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1 #ifndef _RAID10_H
2 #define _RAID10_H
3 
4 struct raid10_info {
5 	struct md_rdev	*rdev, *replacement;
6 	sector_t	head_position;
7 	int		recovery_disabled;	/* matches
8 						 * mddev->recovery_disabled
9 						 * when we shouldn't try
10 						 * recovering this device.
11 						 */
12 };
13 
14 struct r10conf {
15 	struct mddev		*mddev;
16 	struct raid10_info	*mirrors;
17 	struct raid10_info	*mirrors_new, *mirrors_old;
18 	spinlock_t		device_lock;
19 
20 	/* geometry */
21 	struct geom {
22 		int		raid_disks;
23 		int		near_copies;  /* number of copies laid out
24 					       * raid0 style */
25 		int		far_copies;   /* number of copies laid out
26 					       * at large strides across drives
27 					       */
28 		int		far_offset;   /* far_copies are offset by 1
29 					       * stripe instead of many
30 					       */
31 		sector_t	stride;	      /* distance between far copies.
32 					       * This is size / far_copies unless
33 					       * far_offset, in which case it is
34 					       * 1 stripe.
35 					       */
36 		int             far_set_size; /* The number of devices in a set,
37 					       * where a 'set' are devices that
38 					       * contain far/offset copies of
39 					       * each other.
40 					       */
41 		int		chunk_shift; /* shift from chunks to sectors */
42 		sector_t	chunk_mask;
43 	} prev, geo;
44 	int			copies;	      /* near_copies * far_copies.
45 					       * must be <= raid_disks
46 					       */
47 
48 	sector_t		dev_sectors;  /* temp copy of
49 					       * mddev->dev_sectors */
50 	sector_t		reshape_progress;
51 	sector_t		reshape_safe;
52 	unsigned long		reshape_checkpoint;
53 	sector_t		offset_diff;
54 
55 	struct list_head	retry_list;
56 	/* A separate list of r1bio which just need raid_end_bio_io called.
57 	 * This mustn't happen for writes which had any errors if the superblock
58 	 * needs to be written.
59 	 */
60 	struct list_head	bio_end_io_list;
61 
62 	/* queue pending writes and submit them on unplug */
63 	struct bio_list		pending_bio_list;
64 	int			pending_count;
65 
66 	spinlock_t		resync_lock;
67 	atomic_t		nr_pending;
68 	int			nr_waiting;
69 	int			nr_queued;
70 	int			barrier;
71 	int			array_freeze_pending;
72 	sector_t		next_resync;
73 	int			fullsync;  /* set to 1 if a full sync is needed,
74 					    * (fresh device added).
75 					    * Cleared when a sync completes.
76 					    */
77 	int			have_replacement; /* There is at least one
78 						   * replacement device.
79 						   */
80 	wait_queue_head_t	wait_barrier;
81 
82 	mempool_t		*r10bio_pool;
83 	mempool_t		*r10buf_pool;
84 	struct page		*tmppage;
85 
86 	/* When taking over an array from a different personality, we store
87 	 * the new thread here until we fully activate the array.
88 	 */
89 	struct md_thread	*thread;
90 };
91 
92 /*
93  * this is our 'private' RAID10 bio.
94  *
95  * it contains information about what kind of IO operations were started
96  * for this RAID10 operation, and about their status:
97  */
98 
99 struct r10bio {
100 	atomic_t		remaining; /* 'have we finished' count,
101 					    * used from IRQ handlers
102 					    */
103 	sector_t		sector;	/* virtual sector number */
104 	int			sectors;
105 	unsigned long		state;
106 	struct mddev		*mddev;
107 	/*
108 	 * original bio going to /dev/mdx
109 	 */
110 	struct bio		*master_bio;
111 	/*
112 	 * if the IO is in READ direction, then this is where we read
113 	 */
114 	int			read_slot;
115 
116 	struct list_head	retry_list;
117 	/*
118 	 * if the IO is in WRITE direction, then multiple bios are used,
119 	 * one for each copy.
120 	 * When resyncing we also use one for each copy.
121 	 * When reconstructing, we use 2 bios, one for read, one for write.
122 	 * We choose the number when they are allocated.
123 	 * We sometimes need an extra bio to write to the replacement.
124 	 */
125 	struct r10dev {
126 		struct bio	*bio;
127 		union {
128 			struct bio	*repl_bio; /* used for resync and
129 						    * writes */
130 			struct md_rdev	*rdev;	   /* used for reads
131 						    * (read_slot >= 0) */
132 		};
133 		sector_t	addr;
134 		int		devnum;
135 	} devs[0];
136 };
137 
138 /* bits for r10bio.state */
139 enum r10bio_state {
140 	R10BIO_Uptodate,
141 	R10BIO_IsSync,
142 	R10BIO_IsRecover,
143 	R10BIO_IsReshape,
144 	R10BIO_Degraded,
145 /* Set ReadError on bios that experience a read error
146  * so that raid10d knows what to do with them.
147  */
148 	R10BIO_ReadError,
149 /* If a write for this request means we can clear some
150  * known-bad-block records, we set this flag.
151  */
152 	R10BIO_MadeGood,
153 	R10BIO_WriteError,
154 /* During a reshape we might be performing IO on the
155  * 'previous' part of the array, in which case this
156  * flag is set
157  */
158 	R10BIO_Previous,
159 };
160 #endif
161