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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 sysfs_dirent *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 Unmerged, /* device is being added to array and should
133 * be considerred for bvec_merge_fn but not
134 * yet for actual IO
135 */
136 WriteMostly, /* Avoid reading if at all possible */
137 AutoDetected, /* added by auto-detect */
138 Blocked, /* An error occurred but has not yet
139 * been acknowledged by the metadata
140 * handler, so don't allow writes
141 * until it is cleared */
142 WriteErrorSeen, /* A write error has been seen on this
143 * device
144 */
145 FaultRecorded, /* Intermediate state for clearing
146 * Blocked. The Fault is/will-be
147 * recorded in the metadata, but that
148 * metadata hasn't been stored safely
149 * on disk yet.
150 */
151 BlockedBadBlocks, /* A writer is blocked because they
152 * found an unacknowledged bad-block.
153 * This can safely be cleared at any
154 * time, and the writer will re-check.
155 * It may be set at any time, and at
156 * worst the writer will timeout and
157 * re-check. So setting it as
158 * accurately as possible is good, but
159 * not absolutely critical.
160 */
161 WantReplacement, /* This device is a candidate to be
162 * hot-replaced, either because it has
163 * reported some faults, or because
164 * of explicit request.
165 */
166 Replacement, /* This device is a replacement for
167 * a want_replacement device with same
168 * raid_disk number.
169 */
170};
171
172#define BB_LEN_MASK (0x00000000000001FFULL)
173#define BB_OFFSET_MASK (0x7FFFFFFFFFFFFE00ULL)
174#define BB_ACK_MASK (0x8000000000000000ULL)
175#define BB_MAX_LEN 512
176#define BB_OFFSET(x) (((x) & BB_OFFSET_MASK) >> 9)
177#define BB_LEN(x) (((x) & BB_LEN_MASK) + 1)
178#define BB_ACK(x) (!!((x) & BB_ACK_MASK))
179#define BB_MAKE(a, l, ack) (((a)<<9) | ((l)-1) | ((u64)(!!(ack)) << 63))
180
181extern int md_is_badblock(struct badblocks *bb, sector_t s, int sectors,
182 sector_t *first_bad, int *bad_sectors);
183static inline int is_badblock(struct md_rdev *rdev, sector_t s, int sectors,
184 sector_t *first_bad, int *bad_sectors)
185{
186 if (unlikely(rdev->badblocks.count)) {
187 int rv = md_is_badblock(&rdev->badblocks, rdev->data_offset + s,
188 sectors,
189 first_bad, bad_sectors);
190 if (rv)
191 *first_bad -= rdev->data_offset;
192 return rv;
193 }
194 return 0;
195}
196extern int rdev_set_badblocks(struct md_rdev *rdev, sector_t s, int sectors,
197 int is_new);
198extern int rdev_clear_badblocks(struct md_rdev *rdev, sector_t s, int sectors,
199 int is_new);
200extern void md_ack_all_badblocks(struct badblocks *bb);
201
202struct mddev {
203 void *private;
204 struct md_personality *pers;
205 dev_t unit;
206 int md_minor;
207 struct list_head disks;
208 unsigned long flags;
209#define MD_CHANGE_DEVS 0 /* Some device status has changed */
210#define MD_CHANGE_CLEAN 1 /* transition to or from 'clean' */
211#define MD_CHANGE_PENDING 2 /* switch from 'clean' to 'active' in progress */
212#define MD_ARRAY_FIRST_USE 3 /* First use of array, needs initialization */
213
214 int suspended;
215 atomic_t active_io;
216 int ro;
217 int sysfs_active; /* set when sysfs deletes
218 * are happening, so run/
219 * takeover/stop are not safe
220 */
221 int ready; /* See when safe to pass
222 * IO requests down */
223 struct gendisk *gendisk;
224
225 struct kobject kobj;
226 int hold_active;
227#define UNTIL_IOCTL 1
228#define UNTIL_STOP 2
229
230 /* Superblock information */
231 int major_version,
232 minor_version,
233 patch_version;
234 int persistent;
235 int external; /* metadata is
236 * managed externally */
237 char metadata_type[17]; /* externally set*/
238 int chunk_sectors;
239 time_t ctime, utime;
240 int level, layout;
241 char clevel[16];
242 int raid_disks;
243 int max_disks;
244 sector_t dev_sectors; /* used size of
245 * component devices */
246 sector_t array_sectors; /* exported array size */
247 int external_size; /* size managed
248 * externally */
249 __u64 events;
250 /* If the last 'event' was simply a clean->dirty transition, and
251 * we didn't write it to the spares, then it is safe and simple
252 * to just decrement the event count on a dirty->clean transition.
253 * So we record that possibility here.
254 */
255 int can_decrease_events;
256
257 char uuid[16];
258
259 /* If the array is being reshaped, we need to record the
260 * new shape and an indication of where we are up to.
261 * This is written to the superblock.
262 * If reshape_position is MaxSector, then no reshape is happening (yet).
263 */
264 sector_t reshape_position;
265 int delta_disks, new_level, new_layout;
266 int new_chunk_sectors;
267 int reshape_backwards;
268
269 atomic_t plug_cnt; /* If device is expecting
270 * more bios soon.
271 */
272 struct md_thread *thread; /* management thread */
273 struct md_thread *sync_thread; /* doing resync or reconstruct */
274 sector_t curr_resync; /* last block scheduled */
275 /* As resync requests can complete out of order, we cannot easily track
276 * how much resync has been completed. So we occasionally pause until
277 * everything completes, then set curr_resync_completed to curr_resync.
278 * As such it may be well behind the real resync mark, but it is a value
279 * we are certain of.
280 */
281 sector_t curr_resync_completed;
282 unsigned long resync_mark; /* a recent timestamp */
283 sector_t resync_mark_cnt;/* blocks written at resync_mark */
284 sector_t curr_mark_cnt; /* blocks scheduled now */
285
286 sector_t resync_max_sectors; /* may be set by personality */
287
288 sector_t resync_mismatches; /* count of sectors where
289 * parity/replica mismatch found
290 */
291
292 /* allow user-space to request suspension of IO to regions of the array */
293 sector_t suspend_lo;
294 sector_t suspend_hi;
295 /* if zero, use the system-wide default */
296 int sync_speed_min;
297 int sync_speed_max;
298
299 /* resync even though the same disks are shared among md-devices */
300 int parallel_resync;
301
302 int ok_start_degraded;
303 /* recovery/resync flags
304 * NEEDED: we might need to start a resync/recover
305 * RUNNING: a thread is running, or about to be started
306 * SYNC: actually doing a resync, not a recovery
307 * RECOVER: doing recovery, or need to try it.
308 * INTR: resync needs to be aborted for some reason
309 * DONE: thread is done and is waiting to be reaped
310 * REQUEST: user-space has requested a sync (used with SYNC)
311 * CHECK: user-space request for check-only, no repair
312 * RESHAPE: A reshape is happening
313 *
314 * If neither SYNC or RESHAPE are set, then it is a recovery.
315 */
316#define MD_RECOVERY_RUNNING 0
317#define MD_RECOVERY_SYNC 1
318#define MD_RECOVERY_RECOVER 2
319#define MD_RECOVERY_INTR 3
320#define MD_RECOVERY_DONE 4
321#define MD_RECOVERY_NEEDED 5
322#define MD_RECOVERY_REQUESTED 6
323#define MD_RECOVERY_CHECK 7
324#define MD_RECOVERY_RESHAPE 8
325#define MD_RECOVERY_FROZEN 9
326
327 unsigned long recovery;
328 /* If a RAID personality determines that recovery (of a particular
329 * device) will fail due to a read error on the source device, it
330 * takes a copy of this number and does not attempt recovery again
331 * until this number changes.
332 */
333 int recovery_disabled;
334
335 int in_sync; /* know to not need resync */
336 /* 'open_mutex' avoids races between 'md_open' and 'do_md_stop', so
337 * that we are never stopping an array while it is open.
338 * 'reconfig_mutex' protects all other reconfiguration.
339 * These locks are separate due to conflicting interactions
340 * with bdev->bd_mutex.
341 * Lock ordering is:
342 * reconfig_mutex -> bd_mutex : e.g. do_md_run -> revalidate_disk
343 * bd_mutex -> open_mutex: e.g. __blkdev_get -> md_open
344 */
345 struct mutex open_mutex;
346 struct mutex reconfig_mutex;
347 atomic_t active; /* general refcount */
348 atomic_t openers; /* number of active opens */
349
350 int changed; /* True if we might need to
351 * reread partition info */
352 int degraded; /* whether md should consider
353 * adding a spare
354 */
355 int merge_check_needed; /* at least one
356 * member device
357 * has a
358 * merge_bvec_fn */
359
360 atomic_t recovery_active; /* blocks scheduled, but not written */
361 wait_queue_head_t recovery_wait;
362 sector_t recovery_cp;
363 sector_t resync_min; /* user requested sync
364 * starts here */
365 sector_t resync_max; /* resync should pause
366 * when it gets here */
367
368 struct sysfs_dirent *sysfs_state; /* handle for 'array_state'
369 * file in sysfs.
370 */
371 struct sysfs_dirent *sysfs_action; /* handle for 'sync_action' */
372
373 struct work_struct del_work; /* used for delayed sysfs removal */
374
375 spinlock_t write_lock;
376 wait_queue_head_t sb_wait; /* for waiting on superblock updates */
377 atomic_t pending_writes; /* number of active superblock writes */
378
379 unsigned int safemode; /* if set, update "clean" superblock
380 * when no writes pending.
381 */
382 unsigned int safemode_delay;
383 struct timer_list safemode_timer;
384 atomic_t writes_pending;
385 struct request_queue *queue; /* for plugging ... */
386
387 struct bitmap *bitmap; /* the bitmap for the device */
388 struct {
389 struct file *file; /* the bitmap file */
390 loff_t offset; /* offset from superblock of
391 * start of bitmap. May be
392 * negative, but not '0'
393 * For external metadata, offset
394 * from start of device.
395 */
396 unsigned long space; /* space available at this offset */
397 loff_t default_offset; /* this is the offset to use when
398 * hot-adding a bitmap. It should
399 * eventually be settable by sysfs.
400 */
401 unsigned long default_space; /* space available at
402 * default offset */
403 struct mutex mutex;
404 unsigned long chunksize;
405 unsigned long daemon_sleep; /* how many jiffies between updates? */
406 unsigned long max_write_behind; /* write-behind mode */
407 int external;
408 } bitmap_info;
409
410 atomic_t max_corr_read_errors; /* max read retries */
411 struct list_head all_mddevs;
412
413 struct attribute_group *to_remove;
414
415 struct bio_set *bio_set;
416
417 /* Generic flush handling.
418 * The last to finish preflush schedules a worker to submit
419 * the rest of the request (without the REQ_FLUSH flag).
420 */
421 struct bio *flush_bio;
422 atomic_t flush_pending;
423 struct work_struct flush_work;
424 struct work_struct event_work; /* used by dm to report failure event */
425 void (*sync_super)(struct mddev *mddev, struct md_rdev *rdev);
426};
427
428
429static inline void rdev_dec_pending(struct md_rdev *rdev, struct mddev *mddev)
430{
431 int faulty = test_bit(Faulty, &rdev->flags);
432 if (atomic_dec_and_test(&rdev->nr_pending) && faulty)
433 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
434}
435
436static inline void md_sync_acct(struct block_device *bdev, unsigned long nr_sectors)
437{
438 atomic_add(nr_sectors, &bdev->bd_contains->bd_disk->sync_io);
439}
440
441struct md_personality
442{
443 char *name;
444 int level;
445 struct list_head list;
446 struct module *owner;
447 void (*make_request)(struct mddev *mddev, struct bio *bio);
448 int (*run)(struct mddev *mddev);
449 int (*stop)(struct mddev *mddev);
450 void (*status)(struct seq_file *seq, struct mddev *mddev);
451 /* error_handler must set ->faulty and clear ->in_sync
452 * if appropriate, and should abort recovery if needed
453 */
454 void (*error_handler)(struct mddev *mddev, struct md_rdev *rdev);
455 int (*hot_add_disk) (struct mddev *mddev, struct md_rdev *rdev);
456 int (*hot_remove_disk) (struct mddev *mddev, struct md_rdev *rdev);
457 int (*spare_active) (struct mddev *mddev);
458 sector_t (*sync_request)(struct mddev *mddev, sector_t sector_nr, int *skipped, int go_faster);
459 int (*resize) (struct mddev *mddev, sector_t sectors);
460 sector_t (*size) (struct mddev *mddev, sector_t sectors, int raid_disks);
461 int (*check_reshape) (struct mddev *mddev);
462 int (*start_reshape) (struct mddev *mddev);
463 void (*finish_reshape) (struct mddev *mddev);
464 /* quiesce moves between quiescence states
465 * 0 - fully active
466 * 1 - no new requests allowed
467 * others - reserved
468 */
469 void (*quiesce) (struct mddev *mddev, int state);
470 /* takeover is used to transition an array from one
471 * personality to another. The new personality must be able
472 * to handle the data in the current layout.
473 * e.g. 2drive raid1 -> 2drive raid5
474 * ndrive raid5 -> degraded n+1drive raid6 with special layout
475 * If the takeover succeeds, a new 'private' structure is returned.
476 * This needs to be installed and then ->run used to activate the
477 * array.
478 */
479 void *(*takeover) (struct mddev *mddev);
480};
481
482
483struct md_sysfs_entry {
484 struct attribute attr;
485 ssize_t (*show)(struct mddev *, char *);
486 ssize_t (*store)(struct mddev *, const char *, size_t);
487};
488extern struct attribute_group md_bitmap_group;
489
490static inline struct sysfs_dirent *sysfs_get_dirent_safe(struct sysfs_dirent *sd, char *name)
491{
492 if (sd)
493 return sysfs_get_dirent(sd, NULL, name);
494 return sd;
495}
496static inline void sysfs_notify_dirent_safe(struct sysfs_dirent *sd)
497{
498 if (sd)
499 sysfs_notify_dirent(sd);
500}
501
502static inline char * mdname (struct mddev * mddev)
503{
504 return mddev->gendisk ? mddev->gendisk->disk_name : "mdX";
505}
506
507static inline int sysfs_link_rdev(struct mddev *mddev, struct md_rdev *rdev)
508{
509 char nm[20];
510 if (!test_bit(Replacement, &rdev->flags)) {
511 sprintf(nm, "rd%d", rdev->raid_disk);
512 return sysfs_create_link(&mddev->kobj, &rdev->kobj, nm);
513 } else
514 return 0;
515}
516
517static inline void sysfs_unlink_rdev(struct mddev *mddev, struct md_rdev *rdev)
518{
519 char nm[20];
520 if (!test_bit(Replacement, &rdev->flags)) {
521 sprintf(nm, "rd%d", rdev->raid_disk);
522 sysfs_remove_link(&mddev->kobj, nm);
523 }
524}
525
526/*
527 * iterates through some rdev ringlist. It's safe to remove the
528 * current 'rdev'. Dont touch 'tmp' though.
529 */
530#define rdev_for_each_list(rdev, tmp, head) \
531 list_for_each_entry_safe(rdev, tmp, head, same_set)
532
533/*
534 * iterates through the 'same array disks' ringlist
535 */
536#define rdev_for_each(rdev, mddev) \
537 list_for_each_entry(rdev, &((mddev)->disks), same_set)
538
539#define rdev_for_each_safe(rdev, tmp, mddev) \
540 list_for_each_entry_safe(rdev, tmp, &((mddev)->disks), same_set)
541
542#define rdev_for_each_rcu(rdev, mddev) \
543 list_for_each_entry_rcu(rdev, &((mddev)->disks), same_set)
544
545struct md_thread {
546 void (*run) (struct mddev *mddev);
547 struct mddev *mddev;
548 wait_queue_head_t wqueue;
549 unsigned long flags;
550 struct task_struct *tsk;
551 unsigned long timeout;
552};
553
554#define THREAD_WAKEUP 0
555
556#define __wait_event_lock_irq(wq, condition, lock, cmd) \
557do { \
558 wait_queue_t __wait; \
559 init_waitqueue_entry(&__wait, current); \
560 \
561 add_wait_queue(&wq, &__wait); \
562 for (;;) { \
563 set_current_state(TASK_UNINTERRUPTIBLE); \
564 if (condition) \
565 break; \
566 spin_unlock_irq(&lock); \
567 cmd; \
568 schedule(); \
569 spin_lock_irq(&lock); \
570 } \
571 current->state = TASK_RUNNING; \
572 remove_wait_queue(&wq, &__wait); \
573} while (0)
574
575#define wait_event_lock_irq(wq, condition, lock, cmd) \
576do { \
577 if (condition) \
578 break; \
579 __wait_event_lock_irq(wq, condition, lock, cmd); \
580} while (0)
581
582static inline void safe_put_page(struct page *p)
583{
584 if (p) put_page(p);
585}
586
587extern int register_md_personality(struct md_personality *p);
588extern int unregister_md_personality(struct md_personality *p);
589extern struct md_thread *md_register_thread(
590 void (*run)(struct mddev *mddev),
591 struct mddev *mddev,
592 const char *name);
593extern void md_unregister_thread(struct md_thread **threadp);
594extern void md_wakeup_thread(struct md_thread *thread);
595extern void md_check_recovery(struct mddev *mddev);
596extern void md_write_start(struct mddev *mddev, struct bio *bi);
597extern void md_write_end(struct mddev *mddev);
598extern void md_done_sync(struct mddev *mddev, int blocks, int ok);
599extern void md_error(struct mddev *mddev, struct md_rdev *rdev);
600extern void md_finish_reshape(struct mddev *mddev);
601
602extern int mddev_congested(struct mddev *mddev, int bits);
603extern void md_flush_request(struct mddev *mddev, struct bio *bio);
604extern void md_super_write(struct mddev *mddev, struct md_rdev *rdev,
605 sector_t sector, int size, struct page *page);
606extern void md_super_wait(struct mddev *mddev);
607extern int sync_page_io(struct md_rdev *rdev, sector_t sector, int size,
608 struct page *page, int rw, bool metadata_op);
609extern void md_do_sync(struct mddev *mddev);
610extern void md_new_event(struct mddev *mddev);
611extern int md_allow_write(struct mddev *mddev);
612extern void md_wait_for_blocked_rdev(struct md_rdev *rdev, struct mddev *mddev);
613extern void md_set_array_sectors(struct mddev *mddev, sector_t array_sectors);
614extern int md_check_no_bitmap(struct mddev *mddev);
615extern int md_integrity_register(struct mddev *mddev);
616extern void md_integrity_add_rdev(struct md_rdev *rdev, struct mddev *mddev);
617extern int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale);
618extern void restore_bitmap_write_access(struct file *file);
619
620extern void mddev_init(struct mddev *mddev);
621extern int md_run(struct mddev *mddev);
622extern void md_stop(struct mddev *mddev);
623extern void md_stop_writes(struct mddev *mddev);
624extern int md_rdev_init(struct md_rdev *rdev);
625extern void md_rdev_clear(struct md_rdev *rdev);
626
627extern void mddev_suspend(struct mddev *mddev);
628extern void mddev_resume(struct mddev *mddev);
629extern struct bio *bio_clone_mddev(struct bio *bio, gfp_t gfp_mask,
630 struct mddev *mddev);
631extern struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs,
632 struct mddev *mddev);
633extern int mddev_check_plugged(struct mddev *mddev);
634extern void md_trim_bio(struct bio *bio, int offset, int size);
635#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 */