Version:  2.0.40 2.2.26 2.4.37 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8

Linux/drivers/md/md.c

  1 /*
  2    md.c : Multiple Devices driver for Linux
  3      Copyright (C) 1998, 1999, 2000 Ingo Molnar
  4 
  5      completely rewritten, based on the MD driver code from Marc Zyngier
  6 
  7    Changes:
  8 
  9    - RAID-1/RAID-5 extensions by Miguel de Icaza, Gadi Oxman, Ingo Molnar
 10    - RAID-6 extensions by H. Peter Anvin <hpa@zytor.com>
 11    - boot support for linear and striped mode by Harald Hoyer <HarryH@Royal.Net>
 12    - kerneld support by Boris Tobotras <boris@xtalk.msk.su>
 13    - kmod support by: Cyrus Durgin
 14    - RAID0 bugfixes: Mark Anthony Lisher <markal@iname.com>
 15    - Devfs support by Richard Gooch <rgooch@atnf.csiro.au>
 16 
 17    - lots of fixes and improvements to the RAID1/RAID5 and generic
 18      RAID code (such as request based resynchronization):
 19 
 20      Neil Brown <neilb@cse.unsw.edu.au>.
 21 
 22    - persistent bitmap code
 23      Copyright (C) 2003-2004, Paul Clements, SteelEye Technology, Inc.
 24 
 25    This program is free software; you can redistribute it and/or modify
 26    it under the terms of the GNU General Public License as published by
 27    the Free Software Foundation; either version 2, or (at your option)
 28    any later version.
 29 
 30    You should have received a copy of the GNU General Public License
 31    (for example /usr/src/linux/COPYING); if not, write to the Free
 32    Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 33 */
 34 
 35 #include <linux/kthread.h>
 36 #include <linux/blkdev.h>
 37 #include <linux/badblocks.h>
 38 #include <linux/sysctl.h>
 39 #include <linux/seq_file.h>
 40 #include <linux/fs.h>
 41 #include <linux/poll.h>
 42 #include <linux/ctype.h>
 43 #include <linux/string.h>
 44 #include <linux/hdreg.h>
 45 #include <linux/proc_fs.h>
 46 #include <linux/random.h>
 47 #include <linux/module.h>
 48 #include <linux/reboot.h>
 49 #include <linux/file.h>
 50 #include <linux/compat.h>
 51 #include <linux/delay.h>
 52 #include <linux/raid/md_p.h>
 53 #include <linux/raid/md_u.h>
 54 #include <linux/slab.h>
 55 #include "md.h"
 56 #include "bitmap.h"
 57 #include "md-cluster.h"
 58 
 59 #ifndef MODULE
 60 static void autostart_arrays(int part);
 61 #endif
 62 
 63 /* pers_list is a list of registered personalities protected
 64  * by pers_lock.
 65  * pers_lock does extra service to protect accesses to
 66  * mddev->thread when the mutex cannot be held.
 67  */
 68 static LIST_HEAD(pers_list);
 69 static DEFINE_SPINLOCK(pers_lock);
 70 
 71 struct md_cluster_operations *md_cluster_ops;
 72 EXPORT_SYMBOL(md_cluster_ops);
 73 struct module *md_cluster_mod;
 74 EXPORT_SYMBOL(md_cluster_mod);
 75 
 76 static DECLARE_WAIT_QUEUE_HEAD(resync_wait);
 77 static struct workqueue_struct *md_wq;
 78 static struct workqueue_struct *md_misc_wq;
 79 
 80 static int remove_and_add_spares(struct mddev *mddev,
 81                                  struct md_rdev *this);
 82 static void mddev_detach(struct mddev *mddev);
 83 
 84 /*
 85  * Default number of read corrections we'll attempt on an rdev
 86  * before ejecting it from the array. We divide the read error
 87  * count by 2 for every hour elapsed between read errors.
 88  */
 89 #define MD_DEFAULT_MAX_CORRECTED_READ_ERRORS 20
 90 /*
 91  * Current RAID-1,4,5 parallel reconstruction 'guaranteed speed limit'
 92  * is 1000 KB/sec, so the extra system load does not show up that much.
 93  * Increase it if you want to have more _guaranteed_ speed. Note that
 94  * the RAID driver will use the maximum available bandwidth if the IO
 95  * subsystem is idle. There is also an 'absolute maximum' reconstruction
 96  * speed limit - in case reconstruction slows down your system despite
 97  * idle IO detection.
 98  *
 99  * you can change it via /proc/sys/dev/raid/speed_limit_min and _max.
100  * or /sys/block/mdX/md/sync_speed_{min,max}
101  */
102 
103 static int sysctl_speed_limit_min = 1000;
104 static int sysctl_speed_limit_max = 200000;
105 static inline int speed_min(struct mddev *mddev)
106 {
107         return mddev->sync_speed_min ?
108                 mddev->sync_speed_min : sysctl_speed_limit_min;
109 }
110 
111 static inline int speed_max(struct mddev *mddev)
112 {
113         return mddev->sync_speed_max ?
114                 mddev->sync_speed_max : sysctl_speed_limit_max;
115 }
116 
117 static struct ctl_table_header *raid_table_header;
118 
119 static struct ctl_table raid_table[] = {
120         {
121                 .procname       = "speed_limit_min",
122                 .data           = &sysctl_speed_limit_min,
123                 .maxlen         = sizeof(int),
124                 .mode           = S_IRUGO|S_IWUSR,
125                 .proc_handler   = proc_dointvec,
126         },
127         {
128                 .procname       = "speed_limit_max",
129                 .data           = &sysctl_speed_limit_max,
130                 .maxlen         = sizeof(int),
131                 .mode           = S_IRUGO|S_IWUSR,
132                 .proc_handler   = proc_dointvec,
133         },
134         { }
135 };
136 
137 static struct ctl_table raid_dir_table[] = {
138         {
139                 .procname       = "raid",
140                 .maxlen         = 0,
141                 .mode           = S_IRUGO|S_IXUGO,
142                 .child          = raid_table,
143         },
144         { }
145 };
146 
147 static struct ctl_table raid_root_table[] = {
148         {
149                 .procname       = "dev",
150                 .maxlen         = 0,
151                 .mode           = 0555,
152                 .child          = raid_dir_table,
153         },
154         {  }
155 };
156 
157 static const struct block_device_operations md_fops;
158 
159 static int start_readonly;
160 
161 /* bio_clone_mddev
162  * like bio_clone, but with a local bio set
163  */
164 
165 struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs,
166                             struct mddev *mddev)
167 {
168         struct bio *b;
169 
170         if (!mddev || !mddev->bio_set)
171                 return bio_alloc(gfp_mask, nr_iovecs);
172 
173         b = bio_alloc_bioset(gfp_mask, nr_iovecs, mddev->bio_set);
174         if (!b)
175                 return NULL;
176         return b;
177 }
178 EXPORT_SYMBOL_GPL(bio_alloc_mddev);
179 
180 struct bio *bio_clone_mddev(struct bio *bio, gfp_t gfp_mask,
181                             struct mddev *mddev)
182 {
183         if (!mddev || !mddev->bio_set)
184                 return bio_clone(bio, gfp_mask);
185 
186         return bio_clone_bioset(bio, gfp_mask, mddev->bio_set);
187 }
188 EXPORT_SYMBOL_GPL(bio_clone_mddev);
189 
190 /*
191  * We have a system wide 'event count' that is incremented
192  * on any 'interesting' event, and readers of /proc/mdstat
193  * can use 'poll' or 'select' to find out when the event
194  * count increases.
195  *
196  * Events are:
197  *  start array, stop array, error, add device, remove device,
198  *  start build, activate spare
199  */
200 static DECLARE_WAIT_QUEUE_HEAD(md_event_waiters);
201 static atomic_t md_event_count;
202 void md_new_event(struct mddev *mddev)
203 {
204         atomic_inc(&md_event_count);
205         wake_up(&md_event_waiters);
206 }
207 EXPORT_SYMBOL_GPL(md_new_event);
208 
209 /*
210  * Enables to iterate over all existing md arrays
211  * all_mddevs_lock protects this list.
212  */
213 static LIST_HEAD(all_mddevs);
214 static DEFINE_SPINLOCK(all_mddevs_lock);
215 
216 /*
217  * iterates through all used mddevs in the system.
218  * We take care to grab the all_mddevs_lock whenever navigating
219  * the list, and to always hold a refcount when unlocked.
220  * Any code which breaks out of this loop while own
221  * a reference to the current mddev and must mddev_put it.
222  */
223 #define for_each_mddev(_mddev,_tmp)                                     \
224                                                                         \
225         for (({ spin_lock(&all_mddevs_lock);                            \
226                 _tmp = all_mddevs.next;                                 \
227                 _mddev = NULL;});                                       \
228              ({ if (_tmp != &all_mddevs)                                \
229                         mddev_get(list_entry(_tmp, struct mddev, all_mddevs));\
230                 spin_unlock(&all_mddevs_lock);                          \
231                 if (_mddev) mddev_put(_mddev);                          \
232                 _mddev = list_entry(_tmp, struct mddev, all_mddevs);    \
233                 _tmp != &all_mddevs;});                                 \
234              ({ spin_lock(&all_mddevs_lock);                            \
235                 _tmp = _tmp->next;})                                    \
236                 )
237 
238 /* Rather than calling directly into the personality make_request function,
239  * IO requests come here first so that we can check if the device is
240  * being suspended pending a reconfiguration.
241  * We hold a refcount over the call to ->make_request.  By the time that
242  * call has finished, the bio has been linked into some internal structure
243  * and so is visible to ->quiesce(), so we don't need the refcount any more.
244  */
245 static blk_qc_t md_make_request(struct request_queue *q, struct bio *bio)
246 {
247         const int rw = bio_data_dir(bio);
248         struct mddev *mddev = q->queuedata;
249         unsigned int sectors;
250         int cpu;
251 
252         blk_queue_split(q, &bio, q->bio_split);
253 
254         if (mddev == NULL || mddev->pers == NULL) {
255                 bio_io_error(bio);
256                 return BLK_QC_T_NONE;
257         }
258         if (mddev->ro == 1 && unlikely(rw == WRITE)) {
259                 if (bio_sectors(bio) != 0)
260                         bio->bi_error = -EROFS;
261                 bio_endio(bio);
262                 return BLK_QC_T_NONE;
263         }
264         smp_rmb(); /* Ensure implications of  'active' are visible */
265         rcu_read_lock();
266         if (mddev->suspended) {
267                 DEFINE_WAIT(__wait);
268                 for (;;) {
269                         prepare_to_wait(&mddev->sb_wait, &__wait,
270                                         TASK_UNINTERRUPTIBLE);
271                         if (!mddev->suspended)
272                                 break;
273                         rcu_read_unlock();
274                         schedule();
275                         rcu_read_lock();
276                 }
277                 finish_wait(&mddev->sb_wait, &__wait);
278         }
279         atomic_inc(&mddev->active_io);
280         rcu_read_unlock();
281 
282         /*
283          * save the sectors now since our bio can
284          * go away inside make_request
285          */
286         sectors = bio_sectors(bio);
287         /* bio could be mergeable after passing to underlayer */
288         bio->bi_opf &= ~REQ_NOMERGE;
289         mddev->pers->make_request(mddev, bio);
290 
291         cpu = part_stat_lock();
292         part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]);
293         part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw], sectors);
294         part_stat_unlock();
295 
296         if (atomic_dec_and_test(&mddev->active_io) && mddev->suspended)
297                 wake_up(&mddev->sb_wait);
298 
299         return BLK_QC_T_NONE;
300 }
301 
302 /* mddev_suspend makes sure no new requests are submitted
303  * to the device, and that any requests that have been submitted
304  * are completely handled.
305  * Once mddev_detach() is called and completes, the module will be
306  * completely unused.
307  */
308 void mddev_suspend(struct mddev *mddev)
309 {
310         WARN_ON_ONCE(mddev->thread && current == mddev->thread->tsk);
311         if (mddev->suspended++)
312                 return;
313         synchronize_rcu();
314         wait_event(mddev->sb_wait, atomic_read(&mddev->active_io) == 0);
315         mddev->pers->quiesce(mddev, 1);
316 
317         del_timer_sync(&mddev->safemode_timer);
318 }
319 EXPORT_SYMBOL_GPL(mddev_suspend);
320 
321 void mddev_resume(struct mddev *mddev)
322 {
323         if (--mddev->suspended)
324                 return;
325         wake_up(&mddev->sb_wait);
326         mddev->pers->quiesce(mddev, 0);
327 
328         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
329         md_wakeup_thread(mddev->thread);
330         md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
331 }
332 EXPORT_SYMBOL_GPL(mddev_resume);
333 
334 int mddev_congested(struct mddev *mddev, int bits)
335 {
336         struct md_personality *pers = mddev->pers;
337         int ret = 0;
338 
339         rcu_read_lock();
340         if (mddev->suspended)
341                 ret = 1;
342         else if (pers && pers->congested)
343                 ret = pers->congested(mddev, bits);
344         rcu_read_unlock();
345         return ret;
346 }
347 EXPORT_SYMBOL_GPL(mddev_congested);
348 static int md_congested(void *data, int bits)
349 {
350         struct mddev *mddev = data;
351         return mddev_congested(mddev, bits);
352 }
353 
354 /*
355  * Generic flush handling for md
356  */
357 
358 static void md_end_flush(struct bio *bio)
359 {
360         struct md_rdev *rdev = bio->bi_private;
361         struct mddev *mddev = rdev->mddev;
362 
363         rdev_dec_pending(rdev, mddev);
364 
365         if (atomic_dec_and_test(&mddev->flush_pending)) {
366                 /* The pre-request flush has finished */
367                 queue_work(md_wq, &mddev->flush_work);
368         }
369         bio_put(bio);
370 }
371 
372 static void md_submit_flush_data(struct work_struct *ws);
373 
374 static void submit_flushes(struct work_struct *ws)
375 {
376         struct mddev *mddev = container_of(ws, struct mddev, flush_work);
377         struct md_rdev *rdev;
378 
379         INIT_WORK(&mddev->flush_work, md_submit_flush_data);
380         atomic_set(&mddev->flush_pending, 1);
381         rcu_read_lock();
382         rdev_for_each_rcu(rdev, mddev)
383                 if (rdev->raid_disk >= 0 &&
384                     !test_bit(Faulty, &rdev->flags)) {
385                         /* Take two references, one is dropped
386                          * when request finishes, one after
387                          * we reclaim rcu_read_lock
388                          */
389                         struct bio *bi;
390                         atomic_inc(&rdev->nr_pending);
391                         atomic_inc(&rdev->nr_pending);
392                         rcu_read_unlock();
393                         bi = bio_alloc_mddev(GFP_NOIO, 0, mddev);
394                         bi->bi_end_io = md_end_flush;
395                         bi->bi_private = rdev;
396                         bi->bi_bdev = rdev->bdev;
397                         bio_set_op_attrs(bi, REQ_OP_WRITE, WRITE_FLUSH);
398                         atomic_inc(&mddev->flush_pending);
399                         submit_bio(bi);
400                         rcu_read_lock();
401                         rdev_dec_pending(rdev, mddev);
402                 }
403         rcu_read_unlock();
404         if (atomic_dec_and_test(&mddev->flush_pending))
405                 queue_work(md_wq, &mddev->flush_work);
406 }
407 
408 static void md_submit_flush_data(struct work_struct *ws)
409 {
410         struct mddev *mddev = container_of(ws, struct mddev, flush_work);
411         struct bio *bio = mddev->flush_bio;
412 
413         if (bio->bi_iter.bi_size == 0)
414                 /* an empty barrier - all done */
415                 bio_endio(bio);
416         else {
417                 bio->bi_opf &= ~REQ_PREFLUSH;
418                 mddev->pers->make_request(mddev, bio);
419         }
420 
421         mddev->flush_bio = NULL;
422         wake_up(&mddev->sb_wait);
423 }
424 
425 void md_flush_request(struct mddev *mddev, struct bio *bio)
426 {
427         spin_lock_irq(&mddev->lock);
428         wait_event_lock_irq(mddev->sb_wait,
429                             !mddev->flush_bio,
430                             mddev->lock);
431         mddev->flush_bio = bio;
432         spin_unlock_irq(&mddev->lock);
433 
434         INIT_WORK(&mddev->flush_work, submit_flushes);
435         queue_work(md_wq, &mddev->flush_work);
436 }
437 EXPORT_SYMBOL(md_flush_request);
438 
439 void md_unplug(struct blk_plug_cb *cb, bool from_schedule)
440 {
441         struct mddev *mddev = cb->data;
442         md_wakeup_thread(mddev->thread);
443         kfree(cb);
444 }
445 EXPORT_SYMBOL(md_unplug);
446 
447 static inline struct mddev *mddev_get(struct mddev *mddev)
448 {
449         atomic_inc(&mddev->active);
450         return mddev;
451 }
452 
453 static void mddev_delayed_delete(struct work_struct *ws);
454 
455 static void mddev_put(struct mddev *mddev)
456 {
457         struct bio_set *bs = NULL;
458 
459         if (!atomic_dec_and_lock(&mddev->active, &all_mddevs_lock))
460                 return;
461         if (!mddev->raid_disks && list_empty(&mddev->disks) &&
462             mddev->ctime == 0 && !mddev->hold_active) {
463                 /* Array is not configured at all, and not held active,
464                  * so destroy it */
465                 list_del_init(&mddev->all_mddevs);
466                 bs = mddev->bio_set;
467                 mddev->bio_set = NULL;
468                 if (mddev->gendisk) {
469                         /* We did a probe so need to clean up.  Call
470                          * queue_work inside the spinlock so that
471                          * flush_workqueue() after mddev_find will
472                          * succeed in waiting for the work to be done.
473                          */
474                         INIT_WORK(&mddev->del_work, mddev_delayed_delete);
475                         queue_work(md_misc_wq, &mddev->del_work);
476                 } else
477                         kfree(mddev);
478         }
479         spin_unlock(&all_mddevs_lock);
480         if (bs)
481                 bioset_free(bs);
482 }
483 
484 static void md_safemode_timeout(unsigned long data);
485 
486 void mddev_init(struct mddev *mddev)
487 {
488         mutex_init(&mddev->open_mutex);
489         mutex_init(&mddev->reconfig_mutex);
490         mutex_init(&mddev->bitmap_info.mutex);
491         INIT_LIST_HEAD(&mddev->disks);
492         INIT_LIST_HEAD(&mddev->all_mddevs);
493         setup_timer(&mddev->safemode_timer, md_safemode_timeout,
494                     (unsigned long) mddev);
495         atomic_set(&mddev->active, 1);
496         atomic_set(&mddev->openers, 0);
497         atomic_set(&mddev->active_io, 0);
498         spin_lock_init(&mddev->lock);
499         atomic_set(&mddev->flush_pending, 0);
500         init_waitqueue_head(&mddev->sb_wait);
501         init_waitqueue_head(&mddev->recovery_wait);
502         mddev->reshape_position = MaxSector;
503         mddev->reshape_backwards = 0;
504         mddev->last_sync_action = "none";
505         mddev->resync_min = 0;
506         mddev->resync_max = MaxSector;
507         mddev->level = LEVEL_NONE;
508 }
509 EXPORT_SYMBOL_GPL(mddev_init);
510 
511 static struct mddev *mddev_find(dev_t unit)
512 {
513         struct mddev *mddev, *new = NULL;
514 
515         if (unit && MAJOR(unit) != MD_MAJOR)
516                 unit &= ~((1<<MdpMinorShift)-1);
517 
518  retry:
519         spin_lock(&all_mddevs_lock);
520 
521         if (unit) {
522                 list_for_each_entry(mddev, &all_mddevs, all_mddevs)
523                         if (mddev->unit == unit) {
524                                 mddev_get(mddev);
525                                 spin_unlock(&all_mddevs_lock);
526                                 kfree(new);
527                                 return mddev;
528                         }
529 
530                 if (new) {
531                         list_add(&new->all_mddevs, &all_mddevs);
532                         spin_unlock(&all_mddevs_lock);
533                         new->hold_active = UNTIL_IOCTL;
534                         return new;
535                 }
536         } else if (new) {
537                 /* find an unused unit number */
538                 static int next_minor = 512;
539                 int start = next_minor;
540                 int is_free = 0;
541                 int dev = 0;
542                 while (!is_free) {
543                         dev = MKDEV(MD_MAJOR, next_minor);
544                         next_minor++;
545                         if (next_minor > MINORMASK)
546                                 next_minor = 0;
547                         if (next_minor == start) {
548                                 /* Oh dear, all in use. */
549                                 spin_unlock(&all_mddevs_lock);
550                                 kfree(new);
551                                 return NULL;
552                         }
553 
554                         is_free = 1;
555                         list_for_each_entry(mddev, &all_mddevs, all_mddevs)
556                                 if (mddev->unit == dev) {
557                                         is_free = 0;
558                                         break;
559                                 }
560                 }
561                 new->unit = dev;
562                 new->md_minor = MINOR(dev);
563                 new->hold_active = UNTIL_STOP;
564                 list_add(&new->all_mddevs, &all_mddevs);
565                 spin_unlock(&all_mddevs_lock);
566                 return new;
567         }
568         spin_unlock(&all_mddevs_lock);
569 
570         new = kzalloc(sizeof(*new), GFP_KERNEL);
571         if (!new)
572                 return NULL;
573 
574         new->unit = unit;
575         if (MAJOR(unit) == MD_MAJOR)
576                 new->md_minor = MINOR(unit);
577         else
578                 new->md_minor = MINOR(unit) >> MdpMinorShift;
579 
580         mddev_init(new);
581 
582         goto retry;
583 }
584 
585 static struct attribute_group md_redundancy_group;
586 
587 void mddev_unlock(struct mddev *mddev)
588 {
589         if (mddev->to_remove) {
590                 /* These cannot be removed under reconfig_mutex as
591                  * an access to the files will try to take reconfig_mutex
592                  * while holding the file unremovable, which leads to
593                  * a deadlock.
594                  * So hold set sysfs_active while the remove in happeing,
595                  * and anything else which might set ->to_remove or my
596                  * otherwise change the sysfs namespace will fail with
597                  * -EBUSY if sysfs_active is still set.
598                  * We set sysfs_active under reconfig_mutex and elsewhere
599                  * test it under the same mutex to ensure its correct value
600                  * is seen.
601                  */
602                 struct attribute_group *to_remove = mddev->to_remove;
603                 mddev->to_remove = NULL;
604                 mddev->sysfs_active = 1;
605                 mutex_unlock(&mddev->reconfig_mutex);
606 
607                 if (mddev->kobj.sd) {
608                         if (to_remove != &md_redundancy_group)
609                                 sysfs_remove_group(&mddev->kobj, to_remove);
610                         if (mddev->pers == NULL ||
611                             mddev->pers->sync_request == NULL) {
612                                 sysfs_remove_group(&mddev->kobj, &md_redundancy_group);
613                                 if (mddev->sysfs_action)
614                                         sysfs_put(mddev->sysfs_action);
615                                 mddev->sysfs_action = NULL;
616                         }
617                 }
618                 mddev->sysfs_active = 0;
619         } else
620                 mutex_unlock(&mddev->reconfig_mutex);
621 
622         /* As we've dropped the mutex we need a spinlock to
623          * make sure the thread doesn't disappear
624          */
625         spin_lock(&pers_lock);
626         md_wakeup_thread(mddev->thread);
627         spin_unlock(&pers_lock);
628 }
629 EXPORT_SYMBOL_GPL(mddev_unlock);
630 
631 struct md_rdev *md_find_rdev_nr_rcu(struct mddev *mddev, int nr)
632 {
633         struct md_rdev *rdev;
634 
635         rdev_for_each_rcu(rdev, mddev)
636                 if (rdev->desc_nr == nr)
637                         return rdev;
638 
639         return NULL;
640 }
641 EXPORT_SYMBOL_GPL(md_find_rdev_nr_rcu);
642 
643 static struct md_rdev *find_rdev(struct mddev *mddev, dev_t dev)
644 {
645         struct md_rdev *rdev;
646 
647         rdev_for_each(rdev, mddev)
648                 if (rdev->bdev->bd_dev == dev)
649                         return rdev;
650 
651         return NULL;
652 }
653 
654 static struct md_rdev *find_rdev_rcu(struct mddev *mddev, dev_t dev)
655 {
656         struct md_rdev *rdev;
657 
658         rdev_for_each_rcu(rdev, mddev)
659                 if (rdev->bdev->bd_dev == dev)
660                         return rdev;
661 
662         return NULL;
663 }
664 
665 static struct md_personality *find_pers(int level, char *clevel)
666 {
667         struct md_personality *pers;
668         list_for_each_entry(pers, &pers_list, list) {
669                 if (level != LEVEL_NONE && pers->level == level)
670                         return pers;
671                 if (strcmp(pers->name, clevel)==0)
672                         return pers;
673         }
674         return NULL;
675 }
676 
677 /* return the offset of the super block in 512byte sectors */
678 static inline sector_t calc_dev_sboffset(struct md_rdev *rdev)
679 {
680         sector_t num_sectors = i_size_read(rdev->bdev->bd_inode) / 512;
681         return MD_NEW_SIZE_SECTORS(num_sectors);
682 }
683 
684 static int alloc_disk_sb(struct md_rdev *rdev)
685 {
686         rdev->sb_page = alloc_page(GFP_KERNEL);
687         if (!rdev->sb_page) {
688                 printk(KERN_ALERT "md: out of memory.\n");
689                 return -ENOMEM;
690         }
691 
692         return 0;
693 }
694 
695 void md_rdev_clear(struct md_rdev *rdev)
696 {
697         if (rdev->sb_page) {
698                 put_page(rdev->sb_page);
699                 rdev->sb_loaded = 0;
700                 rdev->sb_page = NULL;
701                 rdev->sb_start = 0;
702                 rdev->sectors = 0;
703         }
704         if (rdev->bb_page) {
705                 put_page(rdev->bb_page);
706                 rdev->bb_page = NULL;
707         }
708         badblocks_exit(&rdev->badblocks);
709 }
710 EXPORT_SYMBOL_GPL(md_rdev_clear);
711 
712 static void super_written(struct bio *bio)
713 {
714         struct md_rdev *rdev = bio->bi_private;
715         struct mddev *mddev = rdev->mddev;
716 
717         if (bio->bi_error) {
718                 printk("md: super_written gets error=%d\n", bio->bi_error);
719                 md_error(mddev, rdev);
720         }
721 
722         if (atomic_dec_and_test(&mddev->pending_writes))
723                 wake_up(&mddev->sb_wait);
724         rdev_dec_pending(rdev, mddev);
725         bio_put(bio);
726 }
727 
728 void md_super_write(struct mddev *mddev, struct md_rdev *rdev,
729                    sector_t sector, int size, struct page *page)
730 {
731         /* write first size bytes of page to sector of rdev
732          * Increment mddev->pending_writes before returning
733          * and decrement it on completion, waking up sb_wait
734          * if zero is reached.
735          * If an error occurred, call md_error
736          */
737         struct bio *bio = bio_alloc_mddev(GFP_NOIO, 1, mddev);
738 
739         atomic_inc(&rdev->nr_pending);
740 
741         bio->bi_bdev = rdev->meta_bdev ? rdev->meta_bdev : rdev->bdev;
742         bio->bi_iter.bi_sector = sector;
743         bio_add_page(bio, page, size, 0);
744         bio->bi_private = rdev;
745         bio->bi_end_io = super_written;
746         bio_set_op_attrs(bio, REQ_OP_WRITE, WRITE_FLUSH_FUA);
747 
748         atomic_inc(&mddev->pending_writes);
749         submit_bio(bio);
750 }
751 
752 void md_super_wait(struct mddev *mddev)
753 {
754         /* wait for all superblock writes that were scheduled to complete */
755         wait_event(mddev->sb_wait, atomic_read(&mddev->pending_writes)==0);
756 }
757 
758 int sync_page_io(struct md_rdev *rdev, sector_t sector, int size,
759                  struct page *page, int op, int op_flags, bool metadata_op)
760 {
761         struct bio *bio = bio_alloc_mddev(GFP_NOIO, 1, rdev->mddev);
762         int ret;
763 
764         bio->bi_bdev = (metadata_op && rdev->meta_bdev) ?
765                 rdev->meta_bdev : rdev->bdev;
766         bio_set_op_attrs(bio, op, op_flags);
767         if (metadata_op)
768                 bio->bi_iter.bi_sector = sector + rdev->sb_start;
769         else if (rdev->mddev->reshape_position != MaxSector &&
770                  (rdev->mddev->reshape_backwards ==
771                   (sector >= rdev->mddev->reshape_position)))
772                 bio->bi_iter.bi_sector = sector + rdev->new_data_offset;
773         else
774                 bio->bi_iter.bi_sector = sector + rdev->data_offset;
775         bio_add_page(bio, page, size, 0);
776 
777         submit_bio_wait(bio);
778 
779         ret = !bio->bi_error;
780         bio_put(bio);
781         return ret;
782 }
783 EXPORT_SYMBOL_GPL(sync_page_io);
784 
785 static int read_disk_sb(struct md_rdev *rdev, int size)
786 {
787         char b[BDEVNAME_SIZE];
788 
789         if (rdev->sb_loaded)
790                 return 0;
791 
792         if (!sync_page_io(rdev, 0, size, rdev->sb_page, REQ_OP_READ, 0, true))
793                 goto fail;
794         rdev->sb_loaded = 1;
795         return 0;
796 
797 fail:
798         printk(KERN_WARNING "md: disabled device %s, could not read superblock.\n",
799                 bdevname(rdev->bdev,b));
800         return -EINVAL;
801 }
802 
803 static int uuid_equal(mdp_super_t *sb1, mdp_super_t *sb2)
804 {
805         return  sb1->set_uuid0 == sb2->set_uuid0 &&
806                 sb1->set_uuid1 == sb2->set_uuid1 &&
807                 sb1->set_uuid2 == sb2->set_uuid2 &&
808                 sb1->set_uuid3 == sb2->set_uuid3;
809 }
810 
811 static int sb_equal(mdp_super_t *sb1, mdp_super_t *sb2)
812 {
813         int ret;
814         mdp_super_t *tmp1, *tmp2;
815 
816         tmp1 = kmalloc(sizeof(*tmp1),GFP_KERNEL);
817         tmp2 = kmalloc(sizeof(*tmp2),GFP_KERNEL);
818 
819         if (!tmp1 || !tmp2) {
820                 ret = 0;
821                 printk(KERN_INFO "md.c sb_equal(): failed to allocate memory!\n");
822                 goto abort;
823         }
824 
825         *tmp1 = *sb1;
826         *tmp2 = *sb2;
827 
828         /*
829          * nr_disks is not constant
830          */
831         tmp1->nr_disks = 0;
832         tmp2->nr_disks = 0;
833 
834         ret = (memcmp(tmp1, tmp2, MD_SB_GENERIC_CONSTANT_WORDS * 4) == 0);
835 abort:
836         kfree(tmp1);
837         kfree(tmp2);
838         return ret;
839 }
840 
841 static u32 md_csum_fold(u32 csum)
842 {
843         csum = (csum & 0xffff) + (csum >> 16);
844         return (csum & 0xffff) + (csum >> 16);
845 }
846 
847 static unsigned int calc_sb_csum(mdp_super_t *sb)
848 {
849         u64 newcsum = 0;
850         u32 *sb32 = (u32*)sb;
851         int i;
852         unsigned int disk_csum, csum;
853 
854         disk_csum = sb->sb_csum;
855         sb->sb_csum = 0;
856 
857         for (i = 0; i < MD_SB_BYTES/4 ; i++)
858                 newcsum += sb32[i];
859         csum = (newcsum & 0xffffffff) + (newcsum>>32);
860 
861 #ifdef CONFIG_ALPHA
862         /* This used to use csum_partial, which was wrong for several
863          * reasons including that different results are returned on
864          * different architectures.  It isn't critical that we get exactly
865          * the same return value as before (we always csum_fold before
866          * testing, and that removes any differences).  However as we
867          * know that csum_partial always returned a 16bit value on
868          * alphas, do a fold to maximise conformity to previous behaviour.
869          */
870         sb->sb_csum = md_csum_fold(disk_csum);
871 #else
872         sb->sb_csum = disk_csum;
873 #endif
874         return csum;
875 }
876 
877 /*
878  * Handle superblock details.
879  * We want to be able to handle multiple superblock formats
880  * so we have a common interface to them all, and an array of
881  * different handlers.
882  * We rely on user-space to write the initial superblock, and support
883  * reading and updating of superblocks.
884  * Interface methods are:
885  *   int load_super(struct md_rdev *dev, struct md_rdev *refdev, int minor_version)
886  *      loads and validates a superblock on dev.
887  *      if refdev != NULL, compare superblocks on both devices
888  *    Return:
889  *      0 - dev has a superblock that is compatible with refdev
890  *      1 - dev has a superblock that is compatible and newer than refdev
891  *          so dev should be used as the refdev in future
892  *     -EINVAL superblock incompatible or invalid
893  *     -othererror e.g. -EIO
894  *
895  *   int validate_super(struct mddev *mddev, struct md_rdev *dev)
896  *      Verify that dev is acceptable into mddev.
897  *       The first time, mddev->raid_disks will be 0, and data from
898  *       dev should be merged in.  Subsequent calls check that dev
899  *       is new enough.  Return 0 or -EINVAL
900  *
901  *   void sync_super(struct mddev *mddev, struct md_rdev *dev)
902  *     Update the superblock for rdev with data in mddev
903  *     This does not write to disc.
904  *
905  */
906 
907 struct super_type  {
908         char                *name;
909         struct module       *owner;
910         int                 (*load_super)(struct md_rdev *rdev,
911                                           struct md_rdev *refdev,
912                                           int minor_version);
913         int                 (*validate_super)(struct mddev *mddev,
914                                               struct md_rdev *rdev);
915         void                (*sync_super)(struct mddev *mddev,
916                                           struct md_rdev *rdev);
917         unsigned long long  (*rdev_size_change)(struct md_rdev *rdev,
918                                                 sector_t num_sectors);
919         int                 (*allow_new_offset)(struct md_rdev *rdev,
920                                                 unsigned long long new_offset);
921 };
922 
923 /*
924  * Check that the given mddev has no bitmap.
925  *
926  * This function is called from the run method of all personalities that do not
927  * support bitmaps. It prints an error message and returns non-zero if mddev
928  * has a bitmap. Otherwise, it returns 0.
929  *
930  */
931 int md_check_no_bitmap(struct mddev *mddev)
932 {
933         if (!mddev->bitmap_info.file && !mddev->bitmap_info.offset)
934                 return 0;
935         printk(KERN_ERR "%s: bitmaps are not supported for %s\n",
936                 mdname(mddev), mddev->pers->name);
937         return 1;
938 }
939 EXPORT_SYMBOL(md_check_no_bitmap);
940 
941 /*
942  * load_super for 0.90.0
943  */
944 static int super_90_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor_version)
945 {
946         char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
947         mdp_super_t *sb;
948         int ret;
949 
950         /*
951          * Calculate the position of the superblock (512byte sectors),
952          * it's at the end of the disk.
953          *
954          * It also happens to be a multiple of 4Kb.
955          */
956         rdev->sb_start = calc_dev_sboffset(rdev);
957 
958         ret = read_disk_sb(rdev, MD_SB_BYTES);
959         if (ret) return ret;
960 
961         ret = -EINVAL;
962 
963         bdevname(rdev->bdev, b);
964         sb = page_address(rdev->sb_page);
965 
966         if (sb->md_magic != MD_SB_MAGIC) {
967                 printk(KERN_ERR "md: invalid raid superblock magic on %s\n",
968                        b);
969                 goto abort;
970         }
971 
972         if (sb->major_version != 0 ||
973             sb->minor_version < 90 ||
974             sb->minor_version > 91) {
975                 printk(KERN_WARNING "Bad version number %d.%d on %s\n",
976                         sb->major_version, sb->minor_version,
977                         b);
978                 goto abort;
979         }
980 
981         if (sb->raid_disks <= 0)
982                 goto abort;
983 
984         if (md_csum_fold(calc_sb_csum(sb)) != md_csum_fold(sb->sb_csum)) {
985                 printk(KERN_WARNING "md: invalid superblock checksum on %s\n",
986                         b);
987                 goto abort;
988         }
989 
990         rdev->preferred_minor = sb->md_minor;
991         rdev->data_offset = 0;
992         rdev->new_data_offset = 0;
993         rdev->sb_size = MD_SB_BYTES;
994         rdev->badblocks.shift = -1;
995 
996         if (sb->level == LEVEL_MULTIPATH)
997                 rdev->desc_nr = -1;
998         else
999                 rdev->desc_nr = sb->this_disk.number;
1000 
1001         if (!refdev) {
1002                 ret = 1;
1003         } else {
1004                 __u64 ev1, ev2;
1005                 mdp_super_t *refsb = page_address(refdev->sb_page);
1006                 if (!uuid_equal(refsb, sb)) {
1007                         printk(KERN_WARNING "md: %s has different UUID to %s\n",
1008                                 b, bdevname(refdev->bdev,b2));
1009                         goto abort;
1010                 }
1011                 if (!sb_equal(refsb, sb)) {
1012                         printk(KERN_WARNING "md: %s has same UUID"
1013                                " but different superblock to %s\n",
1014                                b, bdevname(refdev->bdev, b2));
1015                         goto abort;
1016                 }
1017                 ev1 = md_event(sb);
1018                 ev2 = md_event(refsb);
1019                 if (ev1 > ev2)
1020                         ret = 1;
1021                 else
1022                         ret = 0;
1023         }
1024         rdev->sectors = rdev->sb_start;
1025         /* Limit to 4TB as metadata cannot record more than that.
1026          * (not needed for Linear and RAID0 as metadata doesn't
1027          * record this size)
1028          */
1029         if (IS_ENABLED(CONFIG_LBDAF) && (u64)rdev->sectors >= (2ULL << 32) &&
1030             sb->level >= 1)
1031                 rdev->sectors = (sector_t)(2ULL << 32) - 2;
1032 
1033         if (rdev->sectors < ((sector_t)sb->size) * 2 && sb->level >= 1)
1034                 /* "this cannot possibly happen" ... */
1035                 ret = -EINVAL;
1036 
1037  abort:
1038         return ret;
1039 }
1040 
1041 /*
1042  * validate_super for 0.90.0
1043  */
1044 static int super_90_validate(struct mddev *mddev, struct md_rdev *rdev)
1045 {
1046         mdp_disk_t *desc;
1047         mdp_super_t *sb = page_address(rdev->sb_page);
1048         __u64 ev1 = md_event(sb);
1049 
1050         rdev->raid_disk = -1;
1051         clear_bit(Faulty, &rdev->flags);
1052         clear_bit(In_sync, &rdev->flags);
1053         clear_bit(Bitmap_sync, &rdev->flags);
1054         clear_bit(WriteMostly, &rdev->flags);
1055 
1056         if (mddev->raid_disks == 0) {
1057                 mddev->major_version = 0;
1058                 mddev->minor_version = sb->minor_version;
1059                 mddev->patch_version = sb->patch_version;
1060                 mddev->external = 0;
1061                 mddev->chunk_sectors = sb->chunk_size >> 9;
1062                 mddev->ctime = sb->ctime;
1063                 mddev->utime = sb->utime;
1064                 mddev->level = sb->level;
1065                 mddev->clevel[0] = 0;
1066                 mddev->layout = sb->layout;
1067                 mddev->raid_disks = sb->raid_disks;
1068                 mddev->dev_sectors = ((sector_t)sb->size) * 2;
1069                 mddev->events = ev1;
1070                 mddev->bitmap_info.offset = 0;
1071                 mddev->bitmap_info.space = 0;
1072                 /* bitmap can use 60 K after the 4K superblocks */
1073                 mddev->bitmap_info.default_offset = MD_SB_BYTES >> 9;
1074                 mddev->bitmap_info.default_space = 64*2 - (MD_SB_BYTES >> 9);
1075                 mddev->reshape_backwards = 0;
1076 
1077                 if (mddev->minor_version >= 91) {
1078                         mddev->reshape_position = sb->reshape_position;
1079                         mddev->delta_disks = sb->delta_disks;
1080                         mddev->new_level = sb->new_level;
1081                         mddev->new_layout = sb->new_layout;
1082                         mddev->new_chunk_sectors = sb->new_chunk >> 9;
1083                         if (mddev->delta_disks < 0)
1084                                 mddev->reshape_backwards = 1;
1085                 } else {
1086                         mddev->reshape_position = MaxSector;
1087                         mddev->delta_disks = 0;
1088                         mddev->new_level = mddev->level;
1089                         mddev->new_layout = mddev->layout;
1090                         mddev->new_chunk_sectors = mddev->chunk_sectors;
1091                 }
1092 
1093                 if (sb->state & (1<<MD_SB_CLEAN))
1094                         mddev->recovery_cp = MaxSector;
1095                 else {
1096                         if (sb->events_hi == sb->cp_events_hi &&
1097                                 sb->events_lo == sb->cp_events_lo) {
1098                                 mddev->recovery_cp = sb->recovery_cp;
1099                         } else
1100                                 mddev->recovery_cp = 0;
1101                 }
1102 
1103                 memcpy(mddev->uuid+0, &sb->set_uuid0, 4);
1104                 memcpy(mddev->uuid+4, &sb->set_uuid1, 4);
1105                 memcpy(mddev->uuid+8, &sb->set_uuid2, 4);
1106                 memcpy(mddev->uuid+12,&sb->set_uuid3, 4);
1107 
1108                 mddev->max_disks = MD_SB_DISKS;
1109 
1110                 if (sb->state & (1<<MD_SB_BITMAP_PRESENT) &&
1111                     mddev->bitmap_info.file == NULL) {
1112                         mddev->bitmap_info.offset =
1113                                 mddev->bitmap_info.default_offset;
1114                         mddev->bitmap_info.space =
1115                                 mddev->bitmap_info.default_space;
1116                 }
1117 
1118         } else if (mddev->pers == NULL) {
1119                 /* Insist on good event counter while assembling, except
1120                  * for spares (which don't need an event count) */
1121                 ++ev1;
1122                 if (sb->disks[rdev->desc_nr].state & (
1123                             (1<<MD_DISK_SYNC) | (1 << MD_DISK_ACTIVE)))
1124                         if (ev1 < mddev->events)
1125                                 return -EINVAL;
1126         } else if (mddev->bitmap) {
1127                 /* if adding to array with a bitmap, then we can accept an
1128                  * older device ... but not too old.
1129                  */
1130                 if (ev1 < mddev->bitmap->events_cleared)
1131                         return 0;
1132                 if (ev1 < mddev->events)
1133                         set_bit(Bitmap_sync, &rdev->flags);
1134         } else {
1135                 if (ev1 < mddev->events)
1136                         /* just a hot-add of a new device, leave raid_disk at -1 */
1137                         return 0;
1138         }
1139 
1140         if (mddev->level != LEVEL_MULTIPATH) {
1141                 desc = sb->disks + rdev->desc_nr;
1142 
1143                 if (desc->state & (1<<MD_DISK_FAULTY))
1144                         set_bit(Faulty, &rdev->flags);
1145                 else if (desc->state & (1<<MD_DISK_SYNC) /* &&
1146                             desc->raid_disk < mddev->raid_disks */) {
1147                         set_bit(In_sync, &rdev->flags);
1148                         rdev->raid_disk = desc->raid_disk;
1149                         rdev->saved_raid_disk = desc->raid_disk;
1150                 } else if (desc->state & (1<<MD_DISK_ACTIVE)) {
1151                         /* active but not in sync implies recovery up to
1152                          * reshape position.  We don't know exactly where
1153                          * that is, so set to zero for now */
1154                         if (mddev->minor_version >= 91) {
1155                                 rdev->recovery_offset = 0;
1156                                 rdev->raid_disk = desc->raid_disk;
1157                         }
1158                 }
1159                 if (desc->state & (1<<MD_DISK_WRITEMOSTLY))
1160                         set_bit(WriteMostly, &rdev->flags);
1161         } else /* MULTIPATH are always insync */
1162                 set_bit(In_sync, &rdev->flags);
1163         return 0;
1164 }
1165 
1166 /*
1167  * sync_super for 0.90.0
1168  */
1169 static void super_90_sync(struct mddev *mddev, struct md_rdev *rdev)
1170 {
1171         mdp_super_t *sb;
1172         struct md_rdev *rdev2;
1173         int next_spare = mddev->raid_disks;
1174 
1175         /* make rdev->sb match mddev data..
1176          *
1177          * 1/ zero out disks
1178          * 2/ Add info for each disk, keeping track of highest desc_nr (next_spare);
1179          * 3/ any empty disks < next_spare become removed
1180          *
1181          * disks[0] gets initialised to REMOVED because
1182          * we cannot be sure from other fields if it has
1183          * been initialised or not.
1184          */
1185         int i;
1186         int active=0, working=0,failed=0,spare=0,nr_disks=0;
1187 
1188         rdev->sb_size = MD_SB_BYTES;
1189 
1190         sb = page_address(rdev->sb_page);
1191 
1192         memset(sb, 0, sizeof(*sb));
1193 
1194         sb->md_magic = MD_SB_MAGIC;
1195         sb->major_version = mddev->major_version;
1196         sb->patch_version = mddev->patch_version;
1197         sb->gvalid_words  = 0; /* ignored */
1198         memcpy(&sb->set_uuid0, mddev->uuid+0, 4);
1199         memcpy(&sb->set_uuid1, mddev->uuid+4, 4);
1200         memcpy(&sb->set_uuid2, mddev->uuid+8, 4);
1201         memcpy(&sb->set_uuid3, mddev->uuid+12,4);
1202 
1203         sb->ctime = clamp_t(time64_t, mddev->ctime, 0, U32_MAX);
1204         sb->level = mddev->level;
1205         sb->size = mddev->dev_sectors / 2;
1206         sb->raid_disks = mddev->raid_disks;
1207         sb->md_minor = mddev->md_minor;
1208         sb->not_persistent = 0;
1209         sb->utime = clamp_t(time64_t, mddev->utime, 0, U32_MAX);
1210         sb->state = 0;
1211         sb->events_hi = (mddev->events>>32);
1212         sb->events_lo = (u32)mddev->events;
1213 
1214         if (mddev->reshape_position == MaxSector)
1215                 sb->minor_version = 90;
1216         else {
1217                 sb->minor_version = 91;
1218                 sb->reshape_position = mddev->reshape_position;
1219                 sb->new_level = mddev->new_level;
1220                 sb->delta_disks = mddev->delta_disks;
1221                 sb->new_layout = mddev->new_layout;
1222                 sb->new_chunk = mddev->new_chunk_sectors << 9;
1223         }
1224         mddev->minor_version = sb->minor_version;
1225         if (mddev->in_sync)
1226         {
1227                 sb->recovery_cp = mddev->recovery_cp;
1228                 sb->cp_events_hi = (mddev->events>>32);
1229                 sb->cp_events_lo = (u32)mddev->events;
1230                 if (mddev->recovery_cp == MaxSector)
1231                         sb->state = (1<< MD_SB_CLEAN);
1232         } else
1233                 sb->recovery_cp = 0;
1234 
1235         sb->layout = mddev->layout;
1236         sb->chunk_size = mddev->chunk_sectors << 9;
1237 
1238         if (mddev->bitmap && mddev->bitmap_info.file == NULL)
1239                 sb->state |= (1<<MD_SB_BITMAP_PRESENT);
1240 
1241         sb->disks[0].state = (1<<MD_DISK_REMOVED);
1242         rdev_for_each(rdev2, mddev) {
1243                 mdp_disk_t *d;
1244                 int desc_nr;
1245                 int is_active = test_bit(In_sync, &rdev2->flags);
1246 
1247                 if (rdev2->raid_disk >= 0 &&
1248                     sb->minor_version >= 91)
1249                         /* we have nowhere to store the recovery_offset,
1250                          * but if it is not below the reshape_position,
1251                          * we can piggy-back on that.
1252                          */
1253                         is_active = 1;
1254                 if (rdev2->raid_disk < 0 ||
1255                     test_bit(Faulty, &rdev2->flags))
1256                         is_active = 0;
1257                 if (is_active)
1258                         desc_nr = rdev2->raid_disk;
1259                 else
1260                         desc_nr = next_spare++;
1261                 rdev2->desc_nr = desc_nr;
1262                 d = &sb->disks[rdev2->desc_nr];
1263                 nr_disks++;
1264                 d->number = rdev2->desc_nr;
1265                 d->major = MAJOR(rdev2->bdev->bd_dev);
1266                 d->minor = MINOR(rdev2->bdev->bd_dev);
1267                 if (is_active)
1268                         d->raid_disk = rdev2->raid_disk;
1269                 else
1270                         d->raid_disk = rdev2->desc_nr; /* compatibility */
1271                 if (test_bit(Faulty, &rdev2->flags))
1272                         d->state = (1<<MD_DISK_FAULTY);
1273                 else if (is_active) {
1274                         d->state = (1<<MD_DISK_ACTIVE);
1275                         if (test_bit(In_sync, &rdev2->flags))
1276                                 d->state |= (1<<MD_DISK_SYNC);
1277                         active++;
1278                         working++;
1279                 } else {
1280                         d->state = 0;
1281                         spare++;
1282                         working++;
1283                 }
1284                 if (test_bit(WriteMostly, &rdev2->flags))
1285                         d->state |= (1<<MD_DISK_WRITEMOSTLY);
1286         }
1287         /* now set the "removed" and "faulty" bits on any missing devices */
1288         for (i=0 ; i < mddev->raid_disks ; i++) {
1289                 mdp_disk_t *d = &sb->disks[i];
1290                 if (d->state == 0 && d->number == 0) {
1291                         d->number = i;
1292                         d->raid_disk = i;
1293                         d->state = (1<<MD_DISK_REMOVED);
1294                         d->state |= (1<<MD_DISK_FAULTY);
1295                         failed++;
1296                 }
1297         }
1298         sb->nr_disks = nr_disks;
1299         sb->active_disks = active;
1300         sb->working_disks = working;
1301         sb->failed_disks = failed;
1302         sb->spare_disks = spare;
1303 
1304         sb->this_disk = sb->disks[rdev->desc_nr];
1305         sb->sb_csum = calc_sb_csum(sb);
1306 }
1307 
1308 /*
1309  * rdev_size_change for 0.90.0
1310  */
1311 static unsigned long long
1312 super_90_rdev_size_change(struct md_rdev *rdev, sector_t num_sectors)
1313 {
1314         if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
1315                 return 0; /* component must fit device */
1316         if (rdev->mddev->bitmap_info.offset)
1317                 return 0; /* can't move bitmap */
1318         rdev->sb_start = calc_dev_sboffset(rdev);
1319         if (!num_sectors || num_sectors > rdev->sb_start)
1320                 num_sectors = rdev->sb_start;
1321         /* Limit to 4TB as metadata cannot record more than that.
1322          * 4TB == 2^32 KB, or 2*2^32 sectors.
1323          */
1324         if (IS_ENABLED(CONFIG_LBDAF) && (u64)num_sectors >= (2ULL << 32) &&
1325             rdev->mddev->level >= 1)
1326                 num_sectors = (sector_t)(2ULL << 32) - 2;
1327         md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
1328                        rdev->sb_page);
1329         md_super_wait(rdev->mddev);
1330         return num_sectors;
1331 }
1332 
1333 static int
1334 super_90_allow_new_offset(struct md_rdev *rdev, unsigned long long new_offset)
1335 {
1336         /* non-zero offset changes not possible with v0.90 */
1337         return new_offset == 0;
1338 }
1339 
1340 /*
1341  * version 1 superblock
1342  */
1343 
1344 static __le32 calc_sb_1_csum(struct mdp_superblock_1 *sb)
1345 {
1346         __le32 disk_csum;
1347         u32 csum;
1348         unsigned long long newcsum;
1349         int size = 256 + le32_to_cpu(sb->max_dev)*2;
1350         __le32 *isuper = (__le32*)sb;
1351 
1352         disk_csum = sb->sb_csum;
1353         sb->sb_csum = 0;
1354         newcsum = 0;
1355         for (; size >= 4; size -= 4)
1356                 newcsum += le32_to_cpu(*isuper++);
1357 
1358         if (size == 2)
1359                 newcsum += le16_to_cpu(*(__le16*) isuper);
1360 
1361         csum = (newcsum & 0xffffffff) + (newcsum >> 32);
1362         sb->sb_csum = disk_csum;
1363         return cpu_to_le32(csum);
1364 }
1365 
1366 static int super_1_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor_version)
1367 {
1368         struct mdp_superblock_1 *sb;
1369         int ret;
1370         sector_t sb_start;
1371         sector_t sectors;
1372         char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
1373         int bmask;
1374 
1375         /*
1376          * Calculate the position of the superblock in 512byte sectors.
1377          * It is always aligned to a 4K boundary and
1378          * depeding on minor_version, it can be:
1379          * 0: At least 8K, but less than 12K, from end of device
1380          * 1: At start of device
1381          * 2: 4K from start of device.
1382          */
1383         switch(minor_version) {
1384         case 0:
1385                 sb_start = i_size_read(rdev->bdev->bd_inode) >> 9;
1386                 sb_start -= 8*2;
1387                 sb_start &= ~(sector_t)(4*2-1);
1388                 break;
1389         case 1:
1390                 sb_start = 0;
1391                 break;
1392         case 2:
1393                 sb_start = 8;
1394                 break;
1395         default:
1396                 return -EINVAL;
1397         }
1398         rdev->sb_start = sb_start;
1399 
1400         /* superblock is rarely larger than 1K, but it can be larger,
1401          * and it is safe to read 4k, so we do that
1402          */
1403         ret = read_disk_sb(rdev, 4096);
1404         if (ret) return ret;
1405 
1406         sb = page_address(rdev->sb_page);
1407 
1408         if (sb->magic != cpu_to_le32(MD_SB_MAGIC) ||
1409             sb->major_version != cpu_to_le32(1) ||
1410             le32_to_cpu(sb->max_dev) > (4096-256)/2 ||
1411             le64_to_cpu(sb->super_offset) != rdev->sb_start ||
1412             (le32_to_cpu(sb->feature_map) & ~MD_FEATURE_ALL) != 0)
1413                 return -EINVAL;
1414 
1415         if (calc_sb_1_csum(sb) != sb->sb_csum) {
1416                 printk("md: invalid superblock checksum on %s\n",
1417                         bdevname(rdev->bdev,b));
1418                 return -EINVAL;
1419         }
1420         if (le64_to_cpu(sb->data_size) < 10) {
1421                 printk("md: data_size too small on %s\n",
1422                        bdevname(rdev->bdev,b));
1423                 return -EINVAL;
1424         }
1425         if (sb->pad0 ||
1426             sb->pad3[0] ||
1427             memcmp(sb->pad3, sb->pad3+1, sizeof(sb->pad3) - sizeof(sb->pad3[1])))
1428                 /* Some padding is non-zero, might be a new feature */
1429                 return -EINVAL;
1430 
1431         rdev->preferred_minor = 0xffff;
1432         rdev->data_offset = le64_to_cpu(sb->data_offset);
1433         rdev->new_data_offset = rdev->data_offset;
1434         if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE) &&
1435             (le32_to_cpu(sb->feature_map) & MD_FEATURE_NEW_OFFSET))
1436                 rdev->new_data_offset += (s32)le32_to_cpu(sb->new_offset);
1437         atomic_set(&rdev->corrected_errors, le32_to_cpu(sb->cnt_corrected_read));
1438 
1439         rdev->sb_size = le32_to_cpu(sb->max_dev) * 2 + 256;
1440         bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
1441         if (rdev->sb_size & bmask)
1442                 rdev->sb_size = (rdev->sb_size | bmask) + 1;
1443 
1444         if (minor_version
1445             && rdev->data_offset < sb_start + (rdev->sb_size/512))
1446                 return -EINVAL;
1447         if (minor_version
1448             && rdev->new_data_offset < sb_start + (rdev->sb_size/512))
1449                 return -EINVAL;
1450 
1451         if (sb->level == cpu_to_le32(LEVEL_MULTIPATH))
1452                 rdev->desc_nr = -1;
1453         else
1454                 rdev->desc_nr = le32_to_cpu(sb->dev_number);
1455 
1456         if (!rdev->bb_page) {
1457                 rdev->bb_page = alloc_page(GFP_KERNEL);
1458                 if (!rdev->bb_page)
1459                         return -ENOMEM;
1460         }
1461         if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BAD_BLOCKS) &&
1462             rdev->badblocks.count == 0) {
1463                 /* need to load the bad block list.
1464                  * Currently we limit it to one page.
1465                  */
1466                 s32 offset;
1467                 sector_t bb_sector;
1468                 u64 *bbp;
1469                 int i;
1470                 int sectors = le16_to_cpu(sb->bblog_size);
1471                 if (sectors > (PAGE_SIZE / 512))
1472                         return -EINVAL;
1473                 offset = le32_to_cpu(sb->bblog_offset);
1474                 if (offset == 0)
1475                         return -EINVAL;
1476                 bb_sector = (long long)offset;
1477                 if (!sync_page_io(rdev, bb_sector, sectors << 9,
1478                                   rdev->bb_page, REQ_OP_READ, 0, true))
1479                         return -EIO;
1480                 bbp = (u64 *)page_address(rdev->bb_page);
1481                 rdev->badblocks.shift = sb->bblog_shift;
1482                 for (i = 0 ; i < (sectors << (9-3)) ; i++, bbp++) {
1483                         u64 bb = le64_to_cpu(*bbp);
1484                         int count = bb & (0x3ff);
1485                         u64 sector = bb >> 10;
1486                         sector <<= sb->bblog_shift;
1487                         count <<= sb->bblog_shift;
1488                         if (bb + 1 == 0)
1489                                 break;
1490                         if (badblocks_set(&rdev->badblocks, sector, count, 1))
1491                                 return -EINVAL;
1492                 }
1493         } else if (sb->bblog_offset != 0)
1494                 rdev->badblocks.shift = 0;
1495 
1496         if (!refdev) {
1497                 ret = 1;
1498         } else {
1499                 __u64 ev1, ev2;
1500                 struct mdp_superblock_1 *refsb = page_address(refdev->sb_page);
1501 
1502                 if (memcmp(sb->set_uuid, refsb->set_uuid, 16) != 0 ||
1503                     sb->level != refsb->level ||
1504                     sb->layout != refsb->layout ||
1505                     sb->chunksize != refsb->chunksize) {
1506                         printk(KERN_WARNING "md: %s has strangely different"
1507                                 " superblock to %s\n",
1508                                 bdevname(rdev->bdev,b),
1509                                 bdevname(refdev->bdev,b2));
1510                         return -EINVAL;
1511                 }
1512                 ev1 = le64_to_cpu(sb->events);
1513                 ev2 = le64_to_cpu(refsb->events);
1514 
1515                 if (ev1 > ev2)
1516                         ret = 1;
1517                 else
1518                         ret = 0;
1519         }
1520         if (minor_version) {
1521                 sectors = (i_size_read(rdev->bdev->bd_inode) >> 9);
1522                 sectors -= rdev->data_offset;
1523         } else
1524                 sectors = rdev->sb_start;
1525         if (sectors < le64_to_cpu(sb->data_size))
1526                 return -EINVAL;
1527         rdev->sectors = le64_to_cpu(sb->data_size);
1528         return ret;
1529 }
1530 
1531 static int super_1_validate(struct mddev *mddev, struct md_rdev *rdev)
1532 {
1533         struct mdp_superblock_1 *sb = page_address(rdev->sb_page);
1534         __u64 ev1 = le64_to_cpu(sb->events);
1535 
1536         rdev->raid_disk = -1;
1537         clear_bit(Faulty, &rdev->flags);
1538         clear_bit(In_sync, &rdev->flags);
1539         clear_bit(Bitmap_sync, &rdev->flags);
1540         clear_bit(WriteMostly, &rdev->flags);
1541 
1542         if (mddev->raid_disks == 0) {
1543                 mddev->major_version = 1;
1544                 mddev->patch_version = 0;
1545                 mddev->external = 0;
1546                 mddev->chunk_sectors = le32_to_cpu(sb->chunksize);
1547                 mddev->ctime = le64_to_cpu(sb->ctime);
1548                 mddev->utime = le64_to_cpu(sb->utime);
1549                 mddev->level = le32_to_cpu(sb->level);
1550                 mddev->clevel[0] = 0;
1551                 mddev->layout = le32_to_cpu(sb->layout);
1552                 mddev->raid_disks = le32_to_cpu(sb->raid_disks);
1553                 mddev->dev_sectors = le64_to_cpu(sb->size);
1554                 mddev->events = ev1;
1555                 mddev->bitmap_info.offset = 0;
1556                 mddev->bitmap_info.space = 0;
1557                 /* Default location for bitmap is 1K after superblock
1558                  * using 3K - total of 4K
1559                  */
1560                 mddev->bitmap_info.default_offset = 1024 >> 9;
1561                 mddev->bitmap_info.default_space = (4096-1024) >> 9;
1562                 mddev->reshape_backwards = 0;
1563 
1564                 mddev->recovery_cp = le64_to_cpu(sb->resync_offset);
1565                 memcpy(mddev->uuid, sb->set_uuid, 16);
1566 
1567                 mddev->max_disks =  (4096-256)/2;
1568 
1569                 if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BITMAP_OFFSET) &&
1570                     mddev->bitmap_info.file == NULL) {
1571                         mddev->bitmap_info.offset =
1572                                 (__s32)le32_to_cpu(sb->bitmap_offset);
1573                         /* Metadata doesn't record how much space is available.
1574                          * For 1.0, we assume we can use up to the superblock
1575                          * if before, else to 4K beyond superblock.
1576                          * For others, assume no change is possible.
1577                          */
1578                         if (mddev->minor_version > 0)
1579                                 mddev->bitmap_info.space = 0;
1580                         else if (mddev->bitmap_info.offset > 0)
1581                                 mddev->bitmap_info.space =
1582                                         8 - mddev->bitmap_info.offset;
1583                         else
1584                                 mddev->bitmap_info.space =
1585                                         -mddev->bitmap_info.offset;
1586                 }
1587 
1588                 if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE)) {
1589                         mddev->reshape_position = le64_to_cpu(sb->reshape_position);
1590                         mddev->delta_disks = le32_to_cpu(sb->delta_disks);
1591                         mddev->new_level = le32_to_cpu(sb->new_level);
1592                         mddev->new_layout = le32_to_cpu(sb->new_layout);
1593                         mddev->new_chunk_sectors = le32_to_cpu(sb->new_chunk);
1594                         if (mddev->delta_disks < 0 ||
1595                             (mddev->delta_disks == 0 &&
1596                              (le32_to_cpu(sb->feature_map)
1597                               & MD_FEATURE_RESHAPE_BACKWARDS)))
1598                                 mddev->reshape_backwards = 1;
1599                 } else {
1600                         mddev->reshape_position = MaxSector;
1601                         mddev->delta_disks = 0;
1602                         mddev->new_level = mddev->level;
1603                         mddev->new_layout = mddev->layout;
1604                         mddev->new_chunk_sectors = mddev->chunk_sectors;
1605                 }
1606 
1607                 if (le32_to_cpu(sb->feature_map) & MD_FEATURE_JOURNAL)
1608                         set_bit(MD_HAS_JOURNAL, &mddev->flags);
1609         } else if (mddev->pers == NULL) {
1610                 /* Insist of good event counter while assembling, except for
1611                  * spares (which don't need an event count) */
1612                 ++ev1;
1613                 if (rdev->desc_nr >= 0 &&
1614                     rdev->desc_nr < le32_to_cpu(sb->max_dev) &&
1615                     (le16_to_cpu(sb->dev_roles[rdev->desc_nr]) < MD_DISK_ROLE_MAX ||
1616                      le16_to_cpu(sb->dev_roles[rdev->desc_nr]) == MD_DISK_ROLE_JOURNAL))
1617                         if (ev1 < mddev->events)
1618                                 return -EINVAL;
1619         } else if (mddev->bitmap) {
1620                 /* If adding to array with a bitmap, then we can accept an
1621                  * older device, but not too old.
1622                  */
1623                 if (ev1 < mddev->bitmap->events_cleared)
1624                         return 0;
1625                 if (ev1 < mddev->events)
1626                         set_bit(Bitmap_sync, &rdev->flags);
1627         } else {
1628                 if (ev1 < mddev->events)
1629                         /* just a hot-add of a new device, leave raid_disk at -1 */
1630                         return 0;
1631         }
1632         if (mddev->level != LEVEL_MULTIPATH) {
1633                 int role;
1634                 if (rdev->desc_nr < 0 ||
1635                     rdev->desc_nr >= le32_to_cpu(sb->max_dev)) {
1636                         role = MD_DISK_ROLE_SPARE;
1637                         rdev->desc_nr = -1;
1638                 } else
1639                         role = le16_to_cpu(sb->dev_roles[rdev->desc_nr]);
1640                 switch(role) {
1641                 case MD_DISK_ROLE_SPARE: /* spare */
1642                         break;
1643                 case MD_DISK_ROLE_FAULTY: /* faulty */
1644                         set_bit(Faulty, &rdev->flags);
1645                         break;
1646                 case MD_DISK_ROLE_JOURNAL: /* journal device */
1647                         if (!(le32_to_cpu(sb->feature_map) & MD_FEATURE_JOURNAL)) {
1648                                 /* journal device without journal feature */
1649                                 printk(KERN_WARNING
1650                                   "md: journal device provided without journal feature, ignoring the device\n");
1651                                 return -EINVAL;
1652                         }
1653                         set_bit(Journal, &rdev->flags);
1654                         rdev->journal_tail = le64_to_cpu(sb->journal_tail);
1655                         rdev->raid_disk = 0;
1656                         break;
1657                 default:
1658                         rdev->saved_raid_disk = role;
1659                         if ((le32_to_cpu(sb->feature_map) &
1660                              MD_FEATURE_RECOVERY_OFFSET)) {
1661                                 rdev->recovery_offset = le64_to_cpu(sb->recovery_offset);
1662                                 if (!(le32_to_cpu(sb->feature_map) &
1663                                       MD_FEATURE_RECOVERY_BITMAP))
1664                                         rdev->saved_raid_disk = -1;
1665                         } else
1666                                 set_bit(In_sync, &rdev->flags);
1667                         rdev->raid_disk = role;
1668                         break;
1669                 }
1670                 if (sb->devflags & WriteMostly1)
1671                         set_bit(WriteMostly, &rdev->flags);
1672                 if (le32_to_cpu(sb->feature_map) & MD_FEATURE_REPLACEMENT)
1673                         set_bit(Replacement, &rdev->flags);
1674         } else /* MULTIPATH are always insync */
1675                 set_bit(In_sync, &rdev->flags);
1676 
1677         return 0;
1678 }
1679 
1680 static void super_1_sync(struct mddev *mddev, struct md_rdev *rdev)
1681 {
1682         struct mdp_superblock_1 *sb;
1683         struct md_rdev *rdev2;
1684         int max_dev, i;
1685         /* make rdev->sb match mddev and rdev data. */
1686 
1687         sb = page_address(rdev->sb_page);
1688 
1689         sb->feature_map = 0;
1690         sb->pad0 = 0;
1691         sb->recovery_offset = cpu_to_le64(0);
1692         memset(sb->pad3, 0, sizeof(sb->pad3));
1693 
1694         sb->utime = cpu_to_le64((__u64)mddev->utime);
1695         sb->events = cpu_to_le64(mddev->events);
1696         if (mddev->in_sync)
1697                 sb->resync_offset = cpu_to_le64(mddev->recovery_cp);
1698         else if (test_bit(MD_JOURNAL_CLEAN, &mddev->flags))
1699                 sb->resync_offset = cpu_to_le64(MaxSector);
1700         else
1701                 sb->resync_offset = cpu_to_le64(0);
1702 
1703         sb->cnt_corrected_read = cpu_to_le32(atomic_read(&rdev->corrected_errors));
1704 
1705         sb->raid_disks = cpu_to_le32(mddev->raid_disks);
1706         sb->size = cpu_to_le64(mddev->dev_sectors);
1707         sb->chunksize = cpu_to_le32(mddev->chunk_sectors);
1708         sb->level = cpu_to_le32(mddev->level);
1709         sb->layout = cpu_to_le32(mddev->layout);
1710 
1711         if (test_bit(WriteMostly, &rdev->flags))
1712                 sb->devflags |= WriteMostly1;
1713         else
1714                 sb->devflags &= ~WriteMostly1;
1715         sb->data_offset = cpu_to_le64(rdev->data_offset);
1716         sb->data_size = cpu_to_le64(rdev->sectors);
1717 
1718         if (mddev->bitmap && mddev->bitmap_info.file == NULL) {
1719                 sb->bitmap_offset = cpu_to_le32((__u32)mddev->bitmap_info.offset);
1720                 sb->feature_map = cpu_to_le32(MD_FEATURE_BITMAP_OFFSET);
1721         }
1722 
1723         if (rdev->raid_disk >= 0 && !test_bit(Journal, &rdev->flags) &&
1724             !test_bit(In_sync, &rdev->flags)) {
1725                 sb->feature_map |=
1726                         cpu_to_le32(MD_FEATURE_RECOVERY_OFFSET);
1727                 sb->recovery_offset =
1728                         cpu_to_le64(rdev->recovery_offset);
1729                 if (rdev->saved_raid_disk >= 0 && mddev->bitmap)
1730                         sb->feature_map |=
1731                                 cpu_to_le32(MD_FEATURE_RECOVERY_BITMAP);
1732         }
1733         /* Note: recovery_offset and journal_tail share space  */
1734         if (test_bit(Journal, &rdev->flags))
1735                 sb->journal_tail = cpu_to_le64(rdev->journal_tail);
1736         if (test_bit(Replacement, &rdev->flags))
1737                 sb->feature_map |=
1738                         cpu_to_le32(MD_FEATURE_REPLACEMENT);
1739 
1740         if (mddev->reshape_position != MaxSector) {
1741                 sb->feature_map |= cpu_to_le32(MD_FEATURE_RESHAPE_ACTIVE);
1742                 sb->reshape_position = cpu_to_le64(mddev->reshape_position);
1743                 sb->new_layout = cpu_to_le32(mddev->new_layout);
1744                 sb->delta_disks = cpu_to_le32(mddev->delta_disks);
1745                 sb->new_level = cpu_to_le32(mddev->new_level);
1746                 sb->new_chunk = cpu_to_le32(mddev->new_chunk_sectors);
1747                 if (mddev->delta_disks == 0 &&
1748                     mddev->reshape_backwards)
1749                         sb->feature_map
1750                                 |= cpu_to_le32(MD_FEATURE_RESHAPE_BACKWARDS);
1751                 if (rdev->new_data_offset != rdev->data_offset) {
1752                         sb->feature_map
1753                                 |= cpu_to_le32(MD_FEATURE_NEW_OFFSET);
1754                         sb->new_offset = cpu_to_le32((__u32)(rdev->new_data_offset
1755                                                              - rdev->data_offset));
1756                 }
1757         }
1758 
1759         if (mddev_is_clustered(mddev))
1760                 sb->feature_map |= cpu_to_le32(MD_FEATURE_CLUSTERED);
1761 
1762         if (rdev->badblocks.count == 0)
1763                 /* Nothing to do for bad blocks*/ ;
1764         else if (sb->bblog_offset == 0)
1765                 /* Cannot record bad blocks on this device */
1766                 md_error(mddev, rdev);
1767         else {
1768                 struct badblocks *bb = &rdev->badblocks;
1769                 u64 *bbp = (u64 *)page_address(rdev->bb_page);
1770                 u64 *p = bb->page;
1771                 sb->feature_map |= cpu_to_le32(MD_FEATURE_BAD_BLOCKS);
1772                 if (bb->changed) {
1773                         unsigned seq;
1774 
1775 retry:
1776                         seq = read_seqbegin(&bb->lock);
1777 
1778                         memset(bbp, 0xff, PAGE_SIZE);
1779 
1780                         for (i = 0 ; i < bb->count ; i++) {
1781                                 u64 internal_bb = p[i];
1782                                 u64 store_bb = ((BB_OFFSET(internal_bb) << 10)
1783                                                 | BB_LEN(internal_bb));
1784                                 bbp[i] = cpu_to_le64(store_bb);
1785                         }
1786                         bb->changed = 0;
1787                         if (read_seqretry(&bb->lock, seq))
1788                                 goto retry;
1789 
1790                         bb->sector = (rdev->sb_start +
1791                                       (int)le32_to_cpu(sb->bblog_offset));
1792                         bb->size = le16_to_cpu(sb->bblog_size);
1793                 }
1794         }
1795 
1796         max_dev = 0;
1797         rdev_for_each(rdev2, mddev)
1798                 if (rdev2->desc_nr+1 > max_dev)
1799                         max_dev = rdev2->desc_nr+1;
1800 
1801         if (max_dev > le32_to_cpu(sb->max_dev)) {
1802                 int bmask;
1803                 sb->max_dev = cpu_to_le32(max_dev);
1804                 rdev->sb_size = max_dev * 2 + 256;
1805                 bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
1806                 if (rdev->sb_size & bmask)
1807                         rdev->sb_size = (rdev->sb_size | bmask) + 1;
1808         } else
1809                 max_dev = le32_to_cpu(sb->max_dev);
1810 
1811         for (i=0; i<max_dev;i++)
1812                 sb->dev_roles[i] = cpu_to_le16(MD_DISK_ROLE_FAULTY);
1813 
1814         if (test_bit(MD_HAS_JOURNAL, &mddev->flags))
1815                 sb->feature_map |= cpu_to_le32(MD_FEATURE_JOURNAL);
1816 
1817         rdev_for_each(rdev2, mddev) {
1818                 i = rdev2->desc_nr;
1819                 if (test_bit(Faulty, &rdev2->flags))
1820                         sb->dev_roles[i] = cpu_to_le16(MD_DISK_ROLE_FAULTY);
1821                 else if (test_bit(In_sync, &rdev2->flags))
1822                         sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1823                 else if (test_bit(Journal, &rdev2->flags))
1824                         sb->dev_roles[i] = cpu_to_le16(MD_DISK_ROLE_JOURNAL);
1825                 else if (rdev2->raid_disk >= 0)
1826                         sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1827                 else
1828                         sb->dev_roles[i] = cpu_to_le16(MD_DISK_ROLE_SPARE);
1829         }
1830 
1831         sb->sb_csum = calc_sb_1_csum(sb);
1832 }
1833 
1834 static unsigned long long
1835 super_1_rdev_size_change(struct md_rdev *rdev, sector_t num_sectors)
1836 {
1837         struct mdp_superblock_1 *sb;
1838         sector_t max_sectors;
1839         if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
1840                 return 0; /* component must fit device */
1841         if (rdev->data_offset != rdev->new_data_offset)
1842                 return 0; /* too confusing */
1843         if (rdev->sb_start < rdev->data_offset) {
1844                 /* minor versions 1 and 2; superblock before data */
1845                 max_sectors = i_size_read(rdev->bdev->bd_inode) >> 9;
1846                 max_sectors -= rdev->data_offset;
1847                 if (!num_sectors || num_sectors > max_sectors)
1848                         num_sectors = max_sectors;
1849         } else if (rdev->mddev->bitmap_info.offset) {
1850                 /* minor version 0 with bitmap we can't move */
1851                 return 0;
1852         } else {
1853                 /* minor version 0; superblock after data */
1854                 sector_t sb_start;
1855                 sb_start = (i_size_read(rdev->bdev->bd_inode) >> 9) - 8*2;
1856                 sb_start &= ~(sector_t)(4*2 - 1);
1857                 max_sectors = rdev->sectors + sb_start - rdev->sb_start;
1858                 if (!num_sectors || num_sectors > max_sectors)
1859                         num_sectors = max_sectors;
1860                 rdev->sb_start = sb_start;
1861         }
1862         sb = page_address(rdev->sb_page);
1863         sb->data_size = cpu_to_le64(num_sectors);
1864         sb->super_offset = rdev->sb_start;
1865         sb->sb_csum = calc_sb_1_csum(sb);
1866         md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
1867                        rdev->sb_page);
1868         md_super_wait(rdev->mddev);
1869         return num_sectors;
1870 
1871 }
1872 
1873 static int
1874 super_1_allow_new_offset(struct md_rdev *rdev,
1875                          unsigned long long new_offset)
1876 {
1877         /* All necessary checks on new >= old have been done */
1878         struct bitmap *bitmap;
1879         if (new_offset >= rdev->data_offset)
1880                 return 1;
1881 
1882         /* with 1.0 metadata, there is no metadata to tread on
1883          * so we can always move back */
1884         if (rdev->mddev->minor_version == 0)
1885                 return 1;
1886 
1887         /* otherwise we must be sure not to step on
1888          * any metadata, so stay:
1889          * 36K beyond start of superblock
1890          * beyond end of badblocks
1891          * beyond write-intent bitmap
1892          */
1893         if (rdev->sb_start + (32+4)*2 > new_offset)
1894                 return 0;
1895         bitmap = rdev->mddev->bitmap;
1896         if (bitmap && !rdev->mddev->bitmap_info.file &&
1897             rdev->sb_start + rdev->mddev->bitmap_info.offset +
1898             bitmap->storage.file_pages * (PAGE_SIZE>>9) > new_offset)
1899                 return 0;
1900         if (rdev->badblocks.sector + rdev->badblocks.size > new_offset)
1901                 return 0;
1902 
1903         return 1;
1904 }
1905 
1906 static struct super_type super_types[] = {
1907         [0] = {
1908                 .name   = "0.90.0",
1909                 .owner  = THIS_MODULE,
1910                 .load_super         = super_90_load,
1911                 .validate_super     = super_90_validate,
1912                 .sync_super         = super_90_sync,
1913                 .rdev_size_change   = super_90_rdev_size_change,
1914                 .allow_new_offset   = super_90_allow_new_offset,
1915         },
1916         [1] = {
1917                 .name   = "md-1",
1918                 .owner  = THIS_MODULE,
1919                 .load_super         = super_1_load,
1920                 .validate_super     = super_1_validate,
1921                 .sync_super         = super_1_sync,
1922                 .rdev_size_change   = super_1_rdev_size_change,
1923                 .allow_new_offset   = super_1_allow_new_offset,
1924         },
1925 };
1926 
1927 static void sync_super(struct mddev *mddev, struct md_rdev *rdev)
1928 {
1929         if (mddev->sync_super) {
1930                 mddev->sync_super(mddev, rdev);
1931                 return;
1932         }
1933 
1934         BUG_ON(mddev->major_version >= ARRAY_SIZE(super_types));
1935 
1936         super_types[mddev->major_version].sync_super(mddev, rdev);
1937 }
1938 
1939 static int match_mddev_units(struct mddev *mddev1, struct mddev *mddev2)
1940 {
1941         struct md_rdev *rdev, *rdev2;
1942 
1943         rcu_read_lock();
1944         rdev_for_each_rcu(rdev, mddev1) {
1945                 if (test_bit(Faulty, &rdev->flags) ||
1946                     test_bit(Journal, &rdev->flags) ||
1947                     rdev->raid_disk == -1)
1948                         continue;
1949                 rdev_for_each_rcu(rdev2, mddev2) {
1950                         if (test_bit(Faulty, &rdev2->flags) ||
1951                             test_bit(Journal, &rdev2->flags) ||
1952                             rdev2->raid_disk == -1)
1953                                 continue;
1954                         if (rdev->bdev->bd_contains ==
1955                             rdev2->bdev->bd_contains) {
1956                                 rcu_read_unlock();
1957                                 return 1;
1958                         }
1959                 }
1960         }
1961         rcu_read_unlock();
1962         return 0;
1963 }
1964 
1965 static LIST_HEAD(pending_raid_disks);
1966 
1967 /*
1968  * Try to register data integrity profile for an mddev
1969  *
1970  * This is called when an array is started and after a disk has been kicked
1971  * from the array. It only succeeds if all working and active component devices
1972  * are integrity capable with matching profiles.
1973  */
1974 int md_integrity_register(struct mddev *mddev)
1975 {
1976         struct md_rdev *rdev, *reference = NULL;
1977 
1978         if (list_empty(&mddev->disks))
1979                 return 0; /* nothing to do */
1980         if (!mddev->gendisk || blk_get_integrity(mddev->gendisk))
1981                 return 0; /* shouldn't register, or already is */
1982         rdev_for_each(rdev, mddev) {
1983                 /* skip spares and non-functional disks */
1984                 if (test_bit(Faulty, &rdev->flags))
1985                         continue;
1986                 if (rdev->raid_disk < 0)
1987                         continue;
1988                 if (!reference) {
1989                         /* Use the first rdev as the reference */
1990                         reference = rdev;
1991                         continue;
1992                 }
1993                 /* does this rdev's profile match the reference profile? */
1994                 if (blk_integrity_compare(reference->bdev->bd_disk,
1995                                 rdev->bdev->bd_disk) < 0)
1996                         return -EINVAL;
1997         }
1998         if (!reference || !bdev_get_integrity(reference->bdev))
1999                 return 0;
2000         /*
2001          * All component devices are integrity capable and have matching
2002          * profiles, register the common profile for the md device.
2003          */
2004         blk_integrity_register(mddev->gendisk,
2005                                bdev_get_integrity(reference->bdev));
2006 
2007         printk(KERN_NOTICE "md: data integrity enabled on %s\n", mdname(mddev));
2008         if (bioset_integrity_create(mddev->bio_set, BIO_POOL_SIZE)) {
2009                 printk(KERN_ERR "md: failed to create integrity pool for %s\n",
2010                        mdname(mddev));
2011                 return -EINVAL;
2012         }
2013         return 0;
2014 }
2015 EXPORT_SYMBOL(md_integrity_register);
2016 
2017 /*
2018  * Attempt to add an rdev, but only if it is consistent with the current
2019  * integrity profile
2020  */
2021 int md_integrity_add_rdev(struct md_rdev *rdev, struct mddev *mddev)
2022 {
2023         struct blk_integrity *bi_rdev;
2024         struct blk_integrity *bi_mddev;
2025         char name[BDEVNAME_SIZE];
2026 
2027         if (!mddev->gendisk)
2028                 return 0;
2029 
2030         bi_rdev = bdev_get_integrity(rdev->bdev);
2031         bi_mddev = blk_get_integrity(mddev->gendisk);
2032 
2033         if (!bi_mddev) /* nothing to do */
2034                 return 0;
2035 
2036         if (blk_integrity_compare(mddev->gendisk, rdev->bdev->bd_disk) != 0) {
2037                 printk(KERN_NOTICE "%s: incompatible integrity profile for %s\n",
2038                                 mdname(mddev), bdevname(rdev->bdev, name));
2039                 return -ENXIO;
2040         }
2041 
2042         return 0;
2043 }
2044 EXPORT_SYMBOL(md_integrity_add_rdev);
2045 
2046 static int bind_rdev_to_array(struct md_rdev *rdev, struct mddev *mddev)
2047 {
2048         char b[BDEVNAME_SIZE];
2049         struct kobject *ko;
2050         int err;
2051 
2052         /* prevent duplicates */
2053         if (find_rdev(mddev, rdev->bdev->bd_dev))
2054                 return -EEXIST;
2055 
2056         /* make sure rdev->sectors exceeds mddev->dev_sectors */
2057         if (!test_bit(Journal, &rdev->flags) &&
2058             rdev->sectors &&
2059             (mddev->dev_sectors == 0 || rdev->sectors < mddev->dev_sectors)) {
2060                 if (mddev->pers) {
2061                         /* Cannot change size, so fail
2062                          * If mddev->level <= 0, then we don't care
2063                          * about aligning sizes (e.g. linear)
2064                          */
2065                         if (mddev->level > 0)
2066                                 return -ENOSPC;
2067                 } else
2068                         mddev->dev_sectors = rdev->sectors;
2069         }
2070 
2071         /* Verify rdev->desc_nr is unique.
2072          * If it is -1, assign a free number, else
2073          * check number is not in use
2074          */
2075         rcu_read_lock();
2076         if (rdev->desc_nr < 0) {
2077                 int choice = 0;
2078                 if (mddev->pers)
2079                         choice = mddev->raid_disks;
2080                 while (md_find_rdev_nr_rcu(mddev, choice))
2081                         choice++;
2082                 rdev->desc_nr = choice;
2083         } else {
2084                 if (md_find_rdev_nr_rcu(mddev, rdev->desc_nr)) {
2085                         rcu_read_unlock();
2086                         return -EBUSY;
2087                 }
2088         }
2089         rcu_read_unlock();
2090         if (!test_bit(Journal, &rdev->flags) &&
2091             mddev->max_disks && rdev->desc_nr >= mddev->max_disks) {
2092                 printk(KERN_WARNING "md: %s: array is limited to %d devices\n",
2093                        mdname(mddev), mddev->max_disks);
2094                 return -EBUSY;
2095         }
2096         bdevname(rdev->bdev,b);
2097         strreplace(b, '/', '!');
2098 
2099         rdev->mddev = mddev;
2100         printk(KERN_INFO "md: bind<%s>\n", b);
2101 
2102         if ((err = kobject_add(&rdev->kobj, &mddev->kobj, "dev-%s", b)))
2103                 goto fail;
2104 
2105         ko = &part_to_dev(rdev->bdev->bd_part)->kobj;
2106         if (sysfs_create_link(&rdev->kobj, ko, "block"))
2107                 /* failure here is OK */;
2108         rdev->sysfs_state = sysfs_get_dirent_safe(rdev->kobj.sd, "state");
2109 
2110         list_add_rcu(&rdev->same_set, &mddev->disks);
2111         bd_link_disk_holder(rdev->bdev, mddev->gendisk);
2112 
2113         /* May as well allow recovery to be retried once */
2114         mddev->recovery_disabled++;
2115 
2116         return 0;
2117 
2118  fail:
2119         printk(KERN_WARNING "md: failed to register dev-%s for %s\n",
2120                b, mdname(mddev));
2121         return err;
2122 }
2123 
2124 static void md_delayed_delete(struct work_struct *ws)
2125 {
2126         struct md_rdev *rdev = container_of(ws, struct md_rdev, del_work);
2127         kobject_del(&rdev->kobj);
2128         kobject_put(&rdev->kobj);
2129 }
2130 
2131 static void unbind_rdev_from_array(struct md_rdev *rdev)
2132 {
2133         char b[BDEVNAME_SIZE];
2134 
2135         bd_unlink_disk_holder(rdev->bdev, rdev->mddev->gendisk);
2136         list_del_rcu(&rdev->same_set);
2137         printk(KERN_INFO "md: unbind<%s>\n", bdevname(rdev->bdev,b));
2138         rdev->mddev = NULL;
2139         sysfs_remove_link(&rdev->kobj, "block");
2140         sysfs_put(rdev->sysfs_state);
2141         rdev->sysfs_state = NULL;
2142         rdev->badblocks.count = 0;
2143         /* We need to delay this, otherwise we can deadlock when
2144          * writing to 'remove' to "dev/state".  We also need
2145          * to delay it due to rcu usage.
2146          */
2147         synchronize_rcu();
2148         INIT_WORK(&rdev->del_work, md_delayed_delete);
2149         kobject_get(&rdev->kobj);
2150         queue_work(md_misc_wq, &rdev->del_work);
2151 }
2152 
2153 /*
2154  * prevent the device from being mounted, repartitioned or
2155  * otherwise reused by a RAID array (or any other kernel
2156  * subsystem), by bd_claiming the device.
2157  */
2158 static int lock_rdev(struct md_rdev *rdev, dev_t dev, int shared)
2159 {
2160         int err = 0;
2161         struct block_device *bdev;
2162         char b[BDEVNAME_SIZE];
2163 
2164         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL,
2165                                  shared ? (struct md_rdev *)lock_rdev : rdev);
2166         if (IS_ERR(bdev)) {
2167                 printk(KERN_ERR "md: could not open %s.\n",
2168                         __bdevname(dev, b));
2169                 return PTR_ERR(bdev);
2170         }
2171         rdev->bdev = bdev;
2172         return err;
2173 }
2174 
2175 static void unlock_rdev(struct md_rdev *rdev)
2176 {
2177         struct block_device *bdev = rdev->bdev;
2178         rdev->bdev = NULL;
2179         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
2180 }
2181 
2182 void md_autodetect_dev(dev_t dev);
2183 
2184 static void export_rdev(struct md_rdev *rdev)
2185 {
2186         char b[BDEVNAME_SIZE];
2187 
2188         printk(KERN_INFO "md: export_rdev(%s)\n",
2189                 bdevname(rdev->bdev,b));
2190         md_rdev_clear(rdev);
2191 #ifndef MODULE
2192         if (test_bit(AutoDetected, &rdev->flags))
2193                 md_autodetect_dev(rdev->bdev->bd_dev);
2194 #endif
2195         unlock_rdev(rdev);
2196         kobject_put(&rdev->kobj);
2197 }
2198 
2199 void md_kick_rdev_from_array(struct md_rdev *rdev)
2200 {
2201         unbind_rdev_from_array(rdev);
2202         export_rdev(rdev);
2203 }
2204 EXPORT_SYMBOL_GPL(md_kick_rdev_from_array);
2205 
2206 static void export_array(struct mddev *mddev)
2207 {
2208         struct md_rdev *rdev;
2209 
2210         while (!list_empty(&mddev->disks)) {
2211                 rdev = list_first_entry(&mddev->disks, struct md_rdev,
2212                                         same_set);
2213                 md_kick_rdev_from_array(rdev);
2214         }
2215         mddev->raid_disks = 0;
2216         mddev->major_version = 0;
2217 }
2218 
2219 static void sync_sbs(struct mddev *mddev, int nospares)
2220 {
2221         /* Update each superblock (in-memory image), but
2222          * if we are allowed to, skip spares which already
2223          * have the right event counter, or have one earlier
2224          * (which would mean they aren't being marked as dirty
2225          * with the rest of the array)
2226          */
2227         struct md_rdev *rdev;
2228         rdev_for_each(rdev, mddev) {
2229                 if (rdev->sb_events == mddev->events ||
2230                     (nospares &&
2231                      rdev->raid_disk < 0 &&
2232                      rdev->sb_events+1 == mddev->events)) {
2233                         /* Don't update this superblock */
2234                         rdev->sb_loaded = 2;
2235                 } else {
2236                         sync_super(mddev, rdev);
2237                         rdev->sb_loaded = 1;
2238                 }
2239         }
2240 }
2241 
2242 static bool does_sb_need_changing(struct mddev *mddev)
2243 {
2244         struct md_rdev *rdev;
2245         struct mdp_superblock_1 *sb;
2246         int role;
2247 
2248         /* Find a good rdev */
2249         rdev_for_each(rdev, mddev)
2250                 if ((rdev->raid_disk >= 0) && !test_bit(Faulty, &rdev->flags))
2251                         break;
2252 
2253         /* No good device found. */
2254         if (!rdev)
2255                 return false;
2256 
2257         sb = page_address(rdev->sb_page);
2258         /* Check if a device has become faulty or a spare become active */
2259         rdev_for_each(rdev, mddev) {
2260                 role = le16_to_cpu(sb->dev_roles[rdev->desc_nr]);
2261                 /* Device activated? */
2262                 if (role == 0xffff && rdev->raid_disk >=0 &&
2263                     !test_bit(Faulty, &rdev->flags))
2264                         return true;
2265                 /* Device turned faulty? */
2266                 if (test_bit(Faulty, &rdev->flags) && (role < 0xfffd))
2267                         return true;
2268         }
2269 
2270         /* Check if any mddev parameters have changed */
2271         if ((mddev->dev_sectors != le64_to_cpu(sb->size)) ||
2272             (mddev->reshape_position != le64_to_cpu(sb->reshape_position)) ||
2273             (mddev->layout != le64_to_cpu(sb->layout)) ||
2274             (mddev->raid_disks != le32_to_cpu(sb->raid_disks)) ||
2275             (mddev->chunk_sectors != le32_to_cpu(sb->chunksize)))
2276                 return true;
2277 
2278         return false;
2279 }
2280 
2281 void md_update_sb(struct mddev *mddev, int force_change)
2282 {
2283         struct md_rdev *rdev;
2284         int sync_req;
2285         int nospares = 0;
2286         int any_badblocks_changed = 0;
2287         int ret = -1;
2288 
2289         if (mddev->ro) {
2290                 if (force_change)
2291                         set_bit(MD_CHANGE_DEVS, &mddev->flags);
2292                 return;
2293         }
2294 
2295 repeat:
2296         if (mddev_is_clustered(mddev)) {
2297                 if (test_and_clear_bit(MD_CHANGE_DEVS, &mddev->flags))
2298                         force_change = 1;
2299                 if (test_and_clear_bit(MD_CHANGE_CLEAN, &mddev->flags))
2300                         nospares = 1;
2301                 ret = md_cluster_ops->metadata_update_start(mddev);
2302                 /* Has someone else has updated the sb */
2303                 if (!does_sb_need_changing(mddev)) {
2304                         if (ret == 0)
2305                                 md_cluster_ops->metadata_update_cancel(mddev);
2306                         bit_clear_unless(&mddev->flags, BIT(MD_CHANGE_PENDING),
2307                                                          BIT(MD_CHANGE_DEVS) |
2308                                                          BIT(MD_CHANGE_CLEAN));
2309                         return;
2310                 }
2311         }
2312 
2313         /* First make sure individual recovery_offsets are correct */
2314         rdev_for_each(rdev, mddev) {
2315                 if (rdev->raid_disk >= 0 &&
2316                     mddev->delta_disks >= 0 &&
2317                     !test_bit(Journal, &rdev->flags) &&
2318                     !test_bit(In_sync, &rdev->flags) &&
2319                     mddev->curr_resync_completed > rdev->recovery_offset)
2320                                 rdev->recovery_offset = mddev->curr_resync_completed;
2321 
2322         }
2323         if (!mddev->persistent) {
2324                 clear_bit(MD_CHANGE_CLEAN, &mddev->flags);
2325                 clear_bit(MD_CHANGE_DEVS, &mddev->flags);
2326                 if (!mddev->external) {
2327                         clear_bit(MD_CHANGE_PENDING, &mddev->flags);
2328                         rdev_for_each(rdev, mddev) {
2329                                 if (rdev->badblocks.changed) {
2330                                         rdev->badblocks.changed = 0;
2331                                         ack_all_badblocks(&rdev->badblocks);
2332                                         md_error(mddev, rdev);
2333                                 }
2334                                 clear_bit(Blocked, &rdev->flags);
2335                                 clear_bit(BlockedBadBlocks, &rdev->flags);
2336                                 wake_up(&rdev->blocked_wait);
2337                         }
2338                 }
2339                 wake_up(&mddev->sb_wait);
2340                 return;
2341         }
2342 
2343         spin_lock(&mddev->lock);
2344 
2345         mddev->utime = ktime_get_real_seconds();
2346 
2347         if (test_and_clear_bit(MD_CHANGE_DEVS, &mddev->flags))
2348                 force_change = 1;
2349         if (test_and_clear_bit(MD_CHANGE_CLEAN, &mddev->flags))
2350                 /* just a clean<-> dirty transition, possibly leave spares alone,
2351                  * though if events isn't the right even/odd, we will have to do
2352                  * spares after all
2353                  */
2354                 nospares = 1;
2355         if (force_change)
2356                 nospares = 0;
2357         if (mddev->degraded)
2358                 /* If the array is degraded, then skipping spares is both
2359                  * dangerous and fairly pointless.
2360                  * Dangerous because a device that was removed from the array
2361                  * might have a event_count that still looks up-to-date,
2362                  * so it can be re-added without a resync.
2363                  * Pointless because if there are any spares to skip,
2364                  * then a recovery will happen and soon that array won't
2365                  * be degraded any more and the spare can go back to sleep then.
2366                  */
2367                 nospares = 0;
2368 
2369         sync_req = mddev->in_sync;
2370 
2371         /* If this is just a dirty<->clean transition, and the array is clean
2372          * and 'events' is odd, we can roll back to the previous clean state */
2373         if (nospares
2374             && (mddev->in_sync && mddev->recovery_cp == MaxSector)
2375             && mddev->can_decrease_events
2376             && mddev->events != 1) {
2377                 mddev->events--;
2378                 mddev->can_decrease_events = 0;
2379         } else {
2380                 /* otherwise we have to go forward and ... */
2381                 mddev->events ++;
2382                 mddev->can_decrease_events = nospares;
2383         }
2384 
2385         /*
2386          * This 64-bit counter should never wrap.
2387          * Either we are in around ~1 trillion A.C., assuming
2388          * 1 reboot per second, or we have a bug...
2389          */
2390         WARN_ON(mddev->events == 0);
2391 
2392         rdev_for_each(rdev, mddev) {
2393                 if (rdev->badblocks.changed)
2394                         any_badblocks_changed++;
2395                 if (test_bit(Faulty, &rdev->flags))
2396                         set_bit(FaultRecorded, &rdev->flags);
2397         }
2398 
2399         sync_sbs(mddev, nospares);
2400         spin_unlock(&mddev->lock);
2401 
2402         pr_debug("md: updating %s RAID superblock on device (in sync %d)\n",
2403                  mdname(mddev), mddev->in_sync);
2404 
2405         bitmap_update_sb(mddev->bitmap);
2406         rdev_for_each(rdev, mddev) {
2407                 char b[BDEVNAME_SIZE];
2408 
2409                 if (rdev->sb_loaded != 1)
2410                         continue; /* no noise on spare devices */
2411 
2412                 if (!test_bit(Faulty, &rdev->flags)) {
2413                         md_super_write(mddev,rdev,
2414                                        rdev->sb_start, rdev->sb_size,
2415                                        rdev->sb_page);
2416                         pr_debug("md: (write) %s's sb offset: %llu\n",
2417                                  bdevname(rdev->bdev, b),
2418                                  (unsigned long long)rdev->sb_start);
2419                         rdev->sb_events = mddev->events;
2420                         if (rdev->badblocks.size) {
2421                                 md_super_write(mddev, rdev,
2422                                                rdev->badblocks.sector,
2423                                                rdev->badblocks.size << 9,
2424                                                rdev->bb_page);
2425                                 rdev->badblocks.size = 0;
2426                         }
2427 
2428                 } else
2429                         pr_debug("md: %s (skipping faulty)\n",
2430                                  bdevname(rdev->bdev, b));
2431 
2432                 if (mddev->level == LEVEL_MULTIPATH)
2433                         /* only need to write one superblock... */
2434                         break;
2435         }
2436         md_super_wait(mddev);
2437         /* if there was a failure, MD_CHANGE_DEVS was set, and we re-write super */
2438 
2439         if (mddev_is_clustered(mddev) && ret == 0)
2440                 md_cluster_ops->metadata_update_finish(mddev);
2441 
2442         if (mddev->in_sync != sync_req ||
2443             !bit_clear_unless(&mddev->flags, BIT(MD_CHANGE_PENDING),
2444                                BIT(MD_CHANGE_DEVS) | BIT(MD_CHANGE_CLEAN)))
2445                 /* have to write it out again */
2446                 goto repeat;
2447         wake_up(&mddev->sb_wait);
2448         if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
2449                 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
2450 
2451         rdev_for_each(rdev, mddev) {
2452                 if (test_and_clear_bit(FaultRecorded, &rdev->flags))
2453                         clear_bit(Blocked, &rdev->flags);
2454 
2455                 if (any_badblocks_changed)
2456                         ack_all_badblocks(&rdev->badblocks);
2457                 clear_bit(BlockedBadBlocks, &rdev->flags);
2458                 wake_up(&rdev->blocked_wait);
2459         }
2460 }
2461 EXPORT_SYMBOL(md_update_sb);
2462 
2463 static int add_bound_rdev(struct md_rdev *rdev)
2464 {
2465         struct mddev *mddev = rdev->mddev;
2466         int err = 0;
2467         bool add_journal = test_bit(Journal, &rdev->flags);
2468 
2469         if (!mddev->pers->hot_remove_disk || add_journal) {
2470                 /* If there is hot_add_disk but no hot_remove_disk
2471                  * then added disks for geometry changes,
2472                  * and should be added immediately.
2473                  */
2474                 super_types[mddev->major_version].
2475                         validate_super(mddev, rdev);
2476                 if (add_journal)
2477                         mddev_suspend(mddev);
2478                 err = mddev->pers->hot_add_disk(mddev, rdev);
2479                 if (add_journal)
2480                         mddev_resume(mddev);
2481                 if (err) {
2482                         md_kick_rdev_from_array(rdev);
2483                         return err;
2484                 }
2485         }
2486         sysfs_notify_dirent_safe(rdev->sysfs_state);
2487 
2488         set_bit(MD_CHANGE_DEVS, &mddev->flags);
2489         if (mddev->degraded)
2490                 set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
2491         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2492         md_new_event(mddev);
2493         md_wakeup_thread(mddev->thread);
2494         return 0;
2495 }
2496 
2497 /* words written to sysfs files may, or may not, be \n terminated.
2498  * We want to accept with case. For this we use cmd_match.
2499  */
2500 static int cmd_match(const char *cmd, const char *str)
2501 {
2502         /* See if cmd, written into a sysfs file, matches
2503          * str.  They must either be the same, or cmd can
2504          * have a trailing newline
2505          */
2506         while (*cmd && *str && *cmd == *str) {
2507                 cmd++;
2508                 str++;
2509         }
2510         if (*cmd == '\n')
2511                 cmd++;
2512         if (*str || *cmd)
2513                 return 0;
2514         return 1;
2515 }
2516 
2517 struct rdev_sysfs_entry {
2518         struct attribute attr;
2519         ssize_t (*show)(struct md_rdev *, char *);
2520         ssize_t (*store)(struct md_rdev *, const char *, size_t);
2521 };
2522 
2523 static ssize_t
2524 state_show(struct md_rdev *rdev, char *page)
2525 {
2526         char *sep = "";
2527         size_t len = 0;
2528         unsigned long flags = ACCESS_ONCE(rdev->flags);
2529 
2530         if (test_bit(Faulty, &flags) ||
2531             rdev->badblocks.unacked_exist) {
2532                 len+= sprintf(page+len, "%sfaulty",sep);
2533                 sep = ",";
2534         }
2535         if (test_bit(In_sync, &flags)) {
2536                 len += sprintf(page+len, "%sin_sync",sep);
2537                 sep = ",";
2538         }
2539         if (test_bit(Journal, &flags)) {
2540                 len += sprintf(page+len, "%sjournal",sep);
2541                 sep = ",";
2542         }
2543         if (test_bit(WriteMostly, &flags)) {
2544                 len += sprintf(page+len, "%swrite_mostly",sep);
2545                 sep = ",";
2546         }
2547         if (test_bit(Blocked, &flags) ||
2548             (rdev->badblocks.unacked_exist
2549              && !test_bit(Faulty, &flags))) {
2550                 len += sprintf(page+len, "%sblocked", sep);
2551                 sep = ",";
2552         }
2553         if (!test_bit(Faulty, &flags) &&
2554             !test_bit(Journal, &flags) &&
2555             !test_bit(In_sync, &flags)) {
2556                 len += sprintf(page+len, "%sspare", sep);
2557                 sep = ",";
2558         }
2559         if (test_bit(WriteErrorSeen, &flags)) {
2560                 len += sprintf(page+len, "%swrite_error", sep);
2561                 sep = ",";
2562         }
2563         if (test_bit(WantReplacement, &flags)) {
2564                 len += sprintf(page+len, "%swant_replacement", sep);
2565                 sep = ",";
2566         }
2567         if (test_bit(Replacement, &flags)) {
2568                 len += sprintf(page+len, "%sreplacement", sep);
2569                 sep = ",";
2570         }
2571 
2572         return len+sprintf(page+len, "\n");
2573 }
2574 
2575 static ssize_t
2576 state_store(struct md_rdev *rdev, const char *buf, size_t len)
2577 {
2578         /* can write
2579          *  faulty  - simulates an error
2580          *  remove  - disconnects the device
2581          *  writemostly - sets write_mostly
2582          *  -writemostly - clears write_mostly
2583          *  blocked - sets the Blocked flags
2584          *  -blocked - clears the Blocked and possibly simulates an error
2585          *  insync - sets Insync providing device isn't active
2586          *  -insync - clear Insync for a device with a slot assigned,
2587          *            so that it gets rebuilt based on bitmap
2588          *  write_error - sets WriteErrorSeen
2589          *  -write_error - clears WriteErrorSeen
2590          */
2591         int err = -EINVAL;
2592         if (cmd_match(buf, "faulty") && rdev->mddev->pers) {
2593                 md_error(rdev->mddev, rdev);
2594                 if (test_bit(Faulty, &rdev->flags))
2595                         err = 0;
2596                 else
2597                         err = -EBUSY;
2598         } else if (cmd_match(buf, "remove")) {
2599                 if (rdev->mddev->pers) {
2600                         clear_bit(Blocked, &rdev->flags);
2601                         remove_and_add_spares(rdev->mddev, rdev);
2602                 }
2603                 if (rdev->raid_disk >= 0)
2604                         err = -EBUSY;
2605                 else {
2606                         struct mddev *mddev = rdev->mddev;
2607                         err = 0;
2608                         if (mddev_is_clustered(mddev))
2609                                 err = md_cluster_ops->remove_disk(mddev, rdev);
2610 
2611                         if (err == 0) {
2612                                 md_kick_rdev_from_array(rdev);
2613                                 if (mddev->pers)
2614                                         md_update_sb(mddev, 1);
2615                                 md_new_event(mddev);
2616                         }
2617                 }
2618         } else if (cmd_match(buf, "writemostly")) {
2619                 set_bit(WriteMostly, &rdev->flags);
2620                 err = 0;
2621         } else if (cmd_match(buf, "-writemostly")) {
2622                 clear_bit(WriteMostly, &rdev->flags);
2623                 err = 0;
2624         } else if (cmd_match(buf, "blocked")) {
2625                 set_bit(Blocked, &rdev->flags);
2626                 err = 0;
2627         } else if (cmd_match(buf, "-blocked")) {
2628                 if (!test_bit(Faulty, &rdev->flags) &&
2629                     rdev->badblocks.unacked_exist) {
2630                         /* metadata handler doesn't understand badblocks,
2631                          * so we need to fail the device
2632                          */
2633                         md_error(rdev->mddev, rdev);
2634                 }
2635                 clear_bit(Blocked, &rdev->flags);
2636                 clear_bit(BlockedBadBlocks, &rdev->flags);
2637                 wake_up(&rdev->blocked_wait);
2638                 set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2639                 md_wakeup_thread(rdev->mddev->thread);
2640 
2641                 err = 0;
2642         } else if (cmd_match(buf, "insync") && rdev->raid_disk == -1) {
2643                 set_bit(In_sync, &rdev->flags);
2644                 err = 0;
2645         } else if (cmd_match(buf, "-insync") && rdev->raid_disk >= 0 &&
2646                    !test_bit(Journal, &rdev->flags)) {
2647                 if (rdev->mddev->pers == NULL) {
2648                         clear_bit(In_sync, &rdev->flags);
2649                         rdev->saved_raid_disk = rdev->raid_disk;
2650                         rdev->raid_disk = -1;
2651                         err = 0;
2652                 }
2653         } else if (cmd_match(buf, "write_error")) {
2654                 set_bit(WriteErrorSeen, &rdev->flags);
2655                 err = 0;
2656         } else if (cmd_match(buf, "-write_error")) {
2657                 clear_bit(WriteErrorSeen, &rdev->flags);
2658                 err = 0;
2659         } else if (cmd_match(buf, "want_replacement")) {
2660                 /* Any non-spare device that is not a replacement can
2661                  * become want_replacement at any time, but we then need to
2662                  * check if recovery is needed.
2663                  */
2664                 if (rdev->raid_disk >= 0 &&
2665                     !test_bit(Journal, &rdev->flags) &&
2666                     !test_bit(Replacement, &rdev->flags))
2667                         set_bit(WantReplacement, &rdev->flags);
2668                 set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2669                 md_wakeup_thread(rdev->mddev->thread);
2670                 err = 0;
2671         } else if (cmd_match(buf, "-want_replacement")) {
2672                 /* Clearing 'want_replacement' is always allowed.
2673                  * Once replacements starts it is too late though.
2674                  */
2675                 err = 0;
2676                 clear_bit(WantReplacement, &rdev->flags);
2677         } else if (cmd_match(buf, "replacement")) {
2678                 /* Can only set a device as a replacement when array has not
2679                  * yet been started.  Once running, replacement is automatic
2680                  * from spares, or by assigning 'slot'.
2681                  */
2682                 if (rdev->mddev->pers)
2683                         err = -EBUSY;
2684                 else {
2685                         set_bit(Replacement, &rdev->flags);
2686                         err = 0;
2687                 }
2688         } else if (cmd_match(buf, "-replacement")) {
2689                 /* Similarly, can only clear Replacement before start */
2690                 if (rdev->mddev->pers)
2691                         err = -EBUSY;
2692                 else {
2693                         clear_bit(Replacement, &rdev->flags);
2694                         err = 0;
2695                 }
2696         } else if (cmd_match(buf, "re-add")) {
2697                 if (test_bit(Faulty, &rdev->flags) && (rdev->raid_disk == -1)) {
2698                         /* clear_bit is performed _after_ all the devices
2699                          * have their local Faulty bit cleared. If any writes
2700                          * happen in the meantime in the local node, they
2701                          * will land in the local bitmap, which will be synced
2702                          * by this node eventually
2703                          */
2704                         if (!mddev_is_clustered(rdev->mddev) ||
2705                             (err = md_cluster_ops->gather_bitmaps(rdev)) == 0) {
2706                                 clear_bit(Faulty, &rdev->flags);
2707                                 err = add_bound_rdev(rdev);
2708                         }
2709                 } else
2710                         err = -EBUSY;
2711         }
2712         if (!err)
2713                 sysfs_notify_dirent_safe(rdev->sysfs_state);
2714         return err ? err : len;
2715 }
2716 static struct rdev_sysfs_entry rdev_state =
2717 __ATTR_PREALLOC(state, S_IRUGO|S_IWUSR, state_show, state_store);
2718 
2719 static ssize_t
2720 errors_show(struct md_rdev *rdev, char *page)
2721 {
2722         return sprintf(page, "%d\n", atomic_read(&rdev->corrected_errors));
2723 }
2724 
2725 static ssize_t
2726 errors_store(struct md_rdev *rdev, const char *buf, size_t len)
2727 {
2728         unsigned int n;
2729         int rv;
2730 
2731         rv = kstrtouint(buf, 10, &n);
2732         if (rv < 0)
2733                 return rv;
2734         atomic_set(&rdev->corrected_errors, n);
2735         return len;
2736 }
2737 static struct rdev_sysfs_entry rdev_errors =
2738 __ATTR(errors, S_IRUGO|S_IWUSR, errors_show, errors_store);
2739 
2740 static ssize_t
2741 slot_show(struct md_rdev *rdev, char *page)
2742 {
2743         if (test_bit(Journal, &rdev->flags))
2744                 return sprintf(page, "journal\n");
2745         else if (rdev->raid_disk < 0)
2746                 return sprintf(page, "none\n");
2747         else
2748                 return sprintf(page, "%d\n", rdev->raid_disk);
2749 }
2750 
2751 static ssize_t
2752 slot_store(struct md_rdev *rdev, const char *buf, size_t len)
2753 {
2754         int slot;
2755         int err;
2756 
2757         if (test_bit(Journal, &rdev->flags))
2758                 return -EBUSY;
2759         if (strncmp(buf, "none", 4)==0)
2760                 slot = -1;
2761         else {
2762                 err = kstrtouint(buf, 10, (unsigned int *)&slot);
2763                 if (err < 0)
2764                         return err;
2765         }
2766         if (rdev->mddev->pers && slot == -1) {
2767                 /* Setting 'slot' on an active array requires also
2768                  * updating the 'rd%d' link, and communicating
2769                  * with the personality with ->hot_*_disk.
2770                  * For now we only support removing
2771                  * failed/spare devices.  This normally happens automatically,
2772                  * but not when the metadata is externally managed.
2773                  */
2774                 if (rdev->raid_disk == -1)
2775                         return -EEXIST;
2776                 /* personality does all needed checks */
2777                 if (rdev->mddev->pers->hot_remove_disk == NULL)
2778                         return -EINVAL;
2779                 clear_bit(Blocked, &rdev->flags);
2780                 remove_and_add_spares(rdev->mddev, rdev);
2781                 if (rdev->raid_disk >= 0)
2782                         return -EBUSY;
2783                 set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2784                 md_wakeup_thread(rdev->mddev->thread);
2785         } else if (rdev->mddev->pers) {
2786                 /* Activating a spare .. or possibly reactivating
2787                  * if we ever get bitmaps working here.
2788                  */
2789                 int err;
2790 
2791                 if (rdev->raid_disk != -1)
2792                         return -EBUSY;
2793 
2794                 if (test_bit(MD_RECOVERY_RUNNING, &rdev->mddev->recovery))
2795                         return -EBUSY;
2796 
2797                 if (rdev->mddev->pers->hot_add_disk == NULL)
2798                         return -EINVAL;
2799 
2800                 if (slot >= rdev->mddev->raid_disks &&
2801                     slot >= rdev->mddev->raid_disks + rdev->mddev->delta_disks)
2802                         return -ENOSPC;
2803 
2804                 rdev->raid_disk = slot;
2805                 if (test_bit(In_sync, &rdev->flags))
2806                         rdev->saved_raid_disk = slot;
2807                 else
2808                         rdev->saved_raid_disk = -1;
2809                 clear_bit(In_sync, &rdev->flags);
2810                 clear_bit(Bitmap_sync, &rdev->flags);
2811                 err = rdev->mddev->pers->
2812                         hot_add_disk(rdev->mddev, rdev);
2813                 if (err) {
2814                         rdev->raid_disk = -1;
2815                         return err;
2816                 } else
2817                         sysfs_notify_dirent_safe(rdev->sysfs_state);
2818                 if (sysfs_link_rdev(rdev->mddev, rdev))
2819                         /* failure here is OK */;
2820                 /* don't wakeup anyone, leave that to userspace. */
2821         } else {
2822                 if (slot >= rdev->mddev->raid_disks &&
2823                     slot >= rdev->mddev->raid_disks + rdev->mddev->delta_disks)
2824                         return -ENOSPC;
2825                 rdev->raid_disk = slot;
2826                 /* assume it is working */
2827                 clear_bit(Faulty, &rdev->flags);
2828                 clear_bit(WriteMostly, &rdev->flags);
2829                 set_bit(In_sync, &rdev->flags);
2830                 sysfs_notify_dirent_safe(rdev->sysfs_state);
2831         }
2832         return len;
2833 }
2834 
2835 static struct rdev_sysfs_entry rdev_slot =
2836 __ATTR(slot, S_IRUGO|S_IWUSR, slot_show, slot_store);
2837 
2838 static ssize_t
2839 offset_show(struct md_rdev *rdev, char *page)
2840 {
2841         return sprintf(page, "%llu\n", (unsigned long long)rdev->data_offset);
2842 }
2843 
2844 static ssize_t
2845 offset_store(struct md_rdev *rdev, const char *buf, size_t len)
2846 {
2847         unsigned long long offset;
2848         if (kstrtoull(buf, 10, &offset) < 0)
2849                 return -EINVAL;
2850         if (rdev->mddev->pers && rdev->raid_disk >= 0)
2851                 return -EBUSY;
2852         if (rdev->sectors && rdev->mddev->external)
2853                 /* Must set offset before size, so overlap checks
2854                  * can be sane */
2855                 return -EBUSY;
2856         rdev->data_offset = offset;
2857         rdev->new_data_offset = offset;
2858         return len;
2859 }
2860 
2861 static struct rdev_sysfs_entry rdev_offset =
2862 __ATTR(offset, S_IRUGO|S_IWUSR, offset_show, offset_store);
2863 
2864 static ssize_t new_offset_show(struct md_rdev *rdev, char *page)
2865 {
2866         return sprintf(page, "%llu\n",
2867                        (unsigned long long)rdev->new_data_offset);
2868 }
2869 
2870 static ssize_t new_offset_store(struct md_rdev *rdev,
2871                                 const char *buf, size_t len)
2872 {
2873         unsigned long long new_offset;
2874         struct mddev *mddev = rdev->mddev;
2875 
2876         if (kstrtoull(buf, 10, &new_offset) < 0)
2877                 return -EINVAL;
2878 
2879         if (mddev->sync_thread ||
2880             test_bit(MD_RECOVERY_RUNNING,&mddev->recovery))
2881                 return -EBUSY;
2882         if (new_offset == rdev->data_offset)
2883                 /* reset is always permitted */
2884                 ;
2885         else if (new_offset > rdev->data_offset) {
2886                 /* must not push array size beyond rdev_sectors */
2887                 if (new_offset - rdev->data_offset
2888                     + mddev->dev_sectors > rdev->sectors)
2889                                 return -E2BIG;
2890         }
2891         /* Metadata worries about other space details. */
2892 
2893         /* decreasing the offset is inconsistent with a backwards
2894          * reshape.
2895          */
2896         if (new_offset < rdev->data_offset &&
2897             mddev->reshape_backwards)
2898                 return -EINVAL;
2899         /* Increasing offset is inconsistent with forwards
2900          * reshape.  reshape_direction should be set to
2901          * 'backwards' first.
2902          */
2903         if (new_offset > rdev->data_offset &&
2904             !mddev->reshape_backwards)
2905                 return -EINVAL;
2906 
2907         if (mddev->pers && mddev->persistent &&
2908             !super_types[mddev->major_version]
2909             .allow_new_offset(rdev, new_offset))
2910                 return -E2BIG;
2911         rdev->new_data_offset = new_offset;
2912         if (new_offset > rdev->data_offset)
2913                 mddev->reshape_backwards = 1;
2914         else if (new_offset < rdev->data_offset)
2915                 mddev->reshape_backwards = 0;
2916 
2917         return len;
2918 }
2919 static struct rdev_sysfs_entry rdev_new_offset =
2920 __ATTR(new_offset, S_IRUGO|S_IWUSR, new_offset_show, new_offset_store);
2921 
2922 static ssize_t
2923 rdev_size_show(struct md_rdev *rdev, char *page)
2924 {
2925         return sprintf(page, "%llu\n", (unsigned long long)rdev->sectors / 2);
2926 }
2927 
2928 static int overlaps(sector_t s1, sector_t l1, sector_t s2, sector_t l2)
2929 {
2930         /* check if two start/length pairs overlap */
2931         if (s1+l1 <= s2)
2932                 return 0;
2933         if (s2+l2 <= s1)
2934                 return 0;
2935         return 1;
2936 }
2937 
2938 static int strict_blocks_to_sectors(const char *buf, sector_t *sectors)
2939 {
2940         unsigned long long blocks;
2941         sector_t new;
2942 
2943         if (kstrtoull(buf, 10, &blocks) < 0)
2944                 return -EINVAL;
2945 
2946         if (blocks & 1ULL << (8 * sizeof(blocks) - 1))
2947                 return -EINVAL; /* sector conversion overflow */
2948 
2949         new = blocks * 2;
2950         if (new != blocks * 2)
2951                 return -EINVAL; /* unsigned long long to sector_t overflow */
2952 
2953         *sectors = new;
2954         return 0;
2955 }
2956 
2957 static ssize_t
2958 rdev_size_store(struct md_rdev *rdev, const char *buf, size_t len)
2959 {
2960         struct mddev *my_mddev = rdev->mddev;
2961         sector_t oldsectors = rdev->sectors;
2962         sector_t sectors;
2963 
2964         if (test_bit(Journal, &rdev->flags))
2965                 return -EBUSY;
2966         if (strict_blocks_to_sectors(buf, &sectors) < 0)
2967                 return -EINVAL;
2968         if (rdev->data_offset != rdev->new_data_offset)
2969                 return -EINVAL; /* too confusing */
2970         if (my_mddev->pers && rdev->raid_disk >= 0) {
2971                 if (my_mddev->persistent) {
2972                         sectors = super_types[my_mddev->major_version].
2973                                 rdev_size_change(rdev, sectors);
2974                         if (!sectors)
2975                                 return -EBUSY;
2976                 } else if (!sectors)
2977                         sectors = (i_size_read(rdev->bdev->bd_inode) >> 9) -
2978                                 rdev->data_offset;
2979                 if (!my_mddev->pers->resize)
2980                         /* Cannot change size for RAID0 or Linear etc */
2981                         return -EINVAL;
2982         }
2983         if (sectors < my_mddev->dev_sectors)
2984                 return -EINVAL; /* component must fit device */
2985 
2986         rdev->sectors = sectors;
2987         if (sectors > oldsectors && my_mddev->external) {
2988                 /* Need to check that all other rdevs with the same
2989                  * ->bdev do not overlap.  'rcu' is sufficient to walk
2990                  * the rdev lists safely.
2991                  * This check does not provide a hard guarantee, it
2992                  * just helps avoid dangerous mistakes.
2993                  */
2994                 struct mddev *mddev;
2995                 int overlap = 0;
2996                 struct list_head *tmp;
2997 
2998                 rcu_read_lock();
2999                 for_each_mddev(mddev, tmp) {
3000                         struct md_rdev *rdev2;
3001 
3002                         rdev_for_each(rdev2, mddev)
3003                                 if (rdev->bdev == rdev2->bdev &&
3004                                     rdev != rdev2 &&
3005                                     overlaps(rdev->data_offset, rdev->sectors,
3006                                              rdev2->data_offset,
3007                                              rdev2->sectors)) {
3008                                         overlap = 1;
3009                                         break;
3010                                 }
3011                         if (overlap) {
3012                                 mddev_put(mddev);
3013                                 break;
3014                         }
3015                 }
3016                 rcu_read_unlock();
3017                 if (overlap) {
3018                         /* Someone else could have slipped in a size
3019                          * change here, but doing so is just silly.
3020                          * We put oldsectors back because we *know* it is
3021                          * safe, and trust userspace not to race with
3022                          * itself
3023                          */
3024                         rdev->sectors = oldsectors;
3025                         return -EBUSY;
3026                 }
3027         }
3028         return len;
3029 }
3030 
3031 static struct rdev_sysfs_entry rdev_size =
3032 __ATTR(size, S_IRUGO|S_IWUSR, rdev_size_show, rdev_size_store);
3033 
3034 static ssize_t recovery_start_show(struct md_rdev *rdev, char *page)
3035 {
3036         unsigned long long recovery_start = rdev->recovery_offset;
3037 
3038         if (test_bit(In_sync, &rdev->flags) ||
3039             recovery_start == MaxSector)
3040                 return sprintf(page, "none\n");
3041 
3042         return sprintf(page, "%llu\n", recovery_start);
3043 }
3044 
3045 static ssize_t recovery_start_store(struct md_rdev *rdev, const char *buf, size_t len)
3046 {
3047         unsigned long long recovery_start;
3048 
3049         if (cmd_match(buf, "none"))
3050                 recovery_start = MaxSector;
3051         else if (kstrtoull(buf, 10, &recovery_start))
3052                 return -EINVAL;
3053 
3054         if (rdev->mddev->pers &&
3055             rdev->raid_disk >= 0)
3056                 return -EBUSY;
3057 
3058         rdev->recovery_offset = recovery_start;
3059         if (recovery_start == MaxSector)
3060                 set_bit(In_sync, &rdev->flags);
3061         else
3062                 clear_bit(In_sync, &rdev->flags);
3063         return len;
3064 }
3065 
3066 static struct rdev_sysfs_entry rdev_recovery_start =
3067 __ATTR(recovery_start, S_IRUGO|S_IWUSR, recovery_start_show, recovery_start_store);
3068 
3069 /* sysfs access to bad-blocks list.
3070  * We present two files.
3071  * 'bad-blocks' lists sector numbers and lengths of ranges that
3072  *    are recorded as bad.  The list is truncated to fit within
3073  *    the one-page limit of sysfs.
3074  *    Writing "sector length" to this file adds an acknowledged
3075  *    bad block list.
3076  * 'unacknowledged-bad-blocks' lists bad blocks that have not yet
3077  *    been acknowledged.  Writing to this file adds bad blocks
3078  *    without acknowledging them.  This is largely for testing.
3079  */
3080 static ssize_t bb_show(struct md_rdev *rdev, char *page)
3081 {
3082         return badblocks_show(&rdev->badblocks, page, 0);
3083 }
3084 static ssize_t bb_store(struct md_rdev *rdev, const char *page, size_t len)
3085 {
3086         int rv = badblocks_store(&rdev->badblocks, page, len, 0);
3087         /* Maybe that ack was all we needed */
3088         if (test_and_clear_bit(BlockedBadBlocks, &rdev->flags))
3089                 wake_up(&rdev->blocked_wait);
3090         return rv;
3091 }
3092 static struct rdev_sysfs_entry rdev_bad_blocks =
3093 __ATTR(bad_blocks, S_IRUGO|S_IWUSR, bb_show, bb_store);
3094 
3095 static ssize_t ubb_show(struct md_rdev *rdev, char *page)
3096 {
3097         return badblocks_show(&rdev->badblocks, page, 1);
3098 }
3099 static ssize_t ubb_store(struct md_rdev *rdev, const char *page, size_t len)
3100 {
3101         return badblocks_store(&rdev->badblocks, page, len, 1);
3102 }
3103 static struct rdev_sysfs_entry rdev_unack_bad_blocks =
3104 __ATTR(unacknowledged_bad_blocks, S_IRUGO|S_IWUSR, ubb_show, ubb_store);
3105 
3106 static struct attribute *rdev_default_attrs[] = {
3107         &rdev_state.attr,
3108         &rdev_errors.attr,
3109         &rdev_slot.attr,
3110         &rdev_offset.attr,
3111         &rdev_new_offset.attr,
3112         &rdev_size.attr,
3113         &rdev_recovery_start.attr,
3114         &rdev_bad_blocks.attr,
3115         &rdev_unack_bad_blocks.attr,
3116         NULL,
3117 };
3118 static ssize_t
3119 rdev_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
3120 {
3121         struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
3122         struct md_rdev *rdev = container_of(kobj, struct md_rdev, kobj);
3123 
3124         if (!entry->show)
3125                 return -EIO;
3126         if (!rdev->mddev)
3127                 return -EBUSY;
3128         return entry->show(rdev, page);
3129 }
3130 
3131 static ssize_t
3132 rdev_attr_store(struct kobject *kobj, struct attribute *attr,
3133               const char *page, size_t length)
3134 {
3135         struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
3136         struct md_rdev *rdev = container_of(kobj, struct md_rdev, kobj);
3137         ssize_t rv;
3138         struct mddev *mddev = rdev->mddev;
3139 
3140         if (!entry->store)
3141                 return -EIO;
3142         if (!capable(CAP_SYS_ADMIN))
3143                 return -EACCES;
3144         rv = mddev ? mddev_lock(mddev): -EBUSY;
3145         if (!rv) {
3146                 if (rdev->mddev == NULL)
3147                         rv = -EBUSY;
3148                 else
3149                         rv = entry->store(rdev, page, length);
3150                 mddev_unlock(mddev);
3151         }
3152         return rv;
3153 }
3154 
3155 static void rdev_free(struct kobject *ko)
3156 {
3157         struct md_rdev *rdev = container_of(ko, struct md_rdev, kobj);
3158         kfree(rdev);
3159 }
3160 static const struct sysfs_ops rdev_sysfs_ops = {
3161         .show           = rdev_attr_show,
3162         .store          = rdev_attr_store,
3163 };
3164 static struct kobj_type rdev_ktype = {
3165         .release        = rdev_free,
3166         .sysfs_ops      = &rdev_sysfs_ops,
3167         .default_attrs  = rdev_default_attrs,
3168 };
3169 
3170 int md_rdev_init(struct md_rdev *rdev)
3171 {
3172         rdev->desc_nr = -1;
3173         rdev->saved_raid_disk = -1;
3174         rdev->raid_disk = -1;
3175         rdev->flags = 0;
3176         rdev->data_offset = 0;
3177         rdev->new_data_offset = 0;
3178         rdev->sb_events = 0;
3179         rdev->last_read_error = 0;
3180         rdev->sb_loaded = 0;
3181         rdev->bb_page = NULL;
3182         atomic_set(&rdev->nr_pending, 0);
3183         atomic_set(&rdev->read_errors, 0);
3184         atomic_set(&rdev->corrected_errors, 0);
3185 
3186         INIT_LIST_HEAD(&rdev->same_set);
3187         init_waitqueue_head(&rdev->blocked_wait);
3188 
3189         /* Add space to store bad block list.
3190          * This reserves the space even on arrays where it cannot
3191          * be used - I wonder if that matters
3192          */
3193         return badblocks_init(&rdev->badblocks, 0);
3194 }
3195 EXPORT_SYMBOL_GPL(md_rdev_init);
3196 /*
3197  * Import a device. If 'super_format' >= 0, then sanity check the superblock
3198  *
3199  * mark the device faulty if:
3200  *
3201  *   - the device is nonexistent (zero size)
3202  *   - the device has no valid superblock
3203  *
3204  * a faulty rdev _never_ has rdev->sb set.
3205  */
3206 static struct md_rdev *md_import_device(dev_t newdev, int super_format, int super_minor)
3207 {
3208         char b[BDEVNAME_SIZE];
3209         int err;
3210         struct md_rdev *rdev;
3211         sector_t size;
3212 
3213         rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
3214         if (!rdev) {
3215                 printk(KERN_ERR "md: could not alloc mem for new device!\n");
3216                 return ERR_PTR(-ENOMEM);
3217         }
3218 
3219         err = md_rdev_init(rdev);
3220         if (err)
3221                 goto abort_free;
3222         err = alloc_disk_sb(rdev);
3223         if (err)
3224                 goto abort_free;
3225 
3226         err = lock_rdev(rdev, newdev, super_format == -2);
3227         if (err)
3228                 goto abort_free;
3229 
3230         kobject_init(&rdev->kobj, &rdev_ktype);
3231 
3232         size = i_size_read(rdev->bdev->bd_inode) >> BLOCK_SIZE_BITS;
3233         if (!size) {
3234                 printk(KERN_WARNING
3235                         "md: %s has zero or unknown size, marking faulty!\n",
3236                         bdevname(rdev->bdev,b));
3237                 err = -EINVAL;
3238                 goto abort_free;
3239         }
3240 
3241         if (super_format >= 0) {
3242                 err = super_types[super_format].
3243                         load_super(rdev, NULL, super_minor);
3244                 if (err == -EINVAL) {
3245                         printk(KERN_WARNING
3246                                 "md: %s does not have a valid v%d.%d "
3247                                "superblock, not importing!\n",
3248                                 bdevname(rdev->bdev,b),
3249                                super_format, super_minor);
3250                         goto abort_free;
3251                 }
3252                 if (err < 0) {
3253                         printk(KERN_WARNING
3254                                 "md: could not read %s's sb, not importing!\n",
3255                                 bdevname(rdev->bdev,b));
3256                         goto abort_free;
3257                 }
3258         }
3259 
3260         return rdev;
3261 
3262 abort_free:
3263         if (rdev->bdev)
3264                 unlock_rdev(rdev);
3265         md_rdev_clear(rdev);
3266         kfree(rdev);
3267         return ERR_PTR(err);
3268 }
3269 
3270 /*
3271  * Check a full RAID array for plausibility
3272  */
3273 
3274 static void analyze_sbs(struct mddev *mddev)
3275 {
3276         int i;
3277         struct md_rdev *rdev, *freshest, *tmp;
3278         char b[BDEVNAME_SIZE];
3279 
3280         freshest = NULL;
3281         rdev_for_each_safe(rdev, tmp, mddev)
3282                 switch (super_types[mddev->major_version].
3283                         load_super(rdev, freshest, mddev->minor_version)) {
3284                 case 1:
3285                         freshest = rdev;
3286                         break;
3287                 case 0:
3288                         break;
3289                 default:
3290                         printk( KERN_ERR \
3291                                 "md: fatal superblock inconsistency in %s"
3292                                 " -- removing from array\n",
3293                                 bdevname(rdev->bdev,b));
3294                         md_kick_rdev_from_array(rdev);
3295                 }
3296 
3297         super_types[mddev->major_version].
3298                 validate_super(mddev, freshest);
3299 
3300         i = 0;
3301         rdev_for_each_safe(rdev, tmp, mddev) {
3302                 if (mddev->max_disks &&
3303                     (rdev->desc_nr >= mddev->max_disks ||
3304                      i > mddev->max_disks)) {
3305                         printk(KERN_WARNING
3306                                "md: %s: %s: only %d devices permitted\n",
3307                                mdname(mddev), bdevname(rdev->bdev, b),
3308                                mddev->max_disks);
3309                         md_kick_rdev_from_array(rdev);
3310                         continue;
3311                 }
3312                 if (rdev != freshest) {
3313                         if (super_types[mddev->major_version].
3314                             validate_super(mddev, rdev)) {
3315                                 printk(KERN_WARNING "md: kicking non-fresh %s"
3316                                         " from array!\n",
3317                                         bdevname(rdev->bdev,b));
3318                                 md_kick_rdev_from_array(rdev);
3319                                 continue;
3320                         }
3321                 }
3322                 if (mddev->level == LEVEL_MULTIPATH) {
3323                         rdev->desc_nr = i++;
3324                         rdev->raid_disk = rdev->desc_nr;
3325                         set_bit(In_sync, &rdev->flags);
3326                 } else if (rdev->raid_disk >=
3327                             (mddev->raid_disks - min(0, mddev->delta_disks)) &&
3328                            !test_bit(Journal, &rdev->flags)) {
3329                         rdev->raid_disk = -1;
3330                         clear_bit(In_sync, &rdev->flags);
3331                 }
3332         }
3333 }
3334 
3335 /* Read a fixed-point number.
3336  * Numbers in sysfs attributes should be in "standard" units where
3337  * possible, so time should be in seconds.
3338  * However we internally use a a much smaller unit such as
3339  * milliseconds or jiffies.
3340  * This function takes a decimal number with a possible fractional
3341  * component, and produces an integer which is the result of
3342  * multiplying that number by 10^'scale'.
3343  * all without any floating-point arithmetic.
3344  */
3345 int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale)
3346 {
3347         unsigned long result = 0;
3348         long decimals = -1;
3349         while (isdigit(*cp) || (*cp == '.' && decimals < 0)) {
3350                 if (*cp == '.')
3351                         decimals = 0;
3352                 else if (decimals < scale) {
3353                         unsigned int value;
3354                         value = *cp - '';
3355                         result = result * 10 + value;
3356                         if (decimals >= 0)
3357                                 decimals++;
3358                 }
3359                 cp++;
3360         }
3361         if (*cp == '\n')
3362                 cp++;
3363         if (*cp)
3364                 return -EINVAL;
3365         if (decimals < 0)
3366                 decimals = 0;
3367         while (decimals < scale) {
3368                 result *= 10;
3369                 decimals ++;
3370         }
3371         *res = result;
3372         return 0;
3373 }
3374 
3375 static ssize_t
3376 safe_delay_show(struct mddev *mddev, char *page)
3377 {
3378         int msec = (mddev->safemode_delay*1000)/HZ;
3379         return sprintf(page, "%d.%03d\n", msec/1000, msec%1000);
3380 }
3381 static ssize_t
3382 safe_delay_store(struct mddev *mddev, const char *cbuf, size_t len)
3383 {
3384         unsigned long msec;
3385 
3386         if (mddev_is_clustered(mddev)) {
3387                 pr_info("md: Safemode is disabled for clustered mode\n");
3388                 return -EINVAL;
3389         }
3390 
3391         if (strict_strtoul_scaled(cbuf, &msec, 3) < 0)
3392                 return -EINVAL;
3393         if (msec == 0)
3394                 mddev->safemode_delay = 0;
3395         else {
3396                 unsigned long old_delay = mddev->safemode_delay;
3397                 unsigned long new_delay = (msec*HZ)/1000;
3398 
3399                 if (new_delay == 0)
3400                         new_delay = 1;
3401                 mddev->safemode_delay = new_delay;
3402                 if (new_delay < old_delay || old_delay == 0)
3403                         mod_timer(&mddev->safemode_timer, jiffies+1);
3404         }
3405         return len;
3406 }
3407 static struct md_sysfs_entry md_safe_delay =
3408 __ATTR(safe_mode_delay, S_IRUGO|S_IWUSR,safe_delay_show, safe_delay_store);
3409 
3410 static ssize_t
3411 level_show(struct mddev *mddev, char *page)
3412 {
3413         struct md_personality *p;
3414         int ret;
3415         spin_lock(&mddev->lock);
3416         p = mddev->pers;
3417         if (p)
3418                 ret = sprintf(page, "%s\n", p->name);
3419         else if (mddev->clevel[0])
3420                 ret = sprintf(page, "%s\n", mddev->clevel);
3421         else if (mddev->level != LEVEL_NONE)
3422                 ret = sprintf(page, "%d\n", mddev->level);
3423         else
3424                 ret = 0;
3425         spin_unlock(&mddev->lock);
3426         return ret;
3427 }
3428 
3429 static ssize_t
3430 level_store(struct mddev *mddev, const char *buf, size_t len)
3431 {
3432         char clevel[16];
3433         ssize_t rv;
3434         size_t slen = len;
3435         struct md_personality *pers, *oldpers;
3436         long level;
3437         void *priv, *oldpriv;
3438         struct md_rdev *rdev;
3439 
3440         if (slen == 0 || slen >= sizeof(clevel))
3441                 return -EINVAL;
3442 
3443         rv = mddev_lock(mddev);
3444         if (rv)
3445                 return rv;
3446 
3447         if (mddev->pers == NULL) {
3448                 strncpy(mddev->clevel, buf, slen);
3449                 if (mddev->clevel[slen-1] == '\n')
3450                         slen--;
3451                 mddev->clevel[slen] = 0;
3452                 mddev->level = LEVEL_NONE;
3453                 rv = len;
3454                 goto out_unlock;
3455         }
3456         rv = -EROFS;
3457         if (mddev->ro)
3458                 goto out_unlock;
3459 
3460         /* request to change the personality.  Need to ensure:
3461          *  - array is not engaged in resync/recovery/reshape
3462          *  - old personality can be suspended
3463          *  - new personality will access other array.
3464          */
3465 
3466         rv = -EBUSY;
3467         if (mddev->sync_thread ||
3468             test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
3469             mddev->reshape_position != MaxSector ||
3470             mddev->sysfs_active)
3471                 goto out_unlock;
3472 
3473         rv = -EINVAL;
3474         if (!mddev->pers->quiesce) {
3475                 printk(KERN_WARNING "md: %s: %s does not support online personality change\n",
3476                        mdname(mddev), mddev->pers->name);
3477                 goto out_unlock;
3478         }
3479 
3480         /* Now find the new personality */
3481         strncpy(clevel, buf, slen);
3482         if (clevel[slen-1] == '\n')
3483                 slen--;
3484         clevel[slen] = 0;
3485         if (kstrtol(clevel, 10, &level))
3486                 level = LEVEL_NONE;
3487 
3488         if (request_module("md-%s", clevel) != 0)
3489                 request_module("md-level-%s", clevel);
3490         spin_lock(&pers_lock);
3491         pers = find_pers(level, clevel);
3492         if (!pers || !try_module_get(pers->owner)) {
3493                 spin_unlock(&pers_lock);
3494                 printk(KERN_WARNING "md: personality %s not loaded\n", clevel);
3495                 rv = -EINVAL;
3496                 goto out_unlock;
3497         }
3498         spin_unlock(&pers_lock);
3499 
3500         if (pers == mddev->pers) {
3501                 /* Nothing to do! */
3502                 module_put(pers->owner);
3503                 rv = len;
3504                 goto out_unlock;
3505         }
3506         if (!pers->takeover) {
3507                 module_put(pers->owner);
3508                 printk(KERN_WARNING "md: %s: %s does not support personality takeover\n",
3509                        mdname(mddev), clevel);
3510                 rv = -EINVAL;
3511                 goto out_unlock;
3512         }
3513 
3514         rdev_for_each(rdev, mddev)
3515                 rdev->new_raid_disk = rdev->raid_disk;
3516 
3517         /* ->takeover must set new_* and/or delta_disks
3518          * if it succeeds, and may set them when it fails.
3519          */
3520         priv = pers->takeover(mddev);
3521         if (IS_ERR(priv)) {
3522                 mddev->new_level = mddev->level;
3523                 mddev->new_layout = mddev->layout;
3524                 mddev->new_chunk_sectors = mddev->chunk_sectors;
3525                 mddev->raid_disks -= mddev->delta_disks;
3526                 mddev->delta_disks = 0;
3527                 mddev->reshape_backwards = 0;
3528                 module_put(pers->owner);
3529                 printk(KERN_WARNING "md: %s: %s would not accept array\n",
3530                        mdname(mddev), clevel);
3531                 rv = PTR_ERR(priv);
3532                 goto out_unlock;
3533         }
3534 
3535         /* Looks like we have a winner */
3536         mddev_suspend(mddev);
3537         mddev_detach(mddev);
3538 
3539         spin_lock(&mddev->lock);
3540         oldpers = mddev->pers;
3541         oldpriv = mddev->private;
3542         mddev->pers = pers;
3543         mddev->private = priv;
3544         strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
3545         mddev->level = mddev->new_level;
3546         mddev->layout = mddev->new_layout;
3547         mddev->chunk_sectors = mddev->new_chunk_sectors;
3548         mddev->delta_disks = 0;
3549         mddev->reshape_backwards = 0;
3550         mddev->degraded = 0;
3551         spin_unlock(&mddev->lock);
3552 
3553         if (oldpers->sync_request == NULL &&
3554             mddev->external) {
3555                 /* We are converting from a no-redundancy array
3556                  * to a redundancy array and metadata is managed
3557                  * externally so we need to be sure that writes
3558                  * won't block due to a need to transition
3559                  *      clean->dirty
3560                  * until external management is started.
3561                  */
3562                 mddev->in_sync = 0;
3563                 mddev->safemode_delay = 0;
3564                 mddev->safemode = 0;
3565         }
3566 
3567         oldpers->free(mddev, oldpriv);
3568 
3569         if (oldpers->sync_request == NULL &&
3570             pers->sync_request != NULL) {
3571                 /* need to add the md_redundancy_group */
3572                 if (sysfs_create_group(&mddev->kobj, &md_redundancy_group))
3573                         printk(KERN_WARNING
3574                                "md: cannot register extra attributes for %s\n",
3575                                mdname(mddev));
3576                 mddev->sysfs_action = sysfs_get_dirent(mddev->kobj.sd, "sync_action");
3577         }
3578         if (oldpers->sync_request != NULL &&
3579             pers->sync_request == NULL) {
3580                 /* need to remove the md_redundancy_group */
3581                 if (mddev->to_remove == NULL)
3582                         mddev->to_remove = &md_redundancy_group;
3583         }
3584 
3585         module_put(oldpers->owner);
3586 
3587         rdev_for_each(rdev, mddev) {
3588                 if (rdev->raid_disk < 0)
3589                         continue;
3590                 if (rdev->new_raid_disk >= mddev->raid_disks)
3591                         rdev->new_raid_disk = -1;
3592                 if (rdev->new_raid_disk == rdev->raid_disk)
3593                         continue;
3594                 sysfs_unlink_rdev(mddev, rdev);
3595         }
3596         rdev_for_each(rdev, mddev) {
3597                 if (rdev->raid_disk < 0)
3598                         continue;
3599                 if (rdev->new_raid_disk == rdev->raid_disk)
3600                         continue;
3601                 rdev->raid_disk = rdev->new_raid_disk;
3602                 if (rdev->raid_disk < 0)
3603                         clear_bit(In_sync, &rdev->flags);
3604                 else {
3605                         if (sysfs_link_rdev(mddev, rdev))
3606                                 printk(KERN_WARNING "md: cannot register rd%d"
3607                                        " for %s after level change\n",
3608                                        rdev->raid_disk, mdname(mddev));
3609                 }
3610         }
3611 
3612         if (pers->sync_request == NULL) {
3613                 /* this is now an array without redundancy, so
3614                  * it must always be in_sync
3615                  */
3616                 mddev->in_sync = 1;
3617                 del_timer_sync(&mddev->safemode_timer);
3618         }
3619         blk_set_stacking_limits(&mddev->queue->limits);
3620         pers->run(mddev);
3621         set_bit(MD_CHANGE_DEVS, &mddev->flags);
3622         mddev_resume(mddev);
3623         if (!mddev->thread)
3624                 md_update_sb(mddev, 1);
3625         sysfs_notify(&mddev->kobj, NULL, "level");
3626         md_new_event(mddev);
3627         rv = len;
3628 out_unlock:
3629         mddev_unlock(mddev);
3630         return rv;
3631 }
3632 
3633 static struct md_sysfs_entry md_level =
3634 __ATTR(level, S_IRUGO|S_IWUSR, level_show, level_store);
3635 
3636 static ssize_t
3637 layout_show(struct mddev *mddev, char *page)
3638 {
3639         /* just a number, not meaningful for all levels */
3640         if (mddev->reshape_position != MaxSector &&
3641             mddev->layout != mddev->new_layout)
3642                 return sprintf(page, "%d (%d)\n",
3643                                mddev->new_layout, mddev->layout);
3644         return sprintf(page, "%d\n", mddev->layout);
3645 }
3646 
3647 static ssize_t
3648 layout_store(struct mddev *mddev, const char *buf, size_t len)
3649 {
3650         unsigned int n;
3651         int err;
3652 
3653         err = kstrtouint(buf, 10, &n);
3654         if (err < 0)
3655                 return err;
3656         err = mddev_lock(mddev);
3657         if (err)
3658                 return err;
3659 
3660         if (mddev->pers) {
3661                 if (mddev->pers->check_reshape == NULL)
3662                         err = -EBUSY;
3663                 else if (mddev->ro)
3664                         err = -EROFS;
3665                 else {
3666                         mddev->new_layout = n;
3667                         err = mddev->pers->check_reshape(mddev);
3668                         if (err)
3669                                 mddev->new_layout = mddev->layout;
3670                 }
3671         } else {
3672                 mddev->new_layout = n;
3673                 if (mddev->reshape_position == MaxSector)
3674                         mddev->layout = n;
3675         }
3676         mddev_unlock(mddev);
3677         return err ?: len;
3678 }
3679 static struct md_sysfs_entry md_layout =
3680 __ATTR(layout, S_IRUGO|S_IWUSR, layout_show, layout_store);
3681 
3682 static ssize_t
3683 raid_disks_show(struct mddev *mddev, char *page)
3684 {
3685         if (mddev->raid_disks == 0)
3686                 return 0;
3687         if (mddev->reshape_position != MaxSector &&
3688             mddev->delta_disks != 0)
3689                 return sprintf(page, "%d (%d)\n", mddev->raid_disks,
3690                                mddev->raid_disks - mddev->delta_disks);
3691         return sprintf(page, "%d\n", mddev->raid_disks);
3692 }
3693 
3694 static int update_raid_disks(struct mddev *mddev, int raid_disks);
3695 
3696 static ssize_t
3697 raid_disks_store(struct mddev *mddev, const char *buf, size_t len)
3698 {
3699         unsigned int n;
3700         int err;
3701 
3702         err = kstrtouint(buf, 10, &n);
3703         if (err < 0)
3704                 return err;
3705 
3706         err = mddev_lock(mddev);
3707         if (err)
3708                 return err;
3709         if (mddev->pers)
3710                 err = update_raid_disks(mddev, n);
3711         else if (mddev->reshape_position != MaxSector) {
3712                 struct md_rdev *rdev;
3713                 int olddisks = mddev->raid_disks - mddev->delta_disks;
3714 
3715                 err = -EINVAL;
3716                 rdev_for_each(rdev, mddev) {
3717                         if (olddisks < n &&
3718                             rdev->data_offset < rdev->new_data_offset)
3719                                 goto out_unlock;
3720                         if (olddisks > n &&
3721                             rdev->data_offset > rdev->new_data_offset)
3722                                 goto out_unlock;
3723                 }
3724                 err = 0;
3725                 mddev->delta_disks = n - olddisks;
3726                 mddev->raid_disks = n;
3727                 mddev->reshape_backwards = (mddev->delta_disks < 0);
3728         } else
3729                 mddev->raid_disks = n;
3730 out_unlock:
3731         mddev_unlock(mddev);
3732         return err ? err : len;
3733 }
3734 static struct md_sysfs_entry md_raid_disks =
3735 __ATTR(raid_disks, S_IRUGO|S_IWUSR, raid_disks_show, raid_disks_store);
3736 
3737 static ssize_t
3738 chunk_size_show(struct mddev *mddev, char *page)
3739 {
3740         if (mddev->reshape_position != MaxSector &&
3741             mddev->chunk_sectors != mddev->new_chunk_sectors)
3742                 return sprintf(page, "%d (%d)\n",
3743                                mddev->new_chunk_sectors << 9,
3744                                mddev->chunk_sectors << 9);
3745         return sprintf(page, "%d\n", mddev->chunk_sectors << 9);
3746 }
3747 
3748 static ssize_t
3749 chunk_size_store(struct mddev *mddev, const char *buf, size_t len)
3750 {
3751         unsigned long n;
3752         int err;
3753 
3754         err = kstrtoul(buf, 10, &n);
3755         if (err < 0)
3756                 return err;
3757 
3758         err = mddev_lock(mddev);
3759         if (err)
3760                 return err;
3761         if (mddev->pers) {
3762                 if (mddev->pers->check_reshape == NULL)
3763                         err = -EBUSY;
3764                 else if (mddev->ro)
3765                         err = -EROFS;
3766                 else {
3767                         mddev->new_chunk_sectors = n >> 9;
3768                         err = mddev->pers->check_reshape(mddev);
3769                         if (err)
3770                                 mddev->new_chunk_sectors = mddev->chunk_sectors;
3771                 }
3772         } else {
3773                 mddev->new_chunk_sectors = n >> 9;
3774                 if (mddev->reshape_position == MaxSector)
3775                         mddev->chunk_sectors = n >> 9;
3776         }
3777         mddev_unlock(mddev);
3778         return err ?: len;
3779 }
3780 static struct md_sysfs_entry md_chunk_size =
3781 __ATTR(chunk_size, S_IRUGO|S_IWUSR, chunk_size_show, chunk_size_store);
3782 
3783 static ssize_t
3784 resync_start_show(struct mddev *mddev, char *page)
3785 {
3786         if (mddev->recovery_cp == MaxSector)
3787                 return sprintf(page, "none\n");
3788         return sprintf(page, "%llu\n", (unsigned long long)mddev->recovery_cp);
3789 }
3790 
3791 static ssize_t
3792 resync_start_store(struct mddev *mddev, const char *buf, size_t len)
3793 {
3794         unsigned long long n;
3795         int err;
3796 
3797         if (cmd_match(buf, "none"))
3798                 n = MaxSector;
3799         else {
3800                 err = kstrtoull(buf, 10, &n);
3801                 if (err < 0)
3802                         return err;
3803                 if (n != (sector_t)n)
3804                         return -EINVAL;
3805         }
3806 
3807         err = mddev_lock(mddev);
3808         if (err)
3809                 return err;
3810         if (mddev->pers && !test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
3811                 err = -EBUSY;
3812 
3813         if (!err) {
3814                 mddev->recovery_cp = n;
3815                 if (mddev->pers)
3816                         set_bit(MD_CHANGE_CLEAN, &mddev->flags);
3817         }
3818         mddev_unlock(mddev);
3819         return err ?: len;
3820 }
3821 static struct md_sysfs_entry md_resync_start =
3822 __ATTR_PREALLOC(resync_start, S_IRUGO|S_IWUSR,
3823                 resync_start_show, resync_start_store);
3824 
3825 /*
3826  * The array state can be:
3827  *
3828  * clear
3829  *     No devices, no size, no level
3830  *     Equivalent to STOP_ARRAY ioctl
3831  * inactive
3832  *     May have some settings, but array is not active
3833  *        all IO results in error
3834  *     When written, doesn't tear down array, but just stops it
3835  * suspended (not supported yet)
3836  *     All IO requests will block. The array can be reconfigured.
3837  *     Writing this, if accepted, will block until array is quiescent
3838  * readonly
3839  *     no resync can happen.  no superblocks get written.
3840  *     write requests fail
3841  * read-auto
3842  *     like readonly, but behaves like 'clean' on a write request.
3843  *
3844  * clean - no pending writes, but otherwise active.
3845  *     When written to inactive array, starts without resync
3846  *     If a write request arrives then
3847  *       if metadata is known, mark 'dirty' and switch to 'active'.
3848  *       if not known, block and switch to write-pending
3849  *     If written to an active array that has pending writes, then fails.
3850  * active
3851  *     fully active: IO and resync can be happening.
3852  *     When written to inactive array, starts with resync
3853  *
3854  * write-pending
3855  *     clean, but writes are blocked waiting for 'active' to be written.
3856  *
3857  * active-idle
3858  *     like active, but no writes have been seen for a while (100msec).
3859  *
3860  */
3861 enum array_state { clear, inactive, suspended, readonly, read_auto, clean, active,
3862                    write_pending, active_idle, bad_word};
3863 static char *array_states[] = {
3864         "clear", "inactive", "suspended", "readonly", "read-auto", "clean", "active",
3865         "write-pending", "active-idle", NULL };
3866 
3867 static int match_word(const char *word, char **list)
3868 {
3869         int n;
3870         for (n=0; list[n]; n++)
3871                 if (cmd_match(word, list[n]))
3872                         break;
3873         return n;
3874 }
3875 
3876 static ssize_t
3877 array_state_show(struct mddev *mddev, char *page)
3878 {
3879         enum array_state st = inactive;
3880 
3881         if (mddev->pers)
3882                 switch(mddev->ro) {
3883                 case 1:
3884                         st = readonly;
3885                         break;
3886                 case 2:
3887                         st = read_auto;
3888                         break;
3889                 case 0:
3890                         if (mddev->in_sync)
3891                                 st = clean;
3892                         else if (test_bit(MD_CHANGE_PENDING, &mddev->flags))
3893                                 st = write_pending;
3894                         else if (mddev->safemode)
3895                                 st = active_idle;
3896                         else
3897                                 st = active;
3898                 }
3899         else {
3900                 if (list_empty(&mddev->disks) &&
3901                     mddev->raid_disks == 0 &&
3902                     mddev->dev_sectors == 0)
3903                         st = clear;
3904                 else
3905                         st = inactive;
3906         }
3907         return sprintf(page, "%s\n", array_states[st]);
3908 }
3909 
3910 static int do_md_stop(struct mddev *mddev, int ro, struct block_device *bdev);
3911 static int md_set_readonly(struct mddev *mddev, struct block_device *bdev);
3912 static int do_md_run(struct mddev *mddev);
3913 static int restart_array(struct mddev *mddev);
3914 
3915 static ssize_t
3916 array_state_store(struct mddev *mddev, const char *buf, size_t len)
3917 {
3918         int err;
3919         enum array_state st = match_word(buf, array_states);
3920 
3921         if (mddev->pers && (st == active || st == clean) && mddev->ro != 1) {
3922                 /* don't take reconfig_mutex when toggling between
3923                  * clean and active
3924                  */
3925                 spin_lock(&mddev->lock);
3926                 if (st == active) {
3927                         restart_array(mddev);
3928                         clear_bit(MD_CHANGE_PENDING, &mddev->flags);
3929                         wake_up(&mddev->sb_wait);
3930                         err = 0;
3931                 } else /* st == clean */ {
3932                         restart_array(mddev);
3933                         if (atomic_read(&mddev->writes_pending) == 0) {
3934                                 if (mddev->in_sync == 0) {
3935                                         mddev->in_sync = 1;
3936                                         if (mddev->safemode == 1)
3937                                                 mddev->safemode = 0;
3938                                         set_bit(MD_CHANGE_CLEAN, &mddev->flags);
3939                                 }
3940                                 err = 0;
3941                         } else
3942                                 err = -EBUSY;
3943                 }
3944                 if (!err)
3945                         sysfs_notify_dirent_safe(mddev->sysfs_state);
3946                 spin_unlock(&mddev->lock);
3947                 return err ?: len;
3948         }
3949         err = mddev_lock(mddev);
3950         if (err)
3951                 return err;
3952         err = -EINVAL;
3953         switch(st) {
3954         case bad_word:
3955                 break;
3956         case clear:
3957                 /* stopping an active array */
3958                 err = do_md_stop(mddev, 0, NULL);
3959                 break;
3960         case inactive:
3961                 /* stopping an active array */
3962                 if (mddev->pers)
3963                         err = do_md_stop(mddev, 2, NULL);
3964                 else
3965                         err = 0; /* already inactive */
3966                 break;
3967         case suspended:
3968                 break; /* not supported yet */
3969         case readonly:
3970                 if (mddev->pers)
3971                         err = md_set_readonly(mddev, NULL);
3972                 else {
3973                         mddev->ro = 1;
3974                         set_disk_ro(mddev->gendisk, 1);
3975                         err = do_md_run(mddev);
3976                 }
3977                 break;
3978         case read_auto:
3979                 if (mddev->pers) {
3980                         if (mddev->ro == 0)
3981                                 err = md_set_readonly(mddev, NULL);
3982                         else if (mddev->ro == 1)
3983                                 err = restart_array(mddev);
3984                         if (err == 0) {
3985                                 mddev->ro = 2;
3986                                 set_disk_ro(mddev->gendisk, 0);
3987                         }
3988                 } else {
3989                         mddev->ro = 2;
3990                         err = do_md_run(mddev);
3991                 }
3992                 break;
3993         case clean:
3994                 if (mddev->pers) {
3995                         err = restart_array(mddev);
3996                         if (err)
3997                                 break;
3998                         spin_lock(&mddev->lock);
3999                         if (atomic_read(&mddev->writes_pending) == 0) {
4000                                 if (mddev->in_sync == 0) {
4001                                         mddev->in_sync = 1;
4002                                         if (mddev->safemode == 1)
4003                                                 mddev->safemode = 0;
4004                                         set_bit(MD_CHANGE_CLEAN, &mddev->flags);
4005                                 }
4006                                 err = 0;
4007                         } else
4008                                 err = -EBUSY;
4009                         spin_unlock(&mddev->lock);
4010                 } else
4011                         err = -EINVAL;
4012                 break;
4013         case active:
4014                 if (mddev->pers) {
4015                         err = restart_array(mddev);
4016                         if (err)
4017                                 break;
4018                         clear_bit(MD_CHANGE_PENDING, &mddev->flags);
4019                         wake_up(&mddev->sb_wait);
4020                         err = 0;
4021                 } else {
4022                         mddev->ro = 0;
4023                         set_disk_ro(mddev->gendisk, 0);
4024                         err = do_md_run(mddev);
4025                 }
4026                 break;
4027         case write_pending:
4028         case active_idle:
4029                 /* these cannot be set */
4030                 break;
4031         }
4032 
4033         if (!err) {
4034                 if (mddev->hold_active == UNTIL_IOCTL)
4035                         mddev->hold_active = 0;
4036                 sysfs_notify_dirent_safe(mddev->sysfs_state);
4037         }
4038         mddev_unlock(mddev);
4039         return err ?: len;
4040 }
4041 static struct md_sysfs_entry md_array_state =
4042 __ATTR_PREALLOC(array_state, S_IRUGO|S_IWUSR, array_state_show, array_state_store);
4043 
4044 static ssize_t
4045 max_corrected_read_errors_show(struct mddev *mddev, char *page) {
4046         return sprintf(page, "%d\n",
4047                        atomic_read(&mddev->max_corr_read_errors));
4048 }
4049 
4050 static ssize_t
4051 max_corrected_read_errors_store(struct mddev *mddev, const char *buf, size_t len)
4052 {
4053         unsigned int n;
4054         int rv;
4055 
4056         rv = kstrtouint(buf, 10, &n);
4057         if (rv < 0)
4058                 return rv;
4059         atomic_set(&mddev->max_corr_read_errors, n);
4060         return len;
4061 }
4062 
4063 static struct md_sysfs_entry max_corr_read_errors =
4064 __ATTR(max_read_errors, S_IRUGO|S_IWUSR, max_corrected_read_errors_show,
4065         max_corrected_read_errors_store);
4066 
4067 static ssize_t
4068 null_show(struct mddev *mddev, char *page)
4069 {
4070         return -EINVAL;
4071 }
4072 
4073 static ssize_t
4074 new_dev_store(struct mddev *mddev, const char *buf, size_t len)
4075 {
4076         /* buf must be %d:%d\n? giving major and minor numbers */
4077         /* The new device is added to the array.
4078          * If the array has a persistent superblock, we read the
4079          * superblock to initialise info and check validity.
4080          * Otherwise, only checking done is that in bind_rdev_to_array,
4081          * which mainly checks size.
4082          */
4083         char *e;
4084         int major = simple_strtoul(buf, &e, 10);
4085         int minor;
4086         dev_t dev;
4087         struct md_rdev *rdev;
4088         int err;
4089 
4090         if (!*buf || *e != ':' || !e[1] || e[1] == '\n')
4091                 return -EINVAL;
4092         minor = simple_strtoul(e+1, &e, 10);
4093         if (*e && *e != '\n')
4094                 return -EINVAL;
4095         dev = MKDEV(major, minor);
4096         if (major != MAJOR(dev) ||
4097             minor != MINOR(dev))
4098                 return -EOVERFLOW;
4099 
4100         flush_workqueue(md_misc_wq);
4101 
4102         err = mddev_lock(mddev);
4103         if (err)
4104                 return err;
4105         if (mddev->persistent) {
4106                 rdev = md_import_device(dev, mddev->major_version,
4107                                         mddev->minor_version);
4108                 if (!IS_ERR(rdev) && !list_empty(&mddev->disks)) {
4109                         struct md_rdev *rdev0
4110                                 = list_entry(mddev->disks.next,
4111                                              struct md_rdev, same_set);
4112                         err = super_types[mddev->major_version]
4113                                 .load_super(rdev, rdev0, mddev->minor_version);
4114                         if (err < 0)
4115                                 goto out;
4116                 }
4117         } else if (mddev->external)
4118                 rdev = md_import_device(dev, -2, -1);
4119         else
4120                 rdev = md_import_device(dev, -1, -1);
4121 
4122         if (IS_ERR(rdev)) {
4123                 mddev_unlock(mddev);
4124                 return PTR_ERR(rdev);
4125         }
4126         err = bind_rdev_to_array(rdev, mddev);
4127  out:
4128         if (err)
4129                 export_rdev(rdev);
4130         mddev_unlock(mddev);
4131         return err ? err : len;
4132 }
4133 
4134 static struct md_sysfs_entry md_new_device =
4135 __ATTR(new_dev, S_IWUSR, null_show, new_dev_store);
4136 
4137 static ssize_t
4138 bitmap_store(struct mddev *mddev, const char *buf, size_t len)
4139 {
4140         char *end;
4141         unsigned long chunk, end_chunk;
4142         int err;
4143 
4144         err = mddev_lock(mddev);
4145         if (err)
4146                 return err;
4147         if (!mddev->bitmap)
4148                 goto out;
4149         /* buf should be <chunk> <chunk> ... or <chunk>-<chunk> ... (range) */
4150         while (*buf) {
4151                 chunk = end_chunk = simple_strtoul(buf, &end, 0);
4152                 if (buf == end) break;
4153                 if (*end == '-') { /* range */
4154                         buf = end + 1;
4155                         end_chunk = simple_strtoul(buf, &end, 0);
4156                         if (buf == end) break;
4157                 }
4158                 if (*end && !isspace(*end)) break;
4159                 bitmap_dirty_bits(mddev->bitmap, chunk, end_chunk);
4160                 buf = skip_spaces(end);
4161         }
4162         bitmap_unplug(mddev->bitmap); /* flush the bits to disk */
4163 out:
4164         mddev_unlock(mddev);
4165         return len;
4166 }
4167 
4168 static struct md_sysfs_entry md_bitmap =
4169 __ATTR(bitmap_set_bits, S_IWUSR, null_show, bitmap_store);
4170 
4171 static ssize_t
4172 size_show(struct mddev *mddev, char *page)
4173 {
4174         return sprintf(page, "%llu\n",
4175                 (unsigned long long)mddev->dev_sectors / 2);
4176 }
4177 
4178 static int update_size(struct mddev *mddev, sector_t num_sectors);
4179 
4180 static ssize_t
4181 size_store(struct mddev *mddev, const char *buf, size_t len)
4182 {
4183         /* If array is inactive, we can reduce the component size, but
4184          * not increase it (except from 0).
4185          * If array is active, we can try an on-line resize
4186          */
4187         sector_t sectors;
4188         int err = strict_blocks_to_sectors(buf, &sectors);
4189 
4190         if (err < 0)
4191                 return err;
4192         err = mddev_lock(mddev);
4193         if (err)
4194                 return err;
4195         if (mddev->pers) {
4196                 err = update_size(mddev, sectors);
4197                 if (err == 0)
4198                         md_update_sb(mddev, 1);
4199         } else {
4200                 if (mddev->dev_sectors == 0 ||
4201                     mddev->dev_sectors > sectors)
4202                         mddev->dev_sectors = sectors;
4203                 else
4204                         err = -ENOSPC;
4205         }
4206         mddev_unlock(mddev);
4207         return err ? err : len;
4208 }
4209 
4210 static struct md_sysfs_entry md_size =
4211 __ATTR(component_size, S_IRUGO|S_IWUSR, size_show, size_store);
4212 
4213 /* Metadata version.
4214  * This is one of
4215  *   'none' for arrays with no metadata (good luck...)
4216  *   'external' for arrays with externally managed metadata,
4217  * or N.M for internally known formats
4218  */
4219 static ssize_t
4220 metadata_show(struct mddev *mddev, char *page)
4221 {
4222         if (mddev->persistent)
4223                 return sprintf(page, "%d.%d\n",
4224                                mddev->major_version, mddev->minor_version);
4225         else if (mddev->external)
4226                 return sprintf(page, "external:%s\n", mddev->metadata_type);
4227         else
4228                 return sprintf(page, "none\n");
4229 }
4230 
4231 static ssize_t
4232 metadata_store(struct mddev *mddev, const char *buf, size_t len)
4233 {
4234         int major, minor;
4235         char *e;
4236         int err;
4237         /* Changing the details of 'external' metadata is
4238          * always permitted.  Otherwise there must be
4239          * no devices attached to the array.
4240          */
4241 
4242         err = mddev_lock(mddev);
4243         if (err)
4244                 return err;
4245         err = -EBUSY;
4246         if (mddev->external && strncmp(buf, "external:", 9) == 0)
4247                 ;
4248         else if (!list_empty(&mddev->disks))
4249                 goto out_unlock;
4250 
4251         err = 0;
4252         if (cmd_match(buf, "none")) {
4253                 mddev->persistent = 0;
4254                 mddev->external = 0;
4255                 mddev->major_version = 0;
4256                 mddev->minor_version = 90;
4257                 goto out_unlock;
4258         }
4259         if (strncmp(buf, "external:", 9) == 0) {
4260                 size_t namelen = len-9;
4261                 if (namelen >= sizeof(mddev->metadata_type))
4262                         namelen = sizeof(mddev->metadata_type)-1;
4263                 strncpy(mddev->metadata_type, buf+9, namelen);
4264                 mddev->metadata_type[namelen] = 0;
4265                 if (namelen && mddev->metadata_type[namelen-1] == '\n')
4266                         mddev->metadata_type[--namelen] = 0;
4267                 mddev->persistent = 0;
4268                 mddev->external = 1;
4269                 mddev->major_version = 0;
4270                 mddev->minor_version = 90;
4271                 goto out_unlock;
4272         }
4273         major = simple_strtoul(buf, &e, 10);
4274         err = -EINVAL;
4275         if (e==buf || *e != '.')
4276                 goto out_unlock;
4277         buf = e+1;
4278         minor = simple_strtoul(buf, &e, 10);
4279         if (e==buf || (*e && *e != '\n') )
4280                 goto out_unlock;
4281         err = -ENOENT;
4282         if (major >= ARRAY_SIZE(super_types) || super_types[major].name == NULL)
4283                 goto out_unlock;
4284         mddev->major_version = major;
4285         mddev->minor_version = minor;
4286         mddev->persistent = 1;
4287         mddev->external = 0;
4288         err = 0;
4289 out_unlock:
4290         mddev_unlock(mddev);
4291         return err ?: len;
4292 }
4293 
4294 static struct md_sysfs_entry md_metadata =
4295 __ATTR_PREALLOC(metadata_version, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
4296 
4297 static ssize_t
4298 action_show(struct mddev *mddev, char *page)
4299 {
4300         char *type = "idle";
4301         unsigned long recovery = mddev->recovery;
4302         if (test_bit(MD_RECOVERY_FROZEN, &recovery))
4303                 type = "frozen";
4304         else if (test_bit(MD_RECOVERY_RUNNING, &recovery) ||
4305             (!mddev->ro && test_bit(MD_RECOVERY_NEEDED, &recovery))) {
4306                 if (test_bit(MD_RECOVERY_RESHAPE, &recovery))
4307                         type = "reshape";
4308                 else if (test_bit(MD_RECOVERY_SYNC, &recovery)) {
4309                         if (!test_bit(MD_RECOVERY_REQUESTED, &recovery))
4310                                 type = "resync";
4311                         else if (test_bit(MD_RECOVERY_CHECK, &recovery))
4312                                 type = "check";
4313                         else
4314                                 type = "repair";
4315                 } else if (test_bit(MD_RECOVERY_RECOVER, &recovery))
4316                         type = "recover";
4317                 else if (mddev->reshape_position != MaxSector)
4318                         type = "reshape";
4319         }
4320         return sprintf(page, "%s\n", type);
4321 }
4322 
4323 static ssize_t
4324 action_store(struct mddev *mddev, const char *page, size_t len)
4325 {
4326         if (!mddev->pers || !mddev->pers->sync_request)
4327                 return -EINVAL;
4328 
4329 
4330         if (cmd_match(page, "idle") || cmd_match(page, "frozen")) {
4331                 if (cmd_match(page, "frozen"))
4332                         set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4333                 else
4334                         clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4335                 if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&
4336                     mddev_lock(mddev) == 0) {
4337                         flush_workqueue(md_misc_wq);
4338                         if (mddev->sync_thread) {
4339                                 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
4340                                 md_reap_sync_thread(mddev);
4341                         }
4342                         mddev_unlock(mddev);
4343                 }
4344         } else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4345                 return -EBUSY;
4346         else if (cmd_match(page, "resync"))
4347                 clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4348         else if (cmd_match(page, "recover")) {
4349                 clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4350                 set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
4351         } else if (cmd_match(page, "reshape")) {
4352                 int err;
4353                 if (mddev->pers->start_reshape == NULL)
4354                         return -EINVAL;
4355                 err = mddev_lock(mddev);
4356                 if (!err) {
4357                         if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4358                                 err =  -EBUSY;
4359                         else {
4360                                 clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4361                                 err = mddev->pers->start_reshape(mddev);
4362                         }
4363                         mddev_unlock(mddev);
4364                 }
4365                 if (err)
4366                         return err;
4367                 sysfs_notify(&mddev->kobj, NULL, "degraded");
4368         } else {
4369                 if (cmd_match(page, "check"))
4370                         set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
4371                 else if (!cmd_match(page, "repair"))
4372                         return -EINVAL;
4373                 clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4374                 set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
4375                 set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
4376         }
4377         if (mddev->ro == 2) {
4378                 /* A write to sync_action is enough to justify
4379                  * canceling read-auto mode
4380                  */
4381                 mddev->ro = 0;
4382                 md_wakeup_thread(mddev->sync_thread);
4383         }
4384         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4385         md_wakeup_thread(mddev->thread);
4386         sysfs_notify_dirent_safe(mddev->sysfs_action);
4387         return len;
4388 }
4389 
4390 static struct md_sysfs_entry md_scan_mode =
4391 __ATTR_PREALLOC(sync_action, S_IRUGO|S_IWUSR, action_show, action_store);
4392 
4393 static ssize_t
4394 last_sync_action_show(struct mddev *mddev, char *page)
4395 {
4396         return sprintf(page, "%s\n", mddev->last_sync_action);
4397 }
4398 
4399 static struct md_sysfs_entry md_last_scan_mode = __ATTR_RO(last_sync_action);
4400 
4401 static ssize_t
4402 mismatch_cnt_show(struct mddev *mddev, char *page)
4403 {
4404         return sprintf(page, "%llu\n",
4405                        (unsigned long long)
4406                        atomic64_read(&mddev->resync_mismatches));
4407 }
4408 
4409 static struct md_sysfs_entry md_mismatches = __ATTR_RO(mismatch_cnt);
4410 
4411 static ssize_t
4412 sync_min_show(struct mddev *mddev, char *page)
4413 {
4414         return sprintf(page, "%d (%s)\n", speed_min(mddev),
4415                        mddev->sync_speed_min ? "local": "system");
4416 }
4417 
4418 static ssize_t
4419 sync_min_store(struct mddev *mddev, const char *buf, size_t len)
4420 {
4421         unsigned int min;
4422         int rv;
4423 
4424         if (strncmp(buf, "system", 6)==0) {
4425                 min = 0;
4426         } else {
4427                 rv = kstrtouint(buf, 10, &min);
4428                 if (rv < 0)
4429                         return rv;
4430                 if (min == 0)
4431                         return -EINVAL;
4432         }
4433         mddev->sync_speed_min = min;
4434         return len;
4435 }
4436 
4437 static struct md_sysfs_entry md_sync_min =
4438 __ATTR(sync_speed_min, S_IRUGO|S_IWUSR, sync_min_show, sync_min_store);
4439 
4440 static ssize_t
4441 sync_max_show(struct mddev *mddev, char *page)
4442 {
4443         return sprintf(page, "%d (%s)\n", speed_max(mddev),
4444                        mddev->sync_speed_max ? "local": "system");
4445 }
4446 
4447 static ssize_t
4448 sync_max_store(struct mddev *mddev, const char *buf, size_t len)
4449 {
4450         unsigned int max;
4451         int rv;
4452 
4453         if (strncmp(buf, "system", 6)==0) {
4454                 max = 0;
4455         } else {
4456                 rv = kstrtouint(buf, 10, &max);
4457                 if (rv < 0)
4458                         return rv;
4459                 if (max == 0)
4460                         return -EINVAL;
4461         }
4462         mddev->sync_speed_max = max;
4463         return len;
4464 }
4465 
4466 static struct md_sysfs_entry md_sync_max =
4467 __ATTR(sync_speed_max, S_IRUGO|S_IWUSR, sync_max_show, sync_max_store);
4468 
4469 static ssize_t
4470 degraded_show(struct mddev *mddev, char *page)
4471 {
4472         return sprintf(page, "%d\n", mddev->degraded);
4473 }
4474 static struct md_sysfs_entry md_degraded = __ATTR_RO(degraded);
4475 
4476 static ssize_t
4477 sync_force_parallel_show(struct mddev *mddev, char *page)
4478 {
4479         return sprintf(page, "%d\n", mddev->parallel_resync);
4480 }
4481 
4482 static ssize_t
4483 sync_force_parallel_store(struct mddev *mddev, const char *buf, size_t len)
4484 {
4485         long n;
4486 
4487         if (kstrtol(buf, 10, &n))
4488                 return -EINVAL;
4489 
4490         if (n != 0 && n != 1)
4491                 return -EINVAL;
4492 
4493         mddev->parallel_resync = n;
4494 
4495         if (mddev->sync_thread)
4496                 wake_up(&resync_wait);
4497 
4498         return len;
4499 }
4500 
4501 /* force parallel resync, even with shared block devices */
4502 static struct md_sysfs_entry md_sync_force_parallel =
4503 __ATTR(sync_force_parallel, S_IRUGO|S_IWUSR,
4504        sync_force_parallel_show, sync_force_parallel_store);
4505 
4506 static ssize_t
4507 sync_speed_show(struct mddev *mddev, char *page)
4508 {
4509         unsigned long resync, dt, db;
4510         if (mddev->curr_resync == 0)
4511                 return sprintf(page, "none\n");
4512         resync = mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active);
4513         dt = (jiffies - mddev->resync_mark) / HZ;
4514         if (!dt) dt++;
4515         db = resync - mddev->resync_mark_cnt;
4516         return sprintf(page, "%lu\n", db/dt/2); /* K/sec */
4517 }
4518 
4519 static struct md_sysfs_entry md_sync_speed = __ATTR_RO(sync_speed);
4520 
4521 static ssize_t
4522 sync_completed_show(struct mddev *mddev, char *page)
4523 {
4524         unsigned long long max_sectors, resync;
4525 
4526         if (!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4527                 return sprintf(page, "none\n");
4528 
4529         if (mddev->curr_resync == 1 ||
4530             mddev->curr_resync == 2)
4531                 return sprintf(page, "delayed\n");
4532 
4533         if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ||
4534             test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
4535                 max_sectors = mddev->resync_max_sectors;
4536         else
4537                 max_sectors = mddev->dev_sectors;
4538 
4539         resync = mddev->curr_resync_completed;
4540         return sprintf(page, "%llu / %llu\n", resync, max_sectors);
4541 }
4542 
4543 static struct md_sysfs_entry md_sync_completed =
4544         __ATTR_PREALLOC(sync_completed, S_IRUGO, sync_completed_show, NULL);
4545 
4546 static ssize_t
4547 min_sync_show(struct mddev *mddev, char *page)
4548 {
4549         return sprintf(page, "%llu\n",
4550                        (unsigned long long)mddev->resync_min);
4551 }
4552 static ssize_t
4553 min_sync_store(struct mddev *mddev, const char *buf, size_t len)
4554 {
4555         unsigned long long min;
4556         int err;
4557 
4558         if (kstrtoull(buf, 10, &min))
4559                 return -EINVAL;
4560 
4561         spin_lock(&mddev->lock);
4562         err = -EINVAL;
4563         if (min > mddev->resync_max)
4564                 goto out_unlock;
4565 
4566         err = -EBUSY;
4567         if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4568                 goto out_unlock;
4569 
4570         /* Round down to multiple of 4K for safety */
4571         mddev->resync_min = round_down(min, 8);
4572         err = 0;
4573 
4574 out_unlock:
4575         spin_unlock(&mddev->lock);
4576         return err ?: len;
4577 }
4578 
4579 static struct md_sysfs_entry md_min_sync =
4580 __ATTR(sync_min, S_IRUGO|S_IWUSR, min_sync_show, min_sync_store);
4581 
4582 static ssize_t
4583 max_sync_show(struct mddev *mddev, char *page)
4584 {
4585         if (mddev->resync_max == MaxSector)
4586                 return sprintf(page, "max\n");
4587         else
4588                 return sprintf(page, "%llu\n",
4589                                (unsigned long long)mddev->resync_max);
4590 }
4591 static ssize_t
4592 max_sync_store(struct mddev *mddev, const char *buf, size_t len)
4593 {
4594         int err;
4595         spin_lock(&mddev->lock);
4596         if (strncmp(buf, "max", 3) == 0)
4597                 mddev->resync_max = MaxSector;
4598         else {
4599                 unsigned long long max;
4600                 int chunk;
4601 
4602                 err = -EINVAL;
4603                 if (kstrtoull(buf, 10, &max))
4604                         goto out_unlock;
4605                 if (max < mddev->resync_min)
4606                         goto out_unlock;
4607 
4608                 err = -EBUSY;
4609                 if (max < mddev->resync_max &&
4610                     mddev->ro == 0 &&
4611                     test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4612                         goto out_unlock;
4613 
4614                 /* Must be a multiple of chunk_size */
4615                 chunk = mddev->chunk_sectors;
4616                 if (chunk) {
4617                         sector_t temp = max;
4618 
4619                         err = -EINVAL;
4620                         if (sector_div(temp, chunk))
4621                                 goto out_unlock;
4622                 }
4623                 mddev->resync_max = max;
4624         }
4625         wake_up(&mddev->recovery_wait);
4626         err = 0;
4627 out_unlock:
4628         spin_unlock(&mddev->lock);
4629         return err ?: len;
4630 }
4631 
4632 static struct md_sysfs_entry md_max_sync =
4633 __ATTR(sync_max, S_IRUGO|S_IWUSR, max_sync_show, max_sync_store);
4634 
4635 static ssize_t
4636 suspend_lo_show(struct mddev *mddev, char *page)
4637 {
4638         return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_lo);
4639 }
4640 
4641 static ssize_t
4642 suspend_lo_store(struct mddev *mddev, const char *buf, size_t len)
4643 {
4644         unsigned long long old, new;
4645         int err;
4646 
4647         err = kstrtoull(buf, 10, &new);
4648         if (err < 0)
4649                 return err;
4650         if (new != (sector_t)new)
4651                 return -EINVAL;
4652 
4653         err = mddev_lock(mddev);
4654         if (err)
4655                 return err;
4656         err = -EINVAL;
4657         if (mddev->pers == NULL ||
4658             mddev->pers->quiesce == NULL)
4659                 goto unlock;
4660         old = mddev->suspend_lo;
4661         mddev->suspend_lo = new;
4662         if (new >= old)
4663                 /* Shrinking suspended region */
4664                 mddev->pers->quiesce(mddev, 2);
4665         else {
4666                 /* Expanding suspended region - need to wait */
4667                 mddev->pers->quiesce(mddev, 1);
4668                 mddev->pers->quiesce(mddev, 0);
4669         }
4670         err = 0;
4671 unlock:
4672         mddev_unlock(mddev);
4673         return err ?: len;
4674 }
4675 static struct md_sysfs_entry md_suspend_lo =
4676 __ATTR(suspend_lo, S_IRUGO|S_IWUSR, suspend_lo_show, suspend_lo_store);
4677 
4678 static ssize_t
4679 suspend_hi_show(struct mddev *mddev, char *page)
4680 {
4681         return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_hi);
4682 }
4683 
4684 static ssize_t
4685 suspend_hi_store(struct mddev *mddev, const char *buf, size_t len)
4686 {
4687         unsigned long long old, new;
4688         int err;
4689 
4690         err = kstrtoull(buf, 10, &new);
4691         if (err < 0)
4692                 return err;
4693         if (new != (sector_t)new)
4694                 return -EINVAL;
4695 
4696         err = mddev_lock(mddev);
4697         if (err)
4698                 return err;
4699         err = -EINVAL;
4700         if (mddev->pers == NULL ||
4701             mddev->pers->quiesce == NULL)
4702                 goto unlock;
4703         old = mddev->suspend_hi;
4704         mddev->suspend_hi = new;
4705         if (new <= old)
4706                 /* Shrinking suspended region */
4707                 mddev->pers->quiesce(mddev, 2);
4708         else {
4709                 /* Expanding suspended region - need to wait */
4710                 mddev->pers->quiesce(mddev, 1);
4711                 mddev->pers->quiesce(mddev, 0);
4712         }
4713         err = 0;
4714 unlock:
4715         mddev_unlock(mddev);
4716         return err ?: len;
4717 }
4718 static struct md_sysfs_entry md_suspend_hi =
4719 __ATTR(suspend_hi, S_IRUGO|S_IWUSR, suspend_hi_show, suspend_hi_store);
4720 
4721 static ssize_t
4722 reshape_position_show(struct mddev *mddev, char *page)
4723 {
4724         if (mddev->reshape_position != MaxSector)
4725                 return sprintf(page, "%llu\n",
4726                                (unsigned long long)mddev->reshape_position);
4727         strcpy(page, "none\n");
4728         return 5;
4729 }
4730 
4731 static ssize_t
4732 reshape_position_store(struct mddev *mddev, const char *buf, size_t len)
4733 {
4734         struct md_rdev *rdev;
4735         unsigned long long new;
4736         int err;
4737 
4738         err = kstrtoull(buf, 10, &new);
4739         if (err < 0)
4740                 return err;
4741         if (new != (sector_t)new)
4742                 return -EINVAL;
4743         err = mddev_lock(mddev);
4744         if (err)
4745                 return err;
4746         err = -EBUSY;
4747         if (mddev->pers)
4748                 goto unlock;
4749         mddev->reshape_position = new;
4750         mddev->delta_disks = 0;
4751         mddev->reshape_backwards = 0;
4752         mddev->new_level = mddev->level;
4753         mddev->new_layout = mddev->layout;
4754         mddev->new_chunk_sectors = mddev->chunk_sectors;
4755         rdev_for_each(rdev, mddev)
4756                 rdev->new_data_offset = rdev->data_offset;
4757         err = 0;
4758 unlock:
4759         mddev_unlock(mddev);
4760         return err ?: len;
4761 }
4762 
4763 static struct md_sysfs_entry md_reshape_position =
4764 __ATTR(reshape_position, S_IRUGO|S_IWUSR, reshape_position_show,
4765        reshape_position_store);
4766 
4767 static ssize_t
4768 reshape_direction_show(struct mddev *mddev, char *page)
4769 {
4770         return sprintf(page, "%s\n",
4771                        mddev->reshape_backwards ? "backwards" : "forwards");
4772 }
4773 
4774 static ssize_t
4775 reshape_direction_store(struct mddev *mddev, const char *buf, size_t len)
4776 {
4777         int backwards = 0;
4778         int err;
4779 
4780         if (cmd_match(buf, "forwards"))
4781                 backwards = 0;
4782         else if (cmd_match(buf, "backwards"))
4783                 backwards = 1;
4784         else
4785                 return -EINVAL;
4786         if (mddev->reshape_backwards == backwards)
4787                 return len;
4788 
4789         err = mddev_lock(mddev);
4790         if (err)
4791                 return err;
4792         /* check if we are allowed to change */
4793         if (mddev->delta_disks)
4794                 err = -EBUSY;
4795         else if (mddev->persistent &&
4796             mddev->major_version == 0)
4797                 err =  -EINVAL;
4798         else
4799                 mddev->reshape_backwards = backwards;
4800         mddev_unlock(mddev);
4801         return err ?: len;
4802 }
4803 
4804 static struct md_sysfs_entry md_reshape_direction =
4805 __ATTR(reshape_direction, S_IRUGO|S_IWUSR, reshape_direction_show,
4806        reshape_direction_store);
4807 
4808 static ssize_t
4809 array_size_show(struct mddev *mddev, char *page)
4810 {
4811         if (mddev->external_size)
4812                 return sprintf(page, "%llu\n",
4813                                (unsigned long long)mddev->array_sectors/2);
4814         else
4815                 return sprintf(page, "default\n");
4816 }
4817 
4818 static ssize_t
4819 array_size_store(struct mddev *mddev, const char *buf, size_t len)
4820 {
4821         sector_t sectors;
4822         int err;
4823 
4824         err = mddev_lock(mddev);
4825         if (err)
4826                 return err;
4827 
4828         /* cluster raid doesn't support change array_sectors */
4829         if (mddev_is_clustered(mddev))
4830                 return -EINVAL;
4831 
4832         if (strncmp(buf, "default", 7) == 0) {
4833                 if (mddev->pers)
4834                         sectors = mddev->pers->size(mddev, 0, 0);
4835                 else
4836                         sectors = mddev->array_sectors;
4837 
4838                 mddev->external_size = 0;
4839         } else {
4840                 if (strict_blocks_to_sectors(buf, &sectors) < 0)
4841                         err = -EINVAL;
4842                 else if (mddev->pers && mddev->pers->size(mddev, 0, 0) < sectors)
4843                         err = -E2BIG;
4844                 else
4845                         mddev->external_size = 1;
4846         }
4847 
4848         if (!err) {
4849                 mddev->array_sectors = sectors;
4850                 if (mddev->pers) {
4851                         set_capacity(mddev->gendisk, mddev->array_sectors);
4852                         revalidate_disk(mddev->gendisk);
4853                 }
4854         }
4855         mddev_unlock(mddev);
4856         return err ?: len;
4857 }
4858 
4859 static struct md_sysfs_entry md_array_size =
4860 __ATTR(array_size, S_IRUGO|S_IWUSR, array_size_show,
4861        array_size_store);
4862 
4863 static struct attribute *md_default_attrs[] = {
4864         &md_level.attr,
4865         &md_layout.attr,
4866         &md_raid_disks.attr,
4867         &md_chunk_size.attr,
4868         &md_size.attr,
4869         &md_resync_start.attr,
4870         &md_metadata.attr,
4871         &md_new_device.attr,
4872         &md_safe_delay.attr,
4873         &md_array_state.attr,
4874         &md_reshape_position.attr,
4875         &md_reshape_direction.attr,
4876         &md_array_size.attr,
4877         &max_corr_read_errors.attr,
4878         NULL,
4879 };
4880 
4881 static struct attribute *md_redundancy_attrs[] = {
4882         &md_scan_mode.attr,
4883         &md_last_scan_mode.attr,
4884         &md_mismatches.attr,
4885         &md_sync_min.attr,
4886         &md_sync_max.attr,
4887         &md_sync_speed.attr,
4888         &md_sync_force_parallel.attr,
4889         &md_sync_completed.attr,
4890         &md_min_sync.attr,
4891         &md_max_sync.attr,
4892         &md_suspend_lo.attr,
4893         &md_suspend_hi.attr,
4894         &md_bitmap.attr,
4895         &md_degraded.attr,
4896         NULL,
4897 };
4898 static struct attribute_group md_redundancy_group = {
4899         .name = NULL,
4900         .attrs = md_redundancy_attrs,
4901 };
4902 
4903 static ssize_t
4904 md_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
4905 {
4906         struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
4907         struct mddev *mddev = container_of(kobj, struct mddev, kobj);
4908         ssize_t rv;
4909 
4910         if (!entry->show)
4911                 return -EIO;
4912         spin_lock(&all_mddevs_lock);
4913         if (list_empty(&mddev->all_mddevs)) {
4914                 spin_unlock(&all_mddevs_lock);
4915                 return -EBUSY;
4916         }
4917         mddev_get(mddev);
4918         spin_unlock(&all_mddevs_lock);
4919 
4920         rv = entry->show(mddev, page);
4921         mddev_put(mddev);
4922         return rv;
4923 }
4924 
4925 static ssize_t
4926 md_attr_store(struct kobject *kobj, struct attribute *attr,
4927               const char *page, size_t length)
4928 {
4929         struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
4930         struct mddev *mddev = container_of(kobj, struct mddev, kobj);
4931         ssize_t rv;
4932 
4933         if (!entry->store)
4934                 return -EIO;
4935         if (!capable(CAP_SYS_ADMIN))
4936                 return -EACCES;
4937         spin_lock(&all_mddevs_lock);
4938         if (list_empty(&mddev->all_mddevs)) {
4939                 spin_unlock(&all_mddevs_lock);
4940                 return -EBUSY;
4941         }
4942         mddev_get(mddev);
4943         spin_unlock(&all_mddevs_lock);
4944         rv = entry->store(mddev, page, length);
4945         mddev_put(mddev);
4946         return rv;
4947 }
4948 
4949 static void md_free(struct kobject *ko)
4950 {
4951         struct mddev *mddev = container_of(ko, struct mddev, kobj);
4952 
4953         if (mddev->sysfs_state)
4954                 sysfs_put(mddev->sysfs_state);
4955 
4956         if (mddev->queue)
4957                 blk_cleanup_queue(mddev->queue);
4958         if (mddev->gendisk) {
4959                 del_gendisk(mddev->gendisk);
4960                 put_disk(mddev->gendisk);
4961         }
4962 
4963         kfree(mddev);
4964 }
4965 
4966 static const struct sysfs_ops md_sysfs_ops = {
4967         .show   = md_attr_show,
4968         .store  = md_attr_store,
4969 };
4970 static struct kobj_type md_ktype = {
4971         .release        = md_free,
4972         .sysfs_ops      = &md_sysfs_ops,
4973         .default_attrs  = md_default_attrs,
4974 };
4975 
4976 int mdp_major = 0;
4977 
4978 static void mddev_delayed_delete(struct work_struct *ws)
4979 {
4980         struct mddev *mddev = container_of(ws, struct mddev, del_work);
4981 
4982         sysfs_remove_group(&mddev->kobj, &md_bitmap_group);
4983         kobject_del(&mddev->kobj);
4984         kobject_put(&mddev->kobj);
4985 }
4986 
4987 static int md_alloc(dev_t dev, char *name)
4988 {
4989         static DEFINE_MUTEX(disks_mutex);
4990         struct mddev *mddev = mddev_find(dev);
4991         struct gendisk *disk;
4992         int partitioned;
4993         int shift;
4994         int unit;
4995         int error;
4996 
4997         if (!mddev)
4998                 return -ENODEV;
4999 
5000         partitioned = (MAJOR(mddev->unit) != MD_MAJOR);
5001         shift = partitioned ? MdpMinorShift : 0;
5002         unit = MINOR(mddev->unit) >> shift;
5003 
5004         /* wait for any previous instance of this device to be
5005          * completely removed (mddev_delayed_delete).
5006          */
5007         flush_workqueue(md_misc_wq);
5008 
5009         mutex_lock(&disks_mutex);
5010         error = -EEXIST;
5011         if (mddev->gendisk)
5012                 goto abort;
5013 
5014         if (name) {
5015                 /* Need to ensure that 'name' is not a duplicate.
5016                  */
5017                 struct mddev *mddev2;
5018                 spin_lock(&all_mddevs_lock);
5019 
5020                 list_for_each_entry(mddev2, &all_mddevs, all_mddevs)
5021                         if (mddev2->gendisk &&
5022                             strcmp(mddev2->gendisk->disk_name, name) == 0) {
5023                                 spin_unlock(&all_mddevs_lock);
5024                                 goto abort;
5025                         }
5026                 spin_unlock(&all_mddevs_lock);
5027         }
5028 
5029         error = -ENOMEM;
5030         mddev->queue = blk_alloc_queue(GFP_KERNEL);
5031         if (!mddev->queue)
5032                 goto abort;
5033         mddev->queue->queuedata = mddev;
5034 
5035         blk_queue_make_request(mddev->queue, md_make_request);
5036         blk_set_stacking_limits(&mddev->queue->limits);
5037 
5038         disk = alloc_disk(1 << shift);
5039         if (!disk) {
5040                 blk_cleanup_queue(mddev->queue);
5041                 mddev->queue = NULL;
5042                 goto abort;
5043         }
5044         disk->major = MAJOR(mddev->unit);
5045         disk->first_minor = unit << shift;
5046         if (name)
5047                 strcpy(disk->disk_name, name);
5048         else if (partitioned)
5049                 sprintf(disk->disk_name, "md_d%d", unit);
5050         else
5051                 sprintf(disk->disk_name, "md%d", unit);
5052         disk->fops = &md_fops;
5053         disk->private_data = mddev;
5054         disk->queue = mddev->queue;
5055         blk_queue_write_cache(mddev->queue, true, true);
5056         /* Allow extended partitions.  This makes the
5057          * 'mdp' device redundant, but we can't really
5058          * remove it now.
5059          */
5060         disk->flags |= GENHD_FL_EXT_DEVT;
5061         mddev->gendisk = disk;
5062         /* As soon as we call add_disk(), another thread could get
5063          * through to md_open, so make sure it doesn't get too far
5064          */
5065         mutex_lock(&mddev->open_mutex);
5066         add_disk(disk);
5067 
5068         error = kobject_init_and_add(&mddev->kobj, &md_ktype,
5069                                      &disk_to_dev(disk)->kobj, "%s", "md");
5070         if (error) {
5071                 /* This isn't possible, but as kobject_init_and_add is marked
5072                  * __must_check, we must do something with the result
5073                  */
5074                 printk(KERN_WARNING "md: cannot register %s/md - name in use\n",
5075                        disk->disk_name);
5076                 error = 0;
5077         }
5078         if (mddev->kobj.sd &&
5079             sysfs_create_group(&mddev->kobj, &md_bitmap_group))
5080                 printk(KERN_DEBUG "pointless warning\n");
5081         mutex_unlock(&mddev->open_mutex);
5082  abort:
5083         mutex_unlock(&disks_mutex);
5084         if (!error && mddev->kobj.sd) {
5085                 kobject_uevent(&mddev->kobj, KOBJ_ADD);
5086                 mddev->sysfs_state = sysfs_get_dirent_safe(mddev->kobj.sd, "array_state");
5087         }
5088         mddev_put(mddev);
5089         return error;
5090 }
5091 
5092 static struct kobject *md_probe(dev_t dev, int *part, void *data)
5093 {
5094         md_alloc(dev, NULL);
5095         return NULL;
5096 }
5097 
5098 static int add_named_array(const char *val, struct kernel_param *kp)
5099 {
5100         /* val must be "md_*" where * is not all digits.
5101          * We allocate an array with a large free minor number, and
5102          * set the name to val.  val must not already be an active name.
5103          */
5104         int len = strlen(val);
5105         char buf[DISK_NAME_LEN];
5106 
5107         while (len && val[len-1] == '\n')
5108                 len--;
5109         if (len >= DISK_NAME_LEN)
5110                 return -E2BIG;
5111         strlcpy(buf, val, len+1);
5112         if (strncmp(buf, "md_", 3) != 0)
5113                 return -EINVAL;
5114         return md_alloc(0, buf);
5115 }
5116 
5117 static void md_safemode_timeout(unsigned long data)
5118 {
5119         struct mddev *mddev = (struct mddev *) data;
5120 
5121         if (!atomic_read(&mddev->writes_pending)) {
5122                 mddev->safemode = 1;
5123                 if (mddev->external)
5124                         sysfs_notify_dirent_safe(mddev->sysfs_state);
5125         }
5126         md_wakeup_thread(mddev->thread);
5127 }
5128 
5129 static int start_dirty_degraded;
5130 
5131 int md_run(struct mddev *mddev)
5132 {
5133         int err;
5134         struct md_rdev *rdev;
5135         struct md_personality *pers;
5136 
5137         if (list_empty(&mddev->disks))
5138                 /* cannot run an array with no devices.. */
5139                 return -EINVAL;
5140 
5141         if (mddev->pers)
5142                 return -EBUSY;
5143         /* Cannot run until previous stop completes properly */
5144         if (mddev->sysfs_active)
5145                 return -EBUSY;
5146 
5147         /*
5148          * Analyze all RAID superblock(s)
5149          */
5150         if (!mddev->raid_disks) {
5151                 if (!mddev->persistent)
5152                         return -EINVAL;
5153                 analyze_sbs(mddev);
5154         }
5155 
5156         if (mddev->level != LEVEL_NONE)
5157                 request_module("md-level-%d", mddev->level);
5158         else if (mddev->clevel[0])
5159                 request_module("md-%s", mddev->clevel);
5160 
5161         /*
5162          * Drop all container device buffers, from now on
5163          * the only valid external interface is through the md
5164          * device.
5165          */
5166         rdev_for_each(rdev, mddev) {
5167                 if (test_bit(Faulty, &rdev->flags))
5168                         continue;
5169                 sync_blockdev(rdev->bdev);
5170                 invalidate_bdev(rdev->bdev);
5171 
5172                 /* perform some consistency tests on the device.
5173                  * We don't want the data to overlap the metadata,
5174                  * Internal Bitmap issues have been handled elsewhere.
5175                  */
5176                 if (rdev->meta_bdev) {
5177                         /* Nothing to check */;
5178                 } else if (rdev->data_offset < rdev->sb_start) {
5179                         if (mddev->dev_sectors &&
5180                             rdev->data_offset + mddev->dev_sectors
5181                             > rdev->sb_start) {
5182                                 printk("md: %s: data overlaps metadata\n",
5183                                        mdname(mddev));
5184                                 return -EINVAL;
5185                         }
5186                 } else {
5187                         if (rdev->sb_start + rdev->sb_size/512
5188                             > rdev->data_offset) {
5189                                 printk("md: %s: metadata overlaps data\n",
5190                                        mdname(mddev));
5191                                 return -EINVAL;
5192                         }
5193                 }
5194                 sysfs_notify_dirent_safe(rdev->sysfs_state);
5195         }
5196 
5197         if (mddev->bio_set == NULL)
5198                 mddev->bio_set = bioset_create(BIO_POOL_SIZE, 0);
5199 
5200         spin_lock(&pers_lock);
5201         pers = find_pers(mddev->level, mddev->clevel);
5202         if (!pers || !try_module_get(pers->owner)) {
5203                 spin_unlock(&pers_lock);
5204                 if (mddev->level != LEVEL_NONE)
5205                         printk(KERN_WARNING "md: personality for level %d is not loaded!\n",
5206                                mddev->level);
5207                 else
5208                         printk(KERN_WARNING "md: personality for level %s is not loaded!\n",
5209                                mddev->clevel);
5210                 return -EINVAL;
5211         }
5212         spin_unlock(&pers_lock);
5213         if (mddev->level != pers->level) {
5214                 mddev->level = pers->level;
5215                 mddev->new_level = pers->level;
5216         }
5217         strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
5218 
5219         if (mddev->reshape_position != MaxSector &&
5220             pers->start_reshape == NULL) {
5221                 /* This personality cannot handle reshaping... */
5222                 module_put(pers->owner);
5223                 return -EINVAL;
5224         }
5225 
5226         if (pers->sync_request) {
5227                 /* Warn if this is a potentially silly
5228                  * configuration.
5229                  */
5230                 char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
5231                 struct md_rdev *rdev2;
5232                 int warned = 0;
5233 
5234                 rdev_for_each(rdev, mddev)
5235                         rdev_for_each(rdev2, mddev) {
5236                                 if (rdev < rdev2 &&
5237                                     rdev->bdev->bd_contains ==
5238                                     rdev2->bdev->bd_contains) {
5239                                         printk(KERN_WARNING
5240                                                "%s: WARNING: %s appears to be"
5241                                                " on the same physical disk as"
5242                                                " %s.\n",
5243                                                mdname(mddev),
5244                                                bdevname(rdev->bdev,b),
5245                                                bdevname(rdev2->bdev,b2));
5246                                         warned = 1;
5247                                 }
5248                         }
5249 
5250                 if (warned)
5251                         printk(KERN_WARNING
5252                                "True protection against single-disk"
5253                                " failure might be compromised.\n");
5254         }
5255 
5256         mddev->recovery = 0;
5257         /* may be over-ridden by personality */
5258         mddev->resync_max_sectors = mddev->dev_sectors;
5259 
5260         mddev->ok_start_degraded = start_dirty_degraded;
5261 
5262         if (start_readonly && mddev->ro == 0)
5263                 mddev->ro = 2; /* read-only, but switch on first write */
5264 
5265         err = pers->run(mddev);
5266         if (err)
5267                 printk(KERN_ERR "md: pers->run() failed ...\n");
5268         else if (pers->size(mddev, 0, 0) < mddev->array_sectors) {
5269                 WARN_ONCE(!mddev->external_size, "%s: default size too small,"
5270                           " but 'external_size' not in effect?\n", __func__);
5271                 printk(KERN_ERR
5272                        "md: invalid array_size %llu > default size %llu\n",
5273                        (unsigned long long)mddev->array_sectors / 2,
5274                        (unsigned long long)pers->size(mddev, 0, 0) / 2);
5275                 err = -EINVAL;
5276         }
5277         if (err == 0 && pers->sync_request &&
5278             (mddev->bitmap_info.file || mddev->bitmap_info.offset)) {
5279                 struct bitmap *bitmap;
5280 
5281                 bitmap = bitmap_create(mddev, -1);
5282                 if (IS_ERR(bitmap)) {
5283                         err = PTR_ERR(bitmap);
5284                         printk(KERN_ERR "%s: failed to create bitmap (%d)\n",
5285                                mdname(mddev), err);
5286                 } else
5287                         mddev->bitmap = bitmap;
5288 
5289         }
5290         if (err) {
5291                 mddev_detach(mddev);
5292                 if (mddev->private)
5293                         pers->free(mddev, mddev->private);
5294                 mddev->private = NULL;
5295                 module_put(pers->owner);
5296                 bitmap_destroy(mddev);
5297                 return err;
5298         }
5299         if (mddev->queue) {
5300                 mddev->queue->backing_dev_info.congested_data = mddev;
5301                 mddev->queue->backing_dev_info.congested_fn = md_congested;
5302         }
5303         if (pers->sync_request) {
5304                 if (mddev->kobj.sd &&
5305                     sysfs_create_group(&mddev->kobj, &md_redundancy_group))
5306                         printk(KERN_WARNING
5307                                "md: cannot register extra attributes for %s\n",
5308                                mdname(mddev));
5309                 mddev->sysfs_action = sysfs_get_dirent_safe(mddev->kobj.sd, "sync_action");
5310         } else if (mddev->ro == 2) /* auto-readonly not meaningful */
5311                 mddev->ro = 0;
5312 
5313         atomic_set(&mddev->writes_pending,0);
5314         atomic_set(&mddev->max_corr_read_errors,
5315                    MD_DEFAULT_MAX_CORRECTED_READ_ERRORS);
5316         mddev->safemode = 0;
5317         if (mddev_is_clustered(mddev))
5318                 mddev->safemode_delay = 0;
5319         else
5320                 mddev->safemode_delay = (200 * HZ)/1000 +1; /* 200 msec delay */
5321         mddev->in_sync = 1;
5322         smp_wmb();
5323         spin_lock(&mddev->lock);
5324         mddev->pers = pers;
5325         spin_unlock(&mddev->lock);
5326         rdev_for_each(rdev, mddev)
5327                 if (rdev->raid_disk >= 0)
5328                         if (sysfs_link_rdev(mddev, rdev))
5329                                 /* failure here is OK */;
5330 
5331         if (mddev->degraded && !mddev->ro)
5332                 /* This ensures that recovering status is reported immediately
5333                  * via sysfs - until a lack of spares is confirmed.
5334                  */
5335                 set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
5336         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5337 
5338         if (mddev->flags & MD_UPDATE_SB_FLAGS)
5339                 md_update_sb(mddev, 0);
5340 
5341         md_new_event(mddev);
5342         sysfs_notify_dirent_safe(mddev->sysfs_state);
5343         sysfs_notify_dirent_safe(mddev->sysfs_action);
5344         sysfs_notify(&mddev->kobj, NULL, "degraded");
5345         return 0;
5346 }
5347 EXPORT_SYMBOL_GPL(md_run);
5348 
5349 static int do_md_run(struct mddev *mddev)
5350 {
5351         int err;
5352 
5353         err = md_run(mddev);
5354         if (err)
5355                 goto out;
5356         err = bitmap_load(mddev);
5357         if (err) {
5358                 bitmap_destroy(mddev);
5359                 goto out;
5360         }
5361 
5362         if (mddev_is_clustered(mddev))
5363                 md_allow_write(mddev);
5364 
5365         md_wakeup_thread(mddev->thread);
5366         md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
5367 
5368         set_capacity(mddev->gendisk, mddev->array_sectors);
5369         revalidate_disk(mddev->gendisk);
5370         mddev->changed = 1;
5371         kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
5372 out:
5373         return err;
5374 }
5375 
5376 static int restart_array(struct mddev *mddev)
5377 {
5378         struct gendisk *disk = mddev->gendisk;
5379 
5380         /* Complain if it has no devices */
5381         if (list_empty(&mddev->disks))
5382                 return -ENXIO;
5383         if (!mddev->pers)
5384                 return -EINVAL;
5385         if (!mddev->ro)
5386                 return -EBUSY;
5387         if (test_bit(MD_HAS_JOURNAL, &mddev->flags)) {
5388                 struct md_rdev *rdev;
5389                 bool has_journal = false;
5390 
5391                 rcu_read_lock();
5392                 rdev_for_each_rcu(rdev, mddev) {
5393                         if (test_bit(Journal, &rdev->flags) &&
5394                             !test_bit(Faulty, &rdev->flags)) {
5395                                 has_journal = true;
5396                                 break;
5397                         }
5398                 }
5399                 rcu_read_unlock();
5400 
5401                 /* Don't restart rw with journal missing/faulty */
5402                 if (!has_journal)
5403                         return -EINVAL;
5404         }
5405 
5406         mddev->safemode = 0;
5407         mddev->ro = 0;
5408         set_disk_ro(disk, 0);
5409         printk(KERN_INFO "md: %s switched to read-write mode.\n",
5410                 mdname(mddev));
5411         /* Kick recovery or resync if necessary */
5412         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5413         md_wakeup_thread(mddev->thread);
5414         md_wakeup_thread(mddev->sync_thread);
5415         sysfs_notify_dirent_safe(mddev->sysfs_state);
5416         return 0;
5417 }
5418 
5419 static void md_clean(struct mddev *mddev)
5420 {
5421         mddev->array_sectors = 0;
5422         mddev->external_size = 0;
5423         mddev->dev_sectors = 0;
5424         mddev->raid_disks = 0;
5425         mddev->recovery_cp = 0;
5426         mddev->resync_min = 0;
5427         mddev->resync_max = MaxSector;
5428         mddev->reshape_position = MaxSector;
5429         mddev->external = 0;
5430         mddev->persistent = 0;
5431         mddev->level = LEVEL_NONE;
5432         mddev->clevel[0] = 0;
5433         mddev->flags = 0;
5434         mddev->ro = 0;
5435         mddev->metadata_type[0] = 0;
5436         mddev->chunk_sectors = 0;
5437         mddev->ctime = mddev->utime = 0;
5438         mddev->layout = 0;
5439         mddev->max_disks = 0;
5440         mddev->events = 0;
5441         mddev->can_decrease_events = 0;
5442         mddev->delta_disks = 0;
5443         mddev->reshape_backwards = 0;
5444         mddev->new_level = LEVEL_NONE;
5445         mddev->new_layout = 0;
5446         mddev->new_chunk_sectors = 0;
5447         mddev->curr_resync = 0;
5448         atomic64_set(&mddev->resync_mismatches, 0);
5449         mddev->suspend_lo = mddev->suspend_hi = 0;
5450         mddev->sync_speed_min = mddev->sync_speed_max = 0;
5451         mddev->recovery = 0;
5452         mddev->in_sync = 0;
5453         mddev->changed = 0;
5454         mddev->degraded = 0;
5455         mddev->safemode = 0;
5456         mddev->private = NULL;
5457         mddev->bitmap_info.offset = 0;
5458         mddev->bitmap_info.default_offset = 0;
5459         mddev->bitmap_info.default_space = 0;
5460         mddev->bitmap_info.chunksize = 0;
5461         mddev->bitmap_info.daemon_sleep = 0;
5462         mddev->bitmap_info.max_write_behind = 0;
5463 }
5464 
5465 static void __md_stop_writes(struct mddev *mddev)
5466 {
5467         set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5468         flush_workqueue(md_misc_wq);
5469         if (mddev->sync_thread) {
5470                 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
5471                 md_reap_sync_thread(mddev);
5472         }
5473 
5474         del_timer_sync(&mddev->safemode_timer);
5475 
5476         bitmap_flush(mddev);
5477         md_super_wait(mddev);
5478 
5479         if (mddev->ro == 0 &&
5480             ((!mddev->in_sync && !mddev_is_clustered(mddev)) ||
5481              (mddev->flags & MD_UPDATE_SB_FLAGS))) {
5482                 /* mark array as shutdown cleanly */
5483                 if (!mddev_is_clustered(mddev))
5484                         mddev->in_sync = 1;
5485                 md_update_sb(mddev, 1);
5486         }
5487 }
5488 
5489 void md_stop_writes(struct mddev *mddev)
5490 {
5491         mddev_lock_nointr(mddev);
5492         __md_stop_writes(mddev);
5493         mddev_unlock(mddev);
5494 }
5495 EXPORT_SYMBOL_GPL(md_stop_writes);
5496 
5497 static void mddev_detach(struct mddev *mddev)
5498 {
5499         struct bitmap *bitmap = mddev->bitmap;
5500         /* wait for behind writes to complete */
5501         if (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
5502                 printk(KERN_INFO "md:%s: behind writes in progress - waiting to stop.\n",
5503                        mdname(mddev));
5504                 /* need to kick something here to make sure I/O goes? */
5505                 wait_event(bitmap->behind_wait,
5506                            atomic_read(&bitmap->behind_writes) == 0);
5507         }
5508         if (mddev->pers && mddev->pers->quiesce) {
5509                 mddev->pers->quiesce(mddev, 1);
5510                 mddev->pers->quiesce(mddev, 0);
5511         }
5512         md_unregister_thread(&mddev->thread);
5513         if (mddev->queue)
5514                 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
5515 }
5516 
5517 static void __md_stop(struct mddev *mddev)
5518 {
5519         struct md_personality *pers = mddev->pers;
5520         mddev_detach(mddev);
5521         /* Ensure ->event_work is done */
5522         flush_workqueue(md_misc_wq);
5523         spin_lock(&mddev->lock);
5524         mddev->pers = NULL;
5525         spin_unlock(&mddev->lock);
5526         pers->free(mddev, mddev->private);
5527         mddev->private = NULL;
5528         if (pers->sync_request && mddev->to_remove == NULL)
5529                 mddev->to_remove = &md_redundancy_group;
5530         module_put(pers->owner);
5531         clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5532 }
5533 
5534 void md_stop(struct mddev *mddev)
5535 {
5536         /* stop the array and free an attached data structures.
5537          * This is called from dm-raid
5538          */
5539         __md_stop(mddev);
5540         bitmap_destroy(mddev);
5541         if (mddev->bio_set)
5542                 bioset_free(mddev->bio_set);
5543 }
5544 
5545 EXPORT_SYMBOL_GPL(md_stop);
5546 
5547 static int md_set_readonly(struct mddev *mddev, struct block_device *bdev)
5548 {
5549         int err = 0;
5550         int did_freeze = 0;
5551 
5552         if (!test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)) {
5553                 did_freeze = 1;
5554                 set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5555                 md_wakeup_thread(mddev->thread);
5556         }
5557         if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
5558                 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
5559         if (mddev->sync_thread)
5560                 /* Thread might be blocked waiting for metadata update
5561                  * which will now never happen */
5562                 wake_up_process(mddev->sync_thread->tsk);
5563 
5564         if (mddev->external && test_bit(MD_CHANGE_PENDING, &mddev->flags))
5565                 return -EBUSY;
5566         mddev_unlock(mddev);
5567         wait_event(resync_wait, !test_bit(MD_RECOVERY_RUNNING,
5568                                           &mddev->recovery));
5569         wait_event(mddev->sb_wait,
5570                    !test_bit(MD_CHANGE_PENDING, &mddev->flags));
5571         mddev_lock_nointr(mddev);
5572 
5573         mutex_lock(&mddev->open_mutex);
5574         if ((mddev->pers && atomic_read(&mddev->openers) > !!bdev) ||
5575             mddev->sync_thread ||
5576             test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
5577             (bdev && !test_bit(MD_STILL_CLOSED, &mddev->flags))) {
5578                 printk("md: %s still in use.\n",mdname(mddev));
5579                 if (did_freeze) {
5580                         clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5581                         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5582                         md_wakeup_thread(mddev->thread);
5583                 }
5584                 err = -EBUSY;
5585                 goto out;
5586         }
5587         if (mddev->pers) {
5588                 __md_stop_writes(mddev);
5589 
5590                 err  = -ENXIO;
5591                 if (mddev->ro==1)
5592                         goto out;
5593                 mddev->ro = 1;
5594                 set_disk_ro(mddev->gendisk, 1);
5595                 clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5596                 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5597                 md_wakeup_thread(mddev->thread);
5598                 sysfs_notify_dirent_safe(mddev->sysfs_state);
5599                 err = 0;
5600         }
5601 out:
5602         mutex_unlock(&mddev->open_mutex);
5603         return err;
5604 }
5605 
5606 /* mode:
5607  *   0 - completely stop and dis-assemble array
5608  *   2 - stop but do not disassemble array
5609  */
5610 static int do_md_stop(struct mddev *mddev, int mode,
5611                       struct block_device *bdev)
5612 {
5613         struct gendisk *disk = mddev->gendisk;
5614         struct md_rdev *rdev;
5615         int did_freeze = 0;
5616 
5617         if (!test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)) {
5618                 did_freeze = 1;
5619                 set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5620                 md_wakeup_thread(mddev->thread);
5621         }
5622         if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
5623                 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
5624         if (mddev->sync_thread)
5625                 /* Thread might be blocked waiting for metadata update
5626                  * which will now never happen */
5627                 wake_up_process(mddev->sync_thread->tsk);
5628 
5629         mddev_unlock(mddev);
5630         wait_event(resync_wait, (mddev->sync_thread == NULL &&
5631                                  !test_bit(MD_RECOVERY_RUNNING,
5632                                            &mddev->recovery)));
5633         mddev_lock_nointr(mddev);
5634 
5635         mutex_lock(&mddev->open_mutex);
5636         if ((mddev->pers && atomic_read(&mddev->openers) > !!bdev) ||
5637             mddev->sysfs_active ||
5638             mddev->sync_thread ||
5639             test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
5640             (bdev && !test_bit(MD_STILL_CLOSED, &mddev->flags))) {
5641                 printk("md: %s still in use.\n",mdname(mddev));
5642                 mutex_unlock(&mddev->open_mutex);
5643                 if (did_freeze) {
5644                         clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5645                         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5646                         md_wakeup_thread(mddev->thread);
5647                 }
5648                 return -EBUSY;
5649         }
5650         if (mddev->pers) {
5651                 if (mddev->ro)
5652                         set_disk_ro(disk, 0);
5653 
5654                 __md_stop_writes(mddev);
5655                 __md_stop(mddev);
5656                 mddev->queue->backing_dev_info.congested_fn = NULL;
5657 
5658                 /* tell userspace to handle 'inactive' */
5659                 sysfs_notify_dirent_safe(mddev->sysfs_state);
5660 
5661                 rdev_for_each(rdev, mddev)
5662                         if (rdev->raid_disk >= 0)
5663                                 sysfs_unlink_rdev(mddev, rdev);
5664 
5665                 set_capacity(disk, 0);
5666                 mutex_unlock(&mddev->open_mutex);
5667                 mddev->changed = 1;
5668                 revalidate_disk(disk);
5669 
5670                 if (mddev->ro)
5671                         mddev->ro = 0;
5672         } else
5673                 mutex_unlock(&mddev->open_mutex);
5674         /*
5675          * Free resources if final stop
5676          */
5677         if (mode == 0) {
5678                 printk(KERN_INFO "md: %s stopped.\n", mdname(mddev));
5679 
5680                 bitmap_destroy(mddev);
5681                 if (mddev->bitmap_info.file) {
5682                         struct file *f = mddev->bitmap_info.file;
5683                         spin_lock(&mddev->lock);
5684                         mddev->bitmap_info.file = NULL;
5685                         spin_unlock(&mddev->lock);
5686                         fput(f);
5687                 }
5688                 mddev->bitmap_info.offset = 0;
5689 
5690                 export_array(mddev);
5691 
5692                 md_clean(mddev);
5693                 if (mddev->hold_active == UNTIL_STOP)
5694                         mddev->hold_active = 0;
5695         }
5696         md_new_event(mddev);
5697         sysfs_notify_dirent_safe(mddev->sysfs_state);
5698         return 0;
5699 }
5700 
5701 #ifndef MODULE
5702 static void autorun_array(struct mddev *mddev)
5703 {
5704         struct md_rdev *rdev;
5705         int err;
5706 
5707         if (list_empty(&mddev->disks))
5708                 return;
5709 
5710         printk(KERN_INFO "md: running: ");
5711 
5712         rdev_for_each(rdev, mddev) {
5713                 char b[BDEVNAME_SIZE];
5714                 printk("<%s>", bdevname(rdev->bdev,b));
5715         }
5716         printk("\n");
5717 
5718         err = do_md_run(mddev);
5719         if (err) {
5720                 printk(KERN_WARNING "md: do_md_run() returned %d\n", err);
5721                 do_md_stop(mddev, 0, NULL);
5722         }
5723 }
5724 
5725 /*
5726  * lets try to run arrays based on all disks that have arrived
5727  * until now. (those are in pending_raid_disks)
5728  *
5729  * the method: pick the first pending disk, collect all disks with
5730  * the same UUID, remove all from the pending list and put them into
5731  * the 'same_array' list. Then order this list based on superblock
5732  * update time (freshest comes first), kick out 'old' disks and
5733  * compare superblocks. If everything's fine then run it.
5734  *
5735  * If "unit" is allocated, then bump its reference count
5736  */
5737 static void autorun_devices(int part)
5738 {
5739         struct md_rdev *rdev0, *rdev, *tmp;
5740         struct mddev *mddev;
5741         char b[BDEVNAME_SIZE];
5742 
5743         printk(KERN_INFO "md: autorun ...\n");
5744         while (!list_empty(&pending_raid_disks)) {
5745                 int unit;
5746                 dev_t dev;
5747                 LIST_HEAD(candidates);
5748                 rdev0 = list_entry(pending_raid_disks.next,
5749                                          struct md_rdev, same_set);
5750 
5751                 printk(KERN_INFO "md: considering %s ...\n",
5752                         bdevname(rdev0->bdev,b));
5753                 INIT_LIST_HEAD(&candidates);
5754                 rdev_for_each_list(rdev, tmp, &pending_raid_disks)
5755                         if (super_90_load(rdev, rdev0, 0) >= 0) {
5756                                 printk(KERN_INFO "md:  adding %s ...\n",
5757                                         bdevname(rdev->bdev,b));
5758                                 list_move(&rdev->same_set, &candidates);
5759                         }
5760                 /*
5761                  * now we have a set of devices, with all of them having
5762                  * mostly sane superblocks. It's time to allocate the
5763                  * mddev.
5764                  */
5765                 if (part) {
5766                         dev = MKDEV(mdp_major,
5767                                     rdev0->preferred_minor << MdpMinorShift);
5768                         unit = MINOR(dev) >> MdpMinorShift;
5769                 } else {
5770                         dev = MKDEV(MD_MAJOR, rdev0->preferred_minor);
5771                         unit = MINOR(dev);
5772                 }
5773                 if (rdev0->preferred_minor != unit) {
5774                         printk(KERN_INFO "md: unit number in %s is bad: %d\n",
5775                                bdevname(rdev0->bdev, b), rdev0->preferred_minor);
5776                         break;
5777                 }
5778 
5779                 md_probe(dev, NULL, NULL);
5780                 mddev = mddev_find(dev);
5781                 if (!mddev || !mddev->gendisk) {
5782                         if (mddev)
5783                                 mddev_put(mddev);
5784                         printk(KERN_ERR
5785                                 "md: cannot allocate memory for md drive.\n");
5786                         break;
5787                 }
5788                 if (mddev_lock(mddev))
5789                         printk(KERN_WARNING "md: %s locked, cannot run\n",
5790                                mdname(mddev));
5791                 else if (mddev->raid_disks || mddev->major_version
5792                          || !list_empty(&mddev->disks)) {
5793                         printk(KERN_WARNING
5794                                 "md: %s already running, cannot run %s\n",
5795                                 mdname(mddev), bdevname(rdev0->bdev,b));
5796                         mddev_unlock(mddev);
5797                 } else {
5798                         printk(KERN_INFO "md: created %s\n", mdname(mddev));
5799                         mddev->persistent = 1;
5800                         rdev_for_each_list(rdev, tmp, &candidates) {
5801                                 list_del_init(&rdev->same_set);
5802                                 if (bind_rdev_to_array(rdev, mddev))
5803                                         export_rdev(rdev);
5804                         }
5805                         autorun_array(mddev);
5806                         mddev_unlock(mddev);
5807                 }
5808                 /* on success, candidates will be empty, on error
5809                  * it won't...
5810                  */
5811                 rdev_for_each_list(rdev, tmp, &candidates) {
5812                         list_del_init(&rdev->same_set);
5813                         export_rdev(rdev);
5814                 }
5815                 mddev_put(mddev);
5816         }
5817         printk(KERN_INFO "md: ... autorun DONE.\n");
5818 }
5819 #endif /* !MODULE */
5820 
5821 static int get_version(void __user *arg)
5822 {
5823         mdu_version_t ver;
5824 
5825         ver.major = MD_MAJOR_VERSION;
5826         ver.minor = MD_MINOR_VERSION;
5827         ver.patchlevel = MD_PATCHLEVEL_VERSION;
5828 
5829         if (copy_to_user(arg, &ver, sizeof(ver)))
5830                 return -EFAULT;
5831 
5832         return 0;
5833 }
5834 
5835 static int get_array_info(struct mddev *mddev, void __user *arg)
5836 {
5837         mdu_array_info_t info;
5838         int nr,working,insync,failed,spare;
5839         struct md_rdev *rdev;
5840 
5841         nr = working = insync = failed = spare = 0;
5842         rcu_read_lock();
5843         rdev_for_each_rcu(rdev, mddev) {
5844                 nr++;
5845                 if (test_bit(Faulty, &rdev->flags))
5846                         failed++;
5847                 else {
5848                         working++;
5849                         if (test_bit(In_sync, &rdev->flags))
5850                                 insync++;
5851                         else if (test_bit(Journal, &rdev->flags))
5852                                 /* TODO: add journal count to md_u.h */
5853                                 ;
5854                         else
5855                                 spare++;
5856                 }
5857         }
5858         rcu_read_unlock();
5859 
5860         info.major_version = mddev->major_version;
5861         info.minor_version = mddev->minor_version;
5862         info.patch_version = MD_PATCHLEVEL_VERSION;
5863         info.ctime         = clamp_t(time64_t, mddev->ctime, 0, U32_MAX);
5864         info.level         = mddev->level;
5865         info.size          = mddev->dev_sectors / 2;
5866         if (info.size != mddev->dev_sectors / 2) /* overflow */
5867                 info.size = -1;
5868         info.nr_disks      = nr;
5869         info.raid_disks    = mddev->raid_disks;
5870         info.md_minor      = mddev->md_minor;
5871         info.not_persistent= !mddev->persistent;
5872 
5873         info.utime         = clamp_t(time64_t, mddev->utime, 0, U32_MAX);
5874         info.state         = 0;
5875         if (mddev->in_sync)
5876                 info.state = (1<<MD_SB_CLEAN);
5877         if (mddev->bitmap && mddev->bitmap_info.offset)
5878                 info.state |= (1<<MD_SB_BITMAP_PRESENT);
5879         if (mddev_is_clustered(mddev))
5880                 info.state |= (1<<MD_SB_CLUSTERED);
5881         info.active_disks  = insync;
5882         info.working_disks = working;
5883         info.failed_disks  = failed;
5884         info.spare_disks   = spare;
5885 
5886         info.layout        = mddev->layout;
5887         info.chunk_size    = mddev->chunk_sectors << 9;
5888 
5889         if (copy_to_user(arg, &info, sizeof(info)))
5890                 return -EFAULT;
5891 
5892         return 0;
5893 }
5894 
5895 static int get_bitmap_file(struct mddev *mddev, void __user * arg)
5896 {
5897         mdu_bitmap_file_t *file = NULL; /* too big for stack allocation */
5898         char *ptr;
5899         int err;
5900 
5901         file = kzalloc(sizeof(*file), GFP_NOIO);
5902         if (!file)
5903                 return -ENOMEM;
5904 
5905         err = 0;
5906         spin_lock(&mddev->lock);
5907         /* bitmap enabled */
5908         if (mddev->bitmap_info.file) {
5909                 ptr = file_path(mddev->bitmap_info.file, file->pathname,
5910                                 sizeof(file->pathname));
5911                 if (IS_ERR(ptr))
5912                         err = PTR_ERR(ptr);
5913                 else
5914                         memmove(file->pathname, ptr,
5915                                 sizeof(file->pathname)-(ptr-file->pathname));
5916         }
5917         spin_unlock(&mddev->lock);
5918 
5919         if (err == 0 &&
5920             copy_to_user(arg, file, sizeof(*file)))
5921                 err = -EFAULT;
5922 
5923         kfree(file);
5924         return err;
5925 }
5926 
5927 static int get_disk_info(struct mddev *mddev, void __user * arg)
5928 {
5929         mdu_disk_info_t info;
5930         struct md_rdev *rdev;
5931 
5932         if (copy_from_user(&info, arg, sizeof(info)))
5933                 return -EFAULT;
5934 
5935         rcu_read_lock();
5936         rdev = md_find_rdev_nr_rcu(mddev, info.number);
5937         if (rdev) {
5938                 info.major = MAJOR(rdev->bdev->bd_dev);
5939                 info.minor = MINOR(rdev->bdev->bd_dev);
5940                 info.raid_disk = rdev->raid_disk;
5941                 info.state = 0;
5942                 if (test_bit(Faulty, &rdev->flags))
5943                         info.state |= (1<<MD_DISK_FAULTY);
5944                 else if (test_bit(In_sync, &rdev->flags)) {
5945                         info.state |= (1<<MD_DISK_ACTIVE);
5946                         info.state |= (1<<MD_DISK_SYNC);
5947                 }
5948                 if (test_bit(Journal, &rdev->flags))
5949                         info.state |= (1<<MD_DISK_JOURNAL);
5950                 if (test_bit(WriteMostly, &rdev->flags))
5951                         info.state |= (1<<MD_DISK_WRITEMOSTLY);
5952         } else {
5953                 info.major = info.minor = 0;
5954                 info.raid_disk = -1;
5955                 info.state = (1<<MD_DISK_REMOVED);
5956         }
5957         rcu_read_unlock();
5958 
5959         if (copy_to_user(arg, &info, sizeof(info)))
5960                 return -EFAULT;
5961 
5962         return 0;
5963 }
5964 
5965 static int add_new_disk(struct mddev *mddev, mdu_disk_info_t *info)
5966 {
5967         char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
5968         struct md_rdev *rdev;
5969         dev_t dev = MKDEV(info->major,info->minor);
5970 
5971         if (mddev_is_clustered(mddev) &&
5972                 !(info->state & ((1 << MD_DISK_CLUSTER_ADD) | (1 << MD_DISK_CANDIDATE)))) {
5973                 pr_err("%s: Cannot add to clustered mddev.\n",
5974                                mdname(mddev));
5975                 return -EINVAL;
5976         }
5977 
5978         if (info->major != MAJOR(dev) || info->minor != MINOR(dev))
5979                 return -EOVERFLOW;
5980 
5981         if (!mddev->raid_disks) {
5982                 int err;
5983                 /* expecting a device which has a superblock */
5984                 rdev = md_import_device(dev, mddev->major_version, mddev->minor_version);
5985                 if (IS_ERR(rdev)) {
5986                         printk(KERN_WARNING
5987                                 "md: md_import_device returned %ld\n",
5988                                 PTR_ERR(rdev));
5989                         return PTR_ERR(rdev);
5990                 }
5991                 if (!list_empty(&mddev->disks)) {
5992                         struct md_rdev *rdev0
5993                                 = list_entry(mddev->disks.next,
5994                                              struct md_rdev, same_set);
5995                         err = super_types[mddev->major_version]
5996                                 .load_super(rdev, rdev0, mddev->minor_version);
5997                         if (err < 0) {
5998                                 printk(KERN_WARNING
5999                                         "md: %s has different UUID to %s\n",
6000                                         bdevname(rdev->bdev,b),
6001                                         bdevname(rdev0->bdev,b2));
6002                                 export_rdev(rdev);
6003                                 return -EINVAL;
6004                         }
6005                 }
6006                 err = bind_rdev_to_array(rdev, mddev);
6007                 if (err)
6008                         export_rdev(rdev);
6009                 return err;
6010         }
6011 
6012         /*
6013          * add_new_disk can be used once the array is assembled
6014          * to add "hot spares".  They must already have a superblock
6015          * written
6016          */
6017         if (mddev->pers) {
6018                 int err;
6019                 if (!mddev->pers->hot_add_disk) {
6020                         printk(KERN_WARNING
6021                                 "%s: personality does not support diskops!\n",
6022                                mdname(mddev));
6023                         return -EINVAL;
6024                 }
6025                 if (mddev->persistent)
6026                         rdev = md_import_device(dev, mddev->major_version,
6027                                                 mddev->minor_version);
6028                 else
6029                         rdev = md_import_device(dev, -1, -1);
6030                 if (IS_ERR(rdev)) {
6031                         printk(KERN_WARNING
6032                                 "md: md_import_device returned %ld\n",
6033                                 PTR_ERR(rdev));
6034                         return PTR_ERR(rdev);
6035                 }
6036                 /* set saved_raid_disk if appropriate */
6037                 if (!mddev->persistent) {
6038                         if (info->state & (1<<MD_DISK_SYNC)  &&
6039                             info->raid_disk < mddev->raid_disks) {
6040                                 rdev->raid_disk = info->raid_disk;
6041                                 set_bit(In_sync, &rdev->flags);
6042                                 clear_bit(Bitmap_sync, &rdev->flags);
6043                         } else
6044                                 rdev->raid_disk = -1;
6045                         rdev->saved_raid_disk = rdev->raid_disk;
6046                 } else
6047                         super_types[mddev->major_version].
6048                                 validate_super(mddev, rdev);
6049                 if ((info->state & (1<<MD_DISK_SYNC)) &&
6050                      rdev->raid_disk != info->raid_disk) {
6051                         /* This was a hot-add request, but events doesn't
6052                          * match, so reject it.
6053                          */
6054                         export_rdev(rdev);
6055                         return -EINVAL;
6056                 }
6057 
6058                 clear_bit(In_sync, &rdev->flags); /* just to be sure */
6059                 if (info->state & (1<<MD_DISK_WRITEMOSTLY))
6060                         set_bit(WriteMostly, &rdev->flags);
6061                 else
6062                         clear_bit(WriteMostly, &rdev->flags);
6063 
6064                 if (info->state & (1<<MD_DISK_JOURNAL)) {
6065                         struct md_rdev *rdev2;
6066                         bool has_journal = false;
6067 
6068                         /* make sure no existing journal disk */
6069                         rdev_for_each(rdev2, mddev) {
6070                                 if (test_bit(Journal, &rdev2->flags)) {
6071                                         has_journal = true;
6072                                         break;
6073                                 }
6074                         }
6075                         if (has_journal) {
6076                                 export_rdev(rdev);
6077                                 return -EBUSY;
6078                         }
6079                         set_bit(Journal, &rdev->flags);
6080                 }
6081                 /*
6082                  * check whether the device shows up in other nodes
6083                  */
6084                 if (mddev_is_clustered(mddev)) {
6085                         if (info->state & (1 << MD_DISK_CANDIDATE))
6086                                 set_bit(Candidate, &rdev->flags);
6087                         else if (info->state & (1 << MD_DISK_CLUSTER_ADD)) {
6088                                 /* --add initiated by this node */
6089                                 err = md_cluster_ops->add_new_disk(mddev, rdev);
6090                                 if (err) {
6091                                         export_rdev(rdev);
6092                                         return err;
6093                                 }
6094                         }
6095                 }
6096 
6097                 rdev->raid_disk = -1;
6098                 err = bind_rdev_to_array(rdev, mddev);
6099 
6100                 if (err)
6101                         export_rdev(rdev);
6102 
6103                 if (mddev_is_clustered(mddev)) {
6104                         if (info->state & (1 << MD_DISK_CANDIDATE))
6105                                 md_cluster_ops->new_disk_ack(mddev, (err == 0));
6106                         else {
6107                                 if (err)
6108                                         md_cluster_ops->add_new_disk_cancel(mddev);
6109                                 else
6110                                         err = add_bound_rdev(rdev);
6111                         }
6112 
6113                 } else if (!err)
6114                         err = add_bound_rdev(rdev);
6115 
6116                 return err;
6117         }
6118 
6119         /* otherwise, add_new_disk is only allowed
6120          * for major_version==0 superblocks
6121          */
6122         if (mddev->major_version != 0) {
6123                 printk(KERN_WARNING "%s: ADD_NEW_DISK not supported\n",
6124                        mdname(mddev));
6125                 return -EINVAL;
6126         }
6127 
6128         if (!(info->state & (1<<MD_DISK_FAULTY))) {
6129                 int err;
6130                 rdev = md_import_device(dev, -1, 0);
6131                 if (IS_ERR(rdev)) {
6132                         printk(KERN_WARNING
6133                                 "md: error, md_import_device() returned %ld\n",
6134                                 PTR_ERR(rdev));
6135                         return PTR_ERR(rdev);
6136                 }
6137                 rdev->desc_nr = info->number;
6138                 if (info->raid_disk < mddev->raid_disks)
6139                         rdev->raid_disk = info->raid_disk;
6140                 else
6141                         rdev->raid_disk = -1;
6142 
6143                 if (rdev->raid_disk < mddev->raid_disks)
6144                         if (info->state & (1<<MD_DISK_SYNC))
6145                                 set_bit(In_sync, &rdev->flags);
6146 
6147                 if (info->state & (1<<MD_DISK_WRITEMOSTLY))
6148                         set_bit(WriteMostly, &rdev->flags);
6149 
6150                 if (!mddev->persistent) {
6151                         printk(KERN_INFO "md: nonpersistent superblock ...\n");
6152                         rdev->sb_start = i_size_read(rdev->bdev->bd_inode) / 512;
6153                 } else
6154                         rdev->sb_start = calc_dev_sboffset(rdev);
6155                 rdev->sectors = rdev->sb_start;
6156 
6157                 err = bind_rdev_to_array(rdev, mddev);
6158                 if (err) {
6159                         export_rdev(rdev);
6160                         return err;
6161                 }
6162         }
6163 
6164         return 0;
6165 }
6166 
6167 static int hot_remove_disk(struct mddev *mddev, dev_t dev)
6168 {
6169         char b[BDEVNAME_SIZE];
6170         struct md_rdev *rdev;
6171 
6172         rdev = find_rdev(mddev, dev);
6173         if (!rdev)
6174                 return -ENXIO;
6175 
6176         if (rdev->raid_disk < 0)
6177                 goto kick_rdev;
6178 
6179         clear_bit(Blocked, &rdev->flags);
6180         remove_and_add_spares(mddev, rdev);
6181 
6182         if (rdev->raid_disk >= 0)
6183                 goto busy;
6184 
6185 kick_rdev:
6186         if (mddev_is_clustered(mddev))
6187                 md_cluster_ops->remove_disk(mddev, rdev);
6188 
6189         md_kick_rdev_from_array(rdev);
6190         md_update_sb(mddev, 1);
6191         md_new_event(mddev);
6192 
6193         return 0;
6194 busy:
6195         printk(KERN_WARNING "md: cannot remove active disk %s from %s ...\n",
6196                 bdevname(rdev->bdev,b), mdname(mddev));
6197         return -EBUSY;
6198 }
6199 
6200 static int hot_add_disk(struct mddev *mddev, dev_t dev)
6201 {
6202         char b[BDEVNAME_SIZE];
6203         int err;
6204         struct md_rdev *rdev;
6205 
6206         if (!mddev->pers)
6207                 return -ENODEV;
6208 
6209         if (mddev->major_version != 0) {
6210                 printk(KERN_WARNING "%s: HOT_ADD may only be used with"
6211                         " version-0 superblocks.\n",
6212                         mdname(mddev));
6213                 return -EINVAL;
6214         }
6215         if (!mddev->pers->hot_add_disk) {
6216                 printk(KERN_WARNING
6217                         "%s: personality does not support diskops!\n",
6218                         mdname(mddev));
6219                 return -EINVAL;
6220         }
6221 
6222         rdev = md_import_device(dev, -1, 0);
6223         if (IS_ERR(rdev)) {
6224                 printk(KERN_WARNING
6225                         "md: error, md_import_device() returned %ld\n",
6226                         PTR_ERR(rdev));
6227                 return -EINVAL;
6228         }
6229 
6230         if (mddev->persistent)
6231                 rdev->sb_start = calc_dev_sboffset(rdev);
6232         else
6233                 rdev->sb_start = i_size_read(rdev->bdev->bd_inode) / 512;
6234 
6235         rdev->sectors = rdev->sb_start;
6236 
6237         if (test_bit(Faulty, &rdev->flags)) {
6238                 printk(KERN_WARNING
6239                         "md: can not hot-add faulty %s disk to %s!\n",
6240                         bdevname(rdev->bdev,b), mdname(mddev));
6241                 err = -EINVAL;
6242                 goto abort_export;
6243         }
6244 
6245         clear_bit(In_sync, &rdev->flags);
6246         rdev->desc_nr = -1;
6247         rdev->saved_raid_disk = -1;
6248         err = bind_rdev_to_array(rdev, mddev);
6249         if (err)
6250                 goto abort_export;
6251 
6252         /*
6253          * The rest should better be atomic, we can have disk failures
6254          * noticed in interrupt contexts ...
6255          */
6256 
6257         rdev->raid_disk = -1;
6258 
6259         md_update_sb(mddev, 1);
6260         /*
6261          * Kick recovery, maybe this spare has to be added to the
6262          * array immediately.
6263          */
6264         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6265         md_wakeup_thread(mddev->thread);
6266         md_new_event(mddev);
6267         return 0;
6268 
6269 abort_export:
6270         export_rdev(rdev);
6271         return err;
6272 }
6273 
6274 static int set_bitmap_file(struct mddev *mddev, int fd)
6275 {
6276         int err = 0;
6277 
6278         if (mddev->pers) {
6279                 if (!mddev->pers->quiesce || !mddev->thread)
6280                         return -EBUSY;
6281                 if (mddev->recovery || mddev->sync_thread)
6282                         return -EBUSY;
6283                 /* we should be able to change the bitmap.. */
6284         }
6285 
6286         if (fd >= 0) {
6287                 struct inode *inode;
6288                 struct file *f;
6289 
6290                 if (mddev->bitmap || mddev->bitmap_info.file)
6291                         return -EEXIST; /* cannot add when bitmap is present */
6292                 f = fget(fd);
6293 
6294                 if (f == NULL) {
6295                         printk(KERN_ERR "%s: error: failed to get bitmap file\n",
6296                                mdname(mddev));
6297                         return -EBADF;
6298                 }
6299 
6300                 inode = f->f_mapping->host;
6301                 if (!S_ISREG(inode->i_mode)) {
6302                         printk(KERN_ERR "%s: error: bitmap file must be a regular file\n",
6303                                mdname(mddev));
6304                         err = -EBADF;
6305                 } else if (!(f->f_mode & FMODE_WRITE)) {
6306                         printk(KERN_ERR "%s: error: bitmap file must open for write\n",
6307                                mdname(mddev));
6308                         err = -EBADF;
6309                 } else if (atomic_read(&inode->i_writecount) != 1) {
6310                         printk(KERN_ERR "%s: error: bitmap file is already in use\n",
6311                                mdname(mddev));
6312                         err = -EBUSY;
6313                 }
6314                 if (err) {
6315                         fput(f);
6316                         return err;
6317                 }
6318                 mddev->bitmap_info.file = f;
6319                 mddev->bitmap_info.offset = 0; /* file overrides offset */
6320         } else if (mddev->bitmap == NULL)
6321                 return -ENOENT; /* cannot remove what isn't there */
6322         err = 0;
6323         if (mddev->pers) {
6324                 mddev->pers->quiesce(mddev, 1);
6325                 if (fd >= 0) {
6326                         struct bitmap *bitmap;
6327 
6328                         bitmap = bitmap_create(mddev, -1);
6329                         if (!IS_ERR(bitmap)) {
6330                                 mddev->bitmap = bitmap;
6331                                 err = bitmap_load(mddev);
6332                         } else
6333                                 err = PTR_ERR(bitmap);
6334                 }
6335                 if (fd < 0 || err) {
6336                         bitmap_destroy(mddev);
6337                         fd = -1; /* make sure to put the file */
6338                 }
6339                 mddev->pers->quiesce(mddev, 0);
6340         }
6341         if (fd < 0) {
6342                 struct file *f = mddev->bitmap_info.file;
6343                 if (f) {
6344                         spin_lock(&mddev->lock);
6345                         mddev->bitmap_info.file = NULL;
6346                         spin_unlock(&mddev->lock);
6347                         fput(f);
6348                 }
6349         }
6350 
6351         return err;
6352 }
6353 
6354 /*
6355  * set_array_info is used two different ways
6356  * The original usage is when creating a new array.
6357  * In this usage, raid_disks is > 0 and it together with
6358  *  level, size, not_persistent,layout,chunksize determine the
6359  *  shape of the array.
6360  *  This will always create an array with a type-0.90.0 superblock.
6361  * The newer usage is when assembling an array.
6362  *  In this case raid_disks will be 0, and the major_version field is
6363  *  use to determine which style super-blocks are to be found on the devices.
6364  *  The minor and patch _version numbers are also kept incase the
6365  *  super_block handler wishes to interpret them.
6366  */
6367 static int set_array_info(struct mddev *mddev, mdu_array_info_t *info)
6368 {
6369 
6370         if (info->raid_disks == 0) {
6371                 /* just setting version number for superblock loading */
6372                 if (info->major_version < 0 ||
6373                     info->major_version >= ARRAY_SIZE(super_types) ||
6374                     super_types[info->major_version].name == NULL) {
6375                         /* maybe try to auto-load a module? */
6376                         printk(KERN_INFO
6377                                 "md: superblock version %d not known\n",
6378                                 info->major_version);
6379                         return -EINVAL;
6380                 }
6381                 mddev->major_version = info->major_version;
6382                 mddev->minor_version = info->minor_version;
6383                 mddev->patch_version = info->patch_version;
6384                 mddev->persistent = !info->not_persistent;
6385                 /* ensure mddev_put doesn't delete this now that there
6386                  * is some minimal configuration.
6387                  */
6388                 mddev->ctime         = ktime_get_real_seconds();
6389                 return 0;
6390         }
6391         mddev->major_version = MD_MAJOR_VERSION;
6392         mddev->minor_version = MD_MINOR_VERSION;
6393         mddev->patch_version = MD_PATCHLEVEL_VERSION;
6394         mddev->ctime         = ktime_get_real_seconds();
6395 
6396         mddev->level         = info->level;
6397         mddev->clevel[0]     = 0;
6398         mddev->dev_sectors   = 2 * (sector_t)info->size;
6399         mddev->raid_disks    = info->raid_disks;
6400         /* don't set md_minor, it is determined by which /dev/md* was
6401          * openned
6402          */
6403         if (info->state & (1<<MD_SB_CLEAN))
6404                 mddev->recovery_cp = MaxSector;
6405         else
6406                 mddev->recovery_cp = 0;
6407         mddev->persistent    = ! info->not_persistent;
6408         mddev->external      = 0;
6409 
6410         mddev->layout        = info->layout;
6411         mddev->chunk_sectors = info->chunk_size >> 9;
6412 
6413         mddev->max_disks     = MD_SB_DISKS;
6414 
6415         if (mddev->persistent)
6416                 mddev->flags         = 0;
6417         set_bit(MD_CHANGE_DEVS, &mddev->flags);
6418 
6419         mddev->bitmap_info.default_offset = MD_SB_BYTES >> 9;
6420         mddev->bitmap_info.default_space = 64*2 - (MD_SB_BYTES >> 9);
6421         mddev->bitmap_info.offset = 0;
6422 
6423         mddev->reshape_position = MaxSector;
6424 
6425         /*
6426          * Generate a 128 bit UUID
6427          */
6428         get_random_bytes(mddev->uuid, 16);
6429 
6430         mddev->new_level = mddev->level;
6431         mddev->new_chunk_sectors = mddev->chunk_sectors;
6432         mddev->new_layout = mddev->layout;
6433         mddev->delta_disks = 0;
6434         mddev->reshape_backwards = 0;
6435 
6436         return 0;
6437 }
6438 
6439 void md_set_array_sectors(struct mddev *mddev, sector_t array_sectors)
6440 {
6441         WARN(!mddev_is_locked(mddev), "%s: unlocked mddev!\n", __func__);
6442 
6443         if (mddev->external_size)
6444                 return;
6445 
6446         mddev->array_sectors = array_sectors;
6447 }
6448 EXPORT_SYMBOL(md_set_array_sectors);
6449 
6450 static int update_size(struct mddev *mddev, sector_t num_sectors)
6451 {
6452         struct md_rdev *rdev;
6453         int rv;
6454         int fit = (num_sectors == 0);
6455 
6456         /* cluster raid doesn't support update size */
6457         if (mddev_is_clustered(mddev))
6458                 return -EINVAL;
6459 
6460         if (mddev->pers->resize == NULL)
6461                 return -EINVAL;
6462         /* The "num_sectors" is the number of sectors of each device that
6463          * is used.  This can only make sense for arrays with redundancy.
6464          * linear and raid0 always use whatever space is available. We can only
6465          * consider changing this number if no resync or reconstruction is
6466          * happening, and if the new size is acceptable. It must fit before the
6467          * sb_start or, if that is <data_offset, it must fit before the size
6468          * of each device.  If num_sectors is zero, we find the largest size
6469          * that fits.
6470          */
6471         if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
6472             mddev->sync_thread)
6473                 return -EBUSY;
6474         if (mddev->ro)
6475                 return -EROFS;
6476 
6477         rdev_for_each(rdev, mddev) {
6478                 sector_t avail = rdev->sectors;
6479 
6480                 if (fit && (num_sectors == 0 || num_sectors > avail))
6481                         num_sectors = avail;
6482                 if (avail < num_sectors)
6483                         return -ENOSPC;
6484         }
6485         rv = mddev->pers->resize(mddev, num_sectors);
6486         if (!rv)
6487                 revalidate_disk(mddev->gendisk);
6488         return rv;
6489 }
6490 
6491 static int update_raid_disks(struct mddev *mddev, int raid_disks)
6492 {
6493         int rv;
6494         struct md_rdev *rdev;
6495         /* change the number of raid disks */
6496         if (mddev->pers->check_reshape == NULL)
6497                 return -EINVAL;
6498         if (mddev->ro)
6499                 return -EROFS;
6500         if (raid_disks <= 0 ||
6501             (mddev->max_disks && raid_disks >= mddev->max_disks))
6502                 return -EINVAL;
6503         if (mddev->sync_thread ||
6504             test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
6505             mddev->reshape_position != MaxSector)
6506                 return -EBUSY;
6507 
6508         rdev_for_each(rdev, mddev) {
6509                 if (mddev->raid_disks < raid_disks &&
6510                     rdev->data_offset < rdev->new_data_offset)
6511                         return -EINVAL;
6512                 if (mddev->raid_disks > raid_disks &&
6513                     rdev->data_offset > rdev->new_data_offset)
6514                         return -EINVAL;
6515         }
6516 
6517         mddev->delta_disks = raid_disks - mddev->raid_disks;
6518         if (mddev->delta_disks < 0)
6519                 mddev->reshape_backwards = 1;
6520         else if (mddev->delta_disks > 0)
6521                 mddev->reshape_backwards = 0;
6522 
6523         rv = mddev->pers->check_reshape(mddev);
6524         if (rv < 0) {
6525                 mddev->delta_disks = 0;
6526                 mddev->reshape_backwards = 0;
6527         }
6528         return rv;
6529 }
6530 
6531 /*
6532  * update_array_info is used to change the configuration of an
6533  * on-line array.
6534  * The version, ctime,level,size,raid_disks,not_persistent, layout,chunk_size
6535  * fields in the info are checked against the array.
6536  * Any differences that cannot be handled will cause an error.
6537  * Normally, only one change can be managed at a time.
6538  */
6539 static int update_array_info(struct mddev *mddev, mdu_array_info_t *info)
6540 {
6541         int rv = 0;
6542         int cnt = 0;
6543         int state = 0;
6544 
6545         /* calculate expected state,ignoring low bits */
6546         if (mddev->bitmap && mddev->bitmap_info.offset)
6547                 state |= (1 << MD_SB_BITMAP_PRESENT);
6548 
6549         if (mddev->major_version != info->major_version ||
6550             mddev->minor_version != info->minor_version ||
6551 /*          mddev->patch_version != info->patch_version || */
6552             mddev->ctime         != info->ctime         ||
6553             mddev->level         != info->level         ||
6554 /*          mddev->layout        != info->layout        || */
6555             mddev->persistent    != !info->not_persistent ||
6556             mddev->chunk_sectors != info->chunk_size >> 9 ||
6557             /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT to change */
6558             ((state^info->state) & 0xfffffe00)
6559                 )
6560                 return -EINVAL;
6561         /* Check there is only one change */
6562         if (info->size >= 0 && mddev->dev_sectors / 2 != info->size)
6563                 cnt++;
6564         if (mddev->raid_disks != info->raid_disks)
6565                 cnt++;
6566         if (mddev->layout != info->layout)
6567                 cnt++;
6568         if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT))
6569                 cnt++;
6570         if (cnt == 0)
6571                 return 0;
6572         if (cnt > 1)
6573                 return -EINVAL;
6574 
6575         if (mddev->layout != info->layout) {
6576                 /* Change layout
6577                  * we don't need to do anything at the md level, the
6578                  * personality will take care of it all.
6579                  */
6580                 if (mddev->pers->check_reshape == NULL)
6581                         return -EINVAL;
6582                 else {
6583                         mddev->new_layout = info->layout;
6584                         rv = mddev->pers->check_reshape(mddev);
6585                         if (rv)
6586                                 mddev->new_layout = mddev->layout;
6587                         return rv;
6588                 }
6589         }
6590         if (info->size >= 0 && mddev->dev_sectors / 2 != info->size)
6591                 rv = update_size(mddev, (sector_t)info->size * 2);
6592 
6593         if (mddev->raid_disks    != info->raid_disks)
6594                 rv = update_raid_disks(mddev, info->raid_disks);
6595 
6596         if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT)) {
6597                 if (mddev->pers->quiesce == NULL || mddev->thread == NULL) {
6598                         rv = -EINVAL;
6599                         goto err;
6600                 }
6601                 if (mddev->recovery || mddev->sync_thread) {
6602                         rv = -EBUSY;
6603                         goto err;
6604                 }
6605                 if (info->state & (1<<MD_SB_BITMAP_PRESENT)) {
6606                         struct bitmap *bitmap;
6607                         /* add the bitmap */
6608                         if (mddev->bitmap) {
6609                                 rv = -EEXIST;
6610                                 goto err;
6611                         }
6612                         if (mddev->bitmap_info.default_offset == 0) {
6613                                 rv = -EINVAL;
6614                                 goto err;
6615                         }
6616                         mddev->bitmap_info.offset =
6617                                 mddev->bitmap_info.default_offset;
6618                         mddev->bitmap_info.space =
6619                                 mddev->bitmap_info.default_space;
6620                         mddev->pers->quiesce(mddev, 1);
6621                         bitmap = bitmap_create(mddev, -1);
6622                         if (!IS_ERR(bitmap)) {
6623                                 mddev->bitmap = bitmap;
6624                                 rv = bitmap_load(mddev);
6625                         } else
6626                                 rv = PTR_ERR(bitmap);
6627                         if (rv)
6628                                 bitmap_destroy(mddev);
6629                         mddev->pers->quiesce(mddev, 0);
6630                 } else {
6631                         /* remove the bitmap */
6632                         if (!mddev->bitmap) {
6633                                 rv = -ENOENT;
6634                                 goto err;
6635                         }
6636                         if (mddev->bitmap->storage.file) {
6637                                 rv = -EINVAL;
6638                                 goto err;
6639                         }
6640                         if (mddev->bitmap_info.nodes) {
6641                                 /* hold PW on all the bitmap lock */
6642                                 if (md_cluster_ops->lock_all_bitmaps(mddev) <= 0) {
6643                                         printk("md: can't change bitmap to none since the"
6644                                                " array is in use by more than one node\n");
6645                                         rv = -EPERM;
6646                                         md_cluster_ops->unlock_all_bitmaps(mddev);
6647                                         goto err;
6648                                 }
6649 
6650                                 mddev->bitmap_info.nodes = 0;
6651                                 md_cluster_ops->leave(mddev);
6652                         }
6653                         mddev->pers->quiesce(mddev, 1);
6654                         bitmap_destroy(mddev);
6655                         mddev->pers->quiesce(mddev, 0);
6656                         mddev->bitmap_info.offset = 0;
6657                 }
6658         }
6659         md_update_sb(mddev, 1);
6660         return rv;
6661 err:
6662         return rv;
6663 }
6664 
6665 static int set_disk_faulty(struct mddev *mddev, dev_t dev)
6666 {
6667         struct md_rdev *rdev;
6668         int err = 0;
6669 
6670         if (mddev->pers == NULL)
6671                 return -ENODEV;
6672 
6673         rcu_read_lock();
6674         rdev = find_rdev_rcu(mddev, dev);
6675         if (!rdev)
6676                 err =  -ENODEV;
6677         else {
6678                 md_error(mddev, rdev);
6679                 if (!test_bit(Faulty, &rdev->flags))
6680                         err = -EBUSY;
6681         }
6682         rcu_read_unlock();
6683         return err;
6684 }
6685 
6686 /*
6687  * We have a problem here : there is no easy way to give a CHS
6688  * virtual geometry. We currently pretend that we have a 2 heads
6689  * 4 sectors (with a BIG number of cylinders...). This drives
6690  * dosfs just mad... ;-)
6691  */
6692 static int md_getgeo(struct block_device *bdev, struct hd_geometry *geo)
6693 {
6694         struct mddev *mddev = bdev->bd_disk->private_data;
6695 
6696         geo->heads = 2;
6697         geo->sectors = 4;
6698         geo->cylinders = mddev->array_sectors / 8;
6699         return 0;
6700 }
6701 
6702 static inline bool md_ioctl_valid(unsigned int cmd)
6703 {
6704         switch (cmd) {
6705         case ADD_NEW_DISK:
6706         case BLKROSET:
6707         case GET_ARRAY_INFO:
6708         case GET_BITMAP_FILE:
6709         case GET_DISK_INFO:
6710         case HOT_ADD_DISK:
6711         case HOT_REMOVE_DISK:
6712         case RAID_AUTORUN:
6713         case RAID_VERSION:
6714         case RESTART_ARRAY_RW:
6715         case RUN_ARRAY:
6716         case SET_ARRAY_INFO:
6717         case SET_BITMAP_FILE:
6718         case SET_DISK_FAULTY:
6719         case STOP_ARRAY:
6720         case STOP_ARRAY_RO:
6721         case CLUSTERED_DISK_NACK:
6722                 return true;
6723         default:
6724                 return false;
6725         }
6726 }
6727 
6728 static int md_ioctl(struct block_device *bdev, fmode_t mode,
6729                         unsigned int cmd, unsigned long arg)
6730 {
6731         int err = 0;
6732         void __user *argp = (void __user *)arg;
6733         struct mddev *mddev = NULL;
6734         int ro;
6735 
6736         if (!md_ioctl_valid(cmd))
6737                 return -ENOTTY;
6738 
6739         switch (cmd) {
6740         case RAID_VERSION:
6741         case GET_ARRAY_INFO:
6742         case GET_DISK_INFO:
6743                 break;
6744         default:
6745                 if (!capable(CAP_SYS_ADMIN))
6746                         return -EACCES;
6747         }
6748 
6749         /*
6750          * Commands dealing with the RAID driver but not any
6751          * particular array:
6752          */
6753         switch (cmd) {
6754         case RAID_VERSION:
6755                 err = get_version(argp);
6756                 goto out;
6757 
6758 #ifndef MODULE
6759         case RAID_AUTORUN:
6760                 err = 0;
6761                 autostart_arrays(arg);
6762                 goto out;
6763 #endif
6764         default:;
6765         }
6766 
6767         /*
6768          * Commands creating/starting a new array:
6769          */
6770 
6771         mddev = bdev->bd_disk->private_data;
6772 
6773         if (!mddev) {
6774                 BUG();
6775                 goto out;
6776         }
6777 
6778         /* Some actions do not requires the mutex */
6779         switch (cmd) {
6780         case GET_ARRAY_INFO:
6781                 if (!mddev->raid_disks && !mddev->external)
6782                         err = -ENODEV;
6783                 else
6784                         err = get_array_info(mddev, argp);
6785                 goto out;
6786 
6787         case GET_DISK_INFO:
6788                 if (!mddev->raid_disks && !mddev->external)
6789                         err = -ENODEV;
6790                 else
6791                         err = get_disk_info(mddev, argp);
6792                 goto out;
6793 
6794         case SET_DISK_FAULTY:
6795                 err = set_disk_faulty(mddev, new_decode_dev(arg));
6796                 goto out;
6797 
6798         case GET_BITMAP_FILE:
6799                 err = get_bitmap_file(mddev, argp);
6800                 goto out;
6801 
6802         }
6803 
6804         if (cmd == ADD_NEW_DISK)
6805                 /* need to ensure md_delayed_delete() has completed */
6806                 flush_workqueue(md_misc_wq);
6807 
6808         if (cmd == HOT_REMOVE_DISK)
6809                 /* need to ensure recovery thread has run */
6810                 wait_event_interruptible_timeout(mddev->sb_wait,
6811                                                  !test_bit(MD_RECOVERY_NEEDED,
6812                                                            &mddev->flags),
6813                                                  msecs_to_jiffies(5000));
6814         if (cmd == STOP_ARRAY || cmd == STOP_ARRAY_RO) {
6815                 /* Need to flush page cache, and ensure no-one else opens
6816                  * and writes
6817                  */
6818                 mutex_lock(&mddev->open_mutex);
6819                 if (mddev->pers && atomic_read(&mddev->openers) > 1) {
6820                         mutex_unlock(&mddev->open_mutex);
6821                         err = -EBUSY;
6822                         goto out;
6823                 }
6824                 set_bit(MD_STILL_CLOSED, &mddev->flags);
6825                 mutex_unlock(&mddev->open_mutex);
6826                 sync_blockdev(bdev);
6827         }
6828         err = mddev_lock(mddev);
6829         if (err) {
6830                 printk(KERN_INFO
6831                         "md: ioctl lock interrupted, reason %d, cmd %d\n",
6832                         err, cmd);
6833                 goto out;
6834         }
6835 
6836         if (cmd == SET_ARRAY_INFO) {
6837                 mdu_array_info_t info;
6838                 if (!arg)
6839                         memset(&info, 0, sizeof(info));
6840                 else if (copy_from_user(&info, argp, sizeof(info))) {
6841                         err = -EFAULT;
6842                         goto unlock;
6843                 }
6844                 if (mddev->pers) {
6845                         err = update_array_info(mddev, &info);
6846                         if (err) {
6847                                 printk(KERN_WARNING "md: couldn't update"
6848                                        " array info. %d\n", err);
6849                                 goto unlock;
6850                         }
6851                         goto unlock;
6852                 }
6853                 if (!list_empty(&mddev->disks)) {
6854                         printk(KERN_WARNING
6855                                "md: array %s already has disks!\n",
6856                                mdname(mddev));
6857                         err = -EBUSY;
6858                         goto unlock;
6859                 }
6860                 if (mddev->raid_disks) {
6861                         printk(KERN_WARNING
6862                                "md: array %s already initialised!\n",
6863                                mdname(mddev));
6864                         err = -EBUSY;
6865                         goto unlock;
6866                 }
6867                 err = set_array_info(mddev, &info);
6868                 if (err) {
6869                         printk(KERN_WARNING "md: couldn't set"
6870                                " array info. %d\n", err);
6871                         goto unlock;
6872                 }
6873                 goto unlock;
6874         }
6875 
6876         /*
6877          * Commands querying/configuring an existing array:
6878          */
6879         /* if we are not initialised yet, only ADD_NEW_DISK, STOP_ARRAY,
6880          * RUN_ARRAY, and GET_ and SET_BITMAP_FILE are allowed */
6881         if ((!mddev->raid_disks && !mddev->external)
6882             && cmd != ADD_NEW_DISK && cmd != STOP_ARRAY
6883             && cmd != RUN_ARRAY && cmd != SET_BITMAP_FILE
6884             && cmd != GET_BITMAP_FILE) {
6885                 err = -ENODEV;
6886                 goto unlock;
6887         }
6888 
6889         /*
6890          * Commands even a read-only array can execute:
6891          */
6892         switch (cmd) {
6893         case RESTART_ARRAY_RW:
6894                 err = restart_array(mddev);
6895                 goto unlock;
6896 
6897         case STOP_ARRAY:
6898                 err = do_md_stop(mddev, 0, bdev);
6899                 goto unlock;
6900 
6901         case STOP_ARRAY_RO:
6902                 err = md_set_readonly(mddev, bdev);
6903                 goto unlock;
6904 
6905         case HOT_REMOVE_DISK:
6906                 err = hot_remove_disk(mddev, new_decode_dev(arg));
6907                 goto unlock;
6908 
6909         case ADD_NEW_DISK:
6910                 /* We can support ADD_NEW_DISK on read-only arrays
6911                  * only if we are re-adding a preexisting device.
6912                  * So require mddev->pers and MD_DISK_SYNC.
6913                  */
6914                 if (mddev->pers) {
6915                         mdu_disk_info_t info;
6916                         if (copy_from_user(&info, argp, sizeof(info)))
6917                                 err = -EFAULT;
6918                         else if (!(info.state & (1<<MD_DISK_SYNC)))
6919                                 /* Need to clear read-only for this */
6920                                 break;
6921                         else
6922                                 err = add_new_disk(mddev, &info);
6923                         goto unlock;
6924                 }
6925                 break;
6926 
6927         case BLKROSET:
6928                 if (get_user(ro, (int __user *)(arg))) {
6929                         err = -EFAULT;
6930                         goto unlock;
6931                 }
6932                 err = -EINVAL;
6933 
6934                 /* if the bdev is going readonly the value of mddev->ro
6935                  * does not matter, no writes are coming
6936                  */
6937                 if (ro)
6938                         goto unlock;
6939 
6940                 /* are we are already prepared for writes? */
6941                 if (mddev->ro != 1)
6942                         goto unlock;
6943 
6944                 /* transitioning to readauto need only happen for
6945                  * arrays that call md_write_start
6946                  */
6947                 if (mddev->pers) {
6948                         err = restart_array(mddev);
6949                         if (err == 0) {
6950                                 mddev->ro = 2;
6951                                 set_disk_ro(mddev->gendisk, 0);
6952                         }
6953                 }
6954                 goto unlock;
6955         }
6956 
6957         /*
6958          * The remaining ioctls are changing the state of the
6959          * superblock, so we do not allow them on read-only arrays.
6960          */
6961         if (mddev->ro && mddev->pers) {
6962                 if (mddev->ro == 2) {
6963                         mddev->ro = 0;
6964                         sysfs_notify_dirent_safe(mddev->sysfs_state);
6965                         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6966                         /* mddev_unlock will wake thread */
6967                         /* If a device failed while we were read-only, we
6968                          * need to make sure the metadata is updated now.
6969                          */
6970                         if (test_bit(MD_CHANGE_DEVS, &mddev->flags)) {
6971                                 mddev_unlock(mddev);
6972                                 wait_event(mddev->sb_wait,
6973                                            !test_bit(MD_CHANGE_DEVS, &mddev->flags) &&
6974                                            !test_bit(MD_CHANGE_PENDING, &mddev->flags));
6975                                 mddev_lock_nointr(mddev);
6976                         }
6977                 } else {
6978                         err = -EROFS;
6979                         goto unlock;
6980                 }
6981         }
6982 
6983         switch (cmd) {
6984         case ADD_NEW_DISK:
6985         {
6986                 mdu_disk_info_t info;
6987                 if (copy_from_user(&info, argp, sizeof(info)))
6988                         err = -EFAULT;
6989                 else
6990                         err = add_new_disk(mddev, &info);
6991                 goto unlock;
6992         }
6993 
6994         case CLUSTERED_DISK_NACK:
6995                 if (mddev_is_clustered(mddev))
6996                         md_cluster_ops->new_disk_ack(mddev, false);
6997                 else
6998                         err = -EINVAL;
6999                 goto unlock;
7000 
7001         case HOT_ADD_DISK:
7002                 err = hot_add_disk(mddev, new_decode_dev(arg));
7003                 goto unlock;
7004 
7005         case RUN_ARRAY:
7006                 err = do_md_run(mddev);
7007                 goto unlock;
7008 
7009         case SET_BITMAP_FILE:
7010                 err = set_bitmap_file(mddev, (int)arg);
7011                 goto unlock;
7012 
7013         default:
7014                 err = -EINVAL;
7015                 goto unlock;
7016         }
7017 
7018 unlock:
7019         if (mddev->hold_active == UNTIL_IOCTL &&
7020             err != -EINVAL)
7021                 mddev->hold_active = 0;
7022         mddev_unlock(mddev);
7023 out:
7024         return err;
7025 }
7026 #ifdef CONFIG_COMPAT
7027 static int md_compat_ioctl(struct block_device *bdev, fmode_t mode,
7028                     unsigned int cmd, unsigned long arg)
7029 {
7030         switch (cmd) {
7031         case HOT_REMOVE_DISK:
7032         case HOT_ADD_DISK:
7033         case SET_DISK_FAULTY:
7034         case SET_BITMAP_FILE:
7035                 /* These take in integer arg, do not convert */
7036                 break;
7037         default:
7038                 arg = (unsigned long)compat_ptr(arg);
7039                 break;
7040         }
7041 
7042         return md_ioctl(bdev, mode, cmd, arg);
7043 }
7044 #endif /* CONFIG_COMPAT */
7045 
7046 static int md_open(struct block_device *bdev, fmode_t mode)
7047 {
7048         /*
7049          * Succeed if we can lock the mddev, which confirms that
7050          * it isn't being stopped right now.
7051          */
7052         struct mddev *mddev = mddev_find(bdev->bd_dev);
7053         int err;
7054 
7055         if (!mddev)
7056                 return -ENODEV;
7057 
7058         if (mddev->gendisk != bdev->bd_disk) {
7059                 /* we are racing with mddev_put which is discarding this
7060                  * bd_disk.
7061                  */
7062                 mddev_put(mddev);
7063                 /* Wait until bdev->bd_disk is definitely gone */
7064                 flush_workqueue(md_misc_wq);
7065                 /* Then retry the open from the top */
7066                 return -ERESTARTSYS;
7067         }
7068         BUG_ON(mddev != bdev->bd_disk->private_data);
7069 
7070         if ((err = mutex_lock_interruptible(&mddev->open_mutex)))
7071                 goto out;
7072 
7073         err = 0;
7074         atomic_inc(&mddev->openers);
7075         clear_bit(MD_STILL_CLOSED, &mddev->flags);
7076         mutex_unlock(&mddev->open_mutex);
7077 
7078         check_disk_change(bdev);
7079  out:
7080         return err;
7081 }
7082 
7083 static void md_release(struct gendisk *disk, fmode_t mode)
7084 {
7085         struct mddev *mddev = disk->private_data;
7086 
7087         BUG_ON(!mddev);
7088         atomic_dec(&mddev->openers);
7089         mddev_put(mddev);
7090 }
7091 
7092 static int md_media_changed(struct gendisk *disk)
7093 {
7094         struct mddev *mddev = disk->private_data;
7095 
7096         return mddev->changed;
7097 }
7098 
7099 static int md_revalidate(struct gendisk *disk)
7100 {
7101         struct mddev *mddev = disk->private_data;
7102 
7103         mddev->changed = 0;
7104         return 0;
7105 }
7106 static const struct block_device_operations md_fops =
7107 {
7108         .owner          = THIS_MODULE,
7109         .open           = md_open,
7110         .release        = md_release,
7111         .ioctl          = md_ioctl,
7112 #ifdef CONFIG_COMPAT
7113         .compat_ioctl   = md_compat_ioctl,
7114 #endif
7115         .getgeo         = md_getgeo,
7116         .media_changed  = md_media_changed,
7117         .revalidate_disk= md_revalidate,
7118 };
7119 
7120 static int md_thread(void *arg)
7121 {
7122         struct md_thread *thread = arg;
7123 
7124         /*
7125          * md_thread is a 'system-thread', it's priority should be very
7126          * high. We avoid resource deadlocks individually in each
7127          * raid personality. (RAID5 does preallocation) We also use RR and
7128          * the very same RT priority as kswapd, thus we will never get
7129          * into a priority inversion deadlock.
7130          *
7131          * we definitely have to have equal or higher priority than
7132          * bdflush, otherwise bdflush will deadlock if there are too
7133          * many dirty RAID5 blocks.
7134          */
7135 
7136         allow_signal(SIGKILL);
7137         while (!kthread_should_stop()) {
7138 
7139                 /* We need to wait INTERRUPTIBLE so that
7140                  * we don't add to the load-average.
7141                  * That means we need to be sure no signals are
7142                  * pending
7143                  */
7144                 if (signal_pending(current))
7145                         flush_signals(current);
7146 
7147                 wait_event_interruptible_timeout
7148                         (thread->wqueue,
7149                          test_bit(THREAD_WAKEUP, &thread->flags)
7150                          || kthread_should_stop(),
7151                          thread->timeout);
7152 
7153                 clear_bit(THREAD_WAKEUP, &thread->flags);
7154                 if (!kthread_should_stop())
7155                         thread->run(thread);
7156         }
7157 
7158         return 0;
7159 }
7160 
7161 void md_wakeup_thread(struct md_thread *thread)
7162 {
7163         if (thread) {
7164                 pr_debug("md: waking up MD thread %s.\n", thread->tsk->comm);
7165                 set_bit(THREAD_WAKEUP, &thread->flags);
7166                 wake_up(&thread->wqueue);
7167         }
7168 }
7169 EXPORT_SYMBOL(md_wakeup_thread);
7170 
7171 struct md_thread *md_register_thread(void (*run) (struct md_thread *),
7172                 struct mddev *mddev, const char *name)
7173 {
7174         struct md_thread *thread;
7175 
7176         thread = kzalloc(sizeof(struct md_thread), GFP_KERNEL);
7177         if (!thread)
7178                 return NULL;
7179 
7180         init_waitqueue_head(&thread->wqueue);
7181 
7182         thread->run = run;
7183         thread->mddev = mddev;
7184         thread->timeout = MAX_SCHEDULE_TIMEOUT;
7185         thread->tsk = kthread_run(md_thread, thread,
7186                                   "%s_%s",
7187                                   mdname(thread->mddev),
7188                                   name);
7189         if (IS_ERR(thread->tsk)) {
7190                 kfree(thread);
7191                 return NULL;
7192         }
7193         return thread;
7194 }
7195 EXPORT_SYMBOL(md_register_thread);
7196 
7197 void md_unregister_thread(struct md_thread **threadp)
7198 {
7199         struct md_thread *thread = *threadp;
7200         if (!thread)
7201                 return;
7202         pr_debug("interrupting MD-thread pid %d\n", task_pid_nr(thread->tsk));
7203         /* Locking ensures that mddev_unlock does not wake_up a
7204          * non-existent thread
7205          */
7206         spin_lock(&pers_lock);
7207         *threadp = NULL;
7208         spin_unlock(&pers_lock);
7209 
7210         kthread_stop(thread->tsk);
7211         kfree(thread);
7212 }
7213 EXPORT_SYMBOL(md_unregister_thread);
7214 
7215 void md_error(struct mddev *mddev, struct md_rdev *rdev)
7216 {
7217         if (!rdev || test_bit(Faulty, &rdev->flags))
7218                 return;
7219 
7220         if (!mddev->pers || !mddev->pers->error_handler)
7221                 return;
7222         mddev->pers->error_handler(mddev,rdev);
7223         if (mddev->degraded)
7224                 set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
7225         sysfs_notify_dirent_safe(rdev->sysfs_state);
7226         set_bit(MD_RECOVERY_INTR, &mddev->recovery);
7227         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7228         md_wakeup_thread(mddev->thread);
7229         if (mddev->event_work.func)
7230                 queue_work(md_misc_wq, &mddev->event_work);
7231         md_new_event(mddev);
7232 }
7233 EXPORT_SYMBOL(md_error);
7234 
7235 /* seq_file implementation /proc/mdstat */
7236 
7237 static void status_unused(struct seq_file *seq)
7238 {
7239         int i = 0;
7240         struct md_rdev *rdev;
7241 
7242         seq_printf(seq, "unused devices: ");
7243 
7244         list_for_each_entry(rdev, &pending_raid_disks, same_set) {
7245                 char b[BDEVNAME_SIZE];
7246                 i++;
7247                 seq_printf(seq, "%s ",
7248                               bdevname(rdev->bdev,b));
7249         }
7250         if (!i)
7251                 seq_printf(seq, "<none>");
7252 
7253         seq_printf(seq, "\n");
7254 }
7255 
7256 static int status_resync(struct seq_file *seq, struct mddev *mddev)
7257 {
7258         sector_t max_sectors, resync, res;
7259         unsigned long dt, db;
7260         sector_t rt;
7261         int scale;
7262         unsigned int per_milli;
7263 
7264         if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ||
7265             test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
7266                 max_sectors = mddev->resync_max_sectors;
7267         else
7268                 max_sectors = mddev->dev_sectors;
7269 
7270         resync = mddev->curr_resync;
7271         if (resync <= 3) {
7272                 if (test_bit(MD_RECOVERY_DONE, &mddev->recovery))
7273                         /* Still cleaning up */
7274                         resync = max_sectors;
7275         } else
7276                 resync -= atomic_read(&mddev->recovery_active);
7277 
7278         if (resync == 0) {
7279                 if (mddev->recovery_cp < MaxSector) {
7280                         seq_printf(seq, "\tresync=PENDING");
7281                         return 1;
7282                 }
7283                 return 0;
7284         }
7285         if (resync < 3) {
7286                 seq_printf(seq, "\tresync=DELAYED");
7287                 return 1;
7288         }
7289 
7290         WARN_ON(max_sectors == 0);
7291         /* Pick 'scale' such that (resync>>scale)*1000 will fit
7292          * in a sector_t, and (max_sectors>>scale) will fit in a
7293          * u32, as those are the requirements for sector_div.
7294          * Thus 'scale' must be at least 10
7295          */
7296         scale = 10;
7297         if (sizeof(sector_t) > sizeof(unsigned long)) {
7298                 while ( max_sectors/2 > (1ULL<<(scale+32)))
7299                         scale++;
7300         }
7301         res = (resync>>scale)*1000;
7302         sector_div(res, (u32)((max_sectors>>scale)+1));
7303 
7304         per_milli = res;
7305         {
7306                 int i, x = per_milli/50, y = 20-x;
7307                 seq_printf(seq, "[");
7308                 for (i = 0; i < x; i++)
7309                         seq_printf(seq, "=");
7310                 seq_printf(seq, ">");
7311                 for (i = 0; i < y; i++)
7312                         seq_printf(seq, ".");
7313                 seq_printf(seq, "] ");
7314         }
7315         seq_printf(seq, " %s =%3u.%u%% (%llu/%llu)",
7316                    (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)?
7317                     "reshape" :
7318                     (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)?
7319                      "check" :
7320                      (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ?
7321                       "resync" : "recovery"))),
7322                    per_milli/10, per_milli % 10,
7323                    (unsigned long long) resync/2,
7324                    (unsigned long long) max_sectors/2);
7325 
7326         /*
7327          * dt: time from mark until now
7328          * db: blocks written from mark until now
7329          * rt: remaining time
7330          *
7331          * rt is a sector_t, so could be 32bit or 64bit.
7332          * So we divide before multiply in case it is 32bit and close
7333          * to the limit.
7334          * We scale the divisor (db) by 32 to avoid losing precision
7335          * near the end of resync when the number of remaining sectors
7336          * is close to 'db'.
7337          * We then divide rt by 32 after multiplying by db to compensate.
7338          * The '+1' avoids division by zero if db is very small.
7339          */
7340         dt = ((jiffies - mddev->resync_mark) / HZ);
7341         if (!dt) dt++;
7342         db = (mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active))
7343                 - mddev->resync_mark_cnt;
7344 
7345         rt = max_sectors - resync;    /* number of remaining sectors */
7346         sector_div(rt, db/32+1);
7347         rt *= dt;
7348         rt >>= 5;
7349 
7350         seq_printf(seq, " finish=%lu.%lumin", (unsigned long)rt / 60,
7351                    ((unsigned long)rt % 60)/6);
7352 
7353         seq_printf(seq, " speed=%ldK/sec", db/2/dt);
7354         return 1;
7355 }
7356 
7357 static void *md_seq_start(struct seq_file *seq, loff_t *pos)
7358 {
7359         struct list_head *tmp;
7360         loff_t l = *pos;
7361         struct mddev *mddev;
7362 
7363         if (l >= 0x10000)
7364                 return NULL;
7365         if (!l--)
7366                 /* header */
7367                 return (void*)1;
7368 
7369         spin_lock(&all_mddevs_lock);
7370         list_for_each(tmp,&all_mddevs)
7371                 if (!l--) {
7372                         mddev = list_entry(tmp, struct mddev, all_mddevs);
7373                         mddev_get(mddev);
7374                         spin_unlock(&all_mddevs_lock);
7375                         return mddev;
7376                 }
7377         spin_unlock(&all_mddevs_lock);
7378         if (!l--)
7379                 return (void*)2;/* tail */
7380         return NULL;
7381 }
7382 
7383 static void *md_seq_next(struct seq_file *seq, void *v, loff_t *pos)
7384 {
7385         struct list_head *tmp;
7386         struct mddev *next_mddev, *mddev = v;
7387 
7388         ++*pos;
7389         if (v == (void*)2)
7390                 return NULL;
7391 
7392         spin_lock(&all_mddevs_lock);
7393         if (v == (void*)1)
7394                 tmp = all_mddevs.next;
7395         else
7396                 tmp = mddev->all_mddevs.next;
7397         if (tmp != &all_mddevs)
7398                 next_mddev = mddev_get(list_entry(tmp,struct mddev,all_mddevs));
7399         else {
7400                 next_mddev = (void*)2;
7401                 *pos = 0x10000;
7402         }
7403         spin_unlock(&all_mddevs_lock);
7404 
7405         if (v != (void*)1)
7406                 mddev_put(mddev);
7407         return next_mddev;
7408 
7409 }
7410 
7411 static void md_seq_stop(struct seq_file *seq, void *v)
7412 {
7413         struct mddev *mddev = v;
7414 
7415         if (mddev && v != (void*)1 && v != (void*)2)
7416                 mddev_put(mddev);
7417 }
7418 
7419 static int md_seq_show(struct seq_file *seq, void *v)
7420 {
7421         struct mddev *mddev = v;
7422         sector_t sectors;
7423         struct md_rdev *rdev;
7424 
7425         if (v == (void*)1) {
7426                 struct md_personality *pers;
7427                 seq_printf(seq, "Personalities : ");
7428                 spin_lock(&pers_lock);
7429                 list_for_each_entry(pers, &pers_list, list)
7430                         seq_printf(seq, "[%s] ", pers->name);
7431 
7432                 spin_unlock(&pers_lock);
7433                 seq_printf(seq, "\n");
7434                 seq->poll_event = atomic_read(&md_event_count);
7435                 return 0;
7436         }
7437         if (v == (void*)2) {
7438                 status_unused(seq);
7439                 return 0;
7440         }
7441 
7442         spin_lock(&mddev->lock);
7443         if (mddev->pers || mddev->raid_disks || !list_empty(&mddev->disks)) {
7444                 seq_printf(seq, "%s : %sactive", mdname(mddev),
7445                                                 mddev->pers ? "" : "in");
7446                 if (mddev->pers) {
7447                         if (mddev->ro==1)
7448                                 seq_printf(seq, " (read-only)");
7449                         if (mddev->ro==2)
7450                                 seq_printf(seq, " (auto-read-only)");
7451                         seq_printf(seq, " %s", mddev->pers->name);
7452                 }
7453 
7454                 sectors = 0;
7455                 rcu_read_lock();
7456                 rdev_for_each_rcu(rdev, mddev) {
7457                         char b[BDEVNAME_SIZE];
7458                         seq_printf(seq, " %s[%d]",
7459                                 bdevname(rdev->bdev,b), rdev->desc_nr);
7460                         if (test_bit(WriteMostly, &rdev->flags))
7461                                 seq_printf(seq, "(W)");
7462                         if (test_bit(Journal, &rdev->flags))
7463                                 seq_printf(seq, "(J)");
7464                         if (test_bit(Faulty, &rdev->flags)) {
7465                                 seq_printf(seq, "(F)");
7466                                 continue;
7467                         }
7468                         if (rdev->raid_disk < 0)
7469                                 seq_printf(seq, "(S)"); /* spare */
7470                         if (test_bit(Replacement, &rdev->flags))
7471                                 seq_printf(seq, "(R)");
7472                         sectors += rdev->sectors;
7473                 }
7474                 rcu_read_unlock();
7475 
7476                 if (!list_empty(&mddev->disks)) {
7477                         if (mddev->pers)
7478                                 seq_printf(seq, "\n      %llu blocks",
7479                                            (unsigned long long)
7480                                            mddev->array_sectors / 2);
7481                         else
7482                                 seq_printf(seq, "\n      %llu blocks",
7483                                            (unsigned long long)sectors / 2);
7484                 }
7485                 if (mddev->persistent) {
7486                         if (mddev->major_version != 0 ||
7487                             mddev->minor_version != 90) {
7488                                 seq_printf(seq," super %d.%d",
7489                                            mddev->major_version,
7490                                            mddev->minor_version);
7491                         }
7492                 } else if (mddev->external)
7493                         seq_printf(seq, " super external:%s",
7494                                    mddev->metadata_type);
7495                 else
7496                         seq_printf(seq, " super non-persistent");
7497 
7498                 if (mddev->pers) {
7499                         mddev->pers->status(seq, mddev);
7500                         seq_printf(seq, "\n      ");
7501                         if (mddev->pers->sync_request) {
7502                                 if (status_resync(seq, mddev))
7503                                         seq_printf(seq, "\n      ");
7504                         }
7505                 } else
7506                         seq_printf(seq, "\n       ");
7507 
7508                 bitmap_status(seq, mddev->bitmap);
7509 
7510                 seq_printf(seq, "\n");
7511         }
7512         spin_unlock(&mddev->lock);
7513 
7514         return 0;
7515 }
7516 
7517 static const struct seq_operations md_seq_ops = {
7518         .start  = md_seq_start,
7519         .