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1da177e4
LT
1/*
2 md_k.h : kernel internal structure of the Linux MD driver
3 Copyright (C) 1996-98 Ingo Molnar, Gadi Oxman
4
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2, or (at your option)
8 any later version.
9
10 You should have received a copy of the GNU General Public License
11 (for example /usr/src/linux/COPYING); if not, write to the Free
12 Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
13*/
14
15#ifndef _MD_K_H
16#define _MD_K_H
17
06d91a5f
N
18/* and dm-bio-list.h is not under include/linux because.... ??? */
19#include "../../../drivers/md/dm-bio-list.h"
20
1da177e4
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21#define LEVEL_MULTIPATH (-4)
22#define LEVEL_LINEAR (-1)
23#define LEVEL_FAULTY (-5)
24
2604b703
N
25/* we need a value for 'no level specified' and 0
26 * means 'raid0', so we need something else. This is
27 * for internal use only
28 */
29#define LEVEL_NONE (-1000000)
30
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31#define MaxSector (~(sector_t)0)
32#define MD_THREAD_NAME_MAX 14
33
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34typedef struct mddev_s mddev_t;
35typedef struct mdk_rdev_s mdk_rdev_t;
36
37#define MAX_MD_DEVS 256 /* Max number of md dev */
38
39/*
40 * options passed in raidrun:
41 */
42
43#define MAX_CHUNK_SIZE (4096*1024)
44
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45/*
46 * MD's 'extended' device
47 */
48struct mdk_rdev_s
49{
50 struct list_head same_set; /* RAID devices within the same set */
51
52 sector_t size; /* Device size (in blocks) */
53 mddev_t *mddev; /* RAID array if running */
54 unsigned long last_events; /* IO event timestamp */
55
56 struct block_device *bdev; /* block device handle */
57
58 struct page *sb_page;
59 int sb_loaded;
60 sector_t data_offset; /* start of data in array */
61 sector_t sb_offset;
0002b271 62 int sb_size; /* bytes in the superblock */
1da177e4
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63 int preferred_minor; /* autorun support */
64
86e6ffdd
N
65 struct kobject kobj;
66
1da177e4
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67 /* A device can be in one of three states based on two flags:
68 * Not working: faulty==1 in_sync==0
69 * Fully working: faulty==0 in_sync==1
70 * Working, but not
71 * in sync with array
72 * faulty==0 in_sync==0
73 *
74 * It can never have faulty==1, in_sync==1
75 * This reduces the burden of testing multiple flags in many cases
76 */
1da177e4 77
b2d444d7
N
78 unsigned long flags;
79#define Faulty 1 /* device is known to have a fault */
80#define In_sync 2 /* device is in_sync with rest of array */
8ddf9efe 81#define WriteMostly 4 /* Avoid reading if at all possible */
a9701a30 82#define BarriersNotsupp 5 /* BIO_RW_BARRIER is not supported */
8ddf9efe 83
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84 int desc_nr; /* descriptor index in the superblock */
85 int raid_disk; /* role of device in array */
41158c7e
N
86 int saved_raid_disk; /* role that device used to have in the
87 * array and could again if we did a partial
88 * resync from the bitmap
89 */
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90
91 atomic_t nr_pending; /* number of pending requests.
92 * only maintained for arrays that
93 * support hot removal
94 */
ba22dcbf
N
95 atomic_t read_errors; /* number of consecutive read errors that
96 * we have tried to ignore.
97 */
4dbcdc75
N
98 atomic_t corrected_errors; /* number of corrected read errors,
99 * for reporting to userspace and storing
100 * in superblock.
101 */
1da177e4
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102};
103
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104struct mddev_s
105{
106 void *private;
2604b703 107 struct mdk_personality *pers;
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108 dev_t unit;
109 int md_minor;
110 struct list_head disks;
111 int sb_dirty;
112 int ro;
113
114 struct gendisk *gendisk;
115
eae1701f
N
116 struct kobject kobj;
117
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118 /* Superblock information */
119 int major_version,
120 minor_version,
121 patch_version;
122 int persistent;
123 int chunk_size;
124 time_t ctime, utime;
125 int level, layout;
d9d166c2 126 char clevel[16];
1da177e4
LT
127 int raid_disks;
128 int max_disks;
129 sector_t size; /* used size of component devices */
130 sector_t array_size; /* exported array size */
131 __u64 events;
132
133 char uuid[16];
134
f6705578
N
135 /* If the array is being reshaped, we need to record the
136 * new shape and an indication of where we are up to.
137 * This is written to the superblock.
138 * If reshape_position is MaxSector, then no reshape is happening (yet).
139 */
140 sector_t reshape_position;
141 int delta_disks, new_level, new_layout, new_chunk;
142
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143 struct mdk_thread_s *thread; /* management thread */
144 struct mdk_thread_s *sync_thread; /* doing resync or reconstruct */
145 sector_t curr_resync; /* blocks scheduled */
146 unsigned long resync_mark; /* a recent timestamp */
147 sector_t resync_mark_cnt;/* blocks written at resync_mark */
148
149 sector_t resync_max_sectors; /* may be set by personality */
9d88883e
N
150
151 sector_t resync_mismatches; /* count of sectors where
152 * parity/replica mismatch found
153 */
88202a0c
N
154 /* if zero, use the system-wide default */
155 int sync_speed_min;
156 int sync_speed_max;
157
6ff8d8ec 158 int ok_start_degraded;
1da177e4
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159 /* recovery/resync flags
160 * NEEDED: we might need to start a resync/recover
161 * RUNNING: a thread is running, or about to be started
162 * SYNC: actually doing a resync, not a recovery
163 * ERR: and IO error was detected - abort the resync/recovery
164 * INTR: someone requested a (clean) early abort.
165 * DONE: thread is done and is waiting to be reaped
24dd469d
N
166 * REQUEST: user-space has requested a sync (used with SYNC)
167 * CHECK: user-space request for for check-only, no repair
ccfcc3c1
N
168 * RESHAPE: A reshape is happening
169 *
170 * If neither SYNC or RESHAPE are set, then it is a recovery.
1da177e4
LT
171 */
172#define MD_RECOVERY_RUNNING 0
173#define MD_RECOVERY_SYNC 1
174#define MD_RECOVERY_ERR 2
175#define MD_RECOVERY_INTR 3
176#define MD_RECOVERY_DONE 4
177#define MD_RECOVERY_NEEDED 5
24dd469d
N
178#define MD_RECOVERY_REQUESTED 6
179#define MD_RECOVERY_CHECK 7
ccfcc3c1 180#define MD_RECOVERY_RESHAPE 8
1da177e4
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181 unsigned long recovery;
182
183 int in_sync; /* know to not need resync */
184 struct semaphore reconfig_sem;
185 atomic_t active;
186
187 int changed; /* true if we might need to reread partition info */
188 int degraded; /* whether md should consider
189 * adding a spare
190 */
a9701a30
N
191 int barriers_work; /* initialised to true, cleared as soon
192 * as a barrier request to slave
193 * fails. Only supported
194 */
195 struct bio *biolist; /* bios that need to be retried
196 * because BIO_RW_BARRIER is not supported
197 */
1da177e4
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198
199 atomic_t recovery_active; /* blocks scheduled, but not written */
200 wait_queue_head_t recovery_wait;
201 sector_t recovery_cp;
06d91a5f
N
202
203 spinlock_t write_lock;
3d310eb7 204 wait_queue_head_t sb_wait; /* for waiting on superblock updates */
7bfa19f2 205 atomic_t pending_writes; /* number of active superblock writes */
06d91a5f 206
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207 unsigned int safemode; /* if set, update "clean" superblock
208 * when no writes pending.
209 */
210 unsigned int safemode_delay;
211 struct timer_list safemode_timer;
212 atomic_t writes_pending;
213 request_queue_t *queue; /* for plugging ... */
214
4b6d287f
N
215 atomic_t write_behind; /* outstanding async IO */
216 unsigned int max_write_behind; /* 0 = sync */
217
32a7627c
N
218 struct bitmap *bitmap; /* the bitmap for the device */
219 struct file *bitmap_file; /* the bitmap file */
a654b9d8
N
220 long bitmap_offset; /* offset from superblock of
221 * start of bitmap. May be
222 * negative, but not '0'
223 */
36fa3063
N
224 long default_bitmap_offset; /* this is the offset to use when
225 * hot-adding a bitmap. It should
226 * eventually be settable by sysfs.
227 */
32a7627c 228
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229 struct list_head all_mddevs;
230};
231
232
233static inline void rdev_dec_pending(mdk_rdev_t *rdev, mddev_t *mddev)
234{
b2d444d7 235 int faulty = test_bit(Faulty, &rdev->flags);
1da177e4
LT
236 if (atomic_dec_and_test(&rdev->nr_pending) && faulty)
237 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
238}
239
240static inline void md_sync_acct(struct block_device *bdev, unsigned long nr_sectors)
241{
242 atomic_add(nr_sectors, &bdev->bd_contains->bd_disk->sync_io);
243}
244
2604b703 245struct mdk_personality
1da177e4
LT
246{
247 char *name;
2604b703
N
248 int level;
249 struct list_head list;
1da177e4
LT
250 struct module *owner;
251 int (*make_request)(request_queue_t *q, struct bio *bio);
252 int (*run)(mddev_t *mddev);
253 int (*stop)(mddev_t *mddev);
254 void (*status)(struct seq_file *seq, mddev_t *mddev);
255 /* error_handler must set ->faulty and clear ->in_sync
256 * if appropriate, and should abort recovery if needed
257 */
258 void (*error_handler)(mddev_t *mddev, mdk_rdev_t *rdev);
259 int (*hot_add_disk) (mddev_t *mddev, mdk_rdev_t *rdev);
260 int (*hot_remove_disk) (mddev_t *mddev, int number);
261 int (*spare_active) (mddev_t *mddev);
57afd89f 262 sector_t (*sync_request)(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster);
1da177e4
LT
263 int (*resize) (mddev_t *mddev, sector_t sectors);
264 int (*reshape) (mddev_t *mddev, int raid_disks);
265 int (*reconfig) (mddev_t *mddev, int layout, int chunk_size);
36fa3063
N
266 /* quiesce moves between quiescence states
267 * 0 - fully active
268 * 1 - no new requests allowed
269 * others - reserved
270 */
271 void (*quiesce) (mddev_t *mddev, int state);
1da177e4
LT
272};
273
274
007583c9
N
275struct md_sysfs_entry {
276 struct attribute attr;
277 ssize_t (*show)(mddev_t *, char *);
278 ssize_t (*store)(mddev_t *, const char *, size_t);
279};
280
281
1da177e4
LT
282static inline char * mdname (mddev_t * mddev)
283{
284 return mddev->gendisk ? mddev->gendisk->disk_name : "mdX";
285}
286
1da177e4
LT
287/*
288 * iterates through some rdev ringlist. It's safe to remove the
289 * current 'rdev'. Dont touch 'tmp' though.
290 */
291#define ITERATE_RDEV_GENERIC(head,rdev,tmp) \
292 \
293 for ((tmp) = (head).next; \
294 (rdev) = (list_entry((tmp), mdk_rdev_t, same_set)), \
295 (tmp) = (tmp)->next, (tmp)->prev != &(head) \
296 ; )
297/*
298 * iterates through the 'same array disks' ringlist
299 */
300#define ITERATE_RDEV(mddev,rdev,tmp) \
301 ITERATE_RDEV_GENERIC((mddev)->disks,rdev,tmp)
302
303/*
304 * Iterates through 'pending RAID disks'
305 */
306#define ITERATE_RDEV_PENDING(rdev,tmp) \
307 ITERATE_RDEV_GENERIC(pending_raid_disks,rdev,tmp)
308
309typedef struct mdk_thread_s {
310 void (*run) (mddev_t *mddev);
311 mddev_t *mddev;
312 wait_queue_head_t wqueue;
313 unsigned long flags;
1da177e4 314 struct task_struct *tsk;
32a7627c 315 unsigned long timeout;
1da177e4
LT
316} mdk_thread_t;
317
318#define THREAD_WAKEUP 0
319
320#define __wait_event_lock_irq(wq, condition, lock, cmd) \
321do { \
322 wait_queue_t __wait; \
323 init_waitqueue_entry(&__wait, current); \
324 \
325 add_wait_queue(&wq, &__wait); \
326 for (;;) { \
327 set_current_state(TASK_UNINTERRUPTIBLE); \
328 if (condition) \
329 break; \
330 spin_unlock_irq(&lock); \
331 cmd; \
332 schedule(); \
333 spin_lock_irq(&lock); \
334 } \
335 current->state = TASK_RUNNING; \
336 remove_wait_queue(&wq, &__wait); \
337} while (0)
338
339#define wait_event_lock_irq(wq, condition, lock, cmd) \
340do { \
341 if (condition) \
342 break; \
343 __wait_event_lock_irq(wq, condition, lock, cmd); \
344} while (0)
345
1345b1d8
N
346static inline void safe_put_page(struct page *p)
347{
348 if (p) put_page(p);
349}
350
1da177e4
LT
351#endif
352