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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;
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 					       */
26 	int			far_offset;   /* far_copies are offset by 1 stripe
27 					       * instead of many
28 					       */
29 	int			copies;	      /* near_copies * far_copies.
30 					       * must be <= raid_disks
31 					       */
32 	sector_t		stride;	      /* distance between far copies.
33 					       * This is size / far_copies unless
34 					       * far_offset, in which case it is
35 					       * 1 stripe.
36 					       */
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 
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 
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 
118 /* bits for r10bio.state */
119 #define	R10BIO_Uptodate	0
120 #define	R10BIO_IsSync	1
121 #define	R10BIO_IsRecover 2
122 #define	R10BIO_Degraded 3
123 #endif
124