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 | |
18 | struct 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 | |
28 | struct 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 | |
119 | struct 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 */ |
159 | enum 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 |
184 | |