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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _RAID10_H
3#define _RAID10_H
4
5/* Note: raid10_info.rdev can be set to NULL asynchronously by
6 * raid10_remove_disk.
7 * There are three safe ways to access raid10_info.rdev.
8 * 1/ when holding mddev->reconfig_mutex
9 * 2/ when resync/recovery/reshape is known to be happening - i.e. in code
10 * that is called as part of performing resync/recovery/reshape.
11 * 3/ while holding rcu_read_lock(), use rcu_dereference to get the pointer
12 * and if it is non-NULL, increment rdev->nr_pending before dropping the
13 * RCU lock.
14 * When .rdev is set to NULL, the nr_pending count checked again and if it has
15 * been incremented, the pointer is put back in .rdev.
16 */
17
18struct raid10_info {
19 struct md_rdev *rdev, *replacement;
20 sector_t head_position;
21 int recovery_disabled; /* matches
22 * mddev->recovery_disabled
23 * when we shouldn't try
24 * recovering this device.
25 */
26};
27
28struct r10conf {
29 struct mddev *mddev;
30 struct raid10_info *mirrors;
31 struct raid10_info *mirrors_new, *mirrors_old;
32 spinlock_t device_lock;
33
34 /* geometry */
35 struct geom {
36 int raid_disks;
37 int near_copies; /* number of copies laid out
38 * raid0 style */
39 int far_copies; /* number of copies laid out
40 * at large strides across drives
41 */
42 int far_offset; /* far_copies are offset by 1
43 * stripe instead of many
44 */
45 sector_t stride; /* distance between far copies.
46 * This is size / far_copies unless
47 * far_offset, in which case it is
48 * 1 stripe.
49 */
50 int far_set_size; /* The number of devices in a set,
51 * where a 'set' are devices that
52 * contain far/offset copies of
53 * each other.
54 */
55 int chunk_shift; /* shift from chunks to sectors */
56 sector_t chunk_mask;
57 } prev, geo;
58 int copies; /* near_copies * far_copies.
59 * must be <= raid_disks
60 */
61
62 sector_t dev_sectors; /* temp copy of
63 * mddev->dev_sectors */
64 sector_t reshape_progress;
65 sector_t reshape_safe;
66 unsigned long reshape_checkpoint;
67 sector_t offset_diff;
68
69 struct list_head retry_list;
70 /* A separate list of r1bio which just need raid_end_bio_io called.
71 * This mustn't happen for writes which had any errors if the superblock
72 * needs to be written.
73 */
74 struct list_head bio_end_io_list;
75
76 /* queue pending writes and submit them on unplug */
77 struct bio_list pending_bio_list;
78
79 seqlock_t resync_lock;
80 atomic_t nr_pending;
81 int nr_waiting;
82 int nr_queued;
83 int barrier;
84 int array_freeze_pending;
85 sector_t next_resync;
86 int fullsync; /* set to 1 if a full sync is needed,
87 * (fresh device added).
88 * Cleared when a sync completes.
89 */
90 int have_replacement; /* There is at least one
91 * replacement device.
92 */
93 wait_queue_head_t wait_barrier;
94
95 mempool_t r10bio_pool;
96 mempool_t r10buf_pool;
97 struct page *tmppage;
98 struct bio_set bio_split;
99
100 /* When taking over an array from a different personality, we store
101 * the new thread here until we fully activate the array.
102 */
103 struct md_thread __rcu *thread;
104
105 /*
106 * Keep track of cluster resync window to send to other nodes.
107 */
108 sector_t cluster_sync_low;
109 sector_t cluster_sync_high;
110};
111
112/*
113 * this is our 'private' RAID10 bio.
114 *
115 * it contains information about what kind of IO operations were started
116 * for this RAID10 operation, and about their status:
117 */
118
119struct r10bio {
120 atomic_t remaining; /* 'have we finished' count,
121 * used from IRQ handlers
122 */
123 sector_t sector; /* virtual sector number */
124 int sectors;
125 unsigned long state;
126 struct mddev *mddev;
127 /*
128 * original bio going to /dev/mdx
129 */
130 struct bio *master_bio;
131 /*
132 * if the IO is in READ direction, then this is where we read
133 */
134 int read_slot;
135
136 struct list_head retry_list;
137 /*
138 * if the IO is in WRITE direction, then multiple bios are used,
139 * one for each copy.
140 * When resyncing we also use one for each copy.
141 * When reconstructing, we use 2 bios, one for read, one for write.
142 * We choose the number when they are allocated.
143 * We sometimes need an extra bio to write to the replacement.
144 */
145 struct r10dev {
146 struct bio *bio;
147 union {
148 struct bio *repl_bio; /* used for resync and
149 * writes */
150 struct md_rdev *rdev; /* used for reads
151 * (read_slot >= 0) */
152 };
153 sector_t addr;
154 int devnum;
155 } devs[];
156};
157
158/* bits for r10bio.state */
159enum r10bio_state {
160 R10BIO_Uptodate,
161 R10BIO_IsSync,
162 R10BIO_IsRecover,
163 R10BIO_IsReshape,
164 R10BIO_Degraded,
165/* Set ReadError on bios that experience a read error
166 * so that raid10d knows what to do with them.
167 */
168 R10BIO_ReadError,
169/* If a write for this request means we can clear some
170 * known-bad-block records, we set this flag.
171 */
172 R10BIO_MadeGood,
173 R10BIO_WriteError,
174/* During a reshape we might be performing IO on the
175 * 'previous' part of the array, in which case this
176 * flag is set
177 */
178 R10BIO_Previous,
179/* failfast devices did receive failfast requests. */
180 R10BIO_FailFast,
181 R10BIO_Discard,
182};
183#endif
1#ifndef _RAID10_H
2#define _RAID10_H
3
4typedef struct mirror_info mirror_info_t;
5
6struct 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
16typedef struct r10bio_s r10bio_t;
17
18struct 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
74typedef 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
83struct 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