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