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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 *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 unsigned long start_time;
127 struct mddev *mddev;
128 /*
129 * original bio going to /dev/mdx
130 */
131 struct bio *master_bio;
132 /*
133 * if the IO is in READ direction, then this is where we read
134 */
135 int read_slot;
136
137 struct list_head retry_list;
138 /*
139 * if the IO is in WRITE direction, then multiple bios are used,
140 * one for each copy.
141 * When resyncing we also use one for each copy.
142 * When reconstructing, we use 2 bios, one for read, one for write.
143 * We choose the number when they are allocated.
144 * We sometimes need an extra bio to write to the replacement.
145 */
146 struct r10dev {
147 struct bio *bio;
148 union {
149 struct bio *repl_bio; /* used for resync and
150 * writes */
151 struct md_rdev *rdev; /* used for reads
152 * (read_slot >= 0) */
153 };
154 sector_t addr;
155 int devnum;
156 } devs[];
157};
158
159/* bits for r10bio.state */
160enum r10bio_state {
161 R10BIO_Uptodate,
162 R10BIO_IsSync,
163 R10BIO_IsRecover,
164 R10BIO_IsReshape,
165 R10BIO_Degraded,
166/* Set ReadError on bios that experience a read error
167 * so that raid10d knows what to do with them.
168 */
169 R10BIO_ReadError,
170/* If a write for this request means we can clear some
171 * known-bad-block records, we set this flag.
172 */
173 R10BIO_MadeGood,
174 R10BIO_WriteError,
175/* During a reshape we might be performing IO on the
176 * 'previous' part of the array, in which case this
177 * flag is set
178 */
179 R10BIO_Previous,
180/* failfast devices did receive failfast requests. */
181 R10BIO_FailFast,
182 R10BIO_Discard,
183};
184#endif
1#ifndef _RAID10_H
2#define _RAID10_H
3
4struct mirror_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
14struct r10conf {
15 struct mddev *mddev;
16 struct mirror_info *mirrors;
17 struct mirror_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 chunk_shift; /* shift from chunks to sectors */
37 sector_t chunk_mask;
38 } prev, geo;
39 int copies; /* near_copies * far_copies.
40 * must be <= raid_disks
41 */
42
43 sector_t dev_sectors; /* temp copy of
44 * mddev->dev_sectors */
45 sector_t reshape_progress;
46 sector_t reshape_safe;
47 unsigned long reshape_checkpoint;
48 sector_t offset_diff;
49
50 struct list_head retry_list;
51 /* queue pending writes and submit them on unplug */
52 struct bio_list pending_bio_list;
53 int pending_count;
54
55 spinlock_t resync_lock;
56 int nr_pending;
57 int nr_waiting;
58 int nr_queued;
59 int barrier;
60 sector_t next_resync;
61 int fullsync; /* set to 1 if a full sync is needed,
62 * (fresh device added).
63 * Cleared when a sync completes.
64 */
65 int have_replacement; /* There is at least one
66 * replacement device.
67 */
68 wait_queue_head_t wait_barrier;
69
70 mempool_t *r10bio_pool;
71 mempool_t *r10buf_pool;
72 struct page *tmppage;
73
74 /* When taking over an array from a different personality, we store
75 * the new thread here until we fully activate the array.
76 */
77 struct md_thread *thread;
78};
79
80/*
81 * this is our 'private' RAID10 bio.
82 *
83 * it contains information about what kind of IO operations were started
84 * for this RAID10 operation, and about their status:
85 */
86
87struct r10bio {
88 atomic_t remaining; /* 'have we finished' count,
89 * used from IRQ handlers
90 */
91 sector_t sector; /* virtual sector number */
92 int sectors;
93 unsigned long state;
94 struct mddev *mddev;
95 /*
96 * original bio going to /dev/mdx
97 */
98 struct bio *master_bio;
99 /*
100 * if the IO is in READ direction, then this is where we read
101 */
102 int read_slot;
103
104 struct list_head retry_list;
105 /*
106 * if the IO is in WRITE direction, then multiple bios are used,
107 * one for each copy.
108 * When resyncing we also use one for each copy.
109 * When reconstructing, we use 2 bios, one for read, one for write.
110 * We choose the number when they are allocated.
111 * We sometimes need an extra bio to write to the replacement.
112 */
113 struct r10dev {
114 struct bio *bio;
115 union {
116 struct bio *repl_bio; /* used for resync and
117 * writes */
118 struct md_rdev *rdev; /* used for reads
119 * (read_slot >= 0) */
120 };
121 sector_t addr;
122 int devnum;
123 } devs[0];
124};
125
126/* when we get a read error on a read-only array, we redirect to another
127 * device without failing the first device, or trying to over-write to
128 * correct the read error. To keep track of bad blocks on a per-bio
129 * level, we store IO_BLOCKED in the appropriate 'bios' pointer
130 */
131#define IO_BLOCKED ((struct bio*)1)
132/* When we successfully write to a known bad-block, we need to remove the
133 * bad-block marking which must be done from process context. So we record
134 * the success by setting devs[n].bio to IO_MADE_GOOD
135 */
136#define IO_MADE_GOOD ((struct bio *)2)
137
138#define BIO_SPECIAL(bio) ((unsigned long)bio <= 2)
139
140/* bits for r10bio.state */
141enum 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};
162#endif