summaryrefslogtreecommitdiff
path: root/drivers/md/raid10.h
blob: 157d69e83ff401972f395db9bb281faa8df75a65 (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
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
#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;
	/* 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,
};

extern int md_raid10_congested(struct mddev *mddev, int bits);

#endif