xref: /openbmc/linux/drivers/md/raid10.h (revision d3964221)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _RAID10_H
3 #define _RAID10_H
4 
5 struct raid10_info {
6 	struct md_rdev	*rdev, *replacement;
7 	sector_t	head_position;
8 	int		recovery_disabled;	/* matches
9 						 * mddev->recovery_disabled
10 						 * when we shouldn't try
11 						 * recovering this device.
12 						 */
13 };
14 
15 struct r10conf {
16 	struct mddev		*mddev;
17 	struct raid10_info	*mirrors;
18 	struct raid10_info	*mirrors_new, *mirrors_old;
19 	spinlock_t		device_lock;
20 
21 	/* geometry */
22 	struct geom {
23 		int		raid_disks;
24 		int		near_copies;  /* number of copies laid out
25 					       * 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
30 					       * stripe instead of many
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 		int             far_set_size; /* The number of devices in a set,
38 					       * where a 'set' are devices that
39 					       * contain far/offset copies of
40 					       * each other.
41 					       */
42 		int		chunk_shift; /* shift from chunks to sectors */
43 		sector_t	chunk_mask;
44 	} prev, geo;
45 	int			copies;	      /* near_copies * far_copies.
46 					       * must be <= raid_disks
47 					       */
48 
49 	sector_t		dev_sectors;  /* temp copy of
50 					       * mddev->dev_sectors */
51 	sector_t		reshape_progress;
52 	sector_t		reshape_safe;
53 	unsigned long		reshape_checkpoint;
54 	sector_t		offset_diff;
55 
56 	struct list_head	retry_list;
57 	/* A separate list of r1bio which just need raid_end_bio_io called.
58 	 * This mustn't happen for writes which had any errors if the superblock
59 	 * needs to be written.
60 	 */
61 	struct list_head	bio_end_io_list;
62 
63 	/* queue pending writes and submit them on unplug */
64 	struct bio_list		pending_bio_list;
65 	int			pending_count;
66 
67 	spinlock_t		resync_lock;
68 	atomic_t		nr_pending;
69 	int			nr_waiting;
70 	int			nr_queued;
71 	int			barrier;
72 	int			array_freeze_pending;
73 	sector_t		next_resync;
74 	int			fullsync;  /* set to 1 if a full sync is needed,
75 					    * (fresh device added).
76 					    * Cleared when a sync completes.
77 					    */
78 	int			have_replacement; /* There is at least one
79 						   * replacement device.
80 						   */
81 	wait_queue_head_t	wait_barrier;
82 
83 	mempool_t		*r10bio_pool;
84 	mempool_t		*r10buf_pool;
85 	struct page		*tmppage;
86 	struct bio_set		*bio_split;
87 
88 	/* When taking over an array from a different personality, we store
89 	 * the new thread here until we fully activate the array.
90 	 */
91 	struct md_thread	*thread;
92 };
93 
94 /*
95  * this is our 'private' RAID10 bio.
96  *
97  * it contains information about what kind of IO operations were started
98  * for this RAID10 operation, and about their status:
99  */
100 
101 struct r10bio {
102 	atomic_t		remaining; /* 'have we finished' count,
103 					    * used from IRQ handlers
104 					    */
105 	sector_t		sector;	/* virtual sector number */
106 	int			sectors;
107 	unsigned long		state;
108 	struct mddev		*mddev;
109 	/*
110 	 * original bio going to /dev/mdx
111 	 */
112 	struct bio		*master_bio;
113 	/*
114 	 * if the IO is in READ direction, then this is where we read
115 	 */
116 	int			read_slot;
117 
118 	struct list_head	retry_list;
119 	/*
120 	 * if the IO is in WRITE direction, then multiple bios are used,
121 	 * one for each copy.
122 	 * When resyncing we also use one for each copy.
123 	 * When reconstructing, we use 2 bios, one for read, one for write.
124 	 * We choose the number when they are allocated.
125 	 * We sometimes need an extra bio to write to the replacement.
126 	 */
127 	struct r10dev {
128 		struct bio	*bio;
129 		union {
130 			struct bio	*repl_bio; /* used for resync and
131 						    * writes */
132 			struct md_rdev	*rdev;	   /* used for reads
133 						    * (read_slot >= 0) */
134 		};
135 		sector_t	addr;
136 		int		devnum;
137 	} devs[0];
138 };
139 
140 /* bits for r10bio.state */
141 enum r10bio_state {
142 	R10BIO_Uptodate,
143 	R10BIO_IsSync,
144 	R10BIO_IsRecover,
145 	R10BIO_IsReshape,
146 	R10BIO_Degraded,
147 /* Set ReadError on bios that experience a read error
148  * so that raid10d knows what to do with them.
149  */
150 	R10BIO_ReadError,
151 /* If a write for this request means we can clear some
152  * known-bad-block records, we set this flag.
153  */
154 	R10BIO_MadeGood,
155 	R10BIO_WriteError,
156 /* During a reshape we might be performing IO on the
157  * 'previous' part of the array, in which case this
158  * flag is set
159  */
160 	R10BIO_Previous,
161 /* failfast devices did receive failfast requests. */
162 	R10BIO_FailFast,
163 };
164 #endif
165