summaryrefslogtreecommitdiffstats
path: root/drivers/md/raid10.h
blob: c646152ba4e48cb1b39ea306c49b60ce852c0725 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
#ifndef _RAID10_H
#define _RAID10_H

typedef struct mirror_info mirror_info_t;

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

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 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
					       */
	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.
					       */

	sector_t		dev_sectors;  /* temp copy of mddev->dev_sectors */

	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;

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

typedef struct r10_private_data_s conf_t;

/*
 * 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
/* Set ReadError on bios that experience a read error
 * so that raid10d knows what to do with them.
 */
#define	R10BIO_ReadError 4
#endif