[deliverable/linux.git] / drivers / md / raid1.h

#ifndef _RAID1_H
#define _RAID1_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
Commit	Line	Data
1da177e4 LT	1	#ifndef _RAID1_H
	2	#define _RAID1_H
	3
1da177e4 LT	4	typedef struct mirror_info mirror_info_t;
	5
	6	struct mirror_info {
	7	mdk_rdev_t *rdev;
	8	sector_t head_position;
	9	};
	10
	11	/*
	12	* memory pools need a pointer to the mddev, so they can force an unplug
	13	* when memory is tight, and a count of the number of drives that the
	14	* pool was allocated for, so they know how much to allocate and free.
	15	* mddev->raid_disks cannot be used, as it can change while a pool is active
	16	* These two datums are stored in a kmalloced struct.
	17	*/
	18
	19	struct pool_info {
	20	mddev_t *mddev;
	21	int raid_disks;
	22	};
	23
	24
	25	typedef struct r1bio_s r1bio_t;
	26
	27	struct r1_private_data_s {
	28	mddev_t *mddev;
	29	mirror_info_t *mirrors;
	30	int raid_disks;
1da177e4 LT	31	int last_used;
	32	sector_t next_seq_sect;
	33	spinlock_t device_lock;
	34
	35	struct list_head retry_list;
191ea9b2 N	36	/* queue pending writes and submit them on unplug */
	37	struct bio_list pending_bio_list;
	38	/* queue of writes that have been unplugged */
	39	struct bio_list flushing_bio_list;
	40
1da177e4 LT	41	/* for use when syncing mirrors: */
	42
	43	spinlock_t resync_lock;
191ea9b2	44	int nr_pending;
17999be4	45	int nr_waiting;
ddaf22ab	46	int nr_queued;
191ea9b2	47	int barrier;
1da177e4	48	sector_t next_resync;
191ea9b2 N	49	int fullsync; /* set to 1 if a full sync is needed,
	50	* (fresh device added).
	51	* Cleared when a sync completes.
	52	*/
1da177e4	53
17999be4	54	wait_queue_head_t wait_barrier;
1da177e4 LT	55
	56	struct pool_info *poolinfo;
	57
ddaf22ab N	58	struct page *tmppage;
ddaf22ab N	59
1da177e4 LT	60	mempool_t *r1bio_pool;
	61	mempool_t *r1buf_pool;
	62	};
	63
	64	typedef struct r1_private_data_s conf_t;
	65
	66	/*
	67	* this is the only point in the RAID code where we violate
	68	* C type safety. mddev->private is an 'opaque' pointer.
	69	*/
	70	#define mddev_to_conf(mddev) ((conf_t *) mddev->private)
	71
	72	/*
	73	* this is our 'private' RAID1 bio.
	74	*
	75	* it contains information about what kind of IO operations were started
	76	* for this RAID1 operation, and about their status:
	77	*/
	78
	79	struct r1bio_s {
	80	atomic_t remaining; /* 'have we finished' count,
	81	* used from IRQ handlers
	82	*/
4b6d287f N	83	atomic_t behind_remaining; /* number of write-behind ios remaining
	84	* in this BehindIO request
	85	*/
1da177e4 LT	86	sector_t sector;
	87	int sectors;
	88	unsigned long state;
	89	mddev_t *mddev;
	90	/*
	91	* original bio going to /dev/mdx
	92	*/
	93	struct bio *master_bio;
	94	/*
	95	* if the IO is in READ direction, then this is where we read
	96	*/
	97	int read_disk;
	98
	99	struct list_head retry_list;
191ea9b2	100	struct bitmap_update *bitmap_update;
1da177e4 LT	101	/*
	102	* if the IO is in WRITE direction, then multiple bios are used.
	103	* We choose the number when they are allocated.
	104	*/
	105	struct bio *bios[0];
191ea9b2	106	/* DO NOT PUT ANY NEW FIELDS HERE - bios array is contiguously alloced*/
1da177e4 LT	107	};
1da177e4 LT	108
cf30a473 N	109	/* when we get a read error on a read-only array, we redirect to another
	110	* device without failing the first device, or trying to over-write to
	111	* correct the read error. To keep track of bad blocks on a per-bio
	112	* level, we store IO_BLOCKED in the appropriate 'bios' pointer
	113	*/
	114	#define IO_BLOCKED ((struct bio*)1)
	115
1da177e4 LT	116	/* bits for r1bio.state */
	117	#define R1BIO_Uptodate 0
	118	#define R1BIO_IsSync 1
191ea9b2	119	#define R1BIO_Degraded 2
a9701a30 N	120	#define R1BIO_BehindIO 3
	121	#define R1BIO_Barrier 4
	122	#define R1BIO_BarrierRetry 5
4b6d287f N	123	/* For write-behind requests, we call bi_end_io when
	124	* the last non-write-behind device completes, providing
	125	* any write was successful. Otherwise we call when
	126	* any write-behind write succeeds, otherwise we call
	127	* with failure when last write completes (and all failed).
	128	* Record that bi_end_io was called with this flag...
	129	*/
9e71f9c8	130	#define R1BIO_Returned 6
4b6d287f	131
1da177e4	132	#endif