xref: /linux/drivers/md/raid10.h (revision 95f28190aa012b18eab14799b905b6db3cf31529)
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 	 * Keep track of cluster resync window to send to other nodes.
95 	 */
96 	sector_t		cluster_sync_low;
97 	sector_t		cluster_sync_high;
98 };
99 
100 /*
101  * this is our 'private' RAID10 bio.
102  *
103  * it contains information about what kind of IO operations were started
104  * for this RAID10 operation, and about their status:
105  */
106 
107 struct r10bio {
108 	atomic_t		remaining; /* 'have we finished' count,
109 					    * used from IRQ handlers
110 					    */
111 	sector_t		sector;	/* virtual sector number */
112 	int			sectors;
113 	unsigned long		state;
114 	struct mddev		*mddev;
115 	/*
116 	 * original bio going to /dev/mdx
117 	 */
118 	struct bio		*master_bio;
119 	/*
120 	 * if the IO is in READ direction, then this is where we read
121 	 */
122 	int			read_slot;
123 
124 	struct list_head	retry_list;
125 	/*
126 	 * if the IO is in WRITE direction, then multiple bios are used,
127 	 * one for each copy.
128 	 * When resyncing we also use one for each copy.
129 	 * When reconstructing, we use 2 bios, one for read, one for write.
130 	 * We choose the number when they are allocated.
131 	 * We sometimes need an extra bio to write to the replacement.
132 	 */
133 	struct r10dev {
134 		struct bio	*bio;
135 		union {
136 			struct bio	*repl_bio; /* used for resync and
137 						    * writes */
138 			struct md_rdev	*rdev;	   /* used for reads
139 						    * (read_slot >= 0) */
140 		};
141 		sector_t	addr;
142 		int		devnum;
143 	} devs[0];
144 };
145 
146 /* bits for r10bio.state */
147 enum r10bio_state {
148 	R10BIO_Uptodate,
149 	R10BIO_IsSync,
150 	R10BIO_IsRecover,
151 	R10BIO_IsReshape,
152 	R10BIO_Degraded,
153 /* Set ReadError on bios that experience a read error
154  * so that raid10d knows what to do with them.
155  */
156 	R10BIO_ReadError,
157 /* If a write for this request means we can clear some
158  * known-bad-block records, we set this flag.
159  */
160 	R10BIO_MadeGood,
161 	R10BIO_WriteError,
162 /* During a reshape we might be performing IO on the
163  * 'previous' part of the array, in which case this
164  * flag is set
165  */
166 	R10BIO_Previous,
167 /* failfast devices did receive failfast requests. */
168 	R10BIO_FailFast,
169 };
170 #endif
171