[deliverable/linux.git] / drivers / md / raid10.h

#ifndef _RAID10_H
#define _RAID10_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
Commit	Line	Data
1da177e4 LT	1	#ifndef _RAID10_H
	2	#define _RAID10_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	typedef struct r10bio_s r10bio_t;
	12
	13	struct r10_private_data_s {
	14	mddev_t *mddev;
	15	mirror_info_t *mirrors;
	16	int raid_disks;
1da177e4 LT	17	spinlock_t device_lock;
	18
	19	/* geometry */
	20	int near_copies; /* number of copies layed out raid0 style */
	21	int far_copies; /* number of copies layed out
	22	* at large strides across drives
	23	*/
c93983bf N	24	int far_offset; /* far_copies are offset by 1 stripe
	25	* instead of many
	26	*/
1da177e4 LT	27	int copies; /* near_copies * far_copies.
	28	* must be <= raid_disks
	29	*/
	30	sector_t stride; /* distance between far copies.
c93983bf N	31	* This is size / far_copies unless
	32	* far_offset, in which case it is
	33	* 1 stripe.
1da177e4 LT	34	*/
	35
	36	int chunk_shift; /* shift from chunks to sectors */
	37	sector_t chunk_mask;
	38
	39	struct list_head retry_list;
6cce3b23 N	40	/* queue pending writes and submit them on unplug */
	41	struct bio_list pending_bio_list;
	42
1da177e4 LT	43
	44	spinlock_t resync_lock;
	45	int nr_pending;
0a27ec96	46	int nr_waiting;
4443ae10	47	int nr_queued;
1da177e4 LT	48	int barrier;
1da177e4 LT	49	sector_t next_resync;
6cce3b23 N	50	int fullsync; /* set to 1 if a full sync is needed,
	51	* (fresh device added).
	52	* Cleared when a sync completes.
	53	*/
1da177e4	54
0a27ec96	55	wait_queue_head_t wait_barrier;
1da177e4 LT	56
	57	mempool_t *r10bio_pool;
	58	mempool_t *r10buf_pool;
4443ae10	59	struct page *tmppage;
1da177e4 LT	60	};
	61
	62	typedef struct r10_private_data_s conf_t;
	63
	64	/*
	65	* this is the only point in the RAID code where we violate
	66	* C type safety. mddev->private is an 'opaque' pointer.
	67	*/
	68	#define mddev_to_conf(mddev) ((conf_t *) mddev->private)
	69
	70	/*
	71	* this is our 'private' RAID10 bio.
	72	*
	73	* it contains information about what kind of IO operations were started
	74	* for this RAID10 operation, and about their status:
	75	*/
	76
	77	struct r10bio_s {
	78	atomic_t remaining; /* 'have we finished' count,
	79	* used from IRQ handlers
	80	*/
	81	sector_t sector; /* virtual sector number */
	82	int sectors;
	83	unsigned long state;
	84	mddev_t *mddev;
	85	/*
	86	* original bio going to /dev/mdx
	87	*/
	88	struct bio *master_bio;
	89	/*
	90	* if the IO is in READ direction, then this is where we read
	91	*/
	92	int read_slot;
	93
	94	struct list_head retry_list;
	95	/*
	96	* if the IO is in WRITE direction, then multiple bios are used,
	97	* one for each copy.
	98	* When resyncing we also use one for each copy.
	99	* When reconstructing, we use 2 bios, one for read, one for write.
	100	* We choose the number when they are allocated.
	101	*/
	102	struct {
	103	struct bio *bio;
	104	sector_t addr;
	105	int devnum;
	106	} devs[0];
	107	};
	108
0eb3ff12 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 r10bio.state */
	117	#define R10BIO_Uptodate 0
	118	#define R10BIO_IsSync 1
	119	#define R10BIO_IsRecover 2
6cce3b23	120	#define R10BIO_Degraded 3
1da177e4	121	#endif