[linux-block.git] / include / linux / raid / raid10.h

#ifndef _RAID10_H
#define _RAID10_H

#include <linux/raid/md.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
	4	#include <linux/raid/md.h>
	5
	6	typedef struct mirror_info mirror_info_t;
	7
	8	struct mirror_info {
	9	mdk_rdev_t *rdev;
	10	sector_t head_position;
	11	};
	12
	13	typedef struct r10bio_s r10bio_t;
	14
	15	struct r10_private_data_s {
	16	mddev_t *mddev;
	17	mirror_info_t *mirrors;
	18	int raid_disks;
1da177e4 LT	19	spinlock_t device_lock;
	20
	21	/* geometry */
	22	int near_copies; /* number of copies layed out raid0 style */
	23	int far_copies; /* number of copies layed out
	24	* at large strides across drives
	25	*/
c93983bf N	26	int far_offset; /* far_copies are offset by 1 stripe
	27	* instead of many
	28	*/
1da177e4 LT	29	int copies; /* near_copies * far_copies.
	30	* must be <= raid_disks
	31	*/
	32	sector_t stride; /* distance between far copies.
c93983bf N	33	* This is size / far_copies unless
	34	* far_offset, in which case it is
	35	* 1 stripe.
1da177e4 LT	36	*/
	37
	38	int chunk_shift; /* shift from chunks to sectors */
	39	sector_t chunk_mask;
	40
	41	struct list_head retry_list;
6cce3b23 N	42	/* queue pending writes and submit them on unplug */
	43	struct bio_list pending_bio_list;
	44
1da177e4 LT	45
	46	spinlock_t resync_lock;
	47	int nr_pending;
0a27ec96	48	int nr_waiting;
4443ae10	49	int nr_queued;
1da177e4 LT	50	int barrier;
1da177e4 LT	51	sector_t next_resync;
6cce3b23 N	52	int fullsync; /* set to 1 if a full sync is needed,
	53	* (fresh device added).
	54	* Cleared when a sync completes.
	55	*/
1da177e4	56
0a27ec96	57	wait_queue_head_t wait_barrier;
1da177e4 LT	58
	59	mempool_t *r10bio_pool;
	60	mempool_t *r10buf_pool;
4443ae10	61	struct page *tmppage;
1da177e4 LT	62	};
	63
	64	typedef struct r10_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' RAID10 bio.
	74	*
	75	* it contains information about what kind of IO operations were started
	76	* for this RAID10 operation, and about their status:
	77	*/
	78
	79	struct r10bio_s {
	80	atomic_t remaining; /* 'have we finished' count,
	81	* used from IRQ handlers
	82	*/
	83	sector_t sector; /* virtual sector number */
	84	int sectors;
	85	unsigned long state;
	86	mddev_t *mddev;
	87	/*
	88	* original bio going to /dev/mdx
	89	*/
	90	struct bio *master_bio;
	91	/*
	92	* if the IO is in READ direction, then this is where we read
	93	*/
	94	int read_slot;
	95
	96	struct list_head retry_list;
	97	/*
	98	* if the IO is in WRITE direction, then multiple bios are used,
	99	* one for each copy.
	100	* When resyncing we also use one for each copy.
	101	* When reconstructing, we use 2 bios, one for read, one for write.
	102	* We choose the number when they are allocated.
	103	*/
	104	struct {
	105	struct bio *bio;
	106	sector_t addr;
	107	int devnum;
	108	} devs[0];
	109	};
	110
0eb3ff12 N	111	/* when we get a read error on a read-only array, we redirect to another
	112	* device without failing the first device, or trying to over-write to
	113	* correct the read error. To keep track of bad blocks on a per-bio
	114	* level, we store IO_BLOCKED in the appropriate 'bios' pointer
	115	*/
	116	#define IO_BLOCKED ((struct bio*)1)
	117
1da177e4 LT	118	/* bits for r10bio.state */
	119	#define R10BIO_Uptodate 0
	120	#define R10BIO_IsSync 1
	121	#define R10BIO_IsRecover 2
6cce3b23	122	#define R10BIO_Degraded 3
1da177e4	123	#endif