIC(head,rdev,tmp) \
\
for ((tmp) = (head).next; \
(rdev) = (list_entry((tmp), mdk_rdev_t, same_set)), \
(tmp) = (tmp)->next, (tmp)->prev != &(head) \
; )
/*
* iterates through the 'same array disks' ringlist
*/
#define ITERATE_RDEV(mddev,rdev,tmp) \
ITERATE_RDEV_GENERIC((mddev)->disks,rdev,tmp)
/*
* Iterates through 'pending RAID disks'
*/
#define ITERATE_RDEV_PENDING(rdev,tmp) \
ITERATE_RDEV_GENERIC(pending_raid_disks,rdev,tmp)
typedef struct mdk_thread_s {
void (*run) (mddev_t *mddev);
mddev_t *mddev;
wait_queue_head_t wqueue;
unsigned long flags;
struct task_struct *tsk;
unsigned long timeout;
} mdk_thread_t;
#define THREAD_WAKEUP 0
#define __wait_event_lock_irq(wq, condition, lock, cmd) \
do { \
wait_queue_t __wait; \
init_waitqueue_entry(&__wait, current); \
\
add_wait_queue(&wq, &__wait); \
for (;;) { \
set_current_state(TASK_UNINTERRUPTIBLE); \
if (condition) \
break; \
spin_unlock_irq(&lock); \
cmd; \
schedule(); \
spin_lock_irq(&lock); \
} \
current->state = TASK_RUNNING; \
remove_wait_queue(&wq, &__wait); \
} while (0)
#define wait_event_lock_irq(wq, condition, lock, cmd) \
do { \
if (condition) \
break; \
__wait_event_lock_irq(wq, condition, lock, cmd); \
} while (0)
static inline void safe_put_page(struct page *p)
{
if (p) put_page(p);
}
#endif /* CONFIG_BLOCK */
#endif

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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 */
#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 */
/*
* Notes:
* - if an array is being reshaped (restriped) in order to change the
* the number of active devices in the array, 'raid_disks' will be
* the larger of the old and new numbers. 'delta_disks' will
* be the "new - old". So if +ve, raid_disks is the new value, and
* "raid_disks-delta_disks" is the old. If -ve, raid_disks is the
* old value and "raid_disks+delta_disks" is the new (smaller) value.
*/
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 */
/* There are only valid for minor_version > 90 */
__u64 reshape_position; /* 12,13 next address in array-space for reshape */
__u32 new_level; /* 14 new level we are reshaping to */
__u32 delta_disks; /* 15 change in number of raid_disks */
__u32 new_layout; /* 16 new layout */
__u32 new_chunk; /* 17 new chunk size (bytes) */
__u32 gstate_sreserved[MD_SB_GENERIC_STATE_WORDS - 18];
/*
* 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 */
__le32 magic; /* MD_SB_MAGIC: 0xa92b4efc - little endian */
__le32 major_version; /* 1 */
__le32 feature_map; /* bit 0 set if 'bitmap_offset' is meaningful */
__le32 pad0; /* always set to 0 when writing */
__u8 set_uuid[16]; /* user-space generated. */
char set_name[32]; /* set and interpreted by user-space */
__le64 ctime; /* lo 40 bits are seconds, top 24 are microseconds or 0*/
__le32 level; /* -4 (multipath), -1 (linear), 0,1,4,5 */
__le32 layout; /* only for raid5 and raid10 currently */
__le64 size; /* used size of component devices, in 512byte sectors */
__le32 chunksize; /* in 512byte sectors */
__le32 raid_disks;
__le32 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.
*/
/* These are only valid with feature bit '4' */
__le32 new_level; /* new level we are reshaping to */
__le64 reshape_position; /* next address in array-space for reshape */
__le32 delta_disks; /* change in number of raid_disks */
__le32 new_layout; /* new layout */
__le32 new_chunk; /* new chunk size (bytes) */
__u8 pad1[128-124]; /* set to 0 when written */
/* constant this-device information - 64 bytes */
__le64 data_offset; /* sector start of data, often 0 */
__le64 data_size; /* sectors in this device that can be used for data */
__le64 super_offset; /* sector start of this superblock */
__le64 recovery_offset;/* sectors before this offset (from data_offset) have been recovered */
__le32 dev_number; /* permanent identifier of this device - not role in raid */
__le32 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 */
__le64 utime; /* 40 bits second, 24 btes microseconds */
__le64 events; /* incremented when superblock updated */
__le64 resync_offset; /* data before this offset (from data_offset) known to be in sync */
__le32 sb_csum; /* checksum upto devs[max_dev] */
__le32 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.
*/
__le16 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_RECOVERY_OFFSET 2 /* recovery_offset is present and
* must be honoured
*/
#define MD_FEATURE_RESHAPE_ACTIVE 4
#define MD_FEATURE_ALL (1|2|4)
#endif

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/*
md_u.h : user <=> kernel API between Linux raidtools and RAID drivers
Copyright (C) 1998 Ingo Molnar
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_U_H
#define _MD_U_H
/* ioctls */
/* status */
#define RAID_VERSION _IOR (MD_MAJOR, 0x10, mdu_version_t)
#define GET_ARRAY_INFO _IOR (MD_MAJOR, 0x11, mdu_array_info_t)
#define GET_DISK_INFO _IOR (MD_MAJOR, 0x12, mdu_disk_info_t)
#define PRINT_RAID_DEBUG _IO (MD_MAJOR, 0x13)
#define RAID_AUTORUN _IO (MD_MAJOR, 0x14)
#define GET_BITMAP_FILE _IOR (MD_MAJOR, 0x15, mdu_bitmap_file_t)
/* configuration */
#define CLEAR_ARRAY _IO (MD_MAJOR, 0x20)
#define ADD_NEW_DISK _IOW (MD_MAJOR, 0x21, mdu_disk_info_t)
#define HOT_REMOVE_DISK _IO (MD_MAJOR, 0x22)
#define SET_ARRAY_INFO _IOW (MD_MAJOR, 0x23, mdu_array_info_t)
#define SET_DISK_INFO _IO (MD_MAJOR, 0x24)
#define WRITE_RAID_INFO _IO (MD_MAJOR, 0x25)
#define UNPROTECT_ARRAY _IO (MD_MAJOR, 0x26)
#define PROTECT_ARRAY _IO (MD_MAJOR, 0x27)
#define HOT_ADD_DISK _IO (MD_MAJOR, 0x28)
#define SET_DISK_FAULTY _IO (MD_MAJOR, 0x29)
#define HOT_GENERATE_ERROR _IO (MD_MAJOR, 0x2a)
#define SET_BITMAP_FILE _IOW (MD_MAJOR, 0x2b, int)
/* usage */
#define RUN_ARRAY _IOW (MD_MAJOR, 0x30, mdu_param_t)
/* 0x31 was START_ARRAY */
#define STOP_ARRAY _IO (MD_MAJOR, 0x32)
#define STOP_ARRAY_RO _IO (MD_MAJOR, 0x33)
#define RESTART_ARRAY_RW _IO (MD_MAJOR, 0x34)
typedef struct mdu_version_s {
int major;
int minor;
int patchlevel;
} mdu_version_t;
typedef struct mdu_array_info_s {
/*
* Generic constant information
*/
int major_version;
int minor_version;
int patch_version;
int ctime;
int level;
int size;
int nr_disks;
int raid_disks;
int md_minor;
int not_persistent;
/*
* Generic state information
*/
int utime; /* 0 Superblock update time */
int state; /* 1 State bits (clean, ...) */
int active_disks; /* 2 Number of currently active disks */
int working_disks; /* 3 Number of working disks */
int failed_disks; /* 4 Number of failed disks */
int spare_disks; /* 5 Number of spare disks */
/*
* Personality information
*/
int layout; /* 0 the array's physical layout */
int chunk_size; /* 1 chunk size in bytes */
} mdu_array_info_t;
typedef struct mdu_disk_info_s {
/*
* configuration/status of one particular disk
*/
int number;
int major;
int minor;
int raid_disk;
int state;
} mdu_disk_info_t;
typedef struct mdu_start_info_s {
/*
* configuration/status of one particular disk
*/
int major;
int minor;
int raid_disk;
int state;
} mdu_start_info_t;
typedef struct mdu_bitmap_file_s
{
char pathname[4096];
} mdu_bitmap_file_t;
typedef struct mdu_param_s
{
int personality; /* 1,2,3,4 */
int chunk_size; /* in bytes */
int max_fault; /* unused for now */
} mdu_param_t;
#endif

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include/linux/raid/multipath.h Normal file
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#ifndef _MULTIPATH_H
#define _MULTIPATH_H
#include <linux/raid/md.h>
struct multipath_info {
mdk_rdev_t *rdev;
};
struct multipath_private_data {
mddev_t *mddev;
struct multipath_info *multipaths;
int raid_disks;
int working_disks;
spinlock_t device_lock;
struct list_head retry_list;
mempool_t *pool;
};
typedef struct multipath_private_data multipath_conf_t;
/*
* this is the only point in the RAID code where we violate
* C type safety. mddev->private is an 'opaque' pointer.
*/
#define mddev_to_conf(mddev) ((multipath_conf_t *) mddev->private)
/*
* this is our 'private' 'collective' MULTIPATH buffer head.
* it contains information about what kind of IO operations were started
* for this MULTIPATH operation, and about their status:
*/
struct multipath_bh {
mddev_t *mddev;
struct bio *master_bio;
struct bio bio;
int path;
struct list_head retry_list;
};
#endif

30
include/linux/raid/raid0.h Normal file
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#ifndef _RAID0_H
#define _RAID0_H
#include <linux/raid/md.h>
struct strip_zone
{
sector_t zone_offset; /* Zone offset in md_dev */
sector_t dev_offset; /* Zone offset in real dev */
sector_t size; /* Zone size */
int nb_dev; /* # of devices attached to the zone */
mdk_rdev_t **dev; /* Devices attached to the zone */
};
struct raid0_private_data
{
struct strip_zone **hash_table; /* Table of indexes into strip_zone */
struct strip_zone *strip_zone;
mdk_rdev_t **devlist; /* lists of rdevs, pointed to by strip_zone->dev */
int nr_strip_zones;
sector_t hash_spacing;
int preshift; /* shift this before divide by hash_spacing */
};
typedef struct raid0_private_data raid0_conf_t;
#define mddev_to_conf(mddev) ((raid0_conf_t *) mddev->private)
#endif

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#ifndef _RAID1_H
#define _RAID1_H
#include <linux/raid/md.h>
typedef struct mirror_info mirror_info_t;
struct mirror_info {
mdk_rdev_t *rdev;
sector_t head_position;
};
/*
* memory pools need a pointer to the mddev, so they can force an unplug
* when memory is tight, and a count of the number of drives that the
* pool was allocated for, so they know how much to allocate and free.
* mddev->raid_disks cannot be used, as it can change while a pool is active
* These two datums are stored in a kmalloced struct.
*/
struct pool_info {
mddev_t *mddev;
int raid_disks;
};
typedef struct r1bio_s r1bio_t;
struct r1_private_data_s {
mddev_t *mddev;
mirror_info_t *mirrors;
int raid_disks;
int last_used;
sector_t next_seq_sect;
spinlock_t device_lock;
struct list_head retry_list;
/* queue pending writes and submit them on unplug */
struct bio_list pending_bio_list;
/* queue of writes that have been unplugged */
struct bio_list flushing_bio_list;
/* for use when syncing mirrors: */
spinlock_t resync_lock;
int nr_pending;
int nr_waiting;
int nr_queued;
int barrier;
sector_t next_resync;
int fullsync; /* set to 1 if a full sync is needed,
* (fresh device added).
* Cleared when a sync completes.
*/
wait_queue_head_t wait_barrier;
struct pool_info *poolinfo;
struct page *tmppage;
mempool_t *r1bio_pool;
mempool_t *r1buf_pool;
};
typedef struct r1_private_data_s conf_t;
/*
* this is the only point in the RAID code where we violate
* C type safety. mddev->private is an 'opaque' pointer.
*/
#define mddev_to_conf(mddev) ((conf_t *) mddev->private)
/*
* this is our 'private' RAID1 bio.
*
* it contains information about what kind of IO operations were started
* for this RAID1 operation, and about their status:
*/
struct r1bio_s {
atomic_t remaining; /* 'have we finished' count,
* used from IRQ handlers
*/
atomic_t behind_remaining; /* number of write-behind ios remaining
* in this BehindIO request
*/
sector_t sector;
int sectors;
unsigned long state;
mddev_t *mddev;
/*
* original bio going to /dev/mdx
*/
struct bio *master_bio;
/*
* if the IO is in READ direction, then this is where we read
*/
int read_disk;
struct list_head retry_list;
struct bitmap_update *bitmap_update;
/*
* if the IO is in WRITE direction, then multiple bios are used.
* We choose the number when they are allocated.
*/
struct bio *bios[0];
/* DO NOT PUT ANY NEW FIELDS HERE - bios array is contiguously alloced*/
};
/* when we get a read error on a read-only array, we redirect to another
* device without failing the first device, or trying to over-write to
* correct the read error. To keep track of bad blocks on a per-bio
* level, we store IO_BLOCKED in the appropriate 'bios' pointer
*/
#define IO_BLOCKED ((struct bio*)1)
/* bits for r1bio.state */
#define R1BIO_Uptodate 0
#define R1BIO_IsSync 1
#define R1BIO_Degraded 2
#define R1BIO_BehindIO 3
#define R1BIO_Barrier 4
#define R1BIO_BarrierRetry 5
/* For write-behind requests, we call bi_end_io when
* the last non-write-behind device completes, providing
* any write was successful. Otherwise we call when
* any write-behind write succeeds, otherwise we call
* with failure when last write completes (and all failed).
* Record that bi_end_io was called with this flag...
*/
#define R1BIO_Returned 6
#endif

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#ifndef _RAID10_H
#define _RAID10_H
#include <linux/raid/md.h>
typedef struct mirror_info mirror_info_t;
struct mirror_info {
mdk_rdev_t *rdev;
sector_t head_position;
};
typedef struct r10bio_s r10bio_t;
struct r10_private_data_s {
mddev_t *mddev;
mirror_info_t *mirrors;
int raid_disks;
spinlock_t device_lock;
/* geometry */
int near_copies; /* number of copies layed out raid0 style */
int far_copies; /* number of copies layed out
* at large strides across drives
*/
int far_offset; /* far_copies are offset by 1 stripe
* instead of many
*/
int copies; /* near_copies * far_copies.
* must be <= raid_disks
*/
sector_t stride; /* distance between far copies.
* This is size / far_copies unless
* far_offset, in which case it is
* 1 stripe.
*/
int chunk_shift; /* shift from chunks to sectors */
sector_t chunk_mask;
struct list_head retry_list;
/* queue pending writes and submit them on unplug */
struct bio_list pending_bio_list;
spinlock_t resync_lock;
int nr_pending;
int nr_waiting;
int nr_queued;
int barrier;
sector_t next_resync;
int fullsync; /* set to 1 if a full sync is needed,
* (fresh device added).
* Cleared when a sync completes.
*/
wait_queue_head_t wait_barrier;
mempool_t *r10bio_pool;
mempool_t *r10buf_pool;
struct page *tmppage;
};
typedef struct r10_private_data_s conf_t;
/*
* this is the only point in the RAID code where we violate
* C type safety. mddev->private is an 'opaque' pointer.
*/
#define mddev_to_conf(mddev) ((conf_t *) mddev->private)
/*
* this is our 'private' RAID10 bio.
*
* it contains information about what kind of IO operations were started
* for this RAID10 operation, and about their status:
*/
struct r10bio_s {
atomic_t remaining; /* 'have we finished' count,
* used from IRQ handlers
*/
sector_t sector; /* virtual sector number */
int sectors;
unsigned long state;
mddev_t *mddev;
/*
* original bio going to /dev/mdx
*/
struct bio *master_bio;
/*
* if the IO is in READ direction, then this is where we read
*/
int read_slot;
struct list_head retry_list;
/*
* if the IO is in WRITE direction, then multiple bios are used,
* one for each copy.
* When resyncing we also use one for each copy.
* When reconstructing, we use 2 bios, one for read, one for write.
* We choose the number when they are allocated.
*/
struct {
struct bio *bio;
sector_t addr;
int devnum;
} devs[0];
};
/* when we get a read error on a read-only array, we redirect to another
* device without failing the first device, or trying to over-write to
* correct the read error. To keep track of bad blocks on a per-bio
* level, we store IO_BLOCKED in the appropriate 'bios' pointer
*/
#define IO_BLOCKED ((struct bio*)1)
/* bits for r10bio.state */
#define R10BIO_Uptodate 0
#define R10BIO_IsSync 1
#define R10BIO_IsRecover 2
#define R10BIO_Degraded 3
#endif

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#ifndef _RAID5_H
#define _RAID5_H
#include <linux/raid/md.h>
#include <linux/raid/xor.h>
/*
*
* Each stripe contains one buffer per disc. Each buffer can be in
* one of a number of states stored in "flags". Changes between
* these states happen *almost* exclusively under a per-stripe
* spinlock. Some very specific changes can happen in bi_end_io, and
* these are not protected by the spin lock.
*
* The flag bits that are used to represent these states are:
* R5_UPTODATE and R5_LOCKED
*
* State Empty == !UPTODATE, !LOCK
* We have no data, and there is no active request
* State Want == !UPTODATE, LOCK
* A read request is being submitted for this block
* State Dirty == UPTODATE, LOCK
* Some new data is in this buffer, and it is being written out
* State Clean == UPTODATE, !LOCK
* We have valid data which is the same as on disc
*
* The possible state transitions are:
*
* Empty -> Want - on read or write to get old data for parity calc
* Empty -> Dirty - on compute_parity to satisfy write/sync request.(RECONSTRUCT_WRITE)
* Empty -> Clean - on compute_block when computing a block for failed drive
* Want -> Empty - on failed read
* Want -> Clean - on successful completion of read request
* Dirty -> Clean - on successful completion of write request
* Dirty -> Clean - on failed write
* Clean -> Dirty - on compute_parity to satisfy write/sync (RECONSTRUCT or RMW)
*
* The Want->Empty, Want->Clean, Dirty->Clean, transitions
* all happen in b_end_io at interrupt time.
* Each sets the Uptodate bit before releasing the Lock bit.
* This leaves one multi-stage transition:
* Want->Dirty->Clean
* This is safe because thinking that a Clean buffer is actually dirty
* will at worst delay some action, and the stripe will be scheduled
* for attention after the transition is complete.
*
* There is one possibility that is not covered by these states. That
* is if one drive has failed and there is a spare being rebuilt. We
* can't distinguish between a clean block that has been generated
* from parity calculations, and a clean block that has been
* successfully written to the spare ( or to parity when resyncing).
* To distingush these states we have a stripe bit STRIPE_INSYNC that
* is set whenever a write is scheduled to the spare, or to the parity
* disc if there is no spare. A sync request clears this bit, and
* when we find it set with no buffers locked, we know the sync is
* complete.
*
* Buffers for the md device that arrive via make_request are attached
* to the appropriate stripe in one of two lists linked on b_reqnext.
* One list (bh_read) for read requests, one (bh_write) for write.
* There should never be more than one buffer on the two lists
* together, but we are not guaranteed of that so we allow for more.
*
* If a buffer is on the read list when the associated cache buffer is
* Uptodate, the data is copied into the read buffer and it's b_end_io
* routine is called. This may happen in the end_request routine only
* if the buffer has just successfully been read. end_request should
* remove the buffers from the list and then set the Uptodate bit on
* the buffer. Other threads may do this only if they first check
* that the Uptodate bit is set. Once they have checked that they may
* take buffers off the read queue.
*
* When a buffer on the write list is committed for write it is copied
* into the cache buffer, which is then marked dirty, and moved onto a
* third list, the written list (bh_written). Once both the parity
* block and the cached buffer are successfully written, any buffer on
* a written list can be returned with b_end_io.
*
* The write list and read list both act as fifos. The read list is
* protected by the device_lock. The write and written lists are
* protected by the stripe lock. The device_lock, which can be
* claimed while the stipe lock is held, is only for list
* manipulations and will only be held for a very short time. It can
* be claimed from interrupts.
*
*
* Stripes in the stripe cache can be on one of two lists (or on
* neither). The "inactive_list" contains stripes which are not
* currently being used for any request. They can freely be reused
* for another stripe. The "handle_list" contains stripes that need
* to be handled in some way. Both of these are fifo queues. Each
* stripe is also (potentially) linked to a hash bucket in the hash
* table so that it can be found by sector number. Stripes that are
* not hashed must be on the inactive_list, and will normally be at
* the front. All stripes start life this way.
*
* The inactive_list, handle_list and hash bucket lists are all protected by the
* device_lock.
* - stripes on the inactive_list never have their stripe_lock held.
* - stripes have a reference counter. If count==0, they are on a list.
* - If a stripe might need handling, STRIPE_HANDLE is set.
* - When refcount reaches zero, then if STRIPE_HANDLE it is put on
* handle_list else inactive_list
*
* This, combined with the fact that STRIPE_HANDLE is only ever
* cleared while a stripe has a non-zero count means that if the
* refcount is 0 and STRIPE_HANDLE is set, then it is on the
* handle_list and if recount is 0 and STRIPE_HANDLE is not set, then
* the stripe is on inactive_list.
*
* The possible transitions are:
* activate an unhashed/inactive stripe (get_active_stripe())
* lockdev check-hash unlink-stripe cnt++ clean-stripe hash-stripe unlockdev
* activate a hashed, possibly active stripe (get_active_stripe())
* lockdev check-hash if(!cnt++)unlink-stripe unlockdev
* attach a request to an active stripe (add_stripe_bh())
* lockdev attach-buffer unlockdev
* handle a stripe (handle_stripe())
* lockstripe clrSTRIPE_HANDLE ... (lockdev check-buffers unlockdev) .. change-state .. record io needed unlockstripe schedule io
* release an active stripe (release_stripe())
* lockdev if (!--cnt) { if STRIPE_HANDLE, add to handle_list else add to inactive-list } unlockdev
*
* The refcount counts each thread that have activated the stripe,
* plus raid5d if it is handling it, plus one for each active request
* on a cached buffer.
*/
struct stripe_head {
struct hlist_node hash;
struct list_head lru; /* inactive_list or handle_list */
struct raid5_private_data *raid_conf;
sector_t sector; /* sector of this row */
int pd_idx; /* parity disk index */
unsigned long state; /* state flags */
atomic_t count; /* nr of active thread/requests */
spinlock_t lock;
int bm_seq; /* sequence number for bitmap flushes */
int disks; /* disks in stripe */
struct r5dev {
struct bio req;
struct bio_vec vec;
struct page *page;
struct bio *toread, *towrite, *written;
sector_t sector; /* sector of this page */
unsigned long flags;
} dev[1]; /* allocated with extra space depending of RAID geometry */
};
/* Flags */
#define R5_UPTODATE 0 /* page contains current data */
#define R5_LOCKED 1 /* IO has been submitted on "req" */
#define R5_OVERWRITE 2 /* towrite covers whole page */
/* and some that are internal to handle_stripe */
#define R5_Insync 3 /* rdev && rdev->in_sync at start */
#define R5_Wantread 4 /* want to schedule a read */
#define R5_Wantwrite 5
#define R5_Overlap 7 /* There is a pending overlapping request on this block */
#define R5_ReadError 8 /* seen a read error here recently */
#define R5_ReWrite 9 /* have tried to over-write the readerror */
#define R5_Expanded 10 /* This block now has post-expand data */
/*
* Write method
*/
#define RECONSTRUCT_WRITE 1
#define READ_MODIFY_WRITE 2
/* not a write method, but a compute_parity mode */
#define CHECK_PARITY 3
/*
* Stripe state
*/
#define STRIPE_HANDLE 2
#define STRIPE_SYNCING 3
#define STRIPE_INSYNC 4
#define STRIPE_PREREAD_ACTIVE 5
#define STRIPE_DELAYED 6
#define STRIPE_DEGRADED 7
#define STRIPE_BIT_DELAY 8
#define STRIPE_EXPANDING 9
#define STRIPE_EXPAND_SOURCE 10
#define STRIPE_EXPAND_READY 11
/*
* Plugging:
*
* To improve write throughput, we need to delay the handling of some
* stripes until there has been a chance that several write requests
* for the one stripe have all been collected.
* In particular, any write request that would require pre-reading
* is put on a "delayed" queue until there are no stripes currently
* in a pre-read phase. Further, if the "delayed" queue is empty when
* a stripe is put on it then we "plug" the queue and do not process it
* until an unplug call is made. (the unplug_io_fn() is called).
*
* When preread is initiated on a stripe, we set PREREAD_ACTIVE and add
* it to the count of prereading stripes.
* When write is initiated, or the stripe refcnt == 0 (just in case) we
* clear the PREREAD_ACTIVE flag and decrement the count
* Whenever the 'handle' queue is empty and the device is not plugged, we
* move any strips from delayed to handle and clear the DELAYED flag and set
* PREREAD_ACTIVE.
* In stripe_handle, if we find pre-reading is necessary, we do it if
* PREREAD_ACTIVE is set, else we set DELAYED which will send it to the delayed queue.
* HANDLE gets cleared if stripe_handle leave nothing locked.
*/
struct disk_info {
mdk_rdev_t *rdev;
};
struct raid5_private_data {
struct hlist_head *stripe_hashtbl;
mddev_t *mddev;
struct disk_info *spare;
int chunk_size, level, algorithm;
int max_degraded;
int raid_disks;
int max_nr_stripes;
/* used during an expand */
sector_t expand_progress; /* MaxSector when no expand happening */
sector_t expand_lo; /* from here up to expand_progress it out-of-bounds
* as we haven't flushed the metadata yet
*/
int previous_raid_disks;
struct list_head handle_list; /* stripes needing handling */
struct list_head delayed_list; /* stripes that have plugged requests */
struct list_head bitmap_list; /* stripes delaying awaiting bitmap update */
struct bio *retry_read_aligned; /* currently retrying aligned bios */
struct bio *retry_read_aligned_list; /* aligned bios retry list */
atomic_t preread_active_stripes; /* stripes with scheduled io */
atomic_t active_aligned_reads;
atomic_t reshape_stripes; /* stripes with pending writes for reshape */
/* unfortunately we need two cache names as we temporarily have
* two caches.
*/
int active_name;
char cache_name[2][20];
struct kmem_cache *slab_cache; /* for allocating stripes */
int seq_flush, seq_write;
int quiesce;
int fullsync; /* set to 1 if a full sync is needed,
* (fresh device added).
* Cleared when a sync completes.
*/
struct page *spare_page; /* Used when checking P/Q in raid6 */
/*
* Free stripes pool
*/
atomic_t active_stripes;
struct list_head inactive_list;
wait_queue_head_t wait_for_stripe;
wait_queue_head_t wait_for_overlap;
int inactive_blocked; /* release of inactive stripes blocked,
* waiting for 25% to be free
*/
int pool_size; /* number of disks in stripeheads in pool */
spinlock_t device_lock;
struct disk_info *disks;
};
typedef struct raid5_private_data raid5_conf_t;
#define mddev_to_conf(mddev) ((raid5_conf_t *) mddev->private)
/*
* Our supported algorithms
*/
#define ALGORITHM_LEFT_ASYMMETRIC 0
#define ALGORITHM_RIGHT_ASYMMETRIC 1
#define ALGORITHM_LEFT_SYMMETRIC 2
#define ALGORITHM_RIGHT_SYMMETRIC 3
#endif

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include/linux/raid/xor.h Normal file
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#ifndef _XOR_H
#define _XOR_H
#include <linux/raid/md.h>
#define MAX_XOR_BLOCKS 5
extern void xor_block(unsigned int count, unsigned int bytes, void **ptr);
struct xor_block_template {
struct xor_block_template *next;
const char *name;
int speed;
void (*do_2)(unsigned long, unsigned long *, unsigned long *);
void (*do_3)(unsigned long, unsigned long *, unsigned long *,
unsigned long *);
void (*do_4)(unsigned long, unsigned long *, unsigned long *,
unsigned long *, unsigned long *);
void (*do_5)(unsigned long, unsigned long *, unsigned long *,
unsigned long *, unsigned long *, unsigned long *);
};
#endif