xref: /linux/drivers/md/raid10.h (revision d524dac9279b6a41ffdf7ff7958c577f2e387db6)
1 #ifndef _RAID10_H
2 #define _RAID10_H
3 
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;
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 					       */
24 	int			far_offset;   /* far_copies are offset by 1 stripe
25 					       * instead of many
26 					       */
27 	int			copies;	      /* near_copies * far_copies.
28 					       * must be <= raid_disks
29 					       */
30 	sector_t		stride;	      /* distance between far copies.
31 					       * This is size / far_copies unless
32 					       * far_offset, in which case it is
33 					       * 1 stripe.
34 					       */
35 
36 	sector_t		dev_sectors;  /* temp copy of mddev->dev_sectors */
37 
38 	int chunk_shift; /* shift from chunks to sectors */
39 	sector_t chunk_mask;
40 
41 	struct list_head	retry_list;
42 	/* queue pending writes and submit them on unplug */
43 	struct bio_list		pending_bio_list;
44 
45 
46 	spinlock_t		resync_lock;
47 	int nr_pending;
48 	int nr_waiting;
49 	int nr_queued;
50 	int barrier;
51 	sector_t		next_resync;
52 	int			fullsync;  /* set to 1 if a full sync is needed,
53 					    * (fresh device added).
54 					    * Cleared when a sync completes.
55 					    */
56 
57 	wait_queue_head_t	wait_barrier;
58 
59 	mempool_t *r10bio_pool;
60 	mempool_t *r10buf_pool;
61 	struct page		*tmppage;
62 
63 	/* When taking over an array from a different personality, we store
64 	 * the new thread here until we fully activate the array.
65 	 */
66 	struct mdk_thread_s	*thread;
67 };
68 
69 typedef struct r10_private_data_s conf_t;
70 
71 /*
72  * this is our 'private' RAID10 bio.
73  *
74  * it contains information about what kind of IO operations were started
75  * for this RAID10 operation, and about their status:
76  */
77 
78 struct r10bio_s {
79 	atomic_t		remaining; /* 'have we finished' count,
80 					    * used from IRQ handlers
81 					    */
82 	sector_t		sector;	/* virtual sector number */
83 	int			sectors;
84 	unsigned long		state;
85 	mddev_t			*mddev;
86 	/*
87 	 * original bio going to /dev/mdx
88 	 */
89 	struct bio		*master_bio;
90 	/*
91 	 * if the IO is in READ direction, then this is where we read
92 	 */
93 	int			read_slot;
94 
95 	struct list_head	retry_list;
96 	/*
97 	 * if the IO is in WRITE direction, then multiple bios are used,
98 	 * one for each copy.
99 	 * When resyncing we also use one for each copy.
100 	 * When reconstructing, we use 2 bios, one for read, one for write.
101 	 * We choose the number when they are allocated.
102 	 */
103 	struct {
104 		struct bio		*bio;
105 		sector_t addr;
106 		int devnum;
107 	} devs[0];
108 };
109 
110 /* when we get a read error on a read-only array, we redirect to another
111  * device without failing the first device, or trying to over-write to
112  * correct the read error.  To keep track of bad blocks on a per-bio
113  * level, we store IO_BLOCKED in the appropriate 'bios' pointer
114  */
115 #define IO_BLOCKED ((struct bio*)1)
116 
117 /* bits for r10bio.state */
118 #define	R10BIO_Uptodate	0
119 #define	R10BIO_IsSync	1
120 #define	R10BIO_IsRecover 2
121 #define	R10BIO_Degraded 3
122 #endif
123