Version:  2.0.40 2.2.26 2.4.37 3.8 3.9 3.10 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

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         mddev->pers->make_request(mddev, bio);
288 
289         cpu = part_stat_lock();
290         part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]);
291         part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw], sectors);
292         part_stat_unlock();
293 
294         if (atomic_dec_and_test(&mddev->active_io) && mddev->suspended)
295                 wake_up(&mddev->sb_wait);
296 
297         return BLK_QC_T_NONE;
298 }
299 
300 /* mddev_suspend makes sure no new requests are submitted
301  * to the device, and that any requests that have been submitted
302  * are completely handled.
303  * Once mddev_detach() is called and completes, the module will be
304  * completely unused.
305  */
306 void mddev_suspend(struct mddev *mddev)
307 {
308         if (mddev->suspended++)
309                 return;
310         synchronize_rcu();
311         wait_event(mddev->sb_wait, atomic_read(&mddev->active_io) == 0);
312         mddev->pers->quiesce(mddev, 1);
313 
314         del_timer_sync(&mddev->safemode_timer);
315 }
316 EXPORT_SYMBOL_GPL(mddev_suspend);
317 
318 void mddev_resume(struct mddev *mddev)
319 {
320         if (--mddev->suspended)
321                 return;
322         wake_up(&mddev->sb_wait);
323         mddev->pers->quiesce(mddev, 0);
324 
325         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
326         md_wakeup_thread(mddev->thread);
327         md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
328 }
329 EXPORT_SYMBOL_GPL(mddev_resume);
330 
331 int mddev_congested(struct mddev *mddev, int bits)
332 {
333         struct md_personality *pers = mddev->pers;
334         int ret = 0;
335 
336         rcu_read_lock();
337         if (mddev->suspended)
338                 ret = 1;
339         else if (pers && pers->congested)
340                 ret = pers->congested(mddev, bits);
341         rcu_read_unlock();
342         return ret;
343 }
344 EXPORT_SYMBOL_GPL(mddev_congested);
345 static int md_congested(void *data, int bits)
346 {
347         struct mddev *mddev = data;
348         return mddev_congested(mddev, bits);
349 }
350 
351 /*
352  * Generic flush handling for md
353  */
354 
355 static void md_end_flush(struct bio *bio)
356 {
357         struct md_rdev *rdev = bio->bi_private;
358         struct mddev *mddev = rdev->mddev;
359 
360         rdev_dec_pending(rdev, mddev);
361 
362         if (atomic_dec_and_test(&mddev->flush_pending)) {
363                 /* The pre-request flush has finished */
364                 queue_work(md_wq, &mddev->flush_work);
365         }
366         bio_put(bio);
367 }
368 
369 static void md_submit_flush_data(struct work_struct *ws);
370 
371 static void submit_flushes(struct work_struct *ws)
372 {
373         struct mddev *mddev = container_of(ws, struct mddev, flush_work);
374         struct md_rdev *rdev;
375 
376         INIT_WORK(&mddev->flush_work, md_submit_flush_data);
377         atomic_set(&mddev->flush_pending, 1);
378         rcu_read_lock();
379         rdev_for_each_rcu(rdev, mddev)
380                 if (rdev->raid_disk >= 0 &&
381                     !test_bit(Faulty, &rdev->flags)) {
382                         /* Take two references, one is dropped
383                          * when request finishes, one after
384                          * we reclaim rcu_read_lock
385                          */
386                         struct bio *bi;
387                         atomic_inc(&rdev->nr_pending);
388                         atomic_inc(&rdev->nr_pending);
389                         rcu_read_unlock();
390                         bi = bio_alloc_mddev(GFP_NOIO, 0, mddev);
391                         bi->bi_end_io = md_end_flush;
392                         bi->bi_private = rdev;
393                         bi->bi_bdev = rdev->bdev;
394                         atomic_inc(&mddev->flush_pending);
395                         submit_bio(WRITE_FLUSH, bi);
396                         rcu_read_lock();
397                         rdev_dec_pending(rdev, mddev);
398                 }
399         rcu_read_unlock();
400         if (atomic_dec_and_test(&mddev->flush_pending))
401                 queue_work(md_wq, &mddev->flush_work);
402 }
403 
404 static void md_submit_flush_data(struct work_struct *ws)
405 {
406         struct mddev *mddev = container_of(ws, struct mddev, flush_work);
407         struct bio *bio = mddev->flush_bio;
408 
409         if (bio->bi_iter.bi_size == 0)
410                 /* an empty barrier - all done */
411                 bio_endio(bio);
412         else {
413                 bio->bi_rw &= ~REQ_FLUSH;
414                 mddev->pers->make_request(mddev, bio);
415         }
416 
417         mddev->flush_bio = NULL;
418         wake_up(&mddev->sb_wait);
419 }
420 
421 void md_flush_request(struct mddev *mddev, struct bio *bio)
422 {
423         spin_lock_irq(&mddev->lock);
424         wait_event_lock_irq(mddev->sb_wait,
425                             !mddev->flush_bio,
426                             mddev->lock);
427         mddev->flush_bio = bio;
428         spin_unlock_irq(&mddev->lock);
429 
430         INIT_WORK(&mddev->flush_work, submit_flushes);
431         queue_work(md_wq, &mddev->flush_work);
432 }
433 EXPORT_SYMBOL(md_flush_request);
434 
435 void md_unplug(struct blk_plug_cb *cb, bool from_schedule)
436 {
437         struct mddev *mddev = cb->data;
438         md_wakeup_thread(mddev->thread);
439         kfree(cb);
440 }
441 EXPORT_SYMBOL(md_unplug);
442 
443 static inline struct mddev *mddev_get(struct mddev *mddev)
444 {
445         atomic_inc(&mddev->active);
446         return mddev;
447 }
448 
449 static void mddev_delayed_delete(struct work_struct *ws);
450 
451 static void mddev_put(struct mddev *mddev)
452 {
453         struct bio_set *bs = NULL;
454 
455         if (!atomic_dec_and_lock(&mddev->active, &all_mddevs_lock))
456                 return;
457         if (!mddev->raid_disks && list_empty(&mddev->disks) &&
458             mddev->ctime == 0 && !mddev->hold_active) {
459                 /* Array is not configured at all, and not held active,
460                  * so destroy it */
461                 list_del_init(&mddev->all_mddevs);
462                 bs = mddev->bio_set;
463                 mddev->bio_set = NULL;
464                 if (mddev->gendisk) {
465                         /* We did a probe so need to clean up.  Call
466                          * queue_work inside the spinlock so that
467                          * flush_workqueue() after mddev_find will
468                          * succeed in waiting for the work to be done.
469                          */
470                         INIT_WORK(&mddev->del_work, mddev_delayed_delete);
471                         queue_work(md_misc_wq, &mddev->del_work);
472                 } else
473                         kfree(mddev);
474         }
475         spin_unlock(&all_mddevs_lock);
476         if (bs)
477                 bioset_free(bs);
478 }
479 
480 static void md_safemode_timeout(unsigned long data);
481 
482 void mddev_init(struct mddev *mddev)
483 {
484         mutex_init(&mddev->open_mutex);
485         mutex_init(&mddev->reconfig_mutex);
486         mutex_init(&mddev->bitmap_info.mutex);
487         INIT_LIST_HEAD(&mddev->disks);
488         INIT_LIST_HEAD(&mddev->all_mddevs);
489         setup_timer(&mddev->safemode_timer, md_safemode_timeout,
490                     (unsigned long) mddev);
491         atomic_set(&mddev->active, 1);
492         atomic_set(&mddev->openers, 0);
493         atomic_set(&mddev->active_io, 0);
494         spin_lock_init(&mddev->lock);
495         atomic_set(&mddev->flush_pending, 0);
496         init_waitqueue_head(&mddev->sb_wait);
497         init_waitqueue_head(&mddev->recovery_wait);
498         mddev->reshape_position = MaxSector;
499         mddev->reshape_backwards = 0;
500         mddev->last_sync_action = "none";
501         mddev->resync_min = 0;
502         mddev->resync_max = MaxSector;
503         mddev->level = LEVEL_NONE;
504 }
505 EXPORT_SYMBOL_GPL(mddev_init);
506 
507 static struct mddev *mddev_find(dev_t unit)
508 {
509         struct mddev *mddev, *new = NULL;
510 
511         if (unit && MAJOR(unit) != MD_MAJOR)
512                 unit &= ~((1<<MdpMinorShift)-1);
513 
514  retry:
515         spin_lock(&all_mddevs_lock);
516 
517         if (unit) {
518                 list_for_each_entry(mddev, &all_mddevs, all_mddevs)
519                         if (mddev->unit == unit) {
520                                 mddev_get(mddev);
521                                 spin_unlock(&all_mddevs_lock);
522                                 kfree(new);
523                                 return mddev;
524                         }
525 
526                 if (new) {
527                         list_add(&new->all_mddevs, &all_mddevs);
528                         spin_unlock(&all_mddevs_lock);
529                         new->hold_active = UNTIL_IOCTL;
530                         return new;
531                 }
532         } else if (new) {
533                 /* find an unused unit number */
534                 static int next_minor = 512;
535                 int start = next_minor;
536                 int is_free = 0;
537                 int dev = 0;
538                 while (!is_free) {
539                         dev = MKDEV(MD_MAJOR, next_minor);
540                         next_minor++;
541                         if (next_minor > MINORMASK)
542                                 next_minor = 0;
543                         if (next_minor == start) {
544                                 /* Oh dear, all in use. */
545                                 spin_unlock(&all_mddevs_lock);
546                                 kfree(new);
547                                 return NULL;
548                         }
549 
550                         is_free = 1;
551                         list_for_each_entry(mddev, &all_mddevs, all_mddevs)
552                                 if (mddev->unit == dev) {
553                                         is_free = 0;
554                                         break;
555                                 }
556                 }
557                 new->unit = dev;
558                 new->md_minor = MINOR(dev);
559                 new->hold_active = UNTIL_STOP;
560                 list_add(&new->all_mddevs, &all_mddevs);
561                 spin_unlock(&all_mddevs_lock);
562                 return new;
563         }
564         spin_unlock(&all_mddevs_lock);
565 
566         new = kzalloc(sizeof(*new), GFP_KERNEL);
567         if (!new)
568                 return NULL;
569 
570         new->unit = unit;
571         if (MAJOR(unit) == MD_MAJOR)
572                 new->md_minor = MINOR(unit);
573         else
574                 new->md_minor = MINOR(unit) >> MdpMinorShift;
575 
576         mddev_init(new);
577 
578         goto retry;
579 }
580 
581 static struct attribute_group md_redundancy_group;
582 
583 void mddev_unlock(struct mddev *mddev)
584 {
585         if (mddev->to_remove) {
586                 /* These cannot be removed under reconfig_mutex as
587                  * an access to the files will try to take reconfig_mutex
588                  * while holding the file unremovable, which leads to
589                  * a deadlock.
590                  * So hold set sysfs_active while the remove in happeing,
591                  * and anything else which might set ->to_remove or my
592                  * otherwise change the sysfs namespace will fail with
593                  * -EBUSY if sysfs_active is still set.
594                  * We set sysfs_active under reconfig_mutex and elsewhere
595                  * test it under the same mutex to ensure its correct value
596                  * is seen.
597                  */
598                 struct attribute_group *to_remove = mddev->to_remove;
599                 mddev->to_remove = NULL;
600                 mddev->sysfs_active = 1;
601                 mutex_unlock(&mddev->reconfig_mutex);
602 
603                 if (mddev->kobj.sd) {
604                         if (to_remove != &md_redundancy_group)
605                                 sysfs_remove_group(&mddev->kobj, to_remove);
606                         if (mddev->pers == NULL ||
607                             mddev->pers->sync_request == NULL) {
608                                 sysfs_remove_group(&mddev->kobj, &md_redundancy_group);
609                                 if (mddev->sysfs_action)
610                                         sysfs_put(mddev->sysfs_action);
611                                 mddev->sysfs_action = NULL;
612                         }
613                 }
614                 mddev->sysfs_active = 0;
615         } else
616                 mutex_unlock(&mddev->reconfig_mutex);
617 
618         /* As we've dropped the mutex we need a spinlock to
619          * make sure the thread doesn't disappear
620          */
621         spin_lock(&pers_lock);
622         md_wakeup_thread(mddev->thread);
623         spin_unlock(&pers_lock);
624 }
625 EXPORT_SYMBOL_GPL(mddev_unlock);
626 
627 struct md_rdev *md_find_rdev_nr_rcu(struct mddev *mddev, int nr)
628 {
629         struct md_rdev *rdev;
630 
631         rdev_for_each_rcu(rdev, mddev)
632                 if (rdev->desc_nr == nr)
633                         return rdev;
634 
635         return NULL;
636 }
637 EXPORT_SYMBOL_GPL(md_find_rdev_nr_rcu);
638 
639 static struct md_rdev *find_rdev(struct mddev *mddev, dev_t dev)
640 {
641         struct md_rdev *rdev;
642 
643         rdev_for_each(rdev, mddev)
644                 if (rdev->bdev->bd_dev == dev)
645                         return rdev;
646 
647         return NULL;
648 }
649 
650 static struct md_rdev *find_rdev_rcu(struct mddev *mddev, dev_t dev)
651 {
652         struct md_rdev *rdev;
653 
654         rdev_for_each_rcu(rdev, mddev)
655                 if (rdev->bdev->bd_dev == dev)
656                         return rdev;
657 
658         return NULL;
659 }
660 
661 static struct md_personality *find_pers(int level, char *clevel)
662 {
663         struct md_personality *pers;
664         list_for_each_entry(pers, &pers_list, list) {
665                 if (level != LEVEL_NONE && pers->level == level)
666                         return pers;
667                 if (strcmp(pers->name, clevel)==0)
668                         return pers;
669         }
670         return NULL;
671 }
672 
673 /* return the offset of the super block in 512byte sectors */
674 static inline sector_t calc_dev_sboffset(struct md_rdev *rdev)
675 {
676         sector_t num_sectors = i_size_read(rdev->bdev->bd_inode) / 512;
677         return MD_NEW_SIZE_SECTORS(num_sectors);
678 }
679 
680 static int alloc_disk_sb(struct md_rdev *rdev)
681 {
682         rdev->sb_page = alloc_page(GFP_KERNEL);
683         if (!rdev->sb_page) {
684                 printk(KERN_ALERT "md: out of memory.\n");
685                 return -ENOMEM;
686         }
687 
688         return 0;
689 }
690 
691 void md_rdev_clear(struct md_rdev *rdev)
692 {
693         if (rdev->sb_page) {
694                 put_page(rdev->sb_page);
695                 rdev->sb_loaded = 0;
696                 rdev->sb_page = NULL;
697                 rdev->sb_start = 0;
698                 rdev->sectors = 0;
699         }
700         if (rdev->bb_page) {
701                 put_page(rdev->bb_page);
702                 rdev->bb_page = NULL;
703         }
704         badblocks_exit(&rdev->badblocks);
705 }
706 EXPORT_SYMBOL_GPL(md_rdev_clear);
707 
708 static void super_written(struct bio *bio)
709 {
710         struct md_rdev *rdev = bio->bi_private;
711         struct mddev *mddev = rdev->mddev;
712 
713         if (bio->bi_error) {
714                 printk("md: super_written gets error=%d\n", bio->bi_error);
715                 md_error(mddev, rdev);
716         }
717 
718         if (atomic_dec_and_test(&mddev->pending_writes))
719                 wake_up(&mddev->sb_wait);
720         bio_put(bio);
721 }
722 
723 void md_super_write(struct mddev *mddev, struct md_rdev *rdev,
724                    sector_t sector, int size, struct page *page)
725 {
726         /* write first size bytes of page to sector of rdev
727          * Increment mddev->pending_writes before returning
728          * and decrement it on completion, waking up sb_wait
729          * if zero is reached.
730          * If an error occurred, call md_error
731          */
732         struct bio *bio = bio_alloc_mddev(GFP_NOIO, 1, mddev);
733 
734         bio->bi_bdev = rdev->meta_bdev ? rdev->meta_bdev : rdev->bdev;
735         bio->bi_iter.bi_sector = sector;
736         bio_add_page(bio, page, size, 0);
737         bio->bi_private = rdev;
738         bio->bi_end_io = super_written;
739 
740         atomic_inc(&mddev->pending_writes);
741         submit_bio(WRITE_FLUSH_FUA, bio);
742 }
743 
744 void md_super_wait(struct mddev *mddev)
745 {
746         /* wait for all superblock writes that were scheduled to complete */
747         wait_event(mddev->sb_wait, atomic_read(&mddev->pending_writes)==0);
748 }
749 
750 int sync_page_io(struct md_rdev *rdev, sector_t sector, int size,
751                  struct page *page, int rw, bool metadata_op)
752 {
753         struct bio *bio = bio_alloc_mddev(GFP_NOIO, 1, rdev->mddev);
754         int ret;
755 
756         bio->bi_bdev = (metadata_op && rdev->meta_bdev) ?
757                 rdev->meta_bdev : rdev->bdev;
758         if (metadata_op)
759                 bio->bi_iter.bi_sector = sector + rdev->sb_start;
760         else if (rdev->mddev->reshape_position != MaxSector &&
761                  (rdev->mddev->reshape_backwards ==
762                   (sector >= rdev->mddev->reshape_position)))
763                 bio->bi_iter.bi_sector = sector + rdev->new_data_offset;
764         else
765                 bio->bi_iter.bi_sector = sector + rdev->data_offset;
766         bio_add_page(bio, page, size, 0);
767         submit_bio_wait(rw, bio);
768 
769         ret = !bio->bi_error;
770         bio_put(bio);
771         return ret;
772 }
773 EXPORT_SYMBOL_GPL(sync_page_io);
774 
775 static int read_disk_sb(struct md_rdev *rdev, int size)
776 {
777         char b[BDEVNAME_SIZE];
778 
779         if (rdev->sb_loaded)
780                 return 0;
781 
782         if (!sync_page_io(rdev, 0, size, rdev->sb_page, READ, true))
783                 goto fail;
784         rdev->sb_loaded = 1;
785         return 0;
786 
787 fail:
788         printk(KERN_WARNING "md: disabled device %s, could not read superblock.\n",
789                 bdevname(rdev->bdev,b));
790         return -EINVAL;
791 }
792 
793 static int uuid_equal(mdp_super_t *sb1, mdp_super_t *sb2)
794 {
795         return  sb1->set_uuid0 == sb2->set_uuid0 &&
796                 sb1->set_uuid1 == sb2->set_uuid1 &&
797                 sb1->set_uuid2 == sb2->set_uuid2 &&
798                 sb1->set_uuid3 == sb2->set_uuid3;
799 }
800 
801 static int sb_equal(mdp_super_t *sb1, mdp_super_t *sb2)
802 {
803         int ret;
804         mdp_super_t *tmp1, *tmp2;
805 
806         tmp1 = kmalloc(sizeof(*tmp1),GFP_KERNEL);
807         tmp2 = kmalloc(sizeof(*tmp2),GFP_KERNEL);
808 
809         if (!tmp1 || !tmp2) {
810                 ret = 0;
811                 printk(KERN_INFO "md.c sb_equal(): failed to allocate memory!\n");
812                 goto abort;
813         }
814 
815         *tmp1 = *sb1;
816         *tmp2 = *sb2;
817 
818         /*
819          * nr_disks is not constant
820          */
821         tmp1->nr_disks = 0;
822         tmp2->nr_disks = 0;
823 
824         ret = (memcmp(tmp1, tmp2, MD_SB_GENERIC_CONSTANT_WORDS * 4) == 0);
825 abort:
826         kfree(tmp1);
827         kfree(tmp2);
828         return ret;
829 }
830 
831 static u32 md_csum_fold(u32 csum)
832 {
833         csum = (csum & 0xffff) + (csum >> 16);
834         return (csum & 0xffff) + (csum >> 16);
835 }
836 
837 static unsigned int calc_sb_csum(mdp_super_t *sb)
838 {
839         u64 newcsum = 0;
840         u32 *sb32 = (u32*)sb;
841         int i;
842         unsigned int disk_csum, csum;
843 
844         disk_csum = sb->sb_csum;
845         sb->sb_csum = 0;
846 
847         for (i = 0; i < MD_SB_BYTES/4 ; i++)
848                 newcsum += sb32[i];
849         csum = (newcsum & 0xffffffff) + (newcsum>>32);
850 
851 #ifdef CONFIG_ALPHA
852         /* This used to use csum_partial, which was wrong for several
853          * reasons including that different results are returned on
854          * different architectures.  It isn't critical that we get exactly
855          * the same return value as before (we always csum_fold before
856          * testing, and that removes any differences).  However as we
857          * know that csum_partial always returned a 16bit value on
858          * alphas, do a fold to maximise conformity to previous behaviour.
859          */
860         sb->sb_csum = md_csum_fold(disk_csum);
861 #else
862         sb->sb_csum = disk_csum;
863 #endif
864         return csum;
865 }
866 
867 /*
868  * Handle superblock details.
869  * We want to be able to handle multiple superblock formats
870  * so we have a common interface to them all, and an array of
871  * different handlers.
872  * We rely on user-space to write the initial superblock, and support
873  * reading and updating of superblocks.
874  * Interface methods are:
875  *   int load_super(struct md_rdev *dev, struct md_rdev *refdev, int minor_version)
876  *      loads and validates a superblock on dev.
877  *      if refdev != NULL, compare superblocks on both devices
878  *    Return:
879  *      0 - dev has a superblock that is compatible with refdev
880  *      1 - dev has a superblock that is compatible and newer than refdev
881  *          so dev should be used as the refdev in future
882  *     -EINVAL superblock incompatible or invalid
883  *     -othererror e.g. -EIO
884  *
885  *   int validate_super(struct mddev *mddev, struct md_rdev *dev)
886  *      Verify that dev is acceptable into mddev.
887  *       The first time, mddev->raid_disks will be 0, and data from
888  *       dev should be merged in.  Subsequent calls check that dev
889  *       is new enough.  Return 0 or -EINVAL
890  *
891  *   void sync_super(struct mddev *mddev, struct md_rdev *dev)
892  *     Update the superblock for rdev with data in mddev
893  *     This does not write to disc.
894  *
895  */
896 
897 struct super_type  {
898         char                *name;
899         struct module       *owner;
900         int                 (*load_super)(struct md_rdev *rdev,
901                                           struct md_rdev *refdev,
902                                           int minor_version);
903         int                 (*validate_super)(struct mddev *mddev,
904                                               struct md_rdev *rdev);
905         void                (*sync_super)(struct mddev *mddev,
906                                           struct md_rdev *rdev);
907         unsigned long long  (*rdev_size_change)(struct md_rdev *rdev,
908                                                 sector_t num_sectors);
909         int                 (*allow_new_offset)(struct md_rdev *rdev,
910                                                 unsigned long long new_offset);
911 };
912 
913 /*
914  * Check that the given mddev has no bitmap.
915  *
916  * This function is called from the run method of all personalities that do not
917  * support bitmaps. It prints an error message and returns non-zero if mddev
918  * has a bitmap. Otherwise, it returns 0.
919  *
920  */
921 int md_check_no_bitmap(struct mddev *mddev)
922 {
923         if (!mddev->bitmap_info.file && !mddev->bitmap_info.offset)
924                 return 0;
925         printk(KERN_ERR "%s: bitmaps are not supported for %s\n",
926                 mdname(mddev), mddev->pers->name);
927         return 1;
928 }
929 EXPORT_SYMBOL(md_check_no_bitmap);
930 
931 /*
932  * load_super for 0.90.0
933  */
934 static int super_90_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor_version)
935 {
936         char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
937         mdp_super_t *sb;
938         int ret;
939 
940         /*
941          * Calculate the position of the superblock (512byte sectors),
942          * it's at the end of the disk.
943          *
944          * It also happens to be a multiple of 4Kb.
945          */
946         rdev->sb_start = calc_dev_sboffset(rdev);
947 
948         ret = read_disk_sb(rdev, MD_SB_BYTES);
949         if (ret) return ret;
950 
951         ret = -EINVAL;
952 
953         bdevname(rdev->bdev, b);
954         sb = page_address(rdev->sb_page);
955 
956         if (sb->md_magic != MD_SB_MAGIC) {
957                 printk(KERN_ERR "md: invalid raid superblock magic on %s\n",
958                        b);
959                 goto abort;
960         }
961 
962         if (sb->major_version != 0 ||
963             sb->minor_version < 90 ||
964             sb->minor_version > 91) {
965                 printk(KERN_WARNING "Bad version number %d.%d on %s\n",
966                         sb->major_version, sb->minor_version,
967                         b);
968                 goto abort;
969         }
970 
971         if (sb->raid_disks <= 0)
972                 goto abort;
973 
974         if (md_csum_fold(calc_sb_csum(sb)) != md_csum_fold(sb->sb_csum)) {
975                 printk(KERN_WARNING "md: invalid superblock checksum on %s\n",
976                         b);
977                 goto abort;
978         }
979 
980         rdev->preferred_minor = sb->md_minor;
981         rdev->data_offset = 0;
982         rdev->new_data_offset = 0;
983         rdev->sb_size = MD_SB_BYTES;
984         rdev->badblocks.shift = -1;
985 
986         if (sb->level == LEVEL_MULTIPATH)
987                 rdev->desc_nr = -1;
988         else
989                 rdev->desc_nr = sb->this_disk.number;
990 
991         if (!refdev) {
992                 ret = 1;
993         } else {
994                 __u64 ev1, ev2;
995                 mdp_super_t *refsb = page_address(refdev->sb_page);
996                 if (!uuid_equal(refsb, sb)) {
997                         printk(KERN_WARNING "md: %s has different UUID to %s\n",
998                                 b, bdevname(refdev->bdev,b2));
999                         goto abort;
1000                 }
1001                 if (!sb_equal(refsb, sb)) {
1002                         printk(KERN_WARNING "md: %s has same UUID"
1003                                " but different superblock to %s\n",
1004                                b, bdevname(refdev->bdev, b2));
1005                         goto abort;
1006                 }
1007                 ev1 = md_event(sb);
1008                 ev2 = md_event(refsb);
1009                 if (ev1 > ev2)
1010                         ret = 1;
1011                 else
1012                         ret = 0;
1013         }
1014         rdev->sectors = rdev->sb_start;
1015         /* Limit to 4TB as metadata cannot record more than that.
1016          * (not needed for Linear and RAID0 as metadata doesn't
1017          * record this size)
1018          */
1019         if (IS_ENABLED(CONFIG_LBDAF) && (u64)rdev->sectors >= (2ULL << 32) &&
1020             sb->level >= 1)
1021                 rdev->sectors = (sector_t)(2ULL << 32) - 2;
1022 
1023         if (rdev->sectors < ((sector_t)sb->size) * 2 && sb->level >= 1)
1024                 /* "this cannot possibly happen" ... */
1025                 ret = -EINVAL;
1026 
1027  abort:
1028         return ret;
1029 }
1030 
1031 /*
1032  * validate_super for 0.90.0
1033  */
1034 static int super_90_validate(struct mddev *mddev, struct md_rdev *rdev)
1035 {
1036         mdp_disk_t *desc;
1037         mdp_super_t *sb = page_address(rdev->sb_page);
1038         __u64 ev1 = md_event(sb);
1039 
1040         rdev->raid_disk = -1;
1041         clear_bit(Faulty, &rdev->flags);
1042         clear_bit(In_sync, &rdev->flags);
1043         clear_bit(Bitmap_sync, &rdev->flags);
1044         clear_bit(WriteMostly, &rdev->flags);
1045 
1046         if (mddev->raid_disks == 0) {
1047                 mddev->major_version = 0;
1048                 mddev->minor_version = sb->minor_version;
1049                 mddev->patch_version = sb->patch_version;
1050                 mddev->external = 0;
1051                 mddev->chunk_sectors = sb->chunk_size >> 9;
1052                 mddev->ctime = sb->ctime;
1053                 mddev->utime = sb->utime;
1054                 mddev->level = sb->level;
1055                 mddev->clevel[0] = 0;
1056                 mddev->layout = sb->layout;
1057                 mddev->raid_disks = sb->raid_disks;
1058                 mddev->dev_sectors = ((sector_t)sb->size) * 2;
1059                 mddev->events = ev1;
1060                 mddev->bitmap_info.offset = 0;
1061                 mddev->bitmap_info.space = 0;
1062                 /* bitmap can use 60 K after the 4K superblocks */
1063                 mddev->bitmap_info.default_offset = MD_SB_BYTES >> 9;
1064                 mddev->bitmap_info.default_space = 64*2 - (MD_SB_BYTES >> 9);
1065                 mddev->reshape_backwards = 0;
1066 
1067                 if (mddev->minor_version >= 91) {
1068                         mddev->reshape_position = sb->reshape_position;
1069                         mddev->delta_disks = sb->delta_disks;
1070                         mddev->new_level = sb->new_level;
1071                         mddev->new_layout = sb->new_layout;
1072                         mddev->new_chunk_sectors = sb->new_chunk >> 9;
1073                         if (mddev->delta_disks < 0)
1074                                 mddev->reshape_backwards = 1;
1075                 } else {
1076                         mddev->reshape_position = MaxSector;
1077                         mddev->delta_disks = 0;
1078                         mddev->new_level = mddev->level;
1079                         mddev->new_layout = mddev->layout;
1080                         mddev->new_chunk_sectors = mddev->chunk_sectors;
1081                 }
1082 
1083                 if (sb->state & (1<<MD_SB_CLEAN))
1084                         mddev->recovery_cp = MaxSector;
1085                 else {
1086                         if (sb->events_hi == sb->cp_events_hi &&
1087                                 sb->events_lo == sb->cp_events_lo) {
1088                                 mddev->recovery_cp = sb->recovery_cp;
1089                         } else
1090                                 mddev->recovery_cp = 0;
1091                 }
1092 
1093                 memcpy(mddev->uuid+0, &sb->set_uuid0, 4);
1094                 memcpy(mddev->uuid+4, &sb->set_uuid1, 4);
1095                 memcpy(mddev->uuid+8, &sb->set_uuid2, 4);
1096                 memcpy(mddev->uuid+12,&sb->set_uuid3, 4);
1097 
1098                 mddev->max_disks = MD_SB_DISKS;
1099 
1100                 if (sb->state & (1<<MD_SB_BITMAP_PRESENT) &&
1101                     mddev->bitmap_info.file == NULL) {
1102                         mddev->bitmap_info.offset =
1103                                 mddev->bitmap_info.default_offset;
1104                         mddev->bitmap_info.space =
1105                                 mddev->bitmap_info.default_space;
1106                 }
1107 
1108         } else if (mddev->pers == NULL) {
1109                 /* Insist on good event counter while assembling, except
1110                  * for spares (which don't need an event count) */
1111                 ++ev1;
1112                 if (sb->disks[rdev->desc_nr].state & (
1113                             (1<<MD_DISK_SYNC) | (1 << MD_DISK_ACTIVE)))
1114                         if (ev1 < mddev->events)
1115                                 return -EINVAL;
1116         } else if (mddev->bitmap) {
1117                 /* if adding to array with a bitmap, then we can accept an
1118                  * older device ... but not too old.
1119                  */
1120                 if (ev1 < mddev->bitmap->events_cleared)
1121                         return 0;
1122                 if (ev1 < mddev->events)
1123                         set_bit(Bitmap_sync, &rdev->flags);
1124         } else {
1125                 if (ev1 < mddev->events)
1126                         /* just a hot-add of a new device, leave raid_disk at -1 */
1127                         return 0;
1128         }
1129 
1130         if (mddev->level != LEVEL_MULTIPATH) {
1131                 desc = sb->disks + rdev->desc_nr;
1132 
1133                 if (desc->state & (1<<MD_DISK_FAULTY))
1134                         set_bit(Faulty, &rdev->flags);
1135                 else if (desc->state & (1<<MD_DISK_SYNC) /* &&
1136                             desc->raid_disk < mddev->raid_disks */) {
1137                         set_bit(In_sync, &rdev->flags);
1138                         rdev->raid_disk = desc->raid_disk;
1139                         rdev->saved_raid_disk = desc->raid_disk;
1140                 } else if (desc->state & (1<<MD_DISK_ACTIVE)) {
1141                         /* active but not in sync implies recovery up to
1142                          * reshape position.  We don't know exactly where
1143                          * that is, so set to zero for now */
1144                         if (mddev->minor_version >= 91) {
1145                                 rdev->recovery_offset = 0;
1146                                 rdev->raid_disk = desc->raid_disk;
1147                         }
1148                 }
1149                 if (desc->state & (1<<MD_DISK_WRITEMOSTLY))
1150                         set_bit(WriteMostly, &rdev->flags);
1151         } else /* MULTIPATH are always insync */
1152                 set_bit(In_sync, &rdev->flags);
1153         return 0;
1154 }
1155 
1156 /*
1157  * sync_super for 0.90.0
1158  */
1159 static void super_90_sync(struct mddev *mddev, struct md_rdev *rdev)
1160 {
1161         mdp_super_t *sb;
1162         struct md_rdev *rdev2;
1163         int next_spare = mddev->raid_disks;
1164 
1165         /* make rdev->sb match mddev data..
1166          *
1167          * 1/ zero out disks
1168          * 2/ Add info for each disk, keeping track of highest desc_nr (next_spare);
1169          * 3/ any empty disks < next_spare become removed
1170          *
1171          * disks[0] gets initialised to REMOVED because
1172          * we cannot be sure from other fields if it has
1173          * been initialised or not.
1174          */
1175         int i;
1176         int active=0, working=0,failed=0,spare=0,nr_disks=0;
1177 
1178         rdev->sb_size = MD_SB_BYTES;
1179 
1180         sb = page_address(rdev->sb_page);
1181 
1182         memset(sb, 0, sizeof(*sb));
1183 
1184         sb->md_magic = MD_SB_MAGIC;
1185         sb->major_version = mddev->major_version;
1186         sb->patch_version = mddev->patch_version;
1187         sb->gvalid_words  = 0; /* ignored */
1188         memcpy(&sb->set_uuid0, mddev->uuid+0, 4);
1189         memcpy(&sb->set_uuid1, mddev->uuid+4, 4);
1190         memcpy(&sb->set_uuid2, mddev->uuid+8, 4);
1191         memcpy(&sb->set_uuid3, mddev->uuid+12,4);
1192 
1193         sb->ctime = clamp_t(time64_t, mddev->ctime, 0, U32_MAX);
1194         sb->level = mddev->level;
1195         sb->size = mddev->dev_sectors / 2;
1196         sb->raid_disks = mddev->raid_disks;
1197         sb->md_minor = mddev->md_minor;
1198         sb->not_persistent = 0;
1199         sb->utime = clamp_t(time64_t, mddev->utime, 0, U32_MAX);
1200         sb->state = 0;
1201         sb->events_hi = (mddev->events>>32);
1202         sb->events_lo = (u32)mddev->events;
1203 
1204         if (mddev->reshape_position == MaxSector)
1205                 sb->minor_version = 90;
1206         else {
1207                 sb->minor_version = 91;
1208                 sb->reshape_position = mddev->reshape_position;
1209                 sb->new_level = mddev->new_level;
1210                 sb->delta_disks = mddev->delta_disks;
1211                 sb->new_layout = mddev->new_layout;
1212                 sb->new_chunk = mddev->new_chunk_sectors << 9;
1213         }
1214         mddev->minor_version = sb->minor_version;
1215         if (mddev->in_sync)
1216         {
1217                 sb->recovery_cp = mddev->recovery_cp;
1218                 sb->cp_events_hi = (mddev->events>>32);
1219                 sb->cp_events_lo = (u32)mddev->events;
1220                 if (mddev->recovery_cp == MaxSector)
1221                         sb->state = (1<< MD_SB_CLEAN);
1222         } else
1223                 sb->recovery_cp = 0;
1224 
1225         sb->layout = mddev->layout;
1226         sb->chunk_size = mddev->chunk_sectors << 9;
1227 
1228         if (mddev->bitmap && mddev->bitmap_info.file == NULL)
1229                 sb->state |= (1<<MD_SB_BITMAP_PRESENT);
1230 
1231         sb->disks[0].state = (1<<MD_DISK_REMOVED);
1232         rdev_for_each(rdev2, mddev) {
1233                 mdp_disk_t *d;
1234                 int desc_nr;
1235                 int is_active = test_bit(In_sync, &rdev2->flags);
1236 
1237                 if (rdev2->raid_disk >= 0 &&
1238                     sb->minor_version >= 91)
1239                         /* we have nowhere to store the recovery_offset,
1240                          * but if it is not below the reshape_position,
1241                          * we can piggy-back on that.
1242                          */
1243                         is_active = 1;
1244                 if (rdev2->raid_disk < 0 ||
1245                     test_bit(Faulty, &rdev2->flags))
1246                         is_active = 0;
1247                 if (is_active)
1248                         desc_nr = rdev2->raid_disk;
1249                 else
1250                         desc_nr = next_spare++;
1251                 rdev2->desc_nr = desc_nr;
1252                 d = &sb->disks[rdev2->desc_nr];
1253                 nr_disks++;
1254                 d->number = rdev2->desc_nr;
1255                 d->major = MAJOR(rdev2->bdev->bd_dev);
1256                 d->minor = MINOR(rdev2->bdev->bd_dev);
1257                 if (is_active)
1258                         d->raid_disk = rdev2->raid_disk;
1259                 else
1260                         d->raid_disk = rdev2->desc_nr; /* compatibility */
1261                 if (test_bit(Faulty, &rdev2->flags))
1262                         d->state = (1<<MD_DISK_FAULTY);
1263                 else if (is_active) {
1264                         d->state = (1<<MD_DISK_ACTIVE);
1265                         if (test_bit(In_sync, &rdev2->flags))
1266                                 d->state |= (1<<MD_DISK_SYNC);
1267                         active++;
1268                         working++;
1269                 } else {
1270                         d->state = 0;
1271                         spare++;
1272                         working++;
1273                 }
1274                 if (test_bit(WriteMostly, &rdev2->flags))
1275                         d->state |= (1<<MD_DISK_WRITEMOSTLY);
1276         }
1277         /* now set the "removed" and "faulty" bits on any missing devices */
1278         for (i=0 ; i < mddev->raid_disks ; i++) {
1279                 mdp_disk_t *d = &sb->disks[i];
1280                 if (d->state == 0 && d->number == 0) {
1281                         d->number = i;
1282                         d->raid_disk = i;
1283                         d->state = (1<<MD_DISK_REMOVED);
1284                         d->state |= (1<<MD_DISK_FAULTY);
1285                         failed++;
1286                 }
1287         }
1288         sb->nr_disks = nr_disks;
1289         sb->active_disks = active;
1290         sb->working_disks = working;
1291         sb->failed_disks = failed;
1292         sb->spare_disks = spare;
1293 
1294         sb->this_disk = sb->disks[rdev->desc_nr];
1295         sb->sb_csum = calc_sb_csum(sb);
1296 }
1297 
1298 /*
1299  * rdev_size_change for 0.90.0
1300  */
1301 static unsigned long long
1302 super_90_rdev_size_change(struct md_rdev *rdev, sector_t num_sectors)
1303 {
1304         if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
1305                 return 0; /* component must fit device */
1306         if (rdev->mddev->bitmap_info.offset)
1307                 return 0; /* can't move bitmap */
1308         rdev->sb_start = calc_dev_sboffset(rdev);
1309         if (!num_sectors || num_sectors > rdev->sb_start)
1310                 num_sectors = rdev->sb_start;
1311         /* Limit to 4TB as metadata cannot record more than that.
1312          * 4TB == 2^32 KB, or 2*2^32 sectors.
1313          */
1314         if (IS_ENABLED(CONFIG_LBDAF) && (u64)num_sectors >= (2ULL << 32) &&
1315             rdev->mddev->level >= 1)
1316                 num_sectors = (sector_t)(2ULL << 32) - 2;
1317         md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
1318                        rdev->sb_page);
1319         md_super_wait(rdev->mddev);
1320         return num_sectors;
1321 }
1322 
1323 static int
1324 super_90_allow_new_offset(struct md_rdev *rdev, unsigned long long new_offset)
1325 {
1326         /* non-zero offset changes not possible with v0.90 */
1327         return new_offset == 0;
1328 }
1329 
1330 /*
1331  * version 1 superblock
1332  */
1333 
1334 static __le32 calc_sb_1_csum(struct mdp_superblock_1 *sb)
1335 {
1336         __le32 disk_csum;
1337         u32 csum;
1338         unsigned long long newcsum;
1339         int size = 256 + le32_to_cpu(sb->max_dev)*2;
1340         __le32 *isuper = (__le32*)sb;
1341 
1342         disk_csum = sb->sb_csum;
1343         sb->sb_csum = 0;
1344         newcsum = 0;
1345         for (; size >= 4; size -= 4)
1346                 newcsum += le32_to_cpu(*isuper++);
1347 
1348         if (size == 2)
1349                 newcsum += le16_to_cpu(*(__le16*) isuper);
1350 
1351         csum = (newcsum & 0xffffffff) + (newcsum >> 32);
1352         sb->sb_csum = disk_csum;
1353         return cpu_to_le32(csum);
1354 }
1355 
1356 static int super_1_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor_version)
1357 {
1358         struct mdp_superblock_1 *sb;
1359         int ret;
1360         sector_t sb_start;
1361         sector_t sectors;
1362         char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
1363         int bmask;
1364 
1365         /*
1366          * Calculate the position of the superblock in 512byte sectors.
1367          * It is always aligned to a 4K boundary and
1368          * depeding on minor_version, it can be:
1369          * 0: At least 8K, but less than 12K, from end of device
1370          * 1: At start of device
1371          * 2: 4K from start of device.
1372          */
1373         switch(minor_version) {
1374         case 0:
1375                 sb_start = i_size_read(rdev->bdev->bd_inode) >> 9;
1376                 sb_start -= 8*2;
1377                 sb_start &= ~(sector_t)(4*2-1);
1378                 break;
1379         case 1:
1380                 sb_start = 0;
1381                 break;
1382         case 2:
1383                 sb_start = 8;
1384                 break;
1385         default:
1386                 return -EINVAL;
1387         }
1388         rdev->sb_start = sb_start;
1389 
1390         /* superblock is rarely larger than 1K, but it can be larger,
1391          * and it is safe to read 4k, so we do that
1392          */
1393         ret = read_disk_sb(rdev, 4096);
1394         if (ret) return ret;
1395 
1396         sb = page_address(rdev->sb_page);
1397 
1398         if (sb->magic != cpu_to_le32(MD_SB_MAGIC) ||
1399             sb->major_version != cpu_to_le32(1) ||
1400             le32_to_cpu(sb->max_dev) > (4096-256)/2 ||
1401             le64_to_cpu(sb->super_offset) != rdev->sb_start ||
1402             (le32_to_cpu(sb->feature_map) & ~MD_FEATURE_ALL) != 0)
1403                 return -EINVAL;
1404 
1405         if (calc_sb_1_csum(sb) != sb->sb_csum) {
1406                 printk("md: invalid superblock checksum on %s\n",
1407                         bdevname(rdev->bdev,b));
1408                 return -EINVAL;
1409         }
1410         if (le64_to_cpu(sb->data_size) < 10) {
1411                 printk("md: data_size too small on %s\n",
1412                        bdevname(rdev->bdev,b));
1413                 return -EINVAL;
1414         }
1415         if (sb->pad0 ||
1416             sb->pad3[0] ||
1417             memcmp(sb->pad3, sb->pad3+1, sizeof(sb->pad3) - sizeof(sb->pad3[1])))
1418                 /* Some padding is non-zero, might be a new feature */
1419                 return -EINVAL;
1420 
1421         rdev->preferred_minor = 0xffff;
1422         rdev->data_offset = le64_to_cpu(sb->data_offset);
1423         rdev->new_data_offset = rdev->data_offset;
1424         if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE) &&
1425             (le32_to_cpu(sb->feature_map) & MD_FEATURE_NEW_OFFSET))
1426                 rdev->new_data_offset += (s32)le32_to_cpu(sb->new_offset);
1427         atomic_set(&rdev->corrected_errors, le32_to_cpu(sb->cnt_corrected_read));
1428 
1429         rdev->sb_size = le32_to_cpu(sb->max_dev) * 2 + 256;
1430         bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
1431         if (rdev->sb_size & bmask)
1432                 rdev->sb_size = (rdev->sb_size | bmask) + 1;
1433 
1434         if (minor_version
1435             && rdev->data_offset < sb_start + (rdev->sb_size/512))
1436                 return -EINVAL;
1437         if (minor_version
1438             && rdev->new_data_offset < sb_start + (rdev->sb_size/512))
1439                 return -EINVAL;
1440 
1441         if (sb->level == cpu_to_le32(LEVEL_MULTIPATH))
1442                 rdev->desc_nr = -1;
1443         else
1444                 rdev->desc_nr = le32_to_cpu(sb->dev_number);
1445 
1446         if (!rdev->bb_page) {
1447                 rdev->bb_page = alloc_page(GFP_KERNEL);
1448                 if (!rdev->bb_page)
1449                         return -ENOMEM;
1450         }
1451         if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BAD_BLOCKS) &&
1452             rdev->badblocks.count == 0) {
1453                 /* need to load the bad block list.
1454                  * Currently we limit it to one page.
1455                  */
1456                 s32 offset;
1457                 sector_t bb_sector;
1458                 u64 *bbp;
1459                 int i;
1460                 int sectors = le16_to_cpu(sb->bblog_size);
1461                 if (sectors > (PAGE_SIZE / 512))
1462                         return -EINVAL;
1463                 offset = le32_to_cpu(sb->bblog_offset);
1464                 if (offset == 0)
1465                         return -EINVAL;
1466                 bb_sector = (long long)offset;
1467                 if (!sync_page_io(rdev, bb_sector, sectors << 9,
1468                                   rdev->bb_page, READ, true))
1469                         return -EIO;
1470                 bbp = (u64 *)page_address(rdev->bb_page);
1471                 rdev->badblocks.shift = sb->bblog_shift;
1472                 for (i = 0 ; i < (sectors << (9-3)) ; i++, bbp++) {
1473                         u64 bb = le64_to_cpu(*bbp);
1474                         int count = bb & (0x3ff);
1475                         u64 sector = bb >> 10;
1476                         sector <<= sb->bblog_shift;
1477                         count <<= sb->bblog_shift;
1478                         if (bb + 1 == 0)
1479                                 break;
1480                         if (badblocks_set(&rdev->badblocks, sector, count, 1))
1481                                 return -EINVAL;
1482                 }
1483         } else if (sb->bblog_offset != 0)
1484                 rdev->badblocks.shift = 0;
1485 
1486         if (!refdev) {
1487                 ret = 1;
1488         } else {
1489                 __u64 ev1, ev2;
1490                 struct mdp_superblock_1 *refsb = page_address(refdev->sb_page);
1491 
1492                 if (memcmp(sb->set_uuid, refsb->set_uuid, 16) != 0 ||
1493                     sb->level != refsb->level ||
1494                     sb->layout != refsb->layout ||
1495                     sb->chunksize != refsb->chunksize) {
1496                         printk(KERN_WARNING "md: %s has strangely different"
1497                                 " superblock to %s\n",
1498                                 bdevname(rdev->bdev,b),
1499                                 bdevname(refdev->bdev,b2));
1500                         return -EINVAL;
1501                 }
1502                 ev1 = le64_to_cpu(sb->events);
1503                 ev2 = le64_to_cpu(refsb->events);
1504 
1505                 if (ev1 > ev2)
1506                         ret = 1;
1507                 else
1508                         ret = 0;
1509         }
1510         if (minor_version) {
1511                 sectors = (i_size_read(rdev->bdev->bd_inode) >> 9);
1512                 sectors -= rdev->data_offset;
1513         } else
1514                 sectors = rdev->sb_start;
1515         if (sectors < le64_to_cpu(sb->data_size))
1516                 return -EINVAL;
1517         rdev->sectors = le64_to_cpu(sb->data_size);
1518         return ret;
1519 }
1520 
1521 static int super_1_validate(struct mddev *mddev, struct md_rdev *rdev)
1522 {
1523         struct mdp_superblock_1 *sb = page_address(rdev->sb_page);
1524         __u64 ev1 = le64_to_cpu(sb->events);
1525 
1526         rdev->raid_disk = -1;
1527         clear_bit(Faulty, &rdev->flags);
1528         clear_bit(In_sync, &rdev->flags);
1529         clear_bit(Bitmap_sync, &rdev->flags);
1530         clear_bit(WriteMostly, &rdev->flags);
1531 
1532         if (mddev->raid_disks == 0) {
1533                 mddev->major_version = 1;
1534                 mddev->patch_version = 0;
1535                 mddev->external = 0;
1536                 mddev->chunk_sectors = le32_to_cpu(sb->chunksize);
1537                 mddev->ctime = le64_to_cpu(sb->ctime);
1538                 mddev->utime = le64_to_cpu(sb->utime);
1539                 mddev->level = le32_to_cpu(sb->level);
1540                 mddev->clevel[0] = 0;
1541                 mddev->layout = le32_to_cpu(sb->layout);
1542                 mddev->raid_disks = le32_to_cpu(sb->raid_disks);
1543                 mddev->dev_sectors = le64_to_cpu(sb->size);
1544                 mddev->events = ev1;
1545                 mddev->bitmap_info.offset = 0;
1546                 mddev->bitmap_info.space = 0;
1547                 /* Default location for bitmap is 1K after superblock
1548                  * using 3K - total of 4K
1549                  */
1550                 mddev->bitmap_info.default_offset = 1024 >> 9;
1551                 mddev->bitmap_info.default_space = (4096-1024) >> 9;
1552                 mddev->reshape_backwards = 0;
1553 
1554                 mddev->recovery_cp = le64_to_cpu(sb->resync_offset);
1555                 memcpy(mddev->uuid, sb->set_uuid, 16);
1556 
1557                 mddev->max_disks =  (4096-256)/2;
1558 
1559                 if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BITMAP_OFFSET) &&
1560                     mddev->bitmap_info.file == NULL) {
1561                         mddev->bitmap_info.offset =
1562                                 (__s32)le32_to_cpu(sb->bitmap_offset);
1563                         /* Metadata doesn't record how much space is available.
1564                          * For 1.0, we assume we can use up to the superblock
1565                          * if before, else to 4K beyond superblock.
1566                          * For others, assume no change is possible.
1567                          */
1568                         if (mddev->minor_version > 0)
1569                                 mddev->bitmap_info.space = 0;
1570                         else if (mddev->bitmap_info.offset > 0)
1571                                 mddev->bitmap_info.space =
1572                                         8 - mddev->bitmap_info.offset;
1573                         else
1574                                 mddev->bitmap_info.space =
1575                                         -mddev->bitmap_info.offset;
1576                 }
1577 
1578                 if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE)) {
1579                         mddev->reshape_position = le64_to_cpu(sb->reshape_position);
1580                         mddev->delta_disks = le32_to_cpu(sb->delta_disks);
1581                         mddev->new_level = le32_to_cpu(sb->new_level);
1582                         mddev->new_layout = le32_to_cpu(sb->new_layout);
1583                         mddev->new_chunk_sectors = le32_to_cpu(sb->new_chunk);
1584                         if (mddev->delta_disks < 0 ||
1585                             (mddev->delta_disks == 0 &&
1586                              (le32_to_cpu(sb->feature_map)
1587                               & MD_FEATURE_RESHAPE_BACKWARDS)))
1588                                 mddev->reshape_backwards = 1;
1589                 } else {
1590                         mddev->reshape_position = MaxSector;
1591                         mddev->delta_disks = 0;
1592                         mddev->new_level = mddev->level;
1593                         mddev->new_layout = mddev->layout;
1594                         mddev->new_chunk_sectors = mddev->chunk_sectors;
1595                 }
1596 
1597                 if (le32_to_cpu(sb->feature_map) & MD_FEATURE_JOURNAL) {
1598                         set_bit(MD_HAS_JOURNAL, &mddev->flags);
1599                         if (mddev->recovery_cp == MaxSector)
1600                                 set_bit(MD_JOURNAL_CLEAN, &mddev->flags);
1601                 }
1602         } else if (mddev->pers == NULL) {
1603                 /* Insist of good event counter while assembling, except for
1604                  * spares (which don't need an event count) */
1605                 ++ev1;
1606                 if (rdev->desc_nr >= 0 &&
1607                     rdev->desc_nr < le32_to_cpu(sb->max_dev) &&
1608                     (le16_to_cpu(sb->dev_roles[rdev->desc_nr]) < MD_DISK_ROLE_MAX ||
1609                      le16_to_cpu(sb->dev_roles[rdev->desc_nr]) == MD_DISK_ROLE_JOURNAL))
1610                         if (ev1 < mddev->events)
1611                                 return -EINVAL;
1612         } else if (mddev->bitmap) {
1613                 /* If adding to array with a bitmap, then we can accept an
1614                  * older device, but not too old.
1615                  */
1616                 if (ev1 < mddev->bitmap->events_cleared)
1617                         return 0;
1618                 if (ev1 < mddev->events)
1619                         set_bit(Bitmap_sync, &rdev->flags);
1620         } else {
1621                 if (ev1 < mddev->events)
1622                         /* just a hot-add of a new device, leave raid_disk at -1 */
1623                         return 0;
1624         }
1625         if (mddev->level != LEVEL_MULTIPATH) {
1626                 int role;
1627                 if (rdev->desc_nr < 0 ||
1628                     rdev->desc_nr >= le32_to_cpu(sb->max_dev)) {
1629                         role = MD_DISK_ROLE_SPARE;
1630                         rdev->desc_nr = -1;
1631                 } else
1632                         role = le16_to_cpu(sb->dev_roles[rdev->desc_nr]);
1633                 switch(role) {
1634                 case MD_DISK_ROLE_SPARE: /* spare */
1635                         break;
1636                 case MD_DISK_ROLE_FAULTY: /* faulty */
1637                         set_bit(Faulty, &rdev->flags);
1638                         break;
1639                 case MD_DISK_ROLE_JOURNAL: /* journal device */
1640                         if (!(le32_to_cpu(sb->feature_map) & MD_FEATURE_JOURNAL)) {
1641                                 /* journal device without journal feature */
1642                                 printk(KERN_WARNING
1643                                   "md: journal device provided without journal feature, ignoring the device\n");
1644                                 return -EINVAL;
1645                         }
1646                         set_bit(Journal, &rdev->flags);
1647                         rdev->journal_tail = le64_to_cpu(sb->journal_tail);
1648                         rdev->raid_disk = 0;
1649                         break;
1650                 default:
1651                         rdev->saved_raid_disk = role;
1652                         if ((le32_to_cpu(sb->feature_map) &
1653                              MD_FEATURE_RECOVERY_OFFSET)) {
1654                                 rdev->recovery_offset = le64_to_cpu(sb->recovery_offset);
1655                                 if (!(le32_to_cpu(sb->feature_map) &
1656                                       MD_FEATURE_RECOVERY_BITMAP))
1657                                         rdev->saved_raid_disk = -1;
1658                         } else
1659                                 set_bit(In_sync, &rdev->flags);
1660                         rdev->raid_disk = role;
1661                         break;
1662                 }
1663                 if (sb->devflags & WriteMostly1)
1664                         set_bit(WriteMostly, &rdev->flags);
1665                 if (le32_to_cpu(sb->feature_map) & MD_FEATURE_REPLACEMENT)
1666                         set_bit(Replacement, &rdev->flags);
1667         } else /* MULTIPATH are always insync */
1668                 set_bit(In_sync, &rdev->flags);
1669 
1670         return 0;
1671 }
1672 
1673 static void super_1_sync(struct mddev *mddev, struct md_rdev *rdev)
1674 {
1675         struct mdp_superblock_1 *sb;
1676         struct md_rdev *rdev2;
1677         int max_dev, i;
1678         /* make rdev->sb match mddev and rdev data. */
1679 
1680         sb = page_address(rdev->sb_page);
1681 
1682         sb->feature_map = 0;
1683         sb->pad0 = 0;
1684         sb->recovery_offset = cpu_to_le64(0);
1685         memset(sb->pad3, 0, sizeof(sb->pad3));
1686 
1687         sb->utime = cpu_to_le64((__u64)mddev->utime);
1688         sb->events = cpu_to_le64(mddev->events);
1689         if (mddev->in_sync)
1690                 sb->resync_offset = cpu_to_le64(mddev->recovery_cp);
1691         else if (test_bit(MD_JOURNAL_CLEAN, &mddev->flags))
1692                 sb->resync_offset = cpu_to_le64(MaxSector);
1693         else
1694                 sb->resync_offset = cpu_to_le64(0);
1695 
1696         sb->cnt_corrected_read = cpu_to_le32(atomic_read(&rdev->corrected_errors));
1697 
1698         sb->raid_disks = cpu_to_le32(mddev->raid_disks);
1699         sb->size = cpu_to_le64(mddev->dev_sectors);
1700         sb->chunksize = cpu_to_le32(mddev->chunk_sectors);
1701         sb->level = cpu_to_le32(mddev->level);
1702         sb->layout = cpu_to_le32(mddev->layout);
1703 
1704         if (test_bit(WriteMostly, &rdev->flags))
1705                 sb->devflags |= WriteMostly1;
1706         else
1707                 sb->devflags &= ~WriteMostly1;
1708         sb->data_offset = cpu_to_le64(rdev->data_offset);
1709         sb->data_size = cpu_to_le64(rdev->sectors);
1710 
1711         if (mddev->bitmap && mddev->bitmap_info.file == NULL) {
1712                 sb->bitmap_offset = cpu_to_le32((__u32)mddev->bitmap_info.offset);
1713                 sb->feature_map = cpu_to_le32(MD_FEATURE_BITMAP_OFFSET);
1714         }
1715 
1716         if (rdev->raid_disk >= 0 && !test_bit(Journal, &rdev->flags) &&
1717             !test_bit(In_sync, &rdev->flags)) {
1718                 sb->feature_map |=
1719                         cpu_to_le32(MD_FEATURE_RECOVERY_OFFSET);
1720                 sb->recovery_offset =
1721                         cpu_to_le64(rdev->recovery_offset);
1722                 if (rdev->saved_raid_disk >= 0 && mddev->bitmap)
1723                         sb->feature_map |=
1724                                 cpu_to_le32(MD_FEATURE_RECOVERY_BITMAP);
1725         }
1726         /* Note: recovery_offset and journal_tail share space  */
1727         if (test_bit(Journal, &rdev->flags))
1728                 sb->journal_tail = cpu_to_le64(rdev->journal_tail);
1729         if (test_bit(Replacement, &rdev->flags))
1730                 sb->feature_map |=
1731                         cpu_to_le32(MD_FEATURE_REPLACEMENT);
1732 
1733         if (mddev->reshape_position != MaxSector) {
1734                 sb->feature_map |= cpu_to_le32(MD_FEATURE_RESHAPE_ACTIVE);
1735                 sb->reshape_position = cpu_to_le64(mddev->reshape_position);
1736                 sb->new_layout = cpu_to_le32(mddev->new_layout);
1737                 sb->delta_disks = cpu_to_le32(mddev->delta_disks);
1738                 sb->new_level = cpu_to_le32(mddev->new_level);
1739                 sb->new_chunk = cpu_to_le32(mddev->new_chunk_sectors);
1740                 if (mddev->delta_disks == 0 &&
1741                     mddev->reshape_backwards)
1742                         sb->feature_map
1743                                 |= cpu_to_le32(MD_FEATURE_RESHAPE_BACKWARDS);
1744                 if (rdev->new_data_offset != rdev->data_offset) {
1745                         sb->feature_map
1746                                 |= cpu_to_le32(MD_FEATURE_NEW_OFFSET);
1747                         sb->new_offset = cpu_to_le32((__u32)(rdev->new_data_offset
1748                                                              - rdev->data_offset));
1749                 }
1750         }
1751 
1752         if (mddev_is_clustered(mddev))
1753                 sb->feature_map |= cpu_to_le32(MD_FEATURE_CLUSTERED);
1754 
1755         if (rdev->badblocks.count == 0)
1756                 /* Nothing to do for bad blocks*/ ;
1757         else if (sb->bblog_offset == 0)
1758                 /* Cannot record bad blocks on this device */
1759                 md_error(mddev, rdev);
1760         else {
1761                 struct badblocks *bb = &rdev->badblocks;
1762                 u64 *bbp = (u64 *)page_address(rdev->bb_page);
1763                 u64 *p = bb->page;
1764                 sb->feature_map |= cpu_to_le32(MD_FEATURE_BAD_BLOCKS);
1765                 if (bb->changed) {
1766                         unsigned seq;
1767 
1768 retry:
1769                         seq = read_seqbegin(&bb->lock);
1770 
1771                         memset(bbp, 0xff, PAGE_SIZE);
1772 
1773                         for (i = 0 ; i < bb->count ; i++) {
1774                                 u64 internal_bb = p[i];
1775                                 u64 store_bb = ((BB_OFFSET(internal_bb) << 10)
1776                                                 | BB_LEN(internal_bb));
1777                                 bbp[i] = cpu_to_le64(store_bb);
1778                         }
1779                         bb->changed = 0;
1780                         if (read_seqretry(&bb->lock, seq))
1781                                 goto retry;
1782 
1783                         bb->sector = (rdev->sb_start +
1784                                       (int)le32_to_cpu(sb->bblog_offset));
1785                         bb->size = le16_to_cpu(sb->bblog_size);
1786                 }
1787         }
1788 
1789         max_dev = 0;
1790         rdev_for_each(rdev2, mddev)
1791                 if (rdev2->desc_nr+1 > max_dev)
1792                         max_dev = rdev2->desc_nr+1;
1793 
1794         if (max_dev > le32_to_cpu(sb->max_dev)) {
1795                 int bmask;
1796                 sb->max_dev = cpu_to_le32(max_dev);
1797                 rdev->sb_size = max_dev * 2 + 256;
1798                 bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
1799                 if (rdev->sb_size & bmask)
1800                         rdev->sb_size = (rdev->sb_size | bmask) + 1;
1801         } else
1802                 max_dev = le32_to_cpu(sb->max_dev);
1803 
1804         for (i=0; i<max_dev;i++)
1805                 sb->dev_roles[i] = cpu_to_le16(MD_DISK_ROLE_FAULTY);
1806 
1807         if (test_bit(MD_HAS_JOURNAL, &mddev->flags))
1808                 sb->feature_map |= cpu_to_le32(MD_FEATURE_JOURNAL);
1809 
1810         rdev_for_each(rdev2, mddev) {
1811                 i = rdev2->desc_nr;
1812                 if (test_bit(Faulty, &rdev2->flags))
1813                         sb->dev_roles[i] = cpu_to_le16(MD_DISK_ROLE_FAULTY);
1814                 else if (test_bit(In_sync, &rdev2->flags))
1815                         sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1816                 else if (test_bit(Journal, &rdev2->flags))
1817                         sb->dev_roles[i] = cpu_to_le16(MD_DISK_ROLE_JOURNAL);
1818                 else if (rdev2->raid_disk >= 0)
1819                         sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
1820                 else
1821                         sb->dev_roles[i] = cpu_to_le16(MD_DISK_ROLE_SPARE);
1822         }
1823 
1824         sb->sb_csum = calc_sb_1_csum(sb);
1825 }
1826 
1827 static unsigned long long
1828 super_1_rdev_size_change(struct md_rdev *rdev, sector_t num_sectors)
1829 {
1830         struct mdp_superblock_1 *sb;
1831         sector_t max_sectors;
1832         if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
1833                 return 0; /* component must fit device */
1834         if (rdev->data_offset != rdev->new_data_offset)
1835                 return 0; /* too confusing */
1836         if (rdev->sb_start < rdev->data_offset) {
1837                 /* minor versions 1 and 2; superblock before data */
1838                 max_sectors = i_size_read(rdev->bdev->bd_inode) >> 9;
1839                 max_sectors -= rdev->data_offset;
1840                 if (!num_sectors || num_sectors > max_sectors)
1841                         num_sectors = max_sectors;
1842         } else if (rdev->mddev->bitmap_info.offset) {
1843                 /* minor version 0 with bitmap we can't move */
1844                 return 0;
1845         } else {
1846                 /* minor version 0; superblock after data */
1847                 sector_t sb_start;
1848                 sb_start = (i_size_read(rdev->bdev->bd_inode) >> 9) - 8*2;
1849                 sb_start &= ~(sector_t)(4*2 - 1);
1850                 max_sectors = rdev->sectors + sb_start - rdev->sb_start;
1851                 if (!num_sectors || num_sectors > max_sectors)
1852                         num_sectors = max_sectors;
1853                 rdev->sb_start = sb_start;
1854         }
1855         sb = page_address(rdev->sb_page);
1856         sb->data_size = cpu_to_le64(num_sectors);
1857         sb->super_offset = rdev->sb_start;
1858         sb->sb_csum = calc_sb_1_csum(sb);
1859         md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
1860                        rdev->sb_page);
1861         md_super_wait(rdev->mddev);
1862         return num_sectors;
1863 
1864 }
1865 
1866 static int
1867 super_1_allow_new_offset(struct md_rdev *rdev,
1868                          unsigned long long new_offset)
1869 {
1870         /* All necessary checks on new >= old have been done */
1871         struct bitmap *bitmap;
1872         if (new_offset >= rdev->data_offset)
1873                 return 1;
1874 
1875         /* with 1.0 metadata, there is no metadata to tread on
1876          * so we can always move back */
1877         if (rdev->mddev->minor_version == 0)
1878                 return 1;
1879 
1880         /* otherwise we must be sure not to step on
1881          * any metadata, so stay:
1882          * 36K beyond start of superblock
1883          * beyond end of badblocks
1884          * beyond write-intent bitmap
1885          */
1886         if (rdev->sb_start + (32+4)*2 > new_offset)
1887                 return 0;
1888         bitmap = rdev->mddev->bitmap;
1889         if (bitmap && !rdev->mddev->bitmap_info.file &&
1890             rdev->sb_start + rdev->mddev->bitmap_info.offset +
1891             bitmap->storage.file_pages * (PAGE_SIZE>>9) > new_offset)
1892                 return 0;
1893         if (rdev->badblocks.sector + rdev->badblocks.size > new_offset)
1894                 return 0;
1895 
1896         return 1;
1897 }
1898 
1899 static struct super_type super_types[] = {
1900         [0] = {
1901                 .name   = "0.90.0",
1902                 .owner  = THIS_MODULE,
1903                 .load_super         = super_90_load,
1904                 .validate_super     = super_90_validate,
1905                 .sync_super         = super_90_sync,
1906                 .rdev_size_change   = super_90_rdev_size_change,
1907                 .allow_new_offset   = super_90_allow_new_offset,
1908         },
1909         [1] = {
1910                 .name   = "md-1",
1911                 .owner  = THIS_MODULE,
1912                 .load_super         = super_1_load,
1913                 .validate_super     = super_1_validate,
1914                 .sync_super         = super_1_sync,
1915                 .rdev_size_change   = super_1_rdev_size_change,
1916                 .allow_new_offset   = super_1_allow_new_offset,
1917         },
1918 };
1919 
1920 static void sync_super(struct mddev *mddev, struct md_rdev *rdev)
1921 {
1922         if (mddev->sync_super) {
1923                 mddev->sync_super(mddev, rdev);
1924                 return;
1925         }
1926 
1927         BUG_ON(mddev->major_version >= ARRAY_SIZE(super_types));
1928 
1929         super_types[mddev->major_version].sync_super(mddev, rdev);
1930 }
1931 
1932 static int match_mddev_units(struct mddev *mddev1, struct mddev *mddev2)
1933 {
1934         struct md_rdev *rdev, *rdev2;
1935 
1936         rcu_read_lock();
1937         rdev_for_each_rcu(rdev, mddev1) {
1938                 if (test_bit(Faulty, &rdev->flags) ||
1939                     test_bit(Journal, &rdev->flags) ||
1940                     rdev->raid_disk == -1)
1941                         continue;
1942                 rdev_for_each_rcu(rdev2, mddev2) {
1943                         if (test_bit(Faulty, &rdev2->flags) ||
1944                             test_bit(Journal, &rdev2->flags) ||
1945                             rdev2->raid_disk == -1)
1946                                 continue;
1947                         if (rdev->bdev->bd_contains ==
1948                             rdev2->bdev->bd_contains) {
1949                                 rcu_read_unlock();
1950                                 return 1;
1951                         }
1952                 }
1953         }
1954         rcu_read_unlock();
1955         return 0;
1956 }
1957 
1958 static LIST_HEAD(pending_raid_disks);
1959 
1960 /*
1961  * Try to register data integrity profile for an mddev
1962  *
1963  * This is called when an array is started and after a disk has been kicked
1964  * from the array. It only succeeds if all working and active component devices
1965  * are integrity capable with matching profiles.
1966  */
1967 int md_integrity_register(struct mddev *mddev)
1968 {
1969         struct md_rdev *rdev, *reference = NULL;
1970 
1971         if (list_empty(&mddev->disks))
1972                 return 0; /* nothing to do */
1973         if (!mddev->gendisk || blk_get_integrity(mddev->gendisk))
1974                 return 0; /* shouldn't register, or already is */
1975         rdev_for_each(rdev, mddev) {
1976                 /* skip spares and non-functional disks */
1977                 if (test_bit(Faulty, &rdev->flags))
1978                         continue;
1979                 if (rdev->raid_disk < 0)
1980                         continue;
1981                 if (!reference) {
1982                         /* Use the first rdev as the reference */
1983                         reference = rdev;
1984                         continue;
1985                 }
1986                 /* does this rdev's profile match the reference profile? */
1987                 if (blk_integrity_compare(reference->bdev->bd_disk,
1988                                 rdev->bdev->bd_disk) < 0)
1989                         return -EINVAL;
1990         }
1991         if (!reference || !bdev_get_integrity(reference->bdev))
1992                 return 0;
1993         /*
1994          * All component devices are integrity capable and have matching
1995          * profiles, register the common profile for the md device.
1996          */
1997         blk_integrity_register(mddev->gendisk,
1998                                bdev_get_integrity(reference->bdev));
1999 
2000         printk(KERN_NOTICE "md: data integrity enabled on %s\n", mdname(mddev));
2001         if (bioset_integrity_create(mddev->bio_set, BIO_POOL_SIZE)) {
2002                 printk(KERN_ERR "md: failed to create integrity pool for %s\n",
2003                        mdname(mddev));
2004                 return -EINVAL;
2005         }
2006         return 0;
2007 }
2008 EXPORT_SYMBOL(md_integrity_register);
2009 
2010 /*
2011  * Attempt to add an rdev, but only if it is consistent with the current
2012  * integrity profile
2013  */
2014 int md_integrity_add_rdev(struct md_rdev *rdev, struct mddev *mddev)
2015 {
2016         struct blk_integrity *bi_rdev;
2017         struct blk_integrity *bi_mddev;
2018         char name[BDEVNAME_SIZE];
2019 
2020         if (!mddev->gendisk)
2021                 return 0;
2022 
2023         bi_rdev = bdev_get_integrity(rdev->bdev);
2024         bi_mddev = blk_get_integrity(mddev->gendisk);
2025 
2026         if (!bi_mddev) /* nothing to do */
2027                 return 0;
2028 
2029         if (blk_integrity_compare(mddev->gendisk, rdev->bdev->bd_disk) != 0) {
2030                 printk(KERN_NOTICE "%s: incompatible integrity profile for %s\n",
2031                                 mdname(mddev), bdevname(rdev->bdev, name));
2032                 return -ENXIO;
2033         }
2034 
2035         return 0;
2036 }
2037 EXPORT_SYMBOL(md_integrity_add_rdev);
2038 
2039 static int bind_rdev_to_array(struct md_rdev *rdev, struct mddev *mddev)
2040 {
2041         char b[BDEVNAME_SIZE];
2042         struct kobject *ko;
2043         int err;
2044 
2045         /* prevent duplicates */
2046         if (find_rdev(mddev, rdev->bdev->bd_dev))
2047                 return -EEXIST;
2048 
2049         /* make sure rdev->sectors exceeds mddev->dev_sectors */
2050         if (!test_bit(Journal, &rdev->flags) &&
2051             rdev->sectors &&
2052             (mddev->dev_sectors == 0 || rdev->sectors < mddev->dev_sectors)) {
2053                 if (mddev->pers) {
2054                         /* Cannot change size, so fail
2055                          * If mddev->level <= 0, then we don't care
2056                          * about aligning sizes (e.g. linear)
2057                          */
2058                         if (mddev->level > 0)
2059                                 return -ENOSPC;
2060                 } else
2061                         mddev->dev_sectors = rdev->sectors;
2062         }
2063 
2064         /* Verify rdev->desc_nr is unique.
2065          * If it is -1, assign a free number, else
2066          * check number is not in use
2067          */
2068         rcu_read_lock();
2069         if (rdev->desc_nr < 0) {
2070                 int choice = 0;
2071                 if (mddev->pers)
2072                         choice = mddev->raid_disks;
2073                 while (md_find_rdev_nr_rcu(mddev, choice))
2074                         choice++;
2075                 rdev->desc_nr = choice;
2076         } else {
2077                 if (md_find_rdev_nr_rcu(mddev, rdev->desc_nr)) {
2078                         rcu_read_unlock();
2079                         return -EBUSY;
2080                 }
2081         }
2082         rcu_read_unlock();
2083         if (!test_bit(Journal, &rdev->flags) &&
2084             mddev->max_disks && rdev->desc_nr >= mddev->max_disks) {
2085                 printk(KERN_WARNING "md: %s: array is limited to %d devices\n",
2086                        mdname(mddev), mddev->max_disks);
2087                 return -EBUSY;
2088         }
2089         bdevname(rdev->bdev,b);
2090         strreplace(b, '/', '!');
2091 
2092         rdev->mddev = mddev;
2093         printk(KERN_INFO "md: bind<%s>\n", b);
2094 
2095         if ((err = kobject_add(&rdev->kobj, &mddev->kobj, "dev-%s", b)))
2096                 goto fail;
2097 
2098         ko = &part_to_dev(rdev->bdev->bd_part)->kobj;
2099         if (sysfs_create_link(&rdev->kobj, ko, "block"))
2100                 /* failure here is OK */;
2101         rdev->sysfs_state = sysfs_get_dirent_safe(rdev->kobj.sd, "state");
2102 
2103         list_add_rcu(&rdev->same_set, &mddev->disks);
2104         bd_link_disk_holder(rdev->bdev, mddev->gendisk);
2105 
2106         /* May as well allow recovery to be retried once */
2107         mddev->recovery_disabled++;
2108 
2109         return 0;
2110 
2111  fail:
2112         printk(KERN_WARNING "md: failed to register dev-%s for %s\n",
2113                b, mdname(mddev));
2114         return err;
2115 }
2116 
2117 static void md_delayed_delete(struct work_struct *ws)
2118 {
2119         struct md_rdev *rdev = container_of(ws, struct md_rdev, del_work);
2120         kobject_del(&rdev->kobj);
2121         kobject_put(&rdev->kobj);
2122 }
2123 
2124 static void unbind_rdev_from_array(struct md_rdev *rdev)
2125 {
2126         char b[BDEVNAME_SIZE];
2127 
2128         bd_unlink_disk_holder(rdev->bdev, rdev->mddev->gendisk);
2129         list_del_rcu(&rdev->same_set);
2130         printk(KERN_INFO "md: unbind<%s>\n", bdevname(rdev->bdev,b));
2131         rdev->mddev = NULL;
2132         sysfs_remove_link(&rdev->kobj, "block");
2133         sysfs_put(rdev->sysfs_state);
2134         rdev->sysfs_state = NULL;
2135         rdev->badblocks.count = 0;
2136         /* We need to delay this, otherwise we can deadlock when
2137          * writing to 'remove' to "dev/state".  We also need
2138          * to delay it due to rcu usage.
2139          */
2140         synchronize_rcu();
2141         INIT_WORK(&rdev->del_work, md_delayed_delete);
2142         kobject_get(&rdev->kobj);
2143         queue_work(md_misc_wq, &rdev->del_work);
2144 }
2145 
2146 /*
2147  * prevent the device from being mounted, repartitioned or
2148  * otherwise reused by a RAID array (or any other kernel
2149  * subsystem), by bd_claiming the device.
2150  */
2151 static int lock_rdev(struct md_rdev *rdev, dev_t dev, int shared)
2152 {
2153         int err = 0;
2154         struct block_device *bdev;
2155         char b[BDEVNAME_SIZE];
2156 
2157         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL,
2158                                  shared ? (struct md_rdev *)lock_rdev : rdev);
2159         if (IS_ERR(bdev)) {
2160                 printk(KERN_ERR "md: could not open %s.\n",
2161                         __bdevname(dev, b));
2162                 return PTR_ERR(bdev);
2163         }
2164         rdev->bdev = bdev;
2165         return err;
2166 }
2167 
2168 static void unlock_rdev(struct md_rdev *rdev)
2169 {
2170         struct block_device *bdev = rdev->bdev;
2171         rdev->bdev = NULL;
2172         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
2173 }
2174 
2175 void md_autodetect_dev(dev_t dev);
2176 
2177 static void export_rdev(struct md_rdev *rdev)
2178 {
2179         char b[BDEVNAME_SIZE];
2180 
2181         printk(KERN_INFO "md: export_rdev(%s)\n",
2182                 bdevname(rdev->bdev,b));
2183         md_rdev_clear(rdev);
2184 #ifndef MODULE
2185         if (test_bit(AutoDetected, &rdev->flags))
2186                 md_autodetect_dev(rdev->bdev->bd_dev);
2187 #endif
2188         unlock_rdev(rdev);
2189         kobject_put(&rdev->kobj);
2190 }
2191 
2192 void md_kick_rdev_from_array(struct md_rdev *rdev)
2193 {
2194         unbind_rdev_from_array(rdev);
2195         export_rdev(rdev);
2196 }
2197 EXPORT_SYMBOL_GPL(md_kick_rdev_from_array);
2198 
2199 static void export_array(struct mddev *mddev)
2200 {
2201         struct md_rdev *rdev;
2202 
2203         while (!list_empty(&mddev->disks)) {
2204                 rdev = list_first_entry(&mddev->disks, struct md_rdev,
2205                                         same_set);
2206                 md_kick_rdev_from_array(rdev);
2207         }
2208         mddev->raid_disks = 0;
2209         mddev->major_version = 0;
2210 }
2211 
2212 static void sync_sbs(struct mddev *mddev, int nospares)
2213 {
2214         /* Update each superblock (in-memory image), but
2215          * if we are allowed to, skip spares which already
2216          * have the right event counter, or have one earlier
2217          * (which would mean they aren't being marked as dirty
2218          * with the rest of the array)
2219          */
2220         struct md_rdev *rdev;
2221         rdev_for_each(rdev, mddev) {
2222                 if (rdev->sb_events == mddev->events ||
2223                     (nospares &&
2224                      rdev->raid_disk < 0 &&
2225                      rdev->sb_events+1 == mddev->events)) {
2226                         /* Don't update this superblock */
2227                         rdev->sb_loaded = 2;
2228                 } else {
2229                         sync_super(mddev, rdev);
2230                         rdev->sb_loaded = 1;
2231                 }
2232         }
2233 }
2234 
2235 static bool does_sb_need_changing(struct mddev *mddev)
2236 {
2237         struct md_rdev *rdev;
2238         struct mdp_superblock_1 *sb;
2239         int role;
2240 
2241         /* Find a good rdev */
2242         rdev_for_each(rdev, mddev)
2243                 if ((rdev->raid_disk >= 0) && !test_bit(Faulty, &rdev->flags))
2244                         break;
2245 
2246         /* No good device found. */
2247         if (!rdev)
2248                 return false;
2249 
2250         sb = page_address(rdev->sb_page);
2251         /* Check if a device has become faulty or a spare become active */
2252         rdev_for_each(rdev, mddev) {
2253                 role = le16_to_cpu(sb->dev_roles[rdev->desc_nr]);
2254                 /* Device activated? */
2255                 if (role == 0xffff && rdev->raid_disk >=0 &&
2256                     !test_bit(Faulty, &rdev->flags))
2257                         return true;
2258                 /* Device turned faulty? */
2259                 if (test_bit(Faulty, &rdev->flags) && (role < 0xfffd))
2260                         return true;
2261         }
2262 
2263         /* Check if any mddev parameters have changed */
2264         if ((mddev->dev_sectors != le64_to_cpu(sb->size)) ||
2265             (mddev->reshape_position != le64_to_cpu(sb->reshape_position)) ||
2266             (mddev->layout != le64_to_cpu(sb->layout)) ||
2267             (mddev->raid_disks != le32_to_cpu(sb->raid_disks)) ||
2268             (mddev->chunk_sectors != le32_to_cpu(sb->chunksize)))
2269                 return true;
2270 
2271         return false;
2272 }
2273 
2274 void md_update_sb(struct mddev *mddev, int force_change)
2275 {
2276         struct md_rdev *rdev;
2277         int sync_req;
2278         int nospares = 0;
2279         int any_badblocks_changed = 0;
2280         int ret = -1;
2281 
2282         if (mddev->ro) {
2283                 if (force_change)
2284                         set_bit(MD_CHANGE_DEVS, &mddev->flags);
2285                 return;
2286         }
2287 
2288         if (mddev_is_clustered(mddev)) {
2289                 if (test_and_clear_bit(MD_CHANGE_DEVS, &mddev->flags))
2290                         force_change = 1;
2291                 ret = md_cluster_ops->metadata_update_start(mddev);
2292                 /* Has someone else has updated the sb */
2293                 if (!does_sb_need_changing(mddev)) {
2294                         if (ret == 0)
2295                                 md_cluster_ops->metadata_update_cancel(mddev);
2296                         clear_bit(MD_CHANGE_PENDING, &mddev->flags);
2297                         return;
2298                 }
2299         }
2300 repeat:
2301         /* First make sure individual recovery_offsets are correct */
2302         rdev_for_each(rdev, mddev) {
2303                 if (rdev->raid_disk >= 0 &&
2304                     mddev->delta_disks >= 0 &&
2305                     !test_bit(Journal, &rdev->flags) &&
2306                     !test_bit(In_sync, &rdev->flags) &&
2307                     mddev->curr_resync_completed > rdev->recovery_offset)
2308                                 rdev->recovery_offset = mddev->curr_resync_completed;
2309 
2310         }
2311         if (!mddev->persistent) {
2312                 clear_bit(MD_CHANGE_CLEAN, &mddev->flags);
2313                 clear_bit(MD_CHANGE_DEVS, &mddev->flags);
2314                 if (!mddev->external) {
2315                         clear_bit(MD_CHANGE_PENDING, &mddev->flags);
2316                         rdev_for_each(rdev, mddev) {
2317                                 if (rdev->badblocks.changed) {
2318                                         rdev->badblocks.changed = 0;
2319                                         ack_all_badblocks(&rdev->badblocks);
2320                                         md_error(mddev, rdev);
2321                                 }
2322                                 clear_bit(Blocked, &rdev->flags);
2323                                 clear_bit(BlockedBadBlocks, &rdev->flags);
2324                                 wake_up(&rdev->blocked_wait);
2325                         }
2326                 }
2327                 wake_up(&mddev->sb_wait);
2328                 return;
2329         }
2330 
2331         spin_lock(&mddev->lock);
2332 
2333         mddev->utime = ktime_get_real_seconds();
2334 
2335         if (test_and_clear_bit(MD_CHANGE_DEVS, &mddev->flags))
2336                 force_change = 1;
2337         if (test_and_clear_bit(MD_CHANGE_CLEAN, &mddev->flags))
2338                 /* just a clean<-> dirty transition, possibly leave spares alone,
2339                  * though if events isn't the right even/odd, we will have to do
2340                  * spares after all
2341                  */
2342                 nospares = 1;
2343         if (force_change)
2344                 nospares = 0;
2345         if (mddev->degraded)
2346                 /* If the array is degraded, then skipping spares is both
2347                  * dangerous and fairly pointless.
2348                  * Dangerous because a device that was removed from the array
2349                  * might have a event_count that still looks up-to-date,
2350                  * so it can be re-added without a resync.
2351                  * Pointless because if there are any spares to skip,
2352                  * then a recovery will happen and soon that array won't
2353                  * be degraded any more and the spare can go back to sleep then.
2354                  */
2355                 nospares = 0;
2356 
2357         sync_req = mddev->in_sync;
2358 
2359         /* If this is just a dirty<->clean transition, and the array is clean
2360          * and 'events' is odd, we can roll back to the previous clean state */
2361         if (nospares
2362             && (mddev->in_sync && mddev->recovery_cp == MaxSector)
2363             && mddev->can_decrease_events
2364             && mddev->events != 1) {
2365                 mddev->events--;
2366                 mddev->can_decrease_events = 0;
2367         } else {
2368                 /* otherwise we have to go forward and ... */
2369                 mddev->events ++;
2370                 mddev->can_decrease_events = nospares;
2371         }
2372 
2373         /*
2374          * This 64-bit counter should never wrap.
2375          * Either we are in around ~1 trillion A.C., assuming
2376          * 1 reboot per second, or we have a bug...
2377          */
2378         WARN_ON(mddev->events == 0);
2379 
2380         rdev_for_each(rdev, mddev) {
2381                 if (rdev->badblocks.changed)
2382                         any_badblocks_changed++;
2383                 if (test_bit(Faulty, &rdev->flags))
2384                         set_bit(FaultRecorded, &rdev->flags);
2385         }
2386 
2387         sync_sbs(mddev, nospares);
2388         spin_unlock(&mddev->lock);
2389 
2390         pr_debug("md: updating %s RAID superblock on device (in sync %d)\n",
2391                  mdname(mddev), mddev->in_sync);
2392 
2393         bitmap_update_sb(mddev->bitmap);
2394         rdev_for_each(rdev, mddev) {
2395                 char b[BDEVNAME_SIZE];
2396 
2397                 if (rdev->sb_loaded != 1)
2398                         continue; /* no noise on spare devices */
2399 
2400                 if (!test_bit(Faulty, &rdev->flags)) {
2401                         md_super_write(mddev,rdev,
2402                                        rdev->sb_start, rdev->sb_size,
2403                                        rdev->sb_page);
2404                         pr_debug("md: (write) %s's sb offset: %llu\n",
2405                                  bdevname(rdev->bdev, b),
2406                                  (unsigned long long)rdev->sb_start);
2407                         rdev->sb_events = mddev->events;
2408                         if (rdev->badblocks.size) {
2409                                 md_super_write(mddev, rdev,
2410                                                rdev->badblocks.sector,
2411                                                rdev->badblocks.size << 9,
2412                                                rdev->bb_page);
2413                                 rdev->badblocks.size = 0;
2414                         }
2415 
2416                 } else
2417                         pr_debug("md: %s (skipping faulty)\n",
2418                                  bdevname(rdev->bdev, b));
2419 
2420                 if (mddev->level == LEVEL_MULTIPATH)
2421                         /* only need to write one superblock... */
2422                         break;
2423         }
2424         md_super_wait(mddev);
2425         /* if there was a failure, MD_CHANGE_DEVS was set, and we re-write super */
2426 
2427         spin_lock(&mddev->lock);
2428         if (mddev->in_sync != sync_req ||
2429             test_bit(MD_CHANGE_DEVS, &mddev->flags)) {
2430                 /* have to write it out again */
2431                 spin_unlock(&mddev->lock);
2432                 goto repeat;
2433         }
2434         clear_bit(MD_CHANGE_PENDING, &mddev->flags);
2435         spin_unlock(&mddev->lock);
2436         wake_up(&mddev->sb_wait);
2437         if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
2438                 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
2439 
2440         rdev_for_each(rdev, mddev) {
2441                 if (test_and_clear_bit(FaultRecorded, &rdev->flags))
2442                         clear_bit(Blocked, &rdev->flags);
2443 
2444                 if (any_badblocks_changed)
2445                         ack_all_badblocks(&rdev->badblocks);
2446                 clear_bit(BlockedBadBlocks, &rdev->flags);
2447                 wake_up(&rdev->blocked_wait);
2448         }
2449 
2450         if (mddev_is_clustered(mddev) && ret == 0)
2451                 md_cluster_ops->metadata_update_finish(mddev);
2452 }
2453 EXPORT_SYMBOL(md_update_sb);
2454 
2455 static int add_bound_rdev(struct md_rdev *rdev)
2456 {
2457         struct mddev *mddev = rdev->mddev;
2458         int err = 0;
2459         bool add_journal = test_bit(Journal, &rdev->flags);
2460 
2461         if (!mddev->pers->hot_remove_disk || add_journal) {
2462                 /* If there is hot_add_disk but no hot_remove_disk
2463                  * then added disks for geometry changes,
2464                  * and should be added immediately.
2465                  */
2466                 super_types[mddev->major_version].
2467                         validate_super(mddev, rdev);
2468                 if (add_journal)
2469                         mddev_suspend(mddev);
2470                 err = mddev->pers->hot_add_disk(mddev, rdev);
2471                 if (add_journal)
2472                         mddev_resume(mddev);
2473                 if (err) {
2474                         unbind_rdev_from_array(rdev);
2475                         export_rdev(rdev);
2476                         return err;
2477                 }
2478         }
2479         sysfs_notify_dirent_safe(rdev->sysfs_state);
2480 
2481         set_bit(MD_CHANGE_DEVS, &mddev->flags);
2482         if (mddev->degraded)
2483                 set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
2484         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2485         md_new_event(mddev);
2486         md_wakeup_thread(mddev->thread);
2487         return 0;
2488 }
2489 
2490 /* words written to sysfs files may, or may not, be \n terminated.
2491  * We want to accept with case. For this we use cmd_match.
2492  */
2493 static int cmd_match(const char *cmd, const char *str)
2494 {
2495         /* See if cmd, written into a sysfs file, matches
2496          * str.  They must either be the same, or cmd can
2497          * have a trailing newline
2498          */
2499         while (*cmd && *str && *cmd == *str) {
2500                 cmd++;
2501                 str++;
2502         }
2503         if (*cmd == '\n')
2504                 cmd++;
2505         if (*str || *cmd)
2506                 return 0;
2507         return 1;
2508 }
2509 
2510 struct rdev_sysfs_entry {
2511         struct attribute attr;
2512         ssize_t (*show)(struct md_rdev *, char *);
2513         ssize_t (*store)(struct md_rdev *, const char *, size_t);
2514 };
2515 
2516 static ssize_t
2517 state_show(struct md_rdev *rdev, char *page)
2518 {
2519         char *sep = "";
2520         size_t len = 0;
2521         unsigned long flags = ACCESS_ONCE(rdev->flags);
2522 
2523         if (test_bit(Faulty, &flags) ||
2524             rdev->badblocks.unacked_exist) {
2525                 len+= sprintf(page+len, "%sfaulty",sep);
2526                 sep = ",";
2527         }
2528         if (test_bit(In_sync, &flags)) {
2529                 len += sprintf(page+len, "%sin_sync",sep);
2530                 sep = ",";
2531         }
2532         if (test_bit(Journal, &flags)) {
2533                 len += sprintf(page+len, "%sjournal",sep);
2534                 sep = ",";
2535         }
2536         if (test_bit(WriteMostly, &flags)) {
2537                 len += sprintf(page+len, "%swrite_mostly",sep);
2538                 sep = ",";
2539         }
2540         if (test_bit(Blocked, &flags) ||
2541             (rdev->badblocks.unacked_exist
2542              && !test_bit(Faulty, &flags))) {
2543                 len += sprintf(page+len, "%sblocked", sep);
2544                 sep = ",";
2545         }
2546         if (!test_bit(Faulty, &flags) &&
2547             !test_bit(Journal, &flags) &&
2548             !test_bit(In_sync, &flags)) {
2549                 len += sprintf(page+len, "%sspare", sep);
2550                 sep = ",";
2551         }
2552         if (test_bit(WriteErrorSeen, &flags)) {
2553                 len += sprintf(page+len, "%swrite_error", sep);
2554                 sep = ",";
2555         }
2556         if (test_bit(WantReplacement, &flags)) {
2557                 len += sprintf(page+len, "%swant_replacement", sep);
2558                 sep = ",";
2559         }
2560         if (test_bit(Replacement, &flags)) {
2561                 len += sprintf(page+len, "%sreplacement", sep);
2562                 sep = ",";
2563         }
2564 
2565         return len+sprintf(page+len, "\n");
2566 }
2567 
2568 static ssize_t
2569 state_store(struct md_rdev *rdev, const char *buf, size_t len)
2570 {
2571         /* can write
2572          *  faulty  - simulates an error
2573          *  remove  - disconnects the device
2574          *  writemostly - sets write_mostly
2575          *  -writemostly - clears write_mostly
2576          *  blocked - sets the Blocked flags
2577          *  -blocked - clears the Blocked and possibly simulates an error
2578          *  insync - sets Insync providing device isn't active
2579          *  -insync - clear Insync for a device with a slot assigned,
2580          *            so that it gets rebuilt based on bitmap
2581          *  write_error - sets WriteErrorSeen
2582          *  -write_error - clears WriteErrorSeen
2583          */
2584         int err = -EINVAL;
2585         if (cmd_match(buf, "faulty") && rdev->mddev->pers) {
2586                 md_error(rdev->mddev, rdev);
2587                 if (test_bit(Faulty, &rdev->flags))
2588                         err = 0;
2589                 else
2590                         err = -EBUSY;
2591         } else if (cmd_match(buf, "remove")) {
2592                 if (rdev->raid_disk >= 0)
2593                         err = -EBUSY;
2594                 else {
2595                         struct mddev *mddev = rdev->mddev;
2596                         err = 0;
2597                         if (mddev_is_clustered(mddev))
2598                                 err = md_cluster_ops->remove_disk(mddev, rdev);
2599 
2600                         if (err == 0) {
2601                                 md_kick_rdev_from_array(rdev);
2602                                 if (mddev->pers)
2603                                         md_update_sb(mddev, 1);
2604                                 md_new_event(mddev);
2605                         }
2606                 }
2607         } else if (cmd_match(buf, "writemostly")) {
2608                 set_bit(WriteMostly, &rdev->flags);
2609                 err = 0;
2610         } else if (cmd_match(buf, "-writemostly")) {
2611                 clear_bit(WriteMostly, &rdev->flags);
2612                 err = 0;
2613         } else if (cmd_match(buf, "blocked")) {
2614                 set_bit(Blocked, &rdev->flags);
2615                 err = 0;
2616         } else if (cmd_match(buf, "-blocked")) {
2617                 if (!test_bit(Faulty, &rdev->flags) &&
2618                     rdev->badblocks.unacked_exist) {
2619                         /* metadata handler doesn't understand badblocks,
2620                          * so we need to fail the device
2621                          */
2622                         md_error(rdev->mddev, rdev);
2623                 }
2624                 clear_bit(Blocked, &rdev->flags);
2625                 clear_bit(BlockedBadBlocks, &rdev->flags);
2626                 wake_up(&rdev->blocked_wait);
2627                 set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2628                 md_wakeup_thread(rdev->mddev->thread);
2629 
2630                 err = 0;
2631         } else if (cmd_match(buf, "insync") && rdev->raid_disk == -1) {
2632                 set_bit(In_sync, &rdev->flags);
2633                 err = 0;
2634         } else if (cmd_match(buf, "-insync") && rdev->raid_disk >= 0 &&
2635                    !test_bit(Journal, &rdev->flags)) {
2636                 if (rdev->mddev->pers == NULL) {
2637                         clear_bit(In_sync, &rdev->flags);
2638                         rdev->saved_raid_disk = rdev->raid_disk;
2639                         rdev->raid_disk = -1;
2640                         err = 0;
2641                 }
2642         } else if (cmd_match(buf, "write_error")) {
2643                 set_bit(WriteErrorSeen, &rdev->flags);
2644                 err = 0;
2645         } else if (cmd_match(buf, "-write_error")) {
2646                 clear_bit(WriteErrorSeen, &rdev->flags);
2647                 err = 0;
2648         } else if (cmd_match(buf, "want_replacement")) {
2649                 /* Any non-spare device that is not a replacement can
2650                  * become want_replacement at any time, but we then need to
2651                  * check if recovery is needed.
2652                  */
2653                 if (rdev->raid_disk >= 0 &&
2654                     !test_bit(Journal, &rdev->flags) &&
2655                     !test_bit(Replacement, &rdev->flags))
2656                         set_bit(WantReplacement, &rdev->flags);
2657                 set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2658                 md_wakeup_thread(rdev->mddev->thread);
2659                 err = 0;
2660         } else if (cmd_match(buf, "-want_replacement")) {
2661                 /* Clearing 'want_replacement' is always allowed.
2662                  * Once replacements starts it is too late though.
2663                  */
2664                 err = 0;
2665                 clear_bit(WantReplacement, &rdev->flags);
2666         } else if (cmd_match(buf, "replacement")) {
2667                 /* Can only set a device as a replacement when array has not
2668                  * yet been started.  Once running, replacement is automatic
2669                  * from spares, or by assigning 'slot'.
2670                  */
2671                 if (rdev->mddev->pers)
2672                         err = -EBUSY;
2673                 else {
2674                         set_bit(Replacement, &rdev->flags);
2675                         err = 0;
2676                 }
2677         } else if (cmd_match(buf, "-replacement")) {
2678                 /* Similarly, can only clear Replacement before start */
2679                 if (rdev->mddev->pers)
2680                         err = -EBUSY;
2681                 else {
2682                         clear_bit(Replacement, &rdev->flags);
2683                         err = 0;
2684                 }
2685         } else if (cmd_match(buf, "re-add")) {
2686                 if (test_bit(Faulty, &rdev->flags) && (rdev->raid_disk == -1)) {
2687                         /* clear_bit is performed _after_ all the devices
2688                          * have their local Faulty bit cleared. If any writes
2689                          * happen in the meantime in the local node, they
2690                          * will land in the local bitmap, which will be synced
2691                          * by this node eventually
2692                          */
2693                         if (!mddev_is_clustered(rdev->mddev) ||
2694                             (err = md_cluster_ops->gather_bitmaps(rdev)) == 0) {
2695                                 clear_bit(Faulty, &rdev->flags);
2696                                 err = add_bound_rdev(rdev);
2697                         }
2698                 } else
2699                         err = -EBUSY;
2700         }
2701         if (!err)
2702                 sysfs_notify_dirent_safe(rdev->sysfs_state);
2703         return err ? err : len;
2704 }
2705 static struct rdev_sysfs_entry rdev_state =
2706 __ATTR_PREALLOC(state, S_IRUGO|S_IWUSR, state_show, state_store);
2707 
2708 static ssize_t
2709 errors_show(struct md_rdev *rdev, char *page)
2710 {
2711         return sprintf(page, "%d\n", atomic_read(&rdev->corrected_errors));
2712 }
2713 
2714 static ssize_t
2715 errors_store(struct md_rdev *rdev, const char *buf, size_t len)
2716 {
2717         unsigned int n;
2718         int rv;
2719 
2720         rv = kstrtouint(buf, 10, &n);
2721         if (rv < 0)
2722                 return rv;
2723         atomic_set(&rdev->corrected_errors, n);
2724         return len;
2725 }
2726 static struct rdev_sysfs_entry rdev_errors =
2727 __ATTR(errors, S_IRUGO|S_IWUSR, errors_show, errors_store);
2728 
2729 static ssize_t
2730 slot_show(struct md_rdev *rdev, char *page)
2731 {
2732         if (test_bit(Journal, &rdev->flags))
2733                 return sprintf(page, "journal\n");
2734         else if (rdev->raid_disk < 0)
2735                 return sprintf(page, "none\n");
2736         else
2737                 return sprintf(page, "%d\n", rdev->raid_disk);
2738 }
2739 
2740 static ssize_t
2741 slot_store(struct md_rdev *rdev, const char *buf, size_t len)
2742 {
2743         int slot;
2744         int err;
2745 
2746         if (test_bit(Journal, &rdev->flags))
2747                 return -EBUSY;
2748         if (strncmp(buf, "none", 4)==0)
2749                 slot = -1;
2750         else {
2751                 err = kstrtouint(buf, 10, (unsigned int *)&slot);
2752                 if (err < 0)
2753                         return err;
2754         }
2755         if (rdev->mddev->pers && slot == -1) {
2756                 /* Setting 'slot' on an active array requires also
2757                  * updating the 'rd%d' link, and communicating
2758                  * with the personality with ->hot_*_disk.
2759                  * For now we only support removing
2760                  * failed/spare devices.  This normally happens automatically,
2761                  * but not when the metadata is externally managed.
2762                  */
2763                 if (rdev->raid_disk == -1)
2764                         return -EEXIST;
2765                 /* personality does all needed checks */
2766                 if (rdev->mddev->pers->hot_remove_disk == NULL)
2767                         return -EINVAL;
2768                 clear_bit(Blocked, &rdev->flags);
2769                 remove_and_add_spares(rdev->mddev, rdev);
2770                 if (rdev->raid_disk >= 0)
2771                         return -EBUSY;
2772                 set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
2773                 md_wakeup_thread(rdev->mddev->thread);
2774         } else if (rdev->mddev->pers) {
2775                 /* Activating a spare .. or possibly reactivating
2776                  * if we ever get bitmaps working here.
2777                  */
2778                 int err;
2779 
2780                 if (rdev->raid_disk != -1)
2781                         return -EBUSY;
2782 
2783                 if (test_bit(MD_RECOVERY_RUNNING, &rdev->mddev->recovery))
2784                         return -EBUSY;
2785 
2786                 if (rdev->mddev->pers->hot_add_disk == NULL)
2787                         return -EINVAL;
2788 
2789                 if (slot >= rdev->mddev->raid_disks &&
2790                     slot >= rdev->mddev->raid_disks + rdev->mddev->delta_disks)
2791                         return -ENOSPC;
2792 
2793                 rdev->raid_disk = slot;
2794                 if (test_bit(In_sync, &rdev->flags))
2795                         rdev->saved_raid_disk = slot;
2796                 else
2797                         rdev->saved_raid_disk = -1;
2798                 clear_bit(In_sync, &rdev->flags);
2799                 clear_bit(Bitmap_sync, &rdev->flags);
2800                 err = rdev->mddev->pers->
2801                         hot_add_disk(rdev->mddev, rdev);
2802                 if (err) {
2803                         rdev->raid_disk = -1;
2804                         return err;
2805                 } else
2806                         sysfs_notify_dirent_safe(rdev->sysfs_state);
2807                 if (sysfs_link_rdev(rdev->mddev, rdev))
2808                         /* failure here is OK */;
2809                 /* don't wakeup anyone, leave that to userspace. */
2810         } else {
2811                 if (slot >= rdev->mddev->raid_disks &&
2812                     slot >= rdev->mddev->raid_disks + rdev->mddev->delta_disks)
2813                         return -ENOSPC;
2814                 rdev->raid_disk = slot;
2815                 /* assume it is working */
2816                 clear_bit(Faulty, &rdev->flags);
2817                 clear_bit(WriteMostly, &rdev->flags);
2818                 set_bit(In_sync, &rdev->flags);
2819                 sysfs_notify_dirent_safe(rdev->sysfs_state);
2820         }
2821         return len;
2822 }
2823 
2824 static struct rdev_sysfs_entry rdev_slot =
2825 __ATTR(slot, S_IRUGO|S_IWUSR, slot_show, slot_store);
2826 
2827 static ssize_t
2828 offset_show(struct md_rdev *rdev, char *page)
2829 {
2830         return sprintf(page, "%llu\n", (unsigned long long)rdev->data_offset);
2831 }
2832 
2833 static ssize_t
2834 offset_store(struct md_rdev *rdev, const char *buf, size_t len)
2835 {
2836         unsigned long long offset;
2837         if (kstrtoull(buf, 10, &offset) < 0)
2838                 return -EINVAL;
2839         if (rdev->mddev->pers && rdev->raid_disk >= 0)
2840                 return -EBUSY;
2841         if (rdev->sectors && rdev->mddev->external)
2842                 /* Must set offset before size, so overlap checks
2843                  * can be sane */
2844                 return -EBUSY;
2845         rdev->data_offset = offset;
2846         rdev->new_data_offset = offset;
2847         return len;
2848 }
2849 
2850 static struct rdev_sysfs_entry rdev_offset =
2851 __ATTR(offset, S_IRUGO|S_IWUSR, offset_show, offset_store);
2852 
2853 static ssize_t new_offset_show(struct md_rdev *rdev, char *page)
2854 {
2855         return sprintf(page, "%llu\n",
2856                        (unsigned long long)rdev->new_data_offset);
2857 }
2858 
2859 static ssize_t new_offset_store(struct md_rdev *rdev,
2860                                 const char *buf, size_t len)
2861 {
2862         unsigned long long new_offset;
2863         struct mddev *mddev = rdev->mddev;
2864 
2865         if (kstrtoull(buf, 10, &new_offset) < 0)
2866                 return -EINVAL;
2867 
2868         if (mddev->sync_thread ||
2869             test_bit(MD_RECOVERY_RUNNING,&mddev->recovery))
2870                 return -EBUSY;
2871         if (new_offset == rdev->data_offset)
2872                 /* reset is always permitted */
2873                 ;
2874         else if (new_offset > rdev->data_offset) {
2875                 /* must not push array size beyond rdev_sectors */
2876                 if (new_offset - rdev->data_offset
2877                     + mddev->dev_sectors > rdev->sectors)
2878                                 return -E2BIG;
2879         }
2880         /* Metadata worries about other space details. */
2881 
2882         /* decreasing the offset is inconsistent with a backwards
2883          * reshape.
2884          */
2885         if (new_offset < rdev->data_offset &&
2886             mddev->reshape_backwards)
2887                 return -EINVAL;
2888         /* Increasing offset is inconsistent with forwards
2889          * reshape.  reshape_direction should be set to
2890          * 'backwards' first.
2891          */
2892         if (new_offset > rdev->data_offset &&
2893             !mddev->reshape_backwards)
2894                 return -EINVAL;
2895 
2896         if (mddev->pers && mddev->persistent &&
2897             !super_types[mddev->major_version]
2898             .allow_new_offset(rdev, new_offset))
2899                 return -E2BIG;
2900         rdev->new_data_offset = new_offset;
2901         if (new_offset > rdev->data_offset)
2902                 mddev->reshape_backwards = 1;
2903         else if (new_offset < rdev->data_offset)
2904                 mddev->reshape_backwards = 0;
2905 
2906         return len;
2907 }
2908 static struct rdev_sysfs_entry rdev_new_offset =
2909 __ATTR(new_offset, S_IRUGO|S_IWUSR, new_offset_show, new_offset_store);
2910 
2911 static ssize_t
2912 rdev_size_show(struct md_rdev *rdev, char *page)
2913 {
2914         return sprintf(page, "%llu\n", (unsigned long long)rdev->sectors / 2);
2915 }
2916 
2917 static int overlaps(sector_t s1, sector_t l1, sector_t s2, sector_t l2)
2918 {
2919         /* check if two start/length pairs overlap */
2920         if (s1+l1 <= s2)
2921                 return 0;
2922         if (s2+l2 <= s1)
2923                 return 0;
2924         return 1;
2925 }
2926 
2927 static int strict_blocks_to_sectors(const char *buf, sector_t *sectors)
2928 {
2929         unsigned long long blocks;
2930         sector_t new;
2931 
2932         if (kstrtoull(buf, 10, &blocks) < 0)
2933                 return -EINVAL;
2934 
2935         if (blocks & 1ULL << (8 * sizeof(blocks) - 1))
2936                 return -EINVAL; /* sector conversion overflow */
2937 
2938         new = blocks * 2;
2939         if (new != blocks * 2)
2940                 return -EINVAL; /* unsigned long long to sector_t overflow */
2941 
2942         *sectors = new;
2943         return 0;
2944 }
2945 
2946 static ssize_t
2947 rdev_size_store(struct md_rdev *rdev, const char *buf, size_t len)
2948 {
2949         struct mddev *my_mddev = rdev->mddev;
2950         sector_t oldsectors = rdev->sectors;
2951         sector_t sectors;
2952 
2953         if (test_bit(Journal, &rdev->flags))
2954                 return -EBUSY;
2955         if (strict_blocks_to_sectors(buf, &sectors) < 0)
2956                 return -EINVAL;
2957         if (rdev->data_offset != rdev->new_data_offset)
2958                 return -EINVAL; /* too confusing */
2959         if (my_mddev->pers && rdev->raid_disk >= 0) {
2960                 if (my_mddev->persistent) {
2961                         sectors = super_types[my_mddev->major_version].
2962                                 rdev_size_change(rdev, sectors);
2963                         if (!sectors)
2964                                 return -EBUSY;
2965                 } else if (!sectors)
2966                         sectors = (i_size_read(rdev->bdev->bd_inode) >> 9) -
2967                                 rdev->data_offset;
2968                 if (!my_mddev->pers->resize)
2969                         /* Cannot change size for RAID0 or Linear etc */
2970                         return -EINVAL;
2971         }
2972         if (sectors < my_mddev->dev_sectors)
2973                 return -EINVAL; /* component must fit device */
2974 
2975         rdev->sectors = sectors;
2976         if (sectors > oldsectors && my_mddev->external) {
2977                 /* Need to check that all other rdevs with the same
2978                  * ->bdev do not overlap.  'rcu' is sufficient to walk
2979                  * the rdev lists safely.
2980                  * This check does not provide a hard guarantee, it
2981                  * just helps avoid dangerous mistakes.
2982                  */
2983                 struct mddev *mddev;
2984                 int overlap = 0;
2985                 struct list_head *tmp;
2986 
2987                 rcu_read_lock();
2988                 for_each_mddev(mddev, tmp) {
2989                         struct md_rdev *rdev2;
2990 
2991                         rdev_for_each(rdev2, mddev)
2992                                 if (rdev->bdev == rdev2->bdev &&
2993                                     rdev != rdev2 &&
2994                                     overlaps(rdev->data_offset, rdev->sectors,
2995                                              rdev2->data_offset,
2996                                              rdev2->sectors)) {
2997                                         overlap = 1;
2998                                         break;
2999                                 }
3000                         if (overlap) {
3001                                 mddev_put(mddev);
3002                                 break;
3003                         }
3004                 }
3005                 rcu_read_unlock();
3006                 if (overlap) {
3007                         /* Someone else could have slipped in a size
3008                          * change here, but doing so is just silly.
3009                          * We put oldsectors back because we *know* it is
3010                          * safe, and trust userspace not to race with
3011                          * itself
3012                          */
3013                         rdev->sectors = oldsectors;
3014                         return -EBUSY;
3015                 }
3016         }
3017         return len;
3018 }
3019 
3020 static struct rdev_sysfs_entry rdev_size =
3021 __ATTR(size, S_IRUGO|S_IWUSR, rdev_size_show, rdev_size_store);
3022 
3023 static ssize_t recovery_start_show(struct md_rdev *rdev, char *page)
3024 {
3025         unsigned long long recovery_start = rdev->recovery_offset;
3026 
3027         if (test_bit(In_sync, &rdev->flags) ||
3028             recovery_start == MaxSector)
3029                 return sprintf(page, "none\n");
3030 
3031         return sprintf(page, "%llu\n", recovery_start);
3032 }
3033 
3034 static ssize_t recovery_start_store(struct md_rdev *rdev, const char *buf, size_t len)
3035 {
3036         unsigned long long recovery_start;
3037 
3038         if (cmd_match(buf, "none"))
3039                 recovery_start = MaxSector;
3040         else if (kstrtoull(buf, 10, &recovery_start))
3041                 return -EINVAL;
3042 
3043         if (rdev->mddev->pers &&
3044             rdev->raid_disk >= 0)
3045                 return -EBUSY;
3046 
3047         rdev->recovery_offset = recovery_start;
3048         if (recovery_start == MaxSector)
3049                 set_bit(In_sync, &rdev->flags);
3050         else
3051                 clear_bit(In_sync, &rdev->flags);
3052         return len;
3053 }
3054 
3055 static struct rdev_sysfs_entry rdev_recovery_start =
3056 __ATTR(recovery_start, S_IRUGO|S_IWUSR, recovery_start_show, recovery_start_store);
3057 
3058 /* sysfs access to bad-blocks list.
3059  * We present two files.
3060  * 'bad-blocks' lists sector numbers and lengths of ranges that
3061  *    are recorded as bad.  The list is truncated to fit within
3062  *    the one-page limit of sysfs.
3063  *    Writing "sector length" to this file adds an acknowledged
3064  *    bad block list.
3065  * 'unacknowledged-bad-blocks' lists bad blocks that have not yet
3066  *    been acknowledged.  Writing to this file adds bad blocks
3067  *    without acknowledging them.  This is largely for testing.
3068  */
3069 static ssize_t bb_show(struct md_rdev *rdev, char *page)
3070 {
3071         return badblocks_show(&rdev->badblocks, page, 0);
3072 }
3073 static ssize_t bb_store(struct md_rdev *rdev, const char *page, size_t len)
3074 {
3075         int rv = badblocks_store(&rdev->badblocks, page, len, 0);
3076         /* Maybe that ack was all we needed */
3077         if (test_and_clear_bit(BlockedBadBlocks, &rdev->flags))
3078                 wake_up(&rdev->blocked_wait);
3079         return rv;
3080 }
3081 static struct rdev_sysfs_entry rdev_bad_blocks =
3082 __ATTR(bad_blocks, S_IRUGO|S_IWUSR, bb_show, bb_store);
3083 
3084 static ssize_t ubb_show(struct md_rdev *rdev, char *page)
3085 {
3086         return badblocks_show(&rdev->badblocks, page, 1);
3087 }
3088 static ssize_t ubb_store(struct md_rdev *rdev, const char *page, size_t len)
3089 {
3090         return badblocks_store(&rdev->badblocks, page, len, 1);
3091 }
3092 static struct rdev_sysfs_entry rdev_unack_bad_blocks =
3093 __ATTR(unacknowledged_bad_blocks, S_IRUGO|S_IWUSR, ubb_show, ubb_store);
3094 
3095 static struct attribute *rdev_default_attrs[] = {
3096         &rdev_state.attr,
3097         &rdev_errors.attr,
3098         &rdev_slot.attr,
3099         &rdev_offset.attr,
3100         &rdev_new_offset.attr,
3101         &rdev_size.attr,
3102         &rdev_recovery_start.attr,
3103         &rdev_bad_blocks.attr,
3104         &rdev_unack_bad_blocks.attr,
3105         NULL,
3106 };
3107 static ssize_t
3108 rdev_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
3109 {
3110         struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
3111         struct md_rdev *rdev = container_of(kobj, struct md_rdev, kobj);
3112 
3113         if (!entry->show)
3114                 return -EIO;
3115         if (!rdev->mddev)
3116                 return -EBUSY;
3117         return entry->show(rdev, page);
3118 }
3119 
3120 static ssize_t
3121 rdev_attr_store(struct kobject *kobj, struct attribute *attr,
3122               const char *page, size_t length)
3123 {
3124         struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
3125         struct md_rdev *rdev = container_of(kobj, struct md_rdev, kobj);
3126         ssize_t rv;
3127         struct mddev *mddev = rdev->mddev;
3128 
3129         if (!entry->store)
3130                 return -EIO;
3131         if (!capable(CAP_SYS_ADMIN))
3132                 return -EACCES;
3133         rv = mddev ? mddev_lock(mddev): -EBUSY;
3134         if (!rv) {
3135                 if (rdev->mddev == NULL)
3136                         rv = -EBUSY;
3137                 else
3138                         rv = entry->store(rdev, page, length);
3139                 mddev_unlock(mddev);
3140         }
3141         return rv;
3142 }
3143 
3144 static void rdev_free(struct kobject *ko)
3145 {
3146         struct md_rdev *rdev = container_of(ko, struct md_rdev, kobj);
3147         kfree(rdev);
3148 }
3149 static const struct sysfs_ops rdev_sysfs_ops = {
3150         .show           = rdev_attr_show,
3151         .store          = rdev_attr_store,
3152 };
3153 static struct kobj_type rdev_ktype = {
3154         .release        = rdev_free,
3155         .sysfs_ops      = &rdev_sysfs_ops,
3156         .default_attrs  = rdev_default_attrs,
3157 };
3158 
3159 int md_rdev_init(struct md_rdev *rdev)
3160 {
3161         rdev->desc_nr = -1;
3162         rdev->saved_raid_disk = -1;
3163         rdev->raid_disk = -1;
3164         rdev->flags = 0;
3165         rdev->data_offset = 0;
3166         rdev->new_data_offset = 0;
3167         rdev->sb_events = 0;
3168         rdev->last_read_error.tv_sec  = 0;
3169         rdev->last_read_error.tv_nsec = 0;
3170         rdev->sb_loaded = 0;
3171         rdev->bb_page = NULL;
3172         atomic_set(&rdev->nr_pending, 0);
3173         atomic_set(&rdev->read_errors, 0);
3174         atomic_set(&rdev->corrected_errors, 0);
3175 
3176         INIT_LIST_HEAD(&rdev->same_set);
3177         init_waitqueue_head(&rdev->blocked_wait);
3178 
3179         /* Add space to store bad block list.
3180          * This reserves the space even on arrays where it cannot
3181          * be used - I wonder if that matters
3182          */
3183         return badblocks_init(&rdev->badblocks, 0);
3184 }
3185 EXPORT_SYMBOL_GPL(md_rdev_init);
3186 /*
3187  * Import a device. If 'super_format' >= 0, then sanity check the superblock
3188  *
3189  * mark the device faulty if:
3190  *
3191  *   - the device is nonexistent (zero size)
3192  *   - the device has no valid superblock
3193  *
3194  * a faulty rdev _never_ has rdev->sb set.
3195  */
3196 static struct md_rdev *md_import_device(dev_t newdev, int super_format, int super_minor)
3197 {
3198         char b[BDEVNAME_SIZE];
3199         int err;
3200         struct md_rdev *rdev;
3201         sector_t size;
3202 
3203         rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
3204         if (!rdev) {
3205                 printk(KERN_ERR "md: could not alloc mem for new device!\n");
3206                 return ERR_PTR(-ENOMEM);
3207         }
3208 
3209         err = md_rdev_init(rdev);
3210         if (err)
3211                 goto abort_free;
3212         err = alloc_disk_sb(rdev);
3213         if (err)
3214                 goto abort_free;
3215 
3216         err = lock_rdev(rdev, newdev, super_format == -2);
3217         if (err)
3218                 goto abort_free;
3219 
3220         kobject_init(&rdev->kobj, &rdev_ktype);
3221 
3222         size = i_size_read(rdev->bdev->bd_inode) >> BLOCK_SIZE_BITS;
3223         if (!size) {
3224                 printk(KERN_WARNING
3225                         "md: %s has zero or unknown size, marking faulty!\n",
3226                         bdevname(rdev->bdev,b));
3227                 err = -EINVAL;
3228                 goto abort_free;
3229         }
3230 
3231         if (super_format >= 0) {
3232                 err = super_types[super_format].
3233                         load_super(rdev, NULL, super_minor);
3234                 if (err == -EINVAL) {
3235                         printk(KERN_WARNING
3236                                 "md: %s does not have a valid v%d.%d "
3237                                "superblock, not importing!\n",
3238                                 bdevname(rdev->bdev,b),
3239                                super_format, super_minor);
3240                         goto abort_free;
3241                 }
3242                 if (err < 0) {
3243                         printk(KERN_WARNING
3244                                 "md: could not read %s's sb, not importing!\n",
3245                                 bdevname(rdev->bdev,b));
3246                         goto abort_free;
3247                 }
3248         }
3249 
3250         return rdev;
3251 
3252 abort_free:
3253         if (rdev->bdev)
3254                 unlock_rdev(rdev);
3255         md_rdev_clear(rdev);
3256         kfree(rdev);
3257         return ERR_PTR(err);
3258 }
3259 
3260 /*
3261  * Check a full RAID array for plausibility
3262  */
3263 
3264 static void analyze_sbs(struct mddev *mddev)
3265 {
3266         int i;
3267         struct md_rdev *rdev, *freshest, *tmp;
3268         char b[BDEVNAME_SIZE];
3269 
3270         freshest = NULL;
3271         rdev_for_each_safe(rdev, tmp, mddev)
3272                 switch (super_types[mddev->major_version].
3273                         load_super(rdev, freshest, mddev->minor_version)) {
3274                 case 1:
3275                         freshest = rdev;
3276                         break;
3277                 case 0:
3278                         break;
3279                 default:
3280                         printk( KERN_ERR \
3281                                 "md: fatal superblock inconsistency in %s"
3282                                 " -- removing from array\n",
3283                                 bdevname(rdev->bdev,b));
3284                         md_kick_rdev_from_array(rdev);
3285                 }
3286 
3287         super_types[mddev->major_version].
3288                 validate_super(mddev, freshest);
3289 
3290         i = 0;
3291         rdev_for_each_safe(rdev, tmp, mddev) {
3292                 if (mddev->max_disks &&
3293                     (rdev->desc_nr >= mddev->max_disks ||
3294                      i > mddev->max_disks)) {
3295                         printk(KERN_WARNING
3296                                "md: %s: %s: only %d devices permitted\n",
3297                                mdname(mddev), bdevname(rdev->bdev, b),
3298                                mddev->max_disks);
3299                         md_kick_rdev_from_array(rdev);
3300                         continue;
3301                 }
3302                 if (rdev != freshest) {
3303                         if (super_types[mddev->major_version].
3304                             validate_super(mddev, rdev)) {
3305                                 printk(KERN_WARNING "md: kicking non-fresh %s"
3306                                         " from array!\n",
3307                                         bdevname(rdev->bdev,b));
3308                                 md_kick_rdev_from_array(rdev);
3309                                 continue;
3310                         }
3311                 }
3312                 if (mddev->level == LEVEL_MULTIPATH) {
3313                         rdev->desc_nr = i++;
3314                         rdev->raid_disk = rdev->desc_nr;
3315                         set_bit(In_sync, &rdev->flags);
3316                 } else if (rdev->raid_disk >=
3317                             (mddev->raid_disks - min(0, mddev->delta_disks)) &&
3318                            !test_bit(Journal, &rdev->flags)) {
3319                         rdev->raid_disk = -1;
3320                         clear_bit(In_sync, &rdev->flags);
3321                 }
3322         }
3323 }
3324 
3325 /* Read a fixed-point number.
3326  * Numbers in sysfs attributes should be in "standard" units where
3327  * possible, so time should be in seconds.
3328  * However we internally use a a much smaller unit such as
3329  * milliseconds or jiffies.
3330  * This function takes a decimal number with a possible fractional
3331  * component, and produces an integer which is the result of
3332  * multiplying that number by 10^'scale'.
3333  * all without any floating-point arithmetic.
3334  */
3335 int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale)
3336 {
3337         unsigned long result = 0;
3338         long decimals = -1;
3339         while (isdigit(*cp) || (*cp == '.' && decimals < 0)) {
3340                 if (*cp == '.')
3341                         decimals = 0;
3342                 else if (decimals < scale) {
3343                         unsigned int value;
3344                         value = *cp - '';
3345                         result = result * 10 + value;
3346                         if (decimals >= 0)
3347                                 decimals++;
3348                 }
3349                 cp++;
3350         }
3351         if (*cp == '\n')
3352                 cp++;
3353         if (*cp)
3354                 return -EINVAL;
3355         if (decimals < 0)
3356                 decimals = 0;
3357         while (decimals < scale) {
3358                 result *= 10;
3359                 decimals ++;
3360         }
3361         *res = result;
3362         return 0;
3363 }
3364 
3365 static ssize_t
3366 safe_delay_show(struct mddev *mddev, char *page)
3367 {
3368         int msec = (mddev->safemode_delay*1000)/HZ;
3369         return sprintf(page, "%d.%03d\n", msec/1000, msec%1000);
3370 }
3371 static ssize_t
3372 safe_delay_store(struct mddev *mddev, const char *cbuf, size_t len)
3373 {
3374         unsigned long msec;
3375 
3376         if (mddev_is_clustered(mddev)) {
3377                 pr_info("md: Safemode is disabled for clustered mode\n");
3378                 return -EINVAL;
3379         }
3380 
3381         if (strict_strtoul_scaled(cbuf, &msec, 3) < 0)
3382                 return -EINVAL;
3383         if (msec == 0)
3384                 mddev->safemode_delay = 0;
3385         else {
3386                 unsigned long old_delay = mddev->safemode_delay;
3387                 unsigned long new_delay = (msec*HZ)/1000;
3388 
3389                 if (new_delay == 0)
3390                         new_delay = 1;
3391                 mddev->safemode_delay = new_delay;
3392                 if (new_delay < old_delay || old_delay == 0)
3393                         mod_timer(&mddev->safemode_timer, jiffies+1);
3394         }
3395         return len;
3396 }
3397 static struct md_sysfs_entry md_safe_delay =
3398 __ATTR(safe_mode_delay, S_IRUGO|S_IWUSR,safe_delay_show, safe_delay_store);
3399 
3400 static ssize_t
3401 level_show(struct mddev *mddev, char *page)
3402 {
3403         struct md_personality *p;
3404         int ret;
3405         spin_lock(&mddev->lock);
3406         p = mddev->pers;
3407         if (p)
3408                 ret = sprintf(page, "%s\n", p->name);
3409         else if (mddev->clevel[0])
3410                 ret = sprintf(page, "%s\n", mddev->clevel);
3411         else if (mddev->level != LEVEL_NONE)
3412                 ret = sprintf(page, "%d\n", mddev->level);
3413         else
3414                 ret = 0;
3415         spin_unlock(&mddev->lock);
3416         return ret;
3417 }
3418 
3419 static ssize_t
3420 level_store(struct mddev *mddev, const char *buf, size_t len)
3421 {
3422         char clevel[16];
3423         ssize_t rv;
3424         size_t slen = len;
3425         struct md_personality *pers, *oldpers;
3426         long level;
3427         void *priv, *oldpriv;
3428         struct md_rdev *rdev;
3429 
3430         if (slen == 0 || slen >= sizeof(clevel))
3431                 return -EINVAL;
3432 
3433         rv = mddev_lock(mddev);
3434         if (rv)
3435                 return rv;
3436 
3437         if (mddev->pers == NULL) {
3438                 strncpy(mddev->clevel, buf, slen);
3439                 if (mddev->clevel[slen-1] == '\n')
3440                         slen--;
3441                 mddev->clevel[slen] = 0;
3442                 mddev->level = LEVEL_NONE;
3443                 rv = len;
3444                 goto out_unlock;
3445         }
3446         rv = -EROFS;
3447         if (mddev->ro)
3448                 goto out_unlock;
3449 
3450         /* request to change the personality.  Need to ensure:
3451          *  - array is not engaged in resync/recovery/reshape
3452          *  - old personality can be suspended
3453          *  - new personality will access other array.
3454          */
3455 
3456         rv = -EBUSY;
3457         if (mddev->sync_thread ||
3458             test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
3459             mddev->reshape_position != MaxSector ||
3460             mddev->sysfs_active)
3461                 goto out_unlock;
3462 
3463         rv = -EINVAL;
3464         if (!mddev->pers->quiesce) {
3465                 printk(KERN_WARNING "md: %s: %s does not support online personality change\n",
3466                        mdname(mddev), mddev->pers->name);
3467                 goto out_unlock;
3468         }
3469 
3470         /* Now find the new personality */
3471         strncpy(clevel, buf, slen);
3472         if (clevel[slen-1] == '\n')
3473                 slen--;
3474         clevel[slen] = 0;
3475         if (kstrtol(clevel, 10, &level))
3476                 level = LEVEL_NONE;
3477 
3478         if (request_module("md-%s", clevel) != 0)
3479                 request_module("md-level-%s", clevel);
3480         spin_lock(&pers_lock);
3481         pers = find_pers(level, clevel);
3482         if (!pers || !try_module_get(pers->owner)) {
3483                 spin_unlock(&pers_lock);
3484                 printk(KERN_WARNING "md: personality %s not loaded\n", clevel);
3485                 rv = -EINVAL;
3486                 goto out_unlock;
3487         }
3488         spin_unlock(&pers_lock);
3489 
3490         if (pers == mddev->pers) {
3491                 /* Nothing to do! */
3492                 module_put(pers->owner);
3493                 rv = len;
3494                 goto out_unlock;
3495         }
3496         if (!pers->takeover) {
3497                 module_put(pers->owner);
3498                 printk(KERN_WARNING "md: %s: %s does not support personality takeover\n",
3499                        mdname(mddev), clevel);
3500                 rv = -EINVAL;
3501                 goto out_unlock;
3502         }
3503 
3504         rdev_for_each(rdev, mddev)
3505                 rdev->new_raid_disk = rdev->raid_disk;
3506 
3507         /* ->takeover must set new_* and/or delta_disks
3508          * if it succeeds, and may set them when it fails.
3509          */
3510         priv = pers->takeover(mddev);
3511         if (IS_ERR(priv)) {
3512                 mddev->new_level = mddev->level;
3513                 mddev->new_layout = mddev->layout;
3514                 mddev->new_chunk_sectors = mddev->chunk_sectors;
3515                 mddev->raid_disks -= mddev->delta_disks;
3516                 mddev->delta_disks = 0;
3517                 mddev->reshape_backwards = 0;
3518                 module_put(pers->owner);
3519                 printk(KERN_WARNING "md: %s: %s would not accept array\n",
3520                        mdname(mddev), clevel);
3521                 rv = PTR_ERR(priv);
3522                 goto out_unlock;
3523         }
3524 
3525         /* Looks like we have a winner */
3526         mddev_suspend(mddev);
3527         mddev_detach(mddev);
3528 
3529         spin_lock(&mddev->lock);
3530         oldpers = mddev->pers;
3531         oldpriv = mddev->private;
3532         mddev->pers = pers;
3533         mddev->private = priv;
3534         strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
3535         mddev->level = mddev->new_level;
3536         mddev->layout = mddev->new_layout;
3537         mddev->chunk_sectors = mddev->new_chunk_sectors;
3538         mddev->delta_disks = 0;
3539         mddev->reshape_backwards = 0;
3540         mddev->degraded = 0;
3541         spin_unlock(&mddev->lock);
3542 
3543         if (oldpers->sync_request == NULL &&
3544             mddev->external) {
3545                 /* We are converting from a no-redundancy array
3546                  * to a redundancy array and metadata is managed
3547                  * externally so we need to be sure that writes
3548                  * won't block due to a need to transition
3549                  *      clean->dirty
3550                  * until external management is started.
3551                  */
3552                 mddev->in_sync = 0;
3553                 mddev->safemode_delay = 0;
3554                 mddev->safemode = 0;
3555         }
3556 
3557         oldpers->free(mddev, oldpriv);
3558 
3559         if (oldpers->sync_request == NULL &&
3560             pers->sync_request != NULL) {
3561                 /* need to add the md_redundancy_group */
3562                 if (sysfs_create_group(&mddev->kobj, &md_redundancy_group))
3563                         printk(KERN_WARNING
3564                                "md: cannot register extra attributes for %s\n",
3565                                mdname(mddev));
3566                 mddev->sysfs_action = sysfs_get_dirent(mddev->kobj.sd, "sync_action");
3567         }
3568         if (oldpers->sync_request != NULL &&
3569             pers->sync_request == NULL) {
3570                 /* need to remove the md_redundancy_group */
3571                 if (mddev->to_remove == NULL)
3572                         mddev->to_remove = &md_redundancy_group;
3573         }
3574 
3575         rdev_for_each(rdev, mddev) {
3576                 if (rdev->raid_disk < 0)
3577                         continue;
3578                 if (rdev->new_raid_disk >= mddev->raid_disks)
3579                         rdev->new_raid_disk = -1;
3580                 if (rdev->new_raid_disk == rdev->raid_disk)
3581                         continue;
3582                 sysfs_unlink_rdev(mddev, rdev);
3583         }
3584         rdev_for_each(rdev, mddev) {
3585                 if (rdev->raid_disk < 0)
3586                         continue;
3587                 if (rdev->new_raid_disk == rdev->raid_disk)
3588                         continue;
3589                 rdev->raid_disk = rdev->new_raid_disk;
3590                 if (rdev->raid_disk < 0)
3591                         clear_bit(In_sync, &rdev->flags);
3592                 else {
3593                         if (sysfs_link_rdev(mddev, rdev))
3594                                 printk(KERN_WARNING "md: cannot register rd%d"
3595                                        " for %s after level change\n",
3596                                        rdev->raid_disk, mdname(mddev));
3597                 }
3598         }
3599 
3600         if (pers->sync_request == NULL) {
3601                 /* this is now an array without redundancy, so
3602                  * it must always be in_sync
3603                  */
3604                 mddev->in_sync = 1;
3605                 del_timer_sync(&mddev->safemode_timer);
3606         }
3607         blk_set_stacking_limits(&mddev->queue->limits);
3608         pers->run(mddev);
3609         set_bit(MD_CHANGE_DEVS, &mddev->flags);
3610         mddev_resume(mddev);
3611         if (!mddev->thread)
3612                 md_update_sb(mddev, 1);
3613         sysfs_notify(&mddev->kobj, NULL, "level");
3614         md_new_event(mddev);
3615         rv = len;
3616 out_unlock:
3617         mddev_unlock(mddev);
3618         return rv;
3619 }
3620 
3621 static struct md_sysfs_entry md_level =
3622 __ATTR(level, S_IRUGO|S_IWUSR, level_show, level_store);
3623 
3624 static ssize_t
3625 layout_show(struct mddev *mddev, char *page)
3626 {
3627         /* just a number, not meaningful for all levels */
3628         if (mddev->reshape_position != MaxSector &&
3629             mddev->layout != mddev->new_layout)
3630                 return sprintf(page, "%d (%d)\n",
3631                                mddev->new_layout, mddev->layout);
3632         return sprintf(page, "%d\n", mddev->layout);
3633 }
3634 
3635 static ssize_t
3636 layout_store(struct mddev *mddev, const char *buf, size_t len)
3637 {
3638         unsigned int n;
3639         int err;
3640 
3641         err = kstrtouint(buf, 10, &n);
3642         if (err < 0)
3643                 return err;
3644         err = mddev_lock(mddev);
3645         if (err)
3646                 return err;
3647 
3648         if (mddev->pers) {
3649                 if (mddev->pers->check_reshape == NULL)
3650                         err = -EBUSY;
3651                 else if (mddev->ro)
3652                         err = -EROFS;
3653                 else {
3654                         mddev->new_layout = n;
3655                         err = mddev->pers->check_reshape(mddev);
3656                         if (err)
3657                                 mddev->new_layout = mddev->layout;
3658                 }
3659         } else {
3660                 mddev->new_layout = n;
3661                 if (mddev->reshape_position == MaxSector)
3662                         mddev->layout = n;
3663         }
3664         mddev_unlock(mddev);
3665         return err ?: len;
3666 }
3667 static struct md_sysfs_entry md_layout =
3668 __ATTR(layout, S_IRUGO|S_IWUSR, layout_show, layout_store);
3669 
3670 static ssize_t
3671 raid_disks_show(struct mddev *mddev, char *page)
3672 {
3673         if (mddev->raid_disks == 0)
3674                 return 0;
3675         if (mddev->reshape_position != MaxSector &&
3676             mddev->delta_disks != 0)
3677                 return sprintf(page, "%d (%d)\n", mddev->raid_disks,
3678                                mddev->raid_disks - mddev->delta_disks);
3679         return sprintf(page, "%d\n", mddev->raid_disks);
3680 }
3681 
3682 static int update_raid_disks(struct mddev *mddev, int raid_disks);
3683 
3684 static ssize_t
3685 raid_disks_store(struct mddev *mddev, const char *buf, size_t len)
3686 {
3687         unsigned int n;
3688         int err;
3689 
3690         err = kstrtouint(buf, 10, &n);
3691         if (err < 0)
3692                 return err;
3693 
3694         err = mddev_lock(mddev);
3695         if (err)
3696                 return err;
3697         if (mddev->pers)
3698                 err = update_raid_disks(mddev, n);
3699         else if (mddev->reshape_position != MaxSector) {
3700                 struct md_rdev *rdev;
3701                 int olddisks = mddev->raid_disks - mddev->delta_disks;
3702 
3703                 err = -EINVAL;
3704                 rdev_for_each(rdev, mddev) {
3705                         if (olddisks < n &&
3706                             rdev->data_offset < rdev->new_data_offset)
3707                                 goto out_unlock;
3708                         if (olddisks > n &&
3709                             rdev->data_offset > rdev->new_data_offset)
3710                                 goto out_unlock;
3711                 }
3712                 err = 0;
3713                 mddev->delta_disks = n - olddisks;
3714                 mddev->raid_disks = n;
3715                 mddev->reshape_backwards = (mddev->delta_disks < 0);
3716         } else
3717                 mddev->raid_disks = n;
3718 out_unlock:
3719         mddev_unlock(mddev);
3720         return err ? err : len;
3721 }
3722 static struct md_sysfs_entry md_raid_disks =
3723 __ATTR(raid_disks, S_IRUGO|S_IWUSR, raid_disks_show, raid_disks_store);
3724 
3725 static ssize_t
3726 chunk_size_show(struct mddev *mddev, char *page)
3727 {
3728         if (mddev->reshape_position != MaxSector &&
3729             mddev->chunk_sectors != mddev->new_chunk_sectors)
3730                 return sprintf(page, "%d (%d)\n",
3731                                mddev->new_chunk_sectors << 9,
3732                                mddev->chunk_sectors << 9);
3733         return sprintf(page, "%d\n", mddev->chunk_sectors << 9);
3734 }
3735 
3736 static ssize_t
3737 chunk_size_store(struct mddev *mddev, const char *buf, size_t len)
3738 {
3739         unsigned long n;
3740         int err;
3741 
3742         err = kstrtoul(buf, 10, &n);
3743         if (err < 0)
3744                 return err;
3745 
3746         err = mddev_lock(mddev);
3747         if (err)
3748                 return err;
3749         if (mddev->pers) {
3750                 if (mddev->pers->check_reshape == NULL)
3751                         err = -EBUSY;
3752                 else if (mddev->ro)
3753                         err = -EROFS;
3754                 else {
3755                         mddev->new_chunk_sectors = n >> 9;
3756                         err = mddev->pers->check_reshape(mddev);
3757                         if (err)
3758                                 mddev->new_chunk_sectors = mddev->chunk_sectors;
3759                 }
3760         } else {
3761                 mddev->new_chunk_sectors = n >> 9;
3762                 if (mddev->reshape_position == MaxSector)
3763                         mddev->chunk_sectors = n >> 9;
3764         }
3765         mddev_unlock(mddev);
3766         return err ?: len;
3767 }
3768 static struct md_sysfs_entry md_chunk_size =
3769 __ATTR(chunk_size, S_IRUGO|S_IWUSR, chunk_size_show, chunk_size_store);
3770 
3771 static ssize_t
3772 resync_start_show(struct mddev *mddev, char *page)
3773 {
3774         if (mddev->recovery_cp == MaxSector)
3775                 return sprintf(page, "none\n");
3776         return sprintf(page, "%llu\n", (unsigned long long)mddev->recovery_cp);
3777 }
3778 
3779 static ssize_t
3780 resync_start_store(struct mddev *mddev, const char *buf, size_t len)
3781 {
3782         unsigned long long n;
3783         int err;
3784 
3785         if (cmd_match(buf, "none"))
3786                 n = MaxSector;
3787         else {
3788                 err = kstrtoull(buf, 10, &n);
3789                 if (err < 0)
3790                         return err;
3791                 if (n != (sector_t)n)
3792                         return -EINVAL;
3793         }
3794 
3795         err = mddev_lock(mddev);
3796         if (err)
3797                 return err;
3798         if (mddev->pers && !test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
3799                 err = -EBUSY;
3800 
3801         if (!err) {
3802                 mddev->recovery_cp = n;
3803                 if (mddev->pers)
3804                         set_bit(MD_CHANGE_CLEAN, &mddev->flags);
3805         }
3806         mddev_unlock(mddev);
3807         return err ?: len;
3808 }
3809 static struct md_sysfs_entry md_resync_start =
3810 __ATTR_PREALLOC(resync_start, S_IRUGO|S_IWUSR,
3811                 resync_start_show, resync_start_store);
3812 
3813 /*
3814  * The array state can be:
3815  *
3816  * clear
3817  *     No devices, no size, no level
3818  *     Equivalent to STOP_ARRAY ioctl
3819  * inactive
3820  *     May have some settings, but array is not active
3821  *        all IO results in error
3822  *     When written, doesn't tear down array, but just stops it
3823  * suspended (not supported yet)
3824  *     All IO requests will block. The array can be reconfigured.
3825  *     Writing this, if accepted, will block until array is quiescent
3826  * readonly
3827  *     no resync can happen.  no superblocks get written.
3828  *     write requests fail
3829  * read-auto
3830  *     like readonly, but behaves like 'clean' on a write request.
3831  *
3832  * clean - no pending writes, but otherwise active.
3833  *     When written to inactive array, starts without resync
3834  *     If a write request arrives then
3835  *       if metadata is known, mark 'dirty' and switch to 'active'.
3836  *       if not known, block and switch to write-pending
3837  *     If written to an active array that has pending writes, then fails.
3838  * active
3839  *     fully active: IO and resync can be happening.
3840  *     When written to inactive array, starts with resync
3841  *
3842  * write-pending
3843  *     clean, but writes are blocked waiting for 'active' to be written.
3844  *
3845  * active-idle
3846  *     like active, but no writes have been seen for a while (100msec).
3847  *
3848  */
3849 enum array_state { clear, inactive, suspended, readonly, read_auto, clean, active,
3850                    write_pending, active_idle, bad_word};
3851 static char *array_states[] = {
3852         "clear", "inactive", "suspended", "readonly", "read-auto", "clean", "active",
3853         "write-pending", "active-idle", NULL };
3854 
3855 static int match_word(const char *word, char **list)
3856 {
3857         int n;
3858         for (n=0; list[n]; n++)
3859                 if (cmd_match(word, list[n]))
3860                         break;
3861         return n;
3862 }
3863 
3864 static ssize_t
3865 array_state_show(struct mddev *mddev, char *page)
3866 {
3867         enum array_state st = inactive;
3868 
3869         if (mddev->pers)
3870                 switch(mddev->ro) {
3871                 case 1:
3872                         st = readonly;
3873                         break;
3874                 case 2:
3875                         st = read_auto;
3876                         break;
3877                 case 0:
3878                         if (mddev->in_sync)
3879                                 st = clean;
3880                         else if (test_bit(MD_CHANGE_PENDING, &mddev->flags))
3881                                 st = write_pending;
3882                         else if (mddev->safemode)
3883                                 st = active_idle;
3884                         else
3885                                 st = active;
3886                 }
3887         else {
3888                 if (list_empty(&mddev->disks) &&
3889                     mddev->raid_disks == 0 &&
3890                     mddev->dev_sectors == 0)
3891                         st = clear;
3892                 else
3893                         st = inactive;
3894         }
3895         return sprintf(page, "%s\n", array_states[st]);
3896 }
3897 
3898 static int do_md_stop(struct mddev *mddev, int ro, struct block_device *bdev);
3899 static int md_set_readonly(struct mddev *mddev, struct block_device *bdev);
3900 static int do_md_run(struct mddev *mddev);
3901 static int restart_array(struct mddev *mddev);
3902 
3903 static ssize_t
3904 array_state_store(struct mddev *mddev, const char *buf, size_t len)
3905 {
3906         int err;
3907         enum array_state st = match_word(buf, array_states);
3908 
3909         if (mddev->pers && (st == active || st == clean) && mddev->ro != 1) {
3910                 /* don't take reconfig_mutex when toggling between
3911                  * clean and active
3912                  */
3913                 spin_lock(&mddev->lock);
3914                 if (st == active) {
3915                         restart_array(mddev);
3916                         clear_bit(MD_CHANGE_PENDING, &mddev->flags);
3917                         wake_up(&mddev->sb_wait);
3918                         err = 0;
3919                 } else /* st == clean */ {
3920                         restart_array(mddev);
3921                         if (atomic_read(&mddev->writes_pending) == 0) {
3922                                 if (mddev->in_sync == 0) {
3923                                         mddev->in_sync = 1;
3924                                         if (mddev->safemode == 1)
3925                                                 mddev->safemode = 0;
3926                                         set_bit(MD_CHANGE_CLEAN, &mddev->flags);
3927                                 }
3928                                 err = 0;
3929                         } else
3930                                 err = -EBUSY;
3931                 }
3932                 spin_unlock(&mddev->lock);
3933                 return err ?: len;
3934         }
3935         err = mddev_lock(mddev);
3936         if (err)
3937                 return err;
3938         err = -EINVAL;
3939         switch(st) {
3940         case bad_word:
3941                 break;
3942         case clear:
3943                 /* stopping an active array */
3944                 err = do_md_stop(mddev, 0, NULL);
3945                 break;
3946         case inactive:
3947                 /* stopping an active array */
3948                 if (mddev->pers)
3949                         err = do_md_stop(mddev, 2, NULL);
3950                 else
3951                         err = 0; /* already inactive */
3952                 break;
3953         case suspended:
3954                 break; /* not supported yet */
3955         case readonly:
3956                 if (mddev->pers)
3957                         err = md_set_readonly(mddev, NULL);
3958                 else {
3959                         mddev->ro = 1;
3960                         set_disk_ro(mddev->gendisk, 1);
3961                         err = do_md_run(mddev);
3962                 }
3963                 break;
3964         case read_auto:
3965                 if (mddev->pers) {
3966                         if (mddev->ro == 0)
3967                                 err = md_set_readonly(mddev, NULL);
3968                         else if (mddev->ro == 1)
3969                                 err = restart_array(mddev);
3970                         if (err == 0) {
3971                                 mddev->ro = 2;
3972                                 set_disk_ro(mddev->gendisk, 0);
3973                         }
3974                 } else {
3975                         mddev->ro = 2;
3976                         err = do_md_run(mddev);
3977                 }
3978                 break;
3979         case clean:
3980                 if (mddev->pers) {
3981                         err = restart_array(mddev);
3982                         if (err)
3983                                 break;
3984                         spin_lock(&mddev->lock);
3985                         if (atomic_read(&mddev->writes_pending) == 0) {
3986                                 if (mddev->in_sync == 0) {
3987                                         mddev->in_sync = 1;
3988                                         if (mddev->safemode == 1)
3989                                                 mddev->safemode = 0;
3990                                         set_bit(MD_CHANGE_CLEAN, &mddev->flags);
3991                                 }
3992                                 err = 0;
3993                         } else
3994                                 err = -EBUSY;
3995                         spin_unlock(&mddev->lock);
3996                 } else
3997                         err = -EINVAL;
3998                 break;
3999         case active:
4000                 if (mddev->pers) {
4001                         err = restart_array(mddev);
4002                         if (err)
4003                                 break;
4004                         clear_bit(MD_CHANGE_PENDING, &mddev->flags);
4005                         wake_up(&mddev->sb_wait);
4006                         err = 0;
4007                 } else {
4008                         mddev->ro = 0;
4009                         set_disk_ro(mddev->gendisk, 0);
4010                         err = do_md_run(mddev);
4011                 }
4012                 break;
4013         case write_pending:
4014         case active_idle:
4015                 /* these cannot be set */
4016                 break;
4017         }
4018 
4019         if (!err) {
4020                 if (mddev->hold_active == UNTIL_IOCTL)
4021                         mddev->hold_active = 0;
4022                 sysfs_notify_dirent_safe(mddev->sysfs_state);
4023         }
4024         mddev_unlock(mddev);
4025         return err ?: len;
4026 }
4027 static struct md_sysfs_entry md_array_state =
4028 __ATTR_PREALLOC(array_state, S_IRUGO|S_IWUSR, array_state_show, array_state_store);
4029 
4030 static ssize_t
4031 max_corrected_read_errors_show(struct mddev *mddev, char *page) {
4032         return sprintf(page, "%d\n",
4033                        atomic_read(&mddev->max_corr_read_errors));
4034 }
4035 
4036 static ssize_t
4037 max_corrected_read_errors_store(struct mddev *mddev, const char *buf, size_t len)
4038 {
4039         unsigned int n;
4040         int rv;
4041 
4042         rv = kstrtouint(buf, 10, &n);
4043         if (rv < 0)
4044                 return rv;
4045         atomic_set(&mddev->max_corr_read_errors, n);
4046         return len;
4047 }
4048 
4049 static struct md_sysfs_entry max_corr_read_errors =
4050 __ATTR(max_read_errors, S_IRUGO|S_IWUSR, max_corrected_read_errors_show,
4051         max_corrected_read_errors_store);
4052 
4053 static ssize_t
4054 null_show(struct mddev *mddev, char *page)
4055 {
4056         return -EINVAL;
4057 }
4058 
4059 static ssize_t
4060 new_dev_store(struct mddev *mddev, const char *buf, size_t len)
4061 {
4062         /* buf must be %d:%d\n? giving major and minor numbers */
4063         /* The new device is added to the array.
4064          * If the array has a persistent superblock, we read the
4065          * superblock to initialise info and check validity.
4066          * Otherwise, only checking done is that in bind_rdev_to_array,
4067          * which mainly checks size.
4068          */
4069         char *e;
4070         int major = simple_strtoul(buf, &e, 10);
4071         int minor;
4072         dev_t dev;
4073         struct md_rdev *rdev;
4074         int err;
4075 
4076         if (!*buf || *e != ':' || !e[1] || e[1] == '\n')
4077                 return -EINVAL;
4078         minor = simple_strtoul(e+1, &e, 10);
4079         if (*e && *e != '\n')
4080                 return -EINVAL;
4081         dev = MKDEV(major, minor);
4082         if (major != MAJOR(dev) ||
4083             minor != MINOR(dev))
4084                 return -EOVERFLOW;
4085 
4086         flush_workqueue(md_misc_wq);
4087 
4088         err = mddev_lock(mddev);
4089         if (err)
4090                 return err;
4091         if (mddev->persistent) {
4092                 rdev = md_import_device(dev, mddev->major_version,
4093                                         mddev->minor_version);
4094                 if (!IS_ERR(rdev) && !list_empty(&mddev->disks)) {
4095                         struct md_rdev *rdev0
4096                                 = list_entry(mddev->disks.next,
4097                                              struct md_rdev, same_set);
4098                         err = super_types[mddev->major_version]
4099                                 .load_super(rdev, rdev0, mddev->minor_version);
4100                         if (err < 0)
4101                                 goto out;
4102                 }
4103         } else if (mddev->external)
4104                 rdev = md_import_device(dev, -2, -1);
4105         else
4106                 rdev = md_import_device(dev, -1, -1);
4107 
4108         if (IS_ERR(rdev)) {
4109                 mddev_unlock(mddev);
4110                 return PTR_ERR(rdev);
4111         }
4112         err = bind_rdev_to_array(rdev, mddev);
4113  out:
4114         if (err)
4115                 export_rdev(rdev);
4116         mddev_unlock(mddev);
4117         return err ? err : len;
4118 }
4119 
4120 static struct md_sysfs_entry md_new_device =
4121 __ATTR(new_dev, S_IWUSR, null_show, new_dev_store);
4122 
4123 static ssize_t
4124 bitmap_store(struct mddev *mddev, const char *buf, size_t len)
4125 {
4126         char *end;
4127         unsigned long chunk, end_chunk;
4128         int err;
4129 
4130         err = mddev_lock(mddev);
4131         if (err)
4132                 return err;
4133         if (!mddev->bitmap)
4134                 goto out;
4135         /* buf should be <chunk> <chunk> ... or <chunk>-<chunk> ... (range) */
4136         while (*buf) {
4137                 chunk = end_chunk = simple_strtoul(buf, &end, 0);
4138                 if (buf == end) break;
4139                 if (*end == '-') { /* range */
4140                         buf = end + 1;
4141                         end_chunk = simple_strtoul(buf, &end, 0);
4142                         if (buf == end) break;
4143                 }
4144                 if (*end && !isspace(*end)) break;
4145                 bitmap_dirty_bits(mddev->bitmap, chunk, end_chunk);
4146                 buf = skip_spaces(end);
4147         }
4148         bitmap_unplug(mddev->bitmap); /* flush the bits to disk */
4149 out:
4150         mddev_unlock(mddev);
4151         return len;
4152 }
4153 
4154 static struct md_sysfs_entry md_bitmap =
4155 __ATTR(bitmap_set_bits, S_IWUSR, null_show, bitmap_store);
4156 
4157 static ssize_t
4158 size_show(struct mddev *mddev, char *page)
4159 {
4160         return sprintf(page, "%llu\n",
4161                 (unsigned long long)mddev->dev_sectors / 2);
4162 }
4163 
4164 static int update_size(struct mddev *mddev, sector_t num_sectors);
4165 
4166 static ssize_t
4167 size_store(struct mddev *mddev, const char *buf, size_t len)
4168 {
4169         /* If array is inactive, we can reduce the component size, but
4170          * not increase it (except from 0).
4171          * If array is active, we can try an on-line resize
4172          */
4173         sector_t sectors;
4174         int err = strict_blocks_to_sectors(buf, &sectors);
4175 
4176         if (err < 0)
4177                 return err;
4178         err = mddev_lock(mddev);
4179         if (err)
4180                 return err;
4181         if (mddev->pers) {
4182                 err = update_size(mddev, sectors);
4183                 md_update_sb(mddev, 1);
4184         } else {
4185                 if (mddev->dev_sectors == 0 ||
4186                     mddev->dev_sectors > sectors)
4187                         mddev->dev_sectors = sectors;
4188                 else
4189                         err = -ENOSPC;
4190         }
4191         mddev_unlock(mddev);
4192         return err ? err : len;
4193 }
4194 
4195 static struct md_sysfs_entry md_size =
4196 __ATTR(component_size, S_IRUGO|S_IWUSR, size_show, size_store);
4197 
4198 /* Metadata version.
4199  * This is one of
4200  *   'none' for arrays with no metadata (good luck...)
4201  *   'external' for arrays with externally managed metadata,
4202  * or N.M for internally known formats
4203  */
4204 static ssize_t
4205 metadata_show(struct mddev *mddev, char *page)
4206 {
4207         if (mddev->persistent)
4208                 return sprintf(page, "%d.%d\n",
4209                                mddev->major_version, mddev->minor_version);
4210         else if (mddev->external)
4211                 return sprintf(page, "external:%s\n", mddev->metadata_type);
4212         else
4213                 return sprintf(page, "none\n");
4214 }
4215 
4216 static ssize_t
4217 metadata_store(struct mddev *mddev, const char *buf, size_t len)
4218 {
4219         int major, minor;
4220         char *e;
4221         int err;
4222         /* Changing the details of 'external' metadata is
4223          * always permitted.  Otherwise there must be
4224          * no devices attached to the array.
4225          */
4226 
4227         err = mddev_lock(mddev);
4228         if (err)
4229                 return err;
4230         err = -EBUSY;
4231         if (mddev->external && strncmp(buf, "external:", 9) == 0)
4232                 ;
4233         else if (!list_empty(&mddev->disks))
4234                 goto out_unlock;
4235 
4236         err = 0;
4237         if (cmd_match(buf, "none")) {
4238                 mddev->persistent = 0;
4239                 mddev->external = 0;
4240                 mddev->major_version = 0;
4241                 mddev->minor_version = 90;
4242                 goto out_unlock;
4243         }
4244         if (strncmp(buf, "external:", 9) == 0) {
4245                 size_t namelen = len-9;
4246                 if (namelen >= sizeof(mddev->metadata_type))
4247                         namelen = sizeof(mddev->metadata_type)-1;
4248                 strncpy(mddev->metadata_type, buf+9, namelen);
4249                 mddev->metadata_type[namelen] = 0;
4250                 if (namelen && mddev->metadata_type[namelen-1] == '\n')
4251                         mddev->metadata_type[--namelen] = 0;
4252                 mddev->persistent = 0;
4253                 mddev->external = 1;
4254                 mddev->major_version = 0;
4255                 mddev->minor_version = 90;
4256                 goto out_unlock;
4257         }
4258         major = simple_strtoul(buf, &e, 10);
4259         err = -EINVAL;
4260         if (e==buf || *e != '.')
4261                 goto out_unlock;
4262         buf = e+1;
4263         minor = simple_strtoul(buf, &e, 10);
4264         if (e==buf || (*e && *e != '\n') )
4265                 goto out_unlock;
4266         err = -ENOENT;
4267         if (major >= ARRAY_SIZE(super_types) || super_types[major].name == NULL)
4268                 goto out_unlock;
4269         mddev->major_version = major;
4270         mddev->minor_version = minor;
4271         mddev->persistent = 1;
4272         mddev->external = 0;
4273         err = 0;
4274 out_unlock:
4275         mddev_unlock(mddev);
4276         return err ?: len;
4277 }
4278 
4279 static struct md_sysfs_entry md_metadata =
4280 __ATTR_PREALLOC(metadata_version, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
4281 
4282 static ssize_t
4283 action_show(struct mddev *mddev, char *page)
4284 {
4285         char *type = "idle";
4286         unsigned long recovery = mddev->recovery;
4287         if (test_bit(MD_RECOVERY_FROZEN, &recovery))
4288                 type = "frozen";
4289         else if (test_bit(MD_RECOVERY_RUNNING, &recovery) ||
4290             (!mddev->ro && test_bit(MD_RECOVERY_NEEDED, &recovery))) {
4291                 if (test_bit(MD_RECOVERY_RESHAPE, &recovery))
4292                         type = "reshape";
4293                 else if (test_bit(MD_RECOVERY_SYNC, &recovery)) {
4294                         if (!test_bit(MD_RECOVERY_REQUESTED, &recovery))
4295                                 type = "resync";
4296                         else if (test_bit(MD_RECOVERY_CHECK, &recovery))
4297                                 type = "check";
4298                         else
4299                                 type = "repair";
4300                 } else if (test_bit(MD_RECOVERY_RECOVER, &recovery))
4301                         type = "recover";
4302                 else if (mddev->reshape_position != MaxSector)
4303                         type = "reshape";
4304         }
4305         return sprintf(page, "%s\n", type);
4306 }
4307 
4308 static ssize_t
4309 action_store(struct mddev *mddev, const char *page, size_t len)
4310 {
4311         if (!mddev->pers || !mddev->pers->sync_request)
4312                 return -EINVAL;
4313 
4314 
4315         if (cmd_match(page, "idle") || cmd_match(page, "frozen")) {
4316                 if (cmd_match(page, "frozen"))
4317                         set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4318                 else
4319                         clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4320                 if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&
4321                     mddev_lock(mddev) == 0) {
4322                         flush_workqueue(md_misc_wq);
4323                         if (mddev->sync_thread) {
4324                                 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
4325                                 md_reap_sync_thread(mddev);
4326                         }
4327                         mddev_unlock(mddev);
4328                 }
4329         } else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4330                 return -EBUSY;
4331         else if (cmd_match(page, "resync"))
4332                 clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4333         else if (cmd_match(page, "recover")) {
4334                 clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4335                 set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
4336         } else if (cmd_match(page, "reshape")) {
4337                 int err;
4338                 if (mddev->pers->start_reshape == NULL)
4339                         return -EINVAL;
4340                 err = mddev_lock(mddev);
4341                 if (!err) {
4342                         if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4343                                 err =  -EBUSY;
4344                         else {
4345                                 clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4346                                 err = mddev->pers->start_reshape(mddev);
4347                         }
4348                         mddev_unlock(mddev);
4349                 }
4350                 if (err)
4351                         return err;
4352                 sysfs_notify(&mddev->kobj, NULL, "degraded");
4353         } else {
4354                 if (cmd_match(page, "check"))
4355                         set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
4356                 else if (!cmd_match(page, "repair"))
4357                         return -EINVAL;
4358                 clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4359                 set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
4360                 set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
4361         }
4362         if (mddev->ro == 2) {
4363                 /* A write to sync_action is enough to justify
4364                  * canceling read-auto mode
4365                  */
4366                 mddev->ro = 0;
4367                 md_wakeup_thread(mddev->sync_thread);
4368         }
4369         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4370         md_wakeup_thread(mddev->thread);
4371         sysfs_notify_dirent_safe(mddev->sysfs_action);
4372         return len;
4373 }
4374 
4375 static struct md_sysfs_entry md_scan_mode =
4376 __ATTR_PREALLOC(sync_action, S_IRUGO|S_IWUSR, action_show, action_store);
4377 
4378 static ssize_t
4379 last_sync_action_show(struct mddev *mddev, char *page)
4380 {
4381         return sprintf(page, "%s\n", mddev->last_sync_action);
4382 }
4383 
4384 static struct md_sysfs_entry md_last_scan_mode = __ATTR_RO(last_sync_action);
4385 
4386 static ssize_t
4387 mismatch_cnt_show(struct mddev *mddev, char *page)
4388 {
4389         return sprintf(page, "%llu\n",
4390                        (unsigned long long)
4391                        atomic64_read(&mddev->resync_mismatches));
4392 }
4393 
4394 static struct md_sysfs_entry md_mismatches = __ATTR_RO(mismatch_cnt);
4395 
4396 static ssize_t
4397 sync_min_show(struct mddev *mddev, char *page)
4398 {
4399         return sprintf(page, "%d (%s)\n", speed_min(mddev),
4400                        mddev->sync_speed_min ? "local": "system");
4401 }
4402 
4403 static ssize_t
4404 sync_min_store(struct mddev *mddev, const char *buf, size_t len)
4405 {
4406         unsigned int min;
4407         int rv;
4408 
4409         if (strncmp(buf, "system", 6)==0) {
4410                 min = 0;
4411         } else {
4412                 rv = kstrtouint(buf, 10, &min);
4413                 if (rv < 0)
4414                         return rv;
4415                 if (min == 0)
4416                         return -EINVAL;
4417         }
4418         mddev->sync_speed_min = min;
4419         return len;
4420 }
4421 
4422 static struct md_sysfs_entry md_sync_min =
4423 __ATTR(sync_speed_min, S_IRUGO|S_IWUSR, sync_min_show, sync_min_store);
4424 
4425 static ssize_t
4426 sync_max_show(struct mddev *mddev, char *page)
4427 {
4428         return sprintf(page, "%d (%s)\n", speed_max(mddev),
4429                        mddev->sync_speed_max ? "local": "system");
4430 }
4431 
4432 static ssize_t
4433 sync_max_store(struct mddev *mddev, const char *buf, size_t len)
4434 {
4435         unsigned int max;
4436         int rv;
4437 
4438         if (strncmp(buf, "system", 6)==0) {
4439                 max = 0;
4440         } else {
4441                 rv = kstrtouint(buf, 10, &max);
4442                 if (rv < 0)
4443                         return rv;
4444                 if (max == 0)
4445                         return -EINVAL;
4446         }
4447         mddev->sync_speed_max = max;
4448         return len;
4449 }
4450 
4451 static struct md_sysfs_entry md_sync_max =
4452 __ATTR(sync_speed_max, S_IRUGO|S_IWUSR, sync_max_show, sync_max_store);
4453 
4454 static ssize_t
4455 degraded_show(struct mddev *mddev, char *page)
4456 {
4457         return sprintf(page, "%d\n", mddev->degraded);
4458 }
4459 static struct md_sysfs_entry md_degraded = __ATTR_RO(degraded);
4460 
4461 static ssize_t
4462 sync_force_parallel_show(struct mddev *mddev, char *page)
4463 {
4464         return sprintf(page, "%d\n", mddev->parallel_resync);
4465 }
4466 
4467 static ssize_t
4468 sync_force_parallel_store(struct mddev *mddev, const char *buf, size_t len)
4469 {
4470         long n;
4471 
4472         if (kstrtol(buf, 10, &n))
4473                 return -EINVAL;
4474 
4475         if (n != 0 && n != 1)
4476                 return -EINVAL;
4477 
4478         mddev->parallel_resync = n;
4479 
4480         if (mddev->sync_thread)
4481                 wake_up(&resync_wait);
4482 
4483         return len;
4484 }
4485 
4486 /* force parallel resync, even with shared block devices */
4487 static struct md_sysfs_entry md_sync_force_parallel =
4488 __ATTR(sync_force_parallel, S_IRUGO|S_IWUSR,
4489        sync_force_parallel_show, sync_force_parallel_store);
4490 
4491 static ssize_t
4492 sync_speed_show(struct mddev *mddev, char *page)
4493 {
4494         unsigned long resync, dt, db;
4495         if (mddev->curr_resync == 0)
4496                 return sprintf(page, "none\n");
4497         resync = mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active);
4498         dt = (jiffies - mddev->resync_mark) / HZ;
4499         if (!dt) dt++;
4500         db = resync - mddev->resync_mark_cnt;
4501         return sprintf(page, "%lu\n", db/dt/2); /* K/sec */
4502 }
4503 
4504 static struct md_sysfs_entry md_sync_speed = __ATTR_RO(sync_speed);
4505 
4506 static ssize_t
4507 sync_completed_show(struct mddev *mddev, char *page)
4508 {
4509         unsigned long long max_sectors, resync;
4510 
4511         if (!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4512                 return sprintf(page, "none\n");
4513 
4514         if (mddev->curr_resync == 1 ||
4515             mddev->curr_resync == 2)
4516                 return sprintf(page, "delayed\n");
4517 
4518         if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ||
4519             test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
4520                 max_sectors = mddev->resync_max_sectors;
4521         else
4522                 max_sectors = mddev->dev_sectors;
4523 
4524         resync = mddev->curr_resync_completed;
4525         return sprintf(page, "%llu / %llu\n", resync, max_sectors);
4526 }
4527 
4528 static struct md_sysfs_entry md_sync_completed =
4529         __ATTR_PREALLOC(sync_completed, S_IRUGO, sync_completed_show, NULL);
4530 
4531 static ssize_t
4532 min_sync_show(struct mddev *mddev, char *page)
4533 {
4534         return sprintf(page, "%llu\n",
4535                        (unsigned long long)mddev->resync_min);
4536 }
4537 static ssize_t
4538 min_sync_store(struct mddev *mddev, const char *buf, size_t len)
4539 {
4540         unsigned long long min;
4541         int err;
4542 
4543         if (kstrtoull(buf, 10, &min))
4544                 return -EINVAL;
4545 
4546         spin_lock(&mddev->lock);
4547         err = -EINVAL;
4548         if (min > mddev->resync_max)
4549                 goto out_unlock;
4550 
4551         err = -EBUSY;
4552         if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4553                 goto out_unlock;
4554 
4555         /* Round down to multiple of 4K for safety */
4556         mddev->resync_min = round_down(min, 8);
4557         err = 0;
4558 
4559 out_unlock:
4560         spin_unlock(&mddev->lock);
4561         return err ?: len;
4562 }
4563 
4564 static struct md_sysfs_entry md_min_sync =
4565 __ATTR(sync_min, S_IRUGO|S_IWUSR, min_sync_show, min_sync_store);
4566 
4567 static ssize_t
4568 max_sync_show(struct mddev *mddev, char *page)
4569 {
4570         if (mddev->resync_max == MaxSector)
4571                 return sprintf(page, "max\n");
4572         else
4573                 return sprintf(page, "%llu\n",
4574                                (unsigned long long)mddev->resync_max);
4575 }
4576 static ssize_t
4577 max_sync_store(struct mddev *mddev, const char *buf, size_t len)
4578 {
4579         int err;
4580         spin_lock(&mddev->lock);
4581         if (strncmp(buf, "max", 3) == 0)
4582                 mddev->resync_max = MaxSector;
4583         else {
4584                 unsigned long long max;
4585                 int chunk;
4586 
4587                 err = -EINVAL;
4588                 if (kstrtoull(buf, 10, &max))
4589                         goto out_unlock;
4590                 if (max < mddev->resync_min)
4591                         goto out_unlock;
4592 
4593                 err = -EBUSY;
4594                 if (max < mddev->resync_max &&
4595                     mddev->ro == 0 &&
4596                     test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4597                         goto out_unlock;
4598 
4599                 /* Must be a multiple of chunk_size */
4600                 chunk = mddev->chunk_sectors;
4601                 if (chunk) {
4602                         sector_t temp = max;
4603 
4604                         err = -EINVAL;
4605                         if (sector_div(temp, chunk))
4606                                 goto out_unlock;
4607                 }
4608                 mddev->resync_max = max;
4609         }
4610         wake_up(&mddev->recovery_wait);
4611         err = 0;
4612 out_unlock:
4613         spin_unlock(&mddev->lock);
4614         return err ?: len;
4615 }
4616 
4617 static struct md_sysfs_entry md_max_sync =
4618 __ATTR(sync_max, S_IRUGO|S_IWUSR, max_sync_show, max_sync_store);
4619 
4620 static ssize_t
4621 suspend_lo_show(struct mddev *mddev, char *page)
4622 {
4623         return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_lo);
4624 }
4625 
4626 static ssize_t
4627 suspend_lo_store(struct mddev *mddev, const char *buf, size_t len)
4628 {
4629         unsigned long long old, new;
4630         int err;
4631 
4632         err = kstrtoull(buf, 10, &new);
4633         if (err < 0)
4634                 return err;
4635         if (new != (sector_t)new)
4636                 return -EINVAL;
4637 
4638         err = mddev_lock(mddev);
4639         if (err)
4640                 return err;
4641         err = -EINVAL;
4642         if (mddev->pers == NULL ||
4643             mddev->pers->quiesce == NULL)
4644                 goto unlock;
4645         old = mddev->suspend_lo;
4646         mddev->suspend_lo = new;
4647         if (new >= old)
4648                 /* Shrinking suspended region */
4649                 mddev->pers->quiesce(mddev, 2);
4650         else {
4651                 /* Expanding suspended region - need to wait */
4652                 mddev->pers->quiesce(mddev, 1);
4653                 mddev->pers->quiesce(mddev, 0);
4654         }
4655         err = 0;
4656 unlock:
4657         mddev_unlock(mddev);
4658         return err ?: len;
4659 }
4660 static struct md_sysfs_entry md_suspend_lo =
4661 __ATTR(suspend_lo, S_IRUGO|S_IWUSR, suspend_lo_show, suspend_lo_store);
4662 
4663 static ssize_t
4664 suspend_hi_show(struct mddev *mddev, char *page)
4665 {
4666         return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_hi);
4667 }
4668 
4669 static ssize_t
4670 suspend_hi_store(struct mddev *mddev, const char *buf, size_t len)
4671 {
4672         unsigned long long old, new;
4673         int err;
4674 
4675         err = kstrtoull(buf, 10, &new);
4676         if (err < 0)
4677                 return err;
4678         if (new != (sector_t)new)
4679                 return -EINVAL;
4680 
4681         err = mddev_lock(mddev);
4682         if (err)
4683                 return err;
4684         err = -EINVAL;
4685         if (mddev->pers == NULL ||
4686             mddev->pers->quiesce == NULL)
4687                 goto unlock;
4688         old = mddev->suspend_hi;
4689         mddev->suspend_hi = new;
4690         if (new <= old)
4691                 /* Shrinking suspended region */
4692                 mddev->pers->quiesce(mddev, 2);
4693         else {
4694                 /* Expanding suspended region - need to wait */
4695                 mddev->pers->quiesce(mddev, 1);
4696                 mddev->pers->quiesce(mddev, 0);
4697         }
4698         err = 0;
4699 unlock:
4700         mddev_unlock(mddev);
4701         return err ?: len;
4702 }
4703 static struct md_sysfs_entry md_suspend_hi =
4704 __ATTR(suspend_hi, S_IRUGO|S_IWUSR, suspend_hi_show, suspend_hi_store);
4705 
4706 static ssize_t
4707 reshape_position_show(struct mddev *mddev, char *page)
4708 {
4709         if (mddev->reshape_position != MaxSector)
4710                 return sprintf(page, "%llu\n",
4711                                (unsigned long long)mddev->reshape_position);
4712         strcpy(page, "none\n");
4713         return 5;
4714 }
4715 
4716 static ssize_t
4717 reshape_position_store(struct mddev *mddev, const char *buf, size_t len)
4718 {
4719         struct md_rdev *rdev;
4720         unsigned long long new;
4721         int err;
4722 
4723         err = kstrtoull(buf, 10, &new);
4724         if (err < 0)
4725                 return err;
4726         if (new != (sector_t)new)
4727                 return -EINVAL;
4728         err = mddev_lock(mddev);
4729         if (err)
4730                 return err;
4731         err = -EBUSY;
4732         if (mddev->pers)
4733                 goto unlock;
4734         mddev->reshape_position = new;
4735         mddev->delta_disks = 0;
4736         mddev->reshape_backwards = 0;
4737         mddev->new_level = mddev->level;
4738         mddev->new_layout = mddev->layout;
4739         mddev->new_chunk_sectors = mddev->chunk_sectors;
4740         rdev_for_each(rdev, mddev)
4741                 rdev->new_data_offset = rdev->data_offset;
4742         err = 0;
4743 unlock:
4744         mddev_unlock(mddev);
4745         return err ?: len;
4746 }
4747 
4748 static struct md_sysfs_entry md_reshape_position =
4749 __ATTR(reshape_position, S_IRUGO|S_IWUSR, reshape_position_show,
4750        reshape_position_store);
4751 
4752 static ssize_t
4753 reshape_direction_show(struct mddev *mddev, char *page)
4754 {
4755         return sprintf(page, "%s\n",
4756                        mddev->reshape_backwards ? "backwards" : "forwards");
4757 }
4758 
4759 static ssize_t
4760 reshape_direction_store(struct mddev *mddev, const char *buf, size_t len)
4761 {
4762         int backwards = 0;
4763         int err;
4764 
4765         if (cmd_match(buf, "forwards"))
4766                 backwards = 0;
4767         else if (cmd_match(buf, "backwards"))
4768                 backwards = 1;
4769         else
4770                 return -EINVAL;
4771         if (mddev->reshape_backwards == backwards)
4772                 return len;
4773 
4774         err = mddev_lock(mddev);
4775         if (err)
4776                 return err;
4777         /* check if we are allowed to change */
4778         if (mddev->delta_disks)
4779                 err = -EBUSY;
4780         else if (mddev->persistent &&
4781             mddev->major_version == 0)
4782                 err =  -EINVAL;
4783         else
4784                 mddev->reshape_backwards = backwards;
4785         mddev_unlock(mddev);
4786         return err ?: len;
4787 }
4788 
4789 static struct md_sysfs_entry md_reshape_direction =
4790 __ATTR(reshape_direction, S_IRUGO|S_IWUSR, reshape_direction_show,
4791        reshape_direction_store);
4792 
4793 static ssize_t
4794 array_size_show(struct mddev *mddev, char *page)
4795 {
4796         if (mddev->external_size)
4797                 return sprintf(page, "%llu\n",
4798                                (unsigned long long)mddev->array_sectors/2);
4799         else
4800                 return sprintf(page, "default\n");
4801 }
4802 
4803 static ssize_t
4804 array_size_store(struct mddev *mddev, const char *buf, size_t len)
4805 {
4806         sector_t sectors;
4807         int err;
4808 
4809         err = mddev_lock(mddev);
4810         if (err)
4811                 return err;
4812 
4813         if (strncmp(buf, "default", 7) == 0) {
4814                 if (mddev->pers)
4815                         sectors = mddev->pers->size(mddev, 0, 0);
4816                 else
4817                         sectors = mddev->array_sectors;
4818 
4819                 mddev->external_size = 0;
4820         } else {
4821                 if (strict_blocks_to_sectors(buf, &sectors) < 0)
4822                         err = -EINVAL;
4823                 else if (mddev->pers && mddev->pers->size(mddev, 0, 0) < sectors)
4824                         err = -E2BIG;
4825                 else
4826                         mddev->external_size = 1;
4827         }
4828 
4829         if (!err) {
4830                 mddev->array_sectors = sectors;
4831                 if (mddev->pers) {
4832                         set_capacity(mddev->gendisk, mddev->array_sectors);
4833                         revalidate_disk(mddev->gendisk);
4834                 }
4835         }
4836         mddev_unlock(mddev);
4837         return err ?: len;
4838 }
4839 
4840 static struct md_sysfs_entry md_array_size =
4841 __ATTR(array_size, S_IRUGO|S_IWUSR, array_size_show,
4842        array_size_store);
4843 
4844 static struct attribute *md_default_attrs[] = {
4845         &md_level.attr,
4846         &md_layout.attr,
4847         &md_raid_disks.attr,
4848         &md_chunk_size.attr,
4849         &md_size.attr,
4850         &md_resync_start.attr,
4851         &md_metadata.attr,
4852         &md_new_device.attr,
4853         &md_safe_delay.attr,
4854         &md_array_state.attr,
4855         &md_reshape_position.attr,
4856         &md_reshape_direction.attr,
4857         &md_array_size.attr,
4858         &max_corr_read_errors.attr,
4859         NULL,
4860 };
4861 
4862 static struct attribute *md_redundancy_attrs[] = {
4863         &md_scan_mode.attr,
4864         &md_last_scan_mode.attr,
4865         &md_mismatches.attr,
4866         &md_sync_min.attr,
4867         &md_sync_max.attr,
4868         &md_sync_speed.attr,
4869         &md_sync_force_parallel.attr,
4870         &md_sync_completed.attr,
4871         &md_min_sync.attr,
4872         &md_max_sync.attr,
4873         &md_suspend_lo.attr,
4874         &md_suspend_hi.attr,
4875         &md_bitmap.attr,
4876         &md_degraded.attr,
4877         NULL,
4878 };
4879 static struct attribute_group md_redundancy_group = {
4880         .name = NULL,
4881         .attrs = md_redundancy_attrs,
4882 };
4883 
4884 static ssize_t
4885 md_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
4886 {
4887         struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
4888         struct mddev *mddev = container_of(kobj, struct mddev, kobj);
4889         ssize_t rv;
4890 
4891         if (!entry->show)
4892                 return -EIO;
4893         spin_lock(&all_mddevs_lock);
4894         if (list_empty(&mddev->all_mddevs)) {
4895                 spin_unlock(&all_mddevs_lock);
4896                 return -EBUSY;
4897         }
4898         mddev_get(mddev);
4899         spin_unlock(&all_mddevs_lock);
4900 
4901         rv = entry->show(mddev, page);
4902         mddev_put(mddev);
4903         return rv;
4904 }
4905 
4906 static ssize_t
4907 md_attr_store(struct kobject *kobj, struct attribute *attr,
4908               const char *page, size_t length)
4909 {
4910         struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
4911         struct mddev *mddev = container_of(kobj, struct mddev, kobj);
4912         ssize_t rv;
4913 
4914         if (!entry->store)
4915                 return -EIO;
4916         if (!capable(CAP_SYS_ADMIN))
4917                 return -EACCES;
4918         spin_lock(&all_mddevs_lock);
4919         if (list_empty(&mddev->all_mddevs)) {
4920                 spin_unlock(&all_mddevs_lock);
4921                 return -EBUSY;
4922         }
4923         mddev_get(mddev);
4924         spin_unlock(&all_mddevs_lock);
4925         rv = entry->store(mddev, page, length);
4926         mddev_put(mddev);
4927         return rv;
4928 }
4929 
4930 static void md_free(struct kobject *ko)
4931 {
4932         struct mddev *mddev = container_of(ko, struct mddev, kobj);
4933 
4934         if (mddev->sysfs_state)
4935                 sysfs_put(mddev->sysfs_state);
4936 
4937         if (mddev->queue)
4938                 blk_cleanup_queue(mddev->queue);
4939         if (mddev->gendisk) {
4940                 del_gendisk(mddev->gendisk);
4941                 put_disk(mddev->gendisk);
4942         }
4943 
4944         kfree(mddev);
4945 }
4946 
4947 static const struct sysfs_ops md_sysfs_ops = {
4948         .show   = md_attr_show,
4949         .store  = md_attr_store,
4950 };
4951 static struct kobj_type md_ktype = {
4952         .release        = md_free,
4953         .sysfs_ops      = &md_sysfs_ops,
4954         .default_attrs  = md_default_attrs,
4955 };
4956 
4957 int mdp_major = 0;
4958 
4959 static void mddev_delayed_delete(struct work_struct *ws)
4960 {
4961         struct mddev *mddev = container_of(ws, struct mddev, del_work);
4962 
4963         sysfs_remove_group(&mddev->kobj, &md_bitmap_group);
4964         kobject_del(&mddev->kobj);
4965         kobject_put(&mddev->kobj);
4966 }
4967 
4968 static int md_alloc(dev_t dev, char *name)
4969 {
4970         static DEFINE_MUTEX(disks_mutex);
4971         struct mddev *mddev = mddev_find(dev);
4972         struct gendisk *disk;
4973         int partitioned;
4974         int shift;
4975         int unit;
4976         int error;
4977 
4978         if (!mddev)
4979                 return -ENODEV;
4980 
4981         partitioned = (MAJOR(mddev->unit) != MD_MAJOR);
4982         shift = partitioned ? MdpMinorShift : 0;
4983         unit = MINOR(mddev->unit) >> shift;
4984 
4985         /* wait for any previous instance of this device to be
4986          * completely removed (mddev_delayed_delete).
4987          */
4988         flush_workqueue(md_misc_wq);
4989 
4990         mutex_lock(&disks_mutex);
4991         error = -EEXIST;
4992         if (mddev->gendisk)
4993                 goto abort;
4994 
4995         if (name) {
4996                 /* Need to ensure that 'name' is not a duplicate.
4997                  */
4998                 struct mddev *mddev2;
4999                 spin_lock(&all_mddevs_lock);
5000 
5001                 list_for_each_entry(mddev2, &all_mddevs, all_mddevs)
5002                         if (mddev2->gendisk &&
5003                             strcmp(mddev2->gendisk->disk_name, name) == 0) {
5004                                 spin_unlock(&all_mddevs_lock);
5005                                 goto abort;
5006                         }
5007                 spin_unlock(&all_mddevs_lock);
5008         }
5009 
5010         error = -ENOMEM;
5011         mddev->queue = blk_alloc_queue(GFP_KERNEL);
5012         if (!mddev->queue)
5013                 goto abort;
5014         mddev->queue->queuedata = mddev;
5015 
5016         blk_queue_make_request(mddev->queue, md_make_request);
5017         blk_set_stacking_limits(&mddev->queue->limits);
5018 
5019         disk = alloc_disk(1 << shift);
5020         if (!disk) {
5021                 blk_cleanup_queue(mddev->queue);
5022                 mddev->queue = NULL;
5023                 goto abort;
5024         }
5025         disk->major = MAJOR(mddev->unit);
5026         disk->first_minor = unit << shift;
5027         if (name)
5028                 strcpy(disk->disk_name, name);
5029         else if (partitioned)
5030                 sprintf(disk->disk_name, "md_d%d", unit);
5031         else
5032                 sprintf(disk->disk_name, "md%d", unit);
5033         disk->fops = &md_fops;
5034         disk->private_data = mddev;
5035         disk->queue = mddev->queue;
5036         blk_queue_flush(mddev->queue, REQ_FLUSH | REQ_FUA);
5037         /* Allow extended partitions.  This makes the
5038          * 'mdp' device redundant, but we can't really
5039          * remove it now.
5040          */
5041         disk->flags |= GENHD_FL_EXT_DEVT;
5042         mddev->gendisk = disk;
5043         /* As soon as we call add_disk(), another thread could get
5044          * through to md_open, so make sure it doesn't get too far
5045          */
5046         mutex_lock(&mddev->open_mutex);
5047         add_disk(disk);
5048 
5049         error = kobject_init_and_add(&mddev->kobj, &md_ktype,
5050                                      &disk_to_dev(disk)->kobj, "%s", "md");
5051         if (error) {
5052                 /* This isn't possible, but as kobject_init_and_add is marked
5053                  * __must_check, we must do something with the result
5054                  */
5055                 printk(KERN_WARNING "md: cannot register %s/md - name in use\n",
5056                        disk->disk_name);
5057                 error = 0;
5058         }
5059         if (mddev->kobj.sd &&
5060             sysfs_create_group(&mddev->kobj, &md_bitmap_group))
5061                 printk(KERN_DEBUG "pointless warning\n");
5062         mutex_unlock(&mddev->open_mutex);
5063  abort:
5064         mutex_unlock(&disks_mutex);
5065         if (!error && mddev->kobj.sd) {
5066                 kobject_uevent(&mddev->kobj, KOBJ_ADD);
5067                 mddev->sysfs_state = sysfs_get_dirent_safe(mddev->kobj.sd, "array_state");
5068         }
5069         mddev_put(mddev);
5070         return error;
5071 }
5072 
5073 static struct kobject *md_probe(dev_t dev, int *part, void *data)
5074 {
5075         md_alloc(dev, NULL);
5076         return NULL;
5077 }
5078 
5079 static int add_named_array(const char *val, struct kernel_param *kp)
5080 {
5081         /* val must be "md_*" where * is not all digits.
5082          * We allocate an array with a large free minor number, and
5083          * set the name to val.  val must not already be an active name.
5084          */
5085         int len = strlen(val);
5086         char buf[DISK_NAME_LEN];
5087 
5088         while (len && val[len-1] == '\n')
5089                 len--;
5090         if (len >= DISK_NAME_LEN)
5091                 return -E2BIG;
5092         strlcpy(buf, val, len+1);
5093         if (strncmp(buf, "md_", 3) != 0)
5094                 return -EINVAL;
5095         return md_alloc(0, buf);
5096 }
5097 
5098 static void md_safemode_timeout(unsigned long data)
5099 {
5100         struct mddev *mddev = (struct mddev *) data;
5101 
5102         if (!atomic_read(&mddev->writes_pending)) {
5103                 mddev->safemode = 1;
5104                 if (mddev->external)
5105                         sysfs_notify_dirent_safe(mddev->sysfs_state);
5106         }
5107         md_wakeup_thread(mddev->thread);
5108 }
5109 
5110 static int start_dirty_degraded;
5111 
5112 int md_run(struct mddev *mddev)
5113 {
5114         int err;
5115         struct md_rdev *rdev;
5116         struct md_personality *pers;
5117 
5118         if (list_empty(&mddev->disks))
5119                 /* cannot run an array with no devices.. */
5120                 return -EINVAL;
5121 
5122         if (mddev->pers)
5123                 return -EBUSY;
5124         /* Cannot run until previous stop completes properly */
5125         if (mddev->sysfs_active)
5126                 return -EBUSY;
5127 
5128         /*
5129          * Analyze all RAID superblock(s)
5130          */
5131         if (!mddev->raid_disks) {
5132                 if (!mddev->persistent)
5133                         return -EINVAL;
5134                 analyze_sbs(mddev);
5135         }
5136 
5137         if (mddev->level != LEVEL_NONE)
5138                 request_module("md-level-%d", mddev->level);
5139         else if (mddev->clevel[0])
5140                 request_module("md-%s", mddev->clevel);
5141 
5142         /*
5143          * Drop all container device buffers, from now on
5144          * the only valid external interface is through the md
5145          * device.
5146          */
5147         rdev_for_each(rdev, mddev) {
5148                 if (test_bit(Faulty, &rdev->flags))
5149                         continue;
5150                 sync_blockdev(rdev->bdev);
5151                 invalidate_bdev(rdev->bdev);
5152 
5153                 /* perform some consistency tests on the device.
5154                  * We don't want the data to overlap the metadata,
5155                  * Internal Bitmap issues have been handled elsewhere.
5156                  */
5157                 if (rdev->meta_bdev) {
5158                         /* Nothing to check */;
5159                 } else if (rdev->data_offset < rdev->sb_start) {
5160                         if (mddev->dev_sectors &&
5161                             rdev->data_offset + mddev->dev_sectors
5162                             > rdev->sb_start) {
5163                                 printk("md: %s: data overlaps metadata\n",
5164                                        mdname(mddev));
5165                                 return -EINVAL;
5166                         }
5167                 } else {
5168                         if (rdev->sb_start + rdev->sb_size/512
5169                             > rdev->data_offset) {
5170                                 printk("md: %s: metadata overlaps data\n",
5171                                        mdname(mddev));
5172                                 return -EINVAL;
5173                         }
5174                 }
5175                 sysfs_notify_dirent_safe(rdev->sysfs_state);
5176         }
5177 
5178         if (mddev->bio_set == NULL)
5179                 mddev->bio_set = bioset_create(BIO_POOL_SIZE, 0);
5180 
5181         spin_lock(&pers_lock);
5182         pers = find_pers(mddev->level, mddev->clevel);
5183         if (!pers || !try_module_get(pers->owner)) {
5184                 spin_unlock(&pers_lock);
5185                 if (mddev->level != LEVEL_NONE)
5186                         printk(KERN_WARNING "md: personality for level %d is not loaded!\n",
5187                                mddev->level);
5188                 else
5189                         printk(KERN_WARNING "md: personality for level %s is not loaded!\n",
5190                                mddev->clevel);
5191                 return -EINVAL;
5192         }
5193         spin_unlock(&pers_lock);
5194         if (mddev->level != pers->level) {
5195                 mddev->level = pers->level;
5196                 mddev->new_level = pers->level;
5197         }
5198         strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
5199 
5200         if (mddev->reshape_position != MaxSector &&
5201             pers->start_reshape == NULL) {
5202                 /* This personality cannot handle reshaping... */
5203                 module_put(pers->owner);
5204                 return -EINVAL;
5205         }
5206 
5207         if (pers->sync_request) {
5208                 /* Warn if this is a potentially silly
5209                  * configuration.
5210                  */
5211                 char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
5212                 struct md_rdev *rdev2;
5213                 int warned = 0;
5214 
5215                 rdev_for_each(rdev, mddev)
5216                         rdev_for_each(rdev2, mddev) {
5217                                 if (rdev < rdev2 &&
5218                                     rdev->bdev->bd_contains ==
5219                                     rdev2->bdev->bd_contains) {
5220                                         printk(KERN_WARNING
5221                                                "%s: WARNING: %s appears to be"
5222                                                " on the same physical disk as"
5223                                                " %s.\n",
5224                                                mdname(mddev),
5225                                                bdevname(rdev->bdev,b),
5226                                                bdevname(rdev2->bdev,b2));
5227                                         warned = 1;
5228                                 }
5229                         }
5230 
5231                 if (warned)
5232                         printk(KERN_WARNING
5233                                "True protection against single-disk"
5234                                " failure might be compromised.\n");
5235         }
5236 
5237         mddev->recovery = 0;
5238         /* may be over-ridden by personality */
5239         mddev->resync_max_sectors = mddev->dev_sectors;
5240 
5241         mddev->ok_start_degraded = start_dirty_degraded;
5242 
5243         if (start_readonly && mddev->ro == 0)
5244                 mddev->ro = 2; /* read-only, but switch on first write */
5245 
5246         err = pers->run(mddev);
5247         if (err)
5248                 printk(KERN_ERR "md: pers->run() failed ...\n");
5249         else if (pers->size(mddev, 0, 0) < mddev->array_sectors) {
5250                 WARN_ONCE(!mddev->external_size, "%s: default size too small,"
5251                           " but 'external_size' not in effect?\n", __func__);
5252                 printk(KERN_ERR
5253                        "md: invalid array_size %llu > default size %llu\n",
5254                        (unsigned long long)mddev->array_sectors / 2,
5255                        (unsigned long long)pers->size(mddev, 0, 0) / 2);
5256                 err = -EINVAL;
5257         }
5258         if (err == 0 && pers->sync_request &&
5259             (mddev->bitmap_info.file || mddev->bitmap_info.offset)) {
5260                 struct bitmap *bitmap;
5261 
5262                 bitmap = bitmap_create(mddev, -1);
5263                 if (IS_ERR(bitmap)) {
5264                         err = PTR_ERR(bitmap);
5265                         printk(KERN_ERR "%s: failed to create bitmap (%d)\n",
5266                                mdname(mddev), err);
5267                 } else
5268                         mddev->bitmap = bitmap;
5269 
5270         }
5271         if (err) {
5272                 mddev_detach(mddev);
5273                 if (mddev->private)
5274                         pers->free(mddev, mddev->private);
5275                 mddev->private = NULL;
5276                 module_put(pers->owner);
5277                 bitmap_destroy(mddev);
5278                 return err;
5279         }
5280         if (mddev->queue) {
5281                 mddev->queue->backing_dev_info.congested_data = mddev;
5282                 mddev->queue->backing_dev_info.congested_fn = md_congested;
5283         }
5284         if (pers->sync_request) {
5285                 if (mddev->kobj.sd &&
5286                     sysfs_create_group(&mddev->kobj, &md_redundancy_group))
5287                         printk(KERN_WARNING
5288                                "md: cannot register extra attributes for %s\n",
5289                                mdname(mddev));
5290                 mddev->sysfs_action = sysfs_get_dirent_safe(mddev->kobj.sd, "sync_action");
5291         } else if (mddev->ro == 2) /* auto-readonly not meaningful */
5292                 mddev->ro = 0;
5293 
5294         atomic_set(&mddev->writes_pending,0);
5295         atomic_set(&mddev->max_corr_read_errors,
5296                    MD_DEFAULT_MAX_CORRECTED_READ_ERRORS);
5297         mddev->safemode = 0;
5298         if (mddev_is_clustered(mddev))
5299                 mddev->safemode_delay = 0;
5300         else
5301                 mddev->safemode_delay = (200 * HZ)/1000 +1; /* 200 msec delay */
5302         mddev->in_sync = 1;
5303         smp_wmb();
5304         spin_lock(&mddev->lock);
5305         mddev->pers = pers;
5306         spin_unlock(&mddev->lock);
5307         rdev_for_each(rdev, mddev)
5308                 if (rdev->raid_disk >= 0)
5309                         if (sysfs_link_rdev(mddev, rdev))
5310                                 /* failure here is OK */;
5311 
5312         if (mddev->degraded && !mddev->ro)
5313                 /* This ensures that recovering status is reported immediately
5314                  * via sysfs - until a lack of spares is confirmed.
5315                  */
5316                 set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
5317         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5318 
5319         if (mddev->flags & MD_UPDATE_SB_FLAGS)
5320                 md_update_sb(mddev, 0);
5321 
5322         md_new_event(mddev);
5323         sysfs_notify_dirent_safe(mddev->sysfs_state);
5324         sysfs_notify_dirent_safe(mddev->sysfs_action);
5325         sysfs_notify(&mddev->kobj, NULL, "degraded");
5326         return 0;
5327 }
5328 EXPORT_SYMBOL_GPL(md_run);
5329 
5330 static int do_md_run(struct mddev *mddev)
5331 {
5332         int err;
5333 
5334         err = md_run(mddev);
5335         if (err)
5336                 goto out;
5337         err = bitmap_load(mddev);
5338         if (err) {
5339                 bitmap_destroy(mddev);
5340                 goto out;
5341         }
5342 
5343         if (mddev_is_clustered(mddev))
5344                 md_allow_write(mddev);
5345 
5346         md_wakeup_thread(mddev->thread);
5347         md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
5348 
5349         set_capacity(mddev->gendisk, mddev->array_sectors);
5350         revalidate_disk(mddev->gendisk);
5351         mddev->changed = 1;
5352         kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
5353 out:
5354         return err;
5355 }
5356 
5357 static int restart_array(struct mddev *mddev)
5358 {
5359         struct gendisk *disk = mddev->gendisk;
5360 
5361         /* Complain if it has no devices */
5362         if (list_empty(&mddev->disks))
5363                 return -ENXIO;
5364         if (!mddev->pers)
5365                 return -EINVAL;
5366         if (!mddev->ro)
5367                 return -EBUSY;
5368         if (test_bit(MD_HAS_JOURNAL, &mddev->flags)) {
5369                 struct md_rdev *rdev;
5370                 bool has_journal = false;
5371 
5372                 rcu_read_lock();
5373                 rdev_for_each_rcu(rdev, mddev) {
5374                         if (test_bit(Journal, &rdev->flags) &&
5375                             !test_bit(Faulty, &rdev->flags)) {
5376                                 has_journal = true;
5377                                 break;
5378                         }
5379                 }
5380                 rcu_read_unlock();
5381 
5382                 /* Don't restart rw with journal missing/faulty */
5383                 if (!has_journal)
5384                         return -EINVAL;
5385         }
5386 
5387         mddev->safemode = 0;
5388         mddev->ro = 0;
5389         set_disk_ro(disk, 0);
5390         printk(KERN_INFO "md: %s switched to read-write mode.\n",
5391                 mdname(mddev));
5392         /* Kick recovery or resync if necessary */
5393         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5394         md_wakeup_thread(mddev->thread);
5395         md_wakeup_thread(mddev->sync_thread);
5396         sysfs_notify_dirent_safe(mddev->sysfs_state);
5397         return 0;
5398 }
5399 
5400 static void md_clean(struct mddev *mddev)
5401 {
5402         mddev->array_sectors = 0;
5403         mddev->external_size = 0;
5404         mddev->dev_sectors = 0;
5405         mddev->raid_disks = 0;
5406         mddev->recovery_cp = 0;
5407         mddev->resync_min = 0;
5408         mddev->resync_max = MaxSector;
5409         mddev->reshape_position = MaxSector;
5410         mddev->external = 0;
5411         mddev->persistent = 0;
5412         mddev->level = LEVEL_NONE;
5413         mddev->clevel[0] = 0;
5414         mddev->flags = 0;
5415         mddev->ro = 0;
5416         mddev->metadata_type[0] = 0;
5417         mddev->chunk_sectors = 0;
5418         mddev->ctime = mddev->utime = 0;
5419         mddev->layout = 0;
5420         mddev->max_disks = 0;
5421         mddev->events = 0;
5422         mddev->can_decrease_events = 0;
5423         mddev->delta_disks = 0;
5424         mddev->reshape_backwards = 0;
5425         mddev->new_level = LEVEL_NONE;
5426         mddev->new_layout = 0;
5427         mddev->new_chunk_sectors = 0;
5428         mddev->curr_resync = 0;
5429         atomic64_set(&mddev->resync_mismatches, 0);
5430         mddev->suspend_lo = mddev->suspend_hi = 0;
5431         mddev->sync_speed_min = mddev->sync_speed_max = 0;
5432         mddev->recovery = 0;
5433         mddev->in_sync = 0;
5434         mddev->changed = 0;
5435         mddev->degraded = 0;
5436         mddev->safemode = 0;
5437         mddev->private = NULL;
5438         mddev->bitmap_info.offset = 0;
5439         mddev->bitmap_info.default_offset = 0;
5440         mddev->bitmap_info.default_space = 0;
5441         mddev->bitmap_info.chunksize = 0;
5442         mddev->bitmap_info.daemon_sleep = 0;
5443         mddev->bitmap_info.max_write_behind = 0;
5444 }
5445 
5446 static void __md_stop_writes(struct mddev *mddev)
5447 {
5448         set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5449         flush_workqueue(md_misc_wq);
5450         if (mddev->sync_thread) {
5451                 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
5452                 md_reap_sync_thread(mddev);
5453         }
5454 
5455         del_timer_sync(&mddev->safemode_timer);
5456 
5457         bitmap_flush(mddev);
5458         md_super_wait(mddev);
5459 
5460         if (mddev->ro == 0 &&
5461             ((!mddev->in_sync && !mddev_is_clustered(mddev)) ||
5462              (mddev->flags & MD_UPDATE_SB_FLAGS))) {
5463                 /* mark array as shutdown cleanly */
5464                 if (!mddev_is_clustered(mddev))
5465                         mddev->in_sync = 1;
5466                 md_update_sb(mddev, 1);
5467         }
5468 }
5469 
5470 void md_stop_writes(struct mddev *mddev)
5471 {
5472         mddev_lock_nointr(mddev);
5473         __md_stop_writes(mddev);
5474         mddev_unlock(mddev);
5475 }
5476 EXPORT_SYMBOL_GPL(md_stop_writes);
5477 
5478 static void mddev_detach(struct mddev *mddev)
5479 {
5480         struct bitmap *bitmap = mddev->bitmap;
5481         /* wait for behind writes to complete */
5482         if (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
5483                 printk(KERN_INFO "md:%s: behind writes in progress - waiting to stop.\n",
5484                        mdname(mddev));
5485                 /* need to kick something here to make sure I/O goes? */
5486                 wait_event(bitmap->behind_wait,
5487                            atomic_read(&bitmap->behind_writes) == 0);
5488         }
5489         if (mddev->pers && mddev->pers->quiesce) {
5490                 mddev->pers->quiesce(mddev, 1);
5491                 mddev->pers->quiesce(mddev, 0);
5492         }
5493         md_unregister_thread(&mddev->thread);
5494         if (mddev->queue)
5495                 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
5496 }
5497 
5498 static void __md_stop(struct mddev *mddev)
5499 {
5500         struct md_personality *pers = mddev->pers;
5501         mddev_detach(mddev);
5502         /* Ensure ->event_work is done */
5503         flush_workqueue(md_misc_wq);
5504         spin_lock(&mddev->lock);
5505         mddev->pers = NULL;
5506         spin_unlock(&mddev->lock);
5507         pers->free(mddev, mddev->private);
5508         mddev->private = NULL;
5509         if (pers->sync_request && mddev->to_remove == NULL)
5510                 mddev->to_remove = &md_redundancy_group;
5511         module_put(pers->owner);
5512         clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5513 }
5514 
5515 void md_stop(struct mddev *mddev)
5516 {
5517         /* stop the array and free an attached data structures.
5518          * This is called from dm-raid
5519          */
5520         __md_stop(mddev);
5521         bitmap_destroy(mddev);
5522         if (mddev->bio_set)
5523                 bioset_free(mddev->bio_set);
5524 }
5525 
5526 EXPORT_SYMBOL_GPL(md_stop);
5527 
5528 static int md_set_readonly(struct mddev *mddev, struct block_device *bdev)
5529 {
5530         int err = 0;
5531         int did_freeze = 0;
5532 
5533         if (!test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)) {
5534                 did_freeze = 1;
5535                 set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5536                 md_wakeup_thread(mddev->thread);
5537         }
5538         if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
5539                 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
5540         if (mddev->sync_thread)
5541                 /* Thread might be blocked waiting for metadata update
5542                  * which will now never happen */
5543                 wake_up_process(mddev->sync_thread->tsk);
5544 
5545         if (mddev->external && test_bit(MD_CHANGE_PENDING, &mddev->flags))
5546                 return -EBUSY;
5547         mddev_unlock(mddev);
5548         wait_event(resync_wait, !test_bit(MD_RECOVERY_RUNNING,
5549                                           &mddev->recovery));
5550         wait_event(mddev->sb_wait,
5551                    !test_bit(MD_CHANGE_PENDING, &mddev->flags));
5552         mddev_lock_nointr(mddev);
5553 
5554         mutex_lock(&mddev->open_mutex);
5555         if ((mddev->pers && atomic_read(&mddev->openers) > !!bdev) ||
5556             mddev->sync_thread ||
5557             test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
5558             (bdev && !test_bit(MD_STILL_CLOSED, &mddev->flags))) {
5559                 printk("md: %s still in use.\n",mdname(mddev));
5560                 if (did_freeze) {
5561                         clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5562                         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5563                         md_wakeup_thread(mddev->thread);
5564                 }
5565                 err = -EBUSY;
5566                 goto out;
5567         }
5568         if (mddev->pers) {
5569                 __md_stop_writes(mddev);
5570 
5571                 err  = -ENXIO;
5572                 if (mddev->ro==1)
5573                         goto out;
5574                 mddev->ro = 1;
5575                 set_disk_ro(mddev->gendisk, 1);
5576                 clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5577                 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5578                 md_wakeup_thread(mddev->thread);
5579                 sysfs_notify_dirent_safe(mddev->sysfs_state);
5580                 err = 0;
5581         }
5582 out:
5583         mutex_unlock(&mddev->open_mutex);
5584         return err;
5585 }
5586 
5587 /* mode:
5588  *   0 - completely stop and dis-assemble array
5589  *   2 - stop but do not disassemble array
5590  */
5591 static int do_md_stop(struct mddev *mddev, int mode,
5592                       struct block_device *bdev)
5593 {
5594         struct gendisk *disk = mddev->gendisk;
5595         struct md_rdev *rdev;
5596         int did_freeze = 0;
5597 
5598         if (!test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)) {
5599                 did_freeze = 1;
5600                 set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5601                 md_wakeup_thread(mddev->thread);
5602         }
5603         if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
5604                 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
5605         if (mddev->sync_thread)
5606                 /* Thread might be blocked waiting for metadata update
5607                  * which will now never happen */
5608                 wake_up_process(mddev->sync_thread->tsk);
5609 
5610         mddev_unlock(mddev);
5611         wait_event(resync_wait, (mddev->sync_thread == NULL &&
5612                                  !test_bit(MD_RECOVERY_RUNNING,
5613                                            &mddev->recovery)));
5614         mddev_lock_nointr(mddev);
5615 
5616         mutex_lock(&mddev->open_mutex);
5617         if ((mddev->pers && atomic_read(&mddev->openers) > !!bdev) ||
5618             mddev->sysfs_active ||
5619             mddev->sync_thread ||
5620             test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
5621             (bdev && !test_bit(MD_STILL_CLOSED, &mddev->flags))) {
5622                 printk("md: %s still in use.\n",mdname(mddev));
5623                 mutex_unlock(&mddev->open_mutex);
5624                 if (did_freeze) {
5625                         clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
5626                         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5627                         md_wakeup_thread(mddev->thread);
5628                 }
5629                 return -EBUSY;
5630         }
5631         if (mddev->pers) {
5632                 if (mddev->ro)
5633                         set_disk_ro(disk, 0);
5634 
5635                 __md_stop_writes(mddev);
5636                 __md_stop(mddev);
5637                 mddev->queue->backing_dev_info.congested_fn = NULL;
5638 
5639                 /* tell userspace to handle 'inactive' */
5640                 sysfs_notify_dirent_safe(mddev->sysfs_state);
5641 
5642                 rdev_for_each(rdev, mddev)
5643                         if (rdev->raid_disk >= 0)
5644                                 sysfs_unlink_rdev(mddev, rdev);
5645 
5646                 set_capacity(disk, 0);
5647                 mutex_unlock(&mddev->open_mutex);
5648                 mddev->changed = 1;
5649                 revalidate_disk(disk);
5650 
5651                 if (mddev->ro)
5652                         mddev->ro = 0;
5653         } else
5654                 mutex_unlock(&mddev->open_mutex);
5655         /*
5656          * Free resources if final stop
5657          */
5658         if (mode == 0) {
5659                 printk(KERN_INFO "md: %s stopped.\n", mdname(mddev));
5660 
5661                 bitmap_destroy(mddev);
5662                 if (mddev->bitmap_info.file) {
5663                         struct file *f = mddev->bitmap_info.file;
5664                         spin_lock(&mddev->lock);
5665                         mddev->bitmap_info.file = NULL;
5666                         spin_unlock(&mddev->lock);
5667                         fput(f);
5668                 }
5669                 mddev->bitmap_info.offset = 0;
5670 
5671                 export_array(mddev);
5672 
5673                 md_clean(mddev);
5674                 kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
5675                 if (mddev->hold_active == UNTIL_STOP)
5676                         mddev->hold_active = 0;
5677         }
5678         md_new_event(mddev);
5679         sysfs_notify_dirent_safe(mddev->sysfs_state);
5680         return 0;
5681 }
5682 
5683 #ifndef MODULE
5684 static void autorun_array(struct mddev *mddev)
5685 {
5686         struct md_rdev *rdev;
5687         int err;
5688 
5689         if (list_empty(&mddev->disks))
5690                 return;
5691 
5692         printk(KERN_INFO "md: running: ");
5693 
5694         rdev_for_each(rdev, mddev) {
5695                 char b[BDEVNAME_SIZE];
5696                 printk("<%s>", bdevname(rdev->bdev,b));
5697         }
5698         printk("\n");
5699 
5700         err = do_md_run(mddev);
5701         if (err) {
5702                 printk(KERN_WARNING "md: do_md_run() returned %d\n", err);
5703                 do_md_stop(mddev, 0, NULL);
5704         }
5705 }
5706 
5707 /*
5708  * lets try to run arrays based on all disks that have arrived
5709  * until now. (those are in pending_raid_disks)
5710  *
5711  * the method: pick the first pending disk, collect all disks with
5712  * the same UUID, remove all from the pending list and put them into
5713  * the 'same_array' list. Then order this list based on superblock
5714  * update time (freshest comes first), kick out 'old' disks and
5715  * compare superblocks. If everything's fine then run it.
5716  *
5717  * If "unit" is allocated, then bump its reference count
5718  */
5719 static void autorun_devices(int part)
5720 {
5721         struct md_rdev *rdev0, *rdev, *tmp;
5722         struct mddev *mddev;
5723         char b[BDEVNAME_SIZE];
5724 
5725         printk(KERN_INFO "md: autorun ...\n");
5726         while (!list_empty(&pending_raid_disks)) {
5727                 int unit;
5728                 dev_t dev;
5729                 LIST_HEAD(candidates);
5730                 rdev0 = list_entry(pending_raid_disks.next,
5731                                          struct md_rdev, same_set);
5732 
5733                 printk(KERN_INFO "md: considering %s ...\n",
5734                         bdevname(rdev0->bdev,b));
5735                 INIT_LIST_HEAD(&candidates);
5736                 rdev_for_each_list(rdev, tmp, &pending_raid_disks)
5737                         if (super_90_load(rdev, rdev0, 0) >= 0) {
5738                                 printk(KERN_INFO "md:  adding %s ...\n",
5739                                         bdevname(rdev->bdev,b));
5740                                 list_move(&rdev->same_set, &candidates);
5741                         }
5742                 /*
5743                  * now we have a set of devices, with all of them having
5744                  * mostly sane superblocks. It's time to allocate the
5745                  * mddev.
5746                  */
5747                 if (part) {
5748                         dev = MKDEV(mdp_major,
5749                                     rdev0->preferred_minor << MdpMinorShift);
5750                         unit = MINOR(dev) >> MdpMinorShift;
5751                 } else {
5752                         dev = MKDEV(MD_MAJOR, rdev0->preferred_minor);
5753                         unit = MINOR(dev);
5754                 }
5755                 if (rdev0->preferred_minor != unit) {
5756                         printk(KERN_INFO "md: unit number in %s is bad: %d\n",
5757                                bdevname(rdev0->bdev, b), rdev0->preferred_minor);
5758                         break;
5759                 }
5760 
5761                 md_probe(dev, NULL, NULL);
5762                 mddev = mddev_find(dev);
5763                 if (!mddev || !mddev->gendisk) {
5764                         if (mddev)
5765                                 mddev_put(mddev);
5766                         printk(KERN_ERR
5767                                 "md: cannot allocate memory for md drive.\n");
5768                         break;
5769                 }
5770                 if (mddev_lock(mddev))
5771                         printk(KERN_WARNING "md: %s locked, cannot run\n",
5772                                mdname(mddev));
5773                 else if (mddev->raid_disks || mddev->major_version
5774                          || !list_empty(&mddev->disks)) {
5775                         printk(KERN_WARNING
5776                                 "md: %s already running, cannot run %s\n",
5777                                 mdname(mddev), bdevname(rdev0->bdev,b));
5778                         mddev_unlock(mddev);
5779                 } else {
5780                         printk(KERN_INFO "md: created %s\n", mdname(mddev));
5781                         mddev->persistent = 1;
5782                         rdev_for_each_list(rdev, tmp, &candidates) {
5783                                 list_del_init(&rdev->same_set);
5784                                 if (bind_rdev_to_array(rdev, mddev))
5785                                         export_rdev(rdev);
5786                         }
5787                         autorun_array(mddev);
5788                         mddev_unlock(mddev);
5789                 }
5790                 /* on success, candidates will be empty, on error
5791                  * it won't...
5792                  */
5793                 rdev_for_each_list(rdev, tmp, &candidates) {
5794                         list_del_init(&rdev->same_set);
5795                         export_rdev(rdev);
5796                 }
5797                 mddev_put(mddev);
5798         }
5799         printk(KERN_INFO "md: ... autorun DONE.\n");
5800 }
5801 #endif /* !MODULE */
5802 
5803 static int get_version(void __user *arg)
5804 {
5805         mdu_version_t ver;
5806 
5807         ver.major = MD_MAJOR_VERSION;
5808         ver.minor = MD_MINOR_VERSION;
5809         ver.patchlevel = MD_PATCHLEVEL_VERSION;
5810 
5811         if (copy_to_user(arg, &ver, sizeof(ver)))
5812                 return -EFAULT;
5813 
5814         return 0;
5815 }
5816 
5817 static int get_array_info(struct mddev *mddev, void __user *arg)
5818 {
5819         mdu_array_info_t info;
5820         int nr,working,insync,failed,spare;
5821         struct md_rdev *rdev;
5822 
5823         nr = working = insync = failed = spare = 0;
5824         rcu_read_lock();
5825         rdev_for_each_rcu(rdev, mddev) {
5826                 nr++;
5827                 if (test_bit(Faulty, &rdev->flags))
5828                         failed++;
5829                 else {
5830                         working++;
5831                         if (test_bit(In_sync, &rdev->flags))
5832                                 insync++;
5833                         else
5834                                 spare++;
5835                 }
5836         }
5837         rcu_read_unlock();
5838 
5839         info.major_version = mddev->major_version;
5840         info.minor_version = mddev->minor_version;
5841         info.patch_version = MD_PATCHLEVEL_VERSION;
5842         info.ctime         = clamp_t(time64_t, mddev->ctime, 0, U32_MAX);
5843         info.level         = mddev->level;
5844         info.size          = mddev->dev_sectors / 2;
5845         if (info.size != mddev->dev_sectors / 2) /* overflow */
5846                 info.size = -1;
5847         info.nr_disks      = nr;
5848         info.raid_disks    = mddev->raid_disks;
5849         info.md_minor      = mddev->md_minor;
5850         info.not_persistent= !mddev->persistent;
5851 
5852         info.utime         = clamp_t(time64_t, mddev->utime, 0, U32_MAX);
5853         info.state         = 0;
5854         if (mddev->in_sync)
5855                 info.state = (1<<MD_SB_CLEAN);
5856         if (mddev->bitmap && mddev->bitmap_info.offset)
5857                 info.state |= (1<<MD_SB_BITMAP_PRESENT);
5858         if (mddev_is_clustered(mddev))
5859                 info.state |= (1<<MD_SB_CLUSTERED);
5860         info.active_disks  = insync;
5861         info.working_disks = working;
5862         info.failed_disks  = failed;
5863         info.spare_disks   = spare;
5864 
5865         info.layout        = mddev->layout;
5866         info.chunk_size    = mddev->chunk_sectors << 9;
5867 
5868         if (copy_to_user(arg, &info, sizeof(info)))
5869                 return -EFAULT;
5870 
5871         return 0;
5872 }
5873 
5874 static int get_bitmap_file(struct mddev *mddev, void __user * arg)
5875 {
5876         mdu_bitmap_file_t *file = NULL; /* too big for stack allocation */
5877         char *ptr;
5878         int err;
5879 
5880         file = kzalloc(sizeof(*file), GFP_NOIO);
5881         if (!file)
5882                 return -ENOMEM;
5883 
5884         err = 0;
5885         spin_lock(&mddev->lock);
5886         /* bitmap enabled */
5887         if (mddev->bitmap_info.file) {
5888                 ptr = file_path(mddev->bitmap_info.file, file->pathname,
5889                                 sizeof(file->pathname));
5890                 if (IS_ERR(ptr))
5891                         err = PTR_ERR(ptr);
5892                 else
5893                         memmove(file->pathname, ptr,
5894                                 sizeof(file->pathname)-(ptr-file->pathname));
5895         }
5896         spin_unlock(&mddev->lock);
5897 
5898         if (err == 0 &&
5899             copy_to_user(arg, file, sizeof(*file)))
5900                 err = -EFAULT;
5901 
5902         kfree(file);
5903         return err;
5904 }
5905 
5906 static int get_disk_info(struct mddev *mddev, void __user * arg)
5907 {
5908         mdu_disk_info_t info;
5909         struct md_rdev *rdev;
5910 
5911         if (copy_from_user(&info, arg, sizeof(info)))
5912                 return -EFAULT;
5913 
5914         rcu_read_lock();
5915         rdev = md_find_rdev_nr_rcu(mddev, info.number);
5916         if (rdev) {
5917                 info.major = MAJOR(rdev->bdev->bd_dev);
5918                 info.minor = MINOR(rdev->bdev->bd_dev);
5919                 info.raid_disk = rdev->raid_disk;
5920                 info.state = 0;
5921                 if (test_bit(Faulty, &rdev->flags))
5922                         info.state |= (1<<MD_DISK_FAULTY);
5923                 else if (test_bit(In_sync, &rdev->flags)) {
5924                         info.state |= (1<<MD_DISK_ACTIVE);
5925                         info.state |= (1<<MD_DISK_SYNC);
5926                 }
5927                 if (test_bit(Journal, &rdev->flags))
5928                         info.state |= (1<<MD_DISK_JOURNAL);
5929                 if (test_bit(WriteMostly, &rdev->flags))
5930                         info.state |= (1<<MD_DISK_WRITEMOSTLY);
5931         } else {
5932                 info.major = info.minor = 0;
5933                 info.raid_disk = -1;
5934                 info.state = (1<<MD_DISK_REMOVED);
5935         }
5936         rcu_read_unlock();
5937 
5938         if (copy_to_user(arg, &info, sizeof(info)))
5939                 return -EFAULT;
5940 
5941         return 0;
5942 }
5943 
5944 static int add_new_disk(struct mddev *mddev, mdu_disk_info_t *info)
5945 {
5946         char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
5947         struct md_rdev *rdev;
5948         dev_t dev = MKDEV(info->major,info->minor);
5949 
5950         if (mddev_is_clustered(mddev) &&
5951                 !(info->state & ((1 << MD_DISK_CLUSTER_ADD) | (1 << MD_DISK_CANDIDATE)))) {
5952                 pr_err("%s: Cannot add to clustered mddev.\n",
5953                                mdname(mddev));
5954                 return -EINVAL;
5955         }
5956 
5957         if (info->major != MAJOR(dev) || info->minor != MINOR(dev))
5958                 return -EOVERFLOW;
5959 
5960         if (!mddev->raid_disks) {
5961                 int err;
5962                 /* expecting a device which has a superblock */
5963                 rdev = md_import_device(dev, mddev->major_version, mddev->minor_version);
5964                 if (IS_ERR(rdev)) {
5965                         printk(KERN_WARNING
5966                                 "md: md_import_device returned %ld\n",
5967                                 PTR_ERR(rdev));
5968                         return PTR_ERR(rdev);
5969                 }
5970                 if (!list_empty(&mddev->disks)) {
5971                         struct md_rdev *rdev0
5972                                 = list_entry(mddev->disks.next,
5973                                              struct md_rdev, same_set);
5974                         err = super_types[mddev->major_version]
5975                                 .load_super(rdev, rdev0, mddev->minor_version);
5976                         if (err < 0) {
5977                                 printk(KERN_WARNING
5978                                         "md: %s has different UUID to %s\n",
5979                                         bdevname(rdev->bdev,b),
5980                                         bdevname(rdev0->bdev,b2));
5981                                 export_rdev(rdev);
5982                                 return -EINVAL;
5983                         }
5984                 }
5985                 err = bind_rdev_to_array(rdev, mddev);
5986                 if (err)
5987                         export_rdev(rdev);
5988                 return err;
5989         }
5990 
5991         /*
5992          * add_new_disk can be used once the array is assembled
5993          * to add "hot spares".  They must already have a superblock
5994          * written
5995          */
5996         if (mddev->pers) {
5997                 int err;
5998                 if (!mddev->pers->hot_add_disk) {
5999                         printk(KERN_WARNING
6000                                 "%s: personality does not support diskops!\n",
6001                                mdname(mddev));
6002                         return -EINVAL;
6003                 }
6004                 if (mddev->persistent)
6005                         rdev = md_import_device(dev, mddev->major_version,
6006                                                 mddev->minor_version);
6007                 else
6008                         rdev = md_import_device(dev, -1, -1);
6009                 if (IS_ERR(rdev)) {
6010                         printk(KERN_WARNING
6011                                 "md: md_import_device returned %ld\n",
6012                                 PTR_ERR(rdev));
6013                         return PTR_ERR(rdev);
6014                 }
6015                 /* set saved_raid_disk if appropriate */
6016                 if (!mddev->persistent) {
6017                         if (info->state & (1<<MD_DISK_SYNC)  &&
6018                             info->raid_disk < mddev->raid_disks) {
6019                                 rdev->raid_disk = info->raid_disk;
6020                                 set_bit(In_sync, &rdev->flags);
6021                                 clear_bit(Bitmap_sync, &rdev->flags);
6022                         } else
6023                                 rdev->raid_disk = -1;
6024                         rdev->saved_raid_disk = rdev->raid_disk;
6025                 } else
6026                         super_types[mddev->major_version].
6027                                 validate_super(mddev, rdev);
6028                 if ((info->state & (1<<MD_DISK_SYNC)) &&
6029                      rdev->raid_disk != info->raid_disk) {
6030                         /* This was a hot-add request, but events doesn't
6031                          * match, so reject it.
6032                          */
6033                         export_rdev(rdev);
6034                         return -EINVAL;
6035                 }
6036 
6037                 clear_bit(In_sync, &rdev->flags); /* just to be sure */
6038                 if (info->state & (1<<MD_DISK_WRITEMOSTLY))
6039                         set_bit(WriteMostly, &rdev->flags);
6040                 else
6041                         clear_bit(WriteMostly, &rdev->flags);
6042 
6043                 if (info->state & (1<<MD_DISK_JOURNAL)) {
6044                         struct md_rdev *rdev2;
6045                         bool has_journal = false;
6046 
6047                         /* make sure no existing journal disk */
6048                         rdev_for_each(rdev2, mddev) {
6049                                 if (test_bit(Journal, &rdev2->flags)) {
6050                                         has_journal = true;
6051                                         break;
6052                                 }
6053                         }
6054                         if (has_journal) {
6055                                 export_rdev(rdev);
6056                                 return -EBUSY;
6057                         }
6058                         set_bit(Journal, &rdev->flags);
6059                 }
6060                 /*
6061                  * check whether the device shows up in other nodes
6062                  */
6063                 if (mddev_is_clustered(mddev)) {
6064                         if (info->state & (1 << MD_DISK_CANDIDATE))
6065                                 set_bit(Candidate, &rdev->flags);
6066                         else if (info->state & (1 << MD_DISK_CLUSTER_ADD)) {
6067                                 /* --add initiated by this node */
6068                                 err = md_cluster_ops->add_new_disk(mddev, rdev);
6069                                 if (err) {
6070                                         export_rdev(rdev);
6071                                         return err;
6072                                 }
6073                         }
6074                 }
6075 
6076                 rdev->raid_disk = -1;
6077                 err = bind_rdev_to_array(rdev, mddev);
6078 
6079                 if (err)
6080                         export_rdev(rdev);
6081 
6082                 if (mddev_is_clustered(mddev)) {
6083                         if (info->state & (1 << MD_DISK_CANDIDATE))
6084                                 md_cluster_ops->new_disk_ack(mddev, (err == 0));
6085                         else {
6086                                 if (err)
6087                                         md_cluster_ops->add_new_disk_cancel(mddev);
6088                                 else
6089                                         err = add_bound_rdev(rdev);
6090                         }
6091 
6092                 } else if (!err)
6093                         err = add_bound_rdev(rdev);
6094 
6095                 return err;
6096         }
6097 
6098         /* otherwise, add_new_disk is only allowed
6099          * for major_version==0 superblocks
6100          */
6101         if (mddev->major_version != 0) {
6102                 printk(KERN_WARNING "%s: ADD_NEW_DISK not supported\n",
6103                        mdname(mddev));
6104                 return -EINVAL;
6105         }
6106 
6107         if (!(info->state & (1<<MD_DISK_FAULTY))) {
6108                 int err;
6109                 rdev = md_import_device(dev, -1, 0);
6110                 if (IS_ERR(rdev)) {
6111                         printk(KERN_WARNING
6112                                 "md: error, md_import_device() returned %ld\n",
6113                                 PTR_ERR(rdev));
6114                         return PTR_ERR(rdev);
6115                 }
6116                 rdev->desc_nr = info->number;
6117                 if (info->raid_disk < mddev->raid_disks)
6118                         rdev->raid_disk = info->raid_disk;
6119                 else
6120                         rdev->raid_disk = -1;
6121 
6122                 if (rdev->raid_disk < mddev->raid_disks)
6123                         if (info->state & (1<<MD_DISK_SYNC))
6124                                 set_bit(In_sync, &rdev->flags);
6125 
6126                 if (info->state & (1<<MD_DISK_WRITEMOSTLY))
6127                         set_bit(WriteMostly, &rdev->flags);
6128 
6129                 if (!mddev->persistent) {
6130                         printk(KERN_INFO "md: nonpersistent superblock ...\n");
6131                         rdev->sb_start = i_size_read(rdev->bdev->bd_inode) / 512;
6132                 } else
6133                         rdev->sb_start = calc_dev_sboffset(rdev);
6134                 rdev->sectors = rdev->sb_start;
6135 
6136                 err = bind_rdev_to_array(rdev, mddev);
6137                 if (err) {
6138                         export_rdev(rdev);
6139                         return err;
6140                 }
6141         }
6142 
6143         return 0;
6144 }
6145 
6146 static int hot_remove_disk(struct mddev *mddev, dev_t dev)
6147 {
6148         char b[BDEVNAME_SIZE];
6149         struct md_rdev *rdev;
6150 
6151         rdev = find_rdev(mddev, dev);
6152         if (!rdev)
6153                 return -ENXIO;
6154 
6155         if (rdev->raid_disk < 0)
6156                 goto kick_rdev;
6157 
6158         clear_bit(Blocked, &rdev->flags);
6159         remove_and_add_spares(mddev, rdev);
6160 
6161         if (rdev->raid_disk >= 0)
6162                 goto busy;
6163 
6164 kick_rdev:
6165         if (mddev_is_clustered(mddev))
6166                 md_cluster_ops->remove_disk(mddev, rdev);
6167 
6168         md_kick_rdev_from_array(rdev);
6169         md_update_sb(mddev, 1);
6170         md_new_event(mddev);
6171 
6172         return 0;
6173 busy:
6174         printk(KERN_WARNING "md: cannot remove active disk %s from %s ...\n",
6175                 bdevname(rdev->bdev,b), mdname(mddev));
6176         return -EBUSY;
6177 }
6178 
6179 static int hot_add_disk(struct mddev *mddev, dev_t dev)
6180 {
6181         char b[BDEVNAME_SIZE];
6182         int err;
6183         struct md_rdev *rdev;
6184 
6185         if (!mddev->pers)
6186                 return -ENODEV;
6187 
6188         if (mddev->major_version != 0) {
6189                 printk(KERN_WARNING "%s: HOT_ADD may only be used with"
6190                         " version-0 superblocks.\n",
6191                         mdname(mddev));
6192                 return -EINVAL;
6193         }
6194         if (!mddev->pers->hot_add_disk) {
6195                 printk(KERN_WARNING
6196                         "%s: personality does not support diskops!\n",
6197                         mdname(mddev));
6198                 return -EINVAL;
6199         }
6200 
6201         rdev = md_import_device(dev, -1, 0);
6202         if (IS_ERR(rdev)) {
6203                 printk(KERN_WARNING
6204                         "md: error, md_import_device() returned %ld\n",
6205                         PTR_ERR(rdev));
6206                 return -EINVAL;
6207         }
6208 
6209         if (mddev->persistent)
6210                 rdev->sb_start = calc_dev_sboffset(rdev);
6211         else
6212                 rdev->sb_start = i_size_read(rdev->bdev->bd_inode) / 512;
6213 
6214         rdev->sectors = rdev->sb_start;
6215 
6216         if (test_bit(Faulty, &rdev->flags)) {
6217                 printk(KERN_WARNING
6218                         "md: can not hot-add faulty %s disk to %s!\n",
6219                         bdevname(rdev->bdev,b), mdname(mddev));
6220                 err = -EINVAL;
6221                 goto abort_export;
6222         }
6223 
6224         clear_bit(In_sync, &rdev->flags);
6225         rdev->desc_nr = -1;
6226         rdev->saved_raid_disk = -1;
6227         err = bind_rdev_to_array(rdev, mddev);
6228         if (err)
6229                 goto abort_export;
6230 
6231         /*
6232          * The rest should better be atomic, we can have disk failures
6233          * noticed in interrupt contexts ...
6234          */
6235 
6236         rdev->raid_disk = -1;
6237 
6238         md_update_sb(mddev, 1);
6239         /*
6240          * Kick recovery, maybe this spare has to be added to the
6241          * array immediately.
6242          */
6243         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6244         md_wakeup_thread(mddev->thread);
6245         md_new_event(mddev);
6246         return 0;
6247 
6248 abort_export:
6249         export_rdev(rdev);
6250         return err;
6251 }
6252 
6253 static int set_bitmap_file(struct mddev *mddev, int fd)
6254 {
6255         int err = 0;
6256 
6257         if (mddev->pers) {
6258                 if (!mddev->pers->quiesce || !mddev->thread)
6259                         return -EBUSY;
6260                 if (mddev->recovery || mddev->sync_thread)
6261                         return -EBUSY;
6262                 /* we should be able to change the bitmap.. */
6263         }
6264 
6265         if (fd >= 0) {
6266                 struct inode *inode;
6267                 struct file *f;
6268 
6269                 if (mddev->bitmap || mddev->bitmap_info.file)
6270                         return -EEXIST; /* cannot add when bitmap is present */
6271                 f = fget(fd);
6272 
6273                 if (f == NULL) {
6274                         printk(KERN_ERR "%s: error: failed to get bitmap file\n",
6275                                mdname(mddev));
6276                         return -EBADF;
6277                 }
6278 
6279                 inode = f->f_mapping->host;
6280                 if (!S_ISREG(inode->i_mode)) {
6281                         printk(KERN_ERR "%s: error: bitmap file must be a regular file\n",
6282                                mdname(mddev));
6283                         err = -EBADF;
6284                 } else if (!(f->f_mode & FMODE_WRITE)) {
6285                         printk(KERN_ERR "%s: error: bitmap file must open for write\n",
6286                                mdname(mddev));
6287                         err = -EBADF;
6288                 } else if (atomic_read(&inode->i_writecount) != 1) {
6289                         printk(KERN_ERR "%s: error: bitmap file is already in use\n",
6290                                mdname(mddev));
6291                         err = -EBUSY;
6292                 }
6293                 if (err) {
6294                         fput(f);
6295                         return err;
6296                 }
6297                 mddev->bitmap_info.file = f;
6298                 mddev->bitmap_info.offset = 0; /* file overrides offset */
6299         } else if (mddev->bitmap == NULL)
6300                 return -ENOENT; /* cannot remove what isn't there */
6301         err = 0;
6302         if (mddev->pers) {
6303                 mddev->pers->quiesce(mddev, 1);
6304                 if (fd >= 0) {
6305                         struct bitmap *bitmap;
6306 
6307                         bitmap = bitmap_create(mddev, -1);
6308                         if (!IS_ERR(bitmap)) {
6309                                 mddev->bitmap = bitmap;
6310                                 err = bitmap_load(mddev);
6311                         } else
6312                                 err = PTR_ERR(bitmap);
6313                 }
6314                 if (fd < 0 || err) {
6315                         bitmap_destroy(mddev);
6316                         fd = -1; /* make sure to put the file */
6317                 }
6318                 mddev->pers->quiesce(mddev, 0);
6319         }
6320         if (fd < 0) {
6321                 struct file *f = mddev->bitmap_info.file;
6322                 if (f) {
6323                         spin_lock(&mddev->lock);
6324                         mddev->bitmap_info.file = NULL;
6325                         spin_unlock(&mddev->lock);
6326                         fput(f);
6327                 }
6328         }
6329 
6330         return err;
6331 }
6332 
6333 /*
6334  * set_array_info is used two different ways
6335  * The original usage is when creating a new array.
6336  * In this usage, raid_disks is > 0 and it together with
6337  *  level, size, not_persistent,layout,chunksize determine the
6338  *  shape of the array.
6339  *  This will always create an array with a type-0.90.0 superblock.
6340  * The newer usage is when assembling an array.
6341  *  In this case raid_disks will be 0, and the major_version field is
6342  *  use to determine which style super-blocks are to be found on the devices.
6343  *  The minor and patch _version numbers are also kept incase the
6344  *  super_block handler wishes to interpret them.
6345  */
6346 static int set_array_info(struct mddev *mddev, mdu_array_info_t *info)
6347 {
6348 
6349         if (info->raid_disks == 0) {
6350                 /* just setting version number for superblock loading */
6351                 if (info->major_version < 0 ||
6352                     info->major_version >= ARRAY_SIZE(super_types) ||
6353                     super_types[info->major_version].name == NULL) {
6354                         /* maybe try to auto-load a module? */
6355                         printk(KERN_INFO
6356                                 "md: superblock version %d not known\n",
6357                                 info->major_version);
6358                         return -EINVAL;
6359                 }
6360                 mddev->major_version = info->major_version;
6361                 mddev->minor_version = info->minor_version;
6362                 mddev->patch_version = info->patch_version;
6363                 mddev->persistent = !info->not_persistent;
6364                 /* ensure mddev_put doesn't delete this now that there
6365                  * is some minimal configuration.
6366                  */
6367                 mddev->ctime         = ktime_get_real_seconds();
6368                 return 0;
6369         }
6370         mddev->major_version = MD_MAJOR_VERSION;
6371         mddev->minor_version = MD_MINOR_VERSION;
6372         mddev->patch_version = MD_PATCHLEVEL_VERSION;
6373         mddev->ctime         = ktime_get_real_seconds();
6374 
6375         mddev->level         = info->level;
6376         mddev->clevel[0]     = 0;
6377         mddev->dev_sectors   = 2 * (sector_t)info->size;
6378         mddev->raid_disks    = info->raid_disks;
6379         /* don't set md_minor, it is determined by which /dev/md* was
6380          * openned
6381          */
6382         if (info->state & (1<<MD_SB_CLEAN))
6383                 mddev->recovery_cp = MaxSector;
6384         else
6385                 mddev->recovery_cp = 0;
6386         mddev->persistent    = ! info->not_persistent;
6387         mddev->external      = 0;
6388 
6389         mddev->layout        = info->layout;
6390         mddev->chunk_sectors = info->chunk_size >> 9;
6391 
6392         mddev->max_disks     = MD_SB_DISKS;
6393 
6394         if (mddev->persistent)
6395                 mddev->flags         = 0;
6396         set_bit(MD_CHANGE_DEVS, &mddev->flags);
6397 
6398         mddev->bitmap_info.default_offset = MD_SB_BYTES >> 9;
6399         mddev->bitmap_info.default_space = 64*2 - (MD_SB_BYTES >> 9);
6400         mddev->bitmap_info.offset = 0;
6401 
6402         mddev->reshape_position = MaxSector;
6403 
6404         /*
6405          * Generate a 128 bit UUID
6406          */
6407         get_random_bytes(mddev->uuid, 16);
6408 
6409         mddev->new_level = mddev->level;
6410         mddev->new_chunk_sectors = mddev->chunk_sectors;
6411         mddev->new_layout = mddev->layout;
6412         mddev->delta_disks = 0;
6413         mddev->reshape_backwards = 0;
6414 
6415         return 0;
6416 }
6417 
6418 void md_set_array_sectors(struct mddev *mddev, sector_t array_sectors)
6419 {
6420         WARN(!mddev_is_locked(mddev), "%s: unlocked mddev!\n", __func__);
6421 
6422         if (mddev->external_size)
6423                 return;
6424 
6425         mddev->array_sectors = array_sectors;
6426 }
6427 EXPORT_SYMBOL(md_set_array_sectors);
6428 
6429 static int update_size(struct mddev *mddev, sector_t num_sectors)
6430 {
6431         struct md_rdev *rdev;
6432         int rv;
6433         int fit = (num_sectors == 0);
6434 
6435         if (mddev->pers->resize == NULL)
6436                 return -EINVAL;
6437         /* The "num_sectors" is the number of sectors of each device that
6438          * is used.  This can only make sense for arrays with redundancy.
6439          * linear and raid0 always use whatever space is available. We can only
6440          * consider changing this number if no resync or reconstruction is
6441          * happening, and if the new size is acceptable. It must fit before the
6442          * sb_start or, if that is <data_offset, it must fit before the size
6443          * of each device.  If num_sectors is zero, we find the largest size
6444          * that fits.
6445          */
6446         if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
6447             mddev->sync_thread)
6448                 return -EBUSY;
6449         if (mddev->ro)
6450                 return -EROFS;
6451 
6452         rdev_for_each(rdev, mddev) {
6453                 sector_t avail = rdev->sectors;
6454 
6455                 if (fit && (num_sectors == 0 || num_sectors > avail))
6456                         num_sectors = avail;
6457                 if (avail < num_sectors)
6458                         return -ENOSPC;
6459         }
6460         rv = mddev->pers->resize(mddev, num_sectors);
6461         if (!rv)
6462                 revalidate_disk(mddev->gendisk);
6463         return rv;
6464 }
6465 
6466 static int update_raid_disks(struct mddev *mddev, int raid_disks)
6467 {
6468         int rv;
6469         struct md_rdev *rdev;
6470         /* change the number of raid disks */
6471         if (mddev->pers->check_reshape == NULL)
6472                 return -EINVAL;
6473         if (mddev->ro)
6474                 return -EROFS;
6475         if (raid_disks <= 0 ||
6476             (mddev->max_disks && raid_disks >= mddev->max_disks))
6477                 return -EINVAL;
6478         if (mddev->sync_thread ||
6479             test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
6480             mddev->reshape_position != MaxSector)
6481                 return -EBUSY;
6482 
6483         rdev_for_each(rdev, mddev) {
6484                 if (mddev->raid_disks < raid_disks &&
6485                     rdev->data_offset < rdev->new_data_offset)
6486                         return -EINVAL;
6487                 if (mddev->raid_disks > raid_disks &&
6488                     rdev->data_offset > rdev->new_data_offset)
6489                         return -EINVAL;
6490         }
6491 
6492         mddev->delta_disks = raid_disks - mddev->raid_disks;
6493         if (mddev->delta_disks < 0)
6494                 mddev->reshape_backwards = 1;
6495         else if (mddev->delta_disks > 0)
6496                 mddev->reshape_backwards = 0;
6497 
6498         rv = mddev->pers->check_reshape(mddev);
6499         if (rv < 0) {
6500                 mddev->delta_disks = 0;
6501                 mddev->reshape_backwards = 0;
6502         }
6503         return rv;
6504 }
6505 
6506 /*
6507  * update_array_info is used to change the configuration of an
6508  * on-line array.
6509  * The version, ctime,level,size,raid_disks,not_persistent, layout,chunk_size
6510  * fields in the info are checked against the array.
6511  * Any differences that cannot be handled will cause an error.
6512  * Normally, only one change can be managed at a time.
6513  */
6514 static int update_array_info(struct mddev *mddev, mdu_array_info_t *info)
6515 {
6516         int rv = 0;
6517         int cnt = 0;
6518         int state = 0;
6519 
6520         /* calculate expected state,ignoring low bits */
6521         if (mddev->bitmap && mddev->bitmap_info.offset)
6522                 state |= (1 << MD_SB_BITMAP_PRESENT);
6523 
6524         if (mddev->major_version != info->major_version ||
6525             mddev->minor_version != info->minor_version ||
6526 /*          mddev->patch_version != info->patch_version || */
6527             mddev->ctime         != info->ctime         ||
6528             mddev->level         != info->level         ||
6529 /*          mddev->layout        != info->layout        || */
6530             mddev->persistent    != !info->not_persistent ||
6531             mddev->chunk_sectors != info->chunk_size >> 9 ||
6532             /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT to change */
6533             ((state^info->state) & 0xfffffe00)
6534                 )
6535                 return -EINVAL;
6536         /* Check there is only one change */
6537         if (info->size >= 0 && mddev->dev_sectors / 2 != info->size)
6538                 cnt++;
6539         if (mddev->raid_disks != info->raid_disks)
6540                 cnt++;
6541         if (mddev->layout != info->layout)
6542                 cnt++;
6543         if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT))
6544                 cnt++;
6545         if (cnt == 0)
6546                 return 0;
6547         if (cnt > 1)
6548                 return -EINVAL;
6549 
6550         if (mddev->layout != info->layout) {
6551                 /* Change layout
6552                  * we don't need to do anything at the md level, the
6553                  * personality will take care of it all.
6554                  */
6555                 if (mddev->pers->check_reshape == NULL)
6556                         return -EINVAL;
6557                 else {
6558                         mddev->new_layout = info->layout;
6559                         rv = mddev->pers->check_reshape(mddev);
6560                         if (rv)
6561                                 mddev->new_layout = mddev->layout;
6562                         return rv;
6563                 }
6564         }
6565         if (info->size >= 0 && mddev->dev_sectors / 2 != info->size)
6566                 rv = update_size(mddev, (sector_t)info->size * 2);
6567 
6568         if (mddev->raid_disks    != info->raid_disks)
6569                 rv = update_raid_disks(mddev, info->raid_disks);
6570 
6571         if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT)) {
6572                 if (mddev->pers->quiesce == NULL || mddev->thread == NULL) {
6573                         rv = -EINVAL;
6574                         goto err;
6575                 }
6576                 if (mddev->recovery || mddev->sync_thread) {
6577                         rv = -EBUSY;
6578                         goto err;
6579                 }
6580                 if (info->state & (1<<MD_SB_BITMAP_PRESENT)) {
6581                         struct bitmap *bitmap;
6582                         /* add the bitmap */
6583                         if (mddev->bitmap) {
6584                                 rv = -EEXIST;
6585                                 goto err;
6586                         }
6587                         if (mddev->bitmap_info.default_offset == 0) {
6588                                 rv = -EINVAL;
6589                                 goto err;
6590                         }
6591                         mddev->bitmap_info.offset =
6592                                 mddev->bitmap_info.default_offset;
6593                         mddev->bitmap_info.space =
6594                                 mddev->bitmap_info.default_space;
6595                         mddev->pers->quiesce(mddev, 1);
6596                         bitmap = bitmap_create(mddev, -1);
6597                         if (!IS_ERR(bitmap)) {
6598                                 mddev->bitmap = bitmap;
6599                                 rv = bitmap_load(mddev);
6600                         } else
6601                                 rv = PTR_ERR(bitmap);
6602                         if (rv)
6603                                 bitmap_destroy(mddev);
6604                         mddev->pers->quiesce(mddev, 0);
6605                 } else {
6606                         /* remove the bitmap */
6607                         if (!mddev->bitmap) {
6608                                 rv = -ENOENT;
6609                                 goto err;
6610                         }
6611                         if (mddev->bitmap->storage.file) {
6612                                 rv = -EINVAL;
6613                                 goto err;
6614                         }
6615                         if (mddev->bitmap_info.nodes) {
6616                                 /* hold PW on all the bitmap lock */
6617                                 if (md_cluster_ops->lock_all_bitmaps(mddev) <= 0) {
6618                                         printk("md: can't change bitmap to none since the"
6619                                                " array is in use by more than one node\n");
6620                                         rv = -EPERM;
6621                                         md_cluster_ops->unlock_all_bitmaps(mddev);
6622                                         goto err;
6623                                 }
6624 
6625                                 mddev->bitmap_info.nodes = 0;
6626                                 md_cluster_ops->leave(mddev);
6627                         }
6628                         mddev->pers->quiesce(mddev, 1);
6629                         bitmap_destroy(mddev);
6630                         mddev->pers->quiesce(mddev, 0);
6631                         mddev->bitmap_info.offset = 0;
6632                 }
6633         }
6634         md_update_sb(mddev, 1);
6635         return rv;
6636 err:
6637         return rv;
6638 }
6639 
6640 static int set_disk_faulty(struct mddev *mddev, dev_t dev)
6641 {
6642         struct md_rdev *rdev;
6643         int err = 0;
6644 
6645         if (mddev->pers == NULL)
6646                 return -ENODEV;
6647 
6648         rcu_read_lock();
6649         rdev = find_rdev_rcu(mddev, dev);
6650         if (!rdev)
6651                 err =  -ENODEV;
6652         else {
6653                 md_error(mddev, rdev);
6654                 if (!test_bit(Faulty, &rdev->flags))
6655                         err = -EBUSY;
6656         }
6657         rcu_read_unlock();
6658         return err;
6659 }
6660 
6661 /*
6662  * We have a problem here : there is no easy way to give a CHS
6663  * virtual geometry. We currently pretend that we have a 2 heads
6664  * 4 sectors (with a BIG number of cylinders...). This drives
6665  * dosfs just mad... ;-)
6666  */
6667 static int md_getgeo(struct block_device *bdev, struct hd_geometry *geo)
6668 {
6669         struct mddev *mddev = bdev->bd_disk->private_data;
6670 
6671         geo->heads = 2;
6672         geo->sectors = 4;
6673         geo->cylinders = mddev->array_sectors / 8;
6674         return 0;
6675 }
6676 
6677 static inline bool md_ioctl_valid(unsigned int cmd)
6678 {
6679         switch (cmd) {
6680         case ADD_NEW_DISK:
6681         case BLKROSET:
6682         case GET_ARRAY_INFO:
6683         case GET_BITMAP_FILE:
6684         case GET_DISK_INFO:
6685         case HOT_ADD_DISK:
6686         case HOT_REMOVE_DISK:
6687         case RAID_AUTORUN:
6688         case RAID_VERSION:
6689         case RESTART_ARRAY_RW:
6690         case RUN_ARRAY:
6691         case SET_ARRAY_INFO:
6692         case SET_BITMAP_FILE:
6693         case SET_DISK_FAULTY:
6694         case STOP_ARRAY:
6695         case STOP_ARRAY_RO:
6696         case CLUSTERED_DISK_NACK:
6697                 return true;
6698         default:
6699                 return false;
6700         }
6701 }
6702 
6703 static int md_ioctl(struct block_device *bdev, fmode_t mode,
6704                         unsigned int cmd, unsigned long arg)
6705 {
6706         int err = 0;
6707         void __user *argp = (void __user *)arg;
6708         struct mddev *mddev = NULL;
6709         int ro;
6710 
6711         if (!md_ioctl_valid(cmd))
6712                 return -ENOTTY;
6713 
6714         switch (cmd) {
6715         case RAID_VERSION:
6716         case GET_ARRAY_INFO:
6717         case GET_DISK_INFO:
6718                 break;
6719         default:
6720                 if (!capable(CAP_SYS_ADMIN))
6721                         return -EACCES;
6722         }
6723 
6724         /*
6725          * Commands dealing with the RAID driver but not any
6726          * particular array:
6727          */
6728         switch (cmd) {
6729         case RAID_VERSION:
6730                 err = get_version(argp);
6731                 goto out;
6732 
6733 #ifndef MODULE
6734         case RAID_AUTORUN:
6735                 err = 0;
6736                 autostart_arrays(arg);
6737                 goto out;
6738 #endif
6739         default:;
6740         }
6741 
6742         /*
6743          * Commands creating/starting a new array:
6744          */
6745 
6746         mddev = bdev->bd_disk->private_data;
6747 
6748         if (!mddev) {
6749                 BUG();
6750                 goto out;
6751         }
6752 
6753         /* Some actions do not requires the mutex */
6754         switch (cmd) {
6755         case GET_ARRAY_INFO:
6756                 if (!mddev->raid_disks && !mddev->external)
6757                         err = -ENODEV;
6758                 else
6759                         err = get_array_info(mddev, argp);
6760                 goto out;
6761 
6762         case GET_DISK_INFO:
6763                 if (!mddev->raid_disks && !mddev->external)
6764                         err = -ENODEV;
6765                 else
6766                         err = get_disk_info(mddev, argp);
6767                 goto out;
6768 
6769         case SET_DISK_FAULTY:
6770                 err = set_disk_faulty(mddev, new_decode_dev(arg));
6771                 goto out;
6772 
6773         case GET_BITMAP_FILE:
6774                 err = get_bitmap_file(mddev, argp);
6775                 goto out;
6776 
6777         }
6778 
6779         if (cmd == ADD_NEW_DISK)
6780                 /* need to ensure md_delayed_delete() has completed */
6781                 flush_workqueue(md_misc_wq);
6782 
6783         if (cmd == HOT_REMOVE_DISK)
6784                 /* need to ensure recovery thread has run */
6785                 wait_event_interruptible_timeout(mddev->sb_wait,
6786                                                  !test_bit(MD_RECOVERY_NEEDED,
6787                                                            &mddev->flags),
6788                                                  msecs_to_jiffies(5000));
6789         if (cmd == STOP_ARRAY || cmd == STOP_ARRAY_RO) {
6790                 /* Need to flush page cache, and ensure no-one else opens
6791                  * and writes
6792                  */
6793                 mutex_lock(&mddev->open_mutex);
6794                 if (mddev->pers && atomic_read(&mddev->openers) > 1) {
6795                         mutex_unlock(&mddev->open_mutex);
6796                         err = -EBUSY;
6797                         goto out;
6798                 }
6799                 set_bit(MD_STILL_CLOSED, &mddev->flags);
6800                 mutex_unlock(&mddev->open_mutex);
6801                 sync_blockdev(bdev);
6802         }
6803         err = mddev_lock(mddev);
6804         if (err) {
6805                 printk(KERN_INFO
6806                         "md: ioctl lock interrupted, reason %d, cmd %d\n",
6807                         err, cmd);
6808                 goto out;
6809         }
6810 
6811         if (cmd == SET_ARRAY_INFO) {
6812                 mdu_array_info_t info;
6813                 if (!arg)
6814                         memset(&info, 0, sizeof(info));
6815                 else if (copy_from_user(&info, argp, sizeof(info))) {
6816                         err = -EFAULT;
6817                         goto unlock;
6818                 }
6819                 if (mddev->pers) {
6820                         err = update_array_info(mddev, &info);
6821                         if (err) {
6822                                 printk(KERN_WARNING "md: couldn't update"
6823                                        " array info. %d\n", err);
6824                                 goto unlock;
6825                         }
6826                         goto unlock;
6827                 }
6828                 if (!list_empty(&mddev->disks)) {
6829                         printk(KERN_WARNING
6830                                "md: array %s already has disks!\n",
6831                                mdname(mddev));
6832                         err = -EBUSY;
6833                         goto unlock;
6834                 }
6835                 if (mddev->raid_disks) {
6836                         printk(KERN_WARNING
6837                                "md: array %s already initialised!\n",
6838                                mdname(mddev));
6839                         err = -EBUSY;
6840                         goto unlock;
6841                 }
6842                 err = set_array_info(mddev, &info);
6843                 if (err) {
6844                         printk(KERN_WARNING "md: couldn't set"
6845                                " array info. %d\n", err);
6846                         goto unlock;
6847                 }
6848                 goto unlock;
6849         }
6850 
6851         /*
6852          * Commands querying/configuring an existing array:
6853          */
6854         /* if we are not initialised yet, only ADD_NEW_DISK, STOP_ARRAY,
6855          * RUN_ARRAY, and GET_ and SET_BITMAP_FILE are allowed */
6856         if ((!mddev->raid_disks && !mddev->external)
6857             && cmd != ADD_NEW_DISK && cmd != STOP_ARRAY
6858             && cmd != RUN_ARRAY && cmd != SET_BITMAP_FILE
6859             && cmd != GET_BITMAP_FILE) {
6860                 err = -ENODEV;
6861                 goto unlock;
6862         }
6863 
6864         /*
6865          * Commands even a read-only array can execute:
6866          */
6867         switch (cmd) {
6868         case RESTART_ARRAY_RW:
6869                 err = restart_array(mddev);
6870                 goto unlock;
6871 
6872         case STOP_ARRAY:
6873                 err = do_md_stop(mddev, 0, bdev);
6874                 goto unlock;
6875 
6876         case STOP_ARRAY_RO:
6877                 err = md_set_readonly(mddev, bdev);
6878                 goto unlock;
6879 
6880         case HOT_REMOVE_DISK:
6881                 err = hot_remove_disk(mddev, new_decode_dev(arg));
6882                 goto unlock;
6883 
6884         case ADD_NEW_DISK:
6885                 /* We can support ADD_NEW_DISK on read-only arrays
6886                  * on if we are re-adding a preexisting device.
6887                  * So require mddev->pers and MD_DISK_SYNC.
6888                  */
6889                 if (mddev->pers) {
6890                         mdu_disk_info_t info;
6891                         if (copy_from_user(&info, argp, sizeof(info)))
6892                                 err = -EFAULT;
6893                         else if (!(info.state & (1<<MD_DISK_SYNC)))
6894                                 /* Need to clear read-only for this */
6895                                 break;
6896                         else
6897                                 err = add_new_disk(mddev, &info);
6898                         goto unlock;
6899                 }
6900                 break;
6901 
6902         case BLKROSET:
6903                 if (get_user(ro, (int __user *)(arg))) {
6904                         err = -EFAULT;
6905                         goto unlock;
6906                 }
6907                 err = -EINVAL;
6908 
6909                 /* if the bdev is going readonly the value of mddev->ro
6910                  * does not matter, no writes are coming
6911                  */
6912                 if (ro)
6913                         goto unlock;
6914 
6915                 /* are we are already prepared for writes? */
6916                 if (mddev->ro != 1)
6917                         goto unlock;
6918 
6919                 /* transitioning to readauto need only happen for
6920                  * arrays that call md_write_start
6921                  */
6922                 if (mddev->pers) {
6923                         err = restart_array(mddev);
6924                         if (err == 0) {
6925                                 mddev->ro = 2;
6926                                 set_disk_ro(mddev->gendisk, 0);
6927                         }
6928                 }
6929                 goto unlock;
6930         }
6931 
6932         /*
6933          * The remaining ioctls are changing the state of the
6934          * superblock, so we do not allow them on read-only arrays.
6935          */
6936         if (mddev->ro && mddev->pers) {
6937                 if (mddev->ro == 2) {
6938                         mddev->ro = 0;
6939                         sysfs_notify_dirent_safe(mddev->sysfs_state);
6940                         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6941                         /* mddev_unlock will wake thread */
6942                         /* If a device failed while we were read-only, we
6943                          * need to make sure the metadata is updated now.
6944                          */
6945                         if (test_bit(MD_CHANGE_DEVS, &mddev->flags)) {
6946                                 mddev_unlock(mddev);
6947                                 wait_event(mddev->sb_wait,
6948                                            !test_bit(MD_CHANGE_DEVS, &mddev->flags) &&
6949                                            !test_bit(MD_CHANGE_PENDING, &mddev->flags));
6950                                 mddev_lock_nointr(mddev);
6951                         }
6952                 } else {
6953                         err = -EROFS;
6954                         goto unlock;
6955                 }
6956         }
6957 
6958         switch (cmd) {
6959         case ADD_NEW_DISK:
6960         {
6961                 mdu_disk_info_t info;
6962                 if (copy_from_user(&info, argp, sizeof(info)))
6963                         err = -EFAULT;
6964                 else
6965                         err = add_new_disk(mddev, &info);
6966                 goto unlock;
6967         }
6968 
6969         case CLUSTERED_DISK_NACK:
6970                 if (mddev_is_clustered(mddev))
6971                         md_cluster_ops->new_disk_ack(mddev, false);
6972                 else
6973                         err = -EINVAL;
6974                 goto unlock;
6975 
6976         case HOT_ADD_DISK:
6977                 err = hot_add_disk(mddev, new_decode_dev(arg));
6978                 goto unlock;
6979 
6980         case RUN_ARRAY:
6981                 err = do_md_run(mddev);
6982                 goto unlock;
6983 
6984         case SET_BITMAP_FILE:
6985                 err = set_bitmap_file(mddev, (int)arg);
6986                 goto unlock;
6987 
6988         default:
6989                 err = -EINVAL;
6990                 goto unlock;
6991         }
6992 
6993 unlock:
6994         if (mddev->hold_active == UNTIL_IOCTL &&
6995             err != -EINVAL)
6996                 mddev->hold_active = 0;
6997         mddev_unlock(mddev);
6998 out:
6999         return err;
7000 }
7001 #ifdef CONFIG_COMPAT
7002 static int md_compat_ioctl(struct block_device *bdev, fmode_t mode,
7003                     unsigned int cmd, unsigned long arg)
7004 {
7005         switch (cmd) {
7006         case HOT_REMOVE_DISK:
7007         case HOT_ADD_DISK:
7008         case SET_DISK_FAULTY:
7009         case SET_BITMAP_FILE:
7010                 /* These take in integer arg, do not convert */
7011                 break;
7012         default:
7013                 arg = (unsigned long)compat_ptr(arg);
7014                 break;
7015         }
7016 
7017         return md_ioctl(bdev, mode, cmd, arg);
7018 }
7019 #endif /* CONFIG_COMPAT */
7020 
7021 static int md_open(struct block_device *bdev, fmode_t mode)
7022 {
7023         /*
7024          * Succeed if we can lock the mddev, which confirms that
7025          * it isn't being stopped right now.
7026          */
7027         struct mddev *mddev = mddev_find(bdev->bd_dev);
7028         int err;
7029 
7030         if (!mddev)
7031                 return -ENODEV;
7032 
7033         if (mddev->gendisk != bdev->bd_disk) {
7034                 /* we are racing with mddev_put which is discarding this
7035                  * bd_disk.
7036                  */
7037                 mddev_put(mddev);
7038                 /* Wait until bdev->bd_disk is definitely gone */
7039                 flush_workqueue(md_misc_wq);
7040                 /* Then retry the open from the top */
7041                 return -ERESTARTSYS;
7042         }
7043         BUG_ON(mddev != bdev->bd_disk->private_data);
7044 
7045         if ((err = mutex_lock_interruptible(&mddev->open_mutex)))
7046                 goto out;
7047 
7048         err = 0;
7049         atomic_inc(&mddev->openers);
7050         clear_bit(MD_STILL_CLOSED, &mddev->flags);
7051         mutex_unlock(&mddev->open_mutex);
7052 
7053         check_disk_change(bdev);
7054  out:
7055         return err;
7056 }
7057 
7058 static void md_release(struct gendisk *disk, fmode_t mode)
7059 {
7060         struct mddev *mddev = disk->private_data;
7061 
7062         BUG_ON(!mddev);
7063         atomic_dec(&mddev->openers);
7064         mddev_put(mddev);
7065 }
7066 
7067 static int md_media_changed(struct gendisk *disk)
7068 {
7069         struct mddev *mddev = disk->private_data;
7070 
7071         return mddev->changed;
7072 }
7073 
7074 static int md_revalidate(struct gendisk *disk)
7075 {
7076         struct mddev *mddev = disk->private_data;
7077 
7078         mddev->changed = 0;
7079         return 0;
7080 }
7081 static const struct block_device_operations md_fops =
7082 {
7083         .owner          = THIS_MODULE,
7084         .open           = md_open,
7085         .release        = md_release,
7086         .ioctl          = md_ioctl,
7087 #ifdef CONFIG_COMPAT
7088         .compat_ioctl   = md_compat_ioctl,
7089 #endif
7090         .getgeo         = md_getgeo,
7091         .media_changed  = md_media_changed,
7092         .revalidate_disk= md_revalidate,
7093 };
7094 
7095 static int md_thread(void *arg)
7096 {
7097         struct md_thread *thread = arg;
7098 
7099         /*
7100          * md_thread is a 'system-thread', it's priority should be very
7101          * high. We avoid resource deadlocks individually in each
7102          * raid personality. (RAID5 does preallocation) We also use RR and
7103          * the very same RT priority as kswapd, thus we will never get
7104          * into a priority inversion deadlock.
7105          *
7106          * we definitely have to have equal or higher priority than
7107          * bdflush, otherwise bdflush will deadlock if there are too
7108          * many dirty RAID5 blocks.
7109          */
7110 
7111         allow_signal(SIGKILL);
7112         while (!kthread_should_stop()) {
7113 
7114                 /* We need to wait INTERRUPTIBLE so that
7115                  * we don't add to the load-average.
7116                  * That means we need to be sure no signals are
7117                  * pending
7118                  */
7119                 if (signal_pending(current))
7120                         flush_signals(current);
7121 
7122                 wait_event_interruptible_timeout
7123                         (thread->wqueue,
7124                          test_bit(THREAD_WAKEUP, &thread->flags)
7125                          || kthread_should_stop(),
7126                          thread->timeout);
7127 
7128                 clear_bit(THREAD_WAKEUP, &thread->flags);
7129                 if (!kthread_should_stop())
7130                         thread->run(thread);
7131         }
7132 
7133         return 0;
7134 }
7135 
7136 void md_wakeup_thread(struct md_thread *thread)
7137 {
7138         if (thread) {
7139                 pr_debug("md: waking up MD thread %s.\n", thread->tsk->comm);
7140                 set_bit(THREAD_WAKEUP, &thread->flags);
7141                 wake_up(&thread->wqueue);
7142         }
7143 }
7144 EXPORT_SYMBOL(md_wakeup_thread);
7145 
7146 struct md_thread *md_register_thread(void (*run) (struct md_thread *),
7147                 struct mddev *mddev, const char *name)
7148 {
7149         struct md_thread *thread;
7150 
7151         thread = kzalloc(sizeof(struct md_thread), GFP_KERNEL);
7152         if (!thread)
7153                 return NULL;
7154 
7155         init_waitqueue_head(&thread->wqueue);
7156 
7157         thread->run = run;
7158         thread->mddev = mddev;
7159         thread->timeout = MAX_SCHEDULE_TIMEOUT;
7160         thread->tsk = kthread_run(md_thread, thread,
7161                                   "%s_%s",
7162                                   mdname(thread->mddev),
7163                                   name);
7164         if (IS_ERR(thread->tsk)) {
7165                 kfree(thread);
7166                 return NULL;
7167         }
7168         return thread;
7169 }
7170 EXPORT_SYMBOL(md_register_thread);
7171 
7172 void md_unregister_thread(struct md_thread **threadp)
7173 {
7174         struct md_thread *thread = *threadp;
7175         if (!thread)
7176                 return;
7177         pr_debug("interrupting MD-thread pid %d\n", task_pid_nr(thread->tsk));
7178         /* Locking ensures that mddev_unlock does not wake_up a
7179          * non-existent thread
7180          */
7181         spin_lock(&pers_lock);
7182         *threadp = NULL;
7183         spin_unlock(&pers_lock);
7184 
7185         kthread_stop(thread->tsk);
7186         kfree(thread);
7187 }
7188 EXPORT_SYMBOL(md_unregister_thread);
7189 
7190 void md_error(struct mddev *mddev, struct md_rdev *rdev)
7191 {
7192         if (!rdev || test_bit(Faulty, &rdev->flags))
7193                 return;
7194 
7195         if (!mddev->pers || !mddev->pers->error_handler)
7196                 return;
7197         mddev->pers->error_handler(mddev,rdev);
7198         if (mddev->degraded)
7199                 set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
7200         sysfs_notify_dirent_safe(rdev->sysfs_state);
7201         set_bit(MD_RECOVERY_INTR, &mddev->recovery);
7202         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7203         md_wakeup_thread(mddev->thread);
7204         if (mddev->event_work.func)
7205                 queue_work(md_misc_wq, &mddev->event_work);
7206         md_new_event(mddev);
7207 }
7208 EXPORT_SYMBOL(md_error);
7209 
7210 /* seq_file implementation /proc/mdstat */
7211 
7212 static void status_unused(struct seq_file *seq)
7213 {
7214         int i = 0;
7215         struct md_rdev *rdev;
7216 
7217         seq_printf(seq, "unused devices: ");
7218 
7219         list_for_each_entry(rdev, &pending_raid_disks, same_set) {
7220                 char b[BDEVNAME_SIZE];
7221                 i++;
7222                 seq_printf(seq, "%s ",
7223                               bdevname(rdev->bdev,b));
7224         }
7225         if (!i)
7226                 seq_printf(seq, "<none>");
7227 
7228         seq_printf(seq, "\n");
7229 }
7230 
7231 static int status_resync(struct seq_file *seq, struct mddev *mddev)
7232 {
7233         sector_t max_sectors, resync, res;
7234         unsigned long dt, db;
7235         sector_t rt;
7236         int scale;
7237         unsigned int per_milli;
7238 
7239         if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ||
7240             test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
7241                 max_sectors = mddev->resync_max_sectors;
7242         else
7243                 max_sectors = mddev->dev_sectors;
7244 
7245         resync = mddev->curr_resync;
7246         if (resync <= 3) {
7247                 if (test_bit(MD_RECOVERY_DONE, &mddev->recovery))
7248                         /* Still cleaning up */
7249                         resync = max_sectors;
7250         } else
7251                 resync -= atomic_read(&mddev->recovery_active);
7252 
7253         if (resync == 0) {
7254                 if (mddev->recovery_cp < MaxSector) {
7255                         seq_printf(seq, "\tresync=PENDING");
7256                         return 1;
7257                 }
7258                 return 0;
7259         }
7260         if (resync < 3) {
7261                 seq_printf(seq, "\tresync=DELAYED");
7262                 return 1;
7263         }
7264 
7265         WARN_ON(max_sectors == 0);
7266         /* Pick 'scale' such that (resync>>scale)*1000 will fit
7267          * in a sector_t, and (max_sectors>>scale) will fit in a
7268          * u32, as those are the requirements for sector_div.
7269          * Thus 'scale' must be at least 10
7270          */
7271         scale = 10;
7272         if (sizeof(sector_t) > sizeof(unsigned long)) {
7273                 while ( max_sectors/2 > (1ULL<<(scale+32)))
7274                         scale++;
7275         }
7276         res = (resync>>scale)*1000;
7277         sector_div(res, (u32)((max_sectors>>scale)+1));
7278 
7279         per_milli = res;
7280         {
7281                 int i, x = per_milli/50, y = 20-x;
7282                 seq_printf(seq, "[");
7283                 for (i = 0; i < x; i++)
7284                         seq_printf(seq, "=");
7285                 seq_printf(seq, ">");
7286                 for (i = 0; i < y; i++)
7287                         seq_printf(seq, ".");
7288                 seq_printf(seq, "] ");
7289         }
7290         seq_printf(seq, " %s =%3u.%u%% (%llu/%llu)",
7291                    (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)?
7292                     "reshape" :
7293                     (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)?
7294                      "check" :
7295                      (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ?
7296                       "resync" : "recovery"))),
7297                    per_milli/10, per_milli % 10,
7298                    (unsigned long long) resync/2,
7299                    (unsigned long long) max_sectors/2);
7300 
7301         /*
7302          * dt: time from mark until now
7303          * db: blocks written from mark until now
7304          * rt: remaining time
7305          *
7306          * rt is a sector_t, so could be 32bit or 64bit.
7307          * So we divide before multiply in case it is 32bit and close
7308          * to the limit.
7309          * We scale the divisor (db) by 32 to avoid losing precision
7310          * near the end of resync when the number of remaining sectors
7311          * is close to 'db'.
7312          * We then divide rt by 32 after multiplying by db to compensate.
7313          * The '+1' avoids division by zero if db is very small.
7314          */
7315         dt = ((jiffies - mddev->resync_mark) / HZ);
7316         if (!dt) dt++;
7317         db = (mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active))
7318                 - mddev->resync_mark_cnt;
7319 
7320         rt = max_sectors - resync;    /* number of remaining sectors */
7321         sector_div(rt, db/32+1);
7322         rt *= dt;
7323         rt >>= 5;
7324 
7325         seq_printf(seq, " finish=%lu.%lumin", (unsigned long)rt / 60,
7326                    ((unsigned long)rt % 60)/6);
7327 
7328         seq_printf(seq, " speed=%ldK/sec", db/2/dt);
7329         return 1;
7330 }
7331 
7332 static void *md_seq_start(struct seq_file *seq, loff_t *pos)
7333 {
7334         struct list_head *tmp;
7335         loff_t l = *pos;
7336         struct mddev *mddev;
7337 
7338         if (l >= 0x10000)
7339                 return NULL;
7340         if (!l--)
7341                 /* header */
7342                 return (void*)1;
7343 
7344         spin_lock(&all_mddevs_lock);
7345         list_for_each(tmp,&all_mddevs)
7346                 if (!l--) {
7347                         mddev = list_entry(tmp, struct mddev, all_mddevs);
7348                         mddev_get(mddev);
7349                         spin_unlock(&all_mddevs_lock);
7350                         return mddev;
7351                 }
7352         spin_unlock(&all_mddevs_lock);
7353         if (!l--)
7354                 return (void*)2;/* tail */
7355         return NULL;
7356 }
7357 
7358 static void *md_seq_next(struct seq_file *seq, void *v, loff_t *pos)
7359 {
7360         struct list_head *tmp;
7361         struct mddev *next_mddev, *mddev = v;
7362 
7363         ++*pos;
7364         if (v == (void*)2)
7365                 return NULL;
7366 
7367         spin_lock(&all_mddevs_lock);
7368         if (v == (void*)1)
7369                 tmp = all_mddevs.next;
7370         else
7371                 tmp = mddev->all_mddevs.next;
7372         if (tmp != &all_mddevs)
7373                 next_mddev = mddev_get(list_entry(tmp,struct mddev,all_mddevs));
7374         else {
7375                 next_mddev = (void*)2;
7376                 *pos = 0x10000;
7377         }
7378         spin_unlock(&all_mddevs_lock);
7379 
7380         if (v != (void*)1)
7381                 mddev_put(mddev);
7382         return next_mddev;
7383 
7384 }
7385 
7386 static void md_seq_stop(struct seq_file *seq, void *v)
7387 {
7388         struct mddev *mddev = v;
7389 
7390         if (mddev && v != (void*)1 && v != (void*)2)
7391                 mddev_put(mddev);
7392 }
7393 
7394 static int md_seq_show(struct seq_file *seq, void *v)
7395 {
7396         struct mddev *mddev = v;
7397         sector_t sectors;
7398         struct md_rdev *rdev;
7399 
7400         if (v == (void*)1) {
7401                 struct md_personality *pers;
7402                 seq_printf(seq, "Personalities : ");
7403                 spin_lock(&pers_lock);
7404                 list_for_each_entry(pers, &pers_list, list)
7405                         seq_printf(seq, "[%s] ", pers->name);
7406 
7407                 spin_unlock(&pers_lock);
7408                 seq_printf(seq, "\n");
7409                 seq->poll_event = atomic_read(&md_event_count);
7410                 return 0;
7411         }
7412         if (v == (void*)2) {
7413                 status_unused(seq);
7414                 return 0;
7415         }
7416 
7417         spin_lock(&mddev->lock);
7418         if (mddev->pers || mddev->raid_disks || !list_empty(&mddev->disks)) {
7419                 seq_printf(seq, "%s : %sactive", mdname(mddev),
7420                                                 mddev->pers ? "" : "in");
7421                 if (mddev->pers) {
7422                         if (mddev->ro==1)
7423                                 seq_printf(seq, " (read-only)");
7424                         if (mddev->ro==2)
7425                                 seq_printf(seq, " (auto-read-only)");
7426                         seq_printf(seq, " %s", mddev->pers->name);
7427                 }
7428 
7429                 sectors = 0;
7430                 rcu_read_lock();
7431                 rdev_for_each_rcu(rdev, mddev) {
7432                         char b[BDEVNAME_SIZE];
7433                         seq_printf(seq, " %s[%d]",
7434                                 bdevname(rdev->bdev,b), rdev->desc_nr);
7435                         if (test_bit(WriteMostly, &rdev->flags))
7436                                 seq_printf(seq, "(W)");
7437                         if (test_bit(Journal, &rdev->flags))
7438                                 seq_printf(seq, "(J)");
7439                         if (test_bit(Faulty, &rdev->flags)) {
7440                                 seq_printf(seq, "(F)");
7441                                 continue;
7442                         }
7443                         if (rdev->raid_disk < 0)
7444                                 seq_printf(seq, "(S)"); /* spare */
7445                         if (test_bit(Replacement, &rdev->flags))
7446                                 seq_printf(seq, "(R)");
7447                         sectors += rdev->sectors;
7448                 }
7449                 rcu_read_unlock();
7450 
7451                 if (!list_empty(&mddev->disks)) {
7452                         if (mddev->pers)
7453                                 seq_printf(seq, "\n      %llu blocks",
7454                                            (unsigned long long)
7455                                            mddev->array_sectors / 2);
7456                         else
7457                                 seq_printf(seq, "\n      %llu blocks",
7458                                            (unsigned long long)sectors / 2);
7459                 }
7460                 if (mddev->persistent) {
7461                         if (mddev->major_version != 0 ||
7462                             mddev->minor_version != 90) {
7463                                 seq_printf(seq," super %d.%d",
7464                                            mddev->major_version,
7465                                            mddev->minor_version);
7466                         }
7467                 } else if (mddev->external)
7468                         seq_printf(seq, " super external:%s",
7469                                    mddev->metadata_type);
7470                 else
7471                         seq_printf(seq, " super non-persistent");
7472 
7473                 if (mddev->pers) {
7474                         mddev->pers->status(seq, mddev);
7475                         seq_printf(seq, "\n      ");
7476                         if (mddev->pers->sync_request) {
7477                                 if (status_resync(seq, mddev))
7478                                         seq_printf(seq, "\n      ");
7479                         }
7480                 } else
7481                         seq_printf(seq, "\n       ");
7482 
7483                 bitmap_status(seq, mddev->bitmap);
7484 
7485                 seq_printf(seq, "\n");
7486         }
7487         spin_unlock(&mddev->lock);
7488 
7489         return 0;
7490 }
7491 
7492 static const struct seq_operations md_seq_ops = {
7493         .start  = md_seq_start,
7494         .next   = md_seq_next,
7495         .stop   = md_seq_stop,
7496         .show   = md_seq_show,
7497 };
7498 
7499 static int md_seq_open(struct inode *inode, struct file *file)
7500 {
7501         struct seq_file *seq;
7502         int error;
7503 
7504         error = seq_open(file, &md_seq_ops);
7505         if (error)
7506                 return error;
7507 
7508         seq = file->private_data;
7509         seq->poll_event = atomic_read(&md_event_count);
7510         return error;
7511 }
7512 
7513 static int md_unloading;
7514 static unsigned int mdstat_poll(struct file *filp, poll_table *wait)
7515 {
7516         struct seq_file *seq = filp->private_data;
7517         int mask;
7518 
7519         if (md_unloading)
7520                 return POLLIN|POLLRDNORM|POLLERR|POLLPRI;
7521         poll_wait(