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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 | /* and dm-bio-list.h is not under include/linux because.... ??? */ | |
19 | #include "../../../drivers/md/dm-bio-list.h" | |
20 | ||
21 | #ifdef CONFIG_BLOCK | |
22 | ||
23 | #define LEVEL_MULTIPATH (-4) | |
24 | #define LEVEL_LINEAR (-1) | |
25 | #define LEVEL_FAULTY (-5) | |
26 | ||
27 | /* we need a value for 'no level specified' and 0 | |
28 | * means 'raid0', so we need something else. This is | |
29 | * for internal use only | |
30 | */ | |
31 | #define LEVEL_NONE (-1000000) | |
32 | ||
33 | #define MaxSector (~(sector_t)0) | |
34 | ||
35 | typedef struct mddev_s mddev_t; | |
36 | typedef struct mdk_rdev_s mdk_rdev_t; | |
37 | ||
38 | /* | |
39 | * options passed in raidrun: | |
40 | */ | |
41 | ||
42 | /* Currently this must fit in an 'int' */ | |
43 | #define MAX_CHUNK_SIZE (1<<30) | |
44 | ||
45 | /* | |
46 | * MD's 'extended' device | |
47 | */ | |
48 | struct 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 | 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 | __u64 sb_events; | |
61 | sector_t data_offset; /* start of data in array */ | |
62 | sector_t sb_offset; | |
63 | int sb_size; /* bytes in the superblock */ | |
64 | int preferred_minor; /* autorun support */ | |
65 | ||
66 | struct kobject kobj; | |
67 | ||
68 | /* A device can be in one of three states based on two flags: | |
69 | * Not working: faulty==1 in_sync==0 | |
70 | * Fully working: faulty==0 in_sync==1 | |
71 | * Working, but not | |
72 | * in sync with array | |
73 | * faulty==0 in_sync==0 | |
74 | * | |
75 | * It can never have faulty==1, in_sync==1 | |
76 | * This reduces the burden of testing multiple flags in many cases | |
77 | */ | |
78 | ||
79 | unsigned long flags; | |
80 | #define Faulty 1 /* device is known to have a fault */ | |
81 | #define In_sync 2 /* device is in_sync with rest of array */ | |
82 | #define WriteMostly 4 /* Avoid reading if at all possible */ | |
83 | #define BarriersNotsupp 5 /* BIO_RW_BARRIER is not supported */ | |
84 | #define AllReserved 6 /* If whole device is reserved for | |
85 | * one array */ | |
86 | ||
87 | int desc_nr; /* descriptor index in the superblock */ | |
88 | int raid_disk; /* role of device in array */ | |
89 | int saved_raid_disk; /* role that device used to have in the | |
90 | * array and could again if we did a partial | |
91 | * resync from the bitmap | |
92 | */ | |
93 | sector_t recovery_offset;/* If this device has been partially | |
94 | * recovered, this is where we were | |
95 | * up to. | |
96 | */ | |
97 | ||
98 | atomic_t nr_pending; /* number of pending requests. | |
99 | * only maintained for arrays that | |
100 | * support hot removal | |
101 | */ | |
102 | atomic_t read_errors; /* number of consecutive read errors that | |
103 | * we have tried to ignore. | |
104 | */ | |
105 | atomic_t corrected_errors; /* number of corrected read errors, | |
106 | * for reporting to userspace and storing | |
107 | * in superblock. | |
108 | */ | |
109 | struct work_struct del_work; /* used for delayed sysfs removal */ | |
110 | }; | |
111 | ||
112 | struct mddev_s | |
113 | { | |
114 | void *private; | |
115 | struct mdk_personality *pers; | |
116 | dev_t unit; | |
117 | int md_minor; | |
118 | struct list_head disks; | |
119 | unsigned long flags; | |
120 | #define MD_CHANGE_DEVS 0 /* Some device status has changed */ | |
121 | #define MD_CHANGE_CLEAN 1 /* transition to or from 'clean' */ | |
122 | #define MD_CHANGE_PENDING 2 /* superblock update in progress */ | |
123 | ||
124 | int ro; | |
125 | ||
126 | struct gendisk *gendisk; | |
127 | ||
128 | struct kobject kobj; | |
129 | ||
130 | /* Superblock information */ | |
131 | int major_version, | |
132 | minor_version, | |
133 | patch_version; | |
134 | int persistent; | |
135 | int external; /* metadata is | |
136 | * managed externally */ | |
137 | char metadata_type[17]; /* externally set*/ | |
138 | int chunk_size; | |
139 | time_t ctime, utime; | |
140 | int level, layout; | |
141 | char clevel[16]; | |
142 | int raid_disks; | |
143 | int max_disks; | |
144 | sector_t size; /* used size of component devices */ | |
145 | sector_t array_size; /* exported array size */ | |
146 | __u64 events; | |
147 | ||
148 | char uuid[16]; | |
149 | ||
150 | /* If the array is being reshaped, we need to record the | |
151 | * new shape and an indication of where we are up to. | |
152 | * This is written to the superblock. | |
153 | * If reshape_position is MaxSector, then no reshape is happening (yet). | |
154 | */ | |
155 | sector_t reshape_position; | |
156 | int delta_disks, new_level, new_layout, new_chunk; | |
157 | ||
158 | struct mdk_thread_s *thread; /* management thread */ | |
159 | struct mdk_thread_s *sync_thread; /* doing resync or reconstruct */ | |
160 | sector_t curr_resync; /* last block scheduled */ | |
161 | unsigned long resync_mark; /* a recent timestamp */ | |
162 | sector_t resync_mark_cnt;/* blocks written at resync_mark */ | |
163 | sector_t curr_mark_cnt; /* blocks scheduled now */ | |
164 | ||
165 | sector_t resync_max_sectors; /* may be set by personality */ | |
166 | ||
167 | sector_t resync_mismatches; /* count of sectors where | |
168 | * parity/replica mismatch found | |
169 | */ | |
170 | ||
171 | /* allow user-space to request suspension of IO to regions of the array */ | |
172 | sector_t suspend_lo; | |
173 | sector_t suspend_hi; | |
174 | /* if zero, use the system-wide default */ | |
175 | int sync_speed_min; | |
176 | int sync_speed_max; | |
177 | ||
178 | int ok_start_degraded; | |
179 | /* recovery/resync flags | |
180 | * NEEDED: we might need to start a resync/recover | |
181 | * RUNNING: a thread is running, or about to be started | |
182 | * SYNC: actually doing a resync, not a recovery | |
183 | * ERR: and IO error was detected - abort the resync/recovery | |
184 | * INTR: someone requested a (clean) early abort. | |
185 | * DONE: thread is done and is waiting to be reaped | |
186 | * REQUEST: user-space has requested a sync (used with SYNC) | |
187 | * CHECK: user-space request for for check-only, no repair | |
188 | * RESHAPE: A reshape is happening | |
189 | * | |
190 | * If neither SYNC or RESHAPE are set, then it is a recovery. | |
191 | */ | |
192 | #define MD_RECOVERY_RUNNING 0 | |
193 | #define MD_RECOVERY_SYNC 1 | |
194 | #define MD_RECOVERY_ERR 2 | |
195 | #define MD_RECOVERY_INTR 3 | |
196 | #define MD_RECOVERY_DONE 4 | |
197 | #define MD_RECOVERY_NEEDED 5 | |
198 | #define MD_RECOVERY_REQUESTED 6 | |
199 | #define MD_RECOVERY_CHECK 7 | |
200 | #define MD_RECOVERY_RESHAPE 8 | |
201 | #define MD_RECOVERY_FROZEN 9 | |
202 | ||
203 | unsigned long recovery; | |
204 | ||
205 | int in_sync; /* know to not need resync */ | |
206 | struct mutex reconfig_mutex; | |
207 | atomic_t active; | |
208 | ||
209 | int changed; /* true if we might need to reread partition info */ | |
210 | int degraded; /* whether md should consider | |
211 | * adding a spare | |
212 | */ | |
213 | int barriers_work; /* initialised to true, cleared as soon | |
214 | * as a barrier request to slave | |
215 | * fails. Only supported | |
216 | */ | |
217 | struct bio *biolist; /* bios that need to be retried | |
218 | * because BIO_RW_BARRIER is not supported | |
219 | */ | |
220 | ||
221 | atomic_t recovery_active; /* blocks scheduled, but not written */ | |
222 | wait_queue_head_t recovery_wait; | |
223 | sector_t recovery_cp; | |
224 | sector_t resync_max; /* resync should pause | |
225 | * when it gets here */ | |
226 | ||
227 | spinlock_t write_lock; | |
228 | wait_queue_head_t sb_wait; /* for waiting on superblock updates */ | |
229 | atomic_t pending_writes; /* number of active superblock writes */ | |
230 | ||
231 | unsigned int safemode; /* if set, update "clean" superblock | |
232 | * when no writes pending. | |
233 | */ | |
234 | unsigned int safemode_delay; | |
235 | struct timer_list safemode_timer; | |
236 | atomic_t writes_pending; | |
237 | struct request_queue *queue; /* for plugging ... */ | |
238 | ||
239 | atomic_t write_behind; /* outstanding async IO */ | |
240 | unsigned int max_write_behind; /* 0 = sync */ | |
241 | ||
242 | struct bitmap *bitmap; /* the bitmap for the device */ | |
243 | struct file *bitmap_file; /* the bitmap file */ | |
244 | long bitmap_offset; /* offset from superblock of | |
245 | * start of bitmap. May be | |
246 | * negative, but not '0' | |
247 | */ | |
248 | long default_bitmap_offset; /* this is the offset to use when | |
249 | * hot-adding a bitmap. It should | |
250 | * eventually be settable by sysfs. | |
251 | */ | |
252 | ||
253 | struct list_head all_mddevs; | |
254 | }; | |
255 | ||
256 | ||
257 | static inline void rdev_dec_pending(mdk_rdev_t *rdev, mddev_t *mddev) | |
258 | { | |
259 | int faulty = test_bit(Faulty, &rdev->flags); | |
260 | if (atomic_dec_and_test(&rdev->nr_pending) && faulty) | |
261 | set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); | |
262 | } | |
263 | ||
264 | static inline void md_sync_acct(struct block_device *bdev, unsigned long nr_sectors) | |
265 | { | |
266 | atomic_add(nr_sectors, &bdev->bd_contains->bd_disk->sync_io); | |
267 | } | |
268 | ||
269 | struct mdk_personality | |
270 | { | |
271 | char *name; | |
272 | int level; | |
273 | struct list_head list; | |
274 | struct module *owner; | |
275 | int (*make_request)(struct request_queue *q, struct bio *bio); | |
276 | int (*run)(mddev_t *mddev); | |
277 | int (*stop)(mddev_t *mddev); | |
278 | void (*status)(struct seq_file *seq, mddev_t *mddev); | |
279 | /* error_handler must set ->faulty and clear ->in_sync | |
280 | * if appropriate, and should abort recovery if needed | |
281 | */ | |
282 | void (*error_handler)(mddev_t *mddev, mdk_rdev_t *rdev); | |
283 | int (*hot_add_disk) (mddev_t *mddev, mdk_rdev_t *rdev); | |
284 | int (*hot_remove_disk) (mddev_t *mddev, int number); | |
285 | int (*spare_active) (mddev_t *mddev); | |
286 | sector_t (*sync_request)(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster); | |
287 | int (*resize) (mddev_t *mddev, sector_t sectors); | |
288 | int (*check_reshape) (mddev_t *mddev); | |
289 | int (*start_reshape) (mddev_t *mddev); | |
290 | int (*reconfig) (mddev_t *mddev, int layout, int chunk_size); | |
291 | /* quiesce moves between quiescence states | |
292 | * 0 - fully active | |
293 | * 1 - no new requests allowed | |
294 | * others - reserved | |
295 | */ | |
296 | void (*quiesce) (mddev_t *mddev, int state); | |
297 | }; | |
298 | ||
299 | ||
300 | struct md_sysfs_entry { | |
301 | struct attribute attr; | |
302 | ssize_t (*show)(mddev_t *, char *); | |
303 | ssize_t (*store)(mddev_t *, const char *, size_t); | |
304 | }; | |
305 | ||
306 | ||
307 | static inline char * mdname (mddev_t * mddev) | |
308 | { | |
309 | return mddev->gendisk ? mddev->gendisk->disk_name : "mdX"; | |
310 | } | |
311 | ||
312 | /* | |
313 | * iterates through some rdev ringlist. It's safe to remove the | |
314 | * current 'rdev'. Dont touch 'tmp' though. | |
315 | */ | |
316 | #define rdev_for_each_list(rdev, tmp, list) \ | |
317 | \ | |
318 | for ((tmp) = (list).next; \ | |
319 | (rdev) = (list_entry((tmp), mdk_rdev_t, same_set)), \ | |
320 | (tmp) = (tmp)->next, (tmp)->prev != &(list) \ | |
321 | ; ) | |
322 | /* | |
323 | * iterates through the 'same array disks' ringlist | |
324 | */ | |
325 | #define rdev_for_each(rdev, tmp, mddev) \ | |
326 | rdev_for_each_list(rdev, tmp, (mddev)->disks) | |
327 | ||
328 | typedef struct mdk_thread_s { | |
329 | void (*run) (mddev_t *mddev); | |
330 | mddev_t *mddev; | |
331 | wait_queue_head_t wqueue; | |
332 | unsigned long flags; | |
333 | struct task_struct *tsk; | |
334 | unsigned long timeout; | |
335 | } mdk_thread_t; | |
336 | ||
337 | #define THREAD_WAKEUP 0 | |
338 | ||
339 | #define __wait_event_lock_irq(wq, condition, lock, cmd) \ | |
340 | do { \ | |
341 | wait_queue_t __wait; \ | |
342 | init_waitqueue_entry(&__wait, current); \ | |
343 | \ | |
344 | add_wait_queue(&wq, &__wait); \ | |
345 | for (;;) { \ | |
346 | set_current_state(TASK_UNINTERRUPTIBLE); \ | |
347 | if (condition) \ | |
348 | break; \ | |
349 | spin_unlock_irq(&lock); \ | |
350 | cmd; \ | |
351 | schedule(); \ | |
352 | spin_lock_irq(&lock); \ | |
353 | } \ | |
354 | current->state = TASK_RUNNING; \ | |
355 | remove_wait_queue(&wq, &__wait); \ | |
356 | } while (0) | |
357 | ||
358 | #define wait_event_lock_irq(wq, condition, lock, cmd) \ | |
359 | do { \ | |
360 | if (condition) \ | |
361 | break; \ | |
362 | __wait_event_lock_irq(wq, condition, lock, cmd); \ | |
363 | } while (0) | |
364 | ||
365 | static inline void safe_put_page(struct page *p) | |
366 | { | |
367 | if (p) put_page(p); | |
368 | } | |
369 | ||
370 | #endif /* CONFIG_BLOCK */ | |
371 | #endif | |
372 |