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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/* and dm-bio-list.h is not under include/linux because.... ??? */
19#include "../../../drivers/md/dm-bio-list.h"
20
21#define MD_RESERVED 0UL
22#define LINEAR 1UL
23#define RAID0 2UL
24#define RAID1 3UL
25#define RAID5 4UL
26#define TRANSLUCENT 5UL
27#define HSM 6UL
28#define MULTIPATH 7UL
29#define RAID6 8UL
30#define RAID10 9UL
31#define FAULTY 10UL
32#define MAX_PERSONALITY 11UL
33
34#define LEVEL_MULTIPATH (-4)
35#define LEVEL_LINEAR (-1)
36#define LEVEL_FAULTY (-5)
37
38#define MaxSector (~(sector_t)0)
39#define MD_THREAD_NAME_MAX 14
40
41static inline int pers_to_level (int pers)
42{
43 switch (pers) {
44 case FAULTY: return LEVEL_FAULTY;
45 case MULTIPATH: return LEVEL_MULTIPATH;
46 case HSM: return -3;
47 case TRANSLUCENT: return -2;
48 case LINEAR: return LEVEL_LINEAR;
49 case RAID0: return 0;
50 case RAID1: return 1;
51 case RAID5: return 5;
52 case RAID6: return 6;
53 case RAID10: return 10;
54 }
55 BUG();
56 return MD_RESERVED;
57}
58
59static inline int level_to_pers (int level)
60{
61 switch (level) {
62 case LEVEL_FAULTY: return FAULTY;
63 case LEVEL_MULTIPATH: return MULTIPATH;
64 case -3: return HSM;
65 case -2: return TRANSLUCENT;
66 case LEVEL_LINEAR: return LINEAR;
67 case 0: return RAID0;
68 case 1: return RAID1;
69 case 4:
70 case 5: return RAID5;
71 case 6: return RAID6;
72 case 10: return RAID10;
73 }
74 return MD_RESERVED;
75}
76
77typedef struct mddev_s mddev_t;
78typedef struct mdk_rdev_s mdk_rdev_t;
79
80#define MAX_MD_DEVS 256 /* Max number of md dev */
81
82/*
83 * options passed in raidrun:
84 */
85
86#define MAX_CHUNK_SIZE (4096*1024)
87
88/*
89 * default readahead
90 */
91
92static inline int disk_faulty(mdp_disk_t * d)
93{
94 return d->state & (1 << MD_DISK_FAULTY);
95}
96
97static inline int disk_active(mdp_disk_t * d)
98{
99 return d->state & (1 << MD_DISK_ACTIVE);
100}
101
102static inline int disk_sync(mdp_disk_t * d)
103{
104 return d->state & (1 << MD_DISK_SYNC);
105}
106
107static inline int disk_spare(mdp_disk_t * d)
108{
109 return !disk_sync(d) && !disk_active(d) && !disk_faulty(d);
110}
111
112static inline int disk_removed(mdp_disk_t * d)
113{
114 return d->state & (1 << MD_DISK_REMOVED);
115}
116
117static inline void mark_disk_faulty(mdp_disk_t * d)
118{
119 d->state |= (1 << MD_DISK_FAULTY);
120}
121
122static inline void mark_disk_active(mdp_disk_t * d)
123{
124 d->state |= (1 << MD_DISK_ACTIVE);
125}
126
127static inline void mark_disk_sync(mdp_disk_t * d)
128{
129 d->state |= (1 << MD_DISK_SYNC);
130}
131
132static inline void mark_disk_spare(mdp_disk_t * d)
133{
134 d->state = 0;
135}
136
137static inline void mark_disk_removed(mdp_disk_t * d)
138{
139 d->state = (1 << MD_DISK_FAULTY) | (1 << MD_DISK_REMOVED);
140}
141
142static inline void mark_disk_inactive(mdp_disk_t * d)
143{
144 d->state &= ~(1 << MD_DISK_ACTIVE);
145}
146
147static inline void mark_disk_nonsync(mdp_disk_t * d)
148{
149 d->state &= ~(1 << MD_DISK_SYNC);
150}
151
152/*
153 * MD's 'extended' device
154 */
155struct mdk_rdev_s
156{
157 struct list_head same_set; /* RAID devices within the same set */
158
159 sector_t size; /* Device size (in blocks) */
160 mddev_t *mddev; /* RAID array if running */
161 unsigned long last_events; /* IO event timestamp */
162
163 struct block_device *bdev; /* block device handle */
164
165 struct page *sb_page;
166 int sb_loaded;
167 sector_t data_offset; /* start of data in array */
168 sector_t sb_offset;
169 int preferred_minor; /* autorun support */
170
171 /* A device can be in one of three states based on two flags:
172 * Not working: faulty==1 in_sync==0
173 * Fully working: faulty==0 in_sync==1
174 * Working, but not
175 * in sync with array
176 * faulty==0 in_sync==0
177 *
178 * It can never have faulty==1, in_sync==1
179 * This reduces the burden of testing multiple flags in many cases
180 */
181 int faulty; /* if faulty do not issue IO requests */
182 int in_sync; /* device is a full member of the array */
183
184 int desc_nr; /* descriptor index in the superblock */
185 int raid_disk; /* role of device in array */
186 int saved_raid_disk; /* role that device used to have in the
187 * array and could again if we did a partial
188 * resync from the bitmap
189 */
190
191 atomic_t nr_pending; /* number of pending requests.
192 * only maintained for arrays that
193 * support hot removal
194 */
195};
196
197typedef struct mdk_personality_s mdk_personality_t;
198
199struct mddev_s
200{
201 void *private;
202 mdk_personality_t *pers;
203 dev_t unit;
204 int md_minor;
205 struct list_head disks;
206 int sb_dirty;
207 int ro;
208
209 struct gendisk *gendisk;
210
211 /* Superblock information */
212 int major_version,
213 minor_version,
214 patch_version;
215 int persistent;
216 int chunk_size;
217 time_t ctime, utime;
218 int level, layout;
219 int raid_disks;
220 int max_disks;
221 sector_t size; /* used size of component devices */
222 sector_t array_size; /* exported array size */
223 __u64 events;
224
225 char uuid[16];
226
227 struct mdk_thread_s *thread; /* management thread */
228 struct mdk_thread_s *sync_thread; /* doing resync or reconstruct */
229 sector_t curr_resync; /* blocks scheduled */
230 unsigned long resync_mark; /* a recent timestamp */
231 sector_t resync_mark_cnt;/* blocks written at resync_mark */
232
233 sector_t resync_max_sectors; /* may be set by personality */
234 /* recovery/resync flags
235 * NEEDED: we might need to start a resync/recover
236 * RUNNING: a thread is running, or about to be started
237 * SYNC: actually doing a resync, not a recovery
238 * ERR: and IO error was detected - abort the resync/recovery
239 * INTR: someone requested a (clean) early abort.
240 * DONE: thread is done and is waiting to be reaped
241 */
242#define MD_RECOVERY_RUNNING 0
243#define MD_RECOVERY_SYNC 1
244#define MD_RECOVERY_ERR 2
245#define MD_RECOVERY_INTR 3
246#define MD_RECOVERY_DONE 4
247#define MD_RECOVERY_NEEDED 5
248 unsigned long recovery;
249
250 int in_sync; /* know to not need resync */
251 struct semaphore reconfig_sem;
252 atomic_t active;
253
254 int changed; /* true if we might need to reread partition info */
255 int degraded; /* whether md should consider
256 * adding a spare
257 */
258
259 atomic_t recovery_active; /* blocks scheduled, but not written */
260 wait_queue_head_t recovery_wait;
261 sector_t recovery_cp;
262
263 spinlock_t write_lock;
264 wait_queue_head_t sb_wait; /* for waiting on superblock updates */
265 atomic_t pending_writes; /* number of active superblock writes */
266
267 unsigned int safemode; /* if set, update "clean" superblock
268 * when no writes pending.
269 */
270 unsigned int safemode_delay;
271 struct timer_list safemode_timer;
272 atomic_t writes_pending;
273 request_queue_t *queue; /* for plugging ... */
274
275 struct bitmap *bitmap; /* the bitmap for the device */
276 struct file *bitmap_file; /* the bitmap file */
277 long bitmap_offset; /* offset from superblock of
278 * start of bitmap. May be
279 * negative, but not '0'
280 */
281
282 struct list_head all_mddevs;
283};
284
285
286static inline void rdev_dec_pending(mdk_rdev_t *rdev, mddev_t *mddev)
287{
288 int faulty = rdev->faulty;
289 if (atomic_dec_and_test(&rdev->nr_pending) && faulty)
290 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
291}
292
293static inline void md_sync_acct(struct block_device *bdev, unsigned long nr_sectors)
294{
295 atomic_add(nr_sectors, &bdev->bd_contains->bd_disk->sync_io);
296}
297
298struct mdk_personality_s
299{
300 char *name;
301 struct module *owner;
302 int (*make_request)(request_queue_t *q, struct bio *bio);
303 int (*run)(mddev_t *mddev);
304 int (*stop)(mddev_t *mddev);
305 void (*status)(struct seq_file *seq, mddev_t *mddev);
306 /* error_handler must set ->faulty and clear ->in_sync
307 * if appropriate, and should abort recovery if needed
308 */
309 void (*error_handler)(mddev_t *mddev, mdk_rdev_t *rdev);
310 int (*hot_add_disk) (mddev_t *mddev, mdk_rdev_t *rdev);
311 int (*hot_remove_disk) (mddev_t *mddev, int number);
312 int (*spare_active) (mddev_t *mddev);
313 sector_t (*sync_request)(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster);
314 int (*resize) (mddev_t *mddev, sector_t sectors);
315 int (*reshape) (mddev_t *mddev, int raid_disks);
316 int (*reconfig) (mddev_t *mddev, int layout, int chunk_size);
317};
318
319
320static inline char * mdname (mddev_t * mddev)
321{
322 return mddev->gendisk ? mddev->gendisk->disk_name : "mdX";
323}
324
325extern mdk_rdev_t * find_rdev_nr(mddev_t *mddev, int nr);
326
327/*
328 * iterates through some rdev ringlist. It's safe to remove the
329 * current 'rdev'. Dont touch 'tmp' though.
330 */
331#define ITERATE_RDEV_GENERIC(head,rdev,tmp) \
332 \
333 for ((tmp) = (head).next; \
334 (rdev) = (list_entry((tmp), mdk_rdev_t, same_set)), \
335 (tmp) = (tmp)->next, (tmp)->prev != &(head) \
336 ; )
337/*
338 * iterates through the 'same array disks' ringlist
339 */
340#define ITERATE_RDEV(mddev,rdev,tmp) \
341 ITERATE_RDEV_GENERIC((mddev)->disks,rdev,tmp)
342
343/*
344 * Iterates through 'pending RAID disks'
345 */
346#define ITERATE_RDEV_PENDING(rdev,tmp) \
347 ITERATE_RDEV_GENERIC(pending_raid_disks,rdev,tmp)
348
349typedef struct mdk_thread_s {
350 void (*run) (mddev_t *mddev);
351 mddev_t *mddev;
352 wait_queue_head_t wqueue;
353 unsigned long flags;
354 struct completion *event;
355 struct task_struct *tsk;
356 unsigned long timeout;
357 const char *name;
358} mdk_thread_t;
359
360#define THREAD_WAKEUP 0
361
362#define __wait_event_lock_irq(wq, condition, lock, cmd) \
363do { \
364 wait_queue_t __wait; \
365 init_waitqueue_entry(&__wait, current); \
366 \
367 add_wait_queue(&wq, &__wait); \
368 for (;;) { \
369 set_current_state(TASK_UNINTERRUPTIBLE); \
370 if (condition) \
371 break; \
372 spin_unlock_irq(&lock); \
373 cmd; \
374 schedule(); \
375 spin_lock_irq(&lock); \
376 } \
377 current->state = TASK_RUNNING; \
378 remove_wait_queue(&wq, &__wait); \
379} while (0)
380
381#define wait_event_lock_irq(wq, condition, lock, cmd) \
382do { \
383 if (condition) \
384 break; \
385 __wait_event_lock_irq(wq, condition, lock, cmd); \
386} while (0)
387
388#endif
389