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

#ifndef _RAID10_H
#define _RAID10_H

struct raid10_info {
	struct md_rdev	*rdev, *replacement;
	sector_t	head_position;
	int		recovery_disabled;	/* matches
						 * mddev->recovery_disabled
						 * when we shouldn't try
						 * recovering this device.
						 */
};

struct r10conf {
	struct mddev		*mddev;
	struct raid10_info	*mirrors;
	struct raid10_info	*mirrors_new, *mirrors_old;
	spinlock_t		device_lock;

	/* geometry */
	struct geom {
		int		raid_disks;
		int		near_copies;  /* number of copies laid out
					       * raid0 style */
		int		far_copies;   /* number of copies laid out
					       * at large strides across drives
					       */
		int		far_offset;   /* far_copies are offset by 1
					       * stripe instead of many
					       */
		sector_t	stride;	      /* distance between far copies.
					       * This is size / far_copies unless
					       * far_offset, in which case it is
					       * 1 stripe.
					       */
		int             far_set_size; /* The number of devices in a set,
					       * where a 'set' are devices that
					       * contain far/offset copies of
					       * each other.
					       */
		int		chunk_shift; /* shift from chunks to sectors */
		sector_t	chunk_mask;
	} prev, geo;
	int			copies;	      /* near_copies * far_copies.
					       * must be <= raid_disks
					       */

	sector_t		dev_sectors;  /* temp copy of
					       * mddev->dev_sectors */
	sector_t		reshape_progress;
	sector_t		reshape_safe;
	unsigned long		reshape_checkpoint;
	sector_t		offset_diff;

	struct list_head	retry_list;
	/* A separate list of r1bio which just need raid_end_bio_io called.
	 * This mustn't happen for writes which had any errors if the superblock
	 * needs to be written.
	 */
	struct list_head	bio_end_io_list;

	/* queue pending writes and submit them on unplug */
	struct bio_list		pending_bio_list;
	int			pending_count;

	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.
					    */
	int			have_replacement; /* There is at least one
						   * replacement device.
						   */
	wait_queue_head_t	wait_barrier;

	mempool_t		*r10bio_pool;
	mempool_t		*r10buf_pool;
	struct page		*tmppage;

	/* When taking over an array from a different personality, we store
	 * the new thread here until we fully activate the array.
	 */
	struct md_thread	*thread;
};

/*
 * 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 {
	atomic_t		remaining; /* 'have we finished' count,
					    * used from IRQ handlers
					    */
	sector_t		sector;	/* virtual sector number */
	int			sectors;
	unsigned long		state;
	struct mddev		*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.
	 * We sometimes need an extra bio to write to the replacement.
	 */
	struct r10dev {
		struct bio	*bio;
		union {
			struct bio	*repl_bio; /* used for resync and
						    * writes */
			struct md_rdev	*rdev;	   /* used for reads
						    * (read_slot >= 0) */
		};
		sector_t	addr;
		int		devnum;
	} devs[0];
};

/* bits for r10bio.state */
enum r10bio_state {
	R10BIO_Uptodate,
	R10BIO_IsSync,
	R10BIO_IsRecover,
	R10BIO_IsReshape,
	R10BIO_Degraded,
/* Set ReadError on bios that experience a read error
 * so that raid10d knows what to do with them.
 */
	R10BIO_ReadError,
/* If a write for this request means we can clear some
 * known-bad-block records, we set this flag.
 */
	R10BIO_MadeGood,
	R10BIO_WriteError,
/* During a reshape we might be performing IO on the
 * 'previous' part of the array, in which case this
 * flag is set
 */
	R10BIO_Previous,
};
#endif
Commit	Line	Data
1da177e4 LT	1	#ifndef _RAID10_H
	2	#define _RAID10_H
	3
dc280d98	4	struct raid10_info {
69335ef3	5	struct md_rdev rdev, replacement;
1da177e4	6	sector_t head_position;
2bb77736 N	7	int recovery_disabled; /* matches
	8	* mddev->recovery_disabled
	9	* when we shouldn't try
	10	* recovering this device.
	11	*/
1da177e4 LT	12	};
1da177e4 LT	13
e879a879	14	struct r10conf {
fd01b88c	15	struct mddev *mddev;
dc280d98 JB	16	struct raid10_info *mirrors;
dc280d98 JB	17	struct raid10_info mirrors_new, mirrors_old;
1da177e4 LT	18	spinlock_t device_lock;
	19
	20	/* geometry */
5cf00fcd N	21	struct geom {
	22	int raid_disks;
	23	int near_copies; /* number of copies laid out
69335ef3	24	* raid0 style */
5cf00fcd	25	int far_copies; /* number of copies laid out
1da177e4 LT	26	* at large strides across drives
1da177e4 LT	27	*/
5cf00fcd	28	int far_offset; /* far_copies are offset by 1
69335ef3	29	* stripe instead of many
c93983bf	30	*/
5cf00fcd	31	sector_t stride; /* distance between far copies.
c93983bf N	32	* This is size / far_copies unless
	33	* far_offset, in which case it is
	34	* 1 stripe.
1da177e4	35	*/
475901af JB	36	int far_set_size; /* The number of devices in a set,
	37	* where a 'set' are devices that
	38	* contain far/offset copies of
	39	* each other.
	40	*/
5cf00fcd N	41	int chunk_shift; /* shift from chunks to sectors */
5cf00fcd N	42	sector_t chunk_mask;
f8c9e74f	43	} prev, geo;
5cf00fcd N	44	int copies; /* near_copies * far_copies.
	45	* must be <= raid_disks
	46	*/
1da177e4	47
69335ef3 N	48	sector_t dev_sectors; /* temp copy of
69335ef3 N	49	* mddev->dev_sectors */
f8c9e74f	50	sector_t reshape_progress;
3ea7daa5 N	51	sector_t reshape_safe;
	52	unsigned long reshape_checkpoint;
	53	sector_t offset_diff;
dab8b292	54
1da177e4	55	struct list_head retry_list;
95af587e N	56	/* A separate list of r1bio which just need raid_end_bio_io called.
	57	* This mustn't happen for writes which had any errors if the superblock
	58	* needs to be written.
	59	*/
	60	struct list_head bio_end_io_list;
	61
6cce3b23 N	62	/* queue pending writes and submit them on unplug */
6cce3b23 N	63	struct bio_list pending_bio_list;
34db0cd6	64	int pending_count;
1da177e4 LT	65
1da177e4 LT	66	spinlock_t resync_lock;
69335ef3 N	67	int nr_pending;
	68	int nr_waiting;
	69	int nr_queued;
	70	int barrier;
1da177e4	71	sector_t next_resync;
6cce3b23 N	72	int fullsync; /* set to 1 if a full sync is needed,
	73	* (fresh device added).
	74	* Cleared when a sync completes.
	75	*/
69335ef3 N	76	int have_replacement; /* There is at least one
	77	* replacement device.
	78	*/
0a27ec96	79	wait_queue_head_t wait_barrier;
1da177e4	80
69335ef3 N	81	mempool_t *r10bio_pool;
69335ef3 N	82	mempool_t *r10buf_pool;
4443ae10	83	struct page *tmppage;
dab8b292 TM	84
	85	/* When taking over an array from a different personality, we store
	86	* the new thread here until we fully activate the array.
	87	*/
2b8bf345	88	struct md_thread *thread;
1da177e4 LT	89	};
1da177e4 LT	90
1da177e4 LT	91	/*
	92	* this is our 'private' RAID10 bio.
	93	*
	94	* it contains information about what kind of IO operations were started
	95	* for this RAID10 operation, and about their status:
	96	*/
	97
9f2c9d12	98	struct r10bio {
1da177e4 LT	99	atomic_t remaining; /* 'have we finished' count,
	100	* used from IRQ handlers
	101	*/
	102	sector_t sector; /* virtual sector number */
	103	int sectors;
	104	unsigned long state;
fd01b88c	105	struct mddev *mddev;
1da177e4 LT	106	/*
	107	* original bio going to /dev/mdx
	108	*/
	109	struct bio *master_bio;
	110	/*
	111	* if the IO is in READ direction, then this is where we read
	112	*/
	113	int read_slot;
	114
	115	struct list_head retry_list;
	116	/*
	117	* if the IO is in WRITE direction, then multiple bios are used,
	118	* one for each copy.
	119	* When resyncing we also use one for each copy.
	120	* When reconstructing, we use 2 bios, one for read, one for write.
	121	* We choose the number when they are allocated.
69335ef3	122	* We sometimes need an extra bio to write to the replacement.
1da177e4	123	*/
e0ee7785	124	struct r10dev {
69335ef3 N	125	struct bio *bio;
	126	union {
	127	struct bio repl_bio; / used for resync and
	128	* writes */
	129	struct md_rdev rdev; / used for reads
	130	* (read_slot >= 0) */
	131	};
	132	sector_t addr;
	133	int devnum;
1da177e4 LT	134	} devs[0];
	135	};
	136
	137	/* bits for r10bio.state */
69335ef3 N	138	enum r10bio_state {
	139	R10BIO_Uptodate,
	140	R10BIO_IsSync,
	141	R10BIO_IsRecover,
3ea7daa5	142	R10BIO_IsReshape,
69335ef3	143	R10BIO_Degraded,
856e08e2 N	144	/* Set ReadError on bios that experience a read error
	145	* so that raid10d knows what to do with them.
	146	*/
69335ef3	147	R10BIO_ReadError,
749c55e9 N	148	/* If a write for this request means we can clear some
	149	* known-bad-block records, we set this flag.
	150	*/
69335ef3 N	151	R10BIO_MadeGood,
69335ef3 N	152	R10BIO_WriteError,
f8c9e74f N	153	/* During a reshape we might be performing IO on the
	154	* 'previous' part of the array, in which case this
	155	* flag is set
	156	*/
	157	R10BIO_Previous,
69335ef3	158	};
1da177e4	159	#endif