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1da177e4 LT |
1 | #ifndef _RAID1_H |
2 | #define _RAID1_H | |
3 | ||
1da177e4 | 4 | struct mirror_info { |
3cb03002 | 5 | struct md_rdev *rdev; |
1da177e4 LT |
6 | sector_t head_position; |
7 | }; | |
8 | ||
9 | /* | |
10 | * memory pools need a pointer to the mddev, so they can force an unplug | |
11 | * when memory is tight, and a count of the number of drives that the | |
12 | * pool was allocated for, so they know how much to allocate and free. | |
13 | * mddev->raid_disks cannot be used, as it can change while a pool is active | |
14 | * These two datums are stored in a kmalloced struct. | |
15 | */ | |
16 | ||
17 | struct pool_info { | |
fd01b88c | 18 | struct mddev *mddev; |
1da177e4 LT |
19 | int raid_disks; |
20 | }; | |
21 | ||
e8096360 | 22 | struct r1conf { |
fd01b88c | 23 | struct mddev *mddev; |
0f6d02d5 | 24 | struct mirror_info *mirrors; |
1da177e4 | 25 | int raid_disks; |
ce550c20 N |
26 | |
27 | /* When choose the best device for a read (read_balance()) | |
28 | * we try to keep sequential reads one the same device | |
29 | * using 'last_used' and 'next_seq_sect' | |
30 | */ | |
1da177e4 LT |
31 | int last_used; |
32 | sector_t next_seq_sect; | |
ce550c20 N |
33 | /* During resync, read_balancing is only allowed on the part |
34 | * of the array that has been resynced. 'next_resync' tells us | |
35 | * where that is. | |
36 | */ | |
37 | sector_t next_resync; | |
38 | ||
1da177e4 LT |
39 | spinlock_t device_lock; |
40 | ||
9f2c9d12 N |
41 | /* list of 'struct r1bio' that need to be processed by raid1d, |
42 | * whether to retry a read, writeout a resync or recovery | |
43 | * block, or anything else. | |
ce550c20 | 44 | */ |
1da177e4 | 45 | struct list_head retry_list; |
191ea9b2 | 46 | |
ce550c20 N |
47 | /* queue pending writes to be submitted on unplug */ |
48 | struct bio_list pending_bio_list; | |
34db0cd6 | 49 | int pending_count; |
1da177e4 | 50 | |
ce550c20 N |
51 | /* for use when syncing mirrors: |
52 | * We don't allow both normal IO and resync/recovery IO at | |
53 | * the same time - resync/recovery can only happen when there | |
54 | * is no other IO. So when either is active, the other has to wait. | |
55 | * See more details description in raid1.c near raise_barrier(). | |
56 | */ | |
57 | wait_queue_head_t wait_barrier; | |
1da177e4 | 58 | spinlock_t resync_lock; |
191ea9b2 | 59 | int nr_pending; |
17999be4 | 60 | int nr_waiting; |
ddaf22ab | 61 | int nr_queued; |
191ea9b2 | 62 | int barrier; |
1da177e4 | 63 | |
ce550c20 N |
64 | /* Set to 1 if a full sync is needed, (fresh device added). |
65 | * Cleared when a sync completes. | |
66 | */ | |
67 | int fullsync; | |
1da177e4 | 68 | |
ce550c20 N |
69 | /* When the same as mddev->recovery_disabled we don't allow |
70 | * recovery to be attempted as we expect a read error. | |
71 | */ | |
72 | int recovery_disabled; | |
1da177e4 | 73 | |
ddaf22ab | 74 | |
ce550c20 N |
75 | /* poolinfo contains information about the content of the |
76 | * mempools - it changes when the array grows or shrinks | |
77 | */ | |
78 | struct pool_info *poolinfo; | |
9f2c9d12 N |
79 | mempool_t *r1bio_pool; |
80 | mempool_t *r1buf_pool; | |
709ae487 | 81 | |
ce550c20 N |
82 | /* temporary buffer to synchronous IO when attempting to repair |
83 | * a read error. | |
84 | */ | |
85 | struct page *tmppage; | |
86 | ||
87 | ||
709ae487 N |
88 | /* When taking over an array from a different personality, we store |
89 | * the new thread here until we fully activate the array. | |
90 | */ | |
2b8bf345 | 91 | struct md_thread *thread; |
1da177e4 LT |
92 | }; |
93 | ||
1da177e4 LT |
94 | /* |
95 | * this is our 'private' RAID1 bio. | |
96 | * | |
97 | * it contains information about what kind of IO operations were started | |
98 | * for this RAID1 operation, and about their status: | |
99 | */ | |
100 | ||
9f2c9d12 | 101 | struct r1bio { |
1da177e4 LT |
102 | atomic_t remaining; /* 'have we finished' count, |
103 | * used from IRQ handlers | |
104 | */ | |
4b6d287f N |
105 | atomic_t behind_remaining; /* number of write-behind ios remaining |
106 | * in this BehindIO request | |
107 | */ | |
1da177e4 LT |
108 | sector_t sector; |
109 | int sectors; | |
110 | unsigned long state; | |
fd01b88c | 111 | struct mddev *mddev; |
1da177e4 LT |
112 | /* |
113 | * original bio going to /dev/mdx | |
114 | */ | |
115 | struct bio *master_bio; | |
116 | /* | |
117 | * if the IO is in READ direction, then this is where we read | |
118 | */ | |
119 | int read_disk; | |
120 | ||
121 | struct list_head retry_list; | |
af6d7b76 | 122 | /* Next two are only valid when R1BIO_BehindIO is set */ |
2ca68f5e | 123 | struct bio_vec *behind_bvecs; |
af6d7b76 | 124 | int behind_page_count; |
1da177e4 LT |
125 | /* |
126 | * if the IO is in WRITE direction, then multiple bios are used. | |
127 | * We choose the number when they are allocated. | |
128 | */ | |
129 | struct bio *bios[0]; | |
191ea9b2 | 130 | /* DO NOT PUT ANY NEW FIELDS HERE - bios array is contiguously alloced*/ |
1da177e4 LT |
131 | }; |
132 | ||
cf30a473 N |
133 | /* when we get a read error on a read-only array, we redirect to another |
134 | * device without failing the first device, or trying to over-write to | |
135 | * correct the read error. To keep track of bad blocks on a per-bio | |
136 | * level, we store IO_BLOCKED in the appropriate 'bios' pointer | |
137 | */ | |
4367af55 N |
138 | #define IO_BLOCKED ((struct bio *)1) |
139 | /* When we successfully write to a known bad-block, we need to remove the | |
140 | * bad-block marking which must be done from process context. So we record | |
141 | * the success by setting bios[n] to IO_MADE_GOOD | |
142 | */ | |
143 | #define IO_MADE_GOOD ((struct bio *)2) | |
144 | ||
145 | #define BIO_SPECIAL(bio) ((unsigned long)bio <= 2) | |
cf30a473 | 146 | |
1da177e4 LT |
147 | /* bits for r1bio.state */ |
148 | #define R1BIO_Uptodate 0 | |
149 | #define R1BIO_IsSync 1 | |
191ea9b2 | 150 | #define R1BIO_Degraded 2 |
a9701a30 | 151 | #define R1BIO_BehindIO 3 |
d2eb35ac N |
152 | /* Set ReadError on bios that experience a readerror so that |
153 | * raid1d knows what to do with them. | |
154 | */ | |
155 | #define R1BIO_ReadError 4 | |
4b6d287f N |
156 | /* For write-behind requests, we call bi_end_io when |
157 | * the last non-write-behind device completes, providing | |
158 | * any write was successful. Otherwise we call when | |
159 | * any write-behind write succeeds, otherwise we call | |
160 | * with failure when last write completes (and all failed). | |
161 | * Record that bi_end_io was called with this flag... | |
162 | */ | |
9e71f9c8 | 163 | #define R1BIO_Returned 6 |
4367af55 N |
164 | /* If a write for this request means we can clear some |
165 | * known-bad-block records, we set this flag | |
166 | */ | |
cd5ff9a1 N |
167 | #define R1BIO_MadeGood 7 |
168 | #define R1BIO_WriteError 8 | |
4b6d287f | 169 | |
fd01b88c | 170 | extern int md_raid1_congested(struct mddev *mddev, int bits); |
1ed7242e | 171 | |
1da177e4 | 172 | #endif |