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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
1da177e4 LT |
2 | #ifndef _RAID1_H |
3 | #define _RAID1_H | |
4 | ||
fd76863e | 5 | /* |
6 | * each barrier unit size is 64MB fow now | |
7 | * note: it must be larger than RESYNC_DEPTH | |
8 | */ | |
9 | #define BARRIER_UNIT_SECTOR_BITS 17 | |
10 | #define BARRIER_UNIT_SECTOR_SIZE (1<<17) | |
11 | /* | |
12 | * In struct r1conf, the following members are related to I/O barrier | |
13 | * buckets, | |
824e47da | 14 | * atomic_t *nr_pending; |
15 | * atomic_t *nr_waiting; | |
16 | * atomic_t *nr_queued; | |
17 | * atomic_t *barrier; | |
18 | * Each of them points to array of atomic_t variables, each array is | |
19 | * designed to have BARRIER_BUCKETS_NR elements and occupy a single | |
20 | * memory page. The data width of atomic_t variables is 4 bytes, equal | |
21 | * to 1<<(ilog2(sizeof(atomic_t))), BARRIER_BUCKETS_NR_BITS is defined | |
22 | * as (PAGE_SHIFT - ilog2(sizeof(int))) to make sure an array of | |
23 | * atomic_t variables with BARRIER_BUCKETS_NR elements just exactly | |
24 | * occupies a single memory page. | |
fd76863e | 25 | */ |
824e47da | 26 | #define BARRIER_BUCKETS_NR_BITS (PAGE_SHIFT - ilog2(sizeof(atomic_t))) |
fd76863e | 27 | #define BARRIER_BUCKETS_NR (1<<BARRIER_BUCKETS_NR_BITS) |
28 | ||
0eaf822c | 29 | struct raid1_info { |
3cb03002 | 30 | struct md_rdev *rdev; |
1da177e4 | 31 | sector_t head_position; |
be4d3280 SL |
32 | |
33 | /* When choose the best device for a read (read_balance()) | |
34 | * we try to keep sequential reads one the same device | |
35 | */ | |
36 | sector_t next_seq_sect; | |
12cee5a8 | 37 | sector_t seq_start; |
1da177e4 LT |
38 | }; |
39 | ||
40 | /* | |
41 | * memory pools need a pointer to the mddev, so they can force an unplug | |
42 | * when memory is tight, and a count of the number of drives that the | |
43 | * pool was allocated for, so they know how much to allocate and free. | |
44 | * mddev->raid_disks cannot be used, as it can change while a pool is active | |
45 | * These two datums are stored in a kmalloced struct. | |
8f19ccb2 N |
46 | * The 'raid_disks' here is twice the raid_disks in r1conf. |
47 | * This allows space for each 'real' device can have a replacement in the | |
48 | * second half of the array. | |
1da177e4 LT |
49 | */ |
50 | ||
51 | struct pool_info { | |
fd01b88c | 52 | struct mddev *mddev; |
1da177e4 LT |
53 | int raid_disks; |
54 | }; | |
55 | ||
e8096360 | 56 | struct r1conf { |
fd01b88c | 57 | struct mddev *mddev; |
0eaf822c | 58 | struct raid1_info *mirrors; /* twice 'raid_disks' to |
8f19ccb2 N |
59 | * allow for replacements. |
60 | */ | |
1da177e4 | 61 | int raid_disks; |
ce550c20 | 62 | |
1da177e4 LT |
63 | spinlock_t device_lock; |
64 | ||
9f2c9d12 N |
65 | /* list of 'struct r1bio' that need to be processed by raid1d, |
66 | * whether to retry a read, writeout a resync or recovery | |
67 | * block, or anything else. | |
ce550c20 | 68 | */ |
1da177e4 | 69 | struct list_head retry_list; |
55ce74d4 N |
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; | |
191ea9b2 | 75 | |
ce550c20 N |
76 | /* queue pending writes to be submitted on unplug */ |
77 | struct bio_list pending_bio_list; | |
34db0cd6 | 78 | int pending_count; |
1da177e4 | 79 | |
ce550c20 N |
80 | /* for use when syncing mirrors: |
81 | * We don't allow both normal IO and resync/recovery IO at | |
82 | * the same time - resync/recovery can only happen when there | |
83 | * is no other IO. So when either is active, the other has to wait. | |
84 | * See more details description in raid1.c near raise_barrier(). | |
85 | */ | |
86 | wait_queue_head_t wait_barrier; | |
1da177e4 | 87 | spinlock_t resync_lock; |
43ac9b84 | 88 | atomic_t nr_sync_pending; |
824e47da | 89 | atomic_t *nr_pending; |
90 | atomic_t *nr_waiting; | |
91 | atomic_t *nr_queued; | |
92 | atomic_t *barrier; | |
b364e3d0 | 93 | int array_frozen; |
1da177e4 | 94 | |
ce550c20 N |
95 | /* Set to 1 if a full sync is needed, (fresh device added). |
96 | * Cleared when a sync completes. | |
97 | */ | |
98 | int fullsync; | |
1da177e4 | 99 | |
ce550c20 N |
100 | /* When the same as mddev->recovery_disabled we don't allow |
101 | * recovery to be attempted as we expect a read error. | |
102 | */ | |
103 | int recovery_disabled; | |
1da177e4 | 104 | |
ce550c20 N |
105 | /* poolinfo contains information about the content of the |
106 | * mempools - it changes when the array grows or shrinks | |
107 | */ | |
108 | struct pool_info *poolinfo; | |
9f2c9d12 N |
109 | mempool_t *r1bio_pool; |
110 | mempool_t *r1buf_pool; | |
709ae487 | 111 | |
c230e7e5 N |
112 | struct bio_set *bio_split; |
113 | ||
ce550c20 N |
114 | /* temporary buffer to synchronous IO when attempting to repair |
115 | * a read error. | |
116 | */ | |
117 | struct page *tmppage; | |
118 | ||
709ae487 N |
119 | /* When taking over an array from a different personality, we store |
120 | * the new thread here until we fully activate the array. | |
121 | */ | |
2b8bf345 | 122 | struct md_thread *thread; |
c40f341f GR |
123 | |
124 | /* Keep track of cluster resync window to send to other | |
125 | * nodes. | |
126 | */ | |
127 | sector_t cluster_sync_low; | |
128 | sector_t cluster_sync_high; | |
129 | ||
1da177e4 LT |
130 | }; |
131 | ||
1da177e4 LT |
132 | /* |
133 | * this is our 'private' RAID1 bio. | |
134 | * | |
135 | * it contains information about what kind of IO operations were started | |
136 | * for this RAID1 operation, and about their status: | |
137 | */ | |
138 | ||
9f2c9d12 | 139 | struct r1bio { |
1da177e4 LT |
140 | atomic_t remaining; /* 'have we finished' count, |
141 | * used from IRQ handlers | |
142 | */ | |
4b6d287f N |
143 | atomic_t behind_remaining; /* number of write-behind ios remaining |
144 | * in this BehindIO request | |
145 | */ | |
1da177e4 LT |
146 | sector_t sector; |
147 | int sectors; | |
148 | unsigned long state; | |
fd01b88c | 149 | struct mddev *mddev; |
1da177e4 LT |
150 | /* |
151 | * original bio going to /dev/mdx | |
152 | */ | |
153 | struct bio *master_bio; | |
154 | /* | |
155 | * if the IO is in READ direction, then this is where we read | |
156 | */ | |
157 | int read_disk; | |
158 | ||
159 | struct list_head retry_list; | |
841c1316 ML |
160 | |
161 | /* | |
162 | * When R1BIO_BehindIO is set, we store pages for write behind | |
163 | * in behind_master_bio. | |
164 | */ | |
165 | struct bio *behind_master_bio; | |
166 | ||
1da177e4 LT |
167 | /* |
168 | * if the IO is in WRITE direction, then multiple bios are used. | |
169 | * We choose the number when they are allocated. | |
170 | */ | |
171 | struct bio *bios[0]; | |
191ea9b2 | 172 | /* DO NOT PUT ANY NEW FIELDS HERE - bios array is contiguously alloced*/ |
1da177e4 LT |
173 | }; |
174 | ||
175 | /* bits for r1bio.state */ | |
be306c29 N |
176 | enum r1bio_state { |
177 | R1BIO_Uptodate, | |
178 | R1BIO_IsSync, | |
179 | R1BIO_Degraded, | |
180 | R1BIO_BehindIO, | |
d2eb35ac N |
181 | /* Set ReadError on bios that experience a readerror so that |
182 | * raid1d knows what to do with them. | |
183 | */ | |
be306c29 | 184 | R1BIO_ReadError, |
4b6d287f N |
185 | /* For write-behind requests, we call bi_end_io when |
186 | * the last non-write-behind device completes, providing | |
187 | * any write was successful. Otherwise we call when | |
188 | * any write-behind write succeeds, otherwise we call | |
189 | * with failure when last write completes (and all failed). | |
190 | * Record that bi_end_io was called with this flag... | |
191 | */ | |
be306c29 | 192 | R1BIO_Returned, |
4367af55 N |
193 | /* If a write for this request means we can clear some |
194 | * known-bad-block records, we set this flag | |
195 | */ | |
be306c29 N |
196 | R1BIO_MadeGood, |
197 | R1BIO_WriteError, | |
2e52d449 | 198 | R1BIO_FailFast, |
be306c29 | 199 | }; |
fd76863e | 200 | |
201 | static inline int sector_to_idx(sector_t sector) | |
202 | { | |
203 | return hash_long(sector >> BARRIER_UNIT_SECTOR_BITS, | |
204 | BARRIER_BUCKETS_NR_BITS); | |
205 | } | |
1da177e4 | 206 | #endif |