Linux kernel mirror (for testing)
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linux
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
18#define MD_RESERVED 0UL
19#define LINEAR 1UL
20#define RAID0 2UL
21#define RAID1 3UL
22#define RAID5 4UL
23#define TRANSLUCENT 5UL
24#define HSM 6UL
25#define MULTIPATH 7UL
26#define RAID6 8UL
27#define RAID10 9UL
28#define FAULTY 10UL
29#define MAX_PERSONALITY 11UL
30
31#define LEVEL_MULTIPATH (-4)
32#define LEVEL_LINEAR (-1)
33#define LEVEL_FAULTY (-5)
34
35#define MaxSector (~(sector_t)0)
36#define MD_THREAD_NAME_MAX 14
37
38static inline int pers_to_level (int pers)
39{
40 switch (pers) {
41 case FAULTY: return LEVEL_FAULTY;
42 case MULTIPATH: return LEVEL_MULTIPATH;
43 case HSM: return -3;
44 case TRANSLUCENT: return -2;
45 case LINEAR: return LEVEL_LINEAR;
46 case RAID0: return 0;
47 case RAID1: return 1;
48 case RAID5: return 5;
49 case RAID6: return 6;
50 case RAID10: return 10;
51 }
52 BUG();
53 return MD_RESERVED;
54}
55
56static inline int level_to_pers (int level)
57{
58 switch (level) {
59 case LEVEL_FAULTY: return FAULTY;
60 case LEVEL_MULTIPATH: return MULTIPATH;
61 case -3: return HSM;
62 case -2: return TRANSLUCENT;
63 case LEVEL_LINEAR: return LINEAR;
64 case 0: return RAID0;
65 case 1: return RAID1;
66 case 4:
67 case 5: return RAID5;
68 case 6: return RAID6;
69 case 10: return RAID10;
70 }
71 return MD_RESERVED;
72}
73
74typedef struct mddev_s mddev_t;
75typedef struct mdk_rdev_s mdk_rdev_t;
76
77#define MAX_MD_DEVS 256 /* Max number of md dev */
78
79/*
80 * options passed in raidrun:
81 */
82
83#define MAX_CHUNK_SIZE (4096*1024)
84
85/*
86 * default readahead
87 */
88
89static inline int disk_faulty(mdp_disk_t * d)
90{
91 return d->state & (1 << MD_DISK_FAULTY);
92}
93
94static inline int disk_active(mdp_disk_t * d)
95{
96 return d->state & (1 << MD_DISK_ACTIVE);
97}
98
99static inline int disk_sync(mdp_disk_t * d)
100{
101 return d->state & (1 << MD_DISK_SYNC);
102}
103
104static inline int disk_spare(mdp_disk_t * d)
105{
106 return !disk_sync(d) && !disk_active(d) && !disk_faulty(d);
107}
108
109static inline int disk_removed(mdp_disk_t * d)
110{
111 return d->state & (1 << MD_DISK_REMOVED);
112}
113
114static inline void mark_disk_faulty(mdp_disk_t * d)
115{
116 d->state |= (1 << MD_DISK_FAULTY);
117}
118
119static inline void mark_disk_active(mdp_disk_t * d)
120{
121 d->state |= (1 << MD_DISK_ACTIVE);
122}
123
124static inline void mark_disk_sync(mdp_disk_t * d)
125{
126 d->state |= (1 << MD_DISK_SYNC);
127}
128
129static inline void mark_disk_spare(mdp_disk_t * d)
130{
131 d->state = 0;
132}
133
134static inline void mark_disk_removed(mdp_disk_t * d)
135{
136 d->state = (1 << MD_DISK_FAULTY) | (1 << MD_DISK_REMOVED);
137}
138
139static inline void mark_disk_inactive(mdp_disk_t * d)
140{
141 d->state &= ~(1 << MD_DISK_ACTIVE);
142}
143
144static inline void mark_disk_nonsync(mdp_disk_t * d)
145{
146 d->state &= ~(1 << MD_DISK_SYNC);
147}
148
149/*
150 * MD's 'extended' device
151 */
152struct mdk_rdev_s
153{
154 struct list_head same_set; /* RAID devices within the same set */
155
156 sector_t size; /* Device size (in blocks) */
157 mddev_t *mddev; /* RAID array if running */
158 unsigned long last_events; /* IO event timestamp */
159
160 struct block_device *bdev; /* block device handle */
161
162 struct page *sb_page;
163 int sb_loaded;
164 sector_t data_offset; /* start of data in array */
165 sector_t sb_offset;
166 int preferred_minor; /* autorun support */
167
168 /* A device can be in one of three states based on two flags:
169 * Not working: faulty==1 in_sync==0
170 * Fully working: faulty==0 in_sync==1
171 * Working, but not
172 * in sync with array
173 * faulty==0 in_sync==0
174 *
175 * It can never have faulty==1, in_sync==1
176 * This reduces the burden of testing multiple flags in many cases
177 */
178 int faulty; /* if faulty do not issue IO requests */
179 int in_sync; /* device is a full member of the array */
180
181 int desc_nr; /* descriptor index in the superblock */
182 int raid_disk; /* role of device in array */
183
184 atomic_t nr_pending; /* number of pending requests.
185 * only maintained for arrays that
186 * support hot removal
187 */
188};
189
190typedef struct mdk_personality_s mdk_personality_t;
191
192struct mddev_s
193{
194 void *private;
195 mdk_personality_t *pers;
196 dev_t unit;
197 int md_minor;
198 struct list_head disks;
199 int sb_dirty;
200 int ro;
201
202 struct gendisk *gendisk;
203
204 /* Superblock information */
205 int major_version,
206 minor_version,
207 patch_version;
208 int persistent;
209 int chunk_size;
210 time_t ctime, utime;
211 int level, layout;
212 int raid_disks;
213 int max_disks;
214 sector_t size; /* used size of component devices */
215 sector_t array_size; /* exported array size */
216 __u64 events;
217
218 char uuid[16];
219
220 struct mdk_thread_s *thread; /* management thread */
221 struct mdk_thread_s *sync_thread; /* doing resync or reconstruct */
222 sector_t curr_resync; /* blocks scheduled */
223 unsigned long resync_mark; /* a recent timestamp */
224 sector_t resync_mark_cnt;/* blocks written at resync_mark */
225
226 sector_t resync_max_sectors; /* may be set by personality */
227 /* recovery/resync flags
228 * NEEDED: we might need to start a resync/recover
229 * RUNNING: a thread is running, or about to be started
230 * SYNC: actually doing a resync, not a recovery
231 * ERR: and IO error was detected - abort the resync/recovery
232 * INTR: someone requested a (clean) early abort.
233 * DONE: thread is done and is waiting to be reaped
234 */
235#define MD_RECOVERY_RUNNING 0
236#define MD_RECOVERY_SYNC 1
237#define MD_RECOVERY_ERR 2
238#define MD_RECOVERY_INTR 3
239#define MD_RECOVERY_DONE 4
240#define MD_RECOVERY_NEEDED 5
241 unsigned long recovery;
242
243 int in_sync; /* know to not need resync */
244 struct semaphore reconfig_sem;
245 atomic_t active;
246
247 int changed; /* true if we might need to reread partition info */
248 int degraded; /* whether md should consider
249 * adding a spare
250 */
251
252 atomic_t recovery_active; /* blocks scheduled, but not written */
253 wait_queue_head_t recovery_wait;
254 sector_t recovery_cp;
255 unsigned int safemode; /* if set, update "clean" superblock
256 * when no writes pending.
257 */
258 unsigned int safemode_delay;
259 struct timer_list safemode_timer;
260 atomic_t writes_pending;
261 request_queue_t *queue; /* for plugging ... */
262
263 struct list_head all_mddevs;
264};
265
266
267static inline void rdev_dec_pending(mdk_rdev_t *rdev, mddev_t *mddev)
268{
269 int faulty = rdev->faulty;
270 if (atomic_dec_and_test(&rdev->nr_pending) && faulty)
271 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
272}
273
274static inline void md_sync_acct(struct block_device *bdev, unsigned long nr_sectors)
275{
276 atomic_add(nr_sectors, &bdev->bd_contains->bd_disk->sync_io);
277}
278
279struct mdk_personality_s
280{
281 char *name;
282 struct module *owner;
283 int (*make_request)(request_queue_t *q, struct bio *bio);
284 int (*run)(mddev_t *mddev);
285 int (*stop)(mddev_t *mddev);
286 void (*status)(struct seq_file *seq, mddev_t *mddev);
287 /* error_handler must set ->faulty and clear ->in_sync
288 * if appropriate, and should abort recovery if needed
289 */
290 void (*error_handler)(mddev_t *mddev, mdk_rdev_t *rdev);
291 int (*hot_add_disk) (mddev_t *mddev, mdk_rdev_t *rdev);
292 int (*hot_remove_disk) (mddev_t *mddev, int number);
293 int (*spare_active) (mddev_t *mddev);
294 int (*sync_request)(mddev_t *mddev, sector_t sector_nr, int go_faster);
295 int (*resize) (mddev_t *mddev, sector_t sectors);
296 int (*reshape) (mddev_t *mddev, int raid_disks);
297 int (*reconfig) (mddev_t *mddev, int layout, int chunk_size);
298};
299
300
301static inline char * mdname (mddev_t * mddev)
302{
303 return mddev->gendisk ? mddev->gendisk->disk_name : "mdX";
304}
305
306extern mdk_rdev_t * find_rdev_nr(mddev_t *mddev, int nr);
307
308/*
309 * iterates through some rdev ringlist. It's safe to remove the
310 * current 'rdev'. Dont touch 'tmp' though.
311 */
312#define ITERATE_RDEV_GENERIC(head,rdev,tmp) \
313 \
314 for ((tmp) = (head).next; \
315 (rdev) = (list_entry((tmp), mdk_rdev_t, same_set)), \
316 (tmp) = (tmp)->next, (tmp)->prev != &(head) \
317 ; )
318/*
319 * iterates through the 'same array disks' ringlist
320 */
321#define ITERATE_RDEV(mddev,rdev,tmp) \
322 ITERATE_RDEV_GENERIC((mddev)->disks,rdev,tmp)
323
324/*
325 * Iterates through 'pending RAID disks'
326 */
327#define ITERATE_RDEV_PENDING(rdev,tmp) \
328 ITERATE_RDEV_GENERIC(pending_raid_disks,rdev,tmp)
329
330typedef struct mdk_thread_s {
331 void (*run) (mddev_t *mddev);
332 mddev_t *mddev;
333 wait_queue_head_t wqueue;
334 unsigned long flags;
335 struct completion *event;
336 struct task_struct *tsk;
337 const char *name;
338} mdk_thread_t;
339
340#define THREAD_WAKEUP 0
341
342#define __wait_event_lock_irq(wq, condition, lock, cmd) \
343do { \
344 wait_queue_t __wait; \
345 init_waitqueue_entry(&__wait, current); \
346 \
347 add_wait_queue(&wq, &__wait); \
348 for (;;) { \
349 set_current_state(TASK_UNINTERRUPTIBLE); \
350 if (condition) \
351 break; \
352 spin_unlock_irq(&lock); \
353 cmd; \
354 schedule(); \
355 spin_lock_irq(&lock); \
356 } \
357 current->state = TASK_RUNNING; \
358 remove_wait_queue(&wq, &__wait); \
359} while (0)
360
361#define wait_event_lock_irq(wq, condition, lock, cmd) \
362do { \
363 if (condition) \
364 break; \
365 __wait_event_lock_irq(wq, condition, lock, cmd); \
366} while (0)
367
368#endif
369