[mirror_ubuntu-artful-kernel.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"

#define MD_RESERVED       0UL
#define LINEAR            1UL
#define RAID0             2UL
#define RAID1             3UL
#define RAID5             4UL
#define TRANSLUCENT       5UL
#define HSM               6UL
#define MULTIPATH         7UL
#define RAID6		  8UL
#define	RAID10		  9UL
#define FAULTY		  10UL
#define MAX_PERSONALITY   11UL

#define	LEVEL_MULTIPATH		(-4)
#define	LEVEL_LINEAR		(-1)
#define	LEVEL_FAULTY		(-5)

#define MaxSector (~(sector_t)0)
#define MD_THREAD_NAME_MAX 14

static inline int pers_to_level (int pers)
{
	switch (pers) {
		case FAULTY:		return LEVEL_FAULTY;
		case MULTIPATH:		return LEVEL_MULTIPATH;
		case HSM:		return -3;
		case TRANSLUCENT:	return -2;
		case LINEAR:		return LEVEL_LINEAR;
		case RAID0:		return 0;
		case RAID1:		return 1;
		case RAID5:		return 5;
		case RAID6:		return 6;
		case RAID10:		return 10;
	}
	BUG();
	return MD_RESERVED;
}

static inline int level_to_pers (int level)
{
	switch (level) {
		case LEVEL_FAULTY: return FAULTY;
		case LEVEL_MULTIPATH: return MULTIPATH;
		case -3: return HSM;
		case -2: return TRANSLUCENT;
		case LEVEL_LINEAR: return LINEAR;
		case 0: return RAID0;
		case 1: return RAID1;
		case 4:
		case 5: return RAID5;
		case 6: return RAID6;
		case 10: return RAID10;
	}
	return MD_RESERVED;
}

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:
 */

#define MAX_CHUNK_SIZE (4096*1024)

/*
 * 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;
	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
					 */

	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.
					 */
};

typedef struct mdk_personality_s mdk_personality_t;

struct mddev_s
{
	void				*private;
	mdk_personality_t		*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;
	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];

	struct mdk_thread_s		*thread;	/* management thread */
	struct mdk_thread_s		*sync_thread;	/* doing resync or reconstruct */
	sector_t			curr_resync;	/* blocks scheduled */
	unsigned long			resync_mark;	/* a recent timestamp */
	sector_t			resync_mark_cnt;/* blocks written at resync_mark */

	sector_t			resync_max_sectors; /* may be set by personality */

	sector_t			resync_mismatches; /* count of sectors where
							    * parity/replica mismatch found
							    */
	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
	 */
#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
	unsigned long			recovery;

	int				in_sync;	/* know to not need resync */
	struct semaphore		reconfig_sem;
	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_s
{
	char *name;
	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 (*reshape) (mddev_t *mddev, int raid_disks);
	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";
}

extern mdk_rdev_t * find_rdev_nr(mddev_t *mddev, int nr);

/*
 * 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)

#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
1da177e4 LT	21	#define MD_RESERVED 0UL
	22	#define LINEAR 1UL
	23	#define RAID0 2UL
	24	#define RAID1 3UL
	25	#define RAID5 4UL
	26	#define TRANSLUCENT 5UL
	27	#define HSM 6UL
	28	#define MULTIPATH 7UL
	29	#define RAID6 8UL
	30	#define RAID10 9UL
	31	#define FAULTY 10UL
	32	#define MAX_PERSONALITY 11UL
	33
	34	#define LEVEL_MULTIPATH (-4)
	35	#define LEVEL_LINEAR (-1)
	36	#define LEVEL_FAULTY (-5)
	37
	38	#define MaxSector (~(sector_t)0)
	39	#define MD_THREAD_NAME_MAX 14
	40
	41	static inline int pers_to_level (int pers)
	42	{
	43	switch (pers) {
	44	case FAULTY: return LEVEL_FAULTY;
	45	case MULTIPATH: return LEVEL_MULTIPATH;
	46	case HSM: return -3;
	47	case TRANSLUCENT: return -2;
	48	case LINEAR: return LEVEL_LINEAR;
	49	case RAID0: return 0;
	50	case RAID1: return 1;
	51	case RAID5: return 5;
	52	case RAID6: return 6;
	53	case RAID10: return 10;
	54	}
	55	BUG();
	56	return MD_RESERVED;
	57	}
	58
	59	static inline int level_to_pers (int level)
	60	{
	61	switch (level) {
	62	case LEVEL_FAULTY: return FAULTY;
	63	case LEVEL_MULTIPATH: return MULTIPATH;
	64	case -3: return HSM;
	65	case -2: return TRANSLUCENT;
	66	case LEVEL_LINEAR: return LINEAR;
	67	case 0: return RAID0;
	68	case 1: return RAID1;
	69	case 4:
	70	case 5: return RAID5;
	71	case 6: return RAID6;
	72	case 10: return RAID10;
	73	}
	74	return MD_RESERVED;
	75	}
	76
	77	typedef struct mddev_s mddev_t;
	78	typedef struct mdk_rdev_s mdk_rdev_t;
	79
	80	#define MAX_MD_DEVS 256 /* Max number of md dev */
	81
	82	/*
	83	* options passed in raidrun:
	84	*/
85
86	#define MAX_CHUNK_SIZE (4096*1024)
87
1da177e4 LT	88	/*
	89	* MD's 'extended' device
	90	*/
	91	struct mdk_rdev_s
	92	{
	93	struct list_head same_set; /* RAID devices within the same set */
	94
	95	sector_t size; /* Device size (in blocks) */
	96	mddev_t mddev; / RAID array if running */
	97	unsigned long last_events; /* IO event timestamp */
	98
	99	struct block_device bdev; / block device handle */
	100
	101	struct page *sb_page;
	102	int sb_loaded;
	103	sector_t data_offset; /* start of data in array */
	104	sector_t sb_offset;
0002b271	105	int sb_size; /* bytes in the superblock */
1da177e4 LT	106	int preferred_minor; /* autorun support */
1da177e4 LT	107
86e6ffdd N	108	struct kobject kobj;
86e6ffdd N	109
1da177e4 LT	110	/* A device can be in one of three states based on two flags:
	111	* Not working: faulty==1 in_sync==0
	112	* Fully working: faulty==0 in_sync==1
	113	* Working, but not
	114	* in sync with array
	115	* faulty==0 in_sync==0
	116	*
	117	* It can never have faulty==1, in_sync==1
	118	* This reduces the burden of testing multiple flags in many cases
	119	*/
1da177e4	120
b2d444d7 N	121	unsigned long flags;
	122	#define Faulty 1 /* device is known to have a fault */
	123	#define In_sync 2 /* device is in_sync with rest of array */
8ddf9efe	124	#define WriteMostly 4 /* Avoid reading if at all possible */
a9701a30	125	#define BarriersNotsupp 5 /* BIO_RW_BARRIER is not supported */
8ddf9efe	126
1da177e4 LT	127	int desc_nr; /* descriptor index in the superblock */
1da177e4 LT	128	int raid_disk; /* role of device in array */
41158c7e N	129	int saved_raid_disk; /* role that device used to have in the
	130	* array and could again if we did a partial
	131	* resync from the bitmap
	132	*/
1da177e4 LT	133
	134	atomic_t nr_pending; /* number of pending requests.
	135	* only maintained for arrays that
	136	* support hot removal
	137	*/
ba22dcbf N	138	atomic_t read_errors; /* number of consecutive read errors that
	139	* we have tried to ignore.
	140	*/
1da177e4 LT	141	};
	142
	143	typedef struct mdk_personality_s mdk_personality_t;
	144
	145	struct mddev_s
	146	{
	147	void *private;
	148	mdk_personality_t *pers;
	149	dev_t unit;
	150	int md_minor;
	151	struct list_head disks;
	152	int sb_dirty;
	153	int ro;
	154
	155	struct gendisk *gendisk;
	156
eae1701f N	157	struct kobject kobj;
eae1701f N	158
1da177e4 LT	159	/* Superblock information */
	160	int major_version,
	161	minor_version,
	162	patch_version;
	163	int persistent;
	164	int chunk_size;
	165	time_t ctime, utime;
	166	int level, layout;
	167	int raid_disks;
	168	int max_disks;
	169	sector_t size; /* used size of component devices */
	170	sector_t array_size; /* exported array size */
	171	__u64 events;
	172
	173	char uuid[16];
	174
	175	struct mdk_thread_s thread; / management thread */
	176	struct mdk_thread_s sync_thread; / doing resync or reconstruct */
	177	sector_t curr_resync; /* blocks scheduled */
	178	unsigned long resync_mark; /* a recent timestamp */
	179	sector_t resync_mark_cnt;/* blocks written at resync_mark */
	180
	181	sector_t resync_max_sectors; /* may be set by personality */
9d88883e N	182
	183	sector_t resync_mismatches; /* count of sectors where
	184	* parity/replica mismatch found
	185	*/
6ff8d8ec	186	int ok_start_degraded;
1da177e4 LT	187	/* recovery/resync flags
	188	* NEEDED: we might need to start a resync/recover
	189	* RUNNING: a thread is running, or about to be started
	190	* SYNC: actually doing a resync, not a recovery
	191	* ERR: and IO error was detected - abort the resync/recovery
	192	* INTR: someone requested a (clean) early abort.
	193	* DONE: thread is done and is waiting to be reaped
24dd469d N	194	* REQUEST: user-space has requested a sync (used with SYNC)
24dd469d N	195	* CHECK: user-space request for for check-only, no repair
1da177e4 LT	196	*/
	197	#define MD_RECOVERY_RUNNING 0
	198	#define MD_RECOVERY_SYNC 1
	199	#define MD_RECOVERY_ERR 2
	200	#define MD_RECOVERY_INTR 3
	201	#define MD_RECOVERY_DONE 4
	202	#define MD_RECOVERY_NEEDED 5
24dd469d N	203	#define MD_RECOVERY_REQUESTED 6
24dd469d N	204	#define MD_RECOVERY_CHECK 7
1da177e4 LT	205	unsigned long recovery;
	206
	207	int in_sync; /* know to not need resync */
	208	struct semaphore reconfig_sem;
	209	atomic_t active;
	210
	211	int changed; /* true if we might need to reread partition info */
	212	int degraded; /* whether md should consider
	213	* adding a spare
	214	*/
a9701a30 N	215	int barriers_work; /* initialised to true, cleared as soon
	216	* as a barrier request to slave
	217	* fails. Only supported
	218	*/
	219	struct bio biolist; / bios that need to be retried
	220	* because BIO_RW_BARRIER is not supported
	221	*/
1da177e4 LT	222
	223	atomic_t recovery_active; /* blocks scheduled, but not written */
	224	wait_queue_head_t recovery_wait;
	225	sector_t recovery_cp;
06d91a5f N	226
06d91a5f N	227	spinlock_t write_lock;
3d310eb7	228	wait_queue_head_t sb_wait; /* for waiting on superblock updates */
7bfa19f2	229	atomic_t pending_writes; /* number of active superblock writes */
06d91a5f	230
1da177e4 LT	231	unsigned int safemode; /* if set, update "clean" superblock
	232	* when no writes pending.
	233	*/
	234	unsigned int safemode_delay;
	235	struct timer_list safemode_timer;
	236	atomic_t writes_pending;
	237	request_queue_t queue; / for plugging ... */
	238
4b6d287f N	239	atomic_t write_behind; /* outstanding async IO */
	240	unsigned int max_write_behind; /* 0 = sync */
	241
32a7627c N	242	struct bitmap bitmap; / the bitmap for the device */
32a7627c N	243	struct file bitmap_file; / the bitmap file */
a654b9d8 N	244	long bitmap_offset; /* offset from superblock of
	245	* start of bitmap. May be
	246	* negative, but not '0'
	247	*/
36fa3063 N	248	long default_bitmap_offset; /* this is the offset to use when
	249	* hot-adding a bitmap. It should
	250	* eventually be settable by sysfs.
	251	*/
32a7627c	252
1da177e4 LT	253	struct list_head all_mddevs;
	254	};
	255
	256
	257	static inline void rdev_dec_pending(mdk_rdev_t rdev, mddev_t mddev)
	258	{
b2d444d7	259	int faulty = test_bit(Faulty, &rdev->flags);
1da177e4 LT	260	if (atomic_dec_and_test(&rdev->nr_pending) && faulty)
	261	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
	262	}
	263
	264	static inline void md_sync_acct(struct block_device *bdev, unsigned long nr_sectors)
	265	{
	266	atomic_add(nr_sectors, &bdev->bd_contains->bd_disk->sync_io);
	267	}
	268
	269	struct mdk_personality_s
	270	{
	271	char *name;
	272	struct module *owner;
	273	int (make_request)(request_queue_t q, struct bio *bio);
	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 LT	285	int (resize) (mddev_t mddev, sector_t sectors);
	286	int (reshape) (mddev_t mddev, int raid_disks);
	287	int (reconfig) (mddev_t mddev, int layout, int chunk_size);
36fa3063 N	288	/* quiesce moves between quiescence states
	289	* 0 - fully active
	290	* 1 - no new requests allowed
	291	* others - reserved
	292	*/
	293	void (quiesce) (mddev_t mddev, int state);
1da177e4 LT	294	};
	295
	296
007583c9 N	297	struct md_sysfs_entry {
	298	struct attribute attr;
	299	ssize_t (show)(mddev_t , char *);
	300	ssize_t (store)(mddev_t , const char *, size_t);
	301	};
	302
	303
1da177e4 LT	304	static inline char * mdname (mddev_t * mddev)
	305	{
	306	return mddev->gendisk ? mddev->gendisk->disk_name : "mdX";
	307	}
	308
	309	extern mdk_rdev_t * find_rdev_nr(mddev_t *mddev, int nr);
	310
	311	/*
	312	* iterates through some rdev ringlist. It's safe to remove the
	313	* current 'rdev'. Dont touch 'tmp' though.
	314	*/
	315	#define ITERATE_RDEV_GENERIC(head,rdev,tmp) \
	316	\
	317	for ((tmp) = (head).next; \
	318	(rdev) = (list_entry((tmp), mdk_rdev_t, same_set)), \
	319	(tmp) = (tmp)->next, (tmp)->prev != &(head) \
	320	; )
	321	/*
	322	* iterates through the 'same array disks' ringlist
	323	*/
	324	#define ITERATE_RDEV(mddev,rdev,tmp) \
	325	ITERATE_RDEV_GENERIC((mddev)->disks,rdev,tmp)
	326
	327	/*
	328	* Iterates through 'pending RAID disks'
	329	*/
	330	#define ITERATE_RDEV_PENDING(rdev,tmp) \
	331	ITERATE_RDEV_GENERIC(pending_raid_disks,rdev,tmp)
	332
	333	typedef struct mdk_thread_s {
	334	void (run) (mddev_t mddev);
	335	mddev_t *mddev;
	336	wait_queue_head_t wqueue;
	337	unsigned long flags;
1da177e4	338	struct task_struct *tsk;
32a7627c	339	unsigned long timeout;
1da177e4 LT	340	} mdk_thread_t;
	341
	342	#define THREAD_WAKEUP 0
	343
	344	#define __wait_event_lock_irq(wq, condition, lock, cmd) \
	345	do { \
	346	wait_queue_t __wait; \
	347	init_waitqueue_entry(&__wait, current); \
	348	\
	349	add_wait_queue(&wq, &__wait); \
	350	for (;;) { \
	351	set_current_state(TASK_UNINTERRUPTIBLE); \
	352	if (condition) \
	353	break; \
	354	spin_unlock_irq(&lock); \
	355	cmd; \
	356	schedule(); \
	357	spin_lock_irq(&lock); \
	358	} \
	359	current->state = TASK_RUNNING; \
	360	remove_wait_queue(&wq, &__wait); \
	361	} while (0)
	362
	363	#define wait_event_lock_irq(wq, condition, lock, cmd) \
	364	do { \
	365	if (condition) \
	366	break; \
	367	__wait_event_lock_irq(wq, condition, lock, cmd); \
	368	} while (0)
	369
	370	#endif
	371