/*
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"
#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)
#define MD_THREAD_NAME_MAX 14
typedef struct mddev_s mddev_t;
typedef struct mdk_rdev_s mdk_rdev_t;
#define MAX_MD_DEVS 256 /* Max number of md dev */
/*
* options passed in raidrun:
*/
/* Currently this must fix 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 mddev_s
{
void *private;
struct mdk_personality *pers;
dev_t unit;
int md_minor;
struct list_head disks;
int sb_dirty;
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