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 LEVEL_MULTIPATH (-4)
22 #define LEVEL_LINEAR (-1)
23 #define LEVEL_FAULTY (-5)
24
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
31 #define MaxSector (~(sector_t)0)
32 #define MD_THREAD_NAME_MAX 14
33
34 typedef struct mddev_s mddev_t;
35 typedef 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 /* Currently this must fix in an 'int' */
44 #define MAX_CHUNK_SIZE (1<<30)
45
46 /*
47 * MD's 'extended' device
48 */
49 struct mdk_rdev_s
50 {
51 struct list_head same_set; /* RAID devices within the same set */
52
53 sector_t size; /* Device size (in blocks) */
54 mddev_t *mddev; /* RAID array if running */
55 unsigned long last_events; /* IO event timestamp */
56
57 struct block_device *bdev; /* block device handle */
58
59 struct page *sb_page;
60 int sb_loaded;
61 __u64 sb_events;
62 sector_t data_offset; /* start of data in array */
63 sector_t sb_offset;
64 int sb_size; /* bytes in the superblock */
65 int preferred_minor; /* autorun support */
66
67 struct kobject kobj;
68
69 /* A device can be in one of three states based on two flags:
70 * Not working: faulty==1 in_sync==0
71 * Fully working: faulty==0 in_sync==1
72 * Working, but not
73 * in sync with array
74 * faulty==0 in_sync==0
75 *
76 * It can never have faulty==1, in_sync==1
77 * This reduces the burden of testing multiple flags in many cases
78 */
79
80 unsigned long flags;
81 #define Faulty 1 /* device is known to have a fault */
82 #define In_sync 2 /* device is in_sync with rest of array */
83 #define WriteMostly 4 /* Avoid reading if at all possible */
84 #define BarriersNotsupp 5 /* BIO_RW_BARRIER is not supported */
85
86 int desc_nr; /* descriptor index in the superblock */
87 int raid_disk; /* role of device in array */
88 int saved_raid_disk; /* role that device used to have in the
89 * array and could again if we did a partial
90 * resync from the bitmap
91 */
92 sector_t recovery_offset;/* If this device has been partially
93 * recovered, this is where we were
94 * up to.
95 */
96
97 atomic_t nr_pending; /* number of pending requests.
98 * only maintained for arrays that
99 * support hot removal
100 */
101 atomic_t read_errors; /* number of consecutive read errors that
102 * we have tried to ignore.
103 */
104 atomic_t corrected_errors; /* number of corrected read errors,
105 * for reporting to userspace and storing
106 * in superblock.
107 */
108 };
109
110 struct 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 int sb_dirty;
118 int ro;
119
120 struct gendisk *gendisk;
121
122 struct kobject kobj;
123
124 /* Superblock information */
125 int major_version,
126 minor_version,
127 patch_version;
128 int persistent;
129 int chunk_size;
130 time_t ctime, utime;
131 int level, layout;
132 char clevel[16];
133 int raid_disks;
134 int max_disks;
135 sector_t size; /* used size of component devices */
136 sector_t array_size; /* exported array size */
137 __u64 events;
138
139 char uuid[16];
140
141 /* If the array is being reshaped, we need to record the
142 * new shape and an indication of where we are up to.
143 * This is written to the superblock.
144 * If reshape_position is MaxSector, then no reshape is happening (yet).
145 */
146 sector_t reshape_position;
147 int delta_disks, new_level, new_layout, new_chunk;
148
149 struct mdk_thread_s *thread; /* management thread */
150 struct mdk_thread_s *sync_thread; /* doing resync or reconstruct */
151 sector_t curr_resync; /* last block scheduled */
152 unsigned long resync_mark; /* a recent timestamp */
153 sector_t resync_mark_cnt;/* blocks written at resync_mark */
154 sector_t curr_mark_cnt; /* blocks scheduled now */
155
156 sector_t resync_max_sectors; /* may be set by personality */
157
158 sector_t resync_mismatches; /* count of sectors where
159 * parity/replica mismatch found
160 */
161
162 /* allow user-space to request suspension of IO to regions of the array */
163 sector_t suspend_lo;
164 sector_t suspend_hi;
165 /* if zero, use the system-wide default */
166 int sync_speed_min;
167 int sync_speed_max;
168
169 int ok_start_degraded;
170 /* recovery/resync flags
171 * NEEDED: we might need to start a resync/recover
172 * RUNNING: a thread is running, or about to be started
173 * SYNC: actually doing a resync, not a recovery
174 * ERR: and IO error was detected - abort the resync/recovery
175 * INTR: someone requested a (clean) early abort.
176 * DONE: thread is done and is waiting to be reaped
177 * REQUEST: user-space has requested a sync (used with SYNC)
178 * CHECK: user-space request for for check-only, no repair
179 * RESHAPE: A reshape is happening
180 *
181 * If neither SYNC or RESHAPE are set, then it is a recovery.
182 */
183 #define MD_RECOVERY_RUNNING 0
184 #define MD_RECOVERY_SYNC 1
185 #define MD_RECOVERY_ERR 2
186 #define MD_RECOVERY_INTR 3
187 #define MD_RECOVERY_DONE 4
188 #define MD_RECOVERY_NEEDED 5
189 #define MD_RECOVERY_REQUESTED 6
190 #define MD_RECOVERY_CHECK 7
191 #define MD_RECOVERY_RESHAPE 8
192 #define MD_RECOVERY_FROZEN 9
193
194 unsigned long recovery;
195
196 int in_sync; /* know to not need resync */
197 struct mutex reconfig_mutex;
198 atomic_t active;
199
200 int changed; /* true if we might need to reread partition info */
201 int degraded; /* whether md should consider
202 * adding a spare
203 */
204 int barriers_work; /* initialised to true, cleared as soon
205 * as a barrier request to slave
206 * fails. Only supported
207 */
208 struct bio *biolist; /* bios that need to be retried
209 * because BIO_RW_BARRIER is not supported
210 */
211
212 atomic_t recovery_active; /* blocks scheduled, but not written */
213 wait_queue_head_t recovery_wait;
214 sector_t recovery_cp;
215
216 spinlock_t write_lock;
217 wait_queue_head_t sb_wait; /* for waiting on superblock updates */
218 atomic_t pending_writes; /* number of active superblock writes */
219
220 unsigned int safemode; /* if set, update "clean" superblock
221 * when no writes pending.
222 */
223 unsigned int safemode_delay;
224 struct timer_list safemode_timer;
225 atomic_t writes_pending;
226 request_queue_t *queue; /* for plugging ... */
227
228 atomic_t write_behind; /* outstanding async IO */
229 unsigned int max_write_behind; /* 0 = sync */
230
231 struct bitmap *bitmap; /* the bitmap for the device */
232 struct file *bitmap_file; /* the bitmap file */
233 long bitmap_offset; /* offset from superblock of
234 * start of bitmap. May be
235 * negative, but not '0'
236 */
237 long default_bitmap_offset; /* this is the offset to use when
238 * hot-adding a bitmap. It should
239 * eventually be settable by sysfs.
240 */
241
242 struct list_head all_mddevs;
243 };
244
245
rdev_dec_pending(mdk_rdev_t * rdev,mddev_t * mddev)246 static inline void rdev_dec_pending(mdk_rdev_t *rdev, mddev_t *mddev)
247 {
248 int faulty = test_bit(Faulty, &rdev->flags);
249 if (atomic_dec_and_test(&rdev->nr_pending) && faulty)
250 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
251 }
252
md_sync_acct(struct block_device * bdev,unsigned long nr_sectors)253 static inline void md_sync_acct(struct block_device *bdev, unsigned long nr_sectors)
254 {
255 atomic_add(nr_sectors, &bdev->bd_contains->bd_disk->sync_io);
256 }
257
258 struct mdk_personality
259 {
260 char *name;
261 int level;
262 struct list_head list;
263 struct module *owner;
264 int (*make_request)(request_queue_t *q, struct bio *bio);
265 int (*run)(mddev_t *mddev);
266 int (*stop)(mddev_t *mddev);
267 void (*status)(struct seq_file *seq, mddev_t *mddev);
268 /* error_handler must set ->faulty and clear ->in_sync
269 * if appropriate, and should abort recovery if needed
270 */
271 void (*error_handler)(mddev_t *mddev, mdk_rdev_t *rdev);
272 int (*hot_add_disk) (mddev_t *mddev, mdk_rdev_t *rdev);
273 int (*hot_remove_disk) (mddev_t *mddev, int number);
274 int (*spare_active) (mddev_t *mddev);
275 sector_t (*sync_request)(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster);
276 int (*resize) (mddev_t *mddev, sector_t sectors);
277 int (*check_reshape) (mddev_t *mddev);
278 int (*start_reshape) (mddev_t *mddev);
279 int (*reconfig) (mddev_t *mddev, int layout, int chunk_size);
280 /* quiesce moves between quiescence states
281 * 0 - fully active
282 * 1 - no new requests allowed
283 * others - reserved
284 */
285 void (*quiesce) (mddev_t *mddev, int state);
286 };
287
288
289 struct md_sysfs_entry {
290 struct attribute attr;
291 ssize_t (*show)(mddev_t *, char *);
292 ssize_t (*store)(mddev_t *, const char *, size_t);
293 };
294
295
mdname(mddev_t * mddev)296 static inline char * mdname (mddev_t * mddev)
297 {
298 return mddev->gendisk ? mddev->gendisk->disk_name : "mdX";
299 }
300
301 /*
302 * iterates through some rdev ringlist. It's safe to remove the
303 * current 'rdev'. Dont touch 'tmp' though.
304 */
305 #define ITERATE_RDEV_GENERIC(head,rdev,tmp) \
306 \
307 for ((tmp) = (head).next; \
308 (rdev) = (list_entry((tmp), mdk_rdev_t, same_set)), \
309 (tmp) = (tmp)->next, (tmp)->prev != &(head) \
310 ; )
311 /*
312 * iterates through the 'same array disks' ringlist
313 */
314 #define ITERATE_RDEV(mddev,rdev,tmp) \
315 ITERATE_RDEV_GENERIC((mddev)->disks,rdev,tmp)
316
317 /*
318 * Iterates through 'pending RAID disks'
319 */
320 #define ITERATE_RDEV_PENDING(rdev,tmp) \
321 ITERATE_RDEV_GENERIC(pending_raid_disks,rdev,tmp)
322
323 typedef struct mdk_thread_s {
324 void (*run) (mddev_t *mddev);
325 mddev_t *mddev;
326 wait_queue_head_t wqueue;
327 unsigned long flags;
328 struct task_struct *tsk;
329 unsigned long timeout;
330 } mdk_thread_t;
331
332 #define THREAD_WAKEUP 0
333
334 #define __wait_event_lock_irq(wq, condition, lock, cmd) \
335 do { \
336 wait_queue_t __wait; \
337 init_waitqueue_entry(&__wait, current); \
338 \
339 add_wait_queue(&wq, &__wait); \
340 for (;;) { \
341 set_current_state(TASK_UNINTERRUPTIBLE); \
342 if (condition) \
343 break; \
344 spin_unlock_irq(&lock); \
345 cmd; \
346 schedule(); \
347 spin_lock_irq(&lock); \
348 } \
349 current->state = TASK_RUNNING; \
350 remove_wait_queue(&wq, &__wait); \
351 } while (0)
352
353 #define wait_event_lock_irq(wq, condition, lock, cmd) \
354 do { \
355 if (condition) \
356 break; \
357 __wait_event_lock_irq(wq, condition, lock, cmd); \
358 } while (0)
359
safe_put_page(struct page * p)360 static inline void safe_put_page(struct page *p)
361 {
362 if (p) put_page(p);
363 }
364
365 #endif
366
367