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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_MD_H
16#define _MD_MD_H
17
18#include <linux/blkdev.h>
19#include <linux/kobject.h>
20#include <linux/list.h>
21#include <linux/mm.h>
22#include <linux/mutex.h>
23#include <linux/timer.h>
24#include <linux/wait.h>
25#include <linux/workqueue.h>
26
27#define MaxSector (~(sector_t)0)
28
29typedef struct mddev_s mddev_t;
30typedef struct mdk_rdev_s mdk_rdev_t;
31
32/* Bad block numbers are stored sorted in a single page.
33 * 64bits is used for each block or extent.
34 * 54 bits are sector number, 9 bits are extent size,
35 * 1 bit is an 'acknowledged' flag.
36 */
37#define MD_MAX_BADBLOCKS (PAGE_SIZE/8)
38
39/*
40 * MD's 'extended' device
41 */
42struct mdk_rdev_s
43{
44 struct list_head same_set; /* RAID devices within the same set */
45
46 sector_t sectors; /* Device size (in 512bytes sectors) */
47 mddev_t *mddev; /* RAID array if running */
48 int last_events; /* IO event timestamp */
49
50 /*
51 * If meta_bdev is non-NULL, it means that a separate device is
52 * being used to store the metadata (superblock/bitmap) which
53 * would otherwise be contained on the same device as the data (bdev).
54 */
55 struct block_device *meta_bdev;
56 struct block_device *bdev; /* block device handle */
57
58 struct page *sb_page, *bb_page;
59 int sb_loaded;
60 __u64 sb_events;
61 sector_t data_offset; /* start of data in array */
62 sector_t sb_start; /* offset of the super block (in 512byte sectors) */
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 AutoDetected 7 /* added by auto-detect */
84#define Blocked 8 /* An error occurred but has not yet
85 * been acknowledged by the metadata
86 * handler, so don't allow writes
87 * until it is cleared */
88#define WriteErrorSeen 9 /* A write error has been seen on this
89 * device
90 */
91#define FaultRecorded 10 /* Intermediate state for clearing
92 * Blocked. The Fault is/will-be
93 * recorded in the metadata, but that
94 * metadata hasn't been stored safely
95 * on disk yet.
96 */
97#define BlockedBadBlocks 11 /* A writer is blocked because they
98 * found an unacknowledged bad-block.
99 * This can safely be cleared at any
100 * time, and the writer will re-check.
101 * It may be set at any time, and at
102 * worst the writer will timeout and
103 * re-check. So setting it as
104 * accurately as possible is good, but
105 * not absolutely critical.
106 */
107 wait_queue_head_t blocked_wait;
108
109 int desc_nr; /* descriptor index in the superblock */
110 int raid_disk; /* role of device in array */
111 int new_raid_disk; /* role that the device will have in
112 * the array after a level-change completes.
113 */
114 int saved_raid_disk; /* role that device used to have in the
115 * array and could again if we did a partial
116 * resync from the bitmap
117 */
118 sector_t recovery_offset;/* If this device has been partially
119 * recovered, this is where we were
120 * up to.
121 */
122
123 atomic_t nr_pending; /* number of pending requests.
124 * only maintained for arrays that
125 * support hot removal
126 */
127 atomic_t read_errors; /* number of consecutive read errors that
128 * we have tried to ignore.
129 */
130 struct timespec last_read_error; /* monotonic time since our
131 * last read error
132 */
133 atomic_t corrected_errors; /* number of corrected read errors,
134 * for reporting to userspace and storing
135 * in superblock.
136 */
137 struct work_struct del_work; /* used for delayed sysfs removal */
138
139 struct sysfs_dirent *sysfs_state; /* handle for 'state'
140 * sysfs entry */
141
142 struct badblocks {
143 int count; /* count of bad blocks */
144 int unacked_exist; /* there probably are unacknowledged
145 * bad blocks. This is only cleared
146 * when a read discovers none
147 */
148 int shift; /* shift from sectors to block size
149 * a -ve shift means badblocks are
150 * disabled.*/
151 u64 *page; /* badblock list */
152 int changed;
153 seqlock_t lock;
154
155 sector_t sector;
156 sector_t size; /* in sectors */
157 } badblocks;
158};
159
160#define BB_LEN_MASK (0x00000000000001FFULL)
161#define BB_OFFSET_MASK (0x7FFFFFFFFFFFFE00ULL)
162#define BB_ACK_MASK (0x8000000000000000ULL)
163#define BB_MAX_LEN 512
164#define BB_OFFSET(x) (((x) & BB_OFFSET_MASK) >> 9)
165#define BB_LEN(x) (((x) & BB_LEN_MASK) + 1)
166#define BB_ACK(x) (!!((x) & BB_ACK_MASK))
167#define BB_MAKE(a, l, ack) (((a)<<9) | ((l)-1) | ((u64)(!!(ack)) << 63))
168
169extern int md_is_badblock(struct badblocks *bb, sector_t s, int sectors,
170 sector_t *first_bad, int *bad_sectors);
171static inline int is_badblock(mdk_rdev_t *rdev, sector_t s, int sectors,
172 sector_t *first_bad, int *bad_sectors)
173{
174 if (unlikely(rdev->badblocks.count)) {
175 int rv = md_is_badblock(&rdev->badblocks, rdev->data_offset + s,
176 sectors,
177 first_bad, bad_sectors);
178 if (rv)
179 *first_bad -= rdev->data_offset;
180 return rv;
181 }
182 return 0;
183}
184extern int rdev_set_badblocks(mdk_rdev_t *rdev, sector_t s, int sectors,
185 int acknowledged);
186extern int rdev_clear_badblocks(mdk_rdev_t *rdev, sector_t s, int sectors);
187extern void md_ack_all_badblocks(struct badblocks *bb);
188
189struct mddev_s
190{
191 void *private;
192 struct mdk_personality *pers;
193 dev_t unit;
194 int md_minor;
195 struct list_head disks;
196 unsigned long flags;
197#define MD_CHANGE_DEVS 0 /* Some device status has changed */
198#define MD_CHANGE_CLEAN 1 /* transition to or from 'clean' */
199#define MD_CHANGE_PENDING 2 /* switch from 'clean' to 'active' in progress */
200#define MD_ARRAY_FIRST_USE 3 /* First use of array, needs initialization */
201
202 int suspended;
203 atomic_t active_io;
204 int ro;
205 int sysfs_active; /* set when sysfs deletes
206 * are happening, so run/
207 * takeover/stop are not safe
208 */
209 int ready; /* See when safe to pass
210 * IO requests down */
211 struct gendisk *gendisk;
212
213 struct kobject kobj;
214 int hold_active;
215#define UNTIL_IOCTL 1
216#define UNTIL_STOP 2
217
218 /* Superblock information */
219 int major_version,
220 minor_version,
221 patch_version;
222 int persistent;
223 int external; /* metadata is
224 * managed externally */
225 char metadata_type[17]; /* externally set*/
226 int chunk_sectors;
227 time_t ctime, utime;
228 int level, layout;
229 char clevel[16];
230 int raid_disks;
231 int max_disks;
232 sector_t dev_sectors; /* used size of
233 * component devices */
234 sector_t array_sectors; /* exported array size */
235 int external_size; /* size managed
236 * externally */
237 __u64 events;
238 /* If the last 'event' was simply a clean->dirty transition, and
239 * we didn't write it to the spares, then it is safe and simple
240 * to just decrement the event count on a dirty->clean transition.
241 * So we record that possibility here.
242 */
243 int can_decrease_events;
244
245 char uuid[16];
246
247 /* If the array is being reshaped, we need to record the
248 * new shape and an indication of where we are up to.
249 * This is written to the superblock.
250 * If reshape_position is MaxSector, then no reshape is happening (yet).
251 */
252 sector_t reshape_position;
253 int delta_disks, new_level, new_layout;
254 int new_chunk_sectors;
255
256 atomic_t plug_cnt; /* If device is expecting
257 * more bios soon.
258 */
259 struct mdk_thread_s *thread; /* management thread */
260 struct mdk_thread_s *sync_thread; /* doing resync or reconstruct */
261 sector_t curr_resync; /* last block scheduled */
262 /* As resync requests can complete out of order, we cannot easily track
263 * how much resync has been completed. So we occasionally pause until
264 * everything completes, then set curr_resync_completed to curr_resync.
265 * As such it may be well behind the real resync mark, but it is a value
266 * we are certain of.
267 */
268 sector_t curr_resync_completed;
269 unsigned long resync_mark; /* a recent timestamp */
270 sector_t resync_mark_cnt;/* blocks written at resync_mark */
271 sector_t curr_mark_cnt; /* blocks scheduled now */
272
273 sector_t resync_max_sectors; /* may be set by personality */
274
275 sector_t resync_mismatches; /* count of sectors where
276 * parity/replica mismatch found
277 */
278
279 /* allow user-space to request suspension of IO to regions of the array */
280 sector_t suspend_lo;
281 sector_t suspend_hi;
282 /* if zero, use the system-wide default */
283 int sync_speed_min;
284 int sync_speed_max;
285
286 /* resync even though the same disks are shared among md-devices */
287 int parallel_resync;
288
289 int ok_start_degraded;
290 /* recovery/resync flags
291 * NEEDED: we might need to start a resync/recover
292 * RUNNING: a thread is running, or about to be started
293 * SYNC: actually doing a resync, not a recovery
294 * RECOVER: doing recovery, or need to try it.
295 * INTR: resync needs to be aborted for some reason
296 * DONE: thread is done and is waiting to be reaped
297 * REQUEST: user-space has requested a sync (used with SYNC)
298 * CHECK: user-space request for check-only, no repair
299 * RESHAPE: A reshape is happening
300 *
301 * If neither SYNC or RESHAPE are set, then it is a recovery.
302 */
303#define MD_RECOVERY_RUNNING 0
304#define MD_RECOVERY_SYNC 1
305#define MD_RECOVERY_RECOVER 2
306#define MD_RECOVERY_INTR 3
307#define MD_RECOVERY_DONE 4
308#define MD_RECOVERY_NEEDED 5
309#define MD_RECOVERY_REQUESTED 6
310#define MD_RECOVERY_CHECK 7
311#define MD_RECOVERY_RESHAPE 8
312#define MD_RECOVERY_FROZEN 9
313
314 unsigned long recovery;
315 /* If a RAID personality determines that recovery (of a particular
316 * device) will fail due to a read error on the source device, it
317 * takes a copy of this number and does not attempt recovery again
318 * until this number changes.
319 */
320 int recovery_disabled;
321
322 int in_sync; /* know to not need resync */
323 /* 'open_mutex' avoids races between 'md_open' and 'do_md_stop', so
324 * that we are never stopping an array while it is open.
325 * 'reconfig_mutex' protects all other reconfiguration.
326 * These locks are separate due to conflicting interactions
327 * with bdev->bd_mutex.
328 * Lock ordering is:
329 * reconfig_mutex -> bd_mutex : e.g. do_md_run -> revalidate_disk
330 * bd_mutex -> open_mutex: e.g. __blkdev_get -> md_open
331 */
332 struct mutex open_mutex;
333 struct mutex reconfig_mutex;
334 atomic_t active; /* general refcount */
335 atomic_t openers; /* number of active opens */
336
337 int changed; /* True if we might need to
338 * reread partition info */
339 int degraded; /* whether md should consider
340 * adding a spare
341 */
342
343 atomic_t recovery_active; /* blocks scheduled, but not written */
344 wait_queue_head_t recovery_wait;
345 sector_t recovery_cp;
346 sector_t resync_min; /* user requested sync
347 * starts here */
348 sector_t resync_max; /* resync should pause
349 * when it gets here */
350
351 struct sysfs_dirent *sysfs_state; /* handle for 'array_state'
352 * file in sysfs.
353 */
354 struct sysfs_dirent *sysfs_action; /* handle for 'sync_action' */
355
356 struct work_struct del_work; /* used for delayed sysfs removal */
357
358 spinlock_t write_lock;
359 wait_queue_head_t sb_wait; /* for waiting on superblock updates */
360 atomic_t pending_writes; /* number of active superblock writes */
361
362 unsigned int safemode; /* if set, update "clean" superblock
363 * when no writes pending.
364 */
365 unsigned int safemode_delay;
366 struct timer_list safemode_timer;
367 atomic_t writes_pending;
368 struct request_queue *queue; /* for plugging ... */
369
370 struct bitmap *bitmap; /* the bitmap for the device */
371 struct {
372 struct file *file; /* the bitmap file */
373 loff_t offset; /* offset from superblock of
374 * start of bitmap. May be
375 * negative, but not '0'
376 * For external metadata, offset
377 * from start of device.
378 */
379 loff_t default_offset; /* this is the offset to use when
380 * hot-adding a bitmap. It should
381 * eventually be settable by sysfs.
382 */
383 struct mutex mutex;
384 unsigned long chunksize;
385 unsigned long daemon_sleep; /* how many jiffies between updates? */
386 unsigned long max_write_behind; /* write-behind mode */
387 int external;
388 } bitmap_info;
389
390 atomic_t max_corr_read_errors; /* max read retries */
391 struct list_head all_mddevs;
392
393 struct attribute_group *to_remove;
394
395 struct bio_set *bio_set;
396
397 /* Generic flush handling.
398 * The last to finish preflush schedules a worker to submit
399 * the rest of the request (without the REQ_FLUSH flag).
400 */
401 struct bio *flush_bio;
402 atomic_t flush_pending;
403 struct work_struct flush_work;
404 struct work_struct event_work; /* used by dm to report failure event */
405 void (*sync_super)(mddev_t *mddev, mdk_rdev_t *rdev);
406};
407
408
409static inline void rdev_dec_pending(mdk_rdev_t *rdev, mddev_t *mddev)
410{
411 int faulty = test_bit(Faulty, &rdev->flags);
412 if (atomic_dec_and_test(&rdev->nr_pending) && faulty)
413 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
414}
415
416static inline void md_sync_acct(struct block_device *bdev, unsigned long nr_sectors)
417{
418 atomic_add(nr_sectors, &bdev->bd_contains->bd_disk->sync_io);
419}
420
421struct mdk_personality
422{
423 char *name;
424 int level;
425 struct list_head list;
426 struct module *owner;
427 int (*make_request)(mddev_t *mddev, struct bio *bio);
428 int (*run)(mddev_t *mddev);
429 int (*stop)(mddev_t *mddev);
430 void (*status)(struct seq_file *seq, mddev_t *mddev);
431 /* error_handler must set ->faulty and clear ->in_sync
432 * if appropriate, and should abort recovery if needed
433 */
434 void (*error_handler)(mddev_t *mddev, mdk_rdev_t *rdev);
435 int (*hot_add_disk) (mddev_t *mddev, mdk_rdev_t *rdev);
436 int (*hot_remove_disk) (mddev_t *mddev, int number);
437 int (*spare_active) (mddev_t *mddev);
438 sector_t (*sync_request)(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster);
439 int (*resize) (mddev_t *mddev, sector_t sectors);
440 sector_t (*size) (mddev_t *mddev, sector_t sectors, int raid_disks);
441 int (*check_reshape) (mddev_t *mddev);
442 int (*start_reshape) (mddev_t *mddev);
443 void (*finish_reshape) (mddev_t *mddev);
444 /* quiesce moves between quiescence states
445 * 0 - fully active
446 * 1 - no new requests allowed
447 * others - reserved
448 */
449 void (*quiesce) (mddev_t *mddev, int state);
450 /* takeover is used to transition an array from one
451 * personality to another. The new personality must be able
452 * to handle the data in the current layout.
453 * e.g. 2drive raid1 -> 2drive raid5
454 * ndrive raid5 -> degraded n+1drive raid6 with special layout
455 * If the takeover succeeds, a new 'private' structure is returned.
456 * This needs to be installed and then ->run used to activate the
457 * array.
458 */
459 void *(*takeover) (mddev_t *mddev);
460};
461
462
463struct md_sysfs_entry {
464 struct attribute attr;
465 ssize_t (*show)(mddev_t *, char *);
466 ssize_t (*store)(mddev_t *, const char *, size_t);
467};
468extern struct attribute_group md_bitmap_group;
469
470static inline struct sysfs_dirent *sysfs_get_dirent_safe(struct sysfs_dirent *sd, char *name)
471{
472 if (sd)
473 return sysfs_get_dirent(sd, NULL, name);
474 return sd;
475}
476static inline void sysfs_notify_dirent_safe(struct sysfs_dirent *sd)
477{
478 if (sd)
479 sysfs_notify_dirent(sd);
480}
481
482static inline char * mdname (mddev_t * mddev)
483{
484 return mddev->gendisk ? mddev->gendisk->disk_name : "mdX";
485}
486
487static inline int sysfs_link_rdev(mddev_t *mddev, mdk_rdev_t *rdev)
488{
489 char nm[20];
490 sprintf(nm, "rd%d", rdev->raid_disk);
491 return sysfs_create_link(&mddev->kobj, &rdev->kobj, nm);
492}
493
494static inline void sysfs_unlink_rdev(mddev_t *mddev, mdk_rdev_t *rdev)
495{
496 char nm[20];
497 sprintf(nm, "rd%d", rdev->raid_disk);
498 sysfs_remove_link(&mddev->kobj, nm);
499}
500
501/*
502 * iterates through some rdev ringlist. It's safe to remove the
503 * current 'rdev'. Dont touch 'tmp' though.
504 */
505#define rdev_for_each_list(rdev, tmp, head) \
506 list_for_each_entry_safe(rdev, tmp, head, same_set)
507
508/*
509 * iterates through the 'same array disks' ringlist
510 */
511#define rdev_for_each(rdev, tmp, mddev) \
512 list_for_each_entry_safe(rdev, tmp, &((mddev)->disks), same_set)
513
514#define rdev_for_each_rcu(rdev, mddev) \
515 list_for_each_entry_rcu(rdev, &((mddev)->disks), same_set)
516
517typedef struct mdk_thread_s {
518 void (*run) (mddev_t *mddev);
519 mddev_t *mddev;
520 wait_queue_head_t wqueue;
521 unsigned long flags;
522 struct task_struct *tsk;
523 unsigned long timeout;
524} mdk_thread_t;
525
526#define THREAD_WAKEUP 0
527
528#define __wait_event_lock_irq(wq, condition, lock, cmd) \
529do { \
530 wait_queue_t __wait; \
531 init_waitqueue_entry(&__wait, current); \
532 \
533 add_wait_queue(&wq, &__wait); \
534 for (;;) { \
535 set_current_state(TASK_UNINTERRUPTIBLE); \
536 if (condition) \
537 break; \
538 spin_unlock_irq(&lock); \
539 cmd; \
540 schedule(); \
541 spin_lock_irq(&lock); \
542 } \
543 current->state = TASK_RUNNING; \
544 remove_wait_queue(&wq, &__wait); \
545} while (0)
546
547#define wait_event_lock_irq(wq, condition, lock, cmd) \
548do { \
549 if (condition) \
550 break; \
551 __wait_event_lock_irq(wq, condition, lock, cmd); \
552} while (0)
553
554static inline void safe_put_page(struct page *p)
555{
556 if (p) put_page(p);
557}
558
559extern int register_md_personality(struct mdk_personality *p);
560extern int unregister_md_personality(struct mdk_personality *p);
561extern mdk_thread_t * md_register_thread(void (*run) (mddev_t *mddev),
562 mddev_t *mddev, const char *name);
563extern void md_unregister_thread(mdk_thread_t **threadp);
564extern void md_wakeup_thread(mdk_thread_t *thread);
565extern void md_check_recovery(mddev_t *mddev);
566extern void md_write_start(mddev_t *mddev, struct bio *bi);
567extern void md_write_end(mddev_t *mddev);
568extern void md_done_sync(mddev_t *mddev, int blocks, int ok);
569extern void md_error(mddev_t *mddev, mdk_rdev_t *rdev);
570
571extern int mddev_congested(mddev_t *mddev, int bits);
572extern void md_flush_request(mddev_t *mddev, struct bio *bio);
573extern void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
574 sector_t sector, int size, struct page *page);
575extern void md_super_wait(mddev_t *mddev);
576extern int sync_page_io(mdk_rdev_t *rdev, sector_t sector, int size,
577 struct page *page, int rw, bool metadata_op);
578extern void md_do_sync(mddev_t *mddev);
579extern void md_new_event(mddev_t *mddev);
580extern int md_allow_write(mddev_t *mddev);
581extern void md_wait_for_blocked_rdev(mdk_rdev_t *rdev, mddev_t *mddev);
582extern void md_set_array_sectors(mddev_t *mddev, sector_t array_sectors);
583extern int md_check_no_bitmap(mddev_t *mddev);
584extern int md_integrity_register(mddev_t *mddev);
585extern void md_integrity_add_rdev(mdk_rdev_t *rdev, mddev_t *mddev);
586extern int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale);
587extern void restore_bitmap_write_access(struct file *file);
588
589extern void mddev_init(mddev_t *mddev);
590extern int md_run(mddev_t *mddev);
591extern void md_stop(mddev_t *mddev);
592extern void md_stop_writes(mddev_t *mddev);
593extern int md_rdev_init(mdk_rdev_t *rdev);
594
595extern void mddev_suspend(mddev_t *mddev);
596extern void mddev_resume(mddev_t *mddev);
597extern struct bio *bio_clone_mddev(struct bio *bio, gfp_t gfp_mask,
598 mddev_t *mddev);
599extern struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs,
600 mddev_t *mddev);
601extern int mddev_check_plugged(mddev_t *mddev);
602extern void md_trim_bio(struct bio *bio, int offset, int size);
603#endif /* _MD_MD_H */
1/*
2 md.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_MD_H
16#define _MD_MD_H
17
18#include <linux/blkdev.h>
19#include <linux/kobject.h>
20#include <linux/list.h>
21#include <linux/mm.h>
22#include <linux/mutex.h>
23#include <linux/timer.h>
24#include <linux/wait.h>
25#include <linux/workqueue.h>
26
27#define MaxSector (~(sector_t)0)
28
29/* Bad block numbers are stored sorted in a single page.
30 * 64bits is used for each block or extent.
31 * 54 bits are sector number, 9 bits are extent size,
32 * 1 bit is an 'acknowledged' flag.
33 */
34#define MD_MAX_BADBLOCKS (PAGE_SIZE/8)
35
36/*
37 * MD's 'extended' device
38 */
39struct md_rdev {
40 struct list_head same_set; /* RAID devices within the same set */
41
42 sector_t sectors; /* Device size (in 512bytes sectors) */
43 struct mddev *mddev; /* RAID array if running */
44 int last_events; /* IO event timestamp */
45
46 /*
47 * If meta_bdev is non-NULL, it means that a separate device is
48 * being used to store the metadata (superblock/bitmap) which
49 * would otherwise be contained on the same device as the data (bdev).
50 */
51 struct block_device *meta_bdev;
52 struct block_device *bdev; /* block device handle */
53
54 struct page *sb_page, *bb_page;
55 int sb_loaded;
56 __u64 sb_events;
57 sector_t data_offset; /* start of data in array */
58 sector_t new_data_offset;/* only relevant while reshaping */
59 sector_t sb_start; /* offset of the super block (in 512byte sectors) */
60 int sb_size; /* bytes in the superblock */
61 int preferred_minor; /* autorun support */
62
63 struct kobject kobj;
64
65 /* A device can be in one of three states based on two flags:
66 * Not working: faulty==1 in_sync==0
67 * Fully working: faulty==0 in_sync==1
68 * Working, but not
69 * in sync with array
70 * faulty==0 in_sync==0
71 *
72 * It can never have faulty==1, in_sync==1
73 * This reduces the burden of testing multiple flags in many cases
74 */
75
76 unsigned long flags; /* bit set of 'enum flag_bits' bits. */
77 wait_queue_head_t blocked_wait;
78
79 int desc_nr; /* descriptor index in the superblock */
80 int raid_disk; /* role of device in array */
81 int new_raid_disk; /* role that the device will have in
82 * the array after a level-change completes.
83 */
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 struct timespec last_read_error; /* monotonic time since our
101 * last read error
102 */
103 atomic_t corrected_errors; /* number of corrected read errors,
104 * for reporting to userspace and storing
105 * in superblock.
106 */
107 struct work_struct del_work; /* used for delayed sysfs removal */
108
109 struct kernfs_node *sysfs_state; /* handle for 'state'
110 * sysfs entry */
111
112 struct badblocks {
113 int count; /* count of bad blocks */
114 int unacked_exist; /* there probably are unacknowledged
115 * bad blocks. This is only cleared
116 * when a read discovers none
117 */
118 int shift; /* shift from sectors to block size
119 * a -ve shift means badblocks are
120 * disabled.*/
121 u64 *page; /* badblock list */
122 int changed;
123 seqlock_t lock;
124
125 sector_t sector;
126 sector_t size; /* in sectors */
127 } badblocks;
128};
129enum flag_bits {
130 Faulty, /* device is known to have a fault */
131 In_sync, /* device is in_sync with rest of array */
132 Bitmap_sync, /* ..actually, not quite In_sync. Need a
133 * bitmap-based recovery to get fully in sync
134 */
135 Unmerged, /* device is being added to array and should
136 * be considerred for bvec_merge_fn but not
137 * yet for actual IO
138 */
139 WriteMostly, /* Avoid reading if at all possible */
140 AutoDetected, /* added by auto-detect */
141 Blocked, /* An error occurred but has not yet
142 * been acknowledged by the metadata
143 * handler, so don't allow writes
144 * until it is cleared */
145 WriteErrorSeen, /* A write error has been seen on this
146 * device
147 */
148 FaultRecorded, /* Intermediate state for clearing
149 * Blocked. The Fault is/will-be
150 * recorded in the metadata, but that
151 * metadata hasn't been stored safely
152 * on disk yet.
153 */
154 BlockedBadBlocks, /* A writer is blocked because they
155 * found an unacknowledged bad-block.
156 * This can safely be cleared at any
157 * time, and the writer will re-check.
158 * It may be set at any time, and at
159 * worst the writer will timeout and
160 * re-check. So setting it as
161 * accurately as possible is good, but
162 * not absolutely critical.
163 */
164 WantReplacement, /* This device is a candidate to be
165 * hot-replaced, either because it has
166 * reported some faults, or because
167 * of explicit request.
168 */
169 Replacement, /* This device is a replacement for
170 * a want_replacement device with same
171 * raid_disk number.
172 */
173};
174
175#define BB_LEN_MASK (0x00000000000001FFULL)
176#define BB_OFFSET_MASK (0x7FFFFFFFFFFFFE00ULL)
177#define BB_ACK_MASK (0x8000000000000000ULL)
178#define BB_MAX_LEN 512
179#define BB_OFFSET(x) (((x) & BB_OFFSET_MASK) >> 9)
180#define BB_LEN(x) (((x) & BB_LEN_MASK) + 1)
181#define BB_ACK(x) (!!((x) & BB_ACK_MASK))
182#define BB_MAKE(a, l, ack) (((a)<<9) | ((l)-1) | ((u64)(!!(ack)) << 63))
183
184extern int md_is_badblock(struct badblocks *bb, sector_t s, int sectors,
185 sector_t *first_bad, int *bad_sectors);
186static inline int is_badblock(struct md_rdev *rdev, sector_t s, int sectors,
187 sector_t *first_bad, int *bad_sectors)
188{
189 if (unlikely(rdev->badblocks.count)) {
190 int rv = md_is_badblock(&rdev->badblocks, rdev->data_offset + s,
191 sectors,
192 first_bad, bad_sectors);
193 if (rv)
194 *first_bad -= rdev->data_offset;
195 return rv;
196 }
197 return 0;
198}
199extern int rdev_set_badblocks(struct md_rdev *rdev, sector_t s, int sectors,
200 int is_new);
201extern int rdev_clear_badblocks(struct md_rdev *rdev, sector_t s, int sectors,
202 int is_new);
203extern void md_ack_all_badblocks(struct badblocks *bb);
204
205struct mddev {
206 void *private;
207 struct md_personality *pers;
208 dev_t unit;
209 int md_minor;
210 struct list_head disks;
211 unsigned long flags;
212#define MD_CHANGE_DEVS 0 /* Some device status has changed */
213#define MD_CHANGE_CLEAN 1 /* transition to or from 'clean' */
214#define MD_CHANGE_PENDING 2 /* switch from 'clean' to 'active' in progress */
215#define MD_UPDATE_SB_FLAGS (1 | 2 | 4) /* If these are set, md_update_sb needed */
216#define MD_ARRAY_FIRST_USE 3 /* First use of array, needs initialization */
217#define MD_STILL_CLOSED 4 /* If set, then array has not been opened since
218 * md_ioctl checked on it.
219 */
220
221 int suspended;
222 atomic_t active_io;
223 int ro;
224 int sysfs_active; /* set when sysfs deletes
225 * are happening, so run/
226 * takeover/stop are not safe
227 */
228 int ready; /* See when safe to pass
229 * IO requests down */
230 struct gendisk *gendisk;
231
232 struct kobject kobj;
233 int hold_active;
234#define UNTIL_IOCTL 1
235#define UNTIL_STOP 2
236
237 /* Superblock information */
238 int major_version,
239 minor_version,
240 patch_version;
241 int persistent;
242 int external; /* metadata is
243 * managed externally */
244 char metadata_type[17]; /* externally set*/
245 int chunk_sectors;
246 time_t ctime, utime;
247 int level, layout;
248 char clevel[16];
249 int raid_disks;
250 int max_disks;
251 sector_t dev_sectors; /* used size of
252 * component devices */
253 sector_t array_sectors; /* exported array size */
254 int external_size; /* size managed
255 * externally */
256 __u64 events;
257 /* If the last 'event' was simply a clean->dirty transition, and
258 * we didn't write it to the spares, then it is safe and simple
259 * to just decrement the event count on a dirty->clean transition.
260 * So we record that possibility here.
261 */
262 int can_decrease_events;
263
264 char uuid[16];
265
266 /* If the array is being reshaped, we need to record the
267 * new shape and an indication of where we are up to.
268 * This is written to the superblock.
269 * If reshape_position is MaxSector, then no reshape is happening (yet).
270 */
271 sector_t reshape_position;
272 int delta_disks, new_level, new_layout;
273 int new_chunk_sectors;
274 int reshape_backwards;
275
276 struct md_thread *thread; /* management thread */
277 struct md_thread *sync_thread; /* doing resync or reconstruct */
278
279 /* 'last_sync_action' is initialized to "none". It is set when a
280 * sync operation (i.e "data-check", "requested-resync", "resync",
281 * "recovery", or "reshape") is started. It holds this value even
282 * when the sync thread is "frozen" (interrupted) or "idle" (stopped
283 * or finished). It is overwritten when a new sync operation is begun.
284 */
285 char *last_sync_action;
286 sector_t curr_resync; /* last block scheduled */
287 /* As resync requests can complete out of order, we cannot easily track
288 * how much resync has been completed. So we occasionally pause until
289 * everything completes, then set curr_resync_completed to curr_resync.
290 * As such it may be well behind the real resync mark, but it is a value
291 * we are certain of.
292 */
293 sector_t curr_resync_completed;
294 unsigned long resync_mark; /* a recent timestamp */
295 sector_t resync_mark_cnt;/* blocks written at resync_mark */
296 sector_t curr_mark_cnt; /* blocks scheduled now */
297
298 sector_t resync_max_sectors; /* may be set by personality */
299
300 atomic64_t resync_mismatches; /* count of sectors where
301 * parity/replica mismatch found
302 */
303
304 /* allow user-space to request suspension of IO to regions of the array */
305 sector_t suspend_lo;
306 sector_t suspend_hi;
307 /* if zero, use the system-wide default */
308 int sync_speed_min;
309 int sync_speed_max;
310
311 /* resync even though the same disks are shared among md-devices */
312 int parallel_resync;
313
314 int ok_start_degraded;
315 /* recovery/resync flags
316 * NEEDED: we might need to start a resync/recover
317 * RUNNING: a thread is running, or about to be started
318 * SYNC: actually doing a resync, not a recovery
319 * RECOVER: doing recovery, or need to try it.
320 * INTR: resync needs to be aborted for some reason
321 * DONE: thread is done and is waiting to be reaped
322 * REQUEST: user-space has requested a sync (used with SYNC)
323 * CHECK: user-space request for check-only, no repair
324 * RESHAPE: A reshape is happening
325 * ERROR: sync-action interrupted because io-error
326 *
327 * If neither SYNC or RESHAPE are set, then it is a recovery.
328 */
329#define MD_RECOVERY_RUNNING 0
330#define MD_RECOVERY_SYNC 1
331#define MD_RECOVERY_RECOVER 2
332#define MD_RECOVERY_INTR 3
333#define MD_RECOVERY_DONE 4
334#define MD_RECOVERY_NEEDED 5
335#define MD_RECOVERY_REQUESTED 6
336#define MD_RECOVERY_CHECK 7
337#define MD_RECOVERY_RESHAPE 8
338#define MD_RECOVERY_FROZEN 9
339#define MD_RECOVERY_ERROR 10
340
341 unsigned long recovery;
342 /* If a RAID personality determines that recovery (of a particular
343 * device) will fail due to a read error on the source device, it
344 * takes a copy of this number and does not attempt recovery again
345 * until this number changes.
346 */
347 int recovery_disabled;
348
349 int in_sync; /* know to not need resync */
350 /* 'open_mutex' avoids races between 'md_open' and 'do_md_stop', so
351 * that we are never stopping an array while it is open.
352 * 'reconfig_mutex' protects all other reconfiguration.
353 * These locks are separate due to conflicting interactions
354 * with bdev->bd_mutex.
355 * Lock ordering is:
356 * reconfig_mutex -> bd_mutex : e.g. do_md_run -> revalidate_disk
357 * bd_mutex -> open_mutex: e.g. __blkdev_get -> md_open
358 */
359 struct mutex open_mutex;
360 struct mutex reconfig_mutex;
361 atomic_t active; /* general refcount */
362 atomic_t openers; /* number of active opens */
363
364 int changed; /* True if we might need to
365 * reread partition info */
366 int degraded; /* whether md should consider
367 * adding a spare
368 */
369 int merge_check_needed; /* at least one
370 * member device
371 * has a
372 * merge_bvec_fn */
373
374 atomic_t recovery_active; /* blocks scheduled, but not written */
375 wait_queue_head_t recovery_wait;
376 sector_t recovery_cp;
377 sector_t resync_min; /* user requested sync
378 * starts here */
379 sector_t resync_max; /* resync should pause
380 * when it gets here */
381
382 struct kernfs_node *sysfs_state; /* handle for 'array_state'
383 * file in sysfs.
384 */
385 struct kernfs_node *sysfs_action; /* handle for 'sync_action' */
386
387 struct work_struct del_work; /* used for delayed sysfs removal */
388
389 spinlock_t write_lock;
390 wait_queue_head_t sb_wait; /* for waiting on superblock updates */
391 atomic_t pending_writes; /* number of active superblock writes */
392
393 unsigned int safemode; /* if set, update "clean" superblock
394 * when no writes pending.
395 */
396 unsigned int safemode_delay;
397 struct timer_list safemode_timer;
398 atomic_t writes_pending;
399 struct request_queue *queue; /* for plugging ... */
400
401 struct bitmap *bitmap; /* the bitmap for the device */
402 struct {
403 struct file *file; /* the bitmap file */
404 loff_t offset; /* offset from superblock of
405 * start of bitmap. May be
406 * negative, but not '0'
407 * For external metadata, offset
408 * from start of device.
409 */
410 unsigned long space; /* space available at this offset */
411 loff_t default_offset; /* this is the offset to use when
412 * hot-adding a bitmap. It should
413 * eventually be settable by sysfs.
414 */
415 unsigned long default_space; /* space available at
416 * default offset */
417 struct mutex mutex;
418 unsigned long chunksize;
419 unsigned long daemon_sleep; /* how many jiffies between updates? */
420 unsigned long max_write_behind; /* write-behind mode */
421 int external;
422 } bitmap_info;
423
424 atomic_t max_corr_read_errors; /* max read retries */
425 struct list_head all_mddevs;
426
427 struct attribute_group *to_remove;
428
429 struct bio_set *bio_set;
430
431 /* Generic flush handling.
432 * The last to finish preflush schedules a worker to submit
433 * the rest of the request (without the REQ_FLUSH flag).
434 */
435 struct bio *flush_bio;
436 atomic_t flush_pending;
437 struct work_struct flush_work;
438 struct work_struct event_work; /* used by dm to report failure event */
439 void (*sync_super)(struct mddev *mddev, struct md_rdev *rdev);
440};
441
442
443static inline void rdev_dec_pending(struct md_rdev *rdev, struct mddev *mddev)
444{
445 int faulty = test_bit(Faulty, &rdev->flags);
446 if (atomic_dec_and_test(&rdev->nr_pending) && faulty)
447 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
448}
449
450static inline void md_sync_acct(struct block_device *bdev, unsigned long nr_sectors)
451{
452 atomic_add(nr_sectors, &bdev->bd_contains->bd_disk->sync_io);
453}
454
455struct md_personality
456{
457 char *name;
458 int level;
459 struct list_head list;
460 struct module *owner;
461 void (*make_request)(struct mddev *mddev, struct bio *bio);
462 int (*run)(struct mddev *mddev);
463 int (*stop)(struct mddev *mddev);
464 void (*status)(struct seq_file *seq, struct mddev *mddev);
465 /* error_handler must set ->faulty and clear ->in_sync
466 * if appropriate, and should abort recovery if needed
467 */
468 void (*error_handler)(struct mddev *mddev, struct md_rdev *rdev);
469 int (*hot_add_disk) (struct mddev *mddev, struct md_rdev *rdev);
470 int (*hot_remove_disk) (struct mddev *mddev, struct md_rdev *rdev);
471 int (*spare_active) (struct mddev *mddev);
472 sector_t (*sync_request)(struct mddev *mddev, sector_t sector_nr, int *skipped, int go_faster);
473 int (*resize) (struct mddev *mddev, sector_t sectors);
474 sector_t (*size) (struct mddev *mddev, sector_t sectors, int raid_disks);
475 int (*check_reshape) (struct mddev *mddev);
476 int (*start_reshape) (struct mddev *mddev);
477 void (*finish_reshape) (struct mddev *mddev);
478 /* quiesce moves between quiescence states
479 * 0 - fully active
480 * 1 - no new requests allowed
481 * others - reserved
482 */
483 void (*quiesce) (struct mddev *mddev, int state);
484 /* takeover is used to transition an array from one
485 * personality to another. The new personality must be able
486 * to handle the data in the current layout.
487 * e.g. 2drive raid1 -> 2drive raid5
488 * ndrive raid5 -> degraded n+1drive raid6 with special layout
489 * If the takeover succeeds, a new 'private' structure is returned.
490 * This needs to be installed and then ->run used to activate the
491 * array.
492 */
493 void *(*takeover) (struct mddev *mddev);
494};
495
496
497struct md_sysfs_entry {
498 struct attribute attr;
499 ssize_t (*show)(struct mddev *, char *);
500 ssize_t (*store)(struct mddev *, const char *, size_t);
501};
502extern struct attribute_group md_bitmap_group;
503
504static inline struct kernfs_node *sysfs_get_dirent_safe(struct kernfs_node *sd, char *name)
505{
506 if (sd)
507 return sysfs_get_dirent(sd, name);
508 return sd;
509}
510static inline void sysfs_notify_dirent_safe(struct kernfs_node *sd)
511{
512 if (sd)
513 sysfs_notify_dirent(sd);
514}
515
516static inline char * mdname (struct mddev * mddev)
517{
518 return mddev->gendisk ? mddev->gendisk->disk_name : "mdX";
519}
520
521static inline int sysfs_link_rdev(struct mddev *mddev, struct md_rdev *rdev)
522{
523 char nm[20];
524 if (!test_bit(Replacement, &rdev->flags) && mddev->kobj.sd) {
525 sprintf(nm, "rd%d", rdev->raid_disk);
526 return sysfs_create_link(&mddev->kobj, &rdev->kobj, nm);
527 } else
528 return 0;
529}
530
531static inline void sysfs_unlink_rdev(struct mddev *mddev, struct md_rdev *rdev)
532{
533 char nm[20];
534 if (!test_bit(Replacement, &rdev->flags) && mddev->kobj.sd) {
535 sprintf(nm, "rd%d", rdev->raid_disk);
536 sysfs_remove_link(&mddev->kobj, nm);
537 }
538}
539
540/*
541 * iterates through some rdev ringlist. It's safe to remove the
542 * current 'rdev'. Dont touch 'tmp' though.
543 */
544#define rdev_for_each_list(rdev, tmp, head) \
545 list_for_each_entry_safe(rdev, tmp, head, same_set)
546
547/*
548 * iterates through the 'same array disks' ringlist
549 */
550#define rdev_for_each(rdev, mddev) \
551 list_for_each_entry(rdev, &((mddev)->disks), same_set)
552
553#define rdev_for_each_safe(rdev, tmp, mddev) \
554 list_for_each_entry_safe(rdev, tmp, &((mddev)->disks), same_set)
555
556#define rdev_for_each_rcu(rdev, mddev) \
557 list_for_each_entry_rcu(rdev, &((mddev)->disks), same_set)
558
559struct md_thread {
560 void (*run) (struct md_thread *thread);
561 struct mddev *mddev;
562 wait_queue_head_t wqueue;
563 unsigned long flags;
564 struct task_struct *tsk;
565 unsigned long timeout;
566 void *private;
567};
568
569#define THREAD_WAKEUP 0
570
571static inline void safe_put_page(struct page *p)
572{
573 if (p) put_page(p);
574}
575
576extern int register_md_personality(struct md_personality *p);
577extern int unregister_md_personality(struct md_personality *p);
578extern struct md_thread *md_register_thread(
579 void (*run)(struct md_thread *thread),
580 struct mddev *mddev,
581 const char *name);
582extern void md_unregister_thread(struct md_thread **threadp);
583extern void md_wakeup_thread(struct md_thread *thread);
584extern void md_check_recovery(struct mddev *mddev);
585extern void md_reap_sync_thread(struct mddev *mddev);
586extern void md_write_start(struct mddev *mddev, struct bio *bi);
587extern void md_write_end(struct mddev *mddev);
588extern void md_done_sync(struct mddev *mddev, int blocks, int ok);
589extern void md_error(struct mddev *mddev, struct md_rdev *rdev);
590extern void md_finish_reshape(struct mddev *mddev);
591
592extern int mddev_congested(struct mddev *mddev, int bits);
593extern void md_flush_request(struct mddev *mddev, struct bio *bio);
594extern void md_super_write(struct mddev *mddev, struct md_rdev *rdev,
595 sector_t sector, int size, struct page *page);
596extern void md_super_wait(struct mddev *mddev);
597extern int sync_page_io(struct md_rdev *rdev, sector_t sector, int size,
598 struct page *page, int rw, bool metadata_op);
599extern void md_do_sync(struct md_thread *thread);
600extern void md_new_event(struct mddev *mddev);
601extern int md_allow_write(struct mddev *mddev);
602extern void md_wait_for_blocked_rdev(struct md_rdev *rdev, struct mddev *mddev);
603extern void md_set_array_sectors(struct mddev *mddev, sector_t array_sectors);
604extern int md_check_no_bitmap(struct mddev *mddev);
605extern int md_integrity_register(struct mddev *mddev);
606extern void md_integrity_add_rdev(struct md_rdev *rdev, struct mddev *mddev);
607extern int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale);
608
609extern void mddev_init(struct mddev *mddev);
610extern int md_run(struct mddev *mddev);
611extern void md_stop(struct mddev *mddev);
612extern void md_stop_writes(struct mddev *mddev);
613extern int md_rdev_init(struct md_rdev *rdev);
614extern void md_rdev_clear(struct md_rdev *rdev);
615
616extern void mddev_suspend(struct mddev *mddev);
617extern void mddev_resume(struct mddev *mddev);
618extern struct bio *bio_clone_mddev(struct bio *bio, gfp_t gfp_mask,
619 struct mddev *mddev);
620extern struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs,
621 struct mddev *mddev);
622
623extern void md_unplug(struct blk_plug_cb *cb, bool from_schedule);
624static inline int mddev_check_plugged(struct mddev *mddev)
625{
626 return !!blk_check_plugged(md_unplug, mddev,
627 sizeof(struct blk_plug_cb));
628}
629#endif /* _MD_MD_H */