xref: /openbmc/linux/drivers/md/raid10.h (revision 9c1f8594)
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 	int		recovery_disabled;	/* matches
10 						 * mddev->recovery_disabled
11 						 * when we shouldn't try
12 						 * recovering this device.
13 						 */
14 };
15 
16 typedef struct r10bio_s r10bio_t;
17 
18 struct r10_private_data_s {
19 	mddev_t			*mddev;
20 	mirror_info_t		*mirrors;
21 	int			raid_disks;
22 	spinlock_t		device_lock;
23 
24 	/* geometry */
25 	int			near_copies;  /* number of copies laid out raid0 style */
26 	int 			far_copies;   /* number of copies laid out
27 					       * at large strides across drives
28 					       */
29 	int			far_offset;   /* far_copies are offset by 1 stripe
30 					       * instead of many
31 					       */
32 	int			copies;	      /* near_copies * far_copies.
33 					       * must be <= raid_disks
34 					       */
35 	sector_t		stride;	      /* distance between far copies.
36 					       * This is size / far_copies unless
37 					       * far_offset, in which case it is
38 					       * 1 stripe.
39 					       */
40 
41 	sector_t		dev_sectors;  /* temp copy of mddev->dev_sectors */
42 
43 	int chunk_shift; /* shift from chunks to sectors */
44 	sector_t chunk_mask;
45 
46 	struct list_head	retry_list;
47 	/* queue pending writes and submit them on unplug */
48 	struct bio_list		pending_bio_list;
49 
50 
51 	spinlock_t		resync_lock;
52 	int nr_pending;
53 	int nr_waiting;
54 	int nr_queued;
55 	int barrier;
56 	sector_t		next_resync;
57 	int			fullsync;  /* set to 1 if a full sync is needed,
58 					    * (fresh device added).
59 					    * Cleared when a sync completes.
60 					    */
61 
62 	wait_queue_head_t	wait_barrier;
63 
64 	mempool_t *r10bio_pool;
65 	mempool_t *r10buf_pool;
66 	struct page		*tmppage;
67 
68 	/* When taking over an array from a different personality, we store
69 	 * the new thread here until we fully activate the array.
70 	 */
71 	struct mdk_thread_s	*thread;
72 };
73 
74 typedef struct r10_private_data_s conf_t;
75 
76 /*
77  * this is our 'private' RAID10 bio.
78  *
79  * it contains information about what kind of IO operations were started
80  * for this RAID10 operation, and about their status:
81  */
82 
83 struct r10bio_s {
84 	atomic_t		remaining; /* 'have we finished' count,
85 					    * used from IRQ handlers
86 					    */
87 	sector_t		sector;	/* virtual sector number */
88 	int			sectors;
89 	unsigned long		state;
90 	mddev_t			*mddev;
91 	/*
92 	 * original bio going to /dev/mdx
93 	 */
94 	struct bio		*master_bio;
95 	/*
96 	 * if the IO is in READ direction, then this is where we read
97 	 */
98 	int			read_slot;
99 
100 	struct list_head	retry_list;
101 	/*
102 	 * if the IO is in WRITE direction, then multiple bios are used,
103 	 * one for each copy.
104 	 * When resyncing we also use one for each copy.
105 	 * When reconstructing, we use 2 bios, one for read, one for write.
106 	 * We choose the number when they are allocated.
107 	 */
108 	struct {
109 		struct bio		*bio;
110 		sector_t addr;
111 		int devnum;
112 	} devs[0];
113 };
114 
115 /* when we get a read error on a read-only array, we redirect to another
116  * device without failing the first device, or trying to over-write to
117  * correct the read error.  To keep track of bad blocks on a per-bio
118  * level, we store IO_BLOCKED in the appropriate 'bios' pointer
119  */
120 #define IO_BLOCKED ((struct bio*)1)
121 /* When we successfully write to a known bad-block, we need to remove the
122  * bad-block marking which must be done from process context.  So we record
123  * the success by setting devs[n].bio to IO_MADE_GOOD
124  */
125 #define IO_MADE_GOOD ((struct bio *)2)
126 
127 #define BIO_SPECIAL(bio) ((unsigned long)bio <= 2)
128 
129 /* bits for r10bio.state */
130 #define	R10BIO_Uptodate	0
131 #define	R10BIO_IsSync	1
132 #define	R10BIO_IsRecover 2
133 #define	R10BIO_Degraded 3
134 /* Set ReadError on bios that experience a read error
135  * so that raid10d knows what to do with them.
136  */
137 #define	R10BIO_ReadError 4
138 /* If a write for this request means we can clear some
139  * known-bad-block records, we set this flag.
140  */
141 #define	R10BIO_MadeGood 5
142 #define	R10BIO_WriteError 6
143 #endif
144