[linux-2.6-block.git] / include / linux / raid / md_k.h

/*
   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 */
	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 				external;	/* metadata is
							 * managed externally */
	char				metadata_type[17]; /* externally set*/
	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;
	sector_t			resync_max;	/* resync should pause
							 * when it gets here */

	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; 
	struct request_queue		*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)(struct request_queue *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
Commit	Line	Data
1da177e4 LT	1	/*
	2	md_k.h : kernel internal structure of the Linux MD driver
	3	Copyright (C) 1996-98 Ingo Molnar, Gadi Oxman
	4
	5	This program is free software; you can redistribute it and/or modify
	6	it under the terms of the GNU General Public License as published by
	7	the Free Software Foundation; either version 2, or (at your option)
	8	any later version.
	9
	10	You should have received a copy of the GNU General Public License
	11	(for example /usr/src/linux/COPYING); if not, write to the Free
	12	Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	13	*/
	14
	15	#ifndef _MD_K_H
	16	#define _MD_K_H
	17
06d91a5f N	18	/* and dm-bio-list.h is not under include/linux because.... ??? */
	19	#include "../../../drivers/md/dm-bio-list.h"
	20
9361401e DH	21	#ifdef CONFIG_BLOCK
9361401e DH	22
1da177e4 LT	23	#define LEVEL_MULTIPATH (-4)
	24	#define LEVEL_LINEAR (-1)
	25	#define LEVEL_FAULTY (-5)
	26
2604b703 N	27	/* we need a value for 'no level specified' and 0
	28	* means 'raid0', so we need something else. This is
	29	* for internal use only
	30	*/
	31	#define LEVEL_NONE (-1000000)
	32
1da177e4	33	#define MaxSector (~(sector_t)0)
1da177e4	34
1da177e4 LT	35	typedef struct mddev_s mddev_t;
	36	typedef struct mdk_rdev_s mdk_rdev_t;
	37
1da177e4 LT	38	/*
	39	* options passed in raidrun:
	40	*/
	41
e8703fe1	42	/* Currently this must fit in an 'int' */
8932c2e0	43	#define MAX_CHUNK_SIZE (1<<30)
1da177e4	44
1da177e4 LT	45	/*
	46	* MD's 'extended' device
	47	*/
	48	struct mdk_rdev_s
	49	{
	50	struct list_head same_set; /* RAID devices within the same set */
	51
	52	sector_t size; /* Device size (in blocks) */
	53	mddev_t mddev; / RAID array if running */
713f6ab1	54	long last_events; /* IO event timestamp */
1da177e4 LT	55
	56	struct block_device bdev; / block device handle */
	57
	58	struct page *sb_page;
	59	int sb_loaded;
42543769	60	__u64 sb_events;
1da177e4 LT	61	sector_t data_offset; /* start of data in array */
1da177e4 LT	62	sector_t sb_offset;
0002b271	63	int sb_size; /* bytes in the superblock */
1da177e4 LT	64	int preferred_minor; /* autorun support */
1da177e4 LT	65
86e6ffdd N	66	struct kobject kobj;
86e6ffdd N	67
1da177e4 LT	68	/* A device can be in one of three states based on two flags:
	69	* Not working: faulty==1 in_sync==0
	70	* Fully working: faulty==0 in_sync==1
	71	* Working, but not
	72	* in sync with array
	73	* faulty==0 in_sync==0
	74	*
	75	* It can never have faulty==1, in_sync==1
	76	* This reduces the burden of testing multiple flags in many cases
	77	*/
1da177e4	78
b2d444d7 N	79	unsigned long flags;
	80	#define Faulty 1 /* device is known to have a fault */
	81	#define In_sync 2 /* device is in_sync with rest of array */
8ddf9efe	82	#define WriteMostly 4 /* Avoid reading if at all possible */
a9701a30	83	#define BarriersNotsupp 5 /* BIO_RW_BARRIER is not supported */
8ddf9efe	84
1da177e4 LT	85	int desc_nr; /* descriptor index in the superblock */
1da177e4 LT	86	int raid_disk; /* role of device in array */
41158c7e N	87	int saved_raid_disk; /* role that device used to have in the
	88	* array and could again if we did a partial
	89	* resync from the bitmap
	90	*/
5fd6c1dc N	91	sector_t recovery_offset;/* If this device has been partially
	92	* recovered, this is where we were
	93	* up to.
	94	*/
1da177e4 LT	95
	96	atomic_t nr_pending; /* number of pending requests.
	97	* only maintained for arrays that
	98	* support hot removal
	99	*/
ba22dcbf N	100	atomic_t read_errors; /* number of consecutive read errors that
	101	* we have tried to ignore.
	102	*/
4dbcdc75 N	103	atomic_t corrected_errors; /* number of corrected read errors,
	104	* for reporting to userspace and storing
	105	* in superblock.
	106	*/
5792a285	107	struct work_struct del_work; /* used for delayed sysfs removal */
1da177e4 LT	108	};
1da177e4 LT	109
1da177e4 LT	110	struct mddev_s
	111	{
	112	void *private;
2604b703	113	struct mdk_personality *pers;
1da177e4 LT	114	dev_t unit;
	115	int md_minor;
	116	struct list_head disks;
850b2b42 N	117	unsigned long flags;
	118	#define MD_CHANGE_DEVS 0 /* Some device status has changed */
	119	#define MD_CHANGE_CLEAN 1 /* transition to or from 'clean' */
	120	#define MD_CHANGE_PENDING 2 /* superblock update in progress */
	121
1da177e4 LT	122	int ro;
	123
	124	struct gendisk *gendisk;
	125
eae1701f N	126	struct kobject kobj;
eae1701f N	127
1da177e4 LT	128	/* Superblock information */
	129	int major_version,
	130	minor_version,
	131	patch_version;
	132	int persistent;
e691063a N	133	int external; /* metadata is
	134	* managed externally */
	135	char metadata_type[17]; /* externally set*/
1da177e4 LT	136	int chunk_size;
	137	time_t ctime, utime;
	138	int level, layout;
d9d166c2	139	char clevel[16];
1da177e4 LT	140	int raid_disks;
	141	int max_disks;
	142	sector_t size; /* used size of component devices */
	143	sector_t array_size; /* exported array size */
	144	__u64 events;
	145
	146	char uuid[16];
	147
f6705578 N	148	/* If the array is being reshaped, we need to record the
	149	* new shape and an indication of where we are up to.
	150	* This is written to the superblock.
	151	* If reshape_position is MaxSector, then no reshape is happening (yet).
	152	*/
	153	sector_t reshape_position;
	154	int delta_disks, new_level, new_layout, new_chunk;
	155
1da177e4 LT	156	struct mdk_thread_s thread; / management thread */
1da177e4 LT	157	struct mdk_thread_s sync_thread; / doing resync or reconstruct */
ff4e8d9a	158	sector_t curr_resync; /* last block scheduled */
1da177e4 LT	159	unsigned long resync_mark; /* a recent timestamp */
1da177e4 LT	160	sector_t resync_mark_cnt;/* blocks written at resync_mark */
ff4e8d9a	161	sector_t curr_mark_cnt; /* blocks scheduled now */
1da177e4 LT	162
1da177e4 LT	163	sector_t resync_max_sectors; /* may be set by personality */
9d88883e N	164
	165	sector_t resync_mismatches; /* count of sectors where
	166	* parity/replica mismatch found
	167	*/
e464eafd N	168
	169	/* allow user-space to request suspension of IO to regions of the array */
	170	sector_t suspend_lo;
	171	sector_t suspend_hi;
88202a0c N	172	/* if zero, use the system-wide default */
	173	int sync_speed_min;
	174	int sync_speed_max;
	175
6ff8d8ec	176	int ok_start_degraded;
1da177e4 LT	177	/* recovery/resync flags
	178	* NEEDED: we might need to start a resync/recover
	179	* RUNNING: a thread is running, or about to be started
	180	* SYNC: actually doing a resync, not a recovery
	181	* ERR: and IO error was detected - abort the resync/recovery
	182	* INTR: someone requested a (clean) early abort.
	183	* DONE: thread is done and is waiting to be reaped
24dd469d N	184	* REQUEST: user-space has requested a sync (used with SYNC)
24dd469d N	185	* CHECK: user-space request for for check-only, no repair
ccfcc3c1 N	186	* RESHAPE: A reshape is happening
	187	*
	188	* If neither SYNC or RESHAPE are set, then it is a recovery.
1da177e4 LT	189	*/
	190	#define MD_RECOVERY_RUNNING 0
	191	#define MD_RECOVERY_SYNC 1
	192	#define MD_RECOVERY_ERR 2
	193	#define MD_RECOVERY_INTR 3
	194	#define MD_RECOVERY_DONE 4
	195	#define MD_RECOVERY_NEEDED 5
24dd469d N	196	#define MD_RECOVERY_REQUESTED 6
24dd469d N	197	#define MD_RECOVERY_CHECK 7
ccfcc3c1	198	#define MD_RECOVERY_RESHAPE 8
5fd6c1dc N	199	#define MD_RECOVERY_FROZEN 9
5fd6c1dc N	200
1da177e4 LT	201	unsigned long recovery;
	202
	203	int in_sync; /* know to not need resync */
df5b89b3	204	struct mutex reconfig_mutex;
1da177e4 LT	205	atomic_t active;
1da177e4 LT	206
44ce6294	207	int changed; /* true if we might need to reread partition info */
1da177e4 LT	208	int degraded; /* whether md should consider
	209	* adding a spare
	210	*/
a9701a30 N	211	int barriers_work; /* initialised to true, cleared as soon
	212	* as a barrier request to slave
	213	* fails. Only supported
	214	*/
	215	struct bio biolist; / bios that need to be retried
	216	* because BIO_RW_BARRIER is not supported
	217	*/
1da177e4 LT	218
	219	atomic_t recovery_active; /* blocks scheduled, but not written */
	220	wait_queue_head_t recovery_wait;
	221	sector_t recovery_cp;
c6207277 N	222	sector_t resync_max; /* resync should pause
c6207277 N	223	* when it gets here */
06d91a5f N	224
06d91a5f N	225	spinlock_t write_lock;
3d310eb7	226	wait_queue_head_t sb_wait; /* for waiting on superblock updates */
7bfa19f2	227	atomic_t pending_writes; /* number of active superblock writes */
06d91a5f	228
1da177e4 LT	229	unsigned int safemode; /* if set, update "clean" superblock
	230	* when no writes pending.
	231	*/
	232	unsigned int safemode_delay;
	233	struct timer_list safemode_timer;
	234	atomic_t writes_pending;
165125e1	235	struct request_queue queue; / for plugging ... */
1da177e4	236
4b6d287f N	237	atomic_t write_behind; /* outstanding async IO */
	238	unsigned int max_write_behind; /* 0 = sync */
	239
32a7627c N	240	struct bitmap bitmap; / the bitmap for the device */
32a7627c N	241	struct file bitmap_file; / the bitmap file */
a654b9d8 N	242	long bitmap_offset; /* offset from superblock of
	243	* start of bitmap. May be
	244	* negative, but not '0'
	245	*/
36fa3063 N	246	long default_bitmap_offset; /* this is the offset to use when
	247	* hot-adding a bitmap. It should
	248	* eventually be settable by sysfs.
	249	*/
32a7627c	250
1da177e4 LT	251	struct list_head all_mddevs;
	252	};
	253
	254
	255	static inline void rdev_dec_pending(mdk_rdev_t rdev, mddev_t mddev)
	256	{
b2d444d7	257	int faulty = test_bit(Faulty, &rdev->flags);
1da177e4 LT	258	if (atomic_dec_and_test(&rdev->nr_pending) && faulty)
	259	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
	260	}
	261
	262	static inline void md_sync_acct(struct block_device *bdev, unsigned long nr_sectors)
	263	{
	264	atomic_add(nr_sectors, &bdev->bd_contains->bd_disk->sync_io);
	265	}
	266
2604b703	267	struct mdk_personality
1da177e4 LT	268	{
1da177e4 LT	269	char *name;
2604b703 N	270	int level;
2604b703 N	271	struct list_head list;
1da177e4	272	struct module *owner;
165125e1	273	int (make_request)(struct request_queue q, struct bio *bio);
1da177e4 LT	274	int (run)(mddev_t mddev);
	275	int (stop)(mddev_t mddev);
	276	void (status)(struct seq_file seq, mddev_t *mddev);
	277	/* error_handler must set ->faulty and clear ->in_sync
	278	* if appropriate, and should abort recovery if needed
	279	*/
	280	void (error_handler)(mddev_t mddev, mdk_rdev_t *rdev);
	281	int (hot_add_disk) (mddev_t mddev, mdk_rdev_t *rdev);
	282	int (hot_remove_disk) (mddev_t mddev, int number);
	283	int (spare_active) (mddev_t mddev);
57afd89f	284	sector_t (sync_request)(mddev_t mddev, sector_t sector_nr, int *skipped, int go_faster);
1da177e4	285	int (resize) (mddev_t mddev, sector_t sectors);
63c70c4f N	286	int (check_reshape) (mddev_t mddev);
63c70c4f N	287	int (start_reshape) (mddev_t mddev);
1da177e4	288	int (reconfig) (mddev_t mddev, int layout, int chunk_size);
36fa3063 N	289	/* quiesce moves between quiescence states
	290	* 0 - fully active
	291	* 1 - no new requests allowed
	292	* others - reserved
	293	*/
	294	void (quiesce) (mddev_t mddev, int state);
1da177e4 LT	295	};
	296
	297
007583c9 N	298	struct md_sysfs_entry {
	299	struct attribute attr;
	300	ssize_t (show)(mddev_t , char *);
	301	ssize_t (store)(mddev_t , const char *, size_t);
	302	};
	303
	304
1da177e4 LT	305	static inline char * mdname (mddev_t * mddev)
	306	{
	307	return mddev->gendisk ? mddev->gendisk->disk_name : "mdX";
	308	}
	309
1da177e4 LT	310	/*
	311	* iterates through some rdev ringlist. It's safe to remove the
	312	* current 'rdev'. Dont touch 'tmp' though.
	313	*/
	314	#define ITERATE_RDEV_GENERIC(head,rdev,tmp) \
	315	\
	316	for ((tmp) = (head).next; \
	317	(rdev) = (list_entry((tmp), mdk_rdev_t, same_set)), \
	318	(tmp) = (tmp)->next, (tmp)->prev != &(head) \
	319	; )
	320	/*
	321	* iterates through the 'same array disks' ringlist
	322	*/
	323	#define ITERATE_RDEV(mddev,rdev,tmp) \
	324	ITERATE_RDEV_GENERIC((mddev)->disks,rdev,tmp)
	325
	326	/*
	327	* Iterates through 'pending RAID disks'
	328	*/
	329	#define ITERATE_RDEV_PENDING(rdev,tmp) \
	330	ITERATE_RDEV_GENERIC(pending_raid_disks,rdev,tmp)
	331
	332	typedef struct mdk_thread_s {
	333	void (run) (mddev_t mddev);
	334	mddev_t *mddev;
	335	wait_queue_head_t wqueue;
	336	unsigned long flags;
1da177e4	337	struct task_struct *tsk;
32a7627c	338	unsigned long timeout;
1da177e4 LT	339	} mdk_thread_t;
	340
	341	#define THREAD_WAKEUP 0
	342
	343	#define __wait_event_lock_irq(wq, condition, lock, cmd) \
	344	do { \
	345	wait_queue_t __wait; \
	346	init_waitqueue_entry(&__wait, current); \
	347	\
	348	add_wait_queue(&wq, &__wait); \
	349	for (;;) { \
	350	set_current_state(TASK_UNINTERRUPTIBLE); \
	351	if (condition) \
	352	break; \
	353	spin_unlock_irq(&lock); \
	354	cmd; \
	355	schedule(); \
	356	spin_lock_irq(&lock); \
	357	} \
	358	current->state = TASK_RUNNING; \
	359	remove_wait_queue(&wq, &__wait); \
	360	} while (0)
	361
	362	#define wait_event_lock_irq(wq, condition, lock, cmd) \
	363	do { \
	364	if (condition) \
	365	break; \
	366	__wait_event_lock_irq(wq, condition, lock, cmd); \
	367	} while (0)
	368
1345b1d8 N	369	static inline void safe_put_page(struct page *p)
	370	{
	371	if (p) put_page(p);
	372	}
	373
9361401e	374	#endif /* CONFIG_BLOCK */
1da177e4 LT	375	#endif
1da177e4 LT	376