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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
18#ifdef CONFIG_BLOCK
19
20#define MaxSector (~(sector_t)0)
21
22typedef struct mddev_s mddev_t;
23typedef struct mdk_rdev_s mdk_rdev_t;
24
25/*
26 * options passed in raidrun:
27 */
28
29/* Currently this must fit in an 'int' */
30#define MAX_CHUNK_SIZE (1<<30)
31
32/*
33 * MD's 'extended' device
34 */
35struct mdk_rdev_s
36{
37 struct list_head same_set; /* RAID devices within the same set */
38
39 sector_t size; /* Device size (in blocks) */
40 mddev_t *mddev; /* RAID array if running */
41 int last_events; /* IO event timestamp */
42
43 struct block_device *bdev; /* block device handle */
44
45 struct page *sb_page;
46 int sb_loaded;
47 __u64 sb_events;
48 sector_t data_offset; /* start of data in array */
49 sector_t sb_start; /* offset of the super block (in 512byte sectors) */
50 int sb_size; /* bytes in the superblock */
51 int preferred_minor; /* autorun support */
52
53 struct kobject kobj;
54
55 /* A device can be in one of three states based on two flags:
56 * Not working: faulty==1 in_sync==0
57 * Fully working: faulty==0 in_sync==1
58 * Working, but not
59 * in sync with array
60 * faulty==0 in_sync==0
61 *
62 * It can never have faulty==1, in_sync==1
63 * This reduces the burden of testing multiple flags in many cases
64 */
65
66 unsigned long flags;
67#define Faulty 1 /* device is known to have a fault */
68#define In_sync 2 /* device is in_sync with rest of array */
69#define WriteMostly 4 /* Avoid reading if at all possible */
70#define BarriersNotsupp 5 /* BIO_RW_BARRIER is not supported */
71#define AllReserved 6 /* If whole device is reserved for
72 * one array */
73#define AutoDetected 7 /* added by auto-detect */
74#define Blocked 8 /* An error occured on an externally
75 * managed array, don't allow writes
76 * until it is cleared */
77#define StateChanged 9 /* Faulty or Blocked has changed during
78 * interrupt, so it needs to be
79 * notified by the thread */
80 wait_queue_head_t blocked_wait;
81
82 int desc_nr; /* descriptor index in the superblock */
83 int raid_disk; /* role of device in array */
84 int saved_raid_disk; /* role that device used to have in the
85 * array and could again if we did a partial
86 * resync from the bitmap
87 */
88 sector_t recovery_offset;/* If this device has been partially
89 * recovered, this is where we were
90 * up to.
91 */
92
93 atomic_t nr_pending; /* number of pending requests.
94 * only maintained for arrays that
95 * support hot removal
96 */
97 atomic_t read_errors; /* number of consecutive read errors that
98 * we have tried to ignore.
99 */
100 atomic_t corrected_errors; /* number of corrected read errors,
101 * for reporting to userspace and storing
102 * in superblock.
103 */
104 struct work_struct del_work; /* used for delayed sysfs removal */
105
106 struct sysfs_dirent *sysfs_state; /* handle for 'state'
107 * sysfs entry */
108};
109
110struct mddev_s
111{
112 void *private;
113 struct mdk_personality *pers;
114 dev_t unit;
115 int md_minor;
116 struct list_head disks;
117 unsigned long flags;
118#define MD_CHANGE_DEVS 0 /* Some device status has changed */
119#define MD_CHANGE_CLEAN 1 /* transition to or from 'clean' */
120#define MD_CHANGE_PENDING 2 /* superblock update in progress */
121
122 int ro;
123
124 struct gendisk *gendisk;
125
126 struct kobject kobj;
127 int hold_active;
128#define UNTIL_IOCTL 1
129#define UNTIL_STOP 2
130
131 /* Superblock information */
132 int major_version,
133 minor_version,
134 patch_version;
135 int persistent;
136 int external; /* metadata is
137 * managed externally */
138 char metadata_type[17]; /* externally set*/
139 int chunk_size;
140 time_t ctime, utime;
141 int level, layout;
142 char clevel[16];
143 int raid_disks;
144 int max_disks;
145 sector_t size; /* used size of component devices */
146 sector_t array_sectors; /* exported array size */
147 __u64 events;
148
149 char uuid[16];
150
151 /* If the array is being reshaped, we need to record the
152 * new shape and an indication of where we are up to.
153 * This is written to the superblock.
154 * If reshape_position is MaxSector, then no reshape is happening (yet).
155 */
156 sector_t reshape_position;
157 int delta_disks, new_level, new_layout, new_chunk;
158
159 struct mdk_thread_s *thread; /* management thread */
160 struct mdk_thread_s *sync_thread; /* doing resync or reconstruct */
161 sector_t curr_resync; /* last block scheduled */
162 unsigned long resync_mark; /* a recent timestamp */
163 sector_t resync_mark_cnt;/* blocks written at resync_mark */
164 sector_t curr_mark_cnt; /* blocks scheduled now */
165
166 sector_t resync_max_sectors; /* may be set by personality */
167
168 sector_t resync_mismatches; /* count of sectors where
169 * parity/replica mismatch found
170 */
171
172 /* allow user-space to request suspension of IO to regions of the array */
173 sector_t suspend_lo;
174 sector_t suspend_hi;
175 /* if zero, use the system-wide default */
176 int sync_speed_min;
177 int sync_speed_max;
178
179 /* resync even though the same disks are shared among md-devices */
180 int parallel_resync;
181
182 int ok_start_degraded;
183 /* recovery/resync flags
184 * NEEDED: we might need to start a resync/recover
185 * RUNNING: a thread is running, or about to be started
186 * SYNC: actually doing a resync, not a recovery
187 * RECOVER: doing recovery, or need to try it.
188 * INTR: resync needs to be aborted for some reason
189 * DONE: thread is done and is waiting to be reaped
190 * REQUEST: user-space has requested a sync (used with SYNC)
191 * CHECK: user-space request for for check-only, no repair
192 * RESHAPE: A reshape is happening
193 *
194 * If neither SYNC or RESHAPE are set, then it is a recovery.
195 */
196#define MD_RECOVERY_RUNNING 0
197#define MD_RECOVERY_SYNC 1
198#define MD_RECOVERY_RECOVER 2
199#define MD_RECOVERY_INTR 3
200#define MD_RECOVERY_DONE 4
201#define MD_RECOVERY_NEEDED 5
202#define MD_RECOVERY_REQUESTED 6
203#define MD_RECOVERY_CHECK 7
204#define MD_RECOVERY_RESHAPE 8
205#define MD_RECOVERY_FROZEN 9
206
207 unsigned long recovery;
208 int recovery_disabled; /* if we detect that recovery
209 * will always fail, set this
210 * so we don't loop trying */
211
212 int in_sync; /* know to not need resync */
213 struct mutex reconfig_mutex;
214 atomic_t active; /* general refcount */
215 atomic_t openers; /* number of active opens */
216
217 int changed; /* true if we might need to reread partition info */
218 int degraded; /* whether md should consider
219 * adding a spare
220 */
221 int barriers_work; /* initialised to true, cleared as soon
222 * as a barrier request to slave
223 * fails. Only supported
224 */
225 struct bio *biolist; /* bios that need to be retried
226 * because BIO_RW_BARRIER is not supported
227 */
228
229 atomic_t recovery_active; /* blocks scheduled, but not written */
230 wait_queue_head_t recovery_wait;
231 sector_t recovery_cp;
232 sector_t resync_min; /* user requested sync
233 * starts here */
234 sector_t resync_max; /* resync should pause
235 * when it gets here */
236
237 struct sysfs_dirent *sysfs_state; /* handle for 'array_state'
238 * file in sysfs.
239 */
240 struct sysfs_dirent *sysfs_action; /* handle for 'sync_action' */
241
242 struct work_struct del_work; /* used for delayed sysfs removal */
243
244 spinlock_t write_lock;
245 wait_queue_head_t sb_wait; /* for waiting on superblock updates */
246 atomic_t pending_writes; /* number of active superblock writes */
247
248 unsigned int safemode; /* if set, update "clean" superblock
249 * when no writes pending.
250 */
251 unsigned int safemode_delay;
252 struct timer_list safemode_timer;
253 atomic_t writes_pending;
254 struct request_queue *queue; /* for plugging ... */
255
256 atomic_t write_behind; /* outstanding async IO */
257 unsigned int max_write_behind; /* 0 = sync */
258
259 struct bitmap *bitmap; /* the bitmap for the device */
260 struct file *bitmap_file; /* the bitmap file */
261 long bitmap_offset; /* offset from superblock of
262 * start of bitmap. May be
263 * negative, but not '0'
264 */
265 long default_bitmap_offset; /* this is the offset to use when
266 * hot-adding a bitmap. It should
267 * eventually be settable by sysfs.
268 */
269
270 struct list_head all_mddevs;
271};
272
273
274static inline void rdev_dec_pending(mdk_rdev_t *rdev, mddev_t *mddev)
275{
276 int faulty = test_bit(Faulty, &rdev->flags);
277 if (atomic_dec_and_test(&rdev->nr_pending) && faulty)
278 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
279}
280
281static inline void md_sync_acct(struct block_device *bdev, unsigned long nr_sectors)
282{
283 atomic_add(nr_sectors, &bdev->bd_contains->bd_disk->sync_io);
284}
285
286struct mdk_personality
287{
288 char *name;
289 int level;
290 struct list_head list;
291 struct module *owner;
292 int (*make_request)(struct request_queue *q, struct bio *bio);
293 int (*run)(mddev_t *mddev);
294 int (*stop)(mddev_t *mddev);
295 void (*status)(struct seq_file *seq, mddev_t *mddev);
296 /* error_handler must set ->faulty and clear ->in_sync
297 * if appropriate, and should abort recovery if needed
298 */
299 void (*error_handler)(mddev_t *mddev, mdk_rdev_t *rdev);
300 int (*hot_add_disk) (mddev_t *mddev, mdk_rdev_t *rdev);
301 int (*hot_remove_disk) (mddev_t *mddev, int number);
302 int (*spare_active) (mddev_t *mddev);
303 sector_t (*sync_request)(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster);
304 int (*resize) (mddev_t *mddev, sector_t sectors);
305 int (*check_reshape) (mddev_t *mddev);
306 int (*start_reshape) (mddev_t *mddev);
307 int (*reconfig) (mddev_t *mddev, int layout, int chunk_size);
308 /* quiesce moves between quiescence states
309 * 0 - fully active
310 * 1 - no new requests allowed
311 * others - reserved
312 */
313 void (*quiesce) (mddev_t *mddev, int state);
314};
315
316
317struct md_sysfs_entry {
318 struct attribute attr;
319 ssize_t (*show)(mddev_t *, char *);
320 ssize_t (*store)(mddev_t *, const char *, size_t);
321};
322
323
324static inline char * mdname (mddev_t * mddev)
325{
326 return mddev->gendisk ? mddev->gendisk->disk_name : "mdX";
327}
328
329/*
330 * iterates through some rdev ringlist. It's safe to remove the
331 * current 'rdev'. Dont touch 'tmp' though.
332 */
333#define rdev_for_each_list(rdev, tmp, head) \
334 list_for_each_entry_safe(rdev, tmp, head, same_set)
335
336/*
337 * iterates through the 'same array disks' ringlist
338 */
339#define rdev_for_each(rdev, tmp, mddev) \
340 list_for_each_entry_safe(rdev, tmp, &((mddev)->disks), same_set)
341
342#define rdev_for_each_rcu(rdev, mddev) \
343 list_for_each_entry_rcu(rdev, &((mddev)->disks), same_set)
344
345typedef struct mdk_thread_s {
346 void (*run) (mddev_t *mddev);
347 mddev_t *mddev;
348 wait_queue_head_t wqueue;
349 unsigned long flags;
350 struct task_struct *tsk;
351 unsigned long timeout;
352} mdk_thread_t;
353
354#define THREAD_WAKEUP 0
355
356#define __wait_event_lock_irq(wq, condition, lock, cmd) \
357do { \
358 wait_queue_t __wait; \
359 init_waitqueue_entry(&__wait, current); \
360 \
361 add_wait_queue(&wq, &__wait); \
362 for (;;) { \
363 set_current_state(TASK_UNINTERRUPTIBLE); \
364 if (condition) \
365 break; \
366 spin_unlock_irq(&lock); \
367 cmd; \
368 schedule(); \
369 spin_lock_irq(&lock); \
370 } \
371 current->state = TASK_RUNNING; \
372 remove_wait_queue(&wq, &__wait); \
373} while (0)
374
375#define wait_event_lock_irq(wq, condition, lock, cmd) \
376do { \
377 if (condition) \
378 break; \
379 __wait_event_lock_irq(wq, condition, lock, cmd); \
380} while (0)
381
382static inline void safe_put_page(struct page *p)
383{
384 if (p) put_page(p);
385}
386
387#endif /* CONFIG_BLOCK */
388#endif
389
390
391extern int register_md_personality(struct mdk_personality *p);
392extern int unregister_md_personality(struct mdk_personality *p);
393extern mdk_thread_t * md_register_thread(void (*run) (mddev_t *mddev),
394 mddev_t *mddev, const char *name);
395extern void md_unregister_thread(mdk_thread_t *thread);
396extern void md_wakeup_thread(mdk_thread_t *thread);
397extern void md_check_recovery(mddev_t *mddev);
398extern void md_write_start(mddev_t *mddev, struct bio *bi);
399extern void md_write_end(mddev_t *mddev);
400extern void md_done_sync(mddev_t *mddev, int blocks, int ok);
401extern void md_error(mddev_t *mddev, mdk_rdev_t *rdev);
402
403extern void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
404 sector_t sector, int size, struct page *page);
405extern void md_super_wait(mddev_t *mddev);
406extern int sync_page_io(struct block_device *bdev, sector_t sector, int size,
407 struct page *page, int rw);
408extern void md_do_sync(mddev_t *mddev);
409extern void md_new_event(mddev_t *mddev);
410extern int md_allow_write(mddev_t *mddev);
411extern void md_wait_for_blocked_rdev(mdk_rdev_t *rdev, mddev_t *mddev);
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