[PATCH] md: support adding new devices to md arrays via sysfs
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / include / linux / raid / md_k.h
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1da177e4
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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
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18/* and dm-bio-list.h is not under include/linux because.... ??? */
19#include "../../../drivers/md/dm-bio-list.h"
20
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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 */
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63 int preferred_minor; /* autorun support */
64
86e6ffdd
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65 struct kobject kobj;
66
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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
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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
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95 atomic_t read_errors; /* number of consecutive read errors that
96 * we have tried to ignore.
97 */
4dbcdc75
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98 atomic_t corrected_errors; /* number of corrected read errors,
99 * for reporting to userspace and storing
100 * in superblock.
101 */
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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
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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];
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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
135 struct mdk_thread_s *thread; /* management thread */
136 struct mdk_thread_s *sync_thread; /* doing resync or reconstruct */
137 sector_t curr_resync; /* blocks scheduled */
138 unsigned long resync_mark; /* a recent timestamp */
139 sector_t resync_mark_cnt;/* blocks written at resync_mark */
140
141 sector_t resync_max_sectors; /* may be set by personality */
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142
143 sector_t resync_mismatches; /* count of sectors where
144 * parity/replica mismatch found
145 */
6ff8d8ec 146 int ok_start_degraded;
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147 /* recovery/resync flags
148 * NEEDED: we might need to start a resync/recover
149 * RUNNING: a thread is running, or about to be started
150 * SYNC: actually doing a resync, not a recovery
151 * ERR: and IO error was detected - abort the resync/recovery
152 * INTR: someone requested a (clean) early abort.
153 * DONE: thread is done and is waiting to be reaped
24dd469d
N
154 * REQUEST: user-space has requested a sync (used with SYNC)
155 * CHECK: user-space request for for check-only, no repair
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156 */
157#define MD_RECOVERY_RUNNING 0
158#define MD_RECOVERY_SYNC 1
159#define MD_RECOVERY_ERR 2
160#define MD_RECOVERY_INTR 3
161#define MD_RECOVERY_DONE 4
162#define MD_RECOVERY_NEEDED 5
24dd469d
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163#define MD_RECOVERY_REQUESTED 6
164#define MD_RECOVERY_CHECK 7
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165 unsigned long recovery;
166
167 int in_sync; /* know to not need resync */
168 struct semaphore reconfig_sem;
169 atomic_t active;
170
171 int changed; /* true if we might need to reread partition info */
172 int degraded; /* whether md should consider
173 * adding a spare
174 */
a9701a30
N
175 int barriers_work; /* initialised to true, cleared as soon
176 * as a barrier request to slave
177 * fails. Only supported
178 */
179 struct bio *biolist; /* bios that need to be retried
180 * because BIO_RW_BARRIER is not supported
181 */
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182
183 atomic_t recovery_active; /* blocks scheduled, but not written */
184 wait_queue_head_t recovery_wait;
185 sector_t recovery_cp;
06d91a5f
N
186
187 spinlock_t write_lock;
3d310eb7 188 wait_queue_head_t sb_wait; /* for waiting on superblock updates */
7bfa19f2 189 atomic_t pending_writes; /* number of active superblock writes */
06d91a5f 190
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191 unsigned int safemode; /* if set, update "clean" superblock
192 * when no writes pending.
193 */
194 unsigned int safemode_delay;
195 struct timer_list safemode_timer;
196 atomic_t writes_pending;
197 request_queue_t *queue; /* for plugging ... */
198
4b6d287f
N
199 atomic_t write_behind; /* outstanding async IO */
200 unsigned int max_write_behind; /* 0 = sync */
201
32a7627c
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202 struct bitmap *bitmap; /* the bitmap for the device */
203 struct file *bitmap_file; /* the bitmap file */
a654b9d8
N
204 long bitmap_offset; /* offset from superblock of
205 * start of bitmap. May be
206 * negative, but not '0'
207 */
36fa3063
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208 long default_bitmap_offset; /* this is the offset to use when
209 * hot-adding a bitmap. It should
210 * eventually be settable by sysfs.
211 */
32a7627c 212
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213 struct list_head all_mddevs;
214};
215
216
217static inline void rdev_dec_pending(mdk_rdev_t *rdev, mddev_t *mddev)
218{
b2d444d7 219 int faulty = test_bit(Faulty, &rdev->flags);
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220 if (atomic_dec_and_test(&rdev->nr_pending) && faulty)
221 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
222}
223
224static inline void md_sync_acct(struct block_device *bdev, unsigned long nr_sectors)
225{
226 atomic_add(nr_sectors, &bdev->bd_contains->bd_disk->sync_io);
227}
228
2604b703 229struct mdk_personality
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230{
231 char *name;
2604b703
N
232 int level;
233 struct list_head list;
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234 struct module *owner;
235 int (*make_request)(request_queue_t *q, struct bio *bio);
236 int (*run)(mddev_t *mddev);
237 int (*stop)(mddev_t *mddev);
238 void (*status)(struct seq_file *seq, mddev_t *mddev);
239 /* error_handler must set ->faulty and clear ->in_sync
240 * if appropriate, and should abort recovery if needed
241 */
242 void (*error_handler)(mddev_t *mddev, mdk_rdev_t *rdev);
243 int (*hot_add_disk) (mddev_t *mddev, mdk_rdev_t *rdev);
244 int (*hot_remove_disk) (mddev_t *mddev, int number);
245 int (*spare_active) (mddev_t *mddev);
57afd89f 246 sector_t (*sync_request)(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster);
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247 int (*resize) (mddev_t *mddev, sector_t sectors);
248 int (*reshape) (mddev_t *mddev, int raid_disks);
249 int (*reconfig) (mddev_t *mddev, int layout, int chunk_size);
36fa3063
N
250 /* quiesce moves between quiescence states
251 * 0 - fully active
252 * 1 - no new requests allowed
253 * others - reserved
254 */
255 void (*quiesce) (mddev_t *mddev, int state);
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256};
257
258
007583c9
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259struct md_sysfs_entry {
260 struct attribute attr;
261 ssize_t (*show)(mddev_t *, char *);
262 ssize_t (*store)(mddev_t *, const char *, size_t);
263};
264
265
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266static inline char * mdname (mddev_t * mddev)
267{
268 return mddev->gendisk ? mddev->gendisk->disk_name : "mdX";
269}
270
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271/*
272 * iterates through some rdev ringlist. It's safe to remove the
273 * current 'rdev'. Dont touch 'tmp' though.
274 */
275#define ITERATE_RDEV_GENERIC(head,rdev,tmp) \
276 \
277 for ((tmp) = (head).next; \
278 (rdev) = (list_entry((tmp), mdk_rdev_t, same_set)), \
279 (tmp) = (tmp)->next, (tmp)->prev != &(head) \
280 ; )
281/*
282 * iterates through the 'same array disks' ringlist
283 */
284#define ITERATE_RDEV(mddev,rdev,tmp) \
285 ITERATE_RDEV_GENERIC((mddev)->disks,rdev,tmp)
286
287/*
288 * Iterates through 'pending RAID disks'
289 */
290#define ITERATE_RDEV_PENDING(rdev,tmp) \
291 ITERATE_RDEV_GENERIC(pending_raid_disks,rdev,tmp)
292
293typedef struct mdk_thread_s {
294 void (*run) (mddev_t *mddev);
295 mddev_t *mddev;
296 wait_queue_head_t wqueue;
297 unsigned long flags;
1da177e4 298 struct task_struct *tsk;
32a7627c 299 unsigned long timeout;
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300} mdk_thread_t;
301
302#define THREAD_WAKEUP 0
303
304#define __wait_event_lock_irq(wq, condition, lock, cmd) \
305do { \
306 wait_queue_t __wait; \
307 init_waitqueue_entry(&__wait, current); \
308 \
309 add_wait_queue(&wq, &__wait); \
310 for (;;) { \
311 set_current_state(TASK_UNINTERRUPTIBLE); \
312 if (condition) \
313 break; \
314 spin_unlock_irq(&lock); \
315 cmd; \
316 schedule(); \
317 spin_lock_irq(&lock); \
318 } \
319 current->state = TASK_RUNNING; \
320 remove_wait_queue(&wq, &__wait); \
321} while (0)
322
323#define wait_event_lock_irq(wq, condition, lock, cmd) \
324do { \
325 if (condition) \
326 break; \
327 __wait_event_lock_irq(wq, condition, lock, cmd); \
328} while (0)
329
1345b1d8
N
330static inline void safe_put_page(struct page *p)
331{
332 if (p) put_page(p);
333}
334
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335#endif
336