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1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 md.h : kernel internal structure of the Linux MD driver
4 Copyright (C) 1996-98 Ingo Molnar, Gadi Oxman
5
6*/
7
8#ifndef _MD_MD_H
9#define _MD_MD_H
10
11#include <linux/blkdev.h>
12#include <linux/backing-dev.h>
13#include <linux/badblocks.h>
14#include <linux/kobject.h>
15#include <linux/list.h>
16#include <linux/mm.h>
17#include <linux/mutex.h>
18#include <linux/timer.h>
19#include <linux/wait.h>
20#include <linux/workqueue.h>
21#include <trace/events/block.h>
22#include "md-cluster.h"
23
24#define MaxSector (~(sector_t)0)
25
26/*
27 * These flags should really be called "NO_RETRY" rather than
28 * "FAILFAST" because they don't make any promise about time lapse,
29 * only about the number of retries, which will be zero.
30 * REQ_FAILFAST_DRIVER is not included because
31 * Commit: 4a27446f3e39 ("[SCSI] modify scsi to handle new fail fast flags.")
32 * seems to suggest that the errors it avoids retrying should usually
33 * be retried.
34 */
35#define MD_FAILFAST (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT)
36
37/* Status of sync thread. */
38enum sync_action {
39 /*
40 * Represent by MD_RECOVERY_SYNC, start when:
41 * 1) after assemble, sync data from first rdev to other copies, this
42 * must be done first before other sync actions and will only execute
43 * once;
44 * 2) resize the array(notice that this is not reshape), sync data for
45 * the new range;
46 */
47 ACTION_RESYNC,
48 /*
49 * Represent by MD_RECOVERY_RECOVER, start when:
50 * 1) for new replacement, sync data based on the replace rdev or
51 * available copies from other rdev;
52 * 2) for new member disk while the array is degraded, sync data from
53 * other rdev;
54 * 3) reassemble after power failure or re-add a hot removed rdev, sync
55 * data from first rdev to other copies based on bitmap;
56 */
57 ACTION_RECOVER,
58 /*
59 * Represent by MD_RECOVERY_SYNC | MD_RECOVERY_REQUESTED |
60 * MD_RECOVERY_CHECK, start when user echo "check" to sysfs api
61 * sync_action, used to check if data copies from differenct rdev are
62 * the same. The number of mismatch sectors will be exported to user
63 * by sysfs api mismatch_cnt;
64 */
65 ACTION_CHECK,
66 /*
67 * Represent by MD_RECOVERY_SYNC | MD_RECOVERY_REQUESTED, start when
68 * user echo "repair" to sysfs api sync_action, usually paired with
69 * ACTION_CHECK, used to force syncing data once user found that there
70 * are inconsistent data,
71 */
72 ACTION_REPAIR,
73 /*
74 * Represent by MD_RECOVERY_RESHAPE, start when new member disk is added
75 * to the conf, notice that this is different from spares or
76 * replacement;
77 */
78 ACTION_RESHAPE,
79 /*
80 * Represent by MD_RECOVERY_FROZEN, can be set by sysfs api sync_action
81 * or internal usage like setting the array read-only, will forbid above
82 * actions.
83 */
84 ACTION_FROZEN,
85 /*
86 * All above actions don't match.
87 */
88 ACTION_IDLE,
89 NR_SYNC_ACTIONS,
90};
91
92/*
93 * The struct embedded in rdev is used to serialize IO.
94 */
95struct serial_in_rdev {
96 struct rb_root_cached serial_rb;
97 spinlock_t serial_lock;
98 wait_queue_head_t serial_io_wait;
99};
100
101/*
102 * MD's 'extended' device
103 */
104struct md_rdev {
105 struct list_head same_set; /* RAID devices within the same set */
106
107 sector_t sectors; /* Device size (in 512bytes sectors) */
108 struct mddev *mddev; /* RAID array if running */
109 int last_events; /* IO event timestamp */
110
111 /*
112 * If meta_bdev is non-NULL, it means that a separate device is
113 * being used to store the metadata (superblock/bitmap) which
114 * would otherwise be contained on the same device as the data (bdev).
115 */
116 struct block_device *meta_bdev;
117 struct block_device *bdev; /* block device handle */
118 struct file *bdev_file; /* Handle from open for bdev */
119
120 struct page *sb_page, *bb_page;
121 int sb_loaded;
122 __u64 sb_events;
123 sector_t data_offset; /* start of data in array */
124 sector_t new_data_offset;/* only relevant while reshaping */
125 sector_t sb_start; /* offset of the super block (in 512byte sectors) */
126 int sb_size; /* bytes in the superblock */
127 int preferred_minor; /* autorun support */
128
129 struct kobject kobj;
130
131 /* A device can be in one of three states based on two flags:
132 * Not working: faulty==1 in_sync==0
133 * Fully working: faulty==0 in_sync==1
134 * Working, but not
135 * in sync with array
136 * faulty==0 in_sync==0
137 *
138 * It can never have faulty==1, in_sync==1
139 * This reduces the burden of testing multiple flags in many cases
140 */
141
142 unsigned long flags; /* bit set of 'enum flag_bits' bits. */
143 wait_queue_head_t blocked_wait;
144
145 int desc_nr; /* descriptor index in the superblock */
146 int raid_disk; /* role of device in array */
147 int new_raid_disk; /* role that the device will have in
148 * the array after a level-change completes.
149 */
150 int saved_raid_disk; /* role that device used to have in the
151 * array and could again if we did a partial
152 * resync from the bitmap
153 */
154 union {
155 sector_t recovery_offset;/* If this device has been partially
156 * recovered, this is where we were
157 * up to.
158 */
159 sector_t journal_tail; /* If this device is a journal device,
160 * this is the journal tail (journal
161 * recovery start point)
162 */
163 };
164
165 atomic_t nr_pending; /* number of pending requests.
166 * only maintained for arrays that
167 * support hot removal
168 */
169 atomic_t read_errors; /* number of consecutive read errors that
170 * we have tried to ignore.
171 */
172 time64_t last_read_error; /* monotonic time since our
173 * last read error
174 */
175 atomic_t corrected_errors; /* number of corrected read errors,
176 * for reporting to userspace and storing
177 * in superblock.
178 */
179
180 struct serial_in_rdev *serial; /* used for raid1 io serialization */
181
182 struct kernfs_node *sysfs_state; /* handle for 'state'
183 * sysfs entry */
184 /* handle for 'unacknowledged_bad_blocks' sysfs dentry */
185 struct kernfs_node *sysfs_unack_badblocks;
186 /* handle for 'bad_blocks' sysfs dentry */
187 struct kernfs_node *sysfs_badblocks;
188 struct badblocks badblocks;
189
190 struct {
191 short offset; /* Offset from superblock to start of PPL.
192 * Not used by external metadata. */
193 unsigned int size; /* Size in sectors of the PPL space */
194 sector_t sector; /* First sector of the PPL space */
195 } ppl;
196};
197enum flag_bits {
198 Faulty, /* device is known to have a fault */
199 In_sync, /* device is in_sync with rest of array */
200 Bitmap_sync, /* ..actually, not quite In_sync. Need a
201 * bitmap-based recovery to get fully in sync.
202 * The bit is only meaningful before device
203 * has been passed to pers->hot_add_disk.
204 */
205 WriteMostly, /* Avoid reading if at all possible */
206 AutoDetected, /* added by auto-detect */
207 Blocked, /* An error occurred but has not yet
208 * been acknowledged by the metadata
209 * handler, so don't allow writes
210 * until it is cleared */
211 WriteErrorSeen, /* A write error has been seen on this
212 * device
213 */
214 FaultRecorded, /* Intermediate state for clearing
215 * Blocked. The Fault is/will-be
216 * recorded in the metadata, but that
217 * metadata hasn't been stored safely
218 * on disk yet.
219 */
220 BlockedBadBlocks, /* A writer is blocked because they
221 * found an unacknowledged bad-block.
222 * This can safely be cleared at any
223 * time, and the writer will re-check.
224 * It may be set at any time, and at
225 * worst the writer will timeout and
226 * re-check. So setting it as
227 * accurately as possible is good, but
228 * not absolutely critical.
229 */
230 WantReplacement, /* This device is a candidate to be
231 * hot-replaced, either because it has
232 * reported some faults, or because
233 * of explicit request.
234 */
235 Replacement, /* This device is a replacement for
236 * a want_replacement device with same
237 * raid_disk number.
238 */
239 Candidate, /* For clustered environments only:
240 * This device is seen locally but not
241 * by the whole cluster
242 */
243 Journal, /* This device is used as journal for
244 * raid-5/6.
245 * Usually, this device should be faster
246 * than other devices in the array
247 */
248 ClusterRemove,
249 ExternalBbl, /* External metadata provides bad
250 * block management for a disk
251 */
252 FailFast, /* Minimal retries should be attempted on
253 * this device, so use REQ_FAILFAST_DEV.
254 * Also don't try to repair failed reads.
255 * It is expects that no bad block log
256 * is present.
257 */
258 LastDev, /* Seems to be the last working dev as
259 * it didn't fail, so don't use FailFast
260 * any more for metadata
261 */
262 CollisionCheck, /*
263 * check if there is collision between raid1
264 * serial bios.
265 */
266 Nonrot, /* non-rotational device (SSD) */
267};
268
269static inline int is_badblock(struct md_rdev *rdev, sector_t s, int sectors,
270 sector_t *first_bad, int *bad_sectors)
271{
272 if (unlikely(rdev->badblocks.count)) {
273 int rv = badblocks_check(&rdev->badblocks, rdev->data_offset + s,
274 sectors,
275 first_bad, bad_sectors);
276 if (rv)
277 *first_bad -= rdev->data_offset;
278 return rv;
279 }
280 return 0;
281}
282
283static inline int rdev_has_badblock(struct md_rdev *rdev, sector_t s,
284 int sectors)
285{
286 sector_t first_bad;
287 int bad_sectors;
288
289 return is_badblock(rdev, s, sectors, &first_bad, &bad_sectors);
290}
291
292extern int rdev_set_badblocks(struct md_rdev *rdev, sector_t s, int sectors,
293 int is_new);
294extern int rdev_clear_badblocks(struct md_rdev *rdev, sector_t s, int sectors,
295 int is_new);
296struct md_cluster_info;
297
298/**
299 * enum mddev_flags - md device flags.
300 * @MD_ARRAY_FIRST_USE: First use of array, needs initialization.
301 * @MD_CLOSING: If set, we are closing the array, do not open it then.
302 * @MD_JOURNAL_CLEAN: A raid with journal is already clean.
303 * @MD_HAS_JOURNAL: The raid array has journal feature set.
304 * @MD_CLUSTER_RESYNC_LOCKED: cluster raid only, which means node, already took
305 * resync lock, need to release the lock.
306 * @MD_FAILFAST_SUPPORTED: Using MD_FAILFAST on metadata writes is supported as
307 * calls to md_error() will never cause the array to
308 * become failed.
309 * @MD_HAS_PPL: The raid array has PPL feature set.
310 * @MD_HAS_MULTIPLE_PPLS: The raid array has multiple PPLs feature set.
311 * @MD_NOT_READY: do_md_run() is active, so 'array_state', ust not report that
312 * array is ready yet.
313 * @MD_BROKEN: This is used to stop writes and mark array as failed.
314 * @MD_DELETED: This device is being deleted
315 *
316 * change UNSUPPORTED_MDDEV_FLAGS for each array type if new flag is added
317 */
318enum mddev_flags {
319 MD_ARRAY_FIRST_USE,
320 MD_CLOSING,
321 MD_JOURNAL_CLEAN,
322 MD_HAS_JOURNAL,
323 MD_CLUSTER_RESYNC_LOCKED,
324 MD_FAILFAST_SUPPORTED,
325 MD_HAS_PPL,
326 MD_HAS_MULTIPLE_PPLS,
327 MD_NOT_READY,
328 MD_BROKEN,
329 MD_DELETED,
330};
331
332enum mddev_sb_flags {
333 MD_SB_CHANGE_DEVS, /* Some device status has changed */
334 MD_SB_CHANGE_CLEAN, /* transition to or from 'clean' */
335 MD_SB_CHANGE_PENDING, /* switch from 'clean' to 'active' in progress */
336 MD_SB_NEED_REWRITE, /* metadata write needs to be repeated */
337};
338
339#define NR_SERIAL_INFOS 8
340/* record current range of serialize IOs */
341struct serial_info {
342 struct rb_node node;
343 sector_t start; /* start sector of rb node */
344 sector_t last; /* end sector of rb node */
345 sector_t _subtree_last; /* highest sector in subtree of rb node */
346};
347
348/*
349 * mddev->curr_resync stores the current sector of the resync but
350 * also has some overloaded values.
351 */
352enum {
353 /* No resync in progress */
354 MD_RESYNC_NONE = 0,
355 /* Yielded to allow another conflicting resync to commence */
356 MD_RESYNC_YIELDED = 1,
357 /* Delayed to check that there is no conflict with another sync */
358 MD_RESYNC_DELAYED = 2,
359 /* Any value greater than or equal to this is in an active resync */
360 MD_RESYNC_ACTIVE = 3,
361};
362
363struct mddev {
364 void *private;
365 struct md_personality *pers;
366 dev_t unit;
367 int md_minor;
368 struct list_head disks;
369 unsigned long flags;
370 unsigned long sb_flags;
371
372 int suspended;
373 struct mutex suspend_mutex;
374 struct percpu_ref active_io;
375 int ro;
376 int sysfs_active; /* set when sysfs deletes
377 * are happening, so run/
378 * takeover/stop are not safe
379 */
380 struct gendisk *gendisk;
381
382 struct kobject kobj;
383 int hold_active;
384#define UNTIL_IOCTL 1
385#define UNTIL_STOP 2
386
387 /* Superblock information */
388 int major_version,
389 minor_version,
390 patch_version;
391 int persistent;
392 int external; /* metadata is
393 * managed externally */
394 char metadata_type[17]; /* externally set*/
395 int chunk_sectors;
396 time64_t ctime, utime;
397 int level, layout;
398 char clevel[16];
399 int raid_disks;
400 int max_disks;
401 sector_t dev_sectors; /* used size of
402 * component devices */
403 sector_t array_sectors; /* exported array size */
404 int external_size; /* size managed
405 * externally */
406 __u64 events;
407 /* If the last 'event' was simply a clean->dirty transition, and
408 * we didn't write it to the spares, then it is safe and simple
409 * to just decrement the event count on a dirty->clean transition.
410 * So we record that possibility here.
411 */
412 int can_decrease_events;
413
414 char uuid[16];
415
416 /* If the array is being reshaped, we need to record the
417 * new shape and an indication of where we are up to.
418 * This is written to the superblock.
419 * If reshape_position is MaxSector, then no reshape is happening (yet).
420 */
421 sector_t reshape_position;
422 int delta_disks, new_level, new_layout;
423 int new_chunk_sectors;
424 int reshape_backwards;
425
426 struct md_thread __rcu *thread; /* management thread */
427 struct md_thread __rcu *sync_thread; /* doing resync or reconstruct */
428
429 /*
430 * Set when a sync operation is started. It holds this value even
431 * when the sync thread is "frozen" (interrupted) or "idle" (stopped
432 * or finished). It is overwritten when a new sync operation is begun.
433 */
434 enum sync_action last_sync_action;
435 sector_t curr_resync; /* last block scheduled */
436 /* As resync requests can complete out of order, we cannot easily track
437 * how much resync has been completed. So we occasionally pause until
438 * everything completes, then set curr_resync_completed to curr_resync.
439 * As such it may be well behind the real resync mark, but it is a value
440 * we are certain of.
441 */
442 sector_t curr_resync_completed;
443 unsigned long resync_mark; /* a recent timestamp */
444 sector_t resync_mark_cnt;/* blocks written at resync_mark */
445 sector_t curr_mark_cnt; /* blocks scheduled now */
446
447 sector_t resync_max_sectors; /* may be set by personality */
448
449 atomic64_t resync_mismatches; /* count of sectors where
450 * parity/replica mismatch found
451 */
452
453 /* allow user-space to request suspension of IO to regions of the array */
454 sector_t suspend_lo;
455 sector_t suspend_hi;
456 /* if zero, use the system-wide default */
457 int sync_speed_min;
458 int sync_speed_max;
459
460 /* resync even though the same disks are shared among md-devices */
461 int parallel_resync;
462
463 int ok_start_degraded;
464
465 unsigned long recovery;
466 /* If a RAID personality determines that recovery (of a particular
467 * device) will fail due to a read error on the source device, it
468 * takes a copy of this number and does not attempt recovery again
469 * until this number changes.
470 */
471 int recovery_disabled;
472
473 int in_sync; /* know to not need resync */
474 /* 'open_mutex' avoids races between 'md_open' and 'do_md_stop', so
475 * that we are never stopping an array while it is open.
476 * 'reconfig_mutex' protects all other reconfiguration.
477 * These locks are separate due to conflicting interactions
478 * with disk->open_mutex.
479 * Lock ordering is:
480 * reconfig_mutex -> disk->open_mutex
481 * disk->open_mutex -> open_mutex: e.g. __blkdev_get -> md_open
482 */
483 struct mutex open_mutex;
484 struct mutex reconfig_mutex;
485 atomic_t active; /* general refcount */
486 atomic_t openers; /* number of active opens */
487
488 int changed; /* True if we might need to
489 * reread partition info */
490 int degraded; /* whether md should consider
491 * adding a spare
492 */
493
494 atomic_t recovery_active; /* blocks scheduled, but not written */
495 wait_queue_head_t recovery_wait;
496 sector_t recovery_cp;
497 sector_t resync_min; /* user requested sync
498 * starts here */
499 sector_t resync_max; /* resync should pause
500 * when it gets here */
501
502 struct kernfs_node *sysfs_state; /* handle for 'array_state'
503 * file in sysfs.
504 */
505 struct kernfs_node *sysfs_action; /* handle for 'sync_action' */
506 struct kernfs_node *sysfs_completed; /*handle for 'sync_completed' */
507 struct kernfs_node *sysfs_degraded; /*handle for 'degraded' */
508 struct kernfs_node *sysfs_level; /*handle for 'level' */
509
510 /* used for delayed sysfs removal */
511 struct work_struct del_work;
512 /* used for register new sync thread */
513 struct work_struct sync_work;
514
515 /* "lock" protects:
516 * flush_bio transition from NULL to !NULL
517 * rdev superblocks, events
518 * clearing MD_CHANGE_*
519 * in_sync - and related safemode and MD_CHANGE changes
520 * pers (also protected by reconfig_mutex and pending IO).
521 * clearing ->bitmap
522 * clearing ->bitmap_info.file
523 * changing ->resync_{min,max}
524 * setting MD_RECOVERY_RUNNING (which interacts with resync_{min,max})
525 */
526 spinlock_t lock;
527 wait_queue_head_t sb_wait; /* for waiting on superblock updates */
528 atomic_t pending_writes; /* number of active superblock writes */
529
530 unsigned int safemode; /* if set, update "clean" superblock
531 * when no writes pending.
532 */
533 unsigned int safemode_delay;
534 struct timer_list safemode_timer;
535 struct percpu_ref writes_pending;
536 int sync_checkers; /* # of threads checking writes_pending */
537
538 void *bitmap; /* the bitmap for the device */
539 struct bitmap_operations *bitmap_ops;
540 struct {
541 struct file *file; /* the bitmap file */
542 loff_t offset; /* offset from superblock of
543 * start of bitmap. May be
544 * negative, but not '0'
545 * For external metadata, offset
546 * from start of device.
547 */
548 unsigned long space; /* space available at this offset */
549 loff_t default_offset; /* this is the offset to use when
550 * hot-adding a bitmap. It should
551 * eventually be settable by sysfs.
552 */
553 unsigned long default_space; /* space available at
554 * default offset */
555 struct mutex mutex;
556 unsigned long chunksize;
557 unsigned long daemon_sleep; /* how many jiffies between updates? */
558 unsigned long max_write_behind; /* write-behind mode */
559 int external;
560 int nodes; /* Maximum number of nodes in the cluster */
561 char cluster_name[64]; /* Name of the cluster */
562 } bitmap_info;
563
564 atomic_t max_corr_read_errors; /* max read retries */
565 struct list_head all_mddevs;
566
567 const struct attribute_group *to_remove;
568
569 struct bio_set bio_set;
570 struct bio_set sync_set; /* for sync operations like
571 * metadata and bitmap writes
572 */
573 struct bio_set io_clone_set;
574
575 struct work_struct event_work; /* used by dm to report failure event */
576 mempool_t *serial_info_pool;
577 void (*sync_super)(struct mddev *mddev, struct md_rdev *rdev);
578 struct md_cluster_info *cluster_info;
579 unsigned int good_device_nr; /* good device num within cluster raid */
580 unsigned int noio_flag; /* for memalloc scope API */
581
582 /*
583 * Temporarily store rdev that will be finally removed when
584 * reconfig_mutex is unlocked, protected by reconfig_mutex.
585 */
586 struct list_head deleting;
587
588 /* The sequence number for sync thread */
589 atomic_t sync_seq;
590
591 bool has_superblocks:1;
592 bool fail_last_dev:1;
593 bool serialize_policy:1;
594};
595
596enum recovery_flags {
597 /* flags for sync thread running status */
598
599 /*
600 * set when one of sync action is set and new sync thread need to be
601 * registered, or just add/remove spares from conf.
602 */
603 MD_RECOVERY_NEEDED,
604 /* sync thread is running, or about to be started */
605 MD_RECOVERY_RUNNING,
606 /* sync thread needs to be aborted for some reason */
607 MD_RECOVERY_INTR,
608 /* sync thread is done and is waiting to be unregistered */
609 MD_RECOVERY_DONE,
610 /* running sync thread must abort immediately, and not restart */
611 MD_RECOVERY_FROZEN,
612 /* waiting for pers->start() to finish */
613 MD_RECOVERY_WAIT,
614 /* interrupted because io-error */
615 MD_RECOVERY_ERROR,
616
617 /* flags determines sync action, see details in enum sync_action */
618
619 /* if just this flag is set, action is resync. */
620 MD_RECOVERY_SYNC,
621 /*
622 * paired with MD_RECOVERY_SYNC, if MD_RECOVERY_CHECK is not set,
623 * action is repair, means user requested resync.
624 */
625 MD_RECOVERY_REQUESTED,
626 /*
627 * paired with MD_RECOVERY_SYNC and MD_RECOVERY_REQUESTED, action is
628 * check.
629 */
630 MD_RECOVERY_CHECK,
631 /* recovery, or need to try it */
632 MD_RECOVERY_RECOVER,
633 /* reshape */
634 MD_RECOVERY_RESHAPE,
635 /* remote node is running resync thread */
636 MD_RESYNCING_REMOTE,
637};
638
639enum md_ro_state {
640 MD_RDWR,
641 MD_RDONLY,
642 MD_AUTO_READ,
643 MD_MAX_STATE
644};
645
646static inline bool md_is_rdwr(struct mddev *mddev)
647{
648 return (mddev->ro == MD_RDWR);
649}
650
651static inline bool reshape_interrupted(struct mddev *mddev)
652{
653 /* reshape never start */
654 if (mddev->reshape_position == MaxSector)
655 return false;
656
657 /* interrupted */
658 if (!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
659 return true;
660
661 /* running reshape will be interrupted soon. */
662 if (test_bit(MD_RECOVERY_WAIT, &mddev->recovery) ||
663 test_bit(MD_RECOVERY_INTR, &mddev->recovery) ||
664 test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
665 return true;
666
667 return false;
668}
669
670static inline int __must_check mddev_lock(struct mddev *mddev)
671{
672 return mutex_lock_interruptible(&mddev->reconfig_mutex);
673}
674
675/* Sometimes we need to take the lock in a situation where
676 * failure due to interrupts is not acceptable.
677 */
678static inline void mddev_lock_nointr(struct mddev *mddev)
679{
680 mutex_lock(&mddev->reconfig_mutex);
681}
682
683static inline int mddev_trylock(struct mddev *mddev)
684{
685 return mutex_trylock(&mddev->reconfig_mutex);
686}
687extern void mddev_unlock(struct mddev *mddev);
688
689static inline void md_sync_acct(struct block_device *bdev, unsigned long nr_sectors)
690{
691 if (blk_queue_io_stat(bdev->bd_disk->queue))
692 atomic_add(nr_sectors, &bdev->bd_disk->sync_io);
693}
694
695static inline void md_sync_acct_bio(struct bio *bio, unsigned long nr_sectors)
696{
697 md_sync_acct(bio->bi_bdev, nr_sectors);
698}
699
700struct md_personality
701{
702 char *name;
703 int level;
704 struct list_head list;
705 struct module *owner;
706 bool __must_check (*make_request)(struct mddev *mddev, struct bio *bio);
707 /*
708 * start up works that do NOT require md_thread. tasks that
709 * requires md_thread should go into start()
710 */
711 int (*run)(struct mddev *mddev);
712 /* start up works that require md threads */
713 int (*start)(struct mddev *mddev);
714 void (*free)(struct mddev *mddev, void *priv);
715 void (*status)(struct seq_file *seq, struct mddev *mddev);
716 /* error_handler must set ->faulty and clear ->in_sync
717 * if appropriate, and should abort recovery if needed
718 */
719 void (*error_handler)(struct mddev *mddev, struct md_rdev *rdev);
720 int (*hot_add_disk) (struct mddev *mddev, struct md_rdev *rdev);
721 int (*hot_remove_disk) (struct mddev *mddev, struct md_rdev *rdev);
722 int (*spare_active) (struct mddev *mddev);
723 sector_t (*sync_request)(struct mddev *mddev, sector_t sector_nr,
724 sector_t max_sector, int *skipped);
725 int (*resize) (struct mddev *mddev, sector_t sectors);
726 sector_t (*size) (struct mddev *mddev, sector_t sectors, int raid_disks);
727 int (*check_reshape) (struct mddev *mddev);
728 int (*start_reshape) (struct mddev *mddev);
729 void (*finish_reshape) (struct mddev *mddev);
730 void (*update_reshape_pos) (struct mddev *mddev);
731 void (*prepare_suspend) (struct mddev *mddev);
732 /* quiesce suspends or resumes internal processing.
733 * 1 - stop new actions and wait for action io to complete
734 * 0 - return to normal behaviour
735 */
736 void (*quiesce) (struct mddev *mddev, int quiesce);
737 /* takeover is used to transition an array from one
738 * personality to another. The new personality must be able
739 * to handle the data in the current layout.
740 * e.g. 2drive raid1 -> 2drive raid5
741 * ndrive raid5 -> degraded n+1drive raid6 with special layout
742 * If the takeover succeeds, a new 'private' structure is returned.
743 * This needs to be installed and then ->run used to activate the
744 * array.
745 */
746 void *(*takeover) (struct mddev *mddev);
747 /* Changes the consistency policy of an active array. */
748 int (*change_consistency_policy)(struct mddev *mddev, const char *buf);
749 /* convert io ranges from array to bitmap */
750 void (*bitmap_sector)(struct mddev *mddev, sector_t *offset,
751 unsigned long *sectors);
752};
753
754struct md_sysfs_entry {
755 struct attribute attr;
756 ssize_t (*show)(struct mddev *, char *);
757 ssize_t (*store)(struct mddev *, const char *, size_t);
758};
759extern const struct attribute_group md_bitmap_group;
760
761static inline struct kernfs_node *sysfs_get_dirent_safe(struct kernfs_node *sd, char *name)
762{
763 if (sd)
764 return sysfs_get_dirent(sd, name);
765 return sd;
766}
767static inline void sysfs_notify_dirent_safe(struct kernfs_node *sd)
768{
769 if (sd)
770 sysfs_notify_dirent(sd);
771}
772
773static inline char * mdname (struct mddev * mddev)
774{
775 return mddev->gendisk ? mddev->gendisk->disk_name : "mdX";
776}
777
778static inline int sysfs_link_rdev(struct mddev *mddev, struct md_rdev *rdev)
779{
780 char nm[20];
781 if (!test_bit(Replacement, &rdev->flags) &&
782 !test_bit(Journal, &rdev->flags) &&
783 mddev->kobj.sd) {
784 sprintf(nm, "rd%d", rdev->raid_disk);
785 return sysfs_create_link(&mddev->kobj, &rdev->kobj, nm);
786 } else
787 return 0;
788}
789
790static inline void sysfs_unlink_rdev(struct mddev *mddev, struct md_rdev *rdev)
791{
792 char nm[20];
793 if (!test_bit(Replacement, &rdev->flags) &&
794 !test_bit(Journal, &rdev->flags) &&
795 mddev->kobj.sd) {
796 sprintf(nm, "rd%d", rdev->raid_disk);
797 sysfs_remove_link(&mddev->kobj, nm);
798 }
799}
800
801/*
802 * iterates through some rdev ringlist. It's safe to remove the
803 * current 'rdev'. Dont touch 'tmp' though.
804 */
805#define rdev_for_each_list(rdev, tmp, head) \
806 list_for_each_entry_safe(rdev, tmp, head, same_set)
807
808/*
809 * iterates through the 'same array disks' ringlist
810 */
811#define rdev_for_each(rdev, mddev) \
812 list_for_each_entry(rdev, &((mddev)->disks), same_set)
813
814#define rdev_for_each_safe(rdev, tmp, mddev) \
815 list_for_each_entry_safe(rdev, tmp, &((mddev)->disks), same_set)
816
817#define rdev_for_each_rcu(rdev, mddev) \
818 list_for_each_entry_rcu(rdev, &((mddev)->disks), same_set)
819
820struct md_thread {
821 void (*run) (struct md_thread *thread);
822 struct mddev *mddev;
823 wait_queue_head_t wqueue;
824 unsigned long flags;
825 struct task_struct *tsk;
826 unsigned long timeout;
827 void *private;
828};
829
830struct md_io_clone {
831 struct mddev *mddev;
832 struct bio *orig_bio;
833 unsigned long start_time;
834 sector_t offset;
835 unsigned long sectors;
836 struct bio bio_clone;
837};
838
839#define THREAD_WAKEUP 0
840
841static inline void safe_put_page(struct page *p)
842{
843 if (p) put_page(p);
844}
845
846extern int register_md_personality(struct md_personality *p);
847extern int unregister_md_personality(struct md_personality *p);
848extern int register_md_cluster_operations(const struct md_cluster_operations *ops,
849 struct module *module);
850extern int unregister_md_cluster_operations(void);
851extern int md_setup_cluster(struct mddev *mddev, int nodes);
852extern void md_cluster_stop(struct mddev *mddev);
853extern struct md_thread *md_register_thread(
854 void (*run)(struct md_thread *thread),
855 struct mddev *mddev,
856 const char *name);
857extern void md_unregister_thread(struct mddev *mddev, struct md_thread __rcu **threadp);
858extern void md_wakeup_thread(struct md_thread __rcu *thread);
859extern void md_check_recovery(struct mddev *mddev);
860extern void md_reap_sync_thread(struct mddev *mddev);
861extern enum sync_action md_sync_action(struct mddev *mddev);
862extern enum sync_action md_sync_action_by_name(const char *page);
863extern const char *md_sync_action_name(enum sync_action action);
864extern void md_write_start(struct mddev *mddev, struct bio *bi);
865extern void md_write_inc(struct mddev *mddev, struct bio *bi);
866extern void md_write_end(struct mddev *mddev);
867extern void md_done_sync(struct mddev *mddev, int blocks, int ok);
868extern void md_error(struct mddev *mddev, struct md_rdev *rdev);
869extern void md_finish_reshape(struct mddev *mddev);
870void md_submit_discard_bio(struct mddev *mddev, struct md_rdev *rdev,
871 struct bio *bio, sector_t start, sector_t size);
872void md_account_bio(struct mddev *mddev, struct bio **bio);
873void md_free_cloned_bio(struct bio *bio);
874
875extern bool __must_check md_flush_request(struct mddev *mddev, struct bio *bio);
876extern void md_super_write(struct mddev *mddev, struct md_rdev *rdev,
877 sector_t sector, int size, struct page *page);
878extern int md_super_wait(struct mddev *mddev);
879extern int sync_page_io(struct md_rdev *rdev, sector_t sector, int size,
880 struct page *page, blk_opf_t opf, bool metadata_op);
881extern void md_do_sync(struct md_thread *thread);
882extern void md_new_event(void);
883extern void md_allow_write(struct mddev *mddev);
884extern void md_wait_for_blocked_rdev(struct md_rdev *rdev, struct mddev *mddev);
885extern void md_set_array_sectors(struct mddev *mddev, sector_t array_sectors);
886extern int md_check_no_bitmap(struct mddev *mddev);
887extern int md_integrity_register(struct mddev *mddev);
888extern int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale);
889
890extern int mddev_init(struct mddev *mddev);
891extern void mddev_destroy(struct mddev *mddev);
892void md_init_stacking_limits(struct queue_limits *lim);
893struct mddev *md_alloc(dev_t dev, char *name);
894void mddev_put(struct mddev *mddev);
895extern int md_run(struct mddev *mddev);
896extern int md_start(struct mddev *mddev);
897extern void md_stop(struct mddev *mddev);
898extern void md_stop_writes(struct mddev *mddev);
899extern int md_rdev_init(struct md_rdev *rdev);
900extern void md_rdev_clear(struct md_rdev *rdev);
901
902extern bool md_handle_request(struct mddev *mddev, struct bio *bio);
903extern int mddev_suspend(struct mddev *mddev, bool interruptible);
904extern void mddev_resume(struct mddev *mddev);
905extern void md_idle_sync_thread(struct mddev *mddev);
906extern void md_frozen_sync_thread(struct mddev *mddev);
907extern void md_unfrozen_sync_thread(struct mddev *mddev);
908
909extern void md_reload_sb(struct mddev *mddev, int raid_disk);
910extern void md_update_sb(struct mddev *mddev, int force);
911extern void mddev_create_serial_pool(struct mddev *mddev, struct md_rdev *rdev);
912extern void mddev_destroy_serial_pool(struct mddev *mddev,
913 struct md_rdev *rdev);
914struct md_rdev *md_find_rdev_nr_rcu(struct mddev *mddev, int nr);
915struct md_rdev *md_find_rdev_rcu(struct mddev *mddev, dev_t dev);
916
917static inline bool is_rdev_broken(struct md_rdev *rdev)
918{
919 return !disk_live(rdev->bdev->bd_disk);
920}
921
922static inline void rdev_dec_pending(struct md_rdev *rdev, struct mddev *mddev)
923{
924 int faulty = test_bit(Faulty, &rdev->flags);
925 if (atomic_dec_and_test(&rdev->nr_pending) && faulty) {
926 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
927 md_wakeup_thread(mddev->thread);
928 }
929}
930
931extern const struct md_cluster_operations *md_cluster_ops;
932static inline int mddev_is_clustered(struct mddev *mddev)
933{
934 return mddev->cluster_info && mddev->bitmap_info.nodes > 1;
935}
936
937/* clear unsupported mddev_flags */
938static inline void mddev_clear_unsupported_flags(struct mddev *mddev,
939 unsigned long unsupported_flags)
940{
941 mddev->flags &= ~unsupported_flags;
942}
943
944static inline void mddev_check_write_zeroes(struct mddev *mddev, struct bio *bio)
945{
946 if (bio_op(bio) == REQ_OP_WRITE_ZEROES &&
947 !bio->bi_bdev->bd_disk->queue->limits.max_write_zeroes_sectors)
948 mddev->gendisk->queue->limits.max_write_zeroes_sectors = 0;
949}
950
951static inline int mddev_suspend_and_lock(struct mddev *mddev)
952{
953 int ret;
954
955 ret = mddev_suspend(mddev, true);
956 if (ret)
957 return ret;
958
959 ret = mddev_lock(mddev);
960 if (ret)
961 mddev_resume(mddev);
962
963 return ret;
964}
965
966static inline void mddev_suspend_and_lock_nointr(struct mddev *mddev)
967{
968 mddev_suspend(mddev, false);
969 mutex_lock(&mddev->reconfig_mutex);
970}
971
972static inline void mddev_unlock_and_resume(struct mddev *mddev)
973{
974 mddev_unlock(mddev);
975 mddev_resume(mddev);
976}
977
978struct mdu_array_info_s;
979struct mdu_disk_info_s;
980
981extern int mdp_major;
982extern struct workqueue_struct *md_bitmap_wq;
983void md_autostart_arrays(int part);
984int md_set_array_info(struct mddev *mddev, struct mdu_array_info_s *info);
985int md_add_new_disk(struct mddev *mddev, struct mdu_disk_info_s *info);
986int do_md_run(struct mddev *mddev);
987#define MDDEV_STACK_INTEGRITY (1u << 0)
988int mddev_stack_rdev_limits(struct mddev *mddev, struct queue_limits *lim,
989 unsigned int flags);
990int mddev_stack_new_rdev(struct mddev *mddev, struct md_rdev *rdev);
991void mddev_update_io_opt(struct mddev *mddev, unsigned int nr_stripes);
992
993extern const struct block_device_operations md_fops;
994
995/*
996 * MD devices can be used undeneath by DM, in which case ->gendisk is NULL.
997 */
998static inline bool mddev_is_dm(struct mddev *mddev)
999{
1000 return !mddev->gendisk;
1001}
1002
1003static inline void mddev_trace_remap(struct mddev *mddev, struct bio *bio,
1004 sector_t sector)
1005{
1006 if (!mddev_is_dm(mddev))
1007 trace_block_bio_remap(bio, disk_devt(mddev->gendisk), sector);
1008}
1009
1010static inline bool rdev_blocked(struct md_rdev *rdev)
1011{
1012 /*
1013 * Blocked will be set by error handler and cleared by daemon after
1014 * updating superblock, meanwhile write IO should be blocked to prevent
1015 * reading old data after power failure.
1016 */
1017 if (test_bit(Blocked, &rdev->flags))
1018 return true;
1019
1020 /*
1021 * Faulty device should not be accessed anymore, there is no need to
1022 * wait for bad block to be acknowledged.
1023 */
1024 if (test_bit(Faulty, &rdev->flags))
1025 return false;
1026
1027 /* rdev is blocked by badblocks. */
1028 if (test_bit(BlockedBadBlocks, &rdev->flags))
1029 return true;
1030
1031 return false;
1032}
1033
1034#define mddev_add_trace_msg(mddev, fmt, args...) \
1035do { \
1036 if (!mddev_is_dm(mddev)) \
1037 blk_add_trace_msg((mddev)->gendisk->queue, fmt, ##args); \
1038} while (0)
1039
1040#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 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 */