xref: /linux/drivers/md/raid10.h (revision 74ce1896c6c65b2f8cccbf59162d542988835835)
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 	struct bio_set		*bio_split;
86 
87 	/* When taking over an array from a different personality, we store
88 	 * the new thread here until we fully activate the array.
89 	 */
90 	struct md_thread	*thread;
91 };
92 
93 /*
94  * this is our 'private' RAID10 bio.
95  *
96  * it contains information about what kind of IO operations were started
97  * for this RAID10 operation, and about their status:
98  */
99 
100 struct r10bio {
101 	atomic_t		remaining; /* 'have we finished' count,
102 					    * used from IRQ handlers
103 					    */
104 	sector_t		sector;	/* virtual sector number */
105 	int			sectors;
106 	unsigned long		state;
107 	struct mddev		*mddev;
108 	/*
109 	 * original bio going to /dev/mdx
110 	 */
111 	struct bio		*master_bio;
112 	/*
113 	 * if the IO is in READ direction, then this is where we read
114 	 */
115 	int			read_slot;
116 
117 	struct list_head	retry_list;
118 	/*
119 	 * if the IO is in WRITE direction, then multiple bios are used,
120 	 * one for each copy.
121 	 * When resyncing we also use one for each copy.
122 	 * When reconstructing, we use 2 bios, one for read, one for write.
123 	 * We choose the number when they are allocated.
124 	 * We sometimes need an extra bio to write to the replacement.
125 	 */
126 	struct r10dev {
127 		struct bio	*bio;
128 		union {
129 			struct bio	*repl_bio; /* used for resync and
130 						    * writes */
131 			struct md_rdev	*rdev;	   /* used for reads
132 						    * (read_slot >= 0) */
133 		};
134 		sector_t	addr;
135 		int		devnum;
136 	} devs[0];
137 };
138 
139 /* bits for r10bio.state */
140 enum r10bio_state {
141 	R10BIO_Uptodate,
142 	R10BIO_IsSync,
143 	R10BIO_IsRecover,
144 	R10BIO_IsReshape,
145 	R10BIO_Degraded,
146 /* Set ReadError on bios that experience a read error
147  * so that raid10d knows what to do with them.
148  */
149 	R10BIO_ReadError,
150 /* If a write for this request means we can clear some
151  * known-bad-block records, we set this flag.
152  */
153 	R10BIO_MadeGood,
154 	R10BIO_WriteError,
155 /* During a reshape we might be performing IO on the
156  * 'previous' part of the array, in which case this
157  * flag is set
158  */
159 	R10BIO_Previous,
160 /* failfast devices did receive failfast requests. */
161 	R10BIO_FailFast,
162 };
163 #endif
164