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1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3    md.c : Multiple Devices driver for Linux
4      Copyright (C) 1998, 1999, 2000 Ingo Molnar
5
6      completely rewritten, based on the MD driver code from Marc Zyngier
7
8    Changes:
9
10    - RAID-1/RAID-5 extensions by Miguel de Icaza, Gadi Oxman, Ingo Molnar
11    - RAID-6 extensions by H. Peter Anvin <[email protected]>
12    - boot support for linear and striped mode by Harald Hoyer <[email protected]>
13    - kerneld support by Boris Tobotras <[email protected]>
14    - kmod support by: Cyrus Durgin
15    - RAID0 bugfixes: Mark Anthony Lisher <[email protected]>
16    - Devfs support by Richard Gooch <[email protected]>
17
18    - lots of fixes and improvements to the RAID1/RAID5 and generic
19      RAID code (such as request based resynchronization):
20
21      Neil Brown <[email protected]>.
22
23    - persistent bitmap code
24      Copyright (C) 2003-2004, Paul Clements, SteelEye Technology, Inc.
25
26
27    Errors, Warnings, etc.
28    Please use:
29      pr_crit() for error conditions that risk data loss
30      pr_err() for error conditions that are unexpected, like an IO error
31          or internal inconsistency
32      pr_warn() for error conditions that could have been predicated, like
33          adding a device to an array when it has incompatible metadata
34      pr_info() for every interesting, very rare events, like an array starting
35          or stopping, or resync starting or stopping
36      pr_debug() for everything else.
37
38 */
39
40 #include <linux/sched/mm.h>
41 #include <linux/sched/signal.h>
42 #include <linux/kthread.h>
43 #include <linux/blkdev.h>
44 #include <linux/blk-integrity.h>
45 #include <linux/badblocks.h>
46 #include <linux/sysctl.h>
47 #include <linux/seq_file.h>
48 #include <linux/fs.h>
49 #include <linux/poll.h>
50 #include <linux/ctype.h>
51 #include <linux/string.h>
52 #include <linux/hdreg.h>
53 #include <linux/proc_fs.h>
54 #include <linux/random.h>
55 #include <linux/major.h>
56 #include <linux/module.h>
57 #include <linux/reboot.h>
58 #include <linux/file.h>
59 #include <linux/compat.h>
60 #include <linux/delay.h>
61 #include <linux/raid/md_p.h>
62 #include <linux/raid/md_u.h>
63 #include <linux/raid/detect.h>
64 #include <linux/slab.h>
65 #include <linux/percpu-refcount.h>
66 #include <linux/part_stat.h>
67
68 #include "md.h"
69 #include "md-bitmap.h"
70 #include "md-cluster.h"
71
72 static const char *action_name[NR_SYNC_ACTIONS] = {
73         [ACTION_RESYNC]         = "resync",
74         [ACTION_RECOVER]        = "recover",
75         [ACTION_CHECK]          = "check",
76         [ACTION_REPAIR]         = "repair",
77         [ACTION_RESHAPE]        = "reshape",
78         [ACTION_FROZEN]         = "frozen",
79         [ACTION_IDLE]           = "idle",
80 };
81
82 /* pers_list is a list of registered personalities protected by pers_lock. */
83 static LIST_HEAD(pers_list);
84 static DEFINE_SPINLOCK(pers_lock);
85
86 static const struct kobj_type md_ktype;
87
88 const struct md_cluster_operations *md_cluster_ops;
89 EXPORT_SYMBOL(md_cluster_ops);
90 static struct module *md_cluster_mod;
91
92 static DECLARE_WAIT_QUEUE_HEAD(resync_wait);
93 static struct workqueue_struct *md_wq;
94
95 /*
96  * This workqueue is used for sync_work to register new sync_thread, and for
97  * del_work to remove rdev, and for event_work that is only set by dm-raid.
98  *
99  * Noted that sync_work will grab reconfig_mutex, hence never flush this
100  * workqueue whith reconfig_mutex grabbed.
101  */
102 static struct workqueue_struct *md_misc_wq;
103 struct workqueue_struct *md_bitmap_wq;
104
105 static int remove_and_add_spares(struct mddev *mddev,
106                                  struct md_rdev *this);
107 static void mddev_detach(struct mddev *mddev);
108 static void export_rdev(struct md_rdev *rdev, struct mddev *mddev);
109 static void md_wakeup_thread_directly(struct md_thread __rcu *thread);
110
111 /*
112  * Default number of read corrections we'll attempt on an rdev
113  * before ejecting it from the array. We divide the read error
114  * count by 2 for every hour elapsed between read errors.
115  */
116 #define MD_DEFAULT_MAX_CORRECTED_READ_ERRORS 20
117 /* Default safemode delay: 200 msec */
118 #define DEFAULT_SAFEMODE_DELAY ((200 * HZ)/1000 +1)
119 /*
120  * Current RAID-1,4,5 parallel reconstruction 'guaranteed speed limit'
121  * is 1000 KB/sec, so the extra system load does not show up that much.
122  * Increase it if you want to have more _guaranteed_ speed. Note that
123  * the RAID driver will use the maximum available bandwidth if the IO
124  * subsystem is idle. There is also an 'absolute maximum' reconstruction
125  * speed limit - in case reconstruction slows down your system despite
126  * idle IO detection.
127  *
128  * you can change it via /proc/sys/dev/raid/speed_limit_min and _max.
129  * or /sys/block/mdX/md/sync_speed_{min,max}
130  */
131
132 static int sysctl_speed_limit_min = 1000;
133 static int sysctl_speed_limit_max = 200000;
134 static inline int speed_min(struct mddev *mddev)
135 {
136         return mddev->sync_speed_min ?
137                 mddev->sync_speed_min : sysctl_speed_limit_min;
138 }
139
140 static inline int speed_max(struct mddev *mddev)
141 {
142         return mddev->sync_speed_max ?
143                 mddev->sync_speed_max : sysctl_speed_limit_max;
144 }
145
146 static void rdev_uninit_serial(struct md_rdev *rdev)
147 {
148         if (!test_and_clear_bit(CollisionCheck, &rdev->flags))
149                 return;
150
151         kvfree(rdev->serial);
152         rdev->serial = NULL;
153 }
154
155 static void rdevs_uninit_serial(struct mddev *mddev)
156 {
157         struct md_rdev *rdev;
158
159         rdev_for_each(rdev, mddev)
160                 rdev_uninit_serial(rdev);
161 }
162
163 static int rdev_init_serial(struct md_rdev *rdev)
164 {
165         /* serial_nums equals with BARRIER_BUCKETS_NR */
166         int i, serial_nums = 1 << ((PAGE_SHIFT - ilog2(sizeof(atomic_t))));
167         struct serial_in_rdev *serial = NULL;
168
169         if (test_bit(CollisionCheck, &rdev->flags))
170                 return 0;
171
172         serial = kvmalloc(sizeof(struct serial_in_rdev) * serial_nums,
173                           GFP_KERNEL);
174         if (!serial)
175                 return -ENOMEM;
176
177         for (i = 0; i < serial_nums; i++) {
178                 struct serial_in_rdev *serial_tmp = &serial[i];
179
180                 spin_lock_init(&serial_tmp->serial_lock);
181                 serial_tmp->serial_rb = RB_ROOT_CACHED;
182                 init_waitqueue_head(&serial_tmp->serial_io_wait);
183         }
184
185         rdev->serial = serial;
186         set_bit(CollisionCheck, &rdev->flags);
187
188         return 0;
189 }
190
191 static int rdevs_init_serial(struct mddev *mddev)
192 {
193         struct md_rdev *rdev;
194         int ret = 0;
195
196         rdev_for_each(rdev, mddev) {
197                 ret = rdev_init_serial(rdev);
198                 if (ret)
199                         break;
200         }
201
202         /* Free all resources if pool is not existed */
203         if (ret && !mddev->serial_info_pool)
204                 rdevs_uninit_serial(mddev);
205
206         return ret;
207 }
208
209 /*
210  * rdev needs to enable serial stuffs if it meets the conditions:
211  * 1. it is multi-queue device flaged with writemostly.
212  * 2. the write-behind mode is enabled.
213  */
214 static int rdev_need_serial(struct md_rdev *rdev)
215 {
216         return (rdev && rdev->mddev->bitmap_info.max_write_behind > 0 &&
217                 rdev->bdev->bd_disk->queue->nr_hw_queues != 1 &&
218                 test_bit(WriteMostly, &rdev->flags));
219 }
220
221 /*
222  * Init resource for rdev(s), then create serial_info_pool if:
223  * 1. rdev is the first device which return true from rdev_enable_serial.
224  * 2. rdev is NULL, means we want to enable serialization for all rdevs.
225  */
226 void mddev_create_serial_pool(struct mddev *mddev, struct md_rdev *rdev)
227 {
228         int ret = 0;
229
230         if (rdev && !rdev_need_serial(rdev) &&
231             !test_bit(CollisionCheck, &rdev->flags))
232                 return;
233
234         if (!rdev)
235                 ret = rdevs_init_serial(mddev);
236         else
237                 ret = rdev_init_serial(rdev);
238         if (ret)
239                 return;
240
241         if (mddev->serial_info_pool == NULL) {
242                 /*
243                  * already in memalloc noio context by
244                  * mddev_suspend()
245                  */
246                 mddev->serial_info_pool =
247                         mempool_create_kmalloc_pool(NR_SERIAL_INFOS,
248                                                 sizeof(struct serial_info));
249                 if (!mddev->serial_info_pool) {
250                         rdevs_uninit_serial(mddev);
251                         pr_err("can't alloc memory pool for serialization\n");
252                 }
253         }
254 }
255
256 /*
257  * Free resource from rdev(s), and destroy serial_info_pool under conditions:
258  * 1. rdev is the last device flaged with CollisionCheck.
259  * 2. when bitmap is destroyed while policy is not enabled.
260  * 3. for disable policy, the pool is destroyed only when no rdev needs it.
261  */
262 void mddev_destroy_serial_pool(struct mddev *mddev, struct md_rdev *rdev)
263 {
264         if (rdev && !test_bit(CollisionCheck, &rdev->flags))
265                 return;
266
267         if (mddev->serial_info_pool) {
268                 struct md_rdev *temp;
269                 int num = 0; /* used to track if other rdevs need the pool */
270
271                 rdev_for_each(temp, mddev) {
272                         if (!rdev) {
273                                 if (!mddev->serialize_policy ||
274                                     !rdev_need_serial(temp))
275                                         rdev_uninit_serial(temp);
276                                 else
277                                         num++;
278                         } else if (temp != rdev &&
279                                    test_bit(CollisionCheck, &temp->flags))
280                                 num++;
281                 }
282
283                 if (rdev)
284                         rdev_uninit_serial(rdev);
285
286                 if (num)
287                         pr_info("The mempool could be used by other devices\n");
288                 else {
289                         mempool_destroy(mddev->serial_info_pool);
290                         mddev->serial_info_pool = NULL;
291                 }
292         }
293 }
294
295 static struct ctl_table_header *raid_table_header;
296
297 static struct ctl_table raid_table[] = {
298         {
299                 .procname       = "speed_limit_min",
300                 .data           = &sysctl_speed_limit_min,
301                 .maxlen         = sizeof(int),
302                 .mode           = S_IRUGO|S_IWUSR,
303                 .proc_handler   = proc_dointvec,
304         },
305         {
306                 .procname       = "speed_limit_max",
307                 .data           = &sysctl_speed_limit_max,
308                 .maxlen         = sizeof(int),
309                 .mode           = S_IRUGO|S_IWUSR,
310                 .proc_handler   = proc_dointvec,
311         },
312 };
313
314 static int start_readonly;
315
316 /*
317  * The original mechanism for creating an md device is to create
318  * a device node in /dev and to open it.  This causes races with device-close.
319  * The preferred method is to write to the "new_array" module parameter.
320  * This can avoid races.
321  * Setting create_on_open to false disables the original mechanism
322  * so all the races disappear.
323  */
324 static bool create_on_open = true;
325
326 /*
327  * We have a system wide 'event count' that is incremented
328  * on any 'interesting' event, and readers of /proc/mdstat
329  * can use 'poll' or 'select' to find out when the event
330  * count increases.
331  *
332  * Events are:
333  *  start array, stop array, error, add device, remove device,
334  *  start build, activate spare
335  */
336 static DECLARE_WAIT_QUEUE_HEAD(md_event_waiters);
337 static atomic_t md_event_count;
338 void md_new_event(void)
339 {
340         atomic_inc(&md_event_count);
341         wake_up(&md_event_waiters);
342 }
343 EXPORT_SYMBOL_GPL(md_new_event);
344
345 /*
346  * Enables to iterate over all existing md arrays
347  * all_mddevs_lock protects this list.
348  */
349 static LIST_HEAD(all_mddevs);
350 static DEFINE_SPINLOCK(all_mddevs_lock);
351
352 static bool is_md_suspended(struct mddev *mddev)
353 {
354         return percpu_ref_is_dying(&mddev->active_io);
355 }
356 /* Rather than calling directly into the personality make_request function,
357  * IO requests come here first so that we can check if the device is
358  * being suspended pending a reconfiguration.
359  * We hold a refcount over the call to ->make_request.  By the time that
360  * call has finished, the bio has been linked into some internal structure
361  * and so is visible to ->quiesce(), so we don't need the refcount any more.
362  */
363 static bool is_suspended(struct mddev *mddev, struct bio *bio)
364 {
365         if (is_md_suspended(mddev))
366                 return true;
367         if (bio_data_dir(bio) != WRITE)
368                 return false;
369         if (READ_ONCE(mddev->suspend_lo) >= READ_ONCE(mddev->suspend_hi))
370                 return false;
371         if (bio->bi_iter.bi_sector >= READ_ONCE(mddev->suspend_hi))
372                 return false;
373         if (bio_end_sector(bio) < READ_ONCE(mddev->suspend_lo))
374                 return false;
375         return true;
376 }
377
378 bool md_handle_request(struct mddev *mddev, struct bio *bio)
379 {
380 check_suspended:
381         if (is_suspended(mddev, bio)) {
382                 DEFINE_WAIT(__wait);
383                 /* Bail out if REQ_NOWAIT is set for the bio */
384                 if (bio->bi_opf & REQ_NOWAIT) {
385                         bio_wouldblock_error(bio);
386                         return true;
387                 }
388                 for (;;) {
389                         prepare_to_wait(&mddev->sb_wait, &__wait,
390                                         TASK_UNINTERRUPTIBLE);
391                         if (!is_suspended(mddev, bio))
392                                 break;
393                         schedule();
394                 }
395                 finish_wait(&mddev->sb_wait, &__wait);
396         }
397         if (!percpu_ref_tryget_live(&mddev->active_io))
398                 goto check_suspended;
399
400         if (!mddev->pers->make_request(mddev, bio)) {
401                 percpu_ref_put(&mddev->active_io);
402                 if (!mddev->gendisk && mddev->pers->prepare_suspend)
403                         return false;
404                 goto check_suspended;
405         }
406
407         percpu_ref_put(&mddev->active_io);
408         return true;
409 }
410 EXPORT_SYMBOL(md_handle_request);
411
412 static void md_submit_bio(struct bio *bio)
413 {
414         const int rw = bio_data_dir(bio);
415         struct mddev *mddev = bio->bi_bdev->bd_disk->private_data;
416
417         if (mddev == NULL || mddev->pers == NULL) {
418                 bio_io_error(bio);
419                 return;
420         }
421
422         if (unlikely(test_bit(MD_BROKEN, &mddev->flags)) && (rw == WRITE)) {
423                 bio_io_error(bio);
424                 return;
425         }
426
427         bio = bio_split_to_limits(bio);
428         if (!bio)
429                 return;
430
431         if (mddev->ro == MD_RDONLY && unlikely(rw == WRITE)) {
432                 if (bio_sectors(bio) != 0)
433                         bio->bi_status = BLK_STS_IOERR;
434                 bio_endio(bio);
435                 return;
436         }
437
438         /* bio could be mergeable after passing to underlayer */
439         bio->bi_opf &= ~REQ_NOMERGE;
440
441         md_handle_request(mddev, bio);
442 }
443
444 /*
445  * Make sure no new requests are submitted to the device, and any requests that
446  * have been submitted are completely handled.
447  */
448 int mddev_suspend(struct mddev *mddev, bool interruptible)
449 {
450         int err = 0;
451
452         /*
453          * hold reconfig_mutex to wait for normal io will deadlock, because
454          * other context can't update super_block, and normal io can rely on
455          * updating super_block.
456          */
457         lockdep_assert_not_held(&mddev->reconfig_mutex);
458
459         if (interruptible)
460                 err = mutex_lock_interruptible(&mddev->suspend_mutex);
461         else
462                 mutex_lock(&mddev->suspend_mutex);
463         if (err)
464                 return err;
465
466         if (mddev->suspended) {
467                 WRITE_ONCE(mddev->suspended, mddev->suspended + 1);
468                 mutex_unlock(&mddev->suspend_mutex);
469                 return 0;
470         }
471
472         percpu_ref_kill(&mddev->active_io);
473         if (interruptible)
474                 err = wait_event_interruptible(mddev->sb_wait,
475                                 percpu_ref_is_zero(&mddev->active_io));
476         else
477                 wait_event(mddev->sb_wait,
478                                 percpu_ref_is_zero(&mddev->active_io));
479         if (err) {
480                 percpu_ref_resurrect(&mddev->active_io);
481                 mutex_unlock(&mddev->suspend_mutex);
482                 return err;
483         }
484
485         /*
486          * For raid456, io might be waiting for reshape to make progress,
487          * allow new reshape to start while waiting for io to be done to
488          * prevent deadlock.
489          */
490         WRITE_ONCE(mddev->suspended, mddev->suspended + 1);
491
492         /* restrict memory reclaim I/O during raid array is suspend */
493         mddev->noio_flag = memalloc_noio_save();
494
495         mutex_unlock(&mddev->suspend_mutex);
496         return 0;
497 }
498 EXPORT_SYMBOL_GPL(mddev_suspend);
499
500 static void __mddev_resume(struct mddev *mddev, bool recovery_needed)
501 {
502         lockdep_assert_not_held(&mddev->reconfig_mutex);
503
504         mutex_lock(&mddev->suspend_mutex);
505         WRITE_ONCE(mddev->suspended, mddev->suspended - 1);
506         if (mddev->suspended) {
507                 mutex_unlock(&mddev->suspend_mutex);
508                 return;
509         }
510
511         /* entred the memalloc scope from mddev_suspend() */
512         memalloc_noio_restore(mddev->noio_flag);
513
514         percpu_ref_resurrect(&mddev->active_io);
515         wake_up(&mddev->sb_wait);
516
517         if (recovery_needed)
518                 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
519         md_wakeup_thread(mddev->thread);
520         md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
521
522         mutex_unlock(&mddev->suspend_mutex);
523 }
524
525 void mddev_resume(struct mddev *mddev)
526 {
527         return __mddev_resume(mddev, true);
528 }
529 EXPORT_SYMBOL_GPL(mddev_resume);
530
531 /* sync bdev before setting device to readonly or stopping raid*/
532 static int mddev_set_closing_and_sync_blockdev(struct mddev *mddev, int opener_num)
533 {
534         mutex_lock(&mddev->open_mutex);
535         if (mddev->pers && atomic_read(&mddev->openers) > opener_num) {
536                 mutex_unlock(&mddev->open_mutex);
537                 return -EBUSY;
538         }
539         if (test_and_set_bit(MD_CLOSING, &mddev->flags)) {
540                 mutex_unlock(&mddev->open_mutex);
541                 return -EBUSY;
542         }
543         mutex_unlock(&mddev->open_mutex);
544
545         sync_blockdev(mddev->gendisk->part0);
546         return 0;
547 }
548
549 bool md_flush_request(struct mddev *mddev, struct bio *bio)
550 {
551         struct md_rdev *rdev;
552         struct bio *new;
553
554         /*
555          * md_flush_reqeust() should be called under md_handle_request() and
556          * 'active_io' is already grabbed. Hence it's safe to get rdev directly
557          * without rcu protection.
558          */
559         WARN_ON(percpu_ref_is_zero(&mddev->active_io));
560
561         rdev_for_each(rdev, mddev) {
562                 if (rdev->raid_disk < 0 || test_bit(Faulty, &rdev->flags))
563                         continue;
564
565                 new = bio_alloc_bioset(rdev->bdev, 0,
566                                        REQ_OP_WRITE | REQ_PREFLUSH, GFP_NOIO,
567                                        &mddev->bio_set);
568                 bio_chain(new, bio);
569                 submit_bio(new);
570         }
571
572         if (bio_sectors(bio) == 0) {
573                 bio_endio(bio);
574                 return true;
575         }
576
577         bio->bi_opf &= ~REQ_PREFLUSH;
578         return false;
579 }
580 EXPORT_SYMBOL(md_flush_request);
581
582 static inline struct mddev *mddev_get(struct mddev *mddev)
583 {
584         lockdep_assert_held(&all_mddevs_lock);
585
586         if (test_bit(MD_DELETED, &mddev->flags))
587                 return NULL;
588         atomic_inc(&mddev->active);
589         return mddev;
590 }
591
592 static void mddev_delayed_delete(struct work_struct *ws);
593
594 static void __mddev_put(struct mddev *mddev)
595 {
596         if (mddev->raid_disks || !list_empty(&mddev->disks) ||
597             mddev->ctime || mddev->hold_active)
598                 return;
599
600         /* Array is not configured at all, and not held active, so destroy it */
601         set_bit(MD_DELETED, &mddev->flags);
602
603         /*
604          * Call queue_work inside the spinlock so that flush_workqueue() after
605          * mddev_find will succeed in waiting for the work to be done.
606          */
607         queue_work(md_misc_wq, &mddev->del_work);
608 }
609
610 void mddev_put(struct mddev *mddev)
611 {
612         if (!atomic_dec_and_lock(&mddev->active, &all_mddevs_lock))
613                 return;
614
615         __mddev_put(mddev);
616         spin_unlock(&all_mddevs_lock);
617 }
618
619 static void md_safemode_timeout(struct timer_list *t);
620 static void md_start_sync(struct work_struct *ws);
621
622 static void active_io_release(struct percpu_ref *ref)
623 {
624         struct mddev *mddev = container_of(ref, struct mddev, active_io);
625
626         wake_up(&mddev->sb_wait);
627 }
628
629 static void no_op(struct percpu_ref *r) {}
630
631 int mddev_init(struct mddev *mddev)
632 {
633
634         if (percpu_ref_init(&mddev->active_io, active_io_release,
635                             PERCPU_REF_ALLOW_REINIT, GFP_KERNEL))
636                 return -ENOMEM;
637
638         if (percpu_ref_init(&mddev->writes_pending, no_op,
639                             PERCPU_REF_ALLOW_REINIT, GFP_KERNEL)) {
640                 percpu_ref_exit(&mddev->active_io);
641                 return -ENOMEM;
642         }
643
644         /* We want to start with the refcount at zero */
645         percpu_ref_put(&mddev->writes_pending);
646
647         mutex_init(&mddev->open_mutex);
648         mutex_init(&mddev->reconfig_mutex);
649         mutex_init(&mddev->suspend_mutex);
650         mutex_init(&mddev->bitmap_info.mutex);
651         INIT_LIST_HEAD(&mddev->disks);
652         INIT_LIST_HEAD(&mddev->all_mddevs);
653         INIT_LIST_HEAD(&mddev->deleting);
654         timer_setup(&mddev->safemode_timer, md_safemode_timeout, 0);
655         atomic_set(&mddev->active, 1);
656         atomic_set(&mddev->openers, 0);
657         atomic_set(&mddev->sync_seq, 0);
658         spin_lock_init(&mddev->lock);
659         init_waitqueue_head(&mddev->sb_wait);
660         init_waitqueue_head(&mddev->recovery_wait);
661         mddev->reshape_position = MaxSector;
662         mddev->reshape_backwards = 0;
663         mddev->last_sync_action = ACTION_IDLE;
664         mddev->resync_min = 0;
665         mddev->resync_max = MaxSector;
666         mddev->level = LEVEL_NONE;
667         mddev_set_bitmap_ops(mddev);
668
669         INIT_WORK(&mddev->sync_work, md_start_sync);
670         INIT_WORK(&mddev->del_work, mddev_delayed_delete);
671
672         return 0;
673 }
674 EXPORT_SYMBOL_GPL(mddev_init);
675
676 void mddev_destroy(struct mddev *mddev)
677 {
678         percpu_ref_exit(&mddev->active_io);
679         percpu_ref_exit(&mddev->writes_pending);
680 }
681 EXPORT_SYMBOL_GPL(mddev_destroy);
682
683 static struct mddev *mddev_find_locked(dev_t unit)
684 {
685         struct mddev *mddev;
686
687         list_for_each_entry(mddev, &all_mddevs, all_mddevs)
688                 if (mddev->unit == unit)
689                         return mddev;
690
691         return NULL;
692 }
693
694 /* find an unused unit number */
695 static dev_t mddev_alloc_unit(void)
696 {
697         static int next_minor = 512;
698         int start = next_minor;
699         bool is_free = 0;
700         dev_t dev = 0;
701
702         while (!is_free) {
703                 dev = MKDEV(MD_MAJOR, next_minor);
704                 next_minor++;
705                 if (next_minor > MINORMASK)
706                         next_minor = 0;
707                 if (next_minor == start)
708                         return 0;               /* Oh dear, all in use. */
709                 is_free = !mddev_find_locked(dev);
710         }
711
712         return dev;
713 }
714
715 static struct mddev *mddev_alloc(dev_t unit)
716 {
717         struct mddev *new;
718         int error;
719
720         if (unit && MAJOR(unit) != MD_MAJOR)
721                 unit &= ~((1 << MdpMinorShift) - 1);
722
723         new = kzalloc(sizeof(*new), GFP_KERNEL);
724         if (!new)
725                 return ERR_PTR(-ENOMEM);
726
727         error = mddev_init(new);
728         if (error)
729                 goto out_free_new;
730
731         spin_lock(&all_mddevs_lock);
732         if (unit) {
733                 error = -EEXIST;
734                 if (mddev_find_locked(unit))
735                         goto out_destroy_new;
736                 new->unit = unit;
737                 if (MAJOR(unit) == MD_MAJOR)
738                         new->md_minor = MINOR(unit);
739                 else
740                         new->md_minor = MINOR(unit) >> MdpMinorShift;
741                 new->hold_active = UNTIL_IOCTL;
742         } else {
743                 error = -ENODEV;
744                 new->unit = mddev_alloc_unit();
745                 if (!new->unit)
746                         goto out_destroy_new;
747                 new->md_minor = MINOR(new->unit);
748                 new->hold_active = UNTIL_STOP;
749         }
750
751         list_add(&new->all_mddevs, &all_mddevs);
752         spin_unlock(&all_mddevs_lock);
753         return new;
754
755 out_destroy_new:
756         spin_unlock(&all_mddevs_lock);
757         mddev_destroy(new);
758 out_free_new:
759         kfree(new);
760         return ERR_PTR(error);
761 }
762
763 static void mddev_free(struct mddev *mddev)
764 {
765         spin_lock(&all_mddevs_lock);
766         list_del(&mddev->all_mddevs);
767         spin_unlock(&all_mddevs_lock);
768
769         mddev_destroy(mddev);
770         kfree(mddev);
771 }
772
773 static const struct attribute_group md_redundancy_group;
774
775 void mddev_unlock(struct mddev *mddev)
776 {
777         struct md_rdev *rdev;
778         struct md_rdev *tmp;
779         LIST_HEAD(delete);
780
781         if (!list_empty(&mddev->deleting))
782                 list_splice_init(&mddev->deleting, &delete);
783
784         if (mddev->to_remove) {
785                 /* These cannot be removed under reconfig_mutex as
786                  * an access to the files will try to take reconfig_mutex
787                  * while holding the file unremovable, which leads to
788                  * a deadlock.
789                  * So hold set sysfs_active while the remove in happeing,
790                  * and anything else which might set ->to_remove or my
791                  * otherwise change the sysfs namespace will fail with
792                  * -EBUSY if sysfs_active is still set.
793                  * We set sysfs_active under reconfig_mutex and elsewhere
794                  * test it under the same mutex to ensure its correct value
795                  * is seen.
796                  */
797                 const struct attribute_group *to_remove = mddev->to_remove;
798                 mddev->to_remove = NULL;
799                 mddev->sysfs_active = 1;
800                 mutex_unlock(&mddev->reconfig_mutex);
801
802                 if (mddev->kobj.sd) {
803                         if (to_remove != &md_redundancy_group)
804                                 sysfs_remove_group(&mddev->kobj, to_remove);
805                         if (mddev->pers == NULL ||
806                             mddev->pers->sync_request == NULL) {
807                                 sysfs_remove_group(&mddev->kobj, &md_redundancy_group);
808                                 if (mddev->sysfs_action)
809                                         sysfs_put(mddev->sysfs_action);
810                                 if (mddev->sysfs_completed)
811                                         sysfs_put(mddev->sysfs_completed);
812                                 if (mddev->sysfs_degraded)
813                                         sysfs_put(mddev->sysfs_degraded);
814                                 mddev->sysfs_action = NULL;
815                                 mddev->sysfs_completed = NULL;
816                                 mddev->sysfs_degraded = NULL;
817                         }
818                 }
819                 mddev->sysfs_active = 0;
820         } else
821                 mutex_unlock(&mddev->reconfig_mutex);
822
823         md_wakeup_thread(mddev->thread);
824         wake_up(&mddev->sb_wait);
825
826         list_for_each_entry_safe(rdev, tmp, &delete, same_set) {
827                 list_del_init(&rdev->same_set);
828                 kobject_del(&rdev->kobj);
829                 export_rdev(rdev, mddev);
830         }
831 }
832 EXPORT_SYMBOL_GPL(mddev_unlock);
833
834 struct md_rdev *md_find_rdev_nr_rcu(struct mddev *mddev, int nr)
835 {
836         struct md_rdev *rdev;
837
838         rdev_for_each_rcu(rdev, mddev)
839                 if (rdev->desc_nr == nr)
840                         return rdev;
841
842         return NULL;
843 }
844 EXPORT_SYMBOL_GPL(md_find_rdev_nr_rcu);
845
846 static struct md_rdev *find_rdev(struct mddev *mddev, dev_t dev)
847 {
848         struct md_rdev *rdev;
849
850         rdev_for_each(rdev, mddev)
851                 if (rdev->bdev->bd_dev == dev)
852                         return rdev;
853
854         return NULL;
855 }
856
857 struct md_rdev *md_find_rdev_rcu(struct mddev *mddev, dev_t dev)
858 {
859         struct md_rdev *rdev;
860
861         rdev_for_each_rcu(rdev, mddev)
862                 if (rdev->bdev->bd_dev == dev)
863                         return rdev;
864
865         return NULL;
866 }
867 EXPORT_SYMBOL_GPL(md_find_rdev_rcu);
868
869 static struct md_personality *find_pers(int level, char *clevel)
870 {
871         struct md_personality *pers;
872         list_for_each_entry(pers, &pers_list, list) {
873                 if (level != LEVEL_NONE && pers->level == level)
874                         return pers;
875                 if (strcmp(pers->name, clevel)==0)
876                         return pers;
877         }
878         return NULL;
879 }
880
881 /* return the offset of the super block in 512byte sectors */
882 static inline sector_t calc_dev_sboffset(struct md_rdev *rdev)
883 {
884         return MD_NEW_SIZE_SECTORS(bdev_nr_sectors(rdev->bdev));
885 }
886
887 static int alloc_disk_sb(struct md_rdev *rdev)
888 {
889         rdev->sb_page = alloc_page(GFP_KERNEL);
890         if (!rdev->sb_page)
891                 return -ENOMEM;
892         return 0;
893 }
894
895 void md_rdev_clear(struct md_rdev *rdev)
896 {
897         if (rdev->sb_page) {
898                 put_page(rdev->sb_page);
899                 rdev->sb_loaded = 0;
900                 rdev->sb_page = NULL;
901                 rdev->sb_start = 0;
902                 rdev->sectors = 0;
903         }
904         if (rdev->bb_page) {
905                 put_page(rdev->bb_page);
906                 rdev->bb_page = NULL;
907         }
908         badblocks_exit(&rdev->badblocks);
909 }
910 EXPORT_SYMBOL_GPL(md_rdev_clear);
911
912 static void super_written(struct bio *bio)
913 {
914         struct md_rdev *rdev = bio->bi_private;
915         struct mddev *mddev = rdev->mddev;
916
917         if (bio->bi_status) {
918                 pr_err("md: %s gets error=%d\n", __func__,
919                        blk_status_to_errno(bio->bi_status));
920                 md_error(mddev, rdev);
921                 if (!test_bit(Faulty, &rdev->flags)
922                     && (bio->bi_opf & MD_FAILFAST)) {
923                         set_bit(MD_SB_NEED_REWRITE, &mddev->sb_flags);
924                         set_bit(LastDev, &rdev->flags);
925                 }
926         } else
927                 clear_bit(LastDev, &rdev->flags);
928
929         bio_put(bio);
930
931         rdev_dec_pending(rdev, mddev);
932
933         if (atomic_dec_and_test(&mddev->pending_writes))
934                 wake_up(&mddev->sb_wait);
935 }
936
937 void md_super_write(struct mddev *mddev, struct md_rdev *rdev,
938                    sector_t sector, int size, struct page *page)
939 {
940         /* write first size bytes of page to sector of rdev
941          * Increment mddev->pending_writes before returning
942          * and decrement it on completion, waking up sb_wait
943          * if zero is reached.
944          * If an error occurred, call md_error
945          */
946         struct bio *bio;
947
948         if (!page)
949                 return;
950
951         if (test_bit(Faulty, &rdev->flags))
952                 return;
953
954         bio = bio_alloc_bioset(rdev->meta_bdev ? rdev->meta_bdev : rdev->bdev,
955                               1,
956                               REQ_OP_WRITE | REQ_SYNC | REQ_IDLE | REQ_META
957                                   | REQ_PREFLUSH | REQ_FUA,
958                               GFP_NOIO, &mddev->sync_set);
959
960         atomic_inc(&rdev->nr_pending);
961
962         bio->bi_iter.bi_sector = sector;
963         __bio_add_page(bio, page, size, 0);
964         bio->bi_private = rdev;
965         bio->bi_end_io = super_written;
966
967         if (test_bit(MD_FAILFAST_SUPPORTED, &mddev->flags) &&
968             test_bit(FailFast, &rdev->flags) &&
969             !test_bit(LastDev, &rdev->flags))
970                 bio->bi_opf |= MD_FAILFAST;
971
972         atomic_inc(&mddev->pending_writes);
973         submit_bio(bio);
974 }
975
976 int md_super_wait(struct mddev *mddev)
977 {
978         /* wait for all superblock writes that were scheduled to complete */
979         wait_event(mddev->sb_wait, atomic_read(&mddev->pending_writes)==0);
980         if (test_and_clear_bit(MD_SB_NEED_REWRITE, &mddev->sb_flags))
981                 return -EAGAIN;
982         return 0;
983 }
984
985 int sync_page_io(struct md_rdev *rdev, sector_t sector, int size,
986                  struct page *page, blk_opf_t opf, bool metadata_op)
987 {
988         struct bio bio;
989         struct bio_vec bvec;
990
991         if (metadata_op && rdev->meta_bdev)
992                 bio_init(&bio, rdev->meta_bdev, &bvec, 1, opf);
993         else
994                 bio_init(&bio, rdev->bdev, &bvec, 1, opf);
995
996         if (metadata_op)
997                 bio.bi_iter.bi_sector = sector + rdev->sb_start;
998         else if (rdev->mddev->reshape_position != MaxSector &&
999                  (rdev->mddev->reshape_backwards ==
1000                   (sector >= rdev->mddev->reshape_position)))
1001                 bio.bi_iter.bi_sector = sector + rdev->new_data_offset;
1002         else
1003                 bio.bi_iter.bi_sector = sector + rdev->data_offset;
1004         __bio_add_page(&bio, page, size, 0);
1005
1006         submit_bio_wait(&bio);
1007
1008         return !bio.bi_status;
1009 }
1010 EXPORT_SYMBOL_GPL(sync_page_io);
1011
1012 static int read_disk_sb(struct md_rdev *rdev, int size)
1013 {
1014         if (rdev->sb_loaded)
1015                 return 0;
1016
1017         if (!sync_page_io(rdev, 0, size, rdev->sb_page, REQ_OP_READ, true))
1018                 goto fail;
1019         rdev->sb_loaded = 1;
1020         return 0;
1021
1022 fail:
1023         pr_err("md: disabled device %pg, could not read superblock.\n",
1024                rdev->bdev);
1025         return -EINVAL;
1026 }
1027
1028 static int md_uuid_equal(mdp_super_t *sb1, mdp_super_t *sb2)
1029 {
1030         return  sb1->set_uuid0 == sb2->set_uuid0 &&
1031                 sb1->set_uuid1 == sb2->set_uuid1 &&
1032                 sb1->set_uuid2 == sb2->set_uuid2 &&
1033                 sb1->set_uuid3 == sb2->set_uuid3;
1034 }
1035
1036 static int md_sb_equal(mdp_super_t *sb1, mdp_super_t *sb2)
1037 {
1038         int ret;
1039         mdp_super_t *tmp1, *tmp2;
1040
1041         tmp1 = kmalloc(sizeof(*tmp1),GFP_KERNEL);
1042         tmp2 = kmalloc(sizeof(*tmp2),GFP_KERNEL);
1043
1044         if (!tmp1 || !tmp2) {
1045                 ret = 0;
1046                 goto abort;
1047         }
1048
1049         *tmp1 = *sb1;
1050         *tmp2 = *sb2;
1051
1052         /*
1053          * nr_disks is not constant
1054          */
1055         tmp1->nr_disks = 0;
1056         tmp2->nr_disks = 0;
1057
1058         ret = (memcmp(tmp1, tmp2, MD_SB_GENERIC_CONSTANT_WORDS * 4) == 0);
1059 abort:
1060         kfree(tmp1);
1061         kfree(tmp2);
1062         return ret;
1063 }
1064
1065 static u32 md_csum_fold(u32 csum)
1066 {
1067         csum = (csum & 0xffff) + (csum >> 16);
1068         return (csum & 0xffff) + (csum >> 16);
1069 }
1070
1071 static unsigned int calc_sb_csum(mdp_super_t *sb)
1072 {
1073         u64 newcsum = 0;
1074         u32 *sb32 = (u32*)sb;
1075         int i;
1076         unsigned int disk_csum, csum;
1077
1078         disk_csum = sb->sb_csum;
1079         sb->sb_csum = 0;
1080
1081         for (i = 0; i < MD_SB_BYTES/4 ; i++)
1082                 newcsum += sb32[i];
1083         csum = (newcsum & 0xffffffff) + (newcsum>>32);
1084
1085 #ifdef CONFIG_ALPHA
1086         /* This used to use csum_partial, which was wrong for several
1087          * reasons including that different results are returned on
1088          * different architectures.  It isn't critical that we get exactly
1089          * the same return value as before (we always csum_fold before
1090          * testing, and that removes any differences).  However as we
1091          * know that csum_partial always returned a 16bit value on
1092          * alphas, do a fold to maximise conformity to previous behaviour.
1093          */
1094         sb->sb_csum = md_csum_fold(disk_csum);
1095 #else
1096         sb->sb_csum = disk_csum;
1097 #endif
1098         return csum;
1099 }
1100
1101 /*
1102  * Handle superblock details.
1103  * We want to be able to handle multiple superblock formats
1104  * so we have a common interface to them all, and an array of
1105  * different handlers.
1106  * We rely on user-space to write the initial superblock, and support
1107  * reading and updating of superblocks.
1108  * Interface methods are:
1109  *   int load_super(struct md_rdev *dev, struct md_rdev *refdev, int minor_version)
1110  *      loads and validates a superblock on dev.
1111  *      if refdev != NULL, compare superblocks on both devices
1112  *    Return:
1113  *      0 - dev has a superblock that is compatible with refdev
1114  *      1 - dev has a superblock that is compatible and newer than refdev
1115  *          so dev should be used as the refdev in future
1116  *     -EINVAL superblock incompatible or invalid
1117  *     -othererror e.g. -EIO
1118  *
1119  *   int validate_super(struct mddev *mddev, struct md_rdev *dev)
1120  *      Verify that dev is acceptable into mddev.
1121  *       The first time, mddev->raid_disks will be 0, and data from
1122  *       dev should be merged in.  Subsequent calls check that dev
1123  *       is new enough.  Return 0 or -EINVAL
1124  *
1125  *   void sync_super(struct mddev *mddev, struct md_rdev *dev)
1126  *     Update the superblock for rdev with data in mddev
1127  *     This does not write to disc.
1128  *
1129  */
1130
1131 struct super_type  {
1132         char                *name;
1133         struct module       *owner;
1134         int                 (*load_super)(struct md_rdev *rdev,
1135                                           struct md_rdev *refdev,
1136                                           int minor_version);
1137         int                 (*validate_super)(struct mddev *mddev,
1138                                               struct md_rdev *freshest,
1139                                               struct md_rdev *rdev);
1140         void                (*sync_super)(struct mddev *mddev,
1141                                           struct md_rdev *rdev);
1142         unsigned long long  (*rdev_size_change)(struct md_rdev *rdev,
1143                                                 sector_t num_sectors);
1144         int                 (*allow_new_offset)(struct md_rdev *rdev,
1145                                                 unsigned long long new_offset);
1146 };
1147
1148 /*
1149  * Check that the given mddev has no bitmap.
1150  *
1151  * This function is called from the run method of all personalities that do not
1152  * support bitmaps. It prints an error message and returns non-zero if mddev
1153  * has a bitmap. Otherwise, it returns 0.
1154  *
1155  */
1156 int md_check_no_bitmap(struct mddev *mddev)
1157 {
1158         if (!mddev->bitmap_info.file && !mddev->bitmap_info.offset)
1159                 return 0;
1160         pr_warn("%s: bitmaps are not supported for %s\n",
1161                 mdname(mddev), mddev->pers->name);
1162         return 1;
1163 }
1164 EXPORT_SYMBOL(md_check_no_bitmap);
1165
1166 /*
1167  * load_super for 0.90.0
1168  */
1169 static int super_90_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor_version)
1170 {
1171         mdp_super_t *sb;
1172         int ret;
1173         bool spare_disk = true;
1174
1175         /*
1176          * Calculate the position of the superblock (512byte sectors),
1177          * it's at the end of the disk.
1178          *
1179          * It also happens to be a multiple of 4Kb.
1180          */
1181         rdev->sb_start = calc_dev_sboffset(rdev);
1182
1183         ret = read_disk_sb(rdev, MD_SB_BYTES);
1184         if (ret)
1185                 return ret;
1186
1187         ret = -EINVAL;
1188
1189         sb = page_address(rdev->sb_page);
1190
1191         if (sb->md_magic != MD_SB_MAGIC) {
1192                 pr_warn("md: invalid raid superblock magic on %pg\n",
1193                         rdev->bdev);
1194                 goto abort;
1195         }
1196
1197         if (sb->major_version != 0 ||
1198             sb->minor_version < 90 ||
1199             sb->minor_version > 91) {
1200                 pr_warn("Bad version number %d.%d on %pg\n",
1201                         sb->major_version, sb->minor_version, rdev->bdev);
1202                 goto abort;
1203         }
1204
1205         if (sb->raid_disks <= 0)
1206                 goto abort;
1207
1208         if (md_csum_fold(calc_sb_csum(sb)) != md_csum_fold(sb->sb_csum)) {
1209                 pr_warn("md: invalid superblock checksum on %pg\n", rdev->bdev);
1210                 goto abort;
1211         }
1212
1213         rdev->preferred_minor = sb->md_minor;
1214         rdev->data_offset = 0;
1215         rdev->new_data_offset = 0;
1216         rdev->sb_size = MD_SB_BYTES;
1217         rdev->badblocks.shift = -1;
1218
1219         rdev->desc_nr = sb->this_disk.number;
1220
1221         /* not spare disk */
1222         if (rdev->desc_nr >= 0 && rdev->desc_nr < MD_SB_DISKS &&
1223             sb->disks[rdev->desc_nr].state & ((1<<MD_DISK_SYNC) | (1 << MD_DISK_ACTIVE)))
1224                 spare_disk = false;
1225
1226         if (!refdev) {
1227                 if (!spare_disk)
1228                         ret = 1;
1229                 else
1230                         ret = 0;
1231         } else {
1232                 __u64 ev1, ev2;
1233                 mdp_super_t *refsb = page_address(refdev->sb_page);
1234                 if (!md_uuid_equal(refsb, sb)) {
1235                         pr_warn("md: %pg has different UUID to %pg\n",
1236                                 rdev->bdev, refdev->bdev);
1237                         goto abort;
1238                 }
1239                 if (!md_sb_equal(refsb, sb)) {
1240                         pr_warn("md: %pg has same UUID but different superblock to %pg\n",
1241                                 rdev->bdev, refdev->bdev);
1242                         goto abort;
1243                 }
1244                 ev1 = md_event(sb);
1245                 ev2 = md_event(refsb);
1246
1247                 if (!spare_disk && ev1 > ev2)
1248                         ret = 1;
1249                 else
1250                         ret = 0;
1251         }
1252         rdev->sectors = rdev->sb_start;
1253         /* Limit to 4TB as metadata cannot record more than that.
1254          * (not needed for Linear and RAID0 as metadata doesn't
1255          * record this size)
1256          */
1257         if ((u64)rdev->sectors >= (2ULL << 32) && sb->level >= 1)
1258                 rdev->sectors = (sector_t)(2ULL << 32) - 2;
1259
1260         if (rdev->sectors < ((sector_t)sb->size) * 2 && sb->level >= 1)
1261                 /* "this cannot possibly happen" ... */
1262                 ret = -EINVAL;
1263
1264  abort:
1265         return ret;
1266 }
1267
1268 static u64 md_bitmap_events_cleared(struct mddev *mddev)
1269 {
1270         struct md_bitmap_stats stats;
1271         int err;
1272
1273         err = mddev->bitmap_ops->get_stats(mddev->bitmap, &stats);
1274         if (err)
1275                 return 0;
1276
1277         return stats.events_cleared;
1278 }
1279
1280 /*
1281  * validate_super for 0.90.0
1282  * note: we are not using "freshest" for 0.9 superblock
1283  */
1284 static int super_90_validate(struct mddev *mddev, struct md_rdev *freshest, struct md_rdev *rdev)
1285 {
1286         mdp_disk_t *desc;
1287         mdp_super_t *sb = page_address(rdev->sb_page);
1288         __u64 ev1 = md_event(sb);
1289
1290         rdev->raid_disk = -1;
1291         clear_bit(Faulty, &rdev->flags);
1292         clear_bit(In_sync, &rdev->flags);
1293         clear_bit(Bitmap_sync, &rdev->flags);
1294         clear_bit(WriteMostly, &rdev->flags);
1295
1296         if (mddev->raid_disks == 0) {
1297                 mddev->major_version = 0;
1298                 mddev->minor_version = sb->minor_version;
1299                 mddev->patch_version = sb->patch_version;
1300                 mddev->external = 0;
1301                 mddev->chunk_sectors = sb->chunk_size >> 9;
1302                 mddev->ctime = sb->ctime;
1303                 mddev->utime = sb->utime;
1304                 mddev->level = sb->level;
1305                 mddev->clevel[0] = 0;
1306                 mddev->layout = sb->layout;
1307                 mddev->raid_disks = sb->raid_disks;
1308                 mddev->dev_sectors = ((sector_t)sb->size) * 2;
1309                 mddev->events = ev1;
1310                 mddev->bitmap_info.offset = 0;
1311                 mddev->bitmap_info.space = 0;
1312                 /* bitmap can use 60 K after the 4K superblocks */
1313                 mddev->bitmap_info.default_offset = MD_SB_BYTES >> 9;
1314                 mddev->bitmap_info.default_space = 64*2 - (MD_SB_BYTES >> 9);
1315                 mddev->reshape_backwards = 0;
1316
1317                 if (mddev->minor_version >= 91) {
1318                         mddev->reshape_position = sb->reshape_position;
1319                         mddev->delta_disks = sb->delta_disks;
1320                         mddev->new_level = sb->new_level;
1321                         mddev->new_layout = sb->new_layout;
1322                         mddev->new_chunk_sectors = sb->new_chunk >> 9;
1323                         if (mddev->delta_disks < 0)
1324                                 mddev->reshape_backwards = 1;
1325                 } else {
1326                         mddev->reshape_position = MaxSector;
1327                         mddev->delta_disks = 0;
1328                         mddev->new_level = mddev->level;
1329                         mddev->new_layout = mddev->layout;
1330                         mddev->new_chunk_sectors = mddev->chunk_sectors;
1331                 }
1332                 if (mddev->level == 0)
1333                         mddev->layout = -1;
1334
1335                 if (sb->state & (1<<MD_SB_CLEAN))
1336                         mddev->recovery_cp = MaxSector;
1337                 else {
1338                         if (sb->events_hi == sb->cp_events_hi &&
1339                                 sb->events_lo == sb->cp_events_lo) {
1340                                 mddev->recovery_cp = sb->recovery_cp;
1341                         } else
1342                                 mddev->recovery_cp = 0;
1343                 }
1344
1345                 memcpy(mddev->uuid+0, &sb->set_uuid0, 4);
1346                 memcpy(mddev->uuid+4, &sb->set_uuid1, 4);
1347                 memcpy(mddev->uuid+8, &sb->set_uuid2, 4);
1348                 memcpy(mddev->uuid+12,&sb->set_uuid3, 4);
1349
1350                 mddev->max_disks = MD_SB_DISKS;
1351
1352                 if (sb->state & (1<<MD_SB_BITMAP_PRESENT) &&
1353                     mddev->bitmap_info.file == NULL) {
1354                         mddev->bitmap_info.offset =
1355                                 mddev->bitmap_info.default_offset;
1356                         mddev->bitmap_info.space =
1357                                 mddev->bitmap_info.default_space;
1358                 }
1359
1360         } else if (mddev->pers == NULL) {
1361                 /* Insist on good event counter while assembling, except
1362                  * for spares (which don't need an event count) */
1363                 ++ev1;
1364                 if (sb->disks[rdev->desc_nr].state & (
1365                             (1<<MD_DISK_SYNC) | (1 << MD_DISK_ACTIVE)))
1366                         if (ev1 < mddev->events)
1367                                 return -EINVAL;
1368         } else if (mddev->bitmap) {
1369                 /* if adding to array with a bitmap, then we can accept an
1370                  * older device ... but not too old.
1371                  */
1372                 if (ev1 < md_bitmap_events_cleared(mddev))
1373                         return 0;
1374                 if (ev1 < mddev->events)
1375                         set_bit(Bitmap_sync, &rdev->flags);
1376         } else {
1377                 if (ev1 < mddev->events)
1378                         /* just a hot-add of a new device, leave raid_disk at -1 */
1379                         return 0;
1380         }
1381
1382         desc = sb->disks + rdev->desc_nr;
1383
1384         if (desc->state & (1<<MD_DISK_FAULTY))
1385                 set_bit(Faulty, &rdev->flags);
1386         else if (desc->state & (1<<MD_DISK_SYNC)) {
1387                 set_bit(In_sync, &rdev->flags);
1388                 rdev->raid_disk = desc->raid_disk;
1389                 rdev->saved_raid_disk = desc->raid_disk;
1390         } else if (desc->state & (1<<MD_DISK_ACTIVE)) {
1391                 /* active but not in sync implies recovery up to
1392                  * reshape position.  We don't know exactly where
1393                  * that is, so set to zero for now
1394                  */
1395                 if (mddev->minor_version >= 91) {
1396                         rdev->recovery_offset = 0;
1397                         rdev->raid_disk = desc->raid_disk;
1398                 }
1399         }
1400         if (desc->state & (1<<MD_DISK_WRITEMOSTLY))
1401                 set_bit(WriteMostly, &rdev->flags);
1402         if (desc->state & (1<<MD_DISK_FAILFAST))
1403                 set_bit(FailFast, &rdev->flags);
1404         return 0;
1405 }
1406
1407 /*
1408  * sync_super for 0.90.0
1409  */
1410 static void super_90_sync(struct mddev *mddev, struct md_rdev *rdev)
1411 {
1412         mdp_super_t *sb;
1413         struct md_rdev *rdev2;
1414         int next_spare = mddev->raid_disks;
1415
1416         /* make rdev->sb match mddev data..
1417          *
1418          * 1/ zero out disks
1419          * 2/ Add info for each disk, keeping track of highest desc_nr (next_spare);
1420          * 3/ any empty disks < next_spare become removed
1421          *
1422          * disks[0] gets initialised to REMOVED because
1423          * we cannot be sure from other fields if it has
1424          * been initialised or not.
1425          */
1426         int i;
1427         int active=0, working=0,failed=0,spare=0,nr_disks=0;
1428
1429         rdev->sb_size = MD_SB_BYTES;
1430
1431         sb = page_address(rdev->sb_page);
1432
1433         memset(sb, 0, sizeof(*sb));
1434
1435         sb->md_magic = MD_SB_MAGIC;
1436         sb->major_version = mddev->major_version;
1437         sb->patch_version = mddev->patch_version;
1438         sb->gvalid_words  = 0; /* ignored */
1439         memcpy(&sb->set_uuid0, mddev->uuid+0, 4);
1440         memcpy(&sb->set_uuid1, mddev->uuid+4, 4);
1441         memcpy(&sb->set_uuid2, mddev->uuid+8, 4);
1442         memcpy(&sb->set_uuid3, mddev->uuid+12,4);
1443
1444         sb->ctime = clamp_t(time64_t, mddev->ctime, 0, U32_MAX);
1445         sb->level = mddev->level;
1446         sb->size = mddev->dev_sectors / 2;
1447         sb->raid_disks = mddev->raid_disks;
1448         sb->md_minor = mddev->md_minor;
1449         sb->not_persistent = 0;
1450         sb->utime = clamp_t(time64_t, mddev->utime, 0, U32_MAX);
1451         sb->state = 0;
1452         sb->events_hi = (mddev->events>>32);
1453         sb->events_lo = (u32)mddev->events;
1454
1455         if (mddev->reshape_position == MaxSector)
1456                 sb->minor_version = 90;
1457         else {
1458                 sb->minor_version = 91;
1459                 sb->reshape_position = mddev->reshape_position;
1460                 sb->new_level = mddev->new_level;
1461                 sb->delta_disks = mddev->delta_disks;
1462                 sb->new_layout = mddev->new_layout;
1463                 sb->new_chunk = mddev->new_chunk_sectors << 9;
1464         }
1465         mddev->minor_version = sb->minor_version;
1466         if (mddev->in_sync)
1467         {
1468                 sb->recovery_cp = mddev->recovery_cp;
1469                 sb->cp_events_hi = (mddev->events>>32);
1470                 sb->cp_events_lo = (u32)mddev->events;
1471                 if (mddev->recovery_cp == MaxSector)
1472                         sb->state = (1<< MD_SB_CLEAN);
1473         } else
1474                 sb->recovery_cp = 0;
1475
1476         sb->layout = mddev->layout;
1477         sb->chunk_size = mddev->chunk_sectors << 9;
1478
1479         if (mddev->bitmap && mddev->bitmap_info.file == NULL)
1480                 sb->state |= (1<<MD_SB_BITMAP_PRESENT);
1481
1482         sb->disks[0].state = (1<<MD_DISK_REMOVED);
1483         rdev_for_each(rdev2, mddev) {
1484                 mdp_disk_t *d;
1485                 int desc_nr;
1486                 int is_active = test_bit(In_sync, &rdev2->flags);
1487
1488                 if (rdev2->raid_disk >= 0 &&
1489                     sb->minor_version >= 91)
1490                         /* we have nowhere to store the recovery_offset,
1491                          * but if it is not below the reshape_position,
1492                          * we can piggy-back on that.
1493                          */
1494                         is_active = 1;
1495                 if (rdev2->raid_disk < 0 ||
1496                     test_bit(Faulty, &rdev2->flags))
1497                         is_active = 0;
1498                 if (is_active)
1499                         desc_nr = rdev2->raid_disk;
1500                 else
1501                         desc_nr = next_spare++;
1502                 rdev2->desc_nr = desc_nr;
1503                 d = &sb->disks[rdev2->desc_nr];
1504                 nr_disks++;
1505                 d->number = rdev2->desc_nr;
1506                 d->major = MAJOR(rdev2->bdev->bd_dev);
1507                 d->minor = MINOR(rdev2->bdev->bd_dev);
1508                 if (is_active)
1509                         d->raid_disk = rdev2->raid_disk;
1510                 else
1511                         d->raid_disk = rdev2->desc_nr; /* compatibility */
1512                 if (test_bit(Faulty, &rdev2->flags))
1513                         d->state = (1<<MD_DISK_FAULTY);
1514                 else if (is_active) {
1515                         d->state = (1<<MD_DISK_ACTIVE);
1516                         if (test_bit(In_sync, &rdev2->flags))
1517                                 d->state |= (1<<MD_DISK_SYNC);
1518                         active++;
1519                         working++;
1520                 } else {
1521                         d->state = 0;
1522                         spare++;
1523                         working++;
1524                 }
1525                 if (test_bit(WriteMostly, &rdev2->flags))
1526                         d->state |= (1<<MD_DISK_WRITEMOSTLY);
1527                 if (test_bit(FailFast, &rdev2->flags))
1528                         d->state |= (1<<MD_DISK_FAILFAST);
1529         }
1530         /* now set the "removed" and "faulty" bits on any missing devices */
1531         for (i=0 ; i < mddev->raid_disks ; i++) {
1532                 mdp_disk_t *d = &sb->disks[i];
1533                 if (d->state == 0 && d->number == 0) {
1534                         d->number = i;
1535                         d->raid_disk = i;
1536                         d->state = (1<<MD_DISK_REMOVED);
1537                         d->state |= (1<<MD_DISK_FAULTY);
1538                         failed++;
1539                 }
1540         }
1541         sb->nr_disks = nr_disks;
1542         sb->active_disks = active;
1543         sb->working_disks = working;
1544         sb->failed_disks = failed;
1545         sb->spare_disks = spare;
1546
1547         sb->this_disk = sb->disks[rdev->desc_nr];
1548         sb->sb_csum = calc_sb_csum(sb);
1549 }
1550
1551 /*
1552  * rdev_size_change for 0.90.0
1553  */
1554 static unsigned long long
1555 super_90_rdev_size_change(struct md_rdev *rdev, sector_t num_sectors)
1556 {
1557         if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
1558                 return 0; /* component must fit device */
1559         if (rdev->mddev->bitmap_info.offset)
1560                 return 0; /* can't move bitmap */
1561         rdev->sb_start = calc_dev_sboffset(rdev);
1562         if (!num_sectors || num_sectors > rdev->sb_start)
1563                 num_sectors = rdev->sb_start;
1564         /* Limit to 4TB as metadata cannot record more than that.
1565          * 4TB == 2^32 KB, or 2*2^32 sectors.
1566          */
1567         if ((u64)num_sectors >= (2ULL << 32) && rdev->mddev->level >= 1)
1568                 num_sectors = (sector_t)(2ULL << 32) - 2;
1569         do {
1570                 md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
1571                        rdev->sb_page);
1572         } while (md_super_wait(rdev->mddev) < 0);
1573         return num_sectors;
1574 }
1575
1576 static int
1577 super_90_allow_new_offset(struct md_rdev *rdev, unsigned long long new_offset)
1578 {
1579         /* non-zero offset changes not possible with v0.90 */
1580         return new_offset == 0;
1581 }
1582
1583 /*
1584  * version 1 superblock
1585  */
1586
1587 static __le32 calc_sb_1_csum(struct mdp_superblock_1 *sb)
1588 {
1589         __le32 disk_csum;
1590         u32 csum;
1591         unsigned long long newcsum;
1592         int size = 256 + le32_to_cpu(sb->max_dev)*2;
1593         __le32 *isuper = (__le32*)sb;
1594
1595         disk_csum = sb->sb_csum;
1596         sb->sb_csum = 0;
1597         newcsum = 0;
1598         for (; size >= 4; size -= 4)
1599                 newcsum += le32_to_cpu(*isuper++);
1600
1601         if (size == 2)
1602                 newcsum += le16_to_cpu(*(__le16*) isuper);
1603
1604         csum = (newcsum & 0xffffffff) + (newcsum >> 32);
1605         sb->sb_csum = disk_csum;
1606         return cpu_to_le32(csum);
1607 }
1608
1609 static int super_1_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor_version)
1610 {
1611         struct mdp_superblock_1 *sb;
1612         int ret;
1613         sector_t sb_start;
1614         sector_t sectors;
1615         int bmask;
1616         bool spare_disk = true;
1617
1618         /*
1619          * Calculate the position of the superblock in 512byte sectors.
1620          * It is always aligned to a 4K boundary and
1621          * depeding on minor_version, it can be:
1622          * 0: At least 8K, but less than 12K, from end of device
1623          * 1: At start of device
1624          * 2: 4K from start of device.
1625          */
1626         switch(minor_version) {
1627         case 0:
1628                 sb_start = bdev_nr_sectors(rdev->bdev) - 8 * 2;
1629                 sb_start &= ~(sector_t)(4*2-1);
1630                 break;
1631         case 1:
1632                 sb_start = 0;
1633                 break;
1634         case 2:
1635                 sb_start = 8;
1636                 break;
1637         default:
1638                 return -EINVAL;
1639         }
1640         rdev->sb_start = sb_start;
1641
1642         /* superblock is rarely larger than 1K, but it can be larger,
1643          * and it is safe to read 4k, so we do that
1644          */
1645         ret = read_disk_sb(rdev, 4096);
1646         if (ret) return ret;
1647
1648         sb = page_address(rdev->sb_page);
1649
1650         if (sb->magic != cpu_to_le32(MD_SB_MAGIC) ||
1651             sb->major_version != cpu_to_le32(1) ||
1652             le32_to_cpu(sb->max_dev) > (4096-256)/2 ||
1653             le64_to_cpu(sb->super_offset) != rdev->sb_start ||
1654             (le32_to_cpu(sb->feature_map) & ~MD_FEATURE_ALL) != 0)
1655                 return -EINVAL;
1656
1657         if (calc_sb_1_csum(sb) != sb->sb_csum) {
1658                 pr_warn("md: invalid superblock checksum on %pg\n",
1659                         rdev->bdev);
1660                 return -EINVAL;
1661         }
1662         if (le64_to_cpu(sb->data_size) < 10) {
1663                 pr_warn("md: data_size too small on %pg\n",
1664                         rdev->bdev);
1665                 return -EINVAL;
1666         }
1667         if (sb->pad0 ||
1668             sb->pad3[0] ||
1669             memcmp(sb->pad3, sb->pad3+1, sizeof(sb->pad3) - sizeof(sb->pad3[1])))
1670                 /* Some padding is non-zero, might be a new feature */
1671                 return -EINVAL;
1672
1673         rdev->preferred_minor = 0xffff;
1674         rdev->data_offset = le64_to_cpu(sb->data_offset);
1675         rdev->new_data_offset = rdev->data_offset;
1676         if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE) &&
1677             (le32_to_cpu(sb->feature_map) & MD_FEATURE_NEW_OFFSET))
1678                 rdev->new_data_offset += (s32)le32_to_cpu(sb->new_offset);
1679         atomic_set(&rdev->corrected_errors, le32_to_cpu(sb->cnt_corrected_read));
1680
1681         rdev->sb_size = le32_to_cpu(sb->max_dev) * 2 + 256;
1682         bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
1683         if (rdev->sb_size & bmask)
1684                 rdev->sb_size = (rdev->sb_size | bmask) + 1;
1685
1686         if (minor_version
1687             && rdev->data_offset < sb_start + (rdev->sb_size/512))
1688                 return -EINVAL;
1689         if (minor_version
1690             && rdev->new_data_offset < sb_start + (rdev->sb_size/512))
1691                 return -EINVAL;
1692
1693         rdev->desc_nr = le32_to_cpu(sb->dev_number);
1694
1695         if (!rdev->bb_page) {
1696                 rdev->bb_page = alloc_page(GFP_KERNEL);
1697                 if (!rdev->bb_page)
1698                         return -ENOMEM;
1699         }
1700         if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BAD_BLOCKS) &&
1701             rdev->badblocks.count == 0) {
1702                 /* need to load the bad block list.
1703                  * Currently we limit it to one page.
1704                  */
1705                 s32 offset;
1706                 sector_t bb_sector;
1707                 __le64 *bbp;
1708                 int i;
1709                 int sectors = le16_to_cpu(sb->bblog_size);
1710                 if (sectors > (PAGE_SIZE / 512))
1711                         return -EINVAL;
1712                 offset = le32_to_cpu(sb->bblog_offset);
1713                 if (offset == 0)
1714                         return -EINVAL;
1715                 bb_sector = (long long)offset;
1716                 if (!sync_page_io(rdev, bb_sector, sectors << 9,
1717                                   rdev->bb_page, REQ_OP_READ, true))
1718                         return -EIO;
1719                 bbp = (__le64 *)page_address(rdev->bb_page);
1720                 rdev->badblocks.shift = sb->bblog_shift;
1721                 for (i = 0 ; i < (sectors << (9-3)) ; i++, bbp++) {
1722                         u64 bb = le64_to_cpu(*bbp);
1723                         int count = bb & (0x3ff);
1724                         u64 sector = bb >> 10;
1725                         sector <<= sb->bblog_shift;
1726                         count <<= sb->bblog_shift;
1727                         if (bb + 1 == 0)
1728                                 break;
1729                         if (badblocks_set(&rdev->badblocks, sector, count, 1))
1730                                 return -EINVAL;
1731                 }
1732         } else if (sb->bblog_offset != 0)
1733                 rdev->badblocks.shift = 0;
1734
1735         if ((le32_to_cpu(sb->feature_map) &
1736             (MD_FEATURE_PPL | MD_FEATURE_MULTIPLE_PPLS))) {
1737                 rdev->ppl.offset = (__s16)le16_to_cpu(sb->ppl.offset);
1738                 rdev->ppl.size = le16_to_cpu(sb->ppl.size);
1739                 rdev->ppl.sector = rdev->sb_start + rdev->ppl.offset;
1740         }
1741
1742         if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RAID0_LAYOUT) &&
1743             sb->level != 0)
1744                 return -EINVAL;
1745
1746         /* not spare disk */
1747         if (rdev->desc_nr >= 0 && rdev->desc_nr < le32_to_cpu(sb->max_dev) &&
1748             (le16_to_cpu(sb->dev_roles[rdev->desc_nr]) < MD_DISK_ROLE_MAX ||
1749              le16_to_cpu(sb->dev_roles[rdev->desc_nr]) == MD_DISK_ROLE_JOURNAL))
1750                 spare_disk = false;
1751
1752         if (!refdev) {
1753                 if (!spare_disk)
1754                         ret = 1;
1755                 else
1756                         ret = 0;
1757         } else {
1758                 __u64 ev1, ev2;
1759                 struct mdp_superblock_1 *refsb = page_address(refdev->sb_page);
1760
1761                 if (memcmp(sb->set_uuid, refsb->set_uuid, 16) != 0 ||
1762                     sb->level != refsb->level ||
1763                     sb->layout != refsb->layout ||
1764                     sb->chunksize != refsb->chunksize) {
1765                         pr_warn("md: %pg has strangely different superblock to %pg\n",
1766                                 rdev->bdev,
1767                                 refdev->bdev);
1768                         return -EINVAL;
1769                 }
1770                 ev1 = le64_to_cpu(sb->events);
1771                 ev2 = le64_to_cpu(refsb->events);
1772
1773                 if (!spare_disk && ev1 > ev2)
1774                         ret = 1;
1775                 else
1776                         ret = 0;
1777         }
1778         if (minor_version)
1779                 sectors = bdev_nr_sectors(rdev->bdev) - rdev->data_offset;
1780         else
1781                 sectors = rdev->sb_start;
1782         if (sectors < le64_to_cpu(sb->data_size))
1783                 return -EINVAL;
1784         rdev->sectors = le64_to_cpu(sb->data_size);
1785         return ret;
1786 }
1787
1788 static int super_1_validate(struct mddev *mddev, struct md_rdev *freshest, struct md_rdev *rdev)
1789 {
1790         struct mdp_superblock_1 *sb = page_address(rdev->sb_page);
1791         __u64 ev1 = le64_to_cpu(sb->events);
1792         int role;
1793
1794         rdev->raid_disk = -1;
1795         clear_bit(Faulty, &rdev->flags);
1796         clear_bit(In_sync, &rdev->flags);
1797         clear_bit(Bitmap_sync, &rdev->flags);
1798         clear_bit(WriteMostly, &rdev->flags);
1799
1800         if (mddev->raid_disks == 0) {
1801                 mddev->major_version = 1;
1802                 mddev->patch_version = 0;
1803                 mddev->external = 0;
1804                 mddev->chunk_sectors = le32_to_cpu(sb->chunksize);
1805                 mddev->ctime = le64_to_cpu(sb->ctime);
1806                 mddev->utime = le64_to_cpu(sb->utime);
1807                 mddev->level = le32_to_cpu(sb->level);
1808                 mddev->clevel[0] = 0;
1809                 mddev->layout = le32_to_cpu(sb->layout);
1810                 mddev->raid_disks = le32_to_cpu(sb->raid_disks);
1811                 mddev->dev_sectors = le64_to_cpu(sb->size);
1812                 mddev->events = ev1;
1813                 mddev->bitmap_info.offset = 0;
1814                 mddev->bitmap_info.space = 0;
1815                 /* Default location for bitmap is 1K after superblock
1816                  * using 3K - total of 4K
1817                  */
1818                 mddev->bitmap_info.default_offset = 1024 >> 9;
1819                 mddev->bitmap_info.default_space = (4096-1024) >> 9;
1820                 mddev->reshape_backwards = 0;
1821
1822                 mddev->recovery_cp = le64_to_cpu(sb->resync_offset);
1823                 memcpy(mddev->uuid, sb->set_uuid, 16);
1824
1825                 mddev->max_disks =  (4096-256)/2;
1826
1827                 if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BITMAP_OFFSET) &&
1828                     mddev->bitmap_info.file == NULL) {
1829                         mddev->bitmap_info.offset =
1830                                 (__s32)le32_to_cpu(sb->bitmap_offset);
1831                         /* Metadata doesn't record how much space is available.
1832                          * For 1.0, we assume we can use up to the superblock
1833                          * if before, else to 4K beyond superblock.
1834                          * For others, assume no change is possible.
1835                          */
1836                         if (mddev->minor_version > 0)
1837                                 mddev->bitmap_info.space = 0;
1838                         else if (mddev->bitmap_info.offset > 0)
1839                                 mddev->bitmap_info.space =
1840                                         8 - mddev->bitmap_info.offset;
1841                         else
1842                                 mddev->bitmap_info.space =
1843                                         -mddev->bitmap_info.offset;
1844                 }
1845
1846                 if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE)) {
1847                         mddev->reshape_position = le64_to_cpu(sb->reshape_position);
1848                         mddev->delta_disks = le32_to_cpu(sb->delta_disks);
1849                         mddev->new_level = le32_to_cpu(sb->new_level);
1850                         mddev->new_layout = le32_to_cpu(sb->new_layout);
1851                         mddev->new_chunk_sectors = le32_to_cpu(sb->new_chunk);
1852                         if (mddev->delta_disks < 0 ||
1853                             (mddev->delta_disks == 0 &&
1854                              (le32_to_cpu(sb->feature_map)
1855                               & MD_FEATURE_RESHAPE_BACKWARDS)))
1856                                 mddev->reshape_backwards = 1;
1857                 } else {
1858                         mddev->reshape_position = MaxSector;
1859                         mddev->delta_disks = 0;
1860                         mddev->new_level = mddev->level;
1861                         mddev->new_layout = mddev->layout;
1862                         mddev->new_chunk_sectors = mddev->chunk_sectors;
1863                 }
1864
1865                 if (mddev->level == 0 &&
1866                     !(le32_to_cpu(sb->feature_map) & MD_FEATURE_RAID0_LAYOUT))
1867                         mddev->layout = -1;
1868
1869                 if (le32_to_cpu(sb->feature_map) & MD_FEATURE_JOURNAL)
1870                         set_bit(MD_HAS_JOURNAL, &mddev->flags);
1871
1872                 if (le32_to_cpu(sb->feature_map) &
1873                     (MD_FEATURE_PPL | MD_FEATURE_MULTIPLE_PPLS)) {
1874                         if (le32_to_cpu(sb->feature_map) &
1875                             (MD_FEATURE_BITMAP_OFFSET | MD_FEATURE_JOURNAL))
1876                                 return -EINVAL;
1877                         if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_PPL) &&
1878                             (le32_to_cpu(sb->feature_map) &
1879                                             MD_FEATURE_MULTIPLE_PPLS))
1880                                 return -EINVAL;
1881                         set_bit(MD_HAS_PPL, &mddev->flags);
1882                 }
1883         } else if (mddev->pers == NULL) {
1884                 /* Insist of good event counter while assembling, except for
1885                  * spares (which don't need an event count).
1886                  * Similar to mdadm, we allow event counter difference of 1
1887                  * from the freshest device.
1888                  */
1889                 if (rdev->desc_nr >= 0 &&
1890                     rdev->desc_nr < le32_to_cpu(sb->max_dev) &&
1891                     (le16_to_cpu(sb->dev_roles[rdev->desc_nr]) < MD_DISK_ROLE_MAX ||
1892                      le16_to_cpu(sb->dev_roles[rdev->desc_nr]) == MD_DISK_ROLE_JOURNAL))
1893                         if (ev1 + 1 < mddev->events)
1894                                 return -EINVAL;
1895         } else if (mddev->bitmap) {
1896                 /* If adding to array with a bitmap, then we can accept an
1897                  * older device, but not too old.
1898                  */
1899                 if (ev1 < md_bitmap_events_cleared(mddev))
1900                         return 0;
1901                 if (ev1 < mddev->events)
1902                         set_bit(Bitmap_sync, &rdev->flags);
1903         } else {
1904                 if (ev1 < mddev->events)
1905                         /* just a hot-add of a new device, leave raid_disk at -1 */
1906                         return 0;
1907         }
1908
1909         if (rdev->desc_nr < 0 ||
1910             rdev->desc_nr >= le32_to_cpu(sb->max_dev)) {
1911                 role = MD_DISK_ROLE_SPARE;
1912                 rdev->desc_nr = -1;
1913         } else if (mddev->pers == NULL && freshest && ev1 < mddev->events) {
1914                 /*
1915                  * If we are assembling, and our event counter is smaller than the
1916                  * highest event counter, we cannot trust our superblock about the role.
1917                  * It could happen that our rdev was marked as Faulty, and all other
1918                  * superblocks were updated with +1 event counter.
1919                  * Then, before the next superblock update, which typically happens when
1920                  * remove_and_add_spares() removes the device from the array, there was
1921                  * a crash or reboot.
1922                  * If we allow current rdev without consulting the freshest superblock,
1923                  * we could cause data corruption.
1924                  * Note that in this case our event counter is smaller by 1 than the
1925                  * highest, otherwise, this rdev would not be allowed into array;
1926                  * both kernel and mdadm allow event counter difference of 1.
1927                  */
1928                 struct mdp_superblock_1 *freshest_sb = page_address(freshest->sb_page);
1929                 u32 freshest_max_dev = le32_to_cpu(freshest_sb->max_dev);
1930
1931                 if (rdev->desc_nr >= freshest_max_dev) {
1932                         /* this is unexpected, better not proceed */
1933                         pr_warn("md: %s: rdev[%pg]: desc_nr(%d) >= freshest(%pg)->sb->max_dev(%u)\n",
1934                                 mdname(mddev), rdev->bdev, rdev->desc_nr,
1935                                 freshest->bdev, freshest_max_dev);
1936                         return -EUCLEAN;
1937                 }
1938
1939                 role = le16_to_cpu(freshest_sb->dev_roles[rdev->desc_nr]);
1940                 pr_debug("md: %s: rdev[%pg]: role=%d(0x%x) according to freshest %pg\n",
1941                          mdname(mddev), rdev->bdev, role, role, freshest->bdev);
1942         } else {
1943                 role = le16_to_cpu(sb->dev_roles[rdev->desc_nr]);
1944         }
1945         switch (role) {
1946         case MD_DISK_ROLE_SPARE: /* spare */
1947                 break;
1948         case MD_DISK_ROLE_FAULTY: /* faulty */
1949                 set_bit(Faulty, &rdev->flags);
1950                 break;
1951         case MD_DISK_ROLE_JOURNAL: /* journal device */
1952                 if (!(le32_to_cpu(sb->feature_map) & MD_FEATURE_JOURNAL)) {
1953                         /* journal device without journal feature */
1954                         pr_warn("md: journal device provided without journal feature, ignoring the device\n");
1955                         return -EINVAL;
1956                 }
1957                 set_bit(Journal, &rdev->flags);
1958                 rdev->journal_tail = le64_to_cpu(sb->journal_tail);
1959                 rdev->raid_disk = 0;
1960                 break;
1961         default:
1962                 rdev->saved_raid_disk = role;
1963                 if ((le32_to_cpu(sb->feature_map) &
1964                      MD_FEATURE_RECOVERY_OFFSET)) {
1965                         rdev->recovery_offset = le64_to_cpu(sb->recovery_offset);
1966                         if (!(le32_to_cpu(sb->feature_map) &
1967                               MD_FEATURE_RECOVERY_BITMAP))
1968                                 rdev->saved_raid_disk = -1;
1969                 } else {
1970                         /*
1971                          * If the array is FROZEN, then the device can't
1972                          * be in_sync with rest of array.
1973                          */
1974                         if (!test_bit(MD_RECOVERY_FROZEN,
1975                                       &mddev->recovery))
1976                                 set_bit(In_sync, &rdev->flags);
1977                 }
1978                 rdev->raid_disk = role;
1979                 break;
1980         }
1981         if (sb->devflags & WriteMostly1)
1982                 set_bit(WriteMostly, &rdev->flags);
1983         if (sb->devflags & FailFast1)
1984                 set_bit(FailFast, &rdev->flags);
1985         if (le32_to_cpu(sb->feature_map) & MD_FEATURE_REPLACEMENT)
1986                 set_bit(Replacement, &rdev->flags);
1987
1988         return 0;
1989 }
1990
1991 static void super_1_sync(struct mddev *mddev, struct md_rdev *rdev)
1992 {
1993         struct mdp_superblock_1 *sb;
1994         struct md_rdev *rdev2;
1995         int max_dev, i;
1996         /* make rdev->sb match mddev and rdev data. */
1997
1998         sb = page_address(rdev->sb_page);
1999
2000         sb->feature_map = 0;
2001         sb->pad0 = 0;
2002         sb->recovery_offset = cpu_to_le64(0);
2003         memset(sb->pad3, 0, sizeof(sb->pad3));
2004
2005         sb->utime = cpu_to_le64((__u64)mddev->utime);
2006         sb->events = cpu_to_le64(mddev->events);
2007         if (mddev->in_sync)
2008                 sb->resync_offset = cpu_to_le64(mddev->recovery_cp);
2009         else if (test_bit(MD_JOURNAL_CLEAN, &mddev->flags))
2010                 sb->resync_offset = cpu_to_le64(MaxSector);
2011         else
2012                 sb->resync_offset = cpu_to_le64(0);
2013
2014         sb->cnt_corrected_read = cpu_to_le32(atomic_read(&rdev->corrected_errors));
2015
2016         sb->raid_disks = cpu_to_le32(mddev->raid_disks);
2017         sb->size = cpu_to_le64(mddev->dev_sectors);
2018         sb->chunksize = cpu_to_le32(mddev->chunk_sectors);
2019         sb->level = cpu_to_le32(mddev->level);
2020         sb->layout = cpu_to_le32(mddev->layout);
2021         if (test_bit(FailFast, &rdev->flags))
2022                 sb->devflags |= FailFast1;
2023         else
2024                 sb->devflags &= ~FailFast1;
2025
2026         if (test_bit(WriteMostly, &rdev->flags))
2027                 sb->devflags |= WriteMostly1;
2028         else
2029                 sb->devflags &= ~WriteMostly1;
2030         sb->data_offset = cpu_to_le64(rdev->data_offset);
2031         sb->data_size = cpu_to_le64(rdev->sectors);
2032
2033         if (mddev->bitmap && mddev->bitmap_info.file == NULL) {
2034                 sb->bitmap_offset = cpu_to_le32((__u32)mddev->bitmap_info.offset);
2035                 sb->feature_map = cpu_to_le32(MD_FEATURE_BITMAP_OFFSET);
2036         }
2037
2038         if (rdev->raid_disk >= 0 && !test_bit(Journal, &rdev->flags) &&
2039             !test_bit(In_sync, &rdev->flags)) {
2040                 sb->feature_map |=
2041                         cpu_to_le32(MD_FEATURE_RECOVERY_OFFSET);
2042                 sb->recovery_offset =
2043                         cpu_to_le64(rdev->recovery_offset);
2044                 if (rdev->saved_raid_disk >= 0 && mddev->bitmap)
2045                         sb->feature_map |=
2046                                 cpu_to_le32(MD_FEATURE_RECOVERY_BITMAP);
2047         }
2048         /* Note: recovery_offset and journal_tail share space  */
2049         if (test_bit(Journal, &rdev->flags))
2050                 sb->journal_tail = cpu_to_le64(rdev->journal_tail);
2051         if (test_bit(Replacement, &rdev->flags))
2052                 sb->feature_map |=
2053                         cpu_to_le32(MD_FEATURE_REPLACEMENT);
2054
2055         if (mddev->reshape_position != MaxSector) {
2056                 sb->feature_map |= cpu_to_le32(MD_FEATURE_RESHAPE_ACTIVE);
2057                 sb->reshape_position = cpu_to_le64(mddev->reshape_position);
2058                 sb->new_layout = cpu_to_le32(mddev->new_layout);
2059                 sb->delta_disks = cpu_to_le32(mddev->delta_disks);
2060                 sb->new_level = cpu_to_le32(mddev->new_level);
2061                 sb->new_chunk = cpu_to_le32(mddev->new_chunk_sectors);
2062                 if (mddev->delta_disks == 0 &&
2063                     mddev->reshape_backwards)
2064                         sb->feature_map
2065                                 |= cpu_to_le32(MD_FEATURE_RESHAPE_BACKWARDS);
2066                 if (rdev->new_data_offset != rdev->data_offset) {
2067                         sb->feature_map
2068                                 |= cpu_to_le32(MD_FEATURE_NEW_OFFSET);
2069                         sb->new_offset = cpu_to_le32((__u32)(rdev->new_data_offset
2070                                                              - rdev->data_offset));
2071                 }
2072         }
2073
2074         if (mddev_is_clustered(mddev))
2075                 sb->feature_map |= cpu_to_le32(MD_FEATURE_CLUSTERED);
2076
2077         if (rdev->badblocks.count == 0)
2078                 /* Nothing to do for bad blocks*/ ;
2079         else if (sb->bblog_offset == 0)
2080                 /* Cannot record bad blocks on this device */
2081                 md_error(mddev, rdev);
2082         else {
2083                 struct badblocks *bb = &rdev->badblocks;
2084                 __le64 *bbp = (__le64 *)page_address(rdev->bb_page);
2085                 u64 *p = bb->page;
2086                 sb->feature_map |= cpu_to_le32(MD_FEATURE_BAD_BLOCKS);
2087                 if (bb->changed) {
2088                         unsigned seq;
2089
2090 retry:
2091                         seq = read_seqbegin(&bb->lock);
2092
2093                         memset(bbp, 0xff, PAGE_SIZE);
2094
2095                         for (i = 0 ; i < bb->count ; i++) {
2096                                 u64 internal_bb = p[i];
2097                                 u64 store_bb = ((BB_OFFSET(internal_bb) << 10)
2098                                                 | BB_LEN(internal_bb));
2099                                 bbp[i] = cpu_to_le64(store_bb);
2100                         }
2101                         bb->changed = 0;
2102                         if (read_seqretry(&bb->lock, seq))
2103                                 goto retry;
2104
2105                         bb->sector = (rdev->sb_start +
2106                                       (int)le32_to_cpu(sb->bblog_offset));
2107                         bb->size = le16_to_cpu(sb->bblog_size);
2108                 }
2109         }
2110
2111         max_dev = 0;
2112         rdev_for_each(rdev2, mddev)
2113                 if (rdev2->desc_nr+1 > max_dev)
2114                         max_dev = rdev2->desc_nr+1;
2115
2116         if (max_dev > le32_to_cpu(sb->max_dev)) {
2117                 int bmask;
2118                 sb->max_dev = cpu_to_le32(max_dev);
2119                 rdev->sb_size = max_dev * 2 + 256;
2120                 bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
2121                 if (rdev->sb_size & bmask)
2122                         rdev->sb_size = (rdev->sb_size | bmask) + 1;
2123         } else
2124                 max_dev = le32_to_cpu(sb->max_dev);
2125
2126         for (i=0; i<max_dev;i++)
2127                 sb->dev_roles[i] = cpu_to_le16(MD_DISK_ROLE_SPARE);
2128
2129         if (test_bit(MD_HAS_JOURNAL, &mddev->flags))
2130                 sb->feature_map |= cpu_to_le32(MD_FEATURE_JOURNAL);
2131
2132         if (test_bit(MD_HAS_PPL, &mddev->flags)) {
2133                 if (test_bit(MD_HAS_MULTIPLE_PPLS, &mddev->flags))
2134                         sb->feature_map |=
2135                             cpu_to_le32(MD_FEATURE_MULTIPLE_PPLS);
2136                 else
2137                         sb->feature_map |= cpu_to_le32(MD_FEATURE_PPL);
2138                 sb->ppl.offset = cpu_to_le16(rdev->ppl.offset);
2139                 sb->ppl.size = cpu_to_le16(rdev->ppl.size);
2140         }
2141
2142         rdev_for_each(rdev2, mddev) {
2143                 i = rdev2->desc_nr;
2144                 if (test_bit(Faulty, &rdev2->flags))
2145                         sb->dev_roles[i] = cpu_to_le16(MD_DISK_ROLE_FAULTY);
2146                 else if (test_bit(In_sync, &rdev2->flags))
2147                         sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
2148                 else if (test_bit(Journal, &rdev2->flags))
2149                         sb->dev_roles[i] = cpu_to_le16(MD_DISK_ROLE_JOURNAL);
2150                 else if (rdev2->raid_disk >= 0)
2151                         sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
2152                 else
2153                         sb->dev_roles[i] = cpu_to_le16(MD_DISK_ROLE_SPARE);
2154         }
2155
2156         sb->sb_csum = calc_sb_1_csum(sb);
2157 }
2158
2159 static sector_t super_1_choose_bm_space(sector_t dev_size)
2160 {
2161         sector_t bm_space;
2162
2163         /* if the device is bigger than 8Gig, save 64k for bitmap
2164          * usage, if bigger than 200Gig, save 128k
2165          */
2166         if (dev_size < 64*2)
2167                 bm_space = 0;
2168         else if (dev_size - 64*2 >= 200*1024*1024*2)
2169                 bm_space = 128*2;
2170         else if (dev_size - 4*2 > 8*1024*1024*2)
2171                 bm_space = 64*2;
2172         else
2173                 bm_space = 4*2;
2174         return bm_space;
2175 }
2176
2177 static unsigned long long
2178 super_1_rdev_size_change(struct md_rdev *rdev, sector_t num_sectors)
2179 {
2180         struct mdp_superblock_1 *sb;
2181         sector_t max_sectors;
2182         if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
2183                 return 0; /* component must fit device */
2184         if (rdev->data_offset != rdev->new_data_offset)
2185                 return 0; /* too confusing */
2186         if (rdev->sb_start < rdev->data_offset) {
2187                 /* minor versions 1 and 2; superblock before data */
2188                 max_sectors = bdev_nr_sectors(rdev->bdev) - rdev->data_offset;
2189                 if (!num_sectors || num_sectors > max_sectors)
2190                         num_sectors = max_sectors;
2191         } else if (rdev->mddev->bitmap_info.offset) {
2192                 /* minor version 0 with bitmap we can't move */
2193                 return 0;
2194         } else {
2195                 /* minor version 0; superblock after data */
2196                 sector_t sb_start, bm_space;
2197                 sector_t dev_size = bdev_nr_sectors(rdev->bdev);
2198
2199                 /* 8K is for superblock */
2200                 sb_start = dev_size - 8*2;
2201                 sb_start &= ~(sector_t)(4*2 - 1);
2202
2203                 bm_space = super_1_choose_bm_space(dev_size);
2204
2205                 /* Space that can be used to store date needs to decrease
2206                  * superblock bitmap space and bad block space(4K)
2207                  */
2208                 max_sectors = sb_start - bm_space - 4*2;
2209
2210                 if (!num_sectors || num_sectors > max_sectors)
2211                         num_sectors = max_sectors;
2212                 rdev->sb_start = sb_start;
2213         }
2214         sb = page_address(rdev->sb_page);
2215         sb->data_size = cpu_to_le64(num_sectors);
2216         sb->super_offset = cpu_to_le64(rdev->sb_start);
2217         sb->sb_csum = calc_sb_1_csum(sb);
2218         do {
2219                 md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
2220                                rdev->sb_page);
2221         } while (md_super_wait(rdev->mddev) < 0);
2222         return num_sectors;
2223
2224 }
2225
2226 static int
2227 super_1_allow_new_offset(struct md_rdev *rdev,
2228                          unsigned long long new_offset)
2229 {
2230         /* All necessary checks on new >= old have been done */
2231         if (new_offset >= rdev->data_offset)
2232                 return 1;
2233
2234         /* with 1.0 metadata, there is no metadata to tread on
2235          * so we can always move back */
2236         if (rdev->mddev->minor_version == 0)
2237                 return 1;
2238
2239         /* otherwise we must be sure not to step on
2240          * any metadata, so stay:
2241          * 36K beyond start of superblock
2242          * beyond end of badblocks
2243          * beyond write-intent bitmap
2244          */
2245         if (rdev->sb_start + (32+4)*2 > new_offset)
2246                 return 0;
2247
2248         if (!rdev->mddev->bitmap_info.file) {
2249                 struct mddev *mddev = rdev->mddev;
2250                 struct md_bitmap_stats stats;
2251                 int err;
2252
2253                 err = mddev->bitmap_ops->get_stats(mddev->bitmap, &stats);
2254                 if (!err && rdev->sb_start + mddev->bitmap_info.offset +
2255                     stats.file_pages * (PAGE_SIZE >> 9) > new_offset)
2256                         return 0;
2257         }
2258
2259         if (rdev->badblocks.sector + rdev->badblocks.size > new_offset)
2260                 return 0;
2261
2262         return 1;
2263 }
2264
2265 static struct super_type super_types[] = {
2266         [0] = {
2267                 .name   = "0.90.0",
2268                 .owner  = THIS_MODULE,
2269                 .load_super         = super_90_load,
2270                 .validate_super     = super_90_validate,
2271                 .sync_super         = super_90_sync,
2272                 .rdev_size_change   = super_90_rdev_size_change,
2273                 .allow_new_offset   = super_90_allow_new_offset,
2274         },
2275         [1] = {
2276                 .name   = "md-1",
2277                 .owner  = THIS_MODULE,
2278                 .load_super         = super_1_load,
2279                 .validate_super     = super_1_validate,
2280                 .sync_super         = super_1_sync,
2281                 .rdev_size_change   = super_1_rdev_size_change,
2282                 .allow_new_offset   = super_1_allow_new_offset,
2283         },
2284 };
2285
2286 static void sync_super(struct mddev *mddev, struct md_rdev *rdev)
2287 {
2288         if (mddev->sync_super) {
2289                 mddev->sync_super(mddev, rdev);
2290                 return;
2291         }
2292
2293         BUG_ON(mddev->major_version >= ARRAY_SIZE(super_types));
2294
2295         super_types[mddev->major_version].sync_super(mddev, rdev);
2296 }
2297
2298 static int match_mddev_units(struct mddev *mddev1, struct mddev *mddev2)
2299 {
2300         struct md_rdev *rdev, *rdev2;
2301
2302         rcu_read_lock();
2303         rdev_for_each_rcu(rdev, mddev1) {
2304                 if (test_bit(Faulty, &rdev->flags) ||
2305                     test_bit(Journal, &rdev->flags) ||
2306                     rdev->raid_disk == -1)
2307                         continue;
2308                 rdev_for_each_rcu(rdev2, mddev2) {
2309                         if (test_bit(Faulty, &rdev2->flags) ||
2310                             test_bit(Journal, &rdev2->flags) ||
2311                             rdev2->raid_disk == -1)
2312                                 continue;
2313                         if (rdev->bdev->bd_disk == rdev2->bdev->bd_disk) {
2314                                 rcu_read_unlock();
2315                                 return 1;
2316                         }
2317                 }
2318         }
2319         rcu_read_unlock();
2320         return 0;
2321 }
2322
2323 static LIST_HEAD(pending_raid_disks);
2324
2325 /*
2326  * Try to register data integrity profile for an mddev
2327  *
2328  * This is called when an array is started and after a disk has been kicked
2329  * from the array. It only succeeds if all working and active component devices
2330  * are integrity capable with matching profiles.
2331  */
2332 int md_integrity_register(struct mddev *mddev)
2333 {
2334         if (list_empty(&mddev->disks))
2335                 return 0; /* nothing to do */
2336         if (mddev_is_dm(mddev) || !blk_get_integrity(mddev->gendisk))
2337                 return 0; /* shouldn't register */
2338
2339         pr_debug("md: data integrity enabled on %s\n", mdname(mddev));
2340         if (bioset_integrity_create(&mddev->bio_set, BIO_POOL_SIZE) ||
2341             (mddev->level != 1 && mddev->level != 10 &&
2342              bioset_integrity_create(&mddev->io_clone_set, BIO_POOL_SIZE))) {
2343                 /*
2344                  * No need to handle the failure of bioset_integrity_create,
2345                  * because the function is called by md_run() -> pers->run(),
2346                  * md_run calls bioset_exit -> bioset_integrity_free in case
2347                  * of failure case.
2348                  */
2349                 pr_err("md: failed to create integrity pool for %s\n",
2350                        mdname(mddev));
2351                 return -EINVAL;
2352         }
2353         return 0;
2354 }
2355 EXPORT_SYMBOL(md_integrity_register);
2356
2357 static bool rdev_read_only(struct md_rdev *rdev)
2358 {
2359         return bdev_read_only(rdev->bdev) ||
2360                 (rdev->meta_bdev && bdev_read_only(rdev->meta_bdev));
2361 }
2362
2363 static int bind_rdev_to_array(struct md_rdev *rdev, struct mddev *mddev)
2364 {
2365         char b[BDEVNAME_SIZE];
2366         int err;
2367
2368         /* prevent duplicates */
2369         if (find_rdev(mddev, rdev->bdev->bd_dev))
2370                 return -EEXIST;
2371
2372         if (rdev_read_only(rdev) && mddev->pers)
2373                 return -EROFS;
2374
2375         /* make sure rdev->sectors exceeds mddev->dev_sectors */
2376         if (!test_bit(Journal, &rdev->flags) &&
2377             rdev->sectors &&
2378             (mddev->dev_sectors == 0 || rdev->sectors < mddev->dev_sectors)) {
2379                 if (mddev->pers) {
2380                         /* Cannot change size, so fail
2381                          * If mddev->level <= 0, then we don't care
2382                          * about aligning sizes (e.g. linear)
2383                          */
2384                         if (mddev->level > 0)
2385                                 return -ENOSPC;
2386                 } else
2387                         mddev->dev_sectors = rdev->sectors;
2388         }
2389
2390         /* Verify rdev->desc_nr is unique.
2391          * If it is -1, assign a free number, else
2392          * check number is not in use
2393          */
2394         rcu_read_lock();
2395         if (rdev->desc_nr < 0) {
2396                 int choice = 0;
2397                 if (mddev->pers)
2398                         choice = mddev->raid_disks;
2399                 while (md_find_rdev_nr_rcu(mddev, choice))
2400                         choice++;
2401                 rdev->desc_nr = choice;
2402         } else {
2403                 if (md_find_rdev_nr_rcu(mddev, rdev->desc_nr)) {
2404                         rcu_read_unlock();
2405                         return -EBUSY;
2406                 }
2407         }
2408         rcu_read_unlock();
2409         if (!test_bit(Journal, &rdev->flags) &&
2410             mddev->max_disks && rdev->desc_nr >= mddev->max_disks) {
2411                 pr_warn("md: %s: array is limited to %d devices\n",
2412                         mdname(mddev), mddev->max_disks);
2413                 return -EBUSY;
2414         }
2415         snprintf(b, sizeof(b), "%pg", rdev->bdev);
2416         strreplace(b, '/', '!');
2417
2418         rdev->mddev = mddev;
2419         pr_debug("md: bind<%s>\n", b);
2420
2421         if (mddev->raid_disks)
2422                 mddev_create_serial_pool(mddev, rdev);
2423
2424         if ((err = kobject_add(&rdev->kobj, &mddev->kobj, "dev-%s", b)))
2425                 goto fail;
2426
2427         /* failure here is OK */
2428         err = sysfs_create_link(&rdev->kobj, bdev_kobj(rdev->bdev), "block");
2429         rdev->sysfs_state = sysfs_get_dirent_safe(rdev->kobj.sd, "state");
2430         rdev->sysfs_unack_badblocks =
2431                 sysfs_get_dirent_safe(rdev->kobj.sd, "unacknowledged_bad_blocks");
2432         rdev->sysfs_badblocks =
2433                 sysfs_get_dirent_safe(rdev->kobj.sd, "bad_blocks");
2434
2435         list_add_rcu(&rdev->same_set, &mddev->disks);
2436         bd_link_disk_holder(rdev->bdev, mddev->gendisk);
2437
2438         /* May as well allow recovery to be retried once */
2439         mddev->recovery_disabled++;
2440
2441         return 0;
2442
2443  fail:
2444         pr_warn("md: failed to register dev-%s for %s\n",
2445                 b, mdname(mddev));
2446         mddev_destroy_serial_pool(mddev, rdev);
2447         return err;
2448 }
2449
2450 void md_autodetect_dev(dev_t dev);
2451
2452 /* just for claiming the bdev */
2453 static struct md_rdev claim_rdev;
2454
2455 static void export_rdev(struct md_rdev *rdev, struct mddev *mddev)
2456 {
2457         pr_debug("md: export_rdev(%pg)\n", rdev->bdev);
2458         md_rdev_clear(rdev);
2459 #ifndef MODULE
2460         if (test_bit(AutoDetected, &rdev->flags))
2461                 md_autodetect_dev(rdev->bdev->bd_dev);
2462 #endif
2463         fput(rdev->bdev_file);
2464         rdev->bdev = NULL;
2465         kobject_put(&rdev->kobj);
2466 }
2467
2468 static void md_kick_rdev_from_array(struct md_rdev *rdev)
2469 {
2470         struct mddev *mddev = rdev->mddev;
2471
2472         bd_unlink_disk_holder(rdev->bdev, rdev->mddev->gendisk);
2473         list_del_rcu(&rdev->same_set);
2474         pr_debug("md: unbind<%pg>\n", rdev->bdev);
2475         mddev_destroy_serial_pool(rdev->mddev, rdev);
2476         WRITE_ONCE(rdev->mddev, NULL);
2477         sysfs_remove_link(&rdev->kobj, "block");
2478         sysfs_put(rdev->sysfs_state);
2479         sysfs_put(rdev->sysfs_unack_badblocks);
2480         sysfs_put(rdev->sysfs_badblocks);
2481         rdev->sysfs_state = NULL;
2482         rdev->sysfs_unack_badblocks = NULL;
2483         rdev->sysfs_badblocks = NULL;
2484         rdev->badblocks.count = 0;
2485
2486         synchronize_rcu();
2487
2488         /*
2489          * kobject_del() will wait for all in progress writers to be done, where
2490          * reconfig_mutex is held, hence it can't be called under
2491          * reconfig_mutex and it's delayed to mddev_unlock().
2492          */
2493         list_add(&rdev->same_set, &mddev->deleting);
2494 }
2495
2496 static void export_array(struct mddev *mddev)
2497 {
2498         struct md_rdev *rdev;
2499
2500         while (!list_empty(&mddev->disks)) {
2501                 rdev = list_first_entry(&mddev->disks, struct md_rdev,
2502                                         same_set);
2503                 md_kick_rdev_from_array(rdev);
2504         }
2505         mddev->raid_disks = 0;
2506         mddev->major_version = 0;
2507 }
2508
2509 static bool set_in_sync(struct mddev *mddev)
2510 {
2511         lockdep_assert_held(&mddev->lock);
2512         if (!mddev->in_sync) {
2513                 mddev->sync_checkers++;
2514                 spin_unlock(&mddev->lock);
2515                 percpu_ref_switch_to_atomic_sync(&mddev->writes_pending);
2516                 spin_lock(&mddev->lock);
2517                 if (!mddev->in_sync &&
2518                     percpu_ref_is_zero(&mddev->writes_pending)) {
2519                         mddev->in_sync = 1;
2520                         /*
2521                          * Ensure ->in_sync is visible before we clear
2522                          * ->sync_checkers.
2523                          */
2524                         smp_mb();
2525                         set_bit(MD_SB_CHANGE_CLEAN, &mddev->sb_flags);
2526                         sysfs_notify_dirent_safe(mddev->sysfs_state);
2527                 }
2528                 if (--mddev->sync_checkers == 0)
2529                         percpu_ref_switch_to_percpu(&mddev->writes_pending);
2530         }
2531         if (mddev->safemode == 1)
2532                 mddev->safemode = 0;
2533         return mddev->in_sync;
2534 }
2535
2536 static void sync_sbs(struct mddev *mddev, int nospares)
2537 {
2538         /* Update each superblock (in-memory image), but
2539          * if we are allowed to, skip spares which already
2540          * have the right event counter, or have one earlier
2541          * (which would mean they aren't being marked as dirty
2542          * with the rest of the array)
2543          */
2544         struct md_rdev *rdev;
2545         rdev_for_each(rdev, mddev) {
2546                 if (rdev->sb_events == mddev->events ||
2547                     (nospares &&
2548                      rdev->raid_disk < 0 &&
2549                      rdev->sb_events+1 == mddev->events)) {
2550                         /* Don't update this superblock */
2551                         rdev->sb_loaded = 2;
2552                 } else {
2553                         sync_super(mddev, rdev);
2554                         rdev->sb_loaded = 1;
2555                 }
2556         }
2557 }
2558
2559 static bool does_sb_need_changing(struct mddev *mddev)
2560 {
2561         struct md_rdev *rdev = NULL, *iter;
2562         struct mdp_superblock_1 *sb;
2563         int role;
2564
2565         /* Find a good rdev */
2566         rdev_for_each(iter, mddev)
2567                 if ((iter->raid_disk >= 0) && !test_bit(Faulty, &iter->flags)) {
2568                         rdev = iter;
2569                         break;
2570                 }
2571
2572         /* No good device found. */
2573         if (!rdev)
2574                 return false;
2575
2576         sb = page_address(rdev->sb_page);
2577         /* Check if a device has become faulty or a spare become active */
2578         rdev_for_each(rdev, mddev) {
2579                 role = le16_to_cpu(sb->dev_roles[rdev->desc_nr]);
2580                 /* Device activated? */
2581                 if (role == MD_DISK_ROLE_SPARE && rdev->raid_disk >= 0 &&
2582                     !test_bit(Faulty, &rdev->flags))
2583                         return true;
2584                 /* Device turned faulty? */
2585                 if (test_bit(Faulty, &rdev->flags) && (role < MD_DISK_ROLE_MAX))
2586                         return true;
2587         }
2588
2589         /* Check if any mddev parameters have changed */
2590         if ((mddev->dev_sectors != le64_to_cpu(sb->size)) ||
2591             (mddev->reshape_position != le64_to_cpu(sb->reshape_position)) ||
2592             (mddev->layout != le32_to_cpu(sb->layout)) ||
2593             (mddev->raid_disks != le32_to_cpu(sb->raid_disks)) ||
2594             (mddev->chunk_sectors != le32_to_cpu(sb->chunksize)))
2595                 return true;
2596
2597         return false;
2598 }
2599
2600 void md_update_sb(struct mddev *mddev, int force_change)
2601 {
2602         struct md_rdev *rdev;
2603         int sync_req;
2604         int nospares = 0;
2605         int any_badblocks_changed = 0;
2606         int ret = -1;
2607
2608         if (!md_is_rdwr(mddev)) {
2609                 if (force_change)
2610                         set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
2611                 return;
2612         }
2613
2614 repeat:
2615         if (mddev_is_clustered(mddev)) {
2616                 if (test_and_clear_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags))
2617                         force_change = 1;
2618                 if (test_and_clear_bit(MD_SB_CHANGE_CLEAN, &mddev->sb_flags))
2619                         nospares = 1;
2620                 ret = md_cluster_ops->metadata_update_start(mddev);
2621                 /* Has someone else has updated the sb */
2622                 if (!does_sb_need_changing(mddev)) {
2623                         if (ret == 0)
2624                                 md_cluster_ops->metadata_update_cancel(mddev);
2625                         bit_clear_unless(&mddev->sb_flags, BIT(MD_SB_CHANGE_PENDING),
2626                                                          BIT(MD_SB_CHANGE_DEVS) |
2627                                                          BIT(MD_SB_CHANGE_CLEAN));
2628                         return;
2629                 }
2630         }
2631
2632         /*
2633          * First make sure individual recovery_offsets are correct
2634          * curr_resync_completed can only be used during recovery.
2635          * During reshape/resync it might use array-addresses rather
2636          * that device addresses.
2637          */
2638         rdev_for_each(rdev, mddev) {
2639                 if (rdev->raid_disk >= 0 &&
2640                     mddev->delta_disks >= 0 &&
2641                     test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&
2642                     test_bit(MD_RECOVERY_RECOVER, &mddev->recovery) &&
2643                     !test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
2644                     !test_bit(Journal, &rdev->flags) &&
2645                     !test_bit(In_sync, &rdev->flags) &&
2646                     mddev->curr_resync_completed > rdev->recovery_offset)
2647                                 rdev->recovery_offset = mddev->curr_resync_completed;
2648
2649         }
2650         if (!mddev->persistent) {
2651                 clear_bit(MD_SB_CHANGE_CLEAN, &mddev->sb_flags);
2652                 clear_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
2653                 if (!mddev->external) {
2654                         clear_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags);
2655                         rdev_for_each(rdev, mddev) {
2656                                 if (rdev->badblocks.changed) {
2657                                         rdev->badblocks.changed = 0;
2658                                         ack_all_badblocks(&rdev->badblocks);
2659                                         md_error(mddev, rdev);
2660                                 }
2661                                 clear_bit(Blocked, &rdev->flags);
2662                                 clear_bit(BlockedBadBlocks, &rdev->flags);
2663                                 wake_up(&rdev->blocked_wait);
2664                         }
2665                 }
2666                 wake_up(&mddev->sb_wait);
2667                 return;
2668         }
2669
2670         spin_lock(&mddev->lock);
2671
2672         mddev->utime = ktime_get_real_seconds();
2673
2674         if (test_and_clear_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags))
2675                 force_change = 1;
2676         if (test_and_clear_bit(MD_SB_CHANGE_CLEAN, &mddev->sb_flags))
2677                 /* just a clean<-> dirty transition, possibly leave spares alone,
2678                  * though if events isn't the right even/odd, we will have to do
2679                  * spares after all
2680                  */
2681                 nospares = 1;
2682         if (force_change)
2683                 nospares = 0;
2684         if (mddev->degraded)
2685                 /* If the array is degraded, then skipping spares is both
2686                  * dangerous and fairly pointless.
2687                  * Dangerous because a device that was removed from the array
2688                  * might have a event_count that still looks up-to-date,
2689                  * so it can be re-added without a resync.
2690                  * Pointless because if there are any spares to skip,
2691                  * then a recovery will happen and soon that array won't
2692                  * be degraded any more and the spare can go back to sleep then.
2693                  */
2694                 nospares = 0;
2695
2696         sync_req = mddev->in_sync;
2697
2698         /* If this is just a dirty<->clean transition, and the array is clean
2699          * and 'events' is odd, we can roll back to the previous clean state */
2700         if (nospares
2701             && (mddev->in_sync && mddev->recovery_cp == MaxSector)
2702             && mddev->can_decrease_events
2703             && mddev->events != 1) {
2704                 mddev->events--;
2705                 mddev->can_decrease_events = 0;
2706         } else {
2707                 /* otherwise we have to go forward and ... */
2708                 mddev->events ++;
2709                 mddev->can_decrease_events = nospares;
2710         }
2711
2712         /*
2713          * This 64-bit counter should never wrap.
2714          * Either we are in around ~1 trillion A.C., assuming
2715          * 1 reboot per second, or we have a bug...
2716          */
2717         WARN_ON(mddev->events == 0);
2718
2719         rdev_for_each(rdev, mddev) {
2720                 if (rdev->badblocks.changed)
2721                         any_badblocks_changed++;
2722                 if (test_bit(Faulty, &rdev->flags))
2723                         set_bit(FaultRecorded, &rdev->flags);
2724         }
2725
2726         sync_sbs(mddev, nospares);
2727         spin_unlock(&mddev->lock);
2728
2729         pr_debug("md: updating %s RAID superblock on device (in sync %d)\n",
2730                  mdname(mddev), mddev->in_sync);
2731
2732         mddev_add_trace_msg(mddev, "md md_update_sb");
2733 rewrite:
2734         mddev->bitmap_ops->update_sb(mddev->bitmap);
2735         rdev_for_each(rdev, mddev) {
2736                 if (rdev->sb_loaded != 1)
2737                         continue; /* no noise on spare devices */
2738
2739                 if (!test_bit(Faulty, &rdev->flags)) {
2740                         md_super_write(mddev,rdev,
2741                                        rdev->sb_start, rdev->sb_size,
2742                                        rdev->sb_page);
2743                         pr_debug("md: (write) %pg's sb offset: %llu\n",
2744                                  rdev->bdev,
2745                                  (unsigned long long)rdev->sb_start);
2746                         rdev->sb_events = mddev->events;
2747                         if (rdev->badblocks.size) {
2748                                 md_super_write(mddev, rdev,
2749                                                rdev->badblocks.sector,
2750                                                rdev->badblocks.size << 9,
2751                                                rdev->bb_page);
2752                                 rdev->badblocks.size = 0;
2753                         }
2754
2755                 } else
2756                         pr_debug("md: %pg (skipping faulty)\n",
2757                                  rdev->bdev);
2758         }
2759         if (md_super_wait(mddev) < 0)
2760                 goto rewrite;
2761         /* if there was a failure, MD_SB_CHANGE_DEVS was set, and we re-write super */
2762
2763         if (mddev_is_clustered(mddev) && ret == 0)
2764                 md_cluster_ops->metadata_update_finish(mddev);
2765
2766         if (mddev->in_sync != sync_req ||
2767             !bit_clear_unless(&mddev->sb_flags, BIT(MD_SB_CHANGE_PENDING),
2768                                BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_CLEAN)))
2769                 /* have to write it out again */
2770                 goto repeat;
2771         wake_up(&mddev->sb_wait);
2772         if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
2773                 sysfs_notify_dirent_safe(mddev->sysfs_completed);
2774
2775         rdev_for_each(rdev, mddev) {
2776                 if (test_and_clear_bit(FaultRecorded, &rdev->flags))
2777                         clear_bit(Blocked, &rdev->flags);
2778
2779                 if (any_badblocks_changed)
2780                         ack_all_badblocks(&rdev->badblocks);
2781                 clear_bit(BlockedBadBlocks, &rdev->flags);
2782                 wake_up(&rdev->blocked_wait);
2783         }
2784 }
2785 EXPORT_SYMBOL(md_update_sb);
2786
2787 static int add_bound_rdev(struct md_rdev *rdev)
2788 {
2789         struct mddev *mddev = rdev->mddev;
2790         int err = 0;
2791         bool add_journal = test_bit(Journal, &rdev->flags);
2792
2793         if (!mddev->pers->hot_remove_disk || add_journal) {
2794                 /* If there is hot_add_disk but no hot_remove_disk
2795                  * then added disks for geometry changes,
2796                  * and should be added immediately.
2797                  */
2798                 super_types[mddev->major_version].
2799                         validate_super(mddev, NULL/*freshest*/, rdev);
2800                 err = mddev->pers->hot_add_disk(mddev, rdev);
2801                 if (err) {
2802                         md_kick_rdev_from_array(rdev);
2803                         return err;
2804                 }
2805         }
2806         sysfs_notify_dirent_safe(rdev->sysfs_state);
2807
2808         set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
2809         if (mddev->degraded)
2810                 set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
2811         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2812         md_new_event();
2813         return 0;
2814 }
2815
2816 /* words written to sysfs files may, or may not, be \n terminated.
2817  * We want to accept with case. For this we use cmd_match.
2818  */
2819 static int cmd_match(const char *cmd, const char *str)
2820 {
2821         /* See if cmd, written into a sysfs file, matches
2822          * str.  They must either be the same, or cmd can
2823          * have a trailing newline
2824          */
2825         while (*cmd && *str && *cmd == *str) {
2826                 cmd++;
2827                 str++;
2828         }
2829         if (*cmd == '\n')
2830                 cmd++;
2831         if (*str || *cmd)
2832                 return 0;
2833         return 1;
2834 }
2835
2836 struct rdev_sysfs_entry {
2837         struct attribute attr;
2838         ssize_t (*show)(struct md_rdev *, char *);
2839         ssize_t (*store)(struct md_rdev *, const char *, size_t);
2840 };
2841
2842 static ssize_t
2843 state_show(struct md_rdev *rdev, char *page)
2844 {
2845         char *sep = ",";
2846         size_t len = 0;
2847         unsigned long flags = READ_ONCE(rdev->flags);
2848
2849         if (test_bit(Faulty, &flags) ||
2850             (!test_bit(ExternalBbl, &flags) &&
2851             rdev->badblocks.unacked_exist))
2852                 len += sprintf(page+len, "faulty%s", sep);
2853         if (test_bit(In_sync, &flags))
2854                 len += sprintf(page+len, "in_sync%s", sep);
2855         if (test_bit(Journal, &flags))
2856                 len += sprintf(page+len, "journal%s", sep);
2857         if (test_bit(WriteMostly, &flags))
2858                 len += sprintf(page+len, "write_mostly%s", sep);
2859         if (test_bit(Blocked, &flags) ||
2860             (rdev->badblocks.unacked_exist
2861              && !test_bit(Faulty, &flags)))
2862                 len += sprintf(page+len, "blocked%s", sep);
2863         if (!test_bit(Faulty, &flags) &&
2864             !test_bit(Journal, &flags) &&
2865             !test_bit(In_sync, &flags))
2866                 len += sprintf(page+len, "spare%s", sep);
2867         if (test_bit(WriteErrorSeen, &flags))
2868                 len += sprintf(page+len, "write_error%s", sep);
2869         if (test_bit(WantReplacement, &flags))
2870                 len += sprintf(page+len, "want_replacement%s", sep);
2871         if (test_bit(Replacement, &flags))
2872                 len += sprintf(page+len, "replacement%s", sep);
2873         if (test_bit(ExternalBbl, &flags))
2874                 len += sprintf(page+len, "external_bbl%s", sep);
2875         if (test_bit(FailFast, &flags))
2876                 len += sprintf(page+len, "failfast%s", sep);
2877
2878         if (len)
2879                 len -= strlen(sep);
2880
2881         return len+sprintf(page+len, "\n");
2882 }
2883
2884 static ssize_t
2885 state_store(struct md_rdev *rdev, const char *buf, size_t len)
2886 {
2887         /* can write
2888          *  faulty  - simulates an error
2889          *  remove  - disconnects the device
2890          *  writemostly - sets write_mostly
2891          *  -writemostly - clears write_mostly
2892          *  blocked - sets the Blocked flags
2893          *  -blocked - clears the Blocked and possibly simulates an error
2894          *  insync - sets Insync providing device isn't active
2895          *  -insync - clear Insync for a device with a slot assigned,
2896          *            so that it gets rebuilt based on bitmap
2897          *  write_error - sets WriteErrorSeen
2898          *  -write_error - clears WriteErrorSeen
2899          *  {,-}failfast - set/clear FailFast
2900          */
2901
2902         struct mddev *mddev = rdev->mddev;
2903         int err = -EINVAL;
2904         bool need_update_sb = false;
2905
2906         if (cmd_match(buf, "faulty") && rdev->mddev->pers) {
2907                 md_error(rdev->mddev, rdev);
2908
2909                 if (test_bit(MD_BROKEN, &rdev->mddev->flags))
2910                         err = -EBUSY;
2911                 else
2912                         err = 0;
2913         } else if (cmd_match(buf, "remove")) {
2914                 if (rdev->mddev->pers) {
2915                         clear_bit(Blocked, &rdev->flags);
2916                         remove_and_add_spares(rdev->mddev, rdev);
2917                 }
2918                 if (rdev->raid_disk >= 0)
2919                         err = -EBUSY;
2920                 else {
2921                         err = 0;
2922                         if (mddev_is_clustered(mddev))
2923                                 err = md_cluster_ops->remove_disk(mddev, rdev);
2924
2925                         if (err == 0) {
2926                                 md_kick_rdev_from_array(rdev);
2927                                 if (mddev->pers)
2928                                         set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
2929                                 md_new_event();
2930                         }
2931                 }
2932         } else if (cmd_match(buf, "writemostly")) {
2933                 set_bit(WriteMostly, &rdev->flags);
2934                 mddev_create_serial_pool(rdev->mddev, rdev);
2935                 need_update_sb = true;
2936                 err = 0;
2937         } else if (cmd_match(buf, "-writemostly")) {
2938                 mddev_destroy_serial_pool(rdev->mddev, rdev);
2939                 clear_bit(WriteMostly, &rdev->flags);
2940                 need_update_sb = true;
2941                 err = 0;
2942         } else if (cmd_match(buf, "blocked")) {
2943                 set_bit(Blocked, &rdev->flags);
2944                 err = 0;
2945         } else if (cmd_match(buf, "-blocked")) {
2946                 if (!test_bit(Faulty, &rdev->flags) &&
2947                     !test_bit(ExternalBbl, &rdev->flags) &&
2948                     rdev->badblocks.unacked_exist) {
2949                         /* metadata handler doesn't understand badblocks,
2950                          * so we need to fail the device
2951                          */
2952                         md_error(rdev->mddev, rdev);
2953                 }
2954                 clear_bit(Blocked, &rdev->flags);
2955                 clear_bit(BlockedBadBlocks, &rdev->flags);
2956                 wake_up(&rdev->blocked_wait);
2957                 set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2958
2959                 err = 0;
2960         } else if (cmd_match(buf, "insync") && rdev->raid_disk == -1) {
2961                 set_bit(In_sync, &rdev->flags);
2962                 err = 0;
2963         } else if (cmd_match(buf, "failfast")) {
2964                 set_bit(FailFast, &rdev->flags);
2965                 need_update_sb = true;
2966                 err = 0;
2967         } else if (cmd_match(buf, "-failfast")) {
2968                 clear_bit(FailFast, &rdev->flags);
2969                 need_update_sb = true;
2970                 err = 0;
2971         } else if (cmd_match(buf, "-insync") && rdev->raid_disk >= 0 &&
2972                    !test_bit(Journal, &rdev->flags)) {
2973                 if (rdev->mddev->pers == NULL) {
2974                         clear_bit(In_sync, &rdev->flags);
2975                         rdev->saved_raid_disk = rdev->raid_disk;
2976                         rdev->raid_disk = -1;
2977                         err = 0;
2978                 }
2979         } else if (cmd_match(buf, "write_error")) {
2980                 set_bit(WriteErrorSeen, &rdev->flags);
2981                 err = 0;
2982         } else if (cmd_match(buf, "-write_error")) {
2983                 clear_bit(WriteErrorSeen, &rdev->flags);
2984                 err = 0;
2985         } else if (cmd_match(buf, "want_replacement")) {
2986                 /* Any non-spare device that is not a replacement can
2987                  * become want_replacement at any time, but we then need to
2988                  * check if recovery is needed.
2989                  */
2990                 if (rdev->raid_disk >= 0 &&
2991                     !test_bit(Journal, &rdev->flags) &&
2992                     !test_bit(Replacement, &rdev->flags))
2993                         set_bit(WantReplacement, &rdev->flags);
2994                 set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2995                 err = 0;
2996         } else if (cmd_match(buf, "-want_replacement")) {
2997                 /* Clearing 'want_replacement' is always allowed.
2998                  * Once replacements starts it is too late though.
2999                  */
3000                 err = 0;
3001                 clear_bit(WantReplacement, &rdev->flags);
3002         } else if (cmd_match(buf, "replacement")) {
3003                 /* Can only set a device as a replacement when array has not
3004                  * yet been started.  Once running, replacement is automatic
3005                  * from spares, or by assigning 'slot'.
3006                  */
3007                 if (rdev->mddev->pers)
3008                         err = -EBUSY;
3009                 else {
3010                         set_bit(Replacement, &rdev->flags);
3011                         err = 0;
3012                 }
3013         } else if (cmd_match(buf, "-replacement")) {
3014                 /* Similarly, can only clear Replacement before start */
3015                 if (rdev->mddev->pers)
3016                         err = -EBUSY;
3017                 else {
3018                         clear_bit(Replacement, &rdev->flags);
3019                         err = 0;
3020                 }
3021         } else if (cmd_match(buf, "re-add")) {
3022                 if (!rdev->mddev->pers)
3023                         err = -EINVAL;
3024                 else if (test_bit(Faulty, &rdev->flags) && (rdev->raid_disk == -1) &&
3025                                 rdev->saved_raid_disk >= 0) {
3026                         /* clear_bit is performed _after_ all the devices
3027                          * have their local Faulty bit cleared. If any writes
3028                          * happen in the meantime in the local node, they
3029                          * will land in the local bitmap, which will be synced
3030                          * by this node eventually
3031                          */
3032                         if (!mddev_is_clustered(rdev->mddev) ||
3033                             (err = md_cluster_ops->gather_bitmaps(rdev)) == 0) {
3034                                 clear_bit(Faulty, &rdev->flags);
3035                                 err = add_bound_rdev(rdev);
3036                         }
3037                 } else
3038                         err = -EBUSY;
3039         } else if (cmd_match(buf, "external_bbl") && (rdev->mddev->external)) {
3040                 set_bit(ExternalBbl, &rdev->flags);
3041                 rdev->badblocks.shift = 0;
3042                 err = 0;
3043         } else if (cmd_match(buf, "-external_bbl") && (rdev->mddev->external)) {
3044                 clear_bit(ExternalBbl, &rdev->flags);
3045                 err = 0;
3046         }
3047         if (need_update_sb)
3048                 md_update_sb(mddev, 1);
3049         if (!err)
3050                 sysfs_notify_dirent_safe(rdev->sysfs_state);
3051         return err ? err : len;
3052 }
3053 static struct rdev_sysfs_entry rdev_state =
3054 __ATTR_PREALLOC(state, S_IRUGO|S_IWUSR, state_show, state_store);
3055
3056 static ssize_t
3057 errors_show(struct md_rdev *rdev, char *page)
3058 {
3059         return sprintf(page, "%d\n", atomic_read(&rdev->corrected_errors));
3060 }
3061
3062 static ssize_t
3063 errors_store(struct md_rdev *rdev, const char *buf, size_t len)
3064 {
3065         unsigned int n;
3066         int rv;
3067
3068         rv = kstrtouint(buf, 10, &n);
3069         if (rv < 0)
3070                 return rv;
3071         atomic_set(&rdev->corrected_errors, n);
3072         return len;
3073 }
3074 static struct rdev_sysfs_entry rdev_errors =
3075 __ATTR(errors, S_IRUGO|S_IWUSR, errors_show, errors_store);
3076
3077 static ssize_t
3078 slot_show(struct md_rdev *rdev, char *page)
3079 {
3080         if (test_bit(Journal, &rdev->flags))
3081                 return sprintf(page, "journal\n");
3082         else if (rdev->raid_disk < 0)
3083                 return sprintf(page, "none\n");
3084         else
3085                 return sprintf(page, "%d\n", rdev->raid_disk);
3086 }
3087
3088 static ssize_t
3089 slot_store(struct md_rdev *rdev, const char *buf, size_t len)
3090 {
3091         int slot;
3092         int err;
3093
3094         if (test_bit(Journal, &rdev->flags))
3095                 return -EBUSY;
3096         if (strncmp(buf, "none", 4)==0)
3097                 slot = -1;
3098         else {
3099                 err = kstrtouint(buf, 10, (unsigned int *)&slot);
3100                 if (err < 0)
3101                         return err;
3102                 if (slot < 0)
3103                         /* overflow */
3104                         return -ENOSPC;
3105         }
3106         if (rdev->mddev->pers && slot == -1) {
3107                 /* Setting 'slot' on an active array requires also
3108                  * updating the 'rd%d' link, and communicating
3109                  * with the personality with ->hot_*_disk.
3110                  * For now we only support removing
3111                  * failed/spare devices.  This normally happens automatically,
3112                  * but not when the metadata is externally managed.
3113                  */
3114                 if (rdev->raid_disk == -1)
3115                         return -EEXIST;
3116                 /* personality does all needed checks */
3117                 if (rdev->mddev->pers->hot_remove_disk == NULL)
3118                         return -EINVAL;
3119                 clear_bit(Blocked, &rdev->flags);
3120                 remove_and_add_spares(rdev->mddev, rdev);
3121                 if (rdev->raid_disk >= 0)
3122                         return -EBUSY;
3123                 set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
3124         } else if (rdev->mddev->pers) {
3125                 /* Activating a spare .. or possibly reactivating
3126                  * if we ever get bitmaps working here.
3127                  */
3128                 int err;
3129
3130                 if (rdev->raid_disk != -1)
3131                         return -EBUSY;
3132
3133                 if (test_bit(MD_RECOVERY_RUNNING, &rdev->mddev->recovery))
3134                         return -EBUSY;
3135
3136                 if (rdev->mddev->pers->hot_add_disk == NULL)
3137                         return -EINVAL;
3138
3139                 if (slot >= rdev->mddev->raid_disks &&
3140                     slot >= rdev->mddev->raid_disks + rdev->mddev->delta_disks)
3141                         return -ENOSPC;
3142
3143                 rdev->raid_disk = slot;
3144                 if (test_bit(In_sync, &rdev->flags))
3145                         rdev->saved_raid_disk = slot;
3146                 else
3147                         rdev->saved_raid_disk = -1;
3148                 clear_bit(In_sync, &rdev->flags);
3149                 clear_bit(Bitmap_sync, &rdev->flags);
3150                 err = rdev->mddev->pers->hot_add_disk(rdev->mddev, rdev);
3151                 if (err) {
3152                         rdev->raid_disk = -1;
3153                         return err;
3154                 } else
3155                         sysfs_notify_dirent_safe(rdev->sysfs_state);
3156                 /* failure here is OK */;
3157                 sysfs_link_rdev(rdev->mddev, rdev);
3158                 /* don't wakeup anyone, leave that to userspace. */
3159         } else {
3160                 if (slot >= rdev->mddev->raid_disks &&
3161                     slot >= rdev->mddev->raid_disks + rdev->mddev->delta_disks)
3162                         return -ENOSPC;
3163                 rdev->raid_disk = slot;
3164                 /* assume it is working */
3165                 clear_bit(Faulty, &rdev->flags);
3166                 clear_bit(WriteMostly, &rdev->flags);
3167                 set_bit(In_sync, &rdev->flags);
3168                 sysfs_notify_dirent_safe(rdev->sysfs_state);
3169         }
3170         return len;
3171 }
3172
3173 static struct rdev_sysfs_entry rdev_slot =
3174 __ATTR(slot, S_IRUGO|S_IWUSR, slot_show, slot_store);
3175
3176 static ssize_t
3177 offset_show(struct md_rdev *rdev, char *page)
3178 {
3179         return sprintf(page, "%llu\n", (unsigned long long)rdev->data_offset);
3180 }
3181
3182 static ssize_t
3183 offset_store(struct md_rdev *rdev, const char *buf, size_t len)
3184 {
3185         unsigned long long offset;
3186         if (kstrtoull(buf, 10, &offset) < 0)
3187                 return -EINVAL;
3188         if (rdev->mddev->pers && rdev->raid_disk >= 0)
3189                 return -EBUSY;
3190         if (rdev->sectors && rdev->mddev->external)
3191                 /* Must set offset before size, so overlap checks
3192                  * can be sane */
3193                 return -EBUSY;
3194         rdev->data_offset = offset;
3195         rdev->new_data_offset = offset;
3196         return len;
3197 }
3198
3199 static struct rdev_sysfs_entry rdev_offset =
3200 __ATTR(offset, S_IRUGO|S_IWUSR, offset_show, offset_store);
3201
3202 static ssize_t new_offset_show(struct md_rdev *rdev, char *page)
3203 {
3204         return sprintf(page, "%llu\n",
3205                        (unsigned long long)rdev->new_data_offset);
3206 }
3207
3208 static ssize_t new_offset_store(struct md_rdev *rdev,
3209                                 const char *buf, size_t len)
3210 {
3211         unsigned long long new_offset;
3212         struct mddev *mddev = rdev->mddev;
3213
3214         if (kstrtoull(buf, 10, &new_offset) < 0)
3215                 return -EINVAL;
3216
3217         if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
3218                 return -EBUSY;
3219         if (new_offset == rdev->data_offset)
3220                 /* reset is always permitted */
3221                 ;
3222         else if (new_offset > rdev->data_offset) {
3223                 /* must not push array size beyond rdev_sectors */
3224                 if (new_offset - rdev->data_offset
3225                     + mddev->dev_sectors > rdev->sectors)
3226                                 return -E2BIG;
3227         }
3228         /* Metadata worries about other space details. */
3229
3230         /* decreasing the offset is inconsistent with a backwards
3231          * reshape.
3232          */
3233         if (new_offset < rdev->data_offset &&
3234             mddev->reshape_backwards)
3235                 return -EINVAL;
3236         /* Increasing offset is inconsistent with forwards
3237          * reshape.  reshape_direction should be set to
3238          * 'backwards' first.
3239          */
3240         if (new_offset > rdev->data_offset &&
3241             !mddev->reshape_backwards)
3242                 return -EINVAL;
3243
3244         if (mddev->pers && mddev->persistent &&
3245             !super_types[mddev->major_version]
3246             .allow_new_offset(rdev, new_offset))
3247                 return -E2BIG;
3248         rdev->new_data_offset = new_offset;
3249         if (new_offset > rdev->data_offset)
3250                 mddev->reshape_backwards = 1;
3251         else if (new_offset < rdev->data_offset)
3252                 mddev->reshape_backwards = 0;
3253
3254         return len;
3255 }
3256 static struct rdev_sysfs_entry rdev_new_offset =
3257 __ATTR(new_offset, S_IRUGO|S_IWUSR, new_offset_show, new_offset_store);
3258
3259 static ssize_t
3260 rdev_size_show(struct md_rdev *rdev, char *page)
3261 {
3262         return sprintf(page, "%llu\n", (unsigned long long)rdev->sectors / 2);
3263 }
3264
3265 static int md_rdevs_overlap(struct md_rdev *a, struct md_rdev *b)
3266 {
3267         /* check if two start/length pairs overlap */
3268         if (a->data_offset + a->sectors <= b->data_offset)
3269                 return false;
3270         if (b->data_offset + b->sectors <= a->data_offset)
3271                 return false;
3272         return true;
3273 }
3274
3275 static bool md_rdev_overlaps(struct md_rdev *rdev)
3276 {
3277         struct mddev *mddev;
3278         struct md_rdev *rdev2;
3279
3280         spin_lock(&all_mddevs_lock);
3281         list_for_each_entry(mddev, &all_mddevs, all_mddevs) {
3282                 if (test_bit(MD_DELETED, &mddev->flags))
3283                         continue;
3284                 rdev_for_each(rdev2, mddev) {
3285                         if (rdev != rdev2 && rdev->bdev == rdev2->bdev &&
3286                             md_rdevs_overlap(rdev, rdev2)) {
3287                                 spin_unlock(&all_mddevs_lock);
3288                                 return true;
3289                         }
3290                 }
3291         }
3292         spin_unlock(&all_mddevs_lock);
3293         return false;
3294 }
3295
3296 static int strict_blocks_to_sectors(const char *buf, sector_t *sectors)
3297 {
3298         unsigned long long blocks;
3299         sector_t new;
3300
3301         if (kstrtoull(buf, 10, &blocks) < 0)
3302                 return -EINVAL;
3303
3304         if (blocks & 1ULL << (8 * sizeof(blocks) - 1))
3305                 return -EINVAL; /* sector conversion overflow */
3306
3307         new = blocks * 2;
3308         if (new != blocks * 2)
3309                 return -EINVAL; /* unsigned long long to sector_t overflow */
3310
3311         *sectors = new;
3312         return 0;
3313 }
3314
3315 static ssize_t
3316 rdev_size_store(struct md_rdev *rdev, const char *buf, size_t len)
3317 {
3318         struct mddev *my_mddev = rdev->mddev;
3319         sector_t oldsectors = rdev->sectors;
3320         sector_t sectors;
3321
3322         if (test_bit(Journal, &rdev->flags))
3323                 return -EBUSY;
3324         if (strict_blocks_to_sectors(buf, &sectors) < 0)
3325                 return -EINVAL;
3326         if (rdev->data_offset != rdev->new_data_offset)
3327                 return -EINVAL; /* too confusing */
3328         if (my_mddev->pers && rdev->raid_disk >= 0) {
3329                 if (my_mddev->persistent) {
3330                         sectors = super_types[my_mddev->major_version].
3331                                 rdev_size_change(rdev, sectors);
3332                         if (!sectors)
3333                                 return -EBUSY;
3334                 } else if (!sectors)
3335                         sectors = bdev_nr_sectors(rdev->bdev) -
3336                                 rdev->data_offset;
3337                 if (!my_mddev->pers->resize)
3338                         /* Cannot change size for RAID0 or Linear etc */
3339                         return -EINVAL;
3340         }
3341         if (sectors < my_mddev->dev_sectors)
3342                 return -EINVAL; /* component must fit device */
3343
3344         rdev->sectors = sectors;
3345
3346         /*
3347          * Check that all other rdevs with the same bdev do not overlap.  This
3348          * check does not provide a hard guarantee, it just helps avoid
3349          * dangerous mistakes.
3350          */
3351         if (sectors > oldsectors && my_mddev->external &&
3352             md_rdev_overlaps(rdev)) {
3353                 /*
3354                  * Someone else could have slipped in a size change here, but
3355                  * doing so is just silly.  We put oldsectors back because we
3356                  * know it is safe, and trust userspace not to race with itself.
3357                  */
3358                 rdev->sectors = oldsectors;
3359                 return -EBUSY;
3360         }
3361         return len;
3362 }
3363
3364 static struct rdev_sysfs_entry rdev_size =
3365 __ATTR(size, S_IRUGO|S_IWUSR, rdev_size_show, rdev_size_store);
3366
3367 static ssize_t recovery_start_show(struct md_rdev *rdev, char *page)
3368 {
3369         unsigned long long recovery_start = rdev->recovery_offset;
3370
3371         if (test_bit(In_sync, &rdev->flags) ||
3372             recovery_start == MaxSector)
3373                 return sprintf(page, "none\n");
3374
3375         return sprintf(page, "%llu\n", recovery_start);
3376 }
3377
3378 static ssize_t recovery_start_store(struct md_rdev *rdev, const char *buf, size_t len)
3379 {
3380         unsigned long long recovery_start;
3381
3382         if (cmd_match(buf, "none"))
3383                 recovery_start = MaxSector;
3384         else if (kstrtoull(buf, 10, &recovery_start))
3385                 return -EINVAL;
3386
3387         if (rdev->mddev->pers &&
3388             rdev->raid_disk >= 0)
3389                 return -EBUSY;
3390
3391         rdev->recovery_offset = recovery_start;
3392         if (recovery_start == MaxSector)
3393                 set_bit(In_sync, &rdev->flags);
3394         else
3395                 clear_bit(In_sync, &rdev->flags);
3396         return len;
3397 }
3398
3399 static struct rdev_sysfs_entry rdev_recovery_start =
3400 __ATTR(recovery_start, S_IRUGO|S_IWUSR, recovery_start_show, recovery_start_store);
3401
3402 /* sysfs access to bad-blocks list.
3403  * We present two files.
3404  * 'bad-blocks' lists sector numbers and lengths of ranges that
3405  *    are recorded as bad.  The list is truncated to fit within
3406  *    the one-page limit of sysfs.
3407  *    Writing "sector length" to this file adds an acknowledged
3408  *    bad block list.
3409  * 'unacknowledged-bad-blocks' lists bad blocks that have not yet
3410  *    been acknowledged.  Writing to this file adds bad blocks
3411  *    without acknowledging them.  This is largely for testing.
3412  */
3413 static ssize_t bb_show(struct md_rdev *rdev, char *page)
3414 {
3415         return badblocks_show(&rdev->badblocks, page, 0);
3416 }
3417 static ssize_t bb_store(struct md_rdev *rdev, const char *page, size_t len)
3418 {
3419         int rv = badblocks_store(&rdev->badblocks, page, len, 0);
3420         /* Maybe that ack was all we needed */
3421         if (test_and_clear_bit(BlockedBadBlocks, &rdev->flags))
3422                 wake_up(&rdev->blocked_wait);
3423         return rv;
3424 }
3425 static struct rdev_sysfs_entry rdev_bad_blocks =
3426 __ATTR(bad_blocks, S_IRUGO|S_IWUSR, bb_show, bb_store);
3427
3428 static ssize_t ubb_show(struct md_rdev *rdev, char *page)
3429 {
3430         return badblocks_show(&rdev->badblocks, page, 1);
3431 }
3432 static ssize_t ubb_store(struct md_rdev *rdev, const char *page, size_t len)
3433 {
3434         return badblocks_store(&rdev->badblocks, page, len, 1);
3435 }
3436 static struct rdev_sysfs_entry rdev_unack_bad_blocks =
3437 __ATTR(unacknowledged_bad_blocks, S_IRUGO|S_IWUSR, ubb_show, ubb_store);
3438
3439 static ssize_t
3440 ppl_sector_show(struct md_rdev *rdev, char *page)
3441 {
3442         return sprintf(page, "%llu\n", (unsigned long long)rdev->ppl.sector);
3443 }
3444
3445 static ssize_t
3446 ppl_sector_store(struct md_rdev *rdev, const char *buf, size_t len)
3447 {
3448         unsigned long long sector;
3449
3450         if (kstrtoull(buf, 10, &sector) < 0)
3451                 return -EINVAL;
3452         if (sector != (sector_t)sector)
3453                 return -EINVAL;
3454
3455         if (rdev->mddev->pers && test_bit(MD_HAS_PPL, &rdev->mddev->flags) &&
3456             rdev->raid_disk >= 0)
3457                 return -EBUSY;
3458
3459         if (rdev->mddev->persistent) {
3460                 if (rdev->mddev->major_version == 0)
3461                         return -EINVAL;
3462                 if ((sector > rdev->sb_start &&
3463                      sector - rdev->sb_start > S16_MAX) ||
3464                     (sector < rdev->sb_start &&
3465                      rdev->sb_start - sector > -S16_MIN))
3466                         return -EINVAL;
3467                 rdev->ppl.offset = sector - rdev->sb_start;
3468         } else if (!rdev->mddev->external) {
3469                 return -EBUSY;
3470         }
3471         rdev->ppl.sector = sector;
3472         return len;
3473 }
3474
3475 static struct rdev_sysfs_entry rdev_ppl_sector =
3476 __ATTR(ppl_sector, S_IRUGO|S_IWUSR, ppl_sector_show, ppl_sector_store);
3477
3478 static ssize_t
3479 ppl_size_show(struct md_rdev *rdev, char *page)
3480 {
3481         return sprintf(page, "%u\n", rdev->ppl.size);
3482 }
3483
3484 static ssize_t
3485 ppl_size_store(struct md_rdev *rdev, const char *buf, size_t len)
3486 {
3487         unsigned int size;
3488
3489         if (kstrtouint(buf, 10, &size) < 0)
3490                 return -EINVAL;
3491
3492         if (rdev->mddev->pers && test_bit(MD_HAS_PPL, &rdev->mddev->flags) &&
3493             rdev->raid_disk >= 0)
3494                 return -EBUSY;
3495
3496         if (rdev->mddev->persistent) {
3497                 if (rdev->mddev->major_version == 0)
3498                         return -EINVAL;
3499                 if (size > U16_MAX)
3500                         return -EINVAL;
3501         } else if (!rdev->mddev->external) {
3502                 return -EBUSY;
3503         }
3504         rdev->ppl.size = size;
3505         return len;
3506 }
3507
3508 static struct rdev_sysfs_entry rdev_ppl_size =
3509 __ATTR(ppl_size, S_IRUGO|S_IWUSR, ppl_size_show, ppl_size_store);
3510
3511 static struct attribute *rdev_default_attrs[] = {
3512         &rdev_state.attr,
3513         &rdev_errors.attr,
3514         &rdev_slot.attr,
3515         &rdev_offset.attr,
3516         &rdev_new_offset.attr,
3517         &rdev_size.attr,
3518         &rdev_recovery_start.attr,
3519         &rdev_bad_blocks.attr,
3520         &rdev_unack_bad_blocks.attr,
3521         &rdev_ppl_sector.attr,
3522         &rdev_ppl_size.attr,
3523         NULL,
3524 };
3525 ATTRIBUTE_GROUPS(rdev_default);
3526 static ssize_t
3527 rdev_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
3528 {
3529         struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
3530         struct md_rdev *rdev = container_of(kobj, struct md_rdev, kobj);
3531
3532         if (!entry->show)
3533                 return -EIO;
3534         if (!rdev->mddev)
3535                 return -ENODEV;
3536         return entry->show(rdev, page);
3537 }
3538
3539 static ssize_t
3540 rdev_attr_store(struct kobject *kobj, struct attribute *attr,
3541               const char *page, size_t length)
3542 {
3543         struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
3544         struct md_rdev *rdev = container_of(kobj, struct md_rdev, kobj);
3545         struct kernfs_node *kn = NULL;
3546         bool suspend = false;
3547         ssize_t rv;
3548         struct mddev *mddev = READ_ONCE(rdev->mddev);
3549
3550         if (!entry->store)
3551                 return -EIO;
3552         if (!capable(CAP_SYS_ADMIN))
3553                 return -EACCES;
3554         if (!mddev)
3555                 return -ENODEV;
3556
3557         if (entry->store == state_store) {
3558                 if (cmd_match(page, "remove"))
3559                         kn = sysfs_break_active_protection(kobj, attr);
3560                 if (cmd_match(page, "remove") || cmd_match(page, "re-add") ||
3561                     cmd_match(page, "writemostly") ||
3562                     cmd_match(page, "-writemostly"))
3563                         suspend = true;
3564         }
3565
3566         rv = suspend ? mddev_suspend_and_lock(mddev) : mddev_lock(mddev);
3567         if (!rv) {
3568                 if (rdev->mddev == NULL)
3569                         rv = -ENODEV;
3570                 else
3571                         rv = entry->store(rdev, page, length);
3572                 suspend ? mddev_unlock_and_resume(mddev) : mddev_unlock(mddev);
3573         }
3574
3575         if (kn)
3576                 sysfs_unbreak_active_protection(kn);
3577
3578         return rv;
3579 }
3580
3581 static void rdev_free(struct kobject *ko)
3582 {
3583         struct md_rdev *rdev = container_of(ko, struct md_rdev, kobj);
3584         kfree(rdev);
3585 }
3586 static const struct sysfs_ops rdev_sysfs_ops = {
3587         .show           = rdev_attr_show,
3588         .store          = rdev_attr_store,
3589 };
3590 static const struct kobj_type rdev_ktype = {
3591         .release        = rdev_free,
3592         .sysfs_ops      = &rdev_sysfs_ops,
3593         .default_groups = rdev_default_groups,
3594 };
3595
3596 int md_rdev_init(struct md_rdev *rdev)
3597 {
3598         rdev->desc_nr = -1;
3599         rdev->saved_raid_disk = -1;
3600         rdev->raid_disk = -1;
3601         rdev->flags = 0;
3602         rdev->data_offset = 0;
3603         rdev->new_data_offset = 0;
3604         rdev->sb_events = 0;
3605         rdev->last_read_error = 0;
3606         rdev->sb_loaded = 0;
3607         rdev->bb_page = NULL;
3608         atomic_set(&rdev->nr_pending, 0);
3609         atomic_set(&rdev->read_errors, 0);
3610         atomic_set(&rdev->corrected_errors, 0);
3611
3612         INIT_LIST_HEAD(&rdev->same_set);
3613         init_waitqueue_head(&rdev->blocked_wait);
3614
3615         /* Add space to store bad block list.
3616          * This reserves the space even on arrays where it cannot
3617          * be used - I wonder if that matters
3618          */
3619         return badblocks_init(&rdev->badblocks, 0);
3620 }
3621 EXPORT_SYMBOL_GPL(md_rdev_init);
3622
3623 /*
3624  * Import a device. If 'super_format' >= 0, then sanity check the superblock
3625  *
3626  * mark the device faulty if:
3627  *
3628  *   - the device is nonexistent (zero size)
3629  *   - the device has no valid superblock
3630  *
3631  * a faulty rdev _never_ has rdev->sb set.
3632  */
3633 static struct md_rdev *md_import_device(dev_t newdev, int super_format, int super_minor)
3634 {
3635         struct md_rdev *rdev;
3636         sector_t size;
3637         int err;
3638
3639         rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
3640         if (!rdev)
3641                 return ERR_PTR(-ENOMEM);
3642
3643         err = md_rdev_init(rdev);
3644         if (err)
3645                 goto out_free_rdev;
3646         err = alloc_disk_sb(rdev);
3647         if (err)
3648                 goto out_clear_rdev;
3649
3650         rdev->bdev_file = bdev_file_open_by_dev(newdev,
3651                         BLK_OPEN_READ | BLK_OPEN_WRITE,
3652                         super_format == -2 ? &claim_rdev : rdev, NULL);
3653         if (IS_ERR(rdev->bdev_file)) {
3654                 pr_warn("md: could not open device unknown-block(%u,%u).\n",
3655                         MAJOR(newdev), MINOR(newdev));
3656                 err = PTR_ERR(rdev->bdev_file);
3657                 goto out_clear_rdev;
3658         }
3659         rdev->bdev = file_bdev(rdev->bdev_file);
3660
3661         kobject_init(&rdev->kobj, &rdev_ktype);
3662
3663         size = bdev_nr_bytes(rdev->bdev) >> BLOCK_SIZE_BITS;
3664         if (!size) {
3665                 pr_warn("md: %pg has zero or unknown size, marking faulty!\n",
3666                         rdev->bdev);
3667                 err = -EINVAL;
3668                 goto out_blkdev_put;
3669         }
3670
3671         if (super_format >= 0) {
3672                 err = super_types[super_format].
3673                         load_super(rdev, NULL, super_minor);
3674                 if (err == -EINVAL) {
3675                         pr_warn("md: %pg does not have a valid v%d.%d superblock, not importing!\n",
3676                                 rdev->bdev,
3677                                 super_format, super_minor);
3678                         goto out_blkdev_put;
3679                 }
3680                 if (err < 0) {
3681                         pr_warn("md: could not read %pg's sb, not importing!\n",
3682                                 rdev->bdev);
3683                         goto out_blkdev_put;
3684                 }
3685         }
3686
3687         return rdev;
3688
3689 out_blkdev_put:
3690         fput(rdev->bdev_file);
3691 out_clear_rdev:
3692         md_rdev_clear(rdev);
3693 out_free_rdev:
3694         kfree(rdev);
3695         return ERR_PTR(err);
3696 }
3697
3698 /*
3699  * Check a full RAID array for plausibility
3700  */
3701
3702 static int analyze_sbs(struct mddev *mddev)
3703 {
3704         int i;
3705         struct md_rdev *rdev, *freshest, *tmp;
3706
3707         freshest = NULL;
3708         rdev_for_each_safe(rdev, tmp, mddev)
3709                 switch (super_types[mddev->major_version].
3710                         load_super(rdev, freshest, mddev->minor_version)) {
3711                 case 1:
3712                         freshest = rdev;
3713                         break;
3714                 case 0:
3715                         break;
3716                 default:
3717                         pr_warn("md: fatal superblock inconsistency in %pg -- removing from array\n",
3718                                 rdev->bdev);
3719                         md_kick_rdev_from_array(rdev);
3720                 }
3721
3722         /* Cannot find a valid fresh disk */
3723         if (!freshest) {
3724                 pr_warn("md: cannot find a valid disk\n");
3725                 return -EINVAL;
3726         }
3727
3728         super_types[mddev->major_version].
3729                 validate_super(mddev, NULL/*freshest*/, freshest);
3730
3731         i = 0;
3732         rdev_for_each_safe(rdev, tmp, mddev) {
3733                 if (mddev->max_disks &&
3734                     (rdev->desc_nr >= mddev->max_disks ||
3735                      i > mddev->max_disks)) {
3736                         pr_warn("md: %s: %pg: only %d devices permitted\n",
3737                                 mdname(mddev), rdev->bdev,
3738                                 mddev->max_disks);
3739                         md_kick_rdev_from_array(rdev);
3740                         continue;
3741                 }
3742                 if (rdev != freshest) {
3743                         if (super_types[mddev->major_version].
3744                             validate_super(mddev, freshest, rdev)) {
3745                                 pr_warn("md: kicking non-fresh %pg from array!\n",
3746                                         rdev->bdev);
3747                                 md_kick_rdev_from_array(rdev);
3748                                 continue;
3749                         }
3750                 }
3751                 if (rdev->raid_disk >= (mddev->raid_disks - min(0, mddev->delta_disks)) &&
3752                     !test_bit(Journal, &rdev->flags)) {
3753                         rdev->raid_disk = -1;
3754                         clear_bit(In_sync, &rdev->flags);
3755                 }
3756         }
3757
3758         return 0;
3759 }
3760
3761 /* Read a fixed-point number.
3762  * Numbers in sysfs attributes should be in "standard" units where
3763  * possible, so time should be in seconds.
3764  * However we internally use a a much smaller unit such as
3765  * milliseconds or jiffies.
3766  * This function takes a decimal number with a possible fractional
3767  * component, and produces an integer which is the result of
3768  * multiplying that number by 10^'scale'.
3769  * all without any floating-point arithmetic.
3770  */
3771 int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale)
3772 {
3773         unsigned long result = 0;
3774         long decimals = -1;
3775         while (isdigit(*cp) || (*cp == '.' && decimals < 0)) {
3776                 if (*cp == '.')
3777                         decimals = 0;
3778                 else if (decimals < scale) {
3779                         unsigned int value;
3780                         value = *cp - '0';
3781                         result = result * 10 + value;
3782                         if (decimals >= 0)
3783                                 decimals++;
3784                 }
3785                 cp++;
3786         }
3787         if (*cp == '\n')
3788                 cp++;
3789         if (*cp)
3790                 return -EINVAL;
3791         if (decimals < 0)
3792                 decimals = 0;
3793         *res = result * int_pow(10, scale - decimals);
3794         return 0;
3795 }
3796
3797 static ssize_t
3798 safe_delay_show(struct mddev *mddev, char *page)
3799 {
3800         unsigned int msec = ((unsigned long)mddev->safemode_delay*1000)/HZ;
3801
3802         return sprintf(page, "%u.%03u\n", msec/1000, msec%1000);
3803 }
3804 static ssize_t
3805 safe_delay_store(struct mddev *mddev, const char *cbuf, size_t len)
3806 {
3807         unsigned long msec;
3808
3809         if (mddev_is_clustered(mddev)) {
3810                 pr_warn("md: Safemode is disabled for clustered mode\n");
3811                 return -EINVAL;
3812         }
3813
3814         if (strict_strtoul_scaled(cbuf, &msec, 3) < 0 || msec > UINT_MAX / HZ)
3815                 return -EINVAL;
3816         if (msec == 0)
3817                 mddev->safemode_delay = 0;
3818         else {
3819                 unsigned long old_delay = mddev->safemode_delay;
3820                 unsigned long new_delay = (msec*HZ)/1000;
3821
3822                 if (new_delay == 0)
3823                         new_delay = 1;
3824                 mddev->safemode_delay = new_delay;
3825                 if (new_delay < old_delay || old_delay == 0)
3826                         mod_timer(&mddev->safemode_timer, jiffies+1);
3827         }
3828         return len;
3829 }
3830 static struct md_sysfs_entry md_safe_delay =
3831 __ATTR(safe_mode_delay, S_IRUGO|S_IWUSR,safe_delay_show, safe_delay_store);
3832
3833 static ssize_t
3834 level_show(struct mddev *mddev, char *page)
3835 {
3836         struct md_personality *p;
3837         int ret;
3838         spin_lock(&mddev->lock);
3839         p = mddev->pers;
3840         if (p)
3841                 ret = sprintf(page, "%s\n", p->name);
3842         else if (mddev->clevel[0])
3843                 ret = sprintf(page, "%s\n", mddev->clevel);
3844         else if (mddev->level != LEVEL_NONE)
3845                 ret = sprintf(page, "%d\n", mddev->level);
3846         else
3847                 ret = 0;
3848         spin_unlock(&mddev->lock);
3849         return ret;
3850 }
3851
3852 static ssize_t
3853 level_store(struct mddev *mddev, const char *buf, size_t len)
3854 {
3855         char clevel[16];
3856         ssize_t rv;
3857         size_t slen = len;
3858         struct md_personality *pers, *oldpers;
3859         long level;
3860         void *priv, *oldpriv;
3861         struct md_rdev *rdev;
3862
3863         if (slen == 0 || slen >= sizeof(clevel))
3864                 return -EINVAL;
3865
3866         rv = mddev_suspend_and_lock(mddev);
3867         if (rv)
3868                 return rv;
3869
3870         if (mddev->pers == NULL) {
3871                 memcpy(mddev->clevel, buf, slen);
3872                 if (mddev->clevel[slen-1] == '\n')
3873                         slen--;
3874                 mddev->clevel[slen] = 0;
3875                 mddev->level = LEVEL_NONE;
3876                 rv = len;
3877                 goto out_unlock;
3878         }
3879         rv = -EROFS;
3880         if (!md_is_rdwr(mddev))
3881                 goto out_unlock;
3882
3883         /* request to change the personality.  Need to ensure:
3884          *  - array is not engaged in resync/recovery/reshape
3885          *  - old personality can be suspended
3886          *  - new personality will access other array.
3887          */
3888
3889         rv = -EBUSY;
3890         if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
3891             mddev->reshape_position != MaxSector ||
3892             mddev->sysfs_active)
3893                 goto out_unlock;
3894
3895         rv = -EINVAL;
3896         if (!mddev->pers->quiesce) {
3897                 pr_warn("md: %s: %s does not support online personality change\n",
3898                         mdname(mddev), mddev->pers->name);
3899                 goto out_unlock;
3900         }
3901
3902         /* Now find the new personality */
3903         memcpy(clevel, buf, slen);
3904         if (clevel[slen-1] == '\n')
3905                 slen--;
3906         clevel[slen] = 0;
3907         if (kstrtol(clevel, 10, &level))
3908                 level = LEVEL_NONE;
3909
3910         if (request_module("md-%s", clevel) != 0)
3911                 request_module("md-level-%s", clevel);
3912         spin_lock(&pers_lock);
3913         pers = find_pers(level, clevel);
3914         if (!pers || !try_module_get(pers->owner)) {
3915                 spin_unlock(&pers_lock);
3916                 pr_warn("md: personality %s not loaded\n", clevel);
3917                 rv = -EINVAL;
3918                 goto out_unlock;
3919         }
3920         spin_unlock(&pers_lock);
3921
3922         if (pers == mddev->pers) {
3923                 /* Nothing to do! */
3924                 module_put(pers->owner);
3925                 rv = len;
3926                 goto out_unlock;
3927         }
3928         if (!pers->takeover) {
3929                 module_put(pers->owner);
3930                 pr_warn("md: %s: %s does not support personality takeover\n",
3931                         mdname(mddev), clevel);
3932                 rv = -EINVAL;
3933                 goto out_unlock;
3934         }
3935
3936         rdev_for_each(rdev, mddev)
3937                 rdev->new_raid_disk = rdev->raid_disk;
3938
3939         /* ->takeover must set new_* and/or delta_disks
3940          * if it succeeds, and may set them when it fails.
3941          */
3942         priv = pers->takeover(mddev);
3943         if (IS_ERR(priv)) {
3944                 mddev->new_level = mddev->level;
3945                 mddev->new_layout = mddev->layout;
3946                 mddev->new_chunk_sectors = mddev->chunk_sectors;
3947                 mddev->raid_disks -= mddev->delta_disks;
3948                 mddev->delta_disks = 0;
3949                 mddev->reshape_backwards = 0;
3950                 module_put(pers->owner);
3951                 pr_warn("md: %s: %s would not accept array\n",
3952                         mdname(mddev), clevel);
3953                 rv = PTR_ERR(priv);
3954                 goto out_unlock;
3955         }
3956
3957         /* Looks like we have a winner */
3958         mddev_detach(mddev);
3959
3960         spin_lock(&mddev->lock);
3961         oldpers = mddev->pers;
3962         oldpriv = mddev->private;
3963         mddev->pers = pers;
3964         mddev->private = priv;
3965         strscpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
3966         mddev->level = mddev->new_level;
3967         mddev->layout = mddev->new_layout;
3968         mddev->chunk_sectors = mddev->new_chunk_sectors;
3969         mddev->delta_disks = 0;
3970         mddev->reshape_backwards = 0;
3971         mddev->degraded = 0;
3972         spin_unlock(&mddev->lock);
3973
3974         if (oldpers->sync_request == NULL &&
3975             mddev->external) {
3976                 /* We are converting from a no-redundancy array
3977                  * to a redundancy array and metadata is managed
3978                  * externally so we need to be sure that writes
3979                  * won't block due to a need to transition
3980                  *      clean->dirty
3981                  * until external management is started.
3982                  */
3983                 mddev->in_sync = 0;
3984                 mddev->safemode_delay = 0;
3985                 mddev->safemode = 0;
3986         }
3987
3988         oldpers->free(mddev, oldpriv);
3989
3990         if (oldpers->sync_request == NULL &&
3991             pers->sync_request != NULL) {
3992                 /* need to add the md_redundancy_group */
3993                 if (sysfs_create_group(&mddev->kobj, &md_redundancy_group))
3994                         pr_warn("md: cannot register extra attributes for %s\n",
3995                                 mdname(mddev));
3996                 mddev->sysfs_action = sysfs_get_dirent(mddev->kobj.sd, "sync_action");
3997                 mddev->sysfs_completed = sysfs_get_dirent_safe(mddev->kobj.sd, "sync_completed");
3998                 mddev->sysfs_degraded = sysfs_get_dirent_safe(mddev->kobj.sd, "degraded");
3999         }
4000         if (oldpers->sync_request != NULL &&
4001             pers->sync_request == NULL) {
4002                 /* need to remove the md_redundancy_group */
4003                 if (mddev->to_remove == NULL)
4004                         mddev->to_remove = &md_redundancy_group;
4005         }
4006
4007         module_put(oldpers->owner);
4008
4009         rdev_for_each(rdev, mddev) {
4010                 if (rdev->raid_disk < 0)
4011                         continue;
4012                 if (rdev->new_raid_disk >= mddev->raid_disks)
4013                         rdev->new_raid_disk = -1;
4014                 if (rdev->new_raid_disk == rdev->raid_disk)
4015                         continue;
4016                 sysfs_unlink_rdev(mddev, rdev);
4017         }
4018         rdev_for_each(rdev, mddev) {
4019                 if (rdev->raid_disk < 0)
4020                         continue;
4021                 if (rdev->new_raid_disk == rdev->raid_disk)
4022                         continue;
4023                 rdev->raid_disk = rdev->new_raid_disk;
4024                 if (rdev->raid_disk < 0)
4025                         clear_bit(In_sync, &rdev->flags);
4026                 else {
4027                         if (sysfs_link_rdev(mddev, rdev))
4028                                 pr_warn("md: cannot register rd%d for %s after level change\n",
4029                                         rdev->raid_disk, mdname(mddev));
4030                 }
4031         }
4032
4033         if (pers->sync_request == NULL) {
4034                 /* this is now an array without redundancy, so
4035                  * it must always be in_sync
4036                  */
4037                 mddev->in_sync = 1;
4038                 del_timer_sync(&mddev->safemode_timer);
4039         }
4040         pers->run(mddev);
4041         set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
4042         if (!mddev->thread)
4043                 md_update_sb(mddev, 1);
4044         sysfs_notify_dirent_safe(mddev->sysfs_level);
4045         md_new_event();
4046         rv = len;
4047 out_unlock:
4048         mddev_unlock_and_resume(mddev);
4049         return rv;
4050 }
4051
4052 static struct md_sysfs_entry md_level =
4053 __ATTR(level, S_IRUGO|S_IWUSR, level_show, level_store);
4054
4055 static ssize_t
4056 new_level_show(struct mddev *mddev, char *page)
4057 {
4058         return sprintf(page, "%d\n", mddev->new_level);
4059 }
4060
4061 static ssize_t
4062 new_level_store(struct mddev *mddev, const char *buf, size_t len)
4063 {
4064         unsigned int n;
4065         int err;
4066
4067         err = kstrtouint(buf, 10, &n);
4068         if (err < 0)
4069                 return err;
4070         err = mddev_lock(mddev);
4071         if (err)
4072                 return err;
4073
4074         mddev->new_level = n;
4075         md_update_sb(mddev, 1);
4076
4077         mddev_unlock(mddev);
4078         return len;
4079 }
4080 static struct md_sysfs_entry md_new_level =
4081 __ATTR(new_level, 0664, new_level_show, new_level_store);
4082
4083 static ssize_t
4084 layout_show(struct mddev *mddev, char *page)
4085 {
4086         /* just a number, not meaningful for all levels */
4087         if (mddev->reshape_position != MaxSector &&
4088             mddev->layout != mddev->new_layout)
4089                 return sprintf(page, "%d (%d)\n",
4090                                mddev->new_layout, mddev->layout);
4091         return sprintf(page, "%d\n", mddev->layout);
4092 }
4093
4094 static ssize_t
4095 layout_store(struct mddev *mddev, const char *buf, size_t len)
4096 {
4097         unsigned int n;
4098         int err;
4099
4100         err = kstrtouint(buf, 10, &n);
4101         if (err < 0)
4102                 return err;
4103         err = mddev_lock(mddev);
4104         if (err)
4105                 return err;
4106
4107         if (mddev->pers) {
4108                 if (mddev->pers->check_reshape == NULL)
4109                         err = -EBUSY;
4110                 else if (!md_is_rdwr(mddev))
4111                         err = -EROFS;
4112                 else {
4113                         mddev->new_layout = n;
4114                         err = mddev->pers->check_reshape(mddev);
4115                         if (err)
4116                                 mddev->new_layout = mddev->layout;
4117                 }
4118         } else {
4119                 mddev->new_layout = n;
4120                 if (mddev->reshape_position == MaxSector)
4121                         mddev->layout = n;
4122         }
4123         mddev_unlock(mddev);
4124         return err ?: len;
4125 }
4126 static struct md_sysfs_entry md_layout =
4127 __ATTR(layout, S_IRUGO|S_IWUSR, layout_show, layout_store);
4128
4129 static ssize_t
4130 raid_disks_show(struct mddev *mddev, char *page)
4131 {
4132         if (mddev->raid_disks == 0)
4133                 return 0;
4134         if (mddev->reshape_position != MaxSector &&
4135             mddev->delta_disks != 0)
4136                 return sprintf(page, "%d (%d)\n", mddev->raid_disks,
4137                                mddev->raid_disks - mddev->delta_disks);
4138         return sprintf(page, "%d\n", mddev->raid_disks);
4139 }
4140
4141 static int update_raid_disks(struct mddev *mddev, int raid_disks);
4142
4143 static ssize_t
4144 raid_disks_store(struct mddev *mddev, const char *buf, size_t len)
4145 {
4146         unsigned int n;
4147         int err;
4148
4149         err = kstrtouint(buf, 10, &n);
4150         if (err < 0)
4151                 return err;
4152
4153         err = mddev_lock(mddev);
4154         if (err)
4155                 return err;
4156         if (mddev->pers)
4157                 err = update_raid_disks(mddev, n);
4158         else if (mddev->reshape_position != MaxSector) {
4159                 struct md_rdev *rdev;
4160                 int olddisks = mddev->raid_disks - mddev->delta_disks;
4161
4162                 err = -EINVAL;
4163                 rdev_for_each(rdev, mddev) {
4164                         if (olddisks < n &&
4165                             rdev->data_offset < rdev->new_data_offset)
4166                                 goto out_unlock;
4167                         if (olddisks > n &&
4168                             rdev->data_offset > rdev->new_data_offset)
4169                                 goto out_unlock;
4170                 }
4171                 err = 0;
4172                 mddev->delta_disks = n - olddisks;
4173                 mddev->raid_disks = n;
4174                 mddev->reshape_backwards = (mddev->delta_disks < 0);
4175         } else
4176                 mddev->raid_disks = n;
4177 out_unlock:
4178         mddev_unlock(mddev);
4179         return err ? err : len;
4180 }
4181 static struct md_sysfs_entry md_raid_disks =
4182 __ATTR(raid_disks, S_IRUGO|S_IWUSR, raid_disks_show, raid_disks_store);
4183
4184 static ssize_t
4185 uuid_show(struct mddev *mddev, char *page)
4186 {
4187         return sprintf(page, "%pU\n", mddev->uuid);
4188 }
4189 static struct md_sysfs_entry md_uuid =
4190 __ATTR(uuid, S_IRUGO, uuid_show, NULL);
4191
4192 static ssize_t
4193 chunk_size_show(struct mddev *mddev, char *page)
4194 {
4195         if (mddev->reshape_position != MaxSector &&
4196             mddev->chunk_sectors != mddev->new_chunk_sectors)
4197                 return sprintf(page, "%d (%d)\n",
4198                                mddev->new_chunk_sectors << 9,
4199                                mddev->chunk_sectors << 9);
4200         return sprintf(page, "%d\n", mddev->chunk_sectors << 9);
4201 }
4202
4203 static ssize_t
4204 chunk_size_store(struct mddev *mddev, const char *buf, size_t len)
4205 {
4206         unsigned long n;
4207         int err;
4208
4209         err = kstrtoul(buf, 10, &n);
4210         if (err < 0)
4211                 return err;
4212
4213         err = mddev_lock(mddev);
4214         if (err)
4215                 return err;
4216         if (mddev->pers) {
4217                 if (mddev->pers->check_reshape == NULL)
4218                         err = -EBUSY;
4219                 else if (!md_is_rdwr(mddev))
4220                         err = -EROFS;
4221                 else {
4222                         mddev->new_chunk_sectors = n >> 9;
4223                         err = mddev->pers->check_reshape(mddev);
4224                         if (err)
4225                                 mddev->new_chunk_sectors = mddev->chunk_sectors;
4226                 }
4227         } else {
4228                 mddev->new_chunk_sectors = n >> 9;
4229                 if (mddev->reshape_position == MaxSector)
4230                         mddev->chunk_sectors = n >> 9;
4231         }
4232         mddev_unlock(mddev);
4233         return err ?: len;
4234 }
4235 static struct md_sysfs_entry md_chunk_size =
4236 __ATTR(chunk_size, S_IRUGO|S_IWUSR, chunk_size_show, chunk_size_store);
4237
4238 static ssize_t
4239 resync_start_show(struct mddev *mddev, char *page)
4240 {
4241         if (mddev->recovery_cp == MaxSector)
4242                 return sprintf(page, "none\n");
4243         return sprintf(page, "%llu\n", (unsigned long long)mddev->recovery_cp);
4244 }
4245
4246 static ssize_t
4247 resync_start_store(struct mddev *mddev, const char *buf, size_t len)
4248 {
4249         unsigned long long n;
4250         int err;
4251
4252         if (cmd_match(buf, "none"))
4253                 n = MaxSector;
4254         else {
4255                 err = kstrtoull(buf, 10, &n);
4256                 if (err < 0)
4257                         return err;
4258                 if (n != (sector_t)n)
4259                         return -EINVAL;
4260         }
4261
4262         err = mddev_lock(mddev);
4263         if (err)
4264                 return err;
4265         if (mddev->pers && !test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
4266                 err = -EBUSY;
4267
4268         if (!err) {
4269                 mddev->recovery_cp = n;
4270                 if (mddev->pers)
4271                         set_bit(MD_SB_CHANGE_CLEAN, &mddev->sb_flags);
4272         }
4273         mddev_unlock(mddev);
4274         return err ?: len;
4275 }
4276 static struct md_sysfs_entry md_resync_start =
4277 __ATTR_PREALLOC(resync_start, S_IRUGO|S_IWUSR,
4278                 resync_start_show, resync_start_store);
4279
4280 /*
4281  * The array state can be:
4282  *
4283  * clear
4284  *     No devices, no size, no level
4285  *     Equivalent to STOP_ARRAY ioctl
4286  * inactive
4287  *     May have some settings, but array is not active
4288  *        all IO results in error
4289  *     When written, doesn't tear down array, but just stops it
4290  * suspended (not supported yet)
4291  *     All IO requests will block. The array can be reconfigured.
4292  *     Writing this, if accepted, will block until array is quiescent
4293  * readonly
4294  *     no resync can happen.  no superblocks get written.
4295  *     write requests fail
4296  * read-auto
4297  *     like readonly, but behaves like 'clean' on a write request.
4298  *
4299  * clean - no pending writes, but otherwise active.
4300  *     When written to inactive array, starts without resync
4301  *     If a write request arrives then
4302  *       if metadata is known, mark 'dirty' and switch to 'active'.
4303  *       if not known, block and switch to write-pending
4304  *     If written to an active array that has pending writes, then fails.
4305  * active
4306  *     fully active: IO and resync can be happening.
4307  *     When written to inactive array, starts with resync
4308  *
4309  * write-pending
4310  *     clean, but writes are blocked waiting for 'active' to be written.
4311  *
4312  * active-idle
4313  *     like active, but no writes have been seen for a while (100msec).
4314  *
4315  * broken
4316 *     Array is failed. It's useful because mounted-arrays aren't stopped
4317 *     when array is failed, so this state will at least alert the user that
4318 *     something is wrong.
4319  */
4320 enum array_state { clear, inactive, suspended, readonly, read_auto, clean, active,
4321                    write_pending, active_idle, broken, bad_word};
4322 static char *array_states[] = {
4323         "clear", "inactive", "suspended", "readonly", "read-auto", "clean", "active",
4324         "write-pending", "active-idle", "broken", NULL };
4325
4326 static int match_word(const char *word, char **list)
4327 {
4328         int n;
4329         for (n=0; list[n]; n++)
4330                 if (cmd_match(word, list[n]))
4331                         break;
4332         return n;
4333 }
4334
4335 static ssize_t
4336 array_state_show(struct mddev *mddev, char *page)
4337 {
4338         enum array_state st = inactive;
4339
4340         if (mddev->pers && !test_bit(MD_NOT_READY, &mddev->flags)) {
4341                 switch(mddev->ro) {
4342                 case MD_RDONLY:
4343                         st = readonly;
4344                         break;
4345                 case MD_AUTO_READ:
4346                         st = read_auto;
4347                         break;
4348                 case MD_RDWR:
4349                         spin_lock(&mddev->lock);
4350                         if (test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags))
4351                                 st = write_pending;
4352                         else if (mddev->in_sync)
4353                                 st = clean;
4354                         else if (mddev->safemode)
4355                                 st = active_idle;
4356                         else
4357                                 st = active;
4358                         spin_unlock(&mddev->lock);
4359                 }
4360
4361                 if (test_bit(MD_BROKEN, &mddev->flags) && st == clean)
4362                         st = broken;
4363         } else {
4364                 if (list_empty(&mddev->disks) &&
4365                     mddev->raid_disks == 0 &&
4366                     mddev->dev_sectors == 0)
4367                         st = clear;
4368                 else
4369                         st = inactive;
4370         }
4371         return sprintf(page, "%s\n", array_states[st]);
4372 }
4373
4374 static int do_md_stop(struct mddev *mddev, int ro);
4375 static int md_set_readonly(struct mddev *mddev);
4376 static int restart_array(struct mddev *mddev);
4377
4378 static ssize_t
4379 array_state_store(struct mddev *mddev, const char *buf, size_t len)
4380 {
4381         int err = 0;
4382         enum array_state st = match_word(buf, array_states);
4383
4384         /* No lock dependent actions */
4385         switch (st) {
4386         case suspended:         /* not supported yet */
4387         case write_pending:     /* cannot be set */
4388         case active_idle:       /* cannot be set */
4389         case broken:            /* cannot be set */
4390         case bad_word:
4391                 return -EINVAL;
4392         case clear:
4393         case readonly:
4394         case inactive:
4395         case read_auto:
4396                 if (!mddev->pers || !md_is_rdwr(mddev))
4397                         break;
4398                 /* write sysfs will not open mddev and opener should be 0 */
4399                 err = mddev_set_closing_and_sync_blockdev(mddev, 0);
4400                 if (err)
4401                         return err;
4402                 break;
4403         default:
4404                 break;
4405         }
4406
4407         if (mddev->pers && (st == active || st == clean) &&
4408             mddev->ro != MD_RDONLY) {
4409                 /* don't take reconfig_mutex when toggling between
4410                  * clean and active
4411                  */
4412                 spin_lock(&mddev->lock);
4413                 if (st == active) {
4414                         restart_array(mddev);
4415                         clear_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags);
4416                         md_wakeup_thread(mddev->thread);
4417                         wake_up(&mddev->sb_wait);
4418                 } else /* st == clean */ {
4419                         restart_array(mddev);
4420                         if (!set_in_sync(mddev))
4421                                 err = -EBUSY;
4422                 }
4423                 if (!err)
4424                         sysfs_notify_dirent_safe(mddev->sysfs_state);
4425                 spin_unlock(&mddev->lock);
4426                 return err ?: len;
4427         }
4428         err = mddev_lock(mddev);
4429         if (err)
4430                 return err;
4431
4432         switch (st) {
4433         case inactive:
4434                 /* stop an active array, return 0 otherwise */
4435                 if (mddev->pers)
4436                         err = do_md_stop(mddev, 2);
4437                 break;
4438         case clear:
4439                 err = do_md_stop(mddev, 0);
4440                 break;
4441         case readonly:
4442                 if (mddev->pers)
4443                         err = md_set_readonly(mddev);
4444                 else {
4445                         mddev->ro = MD_RDONLY;
4446                         set_disk_ro(mddev->gendisk, 1);
4447                         err = do_md_run(mddev);
4448                 }
4449                 break;
4450         case read_auto:
4451                 if (mddev->pers) {
4452                         if (md_is_rdwr(mddev))
4453                                 err = md_set_readonly(mddev);
4454                         else if (mddev->ro == MD_RDONLY)
4455                                 err = restart_array(mddev);
4456                         if (err == 0) {
4457                                 mddev->ro = MD_AUTO_READ;
4458                                 set_disk_ro(mddev->gendisk, 0);
4459                         }
4460                 } else {
4461                         mddev->ro = MD_AUTO_READ;
4462                         err = do_md_run(mddev);
4463                 }
4464                 break;
4465         case clean:
4466                 if (mddev->pers) {
4467                         err = restart_array(mddev);
4468                         if (err)
4469                                 break;
4470                         spin_lock(&mddev->lock);
4471                         if (!set_in_sync(mddev))
4472                                 err = -EBUSY;
4473                         spin_unlock(&mddev->lock);
4474                 } else
4475                         err = -EINVAL;
4476                 break;
4477         case active:
4478                 if (mddev->pers) {
4479                         err = restart_array(mddev);
4480                         if (err)
4481                                 break;
4482                         clear_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags);
4483                         wake_up(&mddev->sb_wait);
4484                         err = 0;
4485                 } else {
4486                         mddev->ro = MD_RDWR;
4487                         set_disk_ro(mddev->gendisk, 0);
4488                         err = do_md_run(mddev);
4489                 }
4490                 break;
4491         default:
4492                 err = -EINVAL;
4493                 break;
4494         }
4495
4496         if (!err) {
4497                 if (mddev->hold_active == UNTIL_IOCTL)
4498                         mddev->hold_active = 0;
4499                 sysfs_notify_dirent_safe(mddev->sysfs_state);
4500         }
4501         mddev_unlock(mddev);
4502
4503         if (st == readonly || st == read_auto || st == inactive ||
4504             (err && st == clear))
4505                 clear_bit(MD_CLOSING, &mddev->flags);
4506
4507         return err ?: len;
4508 }
4509 static struct md_sysfs_entry md_array_state =
4510 __ATTR_PREALLOC(array_state, S_IRUGO|S_IWUSR, array_state_show, array_state_store);
4511
4512 static ssize_t
4513 max_corrected_read_errors_show(struct mddev *mddev, char *page) {
4514         return sprintf(page, "%d\n",
4515                        atomic_read(&mddev->max_corr_read_errors));
4516 }
4517
4518 static ssize_t
4519 max_corrected_read_errors_store(struct mddev *mddev, const char *buf, size_t len)
4520 {
4521         unsigned int n;
4522         int rv;
4523
4524         rv = kstrtouint(buf, 10, &n);
4525         if (rv < 0)
4526                 return rv;
4527         if (n > INT_MAX)
4528                 return -EINVAL;
4529         atomic_set(&mddev->max_corr_read_errors, n);
4530         return len;
4531 }
4532
4533 static struct md_sysfs_entry max_corr_read_errors =
4534 __ATTR(max_read_errors, S_IRUGO|S_IWUSR, max_corrected_read_errors_show,
4535         max_corrected_read_errors_store);
4536
4537 static ssize_t
4538 null_show(struct mddev *mddev, char *page)
4539 {
4540         return -EINVAL;
4541 }
4542
4543 static ssize_t
4544 new_dev_store(struct mddev *mddev, const char *buf, size_t len)
4545 {
4546         /* buf must be %d:%d\n? giving major and minor numbers */
4547         /* The new device is added to the array.
4548          * If the array has a persistent superblock, we read the
4549          * superblock to initialise info and check validity.
4550          * Otherwise, only checking done is that in bind_rdev_to_array,
4551          * which mainly checks size.
4552          */
4553         char *e;
4554         int major = simple_strtoul(buf, &e, 10);
4555         int minor;
4556         dev_t dev;
4557         struct md_rdev *rdev;
4558         int err;
4559
4560         if (!*buf || *e != ':' || !e[1] || e[1] == '\n')
4561                 return -EINVAL;
4562         minor = simple_strtoul(e+1, &e, 10);
4563         if (*e && *e != '\n')
4564                 return -EINVAL;
4565         dev = MKDEV(major, minor);
4566         if (major != MAJOR(dev) ||
4567             minor != MINOR(dev))
4568                 return -EOVERFLOW;
4569
4570         err = mddev_suspend_and_lock(mddev);
4571         if (err)
4572                 return err;
4573         if (mddev->persistent) {
4574                 rdev = md_import_device(dev, mddev->major_version,
4575                                         mddev->minor_version);
4576                 if (!IS_ERR(rdev) && !list_empty(&mddev->disks)) {
4577                         struct md_rdev *rdev0
4578                                 = list_entry(mddev->disks.next,
4579                                              struct md_rdev, same_set);
4580                         err = super_types[mddev->major_version]
4581                                 .load_super(rdev, rdev0, mddev->minor_version);
4582                         if (err < 0)
4583                                 goto out;
4584                 }
4585         } else if (mddev->external)
4586                 rdev = md_import_device(dev, -2, -1);
4587         else
4588                 rdev = md_import_device(dev, -1, -1);
4589
4590         if (IS_ERR(rdev)) {
4591                 mddev_unlock_and_resume(mddev);
4592                 return PTR_ERR(rdev);
4593         }
4594         err = bind_rdev_to_array(rdev, mddev);
4595  out:
4596         if (err)
4597                 export_rdev(rdev, mddev);
4598         mddev_unlock_and_resume(mddev);
4599         if (!err)
4600                 md_new_event();
4601         return err ? err : len;
4602 }
4603
4604 static struct md_sysfs_entry md_new_device =
4605 __ATTR(new_dev, S_IWUSR, null_show, new_dev_store);
4606
4607 static ssize_t
4608 bitmap_store(struct mddev *mddev, const char *buf, size_t len)
4609 {
4610         char *end;
4611         unsigned long chunk, end_chunk;
4612         int err;
4613
4614         err = mddev_lock(mddev);
4615         if (err)
4616                 return err;
4617         if (!mddev->bitmap)
4618                 goto out;
4619         /* buf should be <chunk> <chunk> ... or <chunk>-<chunk> ... (range) */
4620         while (*buf) {
4621                 chunk = end_chunk = simple_strtoul(buf, &end, 0);
4622                 if (buf == end)
4623                         break;
4624
4625                 if (*end == '-') { /* range */
4626                         buf = end + 1;
4627                         end_chunk = simple_strtoul(buf, &end, 0);
4628                         if (buf == end)
4629                                 break;
4630                 }
4631
4632                 if (*end && !isspace(*end))
4633                         break;
4634
4635                 mddev->bitmap_ops->dirty_bits(mddev, chunk, end_chunk);
4636                 buf = skip_spaces(end);
4637         }
4638         mddev->bitmap_ops->unplug(mddev, true); /* flush the bits to disk */
4639 out:
4640         mddev_unlock(mddev);
4641         return len;
4642 }
4643
4644 static struct md_sysfs_entry md_bitmap =
4645 __ATTR(bitmap_set_bits, S_IWUSR, null_show, bitmap_store);
4646
4647 static ssize_t
4648 size_show(struct mddev *mddev, char *page)
4649 {
4650         return sprintf(page, "%llu\n",
4651                 (unsigned long long)mddev->dev_sectors / 2);
4652 }
4653
4654 static int update_size(struct mddev *mddev, sector_t num_sectors);
4655
4656 static ssize_t
4657 size_store(struct mddev *mddev, const char *buf, size_t len)
4658 {
4659         /* If array is inactive, we can reduce the component size, but
4660          * not increase it (except from 0).
4661          * If array is active, we can try an on-line resize
4662          */
4663         sector_t sectors;
4664         int err = strict_blocks_to_sectors(buf, &sectors);
4665
4666         if (err < 0)
4667                 return err;
4668         err = mddev_lock(mddev);
4669         if (err)
4670                 return err;
4671         if (mddev->pers) {
4672                 err = update_size(mddev, sectors);
4673                 if (err == 0)
4674                         md_update_sb(mddev, 1);
4675         } else {
4676                 if (mddev->dev_sectors == 0 ||
4677                     mddev->dev_sectors > sectors)
4678                         mddev->dev_sectors = sectors;
4679                 else
4680                         err = -ENOSPC;
4681         }
4682         mddev_unlock(mddev);
4683         return err ? err : len;
4684 }
4685
4686 static struct md_sysfs_entry md_size =
4687 __ATTR(component_size, S_IRUGO|S_IWUSR, size_show, size_store);
4688
4689 /* Metadata version.
4690  * This is one of
4691  *   'none' for arrays with no metadata (good luck...)
4692  *   'external' for arrays with externally managed metadata,
4693  * or N.M for internally known formats
4694  */
4695 static ssize_t
4696 metadata_show(struct mddev *mddev, char *page)
4697 {
4698         if (mddev->persistent)
4699                 return sprintf(page, "%d.%d\n",
4700                                mddev->major_version, mddev->minor_version);
4701         else if (mddev->external)
4702                 return sprintf(page, "external:%s\n", mddev->metadata_type);
4703         else
4704                 return sprintf(page, "none\n");
4705 }
4706
4707 static ssize_t
4708 metadata_store(struct mddev *mddev, const char *buf, size_t len)
4709 {
4710         int major, minor;
4711         char *e;
4712         int err;
4713         /* Changing the details of 'external' metadata is
4714          * always permitted.  Otherwise there must be
4715          * no devices attached to the array.
4716          */
4717
4718         err = mddev_lock(mddev);
4719         if (err)
4720                 return err;
4721         err = -EBUSY;
4722         if (mddev->external && strncmp(buf, "external:", 9) == 0)
4723                 ;
4724         else if (!list_empty(&mddev->disks))
4725                 goto out_unlock;
4726
4727         err = 0;
4728         if (cmd_match(buf, "none")) {
4729                 mddev->persistent = 0;
4730                 mddev->external = 0;
4731                 mddev->major_version = 0;
4732                 mddev->minor_version = 90;
4733                 goto out_unlock;
4734         }
4735         if (strncmp(buf, "external:", 9) == 0) {
4736                 size_t namelen = len-9;
4737                 if (namelen >= sizeof(mddev->metadata_type))
4738                         namelen = sizeof(mddev->metadata_type)-1;
4739                 memcpy(mddev->metadata_type, buf+9, namelen);
4740                 mddev->metadata_type[namelen] = 0;
4741                 if (namelen && mddev->metadata_type[namelen-1] == '\n')
4742                         mddev->metadata_type[--namelen] = 0;
4743                 mddev->persistent = 0;
4744                 mddev->external = 1;
4745                 mddev->major_version = 0;
4746                 mddev->minor_version = 90;
4747                 goto out_unlock;
4748         }
4749         major = simple_strtoul(buf, &e, 10);
4750         err = -EINVAL;
4751         if (e==buf || *e != '.')
4752                 goto out_unlock;
4753         buf = e+1;
4754         minor = simple_strtoul(buf, &e, 10);
4755         if (e==buf || (*e && *e != '\n') )
4756                 goto out_unlock;
4757         err = -ENOENT;
4758         if (major >= ARRAY_SIZE(super_types) || super_types[major].name == NULL)
4759                 goto out_unlock;
4760         mddev->major_version = major;
4761         mddev->minor_version = minor;
4762         mddev->persistent = 1;
4763         mddev->external = 0;
4764         err = 0;
4765 out_unlock:
4766         mddev_unlock(mddev);
4767         return err ?: len;
4768 }
4769
4770 static struct md_sysfs_entry md_metadata =
4771 __ATTR_PREALLOC(metadata_version, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
4772
4773 enum sync_action md_sync_action(struct mddev *mddev)
4774 {
4775         unsigned long recovery = mddev->recovery;
4776
4777         /*
4778          * frozen has the highest priority, means running sync_thread will be
4779          * stopped immediately, and no new sync_thread can start.
4780          */
4781         if (test_bit(MD_RECOVERY_FROZEN, &recovery))
4782                 return ACTION_FROZEN;
4783
4784         /*
4785          * read-only array can't register sync_thread, and it can only
4786          * add/remove spares.
4787          */
4788         if (!md_is_rdwr(mddev))
4789                 return ACTION_IDLE;
4790
4791         /*
4792          * idle means no sync_thread is running, and no new sync_thread is
4793          * requested.
4794          */
4795         if (!test_bit(MD_RECOVERY_RUNNING, &recovery) &&
4796             !test_bit(MD_RECOVERY_NEEDED, &recovery))
4797                 return ACTION_IDLE;
4798
4799         if (test_bit(MD_RECOVERY_RESHAPE, &recovery) ||
4800             mddev->reshape_position != MaxSector)
4801                 return ACTION_RESHAPE;
4802
4803         if (test_bit(MD_RECOVERY_RECOVER, &recovery))
4804                 return ACTION_RECOVER;
4805
4806         if (test_bit(MD_RECOVERY_SYNC, &recovery)) {
4807                 /*
4808                  * MD_RECOVERY_CHECK must be paired with
4809                  * MD_RECOVERY_REQUESTED.
4810                  */
4811                 if (test_bit(MD_RECOVERY_CHECK, &recovery))
4812                         return ACTION_CHECK;
4813                 if (test_bit(MD_RECOVERY_REQUESTED, &recovery))
4814                         return ACTION_REPAIR;
4815                 return ACTION_RESYNC;
4816         }
4817
4818         /*
4819          * MD_RECOVERY_NEEDED or MD_RECOVERY_RUNNING is set, however, no
4820          * sync_action is specified.
4821          */
4822         return ACTION_IDLE;
4823 }
4824
4825 enum sync_action md_sync_action_by_name(const char *page)
4826 {
4827         enum sync_action action;
4828
4829         for (action = 0; action < NR_SYNC_ACTIONS; ++action) {
4830                 if (cmd_match(page, action_name[action]))
4831                         return action;
4832         }
4833
4834         return NR_SYNC_ACTIONS;
4835 }
4836
4837 const char *md_sync_action_name(enum sync_action action)
4838 {
4839         return action_name[action];
4840 }
4841
4842 static ssize_t
4843 action_show(struct mddev *mddev, char *page)
4844 {
4845         enum sync_action action = md_sync_action(mddev);
4846
4847         return sprintf(page, "%s\n", md_sync_action_name(action));
4848 }
4849
4850 /**
4851  * stop_sync_thread() - wait for sync_thread to stop if it's running.
4852  * @mddev:      the array.
4853  * @locked:     if set, reconfig_mutex will still be held after this function
4854  *              return; if not set, reconfig_mutex will be released after this
4855  *              function return.
4856  */
4857 static void stop_sync_thread(struct mddev *mddev, bool locked)
4858 {
4859         int sync_seq = atomic_read(&mddev->sync_seq);
4860
4861         if (!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) {
4862                 if (!locked)
4863                         mddev_unlock(mddev);
4864                 return;
4865         }
4866
4867         mddev_unlock(mddev);
4868
4869         set_bit(MD_RECOVERY_INTR, &mddev->recovery);
4870         /*
4871          * Thread might be blocked waiting for metadata update which will now
4872          * never happen
4873          */
4874         md_wakeup_thread_directly(mddev->sync_thread);
4875         if (work_pending(&mddev->sync_work))
4876                 flush_work(&mddev->sync_work);
4877
4878         wait_event(resync_wait,
4879                    !test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
4880                    (!test_bit(MD_RECOVERY_FROZEN, &mddev->recovery) &&
4881                     sync_seq != atomic_read(&mddev->sync_seq)));
4882
4883         if (locked)
4884                 mddev_lock_nointr(mddev);
4885 }
4886
4887 void md_idle_sync_thread(struct mddev *mddev)
4888 {
4889         lockdep_assert_held(&mddev->reconfig_mutex);
4890
4891         clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4892         stop_sync_thread(mddev, true);
4893 }
4894 EXPORT_SYMBOL_GPL(md_idle_sync_thread);
4895
4896 void md_frozen_sync_thread(struct mddev *mddev)
4897 {
4898         lockdep_assert_held(&mddev->reconfig_mutex);
4899
4900         set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4901         stop_sync_thread(mddev, true);
4902 }
4903 EXPORT_SYMBOL_GPL(md_frozen_sync_thread);
4904
4905 void md_unfrozen_sync_thread(struct mddev *mddev)
4906 {
4907         lockdep_assert_held(&mddev->reconfig_mutex);
4908
4909         clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4910         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4911         md_wakeup_thread(mddev->thread);
4912         sysfs_notify_dirent_safe(mddev->sysfs_action);
4913 }
4914 EXPORT_SYMBOL_GPL(md_unfrozen_sync_thread);
4915
4916 static int mddev_start_reshape(struct mddev *mddev)
4917 {
4918         int ret;
4919
4920         if (mddev->pers->start_reshape == NULL)
4921                 return -EINVAL;
4922
4923         if (mddev->reshape_position == MaxSector ||
4924             mddev->pers->check_reshape == NULL ||
4925             mddev->pers->check_reshape(mddev)) {
4926                 clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4927                 ret = mddev->pers->start_reshape(mddev);
4928                 if (ret)
4929                         return ret;
4930         } else {
4931                 /*
4932                  * If reshape is still in progress, and md_check_recovery() can
4933                  * continue to reshape, don't restart reshape because data can
4934                  * be corrupted for raid456.
4935                  */
4936                 clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4937         }
4938
4939         sysfs_notify_dirent_safe(mddev->sysfs_degraded);
4940         return 0;
4941 }
4942
4943 static ssize_t
4944 action_store(struct mddev *mddev, const char *page, size_t len)
4945 {
4946         int ret;
4947         enum sync_action action;
4948
4949         if (!mddev->pers || !mddev->pers->sync_request)
4950                 return -EINVAL;
4951
4952 retry:
4953         if (work_busy(&mddev->sync_work))
4954                 flush_work(&mddev->sync_work);
4955
4956         ret = mddev_lock(mddev);
4957         if (ret)
4958                 return ret;
4959
4960         if (work_busy(&mddev->sync_work)) {
4961                 mddev_unlock(mddev);
4962                 goto retry;
4963         }
4964
4965         action = md_sync_action_by_name(page);
4966
4967         /* TODO: mdadm rely on "idle" to start sync_thread. */
4968         if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) {
4969                 switch (action) {
4970                 case ACTION_FROZEN:
4971                         md_frozen_sync_thread(mddev);
4972                         ret = len;
4973                         goto out;
4974                 case ACTION_IDLE:
4975                         md_idle_sync_thread(mddev);
4976                         break;
4977                 case ACTION_RESHAPE:
4978                 case ACTION_RECOVER:
4979                 case ACTION_CHECK:
4980                 case ACTION_REPAIR:
4981                 case ACTION_RESYNC:
4982                         ret = -EBUSY;
4983                         goto out;
4984                 default:
4985                         ret = -EINVAL;
4986                         goto out;
4987                 }
4988         } else {
4989                 switch (action) {
4990                 case ACTION_FROZEN:
4991                         set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4992                         ret = len;
4993                         goto out;
4994                 case ACTION_RESHAPE:
4995                         clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4996                         ret = mddev_start_reshape(mddev);
4997                         if (ret)
4998                                 goto out;
4999                         break;
5000                 case ACTION_RECOVER:
5001                         clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5002                         set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
5003                         break;
5004                 case ACTION_CHECK:
5005                         set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
5006                         fallthrough;
5007                 case ACTION_REPAIR:
5008                         set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
5009                         set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
5010                         fallthrough;
5011                 case ACTION_RESYNC:
5012                 case ACTION_IDLE:
5013                         clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5014                         break;
5015                 default:
5016                         ret = -EINVAL;
5017                         goto out;
5018                 }
5019         }
5020
5021         if (mddev->ro == MD_AUTO_READ) {
5022                 /* A write to sync_action is enough to justify
5023                  * canceling read-auto mode
5024                  */
5025                 mddev->ro = MD_RDWR;
5026                 md_wakeup_thread(mddev->sync_thread);
5027         }
5028
5029         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5030         md_wakeup_thread(mddev->thread);
5031         sysfs_notify_dirent_safe(mddev->sysfs_action);
5032         ret = len;
5033
5034 out:
5035         mddev_unlock(mddev);
5036         return ret;
5037 }
5038
5039 static struct md_sysfs_entry md_scan_mode =
5040 __ATTR_PREALLOC(sync_action, S_IRUGO|S_IWUSR, action_show, action_store);
5041
5042 static ssize_t
5043 last_sync_action_show(struct mddev *mddev, char *page)
5044 {
5045         return sprintf(page, "%s\n",
5046                        md_sync_action_name(mddev->last_sync_action));
5047 }
5048
5049 static struct md_sysfs_entry md_last_scan_mode = __ATTR_RO(last_sync_action);
5050
5051 static ssize_t
5052 mismatch_cnt_show(struct mddev *mddev, char *page)
5053 {
5054         return sprintf(page, "%llu\n",
5055                        (unsigned long long)
5056                        atomic64_read(&mddev->resync_mismatches));
5057 }
5058
5059 static struct md_sysfs_entry md_mismatches = __ATTR_RO(mismatch_cnt);
5060
5061 static ssize_t
5062 sync_min_show(struct mddev *mddev, char *page)
5063 {
5064         return sprintf(page, "%d (%s)\n", speed_min(mddev),
5065                        mddev->sync_speed_min ? "local": "system");
5066 }
5067
5068 static ssize_t
5069 sync_min_store(struct mddev *mddev, const char *buf, size_t len)
5070 {
5071         unsigned int min;
5072         int rv;
5073
5074         if (strncmp(buf, "system", 6)==0) {
5075                 min = 0;
5076         } else {
5077                 rv = kstrtouint(buf, 10, &min);
5078                 if (rv < 0)
5079                         return rv;
5080                 if (min == 0)
5081                         return -EINVAL;
5082         }
5083         mddev->sync_speed_min = min;
5084         return len;
5085 }
5086
5087 static struct md_sysfs_entry md_sync_min =
5088 __ATTR(sync_speed_min, S_IRUGO|S_IWUSR, sync_min_show, sync_min_store);
5089
5090 static ssize_t
5091 sync_max_show(struct mddev *mddev, char *page)
5092 {
5093         return sprintf(page, "%d (%s)\n", speed_max(mddev),
5094                        mddev->sync_speed_max ? "local": "system");
5095 }
5096
5097 static ssize_t
5098 sync_max_store(struct mddev *mddev, const char *buf, size_t len)
5099 {
5100         unsigned int max;
5101         int rv;
5102
5103         if (strncmp(buf, "system", 6)==0) {
5104                 max = 0;
5105         } else {
5106                 rv = kstrtouint(buf, 10, &max);
5107                 if (rv < 0)
5108                         return rv;
5109                 if (max == 0)
5110                         return -EINVAL;
5111         }
5112         mddev->sync_speed_max = max;
5113         return len;
5114 }
5115
5116 static struct md_sysfs_entry md_sync_max =
5117 __ATTR(sync_speed_max, S_IRUGO|S_IWUSR, sync_max_show, sync_max_store);
5118
5119 static ssize_t
5120 degraded_show(struct mddev *mddev, char *page)
5121 {
5122         return sprintf(page, "%d\n", mddev->degraded);
5123 }
5124 static struct md_sysfs_entry md_degraded = __ATTR_RO(degraded);
5125
5126 static ssize_t
5127 sync_force_parallel_show(struct mddev *mddev, char *page)
5128 {
5129         return sprintf(page, "%d\n", mddev->parallel_resync);
5130 }
5131
5132 static ssize_t
5133 sync_force_parallel_store(struct mddev *mddev, const char *buf, size_t len)
5134 {
5135         long n;
5136
5137         if (kstrtol(buf, 10, &n))
5138                 return -EINVAL;
5139
5140         if (n != 0 && n != 1)
5141                 return -EINVAL;
5142
5143         mddev->parallel_resync = n;
5144
5145         if (mddev->sync_thread)
5146                 wake_up(&resync_wait);
5147
5148         return len;
5149 }
5150
5151 /* force parallel resync, even with shared block devices */
5152 static struct md_sysfs_entry md_sync_force_parallel =
5153 __ATTR(sync_force_parallel, S_IRUGO|S_IWUSR,
5154        sync_force_parallel_show, sync_force_parallel_store);
5155
5156 static ssize_t
5157 sync_speed_show(struct mddev *mddev, char *page)
5158 {
5159         unsigned long resync, dt, db;
5160         if (mddev->curr_resync == MD_RESYNC_NONE)
5161                 return sprintf(page, "none\n");
5162         resync = mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active);
5163         dt = (jiffies - mddev->resync_mark) / HZ;
5164         if (!dt) dt++;
5165         db = resync - mddev->resync_mark_cnt;
5166         return sprintf(page, "%lu\n", db/dt/2); /* K/sec */
5167 }
5168
5169 static struct md_sysfs_entry md_sync_speed = __ATTR_RO(sync_speed);
5170
5171 static ssize_t
5172 sync_completed_show(struct mddev *mddev, char *page)
5173 {
5174         unsigned long long max_sectors, resync;
5175
5176         if (!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
5177                 return sprintf(page, "none\n");
5178
5179         if (mddev->curr_resync == MD_RESYNC_YIELDED ||
5180             mddev->curr_resync == MD_RESYNC_DELAYED)
5181                 return sprintf(page, "delayed\n");
5182
5183         if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ||
5184             test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
5185                 max_sectors = mddev->resync_max_sectors;
5186         else
5187                 max_sectors = mddev->dev_sectors;
5188
5189         resync = mddev->curr_resync_completed;
5190         return sprintf(page, "%llu / %llu\n", resync, max_sectors);
5191 }
5192
5193 static struct md_sysfs_entry md_sync_completed =
5194         __ATTR_PREALLOC(sync_completed, S_IRUGO, sync_completed_show, NULL);
5195
5196 static ssize_t
5197 min_sync_show(struct mddev *mddev, char *page)
5198 {
5199         return sprintf(page, "%llu\n",
5200                        (unsigned long long)mddev->resync_min);
5201 }
5202 static ssize_t
5203 min_sync_store(struct mddev *mddev, const char *buf, size_t len)
5204 {
5205         unsigned long long min;
5206         int err;
5207
5208         if (kstrtoull(buf, 10, &min))
5209                 return -EINVAL;
5210
5211         spin_lock(&mddev->lock);
5212         err = -EINVAL;
5213         if (min > mddev->resync_max)
5214                 goto out_unlock;
5215
5216         err = -EBUSY;
5217         if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
5218                 goto out_unlock;
5219
5220         /* Round down to multiple of 4K for safety */
5221         mddev->resync_min = round_down(min, 8);
5222         err = 0;
5223
5224 out_unlock:
5225         spin_unlock(&mddev->lock);
5226         return err ?: len;
5227 }
5228
5229 static struct md_sysfs_entry md_min_sync =
5230 __ATTR(sync_min, S_IRUGO|S_IWUSR, min_sync_show, min_sync_store);
5231
5232 static ssize_t
5233 max_sync_show(struct mddev *mddev, char *page)
5234 {
5235         if (mddev->resync_max == MaxSector)
5236                 return sprintf(page, "max\n");
5237         else
5238                 return sprintf(page, "%llu\n",
5239                                (unsigned long long)mddev->resync_max);
5240 }
5241 static ssize_t
5242 max_sync_store(struct mddev *mddev, const char *buf, size_t len)
5243 {
5244         int err;
5245         spin_lock(&mddev->lock);
5246         if (strncmp(buf, "max", 3) == 0)
5247                 mddev->resync_max = MaxSector;
5248         else {
5249                 unsigned long long max;
5250                 int chunk;
5251
5252                 err = -EINVAL;
5253                 if (kstrtoull(buf, 10, &max))
5254                         goto out_unlock;
5255                 if (max < mddev->resync_min)
5256                         goto out_unlock;
5257
5258                 err = -EBUSY;
5259                 if (max < mddev->resync_max && md_is_rdwr(mddev) &&
5260                     test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
5261                         goto out_unlock;
5262
5263                 /* Must be a multiple of chunk_size */
5264                 chunk = mddev->chunk_sectors;
5265                 if (chunk) {
5266                         sector_t temp = max;
5267
5268                         err = -EINVAL;
5269                         if (sector_div(temp, chunk))
5270                                 goto out_unlock;
5271                 }
5272                 mddev->resync_max = max;
5273         }
5274         wake_up(&mddev->recovery_wait);
5275         err = 0;
5276 out_unlock:
5277         spin_unlock(&mddev->lock);
5278         return err ?: len;
5279 }
5280
5281 static struct md_sysfs_entry md_max_sync =
5282 __ATTR(sync_max, S_IRUGO|S_IWUSR, max_sync_show, max_sync_store);
5283
5284 static ssize_t
5285 suspend_lo_show(struct mddev *mddev, char *page)
5286 {
5287         return sprintf(page, "%llu\n",
5288                        (unsigned long long)READ_ONCE(mddev->suspend_lo));
5289 }
5290
5291 static ssize_t
5292 suspend_lo_store(struct mddev *mddev, const char *buf, size_t len)
5293 {
5294         unsigned long long new;
5295         int err;
5296
5297         err = kstrtoull(buf, 10, &new);
5298         if (err < 0)
5299                 return err;
5300         if (new != (sector_t)new)
5301                 return -EINVAL;
5302
5303         err = mddev_suspend(mddev, true);
5304         if (err)
5305                 return err;
5306
5307         WRITE_ONCE(mddev->suspend_lo, new);
5308         mddev_resume(mddev);
5309
5310         return len;
5311 }
5312 static struct md_sysfs_entry md_suspend_lo =
5313 __ATTR(suspend_lo, S_IRUGO|S_IWUSR, suspend_lo_show, suspend_lo_store);
5314
5315 static ssize_t
5316 suspend_hi_show(struct mddev *mddev, char *page)
5317 {
5318         return sprintf(page, "%llu\n",
5319                        (unsigned long long)READ_ONCE(mddev->suspend_hi));
5320 }
5321
5322 static ssize_t
5323 suspend_hi_store(struct mddev *mddev, const char *buf, size_t len)
5324 {
5325         unsigned long long new;
5326         int err;
5327
5328         err = kstrtoull(buf, 10, &new);
5329         if (err < 0)
5330                 return err;
5331         if (new != (sector_t)new)
5332                 return -EINVAL;
5333
5334         err = mddev_suspend(mddev, true);
5335         if (err)
5336                 return err;
5337
5338         WRITE_ONCE(mddev->suspend_hi, new);
5339         mddev_resume(mddev);
5340
5341         return len;
5342 }
5343 static struct md_sysfs_entry md_suspend_hi =
5344 __ATTR(suspend_hi, S_IRUGO|S_IWUSR, suspend_hi_show, suspend_hi_store);
5345
5346 static ssize_t
5347 reshape_position_show(struct mddev *mddev, char *page)
5348 {
5349         if (mddev->reshape_position != MaxSector)
5350                 return sprintf(page, "%llu\n",
5351                                (unsigned long long)mddev->reshape_position);
5352         strcpy(page, "none\n");
5353         return 5;
5354 }
5355
5356 static ssize_t
5357 reshape_position_store(struct mddev *mddev, const char *buf, size_t len)
5358 {
5359         struct md_rdev *rdev;
5360         unsigned long long new;
5361         int err;
5362
5363         err = kstrtoull(buf, 10, &new);
5364         if (err < 0)
5365                 return err;
5366         if (new != (sector_t)new)
5367                 return -EINVAL;
5368         err = mddev_lock(mddev);
5369         if (err)
5370                 return err;
5371         err = -EBUSY;
5372         if (mddev->pers)
5373                 goto unlock;
5374         mddev->reshape_position = new;
5375         mddev->delta_disks = 0;
5376         mddev->reshape_backwards = 0;
5377         mddev->new_level = mddev->level;
5378         mddev->new_layout = mddev->layout;
5379         mddev->new_chunk_sectors = mddev->chunk_sectors;
5380         rdev_for_each(rdev, mddev)
5381                 rdev->new_data_offset = rdev->data_offset;
5382         err = 0;
5383 unlock:
5384         mddev_unlock(mddev);
5385         return err ?: len;
5386 }
5387
5388 static struct md_sysfs_entry md_reshape_position =
5389 __ATTR(reshape_position, S_IRUGO|S_IWUSR, reshape_position_show,
5390        reshape_position_store);
5391
5392 static ssize_t
5393 reshape_direction_show(struct mddev *mddev, char *page)
5394 {
5395         return sprintf(page, "%s\n",
5396                        mddev->reshape_backwards ? "backwards" : "forwards");
5397 }
5398
5399 static ssize_t
5400 reshape_direction_store(struct mddev *mddev, const char *buf, size_t len)
5401 {
5402         int backwards = 0;
5403         int err;
5404
5405         if (cmd_match(buf, "forwards"))
5406                 backwards = 0;
5407         else if (cmd_match(buf, "backwards"))
5408                 backwards = 1;
5409         else
5410                 return -EINVAL;
5411         if (mddev->reshape_backwards == backwards)
5412                 return len;
5413
5414         err = mddev_lock(mddev);
5415         if (err)
5416                 return err;
5417         /* check if we are allowed to change */
5418         if (mddev->delta_disks)
5419                 err = -EBUSY;
5420         else if (mddev->persistent &&
5421             mddev->major_version == 0)
5422                 err =  -EINVAL;
5423         else
5424                 mddev->reshape_backwards = backwards;
5425         mddev_unlock(mddev);
5426         return err ?: len;
5427 }
5428
5429 static struct md_sysfs_entry md_reshape_direction =
5430 __ATTR(reshape_direction, S_IRUGO|S_IWUSR, reshape_direction_show,
5431        reshape_direction_store);
5432
5433 static ssize_t
5434 array_size_show(struct mddev *mddev, char *page)
5435 {
5436         if (mddev->external_size)
5437                 return sprintf(page, "%llu\n",
5438                                (unsigned long long)mddev->array_sectors/2);
5439         else
5440                 return sprintf(page, "default\n");
5441 }
5442
5443 static ssize_t
5444 array_size_store(struct mddev *mddev, const char *buf, size_t len)
5445 {
5446         sector_t sectors;
5447         int err;
5448
5449         err = mddev_lock(mddev);
5450         if (err)
5451                 return err;
5452
5453         /* cluster raid doesn't support change array_sectors */
5454         if (mddev_is_clustered(mddev)) {
5455                 mddev_unlock(mddev);
5456                 return -EINVAL;
5457         }
5458
5459         if (strncmp(buf, "default", 7) == 0) {
5460                 if (mddev->pers)
5461                         sectors = mddev->pers->size(mddev, 0, 0);
5462                 else
5463                         sectors = mddev->array_sectors;
5464
5465                 mddev->external_size = 0;
5466         } else {
5467                 if (strict_blocks_to_sectors(buf, &sectors) < 0)
5468                         err = -EINVAL;
5469                 else if (mddev->pers && mddev->pers->size(mddev, 0, 0) < sectors)
5470                         err = -E2BIG;
5471                 else
5472                         mddev->external_size = 1;
5473         }
5474
5475         if (!err) {
5476                 mddev->array_sectors = sectors;
5477                 if (mddev->pers)
5478                         set_capacity_and_notify(mddev->gendisk,
5479                                                 mddev->array_sectors);
5480         }
5481         mddev_unlock(mddev);
5482         return err ?: len;
5483 }
5484
5485 static struct md_sysfs_entry md_array_size =
5486 __ATTR(array_size, S_IRUGO|S_IWUSR, array_size_show,
5487        array_size_store);
5488
5489 static ssize_t
5490 consistency_policy_show(struct mddev *mddev, char *page)
5491 {
5492         int ret;
5493
5494         if (test_bit(MD_HAS_JOURNAL, &mddev->flags)) {
5495                 ret = sprintf(page, "journal\n");
5496         } else if (test_bit(MD_HAS_PPL, &mddev->flags)) {
5497                 ret = sprintf(page, "ppl\n");
5498         } else if (mddev->bitmap) {
5499                 ret = sprintf(page, "bitmap\n");
5500         } else if (mddev->pers) {
5501                 if (mddev->pers->sync_request)
5502                         ret = sprintf(page, "resync\n");
5503                 else
5504                         ret = sprintf(page, "none\n");
5505         } else {
5506                 ret = sprintf(page, "unknown\n");
5507         }
5508
5509         return ret;
5510 }
5511
5512 static ssize_t
5513 consistency_policy_store(struct mddev *mddev, const char *buf, size_t len)
5514 {
5515         int err = 0;
5516
5517         if (mddev->pers) {
5518                 if (mddev->pers->change_consistency_policy)
5519                         err = mddev->pers->change_consistency_policy(mddev, buf);
5520                 else
5521                         err = -EBUSY;
5522         } else if (mddev->external && strncmp(buf, "ppl", 3) == 0) {
5523                 set_bit(MD_HAS_PPL, &mddev->flags);
5524         } else {
5525                 err = -EINVAL;
5526         }
5527
5528         return err ? err : len;
5529 }
5530
5531 static struct md_sysfs_entry md_consistency_policy =
5532 __ATTR(consistency_policy, S_IRUGO | S_IWUSR, consistency_policy_show,
5533        consistency_policy_store);
5534
5535 static ssize_t fail_last_dev_show(struct mddev *mddev, char *page)
5536 {
5537         return sprintf(page, "%d\n", mddev->fail_last_dev);
5538 }
5539
5540 /*
5541  * Setting fail_last_dev to true to allow last device to be forcibly removed
5542  * from RAID1/RAID10.
5543  */
5544 static ssize_t
5545 fail_last_dev_store(struct mddev *mddev, const char *buf, size_t len)
5546 {
5547         int ret;
5548         bool value;
5549
5550         ret = kstrtobool(buf, &value);
5551         if (ret)
5552                 return ret;
5553
5554         if (value != mddev->fail_last_dev)
5555                 mddev->fail_last_dev = value;
5556
5557         return len;
5558 }
5559 static struct md_sysfs_entry md_fail_last_dev =
5560 __ATTR(fail_last_dev, S_IRUGO | S_IWUSR, fail_last_dev_show,
5561        fail_last_dev_store);
5562
5563 static ssize_t serialize_policy_show(struct mddev *mddev, char *page)
5564 {
5565         if (mddev->pers == NULL || (mddev->pers->level != 1))
5566                 return sprintf(page, "n/a\n");
5567         else
5568                 return sprintf(page, "%d\n", mddev->serialize_policy);
5569 }
5570
5571 /*
5572  * Setting serialize_policy to true to enforce write IO is not reordered
5573  * for raid1.
5574  */
5575 static ssize_t
5576 serialize_policy_store(struct mddev *mddev, const char *buf, size_t len)
5577 {
5578         int err;
5579         bool value;
5580
5581         err = kstrtobool(buf, &value);
5582         if (err)
5583                 return err;
5584
5585         if (value == mddev->serialize_policy)
5586                 return len;
5587
5588         err = mddev_suspend_and_lock(mddev);
5589         if (err)
5590                 return err;
5591         if (mddev->pers == NULL || (mddev->pers->level != 1)) {
5592                 pr_err("md: serialize_policy is only effective for raid1\n");
5593                 err = -EINVAL;
5594                 goto unlock;
5595         }
5596
5597         if (value)
5598                 mddev_create_serial_pool(mddev, NULL);
5599         else
5600                 mddev_destroy_serial_pool(mddev, NULL);
5601         mddev->serialize_policy = value;
5602 unlock:
5603         mddev_unlock_and_resume(mddev);
5604         return err ?: len;
5605 }
5606
5607 static struct md_sysfs_entry md_serialize_policy =
5608 __ATTR(serialize_policy, S_IRUGO | S_IWUSR, serialize_policy_show,
5609        serialize_policy_store);
5610
5611
5612 static struct attribute *md_default_attrs[] = {
5613         &md_level.attr,
5614         &md_new_level.attr,
5615         &md_layout.attr,
5616         &md_raid_disks.attr,
5617         &md_uuid.attr,
5618         &md_chunk_size.attr,
5619         &md_size.attr,
5620         &md_resync_start.attr,
5621         &md_metadata.attr,
5622         &md_new_device.attr,
5623         &md_safe_delay.attr,
5624         &md_array_state.attr,
5625         &md_reshape_position.attr,
5626         &md_reshape_direction.attr,
5627         &md_array_size.attr,
5628         &max_corr_read_errors.attr,
5629         &md_consistency_policy.attr,
5630         &md_fail_last_dev.attr,
5631         &md_serialize_policy.attr,
5632         NULL,
5633 };
5634
5635 static const struct attribute_group md_default_group = {
5636         .attrs = md_default_attrs,
5637 };
5638
5639 static struct attribute *md_redundancy_attrs[] = {
5640         &md_scan_mode.attr,
5641         &md_last_scan_mode.attr,
5642         &md_mismatches.attr,
5643         &md_sync_min.attr,
5644         &md_sync_max.attr,
5645         &md_sync_speed.attr,
5646         &md_sync_force_parallel.attr,
5647         &md_sync_completed.attr,
5648         &md_min_sync.attr,
5649         &md_max_sync.attr,
5650         &md_suspend_lo.attr,
5651         &md_suspend_hi.attr,
5652         &md_bitmap.attr,
5653         &md_degraded.attr,
5654         NULL,
5655 };
5656 static const struct attribute_group md_redundancy_group = {
5657         .name = NULL,
5658         .attrs = md_redundancy_attrs,
5659 };
5660
5661 static const struct attribute_group *md_attr_groups[] = {
5662         &md_default_group,
5663         &md_bitmap_group,
5664         NULL,
5665 };
5666
5667 static ssize_t
5668 md_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
5669 {
5670         struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
5671         struct mddev *mddev = container_of(kobj, struct mddev, kobj);
5672         ssize_t rv;
5673
5674         if (!entry->show)
5675                 return -EIO;
5676         spin_lock(&all_mddevs_lock);
5677         if (!mddev_get(mddev)) {
5678                 spin_unlock(&all_mddevs_lock);
5679                 return -EBUSY;
5680         }
5681         spin_unlock(&all_mddevs_lock);
5682
5683         rv = entry->show(mddev, page);
5684         mddev_put(mddev);
5685         return rv;
5686 }
5687
5688 static ssize_t
5689 md_attr_store(struct kobject *kobj, struct attribute *attr,
5690               const char *page, size_t length)
5691 {
5692         struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
5693         struct mddev *mddev = container_of(kobj, struct mddev, kobj);
5694         ssize_t rv;
5695
5696         if (!entry->store)
5697                 return -EIO;
5698         if (!capable(CAP_SYS_ADMIN))
5699                 return -EACCES;
5700         spin_lock(&all_mddevs_lock);
5701         if (!mddev_get(mddev)) {
5702                 spin_unlock(&all_mddevs_lock);
5703                 return -EBUSY;
5704         }
5705         spin_unlock(&all_mddevs_lock);
5706         rv = entry->store(mddev, page, length);
5707         mddev_put(mddev);
5708         return rv;
5709 }
5710
5711 static void md_kobj_release(struct kobject *ko)
5712 {
5713         struct mddev *mddev = container_of(ko, struct mddev, kobj);
5714
5715         if (mddev->sysfs_state)
5716                 sysfs_put(mddev->sysfs_state);
5717         if (mddev->sysfs_level)
5718                 sysfs_put(mddev->sysfs_level);
5719
5720         del_gendisk(mddev->gendisk);
5721         put_disk(mddev->gendisk);
5722 }
5723
5724 static const struct sysfs_ops md_sysfs_ops = {
5725         .show   = md_attr_show,
5726         .store  = md_attr_store,
5727 };
5728 static const struct kobj_type md_ktype = {
5729         .release        = md_kobj_release,
5730         .sysfs_ops      = &md_sysfs_ops,
5731         .default_groups = md_attr_groups,
5732 };
5733
5734 int mdp_major = 0;
5735
5736 /* stack the limit for all rdevs into lim */
5737 int mddev_stack_rdev_limits(struct mddev *mddev, struct queue_limits *lim,
5738                 unsigned int flags)
5739 {
5740         struct md_rdev *rdev;
5741
5742         rdev_for_each(rdev, mddev) {
5743                 queue_limits_stack_bdev(lim, rdev->bdev, rdev->data_offset,
5744                                         mddev->gendisk->disk_name);
5745                 if ((flags & MDDEV_STACK_INTEGRITY) &&
5746                     !queue_limits_stack_integrity_bdev(lim, rdev->bdev))
5747                         return -EINVAL;
5748         }
5749
5750         return 0;
5751 }
5752 EXPORT_SYMBOL_GPL(mddev_stack_rdev_limits);
5753
5754 /* apply the extra stacking limits from a new rdev into mddev */
5755 int mddev_stack_new_rdev(struct mddev *mddev, struct md_rdev *rdev)
5756 {
5757         struct queue_limits lim;
5758
5759         if (mddev_is_dm(mddev))
5760                 return 0;
5761
5762         lim = queue_limits_start_update(mddev->gendisk->queue);
5763         queue_limits_stack_bdev(&lim, rdev->bdev, rdev->data_offset,
5764                                 mddev->gendisk->disk_name);
5765
5766         if (!queue_limits_stack_integrity_bdev(&lim, rdev->bdev)) {
5767                 pr_err("%s: incompatible integrity profile for %pg\n",
5768                        mdname(mddev), rdev->bdev);
5769                 queue_limits_cancel_update(mddev->gendisk->queue);
5770                 return -ENXIO;
5771         }
5772
5773         return queue_limits_commit_update(mddev->gendisk->queue, &lim);
5774 }
5775 EXPORT_SYMBOL_GPL(mddev_stack_new_rdev);
5776
5777 /* update the optimal I/O size after a reshape */
5778 void mddev_update_io_opt(struct mddev *mddev, unsigned int nr_stripes)
5779 {
5780         struct queue_limits lim;
5781
5782         if (mddev_is_dm(mddev))
5783                 return;
5784
5785         /* don't bother updating io_opt if we can't suspend the array */
5786         if (mddev_suspend(mddev, false) < 0)
5787                 return;
5788         lim = queue_limits_start_update(mddev->gendisk->queue);
5789         lim.io_opt = lim.io_min * nr_stripes;
5790         queue_limits_commit_update(mddev->gendisk->queue, &lim);
5791         mddev_resume(mddev);
5792 }
5793 EXPORT_SYMBOL_GPL(mddev_update_io_opt);
5794
5795 static void mddev_delayed_delete(struct work_struct *ws)
5796 {
5797         struct mddev *mddev = container_of(ws, struct mddev, del_work);
5798
5799         kobject_put(&mddev->kobj);
5800 }
5801
5802 void md_init_stacking_limits(struct queue_limits *lim)
5803 {
5804         blk_set_stacking_limits(lim);
5805         lim->features = BLK_FEAT_WRITE_CACHE | BLK_FEAT_FUA |
5806                         BLK_FEAT_IO_STAT | BLK_FEAT_NOWAIT;
5807 }
5808 EXPORT_SYMBOL_GPL(md_init_stacking_limits);
5809
5810 struct mddev *md_alloc(dev_t dev, char *name)
5811 {
5812         /*
5813          * If dev is zero, name is the name of a device to allocate with
5814          * an arbitrary minor number.  It will be "md_???"
5815          * If dev is non-zero it must be a device number with a MAJOR of
5816          * MD_MAJOR or mdp_major.  In this case, if "name" is NULL, then
5817          * the device is being created by opening a node in /dev.
5818          * If "name" is not NULL, the device is being created by
5819          * writing to /sys/module/md_mod/parameters/new_array.
5820          */
5821         static DEFINE_MUTEX(disks_mutex);
5822         struct mddev *mddev;
5823         struct gendisk *disk;
5824         int partitioned;
5825         int shift;
5826         int unit;
5827         int error;
5828
5829         /*
5830          * Wait for any previous instance of this device to be completely
5831          * removed (mddev_delayed_delete).
5832          */
5833         flush_workqueue(md_misc_wq);
5834
5835         mutex_lock(&disks_mutex);
5836         mddev = mddev_alloc(dev);
5837         if (IS_ERR(mddev)) {
5838                 error = PTR_ERR(mddev);
5839                 goto out_unlock;
5840         }
5841
5842         partitioned = (MAJOR(mddev->unit) != MD_MAJOR);
5843         shift = partitioned ? MdpMinorShift : 0;
5844         unit = MINOR(mddev->unit) >> shift;
5845
5846         if (name && !dev) {
5847                 /* Need to ensure that 'name' is not a duplicate.
5848                  */
5849                 struct mddev *mddev2;
5850                 spin_lock(&all_mddevs_lock);
5851
5852                 list_for_each_entry(mddev2, &all_mddevs, all_mddevs)
5853                         if (mddev2->gendisk &&
5854                             strcmp(mddev2->gendisk->disk_name, name) == 0) {
5855                                 spin_unlock(&all_mddevs_lock);
5856                                 error = -EEXIST;
5857                                 goto out_free_mddev;
5858                         }
5859                 spin_unlock(&all_mddevs_lock);
5860         }
5861         if (name && dev)
5862                 /*
5863                  * Creating /dev/mdNNN via "newarray", so adjust hold_active.
5864                  */
5865                 mddev->hold_active = UNTIL_STOP;
5866
5867         disk = blk_alloc_disk(NULL, NUMA_NO_NODE);
5868         if (IS_ERR(disk)) {
5869                 error = PTR_ERR(disk);
5870                 goto out_free_mddev;
5871         }
5872
5873         disk->major = MAJOR(mddev->unit);
5874         disk->first_minor = unit << shift;
5875         disk->minors = 1 << shift;
5876         if (name)
5877                 strcpy(disk->disk_name, name);
5878         else if (partitioned)
5879                 sprintf(disk->disk_name, "md_d%d", unit);
5880         else
5881                 sprintf(disk->disk_name, "md%d", unit);
5882         disk->fops = &md_fops;
5883         disk->private_data = mddev;
5884
5885         disk->events |= DISK_EVENT_MEDIA_CHANGE;
5886         mddev->gendisk = disk;
5887         error = add_disk(disk);
5888         if (error)
5889                 goto out_put_disk;
5890
5891         kobject_init(&mddev->kobj, &md_ktype);
5892         error = kobject_add(&mddev->kobj, &disk_to_dev(disk)->kobj, "%s", "md");
5893         if (error) {
5894                 /*
5895                  * The disk is already live at this point.  Clear the hold flag
5896                  * and let mddev_put take care of the deletion, as it isn't any
5897                  * different from a normal close on last release now.
5898                  */
5899                 mddev->hold_active = 0;
5900                 mutex_unlock(&disks_mutex);
5901                 mddev_put(mddev);
5902                 return ERR_PTR(error);
5903         }
5904
5905         kobject_uevent(&mddev->kobj, KOBJ_ADD);
5906         mddev->sysfs_state = sysfs_get_dirent_safe(mddev->kobj.sd, "array_state");
5907         mddev->sysfs_level = sysfs_get_dirent_safe(mddev->kobj.sd, "level");
5908         mutex_unlock(&disks_mutex);
5909         return mddev;
5910
5911 out_put_disk:
5912         put_disk(disk);
5913 out_free_mddev:
5914         mddev_free(mddev);
5915 out_unlock:
5916         mutex_unlock(&disks_mutex);
5917         return ERR_PTR(error);
5918 }
5919
5920 static int md_alloc_and_put(dev_t dev, char *name)
5921 {
5922         struct mddev *mddev = md_alloc(dev, name);
5923
5924         if (IS_ERR(mddev))
5925                 return PTR_ERR(mddev);
5926         mddev_put(mddev);
5927         return 0;
5928 }
5929
5930 static void md_probe(dev_t dev)
5931 {
5932         if (MAJOR(dev) == MD_MAJOR && MINOR(dev) >= 512)
5933                 return;
5934         if (create_on_open)
5935                 md_alloc_and_put(dev, NULL);
5936 }
5937
5938 static int add_named_array(const char *val, const struct kernel_param *kp)
5939 {
5940         /*
5941          * val must be "md_*" or "mdNNN".
5942          * For "md_*" we allocate an array with a large free minor number, and
5943          * set the name to val.  val must not already be an active name.
5944          * For "mdNNN" we allocate an array with the minor number NNN
5945          * which must not already be in use.
5946          */
5947         int len = strlen(val);
5948         char buf[DISK_NAME_LEN];
5949         unsigned long devnum;
5950
5951         while (len && val[len-1] == '\n')
5952                 len--;
5953         if (len >= DISK_NAME_LEN)
5954                 return -E2BIG;
5955         strscpy(buf, val, len+1);
5956         if (strncmp(buf, "md_", 3) == 0)
5957                 return md_alloc_and_put(0, buf);
5958         if (strncmp(buf, "md", 2) == 0 &&
5959             isdigit(buf[2]) &&
5960             kstrtoul(buf+2, 10, &devnum) == 0 &&
5961             devnum <= MINORMASK)
5962                 return md_alloc_and_put(MKDEV(MD_MAJOR, devnum), NULL);
5963
5964         return -EINVAL;
5965 }
5966
5967 static void md_safemode_timeout(struct timer_list *t)
5968 {
5969         struct mddev *mddev = from_timer(mddev, t, safemode_timer);
5970
5971         mddev->safemode = 1;
5972         if (mddev->external)
5973                 sysfs_notify_dirent_safe(mddev->sysfs_state);
5974
5975         md_wakeup_thread(mddev->thread);
5976 }
5977
5978 static int start_dirty_degraded;
5979
5980 int md_run(struct mddev *mddev)
5981 {
5982         int err;
5983         struct md_rdev *rdev;
5984         struct md_personality *pers;
5985         bool nowait = true;
5986
5987         if (list_empty(&mddev->disks))
5988                 /* cannot run an array with no devices.. */
5989                 return -EINVAL;
5990
5991         if (mddev->pers)
5992                 return -EBUSY;
5993         /* Cannot run until previous stop completes properly */
5994         if (mddev->sysfs_active)
5995                 return -EBUSY;
5996
5997         /*
5998          * Analyze all RAID superblock(s)
5999          */
6000         if (!mddev->raid_disks) {
6001                 if (!mddev->persistent)
6002                         return -EINVAL;
6003                 err = analyze_sbs(mddev);
6004                 if (err)
6005                         return -EINVAL;
6006         }
6007
6008         if (mddev->level != LEVEL_NONE)
6009                 request_module("md-level-%d", mddev->level);
6010         else if (mddev->clevel[0])
6011                 request_module("md-%s", mddev->clevel);
6012
6013         /*
6014          * Drop all container device buffers, from now on
6015          * the only valid external interface is through the md
6016          * device.
6017          */
6018         mddev->has_superblocks = false;
6019         rdev_for_each(rdev, mddev) {
6020                 if (test_bit(Faulty, &rdev->flags))
6021                         continue;
6022                 sync_blockdev(rdev->bdev);
6023                 invalidate_bdev(rdev->bdev);
6024                 if (mddev->ro != MD_RDONLY && rdev_read_only(rdev)) {
6025                         mddev->ro = MD_RDONLY;
6026                         if (!mddev_is_dm(mddev))
6027                                 set_disk_ro(mddev->gendisk, 1);
6028                 }
6029
6030                 if (rdev->sb_page)
6031                         mddev->has_superblocks = true;
6032
6033                 /* perform some consistency tests on the device.
6034                  * We don't want the data to overlap the metadata,
6035                  * Internal Bitmap issues have been handled elsewhere.
6036                  */
6037                 if (rdev->meta_bdev) {
6038                         /* Nothing to check */;
6039                 } else if (rdev->data_offset < rdev->sb_start) {
6040                         if (mddev->dev_sectors &&
6041                             rdev->data_offset + mddev->dev_sectors
6042                             > rdev->sb_start) {
6043                                 pr_warn("md: %s: data overlaps metadata\n",
6044                                         mdname(mddev));
6045                                 return -EINVAL;
6046                         }
6047                 } else {
6048                         if (rdev->sb_start + rdev->sb_size/512
6049                             > rdev->data_offset) {
6050                                 pr_warn("md: %s: metadata overlaps data\n",
6051                                         mdname(mddev));
6052                                 return -EINVAL;
6053                         }
6054                 }
6055                 sysfs_notify_dirent_safe(rdev->sysfs_state);
6056                 nowait = nowait && bdev_nowait(rdev->bdev);
6057         }
6058
6059         if (!bioset_initialized(&mddev->bio_set)) {
6060                 err = bioset_init(&mddev->bio_set, BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS);
6061                 if (err)
6062                         return err;
6063         }
6064         if (!bioset_initialized(&mddev->sync_set)) {
6065                 err = bioset_init(&mddev->sync_set, BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS);
6066                 if (err)
6067                         goto exit_bio_set;
6068         }
6069
6070         if (!bioset_initialized(&mddev->io_clone_set)) {
6071                 err = bioset_init(&mddev->io_clone_set, BIO_POOL_SIZE,
6072                                   offsetof(struct md_io_clone, bio_clone), 0);
6073                 if (err)
6074                         goto exit_sync_set;
6075         }
6076
6077         spin_lock(&pers_lock);
6078         pers = find_pers(mddev->level, mddev->clevel);
6079         if (!pers || !try_module_get(pers->owner)) {
6080                 spin_unlock(&pers_lock);
6081                 if (mddev->level != LEVEL_NONE)
6082                         pr_warn("md: personality for level %d is not loaded!\n",
6083                                 mddev->level);
6084                 else
6085                         pr_warn("md: personality for level %s is not loaded!\n",
6086                                 mddev->clevel);
6087                 err = -EINVAL;
6088                 goto abort;
6089         }
6090         spin_unlock(&pers_lock);
6091         if (mddev->level != pers->level) {
6092                 mddev->level = pers->level;
6093                 mddev->new_level = pers->level;
6094         }
6095         strscpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
6096
6097         if (mddev->reshape_position != MaxSector &&
6098             pers->start_reshape == NULL) {
6099                 /* This personality cannot handle reshaping... */
6100                 module_put(pers->owner);
6101                 err = -EINVAL;
6102                 goto abort;
6103         }
6104
6105         if (pers->sync_request) {
6106                 /* Warn if this is a potentially silly
6107                  * configuration.
6108                  */
6109                 struct md_rdev *rdev2;
6110                 int warned = 0;
6111
6112                 rdev_for_each(rdev, mddev)
6113                         rdev_for_each(rdev2, mddev) {
6114                                 if (rdev < rdev2 &&
6115                                     rdev->bdev->bd_disk ==
6116                                     rdev2->bdev->bd_disk) {
6117                                         pr_warn("%s: WARNING: %pg appears to be on the same physical disk as %pg.\n",
6118                                                 mdname(mddev),
6119                                                 rdev->bdev,
6120                                                 rdev2->bdev);
6121                                         warned = 1;
6122                                 }
6123                         }
6124
6125                 if (warned)
6126                         pr_warn("True protection against single-disk failure might be compromised.\n");
6127         }
6128
6129         /* dm-raid expect sync_thread to be frozen until resume */
6130         if (mddev->gendisk)
6131                 mddev->recovery = 0;
6132
6133         /* may be over-ridden by personality */
6134         mddev->resync_max_sectors = mddev->dev_sectors;
6135
6136         mddev->ok_start_degraded = start_dirty_degraded;
6137
6138         if (start_readonly && md_is_rdwr(mddev))
6139                 mddev->ro = MD_AUTO_READ; /* read-only, but switch on first write */
6140
6141         err = pers->run(mddev);
6142         if (err)
6143                 pr_warn("md: pers->run() failed ...\n");
6144         else if (pers->size(mddev, 0, 0) < mddev->array_sectors) {
6145                 WARN_ONCE(!mddev->external_size,
6146                           "%s: default size too small, but 'external_size' not in effect?\n",
6147                           __func__);
6148                 pr_warn("md: invalid array_size %llu > default size %llu\n",
6149                         (unsigned long long)mddev->array_sectors / 2,
6150                         (unsigned long long)pers->size(mddev, 0, 0) / 2);
6151                 err = -EINVAL;
6152         }
6153         if (err == 0 && pers->sync_request &&
6154             (mddev->bitmap_info.file || mddev->bitmap_info.offset)) {
6155                 err = mddev->bitmap_ops->create(mddev, -1);
6156                 if (err)
6157                         pr_warn("%s: failed to create bitmap (%d)\n",
6158                                 mdname(mddev), err);
6159         }
6160         if (err)
6161                 goto bitmap_abort;
6162
6163         if (mddev->bitmap_info.max_write_behind > 0) {
6164                 bool create_pool = false;
6165
6166                 rdev_for_each(rdev, mddev) {
6167                         if (test_bit(WriteMostly, &rdev->flags) &&
6168                             rdev_init_serial(rdev))
6169                                 create_pool = true;
6170                 }
6171                 if (create_pool && mddev->serial_info_pool == NULL) {
6172                         mddev->serial_info_pool =
6173                                 mempool_create_kmalloc_pool(NR_SERIAL_INFOS,
6174                                                     sizeof(struct serial_info));
6175                         if (!mddev->serial_info_pool) {
6176                                 err = -ENOMEM;
6177                                 goto bitmap_abort;
6178                         }
6179                 }
6180         }
6181
6182         if (pers->sync_request) {
6183                 if (mddev->kobj.sd &&
6184                     sysfs_create_group(&mddev->kobj, &md_redundancy_group))
6185                         pr_warn("md: cannot register extra attributes for %s\n",
6186                                 mdname(mddev));
6187                 mddev->sysfs_action = sysfs_get_dirent_safe(mddev->kobj.sd, "sync_action");
6188                 mddev->sysfs_completed = sysfs_get_dirent_safe(mddev->kobj.sd, "sync_completed");
6189                 mddev->sysfs_degraded = sysfs_get_dirent_safe(mddev->kobj.sd, "degraded");
6190         } else if (mddev->ro == MD_AUTO_READ)
6191                 mddev->ro = MD_RDWR;
6192
6193         atomic_set(&mddev->max_corr_read_errors,
6194                    MD_DEFAULT_MAX_CORRECTED_READ_ERRORS);
6195         mddev->safemode = 0;
6196         if (mddev_is_clustered(mddev))
6197                 mddev->safemode_delay = 0;
6198         else
6199                 mddev->safemode_delay = DEFAULT_SAFEMODE_DELAY;
6200         mddev->in_sync = 1;
6201         smp_wmb();
6202         spin_lock(&mddev->lock);
6203         mddev->pers = pers;
6204         spin_unlock(&mddev->lock);
6205         rdev_for_each(rdev, mddev)
6206                 if (rdev->raid_disk >= 0)
6207                         sysfs_link_rdev(mddev, rdev); /* failure here is OK */
6208
6209         if (mddev->degraded && md_is_rdwr(mddev))
6210                 /* This ensures that recovering status is reported immediately
6211                  * via sysfs - until a lack of spares is confirmed.
6212                  */
6213                 set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
6214         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6215
6216         if (mddev->sb_flags)
6217                 md_update_sb(mddev, 0);
6218
6219         md_new_event();
6220         return 0;
6221
6222 bitmap_abort:
6223         mddev_detach(mddev);
6224         if (mddev->private)
6225                 pers->free(mddev, mddev->private);
6226         mddev->private = NULL;
6227         module_put(pers->owner);
6228         mddev->bitmap_ops->destroy(mddev);
6229 abort:
6230         bioset_exit(&mddev->io_clone_set);
6231 exit_sync_set:
6232         bioset_exit(&mddev->sync_set);
6233 exit_bio_set:
6234         bioset_exit(&mddev->bio_set);
6235         return err;
6236 }
6237 EXPORT_SYMBOL_GPL(md_run);
6238
6239 int do_md_run(struct mddev *mddev)
6240 {
6241         int err;
6242
6243         set_bit(MD_NOT_READY, &mddev->flags);
6244         err = md_run(mddev);
6245         if (err)
6246                 goto out;
6247
6248         err = mddev->bitmap_ops->load(mddev);
6249         if (err) {
6250                 mddev->bitmap_ops->destroy(mddev);
6251                 goto out;
6252         }
6253
6254         if (mddev_is_clustered(mddev))
6255                 md_allow_write(mddev);
6256
6257         /* run start up tasks that require md_thread */
6258         md_start(mddev);
6259
6260         md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
6261
6262         set_capacity_and_notify(mddev->gendisk, mddev->array_sectors);
6263         clear_bit(MD_NOT_READY, &mddev->flags);
6264         mddev->changed = 1;
6265         kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
6266         sysfs_notify_dirent_safe(mddev->sysfs_state);
6267         sysfs_notify_dirent_safe(mddev->sysfs_action);
6268         sysfs_notify_dirent_safe(mddev->sysfs_degraded);
6269 out:
6270         clear_bit(MD_NOT_READY, &mddev->flags);
6271         return err;
6272 }
6273
6274 int md_start(struct mddev *mddev)
6275 {
6276         int ret = 0;
6277
6278         if (mddev->pers->start) {
6279                 set_bit(MD_RECOVERY_WAIT, &mddev->recovery);
6280                 ret = mddev->pers->start(mddev);
6281                 clear_bit(MD_RECOVERY_WAIT, &mddev->recovery);
6282                 md_wakeup_thread(mddev->sync_thread);
6283         }
6284         return ret;
6285 }
6286 EXPORT_SYMBOL_GPL(md_start);
6287
6288 static int restart_array(struct mddev *mddev)
6289 {
6290         struct gendisk *disk = mddev->gendisk;
6291         struct md_rdev *rdev;
6292         bool has_journal = false;
6293         bool has_readonly = false;
6294
6295         /* Complain if it has no devices */
6296         if (list_empty(&mddev->disks))
6297                 return -ENXIO;
6298         if (!mddev->pers)
6299                 return -EINVAL;
6300         if (md_is_rdwr(mddev))
6301                 return -EBUSY;
6302
6303         rcu_read_lock();
6304         rdev_for_each_rcu(rdev, mddev) {
6305                 if (test_bit(Journal, &rdev->flags) &&
6306                     !test_bit(Faulty, &rdev->flags))
6307                         has_journal = true;
6308                 if (rdev_read_only(rdev))
6309                         has_readonly = true;
6310         }
6311         rcu_read_unlock();
6312         if (test_bit(MD_HAS_JOURNAL, &mddev->flags) && !has_journal)
6313                 /* Don't restart rw with journal missing/faulty */
6314                         return -EINVAL;
6315         if (has_readonly)
6316                 return -EROFS;
6317
6318         mddev->safemode = 0;
6319         mddev->ro = MD_RDWR;
6320         set_disk_ro(disk, 0);
6321         pr_debug("md: %s switched to read-write mode.\n", mdname(mddev));
6322         /* Kick recovery or resync if necessary */
6323         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6324         md_wakeup_thread(mddev->sync_thread);
6325         sysfs_notify_dirent_safe(mddev->sysfs_state);
6326         return 0;
6327 }
6328
6329 static void md_clean(struct mddev *mddev)
6330 {
6331         mddev->array_sectors = 0;
6332         mddev->external_size = 0;
6333         mddev->dev_sectors = 0;
6334         mddev->raid_disks = 0;
6335         mddev->recovery_cp = 0;
6336         mddev->resync_min = 0;
6337         mddev->resync_max = MaxSector;
6338         mddev->reshape_position = MaxSector;
6339         /* we still need mddev->external in export_rdev, do not clear it yet */
6340         mddev->persistent = 0;
6341         mddev->level = LEVEL_NONE;
6342         mddev->clevel[0] = 0;
6343         /*
6344          * Don't clear MD_CLOSING, or mddev can be opened again.
6345          * 'hold_active != 0' means mddev is still in the creation
6346          * process and will be used later.
6347          */
6348         if (mddev->hold_active)
6349                 mddev->flags = 0;
6350         else
6351                 mddev->flags &= BIT_ULL_MASK(MD_CLOSING);
6352         mddev->sb_flags = 0;
6353         mddev->ro = MD_RDWR;
6354         mddev->metadata_type[0] = 0;
6355         mddev->chunk_sectors = 0;
6356         mddev->ctime = mddev->utime = 0;
6357         mddev->layout = 0;
6358         mddev->max_disks = 0;
6359         mddev->events = 0;
6360         mddev->can_decrease_events = 0;
6361         mddev->delta_disks = 0;
6362         mddev->reshape_backwards = 0;
6363         mddev->new_level = LEVEL_NONE;
6364         mddev->new_layout = 0;
6365         mddev->new_chunk_sectors = 0;
6366         mddev->curr_resync = MD_RESYNC_NONE;
6367         atomic64_set(&mddev->resync_mismatches, 0);
6368         mddev->suspend_lo = mddev->suspend_hi = 0;
6369         mddev->sync_speed_min = mddev->sync_speed_max = 0;
6370         mddev->recovery = 0;
6371         mddev->in_sync = 0;
6372         mddev->changed = 0;
6373         mddev->degraded = 0;
6374         mddev->safemode = 0;
6375         mddev->private = NULL;
6376         mddev->cluster_info = NULL;
6377         mddev->bitmap_info.offset = 0;
6378         mddev->bitmap_info.default_offset = 0;
6379         mddev->bitmap_info.default_space = 0;
6380         mddev->bitmap_info.chunksize = 0;
6381         mddev->bitmap_info.daemon_sleep = 0;
6382         mddev->bitmap_info.max_write_behind = 0;
6383         mddev->bitmap_info.nodes = 0;
6384 }
6385
6386 static void __md_stop_writes(struct mddev *mddev)
6387 {
6388         del_timer_sync(&mddev->safemode_timer);
6389
6390         if (mddev->pers && mddev->pers->quiesce) {
6391                 mddev->pers->quiesce(mddev, 1);
6392                 mddev->pers->quiesce(mddev, 0);
6393         }
6394
6395         mddev->bitmap_ops->flush(mddev);
6396
6397         if (md_is_rdwr(mddev) &&
6398             ((!mddev->in_sync && !mddev_is_clustered(mddev)) ||
6399              mddev->sb_flags)) {
6400                 /* mark array as shutdown cleanly */
6401                 if (!mddev_is_clustered(mddev))
6402                         mddev->in_sync = 1;
6403                 md_update_sb(mddev, 1);
6404         }
6405         /* disable policy to guarantee rdevs free resources for serialization */
6406         mddev->serialize_policy = 0;
6407         mddev_destroy_serial_pool(mddev, NULL);
6408 }
6409
6410 void md_stop_writes(struct mddev *mddev)
6411 {
6412         mddev_lock_nointr(mddev);
6413         set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
6414         stop_sync_thread(mddev, true);
6415         __md_stop_writes(mddev);
6416         mddev_unlock(mddev);
6417 }
6418 EXPORT_SYMBOL_GPL(md_stop_writes);
6419
6420 static void mddev_detach(struct mddev *mddev)
6421 {
6422         mddev->bitmap_ops->wait_behind_writes(mddev);
6423         if (mddev->pers && mddev->pers->quiesce && !is_md_suspended(mddev)) {
6424                 mddev->pers->quiesce(mddev, 1);
6425                 mddev->pers->quiesce(mddev, 0);
6426         }
6427         md_unregister_thread(mddev, &mddev->thread);
6428
6429         /* the unplug fn references 'conf' */
6430         if (!mddev_is_dm(mddev))
6431                 blk_sync_queue(mddev->gendisk->queue);
6432 }
6433
6434 static void __md_stop(struct mddev *mddev)
6435 {
6436         struct md_personality *pers = mddev->pers;
6437
6438         mddev->bitmap_ops->destroy(mddev);
6439         mddev_detach(mddev);
6440         spin_lock(&mddev->lock);
6441         mddev->pers = NULL;
6442         spin_unlock(&mddev->lock);
6443         if (mddev->private)
6444                 pers->free(mddev, mddev->private);
6445         mddev->private = NULL;
6446         if (pers->sync_request && mddev->to_remove == NULL)
6447                 mddev->to_remove = &md_redundancy_group;
6448         module_put(pers->owner);
6449         clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
6450
6451         bioset_exit(&mddev->bio_set);
6452         bioset_exit(&mddev->sync_set);
6453         bioset_exit(&mddev->io_clone_set);
6454 }
6455
6456 void md_stop(struct mddev *mddev)
6457 {
6458         lockdep_assert_held(&mddev->reconfig_mutex);
6459
6460         /* stop the array and free an attached data structures.
6461          * This is called from dm-raid
6462          */
6463         __md_stop_writes(mddev);
6464         __md_stop(mddev);
6465 }
6466
6467 EXPORT_SYMBOL_GPL(md_stop);
6468
6469 /* ensure 'mddev->pers' exist before calling md_set_readonly() */
6470 static int md_set_readonly(struct mddev *mddev)
6471 {
6472         int err = 0;
6473         int did_freeze = 0;
6474
6475         if (mddev->external && test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags))
6476                 return -EBUSY;
6477
6478         if (!test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)) {
6479                 did_freeze = 1;
6480                 set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
6481         }
6482
6483         stop_sync_thread(mddev, false);
6484         wait_event(mddev->sb_wait,
6485                    !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags));
6486         mddev_lock_nointr(mddev);
6487
6488         if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) {
6489                 pr_warn("md: %s still in use.\n",mdname(mddev));
6490                 err = -EBUSY;
6491                 goto out;
6492         }
6493
6494         __md_stop_writes(mddev);
6495
6496         if (mddev->ro == MD_RDONLY) {
6497                 err  = -ENXIO;
6498                 goto out;
6499         }
6500
6501         mddev->ro = MD_RDONLY;
6502         set_disk_ro(mddev->gendisk, 1);
6503
6504 out:
6505         if (!err || did_freeze) {
6506                 clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
6507                 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6508                 sysfs_notify_dirent_safe(mddev->sysfs_state);
6509         }
6510
6511         return err;
6512 }
6513
6514 /* mode:
6515  *   0 - completely stop and dis-assemble array
6516  *   2 - stop but do not disassemble array
6517  */
6518 static int do_md_stop(struct mddev *mddev, int mode)
6519 {
6520         struct gendisk *disk = mddev->gendisk;
6521         struct md_rdev *rdev;
6522         int did_freeze = 0;
6523
6524         if (!test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)) {
6525                 did_freeze = 1;
6526                 set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
6527         }
6528
6529         stop_sync_thread(mddev, true);
6530
6531         if (mddev->sysfs_active ||
6532             test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) {
6533                 pr_warn("md: %s still in use.\n",mdname(mddev));
6534                 if (did_freeze) {
6535                         clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
6536                         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6537                 }
6538                 return -EBUSY;
6539         }
6540         if (mddev->pers) {
6541                 if (!md_is_rdwr(mddev))
6542                         set_disk_ro(disk, 0);
6543
6544                 __md_stop_writes(mddev);
6545                 __md_stop(mddev);
6546
6547                 /* tell userspace to handle 'inactive' */
6548                 sysfs_notify_dirent_safe(mddev->sysfs_state);
6549
6550                 rdev_for_each(rdev, mddev)
6551                         if (rdev->raid_disk >= 0)
6552                                 sysfs_unlink_rdev(mddev, rdev);
6553
6554                 set_capacity_and_notify(disk, 0);
6555                 mddev->changed = 1;
6556
6557                 if (!md_is_rdwr(mddev))
6558                         mddev->ro = MD_RDWR;
6559         }
6560         /*
6561          * Free resources if final stop
6562          */
6563         if (mode == 0) {
6564                 pr_info("md: %s stopped.\n", mdname(mddev));
6565
6566                 if (mddev->bitmap_info.file) {
6567                         struct file *f = mddev->bitmap_info.file;
6568                         spin_lock(&mddev->lock);
6569                         mddev->bitmap_info.file = NULL;
6570                         spin_unlock(&mddev->lock);
6571                         fput(f);
6572                 }
6573                 mddev->bitmap_info.offset = 0;
6574
6575                 export_array(mddev);
6576
6577                 md_clean(mddev);
6578                 if (mddev->hold_active == UNTIL_STOP)
6579                         mddev->hold_active = 0;
6580         }
6581         md_new_event();
6582         sysfs_notify_dirent_safe(mddev->sysfs_state);
6583         return 0;
6584 }
6585
6586 #ifndef MODULE
6587 static void autorun_array(struct mddev *mddev)
6588 {
6589         struct md_rdev *rdev;
6590         int err;
6591
6592         if (list_empty(&mddev->disks))
6593                 return;
6594
6595         pr_info("md: running: ");
6596
6597         rdev_for_each(rdev, mddev) {
6598                 pr_cont("<%pg>", rdev->bdev);
6599         }
6600         pr_cont("\n");
6601
6602         err = do_md_run(mddev);
6603         if (err) {
6604                 pr_warn("md: do_md_run() returned %d\n", err);
6605                 do_md_stop(mddev, 0);
6606         }
6607 }
6608
6609 /*
6610  * lets try to run arrays based on all disks that have arrived
6611  * until now. (those are in pending_raid_disks)
6612  *
6613  * the method: pick the first pending disk, collect all disks with
6614  * the same UUID, remove all from the pending list and put them into
6615  * the 'same_array' list. Then order this list based on superblock
6616  * update time (freshest comes first), kick out 'old' disks and
6617  * compare superblocks. If everything's fine then run it.
6618  *
6619  * If "unit" is allocated, then bump its reference count
6620  */
6621 static void autorun_devices(int part)
6622 {
6623         struct md_rdev *rdev0, *rdev, *tmp;
6624         struct mddev *mddev;
6625
6626         pr_info("md: autorun ...\n");
6627         while (!list_empty(&pending_raid_disks)) {
6628                 int unit;
6629                 dev_t dev;
6630                 LIST_HEAD(candidates);
6631                 rdev0 = list_entry(pending_raid_disks.next,
6632                                          struct md_rdev, same_set);
6633
6634                 pr_debug("md: considering %pg ...\n", rdev0->bdev);
6635                 INIT_LIST_HEAD(&candidates);
6636                 rdev_for_each_list(rdev, tmp, &pending_raid_disks)
6637                         if (super_90_load(rdev, rdev0, 0) >= 0) {
6638                                 pr_debug("md:  adding %pg ...\n",
6639                                          rdev->bdev);
6640                                 list_move(&rdev->same_set, &candidates);
6641                         }
6642                 /*
6643                  * now we have a set of devices, with all of them having
6644                  * mostly sane superblocks. It's time to allocate the
6645                  * mddev.
6646                  */
6647                 if (part) {
6648                         dev = MKDEV(mdp_major,
6649                                     rdev0->preferred_minor << MdpMinorShift);
6650                         unit = MINOR(dev) >> MdpMinorShift;
6651                 } else {
6652                         dev = MKDEV(MD_MAJOR, rdev0->preferred_minor);
6653                         unit = MINOR(dev);
6654                 }
6655                 if (rdev0->preferred_minor != unit) {
6656                         pr_warn("md: unit number in %pg is bad: %d\n",
6657                                 rdev0->bdev, rdev0->preferred_minor);
6658                         break;
6659                 }
6660
6661                 mddev = md_alloc(dev, NULL);
6662                 if (IS_ERR(mddev))
6663                         break;
6664
6665                 if (mddev_suspend_and_lock(mddev))
6666                         pr_warn("md: %s locked, cannot run\n", mdname(mddev));
6667                 else if (mddev->raid_disks || mddev->major_version
6668                          || !list_empty(&mddev->disks)) {
6669                         pr_warn("md: %s already running, cannot run %pg\n",
6670                                 mdname(mddev), rdev0->bdev);
6671                         mddev_unlock_and_resume(mddev);
6672                 } else {
6673                         pr_debug("md: created %s\n", mdname(mddev));
6674                         mddev->persistent = 1;
6675                         rdev_for_each_list(rdev, tmp, &candidates) {
6676                                 list_del_init(&rdev->same_set);
6677                                 if (bind_rdev_to_array(rdev, mddev))
6678                                         export_rdev(rdev, mddev);
6679                         }
6680                         autorun_array(mddev);
6681                         mddev_unlock_and_resume(mddev);
6682                 }
6683                 /* on success, candidates will be empty, on error
6684                  * it won't...
6685                  */
6686                 rdev_for_each_list(rdev, tmp, &candidates) {
6687                         list_del_init(&rdev->same_set);
6688                         export_rdev(rdev, mddev);
6689                 }
6690                 mddev_put(mddev);
6691         }
6692         pr_info("md: ... autorun DONE.\n");
6693 }
6694 #endif /* !MODULE */
6695
6696 static int get_version(void __user *arg)
6697 {
6698         mdu_version_t ver;
6699
6700         ver.major = MD_MAJOR_VERSION;
6701         ver.minor = MD_MINOR_VERSION;
6702         ver.patchlevel = MD_PATCHLEVEL_VERSION;
6703
6704         if (copy_to_user(arg, &ver, sizeof(ver)))
6705                 return -EFAULT;
6706
6707         return 0;
6708 }
6709
6710 static int get_array_info(struct mddev *mddev, void __user *arg)
6711 {
6712         mdu_array_info_t info;
6713         int nr,working,insync,failed,spare;
6714         struct md_rdev *rdev;
6715
6716         nr = working = insync = failed = spare = 0;
6717         rcu_read_lock();
6718         rdev_for_each_rcu(rdev, mddev) {
6719                 nr++;
6720                 if (test_bit(Faulty, &rdev->flags))
6721                         failed++;
6722                 else {
6723                         working++;
6724                         if (test_bit(In_sync, &rdev->flags))
6725                                 insync++;
6726                         else if (test_bit(Journal, &rdev->flags))
6727                                 /* TODO: add journal count to md_u.h */
6728                                 ;
6729                         else
6730                                 spare++;
6731                 }
6732         }
6733         rcu_read_unlock();
6734
6735         info.major_version = mddev->major_version;
6736         info.minor_version = mddev->minor_version;
6737         info.patch_version = MD_PATCHLEVEL_VERSION;
6738         info.ctime         = clamp_t(time64_t, mddev->ctime, 0, U32_MAX);
6739         info.level         = mddev->level;
6740         info.size          = mddev->dev_sectors / 2;
6741         if (info.size != mddev->dev_sectors / 2) /* overflow */
6742                 info.size = -1;
6743         info.nr_disks      = nr;
6744         info.raid_disks    = mddev->raid_disks;
6745         info.md_minor      = mddev->md_minor;
6746         info.not_persistent= !mddev->persistent;
6747
6748         info.utime         = clamp_t(time64_t, mddev->utime, 0, U32_MAX);
6749         info.state         = 0;
6750         if (mddev->in_sync)
6751                 info.state = (1<<MD_SB_CLEAN);
6752         if (mddev->bitmap && mddev->bitmap_info.offset)
6753                 info.state |= (1<<MD_SB_BITMAP_PRESENT);
6754         if (mddev_is_clustered(mddev))
6755                 info.state |= (1<<MD_SB_CLUSTERED);
6756         info.active_disks  = insync;
6757         info.working_disks = working;
6758         info.failed_disks  = failed;
6759         info.spare_disks   = spare;
6760
6761         info.layout        = mddev->layout;
6762         info.chunk_size    = mddev->chunk_sectors << 9;
6763
6764         if (copy_to_user(arg, &info, sizeof(info)))
6765                 return -EFAULT;
6766
6767         return 0;
6768 }
6769
6770 static int get_bitmap_file(struct mddev *mddev, void __user * arg)
6771 {
6772         mdu_bitmap_file_t *file = NULL; /* too big for stack allocation */
6773         char *ptr;
6774         int err;
6775
6776         file = kzalloc(sizeof(*file), GFP_NOIO);
6777         if (!file)
6778                 return -ENOMEM;
6779
6780         err = 0;
6781         spin_lock(&mddev->lock);
6782         /* bitmap enabled */
6783         if (mddev->bitmap_info.file) {
6784                 ptr = file_path(mddev->bitmap_info.file, file->pathname,
6785                                 sizeof(file->pathname));
6786                 if (IS_ERR(ptr))
6787                         err = PTR_ERR(ptr);
6788                 else
6789                         memmove(file->pathname, ptr,
6790                                 sizeof(file->pathname)-(ptr-file->pathname));
6791         }
6792         spin_unlock(&mddev->lock);
6793
6794         if (err == 0 &&
6795             copy_to_user(arg, file, sizeof(*file)))
6796                 err = -EFAULT;
6797
6798         kfree(file);
6799         return err;
6800 }
6801
6802 static int get_disk_info(struct mddev *mddev, void __user * arg)
6803 {
6804         mdu_disk_info_t info;
6805         struct md_rdev *rdev;
6806
6807         if (copy_from_user(&info, arg, sizeof(info)))
6808                 return -EFAULT;
6809
6810         rcu_read_lock();
6811         rdev = md_find_rdev_nr_rcu(mddev, info.number);
6812         if (rdev) {
6813                 info.major = MAJOR(rdev->bdev->bd_dev);
6814                 info.minor = MINOR(rdev->bdev->bd_dev);
6815                 info.raid_disk = rdev->raid_disk;
6816                 info.state = 0;
6817                 if (test_bit(Faulty, &rdev->flags))
6818                         info.state |= (1<<MD_DISK_FAULTY);
6819                 else if (test_bit(In_sync, &rdev->flags)) {
6820                         info.state |= (1<<MD_DISK_ACTIVE);
6821                         info.state |= (1<<MD_DISK_SYNC);
6822                 }
6823                 if (test_bit(Journal, &rdev->flags))
6824                         info.state |= (1<<MD_DISK_JOURNAL);
6825                 if (test_bit(WriteMostly, &rdev->flags))
6826                         info.state |= (1<<MD_DISK_WRITEMOSTLY);
6827                 if (test_bit(FailFast, &rdev->flags))
6828                         info.state |= (1<<MD_DISK_FAILFAST);
6829         } else {
6830                 info.major = info.minor = 0;
6831                 info.raid_disk = -1;
6832                 info.state = (1<<MD_DISK_REMOVED);
6833         }
6834         rcu_read_unlock();
6835
6836         if (copy_to_user(arg, &info, sizeof(info)))
6837                 return -EFAULT;
6838
6839         return 0;
6840 }
6841
6842 int md_add_new_disk(struct mddev *mddev, struct mdu_disk_info_s *info)
6843 {
6844         struct md_rdev *rdev;
6845         dev_t dev = MKDEV(info->major,info->minor);
6846
6847         if (mddev_is_clustered(mddev) &&
6848                 !(info->state & ((1 << MD_DISK_CLUSTER_ADD) | (1 << MD_DISK_CANDIDATE)))) {
6849                 pr_warn("%s: Cannot add to clustered mddev.\n",
6850                         mdname(mddev));
6851                 return -EINVAL;
6852         }
6853
6854         if (info->major != MAJOR(dev) || info->minor != MINOR(dev))
6855                 return -EOVERFLOW;
6856
6857         if (!mddev->raid_disks) {
6858                 int err;
6859                 /* expecting a device which has a superblock */
6860                 rdev = md_import_device(dev, mddev->major_version, mddev->minor_version);
6861                 if (IS_ERR(rdev)) {
6862                         pr_warn("md: md_import_device returned %ld\n",
6863                                 PTR_ERR(rdev));
6864                         return PTR_ERR(rdev);
6865                 }
6866                 if (!list_empty(&mddev->disks)) {
6867                         struct md_rdev *rdev0
6868                                 = list_entry(mddev->disks.next,
6869                                              struct md_rdev, same_set);
6870                         err = super_types[mddev->major_version]
6871                                 .load_super(rdev, rdev0, mddev->minor_version);
6872                         if (err < 0) {
6873                                 pr_warn("md: %pg has different UUID to %pg\n",
6874                                         rdev->bdev,
6875                                         rdev0->bdev);
6876                                 export_rdev(rdev, mddev);
6877                                 return -EINVAL;
6878                         }
6879                 }
6880                 err = bind_rdev_to_array(rdev, mddev);
6881                 if (err)
6882                         export_rdev(rdev, mddev);
6883                 return err;
6884         }
6885
6886         /*
6887          * md_add_new_disk can be used once the array is assembled
6888          * to add "hot spares".  They must already have a superblock
6889          * written
6890          */
6891         if (mddev->pers) {
6892                 int err;
6893                 if (!mddev->pers->hot_add_disk) {
6894                         pr_warn("%s: personality does not support diskops!\n",
6895                                 mdname(mddev));
6896                         return -EINVAL;
6897                 }
6898                 if (mddev->persistent)
6899                         rdev = md_import_device(dev, mddev->major_version,
6900                                                 mddev->minor_version);
6901                 else
6902                         rdev = md_import_device(dev, -1, -1);
6903                 if (IS_ERR(rdev)) {
6904                         pr_warn("md: md_import_device returned %ld\n",
6905                                 PTR_ERR(rdev));
6906                         return PTR_ERR(rdev);
6907                 }
6908                 /* set saved_raid_disk if appropriate */
6909                 if (!mddev->persistent) {
6910                         if (info->state & (1<<MD_DISK_SYNC)  &&
6911                             info->raid_disk < mddev->raid_disks) {
6912                                 rdev->raid_disk = info->raid_disk;
6913                                 clear_bit(Bitmap_sync, &rdev->flags);
6914                         } else
6915                                 rdev->raid_disk = -1;
6916                         rdev->saved_raid_disk = rdev->raid_disk;
6917                 } else
6918                         super_types[mddev->major_version].
6919                                 validate_super(mddev, NULL/*freshest*/, rdev);
6920                 if ((info->state & (1<<MD_DISK_SYNC)) &&
6921                      rdev->raid_disk != info->raid_disk) {
6922                         /* This was a hot-add request, but events doesn't
6923                          * match, so reject it.
6924                          */
6925                         export_rdev(rdev, mddev);
6926                         return -EINVAL;
6927                 }
6928
6929                 clear_bit(In_sync, &rdev->flags); /* just to be sure */
6930                 if (info->state & (1<<MD_DISK_WRITEMOSTLY))
6931                         set_bit(WriteMostly, &rdev->flags);
6932                 else
6933                         clear_bit(WriteMostly, &rdev->flags);
6934                 if (info->state & (1<<MD_DISK_FAILFAST))
6935                         set_bit(FailFast, &rdev->flags);
6936                 else
6937                         clear_bit(FailFast, &rdev->flags);
6938
6939                 if (info->state & (1<<MD_DISK_JOURNAL)) {
6940                         struct md_rdev *rdev2;
6941                         bool has_journal = false;
6942
6943                         /* make sure no existing journal disk */
6944                         rdev_for_each(rdev2, mddev) {
6945                                 if (test_bit(Journal, &rdev2->flags)) {
6946                                         has_journal = true;
6947                                         break;
6948                                 }
6949                         }
6950                         if (has_journal || mddev->bitmap) {
6951                                 export_rdev(rdev, mddev);
6952                                 return -EBUSY;
6953                         }
6954                         set_bit(Journal, &rdev->flags);
6955                 }
6956                 /*
6957                  * check whether the device shows up in other nodes
6958                  */
6959                 if (mddev_is_clustered(mddev)) {
6960                         if (info->state & (1 << MD_DISK_CANDIDATE))
6961                                 set_bit(Candidate, &rdev->flags);
6962                         else if (info->state & (1 << MD_DISK_CLUSTER_ADD)) {
6963                                 /* --add initiated by this node */
6964                                 err = md_cluster_ops->add_new_disk(mddev, rdev);
6965                                 if (err) {
6966                                         export_rdev(rdev, mddev);
6967                                         return err;
6968                                 }
6969                         }
6970                 }
6971
6972                 rdev->raid_disk = -1;
6973                 err = bind_rdev_to_array(rdev, mddev);
6974
6975                 if (err)
6976                         export_rdev(rdev, mddev);
6977
6978                 if (mddev_is_clustered(mddev)) {
6979                         if (info->state & (1 << MD_DISK_CANDIDATE)) {
6980                                 if (!err) {
6981                                         err = md_cluster_ops->new_disk_ack(mddev,
6982                                                 err == 0);
6983                                         if (err)
6984                                                 md_kick_rdev_from_array(rdev);
6985                                 }
6986                         } else {
6987                                 if (err)
6988                                         md_cluster_ops->add_new_disk_cancel(mddev);
6989                                 else
6990                                         err = add_bound_rdev(rdev);
6991                         }
6992
6993                 } else if (!err)
6994                         err = add_bound_rdev(rdev);
6995
6996                 return err;
6997         }
6998
6999         /* otherwise, md_add_new_disk is only allowed
7000          * for major_version==0 superblocks
7001          */
7002         if (mddev->major_version != 0) {
7003                 pr_warn("%s: ADD_NEW_DISK not supported\n", mdname(mddev));
7004                 return -EINVAL;
7005         }
7006
7007         if (!(info->state & (1<<MD_DISK_FAULTY))) {
7008                 int err;
7009                 rdev = md_import_device(dev, -1, 0);
7010                 if (IS_ERR(rdev)) {
7011                         pr_warn("md: error, md_import_device() returned %ld\n",
7012                                 PTR_ERR(rdev));
7013                         return PTR_ERR(rdev);
7014                 }
7015                 rdev->desc_nr = info->number;
7016                 if (info->raid_disk < mddev->raid_disks)
7017                         rdev->raid_disk = info->raid_disk;
7018                 else
7019                         rdev->raid_disk = -1;
7020
7021                 if (rdev->raid_disk < mddev->raid_disks)
7022                         if (info->state & (1<<MD_DISK_SYNC))
7023                                 set_bit(In_sync, &rdev->flags);
7024
7025                 if (info->state & (1<<MD_DISK_WRITEMOSTLY))
7026                         set_bit(WriteMostly, &rdev->flags);
7027                 if (info->state & (1<<MD_DISK_FAILFAST))
7028                         set_bit(FailFast, &rdev->flags);
7029
7030                 if (!mddev->persistent) {
7031                         pr_debug("md: nonpersistent superblock ...\n");
7032                         rdev->sb_start = bdev_nr_sectors(rdev->bdev);
7033                 } else
7034                         rdev->sb_start = calc_dev_sboffset(rdev);
7035                 rdev->sectors = rdev->sb_start;
7036
7037                 err = bind_rdev_to_array(rdev, mddev);
7038                 if (err) {
7039                         export_rdev(rdev, mddev);
7040                         return err;
7041                 }
7042         }
7043
7044         return 0;
7045 }
7046
7047 static int hot_remove_disk(struct mddev *mddev, dev_t dev)
7048 {
7049         struct md_rdev *rdev;
7050
7051         if (!mddev->pers)
7052                 return -ENODEV;
7053
7054         rdev = find_rdev(mddev, dev);
7055         if (!rdev)
7056                 return -ENXIO;
7057
7058         if (rdev->raid_disk < 0)
7059                 goto kick_rdev;
7060
7061         clear_bit(Blocked, &rdev->flags);
7062         remove_and_add_spares(mddev, rdev);
7063
7064         if (rdev->raid_disk >= 0)
7065                 goto busy;
7066
7067 kick_rdev:
7068         if (mddev_is_clustered(mddev)) {
7069                 if (md_cluster_ops->remove_disk(mddev, rdev))
7070                         goto busy;
7071         }
7072
7073         md_kick_rdev_from_array(rdev);
7074         set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
7075         if (!mddev->thread)
7076                 md_update_sb(mddev, 1);
7077         md_new_event();
7078
7079         return 0;
7080 busy:
7081         pr_debug("md: cannot remove active disk %pg from %s ...\n",
7082                  rdev->bdev, mdname(mddev));
7083         return -EBUSY;
7084 }
7085
7086 static int hot_add_disk(struct mddev *mddev, dev_t dev)
7087 {
7088         int err;
7089         struct md_rdev *rdev;
7090
7091         if (!mddev->pers)
7092                 return -ENODEV;
7093
7094         if (mddev->major_version != 0) {
7095                 pr_warn("%s: HOT_ADD may only be used with version-0 superblocks.\n",
7096                         mdname(mddev));
7097                 return -EINVAL;
7098         }
7099         if (!mddev->pers->hot_add_disk) {
7100                 pr_warn("%s: personality does not support diskops!\n",
7101                         mdname(mddev));
7102                 return -EINVAL;
7103         }
7104
7105         rdev = md_import_device(dev, -1, 0);
7106         if (IS_ERR(rdev)) {
7107                 pr_warn("md: error, md_import_device() returned %ld\n",
7108                         PTR_ERR(rdev));
7109                 return -EINVAL;
7110         }
7111
7112         if (mddev->persistent)
7113                 rdev->sb_start = calc_dev_sboffset(rdev);
7114         else
7115                 rdev->sb_start = bdev_nr_sectors(rdev->bdev);
7116
7117         rdev->sectors = rdev->sb_start;
7118
7119         if (test_bit(Faulty, &rdev->flags)) {
7120                 pr_warn("md: can not hot-add faulty %pg disk to %s!\n",
7121                         rdev->bdev, mdname(mddev));
7122                 err = -EINVAL;
7123                 goto abort_export;
7124         }
7125
7126         clear_bit(In_sync, &rdev->flags);
7127         rdev->desc_nr = -1;
7128         rdev->saved_raid_disk = -1;
7129         err = bind_rdev_to_array(rdev, mddev);
7130         if (err)
7131                 goto abort_export;
7132
7133         /*
7134          * The rest should better be atomic, we can have disk failures
7135          * noticed in interrupt contexts ...
7136          */
7137
7138         rdev->raid_disk = -1;
7139
7140         set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
7141         if (!mddev->thread)
7142                 md_update_sb(mddev, 1);
7143         /*
7144          * Kick recovery, maybe this spare has to be added to the
7145          * array immediately.
7146          */
7147         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7148         md_new_event();
7149         return 0;
7150
7151 abort_export:
7152         export_rdev(rdev, mddev);
7153         return err;
7154 }
7155
7156 static int set_bitmap_file(struct mddev *mddev, int fd)
7157 {
7158         int err = 0;
7159
7160         if (mddev->pers) {
7161                 if (!mddev->pers->quiesce || !mddev->thread)
7162                         return -EBUSY;
7163                 if (mddev->recovery || mddev->sync_thread)
7164                         return -EBUSY;
7165                 /* we should be able to change the bitmap.. */
7166         }
7167
7168         if (fd >= 0) {
7169                 struct inode *inode;
7170                 struct file *f;
7171
7172                 if (mddev->bitmap || mddev->bitmap_info.file)
7173                         return -EEXIST; /* cannot add when bitmap is present */
7174
7175                 if (!IS_ENABLED(CONFIG_MD_BITMAP_FILE)) {
7176                         pr_warn("%s: bitmap files not supported by this kernel\n",
7177                                 mdname(mddev));
7178                         return -EINVAL;
7179                 }
7180                 pr_warn("%s: using deprecated bitmap file support\n",
7181                         mdname(mddev));
7182
7183                 f = fget(fd);
7184
7185                 if (f == NULL) {
7186                         pr_warn("%s: error: failed to get bitmap file\n",
7187                                 mdname(mddev));
7188                         return -EBADF;
7189                 }
7190
7191                 inode = f->f_mapping->host;
7192                 if (!S_ISREG(inode->i_mode)) {
7193                         pr_warn("%s: error: bitmap file must be a regular file\n",
7194                                 mdname(mddev));
7195                         err = -EBADF;
7196                 } else if (!(f->f_mode & FMODE_WRITE)) {
7197                         pr_warn("%s: error: bitmap file must open for write\n",
7198                                 mdname(mddev));
7199                         err = -EBADF;
7200                 } else if (atomic_read(&inode->i_writecount) != 1) {
7201                         pr_warn("%s: error: bitmap file is already in use\n",
7202                                 mdname(mddev));
7203                         err = -EBUSY;
7204                 }
7205                 if (err) {
7206                         fput(f);
7207                         return err;
7208                 }
7209                 mddev->bitmap_info.file = f;
7210                 mddev->bitmap_info.offset = 0; /* file overrides offset */
7211         } else if (mddev->bitmap == NULL)
7212                 return -ENOENT; /* cannot remove what isn't there */
7213         err = 0;
7214         if (mddev->pers) {
7215                 if (fd >= 0) {
7216                         err = mddev->bitmap_ops->create(mddev, -1);
7217                         if (!err)
7218                                 err = mddev->bitmap_ops->load(mddev);
7219
7220                         if (err) {
7221                                 mddev->bitmap_ops->destroy(mddev);
7222                                 fd = -1;
7223                         }
7224                 } else if (fd < 0) {
7225                         mddev->bitmap_ops->destroy(mddev);
7226                 }
7227         }
7228
7229         if (fd < 0) {
7230                 struct file *f = mddev->bitmap_info.file;
7231                 if (f) {
7232                         spin_lock(&mddev->lock);
7233                         mddev->bitmap_info.file = NULL;
7234                         spin_unlock(&mddev->lock);
7235                         fput(f);
7236                 }
7237         }
7238
7239         return err;
7240 }
7241
7242 /*
7243  * md_set_array_info is used two different ways
7244  * The original usage is when creating a new array.
7245  * In this usage, raid_disks is > 0 and it together with
7246  *  level, size, not_persistent,layout,chunksize determine the
7247  *  shape of the array.
7248  *  This will always create an array with a type-0.90.0 superblock.
7249  * The newer usage is when assembling an array.
7250  *  In this case raid_disks will be 0, and the major_version field is
7251  *  use to determine which style super-blocks are to be found on the devices.
7252  *  The minor and patch _version numbers are also kept incase the
7253  *  super_block handler wishes to interpret them.
7254  */
7255 int md_set_array_info(struct mddev *mddev, struct mdu_array_info_s *info)
7256 {
7257         if (info->raid_disks == 0) {
7258                 /* just setting version number for superblock loading */
7259                 if (info->major_version < 0 ||
7260                     info->major_version >= ARRAY_SIZE(super_types) ||
7261                     super_types[info->major_version].name == NULL) {
7262                         /* maybe try to auto-load a module? */
7263                         pr_warn("md: superblock version %d not known\n",
7264                                 info->major_version);
7265                         return -EINVAL;
7266                 }
7267                 mddev->major_version = info->major_version;
7268                 mddev->minor_version = info->minor_version;
7269                 mddev->patch_version = info->patch_version;
7270                 mddev->persistent = !info->not_persistent;
7271                 /* ensure mddev_put doesn't delete this now that there
7272                  * is some minimal configuration.
7273                  */
7274                 mddev->ctime         = ktime_get_real_seconds();
7275                 return 0;
7276         }
7277         mddev->major_version = MD_MAJOR_VERSION;
7278         mddev->minor_version = MD_MINOR_VERSION;
7279         mddev->patch_version = MD_PATCHLEVEL_VERSION;
7280         mddev->ctime         = ktime_get_real_seconds();
7281
7282         mddev->level         = info->level;
7283         mddev->clevel[0]     = 0;
7284         mddev->dev_sectors   = 2 * (sector_t)info->size;
7285         mddev->raid_disks    = info->raid_disks;
7286         /* don't set md_minor, it is determined by which /dev/md* was
7287          * openned
7288          */
7289         if (info->state & (1<<MD_SB_CLEAN))
7290                 mddev->recovery_cp = MaxSector;
7291         else
7292                 mddev->recovery_cp = 0;
7293         mddev->persistent    = ! info->not_persistent;
7294         mddev->external      = 0;
7295
7296         mddev->layout        = info->layout;
7297         if (mddev->level == 0)
7298                 /* Cannot trust RAID0 layout info here */
7299                 mddev->layout = -1;
7300         mddev->chunk_sectors = info->chunk_size >> 9;
7301
7302         if (mddev->persistent) {
7303                 mddev->max_disks = MD_SB_DISKS;
7304                 mddev->flags = 0;
7305                 mddev->sb_flags = 0;
7306         }
7307         set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
7308
7309         mddev->bitmap_info.default_offset = MD_SB_BYTES >> 9;
7310         mddev->bitmap_info.default_space = 64*2 - (MD_SB_BYTES >> 9);
7311         mddev->bitmap_info.offset = 0;
7312
7313         mddev->reshape_position = MaxSector;
7314
7315         /*
7316          * Generate a 128 bit UUID
7317          */
7318         get_random_bytes(mddev->uuid, 16);
7319
7320         mddev->new_level = mddev->level;
7321         mddev->new_chunk_sectors = mddev->chunk_sectors;
7322         mddev->new_layout = mddev->layout;
7323         mddev->delta_disks = 0;
7324         mddev->reshape_backwards = 0;
7325
7326         return 0;
7327 }
7328
7329 void md_set_array_sectors(struct mddev *mddev, sector_t array_sectors)
7330 {
7331         lockdep_assert_held(&mddev->reconfig_mutex);
7332
7333         if (mddev->external_size)
7334                 return;
7335
7336         mddev->array_sectors = array_sectors;
7337 }
7338 EXPORT_SYMBOL(md_set_array_sectors);
7339
7340 static int update_size(struct mddev *mddev, sector_t num_sectors)
7341 {
7342         struct md_rdev *rdev;
7343         int rv;
7344         int fit = (num_sectors == 0);
7345         sector_t old_dev_sectors = mddev->dev_sectors;
7346
7347         if (mddev->pers->resize == NULL)
7348                 return -EINVAL;
7349         /* The "num_sectors" is the number of sectors of each device that
7350          * is used.  This can only make sense for arrays with redundancy.
7351          * linear and raid0 always use whatever space is available. We can only
7352          * consider changing this number if no resync or reconstruction is
7353          * happening, and if the new size is acceptable. It must fit before the
7354          * sb_start or, if that is <data_offset, it must fit before the size
7355          * of each device.  If num_sectors is zero, we find the largest size
7356          * that fits.
7357          */
7358         if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
7359                 return -EBUSY;
7360         if (!md_is_rdwr(mddev))
7361                 return -EROFS;
7362
7363         rdev_for_each(rdev, mddev) {
7364                 sector_t avail = rdev->sectors;
7365
7366                 if (fit && (num_sectors == 0 || num_sectors > avail))
7367                         num_sectors = avail;
7368                 if (avail < num_sectors)
7369                         return -ENOSPC;
7370         }
7371         rv = mddev->pers->resize(mddev, num_sectors);
7372         if (!rv) {
7373                 if (mddev_is_clustered(mddev))
7374                         md_cluster_ops->update_size(mddev, old_dev_sectors);
7375                 else if (!mddev_is_dm(mddev))
7376                         set_capacity_and_notify(mddev->gendisk,
7377                                                 mddev->array_sectors);
7378         }
7379         return rv;
7380 }
7381
7382 static int update_raid_disks(struct mddev *mddev, int raid_disks)
7383 {
7384         int rv;
7385         struct md_rdev *rdev;
7386         /* change the number of raid disks */
7387         if (mddev->pers->check_reshape == NULL)
7388                 return -EINVAL;
7389         if (!md_is_rdwr(mddev))
7390                 return -EROFS;
7391         if (raid_disks <= 0 ||
7392             (mddev->max_disks && raid_disks >= mddev->max_disks))
7393                 return -EINVAL;
7394         if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
7395             test_bit(MD_RESYNCING_REMOTE, &mddev->recovery) ||
7396             mddev->reshape_position != MaxSector)
7397                 return -EBUSY;
7398
7399         rdev_for_each(rdev, mddev) {
7400                 if (mddev->raid_disks < raid_disks &&
7401                     rdev->data_offset < rdev->new_data_offset)
7402                         return -EINVAL;
7403                 if (mddev->raid_disks > raid_disks &&
7404                     rdev->data_offset > rdev->new_data_offset)
7405                         return -EINVAL;
7406         }
7407
7408         mddev->delta_disks = raid_disks - mddev->raid_disks;
7409         if (mddev->delta_disks < 0)
7410                 mddev->reshape_backwards = 1;
7411         else if (mddev->delta_disks > 0)
7412                 mddev->reshape_backwards = 0;
7413
7414         rv = mddev->pers->check_reshape(mddev);
7415         if (rv < 0) {
7416                 mddev->delta_disks = 0;
7417                 mddev->reshape_backwards = 0;
7418         }
7419         return rv;
7420 }
7421
7422 /*
7423  * update_array_info is used to change the configuration of an
7424  * on-line array.
7425  * The version, ctime,level,size,raid_disks,not_persistent, layout,chunk_size
7426  * fields in the info are checked against the array.
7427  * Any differences that cannot be handled will cause an error.
7428  * Normally, only one change can be managed at a time.
7429  */
7430 static int update_array_info(struct mddev *mddev, mdu_array_info_t *info)
7431 {
7432         int rv = 0;
7433         int cnt = 0;
7434         int state = 0;
7435
7436         /* calculate expected state,ignoring low bits */
7437         if (mddev->bitmap && mddev->bitmap_info.offset)
7438                 state |= (1 << MD_SB_BITMAP_PRESENT);
7439
7440         if (mddev->major_version != info->major_version ||
7441             mddev->minor_version != info->minor_version ||
7442 /*          mddev->patch_version != info->patch_version || */
7443             mddev->ctime         != info->ctime         ||
7444             mddev->level         != info->level         ||
7445 /*          mddev->layout        != info->layout        || */
7446             mddev->persistent    != !info->not_persistent ||
7447             mddev->chunk_sectors != info->chunk_size >> 9 ||
7448             /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT to change */
7449             ((state^info->state) & 0xfffffe00)
7450                 )
7451                 return -EINVAL;
7452         /* Check there is only one change */
7453         if (info->size >= 0 && mddev->dev_sectors / 2 != info->size)
7454                 cnt++;
7455         if (mddev->raid_disks != info->raid_disks)
7456                 cnt++;
7457         if (mddev->layout != info->layout)
7458                 cnt++;
7459         if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT))
7460                 cnt++;
7461         if (cnt == 0)
7462                 return 0;
7463         if (cnt > 1)
7464                 return -EINVAL;
7465
7466         if (mddev->layout != info->layout) {
7467                 /* Change layout
7468                  * we don't need to do anything at the md level, the
7469                  * personality will take care of it all.
7470                  */
7471                 if (mddev->pers->check_reshape == NULL)
7472                         return -EINVAL;
7473                 else {
7474                         mddev->new_layout = info->layout;
7475                         rv = mddev->pers->check_reshape(mddev);
7476                         if (rv)
7477                                 mddev->new_layout = mddev->layout;
7478                         return rv;
7479                 }
7480         }
7481         if (info->size >= 0 && mddev->dev_sectors / 2 != info->size)
7482                 rv = update_size(mddev, (sector_t)info->size * 2);
7483
7484         if (mddev->raid_disks    != info->raid_disks)
7485                 rv = update_raid_disks(mddev, info->raid_disks);
7486
7487         if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT)) {
7488                 if (mddev->pers->quiesce == NULL || mddev->thread == NULL) {
7489                         rv = -EINVAL;
7490                         goto err;
7491                 }
7492                 if (mddev->recovery || mddev->sync_thread) {
7493                         rv = -EBUSY;
7494                         goto err;
7495                 }
7496                 if (info->state & (1<<MD_SB_BITMAP_PRESENT)) {
7497                         /* add the bitmap */
7498                         if (mddev->bitmap) {
7499                                 rv = -EEXIST;
7500                                 goto err;
7501                         }
7502                         if (mddev->bitmap_info.default_offset == 0) {
7503                                 rv = -EINVAL;
7504                                 goto err;
7505                         }
7506                         mddev->bitmap_info.offset =
7507                                 mddev->bitmap_info.default_offset;
7508                         mddev->bitmap_info.space =
7509                                 mddev->bitmap_info.default_space;
7510                         rv = mddev->bitmap_ops->create(mddev, -1);
7511                         if (!rv)
7512                                 rv = mddev->bitmap_ops->load(mddev);
7513
7514                         if (rv)
7515                                 mddev->bitmap_ops->destroy(mddev);
7516                 } else {
7517                         struct md_bitmap_stats stats;
7518
7519                         rv = mddev->bitmap_ops->get_stats(mddev->bitmap, &stats);
7520                         if (rv)
7521                                 goto err;
7522
7523                         if (stats.file) {
7524                                 rv = -EINVAL;
7525                                 goto err;
7526                         }
7527
7528                         if (mddev->bitmap_info.nodes) {
7529                                 /* hold PW on all the bitmap lock */
7530                                 if (md_cluster_ops->lock_all_bitmaps(mddev) <= 0) {
7531                                         pr_warn("md: can't change bitmap to none since the array is in use by more than one node\n");
7532                                         rv = -EPERM;
7533                                         md_cluster_ops->unlock_all_bitmaps(mddev);
7534                                         goto err;
7535                                 }
7536
7537                                 mddev->bitmap_info.nodes = 0;
7538                                 md_cluster_ops->leave(mddev);
7539                                 module_put(md_cluster_mod);
7540                                 mddev->safemode_delay = DEFAULT_SAFEMODE_DELAY;
7541                         }
7542                         mddev->bitmap_ops->destroy(mddev);
7543                         mddev->bitmap_info.offset = 0;
7544                 }
7545         }
7546         md_update_sb(mddev, 1);
7547         return rv;
7548 err:
7549         return rv;
7550 }
7551
7552 static int set_disk_faulty(struct mddev *mddev, dev_t dev)
7553 {
7554         struct md_rdev *rdev;
7555         int err = 0;
7556
7557         if (mddev->pers == NULL)
7558                 return -ENODEV;
7559
7560         rcu_read_lock();
7561         rdev = md_find_rdev_rcu(mddev, dev);
7562         if (!rdev)
7563                 err =  -ENODEV;
7564         else {
7565                 md_error(mddev, rdev);
7566                 if (test_bit(MD_BROKEN, &mddev->flags))
7567                         err = -EBUSY;
7568         }
7569         rcu_read_unlock();
7570         return err;
7571 }
7572
7573 /*
7574  * We have a problem here : there is no easy way to give a CHS
7575  * virtual geometry. We currently pretend that we have a 2 heads
7576  * 4 sectors (with a BIG number of cylinders...). This drives
7577  * dosfs just mad... ;-)
7578  */
7579 static int md_getgeo(struct block_device *bdev, struct hd_geometry *geo)
7580 {
7581         struct mddev *mddev = bdev->bd_disk->private_data;
7582
7583         geo->heads = 2;
7584         geo->sectors = 4;
7585         geo->cylinders = mddev->array_sectors / 8;
7586         return 0;
7587 }
7588
7589 static inline int md_ioctl_valid(unsigned int cmd)
7590 {
7591         switch (cmd) {
7592         case GET_ARRAY_INFO:
7593         case GET_DISK_INFO:
7594         case RAID_VERSION:
7595                 return 0;
7596         case ADD_NEW_DISK:
7597         case GET_BITMAP_FILE:
7598         case HOT_ADD_DISK:
7599         case HOT_REMOVE_DISK:
7600         case RESTART_ARRAY_RW:
7601         case RUN_ARRAY:
7602         case SET_ARRAY_INFO:
7603         case SET_BITMAP_FILE:
7604         case SET_DISK_FAULTY:
7605         case STOP_ARRAY:
7606         case STOP_ARRAY_RO:
7607         case CLUSTERED_DISK_NACK:
7608                 if (!capable(CAP_SYS_ADMIN))
7609                         return -EACCES;
7610                 return 0;
7611         default:
7612                 return -ENOTTY;
7613         }
7614 }
7615
7616 static bool md_ioctl_need_suspend(unsigned int cmd)
7617 {
7618         switch (cmd) {
7619         case ADD_NEW_DISK:
7620         case HOT_ADD_DISK:
7621         case HOT_REMOVE_DISK:
7622         case SET_BITMAP_FILE:
7623         case SET_ARRAY_INFO:
7624                 return true;
7625         default:
7626                 return false;
7627         }
7628 }
7629
7630 static int __md_set_array_info(struct mddev *mddev, void __user *argp)
7631 {
7632         mdu_array_info_t info;
7633         int err;
7634
7635         if (!argp)
7636                 memset(&info, 0, sizeof(info));
7637         else if (copy_from_user(&info, argp, sizeof(info)))
7638                 return -EFAULT;
7639
7640         if (mddev->pers) {
7641                 err = update_array_info(mddev, &info);
7642                 if (err)
7643                         pr_warn("md: couldn't update array info. %d\n", err);
7644                 return err;
7645         }
7646
7647         if (!list_empty(&mddev->disks)) {
7648                 pr_warn("md: array %s already has disks!\n", mdname(mddev));
7649                 return -EBUSY;
7650         }
7651
7652         if (mddev->raid_disks) {
7653                 pr_warn("md: array %s already initialised!\n", mdname(mddev));
7654                 return -EBUSY;
7655         }
7656
7657         err = md_set_array_info(mddev, &info);
7658         if (err)
7659                 pr_warn("md: couldn't set array info. %d\n", err);
7660
7661         return err;
7662 }
7663
7664 static int md_ioctl(struct block_device *bdev, blk_mode_t mode,
7665                         unsigned int cmd, unsigned long arg)
7666 {
7667         int err = 0;
7668         void __user *argp = (void __user *)arg;
7669         struct mddev *mddev = NULL;
7670
7671         err = md_ioctl_valid(cmd);
7672         if (err)
7673                 return err;
7674
7675         /*
7676          * Commands dealing with the RAID driver but not any
7677          * particular array:
7678          */
7679         if (cmd == RAID_VERSION)
7680                 return get_version(argp);
7681
7682         /*
7683          * Commands creating/starting a new array:
7684          */
7685
7686         mddev = bdev->bd_disk->private_data;
7687
7688         /* Some actions do not requires the mutex */
7689         switch (cmd) {
7690         case GET_ARRAY_INFO:
7691                 if (!mddev->raid_disks && !mddev->external)
7692                         return -ENODEV;
7693                 return get_array_info(mddev, argp);
7694
7695         case GET_DISK_INFO:
7696                 if (!mddev->raid_disks && !mddev->external)
7697                         return -ENODEV;
7698                 return get_disk_info(mddev, argp);
7699
7700         case SET_DISK_FAULTY:
7701                 return set_disk_faulty(mddev, new_decode_dev(arg));
7702
7703         case GET_BITMAP_FILE:
7704                 return get_bitmap_file(mddev, argp);
7705         }
7706
7707         if (cmd == STOP_ARRAY || cmd == STOP_ARRAY_RO) {
7708                 /* Need to flush page cache, and ensure no-one else opens
7709                  * and writes
7710                  */
7711                 err = mddev_set_closing_and_sync_blockdev(mddev, 1);
7712                 if (err)
7713                         return err;
7714         }
7715
7716         if (!md_is_rdwr(mddev))
7717                 flush_work(&mddev->sync_work);
7718
7719         err = md_ioctl_need_suspend(cmd) ? mddev_suspend_and_lock(mddev) :
7720                                            mddev_lock(mddev);
7721         if (err) {
7722                 pr_debug("md: ioctl lock interrupted, reason %d, cmd %d\n",
7723                          err, cmd);
7724                 goto out;
7725         }
7726
7727         if (cmd == SET_ARRAY_INFO) {
7728                 err = __md_set_array_info(mddev, argp);
7729                 goto unlock;
7730         }
7731
7732         /*
7733          * Commands querying/configuring an existing array:
7734          */
7735         /* if we are not initialised yet, only ADD_NEW_DISK, STOP_ARRAY,
7736          * RUN_ARRAY, and GET_ and SET_BITMAP_FILE are allowed */
7737         if ((!mddev->raid_disks && !mddev->external)
7738             && cmd != ADD_NEW_DISK && cmd != STOP_ARRAY
7739             && cmd != RUN_ARRAY && cmd != SET_BITMAP_FILE
7740             && cmd != GET_BITMAP_FILE) {
7741                 err = -ENODEV;
7742                 goto unlock;
7743         }
7744
7745         /*
7746          * Commands even a read-only array can execute:
7747          */
7748         switch (cmd) {
7749         case RESTART_ARRAY_RW:
7750                 err = restart_array(mddev);
7751                 goto unlock;
7752
7753         case STOP_ARRAY:
7754                 err = do_md_stop(mddev, 0);
7755                 goto unlock;
7756
7757         case STOP_ARRAY_RO:
7758                 if (mddev->pers)
7759                         err = md_set_readonly(mddev);
7760                 goto unlock;
7761
7762         case HOT_REMOVE_DISK:
7763                 err = hot_remove_disk(mddev, new_decode_dev(arg));
7764                 goto unlock;
7765
7766         case ADD_NEW_DISK:
7767                 /* We can support ADD_NEW_DISK on read-only arrays
7768                  * only if we are re-adding a preexisting device.
7769                  * So require mddev->pers and MD_DISK_SYNC.
7770                  */
7771                 if (mddev->pers) {
7772                         mdu_disk_info_t info;
7773                         if (copy_from_user(&info, argp, sizeof(info)))
7774                                 err = -EFAULT;
7775                         else if (!(info.state & (1<<MD_DISK_SYNC)))
7776                                 /* Need to clear read-only for this */
7777                                 break;
7778                         else
7779                                 err = md_add_new_disk(mddev, &info);
7780                         goto unlock;
7781                 }
7782                 break;
7783         }
7784
7785         /*
7786          * The remaining ioctls are changing the state of the
7787          * superblock, so we do not allow them on read-only arrays.
7788          */
7789         if (!md_is_rdwr(mddev) && mddev->pers) {
7790                 if (mddev->ro != MD_AUTO_READ) {
7791                         err = -EROFS;
7792                         goto unlock;
7793                 }
7794                 mddev->ro = MD_RDWR;
7795                 sysfs_notify_dirent_safe(mddev->sysfs_state);
7796                 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7797                 /* mddev_unlock will wake thread */
7798                 /* If a device failed while we were read-only, we
7799                  * need to make sure the metadata is updated now.
7800                  */
7801                 if (test_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags)) {
7802                         mddev_unlock(mddev);
7803                         wait_event(mddev->sb_wait,
7804                                    !test_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags) &&
7805                                    !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags));
7806                         mddev_lock_nointr(mddev);
7807                 }
7808         }
7809
7810         switch (cmd) {
7811         case ADD_NEW_DISK:
7812         {
7813                 mdu_disk_info_t info;
7814                 if (copy_from_user(&info, argp, sizeof(info)))
7815                         err = -EFAULT;
7816                 else
7817                         err = md_add_new_disk(mddev, &info);
7818                 goto unlock;
7819         }
7820
7821         case CLUSTERED_DISK_NACK:
7822                 if (mddev_is_clustered(mddev))
7823                         md_cluster_ops->new_disk_ack(mddev, false);
7824                 else
7825                         err = -EINVAL;
7826                 goto unlock;
7827
7828         case HOT_ADD_DISK:
7829                 err = hot_add_disk(mddev, new_decode_dev(arg));
7830                 goto unlock;
7831
7832         case RUN_ARRAY:
7833                 err = do_md_run(mddev);
7834                 goto unlock;
7835
7836         case SET_BITMAP_FILE:
7837                 err = set_bitmap_file(mddev, (int)arg);
7838                 goto unlock;
7839
7840         default:
7841                 err = -EINVAL;
7842                 goto unlock;
7843         }
7844
7845 unlock:
7846         if (mddev->hold_active == UNTIL_IOCTL &&
7847             err != -EINVAL)
7848                 mddev->hold_active = 0;
7849
7850         md_ioctl_need_suspend(cmd) ? mddev_unlock_and_resume(mddev) :
7851                                      mddev_unlock(mddev);
7852
7853 out:
7854         if (cmd == STOP_ARRAY_RO || (err && cmd == STOP_ARRAY))
7855                 clear_bit(MD_CLOSING, &mddev->flags);
7856         return err;
7857 }
7858 #ifdef CONFIG_COMPAT
7859 static int md_compat_ioctl(struct block_device *bdev, blk_mode_t mode,
7860                     unsigned int cmd, unsigned long arg)
7861 {
7862         switch (cmd) {
7863         case HOT_REMOVE_DISK:
7864         case HOT_ADD_DISK:
7865         case SET_DISK_FAULTY:
7866         case SET_BITMAP_FILE:
7867                 /* These take in integer arg, do not convert */
7868                 break;
7869         default:
7870                 arg = (unsigned long)compat_ptr(arg);
7871                 break;
7872         }
7873
7874         return md_ioctl(bdev, mode, cmd, arg);
7875 }
7876 #endif /* CONFIG_COMPAT */
7877
7878 static int md_set_read_only(struct block_device *bdev, bool ro)
7879 {
7880         struct mddev *mddev = bdev->bd_disk->private_data;
7881         int err;
7882
7883         err = mddev_lock(mddev);
7884         if (err)
7885                 return err;
7886
7887         if (!mddev->raid_disks && !mddev->external) {
7888                 err = -ENODEV;
7889                 goto out_unlock;
7890         }
7891
7892         /*
7893          * Transitioning to read-auto need only happen for arrays that call
7894          * md_write_start and which are not ready for writes yet.
7895          */
7896         if (!ro && mddev->ro == MD_RDONLY && mddev->pers) {
7897                 err = restart_array(mddev);
7898                 if (err)
7899                         goto out_unlock;
7900                 mddev->ro = MD_AUTO_READ;
7901         }
7902
7903 out_unlock:
7904         mddev_unlock(mddev);
7905         return err;
7906 }
7907
7908 static int md_open(struct gendisk *disk, blk_mode_t mode)
7909 {
7910         struct mddev *mddev;
7911         int err;
7912
7913         spin_lock(&all_mddevs_lock);
7914         mddev = mddev_get(disk->private_data);
7915         spin_unlock(&all_mddevs_lock);
7916         if (!mddev)
7917                 return -ENODEV;
7918
7919         err = mutex_lock_interruptible(&mddev->open_mutex);
7920         if (err)
7921                 goto out;
7922
7923         err = -ENODEV;
7924         if (test_bit(MD_CLOSING, &mddev->flags))
7925                 goto out_unlock;
7926
7927         atomic_inc(&mddev->openers);
7928         mutex_unlock(&mddev->open_mutex);
7929
7930         disk_check_media_change(disk);
7931         return 0;
7932
7933 out_unlock:
7934         mutex_unlock(&mddev->open_mutex);
7935 out:
7936         mddev_put(mddev);
7937         return err;
7938 }
7939
7940 static void md_release(struct gendisk *disk)
7941 {
7942         struct mddev *mddev = disk->private_data;
7943
7944         BUG_ON(!mddev);
7945         atomic_dec(&mddev->openers);
7946         mddev_put(mddev);
7947 }
7948
7949 static unsigned int md_check_events(struct gendisk *disk, unsigned int clearing)
7950 {
7951         struct mddev *mddev = disk->private_data;
7952         unsigned int ret = 0;
7953
7954         if (mddev->changed)
7955                 ret = DISK_EVENT_MEDIA_CHANGE;
7956         mddev->changed = 0;
7957         return ret;
7958 }
7959
7960 static void md_free_disk(struct gendisk *disk)
7961 {
7962         struct mddev *mddev = disk->private_data;
7963
7964         mddev_free(mddev);
7965 }
7966
7967 const struct block_device_operations md_fops =
7968 {
7969         .owner          = THIS_MODULE,
7970         .submit_bio     = md_submit_bio,
7971         .open           = md_open,
7972         .release        = md_release,
7973         .ioctl          = md_ioctl,
7974 #ifdef CONFIG_COMPAT
7975         .compat_ioctl   = md_compat_ioctl,
7976 #endif
7977         .getgeo         = md_getgeo,
7978         .check_events   = md_check_events,
7979         .set_read_only  = md_set_read_only,
7980         .free_disk      = md_free_disk,
7981 };
7982
7983 static int md_thread(void *arg)
7984 {
7985         struct md_thread *thread = arg;
7986
7987         /*
7988          * md_thread is a 'system-thread', it's priority should be very
7989          * high. We avoid resource deadlocks individually in each
7990          * raid personality. (RAID5 does preallocation) We also use RR and
7991          * the very same RT priority as kswapd, thus we will never get
7992          * into a priority inversion deadlock.
7993          *
7994          * we definitely have to have equal or higher priority than
7995          * bdflush, otherwise bdflush will deadlock if there are too
7996          * many dirty RAID5 blocks.
7997          */
7998
7999         allow_signal(SIGKILL);
8000         while (!kthread_should_stop()) {
8001
8002                 /* We need to wait INTERRUPTIBLE so that
8003                  * we don't add to the load-average.
8004                  * That means we need to be sure no signals are
8005                  * pending
8006                  */
8007                 if (signal_pending(current))
8008                         flush_signals(current);
8009
8010                 wait_event_interruptible_timeout
8011                         (thread->wqueue,
8012                          test_bit(THREAD_WAKEUP, &thread->flags)
8013                          || kthread_should_stop() || kthread_should_park(),
8014                          thread->timeout);
8015
8016                 clear_bit(THREAD_WAKEUP, &thread->flags);
8017                 if (kthread_should_park())
8018                         kthread_parkme();
8019                 if (!kthread_should_stop())
8020                         thread->run(thread);
8021         }
8022
8023         return 0;
8024 }
8025
8026 static void md_wakeup_thread_directly(struct md_thread __rcu *thread)
8027 {
8028         struct md_thread *t;
8029
8030         rcu_read_lock();
8031         t = rcu_dereference(thread);
8032         if (t)
8033                 wake_up_process(t->tsk);
8034         rcu_read_unlock();
8035 }
8036
8037 void md_wakeup_thread(struct md_thread __rcu *thread)
8038 {
8039         struct md_thread *t;
8040
8041         rcu_read_lock();
8042         t = rcu_dereference(thread);
8043         if (t) {
8044                 pr_debug("md: waking up MD thread %s.\n", t->tsk->comm);
8045                 set_bit(THREAD_WAKEUP, &t->flags);
8046                 if (wq_has_sleeper(&t->wqueue))
8047                         wake_up(&t->wqueue);
8048         }
8049         rcu_read_unlock();
8050 }
8051 EXPORT_SYMBOL(md_wakeup_thread);
8052
8053 struct md_thread *md_register_thread(void (*run) (struct md_thread *),
8054                 struct mddev *mddev, const char *name)
8055 {
8056         struct md_thread *thread;
8057
8058         thread = kzalloc(sizeof(struct md_thread), GFP_KERNEL);
8059         if (!thread)
8060                 return NULL;
8061
8062         init_waitqueue_head(&thread->wqueue);
8063
8064         thread->run = run;
8065         thread->mddev = mddev;
8066         thread->timeout = MAX_SCHEDULE_TIMEOUT;
8067         thread->tsk = kthread_run(md_thread, thread,
8068                                   "%s_%s",
8069                                   mdname(thread->mddev),
8070                                   name);
8071         if (IS_ERR(thread->tsk)) {
8072                 kfree(thread);
8073                 return NULL;
8074         }
8075         return thread;
8076 }
8077 EXPORT_SYMBOL(md_register_thread);
8078
8079 void md_unregister_thread(struct mddev *mddev, struct md_thread __rcu **threadp)
8080 {
8081         struct md_thread *thread = rcu_dereference_protected(*threadp,
8082                                         lockdep_is_held(&mddev->reconfig_mutex));
8083
8084         if (!thread)
8085                 return;
8086
8087         rcu_assign_pointer(*threadp, NULL);
8088         synchronize_rcu();
8089
8090         pr_debug("interrupting MD-thread pid %d\n", task_pid_nr(thread->tsk));
8091         kthread_stop(thread->tsk);
8092         kfree(thread);
8093 }
8094 EXPORT_SYMBOL(md_unregister_thread);
8095
8096 void md_error(struct mddev *mddev, struct md_rdev *rdev)
8097 {
8098         if (!rdev || test_bit(Faulty, &rdev->flags))
8099                 return;
8100
8101         if (!mddev->pers || !mddev->pers->error_handler)
8102                 return;
8103         mddev->pers->error_handler(mddev, rdev);
8104
8105         if (mddev->pers->level == 0)
8106                 return;
8107
8108         if (mddev->degraded && !test_bit(MD_BROKEN, &mddev->flags))
8109                 set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
8110         sysfs_notify_dirent_safe(rdev->sysfs_state);
8111         set_bit(MD_RECOVERY_INTR, &mddev->recovery);
8112         if (!test_bit(MD_BROKEN, &mddev->flags)) {
8113                 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
8114                 md_wakeup_thread(mddev->thread);
8115         }
8116         if (mddev->event_work.func)
8117                 queue_work(md_misc_wq, &mddev->event_work);
8118         md_new_event();
8119 }
8120 EXPORT_SYMBOL(md_error);
8121
8122 /* seq_file implementation /proc/mdstat */
8123
8124 static void status_unused(struct seq_file *seq)
8125 {
8126         int i = 0;
8127         struct md_rdev *rdev;
8128
8129         seq_printf(seq, "unused devices: ");
8130
8131         list_for_each_entry(rdev, &pending_raid_disks, same_set) {
8132                 i++;
8133                 seq_printf(seq, "%pg ", rdev->bdev);
8134         }
8135         if (!i)
8136                 seq_printf(seq, "<none>");
8137
8138         seq_printf(seq, "\n");
8139 }
8140
8141 static void status_personalities(struct seq_file *seq)
8142 {
8143         struct md_personality *pers;
8144
8145         seq_puts(seq, "Personalities : ");
8146         spin_lock(&pers_lock);
8147         list_for_each_entry(pers, &pers_list, list)
8148                 seq_printf(seq, "[%s] ", pers->name);
8149
8150         spin_unlock(&pers_lock);
8151         seq_puts(seq, "\n");
8152 }
8153
8154 static int status_resync(struct seq_file *seq, struct mddev *mddev)
8155 {
8156         sector_t max_sectors, resync, res;
8157         unsigned long dt, db = 0;
8158         sector_t rt, curr_mark_cnt, resync_mark_cnt;
8159         int scale, recovery_active;
8160         unsigned int per_milli;
8161
8162         if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ||
8163             test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
8164                 max_sectors = mddev->resync_max_sectors;
8165         else
8166                 max_sectors = mddev->dev_sectors;
8167
8168         resync = mddev->curr_resync;
8169         if (resync < MD_RESYNC_ACTIVE) {
8170                 if (test_bit(MD_RECOVERY_DONE, &mddev->recovery))
8171                         /* Still cleaning up */
8172                         resync = max_sectors;
8173         } else if (resync > max_sectors) {
8174                 resync = max_sectors;
8175         } else {
8176                 res = atomic_read(&mddev->recovery_active);
8177                 /*
8178                  * Resync has started, but the subtraction has overflowed or
8179                  * yielded one of the special values. Force it to active to
8180                  * ensure the status reports an active resync.
8181                  */
8182                 if (resync < res || resync - res < MD_RESYNC_ACTIVE)
8183                         resync = MD_RESYNC_ACTIVE;
8184                 else
8185                         resync -= res;
8186         }
8187
8188         if (resync == MD_RESYNC_NONE) {
8189                 if (test_bit(MD_RESYNCING_REMOTE, &mddev->recovery)) {
8190                         struct md_rdev *rdev;
8191
8192                         rdev_for_each(rdev, mddev)
8193                                 if (rdev->raid_disk >= 0 &&
8194                                     !test_bit(Faulty, &rdev->flags) &&
8195                                     rdev->recovery_offset != MaxSector &&
8196                                     rdev->recovery_offset) {
8197                                         seq_printf(seq, "\trecover=REMOTE");
8198                                         return 1;
8199                                 }
8200                         if (mddev->reshape_position != MaxSector)
8201                                 seq_printf(seq, "\treshape=REMOTE");
8202                         else
8203                                 seq_printf(seq, "\tresync=REMOTE");
8204                         return 1;
8205                 }
8206                 if (mddev->recovery_cp < MaxSector) {
8207                         seq_printf(seq, "\tresync=PENDING");
8208                         return 1;
8209                 }
8210                 return 0;
8211         }
8212         if (resync < MD_RESYNC_ACTIVE) {
8213                 seq_printf(seq, "\tresync=DELAYED");
8214                 return 1;
8215         }
8216
8217         WARN_ON(max_sectors == 0);
8218         /* Pick 'scale' such that (resync>>scale)*1000 will fit
8219          * in a sector_t, and (max_sectors>>scale) will fit in a
8220          * u32, as those are the requirements for sector_div.
8221          * Thus 'scale' must be at least 10
8222          */
8223         scale = 10;
8224         if (sizeof(sector_t) > sizeof(unsigned long)) {
8225                 while ( max_sectors/2 > (1ULL<<(scale+32)))
8226                         scale++;
8227         }
8228         res = (resync>>scale)*1000;
8229         sector_div(res, (u32)((max_sectors>>scale)+1));
8230
8231         per_milli = res;
8232         {
8233                 int i, x = per_milli/50, y = 20-x;
8234                 seq_printf(seq, "[");
8235                 for (i = 0; i < x; i++)
8236                         seq_printf(seq, "=");
8237                 seq_printf(seq, ">");
8238                 for (i = 0; i < y; i++)
8239                         seq_printf(seq, ".");
8240                 seq_printf(seq, "] ");
8241         }
8242         seq_printf(seq, " %s =%3u.%u%% (%llu/%llu)",
8243                    (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)?
8244                     "reshape" :
8245                     (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)?
8246                      "check" :
8247                      (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ?
8248                       "resync" : "recovery"))),
8249                    per_milli/10, per_milli % 10,
8250                    (unsigned long long) resync/2,
8251                    (unsigned long long) max_sectors/2);
8252
8253         /*
8254          * dt: time from mark until now
8255          * db: blocks written from mark until now
8256          * rt: remaining time
8257          *
8258          * rt is a sector_t, which is always 64bit now. We are keeping
8259          * the original algorithm, but it is not really necessary.
8260          *
8261          * Original algorithm:
8262          *   So we divide before multiply in case it is 32bit and close
8263          *   to the limit.
8264          *   We scale the divisor (db) by 32 to avoid losing precision
8265          *   near the end of resync when the number of remaining sectors
8266          *   is close to 'db'.
8267          *   We then divide rt by 32 after multiplying by db to compensate.
8268          *   The '+1' avoids division by zero if db is very small.
8269          */
8270         dt = ((jiffies - mddev->resync_mark) / HZ);
8271         if (!dt) dt++;
8272
8273         curr_mark_cnt = mddev->curr_mark_cnt;
8274         recovery_active = atomic_read(&mddev->recovery_active);
8275         resync_mark_cnt = mddev->resync_mark_cnt;
8276
8277         if (curr_mark_cnt >= (recovery_active + resync_mark_cnt))
8278                 db = curr_mark_cnt - (recovery_active + resync_mark_cnt);
8279
8280         rt = max_sectors - resync;    /* number of remaining sectors */
8281         rt = div64_u64(rt, db/32+1);
8282         rt *= dt;
8283         rt >>= 5;
8284
8285         seq_printf(seq, " finish=%lu.%lumin", (unsigned long)rt / 60,
8286                    ((unsigned long)rt % 60)/6);
8287
8288         seq_printf(seq, " speed=%ldK/sec", db/2/dt);
8289         return 1;
8290 }
8291
8292 static void *md_seq_start(struct seq_file *seq, loff_t *pos)
8293         __acquires(&all_mddevs_lock)
8294 {
8295         seq->poll_event = atomic_read(&md_event_count);
8296         spin_lock(&all_mddevs_lock);
8297
8298         return seq_list_start_head(&all_mddevs, *pos);
8299 }
8300
8301 static void *md_seq_next(struct seq_file *seq, void *v, loff_t *pos)
8302 {
8303         return seq_list_next(v, &all_mddevs, pos);
8304 }
8305
8306 static void md_seq_stop(struct seq_file *seq, void *v)
8307         __releases(&all_mddevs_lock)
8308 {
8309         spin_unlock(&all_mddevs_lock);
8310 }
8311
8312 static void md_bitmap_status(struct seq_file *seq, struct mddev *mddev)
8313 {
8314         struct md_bitmap_stats stats;
8315         unsigned long used_pages;
8316         unsigned long chunk_kb;
8317         int err;
8318
8319         err = mddev->bitmap_ops->get_stats(mddev->bitmap, &stats);
8320         if (err)
8321                 return;
8322
8323         chunk_kb = mddev->bitmap_info.chunksize >> 10;
8324         used_pages = stats.pages - stats.missing_pages;
8325
8326         seq_printf(seq, "bitmap: %lu/%lu pages [%luKB], %lu%s chunk",
8327                    used_pages, stats.pages, used_pages << (PAGE_SHIFT - 10),
8328                    chunk_kb ? chunk_kb : mddev->bitmap_info.chunksize,
8329                    chunk_kb ? "KB" : "B");
8330
8331         if (stats.file) {
8332                 seq_puts(seq, ", file: ");
8333                 seq_file_path(seq, stats.file, " \t\n");
8334         }
8335
8336         seq_putc(seq, '\n');
8337 }
8338
8339 static int md_seq_show(struct seq_file *seq, void *v)
8340 {
8341         struct mddev *mddev;
8342         sector_t sectors;
8343         struct md_rdev *rdev;
8344
8345         if (v == &all_mddevs) {
8346                 status_personalities(seq);
8347                 if (list_empty(&all_mddevs))
8348                         status_unused(seq);
8349                 return 0;
8350         }
8351
8352         mddev = list_entry(v, struct mddev, all_mddevs);
8353         if (!mddev_get(mddev))
8354                 return 0;
8355
8356         spin_unlock(&all_mddevs_lock);
8357         spin_lock(&mddev->lock);
8358         if (mddev->pers || mddev->raid_disks || !list_empty(&mddev->disks)) {
8359                 seq_printf(seq, "%s : ", mdname(mddev));
8360                 if (mddev->pers) {
8361                         if (test_bit(MD_BROKEN, &mddev->flags))
8362                                 seq_printf(seq, "broken");
8363                         else
8364                                 seq_printf(seq, "active");
8365                         if (mddev->ro == MD_RDONLY)
8366                                 seq_printf(seq, " (read-only)");
8367                         if (mddev->ro == MD_AUTO_READ)
8368                                 seq_printf(seq, " (auto-read-only)");
8369                         seq_printf(seq, " %s", mddev->pers->name);
8370                 } else {
8371                         seq_printf(seq, "inactive");
8372                 }
8373
8374                 sectors = 0;
8375                 rcu_read_lock();
8376                 rdev_for_each_rcu(rdev, mddev) {
8377                         seq_printf(seq, " %pg[%d]", rdev->bdev, rdev->desc_nr);
8378
8379                         if (test_bit(WriteMostly, &rdev->flags))
8380                                 seq_printf(seq, "(W)");
8381                         if (test_bit(Journal, &rdev->flags))
8382                                 seq_printf(seq, "(J)");
8383                         if (test_bit(Faulty, &rdev->flags)) {
8384                                 seq_printf(seq, "(F)");
8385                                 continue;
8386                         }
8387                         if (rdev->raid_disk < 0)
8388                                 seq_printf(seq, "(S)"); /* spare */
8389                         if (test_bit(Replacement, &rdev->flags))
8390                                 seq_printf(seq, "(R)");
8391                         sectors += rdev->sectors;
8392                 }
8393                 rcu_read_unlock();
8394
8395                 if (!list_empty(&mddev->disks)) {
8396                         if (mddev->pers)
8397                                 seq_printf(seq, "\n      %llu blocks",
8398                                            (unsigned long long)
8399                                            mddev->array_sectors / 2);
8400                         else
8401                                 seq_printf(seq, "\n      %llu blocks",
8402                                            (unsigned long long)sectors / 2);
8403                 }
8404                 if (mddev->persistent) {
8405                         if (mddev->major_version != 0 ||
8406                             mddev->minor_version != 90) {
8407                                 seq_printf(seq," super %d.%d",
8408                                            mddev->major_version,
8409                                            mddev->minor_version);
8410                         }
8411                 } else if (mddev->external)
8412                         seq_printf(seq, " super external:%s",
8413                                    mddev->metadata_type);
8414                 else
8415                         seq_printf(seq, " super non-persistent");
8416
8417                 if (mddev->pers) {
8418                         mddev->pers->status(seq, mddev);
8419                         seq_printf(seq, "\n      ");
8420                         if (mddev->pers->sync_request) {
8421                                 if (status_resync(seq, mddev))
8422                                         seq_printf(seq, "\n      ");
8423                         }
8424                 } else
8425                         seq_printf(seq, "\n       ");
8426
8427                 md_bitmap_status(seq, mddev);
8428
8429                 seq_printf(seq, "\n");
8430         }
8431         spin_unlock(&mddev->lock);
8432         spin_lock(&all_mddevs_lock);
8433
8434         if (mddev == list_last_entry(&all_mddevs, struct mddev, all_mddevs))
8435                 status_unused(seq);
8436
8437         if (atomic_dec_and_test(&mddev->active))
8438                 __mddev_put(mddev);
8439
8440         return 0;
8441 }
8442
8443 static const struct seq_operations md_seq_ops = {
8444         .start  = md_seq_start,
8445         .next   = md_seq_next,
8446         .stop   = md_seq_stop,
8447         .show   = md_seq_show,
8448 };
8449
8450 static int md_seq_open(struct inode *inode, struct file *file)
8451 {
8452         struct seq_file *seq;
8453         int error;
8454
8455         error = seq_open(file, &md_seq_ops);
8456         if (error)
8457                 return error;
8458
8459         seq = file->private_data;
8460         seq->poll_event = atomic_read(&md_event_count);
8461         return error;
8462 }
8463
8464 static int md_unloading;
8465 static __poll_t mdstat_poll(struct file *filp, poll_table *wait)
8466 {
8467         struct seq_file *seq = filp->private_data;
8468         __poll_t mask;
8469
8470         if (md_unloading)
8471                 return EPOLLIN|EPOLLRDNORM|EPOLLERR|EPOLLPRI;
8472         poll_wait(filp, &md_event_waiters, wait);
8473
8474         /* always allow read */
8475         mask = EPOLLIN | EPOLLRDNORM;
8476
8477         if (seq->poll_event != atomic_read(&md_event_count))
8478                 mask |= EPOLLERR | EPOLLPRI;
8479         return mask;
8480 }
8481
8482 static const struct proc_ops mdstat_proc_ops = {
8483         .proc_open      = md_seq_open,
8484         .proc_read      = seq_read,
8485         .proc_lseek     = seq_lseek,
8486         .proc_release   = seq_release,
8487         .proc_poll      = mdstat_poll,
8488 };
8489
8490 int register_md_personality(struct md_personality *p)
8491 {
8492         pr_debug("md: %s personality registered for level %d\n",
8493                  p->name, p->level);
8494         spin_lock(&pers_lock);
8495         list_add_tail(&p->list, &pers_list);
8496         spin_unlock(&pers_lock);
8497         return 0;
8498 }
8499 EXPORT_SYMBOL(register_md_personality);
8500
8501 int unregister_md_personality(struct md_personality *p)
8502 {
8503         pr_debug("md: %s personality unregistered\n", p->name);
8504         spin_lock(&pers_lock);
8505         list_del_init(&p->list);
8506         spin_unlock(&pers_lock);
8507         return 0;
8508 }
8509 EXPORT_SYMBOL(unregister_md_personality);
8510
8511 int register_md_cluster_operations(const struct md_cluster_operations *ops,
8512                                    struct module *module)
8513 {
8514         int ret = 0;
8515         spin_lock(&pers_lock);
8516         if (md_cluster_ops != NULL)
8517                 ret = -EALREADY;
8518         else {
8519                 md_cluster_ops = ops;
8520                 md_cluster_mod = module;
8521         }
8522         spin_unlock(&pers_lock);
8523         return ret;
8524 }
8525 EXPORT_SYMBOL(register_md_cluster_operations);
8526
8527 int unregister_md_cluster_operations(void)
8528 {
8529         spin_lock(&pers_lock);
8530         md_cluster_ops = NULL;
8531         spin_unlock(&pers_lock);
8532         return 0;
8533 }
8534 EXPORT_SYMBOL(unregister_md_cluster_operations);
8535
8536 int md_setup_cluster(struct mddev *mddev, int nodes)
8537 {
8538         int ret;
8539         if (!md_cluster_ops)
8540                 request_module("md-cluster");
8541         spin_lock(&pers_lock);
8542         /* ensure module won't be unloaded */
8543         if (!md_cluster_ops || !try_module_get(md_cluster_mod)) {
8544                 pr_warn("can't find md-cluster module or get its reference.\n");
8545                 spin_unlock(&pers_lock);
8546                 return -ENOENT;
8547         }
8548         spin_unlock(&pers_lock);
8549
8550         ret = md_cluster_ops->join(mddev, nodes);
8551         if (!ret)
8552                 mddev->safemode_delay = 0;
8553         return ret;
8554 }
8555
8556 void md_cluster_stop(struct mddev *mddev)
8557 {
8558         if (!md_cluster_ops)
8559                 return;
8560         md_cluster_ops->leave(mddev);
8561         module_put(md_cluster_mod);
8562 }
8563
8564 static int is_mddev_idle(struct mddev *mddev, int init)
8565 {
8566         struct md_rdev *rdev;
8567         int idle;
8568         int curr_events;
8569
8570         idle = 1;
8571         rcu_read_lock();
8572         rdev_for_each_rcu(rdev, mddev) {
8573                 struct gendisk *disk = rdev->bdev->bd_disk;
8574
8575                 if (!init && !blk_queue_io_stat(disk->queue))
8576                         continue;
8577
8578                 curr_events = (int)part_stat_read_accum(disk->part0, sectors) -
8579                               atomic_read(&disk->sync_io);
8580                 /* sync IO will cause sync_io to increase before the disk_stats
8581                  * as sync_io is counted when a request starts, and
8582                  * disk_stats is counted when it completes.
8583                  * So resync activity will cause curr_events to be smaller than
8584                  * when there was no such activity.
8585                  * non-sync IO will cause disk_stat to increase without
8586                  * increasing sync_io so curr_events will (eventually)
8587                  * be larger than it was before.  Once it becomes
8588                  * substantially larger, the test below will cause
8589                  * the array to appear non-idle, and resync will slow
8590                  * down.
8591                  * If there is a lot of outstanding resync activity when
8592                  * we set last_event to curr_events, then all that activity
8593                  * completing might cause the array to appear non-idle
8594                  * and resync will be slowed down even though there might
8595                  * not have been non-resync activity.  This will only
8596                  * happen once though.  'last_events' will soon reflect
8597                  * the state where there is little or no outstanding
8598                  * resync requests, and further resync activity will
8599                  * always make curr_events less than last_events.
8600                  *
8601                  */
8602                 if (init || curr_events - rdev->last_events > 64) {
8603                         rdev->last_events = curr_events;
8604                         idle = 0;
8605                 }
8606         }
8607         rcu_read_unlock();
8608         return idle;
8609 }
8610
8611 void md_done_sync(struct mddev *mddev, int blocks, int ok)
8612 {
8613         /* another "blocks" (512byte) blocks have been synced */
8614         atomic_sub(blocks, &mddev->recovery_active);
8615         wake_up(&mddev->recovery_wait);
8616         if (!ok) {
8617                 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
8618                 set_bit(MD_RECOVERY_ERROR, &mddev->recovery);
8619                 md_wakeup_thread(mddev->thread);
8620                 // stop recovery, signal do_sync ....
8621         }
8622 }
8623 EXPORT_SYMBOL(md_done_sync);
8624
8625 /* md_write_start(mddev, bi)
8626  * If we need to update some array metadata (e.g. 'active' flag
8627  * in superblock) before writing, schedule a superblock update
8628  * and wait for it to complete.
8629  * A return value of 'false' means that the write wasn't recorded
8630  * and cannot proceed as the array is being suspend.
8631  */
8632 void md_write_start(struct mddev *mddev, struct bio *bi)
8633 {
8634         int did_change = 0;
8635
8636         if (bio_data_dir(bi) != WRITE)
8637                 return;
8638
8639         BUG_ON(mddev->ro == MD_RDONLY);
8640         if (mddev->ro == MD_AUTO_READ) {
8641                 /* need to switch to read/write */
8642                 mddev->ro = MD_RDWR;
8643                 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
8644                 md_wakeup_thread(mddev->thread);
8645                 md_wakeup_thread(mddev->sync_thread);
8646                 did_change = 1;
8647         }
8648         rcu_read_lock();
8649         percpu_ref_get(&mddev->writes_pending);
8650         smp_mb(); /* Match smp_mb in set_in_sync() */
8651         if (mddev->safemode == 1)
8652                 mddev->safemode = 0;
8653         /* sync_checkers is always 0 when writes_pending is in per-cpu mode */
8654         if (mddev->in_sync || mddev->sync_checkers) {
8655                 spin_lock(&mddev->lock);
8656                 if (mddev->in_sync) {
8657                         mddev->in_sync = 0;
8658                         set_bit(MD_SB_CHANGE_CLEAN, &mddev->sb_flags);
8659                         set_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags);
8660                         md_wakeup_thread(mddev->thread);
8661                         did_change = 1;
8662                 }
8663                 spin_unlock(&mddev->lock);
8664         }
8665         rcu_read_unlock();
8666         if (did_change)
8667                 sysfs_notify_dirent_safe(mddev->sysfs_state);
8668         if (!mddev->has_superblocks)
8669                 return;
8670         wait_event(mddev->sb_wait,
8671                    !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags));
8672 }
8673 EXPORT_SYMBOL(md_write_start);
8674
8675 /* md_write_inc can only be called when md_write_start() has
8676  * already been called at least once of the current request.
8677  * It increments the counter and is useful when a single request
8678  * is split into several parts.  Each part causes an increment and
8679  * so needs a matching md_write_end().
8680  * Unlike md_write_start(), it is safe to call md_write_inc() inside
8681  * a spinlocked region.
8682  */
8683 void md_write_inc(struct mddev *mddev, struct bio *bi)
8684 {
8685         if (bio_data_dir(bi) != WRITE)
8686                 return;
8687         WARN_ON_ONCE(mddev->in_sync || !md_is_rdwr(mddev));
8688         percpu_ref_get(&mddev->writes_pending);
8689 }
8690 EXPORT_SYMBOL(md_write_inc);
8691
8692 void md_write_end(struct mddev *mddev)
8693 {
8694         percpu_ref_put(&mddev->writes_pending);
8695
8696         if (mddev->safemode == 2)
8697                 md_wakeup_thread(mddev->thread);
8698         else if (mddev->safemode_delay)
8699                 /* The roundup() ensures this only performs locking once
8700                  * every ->safemode_delay jiffies
8701                  */
8702                 mod_timer(&mddev->safemode_timer,
8703                           roundup(jiffies, mddev->safemode_delay) +
8704                           mddev->safemode_delay);
8705 }
8706
8707 EXPORT_SYMBOL(md_write_end);
8708
8709 /* This is used by raid0 and raid10 */
8710 void md_submit_discard_bio(struct mddev *mddev, struct md_rdev *rdev,
8711                         struct bio *bio, sector_t start, sector_t size)
8712 {
8713         struct bio *discard_bio = NULL;
8714
8715         if (__blkdev_issue_discard(rdev->bdev, start, size, GFP_NOIO,
8716                         &discard_bio) || !discard_bio)
8717                 return;
8718
8719         bio_chain(discard_bio, bio);
8720         bio_clone_blkg_association(discard_bio, bio);
8721         mddev_trace_remap(mddev, discard_bio, bio->bi_iter.bi_sector);
8722         submit_bio_noacct(discard_bio);
8723 }
8724 EXPORT_SYMBOL_GPL(md_submit_discard_bio);
8725
8726 static void md_end_clone_io(struct bio *bio)
8727 {
8728         struct md_io_clone *md_io_clone = bio->bi_private;
8729         struct bio *orig_bio = md_io_clone->orig_bio;
8730         struct mddev *mddev = md_io_clone->mddev;
8731
8732         if (bio->bi_status && !orig_bio->bi_status)
8733                 orig_bio->bi_status = bio->bi_status;
8734
8735         if (md_io_clone->start_time)
8736                 bio_end_io_acct(orig_bio, md_io_clone->start_time);
8737
8738         bio_put(bio);
8739         bio_endio(orig_bio);
8740         percpu_ref_put(&mddev->active_io);
8741 }
8742
8743 static void md_clone_bio(struct mddev *mddev, struct bio **bio)
8744 {
8745         struct block_device *bdev = (*bio)->bi_bdev;
8746         struct md_io_clone *md_io_clone;
8747         struct bio *clone =
8748                 bio_alloc_clone(bdev, *bio, GFP_NOIO, &mddev->io_clone_set);
8749
8750         md_io_clone = container_of(clone, struct md_io_clone, bio_clone);
8751         md_io_clone->orig_bio = *bio;
8752         md_io_clone->mddev = mddev;
8753         if (blk_queue_io_stat(bdev->bd_disk->queue))
8754                 md_io_clone->start_time = bio_start_io_acct(*bio);
8755
8756         clone->bi_end_io = md_end_clone_io;
8757         clone->bi_private = md_io_clone;
8758         *bio = clone;
8759 }
8760
8761 void md_account_bio(struct mddev *mddev, struct bio **bio)
8762 {
8763         percpu_ref_get(&mddev->active_io);
8764         md_clone_bio(mddev, bio);
8765 }
8766 EXPORT_SYMBOL_GPL(md_account_bio);
8767
8768 void md_free_cloned_bio(struct bio *bio)
8769 {
8770         struct md_io_clone *md_io_clone = bio->bi_private;
8771         struct bio *orig_bio = md_io_clone->orig_bio;
8772         struct mddev *mddev = md_io_clone->mddev;
8773
8774         if (bio->bi_status && !orig_bio->bi_status)
8775                 orig_bio->bi_status = bio->bi_status;
8776
8777         if (md_io_clone->start_time)
8778                 bio_end_io_acct(orig_bio, md_io_clone->start_time);
8779
8780         bio_put(bio);
8781         percpu_ref_put(&mddev->active_io);
8782 }
8783 EXPORT_SYMBOL_GPL(md_free_cloned_bio);
8784
8785 /* md_allow_write(mddev)
8786  * Calling this ensures that the array is marked 'active' so that writes
8787  * may proceed without blocking.  It is important to call this before
8788  * attempting a GFP_KERNEL allocation while holding the mddev lock.
8789  * Must be called with mddev_lock held.
8790  */
8791 void md_allow_write(struct mddev *mddev)
8792 {
8793         if (!mddev->pers)
8794                 return;
8795         if (!md_is_rdwr(mddev))
8796                 return;
8797         if (!mddev->pers->sync_request)
8798                 return;
8799
8800         spin_lock(&mddev->lock);
8801         if (mddev->in_sync) {
8802                 mddev->in_sync = 0;
8803                 set_bit(MD_SB_CHANGE_CLEAN, &mddev->sb_flags);
8804                 set_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags);
8805                 if (mddev->safemode_delay &&
8806                     mddev->safemode == 0)
8807                         mddev->safemode = 1;
8808                 spin_unlock(&mddev->lock);
8809                 md_update_sb(mddev, 0);
8810                 sysfs_notify_dirent_safe(mddev->sysfs_state);
8811                 /* wait for the dirty state to be recorded in the metadata */
8812                 wait_event(mddev->sb_wait,
8813                            !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags));
8814         } else
8815                 spin_unlock(&mddev->lock);
8816 }
8817 EXPORT_SYMBOL_GPL(md_allow_write);
8818
8819 static sector_t md_sync_max_sectors(struct mddev *mddev,
8820                                     enum sync_action action)
8821 {
8822         switch (action) {
8823         case ACTION_RESYNC:
8824         case ACTION_CHECK:
8825         case ACTION_REPAIR:
8826                 atomic64_set(&mddev->resync_mismatches, 0);
8827                 fallthrough;
8828         case ACTION_RESHAPE:
8829                 return mddev->resync_max_sectors;
8830         case ACTION_RECOVER:
8831                 return mddev->dev_sectors;
8832         default:
8833                 return 0;
8834         }
8835 }
8836
8837 static sector_t md_sync_position(struct mddev *mddev, enum sync_action action)
8838 {
8839         sector_t start = 0;
8840         struct md_rdev *rdev;
8841
8842         switch (action) {
8843         case ACTION_CHECK:
8844         case ACTION_REPAIR:
8845                 return mddev->resync_min;
8846         case ACTION_RESYNC:
8847                 if (!mddev->bitmap)
8848                         return mddev->recovery_cp;
8849                 return 0;
8850         case ACTION_RESHAPE:
8851                 /*
8852                  * If the original node aborts reshaping then we continue the
8853                  * reshaping, so set again to avoid restart reshape from the
8854                  * first beginning
8855                  */
8856                 if (mddev_is_clustered(mddev) &&
8857                     mddev->reshape_position != MaxSector)
8858                         return mddev->reshape_position;
8859                 return 0;
8860         case ACTION_RECOVER:
8861                 start = MaxSector;
8862                 rcu_read_lock();
8863                 rdev_for_each_rcu(rdev, mddev)
8864                         if (rdev->raid_disk >= 0 &&
8865                             !test_bit(Journal, &rdev->flags) &&
8866                             !test_bit(Faulty, &rdev->flags) &&
8867                             !test_bit(In_sync, &rdev->flags) &&
8868                             rdev->recovery_offset < start)
8869                                 start = rdev->recovery_offset;
8870                 rcu_read_unlock();
8871
8872                 /* If there is a bitmap, we need to make sure all
8873                  * writes that started before we added a spare
8874                  * complete before we start doing a recovery.
8875                  * Otherwise the write might complete and (via
8876                  * bitmap_endwrite) set a bit in the bitmap after the
8877                  * recovery has checked that bit and skipped that
8878                  * region.
8879                  */
8880                 if (mddev->bitmap) {
8881                         mddev->pers->quiesce(mddev, 1);
8882                         mddev->pers->quiesce(mddev, 0);
8883                 }
8884                 return start;
8885         default:
8886                 return MaxSector;
8887         }
8888 }
8889
8890 #define SYNC_MARKS      10
8891 #define SYNC_MARK_STEP  (3*HZ)
8892 #define UPDATE_FREQUENCY (5*60*HZ)
8893 void md_do_sync(struct md_thread *thread)
8894 {
8895         struct mddev *mddev = thread->mddev;
8896         struct mddev *mddev2;
8897         unsigned int currspeed = 0, window;
8898         sector_t max_sectors,j, io_sectors, recovery_done;
8899         unsigned long mark[SYNC_MARKS];
8900         unsigned long update_time;
8901         sector_t mark_cnt[SYNC_MARKS];
8902         int last_mark,m;
8903         sector_t last_check;
8904         int skipped = 0;
8905         struct md_rdev *rdev;
8906         enum sync_action action;
8907         const char *desc;
8908         struct blk_plug plug;
8909         int ret;
8910
8911         /* just incase thread restarts... */
8912         if (test_bit(MD_RECOVERY_DONE, &mddev->recovery))
8913                 return;
8914
8915         if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
8916                 goto skip;
8917
8918         if (test_bit(MD_RECOVERY_WAIT, &mddev->recovery) ||
8919             !md_is_rdwr(mddev)) {/* never try to sync a read-only array */
8920                 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
8921                 goto skip;
8922         }
8923
8924         if (mddev_is_clustered(mddev)) {
8925                 ret = md_cluster_ops->resync_start(mddev);
8926                 if (ret)
8927                         goto skip;
8928
8929                 set_bit(MD_CLUSTER_RESYNC_LOCKED, &mddev->flags);
8930                 if (!(test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ||
8931                         test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) ||
8932                         test_bit(MD_RECOVERY_RECOVER, &mddev->recovery))
8933                      && ((unsigned long long)mddev->curr_resync_completed
8934                          < (unsigned long long)mddev->resync_max_sectors))
8935                         goto skip;
8936         }
8937
8938         action = md_sync_action(mddev);
8939         desc = md_sync_action_name(action);
8940         mddev->last_sync_action = action;
8941
8942         /*
8943          * Before starting a resync we must have set curr_resync to
8944          * 2, and then checked that every "conflicting" array has curr_resync
8945          * less than ours.  When we find one that is the same or higher
8946          * we wait on resync_wait.  To avoid deadlock, we reduce curr_resync
8947          * to 1 if we choose to yield (based arbitrarily on address of mddev structure).
8948          * This will mean we have to start checking from the beginning again.
8949          *
8950          */
8951         if (mddev_is_clustered(mddev))
8952                 md_cluster_ops->resync_start_notify(mddev);
8953         do {
8954                 int mddev2_minor = -1;
8955                 mddev->curr_resync = MD_RESYNC_DELAYED;
8956
8957         try_again:
8958                 if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
8959                         goto skip;
8960                 spin_lock(&all_mddevs_lock);
8961                 list_for_each_entry(mddev2, &all_mddevs, all_mddevs) {
8962                         if (test_bit(MD_DELETED, &mddev2->flags))
8963                                 continue;
8964                         if (mddev2 == mddev)
8965                                 continue;
8966                         if (!mddev->parallel_resync
8967                         &&  mddev2->curr_resync
8968                         &&  match_mddev_units(mddev, mddev2)) {
8969                                 DEFINE_WAIT(wq);
8970                                 if (mddev < mddev2 &&
8971                                     mddev->curr_resync == MD_RESYNC_DELAYED) {
8972                                         /* arbitrarily yield */
8973                                         mddev->curr_resync = MD_RESYNC_YIELDED;
8974                                         wake_up(&resync_wait);
8975                                 }
8976                                 if (mddev > mddev2 &&
8977                                     mddev->curr_resync == MD_RESYNC_YIELDED)
8978                                         /* no need to wait here, we can wait the next
8979                                          * time 'round when curr_resync == 2
8980                                          */
8981                                         continue;
8982                                 /* We need to wait 'interruptible' so as not to
8983                                  * contribute to the load average, and not to
8984                                  * be caught by 'softlockup'
8985                                  */
8986                                 prepare_to_wait(&resync_wait, &wq, TASK_INTERRUPTIBLE);
8987                                 if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery) &&
8988                                     mddev2->curr_resync >= mddev->curr_resync) {
8989                                         if (mddev2_minor != mddev2->md_minor) {
8990                                                 mddev2_minor = mddev2->md_minor;
8991                                                 pr_info("md: delaying %s of %s until %s has finished (they share one or more physical units)\n",
8992                                                         desc, mdname(mddev),
8993                                                         mdname(mddev2));
8994                                         }
8995                                         spin_unlock(&all_mddevs_lock);
8996
8997                                         if (signal_pending(current))
8998                                                 flush_signals(current);
8999                                         schedule();
9000                                         finish_wait(&resync_wait, &wq);
9001                                         goto try_again;
9002                                 }
9003                                 finish_wait(&resync_wait, &wq);
9004                         }
9005                 }
9006                 spin_unlock(&all_mddevs_lock);
9007         } while (mddev->curr_resync < MD_RESYNC_DELAYED);
9008
9009         max_sectors = md_sync_max_sectors(mddev, action);
9010         j = md_sync_position(mddev, action);
9011
9012         pr_info("md: %s of RAID array %s\n", desc, mdname(mddev));
9013         pr_debug("md: minimum _guaranteed_  speed: %d KB/sec/disk.\n", speed_min(mddev));
9014         pr_debug("md: using maximum available idle IO bandwidth (but not more than %d KB/sec) for %s.\n",
9015                  speed_max(mddev), desc);
9016
9017         is_mddev_idle(mddev, 1); /* this initializes IO event counters */
9018
9019         io_sectors = 0;
9020         for (m = 0; m < SYNC_MARKS; m++) {
9021                 mark[m] = jiffies;
9022                 mark_cnt[m] = io_sectors;
9023         }
9024         last_mark = 0;
9025         mddev->resync_mark = mark[last_mark];
9026         mddev->resync_mark_cnt = mark_cnt[last_mark];
9027
9028         /*
9029          * Tune reconstruction:
9030          */
9031         window = 32 * (PAGE_SIZE / 512);
9032         pr_debug("md: using %dk window, over a total of %lluk.\n",
9033                  window/2, (unsigned long long)max_sectors/2);
9034
9035         atomic_set(&mddev->recovery_active, 0);
9036         last_check = 0;
9037
9038         if (j >= MD_RESYNC_ACTIVE) {
9039                 pr_debug("md: resuming %s of %s from checkpoint.\n",
9040                          desc, mdname(mddev));
9041                 mddev->curr_resync = j;
9042         } else
9043                 mddev->curr_resync = MD_RESYNC_ACTIVE; /* no longer delayed */
9044         mddev->curr_resync_completed = j;
9045         sysfs_notify_dirent_safe(mddev->sysfs_completed);
9046         md_new_event();
9047         update_time = jiffies;
9048
9049         blk_start_plug(&plug);
9050         while (j < max_sectors) {
9051                 sector_t sectors;
9052
9053                 skipped = 0;
9054
9055                 if (!test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
9056                     ((mddev->curr_resync > mddev->curr_resync_completed &&
9057                       (mddev->curr_resync - mddev->curr_resync_completed)
9058                       > (max_sectors >> 4)) ||
9059                      time_after_eq(jiffies, update_time + UPDATE_FREQUENCY) ||
9060                      (j - mddev->curr_resync_completed)*2
9061                      >= mddev->resync_max - mddev->curr_resync_completed ||
9062                      mddev->curr_resync_completed > mddev->resync_max
9063                             )) {
9064                         /* time to update curr_resync_completed */
9065                         wait_event(mddev->recovery_wait,
9066                                    atomic_read(&mddev->recovery_active) == 0);
9067                         mddev->curr_resync_completed = j;
9068                         if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) &&
9069                             j > mddev->recovery_cp)
9070                                 mddev->recovery_cp = j;
9071                         update_time = jiffies;
9072                         set_bit(MD_SB_CHANGE_CLEAN, &mddev->sb_flags);
9073                         sysfs_notify_dirent_safe(mddev->sysfs_completed);
9074                 }
9075
9076                 while (j >= mddev->resync_max &&
9077                        !test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
9078                         /* As this condition is controlled by user-space,
9079                          * we can block indefinitely, so use '_interruptible'
9080                          * to avoid triggering warnings.
9081                          */
9082                         flush_signals(current); /* just in case */
9083                         wait_event_interruptible(mddev->recovery_wait,
9084                                                  mddev->resync_max > j
9085                                                  || test_bit(MD_RECOVERY_INTR,
9086                                                              &mddev->recovery));
9087                 }
9088
9089                 if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
9090                         break;
9091
9092                 sectors = mddev->pers->sync_request(mddev, j, max_sectors,
9093                                                     &skipped);
9094                 if (sectors == 0) {
9095                         set_bit(MD_RECOVERY_INTR, &mddev->recovery);
9096                         break;
9097                 }
9098
9099                 if (!skipped) { /* actual IO requested */
9100                         io_sectors += sectors;
9101                         atomic_add(sectors, &mddev->recovery_active);
9102                 }
9103
9104                 if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
9105                         break;
9106
9107                 j += sectors;
9108                 if (j > max_sectors)
9109                         /* when skipping, extra large numbers can be returned. */
9110                         j = max_sectors;
9111                 if (j >= MD_RESYNC_ACTIVE)
9112                         mddev->curr_resync = j;
9113                 mddev->curr_mark_cnt = io_sectors;
9114                 if (last_check == 0)
9115                         /* this is the earliest that rebuild will be
9116                          * visible in /proc/mdstat
9117                          */
9118                         md_new_event();
9119
9120                 if (last_check + window > io_sectors || j == max_sectors)
9121                         continue;
9122
9123                 last_check = io_sectors;
9124         repeat:
9125                 if (time_after_eq(jiffies, mark[last_mark] + SYNC_MARK_STEP )) {
9126                         /* step marks */
9127                         int next = (last_mark+1) % SYNC_MARKS;
9128
9129                         mddev->resync_mark = mark[next];
9130                         mddev->resync_mark_cnt = mark_cnt[next];
9131                         mark[next] = jiffies;
9132                         mark_cnt[next] = io_sectors - atomic_read(&mddev->recovery_active);
9133                         last_mark = next;
9134                 }
9135
9136                 if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
9137                         break;
9138
9139                 /*
9140                  * this loop exits only if either when we are slower than
9141                  * the 'hard' speed limit, or the system was IO-idle for
9142                  * a jiffy.
9143                  * the system might be non-idle CPU-wise, but we only care
9144                  * about not overloading the IO subsystem. (things like an
9145                  * e2fsck being done on the RAID array should execute fast)
9146                  */
9147                 cond_resched();
9148
9149                 recovery_done = io_sectors - atomic_read(&mddev->recovery_active);
9150                 currspeed = ((unsigned long)(recovery_done - mddev->resync_mark_cnt))/2
9151                         /((jiffies-mddev->resync_mark)/HZ +1) +1;
9152
9153                 if (currspeed > speed_min(mddev)) {
9154                         if (currspeed > speed_max(mddev)) {
9155                                 msleep(500);
9156                                 goto repeat;
9157                         }
9158                         if (!is_mddev_idle(mddev, 0)) {
9159                                 /*
9160                                  * Give other IO more of a chance.
9161                                  * The faster the devices, the less we wait.
9162                                  */
9163                                 wait_event(mddev->recovery_wait,
9164                                            !atomic_read(&mddev->recovery_active));
9165                         }
9166                 }
9167         }
9168         pr_info("md: %s: %s %s.\n",mdname(mddev), desc,
9169                 test_bit(MD_RECOVERY_INTR, &mddev->recovery)
9170                 ? "interrupted" : "done");
9171         /*
9172          * this also signals 'finished resyncing' to md_stop
9173          */
9174         blk_finish_plug(&plug);
9175         wait_event(mddev->recovery_wait, !atomic_read(&mddev->recovery_active));
9176
9177         if (!test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
9178             !test_bit(MD_RECOVERY_INTR, &mddev->recovery) &&
9179             mddev->curr_resync >= MD_RESYNC_ACTIVE) {
9180                 mddev->curr_resync_completed = mddev->curr_resync;
9181                 sysfs_notify_dirent_safe(mddev->sysfs_completed);
9182         }
9183         mddev->pers->sync_request(mddev, max_sectors, max_sectors, &skipped);
9184
9185         if (!test_bit(MD_RECOVERY_CHECK, &mddev->recovery) &&
9186             mddev->curr_resync > MD_RESYNC_ACTIVE) {
9187                 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
9188                         if (test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
9189                                 if (mddev->curr_resync >= mddev->recovery_cp) {
9190                                         pr_debug("md: checkpointing %s of %s.\n",
9191                                                  desc, mdname(mddev));
9192                                         if (test_bit(MD_RECOVERY_ERROR,
9193                                                 &mddev->recovery))
9194                                                 mddev->recovery_cp =
9195                                                         mddev->curr_resync_completed;
9196                                         else
9197                                                 mddev->recovery_cp =
9198                                                         mddev->curr_resync;
9199                                 }
9200                         } else
9201                                 mddev->recovery_cp = MaxSector;
9202                 } else {
9203                         if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery))
9204                                 mddev->curr_resync = MaxSector;
9205                         if (!test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
9206                             test_bit(MD_RECOVERY_RECOVER, &mddev->recovery)) {
9207                                 rcu_read_lock();
9208                                 rdev_for_each_rcu(rdev, mddev)
9209                                         if (rdev->raid_disk >= 0 &&
9210                                             mddev->delta_disks >= 0 &&
9211                                             !test_bit(Journal, &rdev->flags) &&
9212                                             !test_bit(Faulty, &rdev->flags) &&
9213                                             !test_bit(In_sync, &rdev->flags) &&
9214                                             rdev->recovery_offset < mddev->curr_resync)
9215                                                 rdev->recovery_offset = mddev->curr_resync;
9216                                 rcu_read_unlock();
9217                         }
9218                 }
9219         }
9220  skip:
9221         /* set CHANGE_PENDING here since maybe another update is needed,
9222          * so other nodes are informed. It should be harmless for normal
9223          * raid */
9224         set_mask_bits(&mddev->sb_flags, 0,
9225                       BIT(MD_SB_CHANGE_PENDING) | BIT(MD_SB_CHANGE_DEVS));
9226
9227         if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
9228                         !test_bit(MD_RECOVERY_INTR, &mddev->recovery) &&
9229                         mddev->delta_disks > 0 &&
9230                         mddev->pers->finish_reshape &&
9231                         mddev->pers->size &&
9232                         !mddev_is_dm(mddev)) {
9233                 mddev_lock_nointr(mddev);
9234                 md_set_array_sectors(mddev, mddev->pers->size(mddev, 0, 0));
9235                 mddev_unlock(mddev);
9236                 if (!mddev_is_clustered(mddev))
9237                         set_capacity_and_notify(mddev->gendisk,
9238                                                 mddev->array_sectors);
9239         }
9240
9241         spin_lock(&mddev->lock);
9242         if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
9243                 /* We completed so min/max setting can be forgotten if used. */
9244                 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
9245                         mddev->resync_min = 0;
9246                 mddev->resync_max = MaxSector;
9247         } else if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
9248                 mddev->resync_min = mddev->curr_resync_completed;
9249         set_bit(MD_RECOVERY_DONE, &mddev->recovery);
9250         mddev->curr_resync = MD_RESYNC_NONE;
9251         spin_unlock(&mddev->lock);
9252
9253         wake_up(&resync_wait);
9254         md_wakeup_thread(mddev->thread);
9255         return;
9256 }
9257 EXPORT_SYMBOL_GPL(md_do_sync);
9258
9259 static bool rdev_removeable(struct md_rdev *rdev)
9260 {
9261         /* rdev is not used. */
9262         if (rdev->raid_disk < 0)
9263                 return false;
9264
9265         /* There are still inflight io, don't remove this rdev. */
9266         if (atomic_read(&rdev->nr_pending))
9267                 return false;
9268
9269         /*
9270          * An error occurred but has not yet been acknowledged by the metadata
9271          * handler, don't remove this rdev.
9272          */
9273         if (test_bit(Blocked, &rdev->flags))
9274                 return false;
9275
9276         /* Fautly rdev is not used, it's safe to remove it. */
9277         if (test_bit(Faulty, &rdev->flags))
9278                 return true;
9279
9280         /* Journal disk can only be removed if it's faulty. */
9281         if (test_bit(Journal, &rdev->flags))
9282                 return false;
9283
9284         /*
9285          * 'In_sync' is cleared while 'raid_disk' is valid, which means
9286          * replacement has just become active from pers->spare_active(), and
9287          * then pers->hot_remove_disk() will replace this rdev with replacement.
9288          */
9289         if (!test_bit(In_sync, &rdev->flags))
9290                 return true;
9291
9292         return false;
9293 }
9294
9295 static bool rdev_is_spare(struct md_rdev *rdev)
9296 {
9297         return !test_bit(Candidate, &rdev->flags) && rdev->raid_disk >= 0 &&
9298                !test_bit(In_sync, &rdev->flags) &&
9299                !test_bit(Journal, &rdev->flags) &&
9300                !test_bit(Faulty, &rdev->flags);
9301 }
9302
9303 static bool rdev_addable(struct md_rdev *rdev)
9304 {
9305         /* rdev is already used, don't add it again. */
9306         if (test_bit(Candidate, &rdev->flags) || rdev->raid_disk >= 0 ||
9307             test_bit(Faulty, &rdev->flags))
9308                 return false;
9309
9310         /* Allow to add journal disk. */
9311         if (test_bit(Journal, &rdev->flags))
9312                 return true;
9313
9314         /* Allow to add if array is read-write. */
9315         if (md_is_rdwr(rdev->mddev))
9316                 return true;
9317
9318         /*
9319          * For read-only array, only allow to readd a rdev. And if bitmap is
9320          * used, don't allow to readd a rdev that is too old.
9321          */
9322         if (rdev->saved_raid_disk >= 0 && !test_bit(Bitmap_sync, &rdev->flags))
9323                 return true;
9324
9325         return false;
9326 }
9327
9328 static bool md_spares_need_change(struct mddev *mddev)
9329 {
9330         struct md_rdev *rdev;
9331
9332         rcu_read_lock();
9333         rdev_for_each_rcu(rdev, mddev) {
9334                 if (rdev_removeable(rdev) || rdev_addable(rdev)) {
9335                         rcu_read_unlock();
9336                         return true;
9337                 }
9338         }
9339         rcu_read_unlock();
9340         return false;
9341 }
9342
9343 static int remove_and_add_spares(struct mddev *mddev,
9344                                  struct md_rdev *this)
9345 {
9346         struct md_rdev *rdev;
9347         int spares = 0;
9348         int removed = 0;
9349
9350         if (this && test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
9351                 /* Mustn't remove devices when resync thread is running */
9352                 return 0;
9353
9354         rdev_for_each(rdev, mddev) {
9355                 if ((this == NULL || rdev == this) && rdev_removeable(rdev) &&
9356                     !mddev->pers->hot_remove_disk(mddev, rdev)) {
9357                         sysfs_unlink_rdev(mddev, rdev);
9358                         rdev->saved_raid_disk = rdev->raid_disk;
9359                         rdev->raid_disk = -1;
9360                         removed++;
9361                 }
9362         }
9363
9364         if (removed && mddev->kobj.sd)
9365                 sysfs_notify_dirent_safe(mddev->sysfs_degraded);
9366
9367         if (this && removed)
9368                 goto no_add;
9369
9370         rdev_for_each(rdev, mddev) {
9371                 if (this && this != rdev)
9372                         continue;
9373                 if (rdev_is_spare(rdev))
9374                         spares++;
9375                 if (!rdev_addable(rdev))
9376                         continue;
9377                 if (!test_bit(Journal, &rdev->flags))
9378                         rdev->recovery_offset = 0;
9379                 if (mddev->pers->hot_add_disk(mddev, rdev) == 0) {
9380                         /* failure here is OK */
9381                         sysfs_link_rdev(mddev, rdev);
9382                         if (!test_bit(Journal, &rdev->flags))
9383                                 spares++;
9384                         md_new_event();
9385                         set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
9386                 }
9387         }
9388 no_add:
9389         if (removed)
9390                 set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
9391         return spares;
9392 }
9393
9394 static bool md_choose_sync_action(struct mddev *mddev, int *spares)
9395 {
9396         /* Check if reshape is in progress first. */
9397         if (mddev->reshape_position != MaxSector) {
9398                 if (mddev->pers->check_reshape == NULL ||
9399                     mddev->pers->check_reshape(mddev) != 0)
9400                         return false;
9401
9402                 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
9403                 clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
9404                 return true;
9405         }
9406
9407         /*
9408          * Remove any failed drives, then add spares if possible. Spares are
9409          * also removed and re-added, to allow the personality to fail the
9410          * re-add.
9411          */
9412         *spares = remove_and_add_spares(mddev, NULL);
9413         if (*spares) {
9414                 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
9415                 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
9416                 clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
9417
9418                 /* Start new recovery. */
9419                 set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
9420                 return true;
9421         }
9422
9423         /* Check if recovery is in progress. */
9424         if (mddev->recovery_cp < MaxSector) {
9425                 set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
9426                 clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
9427                 return true;
9428         }
9429
9430         /* Delay to choose resync/check/repair in md_do_sync(). */
9431         if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
9432                 return true;
9433
9434         /* Nothing to be done */
9435         return false;
9436 }
9437
9438 static void md_start_sync(struct work_struct *ws)
9439 {
9440         struct mddev *mddev = container_of(ws, struct mddev, sync_work);
9441         int spares = 0;
9442         bool suspend = false;
9443         char *name;
9444
9445         /*
9446          * If reshape is still in progress, spares won't be added or removed
9447          * from conf until reshape is done.
9448          */
9449         if (mddev->reshape_position == MaxSector &&
9450             md_spares_need_change(mddev)) {
9451                 suspend = true;
9452                 mddev_suspend(mddev, false);
9453         }
9454
9455         mddev_lock_nointr(mddev);
9456         if (!md_is_rdwr(mddev)) {
9457                 /*
9458                  * On a read-only array we can:
9459                  * - remove failed devices
9460                  * - add already-in_sync devices if the array itself is in-sync.
9461                  * As we only add devices that are already in-sync, we can
9462                  * activate the spares immediately.
9463                  */
9464                 remove_and_add_spares(mddev, NULL);
9465                 goto not_running;
9466         }
9467
9468         if (!md_choose_sync_action(mddev, &spares))
9469                 goto not_running;
9470
9471         if (!mddev->pers->sync_request)
9472                 goto not_running;
9473
9474         /*
9475          * We are adding a device or devices to an array which has the bitmap
9476          * stored on all devices. So make sure all bitmap pages get written.
9477          */
9478         if (spares)
9479                 mddev->bitmap_ops->write_all(mddev);
9480
9481         name = test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) ?
9482                         "reshape" : "resync";
9483         rcu_assign_pointer(mddev->sync_thread,
9484                            md_register_thread(md_do_sync, mddev, name));
9485         if (!mddev->sync_thread) {
9486                 pr_warn("%s: could not start resync thread...\n",
9487                         mdname(mddev));
9488                 /* leave the spares where they are, it shouldn't hurt */
9489                 goto not_running;
9490         }
9491
9492         mddev_unlock(mddev);
9493         /*
9494          * md_start_sync was triggered by MD_RECOVERY_NEEDED, so we should
9495          * not set it again. Otherwise, we may cause issue like this one:
9496          *     https://bugzilla.kernel.org/show_bug.cgi?id=218200
9497          * Therefore, use __mddev_resume(mddev, false).
9498          */
9499         if (suspend)
9500                 __mddev_resume(mddev, false);
9501         md_wakeup_thread(mddev->sync_thread);
9502         sysfs_notify_dirent_safe(mddev->sysfs_action);
9503         md_new_event();
9504         return;
9505
9506 not_running:
9507         clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
9508         clear_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
9509         clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
9510         clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
9511         clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
9512         mddev_unlock(mddev);
9513         /*
9514          * md_start_sync was triggered by MD_RECOVERY_NEEDED, so we should
9515          * not set it again. Otherwise, we may cause issue like this one:
9516          *     https://bugzilla.kernel.org/show_bug.cgi?id=218200
9517          * Therefore, use __mddev_resume(mddev, false).
9518          */
9519         if (suspend)
9520                 __mddev_resume(mddev, false);
9521
9522         wake_up(&resync_wait);
9523         if (test_and_clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery) &&
9524             mddev->sysfs_action)
9525                 sysfs_notify_dirent_safe(mddev->sysfs_action);
9526 }
9527
9528 static void unregister_sync_thread(struct mddev *mddev)
9529 {
9530         if (!test_bit(MD_RECOVERY_DONE, &mddev->recovery)) {
9531                 /* resync/recovery still happening */
9532                 clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
9533                 return;
9534         }
9535
9536         if (WARN_ON_ONCE(!mddev->sync_thread))
9537                 return;
9538
9539         md_reap_sync_thread(mddev);
9540 }
9541
9542 /*
9543  * This routine is regularly called by all per-raid-array threads to
9544  * deal with generic issues like resync and super-block update.
9545  * Raid personalities that don't have a thread (linear/raid0) do not
9546  * need this as they never do any recovery or update the superblock.
9547  *
9548  * It does not do any resync itself, but rather "forks" off other threads
9549  * to do that as needed.
9550  * When it is determined that resync is needed, we set MD_RECOVERY_RUNNING in
9551  * "->recovery" and create a thread at ->sync_thread.
9552  * When the thread finishes it sets MD_RECOVERY_DONE
9553  * and wakeups up this thread which will reap the thread and finish up.
9554  * This thread also removes any faulty devices (with nr_pending == 0).
9555  *
9556  * The overall approach is:
9557  *  1/ if the superblock needs updating, update it.
9558  *  2/ If a recovery thread is running, don't do anything else.
9559  *  3/ If recovery has finished, clean up, possibly marking spares active.
9560  *  4/ If there are any faulty devices, remove them.
9561  *  5/ If array is degraded, try to add spares devices
9562  *  6/ If array has spares or is not in-sync, start a resync thread.
9563  */
9564 void md_check_recovery(struct mddev *mddev)
9565 {
9566         if (mddev->bitmap)
9567                 mddev->bitmap_ops->daemon_work(mddev);
9568
9569         if (signal_pending(current)) {
9570                 if (mddev->pers->sync_request && !mddev->external) {
9571                         pr_debug("md: %s in immediate safe mode\n",
9572                                  mdname(mddev));
9573                         mddev->safemode = 2;
9574                 }
9575                 flush_signals(current);
9576         }
9577
9578         if (!md_is_rdwr(mddev) &&
9579             !test_bit(MD_RECOVERY_NEEDED, &mddev->recovery) &&
9580             !test_bit(MD_RECOVERY_DONE, &mddev->recovery))
9581                 return;
9582         if ( ! (
9583                 (mddev->sb_flags & ~ (1<<MD_SB_CHANGE_PENDING)) ||
9584                 test_bit(MD_RECOVERY_NEEDED, &mddev->recovery) ||
9585                 test_bit(MD_RECOVERY_DONE, &mddev->recovery) ||
9586                 (mddev->external == 0 && mddev->safemode == 1) ||
9587                 (mddev->safemode == 2
9588                  && !mddev->in_sync && mddev->recovery_cp == MaxSector)
9589                 ))
9590                 return;
9591
9592         if (mddev_trylock(mddev)) {
9593                 bool try_set_sync = mddev->safemode != 0;
9594
9595                 if (!mddev->external && mddev->safemode == 1)
9596                         mddev->safemode = 0;
9597
9598                 if (!md_is_rdwr(mddev)) {
9599                         struct md_rdev *rdev;
9600
9601                         if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) {
9602                                 unregister_sync_thread(mddev);
9603                                 goto unlock;
9604                         }
9605
9606                         if (!mddev->external && mddev->in_sync)
9607                                 /*
9608                                  * 'Blocked' flag not needed as failed devices
9609                                  * will be recorded if array switched to read/write.
9610                                  * Leaving it set will prevent the device
9611                                  * from being removed.
9612                                  */
9613                                 rdev_for_each(rdev, mddev)
9614                                         clear_bit(Blocked, &rdev->flags);
9615
9616                         /*
9617                          * There is no thread, but we need to call
9618                          * ->spare_active and clear saved_raid_disk
9619                          */
9620                         set_bit(MD_RECOVERY_INTR, &mddev->recovery);
9621                         md_reap_sync_thread(mddev);
9622
9623                         /*
9624                          * Let md_start_sync() to remove and add rdevs to the
9625                          * array.
9626                          */
9627                         if (md_spares_need_change(mddev)) {
9628                                 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
9629                                 queue_work(md_misc_wq, &mddev->sync_work);
9630                         }
9631
9632                         clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
9633                         clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
9634                         clear_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags);
9635
9636                         goto unlock;
9637                 }
9638
9639                 if (mddev_is_clustered(mddev)) {
9640                         struct md_rdev *rdev, *tmp;
9641                         /* kick the device if another node issued a
9642                          * remove disk.
9643                          */
9644                         rdev_for_each_safe(rdev, tmp, mddev) {
9645                                 if (test_and_clear_bit(ClusterRemove, &rdev->flags) &&
9646                                                 rdev->raid_disk < 0)
9647                                         md_kick_rdev_from_array(rdev);
9648                         }
9649                 }
9650
9651                 if (try_set_sync && !mddev->external && !mddev->in_sync) {
9652                         spin_lock(&mddev->lock);
9653                         set_in_sync(mddev);
9654                         spin_unlock(&mddev->lock);
9655                 }
9656
9657                 if (mddev->sb_flags)
9658                         md_update_sb(mddev, 0);
9659
9660                 /*
9661                  * Never start a new sync thread if MD_RECOVERY_RUNNING is
9662                  * still set.
9663                  */
9664                 if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) {
9665                         unregister_sync_thread(mddev);
9666                         goto unlock;
9667                 }
9668
9669                 /* Set RUNNING before clearing NEEDED to avoid
9670                  * any transients in the value of "sync_action".
9671                  */
9672                 mddev->curr_resync_completed = 0;
9673                 spin_lock(&mddev->lock);
9674                 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
9675                 spin_unlock(&mddev->lock);
9676                 /* Clear some bits that don't mean anything, but
9677                  * might be left set
9678                  */
9679                 clear_bit(MD_RECOVERY_INTR, &mddev->recovery);
9680                 clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
9681
9682                 if (test_and_clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery) &&
9683                     !test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)) {
9684                         queue_work(md_misc_wq, &mddev->sync_work);
9685                 } else {
9686                         clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
9687                         wake_up(&resync_wait);
9688                 }
9689
9690         unlock:
9691                 wake_up(&mddev->sb_wait);
9692                 mddev_unlock(mddev);
9693         }
9694 }
9695 EXPORT_SYMBOL(md_check_recovery);
9696
9697 void md_reap_sync_thread(struct mddev *mddev)
9698 {
9699         struct md_rdev *rdev;
9700         sector_t old_dev_sectors = mddev->dev_sectors;
9701         bool is_reshaped = false;
9702
9703         /* resync has finished, collect result */
9704         md_unregister_thread(mddev, &mddev->sync_thread);
9705         atomic_inc(&mddev->sync_seq);
9706
9707         if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery) &&
9708             !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
9709             mddev->degraded != mddev->raid_disks) {
9710                 /* success...*/
9711                 /* activate any spares */
9712                 if (mddev->pers->spare_active(mddev)) {
9713                         sysfs_notify_dirent_safe(mddev->sysfs_degraded);
9714                         set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
9715                 }
9716         }
9717         if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
9718             mddev->pers->finish_reshape) {
9719                 mddev->pers->finish_reshape(mddev);
9720                 if (mddev_is_clustered(mddev))
9721                         is_reshaped = true;
9722         }
9723
9724         /* If array is no-longer degraded, then any saved_raid_disk
9725          * information must be scrapped.
9726          */
9727         if (!mddev->degraded)
9728                 rdev_for_each(rdev, mddev)
9729                         rdev->saved_raid_disk = -1;
9730
9731         md_update_sb(mddev, 1);
9732         /* MD_SB_CHANGE_PENDING should be cleared by md_update_sb, so we can
9733          * call resync_finish here if MD_CLUSTER_RESYNC_LOCKED is set by
9734          * clustered raid */
9735         if (test_and_clear_bit(MD_CLUSTER_RESYNC_LOCKED, &mddev->flags))
9736                 md_cluster_ops->resync_finish(mddev);
9737         clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
9738         clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
9739         clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
9740         clear_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
9741         clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
9742         clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
9743         /*
9744          * We call md_cluster_ops->update_size here because sync_size could
9745          * be changed by md_update_sb, and MD_RECOVERY_RESHAPE is cleared,
9746          * so it is time to update size across cluster.
9747          */
9748         if (mddev_is_clustered(mddev) && is_reshaped
9749                                       && !test_bit(MD_CLOSING, &mddev->flags))
9750                 md_cluster_ops->update_size(mddev, old_dev_sectors);
9751         /* flag recovery needed just to double check */
9752         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
9753         sysfs_notify_dirent_safe(mddev->sysfs_completed);
9754         sysfs_notify_dirent_safe(mddev->sysfs_action);
9755         md_new_event();
9756         if (mddev->event_work.func)
9757                 queue_work(md_misc_wq, &mddev->event_work);
9758         wake_up(&resync_wait);
9759 }
9760 EXPORT_SYMBOL(md_reap_sync_thread);
9761
9762 void md_wait_for_blocked_rdev(struct md_rdev *rdev, struct mddev *mddev)
9763 {
9764         sysfs_notify_dirent_safe(rdev->sysfs_state);
9765         wait_event_timeout(rdev->blocked_wait,
9766                            !test_bit(Blocked, &rdev->flags) &&
9767                            !test_bit(BlockedBadBlocks, &rdev->flags),
9768                            msecs_to_jiffies(5000));
9769         rdev_dec_pending(rdev, mddev);
9770 }
9771 EXPORT_SYMBOL(md_wait_for_blocked_rdev);
9772
9773 void md_finish_reshape(struct mddev *mddev)
9774 {
9775         /* called be personality module when reshape completes. */
9776         struct md_rdev *rdev;
9777
9778         rdev_for_each(rdev, mddev) {
9779                 if (rdev->data_offset > rdev->new_data_offset)
9780                         rdev->sectors += rdev->data_offset - rdev->new_data_offset;
9781                 else
9782                         rdev->sectors -= rdev->new_data_offset - rdev->data_offset;
9783                 rdev->data_offset = rdev->new_data_offset;
9784         }
9785 }
9786 EXPORT_SYMBOL(md_finish_reshape);
9787
9788 /* Bad block management */
9789
9790 /* Returns 1 on success, 0 on failure */
9791 int rdev_set_badblocks(struct md_rdev *rdev, sector_t s, int sectors,
9792                        int is_new)
9793 {
9794         struct mddev *mddev = rdev->mddev;
9795         int rv;
9796         if (is_new)
9797                 s += rdev->new_data_offset;
9798         else
9799                 s += rdev->data_offset;
9800         rv = badblocks_set(&rdev->badblocks, s, sectors, 0);
9801         if (rv == 0) {
9802                 /* Make sure they get written out promptly */
9803                 if (test_bit(ExternalBbl, &rdev->flags))
9804                         sysfs_notify_dirent_safe(rdev->sysfs_unack_badblocks);
9805                 sysfs_notify_dirent_safe(rdev->sysfs_state);
9806                 set_mask_bits(&mddev->sb_flags, 0,
9807                               BIT(MD_SB_CHANGE_CLEAN) | BIT(MD_SB_CHANGE_PENDING));
9808                 md_wakeup_thread(rdev->mddev->thread);
9809                 return 1;
9810         } else
9811                 return 0;
9812 }
9813 EXPORT_SYMBOL_GPL(rdev_set_badblocks);
9814
9815 int rdev_clear_badblocks(struct md_rdev *rdev, sector_t s, int sectors,
9816                          int is_new)
9817 {
9818         int rv;
9819         if (is_new)
9820                 s += rdev->new_data_offset;
9821         else
9822                 s += rdev->data_offset;
9823         rv = badblocks_clear(&rdev->badblocks, s, sectors);
9824         if ((rv == 0) && test_bit(ExternalBbl, &rdev->flags))
9825                 sysfs_notify_dirent_safe(rdev->sysfs_badblocks);
9826         return rv;
9827 }
9828 EXPORT_SYMBOL_GPL(rdev_clear_badblocks);
9829
9830 static int md_notify_reboot(struct notifier_block *this,
9831                             unsigned long code, void *x)
9832 {
9833         struct mddev *mddev, *n;
9834         int need_delay = 0;
9835
9836         spin_lock(&all_mddevs_lock);
9837         list_for_each_entry_safe(mddev, n, &all_mddevs, all_mddevs) {
9838                 if (!mddev_get(mddev))
9839                         continue;
9840                 spin_unlock(&all_mddevs_lock);
9841                 if (mddev_trylock(mddev)) {
9842                         if (mddev->pers)
9843                                 __md_stop_writes(mddev);
9844                         if (mddev->persistent)
9845                                 mddev->safemode = 2;
9846                         mddev_unlock(mddev);
9847                 }
9848                 need_delay = 1;
9849                 mddev_put(mddev);
9850                 spin_lock(&all_mddevs_lock);
9851         }
9852         spin_unlock(&all_mddevs_lock);
9853
9854         /*
9855          * certain more exotic SCSI devices are known to be
9856          * volatile wrt too early system reboots. While the
9857          * right place to handle this issue is the given
9858          * driver, we do want to have a safe RAID driver ...
9859          */
9860         if (need_delay)
9861                 msleep(1000);
9862
9863         return NOTIFY_DONE;
9864 }
9865
9866 static struct notifier_block md_notifier = {
9867         .notifier_call  = md_notify_reboot,
9868         .next           = NULL,
9869         .priority       = INT_MAX, /* before any real devices */
9870 };
9871
9872 static void md_geninit(void)
9873 {
9874         pr_debug("md: sizeof(mdp_super_t) = %d\n", (int)sizeof(mdp_super_t));
9875
9876         proc_create("mdstat", S_IRUGO, NULL, &mdstat_proc_ops);
9877 }
9878
9879 static int __init md_init(void)
9880 {
9881         int ret = -ENOMEM;
9882
9883         md_wq = alloc_workqueue("md", WQ_MEM_RECLAIM, 0);
9884         if (!md_wq)
9885                 goto err_wq;
9886
9887         md_misc_wq = alloc_workqueue("md_misc", 0, 0);
9888         if (!md_misc_wq)
9889                 goto err_misc_wq;
9890
9891         md_bitmap_wq = alloc_workqueue("md_bitmap", WQ_MEM_RECLAIM | WQ_UNBOUND,
9892                                        0);
9893         if (!md_bitmap_wq)
9894                 goto err_bitmap_wq;
9895
9896         ret = __register_blkdev(MD_MAJOR, "md", md_probe);
9897         if (ret < 0)
9898                 goto err_md;
9899
9900         ret = __register_blkdev(0, "mdp", md_probe);
9901         if (ret < 0)
9902                 goto err_mdp;
9903         mdp_major = ret;
9904
9905         register_reboot_notifier(&md_notifier);
9906         raid_table_header = register_sysctl("dev/raid", raid_table);
9907
9908         md_geninit();
9909         return 0;
9910
9911 err_mdp:
9912         unregister_blkdev(MD_MAJOR, "md");
9913 err_md:
9914         destroy_workqueue(md_bitmap_wq);
9915 err_bitmap_wq:
9916         destroy_workqueue(md_misc_wq);
9917 err_misc_wq:
9918         destroy_workqueue(md_wq);
9919 err_wq:
9920         return ret;
9921 }
9922
9923 static void check_sb_changes(struct mddev *mddev, struct md_rdev *rdev)
9924 {
9925         struct mdp_superblock_1 *sb = page_address(rdev->sb_page);
9926         struct md_rdev *rdev2, *tmp;
9927         int role, ret;
9928
9929         /*
9930          * If size is changed in another node then we need to
9931          * do resize as well.
9932          */
9933         if (mddev->dev_sectors != le64_to_cpu(sb->size)) {
9934                 ret = mddev->pers->resize(mddev, le64_to_cpu(sb->size));
9935                 if (ret)
9936                         pr_info("md-cluster: resize failed\n");
9937                 else
9938                         mddev->bitmap_ops->update_sb(mddev->bitmap);
9939         }
9940
9941         /* Check for change of roles in the active devices */
9942         rdev_for_each_safe(rdev2, tmp, mddev) {
9943                 if (test_bit(Faulty, &rdev2->flags))
9944                         continue;
9945
9946                 /* Check if the roles changed */
9947                 role = le16_to_cpu(sb->dev_roles[rdev2->desc_nr]);
9948
9949                 if (test_bit(Candidate, &rdev2->flags)) {
9950                         if (role == MD_DISK_ROLE_FAULTY) {
9951                                 pr_info("md: Removing Candidate device %pg because add failed\n",
9952                                         rdev2->bdev);
9953                                 md_kick_rdev_from_array(rdev2);
9954                                 continue;
9955                         }
9956                         else
9957                                 clear_bit(Candidate, &rdev2->flags);
9958                 }
9959
9960                 if (role != rdev2->raid_disk) {
9961                         /*
9962                          * got activated except reshape is happening.
9963                          */
9964                         if (rdev2->raid_disk == -1 && role != MD_DISK_ROLE_SPARE &&
9965                             !(le32_to_cpu(sb->feature_map) &
9966                               MD_FEATURE_RESHAPE_ACTIVE) &&
9967                             !md_cluster_ops->resync_status_get(mddev)) {
9968                                 /*
9969                                  * -1 to make raid1_add_disk() set conf->fullsync
9970                                  * to 1. This could avoid skipping sync when the
9971                                  * remote node is down during resyncing.
9972                                  */
9973                                 if ((le32_to_cpu(sb->feature_map)
9974                                     & MD_FEATURE_RECOVERY_OFFSET))
9975                                         rdev2->saved_raid_disk = -1;
9976                                 else
9977                                         rdev2->saved_raid_disk = role;
9978                                 ret = remove_and_add_spares(mddev, rdev2);
9979                                 pr_info("Activated spare: %pg\n",
9980                                         rdev2->bdev);
9981                                 /* wakeup mddev->thread here, so array could
9982                                  * perform resync with the new activated disk */
9983                                 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
9984                                 md_wakeup_thread(mddev->thread);
9985                         }
9986                         /* device faulty
9987                          * We just want to do the minimum to mark the disk
9988                          * as faulty. The recovery is performed by the
9989                          * one who initiated the error.
9990                          */
9991                         if (role == MD_DISK_ROLE_FAULTY ||
9992                             role == MD_DISK_ROLE_JOURNAL) {
9993                                 md_error(mddev, rdev2);
9994                                 clear_bit(Blocked, &rdev2->flags);
9995                         }
9996                 }
9997         }
9998
9999         if (mddev->raid_disks != le32_to_cpu(sb->raid_disks)) {
10000                 ret = update_raid_disks(mddev, le32_to_cpu(sb->raid_disks));
10001                 if (ret)
10002                         pr_warn("md: updating array disks failed. %d\n", ret);
10003         }
10004
10005         /*
10006          * Since mddev->delta_disks has already updated in update_raid_disks,
10007          * so it is time to check reshape.
10008          */
10009         if (test_bit(MD_RESYNCING_REMOTE, &mddev->recovery) &&
10010             (le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE)) {
10011                 /*
10012                  * reshape is happening in the remote node, we need to
10013                  * update reshape_position and call start_reshape.
10014                  */
10015                 mddev->reshape_position = le64_to_cpu(sb->reshape_position);
10016                 if (mddev->pers->update_reshape_pos)
10017                         mddev->pers->update_reshape_pos(mddev);
10018                 if (mddev->pers->start_reshape)
10019                         mddev->pers->start_reshape(mddev);
10020         } else if (test_bit(MD_RESYNCING_REMOTE, &mddev->recovery) &&
10021                    mddev->reshape_position != MaxSector &&
10022                    !(le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE)) {
10023                 /* reshape is just done in another node. */
10024                 mddev->reshape_position = MaxSector;
10025                 if (mddev->pers->update_reshape_pos)
10026                         mddev->pers->update_reshape_pos(mddev);
10027         }
10028
10029         /* Finally set the event to be up to date */
10030         mddev->events = le64_to_cpu(sb->events);
10031 }
10032
10033 static int read_rdev(struct mddev *mddev, struct md_rdev *rdev)
10034 {
10035         int err;
10036         struct page *swapout = rdev->sb_page;
10037         struct mdp_superblock_1 *sb;
10038
10039         /* Store the sb page of the rdev in the swapout temporary
10040          * variable in case we err in the future
10041          */
10042         rdev->sb_page = NULL;
10043         err = alloc_disk_sb(rdev);
10044         if (err == 0) {
10045                 ClearPageUptodate(rdev->sb_page);
10046                 rdev->sb_loaded = 0;
10047                 err = super_types[mddev->major_version].
10048                         load_super(rdev, NULL, mddev->minor_version);
10049         }
10050         if (err < 0) {
10051                 pr_warn("%s: %d Could not reload rdev(%d) err: %d. Restoring old values\n",
10052                                 __func__, __LINE__, rdev->desc_nr, err);
10053                 if (rdev->sb_page)
10054                         put_page(rdev->sb_page);
10055                 rdev->sb_page = swapout;
10056                 rdev->sb_loaded = 1;
10057                 return err;
10058         }
10059
10060         sb = page_address(rdev->sb_page);
10061         /* Read the offset unconditionally, even if MD_FEATURE_RECOVERY_OFFSET
10062          * is not set
10063          */
10064
10065         if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RECOVERY_OFFSET))
10066                 rdev->recovery_offset = le64_to_cpu(sb->recovery_offset);
10067
10068         /* The other node finished recovery, call spare_active to set
10069          * device In_sync and mddev->degraded
10070          */
10071         if (rdev->recovery_offset == MaxSector &&
10072             !test_bit(In_sync, &rdev->flags) &&
10073             mddev->pers->spare_active(mddev))
10074                 sysfs_notify_dirent_safe(mddev->sysfs_degraded);
10075
10076         put_page(swapout);
10077         return 0;
10078 }
10079
10080 void md_reload_sb(struct mddev *mddev, int nr)
10081 {
10082         struct md_rdev *rdev = NULL, *iter;
10083         int err;
10084
10085         /* Find the rdev */
10086         rdev_for_each_rcu(iter, mddev) {
10087                 if (iter->desc_nr == nr) {
10088                         rdev = iter;
10089                         break;
10090                 }
10091         }
10092
10093         if (!rdev) {
10094                 pr_warn("%s: %d Could not find rdev with nr %d\n", __func__, __LINE__, nr);
10095                 return;
10096         }
10097
10098         err = read_rdev(mddev, rdev);
10099         if (err < 0)
10100                 return;
10101
10102         check_sb_changes(mddev, rdev);
10103
10104         /* Read all rdev's to update recovery_offset */
10105         rdev_for_each_rcu(rdev, mddev) {
10106                 if (!test_bit(Faulty, &rdev->flags))
10107                         read_rdev(mddev, rdev);
10108         }
10109 }
10110 EXPORT_SYMBOL(md_reload_sb);
10111
10112 #ifndef MODULE
10113
10114 /*
10115  * Searches all registered partitions for autorun RAID arrays
10116  * at boot time.
10117  */
10118
10119 static DEFINE_MUTEX(detected_devices_mutex);
10120 static LIST_HEAD(all_detected_devices);
10121 struct detected_devices_node {
10122         struct list_head list;
10123         dev_t dev;
10124 };
10125
10126 void md_autodetect_dev(dev_t dev)
10127 {
10128         struct detected_devices_node *node_detected_dev;
10129
10130         node_detected_dev = kzalloc(sizeof(*node_detected_dev), GFP_KERNEL);
10131         if (node_detected_dev) {
10132                 node_detected_dev->dev = dev;
10133                 mutex_lock(&detected_devices_mutex);
10134                 list_add_tail(&node_detected_dev->list, &all_detected_devices);
10135                 mutex_unlock(&detected_devices_mutex);
10136         }
10137 }
10138
10139 void md_autostart_arrays(int part)
10140 {
10141         struct md_rdev *rdev;
10142         struct detected_devices_node *node_detected_dev;
10143         dev_t dev;
10144         int i_scanned, i_passed;
10145
10146         i_scanned = 0;
10147         i_passed = 0;
10148
10149         pr_info("md: Autodetecting RAID arrays.\n");
10150
10151         mutex_lock(&detected_devices_mutex);
10152         while (!list_empty(&all_detected_devices) && i_scanned < INT_MAX) {
10153                 i_scanned++;
10154                 node_detected_dev = list_entry(all_detected_devices.next,
10155                                         struct detected_devices_node, list);
10156                 list_del(&node_detected_dev->list);
10157                 dev = node_detected_dev->dev;
10158                 kfree(node_detected_dev);
10159                 mutex_unlock(&detected_devices_mutex);
10160                 rdev = md_import_device(dev,0, 90);
10161                 mutex_lock(&detected_devices_mutex);
10162                 if (IS_ERR(rdev))
10163                         continue;
10164
10165                 if (test_bit(Faulty, &rdev->flags))
10166                         continue;
10167
10168                 set_bit(AutoDetected, &rdev->flags);
10169                 list_add(&rdev->same_set, &pending_raid_disks);
10170                 i_passed++;
10171         }
10172         mutex_unlock(&detected_devices_mutex);
10173
10174         pr_debug("md: Scanned %d and added %d devices.\n", i_scanned, i_passed);
10175
10176         autorun_devices(part);
10177 }
10178
10179 #endif /* !MODULE */
10180
10181 static __exit void md_exit(void)
10182 {
10183         struct mddev *mddev, *n;
10184         int delay = 1;
10185
10186         unregister_blkdev(MD_MAJOR,"md");
10187         unregister_blkdev(mdp_major, "mdp");
10188         unregister_reboot_notifier(&md_notifier);
10189         unregister_sysctl_table(raid_table_header);
10190
10191         /* We cannot unload the modules while some process is
10192          * waiting for us in select() or poll() - wake them up
10193          */
10194         md_unloading = 1;
10195         while (waitqueue_active(&md_event_waiters)) {
10196                 /* not safe to leave yet */
10197                 wake_up(&md_event_waiters);
10198                 msleep(delay);
10199                 delay += delay;
10200         }
10201         remove_proc_entry("mdstat", NULL);
10202
10203         spin_lock(&all_mddevs_lock);
10204         list_for_each_entry_safe(mddev, n, &all_mddevs, all_mddevs) {
10205                 if (!mddev_get(mddev))
10206                         continue;
10207                 spin_unlock(&all_mddevs_lock);
10208                 export_array(mddev);
10209                 mddev->ctime = 0;
10210                 mddev->hold_active = 0;
10211                 /*
10212                  * As the mddev is now fully clear, mddev_put will schedule
10213                  * the mddev for destruction by a workqueue, and the
10214                  * destroy_workqueue() below will wait for that to complete.
10215                  */
10216                 mddev_put(mddev);
10217                 spin_lock(&all_mddevs_lock);
10218         }
10219         spin_unlock(&all_mddevs_lock);
10220
10221         destroy_workqueue(md_misc_wq);
10222         destroy_workqueue(md_bitmap_wq);
10223         destroy_workqueue(md_wq);
10224 }
10225
10226 subsys_initcall(md_init);
10227 module_exit(md_exit)
10228
10229 static int get_ro(char *buffer, const struct kernel_param *kp)
10230 {
10231         return sprintf(buffer, "%d\n", start_readonly);
10232 }
10233 static int set_ro(const char *val, const struct kernel_param *kp)
10234 {
10235         return kstrtouint(val, 10, (unsigned int *)&start_readonly);
10236 }
10237
10238 module_param_call(start_ro, set_ro, get_ro, NULL, S_IRUSR|S_IWUSR);
10239 module_param(start_dirty_degraded, int, S_IRUGO|S_IWUSR);
10240 module_param_call(new_array, add_named_array, NULL, NULL, S_IWUSR);
10241 module_param(create_on_open, bool, S_IRUSR|S_IWUSR);
10242
10243 MODULE_LICENSE("GPL");
10244 MODULE_DESCRIPTION("MD RAID framework");
10245 MODULE_ALIAS("md");
10246 MODULE_ALIAS_BLOCKDEV_MAJOR(MD_MAJOR);
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