Loading...
1#ifndef _RAID1_H
2#define _RAID1_H
3
4typedef struct mirror_info mirror_info_t;
5
6struct mirror_info {
7 mdk_rdev_t *rdev;
8 sector_t head_position;
9};
10
11/*
12 * memory pools need a pointer to the mddev, so they can force an unplug
13 * when memory is tight, and a count of the number of drives that the
14 * pool was allocated for, so they know how much to allocate and free.
15 * mddev->raid_disks cannot be used, as it can change while a pool is active
16 * These two datums are stored in a kmalloced struct.
17 */
18
19struct pool_info {
20 mddev_t *mddev;
21 int raid_disks;
22};
23
24
25typedef struct r1bio_s r1bio_t;
26
27struct r1_private_data_s {
28 mddev_t *mddev;
29 mirror_info_t *mirrors;
30 int raid_disks;
31 int last_used;
32 sector_t next_seq_sect;
33 spinlock_t device_lock;
34
35 struct list_head retry_list;
36 /* queue pending writes and submit them on unplug */
37 struct bio_list pending_bio_list;
38
39 /* for use when syncing mirrors: */
40
41 spinlock_t resync_lock;
42 int nr_pending;
43 int nr_waiting;
44 int nr_queued;
45 int barrier;
46 sector_t next_resync;
47 int fullsync; /* set to 1 if a full sync is needed,
48 * (fresh device added).
49 * Cleared when a sync completes.
50 */
51 int recovery_disabled; /* when the same as
52 * mddev->recovery_disabled
53 * we don't allow recovery
54 * to be attempted as we
55 * expect a read error
56 */
57
58 wait_queue_head_t wait_barrier;
59
60 struct pool_info *poolinfo;
61
62 struct page *tmppage;
63
64 mempool_t *r1bio_pool;
65 mempool_t *r1buf_pool;
66
67 /* When taking over an array from a different personality, we store
68 * the new thread here until we fully activate the array.
69 */
70 struct mdk_thread_s *thread;
71};
72
73typedef struct r1_private_data_s conf_t;
74
75/*
76 * this is our 'private' RAID1 bio.
77 *
78 * it contains information about what kind of IO operations were started
79 * for this RAID1 operation, and about their status:
80 */
81
82struct r1bio_s {
83 atomic_t remaining; /* 'have we finished' count,
84 * used from IRQ handlers
85 */
86 atomic_t behind_remaining; /* number of write-behind ios remaining
87 * in this BehindIO request
88 */
89 sector_t sector;
90 int sectors;
91 unsigned long state;
92 mddev_t *mddev;
93 /*
94 * original bio going to /dev/mdx
95 */
96 struct bio *master_bio;
97 /*
98 * if the IO is in READ direction, then this is where we read
99 */
100 int read_disk;
101
102 struct list_head retry_list;
103 /* Next two are only valid when R1BIO_BehindIO is set */
104 struct bio_vec *behind_bvecs;
105 int behind_page_count;
106 /*
107 * if the IO is in WRITE direction, then multiple bios are used.
108 * We choose the number when they are allocated.
109 */
110 struct bio *bios[0];
111 /* DO NOT PUT ANY NEW FIELDS HERE - bios array is contiguously alloced*/
112};
113
114/* when we get a read error on a read-only array, we redirect to another
115 * device without failing the first device, or trying to over-write to
116 * correct the read error. To keep track of bad blocks on a per-bio
117 * level, we store IO_BLOCKED in the appropriate 'bios' pointer
118 */
119#define IO_BLOCKED ((struct bio *)1)
120/* When we successfully write to a known bad-block, we need to remove the
121 * bad-block marking which must be done from process context. So we record
122 * the success by setting bios[n] to IO_MADE_GOOD
123 */
124#define IO_MADE_GOOD ((struct bio *)2)
125
126#define BIO_SPECIAL(bio) ((unsigned long)bio <= 2)
127
128/* bits for r1bio.state */
129#define R1BIO_Uptodate 0
130#define R1BIO_IsSync 1
131#define R1BIO_Degraded 2
132#define R1BIO_BehindIO 3
133/* Set ReadError on bios that experience a readerror so that
134 * raid1d knows what to do with them.
135 */
136#define R1BIO_ReadError 4
137/* For write-behind requests, we call bi_end_io when
138 * the last non-write-behind device completes, providing
139 * any write was successful. Otherwise we call when
140 * any write-behind write succeeds, otherwise we call
141 * with failure when last write completes (and all failed).
142 * Record that bi_end_io was called with this flag...
143 */
144#define R1BIO_Returned 6
145/* If a write for this request means we can clear some
146 * known-bad-block records, we set this flag
147 */
148#define R1BIO_MadeGood 7
149#define R1BIO_WriteError 8
150
151extern int md_raid1_congested(mddev_t *mddev, int bits);
152
153#endif
1#ifndef _RAID1_H
2#define _RAID1_H
3
4struct mirror_info {
5 struct md_rdev *rdev;
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 * The 'raid_disks' here is twice the raid_disks in r1conf.
16 * This allows space for each 'real' device can have a replacement in the
17 * second half of the array.
18 */
19
20struct pool_info {
21 struct mddev *mddev;
22 int raid_disks;
23};
24
25struct r1conf {
26 struct mddev *mddev;
27 struct mirror_info *mirrors; /* twice 'raid_disks' to
28 * allow for replacements.
29 */
30 int raid_disks;
31
32 /* When choose the best device for a read (read_balance())
33 * we try to keep sequential reads one the same device
34 * using 'last_used' and 'next_seq_sect'
35 */
36 int last_used;
37 sector_t next_seq_sect;
38 /* During resync, read_balancing is only allowed on the part
39 * of the array that has been resynced. 'next_resync' tells us
40 * where that is.
41 */
42 sector_t next_resync;
43
44 spinlock_t device_lock;
45
46 /* list of 'struct r1bio' that need to be processed by raid1d,
47 * whether to retry a read, writeout a resync or recovery
48 * block, or anything else.
49 */
50 struct list_head retry_list;
51
52 /* queue pending writes to be submitted on unplug */
53 struct bio_list pending_bio_list;
54 int pending_count;
55
56 /* for use when syncing mirrors:
57 * We don't allow both normal IO and resync/recovery IO at
58 * the same time - resync/recovery can only happen when there
59 * is no other IO. So when either is active, the other has to wait.
60 * See more details description in raid1.c near raise_barrier().
61 */
62 wait_queue_head_t wait_barrier;
63 spinlock_t resync_lock;
64 int nr_pending;
65 int nr_waiting;
66 int nr_queued;
67 int barrier;
68
69 /* Set to 1 if a full sync is needed, (fresh device added).
70 * Cleared when a sync completes.
71 */
72 int fullsync;
73
74 /* When the same as mddev->recovery_disabled we don't allow
75 * recovery to be attempted as we expect a read error.
76 */
77 int recovery_disabled;
78
79
80 /* poolinfo contains information about the content of the
81 * mempools - it changes when the array grows or shrinks
82 */
83 struct pool_info *poolinfo;
84 mempool_t *r1bio_pool;
85 mempool_t *r1buf_pool;
86
87 /* temporary buffer to synchronous IO when attempting to repair
88 * a read error.
89 */
90 struct page *tmppage;
91
92
93 /* When taking over an array from a different personality, we store
94 * the new thread here until we fully activate the array.
95 */
96 struct md_thread *thread;
97};
98
99/*
100 * this is our 'private' RAID1 bio.
101 *
102 * it contains information about what kind of IO operations were started
103 * for this RAID1 operation, and about their status:
104 */
105
106struct r1bio {
107 atomic_t remaining; /* 'have we finished' count,
108 * used from IRQ handlers
109 */
110 atomic_t behind_remaining; /* number of write-behind ios remaining
111 * in this BehindIO request
112 */
113 sector_t sector;
114 int sectors;
115 unsigned long state;
116 struct mddev *mddev;
117 /*
118 * original bio going to /dev/mdx
119 */
120 struct bio *master_bio;
121 /*
122 * if the IO is in READ direction, then this is where we read
123 */
124 int read_disk;
125
126 struct list_head retry_list;
127 /* Next two are only valid when R1BIO_BehindIO is set */
128 struct bio_vec *behind_bvecs;
129 int behind_page_count;
130 /*
131 * if the IO is in WRITE direction, then multiple bios are used.
132 * We choose the number when they are allocated.
133 */
134 struct bio *bios[0];
135 /* DO NOT PUT ANY NEW FIELDS HERE - bios array is contiguously alloced*/
136};
137
138/* when we get a read error on a read-only array, we redirect to another
139 * device without failing the first device, or trying to over-write to
140 * correct the read error. To keep track of bad blocks on a per-bio
141 * level, we store IO_BLOCKED in the appropriate 'bios' pointer
142 */
143#define IO_BLOCKED ((struct bio *)1)
144/* When we successfully write to a known bad-block, we need to remove the
145 * bad-block marking which must be done from process context. So we record
146 * the success by setting bios[n] to IO_MADE_GOOD
147 */
148#define IO_MADE_GOOD ((struct bio *)2)
149
150#define BIO_SPECIAL(bio) ((unsigned long)bio <= 2)
151
152/* bits for r1bio.state */
153#define R1BIO_Uptodate 0
154#define R1BIO_IsSync 1
155#define R1BIO_Degraded 2
156#define R1BIO_BehindIO 3
157/* Set ReadError on bios that experience a readerror so that
158 * raid1d knows what to do with them.
159 */
160#define R1BIO_ReadError 4
161/* For write-behind requests, we call bi_end_io when
162 * the last non-write-behind device completes, providing
163 * any write was successful. Otherwise we call when
164 * any write-behind write succeeds, otherwise we call
165 * with failure when last write completes (and all failed).
166 * Record that bi_end_io was called with this flag...
167 */
168#define R1BIO_Returned 6
169/* If a write for this request means we can clear some
170 * known-bad-block records, we set this flag
171 */
172#define R1BIO_MadeGood 7
173#define R1BIO_WriteError 8
174
175extern int md_raid1_congested(struct mddev *mddev, int bits);
176
177#endif